Sample records for talk tip sheets

  1. The Efficacy of Written Teacher Advice (Tip Sheets) for Managing Classroom Behaviour Problems.

    ERIC Educational Resources Information Center

    Little, Emma; Hudson, Alan; Wilks, Ray

    2002-01-01

    Evaluates the efficacy of tip sheets for teachers (n=20) that offer strategies for classroom management related to student behavior problems. Explains that the teachers chose students with behavior problems and used the suggestions from the tip sheets. Presents the results in detail. Includes references. (CMK)

  2. Media Monday tip sheet builds Spartanburg's media relations.

    PubMed

    Rees, Tom

    2005-01-01

    Media Monday is published weekly and sent to area newsrooms by the Spartanburg Regional Healthcare System, Spartanburg, S.C. The news and feature tip sheet was started in 1998 in order to disperse a lot of information with a limited number of staff.

  3. Time To Talk with Your Health Care Providers: 4 Tips to Start the Conversation

    MedlinePlus

    ... Y Z 4 Tips: Start Talking With Your Health Care Providers About Complementary Health Approaches Share: When patients ... fully informed and can help patients make wise health care decisions. Here are 4 tips to help you ...

  4. Twelve tips for the production of digital chalk-talk videos.

    PubMed

    Rana, Jasmine; Besche, Henrike; Cockrill, Barbara

    2017-06-01

    Increasingly over the past decade, faculty in medical and graduate schools have received requests from digital millennial learners for concise faculty-made educational videos. At our institution, over the past couple of years alone, several hundred educational videos have been created by faculty who teach in a flipped-classroom setting of the pre-clinical medical school curriculum. Despite the appeal and potential learning benefits of digital chalk-talk videos first popularized by Khan Academy, we have observed that the conceptual and technological barriers for creating chalk-talk videos can be high for faculty. To this end, this tips article offers an easy-to-follow 12-step conceptual framework to guide at-home production of chalk-talk educational videos.

  5. Parent-Teacher Conferences: A Tip Sheet for Teachers

    ERIC Educational Resources Information Center

    Educational Horizons, 2012

    2012-01-01

    Parent-teacher conferences are an important component of ongoing home-school communication and family involvement in your classroom. Did you also know that home-school communication predicts positive outcomes for students and for schools? Although you may already be working hard to engage parents in their children's education, this tip sheet is…

  6. Astronaut Jerry Linenger with sheet of TIPS correspondence

    NASA Image and Video Library

    1994-09-15

    STS064-23-025 (9-20 Sept. 1994) --- With scissors in hand, astronaut Jerry M. Linenger, STS-64 mission specialist, prepares to cut off a lengthy sheet of correspondence from ground controllers. Called the Thermal Imaging Printing System (TIPS), the message center occupies a stowage locker on the space shuttle Discovery's middeck. Astronaut L. Blaine Hammond, pilot, retrieves a clothing item from a nearby locker. Photo credit: NASA or National Aeronautics and Space Administration

  7. Illinois Early Learning Project Tip Sheets: Parenting and Family Life.

    ERIC Educational Resources Information Center

    2003

    The Illinois Early Learning Project (IEL) is funded by the Illinois State Board of Education to provide information resources on early learning and training related to implementing the Illinois Early Learning Standards for parents and for early childhood personnel in all settings. The IEL tip sheets offer suggestions to parents and early childhood…

  8. Illinois Early Learning Project Tip Sheets: Physical Development and Health.

    ERIC Educational Resources Information Center

    2003

    The Illinois Early Learning Project (IEL) is funded by the Illinois State Board of Education to provide information resources on early learning and training related to implementing the Illinois Early Learning Standards for parents and for early childhood personnel in all settings. The IEL tip sheets offer suggestions to parents and early childhood…

  9. Talking about Complementary and Alternative Medicine with Health Care Providers: A Workbook and Tips

    Cancer.gov

    A workbook to help patients and doctors talk about the use of complementary and alternative medicine(CAM) during and after cancer care. Worksheets, tips, and resources are provided for patients and doctors to help track CAM use.

  10. Talking about Complementary and Alternative Medicine with Health Care Provider: A Workbook and Tips

    Cancer.gov

    A workbook to help patients and doctors talk about the use of complementary and alternative medicine(CAM) during and after cancer care. Worksheets, tips, and resources are provided for patients and doctors to help track CAM use.

  11. William James's "Talks to Teachers" (1899) and McKeachie's "Teaching Tips" (1999)

    ERIC Educational Resources Information Center

    McKeachie, Wilbert J.

    2003-01-01

    What has changed and what has stayed the same in the years since the first publication of James's "Talks to Teachers on Psychology: And to Students on some of Life's Ideals" (1899) and the 10 editions of McKeachie's "Teaching Tips"? Although research and theory have given us better understanding of learning, memory, cognition, and motivation, much…

  12. Talking about Complementary and Alternative Medicine with your Health Care Provider: A workbook and tips

    Cancer.gov

    A workbook to help patients and doctors talk about the use of complementary and alternative medicine(CAM) during and after cancer care. Worksheets, tips, and resources are provided for patients and doctors to help track CAM use.

  13. Talking about complementary and alternative medicine with your health care provider: A workbook and Tips

    Cancer.gov

    A workbook to help patients and doctors talk about the use of complementary and alternative medicine(CAM) during and after cancer care. Worksheets, tips, and resources are provided for patients and doctors to help track CAM use.

  14. Cross-talk reduction by correcting the subpixel position in a multiview autostereoscopic three-dimensional display based on a lenticular sheet.

    PubMed

    Wang, Qiong-Hua; Li, Xiao-Fang; Zhou, Lei; Wang, Ai-Hong; Li, Da-Hai

    2011-03-01

    A method is proposed to alleviate the cross talk in multiview autostereoscopic three-dimensional displays based on a lenticular sheet. We analyze the positional relationship between subpixels on the image panel and the lenticular sheet. According to this relationship, optimal synthetic images are synthesized to minimize cross talk by correcting the positions of subpixels on the image panel. Experimental results show that the proposed method significantly reduces the cross talk of view images and improves the quality of stereoscopic images. © 2010 Optical Society of America

  15. Experimental and Numerical Investigations of Applying Tip-bottomed Tool for Bending Advanced Ultra-high Strength Steel Sheet

    NASA Astrophysics Data System (ADS)

    Mitsomwang, Pusit; Borrisutthekul, Rattana; Klaiw-awoot, Ken; Pattalung, Aran

    2017-09-01

    This research was carried out aiming to investigate the application of a tip-bottomed tool for bending an advanced ultra-high strength steel sheet. The V-die bending experiment of a dual phase steel (DP980) sheet which had a thickness of 1.6 mm was executed using a conventional bending and a tip-bottomed punches. Experimental results revealed that the springback of the bent worksheet in the case of the tip-bottomed punch was less than that of the conventional punch case. To further discuss bending characteristics, a finite element (FE) model was developed and used to simulate the bending of the worksheet. From the FE analysis, it was found that the application of the tip-bottomed punch contributed the plastic deformation to occur at the bending region. Consequently, the springback of the worksheet reduced. In addition, the width of the punch tip was found to affect the deformation at the bending region and determined the springback of the bent worksheet. Moreover, the use of the tip-bottomed punch resulted in the apparent increase of the surface hardness of the bent worksheet, compared to the bending with the conventional punch.

  16. Efficient fabrication of carbon nanotube micro tip arrays by tailoring cross-stacked carbon nanotube sheets.

    PubMed

    Wei, Yang; Liu, Peng; Zhu, Feng; Jiang, Kaili; Li, Qunqing; Fan, Shoushan

    2012-04-11

    Carbon nanotube (CNT) micro tip arrays with hairpin structures on patterned silicon wafers were efficiently fabricated by tailoring the cross-stacked CNT sheet with laser. A blade-like structure was formed at the laser-cut edges of the CNT sheet. CNT field emitters, pulled out from the end of the hairpin by an adhesive tape, can provide 150 μA intrinsic emission currents with low beam noise. The nice field emission is ascribed to the Joule-heating-induced desorption of the emitter surface by the hairpin structure, the high temperature annealing effect, and the surface morphology. The CNT emitters with hairpin structures will greatly promote the applications of CNTs in vacuum electronic devices and hold the promises to be used as the hot tips for thermochemical nanolithography. More CNT-based structures and devices can be fabricated on a large scale by this versatile method. © 2012 American Chemical Society

  17. Get Them Talking! Using Student-Led Book Talks in the Primary Grades

    ERIC Educational Resources Information Center

    Hudson, Alida K.

    2016-01-01

    This teaching tip details one teacher's implementation of student-led book talks in her primary-grade classroom. The author describes a simple gradual-release method that she has successfully used with her students in order to get them talking about the books that they are reading independently. She found that when used in the readers' workshop…

  18. A view from the terrace; ice-sheet dynamics during the Eocene Oligocene Transition climate tipping point

    NASA Astrophysics Data System (ADS)

    Scher, Howie; Bohaty, Steven; Huck, Claire

    2017-04-01

    Glaciation of Antarctica was the pièce de résistance of the shift in global climate that took place during the Eocene Oligocene Transition (EOT; ca. 34 Ma). The timing and progression of ice-sheet development is constrained by benthic foraminiferal d18O records and geochemical proxies for continental weathering from deep-sea sediment cores. The terrace interval is the roughly 500 kyr interval after the precursor glaciation at 34.2 Ma, when ice-sheet expansion reached a short-lived plateau prior to the coalescence of a continent-scale ice sheet at 33.7 Ma. The terrace interval appears to be the tipping point between greenhouse and icehouse climate states, however ice-sheet dynamics are poorly understood during this crucial time. We present evidence for rapid changes in the Nd isotopic composition of bottom waters bathing a sediment core on Maud Rise (ODP Site 689) during the terrace interval of the EOT. Three distinct excursions toward less radiogenic eNd values suggest either 1) changes in the flux of Antarctic weathering products into the Weddell Sea and/or 2) pulses of deep water production that brought shelf waters with the Antarctic Nd isotope fingerprint into contact with Maud Rise. Both interpretations support a scenario of expansion and contraction of the Antarctic ice sheet during the terrace interval.

  19. Ten Tips for Parents To Help Their Children Avoid Teen Pregnancy [and] Talking Back: Ten Things Teens Want Parents To Know about Teen Pregnancy. Plus: A List of Resources for Parents.

    ERIC Educational Resources Information Center

    National Campaign To Prevent Teen Pregnancy, Washington, DC.

    The National Campaign to Prevent Teen Pregnancy reviewed recent research about parental influences on children's sexual behavior and talked to experts, teens, and parents. From these sources, the Campaign derived 10 tips for parents and other adults to help reduce the risks of teen pregnancy. The 10 tips discussed in this pamphlet are: (1) be…

  20. Influence of Crack-Tip Configurations on the Fracture Response of 0.04-Inch Thick 2024-T3 Aluminum Alloy Sheet

    NASA Technical Reports Server (NTRS)

    Johnston, William M.; Newman, James C. (Technical Monitor)

    2002-01-01

    A series of fracture tests were conducted on Middle-crack tension M(T) and compact tension C(T) specimens to determine the effects of specimen type, specimen width, notch tip sharpness and buckling on the fracture behavior of cracked thin sheet (0.04 inch thick) 2024-T3 aluminum alloy material. A series of M(T) specimens were tested with three notch tip configurations: (1) a fatigue pre-cracked notch, (2) a 0.010-inch-diameter wire electrical discharge machined (EDM) notch, and (3) a EDM notch sharpened with a razor blade. The test procedures are discussed and the experimental results for failure stress, load vs. crack extension and the material stress-strain response are reported.

  1. Talking with Kids: A Parent's Guide to Sex Education.

    ERIC Educational Resources Information Center

    National PTA, Chicago, IL.

    This guide is designed to help parents determine what is being taught to their children about sex education in school, offering tips on how to talk to children about these issues. The first section presents pointers from the "Talking with Kids" campaign: start early; initiate conversations; talk about sex and relationships; create an open…

  2. Theory of buttressed marine ice sheet dynamics and its application to the assessment of tipping-point conditions

    NASA Astrophysics Data System (ADS)

    Pegler, S.

    2017-12-01

    Understanding the fate of the West Antarctic Ice Sheet is constrained by difficulties of resolving the buttressing effect of ice shelves and its dynamic response to grounding-line migration. This effect may be responsible for protecting a large majority of outlet glaciers in Antarctica against surging into the ocean. I present a theoretical methodology for assessing the positions and stability of grounding lines that incorporates closed-form, dynamic descriptions of ice-shelf buttressing and extensional (stretching) viscous stresses. The method is applied to assess the conditions for grounding-line tipping points. Such points are shown to produce abrupt `cliff-edge' transitions to runaway retreat, representing the so-called marine ice sheet instability. Depending on the bed profile, melt and calving rates, a tipping point can either lie very near to a local maximum in the bed topography or potentially far upstream of it, along a reverse bed. The model predictions for both wide and narrow embayments are validated by numerical simulations and laboratory experiments. A case study of Pine Island Glacier indicates the possibility for long-term stabilisation, with the analytical method affording an extensive exploration of scenarios. The theory also elucidates a mode of grounding-line migration controlled entirely by the determinants of the ice-shelf buttressing force, with a loss of sensitivity to basal conditions, contrasting with the conclusion from one-dimensional theory that the ice shelf is irrelevant. The results provide an interpretive framework for understanding grounding-line dynamics, its coupling with ice-shelf dynamics, an efficient exploration of parameter variation, and a complement to large-scale simulation.

  3. Lighting: Traffic Safety Tips

    DOT National Transportation Integrated Search

    1996-01-01

    This fact sheet, NHTSA Facts: Summer 1996, discusses traffic safety tips on motor vehicle lighting, including headlights, tail lights, and signal lights. It details the cleaning of headlamps, proper aiming of headlamps, and replacement of burned out ...

  4. Uncertainty of tipping elements on risk analysis in hydrology under climate change

    NASA Astrophysics Data System (ADS)

    Kiguchi, M.; Iseri, Y.; Tawatari, R.; Kanae, S.; Oki, T.

    2015-12-01

    Risk analysis in this study characterizes the events that could be caused by climate change and estimates their effects on society. In order to characterize climate change risks, events that might be caused by climate change will be investigated focusing on critical geophysical phenomena such as changes in thermohaline circulation (THC) in oceans and the large-scale melting of the Greenland and other ice sheets. The results of numerical experiments with climate models and paleoclimate studies will be referenced in listing up these phenomena. The trigger mechanisms, tendency to occur and relationship of these phenomena to global climate will be clarified. To clarify that relationship between the RCP scenarios and tipping elements, we identified which year tipping elements in case of "Arctic summer sea ice" and "Greenland ice sheet" are appeared using the increase of global average temperature in 5 GCMs under RCP (2.6, 4.5, 6.0, and 8.5) from Zickfeld et al. (2013) and IPCC (2013), and tipping point of each tipping elements from IPCC (2013). In case of "Greenland ice sheet" (Tipping point takes a value within the range of 1.0oC and 4.0oC), we found that "Greenland ice sheet" may melt down when the tipping point is 1.0oC as lowest value. On the other hand, when tipping point sets as 4.0oC, it may not melt down except for RCP 8.5. As above, we show the uncertainty of tipping point itself. In future, it is necessary how to reflect such uncertainty in risk analysis in hydrology.

  5. Brakes: Traffic Safety Tips

    DOT National Transportation Integrated Search

    1996-01-01

    This fact sheet, NHTSA Facts: Summer 1996, describes traffic safety tips about brakes. It discusses drum brakes, disc brakes, and antilock braking systsms. It notes that there are government standards for brakes, and describes how to take care of bra...

  6. Early warning of climate tipping points

    NASA Astrophysics Data System (ADS)

    Lenton, Timothy M.

    2011-07-01

    A climate 'tipping point' occurs when a small change in forcing triggers a strongly nonlinear response in the internal dynamics of part of the climate system, qualitatively changing its future state. Human-induced climate change could push several large-scale 'tipping elements' past a tipping point. Candidates include irreversible melt of the Greenland ice sheet, dieback of the Amazon rainforest and shift of the West African monsoon. Recent assessments give an increased probability of future tipping events, and the corresponding impacts are estimated to be large, making them significant risks. Recent work shows that early warning of an approaching climate tipping point is possible in principle, and could have considerable value in reducing the risk that they pose.

  7. Mature Drivers: Traffic Safety Tips

    DOT National Transportation Integrated Search

    1996-01-01

    This fact sheet, NHTSA Facts: Summer 1996, discusses safety tips for drivers aged 70 and older. It notes that mature drivers: rank lower in aggressive actions; tend to make necessary safety adjustments in their driving, based on their own experience;...

  8. Safe Travel Tips for Older Adults

    MedlinePlus

    ... our other tip sheets. Before you board a plane, train, cruise, or get in your car for ... sanitizer, especially after spending time on a crowded plane, train, or bus, and before eating. Use common ...

  9. Maniac Talk - Richard Spinrad

    NASA Image and Video Library

    2015-05-27

    Richard Spinrad Maniac Lecture, May 27, 2015 NOAA Chief Scientist Dr. Richard "Rick" Spinrad presented a Maniac Talk entitled "Lately it occurs to me, what a long, strange trip it's been: one technocrat's unguided tour through oceanography." Rick shared his journey and life in science, including tipping points in his career and how he has come to understand the value of transdisciplinarity, odds-weighing, and timing.

  10. Tip Vortices of Isolated Wings and Helicopter Rotor Blades.

    DTIC Science & Technology

    1987-12-01

    root to tip, as expected due to the induced downwash of the tip vor- tex and wake vortex sheet. Although the three different tip-caps produce very...the inherent limitation of not being able to model the vortex wake with these equations, although the Euler formulation has in it the necessary...physics to model vorticity transport correctly. These equations basically lack the physical mecha- nism needed to generate the vortex wake . However, in

  11. Talk with Your Kids...before Everyone Else Does: Talking with Kids about Tough Issues.

    ERIC Educational Resources Information Center

    Children Now, Oakland, CA.

    Parents are challenged daily with a wide range of disturbing issues that are difficult for children to understand and for adults to explain. This booklet offers practical, concrete tips and techniques for talking easily and openly with 8- to 12-year-olds about sex, HIV/AIDS, violence, drugs, and alcohol. The book is divided into five parts. Part 1…

  12. Sport Utility Vehicles: Traffic Safety Tips

    DOT National Transportation Integrated Search

    1996-01-01

    This fact sheet, NHTSA Facts: Summer 1996, describe traffic safety tips for driving sport utility vehicles. Because sport utility vehicles have a higher center of gravity, making them more top heavy than cars, they handle and maneuver differently tha...

  13. Don't Talk, Teach: Breaking Bad Rehearsal Habits.

    ERIC Educational Resources Information Center

    Kruth, Edwin C.

    1984-01-01

    Tips to help conductors improve school music rehearsals are provided. For example, students should learn that the minute the conductor steps on the podium, they should stop playing and talking and direct their attention to the podium. (RM)

  14. Global Projection of Coastal Exposure Associated with Sea-level Rise beyond Tipping Points

    NASA Astrophysics Data System (ADS)

    Tawatari, R.; Miyazaki, C.; Iseri, Y.; Kiguchi, M.; Kanae, S.

    2015-12-01

    Sea-level rise due to global warming becomes a great matter of concern for global coastal area. Additionally, it has reported in fifth report of IPCC (Intergovernmental Panel on Climate Change) that deglaciation of Greenland ice sheet and Antarctic ice sheet would occur rapidly and enhance sea-level rise if temperature passes certain "Tipping point". In terms of projecting damage induced by sea-level rise globally, some previous studies focused on duration until mainly 2100. Furthermore long-term estimations on centuries to millennial climatic response of the ice sheets which are supposed to be triggered within this or next century would be also important to think about future climate and lifestyle in coastal . In this study, I estimated the long term sea-level which take into account the tipping points of Greenland ice sheet (1.4℃) as sum of 4 factors (thermal expansion, glacier and ice cap, Greenland ice sheet, Antarctic ice sheet). The sea-level follows 4 representative concentration pathways up to 3000 obtained through literature reviewing since there were limited available sea-level projections up to 3000. I also estimated a number of affected population lives in coastal area up to 3000 with using the estimated sea-level. The cost for damage, adaptation and mitigation would be also discussed. These estimations would be useful when decision-makers propose policies for construction of dikes and proposing mitigation plans for sustainable future. The result indicates there would be large and relatively rapid increases in both sea-level rise and coastal exposure if global mean temperature passes the tipping point of Greenland ice sheet. However the tipping points, melting rate and timescale of response are highly uncertain and still discussed among experts. Thus more precise and credible information is required for further accurate estimation of long-term sea-level rise and population exposure in the future.

  15. Safety Belt Use: Traffic Safety Tips

    DOT National Transportation Integrated Search

    1996-01-01

    This fact sheet, NHTSA Facts: Summer 1996, discusses traffic safety tips for wearing seat belts. It describes the correct way to wear a seat belt, how to sit, and differentiates between lap belts and shoulder belts. It points out that air bags provid...

  16. Talking with Kids about Tough Issues.

    ERIC Educational Resources Information Center

    Dumas, Lynne S.

    Raising a child can be the most gratifying (and the most difficult) job a person can have. Communication is essential when parenting children, and practical guidance in learning how to speak openly and listen attentively is presented in this booklet. It gives parents and caregivers concrete tips and techniques on talking with young children, ages…

  17. Effect of debond growth on stress-intensity factors in a cracked orthotropic sheet stiffened by a semi-infinite orthotropic sheet

    NASA Technical Reports Server (NTRS)

    Bigelow, C. A.

    1986-01-01

    Stress-intensity factors are determined for a cracked infinite sheet adhesively bonded to a stringer, and debonding of the adhesive layer is predicted. The stringer is modeled as a semi-infinite sheet. Adhesive nonlinearity is also included. Both the sheet and stringer are treated as homogeneous, orthotropic materials. A set of integral equations is formulated and solved to obtain the adhesive shear stresses and crack-tip stress-intensity factors. Adhesive debonding is predicted using a rupture criterion based on the combined adhesive stresses. When the crack is not under the stringer, the debond extends along the edge of the stringer. When the crack tip is beneath the stringer, the debond grows to the end of the crack, then along the edge of the stringer. Stress levels required for debond initiation decrease as the crack tip is moved beneath the stringer. With a nonlinear adhesive, the debond initiates at higher applied stress levels than in linear adhesive cases. Compared with the linear adhesive solution, modeling a nonlinear adhesive causes the stress-intensity factor to increase when the bond is assumed to remain intact but causes the stress-intensity factor to decrease when debonding is included.

  18. Extended Glauert tip correction to include vortex rollup effects

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

    Maniaci, David; Schmitz, Sven

    Wind turbine loads predictions by blade-element momentum theory using the standard tip-loss correction have been shown to over-predict loading near the blade tip in comparison to experimental data. This over-prediction is theorized to be due to the assumption of light rotor loading, inherent in the standard tip-loss correction model of Glauert. A higher- order free-wake method, WindDVE, is used to compute the rollup process of the trailing vortex sheets downstream of wind turbine blades. Results obtained serve an exact correction function to the Glauert tip correction used in blade-element momentum methods. Lastly, it is found that accounting for the effectsmore » of tip vortex rollup within the Glauert tip correction indeed results in improved prediction of blade tip loads computed by blade-element momentum methods.« less

  19. Extended Glauert tip correction to include vortex rollup effects

    DOE PAGES

    Maniaci, David; Schmitz, Sven

    2016-10-03

    Wind turbine loads predictions by blade-element momentum theory using the standard tip-loss correction have been shown to over-predict loading near the blade tip in comparison to experimental data. This over-prediction is theorized to be due to the assumption of light rotor loading, inherent in the standard tip-loss correction model of Glauert. A higher- order free-wake method, WindDVE, is used to compute the rollup process of the trailing vortex sheets downstream of wind turbine blades. Results obtained serve an exact correction function to the Glauert tip correction used in blade-element momentum methods. Lastly, it is found that accounting for the effectsmore » of tip vortex rollup within the Glauert tip correction indeed results in improved prediction of blade tip loads computed by blade-element momentum methods.« less

  20. Talking with Children about Natural Disasters

    ERIC Educational Resources Information Center

    Brodkin, Adele M.

    2005-01-01

    The effects of Hurricane Katrina, Hurricane Rita, and other natural disasters will be felt by young children in the affected areas for a long time to come. This article offers tips on how to talk with children about natural disasters in order to clear up any confusion they might have, how to answer their questions with sensitivity, and how to…

  1. A Transient Initialization Routine of the Community Ice Sheet Model for the Greenland Ice Sheet

    NASA Astrophysics Data System (ADS)

    van der Laan, Larissa; van den Broeke, Michiel; Noël, Brice; van de Wal, Roderik

    2017-04-01

    The Community Ice Sheet Model (CISM) is to be applied in future simulations of the Greenland Ice Sheet under a range of climate change scenarios, determining the sensitivity of the ice sheet to individual climatic forcings. In order to achieve reliable results regarding ice sheet stability and assess the probability of future occurrence of tipping points, a realistic initial ice sheet geometry is essential. The current work describes and evaluates the development of a transient initialization routine, using NGRIP 18O isotope data to create a temperature anomaly field. Based on the latter, surface mass balance components runoff and precipitation are perturbed for the past 125k years. The precipitation and runoff fields originate from a downscaled 1 km resolution version of the regional climate model RACMO2.3 for the period 1961-1990. The result of the initialization routine is a present-day ice sheet with a transient memory of the last glacial-interglacial cycle, which will serve as the future runs' initial condition.

  2. Portfolio Preparation Tips for Teachers, Part 2

    ERIC Educational Resources Information Center

    Hunter-Lombardi, Brooke

    2009-01-01

    In the August/September 2008 issue of "SchoolArts," the author talked about strategies for helping students develop content and good working habits to support making portfolio-quality pieces. In this article, she offers some tips which focus on the importance of critique, presentation, and selection of images to end up with a polished,…

  3. Ultrafast time-resolved photoemission of a metallic tip/substrate junction

    NASA Astrophysics Data System (ADS)

    Meng, Xiang; Jin, Wencan; Yang, Hao; Dadap, Jerry; Osgood, Richard; Camillone, Nicholas, III

    The strong near-field enhancement of metallic-tip nanostructures has attracted great interest in scanning microscopy techniques, such as surface-enhanced Raman scattering, near-field scanning optical microscopy and tip-enhanced nonlinear imaging. In this talk, we use a full vectorial 3D-FDTD method to investigate the spatial characteristics of the optical field confinement and localization between a tungsten nanoprobe and an infinite planar silver substrate, with two-color ultrafast laser excitation scheme. The degree of two-color excited field enhancement, geometry dependence, the exact mechanism of optical tip-substrate coupling and tip-substrate plasmon resonances are significant in understanding the electrodynamical responses at tip-substrate junction. The demonstrated measurements with subpicosecond time and subnanometer spatial resolution suggest a new approach to ultrafast time-resolved measurements of surface electron dynamics. DE-FG 02-90-ER-14104; DE-FG 02-04-ER-46157.

  4. Hazard Communication Standard for Chemical Labels and Safety Data Sheets In GHS Format

    EPA Pesticide Factsheets

    This fact sheet provides an overview of the required contents of Safety Data Sheets (SDSs) and chemical hazard labels, and includes tips on how these materials can be used to better protect health and the environment.

  5. Tipping elements in the Arctic marine ecosystem.

    PubMed

    Duarte, Carlos M; Agustí, Susana; Wassmann, Paul; Arrieta, Jesús M; Alcaraz, Miquel; Coello, Alexandra; Marbà, Núria; Hendriks, Iris E; Holding, Johnna; García-Zarandona, Iñigo; Kritzberg, Emma; Vaqué, Dolors

    2012-02-01

    The Arctic marine ecosystem contains multiple elements that present alternative states. The most obvious of which is an Arctic Ocean largely covered by an ice sheet in summer versus one largely devoid of such cover. Ecosystems under pressure typically shift between such alternative states in an abrupt, rather than smooth manner, with the level of forcing required for shifting this status termed threshold or tipping point. Loss of Arctic ice due to anthropogenic climate change is accelerating, with the extent of Arctic sea ice displaying increased variance at present, a leading indicator of the proximity of a possible tipping point. Reduced ice extent is expected, in turn, to trigger a number of additional tipping elements, physical, chemical, and biological, in motion, with potentially large impacts on the Arctic marine ecosystem.

  6. Geometry of Thin Nematic Elastomer Sheets

    NASA Astrophysics Data System (ADS)

    Aharoni, Hillel; Sharon, Eran; Kupferman, Raz

    A thin sheet of nematic elastomer attains 3D configurations depending on the nematic director field upon heating. In this talk we describe the intrinsic geometry of such a sheet, and derive an expression for the metric induced by general smooth nematic director fields. Furthermore, we investigate the reverse problem of constructing a director field that induces a specified 2D geometry. We provide an explicit analytical recipe for constructing any surface of revolution using this method. We demonstrate how the design of an arbitrary 2D geometry is accessible using approximate numerical methods.

  7. Solid/melt interface studies of high-speed silicon sheet growth

    NASA Technical Reports Server (NTRS)

    Ciszek, T. F.

    1984-01-01

    Radial growth-rate anisotropies and limiting growth forms of point nucleated, dislocation-free silicon sheets spreading horizontally on the free surface of a silicon melt have been measured for (100), (110), (111), and (112) sheet planes. Sixteen-millimeter movie photography was used to record the growth process. Analysis of the sheet edges has lead to predicted geometries for the tip shape of unidirectional, dislocation-free, horizontally growing sheets propagating in various directions within the above-mentioned planes. Similar techniques were used to study polycrystalline sheets and dendrite propagation. For dendrites, growth rates on the order of 2.5 m/min and growth rate anisotropies on the order of 25 were measured.

  8. Talking to Your Kids about Sex: Tips for Tongue-Tied Parents.

    ERIC Educational Resources Information Center

    PTA Today, 1993

    1993-01-01

    Tips to help parents discuss sex with their children include starting early, providing enough information, planning what to say, listening to the children, finding opportunities to discuss sexual roles and attitudes, discussing family values, nurturing self-esteem, avoiding lectures, using written materials as ice-breakers, and starting a family…

  9. Education, 1961-1971: A Balance Sheet. Topical Talks, 27.

    ERIC Educational Resources Information Center

    Auerbach, F. E.

    During the first decade as a republic we have made some great strides in education, but in certain respects we have also fallen behind. As there are differences of opinion about what our most urgent educational priorities are, I have tried to make this a balance sheet, showing assets and liabilities without pronouncing judgment on which side is…

  10. Army Hearing Program Talking Points Calendar Year 2016

    DTIC Science & Technology

    2017-09-12

    Reserve ARMY HEARING PROGRAM TALKING POINTS CALENDAR YEAR 2016 TIP No. 51-065-0817 2 BACKGROUND Hearing health in the Army has improved...over time, largely due to the dedicated work of hearing health experts. However, noise-induced hearing loss and associated problems have not been...eliminated. The Army Hearing Program continually evolves to address hearing health challenges, and maintains the momentum to build iteratively upon

  11. Theoretical study of carbon-based tips for scanning tunnelling microscopy.

    PubMed

    González, C; Abad, E; Dappe, Y J; Cuevas, J C

    2016-03-11

    Motivated by recent experiments, we present here a detailed theoretical analysis of the use of carbon-based conductive tips in scanning tunnelling microscopy. In particular, we employ ab initio methods based on density functional theory to explore a graphitic, an amorphous carbon and two diamond-like tips for imaging with a scanning tunnelling microscope (STM), and we compare them with standard metallic tips made of gold and tungsten. We investigate the performance of these tips in terms of the corrugation of the STM images acquired when scanning a single graphene sheet. Moreover, we analyse the impact of the tip-sample distance and show that it plays a fundamental role in the resolution and symmetry of the STM images. We also explore in depth how the adsorption of single atoms and molecules in the tip apexes modifies the STM images and demonstrate that, in general, it leads to an improved image resolution. The ensemble of our results provides strong evidence that carbon-based tips can significantly improve the resolution of STM images, as compared to more standard metallic tips, which may open a new line of research in scanning tunnelling microscopy.

  12. The effect of broken stringers on the stress intensity factor for a uniformly stiffened sheet containing a crack

    NASA Technical Reports Server (NTRS)

    Poe, C. C., Jr.

    1973-01-01

    A linear elastic stress analysis was made of a centrally cracked sheet stiffened by riveted, uniformly spaced and sized stringers. The stress intensity factor for the sheet and the load concentration factor for the most highly loaded stringer were determined for various numbers of broken stringers. A broken stringer causes the stress intensity factor to be very high when the crack tip is near the broken stringer, but causes little effect when the crack tip extends beyond several intact stringers. A broken stringer also causes an increase in the load concentration factor of the adjacent stringers. The calculated residual strengths and fatigue-crack-growth lives of a stiffened aluminum sheet with a broken stringer were only slightly less than a sheet with all intact stringers, and were still much higher than those of an unstiffened sheet.

  13. Crack-tip-opening angle measurements and crack tunneling under stable tearing in thin sheet 2024-T3 aluminum alloy

    NASA Technical Reports Server (NTRS)

    Dawicke, D. S.; Sutton, M. A.

    1993-01-01

    The stable tearing behavior of thin sheets 2024-T3 aluminum alloy was studied for middle crack tension specimens having initial cracks that were: flat cracks (low fatigue stress) and 45 degrees through-thickness slant cracks (high fatigue stress). The critical crack-tip-opening angle (CTOA) values during stable tearing were measured by two independent methods, optical microscopy and digital image correlation. Results from the two methods agreed well. The CTOA measurements and observations of the fracture surfaces showed that the initial stable tearing behavior of low and high fatigue stress tests is significantly different. The cracks in the low fatigue stress tests underwent a transition from flat-to-slant crack growth, during which the CTOA values were high and significant crack tunneling occurred. After crack growth equal to about the thickness, CTOA reached a constant value of 6 deg and after crack growth equal to about twice the thickness, crack tunneling stabilized. The initial high CTOA values, in the low fatigue crack tests, coincided with large three-dimensional crack front shape changes due to a variation in the through-thickness crack tip constraint. The cracks in the high fatigue stress tests reach the same constant CTOA value after crack growth equal to about the thickness, but produced only a slightly higher CTOA value during initial crack growth. For crack growth on the 45 degree slant, the crack front and local field variables are still highly three-dimensional. However, the constant CTOA values and stable crack front shape may allow the process to be approximated with two-dimensional models.

  14. Choosing Whole-Grain Foods: 10 Tips for Purchasing and Storing Whole-Grain Foods

    MedlinePlus

    ... Price Tag Read the Food Label Kitchen Timesavers Cooking for Your Family Tasty & Low-Cost Recipes Sample 2-Week Menus Resources for Professionals MyPlate Tip Sheets Print Materials Infographics 5 Ways ...

  15. Hable con sus hijos: Antes de que lo hagan todos los demas (Talk with Your Kids...before Everyone Else Does: Talking with Kids about Tough Issues).

    ERIC Educational Resources Information Center

    Children Now, Oakland, CA.

    Parents are challenged daily with a wide range of disturbing issues that are difficult for children to understand and for adults to explain. This Spanish-language booklet offers practical, concrete tips and techniques for talking easily and openly with 8- to 12-year-olds about sex, HIV/AIDS, violence, drugs, and alcohol. The book is divided into…

  16. Using Cascading Style Sheets to Design a Fly-Out Menu with Microsoft Visual Studio

    ERIC Educational Resources Information Center

    Liu, Chang; Downing, Charles

    2010-01-01

    The menu has become an integrated component within nearly all professionally designed websites. This teaching tip presents a no-code way to design either a vertical or a horizontal fly-out menu by using Cascading Style Sheets (CSS) within Microsoft Visual Studio 2008. The approach described in this tip helps students fully understand how to…

  17. Reading Tips for Parents = Consejos practicos de lectura para los padre.

    ERIC Educational Resources Information Center

    Department of Education, Washington, DC. Office of Intergovernmental and Interagency Affairs.

    This booklet for parents, in both English and Spanish, offers suggestions for helping their young children develop and improve their reading skills. The booklet first presents tips for helping infants or preschoolers be ready to read and ready to learn. Suggestions include talking to the infant or toddler, reading aloud starting at 6 months,…

  18. Fact Sheet for Preventing and Detecting PCB Contamination in Used Oil

    EPA Pesticide Factsheets

    This fact sheet provides tips on how to reduce the mismanagement of used oil contaminated with PCBs, a recurring issue faced by EPA and states, commercial and municipal used oil collection centers and recyclers.

  19. The future of ice sheets and sea ice: between reversible retreat and unstoppable loss.

    PubMed

    Notz, Dirk

    2009-12-08

    We discuss the existence of cryospheric "tipping points" in the Earth's climate system. Such critical thresholds have been suggested to exist for the disappearance of Arctic sea ice and the retreat of ice sheets: Once these ice masses have shrunk below an anticipated critical extent, the ice-albedo feedback might lead to the irreversible and unstoppable loss of the remaining ice. We here give an overview of our current understanding of such threshold behavior. By using conceptual arguments, we review the recent findings that such a tipping point probably does not exist for the loss of Arctic summer sea ice. Hence, in a cooler climate, sea ice could recover rapidly from the loss it has experienced in recent years. In addition, we discuss why this recent rapid retreat of Arctic summer sea ice might largely be a consequence of a slow shift in ice-thickness distribution, which will lead to strongly increased year-to-year variability of the Arctic summer sea-ice extent. This variability will render seasonal forecasts of the Arctic summer sea-ice extent increasingly difficult. We also discuss why, in contrast to Arctic summer sea ice, a tipping point is more likely to exist for the loss of the Greenland ice sheet and the West Antarctic ice sheet.

  20. The future of ice sheets and sea ice: Between reversible retreat and unstoppable loss

    PubMed Central

    Notz, Dirk

    2009-01-01

    We discuss the existence of cryospheric “tipping points” in the Earth's climate system. Such critical thresholds have been suggested to exist for the disappearance of Arctic sea ice and the retreat of ice sheets: Once these ice masses have shrunk below an anticipated critical extent, the ice–albedo feedback might lead to the irreversible and unstoppable loss of the remaining ice. We here give an overview of our current understanding of such threshold behavior. By using conceptual arguments, we review the recent findings that such a tipping point probably does not exist for the loss of Arctic summer sea ice. Hence, in a cooler climate, sea ice could recover rapidly from the loss it has experienced in recent years. In addition, we discuss why this recent rapid retreat of Arctic summer sea ice might largely be a consequence of a slow shift in ice-thickness distribution, which will lead to strongly increased year-to-year variability of the Arctic summer sea-ice extent. This variability will render seasonal forecasts of the Arctic summer sea-ice extent increasingly difficult. We also discuss why, in contrast to Arctic summer sea ice, a tipping point is more likely to exist for the loss of the Greenland ice sheet and the West Antarctic ice sheet. PMID:19884496

  1. Generating A Strobed Laser Light Sheet

    NASA Technical Reports Server (NTRS)

    Leighty, Bradley D.; Franke, John M.; Rhodes, David B.; Jones, Stephen B.

    1994-01-01

    An optoelectronic system generating synchronous, strobed sheet of laser light developed for use in making visible flow of air about model helicopter rotor. Used in wind-tunnel tests to determine actual locations of vortices for comparison with locations predicted by mathematical models to validate models. Each blade tip produces vortex. By establishing successive vortex locations, researcher determines trajectory of vortex pattern. Light-sheet strobe circuits provide selection of blade positions, strobe-pulse durations, and multiple pulses per revolution for rotors having two to nine blades. To make flow visible, vaporizing propylene glycol injected upstream of model. System also provides calibrated trigger delay of strobe pulses, adjustable strobe-pulse durations, selectable number of blades, and slip-sync mode to make flow visible as though in slow motion.

  2. Tips for Kids: Lower Your Risk for Type 2 Diabetes

    ERIC Educational Resources Information Center

    US Department of Health and Human Services, 2005

    2005-01-01

    Today, more kids have type 2 diabetes than ever before. This colorful, easy-to-read tip sheet encourages young people to take steps to lower their risk for type 2 diabetes. A list of warning signs and a healthy eating guide is offered, along with a list of websites to learn more. [This brochure was prepared by the Department of Health and Human…

  3. Global Coastal Exposure due to Sea-level Rise beyond Tipping Points with Multiple Warming Pathways

    NASA Astrophysics Data System (ADS)

    Tawatari, R.; Iseri, Y.; Kiguchi, M.; Kanae, S.

    2016-12-01

    Sea-level is observed and estimated to continue rising. In the future, the rise could be abrupt and irreversible in century to millennial timescale even if we conduct strong reduction of greenhouse gas emission. Greenland ice sheet and West Antarctic ice sheet are considered as attributable climate systems which would significantly enhance presently-projected sea-level rise by several meters if global mean temperature passes certain "Tipping points" which would exist around +1-5 degree Celsius above present temperature (1980-1999 average). Therefore, vulnerable coastal low-lying area, especially small islands, deltas or poor developing countries, would suffer from semi-permanent inundation and forced to counteract due to the enhanced sea-level rise. This study estimate range of sea-level rise until the year 2300 and 3000 considering excess of tipping points with using multiple levels of temperature scenarios which consist of excess tipping points and non-excess tipping points pathways. We extract state-of-the-art knowledge of tipping elements from paper reviewing to express reasonable relationship between temperature and abruptly-changing sea-level transition across the ages. This study also calculate coastal exposure globally as affected population, area and asset below the estimated sea-level for each countries with overlaying 30 arc-second gridded topography, population distribution and the sea-level. The result indicates which country would be critically affected if we follow overshooting pathways. Furthermore, this study visualize uncertain coastal exposure due to sea-level rise in the future from the multiple warming pathways. This estimation of possible future beyond tipping point would be useful information for decision-makers to establish new planning of defense, migration or mitigation for the future societies.

  4. Impact of 1.5°C global warming on the Greenland and Antarctic ice sheets

    NASA Astrophysics Data System (ADS)

    Ritz, Catherine; Pattyn, Frank

    2017-04-01

    For strengthening the global response to climate change, it is crucial to assess to what extent limiting global warming to low values may reduce the impacts on society. To tackle this issue, the IPCC has decided to provide a special report in 2018 on the impacts of global warming of 1.5°C above pre-industrial levels and related global greenhouse gas emission pathways. Ice sheets are well known contributors to sea level rise and many studies have aimed to provide projections of their future contribution in response to climate change, although the focus was often on worst-case scenarios. Here we propose to review the present knowledge of how the ice sheets could be affected in the case of a limited warming of 1.5°C to 2.0°C. We will review the various processes and feedbacks known to induce ice sheets vulnerability. They are different for Greenland, where we know that the surface mass balance plays a crucial role, and Antarctica where the major risk is marine ice sheet instability. One point of interest is to define, in terms of local forcing, the tipping points associated with these processes. We note that limiting global warming to 1.5°C may mean substantially more warming in the polar regions. This polar amplification can be assessed from experiments following the RCP2.6 scenario that have been carried out in recent (post IPCC AR5) studies. This scenario can be considered as an upper limit for 1.5°C. The final question concerns the long term (millennial) impact. There is a general consensus that there are tipping points both for Greenland and Antarctica, which potentially lead to irreversible mass loss. We will review the current knowledge of how long it takes to reach these tipping points and whether subsequent ice-sheet demise is, indeed, unstoppable.

  5. Fuels planning: science synthesis and integration; social issues fact sheet 08: The "Golden Rule" and other lessons on communicating about hazards

    Treesearch

    Rocky Mountain Research Station USDA Forest Service

    2004-01-01

    Other fact sheets identified considerations for communicating about hazards, talked about the importance of working locally, and discussed the seven laws of effective hazard communication. This fact sheet introduces the "Golden Rule" of hazard communication and shares some final lessons from hazard educators.

  6. Electrostatic force spectroscopy revealing the degree of reduction of individual graphene oxide sheets.

    PubMed

    Shen, Yue; Wang, Ying; Zhou, Yuan; Hai, Chunxi; Hu, Jun; Zhang, Yi

    2018-01-01

    Electrostatic force spectroscopy (EFS) is a method for monitoring the electrostatic force microscopy (EFM) phase with high resolution as a function of the electrical direct current bias applied either to the probe or sample. Based on the dielectric constant difference of graphene oxide (GO) sheets (reduced using various methods), EFS can be used to characterize the degree of reduction of uniformly reduced one-atom-thick GO sheets at the nanoscale. In this paper, using thermally or chemically reduced individual GO sheets on mica substrates as examples, we characterize their degree of reduction at the nanoscale using EFS. For the reduced graphene oxide (rGO) sheets with a given degree of reduction (sample n), the EFS curve is very close to a parabola within a restricted area. We found that the change in parabola opening direction (or sign the parabola opening value) indicates the onset of reduction on GO sheets. Moreover, the parabola opening value, the peak bias value (tip bias leads to the peak or valley EFM phases) and the EFM phase contrast at a certain tip bias less than the peak value can all indicate the degree of reduction of rGO samples, which is positively correlated with the dielectric constant. In addition, we gave the ranking of degree for reduction on thermally or chemically reduced GO sheets and evaluated the effects of the reducing conditions. The identification of the degree of reduction of GO sheets using EFS is important for reduction strategy optimization and mass application of GO, which is highly desired owing to its mechanical, thermal, optical and electronic applications. Furthermore, as a general and quantitative technique for evaluating the small differences in the dielectric properties of nanomaterials, the EFS technique will extend and facilitate its nanoscale electronic devices applications in the future.

  7. Teenagers and Sexuality at Camp: Understanding Teen Sexuality and Tips for Talking with Them.

    ERIC Educational Resources Information Center

    Ponton, Lynn E.

    2000-01-01

    Camp offers teens a place to try out new things, including sexual experimentation. Two case studies illustrate challenging ways sex can come up at camp, and staff responses. Myths and misconceptions about sex, including HIV and gender roles, are discussed. Sidebars discuss guidelines for adults concerning sexual abuse symptoms and tips for talking…

  8. Evaluating Potential Tipping Points of Antarctic basins

    NASA Astrophysics Data System (ADS)

    Durand, G.; Sainan, S.; Pattyn, F.; Jourdain, N.

    2017-12-01

    Antarctica is currently loosing mass and its forthcoming contribution to sea-level rise could substantially increase during the coming centuries. This is essentially due to geometrical constraints, i.e., in regions where grounded ice lies on a bedrock below sea-level sloping down towards the interior of the ice sheet (retrograde slope). For such a configuration the ice sheet is considered potentially unstable, as suggested by theory. However, recent observations on accelerated grounding-line retreat and new insights in modeling Pine Island and Thwaites glaciers give evidence that such self-sustained retreat, called marine ice sheet instability (MISI), has already been on its way. Although West Antarctica appears to be the most vulnerable region for MISI occurrence, similar topographic configurations are also observed in East Antarctica, in the Wilkes Basin in particular. Therefore, evaluating the MISI potential at a pan-Antarctic scale is becoming a priority. Here, using the f.ETISh ice sheet model, an ensemble of simulations of the entire contemporary Antarctic ice sheet has been carried out. In particular, we investigate the debuttressing of ice shelves required to initiate MISI for each coastal region around Antarctica by forcing the model with realistic sub-shelf melt pulses of varying duration and amplitude. We further identify the currently grounded areas where the outlet glaciers could hardly stabilize, the Amundsen Sea Sector being the more prone to large self-sustained retreats. On the contrary, the ability of Cook and Ninnis ice shelves to recover after large perturbations and enough buttress upstream outlet glaciers tends to limit self-sustained retreat of the sector. For each basin, rates of contribution to sea-level rise are discussed together with the RCPs and time when tipping points could be reached and MISI triggered.

  9. A Hybrid Vortex Sheet / Point Vortex Model for Unsteady Separated Flows

    NASA Astrophysics Data System (ADS)

    Darakananda, Darwin; Eldredge, Jeff D.; Colonius, Tim; Williams, David R.

    2015-11-01

    The control of separated flow over an airfoil is essential for obtaining lift enhancement, drag reduction, and the overall ability to perform high agility maneuvers. In order to develop reliable flight control systems capable of realizing agile maneuvers, we need a low-order aerodynamics model that can accurately predict the force response of an airfoil to arbitrary disturbances and/or actuation. In the present work, we integrate vortex sheets and variable strength point vortices into a method that is able to capture the formation of coherent vortex structures while remaining computationally tractable for control purposes. The role of the vortex sheet is limited to tracking the dynamics of the shear layer immediately behind the airfoil. When parts of the sheet develop into large scale structures, those sections are replaced by variable strength point vortices. We prevent the vortex sheets from growing indefinitely by truncating the tips of the sheets and transfering their circulation into nearby point vortices whenever the length of sheet exceeds a threshold. We demonstrate the model on a variety of canonical problems, including pitch-up and impulse translation of an airfoil at various angles of attack. Support by the U.S. Air Force Office of Scientific Research (FA9550-14-1-0328) with program manager Dr. Douglas Smith is gratefully acknowledged.

  10. Fuels planning: science synthesis and integration; social issues fact sheet 12: Keys to successful collaboration

    Treesearch

    Christine Esposito

    2006-01-01

    Collaborating on fire and fuels management with a host of public and private partners may seem like an impossible undertaking, and presents many challenges. This fact sheet reviews tips for what to focus on as you embark on a collaborative fuels management project.Other...

  11. Resistance Spot Welding of AA5052 Sheet Metal of Dissimilar Thickness

    NASA Astrophysics Data System (ADS)

    Mat Din, N. A.; Zuhailawati, H.; Anasyida, A. S.

    2016-02-01

    Resistance spot welding of dissimilar thickness of AA5052 aluminum alloy was performed in order to investigate the effect of metal thickness on the weldment strength. Resistance spot welding was done using a spot welder machine available in Coraza Systems Sdn Bhd using a hemispherical of chromium copper electrode tip with radius of 6.00 mm under 14 kA of current and 0.02 bar of pressure for all thickness combinations. Lap joint configuration was produced between 2.0 mm thick sheet and 1.2 - 3.2 mm thick sheet, respectively. Microstructure of joint showed asymmetrical nugget shape that was larger on the thicker side indicating larger molten metal volume. Joint 2.0 mm x 3.2 mm sheets has the lowest hardness in both transverse direction and through thickness direction because less heat left in the weld nugget. The microstructure shows that this joint has coarse grains of HAZ. As thickness of sheet metal increased, the failure load of the joints increased. However, there was no linear correlation established between joint strength and metal thickness due to different shape of fusion zone in dissimilar thickness sheet metal.

  12. Let's Talk about Talking: Accountable Talk and Participatory Learning

    ERIC Educational Resources Information Center

    Huss, John A.

    2007-01-01

    Middle-grade students like to talk. This natural "gift of gab" may at times be suppressed by teachers who prefer to impart knowledge rather than allow students to participate in its development. Intelligence is a social practice. Students become adept at socializing their intelligence if they are encouraged to talk in meaningful and constructive…

  13. A fracture criterion for widespread cracking in thin-sheet aluminum alloys

    NASA Technical Reports Server (NTRS)

    Newman, J. C., Jr.; Dawicke, D. S.; Sutton, M. A.; Bigelow, C. A.

    1993-01-01

    An elastic-plastic finite-element analysis was used with a critical crack-tip-opening angle (CTOA) fracture criterion to model stable crack growth in thin-sheet 2024-T3 aluminum alloy panels with single and multiple-site damage (MSD) cracks. Comparisons were made between critical angles determined from the analyses and those measured with photographic methods. Calculated load against crack extension and load against crack-tip displacement on single crack specimens agreed well with test data even for large-scale plastic deformations. The analyses were also able to predict the stable tearing behavior of large lead cracks in the presence of stably tearing MSD cracks. Small MSD cracks significantly reduced the residual strength for large lead cracks.

  14. Talking Black.

    ERIC Educational Resources Information Center

    Abrahams, Roger D.

    This book contains essays which focus on the systems of communication that operate within and between various social segments of Afro-American communities in the United States. The essays are presented under the following headings: (1) "Getting Into It: Black Talk, Black Life and the Academic," (2) "'Talking My Talk': Black Talk Varieties and…

  15. Geomorphic tipping points: convenient metaphor or fundamental landscape property?

    NASA Astrophysics Data System (ADS)

    Lane, Stuart

    2016-04-01

    In 2000 Malcolm Gladwell published as book that has done much to publicise Tipping Points in society but also in academia. His arguments, re-expressed in a geomorphic sense, have three core elements: (1) a "Law of the Few", where rapid change results from the effects of a relatively restricted number of critical elements, ones that are able to rapidly connect systems together, that are particularly sensitive to an external force, of that are spatially organised in a particular way; (2) a "Stickiness" where an element of the landscape is able to assimilate characteristics which make it progressively more applicable to the "Law of the Few"; and (3), given (1) and (2) a history and a geography that means that the same force can have dramatically different effects, according to where and when it occurs. Expressed in this way, it is not clear that Tipping Points bring much to our understanding in geomorphology that existing concepts (e.g. landscape sensitivity and recovery; cusp-catastrophe theory; non-linear dynamics systems) do not already provide. It may also be all too easy to describe change in geomorphology as involving a Tipping Point: we know that geomorphic processes often involve a non-linear response above a certain critical threshold; we know that landscapes can, after Denys Brunsden, be though of as involving long periods of boredom ("stability") interspersed with brief moments of terror ("change"); but these are not, after Gladwell, sufficient for the term Tipping Point to apply. Following from these issues, this talk will address three themes. First, it will question, through reference to specific examples, notably in high Alpine systems, the extent to which the Tipping Point analogy is truly a property of the world in which we live. Second, it will explore how 'tipping points' become assigned metaphorically, sometimes evolving to the point that they themselves gain agency, that is, shaping the way we interpret landscape rather than vice versa. Third, I

  16. Damage Tolerance of Sandwich Plates With Debonded Face Sheets

    NASA Technical Reports Server (NTRS)

    Sankar, Bhavani V.

    2001-01-01

    A nonlinear finite element analysis was performed to simulate axial compression of sandwich beams with debonded face sheets. The load - end-shortening diagrams were generated for a variety of specimens used in a previous experimental study. The energy release rate at the crack tip was computed using the J-integral, and plotted as a function of the load. A detailed stress analysis was performed and the critical stresses in the face sheet and the core were computed. The core was also modeled as an isotropic elastic-perfectly plastic material and a nonlinear post buckling analysis was performed. A Graeco-Latin factorial plan was used to study the effects of debond length, face sheet and core thicknesses, and core density on the load carrying capacity of the sandwich composite. It has been found that a linear buckling analysis is inadequate in determining the maximum load a debonded sandwich beam can carry. A nonlinear post-buckling analysis combined with an elastoplastic model of the core is required to predict the compression behavior of debonded sandwich beams.

  17. Tip Sheets

    Science.gov Websites

    United States Census Bureau Topics Population Latest Information Age and Sex Ancestry Children Mobility Population Estimates Population Projections Race Veterans Economy Latest Information Portal Other Economic Programs Business Latest Information Business Characteristics Classification Codes

  18. Ice sheet climate modeling: past achievements, ongoing challenges, and future endeavors

    NASA Astrophysics Data System (ADS)

    Lenaerts, J.

    2017-12-01

    Fluctuations in surface mass balance (SMB) mask out a substantial portion of contemporary Greenland and Antarctic ice sheet mass loss. That implies that we need accurate, consistent, and long-term SMB time series to isolate the mass loss signal. This in turn requires understanding of the processes driving SMB, and how they interplay. The primary controls on present-day ice sheet SMB are snowfall, which is regulated by large-scale atmospheric variability, and surface meltwater production at the ice sheet's edges, which is a complex result of atmosphere-surface interactions. Additionally, wind-driven snow redistribution and sublimation are large SMB contributors on the downslope areas of the ice sheets. Climate models provide an integrated framework to simulate all these individual ice sheet components. Recent developments in RACMO2, a regional climate model bound by atmospheric reanalyses, have focused on enhancing horizontal resolution, including blowing snow, snow albedo, and meltwater processes. Including these physics not only enhanced our understanding of the ice sheet climate system, but also enabled to obtain increasingly accurate estimates of ice sheet SMB. However, regional models are not suitable to capture the mutual interactions between ice sheet and the remainder of the global climate system in transient climates. To take that next step, global climate models are essential. In this talk, I will highlight our present work on improving ice sheet climate in the Community Earth System Model (CESM). In particular, we focus on an improved representation of polar firn, ice sheet clouds, and precipitation. For this exercise, we extensively use field observations, remote sensing data, as well as RACMO2. Next, I will highlight how CESM is used to enhance our understanding of ice sheet SMB, its drivers, and past and present changes.

  19. MODEL2TALK: An Intervention to Promote Productive Classroom Talk

    ERIC Educational Resources Information Center

    van der Veen, Chiel; van der Wilt, Femke; van Kruistum, Claudia; van Oers, Bert; Michaels, Sarah

    2017-01-01

    This article describes the MODEL2TALK intervention, which aims to promote young children's oral communicative competence through productive classroom talk. Productive classroom talk provides children in early childhood education with many opportunities to talk and think together. Results from a large-scale study show that productive classroom talk…

  20. Remembering tips

    MedlinePlus

    Memory aids; Alzheimer disease - remembering tips; Early memory loss - remembering tips; Dementia - remembering tips ... harder for your brain to create a new memory, even while you can remember actions and events ...

  1. Frictional behavior of atomically thin sheets: hexagonal-shaped graphene islands grown on copper by chemical vapor deposition.

    PubMed

    Egberts, Philip; Han, Gang Hee; Liu, Xin Z; Johnson, A T Charlie; Carpick, Robert W

    2014-05-27

    Single asperity friction experiments using atomic force microscopy (AFM) have been conducted on chemical vapor deposited (CVD) graphene grown on polycrystalline copper foils. Graphene substantially lowers the friction force experienced by the sliding asperity of a silicon AFM tip compared to the surrounding oxidized copper surface by a factor ranging from 1.5 to 7 over loads from the adhesive minimum up to 80 nN. No damage to the graphene was observed over this range, showing that friction force microscopy serves as a facile, high contrast probe for identifying the presence of graphene on Cu. Consistent with studies of epitaxially grown, thermally grown, and mechanically exfoliated graphene films, the friction force measured between the tip and these CVD-prepared films depends on the number of layers of graphene present on the surface and reduces friction in comparison to the substrate. Friction results on graphene indicate that the layer-dependent friction properties result from puckering of the graphene sheet around the sliding tip. Substantial hysteresis in the normal force dependence of friction is observed with repeated scanning without breaking contact with a graphene-covered region. Because of the hysteresis, friction measured on graphene changes with time and maximum applied force, unless the tip slides over the edge of the graphene island or contact with the surface is broken. These results also indicate that relatively weak binding forces exist between the copper foil and these CVD-grown graphene sheets.

  2. Talking About Antismoking Campaigns: What Do Smokers Talk About, and How Does Talk Influence Campaign Effectiveness?

    PubMed

    Brennan, Emily; Durkin, Sarah J; Wakefield, Melanie A; Kashima, Yoshihisa

    2016-01-01

    Campaign-stimulated conversations have been shown to increase the effectiveness of antismoking campaigns. In order to explore why such effects occur, in the current study we coded the content of naturally occurring conversations. We also examined whether the short-term effects of talking, and of different types of talk, on quitting intentions were mediated through intrapersonal message responses. Using the Natural Exposure(SM) methodology, we exposed 411 smokers to 1 of 6 antismoking advertisements while they were watching television at home. Responses to the advertisement-conversation participation and content, emotional responses, personalized perceived effectiveness, and changes in intentions to quit-were measured within 3 days of exposure. Conversations were coded for appraisal of the advertisement (favorable, neutral, or unfavorable) and the presence of quitting talk and emotion talk. Mediation analyses indicated that the positive effects of talking on intention change were mediated through personalized perceived effectiveness and that the positive effects were driven by conversations that contained a favorable appraisal and/or quitting talk. Conversely, conversations that contained an unfavorable appraisal of the advertisement were negatively associated with campaign effectiveness. These findings highlight the importance of measuring interpersonal communication when evaluating campaigns and the need for further research to identify the message characteristics that predict when smokers talk and when they talk only in desirable ways.

  3. Navigating the network: signaling cross-talk in hematopoietic cells

    PubMed Central

    Fraser, Iain D C; Germain, Ronald N

    2009-01-01

    Recent studies in hematopoietic cells have led to a growing appreciation of the diverse modes of molecular and functional cross-talk between canonical signaling pathways. However, these intersections represent only the tip of the iceberg. Emerging global analytical methods are providing an even richer and more complete picture of the many components that measurably interact in a network manner to produce cellular responses. Here we highlight the pieces in this Focus, emphasize the limitations of the present canonical pathway paradigm, and discuss the value of a systems biology approach using more global, quantitative experimental design and data analysis strategies. Lastly, we urge caution about overly facile interpretation of genome- and proteome-level studies. PMID:19295628

  4. Tip-leakage cavitation in the clearance of a 2D hydrofoil with fillets: high-speed visualization and PIV/PTV measurements

    NASA Astrophysics Data System (ADS)

    Zapryagaev, Ivan I.; Timoshevskiy, Mikhail V.; Pervunin, Konstantin S.

    2017-09-01

    Tip-clearance cavitation is one of the most aggressive forms of cavitation as it can cause surface erosion of hydraulic machinery elements and, as a result, their fatigue damage and disturb designed operating conditions. At present, the literature lacks for detailed experimental data on the inception and development of this type of cavitation at various flow conditions. In the paper, a tip-leakage cavitation occurring in the clearance between an end face of a 2D hydrofoil (a scaled-down model of guide vanes (GV) of a Francis turbine) and a transparent wall of the test section was studied. The experiments were carried out for different cavitating regimes on the cavitation number and two attack angles of 3° and 9°, with the gap size (tip clearance width) varied in the range from 0.4 to 0.8 mm. In order to determine the cavitation inception conditions and investigate the dynamics of the tip-leakage cavitation, a high-speed visualization was applied. A modified PIV/PTV technique with a diverging laser beam instead of a laser light sheet was used to measure the mean velocity distributions within the gap. It was shown that the cavitation pattern on the suction side of the GV model impacts the dynamics of the leakage flow in the gap but does not affect the sheet cavity formed close to the foil leading edge in the clearance as well as its size and dynamics. When the gap size is increased, the tip-leakage cavitation initiates at higher cavitation numbers or, in other words, conditions for the cavitation occurrence become more favorable.

  5. TIP maker and TIP marker; EB1 as a master controller of microtubule plus ends.

    PubMed

    Vaughan, Kevin T

    2005-10-24

    The EB1 protein is a member of the exciting and enigmatic family of microtubule (MT) tip-tracking proteins. EB1 acts as an exquisite marker of dynamic MT plus ends in some cases, whereas in others EB1 is thought to directly dictate the behavior of the plus ends. How EB1 differentiates between these two roles remains unclear; however, a growing list of interactions between EB1 and other MT binding proteins suggests there may be a single mechanism. Adding another layer of complexity to these interactions, two studies published in this issue implicate EB1 in cross-talk between mitotic MTs and between MTs and actin filaments (Goshima et al., p. 229; Wu et al., p. 201). These results raise the possibility that EB1 is a central player in MT-based transport, and that the activity of MT-binding proteins depends on their ability or inability to interact with EB1.

  6. Local measurement and numerical modeling of mass/heat transfer from a turbine blade in a linear cascade with tip clearance

    NASA Astrophysics Data System (ADS)

    Jin, Peitong

    2000-11-01

    Local mass/heat transfer measurements from the turbine blade near-tip and the tip surfaces are performed using the naphthalene sublimation technique. The experiments are conducted in a linear cascade consisting of five high-pressure blades with a central test-blade configuration. The incoming flow conditions are close to those of the gas turbine engine environment (boundary layer displacement thickness is about 0.01 of chord) with an exit Reynolds number of 6.2 x 105. The effects of tip clearance level (0.86%--6.90% of chord), mainstream Reynolds number and turbulence intensity (0.2 and 12.0%) are investigated. Two methods of flow visualization---oil and lampblack, laser light sheet smoke wire---as well as static pressure measurement on the blade surface are used to study the tip leakage flow and vortex in the cascade. In addition, numerical modeling of the flow and heat transfer processes in the linear cascade with different tip clearances is conducted using commercial software incorporating advanced turbulence models. The present study confirms many important results on the tip leakage flow and vortex from the literature, contributes to the current understanding in the effects of tip leakage flow and vortex on local heat transfer from the blade near-tip and the tip surfaces, and provides detailed local and average heat/mass transfer data applicable to turbine blade tip cooling design.

  7. Lateral Tip Control Effects in CD-AFM Metrology: The Large Tip Limit.

    PubMed

    Dixson, Ronald G; Orji, Ndubuisi G; Goldband, Ryan S

    2016-01-25

    Sidewall sensing in critical dimension atomic force microscopes (CD-AFMs) usually involves continuous lateral dithering of the tip or the use of a control algorithm and fast response piezo actuator to position the tip in a manner that resembles touch-triggering of coordinate measuring machine (CMM) probes. All methods of tip position control, however, induce an effective tip width that may deviate from the actual geometrical tip width. Understanding the influence and dependence of the effective tip width on the dither settings and lateral stiffness of the tip can improve the measurement accuracy and uncertainty estimation for CD-AFM measurements. Since CD-AFM typically uses tips that range from 15 nm to 850 nm in geometrical width, the behavior of effective tip width throughout this range should be understood. The National Institute of Standards and Technology (NIST) has been investigating the dependence of effective tip width on the dither settings and lateral stiffness of the tip, as well as the possibility of material effects due to sample composition. For tip widths of 130 nm and lower, which also have lower lateral stiffness, the response of the effective tip width to lateral dither is greater than for larger tips. However, we have concluded that these effects will not generally result in a residual bias, provided that the tip calibration and sample measurement are performed under the same conditions. To validate that our prior conclusions about the dependence of effective tip width on lateral stiffness are valid for large CD-tips, we recently performed experiments using a very large non-CD tip with an etched plateau of approximately 2 μm width. The effective lateral stiffness of these tips is at least 20 times greater than typical CD-AFM tips, and these results supported our prior conclusions about the expected behavior for larger tips. The bottom-line importance of these latest observations is that we can now reasonably conclude that a dither slope of 3 nm

  8. Lateral Tip Control Effects in CD-AFM Metrology: The Large Tip Limit

    PubMed Central

    Dixson, Ronald G.; Orji, Ndubuisi G.; Goldband, Ryan S.

    2016-01-01

    Sidewall sensing in critical dimension atomic force microscopes (CD-AFMs) usually involves continuous lateral dithering of the tip or the use of a control algorithm and fast response piezo actuator to position the tip in a manner that resembles touch-triggering of coordinate measuring machine (CMM) probes. All methods of tip position control, however, induce an effective tip width that may deviate from the actual geometrical tip width. Understanding the influence and dependence of the effective tip width on the dither settings and lateral stiffness of the tip can improve the measurement accuracy and uncertainty estimation for CD-AFM measurements. Since CD-AFM typically uses tips that range from 15 nm to 850 nm in geometrical width, the behavior of effective tip width throughout this range should be understood. The National Institute of Standards and Technology (NIST) has been investigating the dependence of effective tip width on the dither settings and lateral stiffness of the tip, as well as the possibility of material effects due to sample composition. For tip widths of 130 nm and lower, which also have lower lateral stiffness, the response of the effective tip width to lateral dither is greater than for larger tips. However, we have concluded that these effects will not generally result in a residual bias, provided that the tip calibration and sample measurement are performed under the same conditions. To validate that our prior conclusions about the dependence of effective tip width on lateral stiffness are valid for large CD-tips, we recently performed experiments using a very large non-CD tip with an etched plateau of approximately 2 μm width. The effective lateral stiffness of these tips is at least 20 times greater than typical CD-AFM tips, and these results supported our prior conclusions about the expected behavior for larger tips. The bottom-line importance of these latest observations is that we can now reasonably conclude that a dither slope of 3 nm

  9. Are Adolescents Talking with Their Parents about Sex before Becoming Sexually Active? Fact Sheet

    ERIC Educational Resources Information Center

    Leuschner, Kristin

    2010-01-01

    This paper examines parent-child discussions of sexual behavior. It finds consistency in the timing and content of such discussions; however, many parents and children do not discuss key topics, such as birth control, before adolescents become sexually active. [This fact sheet is based on Megan K. Beckett, Marc N. Elliott, Steven Martino, David E.…

  10. Microstructure and Mechanical Performance of Friction Stir Spot-Welded Aluminum-5754 Sheets

    NASA Astrophysics Data System (ADS)

    Pathak, N.; Bandyopadhyay, K.; Sarangi, M.; Panda, Sushanta Kumar

    2013-01-01

    Friction stir spot welding (FSSW) is a recent trend of joining light-weight sheet metals while fabricating automotive and aerospace body components. For the successful application of this solid-state welding process, it is imperative to have a thorough understanding of the weld microstructure, mechanical performance, and failure mechanism. In the present study, FSSW of aluminum-5754 sheet metal was tried using tools with circular and tapered pin considering different tool rotational speeds, plunge depths, and dwell times. The effects of tool design and process parameters on temperature distribution near the sheet-tool interface, weld microstructure, weld strength, and failure modes were studied. It was found that the peak temperature was higher while welding with a tool having circular pin compared to tapered pin, leading to a bigger dynamic recrystallized stir zone (SZ) with a hook tip bending towards the upper sheet and away from the keyhole. Hence, higher lap shear separation load was observed in the welds made from circular pin compared to those made from tapered pin. Due to influence of size and hardness of SZ on crack propagation, three different failure modes of weld nugget were observed through optical cross-sectional micrograph and SEM fractographs.

  11. Quantifying athlete self-talk.

    PubMed

    Hardy, James; Hall, Craig R; Hardy, Lew

    2005-09-01

    Two studies were conducted. The aims of Study 1 were (a) to generate quantitative data on the content of athletes' self-talk and (b) to examine differences in the use of self-talk in general as well as the functions of self-talk in practice and competition settings. Differences in self-talk between the sexes, sport types and skill levels were also assessed. Athletes (n = 295, mean age = 21.9 years) from a variety of sports and competitive levels completed the Self-Talk Use Questionnaire (STUQ), which was developed specifically for the study. In Study 1, single-factor between-group multivariate analyses of variance revealed significant differences across sex and sport type for the content of self-talk. Mixed-model multivariate analyses of variance revealed overall greater use of self-talk, as well as increased use of the functions of self-talk, in competition compared with practice. Moreover, individual sport athletes reported greater use of self-talk, as well as the functions of self-talk, than their team sport counterparts. In Study 2, recreational volleyball players (n = 164, mean age = 21.5 years) completed a situationally modified STUQ. The results were very similar to those of Study 1. That the content of athlete self-talk was generally positive, covert and abbreviated lends support to the application of Vygotsky's (1986) verbal self-regulation theory to the study of self-talk in sport. Researchers are encouraged to examine the effectiveness of self-talk in future studies.

  12. Phenomenological Model of Current Sheet Canting in Pulsed Electromagnetic Accelerators

    NASA Technical Reports Server (NTRS)

    Markusic, Thomas; Choueiri, E. Y.

    2003-01-01

    The phenomenon of current sheet canting in pulsed electromagnetic accelerators is the departure of the plasma sheet (that carries the current) from a plane that is perpendicular to the electrodes to one that is skewed, or tipped. Review of pulsed electromagnetic accelerator literature reveals that current sheet canting is a ubiquitous phenomenon - occurring in all of the standard accelerator geometries. Developing an understanding of current sheet canting is important because it can detract from the propellant sweeping capabilities of current sheets and, hence, negatively impact the overall efficiency of pulsed electromagnetic accelerators. In the present study, it is postulated that depletion of plasma near the anode, which results from axial density gradient induced diamagnetic drift, occurs during the early stages of the discharge, creating a density gradient normal to the anode, with a characteristic length on the order of the ion skin depth. Rapid penetration of the magnetic field through this region ensues, due to the Hall effect, leading to a canted current front ahead of the initial current conduction channel. In this model, once the current sheet reaches appreciable speeds, entrainment of stationary propellant replenishes plasma in the anode region, inhibiting further Hall-convective transport of the magnetic field; however, the previously established tilted current sheet remains at a fairly constant canting angle for the remainder of the discharge cycle, exerting a transverse J x B force which drives plasma toward the cathode and accumulates it there. This proposed sequence of events has been incorporated into a phenomenological model. The model predicts that canting can be reduced by using low atomic mass propellants with high propellant loading number density; the model results are shown to give qualitative agreement with experimentally measured canting angle mass dependence trends.

  13. Influence of blade tip rounding on tip leakage vortex cavitation of axial flow pump

    NASA Astrophysics Data System (ADS)

    Wu, S. Q.; Shi, W. D.; Zhang, D. S.; Yao, J.; Cheng, C.

    2013-12-01

    Tip leakage flow in axial flow pumps is mainly caused by the tip clearance, which is the main cause of tip leakage vortex cavitation and blade tip cavitation erosion. In order to improve tip clearance flow and reduce TLV cavitation, four schemes were adopted to the round blade tip. These are: no tip rounding, one time tip clearance tip rounding, two times tip clearance tip rounding, four times tip clearance tip rounding. Using SST k-ω turbulence model and Zwart cavitation model in CFX software, this simulation obtained four kinds of inner flow field results. The numerical results indicated that with the increase of r*, NPSHc gradually increased and the cavitation performance reduced. However, corner vortex was eliminated so that cavitation in gap was restrained. But TLV vorticity increased and cavitation's range here had a little expansion. Combined with the research of this paper and the different analyses of four schemes, we recommend adopting the two times of the tip clearance rounding.

  14. Investigation of tip sonication effects on structural quality of graphene nanoplatelets (GNPs) for superior solvent dispersion.

    PubMed

    Baig, Zeeshan; Mamat, Othman; Mustapha, Mazli; Mumtaz, Asad; Munir, Khurram S; Sarfraz, Mansoor

    2018-07-01

    The exceptional properties of graphene and its structural uniqueness can improve the performance of nanocomposites if it can attain the uniform dispersion. Tip sonication assisted graphene solvent dispersion has been emerged as an efficient approach but it can cause significant degradation of graphene structure. This study aimed to evaluate the parametric influence of tip sonication on the characteristics of sp 2 carbon structure in graphene nanoplatelets by varying the sonication time and respective energy at three different amplitudes (60%, 80% and 100%). The study is essential to identify appropriate parameters so as to achieve high-quality and defect-free graphene with a highly desirable aspect ratio after solvent dispersion for composite reinforcement. Quantitative approach via Raman spectroscopy is used to find the defect ratio and lateral size of graphene evolved under the effect of tip sonication parameters. Results imply that the defect ratio is steady and increases continually with GNPs, along with the transformation to the nano-crystalline stage I up to 60 min sonication at all amplitudes. Exfoliation was clearly observed at all amplitudes together with sheet re-stacking due to considerable size reduction of sheets with large quantity. Finally, considerable GNPs fragmentation occurred during sonication with increased amplitude and time as confirmed by the reduction of sp 2 domain (La) and flake size. This also validates the formation of edge-type defect in graphene. Convincingly, lower amplitude and time (up to 60 min) produce better results for a low defect content and larger particle size as quantified by Raman analysis. Copyright © 2018 Elsevier B.V. All rights reserved.

  15. Glacial uplift: fluid injection beneath an elastic sheet on a poroelastic substrate

    NASA Astrophysics Data System (ADS)

    Neufeld, Jerome; Hewitt, Duncan; Chini, Greg

    2016-11-01

    Supraglacial lakes can drain to the base of glaciers extremely rapidly, causing localised uplift of the surrounding glacier and affecting its sliding velocity. The means by which large volumes of drained water interact with and leak into the subglacial hydrological system is unclear, as is the role of the basal till. A theoretical study of the spread of fluid injected below an elastic sheet (the ice) is presented, where the ice lies above, and initially compresses, a deformable poroelastic layer. As pressurized fluid is injected, the deformable layer swells to accommodate more fluid. If sufficient fluid is injected, a 'blister' of fluid forms above the layer, causing the overburden to lift off the base. The flow is controlled by the local pressure drop across the tip of this blister, which depends subtly on both the flow of fluid through the porous layer below the tip, and on poroelastic deformation in the till ahead of the tip. The spreading behaviour and dependence on key parameters is analysed. Predictions of the model are compared to field measurements of uplift from draining glacial lakes in Greenland.

  16. Know Your School District: Tips for Parents. PACER Center ACTion Information Sheets. PHP-c112

    ERIC Educational Resources Information Center

    PACER Center, 2006

    2006-01-01

    Becoming familiar with the school district will help parents become active and involved partners in their child's education. Research has demonstrated that family involvement in children's education can boost their academic success. Knowing about the following areas, which are discussed in this information sheet, can help parental involvement at…

  17. Multi-scale Modeling, Design Strategies and Physical Properties of 2D Composite Sheets

    DTIC Science & Technology

    2014-09-22

    talks and training of two postdoctoral candidates, one graduate student The theoretical work on thennal, elecu·onic and optical prope1iies of 2D ...materials led to several new experimentalists to validate our predictions. 1S. SUBJECT TERMS 2D materials, multi scale modeling 16. SECURITY...strategies and physical properties of 2D composite sheets: Final Report Report Title This report describes the progress made as part of the subject contract

  18. Comparison of Various Supersonic Turbine Tip Designs to Minimize Aerodynamic Loss and Tip Heating

    NASA Technical Reports Server (NTRS)

    Shyam, Vikram; Ameri, Ali

    2012-01-01

    The rotor tips of axial turbines experience high heat flux and are the cause of aerodynamic losses due to tip clearance flows, and in the case of supersonic tips, shocks. As stage loadings increase, the flow in the tip gap approaches and exceeds sonic conditions. This introduces effects such as shock-boundary layer interactions and choked flow that are not observed for subsonic tip flows that have been studied extensively in literature. This work simulates the tip clearance flow for a flat tip, a diverging tip gap and several contoured tips to assess the possibility of minimizing tip heat flux while maintaining a constant massflow from the pressure side to the suction side of the rotor, through the tip clearance. The Computational Fluid Dynamics (CFD) code GlennHT was used for the simulations. Due to the strong favorable pressure gradients the simulations assumed laminar conditions in the tip gap. The nominal tip gap width to height ratio for this study is 6.0. The Reynolds number of the flow is 2.4 x 10(exp 5) based on nominal tip width and exit velocity. A wavy wall design was found to reduce heat flux by 5 percent but suffered from an additional 6 percent in aerodynamic loss coefficient. Conventional tip recesses are found to perform far worse than a flat tip due to severe shock heating. Overall, the baseline flat tip was the second best performer. A diverging converging tip gap with a hole was found to be the best choice. Average tip heat flux was reduced by 37 percent and aerodynamic losses were cut by over 6 percent.

  19. Probe tip heating assembly

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

    Schmitz, Roger William; Oh, Yunje

    A heating assembly configured for use in mechanical testing at a scale of microns or less. The heating assembly includes a probe tip assembly configured for coupling with a transducer of the mechanical testing system. The probe tip assembly includes a probe tip heater system having a heating element, a probe tip coupled with the probe tip heater system, and a heater socket assembly. The heater socket assembly, in one example, includes a yoke and a heater interface that form a socket within the heater socket assembly. The probe tip heater system, coupled with the probe tip, is slidably receivedmore » and clamped within the socket.« less

  20. Let's Talk... Analytics

    ERIC Educational Resources Information Center

    Oblinger, Diana G.

    2012-01-01

    Talk about analytics seems to be everywhere. Everyone is talking about analytics. Yet even with all the talk, many in higher education have questions about--and objections to--using analytics in colleges and universities. In this article, the author explores the use of analytics in, and all around, higher education. (Contains 1 note.)

  1. Investigation of Unsteady Flow Field in a Low-Speed One and a Half Stage Axial Compressor. Part 2; Effects of Tip Gap Size On the Tip Clearance Flow Structure at Near Stall Operation

    NASA Technical Reports Server (NTRS)

    Hah, Chunill; Hathaway, Michael; Katz, Joseph

    2014-01-01

    The primary focus of this paper is to investigate the effect of rotor tip gap size on how the rotor unsteady tip clearance flow structure changes in a low speed one and half stage axial compressor at near stall operation (for example, where maximum pressure rise is obtained). A Large Eddy Simulation (LES) is applied to calculate the unsteady flow field at this flow condition with both a small and a large tip gaps. The numerically obtained flow fields at the small clearance matches fairly well with the available initial measurements obtained at the Johns Hopkins University with 3-D unsteady PIV in an index-matched test facility which renders the compressor blades and casing optically transparent. With this setup, the unsteady velocity field in the entire flow domain, including the flow inside the tip gap, can be measured. The numerical results are also compared with previously published measurements in a low speed single stage compressor (Maerz et al. [2002]). The current study shows that, with the smaller rotor tip gap, the tip clearance vortex moves to the leading edge plane at near stall operating condition, creating a nearly circumferentially aligned vortex that persists around the entire rotor. On the other hand, with a large tip gap, the clearance vortex stays inside the blade passage at near stall operation. With the large tip gap, flow instability and related large pressure fluctuation at the leading edge are observed in this one and a half stage compressor. Detailed examination of the unsteady flow structure in this compressor stage reveals that the flow instability is due to shed vortices near the leading edge, and not due to a three-dimensional separation vortex originating from the suction side of the blade, which is commonly referred to during a spike-type stall inception. The entire tip clearance flow is highly unsteady. Many vortex structures in the tip clearance flow, including the sheet vortex system near the casing, interact with each other. The

  2. Why Talk Is Important

    ERIC Educational Resources Information Center

    Barnes, Douglas

    2010-01-01

    In this brief retrospective essay, the value of a particular kind of classroom talk is extolled--not the kind of talk that simply feeds back information, but rather talk that has the power to shape knowledge through participant engagement with a range of processes: hypothesising, exploration, debate and synthesis. This kind of talk is the…

  3. A Sea of Talk.

    ERIC Educational Resources Information Center

    Dwyer, John, Ed.

    Arguing that talk has an important place in the English language arts curriculum and across the whole curriculum, this book presents examples of children and teachers talking together, talking about what they are doing "here and now," and talking about what they know and feel about events shaping the world beyond the classroom. Chapter…

  4. Towards a tipping point in responding to change: rising costs, fewer options for Arctic and global societies.

    PubMed

    Huntington, Henry P; Goodstein, Eban; Euskirchen, Eugénie

    2012-02-01

    Climate change incurs costs, but government adaptation budgets are limited. Beyond a certain point, individuals must bear the costs or adapt to new circumstances, creating political-economic tipping points that we explore in three examples. First, many Alaska Native villages are threatened by erosion, but relocation is expensive. To date, critically threatened villages have not yet been relocated, suggesting that we may already have reached a political-economic tipping point. Second, forest fires shape landscape and ecological characteristics in interior Alaska. Climate-driven changes in fire regime require increased fire-fighting resources to maintain current patterns of vegetation and land use, but these resources appear to be less and less available, indicating an approaching tipping point. Third, rapid sea level rise, for example from accelerated melting of the Greenland ice sheet, will create a choice between protection and abandonment for coastal regions throughout the world, a potential global tipping point comparable to those now faced by Arctic communities. The examples illustrate the basic idea that if costs of response increase more quickly than available resources, then society has fewer and fewer options as time passes.

  5. Effect of tip flange on tip leakage flow of small axial flow fans

    NASA Astrophysics Data System (ADS)

    Zhang, Li; Jin, Yingzi; Jin, Yuzhen

    2014-02-01

    Aerodynamic performance of an axial flow fan is closely related to its tip clearance leakage flow. In this paper, the hot-wire anemometer is used to measure the three dimensional mean velocity near the blade tips. Moreover, the filtered N-S equations with finite volume method and RNG k-ɛ turbulence model are adopted to carry out the steady simulation calculation of several fans that differ only in tip flange shape and number. The large eddy simulation and the FW-H noise models are adopted to carry out the unsteady numerical calculation and aerodynamic noise prediction. The results of simulation calculation agree roughly with that of tests, which proves the numerical calculation method is feasible.The effects of tip flange shapes and numbers on the blade tip vortex structure and the characteristics are analyzed. The results show that tip flange of the fan has a certain influence on the characteristics of the fan. The maximum efficiencies for the fans with tip flanges are shifted towards partial flow with respect to the design point of the datum fan. Furthermore, the noise characteristics for the fans with tip flanges have become more deteriorated than that for the datum fan. Tip flange contributes to forming tip vortex shedding and the effect of the half-cylinder tip flange on tip vortex shedding is obvious. There is a distinct relationship between the characteristics of the fan and tip vortex shedding. The research results provide the profitable reference for the internal flow mechanism of the performance optimization of small axial flow fans.

  6. Talking, Listening, Learning

    ERIC Educational Resources Information Center

    Myhill, Debra; Jones, Susan; Hopper, Rosemary

    2005-01-01

    This book looks at an issue which is at the heart of every classroom, the role that talk plays in children's learning. Drawing on a substantial research base, the book provides useful suggestions to facilitate successful talk between teachers and children to improve learning and raise standards. Through analysing the talk that goes on in primary…

  7. Unzip instabilities: Straight to oscillatory transitions in the cutting of thin polymer sheets

    NASA Astrophysics Data System (ADS)

    Reis, P. M.; Kumar, A.; Shattuck, M. D.; Roman, B.

    2008-06-01

    We report an experimental investigation of the cutting of a thin brittle polymer sheet with a blunt tool. It was recently shown that the fracture path becomes oscillatory when the tool is much wider than the sheet thickness. Here we uncover two novel transitions from straight to oscillatory fracture by varying either the tilt angle of the tool or the speed of cutting, respectively. We denote these by angle and speed unzip instabilities and analyze them by quantifying both the dynamics of the crack tip and the final shapes of the fracture paths. Moreover, for the speed unzip instability, the straight crack lip obtained at low speeds exhibits out-of-plane buckling undulations (as opposed to being flat above the instability threshold) suggesting a transition from ductile to brittle fracture.

  8. [Sleep talking].

    PubMed

    Challamel, M J

    2001-11-01

    Sleep talking is very common in the general population. Its prevalence remains stable from childhood through adulthood. Sleep talking is often associated with other parasomnias: sleep walking, sleep terrors or REM sleep behavior disorders. It may arise from either REM or non REM sleep, when associated with REM sleep it is more comprehensible and often associated with clear sentences and recall of sleep mentation. Sleep talking is a benign entity and does not require any treatment; however an exceptional organic cause or psychopathology should be suspected if the onset is late (after 25 years); if the mental content is too violent or too emotional.

  9. TIPsy tour guides: how microtubule plus-end tracking proteins (+TIPs) facilitate axon guidance

    PubMed Central

    Bearce, Elizabeth A.; Erdogan, Burcu; Lowery, Laura Anne

    2015-01-01

    The growth cone is a dynamic cytoskeletal vehicle, which drives the end of a developing axon. It serves to interpret and navigate through the complex landscape and guidance cues of the early nervous system. The growth cone’s distinctive cytoskeletal organization offers a fascinating platform to study how extracellular cues can be translated into mechanical outgrowth and turning behaviors. While many studies of cell motility highlight the importance of actin networks in signaling, adhesion, and propulsion, both seminal and emerging works in the field have highlighted a unique and necessary role for microtubules (MTs) in growth cone navigation. Here, we focus on the role of singular pioneer MTs, which extend into the growth cone periphery and are regulated by a diverse family of microtubule plus-end tracking proteins (+TIPs). These +TIPs accumulate at the dynamic ends of MTs, where they are well-positioned to encounter and respond to key signaling events downstream of guidance receptors, catalyzing immediate changes in microtubule stability and actin cross-talk, that facilitate both axonal outgrowth and turning events. PMID:26175669

  10. Arctic climate tipping points.

    PubMed

    Lenton, Timothy M

    2012-02-01

    There is widespread concern that anthropogenic global warming will trigger Arctic climate tipping points. The Arctic has a long history of natural, abrupt climate changes, which together with current observations and model projections, can help us to identify which parts of the Arctic climate system might pass future tipping points. Here the climate tipping points are defined, noting that not all of them involve bifurcations leading to irreversible change. Past abrupt climate changes in the Arctic are briefly reviewed. Then, the current behaviour of a range of Arctic systems is summarised. Looking ahead, a range of potential tipping phenomena are described. This leads to a revised and expanded list of potential Arctic climate tipping elements, whose likelihood is assessed, in terms of how much warming will be required to tip them. Finally, the available responses are considered, especially the prospects for avoiding Arctic climate tipping points.

  11. Isometric immersions and self-similar buckling in elastic sheets.

    NASA Astrophysics Data System (ADS)

    Gemmer, John

    The edges of torn elastic sheets and growing leaves often display hierarchical self-similar like buckling patterns. On the one hand, such complex, self similar patterns are usually associated with a competition between two distinct energy scales, e.g. elastic sheets with boundary conditions that preclude the possibility of relieving in plane strains, or at alloy-alloy interfaces between distinct crystal structures. On the other hand, within the non-Euclidean plate theory this complex morphology can be understood as low bending energy isometric immersions of hyperbolic Riemannian metrics. In particular, many growth patterns generate residual in-plane strains which can be entirely relieved by the sheet forming part of a surface of revolution or a helix. In this talk we will show that this complex morphology (i) arises from isometric immersions (ii) is driven by a competition between the two principal curvatures, rather than between bending and stretching. We identify the key role of branch-point (or monkey-saddle) singularities, in complex wrinkling patterns within the class of finite bending energy isometric immersions. Using these defects we will give an explicit construction of strain-free embeddings of hyperbolic surfaces that are fractal like and have lower elastic energy than their smooth counterparts US-Israel BSF Grant 2008432. NSF Grant DMS-0807501. NSF-RTG Grant DMS-1148284.

  12. [Over projected tip].

    PubMed

    Duron, J-B; Nguyen, P S; Levet, Y; Bardot, J; Aiach, G

    2014-12-01

    Overprojected tip is a pretty usual request not easy to manage. Preop analysis is crucial in order to evaluate tip support and skin thickness and ability to retract. For example, if the skin is very thick and has poor chance to retract, the surgeon should be very careful in the tip projection decreasing to avoid a skin pollybeak deformity. In such cases, he has to analyze the facial proportions, especially other areas projection (radix, dorsum and chin) and think about augmenting them to balance the profile rather than decreasing tip projection. Correction should always be conducted incrementally, starting with weakening the tip support mechanisms and, only if necessary, continue with alar cartilage interruption. This can be performed on many areas (lateral cruras, domes, medial cruras) and with several techniques (resection or interruption+overlapping). Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  13. Antarctic climate and ice-sheet configuration during the early Pliocene interglacial at 4.23 Ma

    NASA Astrophysics Data System (ADS)

    Golledge, Nicholas R.; Thomas, Zoë A.; Levy, Richard H.; Gasson, Edward G. W.; Naish, Timothy R.; McKay, Robert M.; Kowalewski, Douglas E.; Fogwill, Christopher J.

    2017-07-01

    The geometry of Antarctic ice sheets during warm periods of the geological past is difficult to determine from geological evidence, but is important to know because such reconstructions enable a more complete understanding of how the ice-sheet system responds to changes in climate. Here we investigate how Antarctica evolved under orbital and greenhouse gas conditions representative of an interglacial in the early Pliocene at 4.23 Ma, when Southern Hemisphere insolation reached a maximum. Using offline-coupled climate and ice-sheet models, together with a new synthesis of high-latitude palaeoenvironmental proxy data to define a likely climate envelope, we simulate a range of ice-sheet geometries and calculate their likely contribution to sea level. In addition, we use these simulations to investigate the processes by which the West and East Antarctic ice sheets respond to environmental forcings and the timescales over which these behaviours manifest. We conclude that the Antarctic ice sheet contributed 8.6 ± 2.8 m to global sea level at this time, under an atmospheric CO2 concentration identical to present (400 ppm). Warmer-than-present ocean temperatures led to the collapse of West Antarctica over centuries, whereas higher air temperatures initiated surface melting in parts of East Antarctica that over one to two millennia led to lowering of the ice-sheet surface, flotation of grounded margins in some areas, and retreat of the ice sheet into the Wilkes Subglacial Basin. The results show that regional variations in climate, ice-sheet geometry, and topography produce long-term sea-level contributions that are non-linear with respect to the applied forcings, and which under certain conditions exhibit threshold behaviour associated with behavioural tipping points.

  14. Detection of Steel Fatigue Cracks with Strain Sensing Sheets Based on Large Area Electronics

    PubMed Central

    Yao, Yao; Glisic, Branko

    2015-01-01

    Reliable early-stage damage detection requires continuous monitoring over large areas of structure, and with sensors of high spatial resolution. Technologies based on Large Area Electronics (LAE) can enable direct sensing and can be scaled to the level required for Structural Health Monitoring (SHM) of civil structures and infrastructure. Sensing sheets based on LAE contain dense arrangements of thin-film strain sensors, associated electronics and various control circuits deposited and integrated on a flexible polyimide substrate that can cover large areas of structures. This paper presents the development stage of a prototype strain sensing sheet based on LAE for crack detection and localization. Two types of sensing-sheet arrangements with size 6 × 6 inch (152 × 152 mm) were designed and manufactured, one with a very dense arrangement of sensors and the other with a less dense arrangement of sensors. The sensing sheets were bonded to steel plates, which had a notch on the boundary, so the fatigue cracks could be generated under cyclic loading. The sensors within the sensing sheet that were close to the notch tip successfully detected the initialization of fatigue crack and localized the damage on the plate. The sensors that were away from the crack successfully detected the propagation of fatigue cracks based on the time history of the measured strain. The results of the tests have validated the general principles of the proposed sensing sheets for crack detection and identified advantages and challenges of the two tested designs. PMID:25853407

  15. Let's Talk

    ERIC Educational Resources Information Center

    Woodard, Carol; Haskins, Guy; Schaefer, Grace; Smolen, Linda

    2004-01-01

    This article presents the Let's Talk project as a different approach to oral language development. This approach was based on observations of classrooms in the Netherlands where children talked at large tables while playing with miniature figures representing people and objects they were familiar with in their daily lives. It was also influenced…

  16. Talking Science

    ERIC Educational Resources Information Center

    Shwartz, Yael; Weizman, Ayelet; Fortus, David; Sutherland, LeeAnn; Merrit, Joi; Krajcik, Joe

    2009-01-01

    Science is a social process--one that involves particular ways of talking, reasoning, observing, analyzing, and writing, which often have meaning only when shared within the scientific community. Discussions are one of the best ways to help students learn to "talk science" and construct understanding in a social context. Since inquiry is an…

  17. The tipping point: A mathematical model for the profit-driven abandonment of restaurant tipping.

    PubMed

    Clifton, Sara M; Herbers, Eileen; Chen, Jack; Abrams, Daniel M

    2018-02-01

    The custom of voluntarily tipping for services rendered has gone in and out of fashion in America since its introduction in the 19th century. Restaurant owners that ban tipping in their establishments often claim that social justice drives their decisions, but we show that rational profit-maximization may also justify the decisions. Here, we propose a conceptual model of restaurant competition for staff and customers, and we show that there exists a critical conventional tip rate at which restaurant owners should eliminate tipping to maximize profits. Because the conventional tip rate has been increasing steadily for the last several decades, our model suggests that restaurant owners may abandon tipping en masse when that critical tip rate is reached.

  18. The tipping point: A mathematical model for the profit-driven abandonment of restaurant tipping

    NASA Astrophysics Data System (ADS)

    Clifton, Sara M.; Herbers, Eileen; Chen, Jack; Abrams, Daniel M.

    2018-02-01

    The custom of voluntarily tipping for services rendered has gone in and out of fashion in America since its introduction in the 19th century. Restaurant owners that ban tipping in their establishments often claim that social justice drives their decisions, but we show that rational profit-maximization may also justify the decisions. Here, we propose a conceptual model of restaurant competition for staff and customers, and we show that there exists a critical conventional tip rate at which restaurant owners should eliminate tipping to maximize profits. Because the conventional tip rate has been increasing steadily for the last several decades, our model suggests that restaurant owners may abandon tipping en masse when that critical tip rate is reached.

  19. Reporting Research: A Biologist's Guide to Articles, Talks, and Posters

    NASA Astrophysics Data System (ADS)

    Clymo, R. S.

    2014-12-01

    Want to learn how to present your research successfully? This practical guide for students and postdoctoral scholars offers a unique step-by-step approach to help you avoid the worst, yet most common, mistakes in biology communication. Covering irritants such as sins of ambiguity, circumlocution, inconsistency, vagueness and verbosity, misuse of words and quantitative matters, it also provides guidance to design your next piece of work effectively. Learn how to write scientific articles and get them published, prepare posters and talks that will capture your audience and develop a critical attitude towards your own work as well as that of your colleagues. With numerous practical examples, comparisons among disciplines, valuable tips and real-life anecdotes, this must-read guide will be a valuable resource to both new graduate students and their supervisors.

  20. Documenting Melting Features of the Greenland Ice Sheet

    NASA Astrophysics Data System (ADS)

    Tedesco, M.

    2011-12-01

    There is an increasing interest in studying the Greenland Ice Sheet, its hydrology and dynamics over the short term and longer term because of the potential impact of a warming Arctic. Major studies concern about whether increased surface melting will lead to changes in production of supraglacial lakes and subglacial water pressures and hence , potentially, rates of ice movement. In this talk I will show movies recorded over the past three years form fieldwork activities carried out over the West Greenland ice sheet. In particular, I will project and comment movies concerning surface streams and supraglacial lakes, as the one at http://www.youtube.com/watch?v=QbuFphwJn4c. I will discuss the importance of observing such phenomena and how the recorded videos can be used to summarize scientific studies and communicate the relevance of scientific findings. I will also show, for the first time, the video of the drainage of a supraglacial lake, an event during which a lake ~ 6 m deep and ~ 1 km drained in ~ 1.5 hours. This section of the movie is under development as video material was collected during our latest expedition in June 2011.

  1. Which Individual Therapist Behaviors Elicit Client Change Talk and Sustain Talk in Motivational Interviewing?

    PubMed

    Apodaca, Timothy R; Jackson, Kristina M; Borsari, Brian; Magill, Molly; Longabaugh, Richard; Mastroleo, Nadine R; Barnett, Nancy P

    2016-02-01

    To identify individual therapist behaviors which elicit client change talk or sustain talk in motivational interviewing sessions. Motivational interviewing sessions from a single-session alcohol intervention delivered to college students were audio-taped, transcribed, and coded using the Motivational Interviewing Skill Code (MISC), a therapy process coding system. Participants included 92 college students and eight therapists who provided their treatment. The MISC was used to code 17 therapist behaviors related to the use of motivational interviewing, and client language reflecting movement toward behavior change (change talk), away from behavior change (sustain talk), or unrelated to the target behavior (follow/neutral). Client change talk was significantly more likely to immediately follow individual therapist behaviors [affirm (p=.013), open question (p<.001), simple reflection (p<.001), and complex reflection (p<.001)], but significantly less likely to immediately follow others (giving information (p<.001) and closed question (p<.001)]. Sustain talk was significantly more likely to follow therapist use of open questions (p<.001), simple reflections (p<.001), and complex reflections (p<.001), and significantly less likely to occur following therapist use of therapist affirm (p=.012), giving information (p<.001), and closed questions (p<.001). Certain individual therapist behaviors within motivational interviewing can either elicit both client change talk and sustain talk or suppress both types of client language. Affirm was the only therapist behavior that both increased change talk and also reduced sustain talk. Copyright © 2015 Elsevier Inc. All rights reserved.

  2. Patterns through elastic instabilities, from thin sheets to twisted ribbons

    NASA Astrophysics Data System (ADS)

    Damman, Pascal

    that also reflect stretching and bending deformations. When the tension is progressively relieved, longitudinal and transverse compressive stresses build. To relax the longitudinal stress while keeping the helicoid shape, the ribbons produce wrinkles that ultimately becomes sharp folds similar to the ridge singularities observed in crumpled paper. The relaxation of the transverse compression stress produces cylindrical solutions. All these examples illustrates the natural tendency of an elastic sheet to stay as close as possible to the imposed shape, i.e. flat, spherical, helicoid. The mechanical response of the elastic sheet aims to relieve the compressive stress by growing a given micro-structure, i.e. wrinkles, singularities. In this talk, we will explore the general mechanisms at work, based on geometry and a competition between various energy terms, involving stretching and bending modes.

  3. Growing TiO2 nanowires on the surface of graphene sheets in supercritical CO2: characterization and photoefficiency.

    PubMed

    Farhangi, Nasrin; Medina-Gonzalez, Yaocihuatl; Chowdhury, Rajib Roy; Charpentier, Paul A

    2012-07-27

    Tremendous interest exists towards synthesizing nanoassemblies for dye-sensitized solar cells (DSSCs) using earth-abundant and -friendly materials with green synthetic approaches. In this work, high surface area TiO(2) nanowire arrays were grown on the surface of functionalized graphene sheets (FGSs) containing -COOH functionalities acting as a template by using a sol-gel method in the green solvent, supercritical carbon dioxide (scCO(2)). The effect of scCO(2) pressure (1500, 3000 and 5000 psi), temperature (40, 60 and 80 °C), acetic acid/titanium isopropoxide monomer ratios (HAc/TIP = 2, 4 and 6), functionalized graphene sheets (FGSs)/TIP weight ratios (1:20, 1:40 and 1:60 w/w) and solvents (EtOH, hexane) were investigated. Increasing the HAc/TIPweight ratio from 4 to 6 in scCO(2) resulted in increasing the TiO(2) nanowire diameter from 10 to 40 nm. Raman and high resolution XPS showed the interaction of TiO(2) with the -COOH groups on the surface of the graphene sheets, indicating that graphene acted as a template for polycondensation growth. UV-vis diffuse reflectance and photoluminescence spectroscopy showed a reduction in titania's bandgap and also a significant reduction in electron-hole recombination compared to bare TiO(2) nanowires. Photocurrent measurements showed that the TiO(2)nanowire/graphene composites prepared in scCO(2) gave a 5× enhancement in photoefficiency compared to bare TiO(2) nanowires.

  4. Growing TiO2 nanowires on the surface of graphene sheets in supercritical CO2: characterization and photoefficiency

    NASA Astrophysics Data System (ADS)

    Farhangi, Nasrin; Medina-Gonzalez, Yaocihuatl; Chowdhury, Rajib Roy; Charpentier, Paul A.

    2012-07-01

    Tremendous interest exists towards synthesizing nanoassemblies for dye-sensitized solar cells (DSSCs) using earth-abundant and -friendly materials with green synthetic approaches. In this work, high surface area TiO2 nanowire arrays were grown on the surface of functionalized graphene sheets (FGSs) containing -COOH functionalities acting as a template by using a sol-gel method in the green solvent, supercritical carbon dioxide (scCO2). The effect of scCO2 pressure (1500, 3000 and 5000 psi), temperature (40, 60 and 80 °C), acetic acid/titanium isopropoxide monomer ratios (HAc/TIP = 2, 4 and 6), functionalized graphene sheets (FGSs)/TIP weight ratios (1:20, 1:40 and 1:60 w/w) and solvents (EtOH, hexane) were investigated. Increasing the HAc/TIPweight ratio from 4 to 6 in scCO2 resulted in increasing the TiO2 nanowire diameter from 10 to 40 nm. Raman and high resolution XPS showed the interaction of TiO2 with the -COOH groups on the surface of the graphene sheets, indicating that graphene acted as a template for polycondensation growth. UV-vis diffuse reflectance and photoluminescence spectroscopy showed a reduction in titania’s bandgap and also a significant reduction in electron-hole recombination compared to bare TiO2 nanowires. Photocurrent measurements showed that the TiO2nanowire/graphene composites prepared in scCO2 gave a 5× enhancement in photoefficiency compared to bare TiO2 nanowires.

  5. Technology Tips

    ERIC Educational Resources Information Center

    Mathematics Teacher, 2004

    2004-01-01

    Some inexpensive or free ways that enable to capture and use images in work are mentioned. The first tip demonstrates the methods of using some of the built-in capabilities of the Macintosh and Windows-based PC operating systems, and the second tip describes methods to capture and create images using SnagIt.

  6. Spring back of infinite honeycomb sheets beyond plastic deformation

    NASA Astrophysics Data System (ADS)

    Bonfanti, A.; Bhaskar, A.

    2015-02-01

    Cellular structures are promising for applications where high stiffness and strength are required with the minimal use of material. They are often used in applications where the plastic deformation plays an important role, such as those involving crashworthiness, energy absorption, and stents. The elastic analysis of a honeycomb sheet has been carried out in the past [1]. The present analysis extends this classical work in the elasto-plastic regime. Recoil analysis due to elastic recovery is absent from the published literature. This work aims to develop an analytical model to calculate the spring back for a simplified case, that of an infinite honeycomb sheet. An elastic-perfectly plastic material model is assumed. The recoil for a clamped beam with a load and moment applied at the free edge is analytically calculated first. This is carried out by relating the stress distribution of the cross section to the final deformed shape. The part corresponding to the elastic contribution is subsequently subtracted in order to obtain the final configuration after the external load is removed. This simple elasto-plastic analysis is then incorporated into the analysis of an infinite sheet made of uniform hexagonal cells. The translational symmetry of the lattice is exploited along with the analysis of a beam under tip loading through to plastic stage and recoil. The final shape of the struts upon the removal of the remote stress is completely determined by the plastic deformation which cannot be recovered. The expression for the beam thus obtained is then used to build an analytical model for an infinite honeycomb sheet loaded in both directions.

  7. On talking-as-dreaming.

    PubMed

    Ogden, Thomas H

    2007-06-01

    Many patients are unable to engage in waking-dreaming in the analytic setting in the form of free association or in any other form. The author has found that "talking-as-dreaming" has served as a form of waking-dreaming in which such patients have been able to begin to dream formerly undreamable experience. Such talking is a loosely structured form of conversation between patient and analyst that is often marked by primary process thinking and apparent non sequiturs. Talking-as-dreaming superficially appears to be "unanalytic" in that it may seem to consist "merely" of talking about such topics as books, films, etymology, baseball, the taste of chocolate, the structure of light, and so on. When an analysis is "a going concern," talking-as-dreaming moves unobtrusively into and out of talking about dreaming. The author provides two detailed clinical examples of analytic work with patients who had very little capacity to dream in the analytic setting. In the first clinical example, talking-as-dreaming served as a form of thinking and relating in which the patient was able for the first time to dream her own (and, in a sense, her father's) formerly unthinkable, undreamable experience. The second clinical example involves the use of talking-as-dreaming as an emotional experience in which the formerly "invisible" patient was able to begin to dream himself into existence. The analyst, while engaging with a patient in talking-as-dreaming, must remain keenly aware that it is critical that the difference in roles of patient and analyst be a continuously felt presence; that the therapeutic goals of analysis be firmly held in mind; and that the patient be given the opportunity to dream himself into existence (as opposed to being dreamt up by the analyst).

  8. Tip-enhanced Raman scattering microscopy: Recent advance in tip production

    NASA Astrophysics Data System (ADS)

    Fujita, Yasuhiko; Walke, Peter; De Feyter, Steven; Uji-i, Hiroshi

    2016-08-01

    Tip-enhanced Raman scattering (TERS) microscopy is a technique that combines the chemical sensitivity of Raman spectroscopy with the resolving power of scanning probe microscopy. The key component of any TERS setup is a plasmonically-active noble metal tip, which serves to couple far-field incident radiation with the near-field. Thus, the design and implementation of reproducible probes are crucial for the continued development of TERS as a tool for nanoscopic analysis. Here we discuss conventional methods for the fabrication of TERS-ready tips, highlighting the problems therein, as well as detailing more recent developments to improve reducibility. In addition, the idea of remote excitation-TERS is enlightened upon, whereby TERS sensitivity is further improved by using propagating surface plasmons to separate the incident radiation from the tip apex, as well as how this can be incorporated into the fabrication process.

  9. Cellular functions of TIP60.

    PubMed

    Sapountzi, Vasileia; Logan, Ian R; Robson, Craig N

    2006-01-01

    TIP60 was originally identified as a cellular acetyltransferase protein that interacts with HIV-1 Tat. As a consequence, the role of TIP60 in transcriptional regulation has been investigated intensively. Recent data suggest that TIP60 has more divergent functions than originally thought and roles for TIP60 in many processes, such as cellular signalling, DNA damage repair, cell cycle and checkpoint control and apoptosis are emerging. TIP60 is a tightly regulated transcriptional coregulator, acting in a large multiprotein complex for a range of transcription factors including androgen receptor, Myc, STAT3, NF-kappaB, E2F1 and p53. This usually involves recruitment of TIP60 acetyltransferase activities to chromatin. Additionally, in response to DNA double strand breaks, TIP60 is recruited to DNA lesions where it participates both in the initial as well as the final stages of repair. Here, we describe how TIP60 is a multifunctional enzyme involved in multiple nuclear transactions.

  10. Trailing Vortex Measurements in the Wake of a Hovering Rotor Blade with Various Tip Shapes

    NASA Technical Reports Server (NTRS)

    Martin, Preston B.; Leishman, J. Gordon

    2003-01-01

    This work examined the wake aerodynamics of a single helicopter rotor blade with several tip shapes operating on a hover test stand. Velocity field measurements were conducted using three-component laser Doppler velocimetry (LDV). The objective of these measurements was to document the vortex velocity profiles and then extract the core properties, such as the core radius, peak swirl velocity, and axial velocity. The measured test cases covered a wide range of wake-ages and several tip shapes, including rectangular, tapered, swept, and a subwing tip. One of the primary differences shown by the change in tip shape was the wake geometry. The effect of blade taper reduced the initial peak swirl velocity by a significant fraction. It appears that this is accomplished by decreasing the vortex strength for a given blade loading. The subwing measurements showed that the interaction and merging of the subwing and primary vortices created a less coherent vortical structure. A source of vortex core instability is shown to be the ratio of the peak swirl velocity to the axial velocity deficit. The results show that if there is a turbulence producing region of the vortex structure, it will be outside of the core boundary. The LDV measurements were supported by laser light-sheet flow visualization. The results provide several benchmark test cases for future validation of theoretical vortex models, numerical free-wake models, and computational fluid dynamics results.

  11. Nano-Wilhelmy investigation of dynamic wetting properties of AFM tips through tip-nanobubble interaction

    PubMed Central

    Wang, Yuliang; Wang, Huimin; Bi, Shusheng; Guo, Bin

    2016-01-01

    The dynamic wetting properties of atomic force microscopy (AFM) tips are of much concern in many AFM-related measurement, fabrication, and manipulation applications. In this study, the wetting properties of silicon and silicon nitride AFM tips are investigated through dynamic contact angle measurement using a nano-Wilhelmy balance based method. This is done by capillary force measurement during extension and retraction motion of AFM tips relative to interfacial nanobubbles. The working principle of the proposed method and mathematic models for dynamic contact angle measurement are presented. Geometric models of AFM tips were constructed using scanning electronic microscopy (SEM) images taken from different view directions. The detailed process of tip-nanobubble interaction was investigated using force-distance curves of AFM on nanobubbles. Several parameters including nanobubble height, adhesion and capillary force between tip and nanobubbles are extracted. The variation of these parameters was studied over nanobubble surfaces. The dynamic contact angles of the AFM tips were calculated from the capillary force measurements. The proposed method provides direct measurement of dynamic contact angles for AFM tips and can also be taken as a general approach for nanoscale dynamic wetting property investigation. PMID:27452115

  12. Nano-Wilhelmy investigation of dynamic wetting properties of AFM tips through tip-nanobubble interaction

    NASA Astrophysics Data System (ADS)

    Wang, Yuliang; Wang, Huimin; Bi, Shusheng; Guo, Bin

    2016-07-01

    The dynamic wetting properties of atomic force microscopy (AFM) tips are of much concern in many AFM-related measurement, fabrication, and manipulation applications. In this study, the wetting properties of silicon and silicon nitride AFM tips are investigated through dynamic contact angle measurement using a nano-Wilhelmy balance based method. This is done by capillary force measurement during extension and retraction motion of AFM tips relative to interfacial nanobubbles. The working principle of the proposed method and mathematic models for dynamic contact angle measurement are presented. Geometric models of AFM tips were constructed using scanning electronic microscopy (SEM) images taken from different view directions. The detailed process of tip-nanobubble interaction was investigated using force-distance curves of AFM on nanobubbles. Several parameters including nanobubble height, adhesion and capillary force between tip and nanobubbles are extracted. The variation of these parameters was studied over nanobubble surfaces. The dynamic contact angles of the AFM tips were calculated from the capillary force measurements. The proposed method provides direct measurement of dynamic contact angles for AFM tips and can also be taken as a general approach for nanoscale dynamic wetting property investigation.

  13. Variability of AVHRR-Derived Clear-Sky Surface Temperature over the Greenland Ice Sheet.

    NASA Astrophysics Data System (ADS)

    Stroeve, Julienne; Steffen, Konrad

    1998-01-01

    The Advanced Very High Resolution Radiometer is used to derive surface temperatures for one satellite pass under clear skies over the Greenland ice sheet from 1989 through 1993. The results of these temperatures are presented as monthly means, and their spatial and temporal variability are discussed. Accuracy of the dry snow surface temperatures is estimated to be better than 1 K during summer. This error is expected to increase during polar night due to problems in cloud identification. Results indicate the surface temperature of the Greenland ice sheet is strongly dominated by topography, with minimum surface temperatures associated with the high elevation regions. In the summer, maximum surface temperatures occur during July along the western coast and southern tip of the ice sheet. Minimum temperatures are found at the summit during summer and move farther north during polar night. Large interannual variability in surface temperatures occurs during winter associated with katabatic storm events. Summer temperatures show little variation, although 1992 stands out as being colder than the other years. The reason for the lower temperatures during 1992 is believed to be a result of the 1991 eruption of Mount Pinatubo.

  14. Eliciting Student-Talk.

    ERIC Educational Resources Information Center

    Rudder, Michael E.

    1999-01-01

    The communicative approach to language instruction emphasizes ways to increase student-talk and decrease teacher-talk. It necessitates including the production or performance stage in lesson plans to give students the opportunity to use the new language in simulated real-life situations. (Author/VWL)

  15. Dissatisfaction with Nasal Tip Shape: Secondary Tip Maneuvers.

    PubMed

    Moyer, Jeffrey S

    2018-06-01

    Dissatisfaction with the appearance of the nasal tip is a common compliant in patients seeking revision surgery after rhinoplasty. Revision rhinoplasty is more technically difficult and unpredictable given the frequent presence of scar contracture, impaired skin envelope quality, and missing alar cartilage. This article describes some of the more common causes for tip revision surgery and techniques to address these abnormalities. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  16. At the Tipping Point

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

    Wiley, H. S.

    There comes a time in every field of science when things suddenly change. While it might not be immediately apparent that things are different, a tipping point has occurred. Biology is now at such a point. The reason is the introduction of high-throughput genomics-based technologies. I am not talking about the consequences of the sequencing of the human genome (and every other genome within reach). The change is due to new technologies that generate an enormous amount of data about the molecular composition of cells. These include proteomics, transcriptional profiling by sequencing, and the ability to globally measure microRNAs andmore » post-translational modifications of proteins. These mountains of digital data can be mapped to a common frame of reference: the organism’s genome. With the new high-throughput technologies, we can generate tens of thousands of data points from each sample. Data are now measured in terabytes and the time necessary to analyze data can now require years. Obviously, we can’t wait to interpret the data fully before the next experiment. In fact, we might never be able to even look at all of it, much less understand it. This volume of data requires sophisticated computational and statistical methods for its analysis and is forcing biologists to approach data interpretation as a collaborative venture.« less

  17. Nanostar probes for tip-enhanced spectroscopy

    NASA Astrophysics Data System (ADS)

    Kim, Woong; Kim, Nara; Park, Joon Won; Kim, Zee Hwan

    2015-12-01

    To overcome the current limit of tip-enhanced spectroscopy that is based on metallic nano-probes, we developed a new scanning probe with a metallic nanostar, a nanoparticle with sharp spikes. A Au nanoparticle of 5 nm was first attached to the end of a tip through DNA-DNA hybridization and mechanical pick-up. The nanoparticle was converted to a nanostar with a core diameter of ~70 nm and spike lengths between 50 nm and 80 nm through the reduction of Au3+ with ascorbic acid in the presence of Ag+. Fabrication yields of such tips exceeded 60%, and more than 80% of such tips showed a mechanical durability sufficient for use in scanning microscopy. Effectiveness of the new probes for tip-enhanced Raman scattering (TERS) and tip-enhanced fluorescence (TEF) was confirmed. The probes exhibited the necessary enhancement for TEF, and the tip-on and tip-off ratios varied between 5 and 100. This large tip-to-tip variability may arise from the uncontrolled orientation of the apexes of the spike with respect to the sample surface, which calls for further fabrication improvement. The result overall supports a new fabrication approach for the probe that is effective for tip-enhanced spectroscopy.To overcome the current limit of tip-enhanced spectroscopy that is based on metallic nano-probes, we developed a new scanning probe with a metallic nanostar, a nanoparticle with sharp spikes. A Au nanoparticle of 5 nm was first attached to the end of a tip through DNA-DNA hybridization and mechanical pick-up. The nanoparticle was converted to a nanostar with a core diameter of ~70 nm and spike lengths between 50 nm and 80 nm through the reduction of Au3+ with ascorbic acid in the presence of Ag+. Fabrication yields of such tips exceeded 60%, and more than 80% of such tips showed a mechanical durability sufficient for use in scanning microscopy. Effectiveness of the new probes for tip-enhanced Raman scattering (TERS) and tip-enhanced fluorescence (TEF) was confirmed. The probes exhibited

  18. Talk about Talk with Young Children: Pragmatic Socialization in Two Communities in Norway and the US

    ERIC Educational Resources Information Center

    Aukrust, Vibeke Grover

    2004-01-01

    Recent studies have suggested that cultures vary in subtle ways in the talk about talk that children hear and learn to produce. Twenty-two three-year-old children and their families in respectively Oslo, Norway and Cambridge, Massachusetts were observed during mealtime with the aim of identifying talk-focused talk. The analysis distinguished talk…

  19. How to give a good talk.

    PubMed

    Alon, Uri

    2009-10-23

    We depend on talks to communicate our work, and we spend much of our time as audience members in talks. However, few scientists are taught the well-established principles of giving good talks. Here, I describe how to prepare, present, and answer questions in a scientific talk. We will see how a talk prepared with a single premise and delivered with good eye contact is clear and enjoyable.

  20. The challenge of stereo PIV measurements in the tip gap of a transonic compressor rotor with casing treatment

    NASA Astrophysics Data System (ADS)

    Voges, Melanie; Willert, Christian E.; Mönig, Reinhard; Müller, Martin W.; Schiffer, Heinz-Peter

    2012-03-01

    This contribution is aimed at summarizing the effort taken to apply stereoscopic PIV (SPIV) measurements in the tip clearance of a transonic compressor rotor equipped with a casing treatment. A light sheet probe was placed downstream of the stator and aligned to pass the light sheet through a stator passage into the blade tip clearance of the rotor. A setup with three cameras has been used in order to record the entire 2C velocity field and the smaller area of 3C field of view at the same time instance for comparison with earlier 2C PIV results. A homogeneous seeding distribution was achieved by means of a smoke generator. The main emphasis of the SPIV measurement was to establish a data set with high spatial resolution close to the compressor casing, where the aerodynamic effects of a CT are known to be strong. The paper will discuss some major aspects of the utilized PIV data processing and point out a variety of frequently underestimated error sources that influence the overall quality of the recovered data in spite of the fact that the individual PIV recordings seemed to be of very good quality. Thus, the authors will not focus on the PIV results and related interpretation of the flow field, but on the optimization and procedures applied during setup of the experiment and data processing, respectively.

  1. Child Transportation Safety Tips.

    ERIC Educational Resources Information Center

    National Highway Traffic Safety Administration (DOT), Washington, DC.

    This document presents nine tips regarding safe infant and child transportation, each tip explained in one to two pages. The tips are as follows: (1) quick safety seat checkup; (2) where should your child ride? (3) how to protect your new baby in the car; (4) what safety seat to use for a big baby or toddler? (5) how should preschool and school…

  2. Method to improve the blade tip-timing accuracy of fiber bundle sensor under varying tip clearance

    NASA Astrophysics Data System (ADS)

    Duan, Fajie; Zhang, Jilong; Jiang, Jiajia; Guo, Haotian; Ye, Dechao

    2016-01-01

    Blade vibration measurement based on the blade tip-timing method has become an industry-standard procedure. Fiber bundle sensors are widely used for tip-timing measurement. However, the variation of clearance between the sensor and the blade will bring a tip-timing error to fiber bundle sensors due to the change in signal amplitude. This article presents methods based on software and hardware to reduce the error caused by the tip clearance change. The software method utilizes both the rising and falling edges of the tip-timing signal to determine the blade arrival time, and a calibration process suitable for asymmetric tip-timing signals is presented. The hardware method uses an automatic gain control circuit to stabilize the signal amplitude. Experiments are conducted and the results prove that both methods can effectively reduce the impact of tip clearance variation on the blade tip-timing and improve the accuracy of measurements.

  3. The smart-talk trap.

    PubMed

    Pfeffer, J; Sutton, R I

    1999-01-01

    In today's business world, there's no shortage of know-how. When companies get into trouble, their executives have vast resources at their disposal: their own experiences, colleagues' ideas, reams of computer-generated data, thousands of publications, and consultants armed with the latest managerial concepts and tools. But all too often, even with all that knowledge floating around, companies are plagued with an inertia that comes from knowing too much and doing too little--a phenomenon the authors call the knowing-doing gap. The gap often can be traced to a basic human propensity: the willingness to let talk substitute for action. When confronted with a problem, people act as though discussing it, formulating decisions, and hashing out plans for action are the same as actually fixing it. And after researching organizations of all shapes and sizes, the authors concluded that a particular kind of talk is an especially insidious inhibitor of action: "smart talk." People who can engage in such talk generally sound confident and articulate; they can spout facts and may even have interesting ideas. But such people often exhibit the less benign aspects of smart talk as well: They focus on the negative, and they favor unnecessarily complex or abstract language. The former lapses into criticism for criticism's sake; the latter confuses people. Both tendencies can stop action in its tracks. How can you shut the smart-talk trap and close the knowing-doing gap? The authors lay out five methods that successful companies employ in order to translate the right kind of talk into intelligent action.

  4. Dielectrophoretic positioning of single nanoparticles on atomic force microscope tips for tip-enhanced Raman spectroscopy.

    PubMed

    Leiterer, Christian; Deckert-Gaudig, Tanja; Singh, Prabha; Wirth, Janina; Deckert, Volker; Fritzsche, Wolfgang

    2015-05-01

    Tip-enhanced Raman spectroscopy, a combination of Raman spectroscopy and scanning probe microscopy, is a powerful technique to detect the vibrational fingerprint of molecules at the nanometer scale. A metal nanoparticle at the apex of an atomic force microscope tip leads to a large enhancement of the electromagnetic field when illuminated with an appropriate wavelength, resulting in an increased Raman signal. A controlled positioning of individual nanoparticles at the tip would improve the reproducibility of the probes and is quite demanding due to usually serial and labor-intensive approaches. In contrast to commonly used submicron manipulation techniques, dielectrophoresis allows a parallel and scalable production, and provides a novel approach toward reproducible and at the same time affordable tip-enhanced Raman spectroscopy tips. We demonstrate the successful positioning of an individual plasmonic nanoparticle on a commercial atomic force microscope tip by dielectrophoresis followed by experimental proof of the Raman signal enhancing capabilities of such tips. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Prom Health and Safety Tips

    MedlinePlus

    ... Halloween Prom Tips Spring Break Valentine Tips Winter Holiday Tips 12 Ways Holiday Song Healthy Living Check-Ups are Important Check- ... Test Wash Hands Stay Warm Have a Healthy Holiday Don’t Drink and Drive Widgets Healthy People ...

  6. Talk at Mealtimes

    ERIC Educational Resources Information Center

    Clark, Christina

    2013-01-01

    This short report explores how many young people sit down with their family at mealtimes, how often they talk with their family when they do and the relationship between mealtime talk and young people's confidence in and attitudes towards communication skills. Using data from the latest annual survey of 34,910 children and young people, it shows…

  7. Therapy Talk: Analyzing Therapeutic Discourse

    ERIC Educational Resources Information Center

    Leahy, Margaret M.

    2004-01-01

    Therapeutic discourse is the talk-in-interaction that represents the social practice between clinician and client. This article invites speech-language pathologists to apply their knowledge of language to analyzing therapy talk and to learn how talking practices shape clinical roles and identities. A range of qualitative research approaches,…

  8. Optical cross-talk and surface characterization of SERS nanoimaging bundle substrates

    NASA Astrophysics Data System (ADS)

    Kiser, John B.; Cullum, Brian M.

    2010-04-01

    Due to the narrow vibrational bandwidths and unique molecular fingerprints, Raman spectroscopy can be an information rich transduction technique for chemical imaging. Dynamic systems are often difficult to measure using spontaneous Raman due to the relatively weak scattering cross-sections. Using a Raman enhancement mechanism such as surface enhanced Raman scattering (SERS), exposure times can be reduced to a reasonable level for dynamic imaging, due to the increased Raman signal intensity. This paper will discuss the development of a novel SERS substrate, fabricated on the tips of fiber-optic imaging bundles, which can be integrated into a multispectral imaging system for non-scanning chemical imaging. These substrates are fabricated by mechanically tapering a polished fiber optic imaging bundle consisting of 30,000 individual elements; producing 100-nm or smaller diameter core elements on the distal tip. Chemical etching with hydrofluoric acid creates uniform cladding spikes onto which a SERS active metal is vacuum deposited, forming the SERS active surface. By varying the size of the silver islands deposited on the cladding peaks active, surface plasmons can be tuned to various excitation frequencies. The surface of these tapered fiber optic probes will be evaluated by analysis of the SERS signal, location and shape of the active surface plasmons. The cross talk between the fiber elements will also be evaluated.

  9. Making the Most of Talk

    ERIC Educational Resources Information Center

    Gilles, Carol

    2010-01-01

    Research supports what many teachers have long known: talk is a valuable tool for learning. But how can we incorporate talk and still keep students on task, thinking collectively and deeply? Gillis offers a solid theoretical foundation for incorporating talk throughout the curriculum, and then provides practical help for implementing it, with…

  10. Tip off the HAT– Epigenetic control of learning and memory by Drosophila Tip60

    PubMed Central

    Xu, Songjun; Elefant, Felice

    2015-01-01

    Disruption of epigenetic gene control mechanisms involving histone acetylation in the brain causes cognitive impairment, a debilitating hallmark of most neurodegenerative disorders. Histone acetylation regulates cognitive gene expression via chromatin packaging control in neurons. Unfortunately, the histone acetyltransferases (HATs) that generate such neural epigenetic signatures and their mechanisms of action remain unclear. Our recent findings provide insight into this question by demonstrating that Tip60 HAT action is critical for morphology and function of the mushroom body (MB), the learning and memory center in the Drosophila brain. We show that Tip60 is robustly produced in MB Kenyon cells and extending axonal lobes and that targeted MB Tip60 HAT loss results in axonal outgrowth disruption. Functional consequences of loss and gain of Tip60 HAT levels in the MB are evidenced by defects in memory. Tip60 ChIP-Seq analysis reveals enrichment for genes that function in cognitive processes and accordingly, key genes representing these pathways are misregulated in the Tip60 HAT mutant fly brain. Remarkably, increasing levels of Tip60 in the MB rescues learning and memory deficits resulting from Alzheimer's disease associated amyloid precursor protein (APP) induced neurodegeneration. Our studies highlight the potential of HAT activators as a therapeutic option for cognitive disorders. PMID:26327426

  11. Advanced turbine blade tip seal system

    NASA Technical Reports Server (NTRS)

    Zelahy, J. W.

    1981-01-01

    An advanced blade/shroud system designed to maintain close clearance between blade tips and turbine shrouds and at the same time, be resistant to environmental effects including high temperature oxidation, hot corrosion, and thermal cycling is described. Increased efficiency and increased blade life are attained by using the advanced blade tip seal system. Features of the system include improved clearance control when blade tips preferentially wear the shrouds and a superior single crystal superalloy tip. The tip design, joint location, characterization of the single crystal tip alloy, the abrasive tip treatment, and the component and engine test are among the factors addressed. Results of wear testing, quality control plans, and the total manufacturing cycle required to fully process the blades are also discussed.

  12. Total Telephone Tips.

    ERIC Educational Resources Information Center

    Corder, Lloyd E.; And Others

    This manual of telephone behavior tips for business and sales professionals offers ways to handle the disgruntled caller and makes suggestions on topics relevant to the telephone. The manual is divided into the following sections and subsections: (1) Common Courtesy (staff tips, answering the telephone, screening calls, transferring calls, taking…

  13. Analyses of Buckling and Stable Tearing in Thin-Sheet Materials

    NASA Technical Reports Server (NTRS)

    Seshadri, B. R.; Newman, J. C., Jr.

    1998-01-01

    This paper was to verify the STAGS (general shell, geometric and material nonlinear) code and the critical crack tip opening angle (CTOA) fracture criterion for predicting stable tearing in cracked panels that fail with severe out of plane buckling. Materials considered ranged from brittle to ductile behavior. Test data used in this study are reported elsewhere. The STAGS code was used to model stable tearing using a critical CTOA value that was determined from a cracked panel that was 'restrained' from buckling. ne analysis methodology was then used to predict the influence of buckling on stable tearing and failure loads. Parameters like crack length to specimen width ratio, crack configuration, thickness, and material tensile properties had a significant influence on the buckling behavior of cracked thin sheet materials. Experimental and predicted results showed a varied buckling response for different crack length to sheet thickness ratios because different buckling modes were activated. Effects of material tensile properties and fracture toughness on buckling response were presented. The STAGS code and the CTOA fracture criterion were able to predict the influence of buckling on stable tearing behavior and failure loads on a variety of materials and crack configurations.

  14. Scanning tip microwave near field microscope

    DOEpatents

    Xiang, Xiao-Dong; Schultz, Peter G.; Wei, Tao

    1998-01-01

    A microwave near field microscope has a novel microwave probe structure wherein the probing field of evanescent radiation is emitted from a sharpened metal tip instead of an aperture or gap. This sharpened tip, which is electrically and mechanically connected to a central electrode, extends through and beyond an aperture in an endwall of a microwave resonating device such as a microwave cavity resonator or a microwave stripline resonator. Since the field intensity at the tip increases as the tip sharpens, the total energy which is radiated from the tip and absorbed by the sample increases as the tip sharpens. The result is improved spatial resolution without sacrificing sensitivity.

  15. Fe doped TiO2 nanofibers on the surface of graphene sheets for photovoltaics applications

    NASA Astrophysics Data System (ADS)

    Farhangi, Nasrin; Medina-Gonzalez, Yaocihuatl; Charpentier, Paul A.

    2011-08-01

    Highly ordered, visible light driven TiO2 nanowire arrays doped with Fe photocatalysts were grown on the surface of functionalized graphene sheets (FGSs) using a sol-gel method with titanium isopropoxide (TIP) monomer, acetic acid (HAc) as the polycondensation agent and iron chloride in the green solvent, supercritical carbon dioxide (scCO2). The morphology of the synthesized materials was studied by SEM and TEM, which showed uniform formation of Fe doped TiO2 nanofibers on the surface of graphene sheets, which acted as a template for nanowire growth through surface -COOH functionalities. Increasing Fe content in the nanowires did not change the morphology significantly. Optical properties of the synthesized composites were examined by UV spectroscopy which showed a significant reduction in band gap with increasing Fe content, i.e. 2.25 eV at 0.6% Fe. The enhancement of the optical properties of synthesized materials was confirmed by photocurrent measurement. The optimum sample containing 0.6% Fe doped TiO2 on the graphene sheets increased the power conversation efficiency by 6-fold in comparison to TiO2 alone.

  16. Talk to Your Kids about Sex

    MedlinePlus

    ... Topic En español Talk to Your Kids about Sex Browse Sections The Basics Overview Bodies and Puberty ... healthy expectations for their relationships. Talk about opposite-sex and same-sex relationships. When you talk about ...

  17. Turbine blade with contoured chamfered squealer tip

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

    Lee, Ching-Pang

    2014-12-30

    A squealer tip formed from a pressure side tip wall and a suction side tip wall extending radially outward from a tip of the turbine blade is disclosed. The pressure and suction side tip walls may be positioned along the pressure sidewall and the suction sidewall of the turbine blade, respectively. The pressure side tip wall may include a chamfered leading edge with film cooling holes having exhaust outlets positioned therein. An axially extending tip wall may be formed from at least two outer linear surfaces joined together at an intersection forming a concave axially extending tip wall. The axiallymore » extending tip wall may include a convex inner surface forming a radially outer end to an inner cavity forming a cooling system. The cooling system may include one or more film cooling holes in the axially extending tip wall proximate to the suction sidewall, which promotes increased cooling at the pressure and suction sidewalls.« less

  18. Strategic Talk in Film.

    PubMed

    Payr, Sabine; Skowron, Marcin; Dobrosovestnova, Anna; Trapp, Martin; Trappl, Robert

    2017-01-01

    Conversational robots and agents are being designed for educational and/or persuasive tasks, e.g., health or fitness coaching. To pursue such tasks over a long time, they will need a complex model of the strategic goal, a variety of strategies to implement it in interaction, and the capability of strategic talk. Strategic talk is incipient ongoing conversation in which at least one participant has the objective of changing the other participant's attitudes or goals. The paper is based on the observation that strategic talk can stretch over considerable periods of time and a number of conversational segments. Film dialogues are taken as a source to develop a model of the strategic talk of mentor characters. A corpus of film mentor utterances is annotated on the basis of the model, and the data are interpreted to arrive at insights into mentor behavior, especially into the realization and sequencing of strategies.

  19. Slender tip laser scalpel

    DOEpatents

    Veligdan, James T.

    2004-01-06

    A laser scalpel includes a ribbon optical waveguide extending therethrough and terminating at a slender optical cutting tip. A laser beam is emitted along the height of the cutting tip for cutting tissue therealong.

  20. Talking to the Pharmacist (For Parents)

    MedlinePlus

    ... for Educators Search English Español Talking to the Pharmacist KidsHealth / For Parents / Talking to the Pharmacist What's ... and families privately. Reasons to Talk to the Pharmacist Pharmacists cannot diagnose medical conditions. But they can ...

  1. Scanning tip microwave near field microscope

    DOEpatents

    Xiang, X.D.; Schultz, P.G.; Wei, T.

    1998-10-13

    A microwave near field microscope has a novel microwave probe structure wherein the probing field of evanescent radiation is emitted from a sharpened metal tip instead of an aperture or gap. This sharpened tip, which is electrically and mechanically connected to a central electrode, extends through and beyond an aperture in an end wall of a microwave resonating device such as a microwave cavity resonator or a microwave stripline resonator. Since the field intensity at the tip increases as the tip sharpens, the total energy which is radiated from the tip and absorbed by the sample increases as the tip sharpens. The result is improved spatial resolution without sacrificing sensitivity. 17 figs.

  2. Reference system for scanning probe tip fingerprinting

    NASA Astrophysics Data System (ADS)

    Turansky, Robert; Bamidele, Joseph; Sugawara, Yasuhiro; Kantorovitch, Lev; Stich, Ivan

    2012-02-01

    Knowledge of the chemical structure of the tip asperity in Non-Contact Atomic Force Microscopy (NC-AFM) is crucial as controlled manipulation of atoms and/or molecules on surfaces can only be performed if this information is available. However, a simple and robust protocol for ensuring a specific tip termination has not yet been developed. We propose a procedure for chemical tip finger printing and an example of a reference system, the oxygen-terminated Cu(110) surface, that enables one to ensure a specific tip termination with Si, Cu, or O atoms. To follow this up and unambiguously determine tip types, we performed a theoretical DFT study of the line scans with the tip models in question and found that the tip characterization made based on experimental results (Cu/O-terminated tip imaging Cu/O atoms) is in fact incorrect and the opposite is true (Cu/O-terminated tip imaging O/Cu atoms). This protocol allows the tip asperity's chemical structure to be verified and established both before as well as at any stage of the manipulation experiment when numerous tip changes may take place.

  3. Strategic Talk in Film

    PubMed Central

    Payr, Sabine; Skowron, Marcin; Dobrosovestnova, Anna; Trapp, Martin; Trappl, Robert

    2017-01-01

    ABSTRACT Conversational robots and agents are being designed for educational and/or persuasive tasks, e.g., health or fitness coaching. To pursue such tasks over a long time, they will need a complex model of the strategic goal, a variety of strategies to implement it in interaction, and the capability of strategic talk. Strategic talk is incipient ongoing conversation in which at least one participant has the objective of changing the other participant’s attitudes or goals. The paper is based on the observation that strategic talk can stretch over considerable periods of time and a number of conversational segments. Film dialogues are taken as a source to develop a model of the strategic talk of mentor characters. A corpus of film mentor utterances is annotated on the basis of the model, and the data are interpreted to arrive at insights into mentor behavior, especially into the realization and sequencing of strategies. PMID:29375243

  4. Chemically etched fiber tips for near-field optical microscopy: a process for smoother tips.

    PubMed

    Lambelet, P; Sayah, A; Pfeffer, M; Philipona, C; Marquis-Weible, F

    1998-11-01

    An improved method for producing fiber tips for scanning near-field optical microscopy is presented. The improvement consists of chemically etching quartz optical fibers through their acrylate jacket. This new method is compared with the previous one in which bare fibers were etched. With the new process the meniscus formed by the acid along the fiber does not move during etching, leading to a much smoother surface of the tip cone. Subsequent metallization is thus improved, resulting in better coverage of the tip with an aluminum opaque layer. Our results show that leakage can be avoided along the cone, and light transmission through the tip is spatially limited to an optical aperture of a 100-nm dimension.

  5. Classroom Talk: Co-Constructing a "Difficult Student"

    ERIC Educational Resources Information Center

    Graff, Nelson

    2009-01-01

    Background: Research on teacher-student relationships has focused logically on classroom talk. Investigations of classroom talk range from broad consideration of the structures of such talk to a somewhat narrower focus on the interpersonal dimensions of such talk, and their consequences for student achievement and motivation. Purpose: This study…

  6. Light Sheet Fluorescence Microscopy Quantifies Calcium Oscillations in Root Hairs of Arabidopsis thaliana.

    PubMed

    Candeo, Alessia; Doccula, Fabrizio G; Valentini, Gianluca; Bassi, Andrea; Costa, Alex

    2017-07-01

    Calcium oscillations play a role in the regulation of the development of tip-growing plant cells. Using optical microscopy, calcium oscillations have been observed in a few systems (e.g. pollen tubes, fungal hyphae and algal rhizoids). High-resolution, non-phototoxic and rapid imaging methods are required to study the calcium oscillation in root hairs. We show that light sheet fluorescence microscopy is optimal to image growing root hairs of Arabidopsis thaliana and to follow their oscillatory tip-focused calcium gradient. We describe a protocol for performing live imaging of root hairs in seedlings expressing the cytosol-localized ratiometric calcium indicator Yellow Cameleon 3.6. Using this protocol, we measured the calcium gradient in a large number of root hairs. We characterized their calcium oscillations and correlated them with the rate of hair growth. The method was then used to screen the effect of auxin on the properties of the growing root hairs. © The Author 2017. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists.

  7. ADHD: Tips to Try

    MedlinePlus

    ... Staying Safe Videos for Educators Search English Español ADHD: Tips to Try KidsHealth / For Teens / ADHD: Tips to Try Print en español TDAH: Consejos que puedes probar ADHD , short for attention deficit hyperactivity disorder , is a ...

  8. Progressive failure of sheeted rock slopes: the 2009–2010 Rhombus Wall rock falls in Yosemite Valley, California, USA

    USGS Publications Warehouse

    Stock, Greg M.; Martel, Stephen J.; Collins, Brian D.; Harp, Edwin L.

    2012-01-01

    Progressive rock-fall failures in natural rock slopes are common in many environments, but often elude detailed quantitative documentation and analysis. Here we present high-resolution photography, video, and laser scanning data that document spatial and temporal patterns of a 15-month-long sequence of at least 14 rock falls from the Rhombus Wall, a sheeted granitic cliff in Yosemite Valley, California. The rock-fall sequence began on 26 August 2009 with a small failure at the tip of an overhanging rock slab. Several hours later, a series of five rock falls totaling 736 m3progressed upward along a sheeting joint behind the overhanging slab. Over the next 3 weeks, audible cracking occurred on the Rhombus Wall, suggesting crack propagation, while visual monitoring revealed opening of a sheeting joint adjacent to the previous failure surface. On 14 September 2009 a 110 m3 slab detached along this sheeting joint. Additional rock falls between 30 August and 20 November 2010, totaling 187 m3, radiated outward from the initial failure area along cliff (sub)parallel sheeting joints. We suggest that these progressive failures might have been related to stress redistributions accompanying propagation of sheeting joints behind the cliff face. Mechanical analyses indicate that tensile stresses should occur perpendicular to the cliff face and open sheeting joints, and that sheeting joints should propagate parallel to a cliff face from areas of stress concentrations. The analyses also account for how sheeting joints can propagate to lengths many times greater than their depths behind cliff faces. We posit that as a region of failure spreads across a cliff face, stress concentrations along its margin will spread with it, promoting further crack propagation and rock falls.

  9. Effects of Double-Leakage Tip Clearance Flow on the Performance of a Compressor Stage with a Large Rotor Tip Gap

    NASA Technical Reports Server (NTRS)

    Hah, Chunill

    2016-01-01

    Effects of a large rotor tip gap on the performance of a one and half stage axial compressor are investigated in detail with a numerical simulation based on LES and available PIV data. The current paper studies the main flow physics, including why and how the loss generation is increased with the large rotor tip gap. The present study reveals that when the tip gap becomes large, tip clearance fluid goes over the tip clearance core vortex and enters into the next blade's tip gap, which is called double-leakage tip clearance flow. As the tip clearance flow enters into the adjacent blade's tip gap, a vortex rope with a lower pressure core is generated. This vortex rope breaks up the tip clearance core vortex of the adjacent blade, resulting in a large additional mixing. This double-leakage tip clearance flow occurs at all operating conditions, from design flow to near stall condition, with the large tip gap for the current compressor stage. The double-leakage tip clearance flow, its interaction with the tip clearance core vortex of the adjacent blade, and the resulting large mixing loss are the main flow mechanism of the large rotor tip gap in the compressor. When the tip clearance is smaller, flow near the end wall follows more closely with the main passage flow and this double-leakage tip clearance flow does not happen near the design flow condition for the current compressor stage. When the compressor with a large tip gap operates at near stall operation, a strong vortex rope is generated near the leading edge due to the double-leakage flow. Part of this vortex separates from the path of the tip clearance core vortex and travels from the suction side of the blade toward the pressure side of the blade. This vortex is generated periodically at near stall operation with a large tip gap. As the vortex travels from the suction side to the pressure side of the blade, a large fluctuation of local pressure forces blade vibration. Nonsynchronous blade vibration occurs due

  10. Our Children Are Hurting: Fact Sheet on the Disproportionate Involvement of Indian Young People in the Juvenile Justice and Child Welfare Systems in Ontario, 1981-1982.

    ERIC Educational Resources Information Center

    Jolly, Stan

    This fact sheet documents the disturbing overrepresentation of status Indian youth in the juvenile justice and child welfare systems of Ontario (Canada). However, the information represents only the tip of the iceberg. Data relate solely to children and youth whose parents resided on an Indian reserve; who were dealt with by the family court (not…

  11. Birth talk in second stage labor.

    PubMed

    Bergstrom, Linda; Richards, Lori; Proctor, Adele; Avila, Leticia Bohrer; Morse, Janice M; Roberts, Joyce E

    2009-07-01

    In this secondary analysis of videotape data, we describe birth talk demonstrated by caregivers to women during the second stage of labor. Birth talk is a distinctive verbal register or a set of linguistic features that are used with particular behaviors during specific situations, has a particular communication purpose, and is characterized by distinctive language features. Birth talk is found cross-culturally among speakers of diverse languages. Our findings show that birth talk occurred mainly during contractions and co-occurred with two general styles of caregiving: "directed toward forced bearing down" and "supportive of physiologic bearing down." We also describe talk that occurred during rest periods, which was similar across the two styles. Caregivers' use of language tended to be either procedural (giving directions, instructions) or comfort related (encouraging and supporting). Linguistic features of the talk consisted of utterances of short duration, level pitch patterns with no sudden pitch shifts, and a restricted pitch range.

  12. Possible participation of transient sheets of 1. -->. 4-. beta. -glucans in the biosynthesis of cellulose I. [Acetobacter xylinum

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

    Colvin, J.R.

    1983-01-01

    It is suggested that a primary, essential stage in the biologic formation of a microfibril of cellulose I is an extracellular, lateral association of presynthesized (1..-->..4)-..beta..-D-glucans, by hydrogen bonding, to form long, thin sheets. These sheets then superimpose themselves nonenzymatically by London forces to form the nascent microfibril. The ends of the constituent glucans of the nascent microfibril may undergo extension or rearrangement of the type indicated by Maclachlan and colleagues. The formation of the metastable, native structure (cellulose I) may be deduced from the above suggestion as a natural consequence of closest packing of the sheets. The irreversibility ofmore » the change from cellulose I to cellulose II, either by mercerization or regeneration, also follows from the postulate. The suggestion also explains why cellulose microfibrils and chitin microfibrils may be formed contiguously in cell walls without interfering with each other. High-resolution electron micrographs of the tips of newly formed microfibrils of bacterial cellulose which had been very lightly negatively stained with sodium phosphotungstate are consistent with the suggestion. 33 references, 3 figures.« less

  13. Magnet pole tips

    DOEpatents

    Thorn, Craig E.; Chasman, Chellis; Baltz, Anthony J.

    1984-04-24

    An improved magnet which more easily provides a radially increasing magnetic field, as well as reduced fringe field and requires less power for a given field intensity. The subject invention comprises a pair of spaced, opposed magnetic poles which further comprise a pair of pole roots, each having a pole tip attached to its center. The pole tips define the gap between the magnetic poles and at least a portion of each pole tip is separated from its associated pole root. The separation begins at a predetermined distance from the center of the pole root and increases with increasing radial distance while being constant with azimuth within that portion. Magnets in accordance with the subject invention have been found to be particularly advantageous for use in large isochronous cyclotrons.

  14. Magnet pole tips

    DOEpatents

    Thorn, C.E.; Chasman, C.; Baltz, A.J.

    1981-11-19

    An improved magnet more easily provides a radially increasing magnetic field, as well as reduced fringe field and requires less power for a given field intensity. The subject invention comprises a pair of spaced, opposed magnetic poles which further comprise a pair of pole roots, each having a pole tip attached to its center. The pole tips define the gap between the magnetic poles and at least a portion of each pole tip is separated from its associated pole root. The separation begins at a predetermined distance from the center of the pole root and increases with increasing radial distance while being constant with azimuth within that portion. Magnets in accordance with the subject invention have been found to be particularly advantageous for use in large isochronous cyclotrons.

  15. Gas only nozzle fuel tip

    DOEpatents

    Bechtel, William Theodore; Fitts, David Orus; DeLeonardo, Guy Wayne

    2002-01-01

    A diffusion flame nozzle gas tip is provided to convert a dual fuel nozzle to a gas only nozzle. The nozzle tip diverts compressor discharge air from the passage feeding the diffusion nozzle air swirl vanes to a region vacated by removal of the dual fuel components, so that the diverted compressor discharge air can flow to and through effusion holes in the end cap plate of the nozzle tip. In a preferred embodiment, the nozzle gas tip defines a cavity for receiving the compressor discharge air from a peripheral passage of the nozzle for flow through the effusion openings defined in the end cap plate.

  16. Hack the Planet: What we Talk About When we Talk About Geoengineering

    NASA Astrophysics Data System (ADS)

    Kintisch, E.

    2010-12-01

    Hack the Planet (Wiley, 2010) explores how an idea once basically anathema to meetings like AGU has, in the space of a few years, become part of the geoscience mainstream. Through chapters involving researchers like David Battisti, Stephen Salter, Edward Teller and Brent Constanz the book documents the roots of this shift and how scientists are breaking new ground in the controversial field. And it shows how trying to engineer the planet's climate or manage its carbon poses novel scientific, geopolitical and moral risks and rewards. This session will cover how the topic of climate engineering has moved from something geoscientists don't talk about to something geoscientists can talk about, to something, in my view, that geoscientists must talk about.

  17. Families with Special Needs: Caregiving Tips

    MedlinePlus

    ... Halloween Prom Tips Spring Break Valentine Tips Winter Holiday Tips 12 Ways Holiday Song Healthy Living Check-Ups are Important Check- ... Test Wash Hands Stay Warm Have a Healthy Holiday Don’t Drink and Drive Widgets Healthy People ...

  18. Classroom Talk in Bilingual Class Interaction

    ERIC Educational Resources Information Center

    Puasa, Kuran; Asrifan, Andi; Chen, Yan

    2017-01-01

    This study reveals how the classroom talk was in the bilingual classroom interaction. The classroom talk comprises teacher and pupil talk--in which they cover teacher's explanation, teacher's question, teacher's feedback, and modification to teacher's speech; as well as pupil's responses and pupil's questions. The research findings show that the…

  19. Tip cap for a rotor blade

    NASA Technical Reports Server (NTRS)

    Kofel, W. K.; Tuley, E. N.; Gay, C. H., Jr.; Troeger, R. E.; Sterman, A. P. (Inventor)

    1983-01-01

    A replaceable tip cap for attachment to the end of a rotor blade is described. The tip cap includes a plurality of walls defining a compartment which, if desired, can be divided into a plurality of subcompartments. The tip cap can include inlet and outlet holes in walls thereof to permit fluid communication of a cooling fluid there through. Abrasive material can be attached with the radially outer wall of the tip cap.

  20. Real Talk, Real Teaching

    ERIC Educational Resources Information Center

    Nichols, Maria

    2014-01-01

    What happens in classrooms when we create the time and space for authentic talk about texts? Extended, collaborative conversations that allow understanding to unfold over time can be messy and dynamic. As students wrestle with complex texts and ideas, talk can become lively--and predictable problems can arise. In this article, Marie Nichols uses…

  1. Taxicab tipping and sunlight

    PubMed Central

    2017-01-01

    Does the level of sunlight affect the tipping percentage in taxicab rides in New York City? We examined this question using data on 13.82 million cab rides from January to October in 2009 in New York City combined with data on hourly levels of solar radiation. We found a small but statistically significant positive relationship between sunlight and tipping, with an estimated tipping increase of 0.5 to 0.7 percentage points when transitioning from a dark sky to full sunshine. The findings are robust to two-way clustering of standard errors based on hour-of-the-day and day-of-the-year and controlling for day-of-the-year, month-of-the-year, cab driver fixed effects, weather conditions, and ride characteristics. The NYC cab ride context is suitable for testing the association between sunlight and tipping due to the largely random assignment of riders to drivers, direct exposure to sunlight, and low confounding from variation in service experiences. PMID:28594917

  2. Taxicab tipping and sunlight.

    PubMed

    Devaraj, Srikant; Patel, Pankaj C

    2017-01-01

    Does the level of sunlight affect the tipping percentage in taxicab rides in New York City? We examined this question using data on 13.82 million cab rides from January to October in 2009 in New York City combined with data on hourly levels of solar radiation. We found a small but statistically significant positive relationship between sunlight and tipping, with an estimated tipping increase of 0.5 to 0.7 percentage points when transitioning from a dark sky to full sunshine. The findings are robust to two-way clustering of standard errors based on hour-of-the-day and day-of-the-year and controlling for day-of-the-year, month-of-the-year, cab driver fixed effects, weather conditions, and ride characteristics. The NYC cab ride context is suitable for testing the association between sunlight and tipping due to the largely random assignment of riders to drivers, direct exposure to sunlight, and low confounding from variation in service experiences.

  3. Talking Glossary of Genetic Terms

    MedlinePlus

    ... Y Z Test Your Knowledge Talking Glossary of Genetic Terms Designed to help learners at any level ... in a reference paper. The Talking Glossary of Genetic Terms The Human Genome Defined by Professionals at ...

  4. A Relationship Between Constraint and the Critical Crack Tip Opening Angle

    NASA Technical Reports Server (NTRS)

    Johnston, William M.; James, Mark A.

    2009-01-01

    Of the various approaches used to model and predict fracture, the Crack Tip Opening Angle (CTOA) fracture criterion has been successfully used for a wide range of two-dimensional thin-sheet and thin plate applications. As thicker structure is considered, modeling the full three-dimensional fracture process will become essential. This paper investigates relationships between the local CTOA evaluated along a three-dimensional crack front and the corresponding local constraint. Previously reported tunneling crack front shapes were measured during fracture by pausing each test and fatigue cycling the specimens to mark the crack surface. Finite element analyses were run to model the tunneling shape during fracture, with the analysis loading conditions duplicating those tests. The results show an inverse relationship between the critical fracture value and constraint which is valid both before maximum load and after maximum load.

  5. Assessing the accuracy of self-reported self-talk

    PubMed Central

    Brinthaupt, Thomas M.; Benson, Scott A.; Kang, Minsoo; Moore, Zaver D.

    2015-01-01

    As with most kinds of inner experience, it is difficult to assess actual self-talk frequency beyond self-reports, given the often hidden and subjective nature of the phenomenon. The Self-Talk Scale (STS; Brinthaupt et al., 2009) is a self-report measure of self-talk frequency that has been shown to possess acceptable reliability and validity. However, no research using the STS has examined the accuracy of respondents’ self-reports. In the present paper, we report a series of studies directly examining the measurement of self-talk frequency and functions using the STS. The studies examine ways to validate self-reported self-talk by (1) comparing STS responses from 6 weeks earlier to recent experiences that might precipitate self-talk, (2) using experience sampling methods to determine whether STS scores are related to recent reports of self-talk over a period of a week, and (3) comparing self-reported STS scores to those provided by a significant other who rated the target on the STS. Results showed that (1) overall self-talk scores, particularly self-critical and self-reinforcing self-talk, were significantly related to reports of context-specific self-talk; (2) high STS scorers reported talking to themselves significantly more often during recent events compared to low STS scorers, and, contrary to expectations, (3) friends reported less agreement than strangers in their self-other self-talk ratings. Implications of the results for the validity of the STS and for measuring self-talk are presented. PMID:25999887

  6. Exploring TED Talks as Linked Data for Education

    ERIC Educational Resources Information Center

    Taibi, Davide; Chawla, Saniya; Dietze, Stefan; Marenzi, Ivana; Fetahu, Besnik

    2015-01-01

    In this paper, we present the TED Talks dataset which exposes all metadata and the actual transcripts of available TED talks as structured Linked Data. The TED talks collection is composed of more than 1800 talks, along with 35?000 transcripts in over 30 languages, related to a wide range of topics. In this regard, TED talks metadata available in…

  7. Talking the Talk and Walking the Walk

    ERIC Educational Resources Information Center

    Solomon, Steven

    2010-01-01

    In this diverse collection, editors Killoran and Pendleton Jimenez bring together an important collection of chapters that tackle homophobia, transphobia, and heterosexism. From the hallways and classrooms of elementary and secondary schools to the lecture halls of postsecondary institutions, "Unleashing the Unpopular: Talking About Sexual…

  8. An investigation of tip planform influence on the aerodynamic load characteristics of semispan, upswept wing and wing-tip

    NASA Technical Reports Server (NTRS)

    Vanaken, Johannes M.

    1986-01-01

    A semi-span wing, equipped with an interchangeable tip, which was varied in planform and size was examined. Total wing aerodynamic loading was obtained from the wind tunnel scale system. The wing tip was mounted on a separate six-component strain gauge balance, which provided the aerodynamic loads on the tip. The tests were accomplished in the NASA Ames 7X10-Foot Wind Tunnel at a Mach number of 0.178. The aerodynamic load characteristics of the wing and of the tip were presented with the tip at several incidence angles relative to the wing inboard section.

  9. Turbine blade squealer tip rail with fence members

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

    Little, David A

    2012-11-20

    A turbine blade includes an airfoil, a blade tip section, a squealer tip rail, and a plurality of chordally spaced fence members. The blade tip section includes a blade tip floor located at an end of the airfoil distal from the root. The blade tip floor includes a pressure side and a suction side joined together at chordally spaced apart leading and trailing edges of the airfoil. The squealer tip rail extends radially outwardly from the blade tip floor adjacent to the suction side and extends from a first location adjacent to the airfoil trailing edge to a second locationmore » adjacent to the airfoil leading edge. The fence members are located between the airfoil leading and trailing edges and extend radially outwardly from the blade tip floor and axially from the squealer tip rail toward the pressure side.« less

  10. Fuels planning: science synthesis and integration; social issues fact sheet 04: Three critical topics to cover when talking about hazards

    Treesearch

    Rocky Mountain Research Station USDA Forest Service

    2004-01-01

    The amount of science applicable to the management of wildfire hazards is increasing daily. In addition, the attitudes of landowners and policymakers about fire and fuels management are changing. This fact sheet discusses three critical keys to communicating about wildfire hazards.

  11. 29 CFR 516.28 - Tipped employees.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 3 2010-07-01 2010-07-01 false Tipped employees. 516.28 Section 516.28 Labor Regulations... EMPLOYERS Records Pertaining to Employees Subject to Miscellaneous Exemptions Under the Act; Other Special Requirements § 516.28 Tipped employees. (a) With respect to each tipped employee whose wages are determined...

  12. Why do women engage in fat talk? Examining fat talk using Self-Determination Theory as an explanatory framework.

    PubMed

    Guertin, Camille; Barbeau, Kheana; Pelletier, Luc; Martinelli, Gabrielle

    2017-03-01

    This study used Self-Determination Theory to examine the motivational processes involved in individuals' engagement in fat talk and its association with unhealthy eating behaviors. Female undergraduate students (N=453) completed an online questionnaire, which assessed general and contextual motivation, importance placed on goals, fat talk, and unhealthy eating behaviors. Structural equation modeling revealed that being generally non-self-determined and placing more importance on extrinsic goals, such as thinness, was associated with fat talk. Fat talk was further associated with non-self-determined motivation for eating regulation, which in turn was associated with unhealthy eating. General self-determination and placing more importance on intrinsic goals, such as health, were not associated with fat talk, but instead, were associated with more adaptive forms of eating regulation and diet quality. Findings further current knowledge on the respective roles of motivation and goals on the engagement in fat talk, and its consequences on eating regulation and behavior. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Normal and variant anatomy of the nasal tip.

    PubMed

    Ketcham, Amy S; Dobratz, Eric J

    2012-04-01

    A thorough understanding of nasal tip anatomy is a prerequisite to understanding the nuances of restructuring the nasal tip. The three-dimensional structural anatomy of the nasal tip is complex. Additionally, the interrelationship between these structures determines the ultimate form and function of the nasal tip. As a result, alteration of one structure in the tip will often lead to change in other portions of the nasal tip. This dynamic concept of anatomy in the nasal tip makes proper alteration of the nasal tip one of the most challenging tasks faced by a rhinoplasty surgeon. This article provides a fundamental knowledge of the normal anatomy of the tip structures and how their interaction with each other determines the shape and support of the lower portion of the nose. It also provides a description of some common variants of tip anatomy that cause patients to seek consultation for rhinoplasty. A proper understanding of the concepts presented provides a foundation to build on as the reader continues to explore the "nuances of the nasal tip." Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  14. Talking

    ERIC Educational Resources Information Center

    Rosen, Connie; Rosen, Harold

    1974-01-01

    Excepts from THE LANGUAGE OF PRIMARY SCHOOL CHILDREN (Penguin, 1973), which evolved from a project initiated by the English Committee of the Schools Council of England and conducted under the direction of Mrs. Connie Rosen; focuses on the talk of primary school children in the presence of a teacher. (Author/JM)

  15. Southwestern Pine Tip Moth

    Treesearch

    Daniel T. Jennings; Robert E. Stevens

    1982-01-01

    The southwestern pine tip moth, Rhyacionia neomexicana (Dyar), injures young ponderosa pines (Pinus ponderosa Dougl. ex Laws) in the Southwest, central Rockies, and midwestern plains. Larvae feed on and destroy new, expanding shoots, often seriously reducing terminal growth of both naturally regenerated and planted pines. The tip moth is especially damaging to trees on...

  16. An optical fiber bundle sensor for tip clearance and tip timing measurements in a turbine rig.

    PubMed

    García, Iker; Beloki, Josu; Zubia, Joseba; Aldabaldetreku, Gotzon; Illarramendi, María Asunción; Jiménez, Felipe

    2013-06-05

    When it comes to measuring blade-tip clearance or blade-tip timing in turbines, reflective intensity-modulated optical fiber sensors overcome several traditional limitations of capacitive, inductive or discharging probe sensors. This paper presents the signals and results corresponding to the third stage of a multistage turbine rig, obtained from a transonic wind-tunnel test. The probe is based on a trifurcated bundle of optical fibers that is mounted on the turbine casing. To eliminate the influence of light source intensity variations and blade surface reflectivity, the sensing principle is based on the quotient of the voltages obtained from the two receiving bundle legs. A discrepancy lower than 3% with respect to a commercial sensor was observed in tip clearance measurements. Regarding tip timing measurements, the travel wave spectrum was obtained, which provides the average vibration amplitude for all blades at a particular nodal diameter. With this approach, both blade-tip timing and tip clearance measurements can be carried out simultaneously. The results obtained on the test turbine rig demonstrate the suitability and reliability of the type of sensor used, and suggest the possibility of performing these measurements in real turbines under real working conditions.

  17. An Optical Fiber Bundle Sensor for Tip Clearance and Tip Timing Measurements in a Turbine Rig

    PubMed Central

    García, Iker; Beloki, Josu; Zubia, Joseba; Aldabaldetreku, Gotzon; Illarramendi, María Asunción; Jiménez, Felipe

    2013-01-01

    When it comes to measuring blade-tip clearance or blade-tip timing in turbines, reflective intensity-modulated optical fiber sensors overcome several traditional limitations of capacitive, inductive or discharging probe sensors. This paper presents the signals and results corresponding to the third stage of a multistage turbine rig, obtained from a transonic wind-tunnel test. The probe is based on a trifurcated bundle of optical fibers that is mounted on the turbine casing. To eliminate the influence of light source intensity variations and blade surface reflectivity, the sensing principle is based on the quotient of the voltages obtained from the two receiving bundle legs. A discrepancy lower than 3% with respect to a commercial sensor was observed in tip clearance measurements. Regarding tip timing measurements, the travel wave spectrum was obtained, which provides the average vibration amplitude for all blades at a particular nodal diameter. With this approach, both blade-tip timing and tip clearance measurements can be carried out simultaneously. The results obtained on the test turbine rig demonstrate the suitability and reliability of the type of sensor used, and suggest the possibility of performing these measurements in real turbines under real working conditions. PMID:23739163

  18. Shell-Isolated Tip-Enhanced Raman and Fluorescence Spectroscopy.

    PubMed

    Huang, Ya-Ping; Huang, Sheng-Chao; Wang, Xiang-Jie; Bodappa, Nataraju; Li, Chao-Yu; Yin, Hao; Su, Hai-Sheng; Meng, Meng; Zhang, Hua; Ren, Bin; Yang, Zhi-Lin; Zenobi, Renato; Tian, Zhong-Qun; Li, Jian-Feng

    2018-06-18

    Tip-enhanced Raman spectroscopy can provide molecular fingerprint information with ultrahigh spatial resolution, but the tip will be easily contaminated, thus leading to artifacts. It also remains a great challenge to establish tip-enhanced fluorescence because of the quenching resulting from the proximity of the metal tip. Herein, we report shell-isolated tip-enhanced Raman and fluorescence spectroscopies by employing ultrathin shell-isolated tips fabricated by atomic layer deposition. Such shell-isolated tips not only show outstanding electromagnetic field enhancement in TERS but also exclude interference by contaminants, thus greatly promoting applications in solution. Tip-enhanced fluorescence has also been achieved using these shell-isolated tips, with enhancement factors of up to 1.7×10 3 , consistent with theoretical simulations. Furthermore, tip-enhanced Raman and fluorescence signals are acquired simultaneously, and their relative intensities can be manipulated by changing the shell thickness. This work opens a new avenue for ultrahigh resolution surface analysis using plasmon-enhanced spectroscopies. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Talking the Talk: Translating Research to Practice

    ERIC Educational Resources Information Center

    Grifenhagen, Jill F.; Barnes, Erica M.; Collins, Molly F.; Dickinson, David K.

    2017-01-01

    Decades of research have identified features of classrooms and teachers' talk that are associated with children's language growth. Unfortunately, much of this work has not yet translated to widespread practice in early childhood classrooms. Given the important contributions that early language development makes to later academic achievement,…

  20. Sirt1 physically interacts with Tip60 and negatively regulates Tip60-mediated acetylation of H2AX

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

    Yamagata, Kazutsune, E-mail: kyamagat@ncc.go.jp; Kitabayashi, Issay

    2009-12-25

    Sirt1 appear to be NAD(+)-dependent deacetylase that deacetylates histones and several non-histone proteins. In this study, we identified Sirt1 as a physical interaction partner of Tip60, which is a mammalian MYST-type histone acetyl-transferase that specifically acetylates histones H2A and H4. Although Tip60 also acetylates DNA damage-specific histone H2A variant H2AX in response to DNA damage, which is a process required for appropriate DNA damage response, overexpression of Sirt1 represses Tip60-mediated acetylation of H2AX. Furthermore, Sirt1 depletion by RNAi causes excessive acetylation of H2AX, and enhances accumulation of {gamma}-ray irradiation-induced MDC1, BRCA1, and Rad51 foci in nuclei. These findings suggest thatmore » Sirt1 functions as negative regulator of Tip60-mediated acetylation of H2AX. Moreover, Sirt1 deacetylates an acetylated Tip60 in response to DNA damage and stimulates proteasome-dependent Tip60 degradation in vivo, suggesting that Sirt1 negatively regulates the protein level of Tip60 in vivo. Sirt1 may thus repress excessive activation of the DNA damage response and Rad51-homologous recombination repair by suppressing the function of Tip60.« less

  1. Reliability on ISS Talk Outline

    NASA Technical Reports Server (NTRS)

    Misiora, Mike

    2015-01-01

    1. Overview of ISS 2. Space Environment and it effects a. Radiation b. Microgravity 3. How we ensure reliability a. Requirements b. Component Selection i. Note: I plan to stay away from talk about Rad Hardened components and talk about why we use older processors because they are less susceptible to SEUs. c. Testing d. Redundancy / Failure Tolerance e. Sparing strategies 4. Operational Examples a. Multiple MDM Failures on 6A due to hard drive failure In general, my plan is to only talk about data that is currently available via normal internet sources to ensure that I stay away from any topics that would be Export Controlled, ITAR, or NDA-controlled. The operational example has been well-reported on in the media and those are the details that I plan to cover. Additionally I am not planning on using any slides or showing any photos during the talk.

  2. Tip-Enhanced Raman Scattering Imaging of Two-Dimensional Tungsten Disulfide with Optimized Tip Fabrication Process.

    PubMed

    Lee, Chanwoo; Kim, Sung Tae; Jeong, Byeong Geun; Yun, Seok Joon; Song, Young Jae; Lee, Young Hee; Park, Doo Jae; Jeong, Mun Seok

    2017-01-13

    We successfully achieve the tip-enhanced nano Raman scattering images of a tungsten disulfide monolayer with optimizing a fabrication method of gold nanotip by controlling the concentration of etchant in an electrochemical etching process. By applying a square-wave voltage supplied from an arbitrary waveform generator to a gold wire, which is immersed in a hydrochloric acid solution diluted with ethanol at various ratios, we find that both the conical angle and radius of curvature of the tip apex can be varied by changing the ratio of hydrochloric acid and ethanol. We also suggest a model to explain the origin of these variations in the tip shape. From the systematic study, we find an optimal condition for achieving the yield of ~60% with the radius of ~34 nm and the cone angle of ~35°. Using representative tips fabricated under the optimal etching condition, we demonstrate the tip-enhanced Raman scattering experiment of tungsten disulfide monolayer grown by a chemical vapor deposition method with a spatial resolution of ~40 nm and a Raman enhancement factor of ~4,760.

  3. Tipping elements in the Earth's climate system.

    PubMed

    Lenton, Timothy M; Held, Hermann; Kriegler, Elmar; Hall, Jim W; Lucht, Wolfgang; Rahmstorf, Stefan; Schellnhuber, Hans Joachim

    2008-02-12

    The term "tipping point" commonly refers to a critical threshold at which a tiny perturbation can qualitatively alter the state or development of a system. Here we introduce the term "tipping element" to describe large-scale components of the Earth system that may pass a tipping point. We critically evaluate potential policy-relevant tipping elements in the climate system under anthropogenic forcing, drawing on the pertinent literature and a recent international workshop to compile a short list, and we assess where their tipping points lie. An expert elicitation is used to help rank their sensitivity to global warming and the uncertainty about the underlying physical mechanisms. Then we explain how, in principle, early warning systems could be established to detect the proximity of some tipping points.

  4. Oxygen-Free Welding Contact Tips

    NASA Technical Reports Server (NTRS)

    Pike, James F.

    1993-01-01

    Contact tips for gas/metal arc welding (GMAW) fabricated from oxygen-free copper. Prototype tips tested in robotic welding, for which application intended. Reduces electrical erosion, increases electrical conductivity, and reduces mechanical wear. Productivity of robotic welding increases while time during welding interrupted for removal and replacement of contact tips minimal. Improves alignment of joints and filler metal, reducing rate of rejection and repair of unacceptable weldments. Utility extends beyond aerospace industry to mass production of various types of hardware, including heavy off-highway construction equipment.

  5. Low photon-count tip-tilt sensor

    NASA Astrophysics Data System (ADS)

    Saathof, Rudolf; Schitter, Georg

    2016-07-01

    Due to the low photon-count of dark areas of the universe, signal strength of tip-tilt sensor is low, limiting sky-coverage of reliable tip-tilt measurements. This paper presents the low photon-count tip-tilt (LPC-TT) sensor, which potentially achieves improved signal strength. Its optical design spatially samples and integrates the scene. This increases the probability that several individual sources coincide on a detector segment. Laboratory experiments show feasibility of spatial sampling and integration and the ability to measure tilt angles. By simulation an improvement of the SNR of 10 dB compared to conventional tip-tilt sensors is shown.

  6. RANS computations of tip vortex cavitation

    NASA Astrophysics Data System (ADS)

    Decaix, Jean; Balarac, Guillaume; Dreyer, Matthieu; Farhat, Mohamed; Münch, Cécile

    2015-12-01

    The present study is related to the development of the tip vortex cavitation in Kaplan turbines. The investigation is carried out on a simplified test case consisting of a NACA0009 blade with a gap between the blade tip and the side wall. Computations with and without cavitation are performed using a R ANS modelling and a transport equation for the liquid volume fraction. Compared with experimental data, the R ANS computations turn out to be able to capture accurately the development of the tip vortex. The simulations have also highlighted the influence of cavitation on the tip vortex trajectory.

  7. Smart helicopter rotor with active blade tips

    NASA Astrophysics Data System (ADS)

    Bernhard, Andreas Paul Friedrich

    2000-10-01

    The smart active blade tip (SABT) rotor is an on-blade rotor vibration reduction system, incorporating active blade tips that can be independently pitched with respect to the main blade. The active blade tip rotor development included an experimental test program culminating in a Mach scale hover test, and a parallel development of a coupled, elastic actuator and rotor blade analysis for preliminary design studies and hover performance prediction. The experimental testing focussed on a small scale rotor on a bearingless Bell-412 hub. The fabricated Mach-scale active-tip rotor has a diameter of 1.524 m, a blade chord of 76.2 mm and incorporated a 10% span active tip. The nominal operating speed is 2000 rpm, giving a tip Mach number of 0.47. The blade tips are driven by a novel piezo-induced bending-torsion coupled actuator beam, located spanwise in the hollow mid-cell of the main rotor blade. In hover at 2000 rpm, at 2 deg collective, and for an actuation of 125 Vrms, the measured blade tip deflection at the first four rotor harmonics is between +/-1.7 and +/-2.8 deg, increasing to +/-5.3 deg at 5/rev with resonant amplification. The corresponding oscillatory amplitude of the rotor thrust coefficient is between 0.7 · 10-3 and 1.3 · 10-1 at the first four rotor harmonics, increasing to 2.1 · 10-3 at 5/rev. In general, the experimental blade tip frequency response and corresponding rotor thrust response are well captured by the analysis. The flexbeam root flap bending moment is predicted in trend, but is significantly over-estimated. The blade tips did not deflect as expected at high collective settings, because of the blade tip shaft locking up in the bearing. This is caused by the high flap bending moment on the blade tip shaft. Redesign of the blade tip shaft assembly and bearing support is identified as the primary design improvement for future research. The active blade tip rotor was also used as a testbed for the evaluation of an adaptive neural-network based

  8. Tipping elements in the Earth's climate system

    PubMed Central

    Lenton, Timothy M.; Held, Hermann; Kriegler, Elmar; Hall, Jim W.; Lucht, Wolfgang; Rahmstorf, Stefan; Schellnhuber, Hans Joachim

    2008-01-01

    The term “tipping point” commonly refers to a critical threshold at which a tiny perturbation can qualitatively alter the state or development of a system. Here we introduce the term “tipping element” to describe large-scale components of the Earth system that may pass a tipping point. We critically evaluate potential policy-relevant tipping elements in the climate system under anthropogenic forcing, drawing on the pertinent literature and a recent international workshop to compile a short list, and we assess where their tipping points lie. An expert elicitation is used to help rank their sensitivity to global warming and the uncertainty about the underlying physical mechanisms. Then we explain how, in principle, early warning systems could be established to detect the proximity of some tipping points. PMID:18258748

  9. TED Talks and Leadership Education: Ideas Worth Sharing

    ERIC Educational Resources Information Center

    Raffo, Deana M.

    2016-01-01

    TED Talks are short videos of experts talking about a variety of topics. This paper outlines six TED Talks that connect with the leadership literature and topics commonly taught with an explanation of how they enhance teaching about a corresponding leadership topic. The researcher shares how introducing TED talks related to leadership can…

  10. Biophysical Characterization of the Type III Secretion Tip Proteins and the Tip Proteins Attached to Bacterium-Like Particles

    PubMed Central

    Choudhari, Shyamal P.; Chen, Xiaotong; Kim, Jae Hyun; van Roosmalen, Maarten L.; Greenwood, Jamie C.; Joshi, Sangeeta B.; Picking, William D.; Leenhouts, Kees; Middaugh, C. Russell; Picking, Wendy L.

    2014-01-01

    Bacterium-like particles (BLPs), derived from Lactococcus lactis, offer a self-adjuvanting delivery vehicle for subunit protein vaccines. Proteins can be specifically loaded onto the BLPs via a peptidoglycan anchoring domain (PA). In this study, the tip proteins IpaD, SipD and LcrV belonging to type three secretion systems of Shigella flexneri, Salmonella enterica and Yersinia enterocolitica, respectively, were fused to the PA and loaded onto the BLPs. Herein, we biophysically characterized these nine samples and condensed the spectroscopic results into three-index empirical phase diagrams (EPDs). The EPDs show distinctions between the IpaD/SipD and LcrV subfamilies of tip proteins, based on their physical stability, even upon addition of the PA. Upon attachment to the BLPs, the BLPs become defining moiety in the spectroscopic measurements, leaving the tip proteins to have a subtle yet modulating effect on the structural integrity of the tip proteins-BLPs binding. In summary, this work provides a comprehensive view of physical stability of the tip proteins and tip protein-BLPs and serves as a baseline for screening of excipients to increase the stability of the tip protein-BLPs for future vaccine formulation. PMID:24916512

  11. Methods and Strategies: Talk Strategies

    ERIC Educational Resources Information Center

    Shea, Lauren M.; Shanahan, Therese B.

    2011-01-01

    This article discusses how to promote oral language development through science. The authors describe how they incorporate academic "talk strategies" into science lessons in a nonintrusive and meaningful manner. These talk strategies are adapted from the "Avenues" (2007) curriculum for English learners (ELs), which gives examples of cooperative…

  12. Number Talks Build Numerical Reasoning

    ERIC Educational Resources Information Center

    Parrish, Sherry D.

    2011-01-01

    "Classroom number talks," five- to fifteen-minute conversations around purposefully crafted computation problems, are a productive tool that can be incorporated into classroom instruction to combine the essential processes and habits of mind of doing math. During number talks, students are asked to communicate their thinking when presenting and…

  13. Aerodynamic tip desensitization in axial flow turbines

    NASA Astrophysics Data System (ADS)

    Dey, Debashis

    The leakage flow near the tip of unshrouded rotor blades in axial turbines imposes significant thermal loads on the blade. It is also responsible for up to a third of aerodynamic losses in a turbine stage. The leakage flow, mainly induced by the pressure differential across the rotor tip section, usually rolls into a stream-wise vertical structure near the suction side part of the blade tip. The current study uses several concepts to reduce the severity of losses introduced by the leakage vortex. Three tip desensitization techniques, both active and passive, are examined. Coolant flow from a tip trench is used to counter the momentum of the leakage jet. Next, a very short winglet obtained by slightly extending the tip platform in the tangential direction is investigated. Lastly, the widely used concept of squealer tip is studied. The current investigation is performed in the Axial Flow Turbine Research Facility (AFTRF) of the Pennsylvania State University. Rotating frame five hole probe measurements as well as stationary frame phase averaged total pressure measurements downstream of a single stage turbine facility were taken. The study enables one to draw conclusions about the nature of the flowfield in the rotor tip region. It also shows that significant efficiency gains could be obtained by using some of these techniques.

  14. Ice stream activity scaled to ice sheet volume during Laurentide Ice Sheet deglaciation.

    PubMed

    Stokes, C R; Margold, M; Clark, C D; Tarasov, L

    2016-02-18

    The contribution of the Greenland and West Antarctic ice sheets to sea level has increased in recent decades, largely owing to the thinning and retreat of outlet glaciers and ice streams. This dynamic loss is a serious concern, with some modelling studies suggesting that the collapse of a major ice sheet could be imminent or potentially underway in West Antarctica, but others predicting a more limited response. A major problem is that observations used to initialize and calibrate models typically span only a few decades, and, at the ice-sheet scale, it is unclear how the entire drainage network of ice streams evolves over longer timescales. This represents one of the largest sources of uncertainty when predicting the contributions of ice sheets to sea-level rise. A key question is whether ice streams might increase and sustain rates of mass loss over centuries or millennia, beyond those expected for a given ocean-climate forcing. Here we reconstruct the activity of 117 ice streams that operated at various times during deglaciation of the Laurentide Ice Sheet (from about 22,000 to 7,000 years ago) and show that as they activated and deactivated in different locations, their overall number decreased, they occupied a progressively smaller percentage of the ice sheet perimeter and their total discharge decreased. The underlying geology and topography clearly influenced ice stream activity, but--at the ice-sheet scale--their drainage network adjusted and was linked to changes in ice sheet volume. It is unclear whether these findings can be directly translated to modern ice sheets. However, contrary to the view that sees ice streams as unstable entities that can accelerate ice-sheet deglaciation, we conclude that ice streams exerted progressively less influence on ice sheet mass balance during the retreat of the Laurentide Ice Sheet.

  15. Radiofrequency Wire Recanalization of Chronically Thrombosed TIPS

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

    Majdalany, Bill S., E-mail: bmajdala@med.umich.edu; Elliott, Eric D., E-mail: eric.elliott@osumc.edu; Michaels, Anthony J., E-mail: Anthony.michaels@osumc.edu

    Radiofrequency (RF) guide wires have been applied to cardiac interventions, recanalization of central venous thromboses, and to cross biliary occlusions. Herein, the use of a RF wire technique to revise chronically occluded transjugular intrahepatic portosystemic shunts (TIPS) is described. In both cases, conventional TIPS revision techniques failed to revise the chronically thrombosed TIPS. RF wire recanalization was successfully performed through each of the chronically thrombosed TIPS, demonstrating initial safety and feasibility in this application.

  16. Triggering of explosive reconnection in a thick current sheet via current sheet compression: Less current sheet thinning, more temperature anisotropy

    NASA Astrophysics Data System (ADS)

    Shimizu, K.; Shinohara, I.; Fujimoto, M.

    2016-12-01

    Two-dimensional kinetic simulations of compression of thick current sheets are performed to see how it can lead to triggering of explosive magnetic reconnection. The current sheet under study is simply in a Harris-like anti-paralell and symmetric geometry. A one-dimensional pre-study shows that the compression is more effective to make the plasma anisotropy than to thin the current sheet width. When the lobe magnetic field is amplified by a factor of 2, the plasma temperature anisotropy inside the current sheet reaches 2 but the current sheet thickness is reduced only by 1/sqrt(2). If a current sheet thickness needs to be comparable to the ion inertial scale for reconnection triggering take place, as is widely and frequently mentioned in the research community, the initial thickness cannot be more than a few ion scale for reconnection to set-in. On the other hand, the temperature anisotropy of 2 can be significant for the triggering problem. Two-dimensional simulations show explosive magnetic reconnection to take place even when the initial current sheet thickness more than an order of magnitude thicker than the ion scale, indicating the resilient triggering drive supplied by the temperature anisotropy. We also discuss how the reconnection triggering capability of the temperature anisotropy boosted tearing mode for thick current sheets compares with the instabilities in the plane orthogonal to the reconnecting field.

  17. Talking Circles Promote Equitable Discourse

    ERIC Educational Resources Information Center

    Hung, Marcus

    2015-01-01

    Teachers facilitate math talk in the classroom, but introducing a structured discussion format called the "talking circle" can influence opportunities for equitable student participation. Drawing on his reflections over the 2013-14 academic year and reviewing his detailed teaching notes and lesson plans, Marcus Hung takes a close look at…

  18. Tips for Good Electronic Presentations.

    ERIC Educational Resources Information Center

    Strasser, Dennis

    1996-01-01

    Describes library uses of presentation graphics software and offers tips for creating electronic presentations. Tips include: audience retention; visual aid options; software package options; presentation planning; presentation showing; and use of text, colors, and graphics. Sidebars note common presentation errors and popular presentation…

  19. An experimental investigation of free-tip response to a jet

    NASA Technical Reports Server (NTRS)

    Young, L. A.

    1986-01-01

    The aerodynamic response of passively oscillating tips appended to a model helicopter rotor was investigated during a whirl test. Tip responsiveness was found to meet free-tip rotor requirements. Experimental and analytical estimates of the free-tip aerodynamic spring, mechanical spring, and aerodynamic damping were calculated and compared. The free tips were analytically demonstrated to be operating outside the tip resonant response region at full-scale tip speeds. Further, tip resonance was shown to be independent of tip speed, given the assumption that the tip forcing frequency is linearly dependent upon the rotor rotational speed.

  20. Tipping Points in Texas Rivers

    NASA Astrophysics Data System (ADS)

    Phillips, Jonathan

    2016-04-01

    Anticipating geomorphic tipping points requires that we learn from the past. Major geomorphic changes in coastal plain rivers of Texas resulting in river metamorphosis or regime shifts were identified, and the major driving factors determined. Nine fluvial tipping points were identified from contemporary observations, historical records, and Quaternary reconstructions. Two of the tipping points (between general aggrading and degrading valley states) are associated with reversals in a fundamental system control (sea-level). One (stable or aggrading vs. degrading channels) is associated with an abrupt change in sediment supply due to dam construction, and two others (changes from meandering to anastomosing channel patterns, and different anastomosis styles) are similarly related to changes in sediment supply and/or transport capacity, but with additional elements of historical contingency. Three tipping points are related to avulsions. One, from a regime dominated to reoccupation of former channels to one dominated by progradation into flood basins, is driven by progressive long term filling of incised valleys. Another, nodal avulsions, are driven by disturbances associated with tectonics or listric faults. The third, avulsions and related valley metamorphosis in unfilled incised valleys, is due to fundamental dynamical instabilities within the fluvial system. This synthesis and analysis suggests that geomorphic tipping points are sometimes associated with general extrinsic or intrinsic (to the fluvial system) environmental change, independent of any disturbances or instabilities. Others are associated with natural (e.g., tectonic) or human (dams) disturbances, and still others with intrinsic geomorphic instabilities. This suggests that future tipping points will be equally diverse with respect to their drivers.

  1. Dialogic Talk in Diverse Physical Science Classrooms

    ERIC Educational Resources Information Center

    Taylor, Dale L.; Lelliott, Anthony D.

    2015-01-01

    Dialogic talk, in which different ideas are considered, promotes conceptual understanding in science, and is in line with South Africa's school curriculum. The problem is that dialogic talk is difficult to facilitate and may run counter to cultural norms. As a result, classroom talk is often not dialogic. This paper reports on the nature of…

  2. Terahertz Nanofocusing with Cantilevered Terahertz-Resonant Antenna Tips.

    PubMed

    Mastel, Stefan; Lundeberg, Mark B; Alonso-González, Pablo; Gao, Yuanda; Watanabe, Kenji; Taniguchi, Takashi; Hone, James; Koppens, Frank H L; Nikitin, Alexey Y; Hillenbrand, Rainer

    2017-11-08

    We developed THz-resonant scanning probe tips, yielding strongly enhanced and nanoscale confined THz near fields at their tip apex. The tips with length in the order of the THz wavelength (λ = 96.5 μm) were fabricated by focused ion beam (FIB) machining and attached to standard atomic force microscopy (AFM) cantilevers. Measurements of the near-field intensity at the very tip apex (25 nm radius) as a function of tip length, via graphene-based (thermoelectric) near-field detection, indicate their first and second order geometrical antenna resonances for tip length of 33 and 78 μm, respectively. On resonance, we find that the near-field intensity is enhanced by one order of magnitude compared to tips of 17 μm length (standard AFM tip length), which is corroborated by numerical simulations that further predict remarkable intensity enhancements of about 10 7 relative to the incident field. Because of the strong field enhancement and standard AFM operation of our tips, we envision manifold and straightforward future application in scattering-type THz near-field nanoscopy and THz photocurrent nanoimaging, nanoscale nonlinear THz imaging, or nanoscale control and manipulation of matter employing ultrastrong and ultrashort THz pulses.

  3. 71. PALMDALE WATER COMPANY, EASTWOOD MULTIPLEARCHED DAM: STRESS SHEET, SHEET ...

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

    71. PALMDALE WATER COMPANY, EASTWOOD MULTIPLE-ARCHED DAM: STRESS SHEET, SHEET 3; DECEMBER 20, 1918. Littlerock Water District files. - Little Rock Creek Dam, Little Rock Creek, Littlerock, Los Angeles County, CA

  4. Tip cap for a turbine rotor blade

    DOEpatents

    Kimmel, Keith D

    2014-03-25

    A turbine rotor blade with a spar and shell construction, and a tip cap that includes a row of lugs extending from a bottom side that form dovetail grooves that engage with similar shaped lugs and grooves on a tip end of the spar to secure the tip cap to the spar against radial displacement. The lug on the trailing edge end of the tip cap is aligned perpendicular to a chordwise line of the blade in the trailing edge region in order to minimize stress due to the lugs wanting to bend under high centrifugal loads. A two piece tip cap with lugs at different angles will reduce the bending stress even more.

  5. Efficacy of air/water syringe tip sterilization.

    PubMed

    Inger, M; Bennani, V; Farella, M; Bennani, F; Cannon, R D

    2014-03-01

    Dental procedures involve contact between instruments and the patient's tissues, blood or saliva. This study evaluated the efficacy of the standardized sterilization of non-disposable air/water syringe tips and corrosion and contaminant build-up in these tips. The bacterial contamination of single-use and multiple-use non-disposable air/water syringe tips after routine use and sterilization was compared to that of single-use disposable tips by microbial culturing on PCA and blood agar plates. The effect of flushing the syringe tips prior to sterilization was also measured. The amount of corrosion in single-use and multiple-use non-disposable syringes was measured by SEM and EDS analyses. Non-disposable syringe tips had significantly (p < 0.05) greater bacterial contamination than single-use disposable tips. There were no statistically different levels of contamination between flushed and non-flushed non-disposable syringes or between single-use and multiple-use non-disposable syringes. SEM and EDS analyses showed greater evidence of corrosion and contaminant build-up in multiple-use syringes compared to single-use non-disposable syringes. Sterilization of non-disposable air/water syringes is not completely effective and rinsing, or the number of uses, does not affect the effectiveness of sterilization. There may be a lower risk of cross-infection from the use of disposable air/water syringe tips, instead of non-disposable ones. © 2014 Australian Dental Association.

  6. Comparison of different types of phacoemulsification tips. I. Quantitative analysis of elemental composition and tip surface microroughness.

    PubMed

    Tsaousis, Konstantinos T; Werner, Liliana; Perez, Jesus Paulo; Li, He J; Reiter, Nicholas; Guan, Jia J; Mamalis, Nick

    2016-09-01

    To evaluate the elemental composition of phacoemulsification tips and their surface roughness in the microscale. John A. Moran Eye Center and Utah Nanofab, College of Engineering, University of Utah, Salt Lake City, Utah, USA. Experimental study. Seven types of phacoemulsification tips were studied. The phaco tips were examined through energy-dispersive x-ray spectroscopy (EDS) and x-ray photoelectron spectroscopy (XPS) for elemental composition. In addition, the roughness of the opening in all tips was assessed through 3-dimensional white-light interferometry. Elemental analysis showed considerable differences in the surface layers between manufacturers. Alcon tips had a thinner oxidized titanium (Ti) layer in their surface. Through XPS, vanadium was not detected in the superficial layers of any tip, but only in deeper levels. The microroughness surface analysis showed comparable results regarding their root-mean-square (RMS) metric. Maximum peak valley distance values varied and appeared to be dependent on the quality of material process rather than the material itself. Phacoemulsification tips are made of Ti alloys and showed differences between models, especially regarding their composition in the superficial layers. Their opening end roughness showed an overall appropriate RMS value of less than 1.0 μm in all cases. The existence of small defected areas highlights the importance of adequate quality control of these critical surgical instruments. None of the authors has a financial or proprietary interest in any material or method mentioned. Copyright © 2016 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  7. Mapping cavitation activity around dental ultrasonic tips.

    PubMed

    Walmsley, A Damien; Lea, Simon C; Felver, Bernhard; King, David C; Price, Gareth J

    2013-05-01

    Cavitation arising within the water around the oscillating ultrasonic scaler tip is an area that may lead to advances in enhancing biofilm removal. The aim of this study is to map the occurrence of cavitation around scaler tips under loaded conditions. Two designs of piezoelectric ultrasonic scaling probes were evaluated with a scanning laser vibrometer and luminol dosimetric system under loaded (100 g/200 g) and unloaded conditions. Loads were applied to the probe tips via teeth mounted in a load-measuring apparatus. There was a positive correlation between probe displacement amplitude and cavitation production for ultrasonic probes. The position of cavitation at the tip of each probe was greater under loaded conditions than unloaded and for the longer P probe towards the tip. Whilst increasing vibration displacement amplitude of ultrasonic scalers increases the occurrence of cavitation, factors such as the length of the probe influence the amount of cavitation activity generated. The application of load affects the production of cavitation at the most clinically relevant area-the tip. Loading and the design of ultrasonic scalers lead to maximising the occurrence of the cavitation at the tip and enhance the cleaning efficiency of the scaler.

  8. [TIPS

    PubMed

    Brazzini, Augusto; Carrillo, Alvaro; Cantella, Raúl

    1998-01-01

    Esophageal hemorrage due to variceal bleeding in cirrhotic patients represents a serious problem for the physician in charge, especially in this country where liver transplants are inexistent; and also, it is a drama for the patient and its familly. We propose here the Transjugular Intrahepatic Portosystemic Shunt (TIPS). Twenty one patients were part of a study where 23 TIPS were placed, observing an immediate improval in 18 of them, a rebleeding in 2, within the first 24 and 48 hours. An embolization of the coronary veins was performed in the procedure in 15 patients, and a second intervention due to rebleeding in 2 of them. In the latter patients, the embolization of the coronary veins was rutinary.The survival of the patients has been outstanding.We conclude that this interventional procedure is a worldwide reality in the treatment of esophageal hemorrage by variceal bleeding due to portal hipertension, and it does not cut down the probability of liver transplant, unfortunately inexistent in our country. This procedure results in a low morbimortality with an adequate quality of life.

  9. Ice sheet altimetry

    NASA Technical Reports Server (NTRS)

    Brooks, R. L.

    1981-01-01

    Generalized surface slopes were computed for the Antarctic and Greenland ice sheets by differencing plotted contour levels and dividing them by the distance between the contours. It was observed that more than 90% of the ice sheets have surface slopes less than 1%. Seasat test mode-1 Seasat altimeter measurements over Greenland were analyzed by comparisons with collinear and intersecting normal mode Seasat altimeter passes. Over the ice sheet, the computed surface elevations from test mode-1 measurements were consistently lower by about 45 m and the AGC levels were down by approximately 6 dB. No test mode-1 data were acquired over Antarctica. It is concluded that analysis of the existing altimeter data base over the two ice sheets is crucial in designing a future improved altimeter tracking capability. It is recommended that additional waveform retracking be performed to characterize ice sheet topography as a function of geographic area and elevation.

  10. On the development of a magnetoresistive sensor for blade tip timing and blade tip clearance measurement systems

    NASA Astrophysics Data System (ADS)

    Tomassini, R.; Rossi, G.; Brouckaert, J.-F.

    2014-05-01

    The accurate control of the gap between static and rotating components is vital to preserve the mechanical integrity and ensure a correct functioning of any rotating machinery. Moreover, tip leakage above the airfoil tip results in relevant aerodynamic losses. One way to measure and to monitor blade tip gaps is by the so-called Blade Tip Clearance (BTC) technique. Another fundamental phenomenon to control in the turbomachines is the vibration of the blades. For more than half a century, this has been performed by installing strain gauges on the blades and using telemetry to transmit the signals. The Blade Tip Timing (BTT) technique, (i.e. measuring the blade time of arrival from the casing at different angular locations with proximity sensors) is currently being adopted by all manufacturers as a replacement for the classical strain gauge technique because of its non-intrusive character. This paper presents a novel magnetoresistive sensor for blade tip timing and blade tip clearance systems, which offers high temporal and high spatial resolution simultaneously. The sensing element adopted is a Wheatstone bridge of Permalloy elements. The principle of the sensor is based on the variation of magnetic field at the passage of ferromagnetic objects. Two different configurations have been realized, a digital and an analogue sensor. Measurements of tip clearance have been performed in an high speed compressor and the calibration curve is reported. Measurements of blade vibration have been carried out in a dedicated calibration bench; results are presented and discussed. The magnetoresistive sensor is characterized by high repeatability, low manufacturing costs and measurement accuracy in line with the main probes used in turbomachinery testing. The novel sensor has great potential and is capable of fulfilling the requirements for a simultaneous BTC and BTT measurement system.

  11. The tonoplast intrinsic aquaporin (TIP) subfamily of Eucalyptus grandis: Characterization of EgTIP2, a root-specific and osmotic stress-responsive gene.

    PubMed

    Rodrigues, Marcela I; Bravo, Juliana P; Sassaki, Flávio T; Severino, Fábio E; Maia, Ivan G

    2013-12-01

    Aquaporins have important roles in various physiological processes in plants, including growth, development and adaptation to stress. In this study, a gene encoding a root-specific tonoplast intrinsic aquaporin (TIP) from Eucalyptus grandis (named EgTIP2) was investigated. The root-specific expression of EgTIP2 was validated over a panel of five eucalyptus organ/tissues. In eucalyptus roots, EgTIP2 expression was significantly induced by osmotic stress imposed by PEG treatment. Histochemical analysis of transgenic tobacco lines (Nicotiana tabacum SR1) harboring an EgTIP2 promoter:GUS reporter cassette revealed major GUS staining in the vasculature and in root tips. Consistent with its osmotic-stress inducible expression in eucalyptus, EgTIP2 promoter activity was up-regulated by mannitol treatment, but was down-regulated by abscisic acid. Taken together, these results suggest that EgTIP2 might be involved in eucalyptus response to drought. Additional searches in the eucalyptus genome revealed the presence of four additional putative TIP coding genes, which could be individually assigned to the classical TIP1-5 groups. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  12. 5. Historic American Buildings Survey Taken from drawing sheet, SHEET ...

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

    5. Historic American Buildings Survey Taken from drawing sheet, SHEET #21, Showing the house as restored since Survey. (Dormer windows omitted as not authentic) - Samuel des Marest House, River Road, New Milford, Bergen County, NJ

  13. Arctic tipping points in an Earth system perspective.

    PubMed

    Wassmann, Paul; Lenton, Timothy M

    2012-02-01

    We provide an introduction to the volume The Arctic in the Earth System perspective: the role of tipping points. The terms tipping point and tipping element are described and their role in current science, general debates, and the Arctic are elucidated. From a wider perspective, the volume focuses upon the role of humans in the Arctic component of the Earth system and in particular the envelope for human existence, the Arctic ecosystems. The Arctic climate tipping elements, the tipping elements in Arctic ecosystems and societies, and the challenges of governance and anticipation are illuminated through short summaries of eight publications that derive from the Arctic Frontiers conference in 2011 and the EU FP7 project Arctic Tipping Points. Then some ideas based upon resilience thinking are developed to show how wise system management could ease pressures on Arctic systems in order to keep them away from tipping points.

  14. Talking to Your Kids about Sex

    MedlinePlus

    ... Safety Injury Rehabilitation Emotional Well-Being Mental Health Sex and Birth Control Sex and Sexuality Birth Control Family Health Infants and ... Kids and Teens Talking to Your Kids About Sex Talking to Your Kids About Sex Share Print ...

  15. Compressor airfoil tip clearance optimization system

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

    Little, David A.; Pu, Zhengxiang

    2015-08-18

    A compressor airfoil tip clearance optimization system for reducing a gap between a tip of a compressor airfoil and a radially adjacent component of a turbine engine is disclosed. The turbine engine may include ID and OD flowpath boundaries configured to minimize compressor airfoil tip clearances during turbine engine operation in cooperation with one or more clearance reduction systems that are configured to move the rotor assembly axially to reduce tip clearance. The configurations of the ID and OD flowpath boundaries enhance the effectiveness of the axial movement of the rotor assembly, which includes movement of the ID flowpath boundary.more » During operation of the turbine engine, the rotor assembly may be moved axially to increase the efficiency of the turbine engine.« less

  16. Tip-over Prevention: Adaptive Control Development

    DTIC Science & Technology

    2015-05-30

    used to detect tip- over, with the FA and MHS metrics providing more effective stability measurements than the ZMP metric, in some cases indicating tip...support polygon formed by the robot’s ground contact points, as shown in Figure 1. If the Fig. 1. Tip-over angle definition in Force-Angle stability...0 (6) Therefore, the sum of the inertial, centripetal, Coriolis , and gravitational terms can be used to estimate the impact forces: fI,z = ω̇xry

  17. Exploratory Talk in the Early Years: Analysing Exploratory Talk in Collaborative Group Activities Involving Younger Learners

    ERIC Educational Resources Information Center

    Patterson, Eira Wyn

    2018-01-01

    Collaborative group work has the potential for providing rich opportunities for children to learn through talk with peers; however, in practice, little effective engagement in learning is observed within authentic learning contexts. Exploratory talk is associated with high levels of cognitive challenge within collaborative group work. Detailed…

  18. Tips for Postpartum Dads and Partners

    MedlinePlus

    ... Blues: Partners Interview with Wade Bowen Coping with Suicide & Loss Tips for Postpartum Dads and Partners Pregnancy and postpartum mood and anxiety disorders affect the whole family. Here are some tips ...

  19. Integrated Turbine Tip Clearance and Gas Turbine Engine Simulation

    NASA Technical Reports Server (NTRS)

    Chapman, Jeffryes W.; Kratz, Jonathan; Guo, Ten-Huei; Litt, Jonathan

    2016-01-01

    Gas turbine compressor and turbine blade tip clearance (i.e., the radial distance between the blade tip of an axial compressor or turbine and the containment structure) is a major contributing factor to gas path sealing, and can significantly affect engine efficiency and operational temperature. This paper details the creation of a generic but realistic high pressure turbine tip clearance model that may be used to facilitate active tip clearance control system research. This model uses a first principles approach to approximate thermal and mechanical deformations of the turbine system, taking into account the rotor, shroud, and blade tip components. Validation of the tip clearance model shows that the results are realistic and reflect values found in literature. In addition, this model has been integrated with a gas turbine engine simulation, creating a platform to explore engine performance as tip clearance is adjusted. Results from the integrated model explore the effects of tip clearance on engine operation and highlight advantages of tip clearance management.

  20. Dynamics of Isolated Tip Vortex Cavitation

    NASA Astrophysics Data System (ADS)

    Pennings, Pepijn; Bosschers, Johan; van Terwisga, Tom

    2014-11-01

    Performance of ship propellers and comfort levels in the surroundings are limited by various forms of cavitation. Amongst these forms tip vortex cavitation is one of the first appearing forms and is expected to be mainly responsible for the emission of broadband pressure fluctuations typically occurring between the 4th to the 7th blade passing frequency (approx. 40--70 Hz). These radiated pressure pulses are likely to excite parts of the hull structure resulting in a design compromise between efficiency and comfort. Insight is needed in the mechanism of acoustic emission from the oscillations by a tip vortex cavity. In the current experimental study the tip vortex cavity from a blade with an elliptic planform and sections based on NACA 662 - 415 with meanline a = 0 . 8 is observed using high speed shadowgraphy in combination with blade force and acoustic measurements. An analytic model describing three main cavity deformation modes is verified and used to explain the origin of a cavity eigenfrequency or ``vortex singing'' phenomenon observed by Maines and Arndt (1997) on the tip vortex cavity originating from the same blade. As no hydrodynamic sound originating from the tip vortex cavity was observed it is posed that a tip flow instability is essential for ``vortex singing.'' This research was funded by the Lloyd's Register Foundation as part of the International Institute for Cavitation Research.

  1. Towards force spectroscopy of single tip-link bonds

    NASA Astrophysics Data System (ADS)

    Koussa, Mounir A.; Sotomayor, Marcos; Wong, Wesley P.; Corey, David P.

    2015-12-01

    Inner-ear mechanotransduction relies on tip links, fine protein filaments made of cadherin-23 and protocadherin-15 that convey tension to mechanosensitive channels at the tips of hair-cell stereocilia. The tip-link cadherins are thought to form a heterotetrameric complex, with two cadherin-23 molecules forming the upper part of the filament and two protocadherin-15 molecules forming the lower end. The interaction between cadherin-23 and protocadherin-15 is mediated by their N-terminal tips. Missense mutations that modify the interaction interface impair binding and lead to deafness. Molecular dynamics simulations predict that the tip-link bond is mechanically strong enough to withstand forces in hair cells, but its experimentally determined strength is unknown. We have developed molecular tools to facilitate single-molecule force spectroscopy on the tip link bond. Self-assembling DNA nanoswitches are functionalized with the interacting tips of cadherin-23 and protocadherin-15 using the enzyme sortase under conditions that preserve protein function. These tip link nanoswitches are designed to provide a signature force-extension profile. This molecular signature should allow us to identify single-molecule rupture events in pulling experiments.

  2. Learning to talk

    NASA Astrophysics Data System (ADS)

    Messum, Piers

    2004-05-01

    Is imitation a necessary part of learning to talk? The faithful replication by children of such arbitrary phenomena of English as tense and lax vowel properties, ``rhythm,'' and context-dependent VOT's seems to insist that it is. But a nonimitative account of this is also possible. It relies on two principal mechanisms. First, basic speech sounds are learned by emulation: attempting to reproduce the results achieved by other speakers but without copying their actions to do so. The effectiveness of the output provides sufficient feedback to inform the child of the adequacy of its performance and to guide refinement. Second, phonetic phenomena such as those above appear through aerodynamic accommodation. Key elements of this are (a) that speech breathing is a complex motor skill which dominates other articulatory processes during acquisition and starts pulsatile before becoming smooth, and (b) that a child-scale production system imposes constraints on talking which do not operate in the adult speaker. Much of ``the terrible complexity of phonetic patterns'' [J. Pierrehumbert, Lang. Speech 46, 115-154 (2003)] then becomes epiphenomenal: appearing not as a result of young learners copying phonetic detail that is not linguistically significant, but of them reconciling conflicting production demands while just talking.

  3. Engaging Talk: One Teacher's Scaffolding of Collaborative Talk

    ERIC Educational Resources Information Center

    Newman, Ruth M. C.

    2017-01-01

    This paper reports on an ESRC and British Telecom funded study which explored the teaching of collaborative talk in the secondary English classroom. While research signals the crucial role of the teacher in promoting dialogic pedagogies, less specific attention has been given to how teacher discourse can shape the development of students'…

  4. Optical fiber meta-tips

    NASA Astrophysics Data System (ADS)

    Principe, Maria; Micco, Alberto; Crescitelli, Alessio; Castaldi, Giuseppe; Consales, Marco; Esposito, Emanuela; La Ferrara, Vera; Galdi, Vincenzo; Cusano, Andrea

    2016-04-01

    We report on the first example of a "meta-tip" configuration that integrates a metasurface on the tip of an optical fiber. Our proposed design is based on an inverted-Babinet plasmonic metasurface obtained by patterning (via focused ion beam) a thin gold film deposited on the tip of an optical fiber, so as to realize an array of rectangular aperture nanoantennas with spatially modulated sizes. By properly tuning the resonances of the aperture nanoantennas, abrupt variations can be impressed in the field wavefront and polarization. We fabricated and characterized several proof-of-principle prototypes operating an near-infrared wavelengths, and implementing the beam-steering (with various angles) of the cross-polarized component, as well as the excitation of surface waves. Our results pave the way to the integration of the exceptional field-manipulation capabilities enabled by metasurfaces with the versatility and ubiquity of fiber-optics technological platforms.

  5. Pancreatic two P domain K+ channels TALK-1 and TALK-2 are activated by nitric oxide and reactive oxygen species

    PubMed Central

    Duprat, F; Girard, C; Jarretou, G; Lazdunski, M

    2005-01-01

    This study firstly shows with in situ hybridization on human pancreas that TALK-1 and TALK-2, two members of the 2P domain potassium channel (K2P) family, are highly and specifically expressed in the exocrine pancreas and absent in Langherans islets. On the contrary, expression of TASK-2 in mouse pancreas is found both in the exocrine pancreas and in the Langherans islets. This study also shows that TALK-1 and TALK-2 channels, expressed in Xenopus oocytes, are strongly and specifically activated by nitric oxide (obtained with a mixture of sodium nitroprussate (SNP) and dithiothreitol (DTT)), superoxide anion (obtained with xanthine and xanthine oxidase) and singlet oxygen (obtained upon photoactivation of rose bengal, and with chloramine T). Other nitric oxide and reactive oxygen species (NOS and ROS) donors, as well as reducing conditions were found to be ineffective on TALK-1, TALK-2 and TASK-2 (sin-1, angeli's salt, SNP alone, tBHP, H2O2, and DTT). These results suggest that, in the exocrine pancreas, specific members of the NOS and ROS families could act as endogenous modulators of TALK channels with a role in normal secretion as well as in disease states such as acute pancreatitis and apoptosis. PMID:15513946

  6. Lithotripsy Performance of Specially Designed Laser Fiber Tips.

    PubMed

    Kronenberg, Peter; Traxer, Olivier

    2016-05-01

    We evaluated and compared a standard laser lithotripsy fiber to laser fibers claimed to have lithotripsy performance enhancing features. A special AccuMax™ 200 polished tip fiber and an AccuTrac™ ball-shaped tip fiber, each with an approximately 240 μm core, were compared to a standard 272 μm core fiber (Rocamed™). The polished and ball-shaped tip fibers were used and reused without preparation. The standard fiber was stripped and cleaved according to manufacturer instructions after each experiment. An automated laser fragmentation testing system was used to perform multiple 30-second laser lithotripsy experiments. To mimic most typical lithotripsy conditions soft and hard stone materials were used with high frequency, low pulse energy (20 Hz and 0.5 J) or with low frequency, high pulse energy (5 Hz and 2.0 J) lithotripter settings. Ablation volumes and laser fiber tip photographs before and after lithotripsy were compared. The standard and ball-shaped tip fibers did not differ in ablation volume (p = 0.72) but they ablated 174% and 188% more stone, respectively, than the polished tip fiber (p <0.0001). The ball-shaped tip showed remarkable fiber tip degradation after short-term use at low frequency, high pulse energy settings. When high pulse energy settings were applied first even for short-term use, the ablation volume achieved by the polished and ball-shaped tip fibers at high frequency, low pulse energy settings decreased more than 20%. The standard laser fiber was as good as and sometimes better than the specially designed fibers. Rapid degradation of the specially designed laser fiber tips strongly limits their general usefulness but ball-shaped tip fibers may be useful in specific situations. Copyright © 2016 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

  7. Local Mass and Heat Transfer on a Turbine Blade Tip

    DOE PAGES

    Jin, P.; Goldstein, R. J.

    2003-01-01

    Locmore » al mass and heat transfer measurements on a simulated high-pressure turbine blade-tip surface are conducted in a linear cascade with a nonmoving tip endwall, using a naphthalene sublimation technique. The effects of tip clearance (0.86–6.90% of chord) are investigated at various exit Reynolds numbers (4–7 × 10 5 ) and turbulence intensities (0.2 and 12.0%). The mass transfer on the tip surface is significant along its pressure edge at the smallest tip clearance. At the two largest tip clearances, the separation bubble on the tip surface can cover the whole width of the tip on the second half of the tip surface. The average mass-transfer rate is highest at a tip clearance of 1.72% of chord. The average mass-transfer rate on the tip surface is four and six times as high as on the suction and the pressure surface, respectively. A high mainstream turbulence level of 12.0% reduces average mass-transfer rates on the tip surface, while the higher mainstream Reynolds number generates higher local and average mass-transfer rates on the tip surface.« less

  8. Note: Microelectrode-shielding tip for scanning probe electron energy spectroscopy

    NASA Astrophysics Data System (ADS)

    Huang, Wei; Li, Zhean; Xu, Chunkai; Liu, Jian; Xu, Chunye; Chen, Xiangjun

    2018-04-01

    We report a novel microelectrode-shielding tip (ME tip) for scanning probe electron energy spectroscopy (SPEES). The shielding effect of this tip is studied through comparing the detection efficiency with the normal tip by both experiment and simulation. The results show that the backscattering count rate detected by the SPEES instrument using the normal tip begins to decrease as the tip approaches to the sample surface within 21 μm, while that using the ME tip only starts to drop off within 1 μm. This indicates that the electron energy spectra can be measured with the ME tip at a much closer tip-sample distance. Furthermore, it is also demonstrated that the ME tip can be used to obtain topography of the sample surface in situ simultaneously.

  9. 7 CFR 29.3154 - Tips (T Group).

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... stalk. (See Rule 12.) Grades Grade names and specifications T3F Good Tan Tips. Medium body, mature to...″ in length, 85 percent uniform, and 15 percent injury tolerance. T4F Fair Tan Tips. Medium body..., and 20 percent injury tolerance. T5F Low Tan Tips. Medium body, mature, firm, wrinkly, dingy finish...

  10. 7 CFR 29.3154 - Tips (T Group).

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... stalk. (See Rule 12.) Grades Grade names and specifications T3F Good Tan Tips. Medium body, mature to...″ in length, 85 percent uniform, and 15 percent injury tolerance. T4F Fair Tan Tips. Medium body..., and 20 percent injury tolerance. T5F Low Tan Tips. Medium body, mature, firm, wrinkly, dingy finish...

  11. Injector tip for an internal combustion engine

    DOEpatents

    Shyu, Tsu Pin; Ye, Wen

    2003-05-20

    This invention relates to a the tip structure of a fuel injector as used in a internal combustion engine. Internal combustion engines using Homogeneous Charge Compression Ignition (HCCI) technology require a tip structure that directs fuel spray in a downward direction. This requirement necessitates a tip design that is capable of withstanding mechanical stresses associated with the design.

  12. "Eugenics talk" and the language of bioethics.

    PubMed

    Wilkinson, S

    2008-06-01

    In bioethical discussions of preimplantation genetic diagnosis and prenatal screening, accusations of eugenics are commonplace, as are counter-claims that talk of eugenics is misleading and unhelpful. This paper asks whether "eugenics talk", in this context, is legitimate and useful or something to be avoided. It also looks at the extent to which this linguistic question can be answered without first answering relevant substantive moral questions. Its main conclusion is that the best and most non-partisan argument for avoiding eugenics talk is the Autonomy Argument. According to this, eugenics talk per se is not wrong, but there is something wrong with using its emotive power as a means of circumventing people's critical-rational faculties. The Autonomy Argument does not, however, tell against eugenics talk when such language is used to shock people into critical-rational thought. These conclusions do not depend on unique features of eugenics: similar considerations apply to emotive language throughout bioethics.

  13. Face Sheet/Core Disbond Growth in Honeycomb Sandwich Panels Subjected to Ground-Air-Ground Pressurization and In-Plane Loading

    NASA Technical Reports Server (NTRS)

    Chen, Zhi M.; Krueger, Ronald; Rinker, Martin

    2015-01-01

    Typical damage modes in light honeycomb sandwich structures include face sheet/core disbonding and core fracture, both of which can pose a threat to the structural integrity of a component. These damage modes are of particular interest to aviation certification authorities since several in-service occurrences, such as rudder structural failure and other control surface malfunctions, have been attributed to face sheet/core disbonding. Extensive studies have shown that face sheet/core disbonding and core fracture can lead to damage propagation caused by internal pressure changes in the core. The increasing use of composite sandwich construction in aircraft applications makes it vitally important to understand the effect of ground-air-ground (GAG) cycles and conditions such as maneuver and gust loads on face sheet/core disbonding. The objective of the present study was to use a fracture mechanics based approach developed earlier to evaluate the loading at the disbond front caused by ground-air-ground pressurization and in-plane loading. A honeycomb sandwich panel containing a circular disbond at one face sheet/core interface was modeled with three-dimensional (3D) solid finite elements. The disbond was modeled as a discrete discontinuity and the strain energy release rate along the disbond front was computed using the Virtual Crack Closure Technique (VCCT). Special attention was paid to the pressure-deformation coupling which can decrease the pressure load within the disbonded sandwich section significantly when the structure is highly deformed. The commercial finite element analysis software, Abaqus/Standard, was used for the analyses. The recursive pressure-deformation coupling problem was solved by representing the entrapped air in the honeycomb cells as filled cavities in Abaqus/Standard. The results show that disbond size, face sheet thickness and core thickness are important parameters that determine crack tip loading at the disbond front. Further, the pressure

  14. Turbine blade tip flow discouragers

    DOEpatents

    Bunker, Ronald Scott

    2000-01-01

    A turbine assembly comprises a plurality of rotating blade portions in a spaced relation with a stationery shroud. The rotating blade portions comprise a root section, a tip portion and an airfoil. The tip portion has a pressure side wall and a suction side wall. A number of flow discouragers are disposed on the blade tip portion. In one embodiment, the flow discouragers extend circumferentially from the pressure side wall to the suction side wall so as to be aligned generally parallel to the direction of rotation. In an alternative embodiment, the flow discouragers extend circumferentially from the pressure side wall to the suction side wall so as to be aligned at an angle in the range between about 0.degree. to about 60.degree. with respect to a reference axis aligned generally parallel to the direction of rotation. The flow discouragers increase the flow resistance and thus reduce the flow of hot gas flow leakage for a given pressure differential across the blade tip portion so as to improve overall turbine efficiency.

  15. Effect of rotor tip clearance and configuration on overall performance of a 12.77-centimeter tip diameter axial-flow turbine

    NASA Technical Reports Server (NTRS)

    Haas, J. E.; Kofskey, M. G.

    1978-01-01

    The rotor tip clearance was obtained by use of a recess in the casing above the rotor blades and also by use of a reduced blade height. For the recessed casing configuration, the optimum rotor blade height was found to be the one where the rotor tip diameter was equal to the stator tip diameter. The tip clearance loss associated with this optimum recessed casing configuration was less than that for the reduced blade height configuration.

  16. Dynamic of cold-atom tips in anharmonic potentials

    PubMed Central

    Menold, Tobias; Federsel, Peter; Rogulj, Carola; Hölscher, Hendrik; Fortágh, József

    2016-01-01

    Background: Understanding the dynamics of ultracold quantum gases in an anharmonic potential is essential for applications in the new field of cold-atom scanning probe microscopy. Therein, cold atomic ensembles are used as sensitive probe tips to investigate nanostructured surfaces and surface-near potentials, which typically cause anharmonic tip motion. Results: Besides a theoretical description of this anharmonic tip motion, we introduce a novel method for detecting the cold-atom tip dynamics in situ and real time. In agreement with theory, the first measurements show that particle interactions and anharmonic motion have a significant impact on the tip dynamics. Conclusion: Our findings will be crucial for the realization of high-sensitivity force spectroscopy with cold-atom tips and could possibly allow for the development of advanced spectroscopic techniques such as Q-control. PMID:28144505

  17. Unveiling climate and ice-sheet history from drilling in high-latitude margins and future perspectives

    NASA Astrophysics Data System (ADS)

    Escutia Dotti, Carlota

    2010-05-01

    Polar ice is an important component of the climate system, affecting global sea level, ocean circulation and heat transport, marine productivity, and albedo. During the last decades drilling in the Arctic (IODP ACEX and Bering Expeditions) and in Antarctica (ODP Legs 178, 188, IODP Expedition 318 and ANDRILL) has revealed regional information about sea ice and ice sheets development and evolution. Integration of this data with numerical modeling provide an understanding of the early development of the ice sheets and their variability through the Cenozoic. Much of this work points to atmospheric CO2 and other greenhouse gases concentrations as important triggering mechanism driving the onset of glaciation and subsequent ice volume variability. With current increasing atmospheric greenhouse gases concentrations resulting in rapidly rising global temperatures, studies of polar climates become increasingly prominent on the research agenda. Despite of the relevance of the high-latitudes in the global climate systems, the short- and long-term history of the ice sheets and sea-ice and its relationships with paleoclimatic, paleoceanographic, and sea level changes is still poorly understood. A multinational, multiplatform scientific drilling strategy is being developed to recover key physical evidence from selected high-latitude areas. This strategy is aimed at addressing key knowledge gaps about the role of polar ice in climate change, targeting questions such as timing of events, rates of change, tipping points, regional variations, and northern vs. southern hemispheres (in phase or out-of-phase) variability. This data is critical to provide constrains to sea-ice and ice sheet models, which are the basis for forecasting the future of the cryosphere in a warming world.

  18. Talking to Your Kids about Virginity

    MedlinePlus

    ... MusclesHuman Papillomavirus (HPV)Talking to Your Kids About Sex Home Family Health Kids and Teens Talking to Your Kids About Virginity ... by: familydoctor.org editorial staff Categories: Family Health, Kids and Teens, Sex and SexualityTags: child, teenager January 10, 2017 Copyright © ...

  19. Management of Bleeding Duodenal Varices with Combined TIPS Decompression and Trans-TIPS Transvenous Obliteration Utilizing 3% Sodium Tetradecyl Sulfate Foam Sclerosis.

    PubMed

    Saad, Wael E; Lippert, Allison; Schwaner, Sandra; Al-Osaimi, Abdullah; Sabri, Saher; Saad, Nael

    2014-01-01

    Endoscopic experience in the management of duodenal varices (DVs) is limited and challenging given the anatomic constraints and limited experience. The endovascular management of DVs is not yet established and the controversy of whether to manage them by decompression with a transjugular intrahepatic portosystemic shunt (TIPS) or by transvenous obliteration is unresolved. In the literature, the 6-12 month rebleeding rate of DVs after TIPS is 21-37% and after transvenous obliteration is 13%. The purpose of the study is to evaluate the clinical outcome of combined TIPS decompression and transvenous obliteration/sclerosis. This is a retrospective study (case series) of two institutions, evaluating patients who underwent TIPS and/or transvenous obliteration/sclerosis for bleeding DVs (from January 2009 to June 2013). TIPS was performed according to a standard procedure using covered stents. Transvenous obliteration (variceal sclerosis) from the systemic and/or portal venous circulation was performed utilizing 3% sodium tetradecyl sulfate foam. Transvenous obliteration was commonly augmented with coils and/or vascular plugs. Technical (technical success of establishing TIPS and completely obliterating the DVs) and clinical outcomes (rebleeding rate and survival) were evaluated. Five patients with liver cirrhosis presenting with bleeding DVs were included in the study with all eventually (and coincidentally) receiving TIPS and transvenous obliteration. Two of the five patients underwent concomitant TIPS and transvenous obliteration in the same procedural setting. However, three patients underwent transvenous obliteration due to bleeding despite a patent TIPS that had been previously placed. The average time from TIPS placement to transvenous obliteration was 125 days (range: 3-324 days). After having both procedures, there was no rebleeding in the patients during a mean follow-up period of 22 months (6-50 months). Coils and/or metallic vascular plugs were used to augment

  20. Tips for Talking to Your Doctor

    MedlinePlus

    ... contributed by: familydoctor.org editorial staff Categories: Healthcare Management, Working With Your Doctor, Your Health ResourcesTags: Doctor-Patient Relationships, Health Maintenance August 1, 2005 Copyright © American Academy of Family ...

  1. CSC Tip Sheets: Action Checklists

    EPA Pesticide Factsheets

    Learn how to use action checklists to motivate behavior change by providing a clear and concise list of activities that community members and organizations can use to reduce their carbon footprint and achieve other sustainability goals.

  2. Sports Injury Prevention Tip Sheet

    MedlinePlus

    ... Conferences Press Information Media Kits Embargoed Media ... than ever before. Sports help children and adolescents keep their bodies fit and feel good about themselves. However, there are some important injury ...

  3. CSC Tip Sheets: Testimonial Videos

    EPA Pesticide Factsheets

    Testimonial videos can be used to communicate to your target audience from the perspective of someone like them who has participated in program activities and can speak to the benefits and motivations of the activities your program is promoting.

  4. Effective Teacher Talk: A Threshold Concept in TESOL

    ERIC Educational Resources Information Center

    Skinner, Barbara

    2017-01-01

    English language teachers are expected to use their talk, "teacher talk," effectively; however, teacher education courses do not always clarify how student teachers can achieve this. This article advocates that understanding and using effective teacher talk is crucial for successful ELT and as such is a "threshold concept" in…

  5. Transporter for Treated Sheet Materials

    NASA Technical Reports Server (NTRS)

    Pollack, M., H.

    1983-01-01

    Plastic spacers keep parts separated during transport or storage. Cart with rods and spacers holds sheets with delicate finishes for storage or transport. Sheets supported vertically by rods, or horizontally. Spacers keep sheets separated. Designed to eliminate time and expense of tapping, wrapping, and sometimes refinishing aluminum sheets with delicate anodized finished.

  6. Hard-tip, soft-spring lithography.

    PubMed

    Shim, Wooyoung; Braunschweig, Adam B; Liao, Xing; Chai, Jinan; Lim, Jong Kuk; Zheng, Gengfeng; Mirkin, Chad A

    2011-01-27

    Nanofabrication strategies are becoming increasingly expensive and equipment-intensive, and consequently less accessible to researchers. As an alternative, scanning probe lithography has become a popular means of preparing nanoscale structures, in part owing to its relatively low cost and high resolution, and a registration accuracy that exceeds most existing technologies. However, increasing the throughput of cantilever-based scanning probe systems while maintaining their resolution and registration advantages has from the outset been a significant challenge. Even with impressive recent advances in cantilever array design, such arrays tend to be highly specialized for a given application, expensive, and often difficult to implement. It is therefore difficult to imagine commercially viable production methods based on scanning probe systems that rely on conventional cantilevers. Here we describe a low-cost and scalable cantilever-free tip-based nanopatterning method that uses an array of hard silicon tips mounted onto an elastomeric backing. This method-which we term hard-tip, soft-spring lithography-overcomes the throughput problems of cantilever-based scanning probe systems and the resolution limits imposed by the use of elastomeric stamps and tips: it is capable of delivering materials or energy to a surface to create arbitrary patterns of features with sub-50-nm resolution over centimetre-scale areas. We argue that hard-tip, soft-spring lithography is a versatile nanolithography strategy that should be widely adopted by academic and industrial researchers for rapid prototyping applications.

  7. Perforating Thin Metal Sheets

    NASA Technical Reports Server (NTRS)

    Davidson, M. E.

    1985-01-01

    Sheets only few mils thick bonded together, punched, then debonded. Three-step process yields perforated sheets of metal. (1): Individual sheets bonded together to form laminate. (2): laminate perforated in desired geometric pattern. (3): After baking, laminate separates into individual sheets. Developed for fabricating conductive layer on blankets that collect and remove ions; however, perforated foils have other applications - as conductive surfaces on insulating materials; stiffeners and conductors in plastic laminates; reflectors in antenna dishes; supports for thermal blankets; lightweight grille cover materials; and material for mockup of components.

  8. Investigation on tip enhanced Raman spectra of graphene

    NASA Astrophysics Data System (ADS)

    Li, Xinjuan; Liu, Yanqi; Zeng, Zhuo; Wang, Peijie; Fang, Yan; Zhang, Lisheng

    2018-02-01

    Tip-enhanced Raman scattering (TERS) is a promising analytical approach for some two-dimensional materials and offers the possibility to correlate imaging and chemical data. Tip-enhanced Raman spectra of graphene are discussed in some details, including substrate, gap between tip-apex and sample surface as well as Ag-nanowire. The TERS spectra give special emphasis to the possibility of TERS tip to induce a large number of defects only while got the tip attached to sample surface. Then the dependence of the TERS spectra of graphene and gap between the probe tip and sample surface was studied, and distribution features of electromagnetic (EM) field around tip were also simulated by finite-difference time-domain (FDTD). The Raman signal enhancement of graphene was further discussed with respect to experimental data. Furthermore, the Ag-nanowire as a nano-antenna could significantly enhance the weak Raman signal of D-band of monolayer graphene is shown, and the TERS spectra of graphene with regard to different regions of Ag-nanowires (endpoints, body) were obtained toward investigating into the distribution of electromagnetic field.

  9. The Influence of Welding Parameters on the Nugget Formation of Resistance Spot Welding of Inconel 625 Sheets

    NASA Astrophysics Data System (ADS)

    Rezaei Ashtiani, Hamid Reza; Zarandooz, Roozbeh

    2015-09-01

    A 2D axisymmetric electro-thermo-mechanical finite element (FE) model is developed to investigate the effect of current intensity, welding time, and electrode tip diameter on temperature distributions and nugget size in resistance spot welding (RSW) process of Inconel 625 superalloy sheets using ABAQUS commercial software package. The coupled electro-thermal analysis and uncoupled thermal-mechanical analysis are used for modeling process. In order to improve accuracy of simulation, material properties including physical, thermal, and mechanical properties have been considered to be temperature dependent. The thickness and diameter of computed weld nuggets are compared with experimental results and good agreement is observed. So, FE model developed in this paper provides prediction of quality and shape of the weld nuggets and temperature distributions with variation of each process parameter, suitably. Utilizing this FE model assists in adjusting RSW parameters, so that expensive experimental process can be avoided. The results show that increasing welding time and current intensity lead to an increase in the nugget size and electrode indentation, whereas increasing electrode tip diameter decreases nugget size and electrode indentation.

  10. Supporting Disciplinary Talk from the Start of School: Teaching Students to Think and Talk Like Scientists

    ERIC Educational Resources Information Center

    Wright, Tanya S.; Gotwals, Amelia Wenk

    2017-01-01

    In this article, the authors first review the research literature to show why supporting talk from the start of school is important for students' long-term literacy development. The authors then define and describe disciplinary talk and argue that it is an important entry point into science and disciplinary literacy learning for young students.…

  11. An ice sheet model validation framework for the Greenland ice sheet

    NASA Astrophysics Data System (ADS)

    Price, Stephen F.; Hoffman, Matthew J.; Bonin, Jennifer A.; Howat, Ian M.; Neumann, Thomas; Saba, Jack; Tezaur, Irina; Guerber, Jeffrey; Chambers, Don P.; Evans, Katherine J.; Kennedy, Joseph H.; Lenaerts, Jan; Lipscomb, William H.; Perego, Mauro; Salinger, Andrew G.; Tuminaro, Raymond S.; van den Broeke, Michiel R.; Nowicki, Sophie M. J.

    2017-01-01

    We propose a new ice sheet model validation framework - the Cryospheric Model Comparison Tool (CmCt) - that takes advantage of ice sheet altimetry and gravimetry observations collected over the past several decades and is applied here to modeling of the Greenland ice sheet. We use realistic simulations performed with the Community Ice Sheet Model (CISM) along with two idealized, non-dynamic models to demonstrate the framework and its use. Dynamic simulations with CISM are forced from 1991 to 2013, using combinations of reanalysis-based surface mass balance and observations of outlet glacier flux change. We propose and demonstrate qualitative and quantitative metrics for use in evaluating the different model simulations against the observations. We find that the altimetry observations used here are largely ambiguous in terms of their ability to distinguish one simulation from another. Based on basin-scale and whole-ice-sheet-scale metrics, we find that simulations using both idealized conceptual models and dynamic, numerical models provide an equally reasonable representation of the ice sheet surface (mean elevation differences of < 1 m). This is likely due to their short period of record, biases inherent to digital elevation models used for model initial conditions, and biases resulting from firn dynamics, which are not explicitly accounted for in the models or observations. On the other hand, we find that the gravimetry observations used here are able to unambiguously distinguish between simulations of varying complexity, and along with the CmCt, can provide a quantitative score for assessing a particular model and/or simulation. The new framework demonstrates that our proposed metrics can distinguish relatively better from relatively worse simulations and that dynamic ice sheet models, when appropriately initialized and forced with the right boundary conditions, demonstrate a predictive skill with respect to observed dynamic changes that have occurred on

  12. An ice sheet model validation framework for the Greenland ice sheet

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

    Price, Stephen F.; Hoffman, Matthew J.; Bonin, Jennifer A.

    We propose a new ice sheet model validation framework the Cryospheric Model Comparison Tool (CMCT) that takes advantage of ice sheet altimetry and gravimetry observations collected over the past several decades and is applied here to modeling of the Greenland ice sheet. We use realistic simulations performed with the Community Ice Sheet Model (CISM) along with two idealized, non-dynamic models to demonstrate the framework and its use. Dynamic simulations with CISM are forced from 1991 to 2013 using combinations of reanalysis-based surface mass balance and observations of outlet glacier flux change. We propose and demonstrate qualitative and quanti- tative metricsmore » for use in evaluating the different model simulations against the observations. We find 10 that the altimetry observations used here are largely ambiguous in terms of their ability to distinguish one simulation from another. Based on basin- and whole-ice-sheet scale metrics, the model initial condition as well as output from idealized and dynamic models all provide an equally reasonable representation of the ice sheet surface (mean elevation differences of <1 m). This is likely due to their short period of record, biases inherent to digital elevation models used for model initial conditions, and biases resulting from firn dynamics, which are not explicitly accounted for in the models or observations. On the other hand, we find that the gravimetry observations used here are able to unambiguously distinguish between simulations of varying complexity, and along with the CMCT, can provide a quantitative score for assessing a particular model and/or simulation. The new framework demonstrates that our proposed metrics can distinguish relatively better from relatively worse simulations and that dynamic ice sheet models, when appropriately initialized and forced with the right boundary conditions, demonstrate predictive skill with respect to observed dynamic changes occurring on Greenland over the past few

  13. An ice sheet model validation framework for the Greenland ice sheet

    PubMed Central

    Price, Stephen F.; Hoffman, Matthew J.; Bonin, Jennifer A.; Howat, Ian M.; Neumann, Thomas; Saba, Jack; Tezaur, Irina; Guerber, Jeffrey; Chambers, Don P.; Evans, Katherine J.; Kennedy, Joseph H.; Lenaerts, Jan; Lipscomb, William H.; Perego, Mauro; Salinger, Andrew G.; Tuminaro, Raymond S.; van den Broeke, Michiel R.; Nowicki, Sophie M. J.

    2018-01-01

    We propose a new ice sheet model validation framework – the Cryospheric Model Comparison Tool (CmCt) – that takes advantage of ice sheet altimetry and gravimetry observations collected over the past several decades and is applied here to modeling of the Greenland ice sheet. We use realistic simulations performed with the Community Ice Sheet Model (CISM) along with two idealized, non-dynamic models to demonstrate the framework and its use. Dynamic simulations with CISM are forced from 1991 to 2013 using combinations of reanalysis-based surface mass balance and observations of outlet glacier flux change. We propose and demonstrate qualitative and quantitative metrics for use in evaluating the different model simulations against the observations. We find that the altimetry observations used here are largely ambiguous in terms of their ability to distinguish one simulation from another. Based on basin- and whole-ice-sheet scale metrics, we find that simulations using both idealized conceptual models and dynamic, numerical models provide an equally reasonable representation of the ice sheet surface (mean elevation differences of <1 m). This is likely due to their short period of record, biases inherent to digital elevation models used for model initial conditions, and biases resulting from firn dynamics, which are not explicitly accounted for in the models or observations. On the other hand, we find that the gravimetry observations used here are able to unambiguously distinguish between simulations of varying complexity, and along with the CmCt, can provide a quantitative score for assessing a particular model and/or simulation. The new framework demonstrates that our proposed metrics can distinguish relatively better from relatively worse simulations and that dynamic ice sheet models, when appropriately initialized and forced with the right boundary conditions, demonstrate predictive skill with respect to observed dynamic changes occurring on Greenland over the

  14. An ice sheet model validation framework for the Greenland ice sheet.

    PubMed

    Price, Stephen F; Hoffman, Matthew J; Bonin, Jennifer A; Howat, Ian M; Neumann, Thomas; Saba, Jack; Tezaur, Irina; Guerber, Jeffrey; Chambers, Don P; Evans, Katherine J; Kennedy, Joseph H; Lenaerts, Jan; Lipscomb, William H; Perego, Mauro; Salinger, Andrew G; Tuminaro, Raymond S; van den Broeke, Michiel R; Nowicki, Sophie M J

    2017-01-01

    We propose a new ice sheet model validation framework - the Cryospheric Model Comparison Tool (CmCt) - that takes advantage of ice sheet altimetry and gravimetry observations collected over the past several decades and is applied here to modeling of the Greenland ice sheet. We use realistic simulations performed with the Community Ice Sheet Model (CISM) along with two idealized, non-dynamic models to demonstrate the framework and its use. Dynamic simulations with CISM are forced from 1991 to 2013 using combinations of reanalysis-based surface mass balance and observations of outlet glacier flux change. We propose and demonstrate qualitative and quantitative metrics for use in evaluating the different model simulations against the observations. We find that the altimetry observations used here are largely ambiguous in terms of their ability to distinguish one simulation from another. Based on basin- and whole-ice-sheet scale metrics, we find that simulations using both idealized conceptual models and dynamic, numerical models provide an equally reasonable representation of the ice sheet surface (mean elevation differences of <1 m). This is likely due to their short period of record, biases inherent to digital elevation models used for model initial conditions, and biases resulting from firn dynamics, which are not explicitly accounted for in the models or observations. On the other hand, we find that the gravimetry observations used here are able to unambiguously distinguish between simulations of varying complexity, and along with the CmCt, can provide a quantitative score for assessing a particular model and/or simulation. The new framework demonstrates that our proposed metrics can distinguish relatively better from relatively worse simulations and that dynamic ice sheet models, when appropriately initialized and forced with the right boundary conditions, demonstrate predictive skill with respect to observed dynamic changes occurring on Greenland over the past

  15. An ice sheet model validation framework for the Greenland ice sheet

    DOE PAGES

    Price, Stephen F.; Hoffman, Matthew J.; Bonin, Jennifer A.; ...

    2017-01-17

    We propose a new ice sheet model validation framework the Cryospheric Model Comparison Tool (CMCT) that takes advantage of ice sheet altimetry and gravimetry observations collected over the past several decades and is applied here to modeling of the Greenland ice sheet. We use realistic simulations performed with the Community Ice Sheet Model (CISM) along with two idealized, non-dynamic models to demonstrate the framework and its use. Dynamic simulations with CISM are forced from 1991 to 2013 using combinations of reanalysis-based surface mass balance and observations of outlet glacier flux change. We propose and demonstrate qualitative and quanti- tative metricsmore » for use in evaluating the different model simulations against the observations. We find 10 that the altimetry observations used here are largely ambiguous in terms of their ability to distinguish one simulation from another. Based on basin- and whole-ice-sheet scale metrics, the model initial condition as well as output from idealized and dynamic models all provide an equally reasonable representation of the ice sheet surface (mean elevation differences of <1 m). This is likely due to their short period of record, biases inherent to digital elevation models used for model initial conditions, and biases resulting from firn dynamics, which are not explicitly accounted for in the models or observations. On the other hand, we find that the gravimetry observations used here are able to unambiguously distinguish between simulations of varying complexity, and along with the CMCT, can provide a quantitative score for assessing a particular model and/or simulation. The new framework demonstrates that our proposed metrics can distinguish relatively better from relatively worse simulations and that dynamic ice sheet models, when appropriately initialized and forced with the right boundary conditions, demonstrate predictive skill with respect to observed dynamic changes occurring on Greenland over the past few

  16. An Ice Sheet Model Validation Framework for the Greenland Ice Sheet

    NASA Technical Reports Server (NTRS)

    Price, Stephen F.; Hoffman, Matthew J.; Bonin, Jennifer A.; Howat, Ian M.; Neumann, Thomas A.; Saba, Jack; Tezaur, Irina; Guerber, Jeffrey R.; Chambers, Don P.; Evans, Katherine J.; hide

    2017-01-01

    We propose a new ice sheet model validation framework - the Cryospheric Model Comparison Tool (CmCt) - that takes advantage of ice sheet altimetry and gravimetry observations collected over the past several decades and is applied here to modeling of the Greenland ice sheet. We use realistic simulations performed with the Community Ice Sheet Model (CISM) along with two idealized, non-dynamic models to demonstrate the framework and its use. Dynamic simulations with CISM are forced from 1991 to 2013, using combinations of reanalysis-based surface mass balance and observations of outlet glacier flux change. We propose and demonstrate qualitative and quantitative metrics for use in evaluating the different model simulations against the observations. We find that the altimetry observations used here are largely ambiguous in terms of their ability to distinguish one simulation from another. Based on basin-scale and whole-ice-sheet-scale metrics, we find that simulations using both idealized conceptual models and dynamic, numerical models provide an equally reasonable representation of the ice sheet surface (mean elevation differences of less than 1 meter). This is likely due to their short period of record, biases inherent to digital elevation models used for model initial conditions, and biases resulting from firn dynamics, which are not explicitly accounted for in the models or observations. On the other hand, we find that the gravimetry observations used here are able to unambiguously distinguish between simulations of varying complexity, and along with the CmCt, can provide a quantitative score for assessing a particular model and/or simulation. The new framework demonstrates that our proposed metrics can distinguish relatively better from relatively worse simulations and that dynamic ice sheet models, when appropriately initialized and forced with the right boundary conditions, demonstrate a predictive skill with respect to observed dynamic changes that have occurred

  17. 17. INTAKE PIER, BRIDGE STRESS SHEET, SHEET 8 OF 117, ...

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

    17. INTAKE PIER, BRIDGE STRESS SHEET, SHEET 8 OF 117, 1920. - Sacramento River Water Treatment Plant Intake Pier & Access Bridge, Spanning Sacramento River approximately 175 feet west of eastern levee on river; roughly .5 mile downstream from confluence of Sacramento & American Rivers, Sacramento, Sacramento County, CA

  18. Apparatus for electrical-assisted incremental forming and process thereof

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

    Roth, John; Cao, Jian

    A process and apparatus for forming a sheet metal component using an electric current passing through the component. The process can include providing an incremental forming machine, the machine having at least one arcuate tipped tool and at least electrode spaced a predetermined distance from the arcuate tipped tool. The machine is operable to perform a plurality of incremental deformations on the sheet metal component using the arcuate tipped tool. The machine is also operable to apply an electric direct current through the electrode into the sheet metal component at the predetermined distance from the arcuate tipped tool while themore » machine is forming the sheet metal component.« less

  19. FDTD modeling of thin impedance sheets

    NASA Technical Reports Server (NTRS)

    Luebbers, Raymond; Kunz, Karl

    1991-01-01

    Thin sheets of resistive or dielectric material are commonly encountered in radar cross section calculations. Analysis of such sheets is simplified by using sheet impedances. It is shown that sheet impedances can be modeled easily and accurately using Finite Difference Time Domain (FDTD) methods. These sheets are characterized by a discontinuity in the tangential magnetic field on either side of the sheet but no discontinuity in tangential electric field. This continuity, or single valued behavior of the electric field, allows the sheet current to be expressed in terms of an impedance multiplying this electric field.

  20. Advanced optical blade tip clearance measurement system

    NASA Technical Reports Server (NTRS)

    Ford, M. J.; Honeycutt, R. E.; Nordlund, R. E.; Robinson, W. W.

    1978-01-01

    An advanced electro-optical system was developed to measure single blade tip clearances and average blade tip clearances between a rotor and its gas path seal in an operating gas turbine engine. This system is applicable to fan, compressor, and turbine blade tip clearance measurement requirements, and the system probe is particularly suitable for operation in the extreme turbine environment. A study of optical properties of blade tips was conducted to establish measurement system application limitations. A series of laboratory tests was conducted to determine the measurement system's operational performance characteristics and to demonstrate system capability under simulated operating gas turbine environmental conditions. Operational and environmental performance test data are presented.

  1. Method for heating a glass sheet

    DOEpatents

    Boaz, Premakaran Tucker

    1998-01-01

    A method for heating a glass sheet includes the steps of heating a glass sheet to a first predetermined temperature and applying microwave energy to the glass sheet to heat the glass sheet to at least a second predetermined temperature to allow the glass sheet to be formed.

  2. Technology Tips

    ERIC Educational Resources Information Center

    Santos-Trigo, Manuel

    2004-01-01

    A dynamic program for geometry called Cabri Geometry II is used to examine properties of figures like triangles and make connections with other mathematical ideas like ellipse. The technology tip includes directions for creating such a problem with technology and suggestions for exploring it.

  3. Clinching for sheet materials

    PubMed Central

    He, Xiaocong

    2017-01-01

    Abstract Latest developments in the clinching of sheet materials are reviewed in this article. Important issues are discussed, such as tool design, process parameters and joinability of some new lightweight sheet materials. Hybrid and modified clinching processes are introduced to a general reader. Several unaddressed issues in the clinching of sheet materials are identified. PMID:28656065

  4. Liquid sheet radiator

    NASA Technical Reports Server (NTRS)

    Chubb, Donald L.; White, K. Alan, III

    1987-01-01

    A new external flow radiator concept, the liquid sheet radiator (LSR), is introduced. The LSR sheet flow is described and an expression for the length/width (l/w), ratio is presented. A linear dependence of l/w on velocity is predicted that agrees with experimental results. Specific power for the LSR is calculated and is found to be nearly the same as the specific power of a liquid droplet radiator, (LDR). Several sheet thicknesses and widths were experimentally investigated. In no case was the flow found to be unstable.

  5. An Examination of the Nature of Erotic Talk.

    PubMed

    Jonason, Peter K; Betteridge, Gabrielle L; Kneebone, Ian I

    2016-01-01

    Using a mixed-methods study, we provided the first systematic documentation and exploration of erotic talk. In Study 1 (N = 95), participants provided 569 erotic talk statements in an anonymous online survey, which we classified, using a modified thematic analysis, as being representative of eight themes. In Study 2 (N = 238), we quantified individual differences in these themes, subjected them to factor analysis, and examined the nomological network surrounding them with measures of relationship and sexual satisfaction, sociosexuality, and personality. The eight initial categories represented two higher order factors, which we call individualist talk and mutualistic talk. These factors were orthogonal in factor analysis and distinct in their nomological network. While the majority of people reported using erotic talk, we found few sex differences in its use.

  6. Quasi-linearly polarized hybrid modes in tapered and metal-coated tips with circular apertures: understanding the functionality of aperture tips

    NASA Astrophysics Data System (ADS)

    Tugchin, B. N.; Janunts, N.; Steinert, M.; Dietrich, K.; Kley, E. B.; Tünnermann, A.; Pertsch, T.

    2017-06-01

    In this study, we investigate analytically and experimentally the roles of quasi-linearly polarized (LP), hybrid, plasmonic and photonic modes in optical detection and excitation with aperture tips in scanning near-field optical microscopy. Aperture tips are tapered and metal-coated optical fibers where small circular apertures are made at the apex. In aperture tips, there exist plasmonic modes that are bound at the interface of the metal cladding to the inner dielectric fiber and photonic modes that are guided in the area of the increased index in the dielectric fiber core. The fundamental photonic mode, although excited by the free-space Gaussian beam, experiences cutoff and turns into an evanescent mode. The photonic mode also becomes lossier than the plasmonic mode toward the tip aperture, and its power decay due to absorption and reflection is expected to be at least 10-9. In contrast, the fundamental plasmonic mode has no cutoff and thus reaches all the way to the tip aperture. Due to the non-adiabaticity of both modes’ propagations through the taper below a core radius of 600 nm, there occurs coupling between the modes. The transmission efficiency of the plasmonic mode, including the coupling efficiency and the propagation loss, is expected to be about 10-6 that is at least 3 orders of magnitude larger than that of the photonic mode. Toward the tip aperture, the longitudinal field of the photonic mode becomes stronger than the transverse ones while the transverse fields always dominate for the plasmonic mode. Experimentally, we obtain polarization resolved images of the near-field at the tip aperture and compare with the x- and y-components of the fundamental quasi-LP plasmonic and photonic modes. The results show that not only the pattern but also the intensity ratios of the x- and y-components of the aperture near-field match with that of the fundamental plasmonic mode. Consequently, we conclude that only the plasmonic mode reaches the tip aperture and

  7. Method for heating a glass sheet

    DOEpatents

    Boaz, P.T.

    1998-07-21

    A method for heating a glass sheet includes the steps of heating a glass sheet to a first predetermined temperature and applying microwave energy to the glass sheet to heat the glass sheet to at least a second predetermined temperature to allow the glass sheet to be formed. 5 figs.

  8. Girlfriends' Health and Safety Tips

    MedlinePlus

    ... Disease Fact Sheet Women's Health Healthy Weight Lesbian, Gay, Bisexual, and Transgender Health Minority Health Preconception Health ... Disease Fact Sheet Women's Health Healthy Weight Lesbian, Gay, Bisexual, and Transgender Health Minority Health Preconception Health ...

  9. TIPS Evaluation Project Retrospective Study: Wave 1 and 2.

    ERIC Educational Resources Information Center

    Hubbard, Susan M.; Mulvey, Kevin P.

    2003-01-01

    Measured substance abuse treatment professionals' knowledge, attitudes, and practices regarding the Treatment Improvement Protocol (TIP) series and the 28 TIPs. Results for 3,267 respondents in wave 1 and 1,028 in wave 2 indicate that almost half of all professionals were aware of the TIPs. Attitudes toward TIPs were positive, but professionals…

  10. Advanced ceramic material for high temperature turbine tip seals

    NASA Technical Reports Server (NTRS)

    Vogan, J. W.; Solomon, N. G.; Stetson, A. R.

    1980-01-01

    Forty-one material systems were evaluated for potential use in turbine blade tip seal applications at 1370 C. Both ceramic blade tip inserts and abradable ceramic tip shoes were tested. Hot gas erosion, impact resistance, thermal stability, and dynamic rub performance were the criteria used in rating the various materials. Silicon carbide and silicon nitride were used, both as blade tips and abradables. The blade tip inserts were fabricated by hot pressing while low density and honeycomb abradables were sintered or reaction bonded.

  11. Needle tip localization using stylet vibration.

    PubMed

    Harmat, Adam; Rohling, Robert N; Salcudean, Septimiu E

    2006-09-01

    Power Doppler ultrasound is used to localize the tip of a needle by detecting physical vibrations. Two types of vibrations are investigated, lateral and axial. The lateral vibrations are created by rotating a stylet, whose tip is slightly bent, inside a stationary cannula while the stylet is completely within the cannula. The minute deflection at the needle tip when rotated causes tissue motion. The axial vibration is induced by extending and retracting a straight stylet inside a stationary cannula. The stylet's tip makes contact with the tissue and causes it to move. The lateral vibration method was found to perform approximately the same under a variety of configurations (e.g., different insertion angles and depths) and better than the axial vibration method. Tissue stiffness affects the performance of the lateral vibration method, but good images can be obtained through proper tuning of the ultrasound machine.

  12. Management of Bleeding Duodenal Varices with Combined TIPS Decompression and Trans-TIPS Transvenous Obliteration Utilizing 3% Sodium Tetradecyl Sulfate Foam Sclerosis

    PubMed Central

    Saad, Wael E; Lippert, Allison; Schwaner, Sandra; Al-Osaimi, Abdullah; Sabri, Saher; Saad, Nael

    2014-01-01

    Objectives: Endoscopic experience in the management of duodenal varices (DVs) is limited and challenging given the anatomic constraints and limited experience. The endovascular management of DVs is not yet established and the controversy of whether to manage them by decompression with a transjugular intrahepatic portosystemic shunt (TIPS) or by transvenous obliteration is unresolved. In the literature, the 6–12 month rebleeding rate of DVs after TIPS is 21-37% and after transvenous obliteration is 13%. The purpose of the study is to evaluate the clinical outcome of combined TIPS decompression and transvenous obliteration/sclerosis. Materials and Methods: This is a retrospective study (case series) of two institutions, evaluating patients who underwent TIPS and/or transvenous obliteration/sclerosis for bleeding DVs (from January 2009 to June 2013). TIPS was performed according to a standard procedure using covered stents. Transvenous obliteration (variceal sclerosis) from the systemic and/or portal venous circulation was performed utilizing 3% sodium tetradecyl sulfate foam. Transvenous obliteration was commonly augmented with coils and/or vascular plugs. Technical (technical success of establishing TIPS and completely obliterating the DVs) and clinical outcomes (rebleeding rate and survival) were evaluated. Results: Five patients with liver cirrhosis presenting with bleeding DVs were included in the study with all eventually (and coincidentally) receiving TIPS and transvenous obliteration. Two of the five patients underwent concomitant TIPS and transvenous obliteration in the same procedural setting. However, three patients underwent transvenous obliteration due to bleeding despite a patent TIPS that had been previously placed. The average time from TIPS placement to transvenous obliteration was 125 days (range: 3-324 days). After having both procedures, there was no rebleeding in the patients during a mean follow-up period of 22 months (6–50 months). Coils and

  13. Fabrication of a trimer/single atom tip for gas field ion sources by means of field evaporation without tip heating.

    PubMed

    Kim, Kwang-Il; Kim, Young Heon; Ogawa, Takashi; Choi, Suji; Cho, Boklae; Ahn, Sang Jung; Park, In-Yong

    2018-05-11

    A gas field ion source (GFIS) has many advantages that are suitable for ion microscope sources, such as high brightness and a small virtual source size, among others. In order to apply a tip-based GFIS to an ion microscope, it is better to create a trimer/single atom tip (TSAT), where the ion beam must be generated in several atoms of the tip apex. Here, unlike the conventional method which uses tip heating or a reactive gas, we show that the tip surface can be cleaned using only the field evaporation phenomenon and that the TSAT can also be fabricated using an insulating layer containing tungsten oxide, which remains after electrochemical etching. Using this method, we could get TSAT over 90% of yield. Copyright © 2018. Published by Elsevier B.V.

  14. Cross-Talk Limits of Highly Segmented Semiconductor Detectors

    NASA Astrophysics Data System (ADS)

    Pullia, Alberto; Weisshaar, Dirk; Zocca, Francesca; Bazzacco, Dino

    2011-06-01

    Cross-talk limits of monolithic highly-segmented semiconductor detectors for high-resolution X-gamma spectrometry are investigated. Cross-talk causes false signal components yielding amplitude losses and fold-dependent shifts of the spectral lines, which partially spoil the spectroscopic performance of the detector. Two complementary electrical models are developed, which describe quantitatively the inter-channel cross-talk of monolithic segmented detectors whose electrodes are read out by charge-sensitive preamplifiers. The first is here designated as Cross-Capacitance (CC) model, the second as Split-Charge (SC) model. The CC model builds around the parasitic capacitances Cij linking the preamplifier outputs and the neighbor channel inputs. The SC model builds around the finite-value of the decoupling capacitance CC used to read out the high-voltage detector electrode. The key parameters of the models are individuated and ideas are shown to minimize their impact. Using a quasi-coaxial germanium segmented detector it is found that the SC cross-talk becomes negligible for decoupling capacitances larger than 1 nF, where instead the CC cross-talk tends to dominate. The residual cross-talk may be reduced by minimization of stray capacitances Cij, through a careful design of the layout of the Printed Circuit Board (PCB) where the input transistors are mounted. Cij can be made as low as 5 fF, but it is shown that even in such case the impact of the CC cross-talk on the detector performance is not negligible. Finally, an algorithm for cross-talk correction is presented and elaborated.

  15. Geometry of thin liquid sheet flows

    NASA Technical Reports Server (NTRS)

    Chubb, Donald L.; Calfo, Frederick D.; Mcconley, Marc W.; Mcmaster, Matthew S.; Afjeh, Abdollah A.

    1994-01-01

    Incompresible, thin sheet flows have been of research interest for many years. Those studies were mainly concerned with the stability of the flow in a surrounding gas. Squire was the first to carry out a linear, invicid stability analysis of sheet flow in air and compare the results with experiment. Dombrowski and Fraser did an experimental study of the disintegration of sheet flows using several viscous liquids. They also detected the formulation of holes in their sheet flows. Hagerty and Shea carried out an inviscid stability analysis and calculated growth rates with experimental values. They compared their calculated growth rates with experimental values. Taylor studied extensively the stability of thin liquid sheets both theoretically and experimentally. He showed that thin sheets in a vacuum are stable. Brown experimentally investigated thin liquid sheet flows as a method of application of thin films. Clark and Dumbrowski carried out second-order stability analysis for invicid sheet flows. Lin introduced viscosity into the linear stability analysis of thin sheet flows in a vacuum. Mansour and Chigier conducted an experimental study of the breakup of a sheet flow surrounded by high-speed air. Lin et al. did a linear stability analysis that included viscosity and a surrounding gas. Rangel and Sirignano carried out both a linear and nonlinear invisid stability analysis that applies for any density ratio between the sheet liquid and the surrounding gas. Now there is renewed interest in sheet flows because of their possible application as low mass radiating surfaces. The objective of this study is to investigate the fluid dynamics of sheet flows that are of interest for a space radiator system. Analytical expressions that govern the sheet geometry are compared with experimental results. Since a space radiator will operate in a vacuum, the analysis does not include any drag force on the sheet flow.

  16. Scientifically speaking: Identifying, analyzing, and promoting science talk in small groups

    NASA Astrophysics Data System (ADS)

    Holthuis, Nicole Inamine

    In this dissertation I define, document, and analyze the nature of students' science talk as they work in cooperative learning groups. Three questions form the basis of this research. First, what is science talk? Second, how much and what kind of science talk did students do? And, third, what conditions help promote or inhibit students' science talk? This study was conducted in a total of six classrooms in three high schools. I videotaped and audiotaped students as they worked in small groups during the course of an ecology unit. I analyzed this videotape data and field notes using both quantitative and qualitative methods. I define science talk as talk that serves to move students along in terms of the science (both content and process) required or suggested by the activity. More specifically, I identified five epistemological characteristics that delineate what counts as scientific knowledge and, subsequently, science talk. From this definition, I developed an analytic framework and science talk observation instrument to document the quantity and level of student and teacher talk during groupwork. Analysis of the data from this instrument indicates that the overall level of students' science talk is considerable and students do significantly more science talk than school talk. I also found that while the overall level and type of science talk does not vary by class or by school, it does vary by activity type. Finally, my analysis suggests that science talk does not vary by gender composition of the group. I explored the classroom conditions that promote or inhibit science talk during groupwork. My findings suggest that, among other things, teachers can promote science talk by delegating authority to students, by emphasizing content and the big idea, by implementing open-ended tasks, and by modeling science talk. In conclusion, the findings described in this dissertation point teachers and researchers toward ways in which they may improve practice in order to

  17. 37 CFR 1.76 - Application data sheet.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 37 Patents, Trademarks, and Copyrights 1 2012-07-01 2012-07-01 false Application data sheet. 1.76... Application data sheet. (a) Application data sheet. An application data sheet is a sheet or sheets, that may... bibliographic data, arranged in a format specified by the Office. An application data sheet must be titled...

  18. The Relationship Talk: Assessing Partner Commitment

    ERIC Educational Resources Information Center

    Nelms, Bobbie Jo; Knox, David; Easterling, Beth

    2012-01-01

    "The talk" is culturally understood to mean a discussion whereby both partners in a relationship reveal their feelings about each other and their commitment to a future together. Typically, one partner feels a greater need to clarity the future and instigates "the talk." This study reports the analysis of a 15 item…

  19. Communication Fact Sheet.

    ERIC Educational Resources Information Center

    American Speech-Language-Hearing Association, Rockville, MD.

    This brief fact sheet examines key aspects of communication, communication disabilities, and intervention. The fact sheet addresses the following questions: the nature of communication; communication disabilities (definitions of hearing impairments and speech and language impairments are given); effects of communication disabilities (factors…

  20. Electrohydrodynamic and flow induced tip-streaming

    NASA Astrophysics Data System (ADS)

    Collins, Robert

    2008-11-01

    A liquid subjected to a strong electric field emits thin fluid jets from conical structures (Taylor cones) that form at its surface. Such behavior has both practical and fundamental implications, e.g. for raindrops in thunderclouds and in electrospray mass spectrometry. Theoretical analysis of the temporal development of such electrohydrodynamic (EHD) tip- streaming phenomena has been elusive given the large disparity in length scales between the macroscopic drops/films and the microscopic (nanoscopic) jets. Here, simulation and experiment are used to investigate the mechanisms of EHD tip-streaming from a film of finite conductivity. In the simulations, the full Taylor-Melcher leaky-dielectric model, which accounts for charge relaxation, is solved. Simulations show that tip- streaming does not occur for perfectly conducting or perfectly insulating liquids. Scaling laws for sizes of drops produced from the breakup of the thin jets is developed. Further, simulations demonstrate the critical role played by electrically induced surface shear stresses in the inception of tip-streaming. This invites a comparison to flow focusing, i.e. tip-streaming induced by co-flowing two fluids. The latter phenomenon is also investigated by simulation. In collaboration with Ronald Suryo, Exxon-Mobil; and Jeremy Jones, Michael Harris, and Osman Basaran, Purdue University.

  1. Transonic rotor tip design using numerical optimization

    NASA Technical Reports Server (NTRS)

    Tauber, Michael E.; Langhi, Ronald G.

    1985-01-01

    The aerodynamic design procedure for a new blade tip suitable for operation at transonic speeds is illustrated. For the first time, 3 dimensional numerical optimization was applied to rotor tip design, using the recent derivative of the ROT22 code, program R22OPT. Program R22OPT utilized an efficient quasi-Newton optimization algorithm. Multiple design objectives were specified. The delocalization of the shock wave was to be eliminated in forward flight for an advance ratio of 0.41 and a tip Mach number of 0.92 at psi = 90 deg. Simultaneously, it was sought to reduce torque requirements while maintaining effective restoring pitching moments. Only the outer 10 percent of the blade span was modified; the blade area was not to be reduced by more than 3 percent. The goal was to combine the advantages of both sweptback and sweptforward blade tips. A planform that featured inboard sweepback was combined with a sweptforward tip and a taper ratio of 0.5. Initially, the ROT22 code was used to find by trial and error a planform geometry which met the design goals. This configuration had an inboard section with a leading edge sweep of 20 deg and a tip section swept forward at 25 deg; in addition, the airfoils were modified.

  2. Magnetic elements for switching magnetization magnetic force microscopy tips.

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

    Cambel, V.; Elias, P.; Gregusova, D.

    2010-09-01

    Using combination of micromagnetic calculations and magnetic force microscopy (MFM) imaging we find optimal parameters for novel magnetic tips suitable for switching magnetization MFM. Switching magnetization MFM is based on two-pass scanning atomic force microscopy with reversed tip magnetization between the scans. Within the technique the sum of the scanned data with reversed tip magnetization depicts local atomic forces, while their difference maps the local magnetic forces. Here we propose the design and calculate the magnetic properties of tips suitable for this scanning probe technique. We find that for best performance the spin-polarized tips must exhibit low magnetic moment, lowmore » switching fields, and single-domain state at remanence. The switching field of such tips is calculated and optimum shape of the Permalloy elements for the tips is found. We show excellent correspondence between calculated and experimental results for Py elements.« less

  3. Family food talk, child eating behavior, and maternal feeding practices.

    PubMed

    Roach, Elizabeth; Viechnicki, Gail B; Retzloff, Lauren B; Davis-Kean, Pamela; Lumeng, Julie C; Miller, Alison L

    2017-10-01

    Families discuss food and eating in many ways that may shape child eating habits. Researchers studying how families talk about food have examined this process during meals. Little work has examined parent-child food-related interactions outside of mealtime. We assessed family food talk at home outside of mealtime and tested whether food talk was associated with obesogenic child eating behaviors, maternal feeding practices, or child weight. Preschool and school-aged mother-child dyads (n = 61) participated in naturalistic voice recording using a LENA (Language ENvironment Analysis) recorder. A coding scheme was developed to reliably characterize different types of food talk from LENA transcripts. Mothers completed the Children's Eating Behavior Questionnaire (CEBQ) and Child Feeding Questionnaire (CFQ) to assess child eating behaviors and maternal feeding practices. Child weight and height were measured and body mass index z-score (BMIz) calculated. Bivariate associations among food talk types, as a proportion of total speech, were examined and multivariate regression models used to test associations between food talk and child eating behaviors, maternal feeding practices, and child BMIz. Proportion of child Overall Food Talk and Food Explanations were positively associated with CEBQ Food Responsiveness and Enjoyment of Food (p's < 0.05). Child food Desire/Need and child Prep/Planning talk were positively associated with CEBQ Enjoyment of Food (p < 0.05). Child Food Enjoyment talk and mother Overt Restriction talk were positively associated with CEBQ Emotional Over-Eating (p < 0.05). Mother Monitoring talk was positively associated with CFQ Restriction (p < 0.05). Mother Prep/Planning talk was negatively associated with child BMIz. Food talk outside of mealtimes related to child obesogenic eating behaviors and feeding practices in expected ways; examining food talk outside of meals is a novel way to consider feeding practices and child eating behavior

  4. Sensitivities of Greenland ice sheet volume inferred from an ice sheet adjoint model

    NASA Astrophysics Data System (ADS)

    Heimbach, P.; Bugnion, V.

    2009-04-01

    We present a new and original approach to understanding the sensitivity of the Greenland ice sheet to key model parameters and environmental conditions. At the heart of this approach is the use of an adjoint ice sheet model. Since its introduction by MacAyeal (1992), the adjoint method has become widespread to fit ice stream models to the increasing number and diversity of satellite observations, and to estimate uncertain model parameters such as basal conditions. However, no attempt has been made to extend this method to comprehensive ice sheet models. As a first step toward the use of adjoints of comprehensive three-dimensional ice sheet models we have generated an adjoint of the ice sheet model SICOPOLIS of Greve (1997). The adjoint was generated by means of the automatic differentiation (AD) tool TAF. The AD tool generates exact source code representing the tangent linear and adjoint model of the nonlinear parent model provided. Model sensitivities are given by the partial derivatives of a scalar-valued model diagnostic with respect to the controls, and can be efficiently calculated via the adjoint. By way of example, we determine the sensitivity of the total Greenland ice volume to various control variables, such as spatial fields of basal flow parameters, surface and basal forcings, and initial conditions. Reliability of the adjoint was tested through finite-difference perturbation calculations for various control variables and perturbation regions. Besides confirming qualitative aspects of ice sheet sensitivities, such as expected regional variations, we detect regions where model sensitivities are seemingly unexpected or counter-intuitive, albeit ``real'' in the sense of actual model behavior. An example is inferred regions where sensitivities of ice sheet volume to basal sliding coefficient are positive, i.e. where a local increase in basal sliding parameter increases the ice sheet volume. Similarly, positive ice temperature sensitivities in certain parts

  5. Microcomponent sheet architecture

    DOEpatents

    Wegeng, R.S.; Drost, M.K..; McDonald, C.E.

    1997-03-18

    The invention is a microcomponent sheet architecture wherein macroscale unit processes are performed by microscale components. The sheet architecture may be a single laminate with a plurality of separate microcomponent sections or the sheet architecture may be a plurality of laminates with one or more microcomponent sections on each laminate. Each microcomponent or plurality of like microcomponents perform at least one unit operation. A first laminate having a plurality of like first microcomponents is combined with at least a second laminate having a plurality of like second microcomponents thereby combining at least two unit operations to achieve a system operation. 14 figs.

  6. Microcomponent sheet architecture

    DOEpatents

    Wegeng, Robert S.; Drost, M. Kevin; McDonald, Carolyn E.

    1997-01-01

    The invention is a microcomponent sheet architecture wherein macroscale unit processes are performed by microscale components. The sheet architecture may be a single laminate with a plurality of separate microcomponent sections or the sheet architecture may be a plurality of laminates with one or more microcomponent sections on each laminate. Each microcomponent or plurality of like microcomponents perform at least one unit operation. A first laminate having a plurality of like first microcomponents is combined with at least a second laminate having a plurality of like second microcomponents thereby combining at least two unit operations to achieve a system operation.

  7. News: Tripping over tipping points/elements

    EPA Science Inventory

    The term “tipping point” has been used to identify a critical threshold susceptible to a tiny perturbation that can qualitatively alter the state or development of a system. “Tipping element” has been introduced to describe large-scale components of the Earth system that may pass...

  8. Aircraft Sheet Metal Practices; Sheet Metal Work 2: 9855.01.

    ERIC Educational Resources Information Center

    Dade County Public Schools, Miami, FL.

    The course outline will serve as a guide to the 11th grade student interested in sheet metal occupations. Requiring 135 clock hours, the basic course covers orientation and techniques in aircraft sheet metal. Emphasis will be placed on the proper use of tools and machines, safety, fabrication methods, aircraft materials, basic layout, and special…

  9. Health Lines | NIH Medlineplus the Magazine

    MedlinePlus

    ... that question and more in a new monthly series of "Time to Talk" tips. The easy-to-read information ... The monthly tips can be found on the "Time to Talk" web page at ... Researchers from the Framingham Heart Study say a diet low in omega-3 fatty ...

  10. The Emergence of Inclusive Exploratory Talk in Primary Students' Peer Interaction

    ERIC Educational Resources Information Center

    Rajala, Antti; Hilppo, Jaakko; Lipponen, Lasse

    2012-01-01

    In this study, we examine a prominent type of classroom talk, exploratory talk, in primary school peer interactions. Exploratory talk has been shown to be productive in facilitating problem solving and fostering school achievement. However, within the growing body of research concerning exploratory talk, the relation between exploratory talk and…

  11. Quantitation of Cellular Dynamics in Growing Arabidopsis Roots with Light Sheet Microscopy

    PubMed Central

    Birnbaum, Kenneth D.; Leibler, Stanislas

    2011-01-01

    To understand dynamic developmental processes, living tissues have to be imaged frequently and for extended periods of time. Root development is extensively studied at cellular resolution to understand basic mechanisms underlying pattern formation and maintenance in plants. Unfortunately, ensuring continuous specimen access, while preserving physiological conditions and preventing photo-damage, poses major barriers to measurements of cellular dynamics in growing organs such as plant roots. We present a system that integrates optical sectioning through light sheet fluorescence microscopy with hydroponic culture that enables us to image, at cellular resolution, a vertically growing Arabidopsis root every few minutes and for several consecutive days. We describe novel automated routines to track the root tip as it grows, to track cellular nuclei and to identify cell divisions. We demonstrate the system's capabilities by collecting data on divisions and nuclear dynamics. PMID:21731697

  12. Twelve Tips for Effective Electronic Presentation.

    ERIC Educational Resources Information Center

    Crosby, Joy

    1994-01-01

    Offers 12 tips for effective electronic presentation. This article is intended for readers who may be considering using electronic presentation for the first time. Offers reasons for its popularity and occasions when it may be used. The tips offer assistance in the design and presentation of electronic material. (LZ)

  13. "Talk What Others Think You Can't Talk": HIV/AIDS Clubs as Peer Education in Ugandan Schools

    ERIC Educational Resources Information Center

    Norton, Bonny; Mutonyi, Harriet

    2007-01-01

    In this article, we make the case that HIV/AIDS clubs in Ugandan schools provide valuable information to students who may not have easy access to health services. As one club motto suggests, the clubs "talk what others think you can't talk". The innovative peer education methods, which include drama, popular culture and community…

  14. Imaging Electron Motion in a Few Layer MoS2 Device

    NASA Astrophysics Data System (ADS)

    Bhandari, S.; Wang, K.; Watanabe, K.; Taniguchi, T.; Kim, P.; Westervelt, R. M.

    2017-06-01

    Ultrathin sheets of MoS2 are a newly discovered 2D semiconductor that holds great promise for nanoelectronics. Understanding the pattern of current flow will be crucial for developing devices. In this talk, we present images of current flow in MoS2 obtained with a Scanned Probe Microscope (SPM) cooled to 4 K. We previously used this technique to image electron trajectories in GaAs/AlGaAs heterostructures and graphene. The charged SPM tip is held just above the sample surface, creating an image charge inside the device that scatters electrons. By measuring the change in resistance ΔR while the tip is raster scanned above the sample, an image of electron flow is obtained. We present images of electron flow in an MoS2 device patterned into a hall bar geometry. A three-layer MoS2 sheet is encased by two hBN layers, top and bottom, and patterned into a hall-bar with multilayer graphene contacts. An SPM image shows the current flow pattern from the wide contact at the end of the device for a Hall density n = 1.3×1012 cm-2. The SPM tip tends to block flow, increasing the resistance R. The pattern of flow was also imaged for a narrow side contact on the sample. At density n = 5.4×1011 cm-2; the pattern seen in the SPM image is similar to the wide contact. The ability to image electron flow promises to be very useful for the development of ultrathin devices from new 2D materials.

  15. 13. Photograph of sheet 1 (index and title sheet) of ...

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

    13. Photograph of sheet 1 (index and title sheet) of the Indiana State Highway Commission repair plans of 1969 for the Cicott Street Bridge. Photograph of a 24' by 36' print made from microfilm in the archives of the Indiana Department of Transportation in Indianapolis. - Cicott Street Bridge, Spanning Wabash River at State Road 25, Logansport, Cass County, IN

  16. Nonlinear distortion of thin liquid sheets

    NASA Astrophysics Data System (ADS)

    Mehring, Carsten Ralf

    Thin planar, annular and conical liquid sheets or films are analyzed, in a unified manner, by means of a reduced- dimension approach providing governing equations for the nonlinear motion of planar and swirling annular thin inviscid and incompressible liquid sheets in zero gravity and with axial disturbances only. Temporal analyses of periodically disturbed infinite sheets are considered, as well as spatial analyses of semi-infinite sheets modulated at the nozzle exit. Results on planar and swirling annular or conical sheets are presented for a zero density ambient gas. Here, conical sheets are obtained in the nearfield of the nozzle exit by considering sheets or films with swirl in excess of that needed to stabilize the discharging stream in its annular configuration. For nonswirling annular sheets a spatially and/or temporally constant gas-core pressure is assumed. A model extension considering the influence of aerodynamic effects on planar sheets is proposed. For planar and annular sheets, linear analyses of the pure initial- and pure boundary-value problem provide insight into the propagation characteristics of dilational and sinuous waves, the (linear) coupling between both wave modes, the stability limits for the annular configuration, as well as the appearance of particular waves on semi-infinite modulated sheets downstream from the nozzle exit. Nonlinear steady-state solutions for the conical configuration (without modulation) are illustrated. Comparison between nonlinear and linear numerical and linear analytical solutions for temporally or spatially developing sheets provides detailed information on the nonlinear distortion characteristics including nonlinear wave propagation and mode-coupling for all the considered geometric configurations and for a variety of parameter configurations. Sensitivity studies on the influence of Weber number, modulation frequency, annular radius, forcing amplitude and sheet divergence on breakup or collapse length and times

  17. Bed Bug Tips

    EPA Pesticide Factsheets

    How to deal with bed bugs in one printable page. Ten tips include ensuring correct insect identification, reducing clutter, understand integrated pest management, using mattress and box spring encasements, and heat treatment.

  18. Low Vision Tips

    MedlinePlus

    ... this page: https://medlineplus.gov/lowvision.html MedlinePlus: Low Vision Tips We are sorry. MedlinePlus no longer maintains the For Low Vision Users page. You will still find health resources ...

  19. Tip-Based Nanofabrication of Arbitrary Shapes of Graphene Nanoribbons for Device Applications

    PubMed Central

    Estrada, David; Bashir, Rashid; King, William P.

    2015-01-01

    Graphene nanoribbons (GNRs) have promising applications in future nanoelectronics, chemical sensing and electrical interconnects. Although there are quite a few GNR nanofabrication methods reported, a rapid and low-cost fabrication method that is capable of fabricating arbitrary shapes of GNRs with good-quality is still in demand for using GNRs for device applications. In this paper, we present a tip-based nanofabrication method capable of fabricating arbitrary shapes of GNRs. A heated atomic force microscope (AFM) tip deposits polymer nanowires atop a CVD-grown graphene surface. The polymer nanowires serve as an etch mask to define GNRs through one step of oxygen plasma etching similar to a photoresist in conventional photolithography. Various shapes of GNRs with either linear or curvilinear features are demonstrated. The width of the GNR is around 270 nm and is determined by the width of the depositing polymer nanowire, which we estimate can be scaled down 15 nms. We characterize our TBN-fabricated GNRs using Raman spectroscopy and I-V measurements. The measured sheet resistances of our GNRs fall within the range of 1.65 kΩ/□−1 – 2.64 kΩ/□−1, in agreement with previously reported values. Furthermore, we determined the high-field breakdown current density of GNRs to be approximately 2.94×108 A/cm2. This TBN process is seamlessly compatible with existing nanofabrication processes, and is particularly suitable for fabricating GNR based electronic devices including next generation DNA sequencing technologies and beyond silicon field effect transistors. PMID:26257891

  20. Talking about Talk: Reviewing Oracy in English Primary Education

    ERIC Educational Resources Information Center

    Jones, Deborah

    2017-01-01

    This paper provides a review of oracy in primary education (5-11) in England. It discusses the nature of talk, acknowledging it as integral to the learning and teaching process and traces the history and development of the place of oracy within the curriculum. The article provides a critique of related policy initiatives including various…

  1. Fiber-optic laser Doppler turbine tip clearance probe

    NASA Astrophysics Data System (ADS)

    Büttner, Lars; Pfister, Thorsten; Czarske, Jürgen

    2006-05-01

    A laser Doppler based method for in situ single blade tip clearance measurements of turbomachines with high precision is presented for what we believe is the first time. The sensor is based on two superposed fanlike interference fringe systems generated by two laser wavelengths from a fiber-coupled, passive, and therefore compact measurement head employing diffractive optics. Tip clearance measurements at a transonic centrifugal compressor performed during operation at 50,000 rpm (833 Hz, 586 m/s tip speed) are reported. At these speeds the measured uncertainty of the tip position was less than 20 μm, a factor of 2 more accurate than that of capacitive probes. The sensor offers great potential for in situ and online high-precision tip clearance measurements of metallic and nonmetallic turbine blades.

  2. Fiber-optic laser Doppler turbine tip clearance probe.

    PubMed

    Büttner, Lars; Pfister, Thorsten; Czarske, Jürgen

    2006-05-01

    A laser Doppler based method for in situ single blade tip clearance measurements of turbomachines with high precision is presented for what we believe is the first time. The sensor is based on two superposed fanlike interference fringe systems generated by two laser wavelengths from a fiber-coupled, passive, and therefore compact measurement head employing diffractive optics. Tip clearance measurements at a transonic centrifugal compressor performed during operation at 50,000 rpm (833 Hz, 586 m/s tip speed) are reported. At these speeds the measured uncertainty of the tip position was less than 20 microm, a factor of 2 more accurate than that of capacitive probes. The sensor offers great potential for in situ and online high-precision tip clearance measurements of metallic and nonmetallic turbine blades.

  3. Challenging fat talk: An experimental investigation of reactions to body disparaging conversations.

    PubMed

    Ambwani, Suman; Baumgardner, Megan; Guo, Cai; Simms, Lea; Abromowitz, Emily

    2017-12-01

    Although "fat talk" is associated with increased eating disorder risk, the predictors of fat talk engagement and viable alternatives to these pervasive conversations remain unclear. The current experiment examined responses to fat talk versus feminist-oriented challenging fat talk scenarios. Undergraduate women (N=283) completed baseline questionnaires assessing body dissatisfaction, fat talk engagement, and positive impression management. One week later, they were randomized to view one of the two scenarios, followed by assessment of mood, fat talk engagement, social acceptability, and social likeability. Results indicated that the challenging fat talk vignette (versus the fat talk vignette) yielded less negative affect and fat talk and was perceived as more socially attractive with a more likeable target character. Baseline body dissatisfaction, baseline fat talk tendencies, and momentary negative affect predicted post-exposure fat talk engagement. Current findings highlight possibilities for implementing feminist language and psychoeducation in fat talk prevention efforts. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Time-of-Flight Tip-Clearance Measurements

    NASA Technical Reports Server (NTRS)

    Dhadwal, H. S.; Kurkov, A. P.; Janetzke, D. C.

    1999-01-01

    In this paper a time-of-flight probe system incorporating the two integrated fiber optic probes which are tilted equally relative to the probe holder centerline, is applied for the first time to measure the tip clearance of an advanced fan prototype. Tip clearance is largely independent of the signal amplitude and it relies on timing measurement. This work exposes optical effects associated with the fan blade stagger angle that were absent during the original spin-rig experiment on the zero stagger rotor. Individual blade tip clearances were measured with accuracy of +/- 127-mm (+/- 0.005-in). Probe features are discussed and improvements to the design are suggested.

  5. Aerospace Medicine Talk

    NASA Technical Reports Server (NTRS)

    Williams, Richard S.

    2015-01-01

    The presentation is next Sunday, May 10th. It will be to the Civil Aviation Medical Association, for 2 hours at Disney World in Orlando. It is a high level talk on space medicine, including history, the role of my office, human health risks of space flight, general aspects of space medicine practice, human health risk management (including integrated activities of medical operations and the Human Research Program, and thoughts concerning health risks for long duration exploration class space missions. No proprietary data or material will be used, all is readily available in the public sector. There is also a short (30 min) talk on Monday at the CAMA lunch. There we will describe the Visual Impairment and Intracranial Pressure syndrome, with possible etiologies and plans for research (already selected studies). Again, nothing proprietary will be discussed.

  6. Tips for Reducing Pesticide Impacts on Wildlife

    EPA Pesticide Factsheets

    This Web page provides tips for pesticide users in residential and agricultural settings, as well as tips for certified pesticide applicators for ways to protect wildlife from potentially harmful effects of pesticides.

  7. Ten Fire Safety Tips for Schools.

    ERIC Educational Resources Information Center

    Lake, James D.

    1999-01-01

    Provides 10 basic tips, compiled from the National Fire Protection Association's Life Safety Code 101, to ensure that educational facilities are fire safe. Tips include use of frequent and unexpected fire drills, limiting wall space of student artwork and teaching materials, being alert to preventing arson, planning speedy and safe emergency…

  8. Talking about Poetry--Using the Model of Language in Systemic Functional Linguistics to Talk about Poetic Texts

    ERIC Educational Resources Information Center

    Huisman, Rosemary

    2016-01-01

    Poetry is the art shaped through language; to talk about a poem we need at least to talk about its language--but what can be said will depend on the particular linguistic theory, with its particular modelling of language, which we bring to the description. This paper outlines the approach of SFL (Systemic Functional Linguistics), describing in…

  9. The influence of tip shape on bending force during needle insertion

    PubMed Central

    van de Berg, Nick J.; de Jong, Tonke L.; van Gerwen, Dennis J.; Dankelman, Jenny; van den Dobbelsteen, John J.

    2017-01-01

    Steering of needles involves the planning and timely modifying of instrument-tissue force interactions to allow for controlled deflections during the insertion in tissue. In this work, the effect of tip shape on these forces was studied using 10 mm diameter needle tips. Six different tips were selected, including beveled and conical versions, with or without pre-bend or pre-curve. A six-degree-of-freedom force/torque sensor measured the loads during indentations in tissue simulants. The increased insertion (axial) and bending (radial) forces with insertion depth — the force-displacement slopes — were analyzed. Results showed that the ratio between radial and axial forces was not always proportional. This means that the tip load does not have a constant orientation, as is often assumed in mechanics-based steering models. For all tip types, the tip-load assumed a more radial orientation with increased axial load. This effect was larger for straight tips than for pre-bent or pre-curved tips. In addition, the force-displacement slopes were consistently higher for (1) increased tip angles, and for (2) beveled tips compared to conical tips. Needles with a bent or curved tip allow for an increased bending force and a decreased variability of the tip load vector orientation. PMID:28074939

  10. Nasal tip support: A finite element analysis of the role of the caudal septum during tip depression

    PubMed Central

    Manuel, Cyrus T.; Leary, Ryan; Protsenko, Dmitriy E.; Wong, Brian J.F.

    2014-01-01

    Objective/Hypothesis Although minor and major tip support mechanisms have been described in detail, no quantitative models exist to provide support for the relative contributions of the structural properties of the major alar cartilage, the fibrous attachments to surrounding structures, and the rigid support structures in an objective manner. Study Design The finite element method was used to compute the stress distribution in the nose during simple tip compression, and then identify the specific anatomic structures that resist deformation and thus contribute to “tip support”. Additionally, the impact of caudal septal resection on nasal tip support was examined. Method The computer models consisted of three tissue components with anatomically correct geometries for skin and bone derived from CT data. Septum, upper lateral cartilages, and major alar cartilages were fitted within the model using 3D CAD software. 5mm nasal tip compression was performed on the models with caudal septal resection (3mm and 5 mm) and without resection to simulate palpation, then the resulting spatial distribution of stress and displacement was calculated. Results The von Mises stress in the normal model was primarily concentrated along medial crural angle. As caudal septum length was reduced, stress was redistributed to adjacent soft tissue and bone, resulting in less force acting on the septum. In all models, displacement was greatest near the intermediate crura. Conclusions These models are the first step in the comprehensive mechanical analysis of nasal tip dynamics. Our model supports the concept of the caudal septum and major alar cartilage as providing the majority of critical load-bearing support. Level of Evidence N/A PMID:23878007

  11. 9. Photograph of sheet 1 (index and title sheet) of ...

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

    9. Photograph of sheet 1 (index and title sheet) of the State Highway Department of Indiana repair plans of 1957 for the Cicott Street Bridge. Photograph of a 24' by 36' print made from microfilm in the archives of the Indiana Department of Transportation in Indianapolis. - Cicott Street Bridge, Spanning Wabash River at State Road 25, Logansport, Cass County, IN

  12. FDTD modeling of thin impedance sheets

    NASA Technical Reports Server (NTRS)

    Luebbers, Raymond J.; Kunz, Karl S.

    1991-01-01

    Thin sheets of resistive or dielectric material are commonly encountered in radar cross section calculations. Analysis of such sheets is simplified by using sheet impedances. In this paper it is shown that sheet impedances can be modeled easily and accurately using Finite Difference Time Domain (FDTD) methods.

  13. Invited Review Article: Tip modification methods for tip-enhanced Raman spectroscopy (TERS) and colloidal probe technique: A 10 year update (2006-2016) review

    NASA Astrophysics Data System (ADS)

    Yuan, C. C.; Zhang, D.; Gan, Y.

    2017-03-01

    Engineering atomic force microscopy tips for reliable tip enhanced Raman spectroscopy (TERS) and colloidal probe technique are becoming routine practices in many labs. In this 10 year update review, various new tip modification methods developed over the past decade are briefly reviewed to help researchers select the appropriate method. The perspective is put in a large context to discuss the opportunities and challenges in this area, including novel combinations of seemingly different methods, potential applications of some methods which were not originally intended for TERS tip fabrication, and the problems of high cost and poor reproducibility of tip fabrication.

  14. Propeller noise caused by blade tip radial forces

    NASA Technical Reports Server (NTRS)

    Hanson, D. B.

    1986-01-01

    New experimental evidence which indicates the presence of leading edge and tip edge vortex flow on Prop-Fans is examined, and performance and noise consequences are addressed. It was shown that the tip edge vortex is a significant noise source, particularly for unswept Prop-Fan blades. Preliminary calculations revealed that the addition of the tip side edge source to single rotation Prop-Fans during take off conditions improved the agreement between experiment and theory at blade passing frequency. At high-speed conditions such as the Prop-Fan cruise point, the tip loading effect tends to cancel thickness noise.

  15. BRITICE-CHRONO and GLANAM: new exciting developments in the study of circum-North Atlantic ice sheets

    NASA Astrophysics Data System (ADS)

    Benetti, Sara; Clark, Chris D.; Petter Serjup, Hans

    2013-04-01

    This talk will present two newly funded projects on the reconstruction of former marine-based ice sheets bordering the North Atlantic Ocean and their effects on the surrounding continental margins. The NERC-funded BRITICE-CHRONO started in October 2012 and its consortium involves scientists from all over the UK with partners in Ireland, Canada and Norway. It aims to carry out a systematic campaign to collect and date material to constrain the timing and rates of change of the collapse of the former British-Irish Ice Sheet. This will be achieved by focussing on eight transects running from the shelf edge to a short distance onshore and acquiring marine and terrestrial samples for geochronometric dating. The sampling will be accomplished by two research cruises and eight fieldwork campaigns around UK and Ireland. The project will result in the world's best empirical reconstruction of a shrinking ice sheet, for use in improving ice sheet models, and to provide the long term context against which contemporary observations can be assessed. The FP7-funded Marie Curie Initial Training Networks GLANAM (Glaciated North Atlantic Margins) will start in April 2013 and aims at improving the career prospects and development of young researchers in both the public and private sector within the field of earth science, focusing specifically on North Atlantic glaciated margins. The training network comprises ten partner institutions, both academic and industrial, from Norway, UK and Denmark and will train eleven PhD and four postdoctoral researchers. The young scientists will perform multi-disciplinary research and receive training through three interconnected workpackages that collectively address knowledge gaps related to the glacial sedimentary depocentres on the North Atlantic margins. Filling these gaps will not only result in major new insights regarding glacial processes on continental margins in general, but critically will have particular impact on the exploitation of

  16. Characterization of the interaction between AFM tips and surface nanobubbles.

    PubMed

    Walczyk, Wiktoria; Schönherr, Holger

    2014-06-24

    While the presence of gaseous enclosures observed at various solid-water interfaces, the so-called "surface nanobubles", has been confirmed by many groups in recent years, their formation, properties, and stability have not been convincingly and exhaustively explained. Here we report on an atomic force microscopy (AFM) study of argon nanobubbles on highly oriented pyrolitic graphite (HOPG) in water to elucidate the properties of nanobubble surfaces and the mechanism of AFM tip-nanobubble interaction. In particular, the deformation of the nanobubble-water interface by the AFM tip and the question whether the AFM tip penetrates the nanobubble during scanning were addressed by this combined intermittent contact (tapping) mode and force volume AFM study. We found that the stiffness of nanobubbles was smaller than the cantilever spring constant and comparable with the surface tension of water. The interaction with the AFM tip resulted in severe quasi-linear deformation of the bubbles; however, in the case of tip-bubble attraction, the interface deformed toward the tip. We tested two models of tip-bubble interaction, namely, the capillary force and the dynamic interaction model, and found, depending on the tip properties, good agreement with experimental data. The results showed that the tip-bubble interaction strength and the magnitude of the bubble deformation depend strongly on tip and bubble geometry and on tip and substrate material, and are very sensitive to the presence of contaminations that alter the interfacial tension. In particular, nanobubbles interacted differently with hydrophilic and hydrophobic AFM tips, which resulted in qualitatively and quantitatively different force curves measured on the bubbles in the experiments. To minimize bubble deformation and obtain reliable AFM results, nanobubbles must be measured with a sharp hydrophilic tip and with a cantilever having a very low spring constant in a contamination-free system.

  17. Predicting casualties implied by TIPs

    NASA Astrophysics Data System (ADS)

    Trendafiloski, G.; Wyss, M.; Wyss, B. M.

    2009-12-01

    When an earthquake is predicted, forecast, or expected with a higher than normal probability, losses are implied. We estimated the casualties (fatalities plus injured) that should be expected if earthquakes in TIPs (locations of Temporarily Increased Probability of earthquakes) defined by Kossobokov et al. (2009) should occur. We classified the predictions of losses into the categories red (more than 400 fatalities or more than 1,000 injured), yellow (between 100 and 400 fatalities), green (fewer than 100 fatalities), and gray (undetermined). TIPs in Central Chile, the Philippines, Papua, and Taiwan are in the red class, TIPs in Southern Sumatra, Nicaragua, Vanatu, and Honshu in the yellow class, and TIPs in Tonga, Loyalty Islands, Vanatu, S. Sandwich Islands, Banda Sea, and the Kuriles, are classified as green. TIPs where the losses depend moderately on the assumed point of major energy release were classified as yellow; TIPs such as in the Talaud Islands and in Tonga, where the losses depend very strongly on the location of the epicenter, were classified as gray. The accuracy of loss estimates after earthquakes with known hypocenter and magnitude are affected by uncertainties in transmission and soil properties, the composition of the building stock, the population present, and the method by which the numbers of casualties are calculated. In the case of TIPs, uncertainties in magnitude and location are added, thus we calculate losses for a range of these two parameters. Therefore, our calculations can only be considered order of magnitude estimates. Nevertheless, our predictions can come to within a factor of two of the observed numbers, as in the case of the M7.6 earthquake of October 2005 in Pakistan that resulted in 85,000 fatalities (Wyss, 2005). In subduction zones, the geometrical relationship between the earthquake source capable of a great earthquake and the population is clear because there is only one major fault plane available, thus the epicentral

  18. On the development of a magnetoresistive sensor for blade tip timing and blade tip clearance measurement systems.

    PubMed

    Tomassini, R; Rossi, G; Brouckaert, J-F

    2016-10-01

    A simultaneous blade tip timing (BTT) and blade tip clearance (BTC) measurement system enables the determination of turbomachinery blade vibrations and ensures the monitoring of the existing running gaps between the blade tip and the casing. This contactless instrumentation presents several advantages compared to the well-known telemetry system with strain gauges, at the cost of a more complex data processing procedure. The probes used can be optical, capacitive, eddy current as well as microwaves, everyone with its dedicated electronics and many existing different signal processing algorithms. Every company working in this field has developed its own processing method and sensor technology. Hence, repeating the same test with different instrumentations, the answer is often different. Moreover, rarely it is possible to achieve reliability for in-service measurements. Developments are focused on innovative instrumentations and a common standard. This paper focuses on the results achieved using a novel magnetoresistive sensor for simultaneous tip timing and tip clearance measurements. The sensor measurement principle is described. The sensitivity to gap variation is investigated. In terms of measurement of vibrations, experimental investigations were performed at the Air Force Institute of Technology (ITWL, Warsaw, Poland) in a real aeroengine and in the von Karman Institute (VKI) R2 compressor rig. The advantages and limitations of the magnetoresistive probe for turbomachinery testing are highlighted.

  19. On the development of a magnetoresistive sensor for blade tip timing and blade tip clearance measurement systems

    NASA Astrophysics Data System (ADS)

    Tomassini, R.; Rossi, G.; Brouckaert, J.-F.

    2016-10-01

    A simultaneous blade tip timing (BTT) and blade tip clearance (BTC) measurement system enables the determination of turbomachinery blade vibrations and ensures the monitoring of the existing running gaps between the blade tip and the casing. This contactless instrumentation presents several advantages compared to the well-known telemetry system with strain gauges, at the cost of a more complex data processing procedure. The probes used can be optical, capacitive, eddy current as well as microwaves, everyone with its dedicated electronics and many existing different signal processing algorithms. Every company working in this field has developed its own processing method and sensor technology. Hence, repeating the same test with different instrumentations, the answer is often different. Moreover, rarely it is possible to achieve reliability for in-service measurements. Developments are focused on innovative instrumentations and a common standard. This paper focuses on the results achieved using a novel magnetoresistive sensor for simultaneous tip timing and tip clearance measurements. The sensor measurement principle is described. The sensitivity to gap variation is investigated. In terms of measurement of vibrations, experimental investigations were performed at the Air Force Institute of Technology (ITWL, Warsaw, Poland) in a real aeroengine and in the von Karman Institute (VKI) R2 compressor rig. The advantages and limitations of the magnetoresistive probe for turbomachinery testing are highlighted.

  20. Parametric analysis of swept-wing geometry with sheared wing tips

    NASA Technical Reports Server (NTRS)

    Fremaux, C. M.; Vijgen, P. M. H. W.; Van Dam, C. P.

    1990-01-01

    A computational parameter study is presented of potential reductions in induced drag and increases in lateral-directional stability due to sheared wing tips attached to an untwisted wing of moderate sweep and aspect ratio. Sheared tips are swept and tapered wing-tip devices mounted in the plane of the wing. The induced-drag results are obtained using an inviscid, incompressible surface-panel method that models the nonlinear effects due to the deflected and rolled-up wake behind the lifting surface. The induced-drag results with planar sheared tips are compared to straight-tapered tip extensions and nonplanar winglet geometries. The lateral-directional static-stability characteristics of the wing with sheared tips are estimated using a quasi-vortex-lattice method. For certain combinations of sheared-tip sweep and taper, both the induced efficiency of the wing and the relevant static-stability derivatives are predicted to increase compared to the wing with a straight-tapered tip modification.

  1. Diabetes: Dental Tips

    MedlinePlus

    Diabetes: Dental Tips For more copies contact: National Institute of Dental and Craniofacial Research National Oral Health Information Clearinghouse ... damage the gum and bone that hold your teeth in place and may lead to painful chewing ...

  2. Small Talk: A Big Communicative Function in the Organization?

    ERIC Educational Resources Information Center

    Levine, Deborah Clark

    Defining small talk as "superficial talk about matters of little concern," a study examined the role of small talk in the work place. Subjects, 51 white collar workers and clerical employees at three corporations, an Eastern state university, and two small businesses completed a questionnaire concerning the following questions: (1) What…

  3. Root tips moving through soil

    PubMed Central

    Curlango-Rivera, Gilberto

    2011-01-01

    Root elongation occurs by the generation of new cells from meristematic tissue within the apical 1–2 mm region of root tips. Therefore penetration of the soil environment is carried out by newly synthesized plant tissue, whose cells are inherently vulnerable to invasion by pathogens. This conundrum, on its face, would seem to reflect an intolerable risk to the successful establishment of root systems needed for plant life. Yet root tip regions housing the meristematic tissues repeatedly have been found to be free of microbial infection and colonization. Even when spore germination, chemotaxis, and/or growth of pathogens are stimulated by signals from the root tip, the underlying root tissue can escape invasion. Recent insights into the functions of root border cells, and the regulation of their production by transient exposure to external signals, may shed light on long-standing observations. PMID:21455030

  4. Methamphetamine

    MedlinePlus

    ... OPERATIONS Diversion Control Programs Most Wanted Fugitives Training Intelligence Submit a Tip DRUG INFO Drug Fact Sheets ... Operations Diversion Control Programs Most Wanted Fugitives Training Intelligence Submit a Tip Drug Info Drug Fact Sheets ...

  5. Narcotics

    MedlinePlus

    ... OPERATIONS Diversion Control Programs Most Wanted Fugitives Training Intelligence Submit a Tip DRUG INFO Drug Fact Sheets ... Operations Diversion Control Programs Most Wanted Fugitives Training Intelligence Submit a Tip Drug Info Drug Fact Sheets ...

  6. Methamphetamine Lab Incidents, 2004-2014

    MedlinePlus

    ... OPERATIONS Diversion Control Programs Most Wanted Fugitives Training Intelligence Submit a Tip DRUG INFO Drug Fact Sheets ... Operations Diversion Control Programs Most Wanted Fugitives Training Intelligence Submit a Tip Drug Info Drug Fact Sheets ...

  7. Hydrocodone

    MedlinePlus

    ... OPERATIONS Diversion Control Programs Most Wanted Fugitives Training Intelligence Submit a Tip DRUG INFO Drug Fact Sheets ... Operations Diversion Control Programs Most Wanted Fugitives Training Intelligence Submit a Tip Drug Info Drug Fact Sheets ...

  8. Heroin Photos

    MedlinePlus

    ... OPERATIONS Diversion Control Programs Most Wanted Fugitives Training Intelligence Submit a Tip DRUG INFO Drug Fact Sheets ... Operations Diversion Control Programs Most Wanted Fugitives Training Intelligence Submit a Tip Drug Info Drug Fact Sheets ...

  9. Crack growth through the thickness of thin-sheet Hydrided Zircaloy-4

    NASA Astrophysics Data System (ADS)

    Raynaud, Patrick A. C.

    In recent years, the limits on fuel burnup have been increased to allow an increase in the amount of energy produced by a nuclear fuel assembly thus reducing waste volume and allowing greater capacity factors. As a result, it is paramount to ensure safety after longer reactor exposure times in the case of design-basis accidents, such as reactivity-initiated accidents (RIA). Previously proposed failure criteria do not directly address the particular cladding failure mechanism during a RIA, in which crack initiation in brittle outer-layers is immediately followed by crack growth through the thickness of the thin-wall tubing. In such a case, the fracture toughness of hydrided thin-wall cladding material must be known for the conditions of through-thickness crack growth in order to predict the failure of high-burnup cladding. The fracture toughness of hydrided Zircaloy-4 in the form of thin-sheet has been examined for the condition of through-thickness crack growth as a function of hydride content and distribution at 25°C, 300°C, and 375°C. To achieve this goal, an experimental procedure was developed in which a linear hydride blister formed across the width of a four-point bend specimen was used to inject a sharp crack that was subsequently extended by fatigue pre-cracking. The electrical potential drop method was used to monitor the crack length during fracture toughness testing, thus allowing for correlation of the load-displacement record with the crack length. Elastic-plastic fracture mechanics were used to interpret the experimental test results in terms of fracture toughness, and J-R crack growth resistance curves were generated. Finite element modeling was performed to adapt the classic theories of fracture mechanics applicable to thick-plate specimens to the case of through-thickness crack growth in thin-sheet materials, and to account for non-uniform crack fronts. Finally, the hydride microstructure was characterized in the vicinity of the crack tip by

  10. Horizontal electromagnetic casting of thin metal sheets

    DOEpatents

    Hull, John R.; Lari, Robert J.; Praeg, Walter F.; Turner, Larry R.

    1987-01-01

    Thin metal sheets are cast by magnetically suspending molten metal deposited within a ferromagnetic yoke and between AC conducting coils and linearly displacing the magnetically levitated liquid metal while it is being cooled to form a solid metal sheet. Magnetic flux increases as the molten metal sheet moves downward and decreases as the molten metal sheet moves upward to stabilize the sheet and maintain it in equilibrium as it is linearly displaced and solidified by cooling gases. A conducting shield is electrically coupled to the molten metal sheet by means of either metal sheet engaging rollers or brushes on the solidified metal, and by means of an electrode in the vessel containing the molten metal thereby providing a return path for the eddy currents induced in the metal sheet by the AC coil generated magnetic flux. Variation in the geometry of the conducting shield allows the magnetic flux between the metal sheet and the conducting shield to be varied and the thickness in surface quality of the metal sheet to be controlled. Side guards provide lateral containment for the molten metal sheet and stabilize and shape the magnetic field while a leader sheet having electromagnetic characteristics similar to those of the metal sheet is used to start the casting process and precedes the molten metal sheet through the magnet and forms a continuous sheet therewith. The magnet may be either U-shaped with a single racetrack coil or may be rectangular with a pair of facing bedstead coils.

  11. Horizontal electromagnetic casting of thin metal sheets

    DOEpatents

    Hull, John R.; Lari, Robert J.; Praeg, Walter F.; Turner, Larry R.

    1988-01-01

    Thin metal sheets are cast by magnetically suspending molten metal deposited within a ferromagnetic yoke and between AC conducting coils and linearly displacing the magnetically levitated liquid metal while it is being cooled to form a solid metal sheet. Magnetic flux increases as the molten metal sheet moves downward and decreases as the molten metal sheet moves upward to stabilize the sheet and maintain it in equilibrium as it is linearly displaced and solidified by cooling gases. A conducting shield is electrically coupled to the molten metal sheet by means of either metal sheet engaging rollers or brushes on the solidified metal, and by means of an electrode in the vessel containing the molten metal thereby providing a return path for the eddy currents induced in the metal sheet by the AC coil generated magnetic flux. Variation in the geometry of the conducting shield allows the magnetic flux between the metal sheet and the conducting shield to be varied and the thickness in surface quality of the metal sheet to be controlled. Side guards provide lateral containment for the molten metal sheet and stabilize and shape the magnetic field while a leader sheet having electromagnetic characteristics similar to those of the metal sheet is used to start the casting process and precedes the molten metal sheet through the magnet and forms a continuous sheet therewith. The magnet may be either U-shaped with a single racetrack coil or may be rectangular with a pair of facing bedstead coils.

  12. Regulation of Histone Acetyltransferase TIP60 Function by Histone Deacetylase 3

    PubMed Central

    Yi, Jingjie; Huang, Xiangyang; Yang, Yuxia; Zhu, Wei-Guo; Gu, Wei; Luo, Jianyuan

    2014-01-01

    The key member of the MOZ (monocyticleukaemia zinc finger protein), Ybf2/Sas3, Sas2, and TIP60 acetyltransferases family, Tat-interactive protein, 60 kD (TIP60), tightly modulates a wide array of cellular processes, including chromatin remodeling, gene transcription, apoptosis, DNA repair, and cell cycle arrest. The function of TIP60 can be regulated by SIRT1 through deacetylation. Here we found that TIP60 can also be functionally regulated by HDAC3. We identified six lysine residues as its autoacetylation sites. Mutagenesis of these lysines to arginines completely abolishes the autoacetylation of TIP60. Overexpression of HDAC3 increases TIP60 ubiquitination levels. However, unlike SIRT1, HDAC3 increased the half-life of TIP60. Further study found that HDAC3 colocalized with TIP60 both in the nucleus and the cytoplasm, which could be the reason why HDAC3 can stabilize TIP60. The deacetylation of TIP60 by both SIRT1 and HDAC3 reduces apoptosis induced by DNA damage. Knockdown of HDAC3 in cells increased TIP60 acetylation levels and increased apoptosis after DNA damage. Together, our findings provide a better understanding of TIP60 regulation mechanisms, which is a significant basis for further studies of its cellular functions. PMID:25301942

  13. Turbine-blade tip clearance and tip timing measurements using an optical fiber bundle sensor

    NASA Astrophysics Data System (ADS)

    Garcia, Iker; Beloki, Josu; Zubia, Joseba; Durana, Gaizka; Aldabaldetreku, Gotzon

    2013-04-01

    Traditional limitations of capacitive, inductive or discharging probe sensor for tip timing and tip clearance measurements are overcome by reflective intensity modulated optical fiber sensors. This paper presents the signals and results corresponding to a one stage turbine rig which rotor has 146 blades, obtained from a transonic wind-tunnel test. The probe is based on a trifurcated bundle of optical fibers that is mounted on turbine casing. It is composed of a central illuminating fiber that guides the light from a laser to the turbine blade, and two concentric rings of receiving fibers that collect the reflected light. Two photodetectors turn this reflected light signal from the receiving rings into voltage. The electrical signals are acquired and saved by a high-sample-rate oscilloscope. In tip clearance calculations the ratio of the signals provided by each ring of receiving fibers is evaluated and translated into distance. In the case of tip timing measurements, only one of the signals is considered to get the arrival time of the blade. The differences between the real and theoretical arrival times of the blades are used to obtain the deflections amplitude. The system provides the travelling wave spectrum, which presents the average vibration amplitude of the blades at a certain nodal diameter. The reliability of the results in the turbine rig testing facilities suggests the possibility of performing these measurements in real turbines under real working conditions.

  14. Frequency and Efficacy of Talk-Related Tasks in Primary Science

    NASA Astrophysics Data System (ADS)

    Braund, Martin; Leigh, Joanne

    2013-04-01

    Pupil talk and discussion are seen as having important social and cognitive outcomes. In science classes, pupils' collaborative talk supports the construction of meaning and helps examine the status of evidence, theory and knowledge. However, pupil interactive talk in groups is rare in science lessons. The research reported is part of a project to increase the amount of pupil-pupil talk in primary schools through a programme of teaching and professional development. Pupils' self-reports of the frequency and learning efficacies of talk related activities in science lessons were collected before and after a programme of teaching in 24 schools in one of the most socially and educationally deprived areas of England. Findings showed pupils valued talking about their ideas over listening to those of other pupils. Science talk frequency (STF) was closely correlated with science talk efficacy (STE) and both were positively correlated with pupils' attitudes to school science. Analysis of covariance (ANCOVA) of the correlation of STF with STE showed values were independent of gender and ability but that school experience was a significant factor. After the teaching programme and, contrary to expectations, the frequency of talk activities in science lessons appeared to have decreased but varied according to class grades. The degree of correlation between STF and STE was stronger after the teaching in over half of the schools. Schools where STF/STE strengthened most as a result of teaching were those involved in an additional initiative to use modelled talk related to industrial contexts.

  15. Investigation of the magnetic properties of Si-gradient steel sheet by comparison with 6.5%Si steel sheet

    NASA Astrophysics Data System (ADS)

    Hiratani, T.; Zaizen, Y.; Oda, Y.; Yoshizaki, S.; Senda, K.

    2018-05-01

    In this study, we investigated the magnetic properties of Si-gradient steel sheet produced by CVD (chemical vapor deposition) siliconizing process, comparing with 6.5% Si steel sheet. The Si-gradient steel sheet having silicon concentration gradient in the thickness direction, has larger hysteresis loss and smaller eddy current loss than the 6.5% Si steel sheet. In such a loss configuration, the iron loss of the Si-gradient steel sheet becomes lower than that of the 6.5% Si steel sheet at high frequencies. The experiment suggests that tensile stress is formed at the surface layer and compressive stress is formed at the inner layer in the Si gradient steel sheet. The magnetic anisotropy is induced by the internal stress and it is considered to affect the magnetization behavior of the Si-gradient steel sheet. The small eddy current loss of Si-gradient steel sheet can be explained as an effect of magnetic flux concentration on the surface layer.

  16. Prediction of Unshsrouded Rotor Blade Tip Heat Transfer

    NASA Technical Reports Server (NTRS)

    Ameri, A. A.; Steinthorsson, E.

    1994-01-01

    The rate of heat transfer on the tip of a turbine rotor blade and on the blade surface in the vicinity of the tip, was successfully predicted. The computations were performed with a multiblock computer code which solves the Reynolds Averaged Navier-Stokes equations using an efficient multigrid method. The case considered for the present calculations was the Space Shuttle Main Engine (SSME) high pressure fuel side turbine. The predictions of the blade tip heat transfer agreed reasonably well with the experimental measurements using the present level of grid refinement. On the tip surface, regions with high rate of heat transfer was found to exist close to the pressure side and suction side edges. Enhancement of the heat transfer was also observed on the blade surface near the tip. Further comparison of the predictions was performed with results obtained from correlations based on fully developed channel flow.

  17. Numerical analysis of turbine blade tip treatments

    NASA Technical Reports Server (NTRS)

    Gopalaswamy, Nath S.; Whitaker, Kevin W.

    1992-01-01

    Three-dimensional solutions of the Navier-Stokes equations for a turbine blade with a turning angle of 180 degrees have been computed, including blade tip treatments involving cavities. The geometry approximates a preliminary design for the GGOT (Generic Gas Oxidizer Turbine). The data presented here will be compared with experimental data to be obtained from a linear cascade using original GGOT blades. Results have been computed for a blade with 1 percent clearance, based on chord, and three different cavity sizes. All tests were conducted at a Reynolds number of 4 x 10 exp 7. The grid contains 39,440 points with 10 spanwise planes in the tip clearance region of 5.008E-04 m. Streamline plots and velocity vectors together with velocity divergence plots reveal the general flow behavior in the clearance region. Blade tip temperature calculations suggest placement of a cavity close to the upstream side of the blade tip for reduction of overall blade tip temperature. The solutions do not account for the relative motion between the endwall and the turbine blade. The solutions obtained are generally consistent with previous work done in this area,

  18. Wave-induced drift of large floating sheets

    NASA Astrophysics Data System (ADS)

    Christensen, K. H.; Weber, J. E.

    In this article we study the wave-induced drift of large, flexible shallow floating objects, referred to as sheets. When surface waves propagate through a sheet, they provide a mean stress on the sheet, resulting in a mean drift. In response, the sheet generates an Ekman current. The drift velocity of the sheet is determined by (i) the wave-induced stress, (ii) the viscous stress due to the Ekman current, and (iii) the Coriolis force. The sheet velocity and the current beneath the sheet are determined for constant and depth-varying eddy viscosities.

  19. Relocalization of human chromatin remodeling cofactor TIP48 in mitosis

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

    Sigala, Barbara; Edwards, Mina; Puri, Teena

    2005-11-01

    TIP48 is a highly conserved eukaryotic AAA{sup +} protein which is an essential cofactor for several complexes involved in chromatin acetylation and remodeling, transcriptional and developmental regulation and nucleolar organization and trafficking. We show that TIP48 abundance in HeLa cells did not change during the cell cycle, nor did its distribution in various biochemical fractions. However, we observed distinct changes in the subcellular localization of TIP48 during M phase using immunofluorescence microscopy. Our studies demonstrate that in interphase cells TIP48 was found mainly in the nucleus and exhibited a distinct localization in the nuclear periphery. As the cells entered mitosis,more » TIP48 was excluded from the condensing chromosomes but showed association with the mitotic apparatus. During anaphase, some TIP48 was detected in the centrosome colocalizing with tubulin but the strongest staining appeared in the mitotic equator associated with the midzone central spindle. Accumulation of TIP48 in the midzone and the midbody was observed in late telophase and cytokinesis. This redeployment of TIP48 during anaphase and cytokinesis was independent of microtubule assembly. The relocation of endogenous TIP48 to the midzone/midbody under physiological conditions suggests a novel and distinct function for TIP48 in mitosis and possible involvement in the exit of mitosis.« less

  20. Method of cooling gas only nozzle fuel tip

    DOEpatents

    Bechtel, William Theodore; Fitts, David Orus; DeLeonardo, Guy Wayne

    2002-01-01

    A diffusion flame nozzle gas tip is provided to convert a dual fuel nozzle to a gas only nozzle. The nozle tip diverts compressor discharge air from the passage feeding the diffusion nozzle air swirl vanes to a region vacated by removal of the dual fuel components, so that the diverted compressor discharge air can flow to and through effusion holes in the end cap plate of the nozzle tip. In a preferred embodiment, the nozzle gas tip defines a cavity for receiving the compressor discharge air from a peripheral passage of the nozzle for flow through the effusion openings defined in the end cap plate.

  1. A review of turbine blade tip heat transfer.

    PubMed

    Bunker, R S

    2001-05-01

    This paper presents a review of the publicly available knowledge base concerning turbine blade tip heat transfer, from the early fundamental research which laid the foundations of our knowledge, to current experimental and numerical studies utilizing engine-scaled blade cascades and turbine rigs. Focus is placed on high-pressure, high-temperature axial-turbine blade tips, which are prevalent in the majority of today's aircraft engines and power generating turbines. The state of our current understanding of turbine blade tip heat transfer is in the transitional phase between fundamentals supported by engine-based experience, and the ability to a priori correctly predict and efficiently design blade tips for engine service.

  2. Wind-tunnel test of an articulated helicopter rotor model with several tip shapes

    NASA Technical Reports Server (NTRS)

    Berry, J. D.; Mineck, R. E.

    1980-01-01

    Six interchangeable tip shapes were tested: a square (baseline) tip, an ogee tip, a subwing tip, a swept tip, a winglet tip, and a short ogee tip. In hover at the lower rotational speeds the swept, ogee, and short ogee tips had about the same torque coefficient, and the subwing and winglet tips had a larger torque coefficient than the baseline square tip blades. The ogee and swept tip blades required less torque coefficient at lower rotational speeds and roughly equivalent torque coefficient at higher rotational speeds compared with the baseline square tip blades in forward flight. The short ogee tip required higher torque coefficient at higher lift coefficients than the baseline square tip blade in the forward flight test condition.

  3. User's manual for PEPSIG NASA tip vortex version

    NASA Technical Reports Server (NTRS)

    Tsai, Tommy M.; Dejong, Frederick J.; Levy, Ralph

    1988-01-01

    The tip vortex flowfield plays a significant role in the performance of advanced aircraft propellers. The flowfield in the tip region is complex, three-dimensional and viscous with large secondary velocities. A computer code was developed to predict the tip vortex flowfield of advanced aircraft propellers. This document is the user's manual. The analysis and a series of test cases are presented in NASA-CR-182179.

  4. Tip-enhanced Raman spectroscopy of lipid bilayers in water with an alumina- and silver-coated tungsten tip.

    PubMed

    Nakata, Atsushi; Nomoto, Tomonori; Toyota, Taro; Fujinami, Masanori

    2013-01-01

    Tip-enhanced Raman spectroscopy (TERS) of supported phospholipid bilayers in an aqueous environment is discussed in this paper. Two bilayer membranes were examined: 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) and 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC). We fabricated alumina- and silver-coated tungsten tips that are very robust in water. There was a large time-dependence in the TERS spectra for the DOPC bilayers, whereas no such time-dependence was observed in the DPPC bilayer spectra under the probe tip. The spectral changes of DOPC bilayers are discussed in terms of the fluidity of the liquid crystalline phase. Time-resolved TERS thus has the potential to characterize inhomogeneity and diffusion in fluidic phospholipid bilayer membranes.

  5. A three-talk model for shared decision making: multistage consultation process

    PubMed Central

    Durand, Marie Anne; Song, Julia; Aarts, Johanna; Barr, Paul J; Berger, Zackary; Cochran, Nan; Frosch, Dominick; Galasiński, Dariusz; Gulbrandsen, Pål; Han, Paul K J; Härter, Martin; Kinnersley, Paul; Lloyd, Amy; Mishra, Manish; Perestelo-Perez, Lilisbeth; Scholl, Isabelle; Tomori, Kounosuke; Trevena, Lyndal; Witteman, Holly O; Van der Weijden, Trudy

    2017-01-01

    Objectives To revise an existing three-talk model for learning how to achieve shared decision making, and to consult with relevant stakeholders to update and obtain wider engagement. Design Multistage consultation process. Setting Key informant group, communities of interest, and survey of clinical specialties. Participants 19 key informants, 153 member responses from multiple communities of interest, and 316 responses to an online survey from medically qualified clinicians from six specialties. Results After extended consultation over three iterations, we revised the three-talk model by making changes to one talk category, adding the need to elicit patient goals, providing a clear set of tasks for each talk category, and adding suggested scripts to illustrate each step. A new three-talk model of shared decision making is proposed, based on “team talk,” “option talk,” and “decision talk,” to depict a process of collaboration and deliberation. Team talk places emphasis on the need to provide support to patients when they are made aware of choices, and to elicit their goals as a means of guiding decision making processes. Option talk refers to the task of comparing alternatives, using risk communication principles. Decision talk refers to the task of arriving at decisions that reflect the informed preferences of patients, guided by the experience and expertise of health professionals. Conclusions The revised three-talk model of shared decision making depicts conversational steps, initiated by providing support when introducing options, followed by strategies to compare and discuss trade-offs, before deliberation based on informed preferences. PMID:29109079

  6. Thulium fiber laser lithotripsy using small spherical distal fiber tips

    NASA Astrophysics Data System (ADS)

    Wilson, Christopher R.; Hardy, Luke A.; Kennedy, Joshua D.; Irby, Pierce B.; Fried, Nathaniel M.

    2016-02-01

    This study tests a 100-μm-core fiber with 300-μm-diameter ball tip during Thulium fiber laser (TFL) lithotripsy. The TFL was operated at 1908 nm wavelength with 35-mJ pulse energy, 500-μs pulse duration, and 300-Hz pulse rate. Calcium oxalate/phosphate stone samples were weighed, laser procedure times measured, and ablation rates calculated for ball tip fibers, with comparison to bare tip fibers. Photographs of ball tips were taken before and after each procedure to observe ball tip degradation and determine number of procedures completed before need to replace fiber. Saline irrigation rates and ureteroscope deflection were measured with and without TFL fiber present. There was no statistical difference (P > 0.05) between stone ablation rates for single-use ball tip fiber (1.3 +/- 0.4 mg/s) (n=10), multiple-use ball tip fiber (1.3 +/- 0.5 mg/s) (n=44), and conventional single-use bare tip fibers (1.3 +/- 0.2 mg/s) (n=10). Ball tip durability varied widely, but fibers averaged > 4 stone procedures before decline in stone ablation rates due to mechanical damage at front surface of ball tip. The small fiber diameter did not impact ureteroscope deflection or saline flow rates. The miniature ball tip fiber may provide a cost-effective design for safe fiber insertion through the ureteroscope working channel and the ureter without risk of scope damage or tissue perforation, and without compromising stone ablation efficiency during TFL ablation of kidney stones.

  7. Evaluation of the tip-bending response in clinically used endoscopes.

    PubMed

    Rozeboom, Esther D; Reilink, Rob; Schwartz, Matthijs P; Fockens, Paul; Broeders, Ivo A M J

    2016-04-01

    Endoscopic interventions require accurate and precise control of the endoscope tip. The endoscope tip response depends on a cable pulling system, which is known to deliver a significantly nonlinear response that eventually reduces control. It is unknown whether the current technique of endoscope tip control is adequate for a future of high precision procedures, steerable accessories, and add-on robotics. The aim of this study was to determine the status of the tip response of endoscopes used in clinical practice. We evaluated 20 flexible colonoscopes and five gastroscopes, used in the endoscopy departments of a Dutch university hospital and two Dutch teaching hospitals, in a bench top setup. First, maximal tip bending was determined manually. Next, the endoscope navigation wheels were rotated individually in a motor setup. Tip angulation was recorded with a USB camera. Cable slackness was derived from the resulting hysteresis plot. Only two of the 20 colonoscopes (10 %) and none of the five gastroscopes reached the maximal tip angulation specified by the manufacturer. Four colonoscopes (20 %) and none of the gastroscopes demonstrated the recommended cable tension. Eight colonoscopes (40 %) had undergone a maintenance check 1 month before the measurements were made. The tip responses of these eight colonoscopies did not differ significantly from the tip responses of the other colonoscopes. This study suggests that the majority of clinically used endoscopes are not optimally tuned to reach maximal bending angles and demonstrate adequate tip responses. We suggest a brief check before procedures to predict difficulties with bending angles and tip responses.

  8. 46 CFR 232.4 - Balance sheet accounts.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 8 2010-10-01 2010-10-01 false Balance sheet accounts. 232.4 Section 232.4 Shipping... ACTIVITIES UNIFORM FINANCIAL REPORTING REQUIREMENTS Balance Sheet § 232.4 Balance sheet accounts. (a.... (b) Purpose of balance sheet accounts. The balance sheet accounts are intended to disclose the...

  9. 46 CFR 232.4 - Balance sheet accounts.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 8 2011-10-01 2011-10-01 false Balance sheet accounts. 232.4 Section 232.4 Shipping... ACTIVITIES UNIFORM FINANCIAL REPORTING REQUIREMENTS Balance Sheet § 232.4 Balance sheet accounts. (a.... (b) Purpose of balance sheet accounts. The balance sheet accounts are intended to disclose the...

  10. Authority as an Interactional Accomplishment through Whole-Class Talk

    ERIC Educational Resources Information Center

    Gatto, Lynn Astarita

    2012-01-01

    Talk is at the heart of classroom instruction and, according to the vast research on classroom talk, the teacher that does most of the talking. Thus, an asymmetry of power is created between teachers and students. These asymmetrical relationships are most obvious in urban elementary classrooms where test prep literacy curriculum has become the…

  11. Skill Sheets for Agricultural Mechanics.

    ERIC Educational Resources Information Center

    Iowa State Univ. of Science and Technology, Ames. Dept. of Agricultural Education.

    This set of 33 skill sheets for agricultural mechanics was developed for use in high school and vocational school agricultural mechanics programs. Some sheets teach operational procedures while others are for simple projects. Each skill sheet covers a single topic and includes: (1) a diagram, (2) a step-by-step construction or operational…

  12. Excitation of surface plasmons in Al-coated SNOM tips

    NASA Astrophysics Data System (ADS)

    Palm, Viktor; Rähn, Mihkel; Jäme, Joonas; Hizhnyakov, Vladimir

    2012-10-01

    The mesoscopic effect of spectral modulation occurring due to the interference of two photonic fiber modes filtered out by a metal-coated SNOM tip is used to observe the surface plasmon polariton (SPP) excitation in SNOM tips. In a spectrum of the broadband light transmitted by a SNOM tip a region of highly regular spectral modulation can be found, indicating the spectral interval in which only two photonic modes (apparently HE11 and TM01) are transmitted with significant and comparable amplitudes. The modulation period yields the value of optical path difference (OPD) for this pair of modes. Due to the multimode fiber's inherent modal dispersion, this OPD value depends linearly on the fiber tail length l. An additional contribution to OPD can be generated in a metal-coated SNOM tip due to a mode-dependent photon-plasmon coupling strength resulting in generation of SPPs with different propagation velocities. For an Al-coated 200 nm SNOM tip spectra of transmitted light have been registered for ten different l values. An extrapolation of the linear OPD (l) dependence to l=0 yields a significant residual OPD value, indicating according to our theoretical considerations a mode-selective SPP excitation in the metal-coated tip. The modal dispersion is shown to switch its sign in the SNOM tip. First results of analogous experiments with an Al-coated 150 nm SNOM tip confirm our conclusions.

  13. National CrossTalk. Volume 18, Number 1

    ERIC Educational Resources Information Center

    National Center for Public Policy and Higher Education, 2010

    2010-01-01

    "National CrossTalk" is a publication of the National Center for Public Policy and Higher Education. The National Center promotes public policies that enhance opportunities for quality education and training beyond high school. The primary purpose of "National CrossTalk" is to stimulate informed discussion and debate of higher…

  14. National CrossTalk. Volume 17, Number 2

    ERIC Educational Resources Information Center

    Trombley, William, Ed.

    2009-01-01

    "National CrossTalk" is a publication of the National Center for Public Policy and Higher Education. The National Center promotes public policies that enhance opportunities for quality education and training beyond high school. The primary purpose of "National CrossTalk" is to stimulate informed discussion and debate of higher…

  15. National CrossTalk. Volume 19, Number 1

    ERIC Educational Resources Information Center

    National Center for Public Policy and Higher Education, 2011

    2011-01-01

    "National CrossTalk" is a publication of the National Center for Public Policy and Higher Education. The National Center promotes public policies that enhance opportunities for quality education and training beyond high school. The primary purpose of "National CrossTalk" is to stimulate informed discussion and debate of higher…

  16. National CrossTalk. Volume 18, Number 2

    ERIC Educational Resources Information Center

    National Center for Public Policy and Higher Education, 2010

    2010-01-01

    "National CrossTalk" is a publication of the National Center for Public Policy and Higher Education. The National Center promotes public policies that enhance opportunities for quality education and training beyond high school. The primary purpose of "National CrossTalk" is to stimulate informed discussion and debate of higher…

  17. Sheet production apparatus for removing a crystalline sheet from the surface of a melt using gas jets located above and below the crystalline sheet

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

    Kellerman, Peter L.; Thronson, Gregory D.

    In one embodiment, a sheet production apparatus comprises a vessel configured to hold a melt of a material. A cooling plate is disposed proximate the melt and is configured to form a sheet of the material on the melt. A first gas jet is configured to direct a gas toward an edge of the vessel. A sheet of a material is translated horizontally on a surface of the melt and the sheet is removed from the melt. The first gas jet may be directed at the meniscus and may stabilize this meniscus or increase local pressure within the meniscus.

  18. Talking in Class: Remembering What Is Important about Classroom Talk

    ERIC Educational Resources Information Center

    Johnston, Peter H.; Ivey, Gay; Faulkner, Amy

    2012-01-01

    The writers describe how apparently ordinary decisions about what to say when talking with children can have substantial effects on their learning and development. The language we use with children influences, among other things, who they think they are, what they think they're doing, the relationships they have with others, the strategic…

  19. Wettability of AFM tip influences the profile of interfacial nanobubbles

    NASA Astrophysics Data System (ADS)

    Teshima, Hideaki; Takahashi, Koji; Takata, Yasuyuki; Nishiyama, Takashi

    2018-02-01

    To accurately characterize the shape of interfacial nanobubbles using atomic force microscopy (AFM), we investigated the effect of wettability of the AFM tip while operating in the peak force tapping (PFT) mode. The AFM tips were made hydrophobic and hydrophilic by Teflon AF coating and oxygen plasma treatment, respectively. It was found that the measured base radius of nanobubbles differed between AFM height images and adhesion images, and that this difference depended on the tip wettability. The force curves obtained during the measurements were also different depending on the wettability, especially in the range of the tip/nanobubble interaction and in the magnitude of the maximum attractive force in the retraction period. The difference suggests that hydrophobic tips penetrate the gas/liquid interface of the nanobubbles, with the three phase contact line being pinned on the tip surface; hydrophilic tips on the other hand do not penetrate the interface. We then quantitatively estimated the pinning position and recalculated the true profiles of the nanobubbles by comparing the height images and adhesion images. As the AFM tip was made more hydrophilic, the penetration depth decreased and eventually approached zero. This result suggests that the PFT measurement using a hydrophilic tip is vital for the acquisition of reliable nanobubble profiles.

  20. Kaplan turbine tip vortex cavitation - analysis and prevention

    NASA Astrophysics Data System (ADS)

    Motycak, L.; Skotak, A.; Kupcik, R.

    2012-11-01

    The work is focused on one type of Kaplan turbine runner cavitation - a tip vortex cavitation. For detailed description of the tip vortex, the CFD analysis is used. On the basis of this analysis it is possible to estimate the intensity of cavitating vortex core, danger of possible blade surface and runner chamber cavitation pitting. In the paper, the ways how to avoid the pitting effect of the tip vortex are described. In order to prevent the blade surface against pitting, the following possibilities as the change of geometry of the runner blade, dimension of tip clearance and finally the installation of the anti-cavitation lips are discussed. The knowledge of the shape and intensity of the tip vortex helps to design the anti-cavitation lips more sophistically. After all, the results of the model tests of the Kaplan runner with or without anti-cavitation lips and the results of the CFD analysis are compared.

  1. Nonlinear Aerodynamics and the Design of Wing Tips

    NASA Technical Reports Server (NTRS)

    Kroo, Ilan

    1991-01-01

    The analysis and design of wing tips for fixed wing and rotary wing aircraft still remains part art, part science. Although the design of airfoil sections and basic planform geometry is well developed, the tip regions require more detailed consideration. This is important because of the strong impact of wing tip flow on wing drag; although the tip region constitutes a small portion of the wing, its effect on the drag can be significant. The induced drag of a wing is, for a given lift and speed, inversely proportional to the square of the wing span. Concepts are proposed as a means of reducing drag. Modern computational methods provide a tool for studying these issues in greater detail. The purpose of the current research program is to improve the understanding of the fundamental issues involved in the design of wing tips and to develop the range of computational and experimental tools needed for further study of these ideas.

  2. Theoretical Study of tip apex electronic structure in Scanning Tunneling Microscope

    NASA Astrophysics Data System (ADS)

    Choi, Heesung; Huang, Min; Randall, John; Cho, Kyeongjae

    2011-03-01

    Scanning Tunneling Microscope (STM) has been widely used to explore diverse surface properties with an atomic resolution, and STM tip has played a critical role in controlling surface structures. However, detailed information of atomic and electronic structure of STM tip and the fundamental understanding of STM images are still incomplete. Therefore, it is important to develop a comprehensive understanding of the electronic structure of STM tip. We have studied the atomic and electronic structures of STM tip with various transition metals (TMs) by DFT method. The d-electrons of TM tip apex atoms show different orbital states near the Fermi level. We will present comprehensive data of STM tips from our DFT calculation. Verified quantification of the tip electronic structures will lead to fundamental understanding of STM tip structure-property relationship. This work is supported by the DARPA TBN Program and the Texas ETF. DARPA Tip Based Nanofabrication Program and the Emerging Technology Fund of the State of Texas.

  3. Achievement Goals, Motivational Self-Talk, and Academic Engagement among Chinese Students

    ERIC Educational Resources Information Center

    Wang, Cen; Shim, Sungok Serena; Wolters, Christopher A.

    2017-01-01

    The present study investigated the mediating role of motivational self-talk strategies (i.e., mastery self-talk, extrinsic self-talk, and efficacy enhancement self-talk) in the relationships between achievement goals and academic engagement (i.e., involvement, withdrawal in the face of difficulties, avoidance of challenges, and disruptive…

  4. Talking about GI Disorders

    MedlinePlus

    ... Lifestyle Changes Strategies for Improving Bowel Habits Improving Sleep Quality Kids & Dietary Fiber Fruit Juice Surgery Laxatives Living with GI Disorders Talking About GI Disorders Personal Stories Social Security Benefits ...

  5. The Physics of Ice Sheets

    ERIC Educational Resources Information Center

    Bassis, J. N.

    2008-01-01

    The great ice sheets in Antarctica and Greenland are vast deposits of frozen freshwater that contain enough to raise sea level by approximately 70 m if they were to completely melt. Because of the potentially catastrophic impact that ice sheets can have, it is important that we understand how ice sheets have responded to past climate changes and…

  6. Evaluation of the tip-bending response in clinically used endoscopes

    PubMed Central

    Rozeboom, Esther D.; Reilink, Rob; Schwartz, Matthijs P.; Fockens, Paul; Broeders, Ivo A. M. J.

    2016-01-01

    Background and study aims: Endoscopic interventions require accurate and precise control of the endoscope tip. The endoscope tip response depends on a cable pulling system, which is known to deliver a significantly nonlinear response that eventually reduces control. It is unknown whether the current technique of endoscope tip control is adequate for a future of high precision procedures, steerable accessories, and add-on robotics. The aim of this study was to determine the status of the tip response of endoscopes used in clinical practice. Materials and methods: We evaluated 20 flexible colonoscopes and five gastroscopes, used in the endoscopy departments of a Dutch university hospital and two Dutch teaching hospitals, in a bench top setup. First, maximal tip bending was determined manually. Next, the endoscope navigation wheels were rotated individually in a motor setup. Tip angulation was recorded with a USB camera. Cable slackness was derived from the resulting hysteresis plot. Results: Only two of the 20 colonoscopes (10 %) and none of the five gastroscopes reached the maximal tip angulation specified by the manufacturer. Four colonoscopes (20 %) and none of the gastroscopes demonstrated the recommended cable tension. Eight colonoscopes (40 %) had undergone a maintenance check 1 month before the measurements were made. The tip responses of these eight colonoscopies did not differ significantly from the tip responses of the other colonoscopes. Conclusion: This study suggests that the majority of clinically used endoscopes are not optimally tuned to reach maximal bending angles and demonstrate adequate tip responses. We suggest a brief check before procedures to predict difficulties with bending angles and tip responses. PMID:27092330

  7. Stability of Thin Liquid Sheet Flows

    NASA Technical Reports Server (NTRS)

    McConley, Marc W.; Chubb, Donald L.; McMaster, Matthew S.; Afjeh, Abdollah A.

    1997-01-01

    A two-dimensional, linear stability analysis of a thin nonplanar liquid sheet flow in vacuum is carried out. A sheet flow created by a narrow slit of W and tau attains a nonplanar cross section as a consequence of cylinders forming on the sheet edge under the influence of surface tension forces. The region where these edge cylinders join the sheet is one of high curvature, and this is found to be the location where instability is most likely to occur. The sheet flow is found to be unstable, but with low growth rates for symmetric wave disturbances and high growth rates for antisymmetric disturbances. By combining the symmetric and antisymmetric disturbance modes, a wide range of stability characteristics is obtained. The product of unstable growth rate and flow time is proportional to the width-to-thickness ratio of the sift generating the sheet Three-dimensional effects can alter these results, particularly when the sheet length-to-width ratio is not much greater than unity.

  8. In situ scanning tunneling microscope tip treatment device for spin polarization imaging

    DOEpatents

    Li, An-Ping [Oak Ridge, TN; Jianxing, Ma [Oak Ridge, TN; Shen, Jian [Knoxville, TN

    2008-04-22

    A tip treatment device for use in an ultrahigh vacuum in situ scanning tunneling microscope (STM). The device provides spin polarization functionality to new or existing variable temperature STM systems. The tip treatment device readily converts a conventional STM to a spin-polarized tip, and thereby converts a standard STM system into a spin-polarized STM system. The tip treatment device also has functions of tip cleaning and tip flashing a STM tip to high temperature (>2000.degree. C.) in an extremely localized fashion. Tip coating functions can also be carried out, providing the tip sharp end with monolayers of coating materials including magnetic films. The device is also fully compatible with ultrahigh vacuum sample transfer setups.

  9. Plasma Sheet Circulation Pathways

    NASA Technical Reports Server (NTRS)

    Moore, Thomas E.; Delcourt, D. C.; Slinker, S. P.; Fedder, J. A.; Damiano, P.; Lotko, W.

    2008-01-01

    Global simulations of Earth's magnetosphere in the solar wind compute the pathways of plasma circulation through the plasma sheet. We address the pathways that supply and drain the plasma sheet, by coupling single fluid simulations with Global Ion Kinetic simulations of the outer magnetosphere and the Comprehensive Ring Current Model of the inner magnetosphere, including plasmaspheric plasmas. We find that the plasma sheet is supplied with solar wind plasmas via the magnetospheric flanks, and that this supply is most effective for northward IMF. For southward IMF, the innermost plasma sheet and ring current region are directly supplied from the flanks, with an asymmetry of single particle entry favoring the dawn flank. The central plasma sheet (near midnight) is supplied, as expected, from the lobes and polar cusps, but the near-Earth supply consists mainly of slowly moving ionospheric outflows for typical conditions. Work with the recently developed multi-fluid LFM simulation shows transport via plasma "fingers" extending Earthward from the flanks, suggestive of an interchange instability. We investigate this with solar wind ion trajectories, seeking to understand the fingering mechanisms and effects on transport rates.

  10. The Level and Quality of Accountability Talk in the Science Lessons

    ERIC Educational Resources Information Center

    Motlhabane, Abraham

    2016-01-01

    Teachers are actively encouraged to plan their lessons such that there is maximum classroom talk, namely accountability talk. However, many lessons do not display sufficient accountability talk. This study attempted to better understand the level and quality of accountability talk in six science lessons. The study aimed to provide teachers with…

  11. A project in Zambia: talking to children about AIDS.

    PubMed

    Baker, K

    1988-09-01

    Early in 1987, it became clear to this individual that children were a high priority group for Acquired Immune Deficiency Syndrome (AIDS) education. Preparation for providing AIDS education in Zambia included reading as much as possible about AIDS and AIDS education in schools, contacting the Health Education Unit at the Ministry of Health for their permission and advice, and making posters and preparing a list of 10 basic questions about AIDS. The 1st talks were at a boys' technical school and a large girls' day school. Following an introduction of the subject, the format included: a 10-minute quiz with students writing down their answers; a 35-40 minute talk, using posters as visual aids; a 20-30 minute open question time; and a repeat of the same quiz as a form of "posttest." The students responded positively, and there was a substantial increase in the percentage of correct answers after each talk. Subsequently, talks were given in other Lusaka secondary schools. After the 1st few talks, the pretest and posttest was discontinued as it was considered preferable to spend more time answering the students' questions. The talks varied depending on the audience, but posters were always included as visual aids. Initially, this AIDS education effort was voluntary and unfunded. Subsequently, and as the work grew, NORAD funded the project, paying for duplicating and printing as well as a salary on an hourly basis. A booklet on AIDS for secondary schools has been written and duplicated and accepted by the Intersectorial Committee on AIDS Health Education with minor changes. Late in 1987, the booklet was rewritten totally and expanded, with numerous illustrations. Throughout the booklet, human immunodeficiency virus (HIV) is carefully differentiated from AIDS disease. Talks also have been initiated at the Upper Primary School level. The format has been altered somewhat for these younger children as they tend to be noisy and excited. The primary project planned for 1988 is

  12. The Evolution of Transjugular Intrahepatic Portosystemic Shunt: Tips

    PubMed Central

    Fanelli, Fabrizio

    2014-01-01

    Since Richter's description in the literature in 1989 of the first procedure on human patients, transjugular intrahepatic portosystemic shunt (TIPS) has been worldwide considered as a noninvasive technique to manage portal hypertension complications. TIPS succeeds in lowering the hepatic sinusoidal pressure and in increasing the circulatory flow, thus reducing sodium retention, ascites recurrence, and variceal bleeding. Required several revisions of the shunt TIPS can be performed in case of different conditions such as hepatorenal syndrome, hepatichydrothorax, portal vein thrombosis, and Budd-Chiari syndrome. Most of the previous studies on TIPS procedure were based on the use of bare stents and most patients chose TIPS 2-3 years after traditional treatment, thus making TIPS appear to be not superior to endoscopy in survival rates. Bare stents were associated with higher incidence of shunt failure and consequently patients required several revisions during the follow-up. With the introduction of a dedicated e-PTFE covered stent-graft, these problems were completely solved, No more reinterventions are required with a tremendous improvement of patient's quality of life. One of the main drawbacks of the use of e-PTFE covered stent-graft is higher incidence of hepatic encephalopathy. In those cases refractory to the conventional medical therapy, a shunt reduction must be performed. PMID:27335841

  13. Final Technical Report: Electrohydrodynamic Tip Streaming

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

    Basaran, Osman

    2016-01-06

    When subjected to strong electric fields, liquid drops and films form conical tips and emit thin jets from their tips. Such electrodydrodynamic (EDH) tip streaming or cone-jetting phenomena, which are sometimes referred to as electrospraying, occur widely in nature, e.g., in ejection of streams of small charged drops from pointed tips of raindrops in thunderclouds, and technology, e.g., in electrospray mass spectrometry or electric field-driven solvent extraction. More recently, EHD cone-jetting has emerged as a powerful technique for direct printing of solar cells, micro- and nano- particle production, and microencapsulation for controlled release. In many of the aforementioned situations, ofmore » equal importance to the processes by which one drop disintegrates to form several drops are those by which (a) two drops come together and coalesce and (b) two drops are coupled to form a double droplet system (DDS) or a capillary switch (CS). the main objective of this research program is to advance through simulation, theory, and experiment the breakup, coalescence, and oscillatory dynamics of single and pairs of charged as well as uncharged drops.« less

  14. Scaling results for the liquid sheet radiator

    NASA Technical Reports Server (NTRS)

    Chubb, Donald L.; Calfo, Frederick D.

    1989-01-01

    Surface tension forces at the edges of a thin liquid (approx 100 micrometers) sheet flow result in a triangularly shaped sheet. Such a geometry is ideal for an external flow radiator. The experimental investigation of such sheet flows was extended to large sheets (width = 23.5 cm, length = 3.5 m). Experimental L/W results are greater than the calculated results. However, more experimental results are necessary for a complete comparison. The calculated emissivity of a sheet of Dow-Corning 705 silicone oil, which is low temperature (300-400 K) candidate for a liquid sheet radiator (LSR), is greater than 0.8 for sheet thicknesses greater than 100 micrometers.

  15. Trash Talking and Good Times on the Softball Field

    ERIC Educational Resources Information Center

    Aicinena, Steven

    2008-01-01

    Trash talking can be found in virtually all American sport environments. It is viewed by many as a tool to achieve athletic success. Trash talking can be a harmless form of verbal jousting. However, there comes a point at which trash talking serves as motivation for violence inside of the sport setting and outside of it as well. In this paper, the…

  16. Sonification of cryoconite landscapes over the Greenland ice sheet

    NASA Astrophysics Data System (ADS)

    Tedesco, M.

    2015-12-01

    Sonification is the use of non-speech audio to convey information. In sonification, several elements can be altered, modified or manipulated to change the perception of the sound, and in turn, the perception of the information being transmitted. For example, an increase or decrease in pitch, tempo and amplitude can be used to convey the information but this can also happen by varying other less commonly used components. One of the advantages of using sonification lies in the temporal, spatial, amplitude, and frequency resolution that offer complementary and supplementary possibilities with respect to visualization techniques. Two years ago, the outcomes of the PolarSEEDS project (www.polaseeds.org), consisting of sonification of time series of albedo, melting and surface temperature over the Greenland ice sheet, were presented in this very same session. The work that I will discuss in this presentation builds on the PolarSEEDS experience, focusing on the fascinating microcosm of cryoconite. Cryoconite is a unique and extremely fascinating form of glacial cover consisting of aggregated rock dust, inorganic and detrital organic matter, and active microbial colonies. It can be seen as 'living stones', with this ecosystem containing the only form of life that is sustained on the majestic surface of the Greenland ice sheet. Microbes are, indeed, the catalyst for cryoconite formation and growth. The cryoconite constituents radiate metabolic heat promoting glacier hole development, melt water formation, and decreasing glacier surface albedo. Lower albedos cause a positive feedback that further contributes to glacier ablation. Despite their importance, cryoconite systems are poorly studied and little is known about their evolution. In the talk, I will first present and discuss previous sonification projects whose main focus was on the polar regions; then, I will present new sonifications based on data quantifying the distribution and evolution of cryoconite over the west

  17. Quantification of holmium:YAG optical tip degradation

    NASA Astrophysics Data System (ADS)

    Mues, Adam C.; Teichman, Joel M. H.; Knudsen, Bodo E.

    2009-02-01

    The holmium:yttrium aluminum garnet (YAG) laser is the gold standard laser for intracorporeal lithotripsy. Optical fibers are utilized to transmit laser energy to the surface of a stone for fragmentation. During lithotripsy, fiber tip degradation (burn back) can occur. The exact mechanism for tip degradation and related factors are not completely understood, and have not been investigated. This characteristic is important because fiber burn back may affect diminish fragmentation efficiency, increase operative time, and increase cost due to the need for fiber replacement. We hypothesize that fiber tip degradation (burn back) varies amongst different commercially available holmium:YAG laser fibers.

  18. Flexible Structural-Health-Monitoring Sheets

    NASA Technical Reports Server (NTRS)

    Qing, Xinlin; Kuo, Fuo

    2008-01-01

    A generic design for a type of flexible structural-health-monitoring sheet with multiple sensor/actuator types and a method of manufacturing such sheets has been developed. A sheet of this type contains an array of sensing and/or actuation elements, associated wires, and any other associated circuit elements incorporated into various flexible layers on a thin, flexible substrate. The sheet can be affixed to a structure so that the array of sensing and/or actuation elements can be used to analyze the structure in accordance with structural-health-monitoring techniques. Alternatively, the sheet can be designed to be incorporated into the body of the structure, especially if the structure is made of a composite material. Customarily, structural-health monitoring is accomplished by use of sensors and actuators arrayed at various locations on a structure. In contrast, a sheet of the present type can contain an entire sensor/actuator array, making it unnecessary to install each sensor and actuator individually on or in a structure. Sensors of different types such as piezoelectric and fiber-optic can be embedded in the sheet to form a hybrid sensor network. Similarly, the traces for electric communication can be deposited on one or two layers as required, and an entirely separate layer can be employed to shield the sensor elements and traces.

  19. Tip Fence for Reduction of Lift-Generated Airframe Noise

    NASA Technical Reports Server (NTRS)

    Ross, James C. (Inventor); Storms, Bruce L. (Inventor)

    1998-01-01

    The present invention is directed toward a unique lift-generated noise reduction apparatus. This apparatus includes a plurality of tip fences that are secured to the trailing and leading assemblies of the high-lift system, as close as possible to the discontinuities where the vortices are most likely to form. In one embodiment, these tip fences are secured to some or all of the outboard and inboard tips of the wing slats and flaps. The tip fence includes a generally flat, or an aerodynamically shaped plate or device that could be formed of almost any rigid material, such as metal, wood, plastic, fiber glass, aluminum, etc. In a preferred embodiment, the tip fences extend below and perpendicularly to flaps and the slats to which they are attached, such that these tip fences are aligned with the nominal free stream velocity of the aircraft. In addition to reducing airframe noise, the tip fence tends to decrease drag and to increase lift, thus improving the overall aerodynamic performance of the aircraft. Another advantage presented by the tip fence lies in the simplicity of its design, its elegance, and its ready ability to fit on the wing components, such as the flaps and the slats. Furthermore, it does not require non-standard materials or fabrication techniques, and it can be readily, easily and inexpensively retrofited on most of the existing aircraft, with minimal design changes.

  20. Biophysics and clinical utility of irrigated-tip radiofrequency catheter ablation.

    PubMed

    Houmsse, Mahmoud; Daoud, Emile G

    2012-01-01

    Catheter ablation by radiofrequency (RF) energy has successfully eliminated cardiac tachyarrhythmias. RF ablation lesions are created by thermal energy. Electrode catheters with 4-mm-tips have been adequate to ablate arrhythmias located near the endocardium; however, the 4-mm-tip electrode does not readily ablate deeper tachyarrhythmia substrate. With 8- and 10-mm-tip RF electrodes, ablation lesions were larger; yet, these catheters are associated with increased risk for coagulum, char and thrombus formation, as well as myocardial steam rupture. Cooled-tip catheter technology was designed to cool the electrode tip, prevent excessive temperatures at the electrode tip-tissue interface, and thus allow continued delivery of RF current into the surrounding tissue. This ablation system creates larger and deeper ablation lesions and minimizes steam pops and thrombus formation. The purpose of this article is to review cooled-tip RF ablation biophysics and outcomes of clinical studies as well as to discuss future technological improvements.

  1. Evaluation of cutting efficiency of ultrasonic tips used in orthograde endodontic treatment.

    PubMed

    Lin, Yu-Heng; Mickel, André K; Jones, Jefferson J; Montagnese, Thomas A; González, Alvaro F

    2006-04-01

    The purpose of the present study was to evaluate the cutting efficiency of the three different ultrasonic tips for orthograde endodontic treatment: stainless steel, zirconium nitride-coated, and diamond-coated tips. An ultrasonic handpiece was mounted on a custom-made automated balance, and each tip repeatedly penetrated dental stone blocks to a depth of 3 mm for 10 times. The amount of time taken to penetrate 3 mm of stone was measured. The diamond-coated tips showed significantly greater cutting efficiency than either stainless steel tips or zirconium-nitride coated tips. The stainless steel tips showed initial better cutting efficiency, but over time , there is no significant difference between the cutting efficiency of the stainless steel tips and the zirconium nitride coated tips. The diamond coated tips were the only group that showed breakage in this study.

  2. A panel method study of vortex sheets with special emphasis on sheets of axisymmetric geometry. M.S. Thesis

    NASA Technical Reports Server (NTRS)

    Sugioka, I.; Widnall, S. E.

    1985-01-01

    The self induced evolution of a vortex sheet was simulated by modeling the sheet using an integration of discrete elements of vorticity. Replacing small sections of a vortex sheet by flat panels of constant vorticity is found to reproduce more accurately the initial conditions for the Lagrangian simulation technique than replacement by point vortices. The flat panel method for the vortex sheet was then extended to model axisymmetric vortex sheets. The local and far field velocities induced by the axisymmetric panels were obtained using matched asymptotic analysis, and some of the uncertainties involved in other models of the axisymmetric vortex sheet have been eliminated. One important result of this analysis is the determination of the proper choice of core size for a circular vortex filament which may replace a section of an axisymmetric vortex sheet. Roll-up of both two dimensional and axisymmetric vortex sheets was computed using the panel methods developed in the report.

  3. Dynamics of Radially Expanding Liquid Sheets

    NASA Astrophysics Data System (ADS)

    Majumdar, Nayanika; Tirumkudulu, Mahesh S.

    2018-04-01

    The process of atomization often involves ejecting thin liquid sheets at high speeds from a nozzle that causes the sheet to flap violently and break up into fine droplets. The flapping of the liquid sheet has long been attributed to the sheet's interaction with the surrounding gas phase. Here, we present experimental evidence to the contrary and show that the flapping is caused by the thinning of the liquid sheet as it spreads out from the nozzle exit. The measured growth rates of the waves agree remarkably well with the predictions of a recent theory that accounts for the sheet's thinning but ignores aerodynamic interactions. We anticipate these results to not only lead to more accurate predictions of the final drop-size distribution but also enable more efficient designs of atomizers.

  4. Computation of the tip vortex flowfield for advanced aircraft propellers

    NASA Technical Reports Server (NTRS)

    Tsai, Tommy M.; Dejong, Frederick J.; Levy, Ralph

    1988-01-01

    The tip vortex flowfield plays a significant role in the performance of advanced aircraft propellers. The flowfield in the tip region is complex, three-dimensional and viscous with large secondary velocities. An analysis is presented using an approximate set of equations which contains the physics required by the tip vortex flowfield, but which does not require the resources of the full Navier-Stokes equations. A computer code was developed to predict the tip vortex flowfield of advanced aircraft propellers. A grid generation package was developed to allow specification of a variety of advanced aircraft propeller shapes. Calculations of the tip vortex generation on an SR3 type blade at high Reynolds numbers were made using this code and a parametric study was performed to show the effect of tip thickness on tip vortex intensity. In addition, calculations of the tip vortex generation on a NACA 0012 type blade were made, including the flowfield downstream of the blade trailing edge. Comparison of flowfield calculations with experimental data from an F4 blade was made. A user's manual was also prepared for the computer code (NASA CR-182178).

  5. Identification and functional analysis of endothelial tip cell-enriched genes.

    PubMed

    del Toro, Raquel; Prahst, Claudia; Mathivet, Thomas; Siegfried, Geraldine; Kaminker, Joshua S; Larrivee, Bruno; Breant, Christiane; Duarte, Antonio; Takakura, Nobuyuki; Fukamizu, Akiyoshi; Penninger, Josef; Eichmann, Anne

    2010-11-11

    Sprouting of developing blood vessels is mediated by specialized motile endothelial cells localized at the tips of growing capillaries. Following behind the tip cells, endothelial stalk cells form the capillary lumen and proliferate. Expression of the Notch ligand Delta-like-4 (Dll4) in tip cells suppresses tip cell fate in neighboring stalk cells via Notch signaling. In DLL4(+/-) mouse mutants, most retinal endothelial cells display morphologic features of tip cells. We hypothesized that these mouse mutants could be used to isolate tip cells and so to determine their genetic repertoire. Using transcriptome analysis of retinal endothelial cells isolated from DLL4(+/-) and wild-type mice, we identified 3 clusters of tip cell-enriched genes, encoding extracellular matrix degrading enzymes, basement membrane components, and secreted molecules. Secreted molecules endothelial-specific molecule 1, angiopoietin 2, and apelin bind to cognate receptors on endothelial stalk cells. Knockout mice and zebrafish morpholino knockdown of apelin showed delayed angiogenesis and reduced proliferation of stalk cells expressing the apelin receptor APJ. Thus, tip cells may regulate angiogenesis via matrix remodeling, production of basement membrane, and release of secreted molecules, some of which regulate stalk cell behavior.

  6. The inviscid pressure field on the tip of a semi-infinite wing and its application to the formation of a tip vortex

    NASA Technical Reports Server (NTRS)

    Hall, G. F.; Shamroth, S. J.; Mcdonald, H.; Briley, W. R.

    1976-01-01

    A method was developed for determining the aerodynamic loads on the tip of an infinitely thin, swept, cambered semi-infinite wing at an angle of attack which is operating subsonically in an inviscid medium and is subjected to a sinusoidal gust. Under the assumption of linearized aerodynamics, the loads on the tip are obtained by superposition of the steady aerodynamic results for angle of attack and camber, and the unsteady results for the response to the sinusoidal gust. The near field disturbance pressures in the fluid surrounding the tip are obtained by assuming a dipole representation for the loading on the tip and calculating the pressures accordingly. The near field pressures are used to drive a reduced form of the Navier-Stokes equations which yield the tip vortex formation. The combined viscid-inviscid analysis is applied to determining the pressures and examining the vortex rollup in the vicinity of an unswept, uncambered wing moving steadily at a Mach number of 0.2 at an angle of attack of 0.1 rad. The viscous tip flow calculation shows features expected in the tip flow such as the qualitatively proper development of boundary layers on both the upper and lower airfoil surfaces. In addition, application of the viscous solution leads to the generation of a circular type flow pattern above the airfoil suction surface.

  7. Blade tip timing (BTT) uncertainties

    NASA Astrophysics Data System (ADS)

    Russhard, Pete

    2016-06-01

    Blade Tip Timing (BTT) is an alternative technique for characterising blade vibration in which non-contact timing probes (e.g. capacitance or optical probes), typically mounted on the engine casing (figure 1), and are used to measure the time at which a blade passes each probe. This time is compared with the time at which the blade would have passed the probe if it had been undergoing no vibration. For a number of years the aerospace industry has been sponsoring research into Blade Tip Timing technologies that have been developed as tools to obtain rotor blade tip deflections. These have been successful in demonstrating the potential of the technology, but rarely produced quantitative data, along with a demonstration of a traceable value for measurement uncertainty. BTT technologies have been developed under a cloak of secrecy by the gas turbine OEM's due to the competitive advantages it offered if it could be shown to work. BTT measurements are sensitive to many variables and there is a need to quantify the measurement uncertainty of the complete technology and to define a set of guidelines as to how BTT should be applied to different vehicles. The data shown in figure 2 was developed from US government sponsored program that bought together four different tip timing system and a gas turbine engine test. Comparisons showed that they were just capable of obtaining measurement within a +/-25% uncertainty band when compared to strain gauges even when using the same input data sets.

  8. Toy talk: simple strategies to create richer grammatical input.

    PubMed

    Hadley, Pamela A; Walsh, Kathleen M

    2014-07-01

    The purpose of this initial feasibility study was to determine whether brief instruction in toy talk would change grammatical properties of adult language, specifically 3rd person lexical noun phrase (NP) subjects. Eighteen college students participated in the study. The use of 3rd person subjects was examined before and after instruction on toy talk strategies (i.e., talk about the toys, give the item its name). Change in the input informativeness for tense (i.e., the proportion of verb forms marked for tense out of all verb forms) was also examined, although adults were not instructed on use of tense/agreement morphemes. Following instruction, statistically significant increases with large effect sizes were observed for use of 3rd person subjects, lexical NP subjects, and input informativeness for tense (Cohen's d = 1.20, 2.08, and 0.89, respectively). These findings demonstrate that young adults can learn these simple strategies with relatively brief instruction, and the use of toy talk also changes the richness of tense/agreement marking in adult language input. Considerations for incorporating toy talk into existing language modeling practices and future plans for evaluating the efficacy of toy talk are discussed.

  9. Analysis, design, fabrication and testing of an optical tip clearance sensor. [turbocompressor blade tips

    NASA Technical Reports Server (NTRS)

    Poppel, G. L.; Marple, D. T. F.; Kingsley, J. D.

    1981-01-01

    Analyses and the design, fabrication, and testing of an optical tip clearance sensor with intended application in aircraft propulsion control systems are reported. The design of a sensor test rig, evaluation of optical sensor components at elevated temperatures, sensor design principles, sensor test results at room temperature, and estimations of sensor accuracy at temperatures of an aircraft engine environment are discussed. Room temperature testing indicated possible measurement accuracies of less than 12.7 microns (0.5 mils). Ways to improve performance at engine operating temperatures are recommended. The potential of this tip clearance sensor is assessed.

  10. A three-talk model for shared decision making: multistage consultation process.

    PubMed

    Elwyn, Glyn; Durand, Marie Anne; Song, Julia; Aarts, Johanna; Barr, Paul J; Berger, Zackary; Cochran, Nan; Frosch, Dominick; Galasiński, Dariusz; Gulbrandsen, Pål; Han, Paul K J; Härter, Martin; Kinnersley, Paul; Lloyd, Amy; Mishra, Manish; Perestelo-Perez, Lilisbeth; Scholl, Isabelle; Tomori, Kounosuke; Trevena, Lyndal; Witteman, Holly O; Van der Weijden, Trudy

    2017-11-06

    Objectives  To revise an existing three-talk model for learning how to achieve shared decision making, and to consult with relevant stakeholders to update and obtain wider engagement. Design  Multistage consultation process. Setting  Key informant group, communities of interest, and survey of clinical specialties. Participants  19 key informants, 153 member responses from multiple communities of interest, and 316 responses to an online survey from medically qualified clinicians from six specialties. Results  After extended consultation over three iterations, we revised the three-talk model by making changes to one talk category, adding the need to elicit patient goals, providing a clear set of tasks for each talk category, and adding suggested scripts to illustrate each step. A new three-talk model of shared decision making is proposed, based on "team talk," "option talk," and "decision talk," to depict a process of collaboration and deliberation. Team talk places emphasis on the need to provide support to patients when they are made aware of choices, and to elicit their goals as a means of guiding decision making processes. Option talk refers to the task of comparing alternatives, using risk communication principles. Decision talk refers to the task of arriving at decisions that reflect the informed preferences of patients, guided by the experience and expertise of health professionals. Conclusions  The revised three-talk model of shared decision making depicts conversational steps, initiated by providing support when introducing options, followed by strategies to compare and discuss trade-offs, before deliberation based on informed preferences. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  11. 21 CFR 870.1370 - Catheter tip occluder.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Catheter tip occluder. 870.1370 Section 870.1370 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Diagnostic Devices § 870.1370 Catheter tip occluder...

  12. 21 CFR 880.6025 - Absorbent tipped applicator.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... stick. The device is used to apply medications to, or to take specimens from, a patient. (b...) MEDICAL DEVICES GENERAL HOSPITAL AND PERSONAL USE DEVICES General Hospital and Personal Use Miscellaneous Devices § 880.6025 Absorbent tipped applicator. (a) Identification. An absorbent tipped applicator is a...

  13. 21 CFR 870.1370 - Catheter tip occluder.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Catheter tip occluder. 870.1370 Section 870.1370 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Diagnostic Devices § 870.1370 Catheter tip occluder...

  14. Ultraviolet photodetectors based on ZnO sheets: The effect of sheet size on photoresponse properties

    NASA Astrophysics Data System (ADS)

    Ghasempour Ardakani, Abbas; Pazoki, Meysam; Mahdavi, Seyed Mohammad; Bahrampour, Ali Reza; Taghavinia, Nima

    2012-05-01

    In this work, ultraviolet photodetectors based on electrodeposited ZnO sheet thin films were fabricated on a glass substrate. Before electrodeposition, a thin buffer layer of ZnO was deposited on the glass by pulsed laser deposition method. This layer not only acted as a nucleation site for ZnO sheet growth, but also made it possible to use cheap glass substrate instead of conventional fluorine-doped tin oxide (FTO) substrate. Our results showed that photoresponse properties of the photodetectors strongly depend on the sheet sizes. The smaller sheets exhibited enhanced photosensitivity, shortened fall times and decreased gain compared to larger ones. We showed that photodetectors based on ZnO sheets have a faster response than ones based on polycrystalline films. It was also shown that even less response time could be obtained by using comb-like electrodes instead of two-electrode.

  15. Sharp Tips on the Atomic Force Microscope

    NASA Technical Reports Server (NTRS)

    2008-01-01

    This image shows the eight sharp tips of the NASA's Phoenix Mars Lander's Atomic Force Microscope, or AFM. The AFM is part of Phoenix's Microscopy, Electrochemistry, and Conductivity Analyzer, or MECA.

    The microscope maps the shape of particles in three dimensions by scanning them with one of the tips at the end of a beam. For the AFM image taken, the tip at the end of the upper right beam was used. The tip pointing up in the enlarged image is the size of a smoke particle at its base, or 2 microns. This image was taken with a scanning electron microscope before Phoenix launched on August 4, 2007.

    The AFM was developed by a Swiss-led consortium in collaboration with Imperial College London.

    The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  16. Buckling and stretching of thin viscous sheets

    NASA Astrophysics Data System (ADS)

    O'Kiely, Doireann; Breward, Chris; Griffiths, Ian; Howell, Peter; Lange, Ulrich

    2016-11-01

    Thin glass sheets are used in smartphone, battery and semiconductor technology, and may be manufactured by producing a relatively thick glass slab and subsequently redrawing it to a required thickness. The resulting sheets commonly possess undesired centerline ripples and thick edges. We present a mathematical model in which a viscous sheet undergoes redraw in the direction of gravity, and show that, in a sufficiently strong gravitational field, buckling is driven by compression in a region near the bottom of the sheet, and limited by viscous resistance to stretching of the sheet. We use asymptotic analysis in the thin-sheet, low-Reynolds-number limit to determine the centerline profile and growth rate of such a viscous sheet.

  17. Some observations of tip-vortex cavitation

    NASA Astrophysics Data System (ADS)

    Arndt, R. E. A.; Arakeri, V. H.; Higuchi, H.

    1991-08-01

    Cavitation has been observed in the trailing vortex system of an elliptic platform hydrofoil. A complex dependence on Reynolds number and gas content is noted at inception. Some of the observations can be related to tension effects associated with the lack of sufficiently large-sized nuclei. Inception measurements are compared with estimates of pressure in the vortex obtained from LDV measurements of velocity within the vortex. It is concluded that a complete correlation is not possible without knowledge of the fluctuating levels of pressure in tip-vortex flows. When cavitation is fully developed, the observed tip-vortex trajectory flows. When cavitation is fully developed, the observed tip-vortex trajectory shows a surprising lack of dependence on any of the physical parameters varied, such as angle of attack, Reynolds number, cavitation number, and dissolved gas content.

  18. 100 Consejos para los Padres (100 Tips for Parents).

    ERIC Educational Resources Information Center

    Department of Education, Washington, DC.

    Noting that involved parents can improve their children's chances of succeeding in school, this packet of Spanish-language cards offers 100 tips created to help parents become more involved in their child's education. Following a card of general tips on becoming involved, tips are offered in the following topic areas: keeping a child alcohol,…

  19. Talking Shop: Authentic Conversation and Teacher Learning.

    ERIC Educational Resources Information Center

    Clark, Christopher M., Ed.

    This book presents a set of stories that focus on what teachers learn from talking to one another about their practice, presenting a case for how the ordinary talk among teachers is a potent medium for teacher learning and professional development. Drawing from the work of eight groups of teachers in the United States and Israel who met in…

  20. Computer-Aided Light Sheet Flow Visualization

    NASA Technical Reports Server (NTRS)

    Stacy, Kathryn; Severance, Kurt; Childers, Brooks A.

    1993-01-01

    A computer-aided flow visualization process has been developed to analyze video images acquired from rotating and translating light sheet visualization systems. The computer process integrates a mathematical model for image reconstruction, advanced computer graphics concepts, and digital image processing to provide a quantitative and visual analysis capability. The image reconstruction model, based on photogrammetry, uses knowledge of the camera and light sheet locations and orientations to project two-dimensional light sheet video images into three-dimensional space. A sophisticated computer visualization package, commonly used to analyze computational fluid dynamics (CFD) data sets, was chosen to interactively display the reconstructed light sheet images, along with the numerical surface geometry for the model or aircraft under study. A description is provided of the photogrammetric reconstruction technique, and the image processing and computer graphics techniques and equipment. Results of the computer aided process applied to both a wind tunnel translating light sheet experiment and an in-flight rotating light sheet experiment are presented. The capability to compare reconstructed experimental light sheet images and CFD solutions in the same graphics environment is also demonstrated.

  1. Ice sheet margins and ice shelves

    NASA Technical Reports Server (NTRS)

    Thomas, R. H.

    1984-01-01

    The effect of climate warming on the size of ice sheet margins in polar regions is considered. Particular attention is given to the possibility of a rapid response to warming on the order of tens to hundreds of years. It is found that the early response of the polar regions to climate warming would be an increase in the area of summer melt on the ice sheets and ice shelves. For sufficiently large warming (5-10C) the delayed effects would include the breakup of the ice shelves by an increase in ice drainage rates, particularly from the ice sheets. On the basis of published data for periodic changes in the thickness and melting rates of the marine ice sheets and fjord glaciers in Greenland and Antarctica, it is shown that the rate of retreat (or advance) of an ice sheet is primarily determined by: bedrock topography; the basal conditions of the grounded ice sheet; and the ice shelf condition downstream of the grounding line. A program of satellite and ground measurements to monitor the state of ice sheet equilibrium is recommended.

  2. Computer-aided light sheet flow visualization

    NASA Technical Reports Server (NTRS)

    Stacy, Kathryn; Severance, Kurt; Childers, Brooks A.

    1993-01-01

    A computer-aided flow visualization process has been developed to analyze video images acquired from rotating and translating light sheet visualization systems. The computer process integrates a mathematical model for image reconstruction, advanced computer graphics concepts, and digital image processing to provide a quantitative and visual analysis capability. The image reconstruction model, based on photogrammetry, uses knowledge of the camera and light sheet locations and orientations to project two-dimensional light sheet video images into three-dimensional space. A sophisticated computer visualization package, commonly used to analyze computational fluid dynamics (CFD) data sets, was chosen to interactively display the reconstructed light sheet images, along with the numerical surface geometry for the model or aircraft under study. A description is provided of the photogrammetric reconstruction technique, and the image processing and computer graphics techniques and equipment. Results of the computer aided process applied to both a wind tunnel translating light sheet experiment and an in-flight rotating light sheet experiment are presented. The capability to compare reconstructed experimental light sheet images and CFD solutions in the same graphics environment is also demonstrated.

  3. Ohm's law for a current sheet

    NASA Technical Reports Server (NTRS)

    Lyons, L. R.; Speiser, T. W.

    1985-01-01

    The paper derives an Ohm's law for single-particle motion in a current sheet, where the magnetic field reverses in direction across the sheet. The result is considerably different from the resistive Ohm's law often used in MHD studies of the geomagnetic tail. Single-particle analysis is extended to obtain a self-consistency relation for a current sheet which agrees with previous results. The results are applicable to the concept of reconnection in that the electric field parallel to the current is obtained for a one-dimensional current sheet with constant normal magnetic field. Dissipated energy goes directly into accelerating particles within the current sheet.

  4. Novel cylindrical illuminator tip for ultraviolet light delivery

    NASA Astrophysics Data System (ADS)

    Shangguan, HanQun; Haw, Thomas E.; Gregory, Kenton W.; Casperson, Lee W.

    1993-06-01

    The design, processing, and sequential testing of a novel cylindrical diffusing optical fiber tip for ultraviolet light delivery is described. This device has been shown to uniformly (+/- 15%) illuminate angioplasty balloons, 20 mm in length, that are used in an experimental photochemotherapeutic treatment of swine intimal hyperplasia. Our experiments show that uniform diffusing tips of < 400 micron diameter can be reliably constructed for this and other interstitial applications. Modeling results indicate that this design is scalable to smaller diameters. The diffusing tips are made by stripping the protective buffer and etching away the cladding over a length of 20 mm from the fiber tip and replacing it with a thin layer of optical epoxy mixed with Al2O3 powder. To improve the uniformity and ease of fabrication, we have evaluated a new device configuration where the tip is etched into a modified conical shape, and the distal end face is polished and then coated with an optically opaque epoxy. This is shown to uniformly scatter approximately 70% of the light launched into the fiber without forward transmission.

  5. Study of mechanical behavior of AFM silicon tips under mechanical load

    NASA Astrophysics Data System (ADS)

    Kopycinska-Mueller, M.; Gluch, J.; Köhler, B.

    2016-11-01

    In this paper we address critical issues concerning calibration of AFM based methods used for nanoscale mechanical characterization of materials. It has been shown that calibration approaches based on macroscopic models for contact mechanics may yield excellent results in terms of the indentation modulus of the sample, but fail to provide a comprehensive and actual information concerning the tip-sample contact radius or the mechanical properties of the tip. Explanations for the severely reduced indentation modulus of the tip included the inadequacies of the models used for calculations of the tip-sample contact stiffness, discrepancies in the actual and ideal shape of the tip, presence of the amorphous silicon phase within the silicon tip, as well as negligence of the actual size of the stress field created in the tip during elastic interactions. To clarify these issues, we investigated the influence of the mechanical load applied to four AFM silicon tips on their crystalline state by exposing them to systematically increasing loads, evaluating the character of the tip-sample interactions via the load-unload stiffness curves, and assessing the state of the tips from HR-TEM images. The results presented in this paper were obtained in a series of relatively simple and basic atomic force acoustic microscopy (AFAM) experiments. The novel combination of TEM imaging of the AFM tips with the analysis of the load-unload stiffness curves gave us a detailed insight into their mechanical behavior under load conditions. We were able to identify the limits for the elastic interactions, as well as the hallmarks for phase transformation and dislocation formation and movement. The comparison of the physical dimensions of the AFM tips, geometry parameters determined from the values of the contact stiffness, and the information on the crystalline state of the tips allowed us a better understanding of the nanoscale contact.

  6. Cooling circuit for a gas turbine bucket and tip shroud

    DOEpatents

    Willett, Fred Thomas; Itzel, Gary Michael; Stathopoulos, Dimitrios; Plemmons, Larry Wayne; Plemmons, Helen M.; Lewis, Doyle C.

    2002-01-01

    An open cooling circuit for a gas turbine bucket wherein the bucket has an airfoil portion, and a tip shroud, the cooling circuit including a plurality of radial cooling holes extending through the airfoil portion and communicating with an enlarged internal area within the tip shroud before exiting the tip shroud such that a cooling medium used to cool the airfoil portion is subsequently used to cool the tip shroud.

  7. Turbine blade tip clearance measurements using skewed dual optical beams of tip timing

    NASA Astrophysics Data System (ADS)

    Ye, De-chao; Duan, Fa-jie; Guo, Hao-tian; Li, Yangzong; Wang, Kai

    2011-12-01

    Optimization and active control of the clearance between turbine blades and case of the engine is identified, especially in aerospace community, as a key technology to increase engine efficiency, reduce fuel consumption and emissions and increase service life .However, the tip clearance varies during different operating conditions. Thus a reliable non-contact and online detection system is essential and ultimately used to close the tip clearance control loop. This paper described a fiber optical clearance measuring system applying skewed dual optical beams to detect the traverse time of passing blades. Two beams were specially designed with an outward angle of 18 degree and the beam spot diameters are less than 100μm within 0-4mm working range to achieve high signal-to-noise and high sensitivity. It could be theoretically analyzed that the measuring accuracy is not compromised by degradation of signal intensity caused by any number of environmental conditions such as light source instability, contamination and blade tip imperfection. Experimental tests were undertaken to achieve a high resolution of 10µm in the rotational speed range 2000-18000RPM and a measurement accuracy of 15μm, indicating that the system is capable of providing accurate and reliable data for active clearance control (ACC).

  8. New Technique for Fabrication of Scanning Single-Electron Transistor Microscopy Tips

    NASA Astrophysics Data System (ADS)

    Goodwin, Eric; Tessmer, Stuart

    Fabrication of glass tips for Scanning Single-Electron Transistor Microscopy (SSETM) can be expensive, time consuming, and inconsistent. Various techniques have been tried, with varying levels of success in regards to cost and reproducibility. The main requirement for SSETM tips is to have a sharp tip ending in a micron-scale flat face to allow for deposition of a quantum dot. Drawing inspiration from methods used to create tips from optical fibers for Near-Field Scanning Optical Microscopes, our group has come up with a quick and cost effective process for creating SSETM tips. By utilizing hydrofluoric acid to etch the tips and oleic acid to guide the etch profile, optical fiber tips with appropriate shaping can be rapidly prepared. Once etched, electric leads are thermally evaporated onto each side of the tip, while an aluminum quantum dot is evaporated onto the face. Preliminary results using various metals, oxide layers, and lead thicknesses have proven promising.

  9. Thulium fiber laser lithotripsy using a muzzle brake fiber tip

    NASA Astrophysics Data System (ADS)

    Hutchens, Thomas C.; Gonzalez, David A.; Irby, Pierce B.; Fried, Nathaniel M.

    2017-02-01

    The Thulium fiber laser (TFL) is being explored as an alternative to Holmium:YAG laser for lithotripsy. TFL beam profile allows coupling of higher power into smaller fibers than multimode Holmium laser beam, without proximal fiber tip degradation. A smaller fiber provides more space in ureteroscope working channel for increased saline irrigation and allows maximum ureteroscope flexion. However, distal fiber tip burnback increases as fiber diameter decreases. Previous studies utilizing hollow steel sheaths around recessed distal fiber tips reduced fiber burnback, but increased retropulsion. In this study, a "fiber muzzle brake" was tested for reducing fiber burnback and stone retropulsion. TFL lithotripsy studies were performed at 1908 nm, 35 mJ, 500 μs, and 300 Hz using a 100-μm-core fiber. The optimal stainless steel muzzle brake tip tested consisted of a 1-cm-long, 560-μm-OD, 360-μm-ID tube with 275-μm thru hole located 250-μm from the distal end. The fiber tip was recessed a distance of 500 μm. Stone phantom retropulsion, fiber tip burnback, and calcium oxalate stone ablation studies were performed, ex vivo. Small stones with a mass of 40 +/- 4 mg and 4-mm-diameter were ablated over a 1.5-mm sieve in 25 +/- 4 s (n=10), without distal fiber tip burnback. Reduction in stone phantom retropulsion distance by 50% and 85% was observed when using muzzle brake tips versus 100-μm-core bare fibers and hollow steel tip fibers. The muzzle brake fiber tip provided efficient stone ablation, reduced stone retropulsion, and minimal fiber degradation during TFL lithotripsy.

  10. Jagged gives endothelial tip cells an edge.

    PubMed

    Suchting, Steven; Eichmann, Anne

    2009-06-12

    Sprouting blood vessels have tip cells that lead and stalk cells that follow. Benedito et al. (2009) now show that competition between endothelial cells for the tip position is regulated by glycosylation of Notch receptors and by the opposing actions of the Notch ligands Jagged1 and Delta-like 4.

  11. Talk Show Science.

    ERIC Educational Resources Information Center

    Moore, Mitzi Ruth

    1992-01-01

    Proposes having students perform skits in which they play the roles of the science concepts they are trying to understand. Provides the dialog for a skit in which hot and cold gas molecules are interviewed on a talk show to study how these properties affect wind, rain, and other weather phenomena. (MDH)

  12. Working Talk: Developing a Framework for the Teaching of Collaborative Talk

    ERIC Educational Resources Information Center

    Newman, Ruth

    2016-01-01

    This study draws on the findings of an ESRC and British Telecom funded study which explored the teaching of collaborative talk. A teaching intervention was designed which adopted the principles of dialogic teaching, but which, drawing on educational linguistics, particularly emphasised the role of metatalk in developing students' awareness of the…

  13. Crutches and children - proper fit and safety tips

    MedlinePlus

    ... 000640.htm Crutches and children - proper fit and safety tips To use the sharing features on this ... the crutch, then extended when taking a step. Safety Tips Teach your child to: Always keep crutches ...

  14. Tip cells: master regulators of tubulogenesis?

    PubMed

    Weavers, Helen; Skaer, Helen

    2014-07-01

    The normal development of an organ depends on the coordinated regulation of multiple cell activities. Focusing on tubulogenesis, we review the role of specialised cells or groups of cells that are selected from within tissue primordia and differentiate at the outgrowing tips or leading edge of developing tubules. Tip or leading cells develop distinctive patterns of gene expression that enable them to act both as sensors and transmitters of intercellular signalling. This enables them to explore the environment, respond to both tissue intrinsic signals and extrinsic cues from surrounding tissues and to regulate the behaviour of their neighbours, including the setting of cell fate, patterning cell division, inducing polarity and promoting cell movement and cell rearrangements by neighbour exchange. Tip cells are also able to transmit mechanical tension to promote tissue remodelling and, by interacting with the extracellular matrix, they can dictate migratory pathways and organ shape. Where separate tubular structures fuse to form networks, as in the airways of insects or the vascular system of vertebrates, specialised fusion tip cells act to interconnect disparate elements of the developing network. Finally, we consider their importance in the maturation of mature physiological function and in the development of disease. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

  15. Dual circuit embossed sheet heat transfer panel

    DOEpatents

    Morgan, G.D.

    1984-02-21

    A heat transfer panel provides redundant cooling for fusion reactors or the like environment requiring low-mass construction. Redundant cooling is provided by two independent cooling circuits, each circuit consisting of a series of channels joined to inlet and outlet headers. The panel comprises a welded joinder of two full-size and two much smaller partial-size sheets. The first full-size sheet is embossed to form first portions of channels for the first and second circuits, as well as a header for the first circuit. The second full-sized sheet is then laid over and welded to the first full-size sheet. The first and second partial-size sheets are then overlaid on separate portions of the second full-sized sheet, and are welded thereto. The first and second partial-sized sheets are embossed to form inlet and outlet headers, which communicate with channels of the second circuit through apertures formed in the second full-sized sheet. 6 figs.

  16. Dual-circuit embossed-sheet heat-transfer panel

    DOEpatents

    Morgan, G.D.

    1982-08-23

    A heat transfer panel provides redundant cooling for fusion reactors or the like environment requiring low-mass construction. Redundant cooling is provided by two independent cooling circuits, each circuit consisting of a series of channels joined to inlet and outlet headers. The panel comprises a welded joinder of two full-size and two much smaller partial-size sheets. The first full-size sheet is embossed for form first portions of channels for the first and second circuits, as well as a header for the first circuit. The second full-sized sheet is then laid over and welded to the first full-size sheet. The first and second partial-size sheets are then overlaid on separate portions of the second full-sized sheet, and are welded thereto. The first and second partial-sized sheets are embossed to form inlet and outlet headers, which communicate with channels of the second circuit through apertures formed in the second full-sized sheet.

  17. Dual circuit embossed sheet heat transfer panel

    DOEpatents

    Morgan, Grover D.

    1984-01-01

    A heat transfer panel provides redundant cooling for fusion reactors or the like environment requiring low-mass construction. Redundant cooling is provided by two independent cooling circuits, each circuit consisting of a series of channels joined to inlet and outlet headers. The panel comprises a welded joinder of two full-size and two much smaller partial-size sheets. The first full-size sheet is embossed to form first portions of channels for the first and second circuits, as well as a header for the first circuit. The second full-sized sheet is then laid over and welded to the first full-size sheet. The first and second partial-size sheets are then overlaid on separate portions of the second full-sized sheet, and are welded thereto. The first and second partial-sized sheets are embossed to form inlet and outlet headers, which communicate with channels of the second circuit through apertures formed in the second full-sized sheet.

  18. Collisionless current sheet equilibria

    NASA Astrophysics Data System (ADS)

    Neukirch, T.; Wilson, F.; Allanson, O.

    2018-01-01

    Current sheets are important for the structure and dynamics of many plasma systems. In space and astrophysical plasmas they play a crucial role in activity processes, for example by facilitating the release of magnetic energy via processes such as magnetic reconnection. In this contribution we will focus on collisionless plasma systems. A sensible first step in any investigation of physical processes involving current sheets is to find appropriate equilibrium solutions. The theory of collisionless plasma equilibria is well established, but over the past few years there has been a renewed interest in finding equilibrium distribution functions for collisionless current sheets with particular properties, for example for cases where the current density is parallel to the magnetic field (force-free current sheets). This interest is due to a combination of scientific curiosity and potential applications to space and astrophysical plasmas. In this paper we will give an overview of some of the recent developments, discuss their potential applications and address a number of open questions.

  19. Tips for Breastfeeding Moms

    MedlinePlus

    United States Department of Agriculture Tips for Breastfeeding Moms Making healthy food choices along with regular physical activity will keep you healthy while you breastfeed. Find Your Healthy Eating Style Choose ...

  20. Development and testing of tip devices for horizontal axis wind turbines

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

    Gyatt, G.W.; Lissaman, P.B.S.

    1985-05-01

    A theoretical and field experimental program has been carried out to investigate the use of tip devices on horizontal axis wind turbine rotors. Objective was to improve performance by the reduction of tip losses. A vortex lattice computer model was used to optimize three basic tip configuration types for a 25 kW stall limited commercial wind turbines. The types were a change in tip planform, and a single-element and double-element nonplannar tip extension (winglets). Approximately 270 h of performance data were collected over a three-month period. The sampling interval was 2.4 s; thus over 400,000 raw data points were logged.more » Results for each of the three new tip devices, compared with the original tip, showed a small decrease (of the order of 1 kW) in power output over the measured range of wind speeds from cut-in at about 4 m/s to over 20 m/s, well into the stall limiting region. For aircraft wing tip devices, favorable tip shapes have been reported and it is likely that the tip devices tested in this program did not improve rotor performance because they were not optimally adjusted. The computer model used does not have adequate lifting surface resolution or accuracy to design these small winglet extensions.« less

  1. Monitoring Sand Sheets and Dunes

    NASA Image and Video Library

    2017-06-12

    NASA's Mars Reconnaissance Orbiter (MRO) captured this crater featuring sand dunes and sand sheets on its floor. What are sand sheets? Snow fall on Earth is a good example of sand sheets: when it snows, the ground gets blanketed with up to a few meters of snow. The snow mantles the ground and "mimics" the underlying topography. Sand sheets likewise mantle the ground as a relatively thin deposit. This kind of environment has been monitored by HiRISE since 2007 to look for movement in the ripples covering the dunes and sheets. This is how scientists who study wind-blown sand can track the amount of sand moving through the area and possibly where the sand came from. Using the present environment is crucial to understanding the past: sand dunes, sheets, and ripples sometimes become preserved as sandstone and contain clues as to how they were deposited The map is projected here at a scale of 25 centimeters (9.8 inches) per pixel. [The original image scale is 25 centimeters (9.8 inches) per pixel (with 1 x 1 binning); objects on the order of 75 centimeters (29.5 inches) across are resolved.] North is up. https://photojournal.jpl.nasa.gov/catalog/PIA21757

  2. Magnitude and behavior of cross-talk effects in multichannel electrophysiology experiments.

    PubMed

    Nelson, Matthew J; Valtcheva, Silvana; Venance, Laurent

    2017-07-01

    Modern neurophysiological experiments frequently involve multiple channels separated by very small distances. A unique methodological concern for multiple-electrode experiments is that of capacitive coupling (cross-talk) between channels. Yet the nature of the cross-talk recording circuit is not well known in the field, and the extent to which it practically affects neurophysiology experiments has never been fully investigated. Here we describe a simple electrical circuit model of simultaneous recording and stimulation with two or more channels and experimentally verify the model using ex vivo brain slice and in vivo whole-brain preparations. In agreement with the model, we find that cross-talk amplitudes increase nearly linearly with the impedance of a recording electrode and are larger for higher frequencies. We demonstrate cross-talk contamination of action potential waveforms from intracellular to extracellular channels, which is observable in part because of the different orders of magnitude between the channels. This contamination is electrode impedance-dependent and matches predictions from the model. We use recently published parameters to simulate cross-talk in high-density multichannel extracellular recordings. Cross-talk effectively spatially smooths current source density (CSD) estimates in these recordings and induces artefactual phase shifts where underlying voltage gradients occur; however, these effects are modest. We show that the effects of cross-talk are unlikely to affect most conclusions inferred from neurophysiology experiments when both originating and receiving electrode record signals of similar magnitudes. We discuss other types of experiments and analyses that may be susceptible to cross-talk, techniques for detecting and experimentally reducing cross-talk, and implications for high-density probe design. NEW & NOTEWORTHY We develop and experimentally verify an electrical circuit model describing cross-talk that necessarily occurs between

  3. Twin-Mirrored-Galvanometer Laser-Light-Sheet Generator

    NASA Technical Reports Server (NTRS)

    Rhodes, David B.; Franke, John M.; Jones, Stephen B.; Leighty, Bradley D.

    1991-01-01

    Multiple, rotating laser-light sheets generated to illuminate flows in wind tunnels. Designed and developed to provide flexibility and adaptability to wide range of applications. Design includes capability to control size and location of laser-light sheet in real time, to generate horizontal or vertical sheets, to sweep sheet repeatedly through volume, to generate multiple sheets with controllable separation, and to rotate single or multiple laser-light sheets. Includes electronic equipment and laser mounted on adjustable-height platform. Twin-mirrored galvanometer unit supported by tripod to reduce vibration. Other possible applications include use in construction industry to align beams of building. Artistic or display applications also possible.

  4. Ten Tips for Talking to Townies: Observations on Risk Communication from the Multihazards Demonstration Project

    NASA Astrophysics Data System (ADS)

    Porter, K. A.; Jones, L. M.

    2010-12-01

    The USGS’s Multihazards Demonstration Project (MHDP) seeks to demonstrate how hazard science can improve a community’s resiliency to natural hazards. To do so, it must accurately but clearly communicate scientific concepts and findings to a wide variety of nonscientist stakeholders, many of whom are technical experts in their field primarily interested in the implications of MHDP’s science for them, and relatively uninterested in the science per se. During the development and rollout of the MHDP scenarios we found several strategies of risk communication helpful. Use availability. Relate new ideas to events the audience personally observed. Avoid sensationalism, since even the appearance of an appeal to emotion seemed to undermine the credibility of the message among certain constituencies. Avoid probability. However tempted we are as scientists to emphasize the unknown, stakeholders preferred a single coherent story. We can accompany the coherent story with an acknowledgment of uncertainty and limited knowledge. Engage stakeholders in the science as early as possible. They can help ground, direct, and vet the science as it emerges, and help us avoid “spherical-cow” simplifications. Get to the point. Soundbites, despite negative connotations, promote conciseness. Emphasize consensus. While scientists are primarily interested in the boundaries of knowledge, the public is more interested in what is known, and acts more readily where there is no ambiguity. Confront misinformation. Science sometimes competes with pseudoscience for public mindspace. Where the goal is enhancing community resiliency, the competition becomes a battle. Temper talk with activities. We learn by doing, and some of us have no patience for lectures. Use engaging imagery. We found that modern media such as Youtube videos with high production quality and geospatial imagery that the public sees as cutting edge, captured people’s attention, even senior professionals and academics who

  5. Keratinocyte cytoskeletal roles in cell sheet engineering

    PubMed Central

    2013-01-01

    Background There is an increasing need to understand cell-cell interactions for cell and tissue engineering purposes, such as optimizing cell sheet constructs, as well as for examining adhesion defect diseases. For cell-sheet engineering, one major obstacle to sheet function is that cell sheets in suspension are fragile and, over time, will contract. While the role of the cytoskeleton in maintaining the structure and adhesion of cells cultured on a rigid substrate is well-characterized, a systematic examination of the role played by different components of the cytoskeleton in regulating cell sheet contraction and cohesion in the absence of a substrate has been lacking. Results In this study, keratinocytes were cultured until confluent and cell sheets were generated using dispase to remove the influence of the substrate. The effects of disrupting actin, microtubules or intermediate filaments on cell-cell interactions were assessed by measuring cell sheet cohesion and contraction. Keratin intermediate filament disruption caused comparable effects on cell sheet cohesion and contraction, when compared to actin or microtubule disruption. Interfering with actomyosin contraction demonstrated that interfering with cell contraction can also diminish cell cohesion. Conclusions All components of the cytoskeleton are involved in maintaining cell sheet cohesion and contraction, although not to the same extent. These findings demonstrate that substrate-free cell sheet biomechanical properties are dependent on the integrity of the cytoskeleton network. PMID:23442760

  6. Multipurpose fiber-optic sensor with sloped tip

    NASA Astrophysics Data System (ADS)

    Melnik, Ivan S.; Krivokhizha, A. M.; Ptashnik, O. V.

    1991-08-01

    Fiber-optic sensors C FOS) are wi. del y used for rioncontact measurements due to their simplicity, small size, insensitivity to I nfl uence of el ectromagneti C fiel ds , hi gh metrol ogi cal characteristics, etc. The operation principle of FOS with intensity modul ati on techni que I s based on the photodetector regi strati on of 1ight , reflected from the control 1 ed surface E I ) . The i ntensi ty of detected 1 1 ght depends on th FOS' s di stance from the control 1 ed surface, its form and inclination to sensor's axis, FOS shift speed, etc. So they can be consider multipurpose. We are devel opi ng FOS wi th i ntensi ty modul ati on techni que wi th traight tips as well as with sloped tips. In FOS with sloped tips the light ring spot is appearing on the controlled surface due to the effect of symmetry. We use thi s phenomena to empl oy refl ected 1 i ght more efficiently and to increase the FOS characteristics. Tak i ng I nto account the fact that pr obl ems of cal cul aWl on of fibers with sloped tip were not analyzed in details earlier-, in particular, only the case of light distribution of parallel beams runni ng was consi dered E 2) we wi I 1 conduct a consi stent cal cul ati on of bounds of i rradi ance fi ci d , created by a fi ber wi th sl oped tip, esti mate I i ght di stri buti on I n a 1 1 ght spot , and determi. ne characteristics of the FOS with sloped tip.

  7. Development and testing of tip devices for horizontal axis wind turbines

    NASA Technical Reports Server (NTRS)

    Gyatt, G. W.; Lissaman, P. B. S.

    1985-01-01

    A theoretical and field experimental program has been carried out to investigate the use of tip devices on horizontal axis wind turbine rotors. The objective was to improve performance by the reduction of tip losses. While power output can always be increased by a simple radial tip extension, such a modification also results in an increased gale load both because of the extra projected area and longer moment arm. Tip devices have the potential to increase power output without such a structural penalty. A vortex lattice computer model was used to optimize three basic tip configuration types for a 25 kW stall limited commercial wind turbine. The types were a change in tip planform, and a single-element and double-element nonplanar tip extension (winglets). A complete data acquisition system was developed which recorded three wind speed components, ambient pressure, temperature, and turbine output. The system operated unattended and could perform real-time processing of the data, displaying the measured power curve as data accumulated in either a bin sort mode or polynomial curve fit. Approximately 270 hr of perormance data were collected over a three-month period. The sampling interval was 2.4 sec; thrus over 400,000 raw data points were logged. Results for each of the three new tip devices, compared with the original tip, showed a small decrease (of the order of 1 kW) in power output over the measured range of wind speeds from cut-in at about 4 m/s to over 20 m/s, well into the stall limiting region. Changes in orientation and angle-of-attack of the winglets were not made. For aircraft wing tip devices, favorable tip shapes have been reported and it is likely that the tip devices tested in this program did not improve rotor performance because they were not optimally adjusted.

  8. Ice_Sheets_CCI: Essential Climate Variables for the Greenland Ice Sheet

    NASA Astrophysics Data System (ADS)

    Forsberg, R.; Sørensen, L. S.; Khan, A.; Aas, C.; Evansberget, D.; Adalsteinsdottir, G.; Mottram, R.; Andersen, S. B.; Ahlstrøm, A.; Dall, J.; Kusk, A.; Merryman, J.; Hvidberg, C.; Khvorostovsky, K.; Nagler, T.; Rott, H.; Scharrer, M.; Shepard, A.; Ticconi, F.; Engdahl, M.

    2012-04-01

    As part of the ESA Climate Change Initiative (www.esa-cci.org) a long-term project "ice_sheets_cci" started January 1, 2012, in addition to the existing 11 projects already generating Essential Climate Variables (ECV) for the Global Climate Observing System (GCOS). The "ice_sheets_cci" goal is to generate a consistent, long-term and timely set of key climate parameters for the Greenland ice sheet, to maximize the impact of European satellite data on climate research, from missions such as ERS, Envisat and the future Sentinel satellites. The climate parameters to be provided, at first in a research context, and in the longer perspective by a routine production system, would be grids of Greenland ice sheet elevation changes from radar altimetry, ice velocity from repeat-pass SAR data, as well as time series of marine-terminating glacier calving front locations and grounding lines for floating-front glaciers. The ice_sheets_cci project will involve a broad interaction of the relevant cryosphere and climate communities, first through user consultations and specifications, and later in 2012 optional participation in "best" algorithm selection activities, where prototype climate parameter variables for selected regions and time frames will be produced and validated using an objective set of criteria ("Round-Robin intercomparison"). This comparative algorithm selection activity will be completely open, and we invite all interested scientific groups with relevant experience to participate. The results of the "Round Robin" exercise will form the algorithmic basis for the future ECV production system. First prototype results will be generated and validated by early 2014. The poster will show the planned outline of the project and some early prototype results.

  9. 7 CFR 29.3154 - Tips (T Group).

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... stalk. (See Rule 12.) Grades Grade names and specifications T3F Good Tan Tips. Medium body, mature to..., mature, firm, wavy dull finish, weak color intensity, narrow, under 16″ in length, 80 percent uniform, and 20 percent injury tolerance. T5F Low Tan Tips. Medium body, mature, firm, wrinkly, dingy finish...

  10. 7 CFR 29.3154 - Tips (T Group).

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... stalk. (See Rule 12.) Grades Grade names and specifications T3F Good Tan Tips. Medium body, mature to..., mature, firm, wavy dull finish, weak color intensity, narrow, under 16″ in length, 80 percent uniform, and 20 percent injury tolerance. T5F Low Tan Tips. Medium body, mature, firm, wrinkly, dingy finish...

  11. 7 CFR 29.3154 - Tips (T Group).

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... stalk. (See Rule 12.) Grades Grade names and specifications T3F Good Tan Tips. Medium body, mature to..., mature, firm, wavy dull finish, weak color intensity, narrow, under 16″ in length, 80 percent uniform, and 20 percent injury tolerance. T5F Low Tan Tips. Medium body, mature, firm, wrinkly, dingy finish...

  12. Back-to-School Health Tips: Exercise and Sleep

    MedlinePlus

    ... up the same times each day. Keep room temperature on the cool side. A TV or computer in the bedroom can be a distraction. Read More "Back-to-School" Articles Health Tips: Immunizations / Health Tips: Exercise and ...

  13. Infused polymers for cell sheet release

    NASA Astrophysics Data System (ADS)

    Juthani, Nidhi; Howell, Caitlin; Ledoux, Haylea; Sotiri, Irini; Kelso, Susan; Kovalenko, Yevgen; Tajik, Amanda; Vu, Thy L.; Lin, Jennifer J.; Sutton, Amy; Aizenberg, Joanna

    2016-05-01

    Tissue engineering using whole, intact cell sheets has shown promise in many cell-based therapies. However, current systems for the growth and release of these sheets can be expensive to purchase or difficult to fabricate, hindering their widespread use. Here, we describe a new approach to cell sheet release surfaces based on silicone oil-infused polydimethylsiloxane. By coating the surfaces with a layer of fibronectin (FN), we were able to grow mesenchymal stem cells to densities comparable to those of tissue culture polystyrene controls (TCPS). Simple introduction of oil underneath an edge of the sheet caused it to separate from the substrate. Characterization of sheets post-transfer showed that they retain their FN layer and morphology, remain highly viable, and are able to grow and proliferate normally after transfer. We expect that this method of cell sheet growth and detachment may be useful for low-cost, flexible, and customizable production of cellular layers for tissue engineering.

  14. Infused polymers for cell sheet release

    PubMed Central

    Juthani, Nidhi; Howell, Caitlin; Ledoux, Haylea; Sotiri, Irini; Kelso, Susan; Kovalenko, Yevgen; Tajik, Amanda; Vu, Thy L.; Lin, Jennifer J.; Sutton, Amy; Aizenberg, Joanna

    2016-01-01

    Tissue engineering using whole, intact cell sheets has shown promise in many cell-based therapies. However, current systems for the growth and release of these sheets can be expensive to purchase or difficult to fabricate, hindering their widespread use. Here, we describe a new approach to cell sheet release surfaces based on silicone oil-infused polydimethylsiloxane. By coating the surfaces with a layer of fibronectin (FN), we were able to grow mesenchymal stem cells to densities comparable to those of tissue culture polystyrene controls (TCPS). Simple introduction of oil underneath an edge of the sheet caused it to separate from the substrate. Characterization of sheets post-transfer showed that they retain their FN layer and morphology, remain highly viable, and are able to grow and proliferate normally after transfer. We expect that this method of cell sheet growth and detachment may be useful for low-cost, flexible, and customizable production of cellular layers for tissue engineering. PMID:27189419

  15. Infused polymers for cell sheet release.

    PubMed

    Juthani, Nidhi; Howell, Caitlin; Ledoux, Haylea; Sotiri, Irini; Kelso, Susan; Kovalenko, Yevgen; Tajik, Amanda; Vu, Thy L; Lin, Jennifer J; Sutton, Amy; Aizenberg, Joanna

    2016-05-18

    Tissue engineering using whole, intact cell sheets has shown promise in many cell-based therapies. However, current systems for the growth and release of these sheets can be expensive to purchase or difficult to fabricate, hindering their widespread use. Here, we describe a new approach to cell sheet release surfaces based on silicone oil-infused polydimethylsiloxane. By coating the surfaces with a layer of fibronectin (FN), we were able to grow mesenchymal stem cells to densities comparable to those of tissue culture polystyrene controls (TCPS). Simple introduction of oil underneath an edge of the sheet caused it to separate from the substrate. Characterization of sheets post-transfer showed that they retain their FN layer and morphology, remain highly viable, and are able to grow and proliferate normally after transfer. We expect that this method of cell sheet growth and detachment may be useful for low-cost, flexible, and customizable production of cellular layers for tissue engineering.

  16. Modeling the Interaction between AFM Tips and Pinned Surface Nanobubbles.

    PubMed

    Guo, Zhenjiang; Liu, Yawei; Xiao, Qianxiang; Schönherr, Holger; Zhang, Xianren

    2016-01-26

    Although the morphology of surface nanobubbles has been studied widely with different AFM modes, AFM images may not reflect the real shapes of the nanobubbles due to AFM tip-nanobubble interactions. In addition, the interplay between surface nanobubble deformation and induced capillary force has not been well understood in this context. In our work we used constraint lattice density functional theory to investigate the interaction between AFM tips and pinned surface nanobubbles systematically, especially concentrating on the effects of tip hydrophilicity and shape. For a hydrophilic tip contacting a nanobubble, its hydrophilic nature facilitates its departure from the bubble surface, displaying a weak and intermediate-range attraction. However, when the tip squeezes the nanobubble during the approach process, the nanobubble shows an elastic effect that prevents the tip from penetrating the bubble, leading to a strong nanobubble deformation and repulsive interactions. On the contrary, a hydrophobic tip can easily pierce the vapor-liquid interface of the nanobubble during the approach process, leading to the disappearance of the repulsive force. In the retraction process, however, the adhesion between the tip and the nanobubble leads to a much stronger lengthening effect on nanobubble deformation and a strong long-range attractive force. The trends of force evolution from our simulations agree qualitatively well with recent experimental AFM observations. This favorable agreement demonstrates that our model catches the main intergradient of tip-nanobubble interactions for pinned surface nanobubbles and may therefore provide important insight into how to design minimally invasive AFM experiments.

  17. Coupled ice sheet-ocean modelling to investigate ocean driven melting of marine ice sheets in Antarctica

    NASA Astrophysics Data System (ADS)

    Jong, Lenneke; Gladstone, Rupert; Galton-Fenzi, Ben

    2017-04-01

    Ocean induced melting below the ice shelves of marine ice sheets is a major source of uncertainty for predictions of ice mass loss and Antarctica's resultant contribution to future sea level rise. The floating ice shelves provide a buttressing force against the flow of ice across the grounding line into the ocean. Thinning of these ice shelves due to an increase in melting reduces this force and can lead to an increase in the discharge of grounded ice. Fully coupled modelling of ice sheet-ocean interactions is key to improving understanding the influence of the Southern ocean on the evolution of the Antarctic ice sheet, and to predicting its future behaviour under changing climate conditions. Coupling of ocean and ice sheet models is needed to provide more realistic melt rates at the base of ice shelves and hence make better predictions of the behaviour of the grounding line and the shape of the ice-shelf cavity as the ice sheet evolves. The Framework for Ice Sheet - Ocean Coupling (FISOC) has been developed to provide a flexible platform for performing coupled ice sheet - ocean modelling experiments. We present preliminary results using FISOC to couple the Regional Ocean Modelling System (ROMS) with Elmer/Ice in idealised experiments Marine Ice Sheet-Ocean Model Intercomparison Project (MISOMIP). These experiments use an idealised geometry motivated by that of Pine Island glacier and the adjacent Amundsen Sea in West Antarctica, a region which has shown shown signs of thinning ice and grounding line retreat.

  18. Preparation of scanning tunneling microscopy tips using pulsed alternating current etching

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

    Valencia, Victor A.; Thaker, Avesh A.; Derouin, Jonathan

    An electrochemical method using pulsed alternating current etching (PACE) to produce atomically sharp scanning tunneling microscopy (STM) tips is presented. An Arduino Uno microcontroller was used to control the number and duration of the alternating current (AC) pulses, allowing for ready optimization of the procedures for both Pt:Ir and W tips using a single apparatus. W tips prepared using constant and pulsed AC power were compared. Tips fashioned using PACE were sharper than those etched with continuous AC power alone. Pt:Ir tips were prepared with an initial coarse etching stage using continuous AC power followed by fine etching using PACE.more » The number and potential of the finishing AC pulses was varied and scanning electron microscope imaging was used to compare the results. Finally, tip quality using the optimized procedures was verified by UHV-STM imaging. With PACE, at least 70% of the W tips and 80% of the Pt:Ir tips were of sufficiently high quality to obtain atomically resolved images of HOPG or Ni(111)« less

  19. Frequency and Efficacy of Talk-Related Tasks in Primary Science

    ERIC Educational Resources Information Center

    Braund, Martin; Leigh, Joanne

    2013-01-01

    Pupil talk and discussion are seen as having important social and cognitive outcomes. In science classes, pupils' collaborative talk supports the construction of meaning and helps examine the status of evidence, theory and knowledge. However, pupil interactive talk in groups is rare in science lessons. The research reported is part of a project to…

  20. Fabrication of silver tips for scanning tunneling microscope induced luminescence.

    PubMed

    Zhang, C; Gao, B; Chen, L G; Meng, Q S; Yang, H; Zhang, R; Tao, X; Gao, H Y; Liao, Y; Dong, Z C

    2011-08-01

    We describe a reliable fabrication procedure of silver tips for scanning tunneling microscope (STM) induced luminescence experiments. The tip was first etched electrochemically to yield a sharp cone shape using selected electrolyte solutions and then sputter cleaned in ultrahigh vacuum to remove surface oxidation. The tip status, in particular the tip induced plasmon mode and its emission intensity, can be further tuned through field emission and voltage pulse. The quality of silver tips thus fabricated not only offers atomically resolved STM imaging, but more importantly, also allows us to perform challenging "color" photon mapping with emission spectra taken at each pixel simultaneously during the STM scan under relatively small tunnel currents and relatively short exposure time.

  1. Method for heating and forming a glass sheet

    DOEpatents

    Boaz, Premakaran Tucker

    1997-01-01

    A method for heating and forming a glass sheet includes the steps of heating a glass sheet to at least a first predetermined temperature, applying microwave energy to the glass sheet to heat the glass sheet to at least a second predetermined temperature, cooling an outer surface of the glass sheet to at least a third predetermined temperature and forming the glass sheet using forming rollers to a predetermined configuration.

  2. Graded-index fiber tip optical tweezers: numerical simulation and trapping experiment.

    PubMed

    Gong, Yuan; Ye, Ai-Yan; Wu, Yu; Rao, Yun-Jiang; Yao, Yao; Xiao, Song

    2013-07-01

    Optical fiber tweezers based on a graded-index multimode fiber (GIMMF) tip is proposed. Light propagation characteristics and gradient force distribution near the GIMMF tip are numerically investigated, which are further compared with that of optical fiber tips based on conventional single mode fibers. The simulated results indicated that by selecting optimal GIMMF length, the gradient force of the GIMMF tip tweezers is about 4 times higher than that of the SMF tip tweezers with a same shape. To prove the feasibility of such a new concept, optical trapping of yeast cells with a diameter of ~5 μm using the chemically-etched GIMMF tip is experimentally demonstrated and the trapping force is also calculated.

  3. Static biofilm removal around ultrasonic tips in vitro.

    PubMed

    Thurnheer, Thomas; Rohrer, Elodie; Belibasakis, Georgios N; Attin, Thomas; Schmidlin, Patrick R

    2014-09-01

    This study aims to investigate the biofilm removal capacity of two ultrasonic tips under standardized conditions using a multi-species biofilm model. Six-species biofilms were grown on hydroxyapatite discs for 64.5 h and were treated for 15 s with a standardized load of 40 g with a piezoelectric or magnetostrictive device. Tips were applied either with the tip end or with the side facing downwards. Detached bacteria were determined in the supernatant and colony-forming units (CFUs) counted after 72 h of incubation. Untreated specimens served as controls. Moreover, the biofilms remaining on the hydroxyapatite surface after treatment were stained using the Live/Dead stain, and the pattern of their detachment was assessed by confocal laser scanning microscopy (CLSM). As compared to the untreated control, it was found that only a side application of the magnetostrictive device was able to remove efficiently the biofilm. In contrast, its tip application as well as both applications of the piezoelectric device removed significantly less bacteria from the biofilm structure. These findings were corroborated by CLSM observation. Both ultrasonic tips under investigations led to bacterial detachment, but the action mode as well as the tip configuration and adaptation appeared to be influenced by the biofilm removal effectiveness. Biofilm removal remains a main goal of ultrasonic debridement. This should be reflected in respective laboratory investigations. The presented combination of methods applied on a multi-species biofilm model in vitro allows the evaluation of the effectiveness of different ultrasonic scaler applications.

  4. Effect of Temperature and Sheet Temper on Isothermal Solidification Kinetics in Clad Aluminum Brazing Sheet

    NASA Astrophysics Data System (ADS)

    Benoit, Michael J.; Whitney, Mark A.; Wells, Mary A.; Winkler, Sooky

    2016-09-01

    Isothermal solidification (IS) is a phenomenon observed in clad aluminum brazing sheets, wherein the amount of liquid clad metal is reduced by penetration of the liquid clad into the core. The objective of the current investigation is to quantify the rate of IS through the use of a previously derived parameter, the Interface Rate Constant (IRC). The effect of peak temperature and initial sheet temper on IS kinetics were investigated. The results demonstrated that IS is due to the diffusion of silicon (Si) from the liquid clad layer into the solid core. Reduced amounts of liquid clad at long liquid duration times, a roughened sheet surface, and differences in resolidified clad layer morphology between sheet tempers were observed. Increased IS kinetics were predicted at higher temperatures by an IRC model as well as by experimentally determined IRC values; however, the magnitudes of these values are not in good agreement due to deficiencies in the model when applied to alloys. IS kinetics were found to be higher for sheets in the fully annealed condition when compared with work-hardened sheets, due to the influence of core grain boundaries providing high diffusivity pathways for Si diffusion, resulting in more rapid liquid clad penetration.

  5. Numerical simulation of tip vortices of wings in subsonic and transonic flows

    NASA Technical Reports Server (NTRS)

    Srinivasan, G. R.; Mccroskey, W. J.; Baeder, J. D.; Edwards, T. A.

    1986-01-01

    A multi block zonal algorithm which solves the thin-layer Navier-Stokes and the Euler equations is used to numerically simulate the formation and roll-up of the tip vortex in both subsonic and transonic flows. Four test cases which used small and large aspect ratio wings have been considered to examine the influence of the tip-cap shape, the tip planform and the free-stream Mach number. It appears that both the tip-planform and the tip-cap shape have some influence on the formation of the tip vortex, but its subsequent roll-up seems to be more influenced by the tip-planform shape. In general, a good definition of the formation and the roll-up of the tip vortex has been observed for all the cases considered here. Comparions of the numerical results with the limited, available experimental data show good agreement with both the surface pressures and the tip-vortex strength.

  6. A Blade Tip Timing Method Based on a Microwave Sensor

    PubMed Central

    Zhang, Jilong; Duan, Fajie; Niu, Guangyue; Jiang, Jiajia; Li, Jie

    2017-01-01

    Blade tip timing is an effective method for blade vibration measurements in turbomachinery. This method is increasing in popularity because it is non-intrusive and has several advantages over the conventional strain gauge method. Different kinds of sensors have been developed for blade tip timing, including optical, eddy current and capacitance sensors. However, these sensors are unsuitable in environments with contaminants or high temperatures. Microwave sensors offer a promising potential solution to overcome these limitations. In this article, a microwave sensor-based blade tip timing measurement system is proposed. A patch antenna probe is used to transmit and receive the microwave signals. The signal model and process method is analyzed. Zero intermediate frequency structure is employed to maintain timing accuracy and dynamic performance, and the received signal can also be used to measure tip clearance. The timing method uses the rising and falling edges of the signal and an auto-gain control circuit to reduce the effect of tip clearance change. To validate the accuracy of the system, it is compared experimentally with a fiber optic tip timing system. The results show that the microwave tip timing system achieves good accuracy. PMID:28492469

  7. A Blade Tip Timing Method Based on a Microwave Sensor.

    PubMed

    Zhang, Jilong; Duan, Fajie; Niu, Guangyue; Jiang, Jiajia; Li, Jie

    2017-05-11

    Blade tip timing is an effective method for blade vibration measurements in turbomachinery. This method is increasing in popularity because it is non-intrusive and has several advantages over the conventional strain gauge method. Different kinds of sensors have been developed for blade tip timing, including optical, eddy current and capacitance sensors. However, these sensors are unsuitable in environments with contaminants or high temperatures. Microwave sensors offer a promising potential solution to overcome these limitations. In this article, a microwave sensor-based blade tip timing measurement system is proposed. A patch antenna probe is used to transmit and receive the microwave signals. The signal model and process method is analyzed. Zero intermediate frequency structure is employed to maintain timing accuracy and dynamic performance, and the received signal can also be used to measure tip clearance. The timing method uses the rising and falling edges of the signal and an auto-gain control circuit to reduce the effect of tip clearance change. To validate the accuracy of the system, it is compared experimentally with a fiber optic tip timing system. The results show that the microwave tip timing system achieves good accuracy.

  8. Propeller Tip Flutter

    NASA Technical Reports Server (NTRS)

    Liebers, Fritz

    1932-01-01

    The present report is limited to a case of tip flutter recognized by experience as being important. It is the case where outside interferences force vibrations upon the propeller. Such interferences may be set up by the engine, or they may be the result of an unsymmetrical field of flow.

  9. Method for heating and forming a glass sheet

    DOEpatents

    Boaz, P.T.

    1997-08-12

    A method for heating and forming a glass sheet includes the steps of heating a glass sheet to at least a first predetermined temperature, applying microwave energy to the glass sheet to heat the glass sheet to at least a second predetermined temperature, cooling an outer surface of the glass sheet to at least a third predetermined temperature and forming the glass sheet using forming rollers to a predetermined configuration. 5 figs.

  10. Tips for labor coaches

    MedlinePlus

    ... some tips for getting prepared. Before the big day Arrives Labor coaches should go to childbirth classes ... get through her labor and delivery. When the day Arrives You might be at the hospital for ...

  11. Tipping news in information accumulation system

    NASA Astrophysics Data System (ADS)

    Shin, J. K.

    2010-05-01

    As a continuous opinion dynamics model, the information accumulation system (IAS) includes three basic mechanisms of the news, the inheritance and the diffusion as contributing to the information accumulation process of a system. A system is composed of agents who diffuse information through internal interaction, while each of them has incomplete memory or inheritance rate. The news comes from external sources of information, such as mass media. Previously the model IAS was studied only for the small news problems. In this study, a tipping news problem is considered. A key question of the problem is: what is the minimum strength of advertisement that can tip the minority opinion to a majority one? Dynamics of the IAS is briefly revisited with a special interest on nonlinear behavior of the model. In particular, it is shown that a discrete map of the IAS for a single color problem can be transformed into a logistic map, from which the dynamics of the IAS can be better understood. To show the applicability of the IAS model, the result is applied to explain the concept of the critical population size, which claims that there is a minimum population size for a social knowledge system to be continuously inherited without being lost. And critical size of the tipping news is found analytically in terms of IAS parameters. Some of the key results from the present study are compared in detail with the results from the Brownian particle model, which is believed to be the most similar model to the IAS. The concept of tipping news is used to show that a traditional society can tip at an exceptionally low inter-community exposure. Finally, the result was applied to the language competition problem.

  12. Retention of Nontraditional Students. Tip Sheet.

    ERIC Educational Resources Information Center

    Ohio State Univ., Columbus. Instructional Materials Lab.

    This publication begins with a list of suggestions for increasing the retention of male and female students pursuing nontraditional occupations. It then highlights five successful Ohio programs for the retention of these students: (1) Overcoming Sex Bias and Sex Stereotyping in Secondary Vocational Education--Nontraditional Support (Great Oaks…

  13. CSC Tip Sheets: Working with Students

    EPA Pesticide Factsheets

    Work with students, individually or in teams, who are a volunteer workforce that offers resources to implement projects. In turn, these students are given a valuable hands-on learning experience, academic credit, and a career boost.

  14. CSC Tip Sheets: Working with Corporations

    EPA Pesticide Factsheets

    Programs can work with corporations to reduce companies’ greenhouse gas emissions and energy use, as well as create partnerships to reach employees and the community with local sustainability program offerings.

  15. Predicting pulsar scintillation from refractive plasma sheets

    NASA Astrophysics Data System (ADS)

    Simard, Dana; Pen, Ue-Li

    2018-07-01

    The dynamic and secondary spectra of many pulsars show evidence for long-lived, aligned images of the pulsar that are stationary on a thin scattering sheet. One explanation for this phenomenon considers the effects of wave crests along sheets in the ionized interstellar medium, such as those due to Alfvén waves propagating along current sheets. If these sheets are closely aligned to our line of sight to the pulsar, high bending angles arise at the wave crests and a selection effect causes alignment of images produced at different crests, similar to grazing reflection off of a lake. Using geometric optics, we develop a simple parametrized model of these corrugated sheets that can be constrained with a single observation and that makes observable predictions for variations in the scintillation of the pulsar over time and frequency. This model reveals qualitative differences between lensing from overdense and underdense corrugated sheets: only if the sheet is overdense compared to the surrounding interstellar medium can the lensed images be brighter than the line-of-sight image to the pulsar, and the faint lensed images are closer to the pulsar at higher frequencies if the sheet is underdense, but at lower frequencies if the sheet is overdense.

  16. Predicting Pulsar Scintillation from Refractive Plasma Sheets

    NASA Astrophysics Data System (ADS)

    Simard, Dana; Pen, Ue-Li

    2018-05-01

    The dynamic and secondary spectra of many pulsars show evidence for long-lived, aligned images of the pulsar that are stationary on a thin scattering sheet. One explanation for this phenomenon considers the effects of wave crests along sheets in the ionized interstellar medium, such as those due to Alfvén waves propagating along current sheets. If these sheets are closely aligned to our line-of-sight to the pulsar, high bending angles arise at the wave crests and a selection effect causes alignment of images produced at different crests, similar to grazing reflection off of a lake. Using geometric optics, we develop a simple parameterized model of these corrugated sheets that can be constrained with a single observation and that makes observable predictions for variations in the scintillation of the pulsar over time and frequency. This model reveals qualitative differences between lensing from overdense and underdense corrugated sheets: Only if the sheet is overdense compared to the surrounding interstellar medium can the lensed images be brighter than the line-of-sight image to the pulsar, and the faint lensed images are closer to the pulsar at higher frequencies if the sheet is underdense, but at lower frequencies if the sheet is overdense.

  17. Travel Tips Help IBS Sufferers Enjoy Their Vacations

    MedlinePlus

    ... can feel more in control when traveling." IFFGD's travel tips include: Allow enough time in the morning to get to the airport ... Heartache 2004-0929 Norton Honored 2004-0525 IBS Travel Tips ... Real World 2001-1119 Heartburn or Heart Attack Commentary ...

  18. Energized Oxygen : Speiser Current Sheet Bifurcation

    NASA Astrophysics Data System (ADS)

    George, D. E.; Jahn, J. M.

    2017-12-01

    A single population of energized Oxygen (O+) is shown to produce a cross-tail bifurcated current sheet in 2.5D PIC simulations of the magnetotail without the influence of magnetic reconnection. Treatment of oxygen in simulations of space plasmas, specifically a magnetotail current sheet, has been limited to thermal energies despite observations of and mechanisms which explain energized ions. We performed simulations of a homogeneous oxygen background, that has been energized in a physically appropriate manner, to study the behavior of current sheets and magnetic reconnection, specifically their bifurcation. This work uses a 2.5D explicit Particle-In-a-Cell (PIC) code to investigate the dynamics of energized heavy ions as they stream Dawn-to-Dusk in the magnetotail current sheet. We present a simulation study dealing with the response of a current sheet system to energized oxygen ions. We establish a, well known and studied, 2-species GEM Challenge Harris current sheet as a starting point. This system is known to eventually evolve and produce magnetic reconnection upon thinning of the current sheet. We added a uniform distribution of thermal O+ to the background. This 3-species system is also known to eventually evolve and produce magnetic reconnection. We add one additional variable to the system by providing an initial duskward velocity to energize the O+. We also traced individual particle motion within the PIC simulation. Three main results are shown. First, energized dawn- dusk streaming ions are clearly seen to exhibit sustained Speiser motion. Second, a single population of heavy ions clearly produces a stable bifurcated current sheet. Third, magnetic reconnection is not required to produce the bifurcated current sheet. Finally a bifurcated current sheet is compatible with the Harris current sheet model. This work is the first step in a series of investigations aimed at studying the effects of energized heavy ions on magnetic reconnection. This work differs

  19. A mathematical simulation of the tip-apex distance and the calcar-referenced tip-apex distance for intertrochanteric fractures reduced with lag screws.

    PubMed

    Li, Shuang; Chang, Shi-Min; Jin, Yan-Min; Zhang, Ying-Qi; Niu, Wen-Xin; Du, Shou-Chao; Zhang, Li-Zhi; Ma, Hui

    2016-06-01

    As a predictor of the risk of lag screw cutout, it was recommended that keeping tip-apex distance (TAD)<25mm and placing the screw centrally or inferiorly, but positioning the lag screw too inferiorly in the head would produce TAD>25mm. We aim to simulate various positions of the lag screw in the femoral head and identify whether 25mm is a suitable cut-off value that favours all sizes of femoral heads with intertrochanteric fractures of the hip. Using a general mathematical software, the positions of the screw tip points were simulated. The virtual anterior-posterior and lateral views were then visualised, and the locus of the screw tips was projected into a Cartesian coordinate system according to the TAD and calcar-referenced tip-apex distance (CalTAD) formulas. Each original virtual anterior-posterior and lateral image was zoomed and compiled to match a calculated average image. The screw tip points were recorded, traced and compiled into volumes which could be used to visualise the screw's movements and positioning within the femoral head. The extracted volumes were calculated when 10mmtip were then assessed. For the TAD calculation, the shape of the traced screw tip points had a pancake-like appearance, while the CalTAD plot produced a teardrop-shaped region. The volume ratios of TAD, CalTAD and overlapping region relative to the femoral head volume were respectively 3.51±1.30%, 5.19±1.62% and 2.64±1.32%. The volumes of the traced TAD, CalTAD and overlapping regions increased slower than the volume of an idealised sphere. Positioning the lag screw should address geometrical effects of both tip-apex distance and femoral head size, with an emphasis on measuring the position of the screw tip for the suitable zone by volume ratio. The previous 25mm TAD cut-off value should be adjusted according to the individual femoral head

  20. Brief, embedded, spontaneous metacognitive talk indicates thinking like a physicist

    NASA Astrophysics Data System (ADS)

    Sayre, Eleanor C.; Irving, Paul W.

    2015-12-01

    [This paper is part of the Focused Collection on Upper Division Physics Courses.] Instructors and researchers think "thinking like a physicist" is important for students' professional development. However, precise definitions and observational markers remain elusive. We reinterpret popular beliefs inventories in physics to indicate what physicists think thinking like a physicist entails. Through discourse analysis of upper-division students' speech in natural settings, we show that students may appropriate or resist these elements. We identify a new element in the physicist speech genre: brief, embedded, spontaneous metacognitive talk (BESM talk). BESM talk communicates students' in-the-moment enacted expectations about physics as a technical field and a cultural endeavor. Students use BESM talk to position themselves as physicists or nonphysicists. Students also use BESM talk to communicate their expectations in four ways: understanding, confusion, spotting inconsistencies, and generalized expectations.

  1. Experimental formability analysis of bondal sandwich sheet

    NASA Astrophysics Data System (ADS)

    Kami, Abdolvahed; Banabic, Dorel

    2018-05-01

    Metal/polymer/metal sandwich sheets have recently attracted the interests of industries like automotive industry. These sandwich sheets have superior properties over single-layer metallic sheets including good sound and vibration damping and light weight. However, the formability of these sandwich sheets should be enhanced which requires more research. In this paper, the formability of Bondal sheet (DC06/viscoelastic polymer/DC06 sandwich sheet) was studied through different types of experiments. The mechanical properties of Bondal were determined by uniaxial tensile tests. Hemispherical punch stretching and hydraulic bulge tests were carried out to determine the forming limit diagram (FLD) of Bondal. Furthermore, cylindrical and square cup drawing tests were performed in dry and oil lubricated conditions. These tests were conducted at different blank holding forces (BHFs). An interesting observation about Bondal sheet deep drawing was obtaining of higher drawing depths at dry condition in comparison with oil-lubricated condition.

  2. Online monitoring of dynamic tip clearance of turbine blades in high temperature environments

    NASA Astrophysics Data System (ADS)

    Han, Yu; Zhong, Chong; Zhu, Xiaoliang; Zhe, Jiang

    2018-04-01

    Minimized tip clearance reduces the gas leakage over turbine blade tips and improves the thrust and efficiency of turbomachinery. An accurate tip clearance sensor, measuring the dynamic clearances between blade tips and the turbine case, is a critical component for tip clearance control. This paper presents a robust inductive tip clearance sensor capable of monitoring dynamic tip clearances of turbine machines in high-temperature environments and at high rotational speeds. The sensor can also self-sense the temperature at a blade tip in situ such that temperature effect on tip clearance measurement can be estimated and compensated. To evaluate the sensor’s performance, the sensor was tested for measuring the tip clearances of turbine blades under various working temperatures ranging from 700 K to 1300 K and at turbine rotational speeds ranging from 3000 to 10 000 rpm. The blade tip clearance was varied from 50 to 2000 µm. The experiment results proved that the sensor can accurately measure the blade tip clearances with a temporal resolution of 10 µm. The capability of accurately measuring the tip clearances at high temperatures (~1300 K) and high turbine rotation speeds (~30 000 rpm), along with its compact size, makes it promising for online monitoring and active control of blade tip clearances of high-temperature turbomachinery.

  3. Motivating Young Writers through Write-Talks: Real Writers, Real Audiences, Real Purposes

    ERIC Educational Resources Information Center

    Wilson, Amy Alexandra

    2008-01-01

    Modeled after the popular teaching technique of book talks, write talks are brief motivational talks designed to engage students in writing. Teachers can invite adults from their communities into their classrooms to give write talks, thereby conveying to students that real people go through different writing processes to write real texts for real…

  4. The Case for Using Blunt-Tipped Lightning Rods as Strike Receptors.

    NASA Astrophysics Data System (ADS)

    Moore, C. B.; Aulich, G. D.; Rison, William

    2003-07-01

    Conventional lightning rods used in the United States have sharp tips, a practice derived from Benjamin Franklin's discovery of a means to obtain protection from lightning. However, the virtue of sharp tips for strike reception has never been established. An examination of the relevant physics shows that very strong electric fields are required above the tips of rods in order that they function as strike receptors but that the gradients of the field strength over sharp-tipped rods are so great that, at distances of a few millimeters, the local fields are often too weak for the development of upward-going streamers. In field tests, rods with rounded tips have been found to be better strike receptors than were nearby sharp-tipped rods.

  5. Health Tips for Adults

    MedlinePlus

    ... For Reporters Meetings & Workshops Follow Us Home Health Information Weight Management Health Tips for Adults Related Topics English English ... at NIDDK Technology Advancement & Transfer Meetings & Workshops Health Information ... Disease Urologic Diseases Endocrine Diseases Diet & Nutrition ...

  6. Small-tip fast recovery imaging using non-slice-selective tailored tip-up pulses and RF-spoiling

    PubMed Central

    Nielsen, Jon-Fredrik; Yoon, Daehyun; Noll, Douglas C.

    2012-01-01

    Small-tip fast recovery (STFR) imaging is a new steady-state imaging sequence that is a potential alternative to balanced steady-state free precession (bSSFP). Under ideal imaging conditions, STFR may provide comparable signal-to-noise ratio (SNR) and image contrast as bSSFP, but without signal variations due to resonance offset. STFR relies on a tailored “tip-up”, or “fast recovery”, RF pulse to align the spins with the longitudinal axis after each data readout segment. The design of the tip-up pulse is based on the acquisition of a separate off-resonance (B0) map. Unfortunately, the design of fast (a few ms) slice- or slab-selective RF pulses that accurately tailor the excitation pattern to the local B0 inhomogeneity over the entire imaging volume remains a challenging and unsolved problem. We introduce a novel implementation of STFR imaging based on non-slice-selective tip-up pulses, which simplifies the RF design problem significantly. Out-of-slice magnetization pathways are suppressed using RF-spoiling. Brain images obtained with this technique show excellent gray/white matter contrast, and point to the possibility of rapid steady-state T2/T1-weighted imaging with intrinsic suppression of cerebrospinal fluid, through-plane vessel signal, and off-resonance artifacts. In the future we expect STFR imaging to benefit significantly from parallel excitation hardware and high-order gradient shim systems. PMID:22511367

  7. Talking with a child about a parent's terminal illness

    MedlinePlus

    ... gov/ency/patientinstructions/000848.htm Talking with a child about a parent's terminal illness To use the ... your child's anxiety. How to Talk to Your Child You may wonder when it is the right ...

  8. The Chicken and the Egg: Inviting Response and Talk through Socratic Circles

    ERIC Educational Resources Information Center

    Styslinger, Mary E.; Pollock, Timothy

    2010-01-01

    This collaborative inquiry answers the following questions: 1) What is the nature of talk during Socratic Circles? 2) What is student response to talk? 3) How might knowing more about student response to talk and the nature of talk improve teaching during Socratic Circles? The article first describes the process of implementing Socratic Circles,…

  9. Twelve tips for overnight teaching.

    PubMed

    Richards, Jeremy B; Wilcox, Susan R; Roberts, David H; Schwartzstein, Richard M

    2014-03-01

    The European Working Time Directive and the United States' duty hour restrictions have changed resident physicians' schedules, specifically increasing overnight shifts and decreasing overall time spent in the hospital. As residents' perception of night shifts is that they have little educational value, efforts to improve educational opportunities and night attending teaching are desirable. However, resources about and recommendations for best practices for overnight teaching by faculty are scarce. To provide 12 tips to highlight strategies intended to optimize attending physicians' overnight teaching skills and strategies. The tips provided are based on our experiences and reflections as in-house faculty supervising residents working overnight, by our experience and group discussions as medical educators, and the available literature. The 12 tips presented offer specific strategies to optimize attending physicians' overnight teaching for resident physicians, specifically highlighting the unique logistics, pedagogy and follow-up of overnight teaching. Preparation for teaching is important in any environment, but understanding the unique timing and circumstances associated with overnight teaching is vital to ensure that overnight teaching is effective. Acknowledging and addressing the physical and cognitive obstacles associated with overnight teaching and learning is necessary to maximize the educational value of overnight teaching.

  10. Pinning effects from substrate and AFM tip surfaces on interfacial nanobubbles

    NASA Astrophysics Data System (ADS)

    Teshima, Hideaki; Takahashi, Koji; Takata, Yasuyuki; Nishiyama, Takashi

    2017-11-01

    Measurement accuracy of atomic force microscopy (AFM) is vital to understand the mechanism of interfacial nanobubbles. In this study, we report the influence of pinning derived from both substrate and AFM tip surfaces on the measured shape of interfacial nanobubbles in peak force tapping mode. First, we pushed the nanobubbles using the AFM tip with high peak force setpoint. As a result, the deformed nanobubbles kept their flat shape for several tens of minutes. We quantitatively discuss the pinning force from substrate surface, which retains the flat shape enhancing the stability of nanobubbles. Next, we prepared three AFM tips with different wettability and measured the nanobubbles with an identical setpoint. By comparing the force curves obtained during the measurements, it seems that the (middle-)hydrophobic tips penetrated the liquid/gas interface and received repulsive force resulting from positive meniscus formed by pinning at the tip surface. In contrast, hydrophilic tip didn't penetrate the interface and received the force from the deformation of the interface of the nanobubbles. In addition, the measurements using the (middle-)hydrophobic tips led to the underestimation of the nanobubbles profile corresponding to the pinning position at the tip surfaces.

  11. Restaurant Dining: Seven Tips for Staying Gluten Free

    MedlinePlus

    GiG Education Bulletin Restaurant Dining: Seven Tips for Staying Gluten-Free Updated May 2014 Tips for Dining Away from Home 1. Selection of eating establishment. • Your success at gluten-free dining will be determined by a number of factors, including the ...

  12. Play Chronotopes: Laughter-Talk in Peer Group Conversation

    ERIC Educational Resources Information Center

    Liang, Mei-Ya

    2015-01-01

    Although research has investigated laughter in professional communication settings, fewer studies have explored laughter-talk in second language (L2) classrooms. This study examines L2 university students' use of laughter-talk in peer group conversation to understand the linguistics of affect and its interactional effects. The author draws upon…

  13. Improving Teacher Talk through a Task-Based Approach

    ERIC Educational Resources Information Center

    Moser, Jason; Harris, Justin; Carle, John

    2012-01-01

    This article reports on a teacher-talk training course for Japanese primary school teachers, who are preparing to teach "communicative English" for the first time. The article argues that teacher-talk training is important for communicative classes with young students because most of the input and interaction is by default teacher…

  14. Disintegration of liquid sheets

    NASA Technical Reports Server (NTRS)

    Mansour, Adel; Chigier, Norman

    1990-01-01

    The development, stability, and disintegration of liquid sheets issuing from a two-dimensional air-assisted nozzle is studied. Detailed measurements of mean drop size and velocity are made using a phase Doppler particle analyzer. Without air flow the liquid sheet converges toward the axis as a result of surface tension forces. With airflow a quasi-two-dimensional expanding spray is formed. The air flow causes small variations in sheet thickness to develop into major disturbances with the result that disruption starts before the formation of the main break-up region. In the two-dimensional variable geometry air-blast atomizer, it is shown that the air flow is responsible for the formation of large, ordered, and small chaotic 'cell' structures.

  15. Root-growth-inhibiting sheet

    DOEpatents

    Burton, Frederick G.; Cataldo, Dominic A.; Cline, John F.; Skiens, W. Eugene; Van Voris, Peter

    1993-01-01

    In accordance with this invention, a porous sheet material is provided at intervals with bodies of a polymer which contain a 2,6-dinitroaniline. The sheet material is made porous to permit free passage of water. It may be either a perforated sheet or a woven or non-woven textile material. A particularly desirable embodiment is a non-woven fabric of non-biodegradable material. This type of material is known as a "geotextile" and is used for weed control, prevention of erosion on slopes, and other landscaping purposes. In order to obtain a root repelling property, a dinitroaniline is blended with a polymer which is attached to the geotextile or other porous material.

  16. Root-growth-inhibiting sheet

    DOEpatents

    Burton, F.G.; Cataldo, D.A.; Cline, J.F.; Skiens, W.E.; Van Voris, P.

    1993-01-26

    In accordance with this invention, a porous sheet material is provided at intervals with bodies of a polymer which contain a 2,6-dinitroaniline. The sheet material is made porous to permit free passage of water. It may be either a perforated sheet or a woven or non-woven textile material. A particularly desirable embodiment is a non-woven fabric of non-biodegradable material. This type of material is known as a geotextile'' and is used for weed control, prevention of erosion on slopes, and other landscaping purposes. In order to obtain a root repelling property, a dinitroaniline is blended with a polymer which is attached to the geotextile or other porous material.

  17. Customized atomic force microscopy probe by focused-ion-beam-assisted tip transfer

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

    Wang, Andrew; Butte, Manish J., E-mail: manish.butte@stanford.edu

    2014-08-04

    We present a technique for transferring separately fabricated tips onto tipless atomic force microscopy (AFM) cantilevers, performed using focused ion beam-assisted nanomanipulation. This method addresses the need in scanning probe microscopy for certain tip geometries that cannot be achieved by conventional lithography. For example, in probing complex layered materials or tall biological cells using AFM, a tall tip with a high-aspect-ratio is required to avoid artifacts caused by collisions of the tip's sides with the material being probed. We show experimentally that tall (18 μm) cantilever tips fabricated by this approach reduce squeeze-film damping, which fits predictions from hydrodynamic theory, andmore » results in an increased quality factor (Q) of the fundamental flexural mode. We demonstrate that a customized tip's well-defined geometry, tall tip height, and aspect ratio enable improved measurement of elastic moduli by allowing access to low-laying portions of tall cells (T lymphocytes). This technique can be generally used to attach tips to any micromechanical device when conventional lithography of tips cannot be accomplished.« less

  18. 16 CFR 460.13 - Fact sheets.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... heat flow. The higher the R-value, the greater the insulating power. Compare insulation R-values before... INSULATION § 460.13 Fact sheets. If you are a manufacturer, you must give retailers and installers fact sheets for the insulation products you sell to them. Each sheet must contain what is listed here. You can...

  19. 16 CFR 460.13 - Fact sheets.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... heat flow. The higher the R-value, the greater the insulating power. Compare insulation R-values before... INSULATION § 460.13 Fact sheets. If you are a manufacturer, you must give retailers and installers fact sheets for the insulation products you sell to them. Each sheet must contain what is listed here. You can...

  20. 16 CFR 460.13 - Fact sheets.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... heat flow. The higher the R-value, the greater the insulating power. Compare insulation R-values before... INSULATION § 460.13 Fact sheets. If you are a manufacturer, you must give retailers and installers fact sheets for the insulation products you sell to them. Each sheet must contain what is listed here. You can...