Chair-ish.

Science.gov (United States)

Greenman, Geri

2000-01-01

Presents an art assignment that helps students progress from color theory and the color wheel to understanding watercolor techniques. Explains that students apply their knowledge of watercolor techniques by using three of ten techniques to create different views of a chair in the Cubist style. (CMK)

Raman Chair | About IASc | Indian Academy of Sciences

Indian Academy of Sciences (India)

Raman Chair. The Raman Chair was instituted in 1972 by the Government of India to commemorate the memory of the founder of the Academy, Sir C. V. Raman. Eminent scientists are invited by the Council of the Academy to occupy the Chair, for periods of between six weeks and six months. Raman Professors who have ...

Science Instructional Leadership: The Role of the Department Chair

Science.gov (United States)

Peacock, Jeremy S.

2014-01-01

With science teachers facing comprehensive curriculum reform that will shape science education for decades to come, high school department chairs represent a critical resource for instructional leadership and teacher support. While the historical literature on the department chair indicates that chairs are in prime positions to provide…

Measuring the Emotions Elicited by Office Chairs

NARCIS (Netherlands)

Reijneveld, K.; Looze, M.P. de; Krause, F.; Desmet, P.

2003-01-01

Office chair designers have traditionally focused their design efforts on optimizing the so-called 'ergonomic fit.' Although the effort to design chairs that support physical comfort is commendable, the focus on ergonomics neglects the possible impact of emotional responses on the general experience

Solar wheel chair; Solar kurumaisu (iryokei no tachiba kara no kokoromi)

Energy Technology Data Exchange (ETDEWEB)

Okabe, K [Gunma Prefectural College of Health Sciences, Gunma (Japan)

1996-10-27

Physically handicapped people due to accidents for example have been increasing yearly in number with the increase of the aged, spread of cars, and change in the living environment. Therefore, participation in society by such people as called the weak is indispensable. Under the circumstances, as a means of their participation, a wheel chair as a moving aid was examined from the viewpoint of medical treatment and classified into three categories as follows: (1) for the use of the aged who are healthy but leg muscles are weak, (2) for the use of the invalid incapable of moving a part of the body and (3) for the use in sports by people who are disabled in the lower half of the body but healthy otherwise. In other words, prototypes were made for three kinds of solar wheel chair, for the aged, for the invalid and for sport use by the disabled, with a field test performed for each prototype. The wheel chairs were exhibited in the school, used in welfare facilities and driven by a disabled person who participated in 100km marathon. The users` opinions were favorable stating they were able to drive by themselves the new vehicle utilizing the clean energy and to move around by their own free will. 6 refs., 5 figs.

Sitting into the limelight: Lonely Chairs at CERN turns one

CERN Multimedia

Katarina Anthony

2015-01-01

A picture may be worth a thousand words - but a picture of a chair? It’s worth a story all by itself. Over the past year, the "Lonely Chairs at CERN" photography blog has let the chairs do the talking. Along the way, these chairs have inspired and enchanted people across the globe with their honest depiction of the Laboratory.   This lonely chair outside Building 32 was one of the first Rebeca photographed. When CMS physicist Rebeca Gonzalez Suarez created Lonely Chairs at CERN back in April 2014, she was not expecting the immediate reaction it garnered. Within days, the blog had picked up thousands of followers and was featured in Gizmodo and The Guardian. "The response inside CERN was very positive, but the response outside was overwhelming," says Rebeca. "I’ve got a lot of followers who are really into science and are very excited about CERN. They comment about wanting to work here - sometimes on the ugliest chair I&rsqu...

Secondary School Science Department Chairs Leading Change

Science.gov (United States)

Gaubatz, Julie A.

2012-01-01

Secondary school department chairs are content area specialists in their schools and are responsible for providing students with the most appropriate curricula. However, most secondary school department chairs have limited authority to institute change unilaterally (Gmelch, 1993; Hannay & Erb, 1999). To explore how these educational leaders…

The Strategic Value of Succession Planning for Department Chairs.

Science.gov (United States)

Rayburn, William; Grigsby, Kevin; Brubaker, Linda

2016-04-01

Most faculty who aspire to be department chairs are unaware of succession processes at their institution. This Commentary highlights the importance of succession planning, emphasizing the general need for transparency. Succession planning provides institutional leaders the opportunity to optimize, renew, and revitalize their organization by ensuring successful leadership transitions. In contrast to leadership pathways in the military, corporate business, and hospital administration, planned succession of medical school department chairs has received little attention. Different approaches to succession planning are essential for emergency and planned transitions. Emergency succession plans should be in place at all times, regularly revisited, and modified as needed. Department chairs should begin considering their planned succession between one and five years after their initial appointment. The succession discussion between a chair and medical school dean requires cautious, thoughtful, and open discussions. Intradepartmental annual faculty performance evaluations permit the chair to mentor potential successors in acquiring future-oriented, institution-based leadership qualities necessary to be considered for a future department chair position. If health and time permit, the successful chair should remain in his or her current position until a successor is named or, preferably, is in place. Appointment of an interim chair as part of succession planning can be useful for on-the-job training of an internal candidate, yet awkwardness might ensue if there is more than one internal candidate.Succession development offers the great advantage of maintaining smooth organizational performance while optimizing talent management and exploring opportunities for transitioning individuals into leadership roles.

Exciplex and excimer molecular probes: detection of conformational flip in a myo-inositol chair.

Science.gov (United States)

Kadirvel, Manikandan; Arsic, Biljana; Freeman, Sally; Bichenkova, Elena V

2008-06-07

2-O-tert-Butyldimethylsilyl-4,6-bis-O-pyrenoyl-myo-inositol-1,3,5-orthoformate (6) and 2-O-tert-butyldimethylsilyl-4-O-[4-(dimethylamino)benzoyl]-6-O-pyrenoyl-myo-inositol-1,3,5-orthoacetate (10) adopt conformationally restricted unstable chairs with five axial substituents. In the symmetrical diester 6, the two pi-stacked pyrenoyl groups are electron acceptor-donor partners, giving a strong intramolecular excimer emission. In the mixed ester 10, the pyrenoyl group is the electron acceptor and the 4-(dimethylamino)benzoyl ester is the electron donor, giving a strong intramolecular exciplex emission. The conformation of the mixed ester 10 was assessed using 1H NMR spectroscopy (1H-NOESY) and computational studies. which showed the minimum inter-centroid distance between the two aromatic systems to be approximately 3.9 A. Upon addition of acid, the orthoformate/orthoacetate trigger in 6 and 10 was cleaved, which caused a switch of the conformation of the myo-inositol ring to the more stable penta-equatorial chair, leading to separation of the aromatic ester groups and loss of excimer and exciplex fluorescence, respectively. This study provides proof of principle for the development of novel fluorescent molecular probes.

Leading Learning: Science Departments and the Chair

Science.gov (United States)

Melville, Wayne; Campbell, Todd; Jones, Doug

2016-01-01

In this article, we have considered the role of the chair in leading the learning necessary for a department to become effective in the teaching and learning of science from a reformed perspective. We conceptualize the phrase "leading learning" to mean the chair's constitution of influence, power, and authority to intentionally impact…

Job satisfaction among chairs of surgery from Europe and North America.

Science.gov (United States)

Tschuor, Christoph; Raptis, Dimitri Aristotle; Morf, Manuela Christina; Staffelbach, Bruno; Manser, Tanja; Clavien, Pierre-Alain

2014-11-01

Strong evidence exists associating job satisfaction and risk of burnout with productivity, efficiency, and creativity in many organizations. However no data are available assessing chairs of surgery. This study assessed job satisfaction and risk for burnout of surgical chairs from Europe and North America and identified contributing factors. A survey among 650 chairs in surgery from 23 European and 2 North American countries was conducted in 2012. Satisfaction at work was analyzed using the validated Global Job Satisfaction (GJS) instrument and the abbreviated Maslach Burnout Inventory. Additional items targeting personal and environmental factors were included. The rate of chairs reached successfully was 86%, the overall response rate was 29% (188/650), with 1% female. Median age was 58 years. 11% of chairs were dissatisfied with work. Younger age and being fewer years in practice as a chair was associated with higher job satisfaction (P = .054 and P = .003). Surgical specialty with the greatest median GJS score was hepatopancreatobiliary, whereas vascular surgery scored lowest. Chairs desire to devote 20% more of their time on research. Clerical support as well as the ability to be innovative was suggested by 51% and 45%, respectively, to improve job satisfaction. Compared with Europeans, North American chairs were overall more satisfied and would recommend their job to their children. North American chairs seem to be more satisfied at work and at less risk for burnout than European chairs. The overall job satisfaction was greater among chairs compared with previously published reports of young, board-certified surgeons or residents (89% vs 87% and 66%, respectively). The superior satisfaction in chairs is strongest related to career achievements, innovation, and lifestyle. Copyright © 2014 Elsevier Inc. All rights reserved.

Surgeons’ muscle load during robotic-assisted laparoscopy performed with a regular office chair and the preferred of two ergonomic chairs

DEFF Research Database (Denmark)

Dalager, T.; Jensen, P. T.; Winther, T. S.

2018-01-01

associated with poor ergonomics and musculoskeletal pain. The ergonomic condition in the robotic console is partially dependent upon the chair provided, which often is a regular office chair. Our study quantified and compared the muscular load during robotic-assisted laparoscopy using one of two custom built...

Burnout in United States Academic Chairs of Radiation Oncology Programs

Energy Technology Data Exchange (ETDEWEB)

Kusano, Aaron S. [Department of Radiation Oncology, University of Washington School of Medicine, Seattle, Washington (United States); Thomas, Charles R., E-mail: thomasch@ohsu.edu [Department of Radiation Medicine, Knight Cancer Institute/Oregon Health and Science University, Portland, Oregon (United States); Bonner, James A. [Department of Radiation Oncology, University of Alabama at Birmingham, Birmingham, Alabama (United States); DeWeese, Theodore L. [Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins Medical Institutions, Baltimore, Maryland (United States); Formenti, Silvia C. [Department of Radiation Oncology, New York University, New York, New York (United States); Hahn, Stephen M. [Department of Radiation Oncology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania (United States); Lawrence, Theodore S. [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States); Mittal, Bharat B. [Department of Radiation Oncology, Northwestern University, Chicago, Ilinois (United States)

2014-02-01

Purpose: The aims of this study were to determine the self-reported prevalence of burnout in chairs of academic radiation oncology departments, to identify factors contributing to burnout, and to compare the prevalence of burnout with that seen in other academic chair groups. Methods and Materials: An anonymous online survey was administered to the membership of the Society of Chairs of Academic Radiation Oncology Programs (SCAROP). Burnout was measured with the Maslach Burnout Inventory-Human Services Survey (MBI-HSS). Results: Questionnaires were returned from 66 of 87 chairs (76% response rate). Seventy-nine percent of respondents reported satisfaction with their current positions. Common major stressors were budget deficits and human resource issues. One-quarter of chairs reported that it was at least moderately likely that they would step down in the next 1 to 2 years; these individuals demonstrated significantly higher emotional exhaustion. Twenty-five percent of respondents met the MBI-HSS criteria for low burnout, 75% for moderate burnout, and none for high burnout. Group MBI-HSS subscale scores demonstrated a pattern of moderate emotional exhaustion, low depersonalization, and moderate personal accomplishment, comparing favorably with other specialties. Conclusions: This is the first study of burnout in radiation oncology chairs with a high response rate and using a validated psychometric tool. Radiation oncology chairs share similar major stressors to other chair groups, but they demonstrate relatively high job satisfaction and lower burnout. Emotional exhaustion may contribute to the anticipated turnover in coming years. Further efforts addressing individual and institutional factors associated with burnout may improve the relationship with work of chairs and other department members.

Burnout in United States Academic Chairs of Radiation Oncology Programs

International Nuclear Information System (INIS)

Kusano, Aaron S.; Thomas, Charles R.; Bonner, James A.; DeWeese, Theodore L.; Formenti, Silvia C.; Hahn, Stephen M.; Lawrence, Theodore S.; Mittal, Bharat B.

2014-01-01

Purpose: The aims of this study were to determine the self-reported prevalence of burnout in chairs of academic radiation oncology departments, to identify factors contributing to burnout, and to compare the prevalence of burnout with that seen in other academic chair groups. Methods and Materials: An anonymous online survey was administered to the membership of the Society of Chairs of Academic Radiation Oncology Programs (SCAROP). Burnout was measured with the Maslach Burnout Inventory-Human Services Survey (MBI-HSS). Results: Questionnaires were returned from 66 of 87 chairs (76% response rate). Seventy-nine percent of respondents reported satisfaction with their current positions. Common major stressors were budget deficits and human resource issues. One-quarter of chairs reported that it was at least moderately likely that they would step down in the next 1 to 2 years; these individuals demonstrated significantly higher emotional exhaustion. Twenty-five percent of respondents met the MBI-HSS criteria for low burnout, 75% for moderate burnout, and none for high burnout. Group MBI-HSS subscale scores demonstrated a pattern of moderate emotional exhaustion, low depersonalization, and moderate personal accomplishment, comparing favorably with other specialties. Conclusions: This is the first study of burnout in radiation oncology chairs with a high response rate and using a validated psychometric tool. Radiation oncology chairs share similar major stressors to other chair groups, but they demonstrate relatively high job satisfaction and lower burnout. Emotional exhaustion may contribute to the anticipated turnover in coming years. Further efforts addressing individual and institutional factors associated with burnout may improve the relationship with work of chairs and other department members

The Sit & Stand chair. A revolutionary advance in adaptive seating systems.

Science.gov (United States)

Galumbeck, Michael H; Buschbacher, Ralph M; Wilder, Robert P; Winters, Kathryne L; Hudson, Mary Anne; Edlich, Richard F

2004-01-01

A major factor governing independence for the elderly and persons with disabilities is the ability to stand from a chair. Factors such as pain, reduced joint range of motion, stiffness, and muscle weakness frequently limit the ability to stand. Sit-to-stand position is even further reduced in patients whose hands and shoulders are afflicted with rheumatoid arthritis. When achieving a sit-to-stand position in the elderly and persons with disabilities, there is considerable risk of the individual falling and sustaining bone fracture. The purposes of this scientific report are to achieve the following goals: (1) to provide a narrative discussion of the senior author's contributions to furniture manufacturing as well as his successful patent application for the SIT & STAND chair, (2) to describe the steps involved in the development of the SIT & STAND prototype, and (3) to examine the performance of the SIT & STAND chair in assisting the elderly or persons with disabilities in achieving a sit-to-stand position. The invention of the SIT & STAND chair by the senior author, Michael Galumbeck, was a culmination of his lifelong interest in adaptive seating systems. His electrically operated chair has the unique ability to assist the occupant to achieve safely a sit-to-stand position. The rear portion of his chair remains in a fixed position to support the buttocks of the user during mechanical lift. The front portion of the seat folds down incrementally as the chair rises to allow the feet of the user to be positioned in a more posterior position firmly on the floor. Using its actuator, the height that the chair rises will vary with the length of the legs of the occupant. Using the drawing program Solid Works (Solid Works, Concord, Massachusetts), drawings of the chair were made. To visualize the operation and performance of the chair, separate drawings were made in the lateral position. The prototype of the SIT & STAND chair was manufactured with an electric actuator that

Nouvelle initiative des chaires de recherche Canada-Afrique du Sud ...

International Development Research Centre (IDRC) Digital Library (Canada)

8 déc. 2016 ... Elles s'appuient sur le South African Research Chairs Initiative (SARChl), ainsi que sur le programme de chaires de recherche industrielle, dont le financement provient en partie du Conseil de recherches en sciences naturelles et en génie du Canada (CRSNG) et du Programme des chaires de recherche ...

Influence of Chair Vibrations on Indoor Sonic Boom Annoyance

Science.gov (United States)

Rathsam, Jonathan; Klos, Jacob; Loubeau, Alexandra

2015-01-01

One goal of NASA’s Commercial Supersonic Technology Project is to identify candidate noise metrics suitable for regulating quiet sonic boom aircraft. A suitable metric must consider the short duration and pronounced low frequency content of sonic booms. For indoor listeners, rattle and creaking sounds and floor and chair vibrations may also be important. The current study examined the effect of such vibrations on the annoyance of test subjects seated indoors. The study involved two chairs exposed to nearly identical acoustic levels: one placed directly on the floor, and the other isolated from floor vibrations by pneumatic elastomeric mounts. All subjects experienced both chairs, sitting in one chair for the first half of the experiment and the other chair for the remaining half. Each half of the experiment consisted of 80 impulsive noises played at the exterior of the sonic boom simulator. When all annoyance ratings were analyzed together there appeared to be no difference in mean annoyance with isolation condition. When the apparent effect of transfer bias was removed, a subtle but measurable effect of vibration on annoyance was identified.

[Understanding chair-side digital technology for stomatology from an engineering viewpoint].

Science.gov (United States)

Zhao, Y J; Wang, Y

2018-04-09

In recent years with the rapid development of digital technology for stomatology, the application field, application model, technical features and technical connotation of the chair-side digital technology has got development and change. The open modular system has gradually replaced the traditional closed system, and the application field of digital technology is no longer limited to chair-side dental restoration, it also has been extend to various kinds of chair-side digital treatment-assisted technology. In this paper, from the engineering point of view, the up to date general connotation of chair-side digital technology was explained, the characteristics and the development of each unit in chair-side digital technology were analyzed, and the application pattern and the localization status were also discussed in this paper. The aim of this paper was to introduce the trend of chair-side digital technological to readers and to better guide clinical application.

The Hot Seat: Profiling the Marketing Department Chair

Science.gov (United States)

Aggarwal, Praveen; Rochford, Linda; Vaidyanathan, Rajiv

2009-01-01

The chair of the marketing department serves a critical role in balancing the needs of the university with those of the faculty. Because most department chairs are drawn from the faculty in their departments, the administrative role they take on conflicts with their desire to maintain their academic roles as teacher and researcher. Although there…

Leadership experiences and characteristics of chairs of academic departments of psychiatry.

Science.gov (United States)

Keith, Samuel J; Buckley, Peter F

2011-01-01

Effective leadership in academic medicine requires a broad constellation of skills, experiences, and core values. The authors sought to describe and define these. The authors conducted a web-based survey among 132 Chairs of North American departments of psychiatry. Eighty-five Chairs (64%) responded to the survey, the majority of whom were first-time Chairs. Identified leadership attributes included strategic/visionary acumen, interpersonal communication skills, core administrative and academic/technical skills, motivational capacity, personal integrity, and altruism/tenacity. The identified values are consistent with the leadership attributes that are described as necessary for success in the business community. Developing the required skill-set among faculty who aspire to become a departmental Chair is an important commitment for Deans and extant psychiatry Chairs. Copyright © 2011 Academic Psychiatry

Raman Chair | About IASc | Indian Academy of Sciences

Indian Academy of Sciences (India)

The Raman Chair was instituted in 1972 by the Government of India to commemorate the memory of the founder of the Academy, Sir C. V. Raman. Eminent scientists are invited by the Council of the Academy to occupy the Chair, for periods of between six weeks and six months. Raman Professors who have occupied the ...

What a medical school chair wants from the dean

Directory of Open Access Journals (Sweden)

Hromas R

2018-05-01

Full Text Available Robert Hromas,1 Robert Leverence,1 Lazarus K Mramba,2 J Larry Jameson,3 Caryn Lerman,3 Thomas L Schwenk,4 Ellen M Zimmermann,2 Michael L Good51The Office of the Dean, Department of Medicine, University of Texas Health Science Center San Antonio, San Antonio, TX, USA; 2Department of Medicine, College of Medicine, University of Florida Health, Gainesville, FL, USA; 3Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA; 4Department of Family Medicine, School of Medicine, University of Nevada Reno, Reno, NV, USA; 5Department of Anesthesiology, College of Medicine, University of Florida Health, Gainesville, FL, USAAbstract: Economic pressure has led the evolution of the role of the medical school dean from a clinician educator to a health care system executive. In addition, other dynamic requirements also have likely led to changes in their leadership characteristics. The most important relationship a dean has is with the chairs, yet in the context of the dean’s changing role, little attention has been paid to this relationship. To frame this discussion, we asked medical school chairs what characteristics of a dean’s leadership were most beneficial. We distributed a 26-question survey to 885 clinical and basic science chairs at 41 medical schools. These chairs were confidentially surveyed on their views of six leadership areas: evaluation, barriers to productivity, communication, accountability, crisis management, and organizational values. Of the 491 chairs who responded (response rate =55%, 88% thought that their dean was effective at leading the organization, and 89% enjoyed working with their dean. Chairs indicated that the most important area of expertise of a dean is to define a strategic vision, and the most important value for a dean is integrity between words and deeds. Explaining the reasons behind decisions, providing good feedback, admitting errors, open discussion of complex or

Women chairs in academic medicine: engendering strategic intuition

Science.gov (United States)

Isaac, Carol; Griffin, Lindsay

2017-01-01

Purpose Because stereotypically masculine behaviors are required for effective leadership, examining female chairs’ leadership in academic medicine can provide insight into the complex ways in which gender impacts on their leadership practices. The paper aims to discuss this issue. Design/methodology/approach The author interviewed three female clinical chairs and compared the findings to interviews with 28 of their faculty. Grounded theory analysis of the subsequent text gathered comprehensive, systematic, and in-depth information about this case of interest at a US top-tier academic medical center. Findings Four of five themes from the faculty were consistent with the chair’s narrative with modifications: Prior Environment (Motivated by Excellence), Tough, Direct, Transparent (Developing Trust), Communal Actions (Creating Diversity of Opinion), and Building Power through Consensus (an “Artful Exercise”) with an additional theme, the Significance (and Insignificance) of a Female Chair. While faculty members were acutely aware of the chair’s gender, the chairs paradoxically vacillated between gender being a “non-issue” and noting that male chairs “don’t do laundry.” All three female chairs in this study independently and explicitly stated that gender was not a barrier, yet intuitively used successful strategies derived from the research literature. Originality/value This study suggests that while their gender was highlighted by faculty, these women dismissed gender as a “non-issue.” The duality of gender for these three female leaders was both minimized and subtly affirmed. PMID:26045192

Demographic and Personal Characteristics of Male and Female Chairs in Academic Psychiatry.

Science.gov (United States)

Doyle, Marley; Pederson, Aderonke; Meltzer-Brody, Samantha

2016-06-01

Despite the strong representation of female psychiatrists in residency and early-career positions, the number of female faculty sharply decreases in tenured or executive leadership positions. Why there exists a marked change in representation at the level of senior leadership within academic psychiatry is unclear. The authors investigated the causative factors contributing to this observation and gathered information about the personal characteristics of women in executive leadership roles. The authors surveyed psychiatry chairs at academic institutions. They identified all female chairs and randomly selected a group of male chairs to serve as a control group. The survey assessed perceived barriers, strengths, and weaknesses and differences in demographics and leadership styles between female and male chairs. Ten percent of psychiatry chairs were female. Male chairs were more likely than female chairs to head large departments (p = 0.02, confidence interval (CI) -17.1-69.1) and had a higher H-index (p = 0.001, CI 6.6-37.2). Female chairs were more likely than male chairs to perceive barriers in their career development (p = 0.01, CI 0.7-2.2), citing little or no mentorship (p = 0.04), gender discrimination (p = 0.0001), and family obligations (p = 0.001) more often. Academic institutions must incorporate programs to decrease barriers and work to achieve equitable representation of women in upper-level leadership positions. Moreover, academic medicine must evolve to cultivate a family-friendly environment that successfully supports both genders.

EcoHealth Chairs on Health

International Development Research Centre (IDRC) Digital Library (Canada)

Marie-Isabelle Beyer

2013-09-03

Sep 3, 2013 ... transforming social-ecological systems—including understanding, policies and policy processes ..... IDRC will seek to select Chairs that optimize the Ecohealth field- ..... However, IDRC does not pay import duties, sales tax or.

Analysis of flow coefficient in chair manufacture

OpenAIRE

Ivković Dragoljub; Živković Slaven

2005-01-01

The delivery on time is not possible without the good-quality planning of deadlines, i.e. planning of the manufacturing process duration. The study of flow coefficient enables the realistic forecasting of the manufacturing process duration. This paper points to the significance of the study of flow coefficient on scientific basis so as to determine the terms of the end of the manufacture of chairs made of sawn timber. Chairs are the products of complex construction, often almost completely ma...

Highlight: Research Chair unites four West African universities in ...

International Development Research Centre (IDRC) Digital Library (Canada)

2016-04-14

Apr 14, 2016 ... Local and regional experts including researchers, consultants, and academics convened in Cotonou, Benin, on February 26, 2015 to launch a Research Chair on EcoHealth. The Chair unites four West African universities that have pledged to reduce air pollution and non-communicable respiratory ...

Report of the 10(th) Asia-Pacific Federation of Societies for Surgery of the Hand Congress (Organising Chair and Scientific Chair).

Science.gov (United States)

A, Roohi Sharifah; Abdullah, Shalimar

2016-10-01

A report on the 10(th) Asia-Pacific Federation of Societies for the Surgery of the Hand and 6(th) Asia-Pacific Federation of Societies for Hand Therapists is submitted detailing the numbers of attendees participating, papers presented and support received as well the some of the challenges faced and how best to overcome them from the local conference chair and scientific chair point of view.

Turnover of First-Time Chairs in Departments of Psychiatry

Science.gov (United States)

Buckley, Peter F.; Rayburn, William F.

2011-01-01

Objective: The authors examine the tenure of first-time Chairs in academic departments of psychiatry in order to stimulate discussion on extant workforce and leadership issues. Method: Data on tenure of Chairs in psychiatry and other nonsurgical specialties were derived from the longitudinal database of the Association of American Medical Colleges…

Does physical exposure throughout working life influence chair-rise performance in midlife?

DEFF Research Database (Denmark)

Møller, Anne; Reventlow, Susanne; Hansen, Åse Marie

2015-01-01

OBJECTIVES: Our aim was to study associations between physical exposures throughout working life and physical function measured as chair-rise performance in midlife. METHODS: The Copenhagen Aging and Midlife Biobank (CAMB) provided data about employment and measures of physical function. Individual...... and confirmed the findings. CONCLUSIONS: Higher physical exposure throughout working life is associated with slightly poorer chair-rise performance. The associations between exposure and outcome were non-linear.......-years and chair-rise performance (number of chair-rises in 30 s) were analysed in multivariate linear and non-linear regression models adjusted for covariates. RESULTS: Mean age among the 5095 participants was 59 years in both genders, and, on average, men achieved 21.58 (SD=5.60) and women 20.38 (SD=5.33) chair...

76 FR 17118 - Environmental Management Site-Specific Advisory Board Chairs

Science.gov (United States)

2011-03-28

... DEPARTMENT OF ENERGY Environmental Management Site-Specific Advisory Board Chairs AGENCY... Environmental Management Site-Specific Advisory Board (EM SSAB) Chairs. The Federal Advisory Committee Act (Pub... areas of environmental restoration, waste management, and related activities. Tentative Agenda Topics...

76 FR 62054 - Environmental Management Site-Specific Advisory Board Chairs

Science.gov (United States)

2011-10-06

... DEPARTMENT OF ENERGY Environmental Management Site-Specific Advisory Board Chairs AGENCY... of the Environmental Management Site-Specific Advisory Board (EM SSAB) Chairs. The Federal Advisory... environmental restoration, waste management, and related activities. Tentative Agenda Topics [cir] EM Program...

Cranial nerves neuropraxia after shoulder arthroscopy in beach chair position.

Science.gov (United States)

Cogan, A; Boyer, P; Soubeyrand, M; Hamida, F Ben; Vannier, J-L; Massin, P

2011-05-01

We report a case of neuropraxia of the 9th, 10th and 12th cranial nerve pairs after arthroscopic rotator cuff repair in the beach chair position. The elements in the medical file seem to exclude an intracranial cause of the lesions and support a mechanical, extracranial cause due to intubation and/or the beach chair position. This clinical case report shows the neurological risks of the beach chair position during arthroscopic shoulder surgery and presents the essential safety measures to prevent these risks. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

"Rocking-Chair"-Type Metal Hybrid Supercapacitors.

Science.gov (United States)

Yoo, Hyun Deog; Han, Sang-Don; Bayliss, Ryan D; Gewirth, Andrew A; Genorio, Bostjan; Rajput, Nav Nidhi; Persson, Kristin A; Burrell, Anthony K; Cabana, Jordi

2016-11-16

Hybrid supercapacitors that follow a "rocking-chair"-type mechanism were developed by coupling divalent metal and activated carbon electrodes in nonaqueous electrolytes. Conventional supercapacitors require a large amount of electrolyte to provide a sufficient quantity of ions to the electrodes, due to their Daniell-type mechanism that depletes the ions from the electrolyte while charging. The alternative "rocking-chair"-type mechanism effectively enhances the energy density of supercapacitors by minimizing the necessary amount of electrolyte, because the ion is replenished from the metal anode while it is adsorbed to the cathode. Newly developed nonaqueous electrolytes for Mg and Zn electrochemistry, based on bis(trifluoromethylsulfonyl)imide (TFSI) salts, made the metal hybrid supercapacitors possible by enabling reversible deposition on the metal anodes and reversible adsorption on an activated carbon cathode. Factoring in gains through the cell design, the energy density of the metal hybrid supercapacitors is projected to be a factor of 7 higher than conventional devices thanks to both the "rocking-chair"-type mechanism that minimizes total electrolyte volume and the use of metal anodes, which have substantial merits in capacity and voltage. Self-discharge was also substantially alleviated compared to conventional supercapacitors. This concept offers a route to build supercapacitors that meet dual criteria of power and energy densities with a simple cell design.

Analysis of flow coefficient in chair manufacture

Directory of Open Access Journals (Sweden)

Ivković Dragoljub

2005-01-01

Full Text Available The delivery on time is not possible without the good-quality planning of deadlines, i.e. planning of the manufacturing process duration. The study of flow coefficient enables the realistic forecasting of the manufacturing process duration. This paper points to the significance of the study of flow coefficient on scientific basis so as to determine the terms of the end of the manufacture of chairs made of sawn timber. Chairs are the products of complex construction, often almost completely made of sawn timber as the basic material. They belong to the group of export products, so it is especially significant to analyze the duration of the production cycle, and the type and the degree of stoppages in this type of production. Parallel method of production is applied in chair manufacture. The study shows that the value of flow coefficient is close to one or higher, in most cases. The results indicate that the percentage of interoperational stoppage is unjustifiably high, so it is proposed how to decrease the percentage of stoppages in the manufacturing process.

An Archetype Semi-Ring Fabry-Perot (SRFP) Resonator

Science.gov (United States)

Taghavi-Larigani, Shervin; VanZyl, Jakob

2009-01-01

We introduce and demonstrate the generation of a novel resonator, termed Semi-Ring Fabry-Perot (SRFP), that exhibits unique features, such as, its use of one plane mirror, allowing the SRFP to be easily fabricated as a symmetrical device. In addition to its unique features, it exhibits advantages of ring and Fabry-Perot resonators: 1) compared to a ring resonator that only allows a transmitted intensity, the Semi-Ring Fabry-Perot (SRFP) supports standing waves, allowing both a reflected and transmitted intensity; 2) the reflected light spectrum of the SRFP resonator is much narrower than similar Fabry-Perot, implying higher finesse.

Department Chairs' Perceptions of the Importance of Business Communication Skills.

Science.gov (United States)

Wardrope, William J.

2002-01-01

Determines business department chairs' ratings of topics typically covered in the business communication course. Indicates that department chairs perceive writing skills to be more important to business communication courses than other communication skills, such as speaking, technology-mediated communication, interpersonal communication,…

Advancing Women's Health and Women's Leadership With Endowed Chairs in Women's Health.

Science.gov (United States)

Carnes, Molly; Johnson, Paula; Klein, Wendy; Jenkins, Marjorie; Bairey Merz, C Noel

2017-02-01

Gender-based bias and conflation of gender and status are root causes of disparities in women's health care and the slow advancement of women to leadership in academic medicine. More than a quarter of women physicians train in internal medicine and its subspecialties, and women physicians almost exclusively constitute the women's health focus within internal medicine. Thus, internal medicine has considerable opportunity to develop women leaders in academic medicine and promote women's health equity.To probe whether holding an endowed chair-which confers status-in women's health may be an effective way to advance women leaders in academic medicine and women's health, the authors explored the current status of endowed chairs in women's health in internal medicine. They found that the number of these endowed chairs in North America increased from 7 in 2013 to 19 in 2015, and all were held by women. The perceptions of incumbents and other women's health leaders supported the premise that an endowed chair in women's health would increase women's leadership, the institutional stature of women's health, and activities in women's health research, education, and clinical care.Going forward, it will be important to explore why not all recipients perceived that the endowed chair enhanced their own academic leadership, whether providing women's health leaders with fundraising expertise fosters future success in increasing the number of women's health endowed chairs, and how the conflation of gender and status play out (e.g., salary differences between endowed chairs) as the number of endowed chairs in women's health increases.

7-Hydroxy-8-isopropyl-1,1,4a-trimethyl-4a,9,10,10a-tetrahydro-phenanthren-2(1H-one

Directory of Open Access Journals (Sweden)

Ahmed Benharref

2011-04-01

Full Text Available The title compound, C20H26O2, was isolated from a chloroform extract of Tetraclinis articulata wood. The molecule contains three fused rings which exhibit different conformations. The non-aromatic oxo-substituted ring has a screw-boat conformation, while the central ring has a half-chair conformation. In the crystal, molecules are linked to each other by intermolecular O—H...O hydrogen bonds involving the carbonyl and hydroxy groups.

76 FR 20651 - Environmental Management Site-Specific Advisory Board Chairs

Science.gov (United States)

2011-04-13

... DEPARTMENT OF ENERGY Environmental Management Site-Specific Advisory Board Chairs AGENCY... a meeting on April 13-14, 2011 of the Environmental Management Site-Specific Advisory Board Chairs... R. Butler, Acting Deputy Committee Management Officer. [FR Doc. 2011-8970 Filed 4-8-11; 4:15 pm...

Human Research Program 2010 Chair Standing Review Panel Meeting

Science.gov (United States)

Steinberg, Susan

2011-01-01

The 13 Human Research Program (HRP) Standing Review Panel (SRP) Chairs, and in some cases one or two additional panel members (see section XIV, roster) referred to as the Chair (+1) SRP throughout this document, met at the NASA Johnson Space Center (JSC) on December 7, 2010 to allow the HRP Elements and Projects to report on their progress over the past year, their current status, and their plans for the upcoming year based on NASA's current goals and objectives for human space exploration. A large focus of the meeting was also used to discuss integration across the HRP scientific disciplines based on a recommendation from the 2009 HRP SRP review. During the one-day meeting, each of the HRP Elements and Projects presented the changes they made to the HRP Integrated Research Plan (IRP Rev. B) over the last year, and what their top three areas of integration are between other HRP Elements/Projects. The Chair (+1) SRP spent sufficient time addressing the panel charge, either as a group or in a separate closed session, and the Chair (+1) SRP and the HRP presenters and observers, in most cases, had sufficient time to discuss during and after the presentations. The SRP made a final debriefing to the HRP Program Scientist, Dr. John B. Charles, prior to the close of the meeting on December 7, 2010. Overall, the Chair (+1) SRP concluded that most of the HRP Elements/Projects did a commendable job during the past year in addressing integration across the HRP scientific disciplines with the available resources. The Chair (+1) SRP agreed that the idea of integration between HRP Elements/Projects is noble, but believes all parties involved should have the same definition of integration, in order to be successful. The Chair (+1) SRP also believes that a key to successful integration is communication among the HRP Elements/Projects which may present a challenge. The Chair (+1) SRP recommends that the HRP have a workshop on program integration (with HRP Element

Seat pan and backrest pressure distribution while sitting in office chairs.

Science.gov (United States)

Zemp, Roland; Taylor, William R; Lorenzetti, Silvio

2016-03-01

Nowadays, an increasing amount of time is spent seated, especially in office environments, where sitting comfort and support are increasingly important due to the prevalence of musculoskeletal disorders. The aim of this study was to develop a methodology for chair-specific sensor mat calibration, to evaluate the interconnections between specific pressure parameters and to establish those that are most meaningful and significant in order to differentiate pressure distribution measures between office chairs. The shape of the exponential calibration function was highly influenced by the material properties and geometry of the office chairs, and therefore a chair-specific calibration proved to be essential. High correlations were observed between the eight analysed pressure parameters, whereby the pressure parameters could be reduced to a set of four and three parameters for the seat pan and the backrest respectively. In order to find significant differences between office chairs, gradient parameters should be analysed for the seat pan, whereas for the backrest almost all parameters are suitable. Copyright © 2015 Elsevier Ltd and The Ergonomics Society. All rights reserved.

Joining forces to find answers — The International Research Chairs ...

International Development Research Centre (IDRC) Digital Library (Canada)

2010-10-08

Oct 8, 2010 ... Mobile Nav Footer Links ... the environment, and information technology hopes the new research program that ... Alper observes that the Canada Research Chairs program's success in achieving this goal provides one ... Like the Canada Research Chairs program, the IRCI emphasizes training students to ...

Great auricular neuropraxia with beach chair position

Directory of Open Access Journals (Sweden)

Joshi M

2017-07-01

Full Text Available Minal Joshi,1 Ruth Cheng,2 Hattiyangadi Kamath,1 Joel Yarmush1 1Department of Anesthesiology, New York Methodist Hospital, New York, NY, USA; 2School of Medicine, St. George’s University, Grenada, West Indies Abstract: Shoulder arthroscopy has been shown to be the procedure of choice for many diagnostic and therapeutic interventions. Neuropraxia of the great auricular nerve (GAN is an uncommon complication of shoulder surgery, with the patient in the beach chair position. We report a case of great auricular neuropraxia associated with direct compression by a horseshoe headrest, used in routine positioning for uncomplicated shoulder surgery. In this case, an arthroscopic approach was taken, under regional anesthesia with sedation in the beach chair position. The GAN, a superficial branch of the cervical plexus, is vulnerable to neuropraxia due to its superficial anatomical location. We recommend that for the procedures of the beach chair position, the auricle be protected and covered with cotton and gauze to avoid direct compression and the position of the head and neck be checked and corrected frequently. Keywords: neuropraxia, anesthesia, arthroscopy, great auricular nerve

New product development: A batik multifunctional chair

Science.gov (United States)

Indrawati, Sri; Sukmaningsih, Nias

2017-11-01

The biggest challenge facing by Batik industry in ASEAN Economic Community (AEC) era is the greater number of fashion competitors both domestically and internationally. Based on that condition, the development of new product variants by considering product performance and price is needed. This research was conducted to develop batik products with a new target market. Products that being developed is batik multifunctional chair using integrated value engineering and analytic hierarchy process methods. This research has been done in several stages, ie. Information stage, creative stage, value analysis and product prototyping. The results of this research shows that the batik multifunctional chair product criteria are aesthetic (29%), multifunctional (34%) and ergonomic (37%). There are three new product design alternatives that successfully being developed. Based on value analysis, the product design alternatives that have the highest value is alternative design 2, the value is 2,37. The production cost for this design is Rp. 500.000,-. Alternative design 2 specification are using Mahoni wood, Batik parang rusak pattern with natural coloring process, can be used as table and fit with customer's body anthropometry. Then a batik multifunctional chair prototype is developed based on the best alternative design.

Diamagnetic response in zigzag hexagonal silicene rings

International Nuclear Information System (INIS)

Xu, Ning; Chen, Qiao; Tian, Hongyu; Ding, Jianwen; Liu, Junfeng

2016-01-01

Highlights: • Hexagonal silicene rings possess unusually large diamagnetic moments. • The magnetic-field-driven spin-up electrons flow anticlockwise and spin-down electrons flow clockwise along the rings. • The large diamagnetic moment is the result of competition of spin-up and spin-down electrons. - Abstract: Hexagonal silicene rings with unusually large diamagnetic moments have been found in a theoretical study of the electronic and magnetic properties. In the presence of effective spin–orbit coupling, the magnetic-field-driven spin-up electrons flow anticlockwise exhibiting colossal diamagnetic moments, while the spin-down electrons flow clockwise exhibiting colossal paramagnetic moments along the rings. The large diamagnetic moment is thus the result of competition of spin-up and spin-down electrons, which can be modulated by spin–orbit coupling strength and exchange field.

Diamagnetic response in zigzag hexagonal silicene rings

Energy Technology Data Exchange (ETDEWEB)

Xu, Ning, E-mail: nxu@ycit.cn [Department of Physics, Yancheng Institute of Technology, Yancheng 224051 (China); Chen, Qiao [Department of Physics, Hunan Institute of Engineering, Xiangtan 411104 (China); Tian, Hongyu [Department of Physics, Yancheng Institute of Technology, Yancheng 224051 (China); Ding, Jianwen [Department of Physics, Xiangtan University, Xiangtan 411105 (China); Liu, Junfeng, E-mail: liu.jf@sustc.edu.cn [Department of Physics, South University of Science and Technology of China, Shenzhen 518055 (China)

2016-09-16

Highlights: • Hexagonal silicene rings possess unusually large diamagnetic moments. • The magnetic-field-driven spin-up electrons flow anticlockwise and spin-down electrons flow clockwise along the rings. • The large diamagnetic moment is the result of competition of spin-up and spin-down electrons. - Abstract: Hexagonal silicene rings with unusually large diamagnetic moments have been found in a theoretical study of the electronic and magnetic properties. In the presence of effective spin–orbit coupling, the magnetic-field-driven spin-up electrons flow anticlockwise exhibiting colossal diamagnetic moments, while the spin-down electrons flow clockwise exhibiting colossal paramagnetic moments along the rings. The large diamagnetic moment is thus the result of competition of spin-up and spin-down electrons, which can be modulated by spin–orbit coupling strength and exchange field.

Perceptions of Interior Design Program Chairs Regarding Credentials for Faculty

Science.gov (United States)

Miller, Beth R.

2017-01-01

The purpose of this study was to determine whether program chairs in interior design have a preferred degree credential for candidates seeking a full-time, tenure-track position or other full-time position at their institution and to determine if there is a correlation between this preference and the program chair's university's demographics,…

The Weighing Chair of Sanctorius Sanctorius: A Replica.

Science.gov (United States)

Hollerbach, Teresa

2018-05-14

In 1614, the physician Sanctorius Sanctorius (1561-1636) published his most famous work entitled Ars […] de statica medicina (On static medicine). This is a work composed of aphorisms that present the practical results of a series of weighing procedures, rather than theoretical observations. De statica medicina is the result of a large number of test series that Sanctorius carried out over many years with the weighing chair he constructed himself in order to quantify the so-called perspiratio insensibilis, an insensible perspiration of the human body. Through his weighing experiments, Sanctorius introduced the idea of quantitative research into physiology. Although historical accounts ascribe an important role to Sanctorius as the founder of a new medical science, up until now the design of his weighing chair and the method of measurement have not been closely analysed. The aim of this paper is to close this gap. Through a collaboration between the Max Planck Institute for the History of Science and the Technical University of Berlin (Institute of Vocational Education and Work Studies), Sanctorius's weighing chair was reconstructed and experiments carried out with it. This opened new perspectives on Sanctorius's work and led to a reconsideration of the function and purpose of his weighing chair. With his static medicine, Sanctorius repurposed an old instrument. The replication of the weighing chair and the repetition of the experiments demonstrate that this novel application of scales posed some challenges for the mechanical design of the instrument. We recognized that the instrument fulfilled different functions that might in turn have affected its design, precision, and the measuring method applied. Although in the end we could not clarify how Sanctorius actually conducted his measurements, we were nevertheless able to develop an understanding of Sanctorius's mechanical and practical knowledge that would not have been possible for us to develop solely on

Cardiovascular consequence of reclining vs. sitting beach-chair body position for induction of anesthesia

DEFF Research Database (Denmark)

Larsen, Soren L.; Lyngeraa, Tobias S.; Maschmann, Christian P.

2014-01-01

The sitting beach-chair position is regularly used for shoulder surgery and anesthesia may be induced in that position. We tested the hypothesis that the cardiovascular challenge induced by induction of anesthesia is attenuated if the patient is placed in a reclining beach-chair position....... Anesthesia was induced with propofol in the sitting beach-chair (n = 15) or with the beach-chair tilted backwards to a reclining beach-chair position (n = 15). The last group was stepwise tilted to the sitting beach-chair position prior to surgery. Hypotension was treated with ephedrine. Continuous...... ± 12 vs. 45 ± 15 % reduction from baseline, p = 0.04) and ScO2 (7 ± 6 vs. 1 ± 8% increase from baseline, p = 0.02) and received less ephedrine (mean: 4 vs. 13 mg, p = 0.048). The higher blood pressure and lower need of vasopressor following induction of anesthesia in the reclining compared...

(2-Oxo-2H-benzo[h]chromen-4-ylmethyl morpholine-4-carbodithioate

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Rajni Kant

2012-04-01

Full Text Available In the title compound, C19H17NO3S2, the morpholine ring is in a chair conformation. In the coumarin ring system, the dihedral angle between the benzene and pyran rings is 3.9 (1°. In the crystal, weak C—H...O interactions link the molecules into corrugated layers parallel to (102. The crystal packing also exhibits π–π interactions, with distances of 3.644 (1 and 3.677 (1 Å between the centroids of the benzene rings of neighbouring molecules.

A Profile of Academic Training Program Directors and Chairs in Radiation Oncology

International Nuclear Information System (INIS)

Wilson, Lynn D.; Haffty, Bruce G.; Smith, Benjamin D.

2013-01-01

Purpose: To identify objective characteristics and benchmarks for program leadership in academic radiation oncology. Methods and Materials: A study of the 87 Accreditation Council for Graduate Medical Education radiation oncology training program directors (PD) and their chairs was performed. Variables included age, gender, original training department, highest degree, rank, endowed chair assignment, National Institutes of Health (NIH) funding, and Hirsch index (H-index). Data were gathered from online sources such as departmental websites, NIH RePORTER, and Scopus. Results: There were a total of 87 PD. The median age was 48, and 14 (16%) were MD/PhD. A total of 21 (24%) were female, and rank was relatively equally distributed above instructor. Of the 26 professors, at least 7 (27%) were female. At least 24 (28%) were working at the institution from which they had received their training. A total of 6 individuals held endowed chairs. Only 2 PD had active NIH funding in 2012. The median H-index was 12 (range, 0-51) but the index dropped to 9 (range, 0-38) when those who served as both PD and chair were removed from the group. A total of 76 chairs were identified at the time of the study. The median age was 55, and 9 (12%) were MD/PhD. A total of 7 (9%) of the chairs were female, and rank was professor for all with the exception of 1 who was listed as “Head” and was an associate professor. Of the 76 chairs, at least 10 (13%) were working at the institution from which they received their training. There were a total of 21 individuals with endowed chairs. A total of 13 (17%) had NIH funding in 2012. The median H-index was 29 (range, 3-60). Conclusions: These data provide benchmarks for individuals and departments evaluating leadership positions in the field of academic radiation oncology. Such data are useful for evaluating leadership trends over time and comparing academic radiation oncology with other specialties

A Profile of Academic Training Program Directors and Chairs in Radiation Oncology

Energy Technology Data Exchange (ETDEWEB)

Wilson, Lynn D., E-mail: Lynn.wilson@yale.edu [Department of Therapeutic Radiology, Yale University School of Medicine, Smilow Cancer Hospital, New Haven, Connecticut (United States); Haffty, Bruce G. [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Smith, Benjamin D. [Department of Radiation Oncology, UMDNJ-RWJMS, Cancer Institute of New Jersey, New Brunswick, New Jersey (United States)

2013-04-01

Purpose: To identify objective characteristics and benchmarks for program leadership in academic radiation oncology. Methods and Materials: A study of the 87 Accreditation Council for Graduate Medical Education radiation oncology training program directors (PD) and their chairs was performed. Variables included age, gender, original training department, highest degree, rank, endowed chair assignment, National Institutes of Health (NIH) funding, and Hirsch index (H-index). Data were gathered from online sources such as departmental websites, NIH RePORTER, and Scopus. Results: There were a total of 87 PD. The median age was 48, and 14 (16%) were MD/PhD. A total of 21 (24%) were female, and rank was relatively equally distributed above instructor. Of the 26 professors, at least 7 (27%) were female. At least 24 (28%) were working at the institution from which they had received their training. A total of 6 individuals held endowed chairs. Only 2 PD had active NIH funding in 2012. The median H-index was 12 (range, 0-51) but the index dropped to 9 (range, 0-38) when those who served as both PD and chair were removed from the group. A total of 76 chairs were identified at the time of the study. The median age was 55, and 9 (12%) were MD/PhD. A total of 7 (9%) of the chairs were female, and rank was professor for all with the exception of 1 who was listed as “Head” and was an associate professor. Of the 76 chairs, at least 10 (13%) were working at the institution from which they received their training. There were a total of 21 individuals with endowed chairs. A total of 13 (17%) had NIH funding in 2012. The median H-index was 29 (range, 3-60). Conclusions: These data provide benchmarks for individuals and departments evaluating leadership positions in the field of academic radiation oncology. Such data are useful for evaluating leadership trends over time and comparing academic radiation oncology with other specialties.

Trapezius Muscle Activity in using Ordinary and Ergonomically Designed Dentistry Chairs

Directory of Open Access Journals (Sweden)

O Haddad

2012-03-01

Full Text Available Background: Most dentists complain of musculoskeletal disorders which can be caused by prolonged static posture, lack of suitable rest and other physical and psychological problems. Objective: We evaluated a chair with a new ergonomic design which incorporated forward leaning chest and arm supports. Methods: The chair was evaluated in the laboratory during task simulation and EMG analysis on 12 students and subjectively assessed by 30 professional dentists using an 18-item questionnaire. EMG activity of right and left trapezius muscles for 12 male students with no musculoskeletal disorders was measured while simulating common tasks like working on the teeth of the lower jaw. Results: Normalized EMG data showed significant reduction (p<0.05 in all EMG recordings of the trapezius muscle. Dentists also unanimously preferred the ergonomically designed chair. Conclusion: Such ergonomically designed chairs should be introduced as early as possible in student training before bad postural habits are acquired.

Quality Improvement Practices in Academic Emergency Medicine: Perspectives from the Chairs

Directory of Open Access Journals (Sweden)

DelliFraine, Jami L

2010-12-01

Full Text Available Objective: To assess academic emergency medicine (EM chairs’ perceptions of quality improvement (QI training programs.Methods: A voluntary anonymous 20 item survey was distributed to a sample of academic chairs of EM through the Association of Academic Chairs of Emergency Medicine. Data was collected to assess the percentage of academic emergency physicians who had received QI training, the type of training they received, their perception of the impact of this training on behavior, practice and outcomes, and any perceived barriers to implementing QI programs in the emergency department.Results: The response rate to the survey was 69% (N = 59. 59.3% of respondents report that their hospital has a formal QI program for physicians. Chairs received training in a variety of QI programs. The type of QI program used by respondents was perceived as having no impact on goals achieved by QI (χ2 = 12.382; p = 0.260, but there was a statistically significant (χ2 = 14.383; p = 0.006 relationship between whether or not goals were achieved and academic EM chairs’ perceptions about return on investment for QI training. Only 22% of chairs responded that they have already made changes as a result of the QI training. 78.8% of EM chairs responded that quality programs could have a significant positive impact on their practice and the healthcare industry. Chairs perceived that QI programs had the most potential value in the areas of understanding and reducing medical errors and improving patient flow and throughput. Other areas of potential value of QI include improving specific clinical indicators and standardizing physician care.Conclusion: Academic EM chairs perceived that QI programs were an effective way to drive needed improvements. The results suggest that there is a high level of interest in QI but a low level of adoption of training and implementation.[West J Emerg Med. 2010; 11(5:479-485.

The effects of an office ergonomics training and chair intervention on worker knowledge, behavior and musculoskeletal risk.

Science.gov (United States)

Robertson, Michelle; Amick, Benjamin C; DeRango, Kelly; Rooney, Ted; Bazzani, Lianna; Harrist, Ron; Moore, Anne

2009-01-01

A large-scale field intervention study was undertaken to examine the effects of office ergonomics training coupled with a highly adjustable chair on office workers' knowledge and musculoskeletal risks. Office workers were assigned to one of three study groups: a group receiving the training and adjustable chair (n=96), a training-only group (n=63), and a control group (n=57). The office ergonomics training program was created using an instructional systems design model. A pre/post-training knowledge test was administered to all those who attended the training. Body postures and workstation set-ups were observed before and after the intervention. Perceived control over the physical work environment was higher for both intervention groups as compared to workers in the control group. A significant increase in overall ergonomic knowledge was observed for the intervention groups. Both intervention groups exhibited higher level behavioral translation and had lower musculoskeletal risk than the control group.

Effectiveness of Ergonomic Chair against Musculoskeletal Disorders in Female Batik Workers of Sragen District

Directory of Open Access Journals (Sweden)

Sumardiyono Sumardiyono

2014-08-01

Full Text Available The majority of female batik workers uses non-ergonomic chairs (dingklik that pose risks of musculoskeletal disorders. This study aimed to design an ergonomic chair and evaluate its effectiveness in reducing musculoskeletal disorders among the workers. This is a quasi-experimental study (using one group pre and post-test design on 50 female batik workers selected by quota sampling. Musculoskeletal disorders were measured among the samples before and after the use of the designed ergonomic chair which they were asked to use for two months. T-test, ANCOVA, Wilcoxon test, McNemar test and Chi Square test were used for the analysis. The study found statistical significant differences of risk factor against musculoskeletal disorders among the workers before and after their use of the designed ergonomic chair (p=0.000; and of musculoskeletal disorders before and after using the ergonomic chair (p= 0,035. Body Mass Index (BMI was identified as a confounding factor, and statistical significant difference of musculoskeletal disorders were also found among the workers with 25 BMI even before and after using the ergonomic chair (p=0.033 and p=0.015 respectively. By ANCOVA statistical test, after controlling BMI, another statistical difference of musculoskeletal disorders was also identified before and after using the ergonomic chair (p=0.033. It is concluded that the designed ergonomic chair is effective to reduce the risk of musculoskeletal disorders.

Decision-Making Styles of Department Chairs at Public Jordanian Universities: A High-Expectancy Workforce

Science.gov (United States)

Khasawneh, Samer; Alomari, Aiman; Abu-tineh, Abdullah

2011-01-01

The primary purpose of this study was to determine the decision-making styles of department chairs employed by three public institutions in Jordan. A total of 95 department chairs participated in the study by completing the General Decision-Making Styles survey. The results indicated that department chairs under study have the rational…

Effect of Furniture Weight on Carrying, Lifting, and Turning of Chairs and Desks among Elementary School Children

Science.gov (United States)

Funatsu, Kyotaro; Xiong, Jinghong; Rosyidi, Cucuk Nur

2015-01-01

Rearranging furniture in elementary school classrooms encourages classroom activities. In elementary schools in Indonesia and some other developing countries, usually only one style of furniture is used for all children, and the furniture is heavy and oversized for younger children. This affects their ability to carry it. The objective of this study is to investigate the effects of elementary school furniture weight and children’s age on performance of three carrying tasks (carrying a chair, lifting and turning a chair on a desk, and carrying both a chair and a desk together), from the ergonomics point of view. A total of 42 schoolchildren (ages 6–9; 17 Indonesian, 25 Japanese) participated in this study. Two types of Japanese chairs (Chair A and B, weight: 3.2 kg and 3.9 kg), one type of Indonesian chair (Chair C, weight: 5.0 kg), and two types of desks (height: 58 cm and 68 cm) were used. Indonesian chairs took significantly longer time to carry than the two Japanese chairs, and there was a significant negative relationship between age and task time for Chairs B and C, but not Chair A. Success rates for lifting and turning the chair declined as age decreased and chair weight increased, but were not significantly influenced by desk height. Success rates for carrying a chair and desk together significantly decreased with heavier furniture. Children aged six showed an extremely low success rate in almost all conditions. In conclusion, children’s ability to carry furniture is affected by their age and furniture characteristics, especially weight. In order to encourage classroom activities in elementary school, school furniture should be of appropriate weight. Supervision for younger children is required during classroom furniture arrangement. PMID:26053154

Leadership Experiences and Characteristics of Chairs of Academic Departments of Psychiatry

Science.gov (United States)

Keith, Samuel J.; Buckley, Peter F.

2011-01-01

Objective: Effective leadership in academic medicine requires a broad constellation of skills, experiences, and core values. The authors sought to describe and define these. Method: The authors conducted a web-based survey among 132 Chairs of North American departments of psychiatry. Results: Eighty-five Chairs (64%) responded to the survey, the…

Musculoskeletal discomfort during VDU tasks; input for a smart office chair

NARCIS (Netherlands)

Commissaris, D.A.C.M.; Blok, M.; Bosch, T.; Konemann, R.; Bronkhorst, R.

2008-01-01

TNO and BMA Ergonomics are developing a so-called smart office chair. This chair is supposed to provide feedback on postures and movements during seated office work. The feedback should enable the user (i.e. the worker doing VDU tasks) to perform his or her work with less discomfort and in a more

International Research Chairs Initiative | IDRC - International ...

International Development Research Centre (IDRC) Digital Library (Canada)

The International Research Chairs Initiative (IRCI) is a seven-year, CA$8 million research program that pairs top research talent from universities in Canada with their counterparts in developing countries to address key ... The results of this joint effort: world-class discoveries and healthier, wealthier, fairer societies.

Planetary Rings

Science.gov (United States)

Nicholson, P. D.

2001-11-01

A revolution in the studies in planetary rings studies occurred in the period 1977--1981, with the serendipitous discovery of the narrow, dark rings of Uranus, the first Voyager images of the tenuous jovian ring system, and the many spectacular images returned during the twin Voyager flybys of Saturn. In subsequent years, ground-based stellar occultations, HST observations, and the Voyager flybys of Uranus (1986) and Neptune (1989), as well as a handful of Galileo images, provided much additional information. Along with the completely unsuspected wealth of detail these observations revealed came an unwelcome problem: are the rings ancient or are we privileged to live at a special time in history? The answer to this still-vexing question may lie in the complex gravitational interactions recent studies have revealed between the rings and their retinues of attendant satellites. Among the four known ring systems, we see elegant examples of Lindblad and corotation resonances (first invoked in the context of galactic disks), electromagnetic resonances, spiral density waves and bending waves, narrow ringlets which exhibit internal modes due to collective instabilities, sharp-edged gaps maintained via tidal torques from embedded moonlets, and tenuous dust belts created by meteoroid impact onto parent bodies. Perhaps most puzzling is Saturn's multi-stranded, clumpy F ring, which continues to defy a simple explanation 20 years after it was first glimpsed in grainy images taken by Pioneer 11. Voyager and HST images reveal a complex, probably chaotic, dynamical interaction between unseen parent bodies within this ring and its two shepherd satellites, Pandora and Prometheus. The work described here reflects contributions by Joe Burns, Jeff Cuzzi, Luke Dones, Dick French, Peter Goldreich, Colleen McGhee, Carolyn Porco, Mark Showalter, and Bruno Sicardy, as well as those of the author. This research has been supported by NASA's Planetary Geology and Geophysics program and the

Samuel P. Massie Chair of Excellence Program

Energy Technology Data Exchange (ETDEWEB)

Johnson, James H. [Howard Univ., Washington, DC (United States)

2014-12-01

Abstract In 1994 the Department of Energy established the DOE Chair of Excellence Professorship in Environmental Disciplines Program. In 2004, the Massie Chair of Excellence Professor at Howard University transitioned from Dr. Edward Martin to Dr. James H. Johnson, Jr. At the time of his appointment Dr. Johnson served as professor of civil engineering and Dean of the College of Engineering, Architecture and Computer Sciences. Program activities under Dr. Johnson were in the following areas: • Increase the institution’s capacity to conduct scientific research and technical investigations at the cutting-edge. • Promote interactions, collaborations and partnerships between the private sector, Federal agencies, majority research institutes and other HBCUs. • Assist other HBCUs in reaching parity in engineering and related fields. • Mentor young investigators and be a role model for students.

Systematic Search for Rings around Kepler Planet Candidates: Constraints on Ring Size and Occurrence Rate

Science.gov (United States)

Aizawa, Masataka; Masuda, Kento; Kawahara, Hajime; Suto, Yasushi

2018-05-01

We perform a systematic search for rings around 168 Kepler planet candidates with sufficient signal-to-noise ratios that are selected from all of the short-cadence data. We fit ringed and ringless models to their light curves and compare the fitting results to search for the signatures of planetary rings. First, we identify 29 tentative systems, for which the ringed models exhibit statistically significant improvement over the ringless models. The light curves of those systems are individually examined, but we are not able to identify any candidate that indicates evidence for rings. In turn, we find several mechanisms of false positives that would produce ringlike signals, and the null detection enables us to place upper limits on the size of the rings. Furthermore, assuming the tidal alignment between axes of the planetary rings and orbits, we conclude that the occurrence rate of rings larger than twice the planetary radius is less than 15%. Even though the majority of our targets are short-period planets, our null detection provides statistical and quantitative constraints on largely uncertain theoretical models of the origin, formation, and evolution of planetary rings.

Radiation Pattern of Chair Armed Microstrip Antenna

Science.gov (United States)

Mishra, Rabindra Kishore; Sahu, Kumar Satyabrat

2016-12-01

This work analyzes planar antenna conformable to chair arm shaped surfaces for WLAN application. Closed form expressions for its radiation pattern are developed and validated using measurements on prototype and commercial EM code at 2.4 GHz.

Combined experimental powder X-ray diffraction and DFT data to obtain the lowest energy molecular conformation of friedelin

International Nuclear Information System (INIS)

Oliveira, Djalma Menezes de; Mussel, Wagner da Nova; Duarte, Lucienir Pains; Silva, Gracia Divina de Fatima; Duarte, Helio Anderson; Gomes, Elionai Cassiana de Lima; Guimaraes, Luciana; Vieira Filho, Sidney A.

2012-01-01

Friedelin molecular conformers were obtained by Density Functional Theory (DFT) and by ab initio structure determination from powder X-ray diffraction. Their conformers with the five rings in chair-chair-chair-boat-boat, and with all rings in chair, are energy degenerated in gas-phase according to DFT results. The powder diffraction data reveals that rings A, B and C of friedelin are in chair, and rings D and E in boat-boat, conformation. The high correlation values among powder diffraction data, DFT and reported single crystal data indicate that the use of conventional X-ray diffractometer can be applied in routine laboratory analysis in the absence of a single-crystal diffractometer. (author)

Combined experimental powder X-ray diffraction and DFT data to obtain the lowest energy molecular conformation of friedelin

Energy Technology Data Exchange (ETDEWEB)

Oliveira, Djalma Menezes de; Mussel, Wagner da Nova; Duarte, Lucienir Pains; Silva, Gracia Divina de Fatima; Duarte, Helio Anderson; Gomes, Elionai Cassiana de Lima [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Dept. de Quimica; Guimaraes, Luciana [Universidade Federal de Sao Joao Del-Rei (UFSJ), MG (Brazil). Dept. de Ciencias Naturais; Vieira Filho, Sidney A., E-mail: bibo@ef.ufop.br [Universidade Federal de Ouro Preto (UFOP), MG (Brazil). Dept. de Farmacia

2012-07-01

Friedelin molecular conformers were obtained by Density Functional Theory (DFT) and by ab initio structure determination from powder X-ray diffraction. Their conformers with the five rings in chair-chair-chair-boat-boat, and with all rings in chair, are energy degenerated in gas-phase according to DFT results. The powder diffraction data reveals that rings A, B and C of friedelin are in chair, and rings D and E in boat-boat, conformation. The high correlation values among powder diffraction data, DFT and reported single crystal data indicate that the use of conventional X-ray diffractometer can be applied in routine laboratory analysis in the absence of a single-crystal diffractometer. (author)

Cerebral oxygen desaturation during beach chair position

NARCIS (Netherlands)

Moerman, Annelies T.; de Hert, Stefan G.; Jacobs, Tom F.; de Wilde, Lieven F.; Wouters, Patrick F.

2012-01-01

Cases of ischaemic brain damage have been reported in relatively healthy patients undergoing shoulder surgery in the beach chair position. Unrecognised cerebral hypoperfusion may have contributed to these catastrophic events, indicating that routine anaesthesia monitoring may not suffice.

Annual Energy Savings and Thermal Comfort of Autonomously Heated and Cooled Office Chairs

Energy Technology Data Exchange (ETDEWEB)

Carmichael, Scott [National Renewable Energy Lab. (NREL), Golden, CO (United States); Booten, Chuck [National Renewable Energy Lab. (NREL), Golden, CO (United States); Robertson, Joseph [National Renewable Energy Lab. (NREL), Golden, CO (United States); Chin, Justin [National Renewable Energy Lab. (NREL), Golden, CO (United States); Christensen, Dane [National Renewable Energy Lab. (NREL), Golden, CO (United States); Pless, Jacquelyn [National Renewable Energy Lab. (NREL), Golden, CO (United States); Arent, Doug [National Renewable Energy Lab. (NREL), Golden, CO (United States)

2016-07-01

Energy use in offices buildings is largely driven by air conditioning demands. But the optimal temperature is not the same for all building occupants, leading to the infamous thermostat war. And many occupants have independently overcome building comfort weaknesses with their own space heaters or fans. NREL tested is a customized office chair that automatically heats and cools the occupant along the seat and chair back according to the occupants' personal preferences. This product is shown to deliver markedly better comfort at room temperatures well above typical office cooling setpoints. Experimental subjects reported satisfaction in these elevated air temperatures, partly because the chair's cooling effect was tuned to their own individual needs. Simulation of the chair in office buildings around the U.S. shows that energy can be saved everywhere, with impacts varying due to the climate. Total building HVAC energy savings exceeded 10% in hot-dry climate zones. Due to high product cost, simple payback for the chair we studied is beyond the expected chair life. We then understood the need to establish cost-performance targets for comfort delivery packages. NREL derived several hypothetical energy/cost/comfort targets for personal comfort product systems. In some climate regions around the U.S., these show the potential for office building HVAC energy savings in excess of 20%. This report documents this research, providing an overview of the research team's methods and results while also identifying areas for future research building upon the findings.

Viscosity of ring polymer melts

KAUST Repository

Pasquino, Rossana

2013-10-15

We have measured the linear rheology of critically purified ring polyisoprenes, polystyrenes, and polyethyleneoxides of different molar masses. The ratio of the zero-shear viscosities of linear polymer melts η0,linear to their ring counterparts η0,ring at isofrictional conditions is discussed as a function of the number of entanglements Z. In the unentangled regime η0,linear/η 0,ring is virtually constant, consistent with the earlier data, atomistic simulations, and the theoretical expectation η0,linear/ η0,ring = 2. In the entanglement regime, the Z-dependence of ring viscosity is much weaker than that of linear polymers, in qualitative agreement with predictions from scaling theory and simulations. The power-law extracted from the available experimental data in the rather limited range 1 < Z < 20, η0,linear/η0,ring ∼ Z 1.2±0.3, is weaker than the scaling prediction (η0,linear/η0,ring ∼ Z 1.6±0.3) and the simulations (η0,linear/ η0,ring ∼ Z2.0±0.3). Nevertheless, the present collection of state-of-the-art experimental data unambiguously demonstrates that rings exhibit a universal trend clearly departing from that of their linear counterparts, and hence it represents a major step toward resolving a 30-year-old problem. © 2013 American Chemical Society.

Viscosity of ring polymer melts

KAUST Repository

Pasquino, Rossana; Vasilakopoulos, Thodoris C.; Jeong, Youncheol; Lee, Hyojoon; Rogers, Simon A.; Sakellariou, Georgios; Allgaier, Jü rgen B.; Takano, Atsushi; Brá s, Ana Rita E; Chang, Taihyun; Gooß en, Sebastian; Pyckhout-Hintzen, Wim; Wischnewski, Andreas; Hadjichristidis, Nikolaos; Richter, Dieter R.; Rubinstein, Michael H.; Vlassopoulos, Dimitris

2013-01-01

We have measured the linear rheology of critically purified ring polyisoprenes, polystyrenes, and polyethyleneoxides of different molar masses. The ratio of the zero-shear viscosities of linear polymer melts η0,linear to their ring counterparts η0,ring at isofrictional conditions is discussed as a function of the number of entanglements Z. In the unentangled regime η0,linear/η 0,ring is virtually constant, consistent with the earlier data, atomistic simulations, and the theoretical expectation η0,linear/ η0,ring = 2. In the entanglement regime, the Z-dependence of ring viscosity is much weaker than that of linear polymers, in qualitative agreement with predictions from scaling theory and simulations. The power-law extracted from the available experimental data in the rather limited range 1 < Z < 20, η0,linear/η0,ring ∼ Z 1.2±0.3, is weaker than the scaling prediction (η0,linear/η0,ring ∼ Z 1.6±0.3) and the simulations (η0,linear/ η0,ring ∼ Z2.0±0.3). Nevertheless, the present collection of state-of-the-art experimental data unambiguously demonstrates that rings exhibit a universal trend clearly departing from that of their linear counterparts, and hence it represents a major step toward resolving a 30-year-old problem. © 2013 American Chemical Society.

Repositioning chairs in benign paroxysmal positional vertigo

DEFF Research Database (Denmark)

West, Niels; Hansen, Søren; Møller, Martin Nue

2016-01-01

The objective was to evaluate the clinical value of repositioning chairs in management of refractory benign paroxysmal positional vertigo (BPPV) and to study how different BPPV subtypes respond to treatment. We performed a retrospective chart review of 150 consecutive cases with refractory vertigo...

Order-disorder transition in nanoscopic semiconductor quantum rings

NARCIS (Netherlands)

Borrmann, P.; Harting, J.D.R.

2001-01-01

Using the path integral Monte Carlo technique we show that semiconductor quantum rings with up to six electrons exhibit a temperature, ring diameter, and particle number dependent transition between spin ordered and disordered Wigner crystals. Because of the small number of particles the transition

Ergonomic Chair Explorative Intervention Study: Effect on Chronic ...

African Journals Online (AJOL)

Ergonomic Chair Explorative Intervention Study: Effect on Chronic Upper ... they are associated with a complex relationship between individual, work-related and ... in chronic upper quadrant musculoskeletal dysfunction and work productivity ...

Severe cerebral desaturation during shoulder arthroscopy in the beach-chair position

DEFF Research Database (Denmark)

Dippmann, Christian; Winge, Søren; Nielsen, Henning Bay

2010-01-01

During shoulder arthroscopy in the beach-chair position, cerebral ischemia may be a serious complication because prolonged hypotension may affect regional cerebral oxygen supply. We present the cases of 2 patients in whom a reduction in mean arterial pressure after anesthesia provoked a decrease...... cerebral oxygenation. During surgery in the beach-chair position, hypotension must be avoided, and in all patients regional, cerebral oxygenation should be monitored and optimized....

Democratic Leadership and Faculty Empowerment at the Community College: A Theoretical Model for the Department Chair.

Science.gov (United States)

McArthur, Ronald C.

2002-01-01

Argues that community college organization at the department level presents challenging leadership issues for the newly appointed department chair. Asserts that existing culture, which looks upon the chair with some mistrust, demands chairs who behave as peers rather than military commanders. Concludes that democratic leadership is the most…

ECOHEALTH CHAIRS in HEALTH and GLOBAL ENVIRONMENTAL ...

International Development Research Centre (IDRC) Digital Library (Canada)

Francine Sinzinkayo

funds in the eligible countries where the research will take place. ... What is your definition of “third-party organisations” in an “Ecohealth Chair” application? ... other functions of the Chair (as specified in section 4 of the Call) but will not receive ...

Chair rise capacity and associated factors in older home-care clients.

Science.gov (United States)

Tiihonen, Miia; Hartikainen, Sirpa; Nykänen, Irma

2017-07-01

The aim of this study was to investigate the ability of older home-care clients to perform the five times chair rise test and associated personal characteristics, nutritional status and functioning. The study sample included 267 home-care clients aged ≥75 years living in Eastern and Central Finland. The home-care clients were interviewed at home by home-care nurses, nutritionists and pharmacists. The collected data contained sociodemographic factors, functional ability (Barthel Index, IADL), cognitive functioning (MMSE), nutritional status (MNA), depressive symptoms (GDS-15), medical diagnoses and drug use. The primary outcome was the ability to perform the five times chair rise test. Fifty-one per cent ( n=135) of the home-care clients were unable to complete the five times chair rise test. Twenty-three per cent ( n=64) of the home-care clients had good chair rise capacity (≤17 seconds). In a multivariate logistic regression analysis, fewer years of education (odds ratio [OR] = 1.11, 95% confidence interval [CI] 1.04-1.18), lower ADL (OR = 1.54, 95% CI 1.34-1.78) and low MNA scores (OR = 1.12, 95% CI 1.04-1.20) and a higher number of co-morbidities (OR = 1.21, 95% CI 1.02-1.43) were associated with inability to complete the five times chair rise test. Poor functional mobility, which was associated with less education, a high number of co-morbidities and poor nutritional status, was common among older home-care clients. To maintain and to prevent further decline in functional mobility, physical training and nutritional services are needed. (NutOrMed, ClinicalTrials.gov Identifier: NCT02214758).

Comparison of four specific dynamic office chairs with a conventional office chair: Impact upon muscle activation, physical activity and posture

NARCIS (Netherlands)

Ellegast, R.P.; Kraft, K.; Groenesteijn, L.; Krause, F.; Berger, H.; Vink, P.

2012-01-01

Prolonged and static sitting postures provoke physical inactivity at VDU workplaces and are therefore discussed as risk factors for the musculoskeletal system. Manufacturers have designed specific dynamic office chairs featuring structural elements which promote dynamic sitting and therefore

Administrative Challenges and Response Strategies to the Job Performance of Marketing Department Chairs.

Science.gov (United States)

Dyer, Beverly G.; Miller, Michael T.

This study reports on the job challenges and corresponding response strategies that department chairs at graduate and undergraduate colleges and universities encounter and rely upon. Literature and research related to marketing department chairs, marketing education, and marketing majors indicates that business schools have come under attack by…

Rashba diamond in an Aharonov-Casher ring

KAUST Repository

Wang, Xuhui

2011-10-07

Spin interference due to Rashba spin-orbit interaction(SOI) in a ballistic two-dimensional electron gas ring conductor submitted to a bias voltage is investigated theoretically. We calculate the scattering matrices and differential conductance with lead-ring junction coupling as an adjustable parameter. Due to the interference of electronic waves traversing the ring, the differential conductance modulated by both bias voltage and SOI exhibits a diamond-shaped pattern, thus termed as Rashba diamond. This feature offers a supplementary degree of freedom to manipulate phase interference.

Rashba diamond in an Aharonov-Casher ring

KAUST Repository

Wang, Xuhui; Manchon, Aurelien

2011-01-01

Spin interference due to Rashba spin-orbit interaction(SOI) in a ballistic two-dimensional electron gas ring conductor submitted to a bias voltage is investigated theoretically. We calculate the scattering matrices and differential conductance with lead-ring junction coupling as an adjustable parameter. Due to the interference of electronic waves traversing the ring, the differential conductance modulated by both bias voltage and SOI exhibits a diamond-shaped pattern, thus termed as Rashba diamond. This feature offers a supplementary degree of freedom to manipulate phase interference.

Three essays on the economics of science policy: The impact of funding, collaboration and research chairs

Science.gov (United States)

Mirnezami, Seyed Reza

This thesis studies the determinants that influence the number of citations, the effect of having a research collaboration with top-funded scientists on scientific productivity, and the effect of holding a research chair on scientific productivity. Based on a review study by Bornmann and Daniel (2008), one can argue that non-scientific factors determining the decision to cite do not significantly alter the role of citation as a measure of research impact. Assuming that the number of citations is a good measure for research impact and, in turn, for a certain kind of quality, we showed that the number of articles and the visibility of a researcher, the impact factor of the journal, the size of the research team, and the institutional setting of the university are the important determinants of citation counts. However, we have found that there is no significant effect of public funding and gender in most of the domains examined. The point that funding amount is not a significant determinant of citation counts does not necessarily contradict the positive effect of funding on scientific productivity. We also developed a theoretical model and proposed some hypotheses about the effect of collaboration with top-funded scientists on scientific productivity. We then validated the hypotheses with empirical analysis and showed that such collaboration has a positive effect on scientific productivity. This significant effect may exist through different channels: transfer of tacit knowledge, more scientific publications, economy of scale in knowledge production because of better research equipment, and expanded research network. The results also verified the positive effect of funding, the positive effect of networking (measured by number of co-authors), the inverted U-shaped effect of age, and the fewer number of publications by women compared to men. Finally, we made a distinction between different attributes of research chairs and their effect on scientific productivity. One

15α,20β-Dihydroxy-6β-methoxy-6,7-seco-6,20-epoxy-1,7-olide-ent-kaur-16-ene

Directory of Open Access Journals (Sweden)

Fu-Lin Yan

2010-04-01

Full Text Available The title compound, C21H30O6, a natural ent-kaurane diterpenoid, was obtained from the medicinal plant Isodon serra. The five rings in the molecule exhibit the expected cis and trans junctions. The three six-membered rings adopt chair, twist-boat and boat conformations, while two five-membered rings adopt envelope conformations. There are two molecules in the asymmetric unit, related by a non-crystallographic twofold screw axis; the main difference is in the different degrees of distortion of ring B. In the crystal, the molecules are linked by intermolecular O—H...O hydrogen bonds, forming chains along the b axis.

In situ tetrazole templated chair-like decanuclear azido-cobalt(II) SMM containing both tetra- and octa-hedral Co(II) ions.

Science.gov (United States)

Zhang, Yuan-Zhu; Gao, Song; Sato, Osamu

2015-01-14

An azido-bridged chair-like decanuclear cluster: [Co(II)10(bzp)8(Metz)2(N3)18]·4MeOH·3H2O (1, bzp = 2-benzoylpyridine and HMetz = 5-methyl-1H-tetrazole) was prepared with in situ tetrazolate anions as templates in a sealed system. 1 containing both octahedral and tetrahedral Co(II) ions exhibited slow relaxation of magnetization with an effective barrier of 26 K under an applied dc field of 1 kOe.

Neutrino Signals in Electron-Capture Storage-Ring Experiments

Directory of Open Access Journals (Sweden)

Avraham Gal

2016-06-01

Full Text Available Neutrino signals in electron-capture decays of hydrogen-like parent ions P in storage-ring experiments at GSI are reconsidered, with special emphasis placed on the storage-ring quasi-circular motion of the daughter ions D in two-body decays P → D + ν e . It is argued that, to the extent that daughter ions are detected, these detection rates might exhibit modulations with periods of order seconds, similar to those reported in the GSI storage-ring experiments for two-body decay rates. New dedicated experiments in storage rings, or using traps, could explore these modulations.

New South Africa–Canada Research Chairs Initiative | IDRC ...

International Development Research Centre (IDRC) Digital Library (Canada)

2016-12-08

Dec 8, 2016 ... ... (SARChI), as well as on the Industrial Research Chairs program, funded in part ... Calls for submissions will be launched on January 3, 2017 and will close ... Natural Sciences and Engineering Research Council of Canada.

"Chair Stand Test" as Simple Tool for Sarcopenia Screening in Elderly Women.

Science.gov (United States)

Pinheiro, P A; Carneiro, J A O; Coqueiro, R S; Pereira, R; Fernandes, M H

2016-01-01

To investigate the association between sarcopenia and "chair stand test" performance, and evaluate this test as a screening tool for sarcopenia in community-dwelling elderly women. Cross-sectional Survey. 173 female individuals, aged ≥ 60 years and living in the urban area of the municipality of Lafaiete Coutinho, Bahia's inland, Brazil. The association between sarcopenia (defined by muscle mass, strength and/or performance loss) and performance in the "chair stand test" was tested by binary logistic regression technique. The ROC curve parameters were used to evaluate the diagnostic power of the test in sarcopenia screening. The significance level was set at 5 %. The model showed that the time spent for the "chair stand test" was positively associated (OR = 1.08; 95% CI = 1.01 - 1.16, p = 0.024) to sarcopenia, indicating that, for each 1 second increment in the test performance, the sarcopenia's probability increased by 8% in elderly women. The cut-off point that showed the best balance between sensitivity and specificity was 13 seconds. The performance of "chair stand test" showed predictive ability for sarcopenia, being an effective and simple screening tool for sarcopenia in elderly women. This test could be used for screening sarcopenic elderly women, allowing early interventions.

Political Leadership in Parliament: The Role of Select Committee Chairs in the UK House of Commons

Directory of Open Access Journals (Sweden)

Alexandra Kelso

2016-06-01

Full Text Available Concepts of political leadership have been applied sparingly to parliaments, and not at all to the study of House of Commons select committees in the UK Parliament, where analysis has largely focused on their institutional capacity to scrutinise government and hold it to account. Yet examining these committees through a political leadership lens illuminates the complex role of committee chairs, a role which was significantly reshaped in 2010 with a shift to election of chairs by the whole House. This article analyses select committee chairs through the lens of political leadership, and draws on a series of interviews with chairs in order to delineate the nature of the political leadership they perform. It argues that, as chairs are now increasingly important parliamentary and policy actors, our understanding of them is significantly advanced by conceptualising their role as one of parliamentary political leadership, and that this in turn enriches our analytical toolkit when it comes to the study of parliaments.

Ecohealth Chair on Human and Animal Health in Protected ...

International Development Research Centre (IDRC) Digital Library (Canada)

This has led to more frequent interaction and conflict between human populations and wildlife. ... Applying ecohealth research to benefit local communities The Chair's ... to encompass relevant social, economic, and environmental dimensions.

Pharmacy practice department chairs' perspectives on part-time faculty members.

Science.gov (United States)

Fjortoft, Nancy; Winkler, Susan R; Mai, Thy

2012-05-10

To identify the benefits and consequences of having part-time faculty members in departments of pharmacy practice from the department chair's perspective. A stratified purposive sample of 12 pharmacy practice department chairs was selected. Eleven telephone interviews were conducted. Two investigators independently read interview notes and categorized and enumerated responses to determine major themes using content analysis. The investigators jointly reviewed the data and came to consensus on major themes. Benefits of allowing full-time faculty members to reduce their position to part-time included faculty retention and improved individual faculty work/life balance. Consequences of allowing part-time faculty positions included the challenges of managing individual and departmental workloads, the risk of marginalizing part-time faculty members, and the challenges of promotion and tenure issues. All requests to switch to part-time status were faculty-driven and most were approved. There are a variety of benefits and consequences of having part-time faculty in pharmacy practice departments from the chair's perspective. Clear faculty and departmental expectations of part-time faculty members need to be established to ensure optimal success of this working arrangement.

Analysis of sitting forces on stationary chairs for daily activities.

Science.gov (United States)

Hu, Lingling; Tackett, Bob; Tor, Onder; Zhang, Jilei

2016-04-01

No literature related to the study of sitting forces on chairs sat on by people who weighed over 136 kg was found. The Business Institutional Furniture Manufactures Association needs force data for development of performance test standards to test chairs for users who weigh up to 181 kg. 20 participants who weighed from 136 to 186 kg completed 6 tasks on an instrumented chair in the sequence of sitting down, remaining seated and rising. Effects of sitting motion, armrest use and seat cushion thickness on vertical sitting forces and centre-of-force were investigated. Results indicated hard sitting down yielded the highest sitting force of 213% in terms of participants' body weights. Armrest use affected sitting forces of normal sitting down, but not of rising and hard sitting down. Cushion thickness affected sitting forces of normal and hard sitting down and shifting, but not of rising, static seating or stretching backward situations. Practitioner Summary: Results of the sitting force and centre-of-force data obtained for this research can help furniture manufacturers develop new product performance test standards for creating reliable engineering design and manufacturing quality and durable products to meet a niche market need.

Bourdieu, Department Chairs and the Reform of Science Education

Science.gov (United States)

Melville, Wayne; Hardy, Ian; Bartley, Anthony

2011-11-01

Using the insights of the French sociologist, Pierre Bourdieu, this article considers the role of the science department chair in the reform of school science education. Using Bourdieu's 'thinking tools' of 'field', 'habitus' and 'capital', we case study the work of two teachers who both actively pursue the teaching and learning of science as inquiry. One teacher, Dan, has been a department chair since 2000, and has actively encouraged his department to embrace science as inquiry. The other teacher, Leslie, worked for one year in Dan's department before being transferred to another school where science teaching continues to be more traditional. Our work suggests that there are three crucial considerations for chairs seeking to lead the reform of science teaching within their department. The first of these is the development of a reform-minded habitus, as this appears to be foundational to the capital that can be expended in the leadership of reform. The second is an understanding of how to wield power and position in the promotion of reform. The third is the capacity to operate simultaneously and strategically within, and across, two fields; the departmental field and the larger science education field. This involves downplaying administrative logics, and foregrounding more inquiry-focused logics as a vehicle to challenge traditional science-teaching dispositions-the latter being typically dominated by concerns about curriculum 'coverage'.

Report from the David Peikoff Chair of Deafness Studies: January 1989 through August 1991.

Science.gov (United States)

Schein, Jerome D.

1991-01-01

Following a brief biography of David Peikoff, this paper describes the first occupant of the David Peikoff Chair of Deafness Studies, Jerome D. Schein. The chair's research agenda on mediated communication and demography of impaired hearing are described, as well as organization of an international conference, public addresses, and technical…

Passive scalar transport mediated by laminar vortex rings

Energy Technology Data Exchange (ETDEWEB)

Hernández, R H; Rodríguez, G, E-mail: rohernan@ing.uchile.cl [LEAF-NL, Depto. Ingeniería Civil Mecánica, Universidad de Chile, Casilla 2777, Santiago (Chile)

2017-04-15

Numerical simulations were used to study the dynamics of a passive conserved scalar quantity entrained by a self-propelling viscous vortex ring. The transport and mixing process of the passive scalar variable were studied considering two initial scalar distributions: (i) The scalar substance was introduced into the ring during its formation, further focusing in the shedding into the wake of the ring; (ii) A disk-like scalar layer was placed in the ring’s path where the entrainment of the scalar substance into the ring bubble was studied as a function of the ring strength. In both cases, the scalar concentration inside the vortex bubble exhibits a steady decay with time. In the second case, it was shown that the entrained scalar mass grows with both the Reynolds number of the ring and the thickness of the scalar layer in the propagation direction. The ring can be viewed as a mechanism for scalar transportation along important distances. (paper)

Canada-South Africa trilateral Research Chair in climate change ...

International Development Research Centre (IDRC) Digital Library (Canada)

Canada-South Africa trilateral Research Chair in climate change and ... Decreasing food availability for wildlife is likely to exacerbate the impacts of climate change ... IWRA/IDRC webinar on climate change and adaptive water management.

Persistent current in triangle silicene rings with spin–orbit interaction

Energy Technology Data Exchange (ETDEWEB)

Xu, Ning, E-mail: nxu@ycit.cn [Department of Physics, Yancheng Institute of Technology, Yancheng 224051 (China); Zhang, Haiyang; Wu, Xiuqiang; Bai, Yujie [Department of Physics, Yancheng Institute of Technology, Yancheng 224051 (China); Ding, Jianwen, E-mail: jwding@xtu.edu.cn [Department of Physics, Xiangtan University, Xiangtan 411105 (China)

2017-06-28

The energy spectrum and magnetic response of triangle silicene rings (TSRs) are investigated within the tight-binding model. It is shown that the flux-dependent energy spectrum is divided into bands, with three levels per band, owing to the three-fold rotational symmetry structure of TSRs. The zigzag TSRs are metallic, exhibiting either diamagnetic or paramagnetic response depending on the size of inner ring radius. Armchair TSRs are semiconducting, exhibiting diamagnetic response. Taking into account the intrinsic spin–orbit interaction, the magnetic-field-driven spin-up electrons flow anticlockwise around the TSRs and the spin-down electrons flow clockwise around the TSRs. Additionally, paramagnetism–diamagnetism or diamagnetism–paramagnetism transitions are observed with the increase of exchange field. The results may be very helpful for the design and application of TSR-based nanodevices. - Highlights: • The zigzag TSRs are metallic. • Armchair TSRs which exhibit diamagnetic response are semiconducting. • The spin-up electrons flow anticlockwise and spin-down electrons flow clockwise around the rings.

The Art of Chairing: What Deming Taught the Japanese and the Japanese Taught Me.

Science.gov (United States)

Rodd, Laurel Rasplica

2001-01-01

Reveals how a business model--based on the work of W. Edwards Deming--helped a foreign language department chair become a better leader. Outlines seven principles for department chairs: create constancy of purpose; change and improvement are ongoing; drive out fear; work with suppliers to continually improve the quality of incoming people,…

User Experience of Office Chairs and Anthropometrics of Female Chinese and Hong Kong Chinese Office and Factory Workers

NARCIS (Netherlands)

Reitenbach, E.F.R.; Jochems, A.J.; Molenbroek, J.F.M.; Ball, R.; Eijk, D.J.

2008-01-01

In Hong Kong it was noticed that female office and factory workers use chairs that are oversized and can't support their sitting posture in a comfortable way. In order to set up general recommendations to design a more appropriate office chair, a research of the user experience of office chairs was

Bosonic and fermionic dipoles on a ring

DEFF Research Database (Denmark)

Zöllner, Sascha; Pethick, C. J.; Bruun, Georg Morten

2011-01-01

We show that dipolar bosons and fermions confined in a quasi-one-dimensional ring trap exhibit a rich variety of states because their interaction is inhomogeneous. For purely repulsive interactions, with increasing strength of the dipolar coupling there is a crossover from a gaslike state...... to an inhomogeneous crystal-like one. For small enough angles between the dipoles and the plane of the ring, there are regions with attractive interactions, and clustered states can form....

Grouping and analysis of chair quality and their basic elements

Directory of Open Access Journals (Sweden)

Skakić Dušan

2009-01-01

Full Text Available Both the scientific experience and the engineering practice indicate that the decision making processes in the course of solving complex designing problems require an analysis of a great number of different construction variants. These types of decision-making processes are time consuming and do not always result in the selection of an optimal solution. That is why the methods of numerical optimization are applied in a wide range of technical sciences to assist in the selection of the best solution. The first step in solving the problem by using the Finite element method is to determine the type of chair earmarked for modeling, and to determine the dimensions of the chair elements.

The Body Language Behaviours of the Chairs of the Disputes According to the Disputants

Science.gov (United States)

Caliskan, Nihat

2009-01-01

The perception form of the body language behaviours of the session chairs by disputants affects the efficiency of the process. Therefore, it is important to determine the effects of the mimic, gesture, physical appearance and tonality and accent of the chairs on disputants. That research was conducted to clarify how the disputants perceive the…

Spontaneous vaginal delivery in the birth-chair versus in the conventional dorsal position: a matched controlled comparison.

Science.gov (United States)

Scholz, H S; Benedicic, C; Arikan, M G; Haas, J; Petru, E

2001-09-17

The aim of the study was to assess the effect of a birth-chair on obstetric outcome. We reviewed the hospital records of 220 consecutive pregnant women who gave birth on a birth-chair at our institution. The control group consisted of 440 pregnant women who preceded and followed the index cases and who had spontaneous vaginal deliveries in the conventional dorsal supine position. The controls were matched for parity and for the attending mid-wife. Patients who delivered in the birth-chair had significantly lower rates of episiotomy and manual separation of the placenta. The umbilical blood cord pH was significantly higher in neonates of the birth-chair group. The duration of labour, rate of perineal and vaginal injury, Apgar scores and rate of admission to a neonatal intermediate care unit were not influenced by the mode of delivery. Our data support previous studies that a birth-chair delivery may be a safe alternative to conventional delivery in the supine position.

Does agreement on institutional values and leadership issues between deans and surgery chairs predict their institutions' performance?

Science.gov (United States)

Souba, Wiley W; Mauger, David; Day, David V

2007-03-01

To gain a better understanding of the values that medical school deans and surgery chairs consider most essential for effective leadership, to assess their perceptions of the values and leadership climate in their institutions, and to test the premise that agreement on leadership values and climate predict greater organizational effectiveness and performance. From June 2005 through March 2006, questionnaires designed to assess leadership core values and organizational leadership climate were mailed to medical school deans and surgery chairs of the 125 U.S. academic health centers. Institutional performance measures used were the National Institutes of Health (NIH) standing and U.S. News and World Report ranking of each institution. Sixty-eight surgery chairs (54%) and 60 deans (48%) returned surveys. Q-sort results on 38 positive leadership values indicated that integrity, trust, and vision were considered the most important core values for effective leadership by both chairs and deans. Both groups ranked business acumen, authority, and institutional reputation as least important. Deans consistently ranked the leadership climate as being healthier (more positive) than did their surgery chairs on multiple scale items: leadership is widely shared (P = .005), information is widely shared (P = .002), missions are aligned (P = .003), open communication is the norm (P = .009), good performance is rewarded (P = .01), teamwork is widely practiced (P = .01), and leaders are held accountable (P = 002). Tighter alignment between chairs and deans on core values and on the leadership climate scale correlated with higher school and department NIH standing and higher U.S. News and World Report medical school and hospital ranking (P leadership values, deans believe that a healthier leadership climate exists in their institutions than their surgery chairs do. The study findings suggest that tighter leadership alignment between deans and surgery chairs may predict a higher level of

Vortex Ring Interaction with a Heated Screen

Science.gov (United States)

Smith, Jason; Krueger, Paul S.

2008-11-01

Previous examinations of vortex rings impinging on porous screens has shown the reformation of the vortex ring with a lower velocity after passing through the screen, the creation of secondary vortices, and mixing. A heated screen could, in principle, alter the vortex-screen interaction by changing the local liquid viscosity and density. In the present investigation, a mechanical piston-cylinder vortex ring generator was used to create vortex rings in an aqueous sucrose solution. The rings impinged on a screen of horizontal wires that were heated using electrical current. The flow was visualized with food color and video imaging. Tests with and without heat were conducted at a piston stroke-to-jet diameter ratio of 4 and a jet Reynolds number (Re) of 1000. The vortex rings slowed after passing through the screen, but in tests with heat, they maintained a higher fraction of their before-screen velocity due to reduction in fluid viscosity near the wires. In addition, small ``fingers'' that developed on the front of the vortex rings as they passed through the screen exhibited positive buoyancy effects in the heated case.

Novel Fiber-Optic Ring Acoustic Emission Sensor.

Science.gov (United States)

Wei, Peng; Han, Xiaole; Xia, Dong; Liu, Taolin; Lang, Hao

2018-01-13

Acoustic emission technology has been applied to many fields for many years. However, the conventional piezoelectric acoustic emission sensors cannot be used in extreme environments, such as those with heavy electromagnetic interference, high pressure, or strong corrosion. In this paper, a novel fiber-optic ring acoustic emission sensor is proposed. The sensor exhibits high sensitivity, anti-electromagnetic interference, and corrosion resistance. First, the principle of a novel fiber-optic ring sensor is introduced. Different from piezoelectric and other fiber acoustic emission sensors, this novel sensor includes both a sensing skeleton and a sensing fiber. Second, a heterodyne interferometric demodulating method is presented. In addition, a fiber-optic ring sensor acoustic emission system is built based on this method. Finally, fiber-optic ring acoustic emission experiments are performed. The novel fiber-optic ring sensor is glued onto the surface of an aluminum plate. The 150 kHz standard continuous sinusoidal signals and broken lead signals are successfully detected by the novel fiber-optic ring acoustic emission sensor. In addition, comparison to the piezoelectric acoustic emission sensor is performed, which shows the availability and reliability of the novel fiber-optic ring acoustic emission sensor. In the future, this novel fiber-optic ring acoustic emission sensor will provide a new route to acoustic emission detection in harsh environments.

An N-body Integrator for Planetary Rings

Science.gov (United States)

Hahn, Joseph M.

2011-04-01

A planetary ring that is disturbed by a satellite's resonant perturbation can respond in an organized way. When the resonance lies in the ring's interior, the ring responds via an m-armed spiral wave, while a ring whose edge is confined by the resonance exhibits an m-lobed scalloping along the ring-edge. The amplitude of these disturbances are sensitive to ring surface density and viscosity, so modelling these phenomena can provide estimates of the ring's properties. However a brute force attempt to simulate a ring's full azimuthal extent with an N-body code will likely fail because of the large number of particles needed to resolve the ring's behavior. Another impediment is the gravitational stirring that occurs among the simulated particles, which can wash out the ring's organized response. However it is possible to adapt an N-body integrator so that it can simulate a ring's collective response to resonant perturbations. The code developed here uses a few thousand massless particles to trace streamlines within the ring. Particles are close in a radial sense to these streamlines, which allows streamlines to be treated as straight wires of constant linear density. Consequently, gravity due to these streamline is a simple function of the particle's radial distance to all streamlines. And because particles are responding to smooth gravitating streamlines, rather than discrete particles, this method eliminates the stirring that ordinarily occurs in brute force N-body calculations. Note also that ring surface density is now a simple function of streamline separations, so effects due to ring pressure and viscosity are easily accounted for, too. A poster will describe this N-body method in greater detail. Simulations of spiral density waves and scalloped ring-edges are executed in typically ten minutes on a desktop PC, and results for Saturn's A and B rings will be presented at conference time.

Research Paper: Impact of Air Seat Cushions and Ball Chairs on Classroom Behavior of Students with Autism Spectrum Disorder

Directory of Open Access Journals (Sweden)

Nader Matin Sadr

2016-07-01

Conclusion In the present study, therapy balls and or cushioned chairs for ASD students facilitated in-seat and on-task behaviors and improved classroom performance. It seems that using these alternative seating chairs can satisfy the subjects’ needs to sensory stimuli, and therefore, decreases their sensory seeking behaviors which interferes with their academic achievements. While, using therapy ball chairs for these students may facilitate in-seat behavior and decrease autistic behavior in class, the student’s response to dynamic seating is different individually. Therefore, chair selection must be based on vestibular reaction of the students.

76 FR 2883 - Folding Metal Tables and Chairs From the People's Republic of China: Final Results of 2007-2008...

Science.gov (United States)

2011-01-18

... the chair component of Staples' ``Complete Office-To-Go,'' a folding chair with a tubular steel frame... steel seat frame with screws, and has cross-braces affixed to its legs. On May 1, 2006, the Department... folding tables and folding chairs made primarily or exclusively from steel or other metal, as described...

Development of New Wheel-Chair for Sports Competition

Directory of Open Access Journals (Sweden)

Akira Shionoya

2018-03-01

Full Text Available The purpose of this study was to develop the new wheel-chair which had the function to drive straight by one-hand operation. To perform this purpose, the driving force transmission axis (DFTA which had transmitted the driving force from the one side of wheel to another side of that was developed. The wheel-chair could drive straight by one-hand operation by the DFTA. The large torque, however, was generated in the DFTA, because the DFTA transmitted the driving force from the one side of wheel to another side by the axis of small diameter. Furthermore, the shear stress in the DFTA generated by this torque would lead to the DFTA break. The shear stress in the DFTA was calculated to examine the axial strength and durability. On the DETA of the wheelchair, the maximum shear stress calculated from the torque in driving was 39.53 MP and this was defined as the standard of the demand specifications as a strength and durability of the DFTA.

Benchmarking Academic Anatomic Pathologists: The Association of Pathology Chairs Survey.

Science.gov (United States)

Ducatman, Barbara S; Parslow, Tristram

2016-01-01

The most common benchmarks for faculty productivity are derived from Medical Group Management Association (MGMA) or Vizient-AAMC Faculty Practice Solutions Center ® (FPSC) databases. The Association of Pathology Chairs has also collected similar survey data for several years. We examined the Association of Pathology Chairs annual faculty productivity data and compared it with MGMA and FPSC data to understand the value, inherent flaws, and limitations of benchmarking data. We hypothesized that the variability in calculated faculty productivity is due to the type of practice model and clinical effort allocation. Data from the Association of Pathology Chairs survey on 629 surgical pathologists and/or anatomic pathologists from 51 programs were analyzed. From review of service assignments, we were able to assign each pathologist to a specific practice model: general anatomic pathologists/surgical pathologists, 1 or more subspecialties, or a hybrid of the 2 models. There were statistically significant differences among academic ranks and practice types. When we analyzed our data using each organization's methods, the median results for the anatomic pathologists/surgical pathologists general practice model compared to MGMA and FPSC results for anatomic and/or surgical pathology were quite close. Both MGMA and FPSC data exclude a significant proportion of academic pathologists with clinical duties. We used the more inclusive FPSC definition of clinical "full-time faculty" (0.60 clinical full-time equivalent and above). The correlation between clinical full-time equivalent effort allocation, annual days on service, and annual work relative value unit productivity was poor. This study demonstrates that effort allocations are variable across academic departments of pathology and do not correlate well with either work relative value unit effort or reported days on service. Although the Association of Pathology Chairs-reported median work relative value unit productivity

Middle cerebral artery blood flow velocity during beach chair position for shoulder surgery under general anesthesia.

Science.gov (United States)

Hanouz, Jean-Luc; Fiant, Anne-Lise; Gérard, Jean-Louis

2016-09-01

The goal of the present study was to examine changes of middle cerebral artery (VMCA) blood flow velocity in patients scheduled for shoulder surgery in beach chair position. Prospective observational study. Operating room, shoulder surgery. Fifty-three consecutive patients scheduled for shoulder surgery in beach chair position. Transcranial Doppler performed after induction of general anesthesia (baseline), after beach chair positioning (BC1), during surgery 20minutes (BC2), and after back to supine position before stopping anesthesia (supine). Mean arterial pressure (MAP), end-tidal CO2, and volatile anesthetic concentration and VMCA were recorded at baseline, BC1, BC2, and supine. Postoperative neurologic complications were searched. Beach chair position induced decrease in MAP (baseline: 73±10mm Hg vs lower MAP recorded: 61±10mm Hg; P<.0001) requiring vasopressors and fluid challenge in 44 patients (83%). There was a significant decrease in VMCA after beach chair positioning (BC1: 33±10cm/s vs baseline: 39±14cm/s; P=.001). The VMCA at baseline (39±2cm/s), BC2 (35±14cm/s), and supine (39±14cm/s) were not different. The minimal alveolar concentration of volatile anesthetics, end-tidal CO2, SpO2, and MAP were not different at baseline, BC1, BC2, and supine. Beach chair position resulted in transient decrease in MAP requiring fluid challenge and vasopressors and a moderate decrease in VMCA. Copyright © 2016 Elsevier Inc. All rights reserved.

7 CFR 1900.6 - Chair, Loan Resolution Task Force.

Science.gov (United States)

2010-01-01

... 7 Agriculture 12 2010-01-01 2010-01-01 false Chair, Loan Resolution Task Force. 1900.6 Section 1900.6 Agriculture Regulations of the Department of Agriculture (Continued) RURAL HOUSING SERVICE, RURAL BUSINESS-COOPERATIVE SERVICE, RURAL UTILITIES SERVICE, AND FARM SERVICE AGENCY, DEPARTMENT OF...

The first F-ring modified ciguatoxin analogue showing significant toxicity.

Science.gov (United States)

Ishihara, Yuuki; Lee, Nayoung; Oshiro, Naomasa; Matsuoka, Shigeru; Yamashita, Shuji; Inoue, Masayuki; Hirama, Masahiro

2010-05-07

Ciguatoxins, the principal causative toxins of ciguatera seafood poisoning, are potent neurotoxic polycyclic ethers. We report herein the total synthesis of a 10-membered F-ring analogue of 51-hydroxyCTX3C, which constitutes the first example of an F-ring modified ciguatoxin that exhibits potent cytotoxicity as well as mouse acute toxicity.

A Theoretical Model for Designing an In-House Community College Department Chair Professional Development Program

Science.gov (United States)

Sirkis, Jocelyn Eager

2013-01-01

Academic department chairs serve as front-line managers and leaders who perform a wide variety of tasks. These tasks may include mundane chores, such as ordering office supplies, or important ones, such as changing the department culture to one that embraces assessment. Too often, however, individuals take on the chair position with little to no…

Minister Pratt welcomes new Canada Research Chair at Carleton University

CERN Multimedia

2004-01-01

"The Honourable David Pratt, Minister of National Defence, and Member of Parliament for Nepean-Carleton, today congratulated Carleton University on receiving $638,405 in funding to support a new Canada Research Chair" (1 page)

Novel Fiber-Optic Ring Acoustic Emission Sensor

Directory of Open Access Journals (Sweden)

Peng Wei

2018-01-01

Full Text Available Acoustic emission technology has been applied to many fields for many years. However, the conventional piezoelectric acoustic emission sensors cannot be used in extreme environments, such as those with heavy electromagnetic interference, high pressure, or strong corrosion. In this paper, a novel fiber-optic ring acoustic emission sensor is proposed. The sensor exhibits high sensitivity, anti-electromagnetic interference, and corrosion resistance. First, the principle of a novel fiber-optic ring sensor is introduced. Different from piezoelectric and other fiber acoustic emission sensors, this novel sensor includes both a sensing skeleton and a sensing fiber. Second, a heterodyne interferometric demodulating method is presented. In addition, a fiber-optic ring sensor acoustic emission system is built based on this method. Finally, fiber-optic ring acoustic emission experiments are performed. The novel fiber-optic ring sensor is glued onto the surface of an aluminum plate. The 150 kHz standard continuous sinusoidal signals and broken lead signals are successfully detected by the novel fiber-optic ring acoustic emission sensor. In addition, comparison to the piezoelectric acoustic emission sensor is performed, which shows the availability and reliability of the novel fiber-optic ring acoustic emission sensor. In the future, this novel fiber-optic ring acoustic emission sensor will provide a new route to acoustic emission detection in harsh environments.

Fearing Colleges Slight "Traditional Values," Conservatives Back "Free Enterprise" Chairs.

Science.gov (United States)

Evangelauf, Jean

1987-01-01

In the last 25 years, 80 to 100 chairs or institutes focusing on the study of capitalism have been established on college campuses, sometimes facing criticism because of potential conflict with the institution's mission. (MSE)

Gender, Performativity, and Leadership: Department Chairs in Research Universities

Science.gov (United States)

Lepkowski, Christine

2014-01-01

Women are significantly underrepresented as administrators in higher education leadership. This qualitative study examined the leadership of department chairs at public research universities to better understand how their gender and other identities affected their leadership. The following research questions shaped the study: (1) How do department…

Quantized levitation states of superconducting multiple-ring systems

International Nuclear Information System (INIS)

Haley, S.B.; Fink, H.J.

1996-01-01

The quantized levitation, trapped, and suspension states of a magnetic microsphere held in equilibrium by two fixed superconducting (SC) microrings are calculated by minimizing the free energy of the system. Each state is a discrete function of two independent fluxoid quantum numbers of the rings. When the radii of the SC rings are of the same order as the Ginzburg-Landau coherence length ξ(T), the system exhibits a small set of gravity and temperature-dependent levels. The levels of a weakly magnetized particle are sensitive functions of the gravitational field, indicating potential application as an accelerometer, and for trapping small magnetic particles in outer space or on Earth. The equilibrium states of a SC ring levitated by another SC ring are also calculated. copyright 1996 The American Physical Society

76 FR 16379 - Foreign-Trade Zone 177-Evansville, IN; Application for Manufacturing Authority, Best Chair, Inc...

Science.gov (United States)

2011-03-23

...--Evansville, IN; Application for Manufacturing Authority, Best Chair, Inc. d/b/a Best Home Furnishings... Zones Board (the Board) by the Ports of Indiana, grantee of FTZ 177, requesting manufacturing authority on behalf of Best Chair, Inc. d/b/a Best Home Furnishings (Best Home), to manufacture upholstered...

Control of the rings of exceptional points in photonic crystal slabs

DEFF Research Database (Denmark)

Kaminski, Piotr Marek; Breinbjerg, Olav; Mørk, Jesper

2017-01-01

shown that when the system becomes non-Hermitian, e.g. it is an open system exhibiting radiation losses, Dirac cones can be deformed spawning rings of exceptional points [2]. Within the ring, the dispersion follows the two-dimensional flat band which provides a high density of states and therefore high...

3-[4-(Dimethylaminophenyl]-1-(4a,8-dimethyl-1,2,3,4,4a,5,6,8a-octahydronaphthalen-2-ylprop-2-en-1-one

Directory of Open Access Journals (Sweden)

Moha Berraho

2011-01-01

Full Text Available The title compound, C23H31NO, was semisynthesized from isocostic acid, isolated from the aerial part of Inula Viscosa (L Aiton [or Dittrichia Viscosa (L Greuter]. The cyclohexene ring has a half-chair conformation, whereas the cyclohexane ring displays a chair conformation. The dihedral angle between the latter ring and its substituent is 83.6 (7°.

How to Remove a Stuck Ring Safely

Science.gov (United States)

... with a ring cutter found in jewelry stores, fire departments and emergency rooms. Other Links CME Mission Statement and Disclaimer Policies and Technical Requirements Exhibits and Partners ASSH 822 W. Washington Blvd. Chicago, IL 60607 (312) 880-1900 [email protected] Follow ...

Vortex formation in narrow ferromagnetic rings

International Nuclear Information System (INIS)

Klaeui, M; Vaz, C A F; Lopez-Diaz, L; Bland, J A C

2003-01-01

The high-symmetry ring geometry is shown to exhibit a wide range of intriguing magnetostatic and magnetodynamic properties, which we survey in this topical review. We consider first the patterning and deposition techniques, which are used to fabricate ring structures (diameters between 0.1 and 2 μm) and discuss their respective advantages and disadvantages. The results of direct nanoscale imaging of the novel magnetization configurations present in rings with different geometrical parameters (including discs) are discussed. These results give valuable insight into the influence of the magnetic anisotropies governing the magnetic states. The different types of domain walls that arise are compared quantitatively to micromagnetic simulations. The magnetodynamic switching between the different magnetic states is described in detail. In particular we elaborate on the different geometry-dependent magnetic switchings, since the different transitions occurring allow us to determine which energy terms govern the reversal process. We discuss a process by which fast (sub-ns) and controlled switching can be achieved, therefore making rings an attractive geometry for applications, in addition to studying fundamental issues of nanomagnetism. (topical review)

A radiolucent chair for sitting-posture radiographs in non-ambulatory children: use in biplanar digital slot-scanning

International Nuclear Information System (INIS)

Bouloussa, Houssam; Dubory, Arnaud; Bachy, Manon; Seiler, Catherine; Morel, Baptiste; Vialle, Raphael

2015-01-01

EOS imaging (EOS System; EOS imaging, Paris, France) enables fast 2-D/3-D imaging of children in standing load-bearing position. Non-ambulatory children with neuromuscular scoliosis need evaluation of their spinal balance while in a normal daily position. We designed a customized chair fitting the EOS patient-area dimensions to obtain images in natural sitting postures. The chair is a 360 rotating orthopaedic chair made of fully radiolucent polyethylene and equipped with an adjustable headrest and three-point belts. Out of 41 consecutive patients, 36 (88%, 95% confidence interval 74-96%) had successful imaging. In most patients with severe neuromuscular trunk deformities, the EOS system combined with our chair was useful for assessing preoperative trunk collapse, pelvic obliquity and postoperative corrections in all planes. This specific device changed our daily practice for the assessment of spinal deformities in non-ambulatory patients. (orig.)

A radiolucent chair for sitting-posture radiographs in non-ambulatory children: use in biplanar digital slot-scanning

Energy Technology Data Exchange (ETDEWEB)

Bouloussa, Houssam; Dubory, Arnaud; Bachy, Manon [Universite Pierre et Marie Curie-Paris 6, Armand Trousseau Hospital, Department of Pediatric Orthopaedics, Paris Cedex 12 (France); Seiler, Catherine [Groupe Lagarrigue, Clichy (France); Morel, Baptiste [Universite Pierre et Marie Curie-Paris 6, Armand Trousseau Hospital, Department of Pediatric Imaging, Paris (France); Vialle, Raphael [Universite Pierre et Marie Curie-Paris 6, Armand Trousseau Hospital, Department of Pediatric Orthopaedics, Paris Cedex 12 (France); Armand Trousseau Hospital, The MAMUTH Hospital-University Department for Innovative Therapies in Musculoskeletal Diseases, Paris (France)

2015-11-15

EOS imaging (EOS System; EOS imaging, Paris, France) enables fast 2-D/3-D imaging of children in standing load-bearing position. Non-ambulatory children with neuromuscular scoliosis need evaluation of their spinal balance while in a normal daily position. We designed a customized chair fitting the EOS patient-area dimensions to obtain images in natural sitting postures. The chair is a 360 rotating orthopaedic chair made of fully radiolucent polyethylene and equipped with an adjustable headrest and three-point belts. Out of 41 consecutive patients, 36 (88%, 95% confidence interval 74-96%) had successful imaging. In most patients with severe neuromuscular trunk deformities, the EOS system combined with our chair was useful for assessing preoperative trunk collapse, pelvic obliquity and postoperative corrections in all planes. This specific device changed our daily practice for the assessment of spinal deformities in non-ambulatory patients. (orig.)

77 FR 55813 - Environmental Management Site-Specific Advisory Board Chairs

Science.gov (United States)

2012-09-11

...This notice announces a meeting of the Environmental Management Site-Specific Advisory Board (EM SSAB) Chairs. The Federal Advisory Committee Act (Pub. L. 92-463, 86 Stat. 770) requires that public notice of this meeting be announced in the Federal Register.

77 FR 18242 - Environmental Management Site-Specific Advisory Board Chairs

Science.gov (United States)

2012-03-27

...This notice announces a meeting of the Environmental Management Site-Specific Advisory Board (EM SSAB) Chairs. The Federal Advisory Committee Act (Pub. L. 92-463, 86 Stat. 770) requires that public notice of this meeting be announced in the Federal Register.

78 FR 20311 - Environmental Management Site-Specific Advisory Board Chairs

Science.gov (United States)

2013-04-04

...This notice announces a webinar of the Environmental Management Site-Specific Advisory Board (EM SSAB) Chairs. The Federal Advisory Committee Act (Pub. L. 92-463, 86 Stat. 770) requires that public notice of this webinar be announced in the Federal Register.

78 FR 59012 - Environmental Management Site-Specific Advisory Board Chairs

Science.gov (United States)

2013-09-25

...This notice announces a meeting of the Environmental Management Site-Specific Advisory Board (EM SSAB) Chairs. The Federal Advisory Committee Act (Pub. L. 92-463, 86 Stat. 770) requires that public notice of this meeting be announced in the Federal Register.

Mr Gary Nairn MP, Chair of the Standing Committee on Science and Innovation, Australia

CERN Multimedia

Maximilien Brice

2003-01-01

Photos 01,04,06,07: Mr Gary Nairn MP, Chair of the Standing Committee on Science and Innovation, Australia,visiting the silicon test laboratory, April 2003. Photos 02,03: From left to right: Mr Gary Nairn MP, Chair of the Standing Committee on Science and Innovation, Australia,visiting the silicon test laboratory with Prof. Steinar Stapnes, Physicist in the ATLAS experiment, April 2003. Photos 02,09: Mrs Kerrye Nairn, Australia,visiting the silicon test laboratory, April 2003

Musical Chairs: An Innovative Teaching and Learning Method

Science.gov (United States)

Kuo, Ya-Hui

2010-01-01

How teaching and learning takes place in classrooms can be easily seen by the way classrooms are set up: Students' desks and chairs are arranged in rolls while teachers' desks are up front. Yet, why must teachers be the ones who lecture, why can't it be students? Would it be better or worse when teachers are the receivers and the students are the…

Strings, vortex rings, and modes of instability

Directory of Open Access Journals (Sweden)

Steven S. Gubser

2015-03-01

Full Text Available We treat string propagation and interaction in the presence of a background Neveu–Schwarz three-form field strength, suitable for describing vortex rings in a superfluid or low-viscosity normal fluid. A circular vortex ring exhibits instabilities which have been recognized for many years, but whose precise boundaries we determine for the first time analytically in the small core limit. Two circular vortices colliding head-on exhibit stronger instabilities which cause splitting into many small vortices at late times. We provide an approximate analytic treatment of these instabilities and show that the most unstable wavelength is parametrically larger than a dynamically generated length scale which in many hydrodynamic systems is close to the cutoff. We also summarize how the string construction we discuss can be derived from the Gross–Pitaevskii Lagrangian, and also how it compares to the action for giant gravitons.

78 FR 64208 - Environmental Management Site-Specific Advisory Board Chairs

Science.gov (United States)

2013-10-28

...This notice announces a meeting of the Environmental Management Site-Specific Advisory Board (EM SSAB) Chairs. The Federal Advisory Committee Act (Pub. L. No. 92-463, 86 Stat. 770) requires that public notice of this meeting be announced in the Federal Register.

1-(4a,8-Dimethyl-1,2,3,4,4a,5,6,8a-octahydronaphthalen-2-yl-3-phenylprop-2-en-1-one

Directory of Open Access Journals (Sweden)

Mohamed Tebbaa

2011-04-01

Full Text Available The title compound, C21H26O, was semisynthesized from isocostic acid, isolated from the aerial part of Inula Viscosa (L Aiton [or Dittrichia Viscosa (L Greuter]. The cyclohexene ring has a half-chair conformation, whereas the cyclohexane ring displays a chair conformation.

Toward creating family-friendly work environments in pediatrics: baseline data from pediatric department chairs and pediatric program directors.

Science.gov (United States)

McPhillips, Heather A; Burke, Ann E; Sheppard, Kate; Pallant, Adam; Stapleton, F Bruder; Stanton, Bonita

2007-03-01

The objective was to determine baseline characteristics of pediatric residency training programs and academic departments in regard to family-friendly work environments as outlined in the Report of the Task Force on Women in Pediatrics. We conducted Web-based anonymous surveys of 147 pediatric department chairs and 203 pediatric program directors. The chair's questionnaire asked about child care, lactation facilities, family leave policies, work-life balance, and tenure and promotion policies. The program director's questionnaire asked about family leave, parenting, work-life balance, and perceptions of "family-friendliness." The response rate was 52% for program directors and 51% for chairs. Nearly 60% of chairs reported some access to child care or provided assistance locating child care; however, in half of these departments, demand almost always exceeded supply. Lactation facilities were available to breastfeeding faculty in 74% of departments, although only 57% provided access to breast pumps. A total of 78% of chairs and 90% of program directors reported written maternity leave policies with slightly fewer reporting paternity leave policies. The majority (83%) of chairs reported availability of part-time employment, whereas only 27% of program directors offered part-time residency options. Most departments offered some flexibility in promotion and tenure. Although progress has been made, change still is needed in many areas in pediatric departments and training programs, including better accessibility to quality child care; improved lactation facilities for breastfeeding mothers; clear, written parental leave policies; and flexible work schedules to accommodate changing demands of family life.

A Coaxial Vortex Ring Model for Vortex Breakdown

OpenAIRE

Blackmore, Denis; Brons, Morten; Goullet, Arnaud

2008-01-01

A simple - yet plausible - model for B-type vortex breakdown flows is postulated; one that is based on the immersion of a pair of slender coaxial vortex rings in a swirling flow of an ideal fluid rotating around the axis of symmetry of the rings. It is shown that this model exhibits in the advection of passive fluid particles (kinematics) just about all of the characteristics that have been observed in what is now a substantial body of published research on the phenomenon of vortex breakdown....

3-(4-Chlorophenyl-1-[(2R,4aR,8aR-4a,8-dimethyl-1,2,3,4,4a,5,6,8a-octahydronaphthalen-2-yl]prop-2-en-1-one

Directory of Open Access Journals (Sweden)

Mohamed Tebbaa

2011-06-01

Full Text Available The title compound, C21H25ClO, was semi-synthesized from isocostic acid, isolated from the aerial part of Inula Viscosa (L Aiton [or Dittrichia Viscosa (L Greuter]. The cyclohexene ring has a half-chair conformation, whereas the cyclohexane ring displays a chair conformation.

Development of Leadership Skills in Community College Department Chairs

Science.gov (United States)

Sirkis, Jocelyn Eager

2011-01-01

The role of a community college department chairperson is not well defined and the job is often perceived as more of a burden than an honor. Faculty come to the position frequently by "default" and without a ready set of management and leadership skills. The matter is of concern since chairs influence academic department strategy, culture, and…

Ecohealth Chair on Human and Animal Health in Protected ...

International Development Research Centre (IDRC) Digital Library (Canada)

This project will help establish an Ecohealth Chair in Human and Animal Health in Protected Ecosystems to improve the sustainability of conservation areas and the health of local ... Le nouveau site Web facilitera l'enregistrement des événements démographiques afin d'améliorer l'accès aux services pour tous. Le nouveau ...

Chair Design Analysis Of Work To Reduce Musculoskeletal Part 1 Anthropometry Method

Directory of Open Access Journals (Sweden)

Nelfiyanti

2015-08-01

Full Text Available Refilling of fire extinguishers is a key activity in PT Pinaco Utama Indonesia. In these activities the workers doing the work manually with ergonomic postures that can cause a complaint to the musculoskeletal system. In a preliminary study a questionnaire used Nordic Body Map is used to identify specific problems in parts of the body and using REBA Rapid Entire Body Assessment to determine the level of risk working posture. This preliminary study shows that workers have a lot of complaints on the part of their body with a high level of risk and very high. For that we need a tool that can reduce the complaints of the musculoskeletal system. Tools in the form of work chair. The purpose of this study was to design an ergonomic office chair and is equipped with several features to accommodate the needs and conditions in PT Pinaco Utama Indonesia. The first step of this research is to develop the expectations of the office chair features information then is poured into a design concept. Furthermore this concept is manifested in a more specific design taking into account the anthropometric dimensions of the workers. Making the design and production cost calculation is made to perform a feasibility analysis in this research.

75 FR 51450 - Environmental Management Site-Specific Advisory Board Chairs

Science.gov (United States)

2010-08-20

...' Roundtable Discussion: Day One Presentations and Product Development. Thursday, September 16, 2010 [cir] EM... Product Development. Public Participation: The EM SSAB Chairs welcome the attendance of the public at... in the agenda. The Designated Federal Officer is empowered to conduct the meeting in a fashion that...

Correlated Random Systems Five Different Methods : CIRM Jean-Morlet Chair

CERN Document Server

Kistler, Nicola

2015-01-01

This volume presents five different methods recently developed to tackle the large scale behavior of highly correlated random systems, such as spin glasses, random polymers, local times and loop soups and random matrices. These methods, presented in a series of lectures delivered within the Jean-Morlet initiative (Spring 2013), play a fundamental role in the current development of probability theory and statistical mechanics. The lectures were: Random Polymers by E. Bolthausen, Spontaneous Replica Symmetry Breaking and Interpolation Methods by F. Guerra, Derrida's Random Energy Models by N. Kistler, Isomorphism Theorems by J. Rosen and Spectral Properties of Wigner Matrices by B. Schlein. This book is the first in a co-edition between the Jean-Morlet Chair at CIRM and the Springer Lecture Notes in Mathematics which aims to collect together courses and lectures on cutting-edge subjects given during the term of the Jean-Morlet Chair, as well as new material produced in its wake. It is targeted at researchers, i...

76 FR 35832 - Folding Metal Tables and Chairs From the People's Republic of China: Preliminary Results of...

Science.gov (United States)

2011-06-20

...-Go,'' a folding chair with a tubular steel frame and a seat and back of plastic, with measurements of... polyvinyl chloride, attached to the tubular steel seat frame with screws, and has cross braces affixed to... unassembled folding tables and folding chairs made primarily or exclusively from steel or other metal, as...

(10R,13R-17-(6-Hydroxy-5-methylheptan-2-yl-10,13-dimethyl-2,3,4,7,8,9,10,11,12,13,14,15,16,17-tetradecahydro-1H-cyclopenta[a]phenanthren-3-ol hemihydrate: a bioactive steroid isolated from the Indian herb Artemisia reticulata

Directory of Open Access Journals (Sweden)

A. K. Bauri

2017-08-01

Full Text Available The title tetracyclic steroidal compound, C27H46O2·0.5H2O, crystallized as a monohydrate with two independent molecules (1 and 2 in the asymmetric unit. In both molecules, the conformations of the three cyclohexane rings (A, B and C are chair, half-chair and chair, respectively. The fourth ring, D, has a twisted conformation on the bond linking the D and C rings. The crystal structure is stabilized by hydrogen bonding with the two independent molecules being linked through the solvent water molecule via various O—H...O hydrogen bonds, forming layers parallel to (-101.

Relationship between Features of Desks and Chairs and Prevalence of Skeletal Disorders in Primary School Students in Abadan

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Yadollah Zakeri

2016-11-01

Full Text Available BackgroundSitting on inappropriate benches, as well as the poor posture (body position during the years of growth, can lead to spinal disorders, fatigue and discomfort in students. This study aimed to investigate the relationship between features of desks and chairs and prevalence of some musculoskeletal disorders in primary school students in Abadan.Materials and MethodsThis cross-sectional study was conducted in 2015 in the city of Abadan- South West of Iran; for which, 383 primary school students were selected and studied through cluster sampling method. Data were collected by the checkered board and researcher-made questionnaire. Features and dimensions of desks and chairs of students were recorded and evaluated based on their condition (being standard or not. Statistical analysis was conducted using SPSS, version 22; and then, descriptive statistics and Chi-square test were conducted.ResultsStudy results showed that about 56.1% of the desks and chairs in under study schools were non-standard. It found that drooping shoulder (85.4% and scoliosis (81.7% were the more prevalent disorders and back straight (1.6% was the least frequent disorder. There was a significant relationship between the variable of non-standard desks and chairs and prevalence of drooping shoulders (P=0.001, scoliosis (P= 0.04, kyphosis (P=0.007 and lordosis (P=0.002 disorders in students.ConclusionThe non-standard-sized desks and chairs increase the prevalence of skeletal disorders in schoolchildren. Therefore, it is essential to pay attention to design and build standard classroom desks and chairs, which are best, adjust to students’ physics.

Can Air Seat Cushions and Ball Chairs Improved Classroom Behaviors of Students with Autism Spectrum Disorder: A Single Subject Study

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Nader Matin Sadr

2015-06-01

Full Text Available Background: Classroom behaviorsare disturbed in autistic students because of their repetitive, restlessness, and disruptive behaviors. This study aimed to examine the impacts of sitting on a ball, cushion, and/or common chair on classroom behavior of four students with Autism Spectrum Disorder (ASD. Methods: Four children with Autism participated in this single-subject study. Students’ behaviors were video recorded in three phases: Sitting on their common chairs during phase A, air-sit cushioned in phase B, and ball chairs in phase C. Sitting times and on-task/off-task behaviors were quantified by momentary time sampling (every 10 seconds and compared during different phases for important changes. Social validity was taken by the teacher at the end of the research as well. Results: The findings demonstrated increases in on-task and in-seat behaviors in four students when seated on air sit cushioned chairs. Despite rises of ontask behaviors for all students, only two of the students showed enhanced inseat behaviors when seated on therapy balls. Social validity findings indicated that the teacher preferred the use of the balls and air-cushioned chairs for her students. Conclusion: Therapy balls/cushioned chairs for students with ASD may facilitate in-seat and on-task behavior.

[Key points for esthetic rehabilitation of anterior teeth using chair-side computer aided design and computer aided manufacture technique].

Science.gov (United States)

Yang, J; Feng, H L

2018-04-09

With the rapid development of the chair-side computer aided design and computer aided manufacture (CAD/CAM) technology, its accuracy and operability of have been greatly improved in recent years. Chair-side CAD/CAM system may produce all kinds of indirect restorations, and has the advantages of rapid, accurate and stable production. It has become the future development direction of Stomatology. This paper describes the clinical application of the chair-side CAD/CAM technology for anterior aesthetic restorations from the aspects of shade and shape.

Initiative internationale des chaires de recherche | CRDI - Centre de ...

International Development Research Centre (IDRC) Digital Library (Canada)

Initiative de recherche de sept ans dotée d'un budget de 8 millions de dollars canadiens. L'Initiative internationale des chaires de recherche a pour but de jumeler d'éminents chercheurs d'universités du Canada avec des homologues de pays en développement afin de relever quelques-uns des plus grands défis auxquels ...

(4bS,8aS-1-Isopropyl-4b,8,8-trimethyl-4b,5,6,7,8,8a,9,10-octahydrophenanthren-2-yl benzoate

Directory of Open Access Journals (Sweden)

Radouane Oubabi

2014-08-01

Full Text Available The title compound, C27H34O2, was hemisynthesized through direct benzoylation of the naturally occurring meroterpene totarol. The central fused six-membered ring has a half-chair conformation, whereas the terminal six-membered ring displays a chair conformation. The dihedral angle between the fused benzene ring and the benzoyl benzene ring is 73.05 (14°. The S,S chirality of the molecule is consistent with the synthetic pathway, and confirmed by the refinement of the Flack parameter.

Ring Theory

CERN Document Server

Jara, Pascual; Torrecillas, Blas

1988-01-01

The papers in this proceedings volume are selected research papers in different areas of ring theory, including graded rings, differential operator rings, K-theory of noetherian rings, torsion theory, regular rings, cohomology of algebras, local cohomology of noncommutative rings. The book will be important for mathematicians active in research in ring theory.

Reliability of Arm Curl and Chair Stand tests for assessing muscular endurance in older people

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Boneth M

2012-05-01

Full Text Available Objective: to assess the test-retest reliability and level of agreement between measures of the 30 second (30-s Arm Curl and 30-s Chair Stand test in a sample of older adults from Bucaramanga. Materials and methods: a study of evaluation of diagnostic technology was done. Both tests were administered by the same evaluator to 111 adults older than 59 year-old (70,4 ± 7,3, on two occasions, with an interval of time between measures of 4 to 8 days. In the analysis, test-retest reliability was determined using the Intraclass Correlation Coefficient ICC= 2,1 with their confidence interval 95% (CI 95% respective. The agreement level was established by the Bland and Altman method. Results: the test-retest reproducibility of the 30-s Arm Curl test was very good ICC= 0,88 and to the Chair Stand test was good ICC= 0,78. The agreement was very good for both tests of muscle endurance. The CI 95% were between -3,8 and 3,2 stands to 30-s Chair Stand test and between -3,1 and 2,8 curls to 30-s Arm Curl test. Conclusion: the 30-s Arm Curl and 30-s Chair Stand test have good reliability and agreement to assess muscle endurance in older adults functionally independent.

Organizing awareness and increasing emotion regulation: revising chair work in emotion-focused therapy for borderline personality disorder.

Science.gov (United States)

Pos, Alberta E; Greenberg, Leslie S

2012-02-01

Emotion-focused therapy (EFT) is an empirically supported treatment that may have potential as a stage-two treatment for borderline personality disorder (BPD). Specific aspects of BPD--the tendency to experience fluctuating self-states; weakness in meta-cognitive or reflective functioning; and the tendency for self-states to be organized by presently occurring interpersonal processes--present challenges to applying some EFT interventions with this population. In particular, even within a highly attuned, validating and accepting empathic relationship, clients with BPD may have difficulty with the usual manualizations of chair work interventions. This is because these interventions often employ polarization and intensification of experience in order to activate adaptive alternate emotional resources and self organizations. For the client with borderline personality disorder, these interventions may be counter-productive, emotionally dysregulating and disorganizing. EFT chair work, however, also has the potential to provide structure to the borderline clients experience of self, to stimulate metacognitive awareness, provide an alive experience of the process of polarization, attenuate emotional activation, and increase the experience of self-coherence. This article describes the development of stepwise approximations of EFT two-chair intervention for self-critical splits. It outlines potential stages of two-chair work as well as intervention principles important for productive chair work with this population. The EFT change principles of awareness, expression regulation, reflection, transformation, and corrective experience still centrally apply. However, several additional strategies are discussed to scaffold clients' capacity to both experience and regulate emotion.

Functional roles of the pepper RING finger protein gene, CaRING1, in abscisic acid signaling and dehydration tolerance.

Science.gov (United States)

Lim, Chae Woo; Hwang, Byung Kook; Lee, Sung Chul

2015-09-01

Plants are constantly exposed to a variety of biotic and abiotic stresses, which include pathogens and conditions of high salinity, low temperature, and drought. Abscisic acid (ABA) is a major plant hormone involved in signal transduction pathways that mediate the defense response of plants to abiotic stress. Previously, we isolated Ring finger protein gene (CaRING1) from pepper (Capsicum annuum), which is associated with resistance to bacterial pathogens, accompanied by hypersensitive cell death. Here, we report a new function of the CaRING1 gene product in the ABA-mediated defense responses of plants to dehydration stress. The expression of the CaRING1 gene was induced in pepper leaves treated with ABA or exposed to dehydration or NaCl. Virus-induced gene silencing of CaRING1 in pepper plants exhibited low degree of ABA-induced stomatal closure and high levels of transpirational water loss in dehydrated leaves. These led to be more vulnerable to dehydration stress in CaRING1-silenced pepper than in the control pepper, accompanied by reduction of ABA-regulated gene expression and low accumulation of ABA and H2O2. In contrast, CaRING1-overexpressing transgenic plants showed enhanced sensitivity to ABA during the seedling growth and establishment. These plants were also more tolerant to dehydration stress than the wild-type plants because of high ABA accumulation, enhanced stomatal closure and increased expression of stress-responsive genes. Together, these results suggest that the CaRING1 acts as positive factor for dehydration tolerance in Arabidopsis by modulating ABA biosynthesis and ABA-mediated stomatal closing and gene expression.

The Characteristics of High School Department Chairs: A National Perspective

Science.gov (United States)

DeAngelis, Karen J.

2013-01-01

Department chairs occupy a potentially important leadership position in high schools, yet little is known about them, particularly with regard to who they are and how they compare to other high school teachers. This is surprising given growing expectations for distributed leadership practice in schools. In this study, I utilize a national dataset…

Report of the eRHIC Ring-Ring Working Group

Energy Technology Data Exchange (ETDEWEB)

Aschenauer, E. C. [Brookhaven National Lab. (BNL), Upton, NY (United States); Berg, S. [Brookhaven National Lab. (BNL), Upton, NY (United States); Blaskiewicz, M. [Brookhaven National Lab. (BNL), Upton, NY (United States); Brennan, M. [Brookhaven National Lab. (BNL), Upton, NY (United States); Fedotov, A. [Brookhaven National Lab. (BNL), Upton, NY (United States); Fischer, W. [Brookhaven National Lab. (BNL), Upton, NY (United States); Litvinenko, V. [Brookhaven National Lab. (BNL), Upton, NY (United States); Montag, C. [Brookhaven National Lab. (BNL), Upton, NY (United States); Palmer, R. [Brookhaven National Lab. (BNL), Upton, NY (United States); Parker, B. [Brookhaven National Lab. (BNL), Upton, NY (United States); Peggs, S. [Brookhaven National Lab. (BNL), Upton, NY (United States); Ptitsyn, V. [Brookhaven National Lab. (BNL), Upton, NY (United States); Ranjbar, V. [Brookhaven National Lab. (BNL), Upton, NY (United States); Tepikian, S. [Brookhaven National Lab. (BNL), Upton, NY (United States); Trbojevic, D. [Brookhaven National Lab. (BNL), Upton, NY (United States); Willeke, F. [Brookhaven National Lab. (BNL), Upton, NY (United States)

2015-10-13

This report evaluates the ring-ring option for eRHIC as a lower risk alternative to the linac-ring option. The reduced risk goes along with a reduced initial luminosity performance. However, a luminosity upgrade path is kept open. This upgrade path consists of two branches, with the ultimate upgrade being either a ring-ring or a linac-ring scheme. The linac-ring upgrade could be almost identical to the proposed linac-ring scheme, which is based on an ERL in the RHIC tunnel. This linac-ring version has been studied in great detail over the past ten years, and its significant risks are known. On the other hand, no detailed work on an ultimate performance ring-ring scenario has been performed yet, other than the development of a consistent parameter set. Pursuing the ring-ring upgrade path introduces high risks and requires significant design work that is beyond the scope of this report.

Determination of a sagittal plane axis of rotation for a dynamic office chair.

Science.gov (United States)

Bauer, C M; Rast, F M; Böck, C; Kuster, R P; Baumgartner, D

2018-10-01

This study investigated the location of the axis of rotation in sagittal plane movement of the spine in a free sitting condition to adjust the kinematics of a mobile seat for a dynamic chair. Dynamic office chairs are designed to avoid continuous isometric muscle activity, and to facilitate increased mobility of the back during sitting. However, these chairs incorporate increased upper body movement which could distract office workers from the performance of their tasks. A chair with an axis of rotation above the seat would facilitate a stable upper back during movements of the lower back. The selection of a natural kinematic pattern is of high importance in order to match the properties of the spine. Twenty-one participants performed four cycles of flexion and extension of the spine during an upper arm hang on parallel bars. The location of the axis of rotation relative to the seat was estimated using infrared cameras and reflective skin markers. The median axis of rotation across all participants was located 36 cm above the seat for the complete movement and 39 cm for both the flexion and extension phases, each with an interquartile range of 20 cm. There was no significant effect of the movement direction on the location of the axis of rotation and only a weak, non-significant correlation between body height and the location of the axis of rotation. Individual movement patterns explained the majority of the variance. The axis of rotation for a spinal flexion/extension movement is located above the seat. The recommended radius for a guide rail of a mobile seat is between 36 cm and 39 cm. Copyright © 2018 Elsevier Ltd. All rights reserved.

Severe cerebral desaturation during shoulder arthroscopy in the beach-chair position

DEFF Research Database (Denmark)

Dippmann, Christian; Winge, Søren; Nielsen, Henning Bay

2010-01-01

During shoulder arthroscopy in the beach-chair position, cerebral ischemia may be a serious complication because prolonged hypotension may affect regional cerebral oxygen supply. We present the cases of 2 patients in whom a reduction in mean arterial pressure after anesthesia provoked a decrease...

Can a smart chair improve the sitting behavior of office workers?

NARCIS (Netherlands)

Roossien, C. C.; Stegenga, J.; Hodselmans, A. P.; Spook, S. M.; Koolhaas, W.; Brouwer, S.; Verkerke, G. J.; Reneman, Michiel F.

2017-01-01

Prolonged sitting can cause health problems and musculoskeletal discomfort. There is a need for objective and non-obstructive means of measuring sitting behavior. A ‘smart’ office chair can monitor sitting behavior and provide tactile feedback, aiming to improve sitting behavior. This study aimed to

The effectiveness of a chair intervention in the workplace to reduce musculoskeletal symptoms. A systematic review

Directory of Open Access Journals (Sweden)

van Niekerk Sjan-Mari

2012-08-01

Full Text Available Abstract Background Prolonged sitting has been associated with musculoskeletal dysfunction. For desk workers, workstation modifications frequently address the work surface and chair. Chairs which can prevent abnormal strain of the neuromuscular system may aid in preventing musculo-skeletal pain and discomfort. Anecdotally, adjustability of the seat height and the seat pan depth to match the anthropometrics of the user is the most commonly recommended intervention. Within the constraints of the current economic climate, employers demand evidence for the benefits attributed to an investment in altering workstations, however this evidence-base is currently unclear both in terms of the strength of the evidence and the nature of the chair features. The purpose of this study was to evaluate the evidence for the effectiveness of chair interventions in reducing workplace musculoskeletal symptoms. Methods Pubmed, Cinahl, Pedro, ProQuest, SCOPUS and PhysioFocus were searched. ‘Ergonomic intervention’, ‘chair’, ‘musculoskeletal symptoms’, ‘ergonomics’, ‘seated work’ were used in all the databases. Articles were included if they investigated the influence of chair modifications as an intervention; participants were in predominantly seated occupations; employed a pre/post design (with or without control or randomising and if the outcome measure included neuro-musculoskeletal comfort and/or postural alignment. The risk of bias was assessed using a tool based on The Cochrane Handbook. Results Five studies were included in the review. The number of participants varied from 4 to 293 participants. Three of the five studies were Randomised Controlled Trials, one pre and post-test study was conducted and one single case, multiple baselines (ABAB study was done. Three studies were conducted in a garment factory, one in an office environment and one with university students. All five studies found a reduction in self-reported musculoskeletal pain

Does Academic Blogging Enhance Promotion and Tenure? A Survey of US and Canadian Medicine and Pediatric Department Chairs.

Science.gov (United States)

Cameron, Christian Blake; Nair, Vinay; Varma, Manu; Adams, Martha; Jhaveri, Kenar D; Sparks, Matthew A

2016-06-23

Electronic educational (e-learning) technology usage continues to grow. Many medical journals operate companion blogs (an application of e-learning technology) that enable rapid dissemination of scientific knowledge and discourse. Faculty members participating in promotion and tenure academic tracks spend valuable time and effort contributing, editing, and directing these medical journal blogs. We sought to understand whether chairs of medicine and pediatric departments acknowledge blog authorship as academic achievement. The authors surveyed 267 chairs of US and Canadian medicine and pediatric departments regarding their attitudes toward the role of faculty participation in e-learning and blogging in the promotion and tenure process. The survey completion rate was 22.8% (61/267). A majority of respondents (87%, 53/61) viewed educational scholarship as either important or very important for promotion. However, only 23% (14/61) perceived importance to faculty effort in producing content for journal-based blogs. If faculty were to participate in blog authorship, 72% (44/61) of surveyed chairs favored involvement in a journal-based versus a society-based or a personal (nonaffiliated) blog. We identified a "favorable group" of chairs (19/59, 32%), who rated leadership roles in e-learning tools as important or very important, and an "unfavorable group" of chairs (40/59, 68%), who rated leadership roles in e-learning tools as somewhat important or not important. The favorable group were more likely to be aware of faculty bloggers within their departments (58%, 11/19 vs 25%, 10/40), viewed serving on editorial boards of e-learning tools more favorably (79%, 15/19 vs 31%, 12/39), and were more likely to value effort spent contributing to journal-based blogs (53%, 10/19 vs 10%, 4/40). Our findings demonstrate that although the majority of department chairs value educational scholarship, only a minority perceive value in faculty blogging effort.

Heterocyclic organobismuth (III) compounds containing an eight-membered ring: Inhibitory effects on cell cycle progression.

Science.gov (United States)

Iuchi, Katsuya; Yagura, Tatsuo

2018-03-21

We previously showed that heterocyclic organobismuth compounds have excellent antimicrobial and antitumor potential. These compounds structurally consist of either six- or eight-membered rings. Previous research has shown that bi-chlorodibenzo[c,f][1,5]thiabismocine (Compound 3), an eight-membered ring, induced G 2 /M arrest via inhibition of tubulin polymerization in HeLa cells. Additionally, N-tert-butyl-bi-chlorodi-benzo[c,f][1,5]azabismocine (Compound 1), another eight-membered ring, exhibited higher cytotoxicity than Compound 3 against several cancer cell lines, including HeLa and K562. Finally, bi-chlorophenothiabismin-S,S-dioxide (Compound 5), a six-membered ring, exhibited lower antitumor activity than eight-membered ring compounds. In this study, we investigated the antimitotic activity of Compounds 1 and 5 in HeLa cells. At low concentrations, (0.1 and 0.25 μM), Compound 1 inhibited cell growth and arrested the cell cycle in mitosis. However, 0.5 μM Compound 1 exhibited no antimitotic activity. Conversely, Compound 5 weakly inhibited cell growth and did not markedly arrest the cell cycle. Flow cytometry showed that Compound 1 arrested the cell cycle at G 2 /M, resulting in apoptosis. Compound 1 inhibited tubulin polymerization as revealed by a cell-free assay, and both Compounds 1 and 3 inhibited microtubule spindle formation and chromosome alignment during prometaphase. These results suggest that eight-membered ring-containing organobismuth compounds can induce mitotic arrest by perturbing spindle dynamics. Copyright © 2018. Published by Elsevier Ltd.

Andirobin from X. moluccensis

Directory of Open Access Journals (Sweden)

Chutima Jittaniyom

2012-08-01

Full Text Available The title compound (systematic name: methyl 2-{(1R,2R-2-[(1aS,4S,4aS,8aS-4-(furan-3-yl-4a-methyl-8-methylene-2-oxooctahydrooxireno[2,3-d]isochromen-7-yl]-2,6,6-trimethyl-5-oxocyclohex-3-en-1-yl}acetate, C27H32O7, was isolated from X. moluccensis seeds from Thailand. The conformations of the six-membered rings are distorted half-chair, chair and half-chair for the isolated cyclohexane, fused cyclohexane and lactone rings, respectively. In addition, the lactone ring bears in an equatorial orientation an essentially planar furan ring (r.m.s. deviation = 0.004 Å, which forms an angle of 63.87 (13° with the mean plane defined by the ten atoms of the two fused six-membered rings (r.m.s. deviation = 0.213 Å. The absolute configuration was fixed on the basis of literature data.

77 FR 6536 - Approval for Manufacturing Authority; Foreign-Trade Zone 177; Best Chair, Inc., d/b/a Best Home...

Science.gov (United States)

2012-02-08

... manufacturing authority on behalf of Best Chair, Inc., d/ b/a Best Home Furnishings, Inc., within FTZ 177 in... application for manufacturing authority under zone procedures within FTZ 177 on behalf of Best Chair, Inc., d... DEPARTMENT OF COMMERCE Foreign-Trade Zones Board [Order No. 1807] Approval for Manufacturing...

11-[(E-Benzylidene]-14-hydroxy-8-phenyl-6-thia-3,13-diazaheptacyclo[13.7.1.19,13.02,9.02,14.03,7.019,23]tetracosa-1(22,15(23,16,18,20-pentaen-10-one

Directory of Open Access Journals (Sweden)

Raju Suresh Kumar

2012-07-01

Full Text Available In the title compound, C34H28N2O2S, the piperidine ring adopts a chair conformation. One of the pyrrolidine rings adopts an envelope conformation with the methylene C atom at the flap whereas the other pyrrolidine ring and the thiazolidine ring adopt half-chair conformations. The mean plane of the dihydroacenaphthylene ring system [maximum deviation = 0.067 (1 Å] makes dihedral angles of 28.31 (5 and 31.32 (6° with the two terminal benzene rings. An intramolecular O—H...N hydrogen bond forms an S(5 ring motif. In the crystal, molecules are linked by C—H...O and C—H...S hydrogen bonds into layers lying parallel to the ac plane.

Suppression of coffee ring: (Particle) size matters

Science.gov (United States)

Bansal, Lalit; Seth, Pranjal; Murugappan, Bhubesh; Basu, Saptarshi

2018-05-01

Coffee ring patterns in drying sessile droplets are undesirable in various practical applications. Here, we experimentally demonstrate that on hydrophobic substrates, the coffee ring can be suppressed just by increasing the particle diameter. Particles with larger size flocculate within the evaporation timescale, leading to a significant gravimetric settling (for Pe > 1) triggering a uniform deposit. Interestingly, the transition to a uniform deposit is found to be independent of the internal flow field and substrate properties. Flocculation of particles also alters the particle packing at the nanoscale resulting in order to disorder transitions. In this letter, we exhibit a physical exposition on how particle size affects morphodynamics of the droplet drying at macro-nano length scales.

ASSOCIATIVE RINGS SOLVED AS LIE RINGS

Directory of Open Access Journals (Sweden)

M. B. Smirnov

2011-01-01

Full Text Available The paper has proved that an associative ring which is solvable of a n- class as a Lie ring has a nilpotent ideal of the nilpotent class not more than 3×10n–2  and a corresponding quotient ring satisfies an identity [[x1, x2, [x3, x4

Ėtude sur l’alimentation du poulet de chaire à base du maïs Zenata et Ain kebira

OpenAIRE

KENZI, MOHAMMED ZAKARYA; WAHAJ, MOHAMMED

2016-01-01

Résume L’aliment représente 70% du cout de production dans l’élevage de poulet de chair, il est donc important d’accorder une attention particulière à ce paramètre. Ce dernier est le premier poste intervenant dans le prix de revient du poulet de chair. La supplémentation de l’aliment du poulet en 2 5% de maïs durant le démarrage et croissance permet aussi de réduire le cout d’élevage et d’améliorer le poids a l’abattage. Study chair of chicken feed made of corn Summ...

Can a smart chair improve the sitting behavior of office workers?

NARCIS (Netherlands)

Hodselmans, Audy Paul; Roossien, Charissa; Stegenga, Jan; Spook, SM; Brouwer, Sandra; Verkerke, Bart; Reneman, Michiel

2017-01-01

a b s t r a c t Prolonged sitting can cause health problems and musculoskeletal discomfort. There is a need for objective and non-obstructive means of measuring sitting behavior. A ‘smart’ office chair can monitor sitting behavior and provide tactile feedback, aiming to improve sitting behavior.

Fracture strengths of chair-side-generated veneers cemented with glass fibers.

Science.gov (United States)

Turkaslan, S; Bagis, B; Akan, E; Mutluay, M M; Vallittu, P K

2015-01-01

CAD/CAM (computer-aided design and computer-aided manufacturing) systems have refreshed the idea of chair-side production of restorations, but the fracture of ceramic veneers remains a problem. Cementation with glass fibers may improve the fracture strengths and affect the failure modes of CAD/CAM-generated ceramic veneers. Therefore, this study compared the fracture strengths of ceramic veneers produced at chair side and cemented with or without glass fibers with those of composite veneers. Thirty intact mandibular incisors were randomly divided into three groups ( n = 10) and treated with CAD/CAM-fabricated veneers cemented with dual-cure composite resin luting cement (CRLC; Group 1), CAD/CAM-fabricated veneers cemented with a glass fiber network (GFN) and dual-cure CRLC (Group 2), and a direct particulate filler composite veneer constructed utilizing fiber and a restorative composite resin (Group 3). The specimens were tested with a universal testing machine after thermal cycling treatment. The loads at the start of fracture were the lowest for traditionally fabricated composite veneers and higher for CAD/CAM-generated. Veneers cemented either without or with the GFN. The failure initiation loads (N) for the veneers were 798.92 for Group 1, 836.27 for Group 2, and 585.93 for Group 3. The predominant failure mode is adhesive failure between the laminates and teeth for Group 1, cohesive failure in the luting layer for Group 2, and cohesive laminate failure for Group 3, which showed chipping and small fractures. Ceramic material is a reliable alternative for veneer construction at chair side. Fibers at the cementation interface may improve the clinical longevity and provide higher fracture strength values.

A new potent fusidic acid analogue

DEFF Research Database (Denmark)

Søtofte, Inger; Duvold, Tore

2001-01-01

The crystal structure of the compound, 17S,20S-dihydrofusidic acid diethylene glycol hydrate, C31H50O6.C4H10O3.H2O, consists of 17S,20S-dihydrofusidic acid, diethylene glycol and water. The fusidic acid moiety contains three six-membered rings and one five-membered ring. The fused-ring system...... adopts a chair, a twist boat, a chair and an envelope conformation. The crystal packing is influenced by hydrogen bonds....

Qualitative Assessment of Academic Radiation Oncology Department Chairs' Insights on Diversity, Equity, and Inclusion: Progress, Challenges, and Future Aspirations.

Science.gov (United States)

Jones, Rochelle D; Chapman, Christina H; Holliday, Emma B; Lalani, Nafisha; Wilson, Emily; Bonner, James A; Movsas, Benjamin; Kalnicki, Shalom; Formenti, Silvia C; Thomas, Charles R; Hahn, Stephen M; Liu, Fei-Fei; Jagsi, Reshma

2018-05-01

A lack of diversity has been observed in radiation oncology (RO), with women and certain racial/ethnic groups underrepresented as trainees, faculty, and practicing physicians. We sought to gain a nuanced understanding of how to best promote diversity, equity, and inclusion (DEI) based on the insights of RO department chairs, with particular attention given to the experiences of the few women and underrepresented minorities (URMs) in these influential positions. From March to June 2016, we conducted telephone interviews with 24 RO department chairs (of 27 invited). Purposive sampling was used to invite all chairs who were women (n = 13) or URMs (n = 3) and 11 male chairs who were not URMs. Multiple analysts coded the verbatim transcripts. Five themes were identified: (1) commitment to DEI promotes quality health care and innovation; (2) gaps remain despite some progress with promoting diversity in RO; (3) women and URM faculty continue to experience challenges in various career domains; (4) solutions to DEI issues would be facilitated by acknowledging realities of gender and race; and (5) expansion of the career pipeline is needed. The chairs' insights had policy-relevant implications. Bias training should broach tokenism, blindness, and intersectionality. Efforts to recruit and support diverse talent should be deliberate and proactive. Bridge programs could engage students before their application to medical school. Copyright © 2018 Elsevier Inc. All rights reserved.

Moving chairs in Starbucks: Observational studies find rice-wheat cultural differences in daily life in China.

Science.gov (United States)

Talhelm, Thomas; Zhang, Xuemin; Oishi, Shigehiro

2018-04-01

Traditional paddy rice farmers had to share labor and coordinate irrigation in a way that most wheat farmers did not. We observed people in everyday life to test whether these agricultural legacies gave rice-farming southern China a more interdependent culture and wheat-farming northern China a more independent culture. In Study 1, we counted 8964 people sitting in cafes in six cities and found that people in northern China were more likely to be sitting alone. In Study 2, we moved chairs together in Starbucks across the country so that they were partially blocking the aisle ( n = 678). People in northern China were more likely to move the chair out of the way, which is consistent with findings that people in individualistic cultures are more likely to try to control the environment. People in southern China were more likely to adjust the self to the environment by squeezing through the chairs. Even in China's most modern cities, rice-wheat differences live on in everyday life.

(3R*,6R*,4′S*,8′R*,3′′R*,6′′R*-3,3′′-Diisopropyl-6,6′′-dimethyl-2′,6′-diphenyldispiro[cyclohexane-1,4′-(3,7-dioxa-2,6-diazabicyclo[3.3.0]octane-8′,1′′-cyclohexane]-2,2′′-dione

Directory of Open Access Journals (Sweden)

Abdeslam Ansari

2013-07-01

Full Text Available The two oxazolidine rings (A and B of the title compound, C34H44N2O4, display roughly half-chair conformations, which could be described as twisted on the C—O bond. Together, the fused oxazolidine rings have a butterfly shape, with the H atoms attached to the ring junction C atoms in a cis orientation. The cyclohexane rings of both p-menthone fragments display chair conformations. The absolute configuration could not be determined from the X-ray diffraction data, but the relative configuration of the stereocentres could be deduced.

Multi-functional fitness chair for light weight trainer

OpenAIRE

Fan, Rong; Wu, Peng

2016-01-01

Nowadays, physical inactivity has become a global problem. According to the research, about 5.3 million deaths all over the world in 2008 could be attributed to inactivity [1]. However, it is enough to do a little exercise every day to reduce the risk of premature deaths by as much as 30 percent. Due to the increasing working pressure, people do not have enough time to go to gym and do exercises, which means that the design of multi-functional fitness chair is necessary so that people can do ...

DOE Chair of Excellence in Environmental Disciplines-Final Technical Report

Energy Technology Data Exchange (ETDEWEB)

Kurunganty, Sastry; Loran, Roberto; Roque-Malherbe, Rolando; Hijazi, Yazan; Nieto, Santander; Gomez, Will A.; Duconge, Jose; Cotto, María del C.; Muniz, Carlos; Diaz, Francisco J.; Neira, Carlos F.; Marquez, Francisco; Del Valle, W.; Thommes, M.

2014-02-19

The report Massie Chair of Excellence Program at Universidad del Turabo, contract DE-FG02-95EW12610, during the period of 9/29/1995 to 9/29/2011. The initial program aims included development of academic programs in the Environmental Sciences and Engineering, and Research and Development focused initially on environmentally friendly processes and later revised also include: renewable energy and international cooperation. From 1995 -2005, the Program at UT lead the establishment of the new undergraduate program in electrical engineering at the School of Engineering (SoE), worked on requirements to achieve ABET accreditation of the SoE B.S. Mechanical Engineering and B.S. Electrical Engineering programs, mentored junior faculty, taught undergraduate courses in electrical engineering, and revised the electrical engineering curriculum. Engineering undergraduate laboratories were designed and developed. The following research sub-project was developed: Research and development of new perovskite-alumina hydrogen permeable asymmetrical nanostructured membranes for hydrogen purification, and extremely high specific surface area silica materials for hydrogen storage in the form of ammonia, Dr. Rolando Roque-Malherbe Subproject PI, Dr. Santander Nieto and Mr. Will Gómez Research Assistants. In 2006, the Massie Chair of Excellence Program was transferred to the National Nuclear Security Agency, NNSA and DNN. DoE required a revised proposal aligned with the priorities of the Administration. The revised approved program aims included: (1) Research (2) Student Development: promote the development of minority undergraduate and graduate students through research teams, internships, conferences, new courses; and, (3) Support: (a) Research administration and (b) Dissemination through international conferences, the UT Distinguished Lecturer Series in STEM fields and at the annual Universidad del Turabo (UT) Researchers Conference. Research included: Sub-Project 1: Synthesis and

In Vivo Spinal Posture during Upright and Reclined Sitting in an Office Chair

Directory of Open Access Journals (Sweden)

Roland Zemp

2013-01-01

Full Text Available Increasing numbers of people spend the majority of their working lives seated in an office chair. Musculoskeletal disorders, in particular low back pain, resulting from prolonged static sitting are ubiquitous, but regularly changing sitting position throughout the day is thought to reduce back problems. Nearly all currently available office chairs offer the possibility to alter the backrest reclination angles, but the influence of changing seating positions on the spinal column remains unknown. In an attempt to better understand the potential to adjust or correct spine posture using adjustable seating, five healthy subjects were analysed in an upright and reclined sitting position conducted in an open, upright MRI scanner. The shape of the spine, as described using the vertebral bodies’ coordinates, wedge angles, and curvature angles, showed high inter-subject variability between the two seating positions. The mean lumbar, thoracic, and cervical curvature angles were 29±15°, -29±4°, and 13±8° for the upright and 33±12°, -31±7°, and 7±7° for the reclined sitting positions. Thus, a wide range of seating adaptation is possible through modification of chair posture, and dynamic seating options may therefore provide a key feature in reducing or even preventing back pain caused by prolonged static sitting.

N,N′-Dicyclohexylnaphthalene-1,8;4:5-dicarboximide

Directory of Open Access Journals (Sweden)

Manju Rajeswaran

2008-09-01

Full Text Available The title compound, C26H26N2O4, synthesized by the reaction of naphthalene-1,4,5,8-tetracarboxylic acid anhydride and cyclohexylamine, exhibits good n-type semiconducting properties. Accordingly, thin-film transistor devices comprising this compound show n-type behavior with high field-effect electron moblity ca 6 cm2/Vs [Shukla, Nelson, Freeman, Rajeswaran, Ahearn, Meyer & Carey(2008. Chem. Mater. Submitted]. The asymmetric unit comprises one-quarter of the centrosymmetric molecule in which all but two methylene C atoms of the cyclohexane ring lie on a mirror plane; the point-group symmetry is 2/m. The naphthalenediimide unit is strictly planar, and the cyclohexane rings adopt chair conformations with the diimide unit in an equatorial position on each ring.

Mapping Ring Particle Cooling across Saturn's Rings with Cassini CIRS

Science.gov (United States)

Brooks, Shawn M.; Spilker, L. J.; Edgington, S. G.; Pilorz, S. H.; Deau, E.

2010-10-01

Previous studies have shown that the rings' thermal inertia, a measure of their response to changes in the thermal environment, varies from ring to ring. Thermal inertia can provide insight into the physical structure of Saturn's ring particles and their regoliths. Low thermal inertia and quick temperature responses are suggestive of ring particles that have more porous or fluffy regoliths or that are riddled with cracks. Solid, coherent particles can be expected to have higher thermal inertias (Ferrari et al. 2005). Cassini's Composite Infrared Spectrometer has recorded millions of spectra of Saturn's rings since its arrival at Saturn in 2004 (personal communication, M. Segura). CIRS records far infrared radiation between 10 and 600 cm-1 (16.7 and 1000 µm) at focal plane 1 (FP1), which has a field of view of 3.9 mrad. Thermal emission from Saturn's rings peaks in this wavelength range. FP1 spectra can be used to infer ring temperatures. By tracking how ring temperatures vary, we can determine the thermal inertia of the rings. In this work we focus on CIRS observations of the shadowed portion of Saturn's rings. The thermal budget of the rings is dominated by the solar radiation absorbed by its constituent particles. When ring particles enter Saturn's shadow this source of energy is abruptly cut off. As a result, ring particles cool as they traverse Saturn's shadow. From these shadow observations we can create cooling curves at specific locations across the rings. We will show that the rings' cooling curves and thus their thermal inertia vary not only from ring to ring, but by location within the individual rings. This research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under contract with NASA. Copyright 2010 California Institute of Technology. Government sponsorship acknowledged.

Ring-shaped Wigner crystals of trapped ions at the micronscale

Science.gov (United States)

Li, Haokun; Urban, Erik; Noel, Crystal; Chuang, Alexander; Xia, Yang; Hemmerling, Borge; Wang, Yuan; Zhang, Xiang; Haeffner, Hartmut

Trapped ion crystals are ideal platforms to study many-body physics and quantum information processing, with both the internal electronic states and external motional degree-of-freedoms controllable at the single quantum level. In contrast to conventional, finite, linear chains of ions, a ring topology exhibiting periodic boundary conditions and rotational symmetry opens up a new directions to diverse topics. However, previous implementations of ion rings result in small aspect ratios (electrode distance to ring diameter, making the rotational symmetry of the ion crystals prone to stray electric fields from imperfections of the trap electrodes, particularly evident at low temperatures. Here, using a new trap design with a 60-fold improvement of this aspect ratio, we demonstrate crystallization of 40Ca+ ions in a ring with rotational energy barriers comparable to the thermal energy of Doppler laser cooled ion crystals. When further reducing the rotational energy barriers, we observe delocalization of the ion rings. With this result, we enter a regime where quantum topological effects can be studied and novel quantum computation and simulation experiments can be implemented.

Carbon and prospective: international colloquium jointly organized by the prospective modeling chair and ETSAP

International Nuclear Information System (INIS)

Maizi, N.; Hourcade, J.Ch.; Selosse, S.

2009-01-01

The inauguration of the prospective modeling chair in favour of sustainable development is the result of the joint effort of several schools, organizations and companies, in particular: Mines ParisTech, Ponts ParisTech, Agro ParisTech, the higher education and research pole of ParisTech, the Ecole des Ponts foundation, the mineral, mining and metallurgic industries foundation (FI3M), with the partnership of Ademe, EdF, Renault, Schneider Electric and Total. The main goal of this chair is to perpetuate modeling tools with sustainable development stakes. The scientific program and the expertise of this chair are based on the joint and complementary experience of its two co-founder research teams in the domain of long-term prospective of energy, economy and environment-related questions: the applied mathematics centre (CMA - Mines ParisTech) and the international centre of environment and sustainable development research (CIRED). An inaugural colloquium was organized at the occasion of the launching of this chair. During round tables, representatives of the different intervening parties explained the stakes of this huge project and their expectations, in particular from the scientific, economical and societal point of view. A workshop on the topic 'carbon and prospective' followed the round tables. Six presentations were given about the following topics: energy policy scenarios for 2050 (Moncomble, J.E.), the shadow price of carbon (Chambolle T.), mitigation targets and carbon values: insights from TIMES-FR (Assoumou E.), climate protection and infrastructures (Sassi O.), China's energy and carbon options (Wenying C.), EU 20-20 policy implications on the energy system of Germany - an analysis with TIMES PanEU (Blesl M.). This book gathers the proceedings of both parts of this colloquium, the debates during the round tables (in French) and the presentations given during the workshop (in English). (J.S.)

Multidisciplinary approach to converting power chair into motorized prone cart.

Science.gov (United States)

Brose, Steven W; Wali, Eisha

2014-01-01

Pressure ulcers remain a major source of morbidity and mortality in veterans with neurologic impairment. Management of pressure ulcers typically involves pressure relief over skin regions containing wounds, but this can lead to loss of mobility and independence when the wounds are located in regions that receive pressure from sitting. An innovative, low-cost, multidisciplinary effort was undertaken to maximize quality of life in a veteran with a thoracic-4 level complete spinal cord injury and a stage 4 ischial wound. The person's power wheelchair was converted into a motorized prone cart, allowing navigation of the Department of Veterans Affairs spinal cord injury hospital ward and improved socialization while relieving pressure on the wound. Physical and occupational therapy assisted with the reconfiguration of the power chair and verified safe transfers into the chair and driving of the device. Psychology verified positive psychosocial benefit, while nursing and physician services verified an absence of unwanted pain or skin injury resulting from use of the device. Further investigation of ways to apply this technique is warranted to improve the quality of life of persons with pressure ulcers.

Perceptions of Value-Congruence with One's Department Chair: Does Match Matter?

Science.gov (United States)

Virick, Meghna; Strage, Amy

2016-01-01

Although studies have examined numerous factors that predict junior faculty success, previous research has paid little attention to the role played by department chairs. Drawing on theory from person-environment fit theory and value congruence, we sought to examine the implication of a match versus mismatch between faculty members and their chairs…

Reflections from a chair: Leadership of a clinical department at an academic medical center.

Science.gov (United States)

Willett, Christopher G

2015-11-01

The leadership position of an academic departmental chair can be a positive and rewarding opportunity. These rewards principally stem from the success of the faculty, residents, other trainees, nurses, and everyone supporting the department. With health care reform and the constraints of the federal budget, increasing attention and time has become directed toward administrative management. There are multiple and often competing constituencies and agendas requiring thoughtful strategies to achieve departmental goals. The objectives of a chair are advancing patient care, education, and research. True excellence of a department is achieved by the innovation of its faculty. © 2015 The Authors. Cancer published by Wiley Periodicals, Inc. on behalf of American Cancer Society.

Why aren't there more women leaders in academic medicine? the views of clinical department chairs.

Science.gov (United States)

Yedidia, M J; Bickel, J

2001-05-01

A scarcity of women in leadership positions in academic medicine has persisted despite their increasing numbers in medical training. To understand the barriers confronting women and potential remedies, clinical department chairs with extensive leadership experience were interviewed. In 1998-99, open-ended interviews averaging 80 minutes in length were conducted with 34 chairs and two division chiefs in five specialties. Individuals were selected to achieve a balance for gender, geographic locale, longevity in their positions, and sponsorship and research intensity of their institutions. The interviews were audiotaped and fully transcribed, and the themes reported emerged from inductive analysis of the responses using standard qualitative techniques. The chairs' responses centered on the constraints of traditional gender roles, manifestations of sexism in the medical environment, and lack of effective mentors. Their strategies for addressing these barriers ranged from individual or one-on-one interventions (e.g., counseling, confronting instances of bias, and arranging for appropriate mentors) to institutional changes (e.g., extending tenure probationary periods, instituting mechanisms for responding to unprofessional behavior, establishing mentoring networks across the university). The chairs universally acknowledged the existence of barriers to the advancement of women and proposed a spectrum of approaches to address them. Individual interventions, while adapting faculty to requirements, also tend to preserve existing institutional arrangements, including those that may have adverse effects on all faculty. Departmental or school-level changes address these shortcomings and have a greater likelihood of achieving enduring impact.

1,4a-Dimethyl-6-methyl-ene-5-(5,5,6,6-tetra-cyano-2-methyl-cyclo-hex-2-enylmeth-yl)deca-hydro-naphthalene-1-carboxylic acid: a trans-communic acid derivative.

Science.gov (United States)

Rejouani, Nezha; Auhmani, Aziz; Ait Itto, My Youssef; Benharref, Ahmed; Daran, Jean-Claude

2008-01-18

In the search for cancer chemopreventive agents, we have studied the Diels-Alder reaction of trans-communic acid with tetra-cyano-ethyl-ene in the presence of SiO(2) as catalyst. The title cycloadduct, C(26)H(30)N(4)O(2), was obtained in 75% yield. The mol-ecules are arranged in pairs through O-H⋯O hydrogen bonds, forming an R(2) (2)(8) ring motif. Both the fused cyclohexyl rings adopt a chair conformation, whereas the nonfused ring adopts a half-chair conformation.

Methyl 2-(1a,4a-dimethyl-2,8-dioxo-2,3,4,4a,5,6,7,8-octahydro-1aH-1-oxacyclopropa[d]naphthalen-7-ylacrylate

Directory of Open Access Journals (Sweden)

Mohamed Tebbaa

2012-02-01

Full Text Available The title compound, C16H20O5, was synthesized from ilicic acid [2-(8-hydroxy-4a,8-dimethyldecahydronaphthalen-2-ylacrylic acid], which was isolated from the chloroform extract of the aerial part of Inula viscose (L Aiton [or Dittrichia viscosa (L Greuter]. The molecule is built up from two fused six-membered rings, the epoxidized six-membered ring adopts a half-chair conformation while the other ring displays a perfect chair conformation. The crystal structure features C—H...O hydrogen bonds.

New chair for the Particle Physics and Astronomy Research Council

CERN Multimedia

2001-01-01

Peter Warry has been appointed as Chair of PPARC for the next 4 years. Chairman of Victrex plc, whose business is in speciality chemicals, he has been an Industrial Professor at the University of Warwick since 1993. PPARC pursues a programme of high quality basic research in particle physics, astronomy, cosmology and space science and its budget for 2002 is approximately 220 million GBP.

High performance ring oscillators from 10-nm wide silicon nanowire field-effect transistors

KAUST Repository

Huang, Ruo-Gu; Tham, Douglas; Wang, Dunwei; Heath, James R.

2011-01-01

We explore 10-nm wide Si nanowire (SiNW) field-effect transistors (FETs) for logic applications, via the fabrication and testing of SiNW-based ring oscillators. We report on SiNW surface treatments and dielectric annealing, for producing SiNW FETs that exhibit high performance in terms of large on/off-state current ratio (~108), low drain-induced barrier lowering (~30 mV) and low subthreshold swing (~80 mV/decade). The performance of inverter and ring-oscillator circuits fabricated from these nanowire FETs are also explored. The inverter demonstrates the highest voltage gain (~148) reported for a SiNW-based NOT gate, and the ring oscillator exhibits near rail-to-rail oscillation centered at 13.4 MHz. The static and dynamic characteristics of these NW devices indicate that these SiNW-based FET circuits are excellent candidates for various high-performance nanoelectronic applications. © 2011 Tsinghua University Press and Springer-Verlag Berlin Heidelberg.

High performance ring oscillators from 10-nm wide silicon nanowire field-effect transistors

KAUST Repository

Huang, Ruo-Gu

2011-06-24

We explore 10-nm wide Si nanowire (SiNW) field-effect transistors (FETs) for logic applications, via the fabrication and testing of SiNW-based ring oscillators. We report on SiNW surface treatments and dielectric annealing, for producing SiNW FETs that exhibit high performance in terms of large on/off-state current ratio (~108), low drain-induced barrier lowering (~30 mV) and low subthreshold swing (~80 mV/decade). The performance of inverter and ring-oscillator circuits fabricated from these nanowire FETs are also explored. The inverter demonstrates the highest voltage gain (~148) reported for a SiNW-based NOT gate, and the ring oscillator exhibits near rail-to-rail oscillation centered at 13.4 MHz. The static and dynamic characteristics of these NW devices indicate that these SiNW-based FET circuits are excellent candidates for various high-performance nanoelectronic applications. © 2011 Tsinghua University Press and Springer-Verlag Berlin Heidelberg.

4,5,7,8,17-Pentahydroxy-14,18-dimethyl-6-methylene-3,10-dioxapentacyclo[9.8.0.01,7.04,19.013,18]nonadec-14-ene-9,16-dione methanol solvate dihydrate

Directory of Open Access Journals (Sweden)

Chin Hoe Teh

2009-04-01

Full Text Available The title quassinoid compound, C20H24O9·CH3OH·2H2O, is a natural eurycomanone isolated from the roots of Eurycoma longifolia. The molecules contain a fused five-ring system, with one tetrahydrofuran ring adopting an envelope conformation, one tetrahydropyran-2-one ring in a screw boat conformation, one cyclohexenone ring in a half-chair conformation and two cyclohexane rings in chair conformations. Intramolecular C—H...O interactions generate S(5 ring motifs and an O—H...O interaction generates an S(7 ring motif. In the crystal, molecules are linked via intermolecular O—H...O interactions along the b axis and further stacked along a axis. The absolute configuration of the title compound was inferred from previously solved structures of its analogues.

Crystal ball gazing : chair of foresight takes the long-term view

Energy Technology Data Exchange (ETDEWEB)

Smith, M.

2010-03-15

This article focused on Alberta's primary industry, namely oil and gas, and identifying important emerging opportunity needs in the mid to longer term future. The chair of Alberta Innovates Technology Futures (AITF), an agency which supersedes the Alberta Research Council must look well beyond a 5-year timeframe to a more longer-term strategic thinking. This article discussed how the mandate of the Chair position extended to all areas of research relevant to the province and its future prosperity, from communities of the future and economic development to future energy supply and environmental impacts. The article discussed the 3 stages of foresight methodologies that include studying the current situation in terms of underlying forces and trends to produce knowledge; examining where present circumstances will lead if allowed to evolve naturally, or if intervention occurred to alter those outcomes; and translating those insights into action. The article also addressed the issue of trimming carbon dioxide (CO{sub 2}) emissions. The chair of AITF has turned his attention to reducing the impact of distributed sources, notably those from the tailpipe and the home furnace. Rather than capturing at source, he is looking to ways of removing it directly from the atmosphere, preferably in a biological way. One way is to take plant matter, which accumulates CO{sub 2} as it grows, and burn it in the absence of oxygen, creating carbon-rich biochar. When added to soil, this biochar improves soil quality when used in connection with farming. This creates the possibility of removing CO{sub 2} from the atmosphere and converting it back through plants into carbon, a type of carbon capture and storage (CCS) except for distributed CO{sub 2}. 1 fig.

Interview with Mr Bernard Dormy, Chair of TREF, in November 2017

CERN Multimedia

Staff Association

2018-01-01

Mr Bernard Dormy finished his term of office as the Chair of the Tripartite Employment Conditions Forum (TREF) (see Echo No. 242) at the end of 2017. On this occasion, the Staff Association met with him to discuss CERN and its personnel and, amongst other things, the model for concertation. Moreover, the Staff Association would like to take this opportunity to applaud Mr Dormy for the commitment he has shown since 2003, when he first started at TREF as a delegate of France. It is easy to believe that Mr Dormy found his mandate in this Forum particularly pleasing, since he served as the Vice-Chair of TREF from 2007 to 2011, and then as the Chairman from 2012 to 2017. During his chairmanship, Mr Dormy always made sure that the concertation took place under the best possible conditions, in a constructive manner and in a spirit of mutual respect. Furthermore, he placed great emphasis on diversity at CERN: there was not a single TREF meeting without an update on diversity issues and progress ma...

Can a smart chair improve the sitting behavior of office workers?

Science.gov (United States)

Roossien, C C; Stegenga, J; Hodselmans, A P; Spook, S M; Koolhaas, W; Brouwer, S; Verkerke, G J; Reneman, M F

2017-11-01

Prolonged sitting can cause health problems and musculoskeletal discomfort. There is a need for objective and non-obstructive means of measuring sitting behavior. A 'smart' office chair can monitor sitting behavior and provide tactile feedback, aiming to improve sitting behavior. This study aimed to investigate the effect of the feedback signal on sitting behavior and musculoskeletal discomfort. In a 12-week prospective cohort study (ABCB design) among office workers (n = 45) was measured sitting duration and posture, feedback signals and musculoskeletal discomfort. Between the study phases, small changes were observed in mean sitting duration, posture and discomfort. After turning off the feedback signal, a slight increase in sitting duration was observed (10 min, p = 0.04), a slight decrease in optimally supported posture (2.8%, p < 0.01), and musculoskeletal discomfort (0.8, p < 0.01) was observed. We conclude that the 'smart' chair is able to monitor the sitting behavior, the feedback signal, however, led to small or insignificant changes. Copyright © 2017 Elsevier Ltd. All rights reserved.

A CPW-Fed Rectangular Ring Monopole Antenna for WLAN Applications

Directory of Open Access Journals (Sweden)

Sangjin Jo

2014-01-01

Full Text Available We present a simple coplanar waveguide- (CPW- fed rectangular ring monopole antenna designed for dual-band wireless local area network (WLAN applications. The antenna is based on a simple structure composed of a CPW feed line and a rectangular ring. Dual-band WLAN operation can be achieved by controlling the distance between the rectangular ring and the ground plane of the CPW feed line, as well as the horizontal vertical lengths of the rectangular ring. Simulated and measured data show that the antenna has a compact size of 21.4×59.4 mm2, an impedance bandwidths of 2.21–2.70 GHz and 5.04–6.03 GHz, and a reflection coefficient of less than −10 dB. The antenna also exhibits an almost omnidirectional radiation pattern. This simple compact antenna with favorable frequency characteristics therefore is attractive for applications in dual-band WLAN.

Asymmetric transmission in planar chiral split-ring metamaterials: Microscopic Lorentz-theory approach

DEFF Research Database (Denmark)

Novitsky, Andrey; Galynsky, Vladimir M.; Zhukovsky, Sergei

2012-01-01

The electronic Lorentz theory is employed to explain the optical properties of planar split-ring metamaterials. Starting from the dynamics of individual free carriers, the electromagnetic response of an individual split-ring meta-atom is determined, and the effective permittivity tensor...... of the metamaterial is calculated for normal incidence of light. Whenever the split ring lacks in-plane mirror symmetry, the corresponding permittivity tensor has a crystallographic structure of an elliptically dichroic medium, and the metamaterial exhibits optical properties of planar chiral structures. Its...... transmission spectra are different for right-handed versus left-handed circular polarization of the incident wave, so the structure changes its transmittance when the direction of incidence is reversed. The magnitude of this change is shown to be related to the geometric parameters of the split ring...

The impact of office chair features on lumbar lordosis, intervertebral joint and sacral tilt angles: a radiographic assessment.

Science.gov (United States)

De Carvalho, Diana; Grondin, Diane; Callaghan, Jack

2017-10-01

The purpose of this study was to determine which office chair feature is better at improving spine posture in sitting. Participants (n = 28) were radiographed in standing, maximum flexion and seated in four chair conditions: control, lumbar support, seat pan tilt and backrest with scapular relief. Measures of lumbar lordosis, intervertebral joint angles and sacral tilt were compared between conditions and sex. Sitting consisted of approximately 70% of maximum range of spine flexion. No differences in lumbar flexion were found between the chair features or control. Significantly more anterior pelvic rotation was found with the lumbar support (p = 0.0028) and seat pan tilt (p < 0.0001). Males had significantly more anterior pelvic rotation and extended intervertebral joint angles through L1-L3 in all conditions (p < 0.0001). No one feature was statistically superior with respect to minimising spine flexion, however, seat pan tilt resulted in significantly improved pelvic posture. Practitioner Summary: Seat pan tilt, and to some extent lumbar supports, appear to improve seated postures. However, sitting, regardless of chair features used, still involves near end range flexion of the spine. This will increase stresses to the spine and could be a potential injury generator during prolonged seated exposures.

Estimation of whole body dose in an unusual event: spillage of radioactive material on the chair

International Nuclear Information System (INIS)

Adtani, M.M.; Biju, K.; Deshpande, M.D.; Shivde, R.K.; Kulkarni, V.V.

2005-01-01

The personnel monitoring in India is done using thermoluminescence dosimeters worn at chest level. In research institutions and in nuclear facilities where radiation sources are processed in dispersible forms, a remote possibility exists that radiation source entering in the area where installed monitor does not exist and the source may get spilled on chair and causing exposure to persons sitting on the chair. In such case TLD may not give the correct exposure as there is shielding of individuals body. An attempt is made to find out a factor for estimating the whole body dose by knowing the TLD badge dose or by measuring the gonad dose. Experiments are performed using TLDs and also measurement by teletector. Monte Carlo simulations are also done. It is observed that a factor of 8 to TLD Badge dose will give whole body dose if worker has received dose only on said chair or by applying a factor of 0.23 to dose measured at gonad level will give whole body dose. (author)

(3R,6R,12R,20S,24S-3,6,12-Triacetyl-20,24-epoxydammarane-3,6,12,25-tetraol

Directory of Open Access Journals (Sweden)

Qing-Guo Meng

2011-01-01

Full Text Available The title compound, C36H58O8, was prepared from 20(S-protopanaxatriol, which was degraded from Panax quinquefolium saponin with sodium in glycerine, extracted and seperated by flash chromatography. Three six-membered rings are in chair conformations, the five-membered ring is in an envelope form and the tetrahydrofuran ring has a conformation intermediate between half-chair and envelope. In the crystal, molecules are linked by O—H...O hydrogen bonds, and C—H...O contacts also occur. The absolute structure was assigned on the basis of the synthesis.

(1R,3S,8R-3,7,7,10-Tetramethyltricyclo[6.4.0.01,3]dodec-9-en-11-one

Directory of Open Access Journals (Sweden)

Abdoullah Bimoussa

2014-01-01

Full Text Available The absolute configuration of the title compound, C16H24O, has been deduced from the chemical pathway. The six-membered ring has a roughly half-chair conformation with the quaternary C atom as the flap. The seven-membered ring displays a chair conformation. In the crystal, there is a weak C—H...O hydrogen bond between the methylene group of the cyclopropane ring and the carbonyl group of a screw-axis-related molecule, which builds up a zigzag-like chain along the b-axis direction.

(3S,4S)-3-Ethyl-4-hydroxy-3-(3-methoxyphenyl)-1-methylazepan-1-ium d-tartrate dihydrate

OpenAIRE

Zhui-Bai Qiu; Bo Chao; Xing-Hai Wang

2008-01-01

In the title compound, C16H26NO2+·C4H5O6−·2H2O, a meptazinol derivative, three C atoms of the azepane ring are disordered over two positions, with site-occupancy factors of 0.80 and 0.20; the major disorder component adopts a twist-chair conformation, while the minor component has a chair conformation. The benzene ring is axially substituted on the heterocyclic ring, resulting in a folded conformation of the cation. The absolute configuration was determined with reference to d...

Career development resource: educational leadership in a department of surgery: vice chairs for education.

Science.gov (United States)

Sanfey, Hilary; Boehler, Margaret; DaRosa, Debra; Dunnington, Gary L

2012-07-01

The growing appreciation of the need to adopt an evidence-based approach to teaching and assessment has led to a demand for faculty who are well versed in best practices in education. Surgeons with interest and expertise in instruction, curriculum development, educational research, and evaluation can have an important impact on the educational mission of a department of surgery. The increased fervor for accountability in education together with the challenges imposed by accreditation agencies and hospitals has made educational leadership responsibilities more time consuming and complex. In response to this, an increasing number of department chairs created Vice Chair for Education positions to support clerkship and program directors and ensure the department's education mission statement is fulfilled. Copyright © 2012 Elsevier Inc. All rights reserved.

Extremely sensitive multiple sensing ring PCF sensor for lower indexed chemical detection

Directory of Open Access Journals (Sweden)

Veerpal Kaur

2017-09-01

Full Text Available In this article, we have designed and analysed a photonic crystal fiber with multiple sensing ring in core for chemical and biochemical sensing applications. In this proposed design, three and four sensing ring describe in core which offers remarkable high sensitivity and spiral cladding pattern confines large fraction of power in core region and thus reduce the overall confinement loss. This novel proposed model exhibits simultaneously ultra high relative sensitivity 95.40%, 93.13% and minimum confinement loss 7.108×10−08, 2.47×10−08dB/km for four and three ring pattern. These sensing rings are filled with different sensing liquid. Multiple sensing rings as compared to multiple air holes are desirable feature from fabrication point of view. This proposed PCF design overcomes some experimental challenge such as PCF probe needs some displacement after filling the sensing liquid. These uniform circular sensing rings around the solid core overcome the losses and support better evanescent field matter interaction for sensing application. Multiple sensing rings as compared to multiple tiny air holes are desirable feature from fabrication point of view.

Unconventional low-field magnetic response of a diffusive ring with spin–orbit coupling

International Nuclear Information System (INIS)

Patra, Moumita; Maiti, Santanu K.

2017-01-01

We report an unconventional behavior of electron transport in the limit of zero magnetic flux in a one-dimensional disordered ring, be it completely random or any correlated one, subjected to Rashba spin–orbit (SO) coupling. It exhibits much higher circulating current compared to a fully perfect ring for a wide range of SO coupling yielding larger electrical conductivity which is clearly verified from our Drude weight analysis. - Highlights: • Unconventional behavior of electron transport in a 1D disordered ring is reported. • Interplay between Rashba So interaction and disorder is discussed. • Disordered ring provides much higher current compared to a perfect one. • Results are independent with disorderness, be it correlated or random. • MI transition and selective switching effects are discussed.

Unconventional low-field magnetic response of a diffusive ring with spin–orbit coupling

Energy Technology Data Exchange (ETDEWEB)

Patra, Moumita; Maiti, Santanu K., E-mail: santanu.maiti@isical.ac.in

2017-01-30

We report an unconventional behavior of electron transport in the limit of zero magnetic flux in a one-dimensional disordered ring, be it completely random or any correlated one, subjected to Rashba spin–orbit (SO) coupling. It exhibits much higher circulating current compared to a fully perfect ring for a wide range of SO coupling yielding larger electrical conductivity which is clearly verified from our Drude weight analysis. - Highlights: • Unconventional behavior of electron transport in a 1D disordered ring is reported. • Interplay between Rashba So interaction and disorder is discussed. • Disordered ring provides much higher current compared to a perfect one. • Results are independent with disorderness, be it correlated or random. • MI transition and selective switching effects are discussed.

1,4-Bis(2-diazoacetylpiperazine

Directory of Open Access Journals (Sweden)

Tore Bonge-Hansen

2013-08-01

Full Text Available The asymmetric unit of the title compound, C8H10N6O2, contains one-half molecule, which is completed by a crystallographic center of symmetry. The piperazine ring adopts a chair conformation. In the crystal, weak C—H...O interactions link the molecules into layers parallel to the bc plane. The crystal packing also exhibits short N...N contacts of 3.0467 (16 Å between the terminal diazo N atoms from neighbouring molecules.

Parameters and design optimization of the ring piezoelectric ceramic transformer

Directory of Open Access Journals (Sweden)

Jiří Erhart

2015-09-01

Full Text Available Main aim of the presented paper is the theoretical analysis and experimental verification of the transformation parameters for the new type of nonhomogeneously poled ring transformer. The input part is poled in the thickness direction and output part in the radial direction. Two transformer geometries are studied — the input part is at inner ring segment, or it is at the outer ring segment. The optimum electrode size aspect ratios have been found experimentally as d1∕D≈0.60−0.65 for the ring with aspect ratio d∕D=0.2. The fundamental as well as higher overtone resonances were studied for the transformation ratio, the optimum resistive load, efficiency and no-load transformation ratio. Higher overtones have better transformation parameters compared to the fundamental resonance. The new type ring transformer exhibits very high transformation ratios up to 200 under no-load and up to 13.4 under a high efficiency of 97% at the optimum load conditions of 10 kΩ. Strong electric field gradient at the output circuit is applicable for the electrical discharge generation.

Black rings

International Nuclear Information System (INIS)

Emparan, Roberto; Reall, Harvey S

2006-01-01

A black ring is a five-dimensional black hole with an event horizon of topology S 1 x S 2 . We provide an introduction to the description of black rings in general relativity and string theory. Novel aspects of the presentation include a new approach to constructing black ring coordinates and a critical review of black ring microscopics. (topical review)

(3R,4R,4aS,7aR,12bS-3-Cyclopropylmethyl-4a,9-dihydroxy-3-methyl-7-oxo-2,3,4,4a,5,6,7,7a-octahydro-1H-4,12-methanobenzofuro[3,2-e]isoquinolin-3-ium bromide

Directory of Open Access Journals (Sweden)

Xiangfeng Chen

2012-02-01

Full Text Available The title compound, C21H26NO4+·Br−, also known as R-methylnaltrexone (MNTX bromide, is a selective peripherally acting μ-opioid receptor antagonist with a oroxymorphone skeleton, synthesized by hydroxyl protection, N-methylation, deprotection and anion exchange of naltrexone. It comprises a five-ring system A/B/C/D/E. Rings C and E adopt distorted chair conformations, whereas ring D is in half-chair conformation. The C/E ring junctions are trans fused. The dihedral angle between rings D and E is 82.3 (1°, while the dihedral angles between the planes of rings C and A, and rings D and E are respectively 81.7 (1, 75.9 (1 and 12.2 (1°. In the crystal, molecules are linked by O—H...Br hydrogen bonds.

Variations in Ring Particle Cooling across Saturn's Rings with Cassini CIRS

Science.gov (United States)

Brooks, S. M.; Spilker, L. J.; Pilorz, S.; Edgington, S. G.; Déau, E.; Altobelli, N.

2010-12-01

Cassini's Composite Infrared Spectrometer has recorded over two million of spectra of Saturn's rings in the far infrared since arriving at Saturn in 2004. CIRS records far infrared radiation between 10 and 600 cm-1 ( 16.7 and 1000 μ {m} ) at focal plane 1 (FP1), which has a field of view of 3.9 mrad. Thermal emission from Saturn’s rings peaks in this wavelength range. Ring temperatures can be inferred from FP1 data. By tracking how ring temperatures vary, we can determine the thermal inertia of the rings. Previous studies have shown that the rings' thermal inertia, a measure of their response to changes in the thermal environment, varies from ring to ring. Thermal inertia can provide insight into the physical structure of Saturn's ring particles and their regoliths. Low thermal inertia and rapidly changing temperatures are suggestive of ring particles that have more porous or fluffy regoliths or that are riddled with cracks. Solid particles can be expected to have higher thermal inertias. Ferrari et al. (2005) fit thermal inertia values of 5218 {Jm)-2 {K}-1 {s}-1/2 to their B ring data and 6412 {Jm)-2 {K}-1 {s}-1/2 to their C ring data. In this work we focus on CIRS observations of the shadowed portion of Saturn's rings. The rings’ thermal budget is dominated by its absorption of solar radiation. As a result, ring particles abruptly cool as they traverse Saturn's shadow. From these shadow observations we can create cooling curves at specific locations across the rings. We will show that the rings' cooling curves and thus their thermal inertia vary not only from ring to ring, but by location within the individual rings. This research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under contract with NASA. Copyright 2010 California Institute of Technology. Government sponsorship acknowledged.

Product design and development for dinner chair of Kansei Engineering

OpenAIRE

Sirichai Yodwangjai

2014-01-01

This research investigated the customer’s perception and product properties. The semantic differential method was employed to examine the relationship between customer’s perception and product properties. Fifty-six dinner chairs are selected from website, magazine and publishing and 10 SD words. The product properties divided 8 groups and 34 sub-groups. The new model created base on Quantification Theory Type 1. The research results show 3 high perceptions: comfortable, soft and modern. The r...

Chaotic synchronization of three coupled oscillators with ring connection

International Nuclear Information System (INIS)

Kyprianidis, I.M.; Stouboulos, I.N.

2003-01-01

We study the evolution of three identical, resistively coupled with ring connection, nonlinear and nonautonomous electric circuits from nonsynchronized oscillations to synchronized ones, when they exhibit chaotic behavior. Phase-locked states are also observed, as the coupling parameter is varied. The system's dynamics depends on the way of coupling (unidirectional or bidirectional)

Chaotic synchronization of three coupled oscillators with ring connection

CERN Document Server

Kyprianidis, I M

2003-01-01

We study the evolution of three identical, resistively coupled with ring connection, nonlinear and nonautonomous electric circuits from nonsynchronized oscillations to synchronized ones, when they exhibit chaotic behavior. Phase-locked states are also observed, as the coupling parameter is varied. The system's dynamics depends on the way of coupling (unidirectional or bidirectional).

Four- and eight-membered rings carbon nanotubes: A new class of carbon nanomaterials

Directory of Open Access Journals (Sweden)

Fangfang Li

2018-06-01

Full Text Available A new class of carbon nanomaterials composed of alternating four- and eight-membered rings is studied by density functional theory (DFT, including single-walled carbon nanotubes (SWCNTs double-walled carbon nanotubes (DWCNTs and triple-walled CNTs (TWCNTs. The analysis of geometrical structure shows that carbon atoms’ hybridization in novel carbon tubular clusters (CTCs and the corresponding carbon nanotubes (CNTs are both sp2 hybridization; The thermal properties exhibit the high stability of these new CTCs. The results of energy band and density of state (DOS indicate that the electronic properties of CNTs are independent of their diameter, number of walls and chirality, exhibit obvious metal properties. Keywords: Four- and eight-membered rings, Carbon nanotubes, Stability, Electronic properties

Blowing smoke rings in superfluid helium

International Nuclear Information System (INIS)

Allum, D.R.; McClintock, P.V.E.

1977-01-01

Among experiments designed to investigate the properties of superfluids, measurements are discussed which aim at determining the variation in the speed of an ion with the size of the electric field propelling it through liquid helium. The experimental set up using helium ions is described. The velocity-field characteristic shows an initial rise but at a higher electric field the ions exhibit the curious behaviour of slowing down before again increasing speed with force. The reason for this region of slowing down is here explained as being due to the fact that the charge is no longer carried by a free ion but, rather, by a charged vortex ring. As the ion speeds thorugh the liquid it suddenly creates a vortex ring and as one of the fundamental characteristics of a vortex ring is that its velocity is inversely proportional to its radius the speed reduction is explained. The subsequent rise in the characteristic indicates that the charge carriers are no longer straightforward charged vortex rings. This behaviour is attributed to ions 'falling off' their rings soon after creating them. It would appear that the force exerted by the electric field is so large that it overcomes the hydrodynamic force which binds the ion to the slowly moving vortex, enabling the ion to escape and accelerate away. In a final levelling off part of the characteristic curve it is considered that the ions are travelling faster than the critical velocity for roton creation, but are moving far below that for phonon creation. One may therefore conclude that the ion, as it travels through the liquid, transforms energy extracted from the electric field into rotons, which fan out forming a sort of wake behind it. (U.K.)

Alternative loop rings

CERN Document Server

Goodaire, EG; Polcino Milies, C

1996-01-01

For the past ten years, alternative loop rings have intrigued mathematicians from a wide cross-section of modern algebra. As a consequence, the theory of alternative loop rings has grown tremendously. One of the main developments is the complete characterization of loops which have an alternative but not associative, loop ring. Furthermore, there is a very close relationship between the algebraic structures of loop rings and of group rings over 2-groups. Another major topic of research is the study of the unit loop of the integral loop ring. Here the interaction between loop rings and group ri

Primitivity and weak distributivity in near rings and matrix near rings

International Nuclear Information System (INIS)

Abbasi, S.J.

1993-08-01

This paper shows the structure of matrix near ring constructed over a weakly distributive and primative near ring. It is proved that a weakly distributive primitive near ring is a ring and the matrix near rings constructed over it is also a bag. (author). 14 refs

Silicon rich nitride ring resonators for rare - earth doped telecommunications-band amplifiers pumped at the O-band.

Science.gov (United States)

Xing, P; Chen, G F R; Zhao, X; Ng, D K T; Tan, M C; Tan, D T H

2017-08-22

Ring resonators on silicon rich nitride for potential use as rare-earth doped amplifiers pumped at 1310 nm with amplification at telecommunications-band are designed and characterized. The ring resonators are fabricated on 300 nm and 400 nm silicon rich nitride films and characterized at both 1310 nm and 1550 nm. We demonstrate ring resonators exhibiting similar quality factors exceeding 10,000 simultaneously at 1310 nm and 1550 nm. A Dysprosium-Erbium material system exhibiting photoluminescence at 1510 nm when pumped at 1310 nm is experimentally demonstrated. When used together with Dy-Er co-doped particles, these resonators with similar quality factors at 1310 nm and 1550 nm may be used for O-band pumped amplifiers for the telecommunications-band.

Spectrophotometry of ring nebulae around Wolf-Rayet stars

International Nuclear Information System (INIS)

Kwitter, K.B.

1979-01-01

Spectrophotometric observations of four ring nebulae surrounding population I Wolf-Rayet (WN) stars have been obtained, and four additional filamentary nebulae in order to determine the physical conditions and chemical abundances in these objects. It was concluded that the ring nebulae are enriched in nitrogen and helium as a result of contamination of the ambient interstellar medium by the helium- and nitrogen-rich wind from the central Wolf-Rayet star. Of the additional nebulae studied, two were found to be Peimbert Type I planetary nebulae, overabundant in nitrogen and helium due to mixing of CNO processed material into the parent envelope prior to ejection. One of the remaining objects, a shell around an Oef star, is found to have normal abundances; the other, a small H II region around an early Be star, also exhibits normal abundances. It was attempted to interpret the ring nebulae and the Oef shell as interstellar bubbles, according to recent theory; it met with varying degrees of success. For two of the ring nebulae, the fraction of nebular mass contributed by the central star can be estimated from published stellar abundances. It was found that in these two cases, the stellar wind has provided less than 10% of the observed nebular mass

(4aS,10aS-7-Hydroxy-8-isopropyl-1,1,4a-trimethyl-1,2,3,4,4a,9,10,10a-octahydrophenanthrene: a new diterpenoid compound

Directory of Open Access Journals (Sweden)

Ahmed Benharref

2008-03-01

Full Text Available The new title diterpenoid compound, C20H30O, is a natural product isolated from Tetraclinis articulata wood via chloroform extraction. The asymmetric unit contains four molecules with the same S,S configuration, deduced from the chemical synthesis. Indeed, an overlay analysis, calculated using structure-matching software, shows that the four molecules can be superimposed. The central ring has a half-chair conformation, whereas the saturated ring displays a chair conformation.

1-(4a,8-Dimethyl-1,2,3,4,4a,5,6,8a-octahydronaphthalen-2-yl-3-(4-methylphenylprop-2-en-1-one

Directory of Open Access Journals (Sweden)

Mohamed Tebbaa

2011-06-01

Full Text Available The title compound, C22H28O, was isolated from the aerial part of Inula viscosa (L Aiton [or Dittrichia viscosa (L Greuter]. The cyclohexene ring has a half-chair conformation, whereas the cyclohexane ring displays a chair conformation being substituted at position 2 by a 3-(4-methylphenylprop-2-enoyl group. In the crystal, weak intermolecular C—H...O hydrogen bonds link molecules into chains in the [010] direction.

Bad Enough Ergonomics: A Case Study of an Office Chair

OpenAIRE

Peteri, Virve

2017-01-01

The article analyzes ergonomics as a social and cultural phenomenon, as something that is formulated and described by speakers in a specific social context; in a company that is specialized in producing ergonomic office furniture. Through a case study of an office chair, the article examines how ergonomics and its association with the vision of the potential users and their working spaces are constructed by the relevant actors in project meetings and individual interviews during the manufactu...

Gamming Chairs and Gimballed Beds: Seafaring Women on Board Nineteenth-Century Ships

Science.gov (United States)

Seaborn, Laurel

2017-04-01

During the nineteenth century, many captains' wives from New England took up residence on the ships their husbands commanded. This article focuses on how those women at sea attempted to use material culture to domesticate their voyaging space. While writing in their journals, they referred to not only the small personal things such as books and knitting needles that they brought in their trunks, but also large items, built for and used by women, such as gamming chairs, deckhouses, parlor organs, sewing machines, and gimballed beds. Mary Brewster attempted to retreat from the ship's officers in her small deckhouse, Annie Brassey slept in the gimballed bed, and Lucy Lord Howes disembarked in a gamming chair when captured by Confederates during the Civil War. Evidence of these artifacts found during shipwreck archaeology could be used to further what is known of the culture aboard ships on which women lived. Analysis of the material culture reveals how a captain's wife domesticated space, altered her environment, and made a home on the ship for her family.

Career development needs of vice chairs for education in departments of surgery.

Science.gov (United States)

Sanfey, Hilary; Boehler, Margaret; Darosa, Debra; Dunnington, Gary L

2012-01-01

To identify the career development needs Vice Chair for Education in Surgery Departments (VCESDs). In all, 33 VCESDs were invited to complete an online survey to identify the scope of duties, scholarly activity, job satisfaction, and career development needs. A total of 29/33 (88%) VCESDs responded. Time constraints were the most frequent impediment for MDs vs. PhDs (p teacher programs (1 ± 0), and program performance evaluation systems (1.33 ± 0.76) for PhDs. The skills deemed to be of greatest importance were ability to communicate effectively (1.27 ± 0.55), resolve personnel conflicts (1.32 ± 0.57), and introduce change (1.41 ± 0.59). PhDs revealed a greater need to learn strategies for dealing with disruptive faculty (1.0 ± 0 vs 2.15 ± 0.87). This information will inform the future career development of VCESDs and will assist Department Chairs who wish to recruit and retain VCESDs. Copyright © 2012 Association of Program Directors in Surgery. Published by Elsevier Inc. All rights reserved.

Interaction of ring dark solitons with ring impurities in Bose-Einstein condensates

International Nuclear Information System (INIS)

Xue Jukui

2005-01-01

The interaction of ring dark solitons/vortexes with the ring-shaped repulsive and attractive impurities in two-dimensional Bose-Einstein condensates is investigated numerically. Very rich interaction phenomena are obtained, i.e., not only the interaction between the ring soliton and the impurity, but also the interaction between vortexes and the impurity. The interaction characters, i.e., snaking of ring soliton, quasitrapping or reflection of ring soliton and vortexes by the impurity, strongly depend on initial ring soliton velocity, impurity strength, initial position of ring soliton and impurity. The numerical results also reveal that ring dark solitons/vortexes can be trapped and dragged by an adiabatically moving attractive ring impurity

Dynamic electrical characteristics of low-power ring oscillators constructed with inorganic nanoparticles on flexible plastics.

Science.gov (United States)

Yun, Junggwon; Cho, Kyoungah; Kim, Sangsig

2012-11-01

In this study, we demonstrate for the first time the low-power and stable performance of a ring oscillator constructed on a flexible plastic with solution-processable inorganic nanoparticles (NPs). Our flexible ring oscillator is composed of three inverters based on n- and p-type inorganic NP thin-film transistors. Each of the component inverters exhibits a gain of ∼80 at a voltage of 5 V. For the ring oscillator, the sine waves are generated with a frequency of up to 12 kHz. The waveforms are undistorted under strained conditions and maintained even after 5000 bending cycles. The frequency and waveform of the output waves obtained from our flexible ring oscillator are analyzed and discussed in detail.

10a-Hydroxy-9-(4-methoxyphenyl-3,4,5,6,7,8a,9,10a-octahydro-1H-xanthene-1,8(2H-dione

Directory of Open Access Journals (Sweden)

Hoong-Kun Fun

2012-08-01

Full Text Available In the title compound, C20H22O5, the tetrahydropyran, cyclohexene and cyclohexane rings of the xanthene ring system adopt half-chair, half-boat and chair conformations, respectively. The mean plane of the four roughly planar atoms of the tetrahydropyran ring (r.m.s. deviation = 0.111 Å forms a dihedral angle of 82.91 (4° with the methoxybenzene group. In the crystal, molecules are linked via O—H...O and C—H...O hydrogen bonds into sheets lying parallel to the ac plane. The crystal is further consolidated by weak C—H...π interactions.

Storage Rings

International Nuclear Information System (INIS)

Fischer, W.

2010-01-01

Storage rings are circular machines that store particle beams at a constant energy. Beams are stored in rings without acceleration for a number of reasons (Tab. 1). Storage rings are used in high-energy, nuclear, atomic, and molecular physics, as well as for experiments in chemistry, material and life sciences. Parameters for storage rings such as particle species, energy, beam intensity, beam size, and store time vary widely depending on the application. The beam must be injected into a storage ring but may not be extracted (Fig. 1). Accelerator rings such as synchrotrons are used as storage rings before and after acceleration. Particles stored in rings include electrons and positrons; muons; protons and anti-protons; neutrons; light and heavy, positive and negative, atomic ions of various charge states; molecular and cluster ions, and neutral polar molecules. Spin polarized beams of electrons, positrons, and protons were stored. The kinetic energy of the stored particles ranges from 10 -6 eV to 3.5 x 10 12 eV (LHC, 7 x 10 12 eV planned), the number of stored particles from one (ESR) to 1015 (ISR). To store beam in rings requires bending (dipoles) and transverse focusing (quadrupoles). Higher order multipoles are used to correct chromatic aberrations, to suppress instabilities, and to compensate for nonlinear field errors of dipoles and quadrupoles. Magnetic multipole functions can be combined in magnets. Beams are stored bunched with radio frequency systems, and unbunched. The magnetic lattice and radio frequency system are designed to ensure the stability of transverse and longitudinal motion. New technologies allow for better storage rings. With strong focusing the beam pipe dimensions became much smaller than previously possible. For a given circumference superconducting magnets make higher energies possible, and superconducting radio frequency systems allow for efficient replenishment of synchrotron radiation losses of large current electron or positron beams

Why Do Simple Molecules with "Isolated" Phenyl Rings Emit Visible Light?

Science.gov (United States)

Zhang, Haoke; Zheng, Xiaoyan; Xie, Ni; He, Zikai; Liu, Junkai; Leung, Nelson L C; Niu, Yingli; Huang, Xuhui; Wong, Kam Sing; Kwok, Ryan T K; Sung, Herman H Y; Williams, Ian D; Qin, Anjun; Lam, Jacky W Y; Tang, Ben Zhong

2017-11-15

π-Bonds connected with aromatic rings were generally believed as the standard structures for constructing highly efficient fluorophores. Materials without these typical structures, however, exhibited only low fluorescence quantum yields and emitted in the ultraviolet spectral region. In this work, three molecules, namely bis(2,4,5-trimethylphenyl)methane, 1,1,2,2-tetrakis(2,4,5-trimethylphenyl)ethane, and 1,1,2,2-tetraphenylethane, with nonconjugated structures and isolated phenyl rings were synthesized and their photophysical properties were systematically investigated. Interestingly, the emission spectra of these three molecules could be well extended to 600 nm with high solid-state quantum yields of up to 70%. Experimental and theoretical analyses proved that intramolecular through-space conjugation between the "isolated" phenyl rings played an important role for this abnormal phenomenon.

Does physical exposure throughout working life influence chair-rise performance in midlife? A retrospective cohort study of associations between work and physical function in Denmark.

Science.gov (United States)

Møller, Anne; Reventlow, Susanne; Hansen, Åse Marie; Andersen, Lars L; Siersma, Volkert; Lund, Rikke; Avlund, Kirsten; Andersen, Johan Hviid; Mortensen, Ole Steen

2015-11-04

Our aim was to study associations between physical exposures throughout working life and physical function measured as chair-rise performance in midlife. The Copenhagen Aging and Midlife Biobank (CAMB) provided data about employment and measures of physical function. Individual job histories were assigned exposures from a job exposure matrix. Exposures were standardised to ton-years (lifting 1000 kg each day in 1 year), stand-years (standing/walking for 6 h each day in 1 year) and kneel-years (kneeling for 1 h each day in 1 year). The associations between exposure-years and chair-rise performance (number of chair-rises in 30 s) were analysed in multivariate linear and non-linear regression models adjusted for covariates. Mean age among the 5095 participants was 59 years in both genders, and, on average, men achieved 21.58 (SD=5.60) and women 20.38 (SD=5.33) chair-rises in 30 s. Physical exposures were associated with poorer chair-rise performance in both men and women, however, only associations between lifting and standing/walking and chair-rise remained statistically significant among men in the final model. Spline regression analyses showed non-linear associations and confirmed the findings. Higher physical exposure throughout working life is associated with slightly poorer chair-rise performance. The associations between exposure and outcome were non-linear. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Electric currents induced by twisted light in Quantum Rings.

Science.gov (United States)

Quinteiro, G F; Berakdar, J

2009-10-26

We theoretically investigate the generation of electric currents in quantum rings resulting from the optical excitation with twisted light. Our model describes the kinetics of electrons in a two-band model of a semiconductor-based mesoscopic quantum ring coupled to light having orbital angular momentum (twisted light). We find the analytical solution, which exhibits a "circular" photon-drag effect and an induced magnetization, suggesting that this system is the circular analog of that of a bulk semiconductor excited by plane waves. For realistic values of the electric field and material parameters, the computed electric current can be as large as microA; from an applied perspective, this opens new possibilities to the optical control of the magnetization in semiconductors.

Isotypic crystal structures of 1-benzyl-4-(4-bromophenyl-2-imino-1,2,5,6,7,8,9,10-octahydrocycloocta[b]pyridine-3-carbonitrile and 1-benzyl-4-(4-fluorophenyl-2-imino-1,2,5,6,7,8,9,10-octahydrocycloocta[b]pyridine-3-carbonitrile

Directory of Open Access Journals (Sweden)

R. A. Nagalakshmi

2014-11-01

Full Text Available The molecules of the two isotypic title compounds, C25H24BrN3, (I, and C25H24FN3, (II, comprise a 2-iminopyridine ring fused with a cyclooctane ring. In (I, the cyclooctane ring adopts a twisted chair–chair conformation, while in (II, this ring adopts a twisted boat–chair conformation. The dihedral angles between the planes of the pyridine ring and the bromobenzene and phenyl rings are 80.14 (12 and 71.72 (13°, respectively, in (I. The equivalent angles in (II are 75.25 (8 and 68.34 (9°, respectively. In both crystals, inversion dimers linked by pairs of C—H...N interactions generate R22(14 loops, which are further connected by weak C—H...π interactions, generating (110 sheets.

The Role of the Chair of the School Governing Body in England

Science.gov (United States)

James, Chris; Jones, Jeff; Connolly, Michael; Brammer, Steve; Fertig, Mike; James, Jane

2012-01-01

The research reported here analysed the role of the chair of the school governing body in England, drawing on a national survey of governors and the study of governing in 30 schools. The role encompassed: being a governor; appointing and working with the head teacher; acting as a change agent; active participation in the school; organising the…

Secondary School Department Chairs Leading Successful Change

Directory of Open Access Journals (Sweden)

Julie Ann Gaubatz

2015-12-01

Full Text Available A foundational understanding within education leadership literature is that education leaders are expected to guide reform efforts within school. This expectation mirrors organizational development literature that describes leaders as individuals who constructively institute change within their organizations. Although leadership and change are portrayed as codependent, no scholarship has linked change models with leadership theories. This article describes a multiple case study that explored the relationship between leadership behaviors and the change process through secondary school department chair stories of change. From this analysis, a clearer picture emerged that illustrates how leaders with little control over decisions implement change. Findings included distinct connections between CREATER change process stages and the Leadership Grid. Suggestions as to how education leaders should approach change attempts within their schools are discussed.

Ring ductility of irradiated Inconel 706 and Nimonic PE16

International Nuclear Information System (INIS)

Huang, F.H.; Fish, R.L.

1984-01-01

The tensile ductility of fast neutron-irradiated, precipitation-hardened alloys Inconel 706 and Nimonic PE16 has been observed to be very low for certain test conditions. Explanations for the low ductility behavior have been sought by examination of broken tensile specimens with microscopy and other similar techniques. A ring compression test provides a method of evaluating the ductility of irradiated cladding specimens. Unlike the conventional uniaxial tensile testing in which the tensile specimen is deformed uniformly, the ring specimen is subjected to localized bending where the crack is initiated. The ductility can be estimated through an analysis of the bending of a ring in terms of strain hardening. Ring sections from irradiated, solution-treated Inconel 706 and Nimonic PE16 were compressed in the diametral direction to provide load-deflection records over a wide range of irradiation and test temperatures. Results showed that ductility in both alloys decreased with increasing test temperatures. The poorest ductility was exhibited at different irradiation temperatures in the two alloys - near 550 0 C for PE16 and 460 to 520 0 C for Inconel 706. The ring ductility data indicate that the grain boundary strength is a major factor in controlling the ductility of the PE16 alloy

Racemic methyl 3,10-dioxa-2-azatricyclo[6.2.1.02,6]undecane-4- carboxylate

KAUST Repository

Moosa, Basem; Fazal, Atif; Ali, Shaikh A.; Fettouhi, Mohammed

2011-01-01

The structure of the racemic title compound, C10H 15NO4, consists of a tricyclic skeleton comprising a six-membered piperidine ring and five-membered isoxazolidine and tetrahydrofuran rings. The piperidine ring adopts a distorted chair conformation

Rings in drugs.

Science.gov (United States)

Taylor, Richard D; MacCoss, Malcolm; Lawson, Alastair D G

2014-07-24

We have analyzed the rings, ring systems, and frameworks in drugs listed in the FDA Orange Book to understand the frequency, timelines, molecular property space, and the application of these rings in different therapeutic areas and target classes. This analysis shows that there are only 351 ring systems and 1197 frameworks in drugs that came onto the market before 2013. Furthermore, on average six new ring systems enter drug space each year and approximately 28% of new drugs contain a new ring system. Moreover, it is very unusual for a drug to contain more than one new ring system and the majority of the most frequently used ring systems (83%) were first used in drugs developed prior to 1983. These observations give insight into the chemical novelty of drugs and potentially efficient ways to assess compound libraries and develop compounds from hit identification to lead optimization and beyond.

Conformational analysis of 9β,19-cyclopropyl sterols: Detection of the pseudoplanar conformer by nuclear Overhauser effects and its functional implications

International Nuclear Information System (INIS)

Nes, W.D.; Benson, M.; Lundin, R.E.; Le, P.H.

1988-01-01

Nuclear Overhauser difference spectroscopy and variable temperature studies of the 9β,19-cyclopropyl sterols 24,25-dehydropollinastanol (4,4-desmethyl-5α-cycloart-24-en-3β-ol) and cyclolaudenol [(24S)-24-methyl-5α-cycloart-25(27)-en-3β-ol] have shown the solution conformation of the B/C rings to be twist-chair/twist-boat rather than boat/chair as suggested in the literature. This is very similar to the known crystal structure conformation of 9β,19-cyclopropyl sterols. The effect of these conformations on the molecular shape is highly significant; the first conformation orients into a pseudoplanar or flat shape analogous to lanosterol, whereas the latter conformation exhibits a bent shape. The results are interpreted to imply that, for conformational reasons, cyclopropyl sterols can be expected to maintain the pseudoplanar shape in membrane bilayers

Verification of annual growth rings in Egyptian trees by C-14 method

International Nuclear Information System (INIS)

Belacy, N.; Abou El-Nour, F.; Jacoby, G.C.

1990-01-01

Annual growth rings in trees were thought to be due to sharp seasonal variations in the precipitation rates during the year. Accordingly temperature zone trees such as Egyptian trees were supposed to be away from this phenomenon. The temperature zones which are meant here are those of no sharp seasonal variations in the precipitation rates. The present study applied carbon-14 dating to prove that the growth rings in some Egyptian trees are annual. The method was based on the tropospheric measurements of C-14 during the period 1954-1981. C-14 exhibited a sharp peak resulting from the ever greater series of nuclear tests during 1963-1965. The presence of this peak for Egyptian trees proved that they form annual growth rings. (orig.) [de

A survey of the bacterial diversity in the cup filler of dental chair units.

Science.gov (United States)

Silva, Vítor; Figueira, Vânia; Figueiral, Helena; Manaia, Célia M

2011-07-01

Water from the cup filler of dental chair units (CFDC) was observed to contain sphingomonads, environmental mycobacteria and methylobacteria, among other minor bacteria. Some of the bacteria detected are recognized opportunistic pathogens. Some of these, tended to persist over time.

Tramadolium 2-chlorobenzoate

Directory of Open Access Journals (Sweden)

S. N. Sheshadri

2016-01-01

Full Text Available In the title molecular salt, C16H26NO2+·C7H4ClO2−, {systematic name: [2-hydroxy-2-(3-methoxyphenylcyclohexylmethyl]dimethylammonium 2-chlorobenzoate}, the cyclohexane ring of the cation exhibits a chair conformation with the aromatic and amine substituents in equatorial orientations and the hydroxyl group in an axial orientation. In the anion, the dihedral angle between the aromatic ring and the carboxylate group is 39.16 (13°. In the crystal, the cations are linked to the anions by O—H...O, N—H...O and C—H...O hydrogen bonds, generating [010] chains. Further C—H...O and C—H...π interactions are also observed, which link the chains into a three-dimensional framework.

Selective Tree-ring Models: A Novel Method for Reconstructing Streamflow Using Tree Rings

Science.gov (United States)

Foard, M. B.; Nelson, A. S.; Harley, G. L.

2017-12-01

Surface water is among the most instrumental and vulnerable resources in the Northwest United States (NW). Recent observations show that overall water quantity is declining in streams across the region, while extreme flooding events occur more frequently. Historical streamflow models inform probabilities of extreme flow events (flood or drought) by describing frequency and duration of past events. There are numerous examples of tree-rings being utilized to reconstruct streamflow in the NW. These models confirm that tree-rings are highly accurate at predicting streamflow, however there are many nuances that limit their applicability through time and space. For example, most models predict streamflow from hydrologically altered rivers (e.g. dammed, channelized) which may hinder our ability to predict natural prehistoric flow. They also have a tendency to over/under-predict extreme flow events. Moreover, they often neglect to capture the changing relationships between tree-growth and streamflow over time and space. To address these limitations, we utilized national tree-ring and streamflow archives to investigate the relationships between the growth of multiple coniferous species and free-flowing streams across the NW using novel species-and site-specific streamflow models - a term we coined"selective tree-ring models." Correlation function analysis and regression modeling were used to evaluate the strengths and directions of the flow-growth relationships. Species with significant relationships in the same direction were identified as strong candidates for selective models. Temporal and spatial patterns of these relationships were examined using running correlations and inverse distance weighting interpolation, respectively. Our early results indicate that (1) species adapted to extreme climates (e.g. hot-dry, cold-wet) exhibit the most consistent relationships across space, (2) these relationships weaken in locations with mild climatic variability, and (3) some

Racemic methyl 3,10-dioxa-2-azatricyclo[6.2.1.02,6]undecane-4- carboxylate

KAUST Repository

Moosa, Basem

2011-04-29

The structure of the racemic title compound, C10H 15NO4, consists of a tricyclic skeleton comprising a six-membered piperidine ring and five-membered isoxazolidine and tetrahydrofuran rings. The piperidine ring adopts a distorted chair conformation, while the isoxazolidine and tetrahydrofuran rings have envelope conformations.

Toward Detection of Exoplanetary Rings via Transit Photometry: Methodology and a Possible Candidate

Energy Technology Data Exchange (ETDEWEB)

Aizawa, Masataka; Masuda, Kento; Suto, Yasushi [Department of Physics, The University of Tokyo, Tokyo, 113-0033 (Japan); Uehara, Sho [Department of Physics, Tokyo Metropolitan University, Tokyo 192-4397 (Japan); Kawahara, Hajime, E-mail: aizawa@utap.phys.s.u-tokyo.ac.jp [Department of Earth and Planetary Science, The University of Tokyo, Tokyo 113-0033 (Japan)

2017-04-01

The detection of a planetary ring of exoplanets remains one of the most attractive, but challenging, goals in the field of exoplanetary science. We present a methodology that implements a systematic search for exoplanetary rings via transit photometry of long-period planets. This methodology relies on a precise integration scheme that we develop to compute a transit light curve of a ringed planet. We apply the methodology to 89 long-period planet candidates from the Kepler data so as to estimate, and/or set upper limits on, the parameters of possible rings. While the majority of our samples do not have sufficient signal-to-noise ratios (S/Ns) to place meaningful constraints on ring parameters, we find that six systems with higher S/Ns are inconsistent with the presence of a ring larger than 1.5 times the planetary radius, assuming a grazing orbit and a tilted ring. Furthermore, we identify five preliminary candidate systems whose light curves exhibit ring-like features. After removing four false positives due to the contamination from nearby stars, we identify KIC 10403228 as a reasonable candidate for a ringed planet. A systematic parameter fit of its light curve with a ringed planet model indicates two possible solutions corresponding to a Saturn-like planet with a tilted ring. There also remain two other possible scenarios accounting for the data; a circumstellar disk and a hierarchical triple. Due to large uncertain factors, we cannot choose one specific model among the three.

Patient state index and cerebral blood flow changes during shoulder arthroscopy in beach chair position.

Science.gov (United States)

Buget, Mehmet Ilke; Atalar, Ata Can; Edipoglu, Ipek Saadet; Sungur, Zerrin; Sivrikoz, Nukhet; Karadeniz, Meltem; Saka, Esra; Kucukay, Suleyman; Senturk, Mert N

2016-01-01

The aim of the study were to demonstrate the possible hemodynamic changes and cerebral blood flow alterations in patients who were positioned from supine to beach chair position; and to detect if the position change causes any cortical activity alteration as measured by the 4-channeled electroencephalography monitor. 35 patients were included. Before the induction, mean arterial pressure and patient state index values were recorded (T0). After the intubation, doppler-ultrasonography of the patients' internal carotid and vertebral arteries were evaluated to acquire cerebral blood flow values from the formula. In supine position, mean arterial pressure, patient state index and cerebral blood flow values were recorded (T1) and the patient was positioned to beach chair position. After 5min all measurements were repeated (T2). Measurements of patient state index and mean arterial pressure were repeated after 20 (T3), and 40 (T4)min. There was a significant decrease between T0 and T1 in heart rate (80.5±11.6 vs. 75.9±14.4beats/min), MAP (105.8±21.9 vs. 78.9±18.4mmHg) and PSI (88.5±8.3 vs. 30.3±9.7) (all pstate index values (T1-T4) showed no significant change; however, comparing only T1 and T2 resulted in a statically significant decrease in patient state index. There was a significant decrease in cerebral blood flow after beach chair position. Beach chair position was associated with a decrease in cerebral blood flow and patient state index values. Patient state index was affected by the gravitational change of the cerebral blood flow; however, both factors were not directly correlated to each other. Moreover, the decrease in patient state index value was transient and returned to normal values within 20min. Copyright © 2015 Sociedade Brasileira de Anestesiologia. Published by Elsevier Editora Ltda. All rights reserved.

[Patient state index and cerebral blood flow changes during shoulder arthroscopy in beach chair position].

Science.gov (United States)

Buget, Mehmet Ilke; Atalar, Ata Can; Edipoglu, Ipek Saadet; Sungur, Zerrin; Sivrikoz, Nukhet; Karadeniz, Meltem; Saka, Esra; Kucukay, Suleyman; Senturk, Mert N

2016-01-01

The aim of the study were to demonstrate the possible hemodynamic changes and cerebral blood flow alterations in patients who were positioned from supine to beach chair position; and to detect if the position change causes any cortical activity alteration as measured by the 4-channeled electroencephalography monitor. 35 patients were included. Before the induction, mean arterial pressure and patient state index values were recorded (T0). After the intubation, doppler-ultrasonography of the patients' internal carotid and vertebral arteries were evaluated to acquire cerebral blood flow values from the formula. In supine position, mean arterial pressure, patient state index and cerebral blood flow values were recorded (T1) and the patient was positioned to beach chair position. After 5min all measurements were repeated (T2). Measurements of patient state index and mean arterial pressure were repeated after 20 (T3), and 40 (T4)min. There was a significant decrease between T0 and T1 in heart rate (80.5±11.6 vs. 75.9±14.4beats/min), MAP (105.8±21.9 vs. 78.9±18.4mmHg) and PSI (88.5±8.3 vs. 30.3±9.7) (all pstate index values (T1-T4) showed no significant change; however, comparing only T1 and T2 resulted in a statically significant decrease in patient state index. There was a significant decrease in cerebral blood flow after beach chair position. Beach chair position was associated with a decrease in cerebral blood flow and patient state index values. Patient state index was affected by the gravitational change of the cerebral blood flow; however, both factors were not directly correlated to each other. Moreover, the decrease in patient state index value was transient and returned to normal values within 20min. Copyright © 2015 Sociedade Brasileira de Anestesiologia. Publicado por Elsevier Editora Ltda. All rights reserved.

Utilisation du moringa, de la spiruline, de la patate douce à chair ...

African Journals Online (AJOL)

Les biscuits peuvent contribuer à améliorer le statut nutritionnel des jeunes enfants. L'effet de l'incorporation du moringa, de la spiruline, de la patate douce à chair orange (PDCO) et d'un complexe minéral et vitaminique (CMV) sur la qualité nutritionnelle des biscuits de sorgho est étudié. Pour ces ingrédients nutritionnels, ...

Spiral and Rotor Patterns Produced by Fairy Ring Fungi

Science.gov (United States)

Karst, N.; Dralle, D.; Thompson, S. E.

2015-12-01

Soil fungi fill many essential ecological and biogeochemical roles, e.g. decomposing litter, redistributing nutrients, and promoting biodiversity. Fairy ring fungi offer a rare glimpse into the otherwise opaque spatiotemporal dynamics of soil fungal growth, because subsurface mycelial patterns can be inferred from observations at the soil's surface. These observations can be made directly when the fungi send up fruiting bodies (e.g., mushrooms and toadstools), or indirectly via the effect the fungi have on neighboring organisms. Grasses in particular often temporarily thrive on the nutrients liberated by the fungus, creating bands of rich, dark green turf at the edge of the fungal mat. To date, only annular (the "ring" in fairy ring) and arc patterns have been described in the literature. We report observations of novel spiral and rotor pattern formation in fairy ring fungi, as seen in publically available high-resolution aerial imagery of 22 sites across the continental United States. To explain these new behaviors, we first demonstrate that a well-known model describing fairy ring formation is equivalent to the Gray-Scott reaction-diffusion model, which is known to support a wide range of dynamical behaviors, including annular traveling waves, rotors, spirals, and stable spatial patterns including spots and stripes. Bifurcation analysis and numerical simulation are then used to define the region of parameter space that supports spiral and rotor formation. We find that this region is adjacent to one within which typical fairy rings develop. Model results suggest simple experimental procedures that could potentially induce traditional ring structures to exhibit rotor or spiral dynamics. Intriguingly, the Gray-Scott model predicts that these same procedures could be used to solicit even richer patterns, including spots and stripes, which have not yet been identified in the field.

A survey of the bacterial diversity in the cup filler of dental chair units

Directory of Open Access Journals (Sweden)

Vítor Silva

2011-09-01

Full Text Available Water from the cup filler of dental chair units (CFDC was observed to contain sphingomonads, environmental mycobacteria and methylobacteria, among other minor bacteria. Some of the bacteria detected are recognized opportunistic pathogens. Some of these, tended to persist over time.

The Effect of Holding a Research Chair on Scientists’ Impact

Energy Technology Data Exchange (ETDEWEB)

Mirnezami, S.R.; Beaudry, C.

2016-07-01

This paper examines the effect of holding Canada Research Chair (CRC) on a scientist’s number of citations as a measure of research impact, based on an econometric analysis with combined data on Quebec scientists’ funding and journal publication. Using Generalized Least Square (GLS) method for regression analysis, the results show that holding either tier-1 or tier- 2 of CRC significantly and positively results in conducting research with higher impact. This finding, however, does not necessarily imply that the others are the lesser scientists. (Author)

Vestibulo-Ocular Responses to Vertical Translation using a Hand-Operated Chair as a Field Measure of Otolith Function

Science.gov (United States)

Wood, S. J.; Campbell, D. J.; Reschke, M. F.; Prather, L.; Clement, G.

2016-01-01

The translational Vestibulo-Ocular Reflex (tVOR) is an important otolith-mediated response to stabilize gaze during natural locomotion. One goal of this study was to develop a measure of the tVOR using a simple hand-operated chair that provided passive vertical motion. Binocular eye movements were recorded with a tight-fitting video mask in ten healthy subjects. Vertical motion was provided by a modified spring-powered chair (swopper.com) at approximately 2 Hz (+/- 2 cm displacement) to approximate the head motion during walking. Linear acceleration was measured with wireless inertial sensors (Xsens) mounted on the head and torso. Eye movements were recorded while subjects viewed near (0.5m) and far (approximately 4m) targets, and then imagined these targets in darkness. Subjects also provided perceptual estimates of target distances. Consistent with the kinematic properties shown in previous studies, the tVOR gain was greater with near targets, and greater with vision than in darkness. We conclude that this portable chair system can provide a field measure of otolith-ocular function at frequencies sufficient to elicit a robust tVOR.

White Ring; White ring

Energy Technology Data Exchange (ETDEWEB)

Aoki, H.; Yuzawa, H. [Nikken Sekkei Ltd., Osaka (Japan)

1998-01-05

White Ring is a citizen`s gymnasium used for figure skating and short track speed skating games of 18th Winter Olympic Games in 1998. White Ring is composed of a main-arena and a sub-arena. For the main-arena with an area 41mtimes66m, an ice link can be made by disengaging the potable floor and by flowing brine in the bridged polystyrene pipes embedded in the concrete floor. Due to the fortunate groundwater in this site, well water is used for the outside air treatment energy in 63% during heating and in 35% during cooling. Ammonia is used as a cooling medium for refrigerating facility. For the heating of audience area in the large space, heat load from the outside is reduced by enhancing the heat insulation performance of the roof of arena. The audience seats are locally heated using heaters. For the White Ring, high quality environment is realized for games through various functions of the large-scale roof of the large space. Success of the big event was expected. 15 figs., 4 tabs.

Token Ring Project

Directory of Open Access Journals (Sweden)

Adela Ionescu

2007-01-01

Full Text Available Ring topology is a simple configuration used to connect processes that communicate among themselves. A number of network standards such as token ring, token bus, and FDDI are based on the ring connectivity. This article will develop an implementation of a ring of processes that communicate among themselves via pipe links. The processes are nodes in the ring. Each process reads from its standard input and writes in its standard output. N-1 process redirects the its standard output to a standard input of the process through a pipe. When the ring-structure is designed, the project can be extended to simulate networks or to implement algorithms for mutual exclusion

Racemic methyl 3,10-dioxa-2-azatricyclo[6.2.1.02,6]undecane-4-carboxylate

Directory of Open Access Journals (Sweden)

Basem A. Moosa

2011-05-01

Full Text Available The structure of the racemic title compound, C10H15NO4, consists of a tricyclic skeleton comprising a six-membered piperidine ring and five-membered isoxazolidine and tetrahydrofuran rings. The piperidine ring adopts a distorted chair conformation, while the isoxazolidine and tetrahydrofuran rings have envelope conformations.

Type 2 diabetes sits in a chair

DEFF Research Database (Denmark)

Solomon, Thomas; Thyfault, J P

2013-01-01

for prevention and treatment are desperately needed. Accumulating evidence suggests that increased sedentary time (i.e. 'sitting time') combined with reduced physical activity levels, plays both a major role in the development of T2D and may contribute to the worsening of the condition after diagnosis......The incidence of type 2 diabetes (T2D) continues to skyrocket across the industrialized world leading to soaring medical costs, reduced quality of life and increased mortality rates. Therefore, a more firm understanding of the development of the disease and effective, low cost therapies....... In this review, we cover these topics and use current scientific evidence to support our belief that 'type 2 diabetes sits in a chair'. We also discuss a relatively new question that has yet to be examined: Would reducing sitting time be an effective treatment for T2D?...

(1S*,2S*,5R*,8S*,11S*,14R*,17S*,20R*-14-Methyl-6-methylene-10,16,18-trioxahexacyclo[12.5.1.15,8.01,11.02,8.017,20]henicosane-7,9-dione: natural diterpenoid macrocalyxoformin B

Directory of Open Access Journals (Sweden)

Hao Shi

2008-01-01

Full Text Available The title compound, C20H24O5, isolated from Rabdosia var. lophanthoides Hara, is built up from six fused rings. Cyclohexane ring A adopts a chair conformation, ring B exists in a screw-boat conformation and ring C adopts a boat conformation; the three five-membered rings D, E and F adopt envelope conformations.

Effects of chair yoga therapy on physical fitness in patients with psychiatric disorders: A 12-week single-blind randomized controlled trial.

Science.gov (United States)

Ikai, Saeko; Uchida, Hiroyuki; Mizuno, Yuya; Tani, Hideaki; Nagaoka, Maki; Tsunoda, Kenichi; Mimura, Masaru; Suzuki, Takefumi

2017-11-01

Since falls may lead to fractures and have serious, potentially fatal outcomes, prevention of falls is an urgent public health issue. We examined the effects of chair yoga therapy on physical fitness among psychiatric patients in order to reduce the risk of falls, which has not been previously reported in the literature. In this 12-week single-blind randomized controlled trial with a 6-week follow-up, inpatients with mixed psychiatric diagnoses were randomly assigned to either chair yoga therapy in addition to ongoing treatment, or treatment-as-usual. Chair yoga therapy was conducted as twice-weekly 20-min sessions over 12 weeks. Assessments included anteflexion in sitting, degree of muscle strength, and Modified Falls Efficacy Scale (MFES) as well as QOL, psychopathology and functioning. Fifty-six inpatients participated in this study (36 men; mean ± SD age, 55.3 ± 13.7 years; schizophrenia 87.5%). In the chair yoga group, significant improvements were observed in flexibility, hand-grip, lower limb muscle endurance, and MFES at week 12 (mean ± SD: 55.1 ± 16.6 to 67.2 ± 14.0 cm, 23.6 ± 10.6 to 26.8 ± 9.7 kg, 4.9 ± 4.0 to 7.0 ± 3.9 kg, and 114.9 ± 29.2 to 134.1 ± 11.6, respectively). Additionally, these improvements were observable six weeks after the intervention was over. The QOL-VAS improved in the intervention group while no differences were noted in psychopathology and functioning between the groups. The intervention appeared to be highly tolerable without any notable adverse effects. The results indicated sustainable effects of 20-min, 12-week, 24-session chair yoga therapy on physical fitness. Chair yoga therapy may contribute to reduce the risk of falls and their unwanted consequences in psychiatric patients. Copyright © 2017 Elsevier Ltd. All rights reserved.

Semi-algebraic function rings and reflectors of partially ordered rings

CERN Document Server

Schwartz, Niels

1999-01-01

The book lays algebraic foundations for real geometry through a systematic investigation of partially ordered rings of semi-algebraic functions. Real spectra serve as primary geometric objects, the maps between them are determined by rings of functions associated with the spectra. The many different possible choices for these rings of functions are studied via reflections of partially ordered rings. Readers should feel comfortable using basic algebraic and categorical concepts. As motivational background some familiarity with real geometry will be helpful. The book aims at researchers and graduate students with an interest in real algebra and geometry, ordered algebraic structures, topology and rings of continuous functions.

Rotating ring-ring electrode theory and experiment

NARCIS (Netherlands)

Kuiken, H.K.; Bakkers, E.P.A.M.; Ligthart, H.; Kellyb, J.J.

2000-01-01

A model is presented for the rotating ring-ring electrode. Although the electrode is defined by four characteristic lengths, it is shown that the collection efficiency depends on only two dimensionless parameters. A simple relationship between these and the corresponding parameters for the rotating

Lord of the Rings - Return of the King: Swift-XRT observations of dust scattering rings around V404 Cygni

Science.gov (United States)

Beardmore, A. P.; Willingale, R.; Kuulkers, E.; Altamirano, D.; Motta, S. E.; Osborne, J. P.; Page, K. L.; Sivakoff, G. R.

2016-10-01

On 2015 June 15, the black hole X-ray binary V404 Cygni went into outburst, exhibiting extreme X-ray variability which culminated in a final flare on June 26. Over the following days, the Swift-X-ray Telescope detected a series of bright rings, comprising five main components that expanded and faded with time, caused by X-rays scattered from the otherwise unobservable dust layers in the interstellar medium in the direction of the source. Simple geometrical modelling of the rings' angular evolution reveals that they have a common temporal origin, coincident with the final, brightest flare seen by INTEGRAL's JEM X-1, which reached a 3-10 keV flux of ˜25 Crab. The high quality of the data allows the dust properties and density distribution along the line of sight to the source to be estimated. Using the Rayleigh-Gans approximation for the dust scattering cross-section and a power-law distribution of grain sizes a, ∝ a-q, the average dust emission is well modelled by q = 3.90^{+0.09}_{-0.08} and maximum grain size of a_+ = 0.147^{+0.024}_{-0.004} { μ m}, though significant variations in q are seen between the rings. The recovered dust density distribution shows five peaks associated with the dense sheets responsible for the rings at distances ranging from 1.19 to 2.13 kpc, with thicknesses of ˜40-80 pc and a maximum density occurring at the location of the nearest sheet. We find a dust column density of Ndust ≈ (2.0-2.5) × 1011 cm-2, consistent with the optical extinction to the source. Comparison of the inner rings' azimuthal X-ray evolution with archival Wide-field Infrared Survey Explorer mid-IR data suggests that the second most distant ring follows the general IR emission trend, which increases in brightness towards the Galactic north side of the source.

Topological ring currents in the "empty" ring of benzo-annelated perylenes.

Science.gov (United States)

Dickens, Timothy K; Mallion, Roger B

2011-01-27

Cyclic conjugation in benzo-annelated perylenes is examined by means of the topological π-electron ring currents calculated for each of their constituent rings, in a study that is an exact analogy of a recent investigation by Gutman et al. based on energy-effect values for the corresponding rings in each of these structures. "Classical" approaches, such as Kekulé structures, Clar "sextet" formulas, and circuits of conjugation, predict that the central ring in perylene is "empty" and thus contributes negligibly to cyclic conjugation. However, conclusions from the present calculations of topological ring currents agree remarkably with those arising from the earlier study involving energy-effect values in that, contrary to what would be predicted from the classical approaches, rings annelated in an angular fashion relative to the central ring of these perylene structures materially increase the extent of that ring's involvement in cyclic conjugation. It is suggested that such close quantitative agreement between the predictions of these two superficially very different indices (energy effect and topological ring current) might be due to the fact that, ultimately, both depend, albeit in ostensibly quite different ways, only on an adjacency matrix that contains information about the carbon-carbon connectivity of the conjugated system in question.

Design and Testing of Low Cost Chair with Round Mortise and Tenon Joints

Directory of Open Access Journals (Sweden)

Jaroslav Začal

2016-01-01

Full Text Available The present paper focuses on construction of school seats for developing countries from locally available resources using the local industry and low-end technology. Aim of the work is experimental assessment of mechanical properties of joints flexion in angular plane. Furthermore work considers assessment of joint firmness and comparison between various joint types. Paper encloses the review of various joint manufacturing designs (tenon and mortise, which were proposed for its suitable mechanical properties and simplicity of manufacturing. Designated joint type is easiest form of joint construction and technologically feasible for chair manufacturing. The joints were constructed from fir wood. Further the work introduces design of simple seat construction made from massive wood material manufactured by low-end technology with regards to achieving the due specifications. The task of this work is to design the viable manufacturing process of seats and chairs from raw wood and scrap material. Essential part of work is also manufacturing of seat prototype and simplified model of proposed mortise and tenon drill.

Kayser-Fleischer Rings

Science.gov (United States)

... Support Contacts Lab Tracker/Copper Calculator Stories Programs & Research ... About Everything you need to know about Wilson Disease Kayser-Fleischer Rings Definition Kayser-Fleischer Ring: Clinical sign. Brownish-yellow ring visible around the corneo- ...

Graduate Medical Education Funding and Curriculum in Physical Medicine and Rehabilitation: A Survey of Physical Medicine and Rehabilitation Department Chairs.

Science.gov (United States)

Perret, Danielle; Knowlton, Tiffany; Worsowicz, Gregory

2018-03-01

This national survey highlights graduate medical education funding sources for physical medicine and rehabilitation (PM&R) residency programs as well as perceived funding stability, alignment of the current funding and educational model, the need of further education in postacute care settings, and the practice of contemporary PM&R graduates as perceived by PM&R department/division chairs. Approximately half of the reported PM&R residency positions seem to be funded by Centers of Medicare and Medicaid Services; more than 40% of PM&R chairs believe that their residency program is undersized and nearly a quarter feel at risk for losing positions. A total of 30% of respondents report PM&R resident experiences in home health, 15% in long-term acute care, and 52.5% in a skilled nursing facility/subacute rehabilitation facility. In programs that do not offer these experiences, most chairs feel that this training should be included. In addition, study results suggest that most PM&R graduates work in an outpatient setting. Based on the results that chairs strongly feel the need for resident education in postacute care settings and that most graduates go on to practice in outpatient settings, there is a potential discordance for our current Centers of Medicare and Medicaid Services graduate medical education funding model being linked to the acute care setting.

Ring-shaped quasi-soliton solutions to the two-and three-dimensional Sine-Gordon equation

International Nuclear Information System (INIS)

Christiansen, P.L.; Olsen, O.H.

1979-01-01

Ring-shaped solitary wave solutions to the Sine-Gordon equation in two and three spatial dimensions are investigated by numerical computation. Each expanding wave exhibits a return effect. The reflection of the shrinking wave at the singularity at the center of the wave is investigated in a particular case. Collision experiments in numero for expanding and shrinking concentric ring waves show that the solutions possess quasisoliton properties. A Baecklund transformation for the non-symmetric three-dimensional case is given. (Auth.)

Flow dynamics in distillation columns packed with Dixon rings as used in isotope separation

International Nuclear Information System (INIS)

Gilath, C.; Cohen, H.; Wolf, D.

1977-01-01

Packed distillation columns are common in isotope separation. The pressure drop serves as an indication for the hydrodynamic state of the column. Models were formulated for flow and pressure drop dynamics in packed distillation columns. These models were confirmed on columns packed with Dixon rings and operated with water for separation of oxygen isotopes. Liquid holdup displacement is very important in isotope separation practice. Experiments proved that distillation columns packed with Dixon rings exhibit a behaviour close to plug flow. (author)

Cerebral oxygenation in the beach chair position for shoulder surgery in regional anesthesia: impact on cerebral blood flow and neurobehavioral outcome.

Science.gov (United States)

Aguirre, José A; Märzendorfer, Olivia; Brada, Muriel; Saporito, Andrea; Borgeat, Alain; Bühler, Philipp

2016-12-01

Beach chair position is considered a potential risk factor for central neurological events particularly if combined with low blood pressure. The aim of this study was to assess the impact of regional anesthesia on cerebral blood flow and neurobehavioral outcome. This is a prospective, assessor-blinded observational study evaluating patients in the beach chair position undergoing shoulder surgery under regional anesthesia. University hospital operating room. Forty patients with American Society of Anesthesiologists classes I-II physical status scheduled for elective shoulder surgery. Cerebral saturation and blood flow of the middle cerebral artery were measured prior to anesthesia and continued after beach chair positioning until discharge to the postanesthesia care unit. The anesthesiologist was blinded for these values. Controlled hypotension with systolic blood pressure≤100mm Hg was maintained during surgery. Neurobehavioral tests and values of regional cerebral saturation, bispectral index, the mean maximal blood flow of the middle cerebral artery, and invasive blood pressure were measured prior to regional anesthesia, and measurements were repeated after placement of the patient on the beach chair position and every 20 minutes thereafter until discharge to postanesthesia care unit. The neurobehavioral tests were repeated the day after surgery. The incidence of cerebral desaturation events was 5%. All patients had a significant blood pressure drop 5 minutes after beach chair positioning, measured at the heart as well as the acoustic meatus levels, when compared with baseline values (Psurgery (Pshoulder surgery had no major impact on cerebral blood flow and cerebral oxygenation. However, some impact on neurobehavioral outcome 24 hours after surgery was observed. Copyright © 2016 Elsevier Inc. All rights reserved.

Le Kenya nomme le titulaire de sa première chaire de recherche

International Development Research Centre (IDRC) Digital Library (Canada)

14 avr. 2016 ... De concert avec le CRDI, la National Commission for Science, Technology and Innovation (NACOSTI) du Kenya a inauguré sa première chaire de recherche à Nairobi, le 31 mars 2015. Le professeur Fabian Omoding Esamai, qui dirige actuellement le College of Health Sciences de la Moi University, a été ...

Preparation for electron ring - plasma ring merging experiments in RECE-MERGE

International Nuclear Information System (INIS)

Taggart, D.; Sekiguchi, A.; Fleischmann, H.H.

1986-01-01

The formation of a mixed-CT using relativistic electron rings and gun-produced plasma rings by MERGE-ing them axially is simulated. This process is similar to the axial stacking of relativistic electron rings in RECE-Christa. The results of their first plasm production experiment are reported here. After study of the gun-produced plasma's properties is completed, the gun will be mounted at the downstream end of the vacuum tank and the source of relativistic electron rings will be at the upstream end. The two rings, formed at opposite ends of the tank, will be translated axially and merged

The Centaur Chariklo and its rings system from stellar occultations in 2017

Science.gov (United States)

Leiva, Rodrigo; Sicardy, Bruno; Camargo, Julio; Ortiz, Jose Luis; Berard, Diane; Desmars, Josselin; Chariklo Occultations Team; Rio Group; Lucky Star Occultation Team; Granada Occultation Team

2017-10-01

A stellar occultation in June 3, 2013 revealed the presence of a dense ring system around the Centaur object (10199) Chariklo (Braga-Ribas et al., Nature 2014). Subsequent analysis of occultation data and long-term photometric variations indicate that Chariklo's body is elongated (Leiva et al. 2017, submitted) and that the main ring exhibits significant longitudinal variations of the radial width (Bérard et al. 2017, in press). We report three multi-chord high-quality stellar occultation by Chariklo on April 9, 2017 and June 22, 2017 from Namibia, and July 23 2017 from South America. The analysis of this new data set is underway, but preliminary results are consistent with triaxial ellipsoidal models. From this analysis we will:-present refined models for the size and shape of Chariklo's main body andevaluate the heights and slopes of its topographic features.-give constraints on the longitudinal width variations of Chariklo's rings andexplore the possibility to obtain the rings apsidal precession rate.Chariklo's shape and topography have strong consequences on the dynamics of the rings through Lindblad-type resonances between mean motion of the ring particles and the spin of the main body, while the rings precession rate gives constraints on the dynamical oblateness of the main body.**Part of the research leading to these results has received funding from the European Research Council under the European Community’s H2020 (2014-2020/ ERC Grant Agreement n 669416 ”LUCKY STAR”).

Quantum Entanglement and Projective Ring Geometry

Directory of Open Access Journals (Sweden)

Michel Planat

2006-08-01

Full Text Available The paper explores the basic geometrical properties of the observables characterizing two-qubit systems by employing a novel projective ring geometric approach. After introducing the basic facts about quantum complementarity and maximal quantum entanglement in such systems, we demonstrate that the 15 × 15 multiplication table of the associated four-dimensional matrices exhibits a so-far-unnoticed geometrical structure that can be regarded as three pencils of lines in the projective plane of order two. In one of the pencils, which we call the kernel, the observables on two lines share a base of Bell states. In the complement of the kernel, the eight vertices/observables are joined by twelve lines which form the edges of a cube. A substantial part of the paper is devoted to showing that the nature of this geometry has much to do with the structure of the projective lines defined over the rings that are the direct product of n copies of the Galois field GF(2, with n = 2, 3 and 4.

An Ergonomic Desk and Chair Prototype to Improve Seating Position on Senior High School Students at Kabupaten Gresik

Directory of Open Access Journals (Sweden)

Neffrety Nilamsari

2015-04-01

chair N, length = 48 cm, wide = 43 cm, cushion base’s height from floor surfaces = 47 cm, bag keeper’s height from floor surfaces =3cm, bag keeper’s wide= 43 cm, bag keeper’s length = 47 cm, cushion’s wide = 41 cm, cushion’s length = 46cm, handrest’s height = 22 cm, handrest’s length = 30 cm, backrest’s height = 38 cm, backrest’s wide = 43 cm, cushion’s foam thickness = 4 cm, backrest’s foam thickness = 4 cm; 2 Prototype desk N, length = 50 cm, wide = 66 cm, back section’s height = 85 cm, front section’s height = 75 cm, footrest from fl oor surfaces = 10 cm, drawer’s height = 10cm, front bamper’s height = 40 cm, and table’s angle = 10o. Discussion: An ergonomic desks and chairs are very important for students at school, it will help teaching learning process run well and comfortable. The measurement of desk and chair must be reviewed after fi ve years, because of student’s anthropometric development. So then students will feel no fatigue. Keywords: ergonomy, senior high school student’s seating position

DOE Chair of Excellence Professorship in Environmental Disciplines

Energy Technology Data Exchange (ETDEWEB)

Shoou-Yuh Chang

2013-01-31

The United States (US) nuclear weapons program during the Cold War left a legacy of radioactive, hazardous, chemical wastes and facilities that may seriously harm the environment and people even today. Widespread public concern about the environmental pollution has created an extraordinary demand for the treatment and disposal of wastes in a manner to protect the public health and safety. The pollution abatement and environmental protection require an understanding of technical, regulatory, economic, permitting, institutional, and public policy issues. Scientists and engineers have a major role in this national effort to clean our environment, especially in developing alternative solutions and evaluation criteria and designing the necessary facilities to implement the solutions. The objective of the DOE Chair of Excellence project is to develop a high quality educational and research program in environmental engineering at North Carolina A&T State University (A&T). This project aims to increase the number of graduate and undergraduate students trained in environmental areas while developing a faculty concentrated in environmental education and research. Although A&T had a well developed environmental program prior to the Massie Chair grant, A&T's goal is to become a model of excellence in environmental engineering through the program's support. The program will provide a catalyst to enhance collaboration of faculty and students among various engineering departments to work together in a focus research area. The collaboration will be expanded to other programs at A&T. The past research focus areas include: hazardous and radioactive waste treatment and disposal fate and transport of hazardous chemicals in the environment innovative technologies for hazardous waste site remediation pollution prevention Starting from 2005, the new research focus was in the improvement of accuracy for radioactive contaminant transport models by ensemble based data assimilation

Perfect Lighting for Facial Photography in Aesthetic Surgery: Ring Light.

Science.gov (United States)

Dölen, Utku Can; Çınar, Selçuk

2016-04-01

Photography is indispensable for plastic surgery. On-camera flashes can result in bleached out detail and colour. This is why most of the plastic surgery clinics prefer studio lighting similar to professional photographers'. In this article, we want to share a simple alternative to studio lighting that does not need extra space: Ring light. We took five different photographs of the same person with five different camera and lighting settings: Smartphone and ring light; point and shoot camera and on-camera flash; point and shoot camera and studio lighting; digital single-lens reflex (DLSR) camera and studio lighting; DSLR and ring light. Then, those photographs were assessed objectively with an online survey of five questions answered by three distinct populations: plastic surgeons (n: 28), professional portrait photographers (n: 24) and patients (n: 22) who had facial aesthetic procedures. Compared to the on-camera flash, studio lighting better showed the wrinkles of the subject. The ring light facilitated the perception of the wrinkles by providing homogenous soft light in a circular shape rather than bursting flashes. The combination of a DSLR camera and ring light gave the oldest looking subject according to 64 % of responders. The DSLR camera and the studio lighting demonstrated the youngest looking subject according to 70 % of the responders. The majority of the responders (78 %) chose the combination of DSLR camera and ring light that exhibited the wrinkles the most. We suggest using a ring light to obtain well-lit photographs without loss of detail, with any type of cameras. However, smartphones must be avoided if standard pictures are desired. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266.

Development and evaluation of accelerated drug release testing methods for a matrix-type intravaginal ring.

Science.gov (United States)

Externbrink, Anna; Eggenreich, Karin; Eder, Simone; Mohr, Stefan; Nickisch, Klaus; Klein, Sandra

2017-01-01

Accelerated drug release testing is a valuable quality control tool for long-acting non-oral extended release formulations. Currently, several intravaginal ring candidates designed for the long-term delivery of steroids or anti-infective drugs are being in the developing pipeline. The present article addresses the demand for accelerated drug release methods for these formulations. We describe the development and evaluation of accelerated release methods for a steroid releasing matrix-type intravaginal ring. The drug release properties of the formulation were evaluated under real-time and accelerated test conditions. Under real-time test conditions drug release from the intravaginal ring was strongly affected by the steroid solubility in the release medium. Under sufficient sink conditions that were provided in release media containing surfactants drug release was Fickian diffusion driven. Both temperature and hydro-organic dissolution media were successfully employed to accelerate drug release from the formulation. Drug release could be further increased by combining the temperature effect with the application of a hydro-organic release medium. The formulation continued to exhibit a diffusion controlled release kinetic under the investigated accelerated conditions. Moreover, the accelerated methods were able to differentiate between different prototypes of the intravaginal ring that exhibited different release profiles under real-time test conditions. Overall, the results of the present study indicate that both temperature and hydro-organic release media are valid parameters for accelerating drug release from the intravaginal ring. Variation of either a single or both parameters yielded release profiles that correlated well with real-time release. Copyright © 2016 Elsevier B.V. All rights reserved.

Ring faults and ring dikes around the Orientale basin on the Moon.

Science.gov (United States)

Andrews-Hanna, Jeffrey C; Head, James W; Johnson, Brandon; Keane, James T; Kiefer, Walter S; McGovern, Patrick J; Neumann, Gregory A; Wieczorek, Mark A; Zuber, Maria T

2018-08-01

The Orientale basin is the youngest and best-preserved multiring impact basin on the Moon, having experienced only modest modification by subsequent impacts and volcanism. Orientale is often treated as the type example of a multiring basin, with three prominent rings outside of the inner depression: the Inner Rook Montes, the Outer Rook Montes, and the Cordillera. Here we use gravity data from NASA's Gravity Recovery and Interior Laboratory (GRAIL) mission to reveal the subsurface structure of Orientale and its ring system. Gradients of the gravity data reveal a continuous ring dike intruded into the Outer Rook along the plane of the fault associated with the ring scarp. The volume of this ring dike is ~18 times greater than the volume of all extrusive mare deposits associated with the basin. The gravity gradient signature of the Cordillera ring indicates an offset along the fault across a shallow density interface, interpreted to be the base of the low-density ejecta blanket. Both gravity gradients and crustal thickness models indicate that the edge of the central cavity is shifted inward relative to the equivalent Inner Rook ring at the surface. Models of the deep basin structure show inflections along the crust-mantle interface at both the Outer Rook and Cordillera rings, indicating that the basin ring faults extend from the surface to at least the base of the crust. Fault dips range from 13-22° for the Cordillera fault in the northeastern quadrant, to 90° for the Outer Rook in the northwestern quadrant. The fault dips for both outer rings are lowest in the northeast, possibly due to the effects of either the direction of projectile motion or regional gradients in pre-impact crustal thickness. Similar ring dikes and ring faults are observed around the majority of lunar basins.

Groups, rings, modules

CERN Document Server

Auslander, Maurice

2014-01-01

This classic monograph is geared toward advanced undergraduates and graduate students. The treatment presupposes some familiarity with sets, groups, rings, and vector spaces. The four-part approach begins with examinations of sets and maps, monoids and groups, categories, and rings. The second part explores unique factorization domains, general module theory, semisimple rings and modules, and Artinian rings. Part three's topics include localization and tensor products, principal ideal domains, and applications of fundamental theorem. The fourth and final part covers algebraic field extensions

Saturn's Rings Edge-on

Science.gov (United States)

1995-01-01

In one of nature's most dramatic examples of 'now-you see-them, now-you-don't', NASA's Hubble Space Telescope captured Saturn on May 22, 1995 as the planet's magnificent ring system turned edge-on. This ring-plane crossing occurs approximately every 15 years when the Earth passes through Saturn's ring plane.For comparison, the top picture was taken by Hubble on December 1, 1994 and shows the rings in a more familiar configuration for Earth observers.The bottom picture was taken shortly before the ring plane crossing. The rings do not disappear completely because the edge of the rings reflects sunlight. The dark band across the middle of Saturn is the shadow of the rings cast on the planet (the Sun is almost 3 degrees above the ring plane.) The bright stripe directly above the ring shadow is caused by sunlight reflected off the rings onto Saturn's atmosphere. Two of Saturn's icy moons are visible as tiny starlike objects in or near the ring plane. They are, from left to right, Tethys (slightly above the ring plane) and Dione.This observation will be used to determine the time of ring-plane crossing and the thickness of the main rings and to search for as yet undiscovered satellites. Knowledge of the exact time of ring-plane crossing will lead to an improved determination of the rate at which Saturn 'wobbles' about its axis (polar precession).Both pictures were taken with Hubble's Wide Field Planetary Camera 2. The top image was taken in visible light. Saturn's disk appears different in the bottom image because a narrowband filter (which only lets through light that is not absorbed by methane gas in Saturn's atmosphere) was used to reduce the bright glare of the planet. Though Saturn is approximately 900 million miles away, Hubble can see details as small as 450 miles across.The Wide Field/Planetary Camera 2 was developed by the Jet Propulsion Laboratory and managed by the Goddard Spaced Flight Center for NASA's Office of Space Science.This image and other images and

PREFACE: Proceedings of the 7th Edoardo Amaldi Conference on Gravitational Waves (Amaldi7), Sydney Convention and Exhibition Centre, Darling Harbour, Sydney, Australia, 8 14 July 2007

Science.gov (United States)

Scott, Susan M.; McClelland, David E.

2008-07-01

18 Scientific Organising Committee, GWIC and the Local Organising Committee for all their hard work in putting together these very successful combined conferences, which attracted 520 participants. Many of the practical aspects of the organisation were handled by the event management company Conexion, and their professionalism, expertise and dedication were greatly appreciated. Finally, we would like to thank all the participants for their lively and colourful contributions to making these conferences a success. Susan M Scott Chair, Local Organising Committee David E McClelland Deputy Chair, Local Organising Committee Centre for Gravitational Physics, The Australian National University, Australia Guest Editors Participants gather prior to opening ceremony Participants gather prior to opening ceremony Participants entering auditorium for opening ceremony Participants entering auditorium for opening ceremony Chair of Local Organising Committee Susan M Scott opening ceremony Chair of Local Organising Committee Susan M Scott opening ceremony President of the International Society on General Relativity and Gravitation Clifford M Will opening ceremony President of the International Society on General Relativity and Gravitation Clifford M Will opening ceremony Amusing moment at opening ceremony Amusing moment at opening ceremony Chair of the Gravitational Wave International Committee James Hough opening ceremony Chair of the Gravitational Wave International Committee James Hough opening ceremony Welcome to the land by traditional land owner Welcome to the land by traditional land owner Welcome to the land by traditional land owner Welcome to the land by traditional land owner First plenary speaker Stan E Whitcomb First plenary speaker Stan E Whitcomb Exhibition booth Australian National University College of Science Kimberley Heenan (left), Lachlan McCalman (right) Exhibition booth Australian National University College of Science Kimberley Heenan (left), Lachlan Mc

Persistent current and transmission probability in the Aharonov-Bohm ring with an embedded quantum dot

International Nuclear Information System (INIS)

Wu Suzhi; Li Ning; Jin Guojun; Ma Yuqiang

2008-01-01

Persistent current and transmission probability in the Aharonov-Bohm (AB) ring with an embedded quantum dot (QD) are studied using the technique of the scattering matrix. For the first time, we find that the persistent current can arise in the absence of magnetic flux in the ring with an embedded QD. The persistent current and the transmission probability are sensitive to the lead-ring coupling and the short-range potential barrier. It is shown that increasing the lead-ring coupling or the short-range potential barrier causes the suppression of the persistent current and the increasing resonance width of the transmission probability. The effect of the potential barrier on the number of the transmission peaks is also investigated. The dependence of the persistent current and the transmission probability on the magnetic flux exhibits a periodic property with period of the flux quantum

Colloidal-Quantum-Dot Ring Lasers with Active Color Control.

Science.gov (United States)

le Feber, Boris; Prins, Ferry; De Leo, Eva; Rabouw, Freddy T; Norris, David J

2018-02-14

To improve the photophysical performance of colloidal quantum dots for laser applications, sophisticated core/shell geometries have been developed. Typically, a wider bandgap semiconductor is added as a shell to enhance the gain from the quantum-dot core. This shell is designed to electronically isolate the core, funnel excitons to it, and reduce nonradiative Auger recombination. However, the shell could also potentially provide a secondary source of gain, leading to further versatility in these materials. Here we develop high-quality quantum-dot ring lasers that not only exhibit lasing from both the core and the shell but also the ability to switch between them. We fabricate ring resonators (with quality factors up to ∼2500) consisting only of CdSe/CdS/ZnS core/shell/shell quantum dots using a simple template-stripping process. We then examine lasing as a function of the optical excitation power and ring radius. In resonators with quality factors >1000, excitons in the CdSe cores lead to red lasing with thresholds at ∼25 μJ/cm 2 . With increasing power, green lasing from the CdS shell emerges (>100 μJ/cm 2 ) and then the red lasing begins to disappear (>250 μJ/cm 2 ). We present a rate-equation model that can explain this color switching as a competition between exciton localization into the core and stimulated emission from excitons in the shell. Moreover, by lowering the quality factor of the cavity we can engineer the device to exhibit only green lasing. The mechanism demonstrated here provides a potential route toward color-switchable quantum-dot lasers.

The Rotating Ring-Ring Electrode. Theory and Experiment

NARCIS (Netherlands)

Kuiken, H.K.; Bakkers, E.P.A.M.; Ligthart, H.; Kelly, J.J.

2000-01-01

A model is presented for the rotating ring-ring electrode. Although the electrode is defined by four characteristic lengths, it is shown that the collection efficiency depends on only two dimensionless parameters. A simple relationship between these and the corresponding parameters for the rotating

Crescentic and ring-shaped opacities. CT features in two cases of bronchiolitis obliterans organizing pneumonia (BOOP)

International Nuclear Information System (INIS)

Voloudaki, A.E.; Bouros, D.E.; Froudarakis, M.E.; Datseris, G.E.; Apostolaki, E.G.; Gourtsoyiannis, N.C.

1996-01-01

Two cases of idiopathic bronchilitis obliterans organizing pneumonia (BOOP) with unusual CT findings are presented. On CT both cases exhibited crescentic and ring-shaped opacities, surrounding areas of groundglass attenuation, and associated with a nodular pattern in one patient and airspace consolidations in the second patient. CT-pathologic correlation dislosed that the central areas of groundglass attenuation corresponded to alveolar septal inflammation, in contrast to the denser periphery where granulomatous tissue in peripheral airspaces predominated. In the broad spectrum of CT findings, BOOP can exhibit specific CT features with regard to the crescentic or ring-shaped opacities with a central groundglass attenuation area. Since these features have not been described in any other disease, they might be characteristic features for the diagnosis of BOOP. (orig.)

Bien-être animal en élevage de poulets de chair

OpenAIRE

Arnould, Cécile; Leterrier, Christine

2007-01-01

L’élevage des poulets de chair s’est intensifié ces dernières décennies et de nombreux problèmes de bien-être animal sont apparus, en particulier chez les poulets standards et les reproducteurs à l’origine de ces croisements. Les poulets standards ont un niveau d’activité très faible et ils sont notamment atteints de troubles locomoteurs, de lésions cutanées et de pathologies cardio-vasculaires. Des solutions à ces altérations du bien-être peuvent être apportées en contrôlant des facteurs lié...

Product design and development for dinner chair of Kansei Engineering

Directory of Open Access Journals (Sweden)

Sirichai Yodwangjai

2014-06-01

Full Text Available This research investigated the customer’s perception and product properties. The semantic differential method was employed to examine the relationship between customer’s perception and product properties. Fifty-six dinner chairs are selected from website, magazine and publishing and 10 SD words. The product properties divided 8 groups and 34 sub-groups. The new model created base on Quantification Theory Type 1. The research results show 3 high perceptions: comfortable, soft and modern. The research is expected to help support the designer to design a new model that satisfied the customer’s perception.

Wear Analysis of Top Piston Ring to Reduce Top Ring Reversal Bore Wear

Directory of Open Access Journals (Sweden)

P. Ilanthirayan

2017-12-01

Full Text Available The piston rings are the most important part in engine which controls the lubricating oil consumption and blowby of the gases. The lubricating film of oil is provided to seal of gases towards crankcase and also to give smooth friction free translatory motion between rings and liner. Of the three rings present top ring is more crucial as it does the main work of restricting gases downwards the crankcase. Boundary lubrication is present at the Top dead centre (TDC and Bottom dead centre (BDC of the liner surface. In addition to this, top ring is exposed to high temperature gases which makes the oil present near the top ring to get evaporated and decreasing its viscosity, making metal-metal contact most of the time. Due to this at TDC, excess wear happens on the liner which is termed as Top ring reversal bore wear. The wear rate depends upon many parameters such as lubrication condition, viscosity index, contact type, normal forces acting on ring, geometry of ring face, surface roughness, material property. The present work explores the wear depth for different geometries of barrel ring using Finite Element model with the help of Archard wear law and the same is validated through experimentation. The study reveals that Asymmetric barrel rings have less contact pressure which in turn reduces the wear at Top dead centre.

(4bS,8aS-1-Isopropyl-4b,8,8-trimethyl-4b,5,6,7,8,8a,9,10-octahydrophenanthren-2-yl acetate

Directory of Open Access Journals (Sweden)

Radouane Oubabi

2014-03-01

Full Text Available The hemisynthesis of the title compound, C22H32O2, was carried out through direct acetylation reaction of the naturally occurring diterpene totarol [systematic name: (4bS,8aS-4b,8,8-trimethyl-1-propan-2-yl-5,6,7,8a,9,10-hexahydrophenanthren-2-ol]. The molecule is built up from three fused six membered rings, one saturated and two unsaturated. The central unsaturated ring has a half-chair conformation, whereas the other unsaturated ring displays a chair conformation. The absolute configuration is deduced from the chemical pathway. The value of the Hooft parameter [−0.10 (6] allowed this absolute configuration to be confirmed.

(3S,4S)-3-Ethyl-4-hydr-oxy-3-(3-methoxy-phen-yl)-1-methyl-azepan-1-ium d-tartrate dihydrate.

Science.gov (United States)

Wang, Xing-Hai; Chao, Bo; Qiu, Zhui-Bai

2008-04-02

In the title compound, C(16)H(26)NO(2) (+)·C(4)H(5)O(6) (-)·2H(2)O, a meptaz-inol derivative, three C atoms of the azepane ring are disordered over two positions, with site-occupancy factors of 0.80 and 0.20; the major disorder component adopts a twist-chair conformation, while the minor component has a chair conformation. The benzene ring is axially substituted on the heterocyclic ring, resulting in a folded conformation of the cation. The absolute configuration was determined with reference to d-tartaric acid. The crystal structure is stabilized by an extensive network of intra- and inter-molecular O-H⋯O hydrogen bonds.

α-Costic anhydride

Directory of Open Access Journals (Sweden)

Moha Berraho

2010-03-01

Full Text Available The title compound [systematic name: 2-(4a,8-dimethyl-1,2,3,4,4a,5,6,8a-octahydronaphthalen-2-ylacrylic acid anhydride], C30H42O3, is a new isocostic anhydride which was synthesized from the aerial part of Inula Viscosa (L Aiton [or Dittrichia Viscosa (L Greuter]. The molecule adopts an essentially linear shape with two terminal fused-rings bridged by the anhydride group. The external rings have the same conformation (half-chair while each of the two inner rings has an almost ideal chair conformation. In the crystal, intermolecular C—H...O interactions link the molecules into a two-dimensional array in the bc plane.

Effect of B-ring substitution pattern on binding mode of propionamide selective androgen receptor modulators.

Science.gov (United States)

Bohl, Casey E; Wu, Zengru; Chen, Jiyun; Mohler, Michael L; Yang, Jun; Hwang, Dong Jin; Mustafa, Suni; Miller, Duane D; Bell, Charles E; Dalton, James T

2008-10-15

Selective androgen receptor modulators (SARMs) are essentially prostate sparing androgens, which provide therapeutic potential in osteoporosis, male hormone replacement, and muscle wasting. Herein we report crystal structures of the androgen receptor (AR) ligand-binding domain (LBD) complexed to a series of potent synthetic nonsteroidal SARMs with a substituted pendant arene referred to as the B-ring. We found that hydrophilic B-ring para-substituted analogs exhibit an additional region of hydrogen bonding not seen with steroidal compounds and that multiple halogen substitutions affect the B-ring conformation and aromatic interactions with Trp741. This information elucidates interactions important for high AR binding affinity and provides new insight for structure-based drug design.

PREFACE: Special section on vortex rings Special section on vortex rings

Science.gov (United States)

Fukumoto, Yasuhide

2009-10-01

This special section of Fluid Dynamics Research includes five articles on vortex rings in both classical and quantum fluids. The leading scientists of the field describe the trends in and the state-of-the-art development of experiments, theories and numerical simulations of vortex rings. The year 2008 was the 150th anniversary of 'vortex motion' since Hermann von Helmholtz opened up this field. In 1858, Helmholtz published a paper in Crelle's Journal which put forward the concept of 'vorticity' and made the first analysis of vortex motion. Fluid mechanics before that was limited to irrotational motion. In the absence of vorticity, the motion of an incompressible homogeneous fluid is virtually equivalent to a rigid-body motion in the sense that the fluid motion is determined once the boundary configuration is specified. Helmholtz proved, among other things, that, without viscosity, a vortex line is frozen into the fluid. This Helmholtz's law immediately implies the preservation of knots and links of vortex lines and its implication is enormous. One of the major trends of fluid mechanics since the latter half of the 20th century is to clarify the topological meaning of Helmholtz's law and to exploit it to develop theoretical and numerical methods to find the solutions of the Euler equations and to develop experimental techniques to gain an insight into fluid motion. Vortex rings are prominent coherent structures in a variety of fluid motions from the microscopic scale, through human and mesoscale to astrophysical scales, and have attracted people's interest. The late professor Philip G Saffman (1981) emphasized the significance of studies on vortex rings. One particular motion exemplifies the whole range of problems of vortex motion and is also a commonly known phenomenon, namely the vortex ring or smoke ring. Vortex rings are easily produced by dropping drops of one liquid into another, or by puffing fluid out of a hole, or by exhaling smoke if one has the skill

Vortex rings

CERN Document Server

Akhmetov, D G

2009-01-01

This text on vortex rings covers their theoretical foundation, systematic investigations, and practical applications such as the extinction of fires at gushing oil wells. It pays special attention to the formation and motion of turbulent vortex rings.

FUZZY RINGS AND ITS PROPERTIES

Directory of Open Access Journals (Sweden)

Karyati Karyati

2017-01-01

  One of algebraic structure that involves a binary operation is a group that is defined  an un empty set (classical with an associative binary operation, it has identity elements and each element has an inverse. In the structure of the group known as the term subgroup, normal subgroup, subgroup and factor group homomorphism and its properties. Classical algebraic structure is developed to algebraic structure fuzzy by the researchers as an example semi group fuzzy and fuzzy group after fuzzy sets is introduced by L. A. Zadeh at 1965. It is inspired of writing about semi group fuzzy and group of fuzzy, a research on the algebraic structure of the ring is held with reviewing ring fuzzy, ideal ring fuzzy, homomorphism ring fuzzy and quotient ring fuzzy with its properties. The results of this study are obtained fuzzy properties of the ring, ring ideal properties fuzzy, properties of fuzzy ring homomorphism and properties of fuzzy quotient ring by utilizing a subset of a subset level  and strong level  as well as image and pre-image homomorphism fuzzy ring.   Keywords: fuzzy ring, subset level, homomorphism fuzzy ring, fuzzy quotient ring

Interdecadal modulation of the relationship between ENSO, IPO and precipitation: insights from tree rings in Australia

Energy Technology Data Exchange (ETDEWEB)

Heinrich, Ingo [School of Resources, Environment and Society, Australian National University, Canberra, ACT (Australia); Helmholtz Centre Potsdam, GFZ German Research Centre for Geosciences, Climate Dynamics and Landscape Evolution, Potsdam (Germany); Weidner, Kathrin [Helmholtz Centre Potsdam, GFZ German Research Centre for Geosciences, Climate Dynamics and Landscape Evolution, Potsdam (Germany); Forschungszentrum Juelich GmbH, Institute for Chemistry and Dynamics of the Geosphere, Juelich (Germany); Helle, Gerhard [Helmholtz Centre Potsdam, GFZ German Research Centre for Geosciences, Climate Dynamics and Landscape Evolution, Potsdam (Germany); Vos, Heinz [Forschungszentrum Juelich GmbH, Institute for Chemistry and Dynamics of the Geosphere, Juelich (Germany); Lindesay, Janette; Banks, John C.G. [School of Resources, Environment and Society, Australian National University, Canberra, ACT (Australia)

2009-07-15

Australian climate-proxy reconstructions based on tree rings from tropical and subtropical forests have not been achieved so far due to the rarity of species producing anatomically distinct annual growth rings. Our study identifies the Australian Red Cedar (Toona ciliata) as one of the most promising tree species for tree-ring research in Australasia because this species exhibits distinct annual tree rings, a prerequisite for high quality tropical dendroclimatology. Based on these preliminary studies, we were able, for the first time in subtropical and tropical Australia, to develop a statistically robust, precisely dated and annually resolved chronology back to AD1854. We show that the variability in ring widths of T. ciliata is mainly dependent on annual precipitation. The developed proxy data series contains both high- and low-frequency climate signals which can be associated with the El Nino Southern Oscillation (ENSO) and the Interdecadal Pacific Oscillation (IPO). A comparison of different data sets (Brisbane precipitation, tree rings, coral luminescence record from the Great Barrier Reef, ENSO and IPO) revealed non-stationary correlation patterns throughout the twentieth century but little instability between the new tree-ring chronology and Brisbane precipitation. (orig.)

Polarization Insensitivity in Double-Split Ring and Triple-Split Ring Terahertz Resonators

International Nuclear Information System (INIS)

Wu Qian-Nan; Lan Feng; Tang Xiao-Pin; Yang Zi-Qiang

2015-01-01

A modified double-split ring resonator and a modified triple-split ring resonator, which offer polarization-insensitive performance, are investigated, designed and fabricated. By displacing the two gaps of the conventional double-split ring resonator away from the center, the second resonant frequency for the 0° polarized wave and the resonant frequency for the 90° polarized wave become increasingly close to each other until they are finally identical. Theoretical and experimental results show that the modified double-split ring resonator and the modified triple-split ring resonator are insensitive to different polarized waves and show strong resonant frequency dips near 433 and 444 GHz, respectively. The results of this work suggest new opportunities for the investigation and design of polarization-dependent terahertz devices based on split ring resonators. (paper)

THE 30-S CHAIR STAND TEST AND HABITUAL MOBILITY PREDICT REHABILITATION NEEDS AFTER ACUTE ADMISSION

DEFF Research Database (Denmark)

Hansen Bruun, Inge; Nørgaard, Birgitte; Backer Mogensen, Christian

2016-01-01

that no approval is needed. Purpose The study aimed to evaluate if the 30 Second Chair Stand test (30s-CST) combined with other variables was able to predict rehabilitation needs among acutely admitted elderly patient. Low physical ability were defined as a 30s-CST–score ≤ 8 one month after admission......Relevance: Responding to Changing Population Needs. The elderly population is growing and represents an increasing proportion of elderly admitted to a short stay unit in an emergency department (ED). One month after admission a fifth of the elderly patients have low physical ability and therefore...... were included if oriented in time and place, able to sit on a chair and have a 30s-CST–score ≤ 8. Baseline data were collected within the first 48 hours of admission and the 30s-CST again one month after admission. All risk factors are identified in the literature. The 30s-CST is used at community...

Persistent currents in metallic rings containing a quantum dot

International Nuclear Information System (INIS)

Machura, Lukasz; Łuczka, Jerzy

2015-01-01

Currents in metallic rings with a quantum dot are studied in the framework of a Langevin equation for a magnetic flux passing through the ring. Two scenarios are considered: one in which thermal fluctuations of the dissipative part of the current are modeled by classical Johnson–Nyquist noise and one in which quantum character of thermal fluctuations is taken into account in terms of a quantum Smoluchowski equation. The impact of the amplitude and phase of the transmission coefficient of the electron through a quantum dot on current characteristics is analyzed. In tailored parameter regimes, both scenarios can exhibit the transition from para- to diamagnetic response of the current versus external magnetic flux. The type of response is more robust to changes of the amplitude of the transmission coefficient and more sensitive to changes of the phase around some values. - Highlights: • Langevin dynamics of the magnetic flux for classical and quantum Smoluchowski regimes. • Current-flux characteristics vs the amplitude and phase of the transmission coefficient. • Crucial role of the phase of the transmission coefficient. • Contribution to the development of effective control of current in mesoscopic rings

Physiological Motion Axis for the Seat of a Dynamic Office Chair

Science.gov (United States)

Kuster, Roman Peter; Bauer, Christoph Markus; Oetiker, Sarah; Kool, Jan

2016-01-01

Objective The aim of this study was to determine and verify the optimal location of the motion axis (MA) for the seat of a dynamic office chair. Background A dynamic seat that supports pelvic motion may improve physical well-being and decrease the risk of sitting-associated disorders. However, office work requires an undisturbed view on the work task, which means a stable position of the upper trunk and head. Current dynamic office chairs do not fulfill this need. Consequently, a dynamic seat was adapted to the physiological kinematics of the human spine. Method Three-dimensional motion tracking in free sitting helped determine the physiological MA of the spine in the frontal plane. Three dynamic seats with physiological, lower, and higher MA were compared in stable upper body posture (thorax inclination) and seat support of pelvic motion (dynamic fitting accuracy). Spinal kinematics during sitting and walking were compared. Results The physiological MA was at the level of the 11th thoracic vertebra, causing minimal thorax inclination and high dynamic fitting accuracy. Spinal motion in active sitting and walking was similar. Conclusion The physiological MA of the seat allows considerable lateral flexion of the spine similar to walking with a stable upper body posture and a high seat support of pelvic motion. Application The physiological MA enables lateral flexion of the spine, similar to walking, without affecting stable upper body posture, thus allowing active sitting while focusing on work. PMID:27150530

Planetary Rings: a Brief History of Observation and Theory

Science.gov (United States)

Nicholson, P. D.

2000-05-01

Over several centuries, and extending down to today, the ring systems encircling Saturn and the other jovian planets have provided an endless source of speculation and theorizing for astronomers, theologians, and physicists. In the past two decades they have also become a testing ground for dynamical models of more distant astrophysical disks, such as those which surround protostars and even the stellar disks of spiral galaxies. I will review some of the early theories, and their sometimes rude confrontation with observational data, starting with Christiaan Huygens and touching on seminal contributions by Laplace, Bessel, Maxwell, Barnard, Russell (of H-R diagram fame) and Jeffreys. In the modern era, observations at infrared and radio wavelengths have revealed Saturn's rings to be composed of large chunks of almost pure water ice, and to have a vertical thickness measured in tens of meters. A renaissance in planetary rings studies occurred in the period 1977--1981, first with the discoveries of the narrow, dark and non-circular rings of Uranus and the tenuous jovian ring system, and capped off by the spectacular images returned during the twin Voyager flybys of Saturn. Along with the completely unsuspected wealth of detail these observations revealed came an unwelcome problem: are the rings ancient or are we privileged to live at a special time in history? The answer to this still-vexing question may lie in the complex gravitational interactions recent studies have revealed between the rings themselves and their retinues of attendant satellites. Between the four known ring systems, we see elegant examples of Lindblad and corotation resonances (first invoked in the galactic context), electromagnetic resonances, many-armed spiral density waves and bending waves, narrow ringlets which exhibit internal modes due to a collective instability, sharp-edged gaps maintained via tidal torques from embedded moonlets, and tenuous dust belts created by meteoroid impact onto

An empirical study of preferred settings for lumbar support on adjustable office chairs.

Science.gov (United States)

Coleman, N; Hull, B P; Ellitt, G

1998-04-01

The preferred settings for lumbar support height and depth of 43 male and 80 female office workers were investigated. All subjects were equipped with identical modern office chairs with foam-padded backrests adjustable in both height and depth. Measurements of lumbar support settings were recorded in the workplace, outside of working hours, on four different occasions, over a 5 week period. Preferred lumbar support height and depth settings extended to both extremes of the adjustment range. The mean preferred height setting was 190 mm above the compressed seat surface. The mean depth setting (horizontal distance from front of seat to lumbar support point) was 387 mm. A regression model examining the effects of standing height, Body Mass Index (BMI) and gender on mean preferred lumbar support height showed a significant relationship between preferred height and BMI. Higher lumbar supports were chosen by subjects with greater BMIs. Gender and standing height were not associated with preferred lumbar support height settings. Preferred lumbar support depth was not significantly associated with standing height, gender or BMI. Older subjects were more likely to readjust their lumbar support from a disrupted position than younger subjects, indicating that older users are more sensitive to the position of their lumbar support. Subjects who reported recent back pain or discomfort that they believed to be associated with their chair or office work were found to set their lumbar support significantly closer to the front of the seat, probably to ensure greater support for their back. Based on the evidence that a high proportion of users do make adjustments to the height and depth of their lumbar support, and the finding that different groups of users, with different physical characteristics, adjust the position of their lumbar support in distinct and predictable ways, the researchers conclude that office chairs with traditional padded fixed-height lumbar supports are unlikely

Radiology textbook for dental chair assistants

International Nuclear Information System (INIS)

Diewald, H.

1990-01-01

One of the goals of the X-ray Ordinance (of January 8, 1987) being to protect individuals or the population at large against the harmful effects of X-rays, every dentist using X-ray equipment in his practice has to acquire the necessary expert knowledge in radiation protection. The same applies to dental chair assistants, who under permanent supervision of the responsible dentist, carry out radiological examinations. Assistants have to give proof of the necessary training in radiation protection in connection with the methods and equipment applied in the practice. The training consists of a theoretical and practical part tailored to the assistants' practical work, and lectures on radiological hazards and the relevant radiation protection measures. The subject matters of the courses in radiation protection are defined by the X-ray Ordinance, as well as the examination. The author of this textbook has collected a list of examination questions and problems taken from the practice. They completely cover the various subject matters of dental radiology so that the required knowledge can be acquired, which will ensure in practice good image quality and optimal radiation protection. (orig./HP) [de

Lord of the Rings – Return of the King: Swift-XRT observations of dust scattering rings around V404 Cygni

OpenAIRE

Beardmore, A.P.; Willingale, R.; Kuulkers, E.; Altamirano, D.; Motta, S.E.; Osborne, J.P.; Page, K.L.; Sivakoff, G.R.

2016-01-01

On 2015 June 15, the black hole X-ray binary V404 Cygni went into outburst, exhibiting extreme X-ray variability which culminated in a final flare on June 26. Over the following days, the Swift-X-ray Telescope detected a series of bright rings, comprising five main components that expanded and faded with time, caused by X-rays scattered from the otherwise unobservable dust layers in the interstellar medium in the direction of the source. Simple geometrical modelling of the rings’ angular evol...

RINGED ACCRETION DISKS: EQUILIBRIUM CONFIGURATIONS

Energy Technology Data Exchange (ETDEWEB)

Pugliese, D.; Stuchlík, Z., E-mail: d.pugliese.physics@gmail.com, E-mail: zdenek.stuchlik@physics.cz [Institute of Physics and Research Centre of Theoretical Physics and Astrophysics, Faculty of Philosophy and Science, Silesian University in Opava, Bezručovo náměstí 13, CZ-74601 Opava (Czech Republic)

2015-12-15

We investigate a model of a ringed accretion disk, made up by several rings rotating around a supermassive Kerr black hole attractor. Each toroid of the ringed disk is governed by the general relativity hydrodynamic Boyer condition of equilibrium configurations of rotating perfect fluids. Properties of the tori can then be determined by an appropriately defined effective potential reflecting the background Kerr geometry and the centrifugal effects. The ringed disks could be created in various regimes during the evolution of matter configurations around supermassive black holes. Therefore, both corotating and counterrotating rings have to be considered as being a constituent of the ringed disk. We provide constraints on the model parameters for the existence and stability of various ringed configurations and discuss occurrence of accretion onto the Kerr black hole and possible launching of jets from the ringed disk. We demonstrate that various ringed disks can be characterized by a maximum number of rings. We present also a perturbation analysis based on evolution of the oscillating components of the ringed disk. The dynamics of the unstable phases of the ringed disk evolution seems to be promising in relation to high-energy phenomena demonstrated in active galactic nuclei.

Stirling engine piston ring

Science.gov (United States)

Howarth, Roy B.

1983-01-01

A piston ring design for a Stirling engine wherein the contact pressure between the piston and the cylinder is maintained at a uniform level, independent of engine conditions through a balancing of the pressure exerted upon the ring's surface and thereby allowing the contact pressure on the ring to be predetermined through the use of a preloaded expander ring.

Physics of quantum rings

International Nuclear Information System (INIS)

Fomin, Vladimir M.

2014-01-01

Presents the new class of materials of quantum rings. Provides an elemental basis for low-cost high-performance devices promising for electronics, optoelectronics, spintronics and quantum information processing. Explains the physical properties of quantum rings to cover a gap in scientific literature. Presents the application of most advanced nanoengineering and nanocharacterization techniques. This book deals with a new class of materials, quantum rings. Innovative recent advances in experimental and theoretical physics of quantum rings are based on the most advanced state-of-the-art fabrication and characterization techniques as well as theoretical methods. The experimental efforts allow to obtain a new class of semiconductor quantum rings formed by capping self-organized quantum dots grown by molecular beam epitaxy. Novel optical and magnetic properties of quantum rings are associated with non-trivial topologies at the nanoscale. An adequate characterization of quantum rings is possible on the basis of modern characterization methods of nanostructures, such as Scanning Tunneling Microscopy. A high level of complexity is demonstrated to be needed for a dedicated theoretical model to adequately represent the specific features of quantum rings. The findings presented in this book contribute to develop low-cost high-performance electronic, spintronic, optoelectronic and information processing devices based on quantum rings.

Cell-autonomous correction of ring chromosomes in human induced pluripotent stem cells

Science.gov (United States)

Bershteyn, Marina; Hayashi, Yohei; Desachy, Guillaume; Hsiao, Edward C.; Sami, Salma; Tsang, Kathryn M.; Weiss, Lauren A.; Kriegstein, Arnold R.; Yamanaka, Shinya; Wynshaw-Boris, Anthony

2014-03-01

Ring chromosomes are structural aberrations commonly associated with birth defects, mental disabilities and growth retardation. Rings form after fusion of the long and short arms of a chromosome, and are sometimes associated with large terminal deletions. Owing to the severity of these large aberrations that can affect multiple contiguous genes, no possible therapeutic strategies for ring chromosome disorders have been proposed. During cell division, ring chromosomes can exhibit unstable behaviour leading to continuous production of aneuploid progeny with low viability and high cellular death rate. The overall consequences of this chromosomal instability have been largely unexplored in experimental model systems. Here we generated human induced pluripotent stem cells (iPSCs) from patient fibroblasts containing ring chromosomes with large deletions and found that reprogrammed cells lost the abnormal chromosome and duplicated the wild-type homologue through the compensatory uniparental disomy (UPD) mechanism. The karyotypically normal iPSCs with isodisomy for the corrected chromosome outgrew co-existing aneuploid populations, enabling rapid and efficient isolation of patient-derived iPSCs devoid of the original chromosomal aberration. Our results suggest a fundamentally different function for cellular reprogramming as a means of `chromosome therapy' to reverse combined loss-of-function across many genes in cells with large-scale aberrations involving ring structures. In addition, our work provides an experimentally tractable human cellular system for studying mechanisms of chromosomal number control, which is of critical relevance to human development and disease.

How does the blue-ringed octopus (Hapalochlaena lunulata) flash its blue rings?

Science.gov (United States)

Mäthger, Lydia M; Bell, George R R; Kuzirian, Alan M; Allen, Justine J; Hanlon, Roger T

2012-11-01

The blue-ringed octopus (Hapalochlaena lunulata), one of the world's most venomous animals, has long captivated and endangered a large audience: children playing at the beach, divers turning over rocks, and biologists researching neurotoxins. These small animals spend much of their time in hiding, showing effective camouflage patterns. When disturbed, the octopus will flash around 60 iridescent blue rings and, when strongly harassed, bite and deliver a neurotoxin that can kill a human. Here, we describe the flashing mechanism and optical properties of these rings. The rings contain physiologically inert multilayer reflectors, arranged to reflect blue-green light in a broad viewing direction. Dark pigmented chromatophores are found beneath and around each ring to enhance contrast. No chromatophores are above the ring; this is unusual for cephalopods, which typically use chromatophores to cover or spectrally modify iridescence. The fast flashes are achieved using muscles under direct neural control. The ring is hidden by contraction of muscles above the iridophores; relaxation of these muscles and contraction of muscles outside the ring expose the iridescence. This mechanism of producing iridescent signals has not previously been reported in cephalopods and we suggest that it is an exceptionally effective way to create a fast and conspicuous warning display.

α-Skew π-McCoy Rings

Directory of Open Access Journals (Sweden)

Areej M. Abduldaim

2013-01-01

Full Text Available As a generalization of α-skew McCoy rings, we introduce the concept of α-skew π-McCoy rings, and we study the relationships with another two new generalizations, α-skew π1-McCoy rings and α-skew π2-McCoy rings, observing the relations with α-skew McCoy rings, π-McCoy rings, α-skew Armendariz rings, π-regular rings, and other kinds of rings. Also, we investigate conditions such that α-skew π1-McCoy rings imply α-skew π-McCoy rings and α-skew π2-McCoy rings. We show that in the case where R is a nonreduced ring, if R is 2-primal, then R is an α-skew π-McCoy ring. And, let R be a weak (α,δ-compatible ring; if R is an α-skew π1-McCoy ring, then R is α-skew π2-McCoy.

VUV optical ring resonator for Duke storage ring free electron laser

Energy Technology Data Exchange (ETDEWEB)

Park, S.H.; Litvinenko, V.N.; Madey, J.M.J. [Duke Univ., Durham, NC (United States)] [and others

1995-12-31

The conceptual design of the multifaceted-mirror ring resonator for Duke storage ring VUV FEL is presented. The expected performance of the OK-4 FEL with ring resonator is described. We discuss in this paper our plans to study reflectivity of VUV mirrors and their resistivity to soft X-ray spontaneous radiation from OK-4 undulator.

Simple equations to predict concentric lower-body muscle power in older adults using the 30-second chair-rise test: a pilot study

Directory of Open Access Journals (Sweden)

Wesley N Smith

2010-07-01

Full Text Available Wesley N Smith1, Gianluca Del Rossi1, Jessica B Adams1, KZ Abderlarahman2, Shihab A Asfour2, Bernard A Roos1,3,4,5, Joseph F Signorile1,31Department of Exercise and Sport Sciences,2Department of Industrial Engineering, University of Miami, Coral Gables, FL, USA; 3Geriatric Research, Education, and Clinical Center, Bruce W Carter Department of Veterans Affairs Medical Center, Miami, FL, USA; 4Departments of Medicine and Neurology, University of Miami Miller School of Medicine, Miami, FL, USA; 5Stein Gerontological Institute, Miami Jewish Health Systems, Miami, FL, USAAbstract: Although muscle power is an important factor affecting independence in older adults, there is no inexpensive or convenient test to quantify power in this population. Therefore, this pilot study examined whether regression equations for evaluating muscle power in older adults could be derived from a simple chair-rise test. We collected data from a 30-second chair-rise test performed by fourteen older adults (76 ± 7.19 years. Average (AP and peak (PP power values were computed using data from force-platform and high-speed motion analyses. Using each participant’s body mass and the number of chair rises performed during the first 20 seconds of the 30-second trial, we developed multivariate linear regression equations to predict AP and PP. The values computed using these equations showed a significant linear correlation with the values derived from our force-platform and high-speed motion analyses (AP: R = 0.89; PP: R = 0.90; P < 0.01. Our results indicate that lower-body muscle power in fit older adults can be accurately evaluated using the data from the initial 20 seconds of a simple 30-second chair-rise test, which requires no special equipment, preparation, or setting.Keywords: instrumental activity of daily living, clinical test, elderly, chair-stand test, leg power

Interaction Region Design for a Ring-Ring LHeC

CERN Document Server

Thompson, L N S; Bernard, N R; Fitterer, M; Holzer, B; Klein, M; Kostka, P

2011-01-01

tively low energy and moderately high intensity provides high luminosity TeV-scale e-p collisions at one of the LHC interaction points, running simultaneously with existing experiments. Two designs are studied; an electron ring situated in the LHC tunnel, and an electron linac. The focus of this paper is on the ring design. Designing an e-p machine presents interesting accelerator physics and design challenges, particularly when considering the interaction region. These include coupled optics, beam separation and unconventional mini-beta focusing schemes. Designs are constrained by an array of interdependent factors, including beam-beam interaction, detector dimensions and acceptance, luminosity and synchrotron radiation. Methods of addressing these complex issues are discussed. The current designs for the LHeC Ring-Ring interaction region and long straight section are presented and discussed, in the context of the project goals and design challenges encountered. Future developments and work are also discusse...

Simulation of a Congress at the Chair of Biology II in Bioengineering

International Nuclear Information System (INIS)

Naranjo, A V; Reznichenco, V; Lopez, N; Hernandez, R; Bajinay, S

2007-01-01

This work has been developed in the Chair of Biology II, the curricular contents of which correspond to Human Anatomy. This subject is taught in the second semester of the second year of studies in Bioengineering. Our main objective is that the students attending the course may integrate the syllabus contents of Anatomy with those of other subjects in the career. Ever since 1998 we have organized a congress named Congreso Intracatedra de BiologIa II (Intra Chair Congress on Biology II). This is the last assignment in the semester and is compulsory for regular students of the subject. It consists in simulating a scientific congress with international characteristics. The guidelines for the congress are made known to the students at the beginning of the semester. In groups of up to three members, the students must undertake a work that relates aspects of Anatomy with Bioengineering. Students are expected to investigate on diagnostic and/or therapeutic technology in order to write a paper that must be accepted in advance of the event. The presentation of the work must be made through PowerPoint. The originality of the research work done and the wide range of topics selected are surprising. Problems are tackled from the standpoints both of the various medical fields and of bioengineering despite the fact that they are just students of the second year in Bioengineering

Machining variability impacts on the strength of a 'chair-side' CAD-CAM ceramic.

LENUS (Irish Health Repository)

Addison, Owen

2012-08-01

To develop a novel methodology to generate specimens for bi-axial flexure strength (BFS) determination from a \\'chair-side\\' CAD-CAM feldspathic ceramic with surface defect integrals analogous to the clinical state. The hypotheses tested were: BFS and surface roughness (R(a)) are independent of machining variability introduced by the renewal or deterioration of form-grinding tools and that a post-machining annealing cycle would significantly modify BFS.

Cerebral oxygenation in patients undergoing shoulder surgery in beach chair position: comparing general to regional anesthesia and the impact on neurobehavioral outcome.

Science.gov (United States)

Aguirre, J; Borgeat, A; Trachsel, T; Cobo Del Prado, I; De Andrés, J; Bühler, P

2014-02-01

Ischemic brain damage has been reported in healthy patients after beach chair position for surgery due to cerebral hypoperfusion. Near-infrared spectroscopy has been described as a non-invasive, continuous method to monitor cerebral oxygen saturation. However, its impact on neurobehavioral outcome comparing different anesthesia regimens has been poorly described. In this prospective, assessor-blinded study, 90 patients undergoing shoulder surgery in beach chair position following general (G-group, n=45) or regional anesthesia (R-group; n=45) were enrolled to assess the prevalence of cerebral desaturation events comparing anesthesia regimens and their impact on neurobehavioral and neurological outcome. Anesthesiologists were blinded to regional cerebral oxygen saturation values. Baseline data assessed the day before surgery included neurological and neurobehavioral tests, which were repeated the day after surgery. The baseline data for regional cerebral oxygen saturation/bispectral index and invasive blood pressure both at heart and auditory meatus levels were taken prior to anesthesia, 5 min after induction of anesthesia, 5 min after beach chair positioning, after skin incision and thereafter all 20 min until discharge. Patients in the R-group showed significantly less cerebral desaturation events (psurgery (pshoulder surgery in beach chair position influencing neurobehavioral test results at 24h. Copyright © 2013 Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor. Published by Elsevier España. All rights reserved.

Uniquely Strongly Clean Group Rings

Institute of Scientific and Technical Information of China (English)

WANG XIU-LAN

2012-01-01

A ring R is called clean if every element is the sum of an idempotent and a unit,and R is called uniquely strongly clean (USC for short) if every element is uniquely the sum of an idempotent and a unit that commute.In this article,some conditions on a ring R and a group G such that RG is clean are given.It is also shown that if G is a locally finite group,then the group ring RG is USC if and only if R is USC,and G is a 2-group.The left uniquely exchange group ring,as a middle ring of the uniquely clean ring and the USC ring,does not possess this property,and so does the uniquely exchange group ring.

The Mechanics of a Chain or Ring of Spherical Magnets

KAUST Repository

Hall, Cameron L.; Vella, Dominic; Goriely, Alain

2013-01-01

Strong magnets, such as neodymium-iron-boron magnets, are increasingly being manufactured as spheres. Because of their dipolar characters, these spheres can easily be arranged into long chains that exhibit mechanical properties reminiscent of elastic strings or rods. While simple formulations exist for the energy of a deformed elastic rod, it is not clear whether or not they are also appropriate for a chain of spherical magnets. In this paper, we use discrete-to-continuum asymptotic analysis to derive a continuum model for the energy of a deformed chain of magnets based on the magnetostatic interactions between individual spheres. We find that the mechanical properties of a chain of magnets differ significantly from those of an elastic rod: while both magnetic chains and elastic rods support bending by change of local curvature, nonlocal interaction terms also appear in the energy formulation for a magnetic chain. This continuum model for the energy of a chain of magnets is used to analyze small deformations of a circular ring of magnets and hence obtain theoretical predictions for the vibrational modes of a circular ring of magnets. Surprisingly, despite the contribution of nonlocal energy terms, we find that the vibrations of a circular ring of magnets are governed by the same equation that governs the vibrations of a circular elastic ring. Copyright © by SIAM.

Reconstructing Northeastern United States temperatures using Atlantic white cedar tree rings

Science.gov (United States)

Pearl, Jessie K.; Anchukaitis, Kevin J.; Pederson, Neil; Donnelly, Jeffrey P.

2017-11-01

Our knowledge of climate variability in the densely populated Northeastern United States is limited to instrumental data of the last century. Most regional paleoclimate proxies reflect a mix of climate responses, which makes reconstructing historical climate a challenge. Here we analyze tree-ring chronologies from Atlantic white cedar (Chamaecyparis thyoides) as a potential regional paleotemperature proxy. We evaluate our tree-ring network for spatiotemporal climate signal strength and reconstruction skill across New England. Atlantic white cedar sites in the northern section of the species’ range exhibit positive significant annual growth relationships with local and regional temperatures. Chronologies constructed from northern sites yield skillful reconstructions of temperature that reproduce centennial, multidecadal, and interannual variability in the instrumental record, providing a novel paleotemperature record for New England.

Influence of ring growth rate on damage development in hot ring rolling

NARCIS (Netherlands)

Wang, C.; Geijselaers, H. J.M.; Omerspahic, E.; Recina, V.; van den Boogaard, A. H.

2015-01-01

As an incremental forming process of bulk metal, ring rolling provides a cost effective process route to manufacture seamless rings. In the production of hot rolled rings, defects such as porosity can sometimes be found in high alloyed steel, manufactured from ingots having macro-segregation. For

Ring rotational speed trend analysis by FEM approach in a Ring Rolling process

Science.gov (United States)

Allegri, G.; Giorleo, L.; Ceretti, E.

2018-05-01

Ring Rolling is an advanced local incremental forming technology to fabricate directly precise seamless ring-shape parts with various dimensions and materials. In this process two different deformations occur in order to reduce the width and the height of a preform hollow ring; as results a diameter expansion is obtained. In order to guarantee a uniform deformation, the preform is forced toward the Driver Roll whose aim is to transmit the rotation to the ring. The ring rotational speed selection is fundamental because the higher is the speed the higher will be the axial symmetry of the deformation process. However, it is important to underline that the rotational speed will affect not only the final ring geometry but also the loads and energy needed to produce it. Despite this importance in industrial environment, usually, a constant value for the Driver Roll angular velocity is set so to result in a decreasing trend law for the ring rotational speed. The main risk due to this approach is not fulfilling the axial symmetric constrain (due to the diameter expansion) and to generate a high localized ring section deformation. In order to improve the knowledge about this topic in the present paper three different ring rotational speed trends (constant, linearly increasing and linearly decreasing) were investigated by FEM approach. Results were compared in terms of geometrical and dimensional analysis, loads and energies required.

Mechanical improvement of metal reinforcement rings for a finite ring-shaped superconducting bulk

Science.gov (United States)

Huang, Chen-Guang; Zhou, You-He

2018-03-01

As a key technique, reinforcement of type-II superconducting bulks with metal rings can efficiently improve their mechanical properties to enhance the maximum trapped field. In this paper, we study the magnetostrictive and fracture behaviors of a finite superconducting ring bulk reinforced by three typical reinforcing structures composed of metal rings during the magnetizing process by means of the minimization of magnetic energy and the finite element method. After a field-dependent critical current density is adopted, the magnetostriction, pinning-induced stress, and crack tip stress intensity factor are calculated considering the demagnetization effects. The results show that the mechanical properties of the ring bulk are strongly dependent on the reinforcing structure and the material and geometrical parameters of the metal rings. Introducing the metal ring can significantly reduce the hoop stress, and the reduction effect by internal reinforcement is much improved relative to external reinforcement. By comparison, bilateral reinforcement seems to be the best candidate structure. Only when the metal rings have particular Young's modulus and radial thickness will they contribute to improve the mechanical properties the most. In addition, if an edge crack is pre-existing in the ring bulk, the presence of metal rings can effectively avoid crack propagation since it reduces the crack tip stress intensity factor by nearly one order of magnitude.

Ring correlations in random networks.

Science.gov (United States)

Sadjadi, Mahdi; Thorpe, M F

2016-12-01

We examine the correlations between rings in random network glasses in two dimensions as a function of their separation. Initially, we use the topological separation (measured by the number of intervening rings), but this leads to pseudo-long-range correlations due to a lack of topological charge neutrality in the shells surrounding a central ring. This effect is associated with the noncircular nature of the shells. It is, therefore, necessary to use the geometrical distance between ring centers. Hence we find a generalization of the Aboav-Weaire law out to larger distances, with the correlations between rings decaying away when two rings are more than about three rings apart.

How Academic Department Chairs View the Influence of Corporate Ethics Scandals on Ethics Education in Arizona Business Schools: A Qualitative Case Study at the Postsecondary Level

Science.gov (United States)

Gillis, Robert James

2017-01-01

The purpose of this qualitative single case study was to explore how department chairs described the influence of recent corporate ethics scandals on content and availability of ethics education in postsecondary business schools in Arizona. The following research questions guided this study: RQ1: How do department chairs describe the influence of…

Spectral analysis and quantum chemical studies of chair and twist-boat conformers of cycloheximide in gas and solution phases

Science.gov (United States)

Tokatli, A.; Ucun, F.; Sütçü, K.; Osmanoğlu, Y. E.; Osmanoğlu, Ş.

2018-02-01

In this study the conformational behavior of cycloheximide in the gas and solution (CHCl3) phases has theoretically been investigated by spectroscopic and quantum chemical properties using density functional theory (wB97X-D) method with 6-31++G(d,p) basis set, for the first time. The calculated IR results reveal that in the ground state the molecule exits as a mixture of the chair and twist-boat conformers in the gas phase, while the calculated NMR results reveal that it only exits as the chair conformer in the solution phase. In order to obtain the contributions coming from intramolecular interactions to the stability of the conformers in the gas and solution phases, the quantum theory of atoms in molecules (QTAIM), noncovalent interactions (NCI) method, and natural bond orbital analysis (NBO) have been employed. The QTAIM and NCI methods indicated that by intramolecular interactions with bond critical point (BCP) the twist-boat conformer is more stabilized than the chair conformer, while by steric interactions it is more destabilized. Considering that these interactions balance each other, the stabilities of the conformers are understood to be dictated by the van der Waals interactions. The NBO analyses show that the hyperconjugative and steric effects play an important role in the stabilization in the gas and solution phases. Furthermore, to get a better understanding of the chemical behavior of this important antibiotic drug we have evaluated and, commented the global and local reactivity descriptors of the both conformers. Finally, the EPR analysis of γ-irradiated cycloheximide has been done. The comparison of the experimental and calculated data have showed the inducement of a radical structure of (CH2)2ĊCH2 in the molecule. The experimental EPR spectrum has also confirmed that the molecule simultaneously exists in the chair and twist-boat conformers in the solid phase.

Enhanced photoluminescence from ring resonators in hydrogenated amorphous silicon thin films at telecommunications wavelengths.

Science.gov (United States)

Patton, Ryan J; Wood, Michael G; Reano, Ronald M

2017-11-01

We report enhanced photoluminescence in the telecommunications wavelength range in ring resonators patterned in hydrogenated amorphous silicon thin films deposited via low-temperature plasma enhanced chemical vapor deposition. The thin films exhibit broadband photoluminescence that is enhanced by up to 5 dB by the resonant modes of the ring resonators due to the Purcell effect. Ellipsometry measurements of the thin films show a refractive index comparable to crystalline silicon and an extinction coefficient on the order of 0.001 from 1300 nm to 1600 nm wavelengths. The results are promising for chip-scale integrated optical light sources.

Alpha - Skew Pi - Armendariz Rings

Directory of Open Access Journals (Sweden)

Areej M Abduldaim

2018-03-01

Full Text Available In this article we introduce a new concept called Alpha-skew Pi-Armendariz rings (Alpha - S Pi - ARas a generalization of the notion of Alpha-skew Armendariz rings.Another important goal behind studying this class of rings is to employ it in order to design a modern algorithm of an identification scheme according to the evolution of using modern algebra in the applications of the field of cryptography.We investigate general properties of this concept and give examples for illustration. Furthermore, this paperstudy the relationship between this concept and some previous notions related to Alpha-skew Armendariz rings. It clearly presents that every weak Alpha-skew Armendariz ring is Alpha-skew Pi-Armendariz (Alpha-S Pi-AR. Also, thisarticle showsthat the concepts of Alpha-skew Armendariz rings and Alpha-skew Pi- Armendariz rings are equivalent in case R is 2-primal and semiprime ring.Moreover, this paper proves for a semicommutative Alpha-compatible ringR that if R[x;Alpha] is nil-Armendariz, thenR is an Alpha-S Pi-AR. In addition, if R is an Alpha - S Pi -AR, 2-primal and semiprime ring, then N(R[x;Alpha]=N(R[x;Alpha]. Finally, we look forwardthat Alpha-skew Pi-Armendariz rings (Alpha-S Pi-ARbe more effect (due to their properties in the field of cryptography than Pi-Armendariz rings, weak Armendariz rings and others.For these properties and characterizations of the introduced concept Alpha-S Pi-AR, we aspire to design a novel algorithm of an identification scheme.

Feasibility of beam crystallization in a cooler storage ring

Directory of Open Access Journals (Sweden)

Yosuke Yuri

2005-11-01

Full Text Available It has been known theoretically that a charged-particle beam circulating in a storage ring exhibits an “ordered” configuration at the space-charge limit. Such an ultimate state of matter is called a crystalline beam whose emittance is ideally equal to zero except for quantum noise. This paper discusses how close one can come to various ordered states by employing currently available accelerator technologies. The dynamic nature of ultracold beams and conditions required for crystallization are briefly reviewed. Molecular dynamics simulations are performed to study the feasibility of this unique phenomenon, considering practical situations in general cooling experiments. It is pointed out that several essential obstacles must be overcome to reach a three-dimensional crystalline state in a storage ring. Doppler laser cooling of ion beams is also numerically simulated to explore the possibility of beam crystallization in an existing machine.

Molecular cytogenetic analysis and clinical manifestations of a case with de novo mosaic ring chromosome 7

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Fang Jye-Siung

2011-02-01

Full Text Available Abstract Aim Clinical and molecular cytogenetic investigations of a newborn girl exhibiting facial dysmorphism with developmental delay. Methods Phenotypic evaluation was first applied to examine the proband's developmental status. Computed tomography and colour transcranial Doppler were used then to investigate her brain structure and function. Subsequently, chromosomal abnormalities were examined by karyotyping and fluorescent in situ hybridization was performed to investigate size of fragments lost at the two distal ends of the ring chromosome 7. In addition, multicolour banding was applied to rule out structural rearrangement occurs in between the ring chromosome 7. Results The proband was born with mosaic supernumerary ring chromosome 7, without a normal karyotype detected in the peripheral blood lymphocytes. The distal arm of chromosome 7p (at least 255 kb from the telomere was part of an extra ring chromosome 7. In addition, the distal arm of 7q, at least 8 kb from the telomere, was missing. There was no other chromosomal rearrangement detected by multicolour banding. Interpretation This is the 19th reported case of complete ring chromosome 7 mosaicism and the first survived case with mosaic supernumerary ring 7 without a normal karyotype detected in the peripheral lymphocytes.

Modelling and simulation of a thermally induced optical transparency in a dual micro-ring resonator.

Science.gov (United States)

Lydiate, Joseph

2017-07-01

This paper introduces the simulation and modelling of a novel dual micro-ring resonator. The geometric configuration of the resonators, and the implementation of a simulated broadband excitation source, results in the realization of optical transparencies in the combined through port output spectrum. The 130 nm silicon on insulator rib fabrication process is adopted for the simulation of the dual-ring configuration. Two titanium nitride heaters are positioned over the coupling regions of the resonators, which can be operated independently, to control the spectral position of the optical transparency. A third heater, centrally located above the dual resonator rings, can be used to red shift the entire spectrum to a required reference resonant wavelength. The free spectral range with no heater currents applied is 4.29 nm. For a simulated heater current of 7 mA (55.7 mW heater power) applied to one of the through coupling heaters, the optical transparency exhibits a red shift of 1.79 nm from the reference resonant wavelength. The ring-to-ring separation of approximately 900 nm means that it can be assumed that there is a zero ring-to-ring coupling field in this model. This novel arrangement has potential applications as a gas mass airflow sensor or a gas species identification sensor.

Plasma-ring, fast-opening switch

International Nuclear Information System (INIS)

Hartman, C.W.; Eddleman, J.; Hammer, J.H.

1986-01-01

The authors discuss a fast-opening switch concept based on magnetically confined plasma rings, PROS (for Plasma Ring Opening Switch). In PROS, the plasma ring, confined by Bθ /sub and B/poloidal /sub fields of a compact torus, provide a low mass, localized conduction path between coaxial electrodes. To operate the switch, driver current is passed across the electrodes through the ring, storing inductive energy in external inductance and between the electrodes on the driver side of the ring. The ring is accelerated away from the driver by the field of the driver current and passes over a load gap transferring the current to the load. The authors distinguish two configurations in PROS, straight PROS where the electrodes are coaxial cylinders, and cone PROS with conical electrodes. In straight PROS ring acceleration takes place during the inductive store period as in foil switches, but with the localized ring providing the current path. Increased performance is predicted for the cone PROS (see figure) which employs compression of the ring in the cone during the inductive store period. Here, the B/θ /sub field of the driver forces the ring towards the apex of the cone but the force is in near balance with the opposing component of the radial equilibrium force of the ring along the cone. As a result, the ring undergoes a slow, quasistatic compression limited only by resistive decay of the ring field. Slow compression allows inductive storage with low-power drivers (homopoloar, magneto cumulative generators, high C-low V capacitor banks, etc.). Near the apex of the cone, near peak compression, the ring is allowed to enter a straight coaxial section where, because of low-mass, it rapidly accelerates to high velocity and crosses the load gap

Fusion Rings for Quantum Groups

DEFF Research Database (Denmark)

Andersen, Henning Haahr; Stroppel, Catharina

2014-01-01

We study the fusion rings of tilting modules for a quantum group at a root of unity modulo the tensor ideal of negligible tilting modules. We identify them in type A with the combinatorial rings from Korff, C., Stroppel, C.: The sl(ˆn)k-WZNW fusion ring: a combinato-rial construction...... and a realisation as quotient of quantum cohomology. Adv. Math. 225(1), 200–268, (2010) and give a similar description of the sp2n-fusion ring in terms of non-commutative symmetric functions. Moreover we give a presentation of all fusion rings in classical types as quotients of polynomial rings. Finally we also...... compute the fusion rings for type G2....

The LSU Electron Storage Ring, the first commercially-built storage ring

International Nuclear Information System (INIS)

Sah, R.

1990-01-01

The Brobeck Division of Maxwell Laboratories, Inc., is building the first industrially-produced storage ring. It will be located at Louisiana State University (LSU) at the Center for Advanced Microstructures and Devices (CAMD) in Baton Rouge. The purpose of this electron storage ring is to provide intense beams of x-rays to advance the state-of-the-art in lithography and to permit research in a broad area. This facility consists of a 1.2 GeV, 400 mA electron storage ring with a 200 MeV linac injector. The magnet lattice is a Chasman-Green design (double-bend achromat), and the ring circumference is 55.2 meters. There are four 3.0 meter, dispersion-free straight sections, one for injection, one for the 500 MHz RF cavity, and two for possible future insertion devices. The storge ring construction project is in the detailed-design stage, and many systems are in the initial stages of fabrication. 4 figs., 1 tab

Fusion rings and fusion ideals

DEFF Research Database (Denmark)

Andersen, Troels Bak

by the so-called fusion ideals. The fusion rings of Wess-Zumino-Witten models have been widely studied and are well understood in terms of precise combinatorial descriptions and explicit generating sets of the fusion ideals. They also appear in another, more general, setting via tilting modules for quantum......This dissertation investigates fusion rings, which are Grothendieck groups of rigid, monoidal, semisimple, abelian categories. Special interest is in rational fusion rings, i.e., fusion rings which admit a finite basis, for as commutative rings they may be presented as quotients of polynomial rings...

1-Benzyl-3-(2-furylmethyl-1,2,3,4,5,6-hexahydrospiro[benzo[h]quinazoline-5,1′-cyclohexane]-2,4-dione

Directory of Open Access Journals (Sweden)

Siranush Gabrielyan

2008-04-01

Full Text Available The title compound, C29H28N2O3, displays antidepressant and anticancer activities. The furan ring is disordered over two orientations [site occupancies 0.690 (12/0.310 (12] related by a rotation of 180°. The ring conformations are chair for the cyclohexane ring, boat for the cyclohexadiene ring and twist for the pyrimidine ring. The crystal packing is determined solely by van der Waals interactions.

Oscillatory persistent currents in self-assembled quantum rings.

Science.gov (United States)

Kleemans, N A J M; Bominaar-Silkens, I M A; Fomin, V M; Gladilin, V N; Granados, D; Taboada, A G; García, J M; Offermans, P; Zeitler, U; Christianen, P C M; Maan, J C; Devreese, J T; Koenraad, P M

2007-10-05

We report the direct measurement of the persistent current carried by a single electron by means of magnetization experiments on self-assembled InAs/GaAs quantum rings. We measured the first Aharonov-Bohm oscillation at a field of 14 T, in perfect agreement with our model based on the structural properties determined by cross-sectional scanning tunneling microscopy measurements. The observed oscillation magnitude of the magnetic moment per electron is remarkably large for the topology of our nanostructures, which are singly connected and exhibit a pronounced shape asymmetry.

Total Synthesis of Bryostatins. Development of Methodology for Atom-Economic and Stereoselective Synthesis of the C-ring Subunit

Science.gov (United States)

Trost, Barry M.; Frontier, Alison J.; Thiel, Oliver R.; Yang, Hanbiao; Dong, Guangbin

2012-01-01

Bryostatins, a family of structurally complicated macrolides, exhibit an exceptional range of biological activities. The limited availability and structural complexity of these molecules makes development of an efficient total synthesis particularly important. This article describes our initial efforts towards the total synthesis of bryostatins, in which chemoselective and atom-economical methods for stereoselective assembly of the C-ring subunit were developed. A Pd-catalyzed tandem alkyne-alkyne coupling/6-endo-dig cyclization sequence was explored and successfully pursued in the synthesis of a dihydropyran ring system. Elaboration of this methodology ultimately led to a concise synthesis of the C-ring subunit of bryostatins. PMID:21793057

Evaluation of ring impedance of the Photon Factory storage ring

International Nuclear Information System (INIS)

Kiuchi, T.; Izawa, M.; Tokumoto, S.; Hori, Y.; Sakanaka, S.; Kobayashi, M.; Kobayakawa, H.

1992-05-01

The loss parameters of the ducts in the Photon Factory (PF) storage ring were evaluated using the wire method and the code TBCI. Both the measurement and the calculation were done for a different bunch length (σ) ranging from 23 to 80 ps. The PF ring impedance was estimated to be |Z/n|=3.2 Ω using the broadband impedance model. The major contribution to the impedance comes from the bellows and the gate valve sections. Improvements of these components will lower the ring impedance by half. (author)

1,5,6-Triphenyl-8-oxa-7-selena-6-phosphabicyclo[3.2.1]octane-6-selone

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Yang Li

2008-01-01

Full Text Available The structure of the title compound, C23H21OPSe2, consists of fused puckered five- and six-membered rings, PSeC2O and C5O, respectively, with a C2O bridgehead. The C5O ring adopts a chair conformation, whilst the C2PSeO ring has an envelope conformation.

N-tert-Butyl-3-hydroxy-5-androstene-17-carboxamide monohydrate

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Jiang-Sheng Li

2009-07-01

Full Text Available In the title compound, C24H39NO2·H2O, the A and C rings of the pregnolene derivative sterol adopt chair conformations, with the B ring in a flattened chair conformation and the five-membered ring in an envelope conformation twisted about the C/D ring junction. The N-tert-butylcarboxamide substituent is equatorial. The 3β-hydroxy H atom and one H atom of the water molecule are disordered over two positions with equal occupancies. In the crystal structure, O—H...O hydrogen bonds between the 3β-hydroxy groups of neighbouring molecules form dimers in the bc plane and these dimers are stacked along the a axis by additional O—H...O hydrogen bonds involving the water molecules. The steric effect of the bulky tert-butyl substituent in the carboxamide chain precludes hydrogen-bond formation by the N—H group.

Tree Rings: Timekeepers of the Past.

Science.gov (United States)

Phipps, R. L.; McGowan, J.

One of a series of general interest publications on science issues, this booklet describes the uses of tree rings in historical and biological recordkeeping. Separate sections cover the following topics: dating of tree rings, dating with tree rings, tree ring formation, tree ring identification, sample collections, tree ring cross dating, tree…

Crystal structure of (1S,3R,8R,9R-2,2-dichloro-3,7,7-trimethyl-10-methylenetricyclo[6.4.0.01,3]dodecan-9-ol

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Ahmed Benzalim

2016-08-01

Full Text Available The title compound, C16H24Cl2O, was synthesized by treating (1S,3R,8S,9R,10S-2,2-dichloro-3,7,7,10-tetramethyl-9,10-epoxytricyclo[6.4.0.01,3]dodecane with a concentrated solution of hydrobromic acid. It is built up from three fused rings: a cycloheptane ring, a cyclohexyl ring bearing alkene and hydroxy substituents, and a cyclopropane ring bearing two chlorine atoms. The asymmetric unit contains two molecules linked by an O—H...O hydrogen bond. In the crystal, further O—H...O hydrogen bonds build up an R44(8 cyclic tetramer. One of the molecules presents disorder that affects the seven-membered ring. In both molecules, the six-membered rings display a chair conformation, whereas the seven-membered rings display conformations intermediate between boat and twist-boat for the non-disordered molecule and either a chair or boat and twist-boat for the disordered molecule owing to the disorder. The absolute configuration for both molecules is 1S,3R,8R,9R and was deduced from the chemical pathway and further confirmed by the X-ray structural analysis.

Signatures of topological phase transitions in mesoscopic superconducting rings

International Nuclear Information System (INIS)

Pientka, Falko; Romito, Alessandro; Duckheim, Mathias; Oppen, Felix von; Oreg, Yuval

2013-01-01

We investigate Josephson currents in mesoscopic rings with a weak link which are in or near a topological superconducting phase. As a paradigmatic example, we consider the Kitaev model of a spinless p-wave superconductor in one dimension, emphasizing how this model emerges from more realistic settings based on semiconductor nanowires. We show that the flux periodicity of the Josephson current provides signatures of the topological phase transition and the emergence of Majorana fermions (MF) situated on both sides of the weak link even when fermion parity is not a good quantum number. In large rings, the MF hybridize only across the weak link. In this case, the Josephson current is h/e periodic in the flux threading the loop when fermion parity is a good quantum number but reverts to the more conventional h/2e periodicity in the presence of fermion-parity changing relaxation processes. In mesoscopic rings, the MF also hybridize through their overlap in the interior of the superconducting ring. We find that in the topological superconducting phase, this gives rise to an h/e-periodic contribution even when fermion parity is not conserved and that this contribution exhibits a peak near the topological phase transition. This signature of the topological phase transition is robust to the effects of disorder. As a byproduct, we find that close to the topological phase transition, disorder drives the system deeper into the topological phase. This is in stark contrast to the known behavior far from the phase transition, where disorder tends to suppress the topological phase. (paper)

Mother chair reparation to decrease subjective disorders in exclusive breast-feeding period

Science.gov (United States)

Santiana, M. A.; Yusuf, M.; Lokantara, W. D.

2018-01-01

Exclusive breastfeeding is the responsibility of the mother after childbirth. A specific constraint arise for the mother when during the breastfeeding process, the place is not in accordance with the physiological condition of the mother's body. A not physiologically corrected lactation place will cause subjective disorders for breastfeeding mothers. Complaints that arise include quick tiredness, with certain muscles sore and pain, which will ultimately decrease the motivation of the mothers to perform exclusive breastfeeding especially in the first six months of the baby's birth. An improved ergonomic designed chair, this research used experimental method with group within treatment (treatment by subject) to solve the problem. The study took place in Maternity Clinic “CB” Badung regency, Bali. Subjective disorders are measured based on general fatigue and musculoskeletal disorders mothers breastfeeding. Fatigue is predicted using 30 items of questionnaires while musculoskeletal compaints are predicted from the Nordic Body Map questionnaire. Data were analyzed descriptively and inferentially in an experiment condition using using t-pair test. The results showed that there were significant differences in fatigue in general and skeletal musculoskeletal disorders between treatment 1 (using old chair) with treatment 2 (using repaired seats) in breastfeeding mothers. Fatigue in general decreased by 35.6% and skeletal musculoskeletal disorders decreased by 26.8%. It was concluded that improved breastfeeding mothers' seats may decrease subjective disorders during exclusive breastfeeding. It is therefore advisable for breastfeeding mothers to use seats that match their anthropometry.

Some Aspects of Ring Theory

CERN Document Server

Herstein, IN

2011-01-01

S. Amitsur: Associative rings with identities.- I.N. Herstein: Topics in ring theory.- N. Jacobson: Representation theory of Jordan algebras.- I. Kaplansky: The theory of homological dimension.- D. Buchsbaum: Complexes in local ring theory.- P.H. Cohn: Two topics in ring theory.- A.W. Goldie: Non-commutative localisation.

Improving the Accuracy of Laplacian Estimation with Novel Variable Inter-Ring Distances Concentric Ring Electrodes

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Oleksandr Makeyev

2016-06-01

Full Text Available Noninvasive concentric ring electrodes are a promising alternative to conventional disc electrodes. Currently, the superiority of tripolar concentric ring electrodes over disc electrodes, in particular, in accuracy of Laplacian estimation, has been demonstrated in a range of applications. In our recent work, we have shown that accuracy of Laplacian estimation can be improved with multipolar concentric ring electrodes using a general approach to estimation of the Laplacian for an (n + 1-polar electrode with n rings using the (4n + 1-point method for n ≥ 2. This paper takes the next step toward further improving the Laplacian estimate by proposing novel variable inter-ring distances concentric ring electrodes. Derived using a modified (4n + 1-point method, linearly increasing and decreasing inter-ring distances tripolar (n = 2 and quadripolar (n = 3 electrode configurations are compared to their constant inter-ring distances counterparts. Finite element method modeling and analytic results are consistent and suggest that increasing inter-ring distances electrode configurations may decrease the truncation error resulting in more accurate Laplacian estimates compared to respective constant inter-ring distances configurations. For currently used tripolar electrode configuration, the truncation error may be decreased more than two-fold, while for the quadripolar configuration more than a six-fold decrease is expected.

Improving the Accuracy of Laplacian Estimation with Novel Variable Inter-Ring Distances Concentric Ring Electrodes

Science.gov (United States)

Makeyev, Oleksandr; Besio, Walter G.

2016-01-01

Noninvasive concentric ring electrodes are a promising alternative to conventional disc electrodes. Currently, the superiority of tripolar concentric ring electrodes over disc electrodes, in particular, in accuracy of Laplacian estimation, has been demonstrated in a range of applications. In our recent work, we have shown that accuracy of Laplacian estimation can be improved with multipolar concentric ring electrodes using a general approach to estimation of the Laplacian for an (n + 1)-polar electrode with n rings using the (4n + 1)-point method for n ≥ 2. This paper takes the next step toward further improving the Laplacian estimate by proposing novel variable inter-ring distances concentric ring electrodes. Derived using a modified (4n + 1)-point method, linearly increasing and decreasing inter-ring distances tripolar (n = 2) and quadripolar (n = 3) electrode configurations are compared to their constant inter-ring distances counterparts. Finite element method modeling and analytic results are consistent and suggest that increasing inter-ring distances electrode configurations may decrease the truncation error resulting in more accurate Laplacian estimates compared to respective constant inter-ring distances configurations. For currently used tripolar electrode configuration, the truncation error may be decreased more than two-fold, while for the quadripolar configuration more than a six-fold decrease is expected. PMID:27294933

Radar imaging of Saturn's rings

Science.gov (United States)

Nicholson, Philip D.; French, Richard G.; Campbell, Donald B.; Margot, Jean-Luc; Nolan, Michael C.; Black, Gregory J.; Salo, Heikki J.

2005-09-01

We present delay-Doppler images of Saturn's rings based on radar observations made at Arecibo Observatory between 1999 and 2003, at a wavelength of 12.6 cm and at ring opening angles of 20.1°⩽|B|⩽26.7°. The average radar cross-section of the A ring is ˜77% relative to that of the B ring, while a stringent upper limit of 3% is placed on the cross-section of the C ring and 9% on that of the Cassini Division. These results are consistent with those obtained by Ostro et al. [1982, Icarus 49, 367-381] from radar observations at |B|=21.4°, but provide higher resolution maps of the rings' reflectivity profile. The average cross-section of the A and B rings, normalized by their projected unblocked area, is found to have decreased from 1.25±0.31 to 0.74±0.19 as the rings have opened up, while the circular polarization ratio has increased from 0.64±0.06 to 0.77±0.06. The steep decrease in cross-section is at variance with previous radar measurements [Ostro et al., 1980, Icarus 41, 381-388], and neither this nor the polarization variations are easily understood within the framework of either classical, many-particle-thick or monolayer ring models. One possible explanation involves vertical size segregation in the rings, whereby observations at larger elevation angles which see deeper into the rings preferentially see the larger particles concentrated near the rings' mid-plane. These larger particles may be less reflective and/or rougher and thus more depolarizing than the smaller ones. Images from all four years show a strong m=2 azimuthal asymmetry in the reflectivity of the A ring, with an amplitude of ±20% and minima at longitudes of 67±4° and 247±4° from the sub-Earth point. We attribute the asymmetry to the presence of gravitational wakes in the A ring as invoked by Colombo et al. [1976, Nature 264, 344-345] to explain the similar asymmetry long seen at optical wavelengths. A simple radiative transfer model suggests that the enhancement of the azimuthal

Study of improvement in 1st ring`s gas-seal; Top ring no gas seal seino kojo no kento

Energy Technology Data Exchange (ETDEWEB)

Ando, H; Tateishi, Y; Fujimura, K; Hitosugi, H [Nippon Piston Ring Co. Ltd., Tokyo (Japan)

1997-10-01

The authors studied the effect of an angle of 1st ring twist on the amount of blow-by concerning higher speed/higher output engines for motorcycles. As a result, the authors found the twist made the ring restrained in a ring groove of piston , and confirmed its suitable range for blow-by. By means of the developed optimization method, the authors have achieved significant reduction in blow-by at high engine speed. 1 ref., 9 figs., 2 tabs.

Single and multi-band electromagnetic induced transparency-like metamaterials with coupled split ring resonators

Science.gov (United States)

Bagci, Fulya; Akaoglu, Baris

2017-08-01

We present a metamaterial configuration exhibiting single and multi-band electromagnetic induced transparency (EIT)-like properties. The unit cell of the single band EIT-like metamaterial consists of a multi-split ring resonator surrounded by a split ring resonator. The multi-split ring resonator acts as a quasi-dark or dark resonator, depending on the polarization of the incident wave, and the split ring resonator serves as the bright resonator. Combination of these two resonators results in a single band EIT-like transmission inside the stop band. EIT-like transmission phenomenon is also clearly observed in the measured transmission spectrum at almost the same frequencies for vertical and horizontal polarized waves, and the numerical results are verified for normal incidence. Moreover, multi-band transmission windows are created within a wide band by combining the two slightly different single band EIT-like metamaterial unit cells that exhibit two different coupling strengths inside a supercell configuration. Group indices as high as 123 for single band and 488 for tri-band transmission, accompanying with high transmission rates (over 80%), are achieved, rendering the metamaterial very suitable for multi-band slow light applications. It is shown that the group delay of the propagating wave can be increased and dynamically controlled by changing the polarization angle. Multi-band EIT-like transmission is also verified experimentally, and a good agreement with simulations is obtained. The proposed novel methodology for obtaining multi-band EIT, which takes advantage of a supercell configuration by hosting slightly different configured unit cells, can be utilized for easily formation and manipulation of multi-band transmission windows inside a stop band.

A Compact Annular Ring Microstrip Antenna for WSN Applications

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Daihua Wang

2012-06-01

Full Text Available A compact annular ring microstrip antenna was proposed for a wireless sensor network (WSN application in the 2.4 GHz band. In this paper the major considerations of the conformal antenna design were the compact size and the impact on antenna’s performance of a steel installation base. By using a chip resistor of large resistance (120 Ω the antenna size was reduced to 38% of that a conventional annular ring patch antenna. With the addition of the steel installation base the resonant frequency of the antenna increases about 4.2% and the bandwidth reduces from 17.5% to 11.7% by adjusting the load resistance simultaneously. Several key parameters were discussed and optimized, and the antenna was fabricated and its performance measured. The antenna is well matched at 2.4 GHz with 34.2 dB return loss and –2.5 dBi peak gain. Meanwhile, it exhibits excellent radiation patterns with very low cross-polarization levels.

Solar system history as recorded in the Saturnian ring structure

International Nuclear Information System (INIS)

Alfven, H.

1983-04-01

The paper is based on Holbergs analysis of the Voyager photographs in both reflected and transparent light, combined with occulation data of stars seen through the rings. Besides rapidly varying phenomena (spokes, braided ring, etc.), which according to Mendis are due to gravito-electromagnetic effects, the ring consists of a bulk structure, a fine structure, and also a hyperfine structure, showing more than 10000 ringlets. The large number of ringlets can be explained by the Baxter-Thompson negative diffusion. This gives the ringlets a stability which makes it possible to interprete them as fossils, which originated at cosmogonic times. It is shown that the bulk structure can be explained by the combined cosmogonic shadows of the satellites Mimas, Janus (co-orbiting satellites) and the Shepherd satellites. This structure originated at the transition from the plasma phase to the planetesimal phase (which probably took place 4-5 times 10 9 years ago). Further, Holberg has discovered that the shadows are not simple void regions but exhibit a certain characteristic signature. This is not yet understood theoretically. Parts of the fine structure are explained by Holberg as resonances with the satellites. Parts are here interpreted as cosmogonic shadow effects. However, there are a number of ringlets which can neither be explained by cosmogonic nor by resonance effects. The most important conclusion is that an analysis of the ring data is liekly to lead to a reconstruction of the plasma-planetesimal transition with an accuracy of a few percent. (author)

How well does the 30-second Chair Stand Test predict rehabilitation needs?

DEFF Research Database (Denmark)

Hansen Bruun, Inge; Nørgaard, Birgitte; Backer Mogensen, Christian

of functional decline. The 30-Second Chair Stand Test (30s-CST) is recommended by the Danish Health and Medicines Authority for screening of functional decline in elderly citizens living in their own home. However, its validity with hospitalized patients is undocumented, and it is unclear whether loss...... performance, e) patient-related data. Both patients and health professionals will contribute to the face validity assessment. Results The results will be available by the end of 2014. Conclusions Face validations of 30s-CST and DEMMI are relevant as validated tests for short-term hospitalized patients...

Læring og refleksion

DEFF Research Database (Denmark)

Wahlgren, B.; Rattleff, Pernille; Høyrup, S.

State of the art inden for forskning om læring på arbejdspladsen samt gennemgang af læringsteori og refleksionsbegrebet hos Dewey, Dreyfus, Schön, Argyris, Kolb, Jarvis, Mezirow og Brookfield. Afsluttes med diskussion af syntetiseret model for læring på arbejdspladsen.......State of the art inden for forskning om læring på arbejdspladsen samt gennemgang af læringsteori og refleksionsbegrebet hos Dewey, Dreyfus, Schön, Argyris, Kolb, Jarvis, Mezirow og Brookfield. Afsluttes med diskussion af syntetiseret model for læring på arbejdspladsen....

Birth Control Ring

Science.gov (United States)

... Health Food & Fitness Diseases & Conditions Infections Drugs & Alcohol School & Jobs Sports Expert Answers (Q&A) Staying Safe Videos for Educators Search English Español Birth Control Ring KidsHealth / For Teens / Birth Control Ring What's ...

From coffee ring to spherulites ring of poly(ethylene oxide) film from drying droplet

Science.gov (United States)

Hu, Yinchun; Zhang, Xuerong; Qiu, Maibo; Wei, Yan; Zhou, Qiong; Huang, Di

2018-03-01

We discuss how the "spherulites ring" morphology and "coffee ring" profile of PEO film formed by the drying droplet at glass substrate with different heating rate. Upon increasing the heating rate of substrate, it is found that deposited PEO film from drying droplet shows the unusually observed "coffee ring" profile and "spherulites ring" morphology. The main mechanism for this phenomenon is proposed to be an enhanced Marangoni convection which is induced by the increased solute concentration gradient and reduced viscous force above 70 °C. A simple formation mechanism of the unusually observed "coffee ring" profile and "spherulites ring" morphology is proposed. These findings can be exploited to trace the center of Marangoni convection, with potential applications in designing the spherulite patterns of crystalline polymer films in ink-jet printing and self-assembly fields.

Background modelling of diffraction data in the presence of ice rings

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James M. Parkhurst

2017-09-01

Full Text Available An algorithm for modelling the background for each Bragg reflection in a series of X-ray diffraction images containing Debye–Scherrer diffraction from ice in the sample is presented. The method involves the use of a global background model which is generated from the complete X-ray diffraction data set. Fitting of this model to the background pixels is then performed for each reflection independently. The algorithm uses a static background model that does not vary over the course of the scan. The greatest improvement can be expected for data where ice rings are present throughout the data set and the local background shape at the size of a spot on the detector does not exhibit large time-dependent variation. However, the algorithm has been applied to data sets whose background showed large pixel variations (variance/mean > 2 and has been shown to improve the results of processing for these data sets. It is shown that the use of a simple flat-background model as in traditional integration programs causes systematic bias in the background determination at ice-ring resolutions, resulting in an overestimation of reflection intensities at the peaks of the ice rings and an underestimation of reflection intensities either side of the ice ring. The new global background-model algorithm presented here corrects for this bias, resulting in a noticeable improvement in R factors following refinement.

-NH-dansyl isocolchicine exhibits a significantly improved tubulin-binding affinity and microtubule inhibition in comparison to isocolchicine by binding tubulin through its A and B rings.

Science.gov (United States)

Das, Lalita; Datta, Ajit B; Gupta, Suvroma; Poddar, Asim; Sengupta, Suparna; Janik, Mark E; Bhattacharyya, Bhabatarak

2005-03-08

Structure-activity relationship studies have established that the A and C rings of colchicine comprise the minimum structural feature necessary for high affinity drug-tubulin binding. Thus, colchicine acts as a bifunctional ligand by making two points of attachment to the protein. Furthermore, analogues belonging to the iso series of colchicine are virtually inactive in binding to tubulin and inhibiting microtubule assembly. In the present study, we found that the substitution of a hydrophobic dansyl group on the B-ring side chain (C7 position) of isocolchicine reverses the structural alterations at the C ring and the newly synthesized -NH-dansyl isocolchicine restores the lost biological activity of the compound. It inhibits microtubule assembly efficiently with an IC(50) value of 10 microM and competes with [(3)H]colchicine for binding to tubulin. Moreover, although -NH-dansyl colchicine binding to tubulin involves two steps, the -NH-dansyl isocolchicine-tubulin interaction has been found to occur via a one-step process. Also, the affinity constant of the -NH-dansyl isocolchicine-tubulin interaction is roughly only 3 times lower than that of the -NH-dansyl colchicine-tubulin interaction. These results suggest that the enhanced microtubule inhibitory ability of -NH-dansyl isocolchicine is therefore related to the affinity of the drug-tubulin interaction and not to any conformational changes upon binding tubulin. We also observed that the competition of -NH-dansyl isocolchicine with [(3)H]colchicine for binding to tubulin was dependent on the tubulin concentration. In conclusion, this paper for the first time indicates that a biologically active bifuntional colchicine analogue can be designed where the drug binds tubulin through its A and B rings, while the C ring remains inactive.

The influence of climate variability on polar bear (Ursus maritimus) and ringed seal (Pusa hispida) population dynamics

DEFF Research Database (Denmark)

Rosing-Asvid, A.

2006-01-01

Unusually high polar bear (Ursus maritimus Phipps, 1774) predation on ringed seal (Pusa hispida (Schreber, 1775)) pups and increased survival of polar bear cubs during mild springs is documented in published articles. Strong predation on newborn ringed seal pups in early spring, however, is likely...... to lower the overall energy intake of polar bears if ringed seal pups are their main food, because the energetic value of ringed seal pups increases 7-8 times during the 6 week lactation period. So although hunting success in early spring increases cub survival during the period after den emergence......,when they are most vulnerable, it is likely to increase the number of starving bears later in the season. This negative-feedback effect of strong spring predation will not occur in areas where other seal species are abundant during summer, and polar bears in such areas are likely to exhibit population growth during...

Structure and dynamics of ringed galaxies

International Nuclear Information System (INIS)

Buta, R.J.

1984-01-01

In many spiral and SO galaxies, single or multiple ring structures are visible in the disk. These inner rings (r), outer rings (R), and nuclear rings (nr) were investigated by means of morphology, photometry, and spectroscopy in order to provide basic data on a long neglected phenomenon. The metric properties of each ring are investigated and found to correlate with the structure of the parent galaxy. When properly calibrated, inner rings in barred (SB) systems can be used as geometric extragalactic distance indicators to distances in excess of 100 Mpc. Other statistics are presented that confirm previous indications that the rings have preferred shapes, relative sizes, and orientations with respect to bars. A survey is made of the less homogeneous non-barred (SA) ringed systems, and the causes of the inhomogeneity are isolated. It is shown that rings can be identified in multiple-ring SA systems that are exactly analogous to those in barred spirals

Multiplicative Structure and Hecke Rings of Generator Matrices for Codes over Quotient Rings of Euclidean Domains

Directory of Open Access Journals (Sweden)

Hajime Matsui

2017-12-01

Full Text Available In this study, we consider codes over Euclidean domains modulo their ideals. In the first half of the study, we deal with arbitrary Euclidean domains. We show that the product of generator matrices of codes over the rings mod a and mod b produces generator matrices of all codes over the ring mod a b , i.e., this correspondence is onto. Moreover, we show that if a and b are coprime, then this correspondence is one-to-one, i.e., there exist unique codes over the rings mod a and mod b that produce any given code over the ring mod a b through the product of their generator matrices. In the second half of the study, we focus on the typical Euclidean domains such as the rational integer ring, one-variable polynomial rings, rings of Gaussian and Eisenstein integers, p-adic integer rings and rings of one-variable formal power series. We define the reduced generator matrices of codes over Euclidean domains modulo their ideals and show their uniqueness. Finally, we apply our theory of reduced generator matrices to the Hecke rings of matrices over these Euclidean domains.

4-Benzyloxy-1-oxaspiro[4.6]undec-3-en-2-one

Directory of Open Access Journals (Sweden)

Jose H. Quintana Mendoza

2016-10-01

Full Text Available The title compound, C17H20O3, the cycloheptane ring adopts a slightly distorted chair conformation. The planar five-membered ring is inclined at 57.13 (11° to the phenyl ring of the benzyloxy substituent. In the crystal structure, C—H...O and C—H...π hydrogen bonds generate layers in the ac plane.

Electromyographic activity of the trunk extensor muscles: effect of varying hip position and lumbar posture during Roman chair exercise.

Science.gov (United States)

Mayer, John M; Verna, Joe L; Manini, Todd M; Mooney, Vert; Graves, James E

2002-11-01

To evaluate the effect of hip position and lumbar posture on the surface electromyographic activity of the trunk extensors during Roman chair exercise. Descriptive, repeated measures. University-based musculoskeletal research laboratory. Twelve healthy volunteers (7 men, 5 women; age range, 18-35y) without a history of low back pain were recruited from a university setting. Not applicable. Surface electromyographic activity was recorded from the lumbar extensor, gluteal, and hamstring musculature during dynamic Roman chair exercise. For each muscle group, electromyographic activity (mV/rep) was compared among exercises with internal hip rotation and external hip rotation and among exercises by using a typical lumbar posture (nonbiphasic) and a posture that accentuated lumbar lordosis (biphasic). For the lumbar extensors, electromyographic activity during exercise was 18% greater with internal hip rotation than external hip rotation (Phamstrings, there was no difference in electromyographic activity between internal and external hip rotation or between biphasic and nonbiphasic postures (P >.05). The level of recruitment of the lumbar extensors can be modified during Roman chair exercise by altering hip position and lumbar posture. Clinicians can use these data to develop progressive exercise protocols for the lumbar extensors with a variety of resistance levels without the need for complex equipment. Copyright 2002 by the American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation

Binomial Rings: Axiomatisation, Transfer and Classification

OpenAIRE

Xantcha, Qimh Richey

2011-01-01

Hall's binomial rings, rings with binomial coefficients, are given an axiomatisation and proved identical to the numerical rings studied by Ekedahl. The Binomial Transfer Principle is established, enabling combinatorial proofs of algebraical identities. The finitely generated binomial rings are completely classified. An application to modules over binomial rings is given.

AN N-BODY INTEGRATOR FOR GRAVITATING PLANETARY RINGS, AND THE OUTER EDGE OF SATURN'S B RING

International Nuclear Information System (INIS)

Hahn, Joseph M.; Spitale, Joseph N.

2013-01-01

A new symplectic N-body integrator is introduced, one designed to calculate the global 360° evolution of a self-gravitating planetary ring that is in orbit about an oblate planet. This freely available code is called epi i nt, and it is distinct from other such codes in its use of streamlines to calculate the effects of ring self-gravity. The great advantage of this approach is that the perturbing forces arise from smooth wires of ring matter rather than discreet particles, so there is very little gravitational scattering and so only a modest number of particles are needed to simulate, say, the scalloped edge of a resonantly confined ring or the propagation of spiral density waves. The code is applied to the outer edge of Saturn's B ring, and a comparison of Cassini measurements of the ring's forced response to simulations of Mimas's resonant perturbations reveals that the B ring's surface density at its outer edge is σ 0 = 195 ± 60 g cm –2 , which, if the same everywhere across the ring, would mean that the B ring's mass is about 90% of Mimas's mass. Cassini observations show that the B ring-edge has several free normal modes, which are long-lived disturbances of the ring-edge that are not driven by any known satellite resonances. Although the mechanism that excites or sustains these normal modes is unknown, we can plant such a disturbance at a simulated ring's edge and find that these modes persist without any damping for more than ∼10 5 orbits or ∼100 yr despite the simulated ring's viscosity ν s = 100 cm 2 s –1 . These simulations also indicate that impulsive disturbances at a ring can excite long-lived normal modes, which suggests that an impact in the recent past by perhaps a cloud of cometary debris might have excited these disturbances, which are quite common to many of Saturn's sharp-edged rings

Galactic rings revisited - I. CVRHS classifications of 3962 ringed galaxies from the Galaxy Zoo 2 Database

Science.gov (United States)

Buta, Ronald J.

2017-11-01

Rings are important and characteristic features of disc-shaped galaxies. This paper is the first in a series that re-visits galactic rings with the goals of further understanding the nature of the features and for examining their role in the secular evolution of galaxy structure. The series begins with a new sample of 3962 galaxies drawn from the Galaxy Zoo 2 citizen science data base, selected because zoo volunteers recognized a ring-shaped pattern in the morphology as seen in Sloan Digital Sky Survey colour images. The galaxies are classified within the framework of the Comprehensive de Vaucouleurs revised Hubble-Sandage system. It is found that zoo volunteers cued on the same kinds of ring-like features that were recognized in the 1995 Catalogue of Southern Ringed Galaxies. This paper presents the full catalogue of morphological classifications, comparisons with other sources of classifications and some histograms designed mainly to highlight the content of the catalogue. The advantages of the sample are its large size and the generally good quality of the images; the main disadvantage is the low physical resolution that limits the detectability of linearly small rings such as nuclear rings. The catalogue includes mainly inner and outer disc rings and lenses. Cataclysmic (`encounter-driven') rings (such as ring and polar ring galaxies) are recognized in less than 1 per cent of the sample.

Quantum Fourier Transform Over Galois Rings

OpenAIRE

Zhang, Yong

2009-01-01

Galois rings are regarded as "building blocks" of a finite commutative ring with identity. There have been many papers on classical error correction codes over Galois rings published. As an important warm-up before exploring quantum algorithms and quantum error correction codes over Galois rings, we study the quantum Fourier transform (QFT) over Galois rings and prove it can be efficiently preformed on a quantum computer. The properties of the QFT over Galois rings lead to the quantum algorit...

Lancement de la chaire Unesco Pratiques émergentes des technologies et communication pour le développement – Université Bordeaux-Montaigne

OpenAIRE

Kiyindou, Alain

2015-01-01

L'Université Bordeaux Montaigne a célébré le lancement de la chaire Unesco Pratiques émergentes des technologies et communication pour le développement les 4, 5, 6 et 7 novembre 2014 à la Maison des Sciences de l'Homme d'Aquitaine et la Maison des Suds (Esplanade des Antilles, Pessac). Cette manifestation a intégré deux grands événements internationaux : le Colloque annuel du réseau mondial des chaires Unesco en communication, ORBICOM (Les médias sociaux) et le Colloque international Terminau...

Utilizing Chair Massage to Address One Woman's Health in Rural Ghana West Africa: a Case Report.

Science.gov (United States)

Meryanos, Cathy J

2016-12-01

There is limited access to health care in rural Ghana and virtually no rehabilitative services available. This situation presents a unique opportunity to utilize chair massage in addressing women's health in rural Ghana, particularly when it comes to muscle pain and fatigue from heavy labor. The objective of this case report is to determine the results of chair massage as a strategy to reduce neck, shoulder, and back pain, while increasing range of motion. The patient is a 63-year-old Ghanaian female, who was struck by a public transport van while carrying a 30-50 pound load on her head, two years prior. The accident resulted in a broken right humerus and soft tissue pain. A traditional medicine practitioner set the bone, however there was no post-accident rehabilitation available. At the time of referral, she presented complaints of shoulder, elbow, and wrist pain. In addition, she was unable to raise her right hand to her mouth for food intake. The results of this case report include an increase in range of motion, as well as elimination of pain in the right shoulder, elbow, and hand. Visual assessments showed an approximate increase of ROM within the ranges of 45-65 degrees in the right arm, as well as 10-15 degrees in 4th and 5th fingers. There was also a decrease in muscle hypertonicity in the thoracic and cervical areas, and a profound increase in quality of life for the patient. This case report illustrates how therapeutic chair massage was utilized to address a common health concern for one woman in rural Ghana. It also demonstrates that pre-existing musculoskeletal disorders and pain may be eliminated with massage intervention. Massage therapy may be important to ameliorating certain types of health problems in remote rural villages in low income countries.

Novel manifestations of the Aharonov-Bohm effect in quantum rings and Moebius rings

International Nuclear Information System (INIS)

Fomin, Vladimir M.

2013-01-01

- An overview is given on the recent experimental and theoretical advancements in studies of novel manifestations of the Aharonov-Bohm quantum-interference effect for excitons confined to self assembled quantum rings and other semiconductor nanostructures with ring-like states of charge carriers as well as for electrons in Moebius rings at the micro- and nanoscale. The exciton Aharonov-Bohm effect can be effectively controlled by an out-of-plane magnetic field, a vertical electric field, a spin disorder. A 'delocalization-to-localization' transition for the electron ground state occurs in a Moebius ring as it is made more inhomogeneous. (authors)

76 FR 35007 - Notice of Issuance of Final Determination Concerning the Country of Origin of Certain Office Chairs

Science.gov (United States)

2011-06-15

... H154135 June 9, 2011 OT:RR:CTF:VS H154135 EE CATEGORY: Marking Lisa A. Crosby Sidley Austin, LLP 1501 K... 1979 (19 U.S.C. Sec. 2511); Subpart B, Part 177, CBP Regulations; Office Chairs Dear Ms. Crosby: This...

Ring closure in actin polymers

Energy Technology Data Exchange (ETDEWEB)

Sinha, Supurna, E-mail: supurna@rri.res.in [Raman Research Institute, Bangalore 560080 (India); Chattopadhyay, Sebanti [Doon University, Dehradun 248001 (India)

2017-03-18

We present an analysis for the ring closure probability of semiflexible polymers within the pure bend Worm Like Chain (WLC) model. The ring closure probability predicted from our analysis can be tested against fluorescent actin cyclization experiments. We also discuss the effect of ring closure on bend angle fluctuations in actin polymers. - Highlights: • Ring closure of biopolymers. • Worm like chain model. • Predictions for experiments.

On P-coherent endomorphism rings

Indian Academy of Sciences (India)

A ring is called right -coherent if every principal right ideal is finitely presented. Let M R be a right -module. We study the -coherence of the endomorphism ring of M R . It is shown that is a right -coherent ring if and only if every endomorphism of M R has a pseudokernel in add M R ; S is a left -coherent ring if and ...

Faithfully quadratic rings

CERN Document Server

Dickmann, M

2015-01-01

In this monograph the authors extend the classical algebraic theory of quadratic forms over fields to diagonal quadratic forms with invertible entries over broad classes of commutative, unitary rings where -1 is not a sum of squares and 2 is invertible. They accomplish this by: (1) Extending the classical notion of matrix isometry of forms to a suitable notion of T-isometry, where T is a preorder of the given ring, A, or T = A^2. (2) Introducing in this context three axioms expressing simple properties of (value) representation of elements of the ring by quadratic forms, well-known to hold in

BERKELEY: ALS ring

Energy Technology Data Exchange (ETDEWEB)

Anon.

1993-06-15

Everybody at Lawrence Berkeley Laboratory's Center for Beam Physics is pleased with the rapid progress in commissioning LBL's Advanced Light Source (ALS) electron storage ring, the foundation for this third-generation synchrotron radiation facility. Designed for a maximum current of 400 mA, the ALS storage ring reached 407 mA just 24 days after storing the first beam on 16 March. ALS construction as a US Department of Energy (DOE) national user facility to provide high-brightness vacuum ultra-violet and soft x-ray radiation began in October 1987. One technical requirement marking project completion was to accumulate a 50-mA current in the storage ring. The ALS passed this milestone on 24 March, a week ahead of the official deadline. Once injected, the electron beam decays quasi-exponentially primarily because of interactions with residual gas molecules in the storage-ring vacuum chamber. Eventually, when the pressure in the vacuum chamber with beam decreases toward the expected operating level of 1 nano Torr, it will only be necessary to refill the storage ring at intervals of four to eight hours. At present the vacuum is improving rapidly as surfaces are irradiated (scrubbed) by the synchrotron radiation itself. At 100 mA, beam lifetime was about one hour (9 April)

Compressible Vortex Ring

Science.gov (United States)

Elavarasan, Ramasamy; Arakeri, Jayawant; Krothapalli, Anjaneyulu

1999-11-01

The interaction of a high-speed vortex ring with a shock wave is one of the fundamental issues as it is a source of sound in supersonic jets. The complex flow field induced by the vortex alters the propagation of the shock wave greatly. In order to understand the process, a compressible vortex ring is studied in detail using Particle Image Velocimetry (PIV) and shadowgraphic techniques. The high-speed vortex ring is generated from a shock tube and the shock wave, which precedes the vortex, is reflected back by a plate and made to interact with the vortex. The shadowgraph images indicate that the reflected shock front is influenced by the non-uniform flow induced by the vortex and is decelerated while passing through the vortex. It appears that after the interaction the shock is "split" into two. The PIV measurements provided clear picture about the evolution of the vortex at different time interval. The centerline velocity traces show the maximum velocity to be around 350 m/s. The velocity field, unlike in incompressible rings, contains contributions from both the shock and the vortex ring. The velocity distribution across the vortex core, core diameter and circulation are also calculated from the PIV data.

BERKELEY: ALS ring

International Nuclear Information System (INIS)

Anon.

1993-01-01

Everybody at Lawrence Berkeley Laboratory's Center for Beam Physics is pleased with the rapid progress in commissioning LBL's Advanced Light Source (ALS) electron storage ring, the foundation for this third-generation synchrotron radiation facility. Designed for a maximum current of 400 mA, the ALS storage ring reached 407 mA just 24 days after storing the first beam on 16 March. ALS construction as a US Department of Energy (DOE) national user facility to provide high-brightness vacuum ultra-violet and soft x-ray radiation began in October 1987. One technical requirement marking project completion was to accumulate a 50-mA current in the storage ring. The ALS passed this milestone on 24 March, a week ahead of the official deadline. Once injected, the electron beam decays quasi-exponentially primarily because of interactions with residual gas molecules in the storage-ring vacuum chamber. Eventually, when the pressure in the vacuum chamber with beam decreases toward the expected operating level of 1 nano Torr, it will only be necessary to refill the storage ring at intervals of four to eight hours. At present the vacuum is improving rapidly as surfaces are irradiated (scrubbed) by the synchrotron radiation itself. At 100 mA, beam lifetime was about one hour (9 April)

Accidental ingestion of BiTine ring and a note on inefficient ring separation forceps

Directory of Open Access Journals (Sweden)

Baghele ON

2011-05-01

Full Text Available Om Nemichand Baghele1, Mangala Om Baghele21Department of Periodontology, SMBT Dental College and Hospital, Sangamner, Ahmednagar, Maharashtra, India; 2Private General Dental Practice, Mumbai, IndiaBackground: Accidental ingestion of medium-to-large instruments is relatively uncommon during dental treatment but can be potentially dangerous. A case of BiTine ring ingestion is presented with a note on inefficient ring separation forceps.Case description: A 28-year-old male patient accidentally ingested the BiTine ring (2 cm diameter, 0.5 cm outward projections while it was being applied to a distoproximal cavity in tooth # 19. The ring placement forceps were excessively flexible; bending of the beaks towards the ring combined with a poor no-slippage mechanism led to sudden disengagement of the ring and accelerated movement towards the pharynx. We followed the patient with bulk forming agents and radiographs. Fortunately the ring passed out without any complications.Clinical implications: Checking equipment and methods is as important as taking precautions against any preventable medical emergency. It is the responsibility of the clinician to check, verify and then use any instrument/equipment.Keywords: foreign bodies/radiography, foreign bodies/complications, equipment failure, dental instrument, accidental ingestion

5,5-Dihydroxybarbituric acid 1,4-dioxane hemisolvate

Directory of Open Access Journals (Sweden)

Thomas Gelbrich

2010-05-01

Full Text Available The asymmetric unit of the title compound,, C4H4N2O5·0.5C4H8O2, contains one molecule of 5,5-dihydroxybarbituric acid with a nearly planar barbiturate ring and half a molecule of 1,4-dioxane. The geometry of the centrosymmetric dioxane molecule is close to an ideal chair conformation. The crystal structure exhibits a complex three-dimensional hydrogen-bonded network. Barbiturate molecules are connected to one another via N—H...O=C, O—H...O=C and N—H...O(hydroxy interactions, while the barbituric acid molecule is linked to dioxane by an O—H...O contact.

Biomarkers and biometric measures of adherence to use of ARV-based vaginal rings.

Science.gov (United States)

Stalter, Randy M; Moench, Thomas R; MacQueen, Kathleen M; Tolley, Elizabeth E; Owen, Derek H

2016-01-01

Poor adherence to product use has been observed in recent trials of antiretroviral (ARV)-based oral and vaginal gel HIV prevention products, resulting in an inability to determine product efficacy. The delivery of microbicides through vaginal rings is widely perceived as a way to achieve better adherence but vaginal rings do not eliminate the adherence challenges exhibited in clinical trials. Improved objective measures of adherence are needed as new ARV-based vaginal ring products enter the clinical trial stage. To identify technologies that have potential future application for vaginal ring adherence measurement, a comprehensive literature search was conducted that covered a number of biomedical and public health databases, including PubMed, Embase, POPLINE and the Web of Science. Published patents and patent applications were also searched. Technical experts were also consulted to gather more information and help evaluate identified technologies. Approaches were evaluated as to feasibility of development and clinical trial implementation, cost and technical strength. Numerous approaches were identified through our landscape analysis and classified as either point measures or cumulative measures of vaginal ring adherence. Point measurements are those that give a measure of adherence at a particular point in time. Cumulative measures attempt to measure ring adherence over a period of time. Approaches that require modifications to an existing ring product are at a significant disadvantage, as this will likely introduce additional regulatory barriers to the development process and increase manufacturing costs. From the point of view of clinical trial implementation, desirable attributes would be high acceptance by trial participants, and little or no additional time or training requirements on the part of participants or clinic staff. We have identified four promising approaches as being high priority for further development based on the following measurements

On the Laurent polynomial rings

International Nuclear Information System (INIS)

Stefanescu, D.

1985-02-01

We describe some properties of the Laurent polynomial rings in a finite number of indeterminates over a commutative unitary ring. We study some subrings of the Laurent polynomial rings. We finally obtain two cancellation properties. (author)

The Hi-Ring DCN Architecture

DEFF Research Database (Denmark)

Galili, Michael; Kamchevska, Valerija; Ding, Yunhong

2016-01-01

We will review recent work on the proposed hierarchical ring-based architecture (HiRing) proposed for data center networks. We will discuss the architecture and initial demonstrations of optical switching performance and time-domain synchronization......We will review recent work on the proposed hierarchical ring-based architecture (HiRing) proposed for data center networks. We will discuss the architecture and initial demonstrations of optical switching performance and time-domain synchronization...

(6S,7S,8S,8aS-6-Ethyl-7,8-dihydroxy-1,5,6,7,8,8a-hexahydroindolizin-3(2H-one monohydrate

Directory of Open Access Journals (Sweden)

Jozefína Žúžiová

2010-12-01

Full Text Available The absolute configuration of the title compound, C10H17NO3·H2O, was assigned from the synthesis. In the molecular structure, the central six-membered ring of the indolizine moiety adopts a chair conformation, with two atoms displaced by −0.578 (2 and 0.651 (1 Å from the plane of the other four atoms [maximum deviation 0.019 (2 Å] The conformation of the fused oxopyrrolidine ring is close to that of a flat envelope, with the flap atom displaced by 0.294 (1 Å from the plane through the remaining four atoms. In the crystal, one of the hydroxy groups is hydrogen-bonded to two water molecules, while the other hydroxy group exhibits an intermolecular hydrogen bond to the carbonyl O atom, resulting in a chain parallel to the b axis.

EBT ring physics

International Nuclear Information System (INIS)

Uckan, N.A.

1980-04-01

This workshop attempted to evaluate the status of the current experimental and theoretical understanding of hot electron ring properties. The dominant physical processes that influence ring formation, scaling, and their optimal behavior are also studied. Separate abstracts were prepared for each of the 27 included papers

Do Institutional Logics Predict Interpretation of Contract Rules at the Dental Chair-side?

DEFF Research Database (Denmark)

Harris, Rebecca; Brown, Stephen; Holt, Robin

2014-01-01

understands opportunism as fully rational, individual responses selecting maximally efficient outcomes from a set of possibilities. We take a more emotive and collective view of contracting, exploring the influence of institutional logics in relation to the opportunistic behaviour of dentists. Following...... earlier qualitative work where we identified four institutional logics in English general dental practice, and six dental contract areas where there was scope for opportunism; in 2013 we surveyed 924 dentists to investigate these logics and whether they had predictive purchase over dentists' chair...

Ground Movement in SSRL Ring

International Nuclear Information System (INIS)

Sunikumar, Nikita

2011-01-01

Users of the Stanford Synchrotron Radiation Lightsource (SSRL) are being affected by diurnal motion of the synchrotron's storage ring, which undergoes structural changes due to outdoor temperature fluctuations. In order to minimize the effects of diurnal temperature fluctuations, especially on the vertical motion of the ring floor, scientists at SSRL tried three approaches: painting the storage ring white, covering the asphalt in the middle of the ring with highly reflective Mylar and installing Mylar on a portion of the ring roof and walls. Vertical motion in the storage ring is measured by a Hydrostatic Leveling System (HLS), which calculates the relative height of water in a pipe that extends around the ring. The 24-hr amplitude of the floor motion was determined using spectral analysis of HLS data, and the ratio of this amplitude before and after each experiment was used to quantitatively determine the efficacy of each approach. The results of this analysis showed that the Mylar did not have any significant effect on floor motion, although the whitewash project did yield a reduction in overall HLS variation of 15 percent. However, further analysis showed that the reduction can largely be attributed to a few local changes rather than an overall reduction in floor motion around the ring. Future work will consist of identifying and selectively insulating these local regions in order to find the driving force behind diurnal floor motion in the storage ring.

Designing a ring-VCO for RFID transponders in 0.18 μm CMOS process.

Science.gov (United States)

Jalil, Jubayer; Reaz, Mamun Bin Ibne; Bhuiyan, Mohammad Arif Sobhan; Rahman, Labonnah Farzana; Chang, Tae Gyu

2014-01-01

In radio frequency identification (RFID) systems, performance degradation of phase locked loops (PLLs) mainly occurs due to high phase noise of voltage-controlled oscillators (VCOs). This paper proposes a low power, low phase noise ring-VCO developed for 2.42 GHz operated active RFID transponders compatible with IEEE 802.11 b/g, Bluetooth, and Zigbee protocols. For ease of integration and implementation of the module in tiny die area, a novel pseudodifferential delay cell based 3-stage ring oscillator has been introduced to fabricate the ring-VCO. In CMOS technology, 0.18 μm process is adopted for designing the circuit with 1.5 V power supply. The postlayout simulated results show that the proposed oscillator works in the tuning range of 0.5-2.54 GHz and dissipates 2.47 mW of power. It exhibits a phase noise of -126.62 dBc/Hz at 25 MHz offset from 2.42 GHz carrier frequency.

Token ring technology report

CERN Document Server

2013-01-01

Please note this is a Short Discount publication. This report provides an overview of the IBM Token-Ring technology and products built by IBM and compatible vendors. It consists of two sections: 1. A summary of the design trade-offs for the IBM Token-Ring. 2. A summary of the products of the major token-ring compatible vendors broken down by adapters and components, wiring systems, testing, and new chip technology.

Quality factor enhancement in photonic crystal slabs by manipulation of the ring of exceptional points

DEFF Research Database (Denmark)

Kaminski, Piotr Marek; Taghizadeh, Alireza; Breinbjerg, Olav

2017-01-01

Presently, we investigate the influence of the extent of a ring of exceptional points on the Q-factor of three-dimensional photonic crystal slabs. By changing the thickness of the slab, the extent of the ring of exceptional points is varied, allowing us to recover the Dirac cones in open, non......-Hermitian systems. In this case, three bound states in the continuum are exhibited close to the Gamma-point. For an optimized thickness of the slab, the associated Q-factors are found to grow rapidly with the size of the slab. The present results may lead to novel, small area and high Q-factor photonic crystal...

Measurement of variable magnetic reversal paths in electrically contacted pseudo-spin-valve rings

International Nuclear Information System (INIS)

Hayward, T J; Llandro, J; Schackert, F D O; Morecroft, D; Balsod, R B; Bland, J A C; Castano, F J; Ross, C A

2007-01-01

In this work we show that the measurement of single magnetic reversal events is of critical importance in order to correctly characterize the switching of magnetic microstructures. Magnetoresistance measurements are performed on two pseudo-spin-valve ring structures with high enough signal to noise to allow the probing of single reversal events. Using this technique we acquire 'switching spectra' which demonstrate that the rings exhibit a range of variable reversal paths, including a bistable reversal mechanism of the hard layer, where the two switching routes have substantially different switching fields. The signature of the variable reversal paths would have been obscured in field cycle averaged data and in the bistable case would cause a fundamental misinterpretation of the reversal behaviour

Prototype moving-ring reactor

International Nuclear Information System (INIS)

Smith, A.C. Jr.; Ashworth, C.P.; Abreu, K.E.

1982-01-01

We have completed a design of the Prototype Moving-Ring Reactor. The fusion fuel is confined in current-carrying rings of magnetically-field-reversed plasma (Compact Toroids). The plasma rings, formed by a coaxial plasma gun, undergo adiabatic magnetic compression to ignition temperature while they are being injected into the reactor's burner section. The cylindrical burner chamber is divided into three burn stations. Separator coils and a slight axial guide field gradient are used to shuttle the ignited toroids rapidly from one burn station to the next, pausing for 1/3 of the total burn time at each station. D-T- 3 He ice pellets refuel the rings at a rate which maintains constant radiated power

Photoswitchable Dihydroazulene Macrocycles for Solar Energy Storage: The Effects of Ring Strain.

Science.gov (United States)

Vlasceanu, Alexandru; Frandsen, Benjamin N; Skov, Anders B; Hansen, Anne Schou; Rasmussen, Mads Georg; Kjaergaard, Henrik G; Mikkelsen, Kurt V; Nielsen, Mogens Brøndsted

2017-10-06

Efficient energy storage and release are two major challenges of solar energy harvesting technologies. The development of molecular solar thermal systems presents one approach to address these issues by tuning the isomerization reactions of photo/thermoswitches. Here we show that the incorporation of photoswitches into macrocyclic structures is a particularly attractive solution for increasing the storage time. We present the synthesis and properties of a series of macrocycles incorporating two dihydroazulene (DHA) photoswitching subunits, bridged by linkers of varying chain length. Independent of ring size, all macrocycles exhibit stepwise, light-induced, ring-opening reactions (DHA-DHA to DHA-VHF to VHF-VHF; VHF = vinylheptafulvene) with the first DHA undergoing isomerization with a similar efficiency as the uncyclized parent system while the second (DHA-VHF to VHF-VHF) is significantly slower. The energy-releasing, VHF-to-DHA, ring closures also occur in a stepwise manner and are systematically found to proceed slower in the more strained (smaller) cycles, but in all cases with a remarkably slow conversion of the second VHF to DHA. We managed to increase the half-life of the second VHF-to-DHA conversion from 65 to 202 h at room temperature by simply decreasing the ring size. A computational study reveals the smallest macrocycle to have the most energetic VHF-VHF state and hence highest energy density.

Polycomb Group Proteins RING1A and RING1B Regulate the Vegetative Phase Transition in Arabidopsis

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Jian Li

2017-05-01

Full Text Available Polycomb group (PcG protein-mediated gene silencing is a major regulatory mechanism in higher eukaryotes that affects gene expression at the transcriptional level. Here, we report that two conserved homologous PcG proteins, RING1A and RING1B (RING1A/B, are required for global H2A monoubiquitination (H2Aub in Arabidopsis. The mutation of RING1A/B increased the expression of members of the SQUAMOSA PROMOTER BINDING PROTEIN-LIKE (SPL gene family and caused an early vegetative phase transition. The early vegetative phase transition observed in ring1a ring1b double mutant plants was dependent on an SPL family gene, and the H2Aub status of the chromatin at SPL locus was dependent on RING1A/B. Moreover, mutation in RING1A/B affected the miRNA156a-mediated vegetative phase transition, and RING1A/B and the AGO7-miR390-TAS3 pathway were found to additively regulate this transition in Arabidopsis. Together, our results demonstrate that RING1A/B regulates the vegetative phase transition in Arabidopsis through the repression of SPL family genes.

The Professorial Chair (kursī ‘ilmī or kursī li-l-wa‘ẓ wa-l-irshād in Morocco

Directory of Open Access Journals (Sweden)

Erzini, Nadia

2013-06-01

Full Text Available Moroccan congregational mosques are equipped with a minbar (pulpit which is used for the Friday sermon. Many mosques in Morocco are also equipped with one or more smaller chairs, which differ in their form and function from the minbar. These chairs are used by professors to give regular lectures to students of traditional education, and by scholars to give occasional lectures to the general public. This tradition of the professorial chair was probably introduced to Morocco from the Middle East in the thirteenth century. Most of the existing chairs in Morocco seem to date from the nineteenth and twentieth centuries, and they continue to be made and used today. The chairs always have two steps, a seat, a backrest and armrests. This form probably evokes the original minbar of the Prophet in Medina, which had two steps and a seat, and this is one of many aspects of the conservatism and se parate evolution of Moroccan Malikism.Las mezquitas congregacionales en Marruecos suelen tener un almimbar (p?lpito que se utiliza durante el sermón de los viernes. Muchas mezquitas de Marruecos cuentan también con una o más sillas, diferenciadas del almimbar en su forma y su función ya que son utilizadas por los profesores para ensenar a los estudiantes de la educación tradicional, y por eruditos que dan conferencias ocasionales al p?blico en general. Esta tradición de cátedras se introduce probablemente en Marruecos desde Próximo Oriente en el siglo XIII. La mayoría de las cátedras existentes parecen datar de los siglos XIX y XX, manteniéndose hasta nuestros días la fabricación y utilización de estas sillas. Las cátedras siempre tienen dos peldanos, un asiento, un respaldo y apoyabrazos. La forma de las sillas parece evocar el almimbar original del Profeta en Medina, tradición que se muestra como uno de los muchos aspectos del conservadurismo y de la evolución distinta del Malikismo marroquí.

Three-dimensional chitin rings from body segments of a pet diplopod species: Characterization and protein interaction studies

Energy Technology Data Exchange (ETDEWEB)

Kaya, Murat, E-mail: muratkaya3806@yahoo.com [Department of Biotechnology and Molecular Biology, Faculty of Science and Letters, Aksaray University, 68100 Aksaray (Turkey); Mulerčikas, Povilas [Department of Biology and Plant Protection, Lithuanian University of Agriculture, LT-53361 (Lithuania); Sargin, Idris [Department of Chemistry, Faculty of Science, Selcuk University, 42075 Konya (Turkey); Kazlauskaitė, Sonata [Department of Biology and Plant Protection, Lithuanian University of Agriculture, LT-53361 (Lithuania); Baublys, Vykintas [Department of Biology, Vytautas Magnus University, LT-44404 Kaunas (Lithuania); Akyuz, Bahar; Bulut, Esra [Department of Biotechnology and Molecular Biology, Faculty of Science and Letters, Aksaray University, 68100 Aksaray (Turkey); Tubelytė, Vaida [Department of Biology, Vytautas Magnus University, LT-44404 Kaunas (Lithuania)

2016-11-01

Physicochemical characterization of new chitin isolates can provide valuable insights into designing of biomimetic materials. Chitin isolates with a definite three-dimensional (3D) structure can exhibit characteristics that distinguish them from other chitin specimens that are in form of powder or flakes without a definite and uniform shape. Herein, 3D chitin rings were produced from body segments of a diplopod (Archispirostreptus gigas) inhabiting tropical regions. This organism is cultured easily and can reach 38 cm in length, which makes it a suitable source for isolation of chitin. The chitin rings were characterized via TGA, FT-IR, SEM and XRD analyses. Enzymatic digestion test with chitinase demonstrated that chitin isolates had high purity (digestion rate: 97.4%). The source organism had high chitin content; 21.02 ± 2.23% on dry weight. Interactions of the chitin rings with bovine serum albumin (BSA) protein were studied under different conditions (pH: 4.0–8.0, chitin amount: 6–14 mg, contact time: 30–360 min, protein concentration: 0.2–1 mg/mL). The highest BSA adsorption was observed at pH 5.0 at 20 °C. The adsorption equilibrium data exhibited a better fit to Langmuir adsorption and the pseudo-first order kinetic models. The findings presented here can be useful for further studies aiming to develop biocompatible and nontoxic biomaterials. - Highlights: • Three-dimensional ring shaped chitin was produced from a pet diplopod species. • Archispirostreptus gigas has high chitin content; 21.02 ± 2.23% on dry weight. • Chitinase enzyme showed activity on the chitin rings with digestion rate of 97.4%. • The highest bovine serum albumin (BSA) adsorption was observed at pH 5.0 at 20 °C.

Researches on the Piston Ring

Science.gov (United States)

Ehihara, Keikiti

1944-01-01

In internal combustion engines, steam engines, air compressors, and so forth, the piston ring plays an important role. Especially, the recent development of Diesel engines which require a high compression pressure for their working, makes, nowadays, the packing action of the piston ring far more important than ever. Though a number of papers have been published in regard to researches on the problem of the piston ring, none has yet dealt with an exact measurement of pressure exerted on the cylinder wall at any given point of the ring. The only paper that can be traced on this subject so far is Mr. Nakagawa's report on the determination of the relative distribution of pressure on the cylinder wall, but the measuring method adopted therein appears to need further consideration. No exact idea has yet been obtained as to how the obturation of gas between the piston and cylinder, the frictional resistance of the piston, and the wear of the cylinder wall are affected by the intensity and the distribution of the radial pressure of the piston ring. Consequently, the author has endeavored, by employing an apparatus of his own invention, to get an exact determination of the pressure distribution of the piston ring. By means of a newly devised ring tester, to which piezoelectricity of quartz was applied, the distribution of the radial pressure of many sample rings on the market was accurately determined. Since many famous piston rings show very irregular pressure distribution, the author investigated and achieved a manufacturing process of the piston ring which will exert uniform pressure on the cylinder wall. Temperature effects on the configuration and on the mean spring power have also been studied. Further, the tests were performed to ascertain how the gas tightness of the piston ring may be affected by the number or spring power. The researches as to the frictional resistance between the piston ring and the cylinder wall were carried out, too. The procedure of study, and

Generation of stable mixed-compact-toroid rings by inducing plasma currents in strong E rings

International Nuclear Information System (INIS)

Jayakumar, R.; Taggart, D.P.; Parker, M.R.; Fleischmann, H.H.

1989-01-01

In the RECE-Christa device, hybrid-type compact toroid rings are generated by inducing large toroidal plasma currents I rho in strong electron rings using a thin induction coil positioned along the ring axis. Starting from field-reversal values δ ο = 50 - 120 percent of the original pure fast-electron ring, the induced plasma current I rho raises δ to a maximum value of up to 240 percent with I rho contributing more than 50 percent of the total ring current. Quite interestingly, the generated hybrid compact toroid configurations appear gross-stable during the full I rho pulse length (half-amplitude width about 100 μs)

Solar system history as recorded in the Saturnian ring structure

Science.gov (United States)

Alfven, H.

1983-01-01

Holberg's analysis of the Voyager Saturn photographs in reflected and transparent light, and occultation data of stars seen through the rings are discussed. A hyperfine structure, with 10,000 ringlets can be explained by the Baxter-Thompson negative diffusion. This gives the ringlets a stability which makes it possible to interpret them as fossils, which originated at cosmogonic times. It is shown that the bulk structure can be explained by the combined cosmogonic shadows of the satellites Mimas, Janus and the Shepherd satellites. This structure originated at the transition from the plasma phase to the planetesimal phase. The shadows are not simple void regions but exhibit a characteristic signature. Parts of the fine structure, explained by Holberg as resonances with satellites, are interpreted as cosmogonic shadow effects. However, there are a number of ringlets which can neither be explained by cosmogonic nor by resonance effects. Analysis of ring data can reconstruct the plasma-planetesimal transition with an accuracy of a few percent.

Factors Influencing Dental Students' Interest in Advanced Periodontal Education: Perspectives of Department Chairs.

Science.gov (United States)

Hearty, Luke; Demko, Catherine; Bissada, Nabil F; da Silva, Andre Paes B

2017-06-01

The number of graduates of U.S. dental schools enrolled in U.S. postdoctoral programs in periodontics has been decreasing. The aims of this study were to determine the perspectives of periodontics department chairs regarding 1) features of a school's predoctoral curriculum that promote student interest in advanced periodontal education and 2) characteristics of a periodontal residency program that make it more attractive to dental students over other specialty programs. In 2015, a 14-question survey was designed and sent to chairs of periodontics departments at all 65 U.S. dental schools at the time. Questions addressed number of instructional hours; specialty clinic rotations; elective courses; number of applicants to periodontal residency; existence of a residency program; length of the residency program; and externships, fellowships, and financial stipends offered. The survey response rate was 73.8%. The results showed that departments offering more than seven clinical credit hours in periodontics to predoctoral students had the greatest number of residency applicants. Most of the applicants were from institutions that offered specialty clinic rotations, elective courses, and residency programs in periodontics. The number of applicants did not change significantly if a stipend or fellowship was offered. However, the availability of an externship was significantly associated with a greater number of applicants (p=0.042). These results suggest that offering periodontal clinical rotations, elective courses, and especially externships in periodontics during predoctoral education may encourage more graduating students to pursue postdoctoral periodontal education.

Chair-side detection of Prevotella Intermedia in mature dental plaque by its fluorescence.

Science.gov (United States)

Nomura, Yoshiaki; Takeuchi, Hiroaki; Okamoto, Masaaki; Sogabe, Kaoru; Okada, Ayako; Hanada, Nobuhiro

2017-06-01

Prevotella intermedia/nigrescens is one of the well-known pathogens causing periodontal diseases, and the red florescence excited by the visible blue light caused by the protoporphyrin IX in the bacterial cells could be useful for the chair-side detection. The aim of this study was to evaluated levels of periodontal pathogen, especially P. intermedia in clinical samples of red fluorescent dental plaque. Thirty two supra gingival plaque samples from six individuals were measured its fluorescence at 640nm wavelength excited by 409nm. Periodontopathic bacteria were counted by the Invader PLUS PCR assay. Co-relations the fluorescence intensity and bacterial counts were analyzed by Person's correlation coefficient and simple and multiple regression analysis. Positive and negative predictive values of the fluorescence intensities for with or without P. intermedia in supragingival plaque was calculated. When relative fluorescence unit (RFU) were logarithmic transformed, statistically significant linear relations between RFU and bacterial counts were obtained for P. intermedia, Porphyromonas gingivalis and Tannerella forsythia. By the multiple regression analysis, only P. intermedia had statistically significant co-relation with fluorescence intensities. All of the fluorescent dental plaque contained P. intermedia m. In contrast, 28% of non-fluorescent plaques contained P. intermedia. To check the fluorescence dental plaque in the oral cavity could be the simple chair-side screening of the mature dental plaque before examining the periodontal pathogens especially P. intermedia by the PCR method. Copyright © 2017 Elsevier B.V. All rights reserved.

Magnetization of two coupled rings

International Nuclear Information System (INIS)

Avishai, Y; Luck, J M

2009-01-01

We investigate the persistent currents and magnetization of a mesoscopic system consisting of two clean metallic rings sharing a single contact point in a magnetic field. Many novel features with respect to the single-ring geometry are underlined, including the explicit dependence of wavefunctions on the Aharonov-Bohm fluxes, the complex pattern of two-fold and three-fold degeneracies, the key role of length and flux commensurability, and in the case of commensurate ring lengths the occurrence of idle levels which do not carry any current. Spin-orbit interactions, induced by the electric fields of charged wires threading the rings, give rise to a peculiar version of the Aharonov-Casher effect where, unlike for a single ring, spin is not conserved. Remarkably enough, this can only be realized when the Aharonov-Bohm fluxes in both rings are neither integer nor half-integer multiples of the flux quantum

A simplified chair-side remount technique using customized mounting platforms.

Science.gov (United States)

Chauhan, Mamta Devendrakumar; Dange, Shankar Pandharinath; Khalikar, Arun Narayan; Vaidya, Smita Padmakar

2012-08-01

Correct occlusal relationships are part of the successful prosthetic treatment for edentulous patients. Fabrication of complete dentures comprises of clinical and laboratory procedures that should be executed accurately for achieving success with fabricated dentures. Errors occurring during the clinical and laboratory procedures of a denture may subsequently lead to the occlusal errors in the final prosthesis. These occlusal errors can be corrected in two ways: i) in patient's mouth ii) by recording new centric relation and remounting dentures on an articulator. The latter method is more feasible because the mobility of denture base on the mucosa in oral cavity does not permit the identification of premature contacts in centric occlusion and tooth guided eccentric excursions. This article describes a modest and effective clinical chair-side remount procedure using customized mounting platforms.

Radioactive gold ring dermatitis

International Nuclear Information System (INIS)

Miller, R.A.; Aldrich, J.E.

1990-01-01

A superficial squamous cell carcinoma developed in a woman who wore a radioactive gold ring for more than 30 years. Only part of the ring was radioactive. Radiation dose measurements indicated that the dose to basal skin layer was 2.4 Gy (240 rad) per week. If it is assumed that the woman continually wore her wedding ring for 37 years since purchase, she would have received a maximum dose of approximately 4600 Gy

Analytical model for double split ring resonators with arbitrary ring width

DEFF Research Database (Denmark)

Zhurbenko, Vitaliy; Jensen, Thomas; Krozer, Viktor

2008-01-01

For the first time, the analytical model for a double split ring resonator with unequal width rings is developed. The proposed models for the resonators with equal and unequal widths are based on an impedance matrix representation and provide the prediction of performance in a wide frequency range...

Pure subrings of the rings Zχ

International Nuclear Information System (INIS)

Tsarev, Andrei V

2009-01-01

Pure subrings of finite rank in the Z-adic completion of the ring of integers and in its homomorphic images are considered. Certain properties of these rings are studied (existence of an identity element, decomposability into a direct sum of essentially indecomposable ideals, condition for embeddability into a csp-ring, etc.). Additive groups of these rings and conditions under which these rings are subrings of algebraic number fields are described. Bibliography: 12 titles.

Ring accelerators

International Nuclear Information System (INIS)

Gisler, G.; Faehl, R.

1983-01-01

We present two-dimensional simulations in (r-z) and r-theta) cylinderical geometries of imploding-liner-driven accelerators of rings of charged particles. We address issues of azimuthal and longitudinal stability of the rings. We discuss self-trapping designs in which beam injection and extraction is aided by means of external cusp fields. Our simulations are done with the 2-1/2-D particle-in-cell plasma simulation code CLINER, which combines collisionless, electromagnetic PIC capabilities with a quasi-MHD finite element package

Comparison of two chair-side tests for enumeration of Mutans Streptococci in saliva

DEFF Research Database (Denmark)

Twetman, Lisa; Twetman, Svante

2014-01-01

AIM: To compare the prevalence and levels of salivary Mutans Streptococci (MS) assessed with two commercial chair-side methods based on culture growth or monoclonal antibodies, respectively. MATERIAL AND METHODS: The study group consisted of a convenience sample of 89 adults, 23-72 years of age......, referred to a maxillofacial hospital clinic with a caries history. Stimulated whole saliva samples were collected and the number of MS was assessed with the Dentocult-SM Strip Mutans (DSM) and the Saliva-Check Mutans (SCM). The outcome was compared with conventional anaerobic laboratory cultivation...

Manipulation of vortex rings for flow control

International Nuclear Information System (INIS)

Toyoda, Kuniaki; Hiramoto, Riho

2009-01-01

This paper reviews the dynamics of vortex rings and the control of flow by the manipulation of vortex rings. Vortex rings play key roles in many flows; hence, the understanding of the dynamics of vortex rings is crucial for scientists and engineers dealing with flow phenomena. We describe the structures and motions of vortex rings in circular and noncircular jets, which are typical examples of flows evolving into vortex rings. For circular jets the mechanism of evolving, merging and breakdown of vortex rings is described, and for noncircular jets the dynamics of three-dimensional deformation and interaction of noncircular vortex rings under the effect of self- and mutual induction is discussed. The application of vortex-ring manipulation to the control of various flows is reviewed with successful examples, based on the relationship between the vortex ring dynamics and the flow properties. (invited paper)

5′-Methylsulfanyl-4′-oxo-7′-phenyl-3′,4′-dihydro-1′H-spiro[cyclohexane-1,2′-quinazoline]-8′-carbonitrile dimethylformamide monosolvate

Directory of Open Access Journals (Sweden)

Xuan Liu

2011-08-01

Full Text Available In the title compound, C21H21N3OS·C3H7NO, the carbonitrile molecule is built up of two fused six-membered rings and one six-membered ring linked through a spiro C atom. The 1,3-diaza ring adopts an envelope conformation and the cyclohexane ring adopts a chair conformation. The dihedral angle between the aromatic rings is 46.7 (3°. In the crystal, the components are linked by N—H...O hydrogen bonds.

The Rings of Saturn

Science.gov (United States)

Cuzzi, J. N.; Filacchione, G.; Marouf, E. A.

2018-03-01

One could become an expert on Saturn's iconic rings pretty easily in the early 1970s, as very little was known about them beyond the distinction between the A, B, and C rings, and the Cassini Division or "gap" between rings A and B (Alexander, 1962; Bobrov, 1970). Water ice was discovered spectroscopically on the ring particle surfaces, and radar and microwave emission observations proved that the particles must be centimeters to meters in size, consisting primarily, not just superficially, of water ice (Pollack, 1975). While a 2:1 orbital resonance with Mimas had long been suspected of having something to do with the Cassini Division, computers of the time were unable to model the subtle dynamical effects that we now know to dominate ring structure. This innocent state of affairs was exploded by the Voyager 1 and 2 encounters in 1980 and 1981. Spectacular images revealed filigree structure and odd regional color variations, and exquisitely detailed radial profiles of fluctuating particle abundance were obtained from the first stellar and radio occultations, having resolution almost at the scale of single particles. Voyager-era understanding was reviewed by Cuzzi et al. (1984) and Esposito et al. (1984). While the Voyager data kept ring scientists busy for decades, planning which led to the monumentally successful NASA-ESA-ASI Cassini mission, which arrived in 2004, had been under way even before Voyager got to Saturn. A review of pre-Cassini knowledge of Saturn's Rings can be found in Orton et al. (2009). This chapter will build on recent topical and process-specific reviews that treat the gamut of ring phenomena and its underlying physics in considerable detail (Colwell et al., 2009; Cuzzi et al., 2009; Horányi et al., 2009; Schmidt et al., 2009; Esposito, 2010; Tiscareno, 2013b; Esposito, 2014). We will follow and extend the general organization of Cuzzi et al. (2010), the most recent general discussion of Saturn's rings. For brevity and the benefit of the

Examination techniques for non-magnetic rings

International Nuclear Information System (INIS)

Metala, M.J.; Kilpatrick, N.L.; Frank, W.W.

1990-01-01

Until the introduction of 18Mn18Cr rings a few years ago, most non-magnetic steel rings for generator rotors were made from 18Mn5Cr alloy steel, which is highly susceptible to stress corrosion cracking in the presence of water. This, the latest in a series of papers on the subject of non-magnetic rings by the authors' company, provides a discussion of nondestructive examination of 18Mn5Cr rings for stress corrosion distress. With rings on the rotor, fluorescent penetrant, ultrasonic and special visual techniques are applied. With rings off the rotor, the fluorescent penetrant technique is used, with and without stress enhancement

Ionization cooling ring for muons

Directory of Open Access Journals (Sweden)

R. Palmer

2005-06-01

Full Text Available Practical ionization cooling rings could lead to lower cost or improved performance in neutrino factory or muon collider designs. The ring modeled here uses realistic three-dimensional fields. The performance of the ring compares favorably with the linear cooling channel used in the second U.S. Neutrino Factory Study. The normalized 6D emittance of an ideal ring is decreased by a factor of approximately 240, compared with a factor of only 15 for the linear channel. We also examine such real-world effects as windows on the absorbers and rf cavities and leaving empty lattice cells for injection and extraction. For realistic conditions the ring decreases the normalized 6D emittance by a factor of 49.

A question of merit: John Hutton Balfour, Joseph Hooker and the 'concussion' over the Edinburgh chair of botany.

Science.gov (United States)

Bellon, Richard

2005-03-01

In 1845, Robert Graham's death created a vacancy for the traditionally dual appointment to the University of Edinburgh's chair of botany and the Regius Keepership of the Edinburgh Royal Botanic Garden. John Hutton Balfour and Joseph Hooker emerged as the leading candidates. The contest quickly became embroiled in long running controversies over the nature and control of Scottish university education at a time of particular social and political tension after a recent schism in Church of Scotland. The politics of the appointment were complicated by the fact that the Edinburgh Town Council (which preferred Balfour) chose the chair while the keepership was under the patronage of the Westminster government (which preferred Hooker). Balfour eventually emerged triumphant after a bitter campaign marked on all sides by intense politicking. The struggle to replace Graham provides a case study in how Victorian men of science adapted their aspirations to the practical realities of life in industrial, reforming, imperial, multinational Britain.

Four- and eight-membered rings carbon nanotubes: A new class of carbon nanomaterials

Science.gov (United States)

Li, Fangfang; Lu, Junzhe; Zhu, Hengjiang; Lin, Xiang

2018-06-01

A new class of carbon nanomaterials composed of alternating four- and eight-membered rings is studied by density functional theory (DFT), including single-walled carbon nanotubes (SWCNTs) double-walled carbon nanotubes (DWCNTs) and triple-walled CNTs (TWCNTs). The analysis of geometrical structure shows that carbon atoms' hybridization in novel carbon tubular clusters (CTCs) and the corresponding carbon nanotubes (CNTs) are both sp2 hybridization; The thermal properties exhibit the high stability of these new CTCs. The results of energy band and density of state (DOS) indicate that the electronic properties of CNTs are independent of their diameter, number of walls and chirality, exhibit obvious metal properties.

Self-gravitation in Saturn's rings

International Nuclear Information System (INIS)

Salo, H.; Lukkari, J.

1982-01-01

In a ring-shaped collisional system self-gravitation reduces the equilibrium values of the geometric and optical thickness. In Saturn's rings both effects are appreciable. The previously found discrepancy between the calculated profile and the observed profile of the rings is chiefly caused by the omission of self-gravitation. (Auth.)

Saturn’s ring temperatures at equinox

Science.gov (United States)

Spilker, Linda J.; Ferrari, C.; Morishima, R.

2013-10-01

Modeling the thermal emission of Saturn's rings is challenging due to the numerous heating sources as well as the structural properties of the disk and of the particles that are closely related. At equinox, however, the main rings are externally heated by Saturn alone and the problem is somewhat simplified. We test the abilities of our current models to reproduce the temperatures observed with the Cassini CIRS instrument around equinox in August 2009. A simple semi-analytic model which includes mutual shadowing effects can mostly explain the radial profile of the equinox ring temperatures, except the model predicts lower temperatures than those observed for the A ring. The temperature variation at a given saturnocentric radius is primarily caused by observational geometry variations relative to Saturn. The observed temperature increases with decreasing Saturn-ring-observer angle. In addition, we found evidence that the leading hemispheres of particles are warmer than the trailing hemispheres at least for the C ring and probably for the A and B rings as well. This is explained if some fraction of particles has spin rates lower than the synchronous rotation rate as predicted by N-body simulations. The spin model for a monolayer ring (Ferrari, C., Leyrat, C., 2006, Astron. Astrophys. 447, 745-760) can fit the temperature variations with spacecraft longitude observed in the C ring with currently known thermal properties and a mixing of slow and fast rotators. The multilayer model (Morishima, R., Salo, H., Ohtsuki, K., 2009, Icarus 201, 634-654) can reproduce the temperatures of the B and C rings but gives A ring temperatures that are significantly lower than those observed as does the simple semi-analytic model. More advanced models which take into account self-gravity wakes may explain the A ring temperature behavior.

Solid state conformational classification of eight-membered rings

DEFF Research Database (Denmark)

Pérez, J.; García, L.; Kessler, M.

2005-01-01

A statistical classification of the solid state conformation in the title complexes using data retrieved from the Cambridge Structural Database (CSD) has been made. Phosphate and phosphinate complexes show a chair conformation preferably. In phosphonate complexes, the most frequent conformations...

Split ring containment attachment device

International Nuclear Information System (INIS)

Sammel, A.G.

1996-01-01

A containment attachment device is described for operatively connecting a glovebag to plastic sheeting covering hazardous material. The device includes an inner split ring member connected on one end to a middle ring member wherein the free end of the split ring member is inserted through a slit in the plastic sheeting to captively engage a generally circular portion of the plastic sheeting. A collar potion having an outer ring portion is provided with fastening means for securing the device together wherein the glovebag is operatively connected to the collar portion. 5 figs

Total synthesis of bryostatins: the development of methodology for the atom-economic and stereoselective synthesis of the ring C subunit.

Science.gov (United States)

Trost, Barry M; Frontier, Alison J; Thiel, Oliver R; Yang, Hanbiao; Dong, Guangbin

2011-08-22

Bryostatins, a family of structurally complicated macrolides, exhibit an exceptional range of biological activities. The limited availability and structural complexity of these molecules makes development of an efficient total synthesis particularly important. This article describes our initial efforts towards the total synthesis of bryostatins, in which chemoselective and atom-economical methods for the stereoselective assembly of the ring C subunit were developed. A Pd-catalyzed tandem alkyne-alkyne coupling/6-endo-dig cyclization sequence was explored and successfully pursued in the synthesis of a dihydropyran ring system. Elaboration of this methodology ultimately led to a concise synthesis of the ring C subunit of bryostatins. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Minimal Gromov-Witten rings

International Nuclear Information System (INIS)

Przyjalkowski, V V

2008-01-01

We construct an abstract theory of Gromov-Witten invariants of genus 0 for quantum minimal Fano varieties (a minimal class of varieties which is natural from the quantum cohomological viewpoint). Namely, we consider the minimal Gromov-Witten ring: a commutative algebra whose generators and relations are of the form used in the Gromov-Witten theory of Fano varieties (of unspecified dimension). The Gromov-Witten theory of any quantum minimal variety is a homomorphism from this ring to C. We prove an abstract reconstruction theorem which says that this ring is isomorphic to the free commutative ring generated by 'prime two-pointed invariants'. We also find solutions of the differential equation of type DN for a Fano variety of dimension N in terms of the generating series of one-pointed Gromov-Witten invariants

Electro-optical hybrid slip ring

Science.gov (United States)

Hong, En

2005-11-01

The slip ring is a rotary electrical interface, collector, swivel or rotary joint. It is a physical system that can perform continuous data transfer and data exchange between a stationary and a rotating structure. A slip ring is generally used to transfer data or power from an unrestrained, continuously rotating electro-mechanical system in real-time, thereby simplifying operations and eliminating damage-prone wires dangling from moving joints. Slip rings are widely used for testing, evaluating, developing and improving various technical equipment and facilities with rotating parts. They are widely used in industry, especially in manufacturing industries employing turbo machinery, as in aviation, shipbuilding, aerospace, defense, and in precise facilities having rotating parts such as medical Computerized Tomography (CT) and MRI scanners and so forth. Therefore, any improvement in slip ring technology can impact large markets. Research and development in this field will have broad prospects long into the future. The goal in developing the current slip ring technology is to improve and increase the reliability, stability, anti-interference, and high data fidelity between rotating and stationary structures. Up to now, there have been numerous approaches used for signal and data transfer utilizing a slip ring such as metal contacts, wires, radio transmission, and even liquid media. However, all suffer from drawbacks such as data transfer speed limitations, reliability, stability, electro-magnetic interference and durability. The purpose of the current research is to break through these basic limitations using an optical solution, thereby improving performance in current slip ring applications. This dissertation introduces a novel Electro-Optical Hybrid Slip Ring technology, which makes "through the air" digital-optical communication between stationary and rotating systems a reality with high data transfer speed, better reliability and low interference susceptibility

(±-Pestalachloride D, an Antibacterial Racemate of Chlorinated Benzophenone Derivative from a Soft Coral-Derived Fungus Pestalotiopsis sp.

Directory of Open Access Journals (Sweden)

Dong-Sheng Deng

2013-03-01

Full Text Available A new antibacterial chlorinated benzophenone derivative, (±-pestalachloride D (1, along with a related analog, (±-pestalachloride C (2, was recently isolated from the marine-derived fungus Pestalotiopsis sp. isolated from a soft coral Sarcophyton sp. collected from Yongxing Island in the South China Sea. Both chiral HPLC analysis and single-crystal X-ray data indicated that 1 is a racemic mixture. Interestingly, 1 did not exhibit any effect in the zebrafish embryo teratogenicity assay, while 2 led to abnormal growth. The potential impact on zebrafish embryo growth is discussed based on their crystal structures. The main difference of crystal structures between 1 and 2 is that the six-member non-aromatic ring (O4, C10, C9, C8, C2′, and C3′ in 1 exhibits a distorted chair conformation, while 2 shows a distorted boat conformation. Moreover, compounds 1 and 2 both exhibited moderate antibacterial activity.

Double acting stirling engine piston ring

Science.gov (United States)

Howarth, Roy B.

1986-01-01

A piston ring design for a Stirling engine wherein the contact pressure between the piston and the cylinder is maintained at a uniform level, independent of engine conditions through a balancing of the pressure exerted upon the ring's surface and thereby allowing the contact pressure on the ring to be predetermined through the use of a preloaded expander ring.

Situating the embodied mind in a landscape of standing affordances for living without chairs : Materializing a philosophical worldview

NARCIS (Netherlands)

Rietveld, E.

Sitting too much is unhealthy, but a widespread habit in many societies. Realizing behavioral change in this area is hard. Our societies promote being seated via the way its places are structured: they are filled with chairs for example. How can we make healthier environments that invite people to

Situating the Embodied Mind in a Landscape of Standing Affordances for Living Without Chairs: Materializing a Philosophical Worldview

NARCIS (Netherlands)

Rietveld, Erik

2016-01-01

Sitting too much is unhealthy, but a widespread habit in many societies. Realizing behavioral change in this area is hard. Our societies promote being seated via the way its places are structured: they are filled with chairs for example. How can we make healthier environments that invite people to

Piezoelectric Lead Zirconate Titanate (PZT) Ring Shaped Contour-Mode MEMS Resonators

Science.gov (United States)

Kasambe, P. V.; Asgaonkar, V. V.; Bangera, A. D.; Lokre, A. S.; Rathod, S. S.; Bhoir, D. V.

2018-02-01

Flexibility in setting fundamental frequency of resonator independent of its motional resistance is one of the desired criteria in micro-electromechanical (MEMS) resonator design. It is observed that ring-shaped piezoelectric contour-mode MEMS resonators satisfy this design criterion than in case of rectangular plate MEMS resonators. Also ring-shaped contour-mode piezoelectric MEMS resonator has an advantage that its fundamental frequency is defined by in-plane dimensions, but they show variation of fundamental frequency with different Platinum (Pt) thickness referred as change in ratio of fNEW /fO . This paper presents the effects of variation in geometrical parameters and change in piezoelectric material on the resonant frequencies of Platinum piezoelectric-Aluminium ring-shaped contour-mode MEMS resonators and its electrical parameters. The proposed structure with Lead Zirconate Titanate (PZT) as the piezoelectric material was observed to be a piezoelectric material with minimal change in fundamental resonant frequency due to Platinum thickness variation. This structure was also found to exhibit extremely low motional resistance of 0.03 Ω as compared to the 31-35 Ω range obtained when using AlN as the piezoelectric material. CoventorWare 10 is used for the design, simulation and corresponding analysis of resonators which is Finite Element Method (FEM) analysis and design tool for MEMS devices.

Fusion Rings for Quantum Groups

DEFF Research Database (Denmark)

Andersen, Henning Haahr; Stroppel, Catharina

2012-01-01

We study the fusion rings of tilting modules for a quantum group at a root of unity modulo the tensor ideal of negligible tilting modules. We identify them in type A with the combinatorial rings from [12] and give a similar description of the sp2n-fusion ring in terms of noncommutative symmetric...

Topological rings

CERN Document Server

Warner, S

1993-01-01

This text brings the reader to the frontiers of current research in topological rings. The exercises illustrate many results and theorems while a comprehensive bibliography is also included. The book is aimed at those readers acquainted with some very basic point-set topology and algebra, as normally presented in semester courses at the beginning graduate level or even at the advanced undergraduate level. Familiarity with Hausdorff, metric, compact and locally compact spaces and basic properties of continuous functions, also with groups, rings, fields, vector spaces and modules, and with Zorn''s Lemma, is also expected.

Energy spectra of quantum rings.

Science.gov (United States)

Fuhrer, A; Lüscher, S; Ihn, T; Heinzel, T; Ensslin, K; Wegscheider, W; Bichler, M

2001-10-25

Quantum mechanical experiments in ring geometries have long fascinated physicists. Open rings connected to leads, for example, allow the observation of the Aharonov-Bohm effect, one of the best examples of quantum mechanical phase coherence. The phase coherence of electrons travelling through a quantum dot embedded in one arm of an open ring has also been demonstrated. The energy spectra of closed rings have only recently been studied by optical spectroscopy. The prediction that they allow persistent current has been explored in various experiments. Here we report magnetotransport experiments on closed rings in the Coulomb blockade regime. Our experiments show that a microscopic understanding of energy levels, so far limited to few-electron quantum dots, can be extended to a many-electron system. A semiclassical interpretation of our results indicates that electron motion in the rings is governed by regular rather than chaotic motion, an unexplored regime in many-electron quantum dots. This opens a way to experiments where even more complex structures can be investigated at a quantum mechanical level.

Forandringslæring med autismediagnoser?

DEFF Research Database (Denmark)

Gustafson, Kari Ingrid; Mørck, Line Lerche

2013-01-01

Artiklen drøfter en række aktuelle spørgsmål omkring læring hos børn og unge med autisme-spektrum-forstyrrelses diagnoser. Der introduceres til en social praksisteoretisk forståelse af forandringslæring, der diskuterer forandring ikke kun i relation til en persons identitet, men også aktuelle og...... potentielle forandringer, når det gælder overskridelse af binær logik i autisme versus normalitet, samt i relation til at overskride individualiserede og dualistiske problem-forståelser af fejl og mangler ved det autistiske barn. Det illustreres, hvordan disse former for dualistisk tænkning er forankret i et...... Rasmus’ ændringer i læring, selvforståelse og tilhørsforhold perspektiveres med andre ASF-diagnostiseredes læring udforsket bl.a. gennem gruppeinterviews i regi af Asperger-foreningen. Artiklen byder således på et alternativ i form af at forstå forandringslæring som overskridende læring, med langt større...

1-Bromo-2,4,6-tricyclohexylbenzene

Directory of Open Access Journals (Sweden)

Joel T. Mague

2008-01-01

Full Text Available The title compound, C24H25Br, packs efficiently in the crystal structure with no solvent-accessible voids and several intermolecular H...H contacts approximating the sum of the van der Waals radii. The molecule is quite crowded, with intramolecular Br...H and C...H contacts ca 0.38 and 0.30 Å, respectively, less than the sum of the corresponding van der Waals radii. All cyclohexyl rings adopt chair conformations with the `seat' of the chair inclined at approximately 57–81° to the mean plane of the benzene ring, while those ortho to bromine have their centroids displaced in opposite directions from this plane.

The Lord of Rings - the mysterious case of the stolen rings: a critical analysis

Science.gov (United States)

Sandrelli, S.

The Lord of Rings - the mysterious case of the stolen rings: a critical analysis S. Sandrelli INAF - Osservatorio Astronomico di Brera, Milano, Italy (stefano.sandrelli@brera.inaf.it / Fax: 02 72001600 / Phone: +39 02 72320337) "The Lord of Rings - the mysterious case of the stolen rings" is a live astronomical role-playing game for kids aged 10 -13. Its goal is to introduce them to some of the main topics of the Solar System: a) the role of gravity; b) the distribution of mass & light; c) the effects of rotation; d) the distribution of water. The game was held both at the Perugia (2004) and the Genova Science Festival (2005), obtaining great success. Teams of about 6-8 members are introduced to Mr Schioppanelli, the astro-detective of the town (the name is a pun: it reminds Schiaparelli, the famous italian astronomer, and it is a slang expression meaning "ring-breaker"). Mr Schioppanelli has his office in an "gastronomical astronomical observatory", known as The Red Giant Pizzeria. Schioppanelli informs the kids that a mysterious Centaur succeded in stealing the rings of Saturn. The partecipants are appointed astro-detectives in-charge and asked to find the rings by browsing around the Solar System, which is scaled so as to fit the town historical centre or a pedestrian area, going from the Sun to Saturn or beyond, depending on the actual area at disposal. Great care must be taken allowing children playing only in a car-free area of the town. At the right scaled distances, the partecipants meet characters playing as the various planets. The kids can talk to them after solving a riddle, obtaining useful informations. A special characters play as a comet, timely going in and out of the inner solar system. The teams can also talk to some shepherd-moons of the rings. They easily discover that the rings were totally destroyed by the Centaur: a real disaster! They are also suggested to gather the necessary ingredients (gravity, light, rotation, inclination, dust and

Vortex rings in classical and quantum systems

International Nuclear Information System (INIS)

Barenghi, C F; Donnelly, R J

2009-01-01

The study of vortex rings has been pursued for decades and is a particularly difficult subject. However, the discovery of quantized vortex rings in superfluid helium has greatly increased interest in vortex rings with very thin cores. While rapid progress has been made in the simulation of quantized vortex rings, there has not been comparable progress in laboratory studies of vortex rings in a viscous fluid such as water. This article overviews the history and current frontiers of classical and quantum vortex rings. After introducing the classical results, this review discusses thin-cored vortex rings in superfluid helium in section 2, and recent progress in understanding vortex rings of very thin cores propagating in water in section 3. (invited paper)

Laparoscopic appendicectomy using endo-ring applicator and fallope rings

International Nuclear Information System (INIS)

Ali, Iyoob V; Maliekkal, Joji I

2009-01-01

Wider adoption of laparoscopic appendicectomy (LA) is limited by problems in securing the appendiceal base as well as the cost and the duration compared with the open procedure. The objective of this study was to assess the feasibility and efficacy of a new method for securing the appendiceal base in LA, so as to make the entire procedure simpler and cheaper, and hence, more popular. Twenty-five patients who were candidates for appendicectomy (emergency as well as elective) and willing for the laparoscopic procedure were selected for this study. Ports used were 10 mm at the umbilicus, 5 mm at the lower right iliac fossa, and 10 mm at the left iliac fossa. Extremely friable, ruptured, or turgid organs of diameters larger than 8 mm were excluded from the study. The mesoappendix was divided close to the appendix by diathermy. Fallope rings were applied to the appendiceal base using a special ring applicator, and the appendix was divided and extracted through the lumen of the applicator. The procedure was successful in 23 (92%) cases, and the mean duration of the procedure was 20 minutes (15-32 minutes). There were no procedural complications seen during a median follow-up of two weeks. The equipment and rings were cheaper when compared with that of the standard methods of securing the base of the appendix. LA using fallope rings is a safe, simple, easy-to-learn, and economically viable method. (author)

Experimental evidence for interactions between anions and electron-deficient aromatic rings.

Science.gov (United States)

Berryman, Orion B; Johnson, Darren W

2009-06-14

This feature article summarizes our research aimed at using electron-deficient aromatic rings to bind anions in the context of complementary research in this active field. Particular attention is paid to the different types of interactions exhibited between anions and electron-deficient arenes in solution. The 120+ references cited in this article underscore the flurry of recent activity by numerous researchers in this field, which was relatively nascent when our efforts began in 2005. While the interaction of anions with electron-deficient aromatic rings has recently garnered much attention by supramolecular chemists, the observation of these interactions is not a recent discovery. Therefore, we begin with a historical perspective on early examples of anions interacting with electron-deficient arenes. An introduction to recent (and not so recent) computational investigations concerning anions and electron-deficient aromatic rings as well as a brief structural survey of crystalline examples of this interaction are provided. Finally, the limited solution-based observations of anions interacting with electron-deficient aromatic rings are summarized to introduce our current investigations in this area. We highlight three different systems from our lab where anion-arene interactions have been investigated. First, we show that tandem hydrogen bonds and anion-arene interactions augment halide binding in solution. Second, a crystallographic and computational study highlights the multiple types of interactions possible between anions and electron-deficient arenes. Third, we summarize the first example of a class of designed receptors that emphasize the different types of anion-arene interactions possible in solution.

SMARANDACHE NON-ASSOCIATIVE RINGS

OpenAIRE

Vasantha, Kandasamy

2002-01-01

An associative ring is just realized or built using reals or complex; finite or infinite by defining two binary operations on it. But on the contrary when we want to define or study or even introduce a non-associative ring we need two separate algebraic structures say a commutative ring with 1 (or a field) together with a loop or a groupoid or a vector space or a linear algebra. The two non-associative well-known algebras viz. Lie algebras and Jordan algebras are mainly built using a vecto...

Heavy ion storage rings

International Nuclear Information System (INIS)

Schuch, R.

1987-01-01

A brief overview of synchrotron storage rings for heavy ions, which are presently under construction in different accelerator laboratories is given. Ions ranging from protons up to uranium ions at MeV/nucleon energies will be injected into these rings using multiturn injection from the accelerators available or being built in these laboratories. After injection, it is planned to cool the phase space distribution of the ions by merging them with cold electron beams or laser beams, or by using stochastic cooling. Some atomic physics experiments planned for these rings are presented. 35 refs

Moving ring reactor 'Karin-1'

International Nuclear Information System (INIS)

1983-12-01

The conceptual design of a moving ring reactor ''Karin-1'' has been carried out to advance fusion system design, to clarify the research and development problems, and to decide their priority. In order to attain these objectives, a D-T reactor with tritium breeding blanket is designed, a commercial reactor with net power output of 500 MWe is designed, the compatibility of plasma physics with fusion engineering is demonstrated, and some other guideline is indicated. A moving ring reactor is composed mainly of three parts. In the first formation section, a plasma ring is formed and heated up to ignition temperature. The plasma ring of compact torus is transported from the formation section through the next burning section to generate fusion power. Then the plasma ring moves into the last recovery section, and the energy and particles of the plasma ring are recovered. The outline of a moving ring reactor ''Karin-1'' is described. As a candidate material for the first wall, SiC was adopted to reduce the MHD effect and to minimize the interaction with neutrons and charged particles. The thin metal lining was applied to the SiC surface to solve the problem of the compatibility with lithium blanket. Plasma physics, the engineering aspect and the items of research and development are described. (Kako, I.)

Tinkering at the main-ring lattice

Energy Technology Data Exchange (ETDEWEB)

Ohnuma, S.

1982-08-23

To improve production of usable antiprotons using the proton beam from the main ring and the lossless injection of cooled antiprotons into the main ring, modifications of the main ring lattice are recommended.

The ring plus project: safety and acceptability of vaginal rings that protect women from unintended pregnancy

OpenAIRE

Schurmans, C?line; De Baetselier, Irith; Kestelyn, Evelyne; Jespers, Vicky; Delvaux, Th?r?se; Agaba, Stephen K; van Loen, Harry; Menten, Joris; van de Wijgert, Janneke; Crucitti, Tania

2015-01-01

Background Research is ongoing to develop multipurpose vaginal rings to be used continuously for contraception and to prevent Human Immunodeficiency Virus (HIV) infection. Contraceptive vaginal rings (CVRs) are available in a number of countries and are most of the time used intermittently i.e. three weeks out of a 4-week cycle. Efficacy trials with a dapivirine-containing vaginal ring for HIV prevention are ongoing and plans to develop multi-purpose vaginal rings for prevention of both HIV a...

Pyrimidine-pyridine ring interconversion

NARCIS (Netherlands)

Plas, van der H.C.

2003-01-01

This chapter discusses the pyrimidine-to-pyridine ring transformation and pyridine-to-pyrimidine ring transformation. In nucleophile-induced pyrimidine-to-pyridine rearrangements, two types of reactions can be distinguished depending on the structure of the nucleophile: (1) reactions in which the

Electron beam cooling at a magnetic storage ring, TARN II, and an electrostatic storage ring

International Nuclear Information System (INIS)

Tanabe, Tetsumi

2006-01-01

At the High Energy Accelerator Research Organization (KEK), a magnetic storage ring, TARN II, with an electron cooler was operated from 1989 to 1999, while an electrostatic storage ring with a small electron cooler has been operational since 2000. In this paper, the electron cooling at TARN II and the electrostatic storage ring is described. (author)

Leapfrogging of multiple coaxial viscous vortex rings

International Nuclear Information System (INIS)

Cheng, M.; Lou, J.; Lim, T. T.

2015-01-01

A recent theoretical study [Borisov, Kilin, and Mamaev, “The dynamics of vortex rings: Leapfrogging, choreographies and the stability problem,” Regular Chaotic Dyn. 18, 33 (2013); Borisov et al., “The dynamics of vortex rings: Leapfrogging in an ideal and viscous fluid,” Fluid Dyn. Res. 46, 031415 (2014)] shows that when three coaxial vortex rings travel in the same direction in an incompressible ideal fluid, each of the vortex rings alternately slips through (or leapfrogs) the other two ahead. Here, we use a lattice Boltzmann method to simulate viscous vortex rings with an identical initial circulation, radius, and separation distance with the aim of studying how viscous effect influences the outcomes of the leapfrogging process. For the case of two identical vortex rings, our computation shows that leapfrogging can be achieved only under certain favorable conditions, which depend on Reynolds number, vortex core size, and initial separation distance between the two rings. For the case of three coaxial vortex rings, the result differs from the inviscid model and shows that the second vortex ring always slips through the leading ring first, followed by the third ring slipping through the other two ahead. A simple physical model is proposed to explain the observed behavior

A replicated field intervention study evaluating the impact of a highly adjustable chair and office ergonomics training on visual symptoms☆

Science.gov (United States)

Menéndez, Cammie Chaumont; Amick, Benjamin C.; Robertson, Michelle; Bazzani, Lianna; DeRango, Kelly; Rooney, Ted; Moore, Anne

2016-01-01

Objective Examine the effects of two office ergonomics interventions in reducing visual symptoms at a private sector worksite. Methods A quasi-experimental study design evaluated the effects of a highly adjustable chair with office ergonomics training intervention (CWT group) and the training only (TO group) compared with no intervention (CO group). Data collection occurred 2 and 1 month(s) pre-intervention and 2, 6 and 12 months post-intervention. During each data collection period, a work environment and health questionnaire (covariates) and daily health diary (outcomes) were completed. Multilevel statistical models tested hypotheses. Results Both the training only intervention (p office ergonomics training alone and coupled with a highly adjustable chair reduced visual symptoms. In replicating results from a public sector worksite at a private sector worksite the external validity of the interventions is strengthened, thus broadening its generalizability. PMID:22030069

A replicated field intervention study evaluating the impact of a highly adjustable chair and office ergonomics training on visual symptoms.

Science.gov (United States)

Menéndez, Cammie Chaumont; Amick, Benjamin C; Robertson, Michelle; Bazzani, Lianna; DeRango, Kelly; Rooney, Ted; Moore, Anne

2012-07-01

Examine the effects of two office ergonomics interventions in reducing visual symptoms at a private sector worksite. A quasi-experimental study design evaluated the effects of a highly adjustable chair with office ergonomics training intervention (CWT group) and the training only (TO group) compared with no intervention (CO group). Data collection occurred 2 and 1 month(s) pre-intervention and 2, 6 and 12 months post-intervention. During each data collection period, a work environment and health questionnaire (covariates) and daily health diary (outcomes) were completed. Multilevel statistical models tested hypotheses. Both the training only intervention (poffice ergonomics training alone and coupled with a highly adjustable chair reduced visual symptoms. In replicating results from a public sector worksite at a private sector worksite the external validity of the interventions is strengthened, thus broadening its generalizability. Published by Elsevier Ltd.

2-Isopropyl-5-methylcyclohexyl quinoline-2-carboxylate

Directory of Open Access Journals (Sweden)

E. Fazal

2014-01-01

Full Text Available In the title compound, C20H25NO2, the cyclohexyl ring adopts a slightly disordered chair conformation. The dihedral angle between the mean planes of the quinoline ring and the carboxylate group is 22.2 (6°. In the crystal, weak C—H...N interactions make chains along [010].

Crystal structure of 7,7-dimethyl-6-methylidenetricyclo[6.2.1.01,5]undecane-2-carboxylic acid

Directory of Open Access Journals (Sweden)

Noureddine Beghidja

2015-02-01

Full Text Available In the title compound, C15H22O2, both five-membered rings display an envelope conformation whereas the six-membered ring displays a chair conformation. In the crystal, pairs of O—H...O hydrogen bonds between carboxylic groups link molecules, related by a twofold rotation axis, into supramolecular dimers.

Redox shuttles having an aromatic ring fused to a 1,1,4,4-tetrasubstituted cyclohexane ring

Science.gov (United States)

Weng, Wei; Zhang, Zhengcheng; Amine, Khalil

2015-12-01

An electrolyte includes an alkali metal salt; an aprotic solvent; and a redox shuttle additive including an aromatic compound having at least one aromatic ring fused with at least one non-aromatic ring, the aromatic ring having two or more oxygen or phosphorus-containing substituents.

meso-4,4′-Dimethoxy-2,2′-{[(3aR,7aS-2,3,3a,4,5,6,7,7a-octahydro-1H-benzimidazole-1,3-diyl]bis(methylene}diphenol

Directory of Open Access Journals (Sweden)

Augusto Rivera

2013-07-01

Full Text Available The title compound, C23H30N2O4, a di-Mannich base derived from 4-methoxyphenol and cis-1,2-diaminecyclohexane, has a perhydrobenzimidazolidine nucleus, in which the cyclohexane ring adopts a chair conformation and the heterocyclic ring has a half-chair conformation with a C—N—C—C torsion angles of −48.14 (15 and −14.57 (16°. The mean plane of the heterocycle makes dihedral angles of 86.29 (6 and 78.92 (6° with the pendant benzene rings. The molecular structure of the title compound shows the presence of two interactions between the N atoms of the imidazolidine ring and the hydroxyl groups through intramolecular O—H...N hydrogen bonds with graph-set motif S(6. The unobserved lone pairs of the N atoms are presumed to be disposed in a syn conformation, being only the second example of an exception to the typical `rabbit-ears' effect in 1,2-diamines.

Interaction of Vortex Ring with Cutting Plate

Science.gov (United States)

Musta, Mustafa

2015-11-01

The interaction of a vortex ring impinging on a thin cutting plate was made experimentally using Volumetric 3-component Velocitmetry (v3v) technique. The vortex rings were generated with piston-cylinder vortex ring generator using piston stroke-to-diameter ratios and Re at 2-3 and 1500 - 3000, respectively. The cutting of vortex rings below center line leads to the formation of secondary vortices on each side of the plate which is look like two vortex rings, and a third vortex ring propagates further downstream in the direction of the initial vortex ring, which is previously showed by flow visualization study of Weigand (1993) and called ``trifurcation''. Trifurcation is very sensitive to the initial Reynolds number and the position of the plate with respect to the vortex ring generator pipe. The present work seeks more detailed investigation on the trifurcation using V3V technique. Conditions for the formation of trifurcation is analyzed and compared with Weigand (1993). The formed secondary vortex rings and the propagation of initial vortex ring in the downstream of the plate are analyzed by calculating their circulation, energy and trajectories.

Magnetic ring for stripping enhancement

International Nuclear Information System (INIS)

Selph, F.

1992-10-01

A ring designed to recycle ions through a stripping medium offers the possibility for increasing output of the desired charge state by up to 4x. This could be a very important component of a Radioactive Nuclear Beam Facility. In order for such a ring to work effectively it must satisfy certain design conditions. These include achromaticity at the stripper, a dispersed region for an extraction magnet, and a number of first and higher order optics constraints which are necessary to insure that the beam emittance is not degraded unduly by the ring. An example is given of a candidate design of a stripping ring

Acceleration of magnetized plasma rings

International Nuclear Information System (INIS)

Hartman, D.; Eddleman, J.; Hammer, J.H.

1982-01-01

One scheme is considered, acceleration of a ring between coaxial electrodes by a B/sub theta/ field as in a coaxial rail-gun. If the electrodes are conical, a ring accelerated towards the apex of the cone undergoes self-similar compression (focussing) during acceleration. Because the allowable acceleration force F/sub a/ = kappa U/sub m//R (kappa - 2 , the accelerating distance for conical electrodes is considerably shortened over that required for coaxial electrodes. In either case however, since the accelerating flux can expand as the ring moves, most of the accelerating field energy can be converted into kinetic energy of the ring leading to high efficiency

A first course in noncommutative rings

CERN Document Server

Lam, T Y

2001-01-01

A First Course in Noncommutative Rings, an outgrowth of the author's lectures at the University of California at Berkeley, is intended as a textbook for a one-semester course in basic ring theory. The material covered includes the Wedderburn-Artin theory of semisimple rings, Jacobson's theory of the radical, representation theory of groups and algebras, prime and semiprime rings, local and semilocal rings, perfect and semiperfect rings, etc. By aiming the level of writing at the novice rather than the connoisseur and by stressing th the role of examples and motivation, the author has produced a text that is suitable not only for use in a graduate course, but also for self- study in the subject by interested graduate students. More than 400 exercises testing the understanding of the general theory in the text are included in this new edition.

Design of Piston Ring Friction Tester Apparatus

DEFF Research Database (Denmark)

Klit, Peder

2006-01-01

One of the major prerequisites for calculating piston ring friction is a good description of the tribological situation. Piston rings operate in three different lubrication regimes and the theoretical models should be capable to describe this. A very important condition for describing the frictio......One of the major prerequisites for calculating piston ring friction is a good description of the tribological situation. Piston rings operate in three different lubrication regimes and the theoretical models should be capable to describe this. A very important condition for describing...... the frictional behavior of a piston ring correctly is knowledge about the amount of lubricant present. For piston rings the external load may be established by measuring the pressure distribution, i.e. the pressure drop in the piston ring package. Speed and temperature may also be established. The amount...... available is reflected in the friction absorbed in the bearing. The following properties will be measured: Oil fillm thickness - along liner (axial variation), oil film thickness - along piston ring (circumferential variation), piston tilt, temperature of piston rings and liner, pressure at piston lands...

Study for ILC Damping Ring at KEKB

Energy Technology Data Exchange (ETDEWEB)

Flanagan, J.W.; Fukuma, H.; Kanazawa, K.I.; Koiso, H.; Masuzawa, M.; Ohmi, Kazuhito; Ohnishi, Y.; Oide, Katsunobu; Suetsugu, Y.; Tobiyama, M.; /KEK, Tsukuba; Pivi, M.; /SLAC

2011-11-04

ILC damping ring consists of very low emittance electron and positron storage rings. It is necessary for ILC damping ring to study electron cloud effects in such low emittance positron ring. We propose a low emittance operation of KEKB to study the effects.

Planetary ring systems properties, structures, and evolution

CERN Document Server

Murray, Carl D

2018-01-01

Planetary rings are among the most intriguing structures of our solar system and have fascinated generations of astronomers. Collating emerging knowledge in the field, this volume reviews our current understanding of ring systems with reference to the rings of Saturn, Uranus, Neptune, and more. Written by leading experts, the history of ring research and the basics of ring–particle orbits is followed by a review of the known planetary ring systems. All aspects of ring system science are described in detail, including specific dynamical processes, types of structures, thermal properties and their origins, and investigations using computer simulations and laboratory experiments. The concluding chapters discuss the prospects of future missions to planetary rings, the ways in which ring science informs and is informed by the study of other astrophysical disks, and a perspective on the field's future. Researchers of all levels will benefit from this thorough and engaging presentation.

Longitudinal beam instability due to the ring impedance at KEK's accelerator test facility damping ring

International Nuclear Information System (INIS)

Kim, Eun-San

2003-01-01

This paper shows the results of a numerical study of the impedance in the Accelerator Test Facility damping ring. The longitudinal impedance in the damping ring is shown to be inductive. It is shown that the total impedance |Z || /n| is 0.23 Ω and the inductance is L = 14 nH. In the extremely low emittance beam of the damping ring, bunch lengthening is caused by both the effects of potential-well distortion and intra-beam scattering. In this paper, the bunch-lengthening due to the ring impedance is numerically investigated, and the result shows qualitative agreement with the result of an analysis performed using the bunch-length measurement. With the calculated longitudinal impedance, the instability threshold in the damping ring is estimated to be a bunch population of 3.3 x 10 10 by using both a Vlasov equation approach and a multi-particle tracking method.

Immersive Exhibitions

DEFF Research Database (Denmark)

Achiam, Marianne

2015-01-01

The immersive exhibition is a specialized exhibition genre in museums, which creates the illusion of time and place by representing key characteristics of a reference world and by integrating the visitor in this three-dimensionally reconstructed world (Mortensen 2010). A successful representation...... of the reference world depends on three criteria: whether the exhibition is staged as a coherent whole with all the displayed objects supporting the representation, whether the visitor is integrated as a component of the exhibition, and whether the content and message of the exhibition become dramatized...

Accretion in Saturn's F Ring

Science.gov (United States)

Meinke, B. K.; Esposito, L. W.; Stewart, G.

2012-12-01

Saturn's F ring is the solar system's principal natural laboratory for direct observation of accretion and disruption processes. The ring resides in the Roche zone, where tidal disruption competes with self-gravity, which allows us to observe the lifecycle of moonlets. Just as nearby moons create structure at the B ring edge (Esposito et al. 2012) and the Keeler gap (Murray 2007), the F ring "shepherding" moons Prometheus and Pandora stir up ring material and create observably changing structures on timescales of days to decades. In fact, Beurle et al (2010) show that Prometheus makes it possible for "distended, yet gravitationally coherent clumps" to form in the F ring, and Barbara and Esposito (2002) predicted a population of ~1 km bodies in the ring. In addition to the observations over the last three decades, the Cassini Ultraviolet Imaging Spectrograph (UVIS) has detected 27 statistically significant features in 101 occultations by Saturn's F ring since July 2004. Seventeen of those 27 features are associated with clumps of ring material. Two features are opaque in occultation, which makes them candidates for solid objects, which we refer to as Moonlets. The 15 other features partially block stellar signal for 22 m to just over 3.7 km along the radial expanse of the occultation. Upon visual inspection of the occultation profile, these features resemble Icicles, thus we will refer to them as such here. The density enhancements responsible for such signal attenuations are likely due to transient clumping of material, evidence that aggregations of material are ubiquitous in the F ring. Our lengthy observing campaign reveals that Icicles are likely transient clumps, while Moonlets are possible solid objects. Optical depth is an indicator of clumping because more-densely aggregated material blocks more light; therefore, it is natural to imagine moonlets as later evolutionary stage of icicle, when looser clumps of material compact to form a feature that appears

(4S)-4-(3,4-Dichloro?phen?yl)-1?-methyl-4?-phenyl-3,4-dihydronaphthalene-2-spiro-3?-pyrrolidine-2?-spiro-1??-acenaphthyl?ene-1,2??(2H,1??H)-dione

OpenAIRE

Murugan, R.; Gunasekaran, B.; Narayanan, S. Sriman; Manivannan, V.

2008-01-01

In the title compound, C37H27Cl2NO2, the 3,4-dichloro?phenyl ring makes a dihedral angle of 46.66?(6)? with the phenyl ring. The mol?ecular structure is stabilized by weak intra?molecular C?H?O inter?actions and the crystal structure is stabilized by weak inter?molecular C?H?O inter?actions. The C?C?C?C?C five-membered ring is planar, while the C?C?C?C?N five-membered ring adopts a half-chair conformation.