Science.gov

Sample records for bainitic back-up roll

  1. Development of Fine-Grained, Low-Carbon Bainitic Steels with High Strength and Toughness Produced Through the Conventional Hot-Rolling and Air-Cooling

    NASA Astrophysics Data System (ADS)

    Dhua, Sanjay Kumar; Sarkar, Partha Pratim; Saxena, Atul; Jha, Bimal Kumar

    2016-09-01

    Low-carbon bainitic steels have created enormous interest among scientists across the world in the past few decades because of their high strength, toughness, and weldability replacing the conventional quenched and tempered medium-carbon steels. Three experimental steels with varying alloy additions were made in a 100-kg laboratory induction furnace and cast into 100-mm-diameter cylindrical ingots. These ingots were hot-rolled and air-cooled to 6-mm plates in an experimental rolling mill with selected thermomechanical parameters. Steels processed through this process provided an ultrafine low-carbon bainitic microstructure with maximum yield strength (YS) and ultimate tensile strength (UTS) 575 and 705 MPa, respectively. The Charpy impact toughness of the experimental steels was excellent, and at 253 K (-20 °C), it varied from 114 to 170 Joules. Cu-B-added steel was found to give an optimum combination of strength, YS-575 MPa, and toughness, 114 J at 253 K (-20 °C). Thus, fine-grained, low-carbon bainitic steels could be developed with a proper combination of alloying elements and thermomechanical parameters even by air-cooling.

  2. Crystallographic Reconstruction Study of the Effects of Finish Rolling Temperature on the Variant Selection During Bainite Transformation in C-Mn High-Strength Steels

    NASA Astrophysics Data System (ADS)

    Bernier, Nicolas; Bracke, Lieven; Malet, Loïc; Godet, Stéphane

    2014-12-01

    The effect of finish rolling temperature on the austenite-( γ) to-bainite ( α) phase transformation is quantitatively investigated in high-strength C-Mn steels using an alternative crystallographic γ reconstruction procedure, which can be directly applied to experimental electron backscatter diffraction mappings. In particular, the current study aims to clarify the respective contributions of the γ conditioning during the hot rolling and the variant selection during the phase transformation to the inherited texture. The results confirm that the sample finish rolled at the lowest temperature [1102 K (829 °C)] exhibits the sharpest transformation texture. It is shown that this sharp texture is exclusively due to a strong variant selection from parent brass {110}, S {213} and Goss {110}<001> grains, whereas the variant selection from the copper {112} grains is insensitive to the finish rolling temperature. In addition, a statistical variant selection analysis proves that the habit planes of the selected variants do not systematically correspond to the predicted active γ slip planes using the Taylor model. In contrast, a correlation between the Bain group to which the selected variants belong and the finish rolling temperature is clearly revealed, regardless of the parent orientation. These results are discussed in terms of polygranular accommodation mechanisms, especially in view of the observed development in the hot-rolled samples of high-angle grain boundaries with misorientation axes between <111> γ and <110> γ.

  3. Crystallographic Reconstruction Study of the Effects of Finish Rolling Temperature on the Variant Selection During Bainite Transformation in C-Mn High-Strength Steels

    NASA Astrophysics Data System (ADS)

    Bernier, Nicolas; Bracke, Lieven; Malet, Loïc; Godet, Stéphane

    2014-09-01

    The effect of finish rolling temperature on the austenite-(γ) to-bainite (α) phase transformation is quantitatively investigated in high-strength C-Mn steels using an alternative crystallographic γ reconstruction procedure, which can be directly applied to experimental electron backscatter diffraction mappings. In particular, the current study aims to clarify the respective contributions of the γ conditioning during the hot rolling and the variant selection during the phase transformation to the inherited texture. The results confirm that the sample finish rolled at the lowest temperature [1102 K (829 °C)] exhibits the sharpest transformation texture. It is shown that this sharp texture is exclusively due to a strong variant selection from parent brass {110} < {1bar{1}2} > , S {213} < {bar{3}bar{6}4} > and Goss {110}<001> grains, whereas the variant selection from the copper {112} < {bar{1}bar{1}1} > grains is insensitive to the finish rolling temperature. In addition, a statistical variant selection analysis proves that the habit planes of the selected variants do not systematically correspond to the predicted active γ slip planes using the Taylor model. In contrast, a correlation between the Bain group to which the selected variants belong and the finish rolling temperature is clearly revealed, regardless of the parent orientation. These results are discussed in terms of polygranular accommodation mechanisms, especially in view of the observed development in the hot-rolled samples of high-angle grain boundaries with misorientation axes between <111>γ and <110>γ.

  4. How to Back up Your Files

    ERIC Educational Resources Information Center

    Branzburg, Jeffrey

    2004-01-01

    In this article, the author gives tips on how to back up files to avoid losing work. Some of the methods he suggests include: (1) Floppy Disks; (2) Other Removable Media; (3) External Hard Drives; (4) Online; and (5) Backup Tape. He discusses manually backing up files in addition to using software to do so.

  5. Sleep Better at Night...Back Up Your Data.

    ERIC Educational Resources Information Center

    Smith, Russell

    1996-01-01

    Discusses the need to back up computer files, and describes the technological evolution of back-up methods. Reviews tape drive and external hard drive back-up products offered by computer companies and presents back-up strategies to use with all back-up methods. A sidebar lists information on the reviewed products. (JMV)

  6. OVERHILLS GOLF COURSE LOOKING NORTHEAST FROM SPECTATOR SHELTER BACK UP ...

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

    OVERHILLS GOLF COURSE LOOKING NORTHEAST FROM SPECTATOR SHELTER BACK UP FAIRWAY #1 - Overhills, Fort Bragg Military Reservation, Approximately 15 miles NW of Fayetteville, Overhills, Harnett County, NC

  7. Adding Back-Up Care to Your Center.

    ERIC Educational Resources Information Center

    Kinstlinger, Liz

    1999-01-01

    Discusses a strategy for day care centers to establish a back-up child care program that would provide care on an "as needed" basis. Suggests ways of marketing back-up care, scheduling staff, maximizing a separate room, determining fees, and integrating children into classroom routines. (JPB)

  8. 29. Lower level, back up, shockmounted storage batteries, front, looking ...

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

    29. Lower level, back up, shock-mounted storage batteries, front, looking south - Ellsworth Air Force Base, Delta Flight, Launch Facility, On County Road T512, south of Exit 116 off I-90, Interior, Jackson County, SD

  9. 30. Lower level, back up, shockmounted storage batteries, front and ...

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

    30. Lower level, back up, shock-mounted storage batteries, front and top, looking south - Ellsworth Air Force Base, Delta Flight, Launch Facility, On County Road T512, south of Exit 116 off I-90, Interior, Jackson County, SD

  10. Gemini 11 prime and back-up crews at Gemini Mission Simulator at Cape Kennedy

    NASA Technical Reports Server (NTRS)

    1966-01-01

    Gemini 11 prime and back-up crews at Gemini Mission Simulator at Cape Kennedy, Florida. Left to right are Astronauts William A. Anders, back-up crew pilot; Richard F. Gordon Jr., prime crew pilot; Charles Conrad Jr. (foot on desk), prime crew command pilot; and Neil A. Armstrong, back-up crew command pilot.

  11. Driver Training Simulator for Backing Up Commercial Vehicles with Trailers

    NASA Astrophysics Data System (ADS)

    Berg, Uwe; Wojke, Philipp; Zöbel, Dieter

    Backing up tractors with trailers is a difficult task since the kinematic behavior of articulated vehicles is complex and hard to control. Especially unskilled drivers are overstrained with the complicated steering process. To learn and practice the steering behavior of articulated vehicles, we developed a 3D driving simulator. The simulator can handle different types of articulated vehicles like semi-trailers, one- and two-axle trailers, or gigaliners. The use of a driving simulator offers many advantages over the use of real vehicles. One of the main advantages is the possibility to learn the steering behavior of all vehicle types. Drivers can be given more and better driving instructions like collision warnings or steering hints. Furthermore, the driver training costs can be reduced. Moreover, mistakes of the student do not lead to real damages and costly repairs. The hardware of the simulator consists of a low cost commercial driving stand with original truck parts, a projection of the windshield and two flat panel monitors for the left and right exterior mirrors. Standard PC hardware is used for controlling the driving stand and for generating the realtime 3D environment. Each aspect of the simulation like realistic vehicle movements or generation of different views, is handled by a specific software module. This flexible system can be easily extended which offers the opportunity for other uses than just driver training. Therefore, we use the simulator for the development and test of driver assistance systems.

  12. Modeling of mechanical behaviour of HSLA low carbon bainitic steel thermomechanically processed

    NASA Astrophysics Data System (ADS)

    Santos, D. B.; Rodrigues, P. C. M.; Cota, A. B.

    2003-10-01

    A comparative study of the microstructure characterization and mechanical properties was done in a HSLA low carbon (0.08%) bainitic steel containing boron, developed by industry as a bainitic steel grade APIX80. The steel was submitted to two different thermomechanical processes. In the first one, controlled rolling followed by accelerated cooling was applied in laboratory mill. In the second processing, specimens of the same steel were submitted to hot torsion testing. The influence of cooling conditions like start cooling temperature, cooling rates and finish cooling temperature on the microstructure and mechanical properties were investigated. The final microstructure obtained was a complex mixture of polygonal ferrite, perlite, bainite and martensite/retained austenite constituent. The use of multiple regression analysis allowed the establishment of quantitative relationships between the accelerated cooling variables and mechanical properties of the steel available from Vickers microhardness and tensile tests.

  13. Hydrogen Permeation in Nanostructured Bainitic Steel

    NASA Astrophysics Data System (ADS)

    Kazum, Oluwole; Beladi, Hossein; Timokhina, Ilana B.; He, Yinghe; Bobby Kannan, M.

    2016-07-01

    Hydrogen permeation of nanostructured bainitic steel, produced at two different transformation temperatures, i.e., 473.15 K (200 °C) BS-200 and 623.15 K (350 °C) BS-350, was determined using Devanathan-Stachurski hydrogen permeation cell and compared with that of mild steel. Nanostructured bainitic steel showed lower effective diffusivity of hydrogen as compared to the mild steel. The BS-200 steel, which exhibited higher volume fraction of bainitic ferrite phase, showed lower effective diffusivity than BS-350 steel. The finer microstructural constituents (bainitic ferrite laths and retained austenite films) and higher dislocation density in the bainitic ferrite phase of BS-200 steel can be attributed to its lower effective diffusivity as compared to BS-350 steel and mild steel.

  14. Hydrogen Permeation in Nanostructured Bainitic Steel

    NASA Astrophysics Data System (ADS)

    Kazum, Oluwole; Beladi, Hossein; Timokhina, Ilana B.; He, Yinghe; Bobby Kannan, M.

    2016-10-01

    Hydrogen permeation of nanostructured bainitic steel, produced at two different transformation temperatures, i.e., 473.15 K (200 °C) BS-200 and 623.15 K (350 °C) BS-350, was determined using Devanathan-Stachurski hydrogen permeation cell and compared with that of mild steel. Nanostructured bainitic steel showed lower effective diffusivity of hydrogen as compared to the mild steel. The BS-200 steel, which exhibited higher volume fraction of bainitic ferrite phase, showed lower effective diffusivity than BS-350 steel. The finer microstructural constituents (bainitic ferrite laths and retained austenite films) and higher dislocation density in the bainitic ferrite phase of BS-200 steel can be attributed to its lower effective diffusivity as compared to BS-350 steel and mild steel.

  15. Back-Up/ Peak Shaving Fuel Cell System

    SciTech Connect

    Staudt, Rhonda L.

    2008-05-28

    This Final Report covers the work executed by Plug Power from 8/11/03 – 10/31/07 statement of work for Topic 2: advancing the state of the art of fuel cell technology with the development of a new generation of commercially viable, stationary, Back-up/Peak-Shaving fuel cell systems, the GenCore II. The Program cost was $7.2 M with the Department of Energy share being $3.6M and Plug Power’s share being $3.6 M. The Program started in August of 2003 and was scheduled to end in January of 2006. The actual program end date was October of 2007. A no cost extension was grated. The Department of Energy barriers addressed as part of this program are: Technical Barriers for Distributed Generation Systems: o Durability o Power Electronics o Start up time Technical Barriers for Fuel Cell Components: o Stack Material and Manufacturing Cost o Durability o Thermal and water management Background The next generation GenCore backup fuel cell system to be designed, developed and tested by Plug Power under the program is the first, mass-manufacturable design implementation of Plug Power’s GenCore architected platform targeted for battery and small generator replacement applications in the telecommunications, broadband and UPS markets. The next generation GenCore will be a standalone, H2 in-DC-out system. In designing the next generation GenCore specifically for the telecommunications market, Plug Power is teaming with BellSouth Telecommunications, Inc., a leading industry end user. The final next generation GenCore system is expected to represent a market-entry, mass-manufacturable and economically viable design. The technology will incorporate: • A cost-reduced, polymer electrolyte membrane (PEM) fuel cell stack tailored to hydrogen fuel use • An advanced electrical energy storage system • A modular, scalable power conditioning system tailored to market requirements • A scaled-down, cost-reduced balance of plant (BOP) • Network Equipment Building Standards (NEBS), UL

  16. Regularities of bainitic steel deformation transition

    NASA Astrophysics Data System (ADS)

    Gromov, V. E.; Nikitina, E. N.; Ivanov, Yu F.; Aksenova, K. V.

    2016-09-01

    Quantitative analysis of defect and carbide subsystems evolution in medium-carbon bainitic steel subjected to compressive strain up to 36% was performed by means of transmission electron diffraction microscopy. Dislocation substructure and carbide phase parameters dependence on degree of deformation are identified, possible reasons of staging in their changes are discussed. It is suggested that the reason for bainitic steel softening at high (over 15%) degrees of deformation is activation of deformation microtwinning process.

  17. 30 CFR 75.1101-9 - Back-up water system.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Back-up water system. 75.1101-9 Section 75.1101-9 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Fire Protection § 75.1101-9 Back-up water...

  18. 30 CFR 75.1101-9 - Back-up water system.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Back-up water system. 75.1101-9 Section 75.1101-9 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Fire Protection § 75.1101-9 Back-up water...

  19. 30 CFR 75.1101-9 - Back-up water system.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Back-up water system. 75.1101-9 Section 75.1101-9 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Fire Protection § 75.1101-9 Back-up water...

  20. 30 CFR 75.1101-9 - Back-up water system.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Back-up water system. 75.1101-9 Section 75.1101-9 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Fire Protection § 75.1101-9 Back-up water...

  1. 30 CFR 75.1101-9 - Back-up water system.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Back-up water system. 75.1101-9 Section 75.1101-9 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Fire Protection § 75.1101-9 Back-up water...

  2. 26 CFR 48.4082-4 - Diesel fuel and kerosene; back-up tax.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 16 2010-04-01 2010-04-01 true Diesel fuel and kerosene; back-up tax. 48.4082-4 Section 48.4082-4 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED..., and Taxable Fuel Taxable Fuel § 48.4082-4 Diesel fuel and kerosene; back-up tax. (a) Imposition of...

  3. 26 CFR 48.4082-4 - Diesel fuel and kerosene; back-up tax.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 26 Internal Revenue 16 2012-04-01 2012-04-01 false Diesel fuel and kerosene; back-up tax. 48.4082-4 Section 48.4082-4 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED..., and Taxable Fuel Taxable Fuel § 48.4082-4 Diesel fuel and kerosene; back-up tax. (a) Imposition of...

  4. 26 CFR 48.4082-4 - Diesel fuel and kerosene; back-up tax.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 26 Internal Revenue 16 2013-04-01 2013-04-01 false Diesel fuel and kerosene; back-up tax. 48.4082-4 Section 48.4082-4 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED..., and Taxable Fuel Taxable Fuel § 48.4082-4 Diesel fuel and kerosene; back-up tax. (a) Imposition of...

  5. 26 CFR 48.4082-4 - Diesel fuel and kerosene; back-up tax.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 26 Internal Revenue 16 2011-04-01 2011-04-01 false Diesel fuel and kerosene; back-up tax. 48.4082-4 Section 48.4082-4 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED..., and Taxable Fuel Taxable Fuel § 48.4082-4 Diesel fuel and kerosene; back-up tax. (a) Imposition of...

  6. Backing up behaviors in teams: the role of personality and legitimacy of need.

    PubMed

    Porter, Christopher O L H; Hollenbeck, John R; Ilgen, Daniel R; Ellis, Aleksander P J; West, Bradley J; Moon, Henry

    2003-06-01

    In this article, the authors developed several hypotheses regarding both the main and interactive effects of 2 types of team inputs on backing up behaviors in teams: (a) team composition characteristics in terms of the personality of the members of the team and (b) team task characteristics in terms of the extent to which the nature of the task is one that legitimately calls for some members of the team to back up other members of the team. Results from a study of 71 4-person teams performing a computerized tactical decision-making task suggest that the legitimacy of the need for back up has an important main effect on the extent to which team members provide assistance to and receive assistance from each other. In addition, the legitimacy of the need for back up also has important interactive effects with both the personality of the back up recipient and the personality of the back up providers on backing up behaviors in teams.

  7. Roll Eccentricity Control Using Identified Eccentricity of Top/Bottom Rolls by Roll Force

    NASA Astrophysics Data System (ADS)

    Imanari, Hiroyuki; Koshinuma, Kazuyoshi

    Roll eccentricity is a periodic disturbance caused by a structure of back up rolls in rolling mills, and it affects product thickness accuracy. It cannot be measured directly by sensors, so it should be identified by measured thickness or measured roll force. When there is a large difference of diameters between top and bottom back up roll, the performance of roll eccentricity control using feedback signals of roll force or thickness has not been so good. Also it has been difficult for the control to be applied from the most head end because it is necessary to identify the roll eccentricity during rolling. A new roll eccentricity control has been developed to improve these disadvantages and to get better performance. The method identifies top and bottom roll eccentricity respectively from one signal of roll force and it can start the control from head end. In this paper the new control method is introduced and actual application results to a hot strip mill are shown.

  8. Modeling the austenite decomposition into ferrite and bainite

    NASA Astrophysics Data System (ADS)

    Fazeli, Fateh

    2005-12-01

    Novel advanced high-strength steels such as dual-phase (DP) and transformation induced plasticity (TRIP) steels, are considered as promising materials for new generation of lightweight vehicles. The superior mechanical properties of these steels, compared to classical high strength steels, are associated with their complex microstructures. The desired phase configuration and morphology can only be achieved through well-controlled processing paths with rather tight processing windows. To implement such challenging processing stages into the current industrial facilities a significant amount of development efforts, in terms of mill trials, have to be performed. Alternatively, process models as predictive tools can be employed to aid the process development' and also to design new steel grades. Knowledge-based process models are developed by virtue of the underlying physical phenomena occurring during the industrial processing and are validated with experimental data. The goal of the present work is to develop an integrated microstructure model to adequately describe the kinetics of austenite decomposition into polygonal ferrite and bainite, such that for complex thermal paths simulating those of industrial practice, the final microstructure in advanced high strength steels can reasonably be predicted. This is in particular relevant to hot-rolled DP and TRIP steels, where the intercritical ferrite evolution due to its crucial influence on the onset and kinetics of the subsequent bainite formation, has to be quantified precisely. The calculated fraction, size and spatial carbon distribution of the intercritical austenite are employed as input to characterize adequately the kinetic of the bainite reaction. Pertinent to ferrite formation, a phenomenological, physically-based model was developed on the ground of the mixed-mode approach. The model deals with the growth stage since nucleation site saturation at prior austenite grain boundaries is likely to be attained

  9. 30 CFR 75.1101-21 - Back-up water system.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Back-up water system. 75.1101-21 Section 75.1101-21 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY... water system. One fire hose outlet together with a length of hose capable of extending to the belt...

  10. 30 CFR 75.1101-21 - Back-up water system.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Back-up water system. 75.1101-21 Section 75.1101-21 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY... water system. One fire hose outlet together with a length of hose capable of extending to the belt...

  11. 30 CFR 75.1101-21 - Back-up water system.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Back-up water system. 75.1101-21 Section 75.1101-21 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY... water system. One fire hose outlet together with a length of hose capable of extending to the belt...

  12. 30 CFR 75.1101-21 - Back-up water system.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Back-up water system. 75.1101-21 Section 75.1101-21 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY... water system. One fire hose outlet together with a length of hose capable of extending to the belt...

  13. 30 CFR 75.1101-21 - Back-up water system.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Back-up water system. 75.1101-21 Section 75.1101-21 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY... water system. One fire hose outlet together with a length of hose capable of extending to the belt...

  14. Rationale for Isidis Planitia as a back-up landing site for the Mars Pathfinder mission

    NASA Technical Reports Server (NTRS)

    Craddock, Robert A.

    1994-01-01

    The present engineering constraints imposed on the Mars Pathfinder mission leave only three broad regions available for site selection: Amazonis, Chryse, and Isidis Planitia. Because of the knowledge gained by the Viking 1 mission, Chryse Planitia would make an ideal primary landing site. Geological characteristics of Isidis Planitia are discussed with a view to making it a back-up landing site.

  15. Intelligent controller for backing up a tractor-trailer truck using state transition table

    NASA Astrophysics Data System (ADS)

    Enab, Yehia M.

    1997-09-01

    The paper introduces a technique for constructing a look-up table that contains information about selected points in the state space of the nonlinear process to be controlled. The new states to which a specific state point transfers when the process is issued different control commands are registered. The controller designed to make use of the table depends on the heuristic assumption that the behavior of the process at a specific state space point is similar to its behavior at a nearby point provided that the process is issued a similar control command at each state. The table design aspects for reducing the storage requirements and minimizing the computational effort for producing control decisions are investigated. The applicability of the controller is tested for the tractor-trailer truck steering problem backing up at a constant speed. The truck backs up in an environment that contains obstacles to be avoided. Computer simulation of the truck and its controller has demonstrated workability.

  16. Back-Up Childcare: A Quality Alternative to Regular Care Which Fosters Resilience in Infants and Toddlers.

    ERIC Educational Resources Information Center

    La Bar, Nicole J.

    To many in the field of early care and education, back-up child care may be viewed as a stressful disruption that could interfere with attachment and be detrimental to continuity of care. This paper attempts to prove that high-quality back-up child care offered by employers actually fosters the development of resiliency in young children by…

  17. Retained austenite thermal stability in a nanostructured bainitic steel

    SciTech Connect

    Avishan, Behzad; Garcia-Mateo, Carlos; Yazdani, Sasan; Caballero, Francisca G.

    2013-07-15

    The unique microstructure of nanostructured bainite consists of very slender bainitic ferrite plates and high carbon retained austenite films. As a consequence, the reported properties are opening a wide range of different commercial uses. However, bainitic transformation follows the T{sub 0} criteria, i.e. the incomplete reaction phenomena, which means that the microstructure is not thermodynamically stable because the bainitic transformation stops well before austenite reaches an equilibrium carbon level. This article aims to study the different microstructural changes taking place when nanostructured bainite is destabilized by austempering for times well in excess of that strictly necessary to end the transformation. Results indicate that while bainitic ferrite seems unaware of the extended heat treatment, retained austenite exhibits a more receptive behavior to it. - Highlights: • Nanostructured bainitic steel is not thermodynamically stable. • Extensive austempering in these microstructures has not been reported before. • Precipitation of cementite particles is unavoidable at longer austempering times. • TEM, FEG-SEM and XRD analysis were used for microstructural characterization.

  18. Examination of carbon partitioning into austenite during tempering of bainite

    SciTech Connect

    Clarke, Amy J; Caballero, Francisca G; Miller, Michael K; Garcia - Mateo, C

    2010-01-01

    The redistribution of carbon after tempering of a novel nanocrystalline bainitic steel consisting of a mixture of supersaturated ferrite and retained austenite, has been analyzed by atom probe tomography. Direct supporting evidence of additional austenite carbon enrichment beyond that initially achieved during the bainite heat treatment was not obtained during subsequent tempering of this high carbon, high silicon steel. Evidence of competing reactions during tempering, such as the formation of carbon clusters in bainitic ferrite that signify the onset of the transitional carbides precipitation, was observed.

  19. Yeast mitochondrial glutathione is an essential antioxidant with mitochondrial thioredoxin providing a back-up system

    PubMed Central

    Gostimskaya, Irina; Grant, Chris M.

    2016-01-01

    Glutathione is an abundant, low-molecular-weight tripeptide whose biological importance is dependent upon its redox-active free sulphydryl moiety. Its role as the main determinant of thiol-redox control has been challenged such that it has been proposed to play a crucial role in iron–sulphur clusters maturation, and only a minor role in thiol redox regulation, predominantly as a back-up system for the cytoplasmic thioredoxin system. Here, we have tested the importance of mitochondrial glutathione in thiol-redox regulation. Glutathione reductase (Glr1) is an oxidoreductase which converts oxidized glutathione to its reduced form. Yeast Glr1 localizes to both the cytosol and mitochondria and we have used a Glr1M1L mutant that is constitutively localized to the cytosol to test the requirement for mitochondrial Glr1. We show that the loss of mitochondrial Glr1 specifically accounts for oxidant sensitivity of a glr1 mutant. Loss of mitochondrial Glr1 does not influence iron–sulphur cluster maturation and we have used targeted roGFP2 fluorescent probes to show that oxidant sensitivity is linked to an altered redox environment. Our data indicate mitochondrial glutathione is crucial for mitochondrial thiol-redox regulation, and the mitochondrial thioredoxin system provides a back-up system, but cannot bear the redox load of the mitochondria on its own. PMID:26898146

  20. Mechanism of bainitic transformation in compacted graphite cast irons

    NASA Astrophysics Data System (ADS)

    Guilemany, J. M.; Llorca-Isern, N.

    1990-03-01

    Samples of unalloyed compacted graphite cast iron (CGI) have been thermally treated to obtain a bainitic structure. Heat treatments consisting of various holding times at two different austenitizing temperatures and two different austempering temperatures have been carried out followed by metallographic observations of the resultant structures by scanning electron microscopy (SEM). The formation of bainite is discussed in terms of the temperature difference (undercooling) between the austenitizing temperature and austempering temperature, and the subsequent development of the phases present to bainite is related to the carbon concentration gradient caused by compacted graphite acting as a sink for carbon. This favors the final stages of the transformation. A hypothesis for the bainitic transformation mechanism in CGI's is thus proposed.

  1. Rolling cuff flexible bellows

    DOEpatents

    Lambert, Donald R.

    1985-01-01

    A flexible connector apparatus used to join two stiff non-deformable members, such as piping. The apparatus is provided with one or more flexible sections or assemblies each utilizing a bellows of a rolling cuff type connected between two ridge members, with the bellows being supported by a back-up ring, such that only the curved end sections of the bellows are unsupported. Thus, the bellows can be considered as being of a tube-shaped configuration and thus have high pressure resistance. The components of the flexible apparatus are sealed or welded one to another such that it is fluid tight.

  2. Kinetics of bainite transformation in carburized 4317 M2

    NASA Astrophysics Data System (ADS)

    Chupatanakul, Smati

    The bainite transformation in steels has become increasingly important for industry in recent years. Nevertheless certain aspects the bainite transformation are still not fully understood. Understanding the bainite transformation in 4317 M2 type steels requires a thorough knowledge of the bainite transformation kinetics, the effect of carbon concentration to the kinetics and the understanding of carbon partitioning during the bainite transformation. Austempering experiments were performed in order to study the bainite transformation kinetics in three steels based on 4317 M2 with different carbon contents. The dilatometry technique was used to obtain the dilation as a function of transformation time and temperature. The fraction transformed ( f) was determined as a function of transformation time to generate a TTT diagram. The relationship of Ms temperature as a function of carbon content was determined. For the first time carbon partitioning during the bainite transformation was deduced from the change in Ms as a function of austempering holding time and temperature. The maximum values of carbon content achieved in the residual austenite were determined and compared to the T0 carbon composition calculated from Thermocalc(TM) for each austempering temperature. Excellent agreement was found and the experimental results therefore support the bainite transformation model of shear displacement followed by carbon partitioning. X-ray diffraction, microstructure examination and hardness analysis were used in order to understand the transformation kinetics and optimize processing for case carburized 4317 M2. All the results were compared and analyzed in terms of the carbon concentration gradient in case carburized 4317 M2 steel.

  3. [Current situation of available back-up beds for terminal home care patients].

    PubMed

    Kato, Toshihiko; Takahashi, Osamu; Shimizu, Kazuko; Chiba, Yasuko

    2014-12-01

    The Palliative Care Unit at Heiwa Hospital has 16 beds, and offers inpatient support in general wards, as well as back-up beds in emergencies in collaboration with local home care support clinics. For two years from January 2012 to December 2013, there were 1,213 cases where patients were seen for initial outpatient visits at the Department of Palliative Care. At the time of the initial visit, visiting medical care had been introduced for 25% of the cases. Although 59% of the patients who visited our department are hospitalized, 20% of inpatients have been hospitalized at the request of their home care physician. The availability of back-upbeds offers patients and their families, as well as related medical institutions, a sense of security, and enables home care to continue. The significance of back-upbeds will become even more important in the future.

  4. Moving Object Detection on a Vehicle Mounted Back-Up Camera

    PubMed Central

    Kim, Dong-Sun; Kwon, Jinsan

    2015-01-01

    In the detection of moving objects from vision sources one usually assumes that the scene has been captured by stationary cameras. In case of backing up a vehicle, however, the camera mounted on the vehicle moves according to the vehicle’s movement, resulting in ego-motions on the background. This results in mixed motion in the scene, and makes it difficult to distinguish between the target objects and background motions. Without further treatments on the mixed motion, traditional fixed-viewpoint object detection methods will lead to many false-positive detection results. In this paper, we suggest a procedure to be used with the traditional moving object detection methods relaxing the stationary cameras restriction, by introducing additional steps before and after the detection. We also decribe the implementation as a FPGA platform along with the algorithm. The target application of this suggestion is use with a road vehicle’s rear-view camera systems. PMID:26712761

  5. Moving Object Detection on a Vehicle Mounted Back-Up Camera.

    PubMed

    Kim, Dong-Sun; Kwon, Jinsan

    2015-01-01

    In the detection of moving objects from vision sources one usually assumes that the scene has been captured by stationary cameras. In case of backing up a vehicle, however, the camera mounted on the vehicle moves according to the vehicle's movement, resulting in ego-motions on the background. This results in mixed motion in the scene, and makes it difficult to distinguish between the target objects and background motions. Without further treatments on the mixed motion, traditional fixed-viewpoint object detection methods will lead to many false-positive detection results. In this paper, we suggest a procedure to be used with the traditional moving object detection methods relaxing the stationary cameras restriction, by introducing additional steps before and after the detection. We also decribe the implementation as a FPGA platform along with the algorithm. The target application of this suggestion is use with a road vehicle's rear-view camera systems. PMID:26712761

  6. Microstructural characterization of Charpy-impact-tested nanostructured bainite

    SciTech Connect

    Tsai, Y.T.; Chang, H.T.; Huang, B.M.; Huang, C.Y.; Yang, J.R.

    2015-09-15

    In this work, a possible cause of the extraordinary low impact toughness of nanostructured bainite has been investigated. The microstructure of nanostructured bainite consisted chiefly of carbide-free bainitic ferrite with retained austenite films. X-ray diffractometry (XRD) measurement indicated that no retained austenite existed in the fractured surface of the Charpy-impact-tested specimens. Fractographs showed that cracks propagated mainly along bainitic ferrite platelet boundaries. The change in microstructure after impact loading was verified by transmission electron microscopy (TEM) observations, confirming that retained austenite was completely transformed to strain-induced martensite during the Charpy impact test. However, the zone affected by strained-induced martensite was found to be extremely shallow, only to a depth of several micrometers from the fracture surface. It is appropriately concluded that upon impact, as the crack forms and propagates, strain-induced martensitic transformation immediately occurs ahead of the advancing crack tip. The successive martensitic transformation profoundly facilitates the crack propagation, resulting in the extremely low impact toughness of nanostructured bainite. Retained austenite, in contrast to its well-known beneficial role, has a deteriorating effect on toughness during the course of Charpy impact. - Highlights: • The microstructure of nanostructured bainite consisted of nano-sized bainitic ferrite subunits with retained austenite films. • Special sample preparations for SEM, XRD and TEM were made, and the strain-affected structures have been explored. • Retained austenite films were found to transform into martensite after impact loading, as evidenced by XRD and TEM results. • The zone of strain-induced martensite was found to extend to only several micrometers from the fracture surface. • The poor Charpy impact toughness is associated with the fracture of martensite at a high strain rate during

  7. Selection of a rechargeable internal back-up battery for a totally implantable artificial heart.

    PubMed

    Honda, H; Shiba, K; Shu, E; Koshiji, K; Murai, T; Nakamura, T; Masuzawa, T; Tatsumi, E; Taenaka, Y; Takano, H

    1999-01-01

    Three kinds of rechargeable batteries, NiCd, NiMH, and Li+, were compared for the purpose of selecting the most appropriate battery for use in a Rechargeable Internal Back-up Battery (RIBB) unit for a Totally Implantable Artificial Heart. Batteries of each kind were connected in series to obtain the required driving voltage of 24 V. The NiCd and NiMH batteries were charged by a constant current of 1 C, and the Li+ batteries were charged first by a constant current of 1 C and later by a constant voltage of 28.7 V. All three types of batteries were discharged using a dummy electronic pulsatile load consuming 20 W of power. The tests showed that the Li+ batteries were capable of supplying the required energy for more than 60 minutes. The Li+ batteries had a specific energy of 121.5 Wh/kg, which was more than 3x that of the NiCd and NiMH, and an energy density of 282.5 Wh/L more than double that of the other two. In addition, the Li+ batteries recorded the least temperature rise during charging and discharging. The results of our tests conclusively showed that the Li+ battery is the best among the three for use in an RIBB from the viewpoint of energy density and temperature rise.

  8. Wear Behavior of Newly Developed Bainitic Wheel Steels

    NASA Astrophysics Data System (ADS)

    Sharma, S.; Sangal, S.; Mondal, K.

    2015-02-01

    The present work concentrates on the analysis of wear behavior of bainitic steels made by austempering from a microalloyed steel MAS2, meant for making railway wheel, and comparison with that of a conventional railway wheel steel, wheel-R19. Austempering of the MAS2 steel samples has been performed at different times and temperatures to obtain different morphologies of bainite. Linearly reciprocating dry sliding wear tests of these samples have been carried out at laboratory scale using five different loads. The wear behavior of the bainitic steels has been compared with that of the ferritic-pearlitic steel, wheel-R19. Mechanical properties of the bainitic MAS2 steels are found to be more than that of the wheel-R19 steel. Considerable enhancement in wear resistance of the bainitic steels is attributed to high hardness and strength of the steels. The wear mechanism has been critically analyzed by examining wear track morphology. The wear data gathered have been graphically presented in the form of wear mechanism map to understand the material behavior under different sliding conditions and subsequent morphological variations.

  9. Bainitic microstructures formed by split isothermal transformation in an Fe-C-Si-Mn-Mo steel

    SciTech Connect

    Ali, A.

    1996-05-01

    Effect of split isothermal transformations (SITs) on bainitic microstructure has been studied in an Fe-C-Si-Mn-Mo steel by optical and transmission electron microscopy. Split isothermal transformations caused the spheroidization and coalescence of bainitic ferrite subunits, suggesting that bainite probably formed by a displacive transformation mechanism.

  10. Corrosion Behavior of High-Strength Bainitic Rail Steels

    NASA Astrophysics Data System (ADS)

    Moon, A. P.; Sangal, S.; Layek, S.; Giribaskar, S.; Mondal, Kallol

    2015-04-01

    The present work discusses corrosion behavior of newly developed bainitic steels made by isothermal heat treatment of a new steel composition (0.71 pct C, 1.15 pct Mn, 0.20 pct Ni, 0.59 pct Cr, 0.40 pct Cu, 0.35 pct Si, 0.026 pct S, 0.027 pct P, and rest Fe (weight percent)). Corrosion behavior of the pearlitic steel made by normalization is also studied. Electrochemical polarization and salt fog tests are carried out in 0.6 M NaCl. Steel rusts after salt fog tests are analyzed. Modified composition, finer microstructures, and compact rust morphology attribute to better corrosion resistance of the bainitic steels. Corrosion mechanisms for the pearlitic and bainitic steels are discussed.

  11. Carbon distribution in bainitic steel subjected to deformation

    SciTech Connect

    Ivanov, Yu. F.; Nikitina, E. N. Gromov, V. E.

    2015-10-27

    Analysis of the formation and evolution of carbide phase in medium carbon steel with a bainitic structure during compressive deformation was performed by means of transmission electron diffraction microscopy. Qualitative transformations in carbide phase medium size particles, their density and volume concentration depended on the degree of deformation.

  12. Influence of Composition and Hot Rolling on the Subsurface Microstructure and Bendability of Ultrahigh-Strength Strip

    NASA Astrophysics Data System (ADS)

    Kaijalainen, Antti Juhani; Liimatainen, Mia; Kesti, Vili; Heikkala, Jouko; Liimatainen, Tommi; Porter, David A.

    2016-08-01

    The effect of subsurface microstructure on the bendability of three 8-mm-thick low-alloyed hot-rolled and direct-quenched ultrahigh-strength strip steels with yield strengths in the range 800 to 1100 MPa has been investigated. Rolling to lower finish rolling temperatures increased austenite pancaking, leading to the formation of ferritic/granular bainitic subsurface microstructures that are softer than the upper bainitic microstructures found with higher finish rolling temperature. In addition, increased austenite pancaking was found to increase the intensities of {112}<111>α and {110}<112>α to {110}<111>α texture components in the surface layers, especially in upper bainitic microstructures. It is shown that the bendability of ultrahigh-strength steels is governed by subsurface hardness and crystallographic texture. Bendability was found to be related to mean microhardness 0.1 to 0.4 mm below the surface, such that excellent bendability was achieved with a relatively soft subsurface layer down to a depth of 0.4 mm, i.e., 5 pct of the sheet thickness. Intense {112}<111>α texture combined with upper bainite containing MA islands in the subsurface region is shown to be detrimental to bendability when the bend axis is perpendicular to the rolling direction probably as a result of geometrical softening combined with high hardness.

  13. Rolling-cuff flexible bellows

    DOEpatents

    Lambert, D.R.

    1982-09-27

    A flexible connector apparatus used to join two stiff non-deformable members, such as piping, is described. The apparatus is provided with one or more flexible sections or assemblies each utilizing a bellows of a rolling cuff type connected between two ridge members, with the bellows being supported by a back-up ring, such that only the curved end sections of the bellows are unsupported. Thus, the bellows can be considered as being of a tube-shaped configuration and thus have high pressure resistance. The components of the flexible apparatus are sealed or welded one to another such that it is fluid tight.

  14. Correlative microscopy of a carbide-free bainitic steel.

    PubMed

    Hofer, Christina; Bliznuk, Vitaliy; Verdiere, An; Petrov, Roumen; Winkelhofer, Florian; Clemens, Helmut; Primig, Sophie

    2016-02-01

    In this work a carbide-free bainitic steel was examined by a novel correlative microscopy approach using transmission Kikuchi diffraction (TKD) and transmission electron microscopy (TEM). The individual microstructural constituents could be identified by TKD based on their different crystal structure for bainitic ferrite and retained austenite and by image quality for the martensite-austenite (M-A) constituent. Subsequently, the same area was investigated in the TEM and a good match of these two techniques regarding the identification of the area position and crystal orientation could be proven. Additionally, the M-A constituent was examined in the TEM for the first time after preceded unambiguous identification using a correlative microscopy approach. The selected area diffraction pattern showed satellites around the main reflexes which might indicate a structural modulation.

  15. Correlative microscopy of a carbide-free bainitic steel.

    PubMed

    Hofer, Christina; Bliznuk, Vitaliy; Verdiere, An; Petrov, Roumen; Winkelhofer, Florian; Clemens, Helmut; Primig, Sophie

    2016-02-01

    In this work a carbide-free bainitic steel was examined by a novel correlative microscopy approach using transmission Kikuchi diffraction (TKD) and transmission electron microscopy (TEM). The individual microstructural constituents could be identified by TKD based on their different crystal structure for bainitic ferrite and retained austenite and by image quality for the martensite-austenite (M-A) constituent. Subsequently, the same area was investigated in the TEM and a good match of these two techniques regarding the identification of the area position and crystal orientation could be proven. Additionally, the M-A constituent was examined in the TEM for the first time after preceded unambiguous identification using a correlative microscopy approach. The selected area diffraction pattern showed satellites around the main reflexes which might indicate a structural modulation. PMID:26642344

  16. Three phase crystallography and solute distribution analysis during residual austenite decomposition in tempered nanocrystalline bainitic steels

    SciTech Connect

    Caballero, F.G.; Yen, Hung-Wei; Miller, M.K.; Cornide, J.; Chang, Hsiao-Tzu; Garcia-Mateo, C.; Yang, Jer-Ren

    2014-02-15

    Interphase carbide precipitation due to austenite decomposition was investigated by high resolution transmission electron microscopy and atom probe tomography in tempered nanostructured bainitic steels. Results showed that cementite (θ) forms by a paraequilibrium transformation mechanism at the bainitic ferrite–austenite interface with a simultaneous three phase crystallographic orientation relationship. - Highlights: • Interphase carbide precipitation due to austenite decomposition • Tempered nanostructured bainitic steels • High resolution transmission electron microscopy and atom probe tomography • Paraequilibrium θ with three phase crystallographic orientation relationship.

  17. "We don't have a back-up plan": an exploration of family contingency planning for emergencies following stroke.

    PubMed

    O'Sullivan, Tracey; Ghazzawi, Andrea; Stanek, Agatha; Lemyre, Louise

    2012-01-01

    Little research has explored emergency preparedness among families coping with stroke. In this longitudinal qualitative study, we explored contingency caregiving planning by interviewing (N = 18) family caregivers providing care for a stroke survivor at home during the first 6 months post-discharge from the hospital. Emergent themes showed most families did not have a concrete "back-up plan" for a crisis or disaster situation involving the primary caregiver being unable to provide care. Furthermore, they assumed formal respite services or long-term care would be available should the need arise. Despite increased awareness over time, most caregivers had not devised contingency plans at 6 months.

  18. Bainite Formation in Medium-Carbon Low-Silicon Spring Steels Accounting for Chemical Segregation

    NASA Astrophysics Data System (ADS)

    Goulas, C.; Mecozzi, M. G.; Sietsma, J.

    2016-06-01

    In this paper, the effect of chemical inhomogeneity on the isothermal bainite formation is investigated in medium-carbon low-silicon spring steel by dilatometry and microscopy. The analysis of the microstructure at different times during transformation shows that chemical segregation of substitutional alloying elements resulting from casting strongly affects the bainite formation by retarding the transformation kinetics and limiting the maximum achievable bainite fraction. During holding at temperatures close to and above the martensite start temperature, a homogeneous lower bainitic microstructure can be eventually obtained, whereas at higher temperatures, incomplete bainitic reaction is evident. It was also found that at the early stages of the transformation, differences in the bainite formation kinetics, due to local inhomogeneities in Cr and Mn concentration, result in retardation of the growth of bainite in the high Mn and Cr concentration regions. The calculated difference in driving force for nucleation between the enriched and the depleted areas is not by itself sufficient to explain the microstructures obtained and thus significant influence of growth on bainite formation is observed. Particularly, it was calculated and experimentally observed that Cr partitions in the carbides in the high Mn, Cr regions during the isothermal treatment, limiting the transformation kinetics.

  19. STS-90 M.S. Williams and back-up P.S. Mukai, participate in CEIT

    NASA Technical Reports Server (NTRS)

    1998-01-01

    STS-90 Mission Specialist Dafydd 'Dave' Rhys Williams, M.D., with the Canadian Space Agency, and back-up Payload Specialist Chiaki Mukai, M.D., Ph.D., with the National Space Development Agency of Japan, examine items to be used during the Crew Equipment Interface Test (CEIT) in Kennedy Space Center's (KSC's) Operations and Checkout Building, where the Neurolab payload is undergoing processing. The CEIT gives astronauts an opportunity to get a hands-on look at the payloads with which they will be working on-orbit. STS-90 is scheduled to launch aboard the Shuttle Columbia from KSC on April 2. Investigations during the Neurolab mission will focus on the effects of microgravity on the nervous system. Specifically, experiments will study the adaptation of the vestibular system, the central nervous system, and the pathways that control the ability to sense location in the absence of gravity, as well as the effect of microgravity on a developing nervous system.

  20. Optimization of Tape Winding Process Parameters to Enhance the Performance of Solid Rocket Nozzle Throat Back Up Liners using Taguchi's Robust Design Methodology

    NASA Astrophysics Data System (ADS)

    Nath, Nayani Kishore

    2016-06-01

    The throat back up liners is used to protect the nozzle structural members from the severe thermal environment in solid rocket nozzles. The throat back up liners is made with E-glass phenolic prepregs by tape winding process. The objective of this work is to demonstrate the optimization of process parameters of tape winding process to achieve better insulative resistance using Taguchi's robust design methodology. In this method four control factors machine speed, roller pressure, tape tension, tape temperature that were investigated for the tape winding process. The presented work was to study the cogency and acceptability of Taguchi's methodology in manufacturing of throat back up liners. The quality characteristic identified was Back wall temperature. Experiments carried out using L{9/'} (34) orthogonal array with three levels of four different control factors. The test results were analyzed using smaller the better criteria for Signal to Noise ratio in order to optimize the process. The experimental results were analyzed conformed and successfully used to achieve the minimum back wall temperature of the throat back up liners. The enhancement in performance of the throat back up liners was observed by carrying out the oxy-acetylene tests. The influence of back wall temperature on the performance of throat back up liners was verified by ground firing test.

  1. Metal rolling - Asymmetrical rolling process

    NASA Astrophysics Data System (ADS)

    Alexa, V.; Raţiu, S.; Kiss, I.

    2016-02-01

    The development of theory and practice related to the asymmetric longitudinal rolling process is based on the general theory of metalworking by pressure and symmetric rolling theory, to which a large number of scientists brought their contribution. The rolling of metal materials was a serious problem throughout history, either economically or technically, because the plating technologies enabled the consumption of raw materials (scarce and expensive) to be reduced, while improving the mechanical properties. Knowing the force parameters related to asymmetric rolling leads to the optimization of energy and raw material consumption. This paper presents data on symmetric rolling process, in order to comparatively highlight the particularities of the asymmetric process.

  2. Low temperature bainitic ferrite: Evidence of carbon super-saturation and tetragonality

    DOE PAGESBeta

    Garcia-Mateo, C.; Jimenez, J. A.; Yen, Hung-Wei; Miller, Michael K.; Morales-Rivas, L; Kuntz, M; Ringer, S. P.; Yang, Jer-Ren; Caballero, Francesca G.

    2015-03-31

    Experimental evidence indicates that bainitic ferrite formed by transformation at low temperatures (200-350 °C) includes quantities of carbon in solid solution far beyond those expected from para-equilibrium. A change in the conventional symmetry of the bainitic ferrite lattice from cubic to tetragonal explains the abnormal solid solubility detected. This carbon supersaturation was measured by atom probe tomography, and the tetragonality of the bainitic ferrite, was characterized by means of X-ray diffraction analysis and high resolution transmission electron microscopy.

  3. Rolling Reloaded

    ERIC Educational Resources Information Center

    Jones, Simon A.; Nieminen, John M.

    2008-01-01

    Not so long ago a new observation about rolling motion was described: for a rolling wheel, there is a set of points with instantaneous velocities directed at or away from the centre of the wheel; these points form a circle whose diameter connects the centre of the wheel to the wheel's point of contact with the ground (Sharma 1996 "Eur. J. Phys."…

  4. Nanomechanical characterization of nanostructured bainitic steel: Peak Force Microscopy and Nanoindentation with AFM.

    PubMed

    Morales-Rivas, Lucia; González-Orive, Alejandro; Garcia-Mateo, Carlos; Hernández-Creus, Alberto; Caballero, Francisca G; Vázquez, Luis

    2015-01-01

    The full understanding of the deformation mechanisms in nanostructured bainite requires the local characterization of its mechanical properties, which are expected to change from one phase, bainitic ferrite, to another, austenite. This study becomes a challenging process due to the bainitic nanostructured nature and high Young's modulus. In this work, we have carried out such study by means of the combination of AFM-based techniques, such as nanoindentation and Peak Force Quantitative Nanomechanical Mapping (PF-QNM) measurements. We have addressed critically the limits and advantages of these techniques and been able to measure some elastoplastic parameters of both phases. Specifically, we have analyzed by PF-QNM two nanostructured bainitic steels, with a finer and a coarser structure, and found that both phases have a similar Young's modulus. PMID:26602631

  5. Carbide-Free Bainitic Weld Metal: A New Concept in Welding of Armor Steels

    NASA Astrophysics Data System (ADS)

    Krishna Murthy, N.; Janaki Ram, G. D.; Murty, B. S.; Reddy, G. M.; Rao, T. J. P.

    2014-12-01

    Carbide-free bainite, a fine mixture of bainitic ferrite and austenite, is a relatively recent development in steel microstructures. Apart from being very strong and tough, the microstructure is hydrogen-tolerant. These characteristics make it well-suited for weld metals. In the current work, an armor-grade quenched and tempered steel was welded such that the fusion zone developed a carbide-free bainitic microstructure. These welds showed very high joint efficiency and ballistic performance compared to those produced, as per the current industrial practice, using austenitic stainless steel fillers. Importantly, these welds showed no vulnerability to cold cracking, as verified using oblique Y-groove tests. The concept of carbide-free bainitic weld metal thus promises many useful new developments in welding of high-strength steels.

  6. Nanomechanical characterization of nanostructured bainitic steel: Peak Force Microscopy and Nanoindentation with AFM

    PubMed Central

    Morales-Rivas, Lucia; González-Orive, Alejandro; Garcia-Mateo, Carlos; Hernández-Creus, Alberto; Caballero, Francisca G.; Vázquez, Luis

    2015-01-01

    The full understanding of the deformation mechanisms in nanostructured bainite requires the local characterization of its mechanical properties, which are expected to change from one phase, bainitic ferrite, to another, austenite. This study becomes a challenging process due to the bainitic nanostructured nature and high Young’s modulus. In this work, we have carried out such study by means of the combination of AFM-based techniques, such as nanoindentation and Peak Force Quantitative Nanomechanical Mapping (PF-QNM) measurements. We have addressed critically the limits and advantages of these techniques and been able to measure some elastoplastic parameters of both phases. Specifically, we have analyzed by PF-QNM two nanostructured bainitic steels, with a finer and a coarser structure, and found that both phases have a similar Young’s modulus. PMID:26602631

  7. Effect of 30 T magnetic field on transformations in a novel bainitic steel

    SciTech Connect

    Jaramillo, Roger A; Babu, Sudarsanam S; Ludtka, Gerard Michael; Kisner, Roger A; Wilgen, John B; Ludtka, Gail Mackiewicz-; Nicholson, Don M; Kelly, Shawn; Murugananth, M; Bhadeshia, H. K. D. H.

    2005-01-01

    The continuous cooling transformation characteristics of novel bainitic steels have been studied, both under ordinary conditions and whilst subjected to a 30T magnetic field. The magnetic field has been found to completely change the microstructure obtained, from a mixture of bainite and martensite to one containing an incredibly fine pearlite with an interlamellar spacing of about 50nm. As a consequence, the pearlite is found to be much harder than any other examples found in the published literature.

  8. Mechanical properties of steels with a microstructure of bainite/martensite and austenite islands

    NASA Astrophysics Data System (ADS)

    Syammach, Sami M.

    Advanced high strength steels (AHSS) are continually being developed in order to reduce weight and improve safety for automotive applications. There is need for economic steels with improved strength and ductility combinations. These demands have led to research and development of third generation AHSS. Third generation AHSS include steel grades with a bainitic and tempered martensitic matrix with retained austenite islands. These steels may provide improved mechanical properties compared to first generation AHSS and should be more economical than second generation AHSS. There is a need to investigate these newer types of steels to determine their strength and formability properties. Understanding these bainitic and tempered martensitic steels is important because they likely can be produced using currently available production systems. If viable, these steels could be a positive step in the evolution of AHSS. The present work investigates the effect of the microstructure on the mechanical properties of steels with a microstructure of bainite, martensite, and retained austenite, so called TRIP aided bainitic ferrite (TBF) steels. The first step in this project was creating the desired microstructure. To create a microstructure of bainite, martensite, and austenite an interrupted austempering heat treatment was used. Varying the heat treatment times and temperatures produced microstructures of varying amounts of bainite, martensite, and austenite. Mechanical properties such as strength, ductility, strain hardening, and hole-expansion ratios were then evaluated for each heat treatment. Correlations between mechanical properties and microstructure were then evaluated. It was found that samples after each of the heat treatments exhibited strengths between 1050 MPa and 1350 MPa with total elongations varying from 8 pct to 16 pct. By increasing the bainite and austenite volume fraction the strength of the steel was found to decrease, but the ductility increased. Larger

  9. Microstructures and Mechanical Properties of Bearing Steels Modified for Preparing Nanostructured Bainite

    NASA Astrophysics Data System (ADS)

    Zhao, J.; Hou, C. S.; Zhao, G.; Zhao, T.; Zhang, F. C.; Wang, T. S.

    2016-08-01

    Mo containing high-C-Cr bearing steel was modified with Si (0.8-1.5 wt.%) and 0.8Si-1.0Al to prepare nanostructured bainite by low-temperature isothermal heat treatment. The modified steels were isothermal held at 220 to 240 °C after partial austenitization in an intercritical gamma+carbide region, and the resultant microstructure and mechanical properties were studied. Carbide-free nanostructured bainite with plate thickness below 100 nm and film retained austenite, as well as a small amount of undissolved carbide particles, was obtained in the modified steels except in 0.8Si steel, in which carbides precipitated in bainitic ferrite. As Si content increased, the mean thickness of bainitic ferrite plates modestly decreased, whereas the fraction of retained austenite markedly increased. The thickness of bainitic ferrite plate and the fraction of retained austenite in Si-Al-modified steel were smaller than those in Si-modified steels. The hardness and elongation of the Si-Al-modified steel were lower than those of Si-modified steels. The yield strength of Si-Al-modified steel was superior to that of Si-modified steels. Mid-level ultimate tensile strength and impact toughness were achieved in Si-Al-modified steel. For bearing applications, Si-modified steels could provide higher hardness and toughness but lower dimensional stability. Meanwhile, Si-Al-modified steel could offer higher dimensional stability but lower hardness and toughness.

  10. Microstructures and Mechanical Properties of Bearing Steels Modified for Preparing Nanostructured Bainite

    NASA Astrophysics Data System (ADS)

    Zhao, J.; Hou, C. S.; Zhao, G.; Zhao, T.; Zhang, F. C.; Wang, T. S.

    2016-10-01

    Mo containing high-C-Cr bearing steel was modified with Si (0.8-1.5 wt.%) and 0.8Si-1.0Al to prepare nanostructured bainite by low-temperature isothermal heat treatment. The modified steels were isothermal held at 220 to 240 °C after partial austenitization in an intercritical gamma+carbide region, and the resultant microstructure and mechanical properties were studied. Carbide-free nanostructured bainite with plate thickness below 100 nm and film retained austenite, as well as a small amount of undissolved carbide particles, was obtained in the modified steels except in 0.8Si steel, in which carbides precipitated in bainitic ferrite. As Si content increased, the mean thickness of bainitic ferrite plates modestly decreased, whereas the fraction of retained austenite markedly increased. The thickness of bainitic ferrite plate and the fraction of retained austenite in Si-Al-modified steel were smaller than those in Si-modified steels. The hardness and elongation of the Si-Al-modified steel were lower than those of Si-modified steels. The yield strength of Si-Al-modified steel was superior to that of Si-modified steels. Mid-level ultimate tensile strength and impact toughness were achieved in Si-Al-modified steel. For bearing applications, Si-modified steels could provide higher hardness and toughness but lower dimensional stability. Meanwhile, Si-Al-modified steel could offer higher dimensional stability but lower hardness and toughness.

  11. In situ heating SEM observation of the bainitic transformation process in Cu-17Al-11Mn (at.%) alloys.

    PubMed

    Motomura, Shunichi; Soejima, Yohei; Miyoshi, Takayuki; Hara, Toru; Omori, Toshihiro; Kainuma, Ryosuke; Nishida, Minoru

    2016-04-01

    To understand the bainitic transformation behavior in Cu-17Al-11Mn (at.%) alloys, dynamicin situobservation during heating was carried out in a scanning electron microscope (SEM). In this study, after optimizing the sample preparation method and observation conditions, we successfully observed the transformation process with sufficient resolution and contrast. From the observation results, bainite is first formed preferentially at the grain boundaries of the parent phase. Bainite is also formed inside the grains to relax the elastic strain generated by the initial bainite. Regarding the growth mode, in the early stage of the transformation, bainite grows along the longitudinal direction, and in the late stage, it grows along the lateral direction. The growth rate of the bainite was also evaluated by continuous observation of the same plate. Dynamicin situobservation of a martensitic transformation in the same alloy was also performed to compare the growth mode with that of bainite, and it was found that the behavior is considerably different between bainitic and the martensitic transformations.

  12. In situ observations of austenite grain growth in Fe-C-Mn-Si super bainitic steel

    NASA Astrophysics Data System (ADS)

    Liu, Feng; Xu, Guang; Zhang, Yu-long; Hu, Hai-jiang; Zhou, Lin-xin; Xue, Zheng-liang

    2013-11-01

    In situ observations of austenite grain growth in Fe-C-Mn-Si super bainitic steel were conducted on a high-temperature laser scanning confocal microscope during continuous heating and subsequent isothermal holding at 850, 1000, and 1100°C for 30 min. A grain growth model was proposed based on experimental results. It is indicated that the austenite grain size increases with austenitizing temperature and holding time. When the austenitizing temperature is above 1100°C, the austenite grains grow rapidly, and abnormal austenite grains occur. In addition, the effect of heating rate on austenite grain growth was investigated, and the relation between austenite grains and bainite morphology after bainitic transformations was also discussed.

  13. The role of silicon, vacancies, and strain in carbon distribution for low temperature bainite

    DOE PAGESBeta

    Sampath, S.; Rementeria, R.; Huang, X.; Caballero, Francesca G.; Janisch, R.; Poplawsky, J. D.; Garcia-Mateo, C.

    2016-02-19

    Here, we investigated the phenomenon of carbon supersaturation and carbon clustering in bainitic ferrite with atom probe tomography (APT) and ab-initio density functional theory (DFT) calculations. The experimental results show a homogeneous distribution of silicon in the microstructure, which contains both ferrite and retained austenite. This distribution is mimicked well by the computational approach. In addition, an accumulation of C in certain regions of the bainitic ferrite with C concentrations up to 13 at % is observed. Based on the DFT results, these clusters are explained as strained, tetragonal regions in the ferritic bainite, in which the solution enthalpy ofmore » C can reach large, negative values. It seems that Si itself only has a minor influence on this phenomenon.« less

  14. In-situ characterization of transformation plasticity during an isothermal austenite-to-bainite phase transformation

    SciTech Connect

    Holzweissig, M.J.; Canadinc, D.; Maier, H.J.

    2012-03-15

    This paper elucidates the stress-induced variant selection process during the isothermal austenite-to-bainite phase transformation in a tool steel. Specifically, a thorough set of experiments combining electron backscatter diffraction and in-situ digital image correlation (DIC) was carried out to establish the role of superimposed stress level on the evolution of transformation plasticity (TP) strains. The important finding is that TP increases concomitant with the superimposed stress level, and strain localization accompanies phase transformation at all stress levels considered. Furthermore, TP strain distribution within the whole material becomes more homogeneous with increasing stress, such that fewer bainitic variants are selected to grow under higher stresses, yielding a more homogeneous strain distribution. In particular, the bainitic variants oriented along [101] and [201] directions are favored to grow parallel to the loading axis and are associated with large TP strains. Overall, this very first in-situ DIC investigation of the austenite-to-bainite phase transformation in steels evidences the clear relationship between the superimposed stress level, variant selection, and evolution of TP strains. - Highlights: Black-Right-Pointing-Pointer Local variations of strain were observed by DIC throughout the phase transformation. Black-Right-Pointing-Pointer The study clearly established the role of the stress-induced variant selection. Black-Right-Pointing-Pointer Variant selection is a key parameter that governs distortion.

  15. Bainitic transformation in austempered ductile iron with reference to untransformed austenite volume phenomenon

    SciTech Connect

    Ahmadabadai, M.N.

    1997-10-01

    Much interest has been focused on austempered ductile iron (ADI) because of its superior mechanical properties, which might be improved by further control of microstructure. It has so far been assumed that segregation of alloying elements in the intercellular region just delays bainitic reaction in these regions. However, the existence of bainite-free regions (UAV) even after 10,000 minutes at test temperature, e.g., 375 C, indicates something intrinsic to the mechanism of bainitic transformation. The bainitic transformation start (B{sub s}) temperature is a function of alloying elements; segregation of alloying elements can also alter the B{sub s} temperature. In other words, B{sub s} temperature in the region near graphite should be different from the intercellular region. Therefore, the intercellular region with higher concentration of alloying elements such as Mn should have a lower B{sub s} temperature, which leads to formation of UAV even after a long high-temperature austempering time (hereafter, this stable UAV will be named as the minimum UAV value). To examine this concept, theoretical and experimental procedures were employed.

  16. Characterization of coarse bainite transformation in low carbon steel during simulated welding thermal cycles

    SciTech Connect

    Lan, Liangyun; Kong, Xiangwei; Qiu, Chunlin

    2015-07-15

    Coarse austenite to bainite transformation in low carbon steel under simulated welding thermal cycles was morphologically and crystallographically characterized by means of optical microscope, transmission electron microscope and electron backscattered diffraction technology. The results showed that the main microstructure changes from a mixture of lath martensite and bainitic ferrite to granular bainite with the increase in cooling time. The width of bainitic laths also increases gradually with the cooling time. For a welding thermal cycle with relatively short cooling time (e.g. t{sub 8/5} is 30 s), the main mode of variant grouping at the scale of individual prior austenite grains changes from Bain grouping to close-packed plane grouping with the progress of phase transformation, which results in inhomogeneous distribution of high angle boundaries. As the cooling time is increased, the Bain grouping of variants becomes predominant mode, which enlarges the effective grain size of product phase. - Highlights: • Main microstructure changes and the width of lath structure increases with cooling time. • Variant grouping changes from Bain zone to close-packed plane grouping with the transformation. • The change of variant grouping results in uneven distribution of high angle grain boundary. • Bain grouping is main mode for large heat input, which lowers the density of high angle boundary.

  17. The Effect of Interfacial Element Partitioning on Ferrite and Bainite Formation

    NASA Astrophysics Data System (ADS)

    Chen, Hao; van der Zwaag, Sybrand

    2016-05-01

    The formation of bainitic ferrite and that of grain boundary ferrite in low alloy steels have been two of the most important and interesting research topics in the field of solid state ferrous phase transformation for several decades, and various aspects of these two transformations have been discussed extensively in the literature. Recently, a so-called Gibbs energy balance (GEB) model was proposed by the authors to evaluate alloying element effects on the growth of bainitic ferrite and grain boundary ferrite. The model predicts a growth mode transition from paraequilibrium, negligible partitioning to partitioning during the isothermal formation of bainitic ferrite and grain boundary ferrite. Transformation stasis and bay phenomenon are well explained by the GEB model and both of them are found to be due to alloying element diffusion at the interface. This overview gives a summary of the authors' recent progress in the understanding of the growth of bainitic ferrite and grain boundary ferrite, with particular focus on the growth mode transition, the transformation stasis phenomenon and the bay phenomenon.

  18. Central-Approach Surgical Repair of Coarctation of the Aorta with a Back-up Left Ventricular Assist Device for an Infant Presenting with Severe Left Ventricular Dysfunction

    PubMed Central

    Kim, Tae Hoon; Shin, Yu Rim; Kim, Young Sam; Kim, Do Jung; Kim, Hyohyun; Shin, Hong Ju; Htut, Aung Thein; Park, Han Ki

    2015-01-01

    A two-month-old infant presented with coarctation of the aorta, severe left ventricular dysfunction, and moderate to severe mitral regurgitation. Through median sternotomy, the aortic arch was repaired under cardiopulmonary bypass and regional cerebral perfusion. The patient was postoperatively supported with a left ventricular assist device for five days. Left ventricular function gradually improved, eventually recovering with the concomitant regression of mitral regurgitation. Prompt surgical repair of coarctation of the aorta is indicated for patients with severe left ventricular dysfunction. A central approach for surgical repair with a back-up left ventricular assist device is a safe and effective treatment strategy for these patients. PMID:26665108

  19. Central-Approach Surgical Repair of Coarctation of the Aorta with a Back-up Left Ventricular Assist Device for an Infant Presenting with Severe Left Ventricular Dysfunction.

    PubMed

    Kim, Tae Hoon; Shin, Yu Rim; Kim, Young Sam; Kim, Do Jung; Kim, Hyohyun; Shin, Hong Ju; Htut, Aung Thein; Park, Han Ki

    2015-12-01

    A two-month-old infant presented with coarctation of the aorta, severe left ventricular dysfunction, and moderate to severe mitral regurgitation. Through median sternotomy, the aortic arch was repaired under cardiopulmonary bypass and regional cerebral perfusion. The patient was postoperatively supported with a left ventricular assist device for five days. Left ventricular function gradually improved, eventually recovering with the concomitant regression of mitral regurgitation. Prompt surgical repair of coarctation of the aorta is indicated for patients with severe left ventricular dysfunction. A central approach for surgical repair with a back-up left ventricular assist device is a safe and effective treatment strategy for these patients.

  20. Preparation and microstructure characteristics of low-temperature bainite in surface layer of low carbon gear steel

    NASA Astrophysics Data System (ADS)

    Zhang, P.; Zhang, F. C.; Wang, T. S.

    2011-06-01

    A kind of technology was proposed for the development of low-temperature bainitic microstructure in the surface layer of low-carbon gear steel 20CrMnMo, which is based on carburization and succedent low-temperature austempering. The carbon content in the surface carburization layer increases to 0.81 wt.%, making the martensite starting point depressed. Low-temperature bainite formed in the carburization layer and lath martensite with low carbon content in the center by austempering at a low temperature slightly higher than the martensite starting point of the surface layer. Aluminum is added as alloying elements with the purpose of enhancing the driving force of bainitic transformation and retarding the precipitation of cementite during austempering. With the excellent toughness of low-temperature bainite, this low-temperature austempering technology could be a potential substitute of the traditional quenching and tempering heat treatment in the manufacture of gear.

  1. Rolling-Element Bearings

    NASA Technical Reports Server (NTRS)

    Hamrock, B. J.; Anderson, W. J.

    1983-01-01

    Rolling element bearings are a precision, yet simple, machine element of great utility. A brief history of rolling element bearings is reviewed and the type of rolling element bearings, their geometry and kinematics, as well as the materials they are made from and the manufacturing processes they involve are described. Unloaded and unlubricated rolling element bearings, loaded but unlubricated rolling element bearings and loaded and lubricated rolling element bearings are considered. The recognition and understanding of elastohydrodynamic lubrication covered, represents one of the major development in rolling element bearings.

  2. Atom Probe Tomography Analysis of Precipitation during Tempering of a Nanostructured Bainitic Steel

    SciTech Connect

    Caballero, Francesca G.; Miller, Michael K; Garcia-Mateo, C.

    2011-01-01

    Carbon distribution during tempering of a nanostructured bainitic steel was analyzed by atom probe tomography (APT). Three different types of particles are detected on samples tempered at 673 K (400 C) for 30 minutes: lower bainite cementite with a carbon content of {approx}25 at. pct, {var_epsilon}-carbides with a carbon content close to 30 at. pct, and carbon clusters, small features with a carbon content of {approx}14 at. pct indicative of a stage of tempering prior to precipitation of {var_epsilon}-carbide. After tempering at 773 K (500 C) for 30 minutes, the {var_epsilon}-carbide-to-cementite transition was observed. Solute concentration profiles across carbide/ferrite interfaces showed the distribution of substitutional elements in {var_epsilon}-carbide and cementite for all the tempering conditions.

  3. Backing up the online catalog

    SciTech Connect

    Sutherland, C.T.

    1991-12-31

    This paper explains the reasons for a backup or alternative to an online system and discusses the development of two such systems. This article updates the author`s presentation at the 1990 SLA conference and the article which appeared in the proceedings.

  4. Backing up the online catalog

    SciTech Connect

    Sutherland, C.T.

    1991-01-01

    This paper explains the reasons for a backup or alternative to an online system and discusses the development of two such systems. This article updates the author's presentation at the 1990 SLA conference and the article which appeared in the proceedings.

  5. Determination of carbon content in bainitic ferrite and carbon distribution in austenite by using CBKLDP

    SciTech Connect

    Zhang, M.X.; Kelly, P.M.

    1998-03-01

    Convergent beam Kikuchi line diffraction patterns taken with a 10nm-diameter electron beam have been used to determine the lattice parameter and hence the carbon concentration in both ferrite and austenite. The experimental results show that bainitic ferrite is supersaturated in carbon and that, during ageing of austenite prior to the precipitation of cementite, the original carbon distribution across a grain becomes very nonuniform with distinct regions of both carbon enrichment and carbon depletion.

  6. Microstructural evolution of bainitic steel severely deformed by equal channel angular pressing.

    PubMed

    Nili-Ahmadabadi, M; Haji Akbari, F; Rad, F; Karimi, Z; Iranpour, M; Poorganji, B; Furuhara, T

    2010-09-01

    High Si bainitic steel has been received much of interest because of combined ultra high strength, good ductility along with high wear resistance. In this study a high Si bainitic steel (Fe-0.22C-2.0Si-3.0Mn) was used with a proper microstructure which could endure severe plastic deformation. In order to study the effect of severe plastic deformation on the microstructure and properties of bainitic steel, Equal Channel Angular Pressing was performed in two passes at room temperature. Optical, SEM and TEM microscopies were used to examine the microstructure of specimens before and after Equal Channel Angular Pressing processing. X-ray diffraction was used to measure retained austenite after austempering and Equal Channel Angular Pressing processing. It can be seen that retained austenite picks had removed after Equal Channel Angular Pressing which could attributed to the transformation of austenite to martensite during severe plastic deformation. Enhancement of hardness values by number of Equal Channel Angular Pressing confirms this idea. PMID:21133137

  7. On the Low Temperature Strain Aging of Bainite in the TRIP Steel

    NASA Astrophysics Data System (ADS)

    Timokhina, Ilana; Beladi, Hossein; Xiong, Xiang-Yuan; Hodgson, Peter D.

    2013-11-01

    The aging behavior of a thermomechanically processed Mo-Al-Nb transformation-induced plasticity steel with ultrafine microstructure was investigated using transmission electron microscopy and atom probe tomography (APT). Strain aging at 73 K (200 °C) for 1800 seconds led to a significant bake-hardening response (up to 222 MPa). Moreover, aging for 1800 seconds at room temperature after 4 pct pre-strain also revealed a bake-hardening response (~60 MPa). The experimental results showed the formation of carbon Cottrell atmospheres around dislocations and the formation of carbon clusters/fine carbides in the bainitic ferrite during aging. It is proposed that this is associated with the high dislocation density of bainitic ferrite with formation of a complex dislocation substructure after pre-straining and its high average carbon content (~0.35 at. pct). The segregation of carbon and substitutional elements such as Mn and Mo to the retained austenite/bainitic ferrite interface during aging was observed by APT. This segregation is likely to be the preliminary stage for Mo-C particles' formation. The aging after pre-straining also induced the decomposition of retained austenite with formation of ferrite and carbides.

  8. Effect of Coiling Temperature on Microstructure and Tensile Behavior of a Hot-Rolled Ferritic Lightweight Steel

    NASA Astrophysics Data System (ADS)

    Wang, Junfeng; Yang, Qi; Wang, Xiaodong; Wang, Li

    2016-09-01

    Effects of coiling temperature (CT) ranging from 673 K to 973 K (400 °C to 700 °C) on microstructure and tensile property of a hot-rolled ferritic lightweight steel containing 0.35 wt pct C and 4.1 wt pct Al are investigated in the present study. Basically, the microstructure of the hot-rolled steel is composed of δ-ferrite grain bands and secondary phase bands which are originated from the decomposition of antecedent austenite. The secondary phase band is a bainite band at coiling temperatures (CTs) lower than 723 K (450 °C). More specifically, the bainite band mainly consists of lower bainite together with blocky retained austenite at the CT of 673 K (400 °C), while it primarily contains carbide-free bainite being an aggregate of lath-shaped ferrite and austenite at the CT of 723 K (450 °C). The secondary phase band is a carbide band which mainly contains a pearlite structure at CTs higher than 773 K (500 °C). There are three types of carbides in the steel matrix: transitional ɛ-carbide present inside lower bainite, cementite present within carbide bands as well as at the boundaries between carbide bands and δ-ferrite bands, and κ-carbide present at δ-ferrite grain boundaries which is clearly seen at CTs higher than 773 K (500 °C). The volume fraction of retained austenite reaches the peak value of 9.6 pct at the CT of 723 K (450 °C), and abruptly drops to zero when the CTs are higher than 773 K (500 °C). Lath-shaped retained austenite with a higher volume fraction induces significant enhancement of elongation through the TRIP effect, leading to a uniform elongation of 25 pct and an elongation-to-failure of 32 pct at the CT of 723 K (450 °C). Crack initiation and propagation inside the tested specimens are tracked and fracture surface is observed to help understand the deformation and fracture behavior of the hot-rolled steel.

  9. WORK ROLLS AND BACKUP ROLLS FROM #43 AND #44 MILLS ...

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

    WORK ROLLS AND BACKUP ROLLS FROM #43 AND #44 MILLS AWAIT DRESSING IN ROLL GRINDER. ROLL SHOP OPERATIONS, INCLUDING REPAIR, CLEANING AND GREASING, ARE HOUSED IN THE REROLL BAY. - American Brass Foundry, 70 Sayre Street, Buffalo, Erie County, NY

  10. Internal roll compression system

    DOEpatents

    Anderson, Graydon E.

    1985-01-01

    This invention is a machine for squeezing water out of peat or other material of low tensile strength; the machine including an inner roll eccentrically positioned inside a tubular outer roll, so as to form a gradually increasing pinch area at one point therebetween, so that, as the rolls rotate, the material is placed between the rolls, and gets wrung out when passing through the pinch area.

  11. Cr-W-V bainitic/ferritic steel with improved strength and toughness and method of making

    DOEpatents

    Klueh, R.L.; Maziasz, P.J.

    1994-03-08

    This work describes a high strength, high toughness bainitic/ferritic steel alloy comprising about 2.75% to 4.0% chromium, about 2.0% to 3.5% tungsten, about 0.10% to 0.30% vanadium, and about 0.1% to 0.15% carbon with the balance iron, wherein the percentages are by total weight of the composition, wherein the alloy having been heated to an austenitizing temperature and then cooled at a rate sufficient to produce carbide-free acicular bainite. 15 figures.

  12. Effect of Rolling Temperature and Ultrafast Cooling Rate on Microstructure and Mechanical Properties of Steel Plate

    NASA Astrophysics Data System (ADS)

    Ye, Qibin; Liu, Zhenyu; Yang, Yu; Wang, Guodong

    2016-07-01

    Microstructure can vary significantly through thickness after ultrafast cooling of rolled steel plates, impacting their mechanical properties. This study examined the microstructure, microstructural banding at centerline, and mechanical properties through thickness for different ultrafast cooling conditions and rolling temperatures. One set of steels (UC1 and UC2) were ultrafast-cooled (UFC) at 40 K/s after finish rolling at 1223 K and 1193 K (950 °C and 910 °C), respectively, while the second set (LC) was cooled by laminar cooling at 17 K/s after finish rolling at 1238 K (965 °C). UFC produced microstructural variation through thickness; highly dislocated lath-type bainitic ferrite was formed near the surface, whereas the primary microstructure was acicular ferrite and irregular polygonal ferrite in the interior of UC1 and UC2 steels, respectively. However, UFC has the advantage of suppression of microstructural banding in centerline segregation regions. The ferrite grain size in both UFC-cooled steels was refined to ~5 μm, increasing strength and toughness. The optimum combination of properties was obtained in UC2 steel with appropriate low finish rolling temperature, being attributed to the distinct microstructure resulting from work-hardened austenite before UFC.

  13. Structural characterization of “carbide-free” bainite in a Fe–0.2C–1.5Si–2.5Mn steel

    SciTech Connect

    Hofer, Christina; Leitner, Harald; Winkelhofer, Florian; Clemens, Helmut; Primig, Sophie

    2015-04-15

    Low-alloyed, low C containing carbide-free bainitic steels are attractive candidates for applications in the automotive industry due to their well-balanced combination of high strength and ductility achieved in an economic way. In this work, their complex microstructure consisting of a mixture of bainitic ferrite, austenite with different morphologies and stabilities, martensite, M/A constituent and a few carbides has been investigated with metallographic and high-resolution techniques. After specific isothermal heat treatments in a dilatometer, a combination of LePera and Nital etching was applied to distinguish between bainite and martensite. Site-specific atom probe tips were prepared by means of scanning electron microscopy, electron backscatter diffraction and focused ion beam, revealing that “carbide-free” bainite consists of C depleted bainitic ferrite, C enriched retained austenite and occasional ε-carbides. Furthermore, it was found that the M/A constituent is highly dislocated and mainly martensitic. Its C content is increased compared to the nominal composition, but below the values obtained for retained austenite, explaining the lower transformation resistance. - Highlights: • Detailed top-down characterization of low C “carbide-free” bainitic steel • APT of all constituents in “carbide-free” bainite • Identification of ε-carbide based on its C content determined by APT • M/A constituent is mainly martensitic with austenitic areas at the boundaries • Lower C content of M/A constituent explains its lower stability.

  14. Understanding Rolle's Theorem

    ERIC Educational Resources Information Center

    Parameswaran, Revathy

    2009-01-01

    This paper reports on an experiment studying twelfth grade students' understanding of Rolle's Theorem. In particular, we study the influence of different concept images that students employ when solving reasoning tasks related to Rolle's Theorem. We argue that students' "container schema" and "motion schema" allow for rich concept images.…

  15. On the nucleation of cementite on bainitic ferrite-austenite interphase boundaries

    NASA Astrophysics Data System (ADS)

    Hadian, Raheleh; Purdy, Gary R.

    2014-08-01

    Among all possible variants of the Isaichev orientation relationship between cementite and ferrite, a single major cementite variant has been observed to appear in bainite. Interphase boundary nucleation of cementite on ferrite-austenite semi-coherent interfaces is considered a plausible reason for this observation. With the aid of known crystallographic relations and habit planes of the ferrite-cementite, ferrite-austenite and austenite-cementite phases, a model for cementite nucleation has been proposed. The interphase-boundary nucleus is assumed to form on a semi-coherent ferrite-austenite interface and to possess ferrite-cementite and austenite-cementite habits as two main facets of the nucleus. It is shown that interphase cementite nucleation will be viable if the energies of all facets of the nucleus are in the semi-coherent range.

  16. The Impact of Retained Austenite Characteristics on the Two-Body Abrasive Wear Behavior of Ultrahigh Strength Bainitic Steels

    NASA Astrophysics Data System (ADS)

    Narayanaswamy, Balaji; Hodgson, Peter; Timokhina, Ilana; Beladi, Hossein

    2016-10-01

    In the current study, a high-carbon, high-alloy steel (0.79 pct C, 1.5 pct Si, 1.98 pct Mn, 0.98 pct Cr, 0.24 pct Mo, 1.06 pct Al, and 1.58 pct Co in wt pct) was subjected to an isothermal bainitic transformation at a temperature range of 473 K to 623 K (200 °C to 350 °C), resulting in different fully bainitic microstructures consisting of bainitic ferrite and retained austenite. With a decrease in the transformation temperature, the microstructure was significantly refined from ~300 nm at 623 K (350 °C) to less than 60 nm at 473 K (200 °C), forming nanostructured bainitic microstructure. In addition, the morphology of retained austenite was progressively altered from film + blocky to an exclusive film morphology with a decrease in the temperature. This resulted in an enhanced wear resistance in nanobainitic microstructures formed at low transformation temperature, e.g., 473 K (200 °C). Meanwhile, it gradually deteriorated with an increase in the phase transformation temperature. This was mostly attributed to the retained austenite characteristics ( i.e., thin film vs blocky), which significantly altered their mechanical stability. The presence of blocky retained austenite at high transformation temperature, e.g., 623 K (350 °C) resulted in an early onset of TRIPing phenomenon during abrasion. This led to the formation of coarse martensite with irregular morphology, which is more vulnerable to crack initiation and propagation than that of martensite formed from the thin film austenite, e.g., 473 K (200 °C). This resulted in a pronounced material loss for the fully bainitic microstructures transformed at high temperature, e.g., 623 K (350 °C), leading to distinct sub-surface layer and friction coefficient curve characteristics. A comparison of the abrasive behavior of the fully bainitic microstructure formed at 623 K (350 °C) and fully pearlitic microstructure demonstrated a detrimental effect of blocky retained austenite with low mechanical stability on

  17. The Impact of Retained Austenite Characteristics on the Two-Body Abrasive Wear Behavior of Ultrahigh Strength Bainitic Steels

    NASA Astrophysics Data System (ADS)

    Narayanaswamy, Balaji; Hodgson, Peter; Timokhina, Ilana; Beladi, Hossein

    2016-08-01

    In the current study, a high-carbon, high-alloy steel (0.79 pct C, 1.5 pct Si, 1.98 pct Mn, 0.98 pct Cr, 0.24 pct Mo, 1.06 pct Al, and 1.58 pct Co in wt pct) was subjected to an isothermal bainitic transformation at a temperature range of 473 K to 623 K (200 °C to 350 °C), resulting in different fully bainitic microstructures consisting of bainitic ferrite and retained austenite. With a decrease in the transformation temperature, the microstructure was significantly refined from ~300 nm at 623 K (350 °C) to less than 60 nm at 473 K (200 °C), forming nanostructured bainitic microstructure. In addition, the morphology of retained austenite was progressively altered from film + blocky to an exclusive film morphology with a decrease in the temperature. This resulted in an enhanced wear resistance in nanobainitic microstructures formed at low transformation temperature, e.g., 473 K (200 °C). Meanwhile, it gradually deteriorated with an increase in the phase transformation temperature. This was mostly attributed to the retained austenite characteristics (i.e., thin film vs blocky), which significantly altered their mechanical stability. The presence of blocky retained austenite at high transformation temperature, e.g., 623 K (350 °C) resulted in an early onset of TRIPing phenomenon during abrasion. This led to the formation of coarse martensite with irregular morphology, which is more vulnerable to crack initiation and propagation than that of martensite formed from the thin film austenite, e.g., 473 K (200 °C). This resulted in a pronounced material loss for the fully bainitic microstructures transformed at high temperature, e.g., 623 K (350 °C), leading to distinct sub-surface layer and friction coefficient curve characteristics. A comparison of the abrasive behavior of the fully bainitic microstructure formed at 623 K (350 °C) and fully pearlitic microstructure demonstrated a detrimental effect of blocky retained austenite with low mechanical stability on the

  18. Analyses of Transformation Kinetics of Carbide-Free Bainite Above and Below the Athermal Martensite-Start Temperature

    NASA Astrophysics Data System (ADS)

    Yakubtsov, I. A.; Purdy, G. R.

    2012-02-01

    The isothermal transformation kinetics of austenite decomposition in Fe-0.4C-2.78Mn-1.81Si was analyzed by an electrical resistivity technique in the temperature interval 723 K to 418 K (450 °C to 145 °C). The analysis of transformation kinetics of the bainite transformation was performed using the Johnson-Mehl-Avrami-Kolgomorov (JMAK) and Austin-Rickett (AR) approaches. The kinetic parameters, the reaction constant n, rate constant k = k( T), and apparent activation energy Q were evaluated for isothermal transformations below and above the martensite-start temperature M S = 548 K (275 °C), which was determined experimentally. The formation of strain-induced martensite, which starts to accompany the bainite transformation at just above M S , increases the rate of transformation and decreases the apparent activation energy of austenite decomposition.

  19. Microstructural Refinement of Bainite and Martensite for Enhanced Strength and Toughness in High-Carbon Low-Alloy Steel

    NASA Astrophysics Data System (ADS)

    Chakraborty, J.; Chattopadhyay, P. P.; Bhattacharjee, D.; Manna, I.

    2010-11-01

    This study attempts to determine the scope and extent of microstructural refinement through complete/partial recrystallization of prior cold deformed ferrite during austenitizing (1223 K (950 °C), 15 minutes) and/or austempering (543 K (270 °C), 30 minutes) followed by water quenching to obtain ultrafine bainitic sheaves along with thin martensitic plates in SAE 52100 steel. The volume fraction and sheaf/plate dimension (thickness/length) of bainitic ferrite and martensite were determined by optical and scanning/transmission electron microscopy studies coupled with compositional microanalysis. Marginal improvement in the tensile strength and significant improvement in the impact properties is obtained at an optimum level of prior cold deformation by tension in comparison to that recorded in austempered condition without prior deformation.

  20. Spray Rolling Aluminum Strip

    SciTech Connect

    Lavernia, E.J.; Delplanque, J-P; McHugh, K.M.

    2006-05-10

    Spray forming is a competitive low-cost alternative to ingot metallurgy for manufacturing ferrous and non-ferrous alloy shapes. It produces materials with a reduced number of processing steps, while maintaining materials properties, with the possibility of near-net-shape manufacturing. However, there are several hurdles to large-scale commercial adoption of spray forming: 1) ensuring strip is consistently flat, 2) eliminating porosity, particularly at the deposit/substrate interface, and 3) improving material yield. Through this program, a new strip/sheet casting process, termed spray rolling, has been developed, which is an innovative manufacturing technique to produce aluminum net-shape products. Spray rolling combines the benefits of twin-roll casting and conventional spray forming, showing a promising potential to overcome the above hurdles associated with spray forming. Spray rolling requires less energy and generates less scrap than conventional processes and, consequently, enables the development of materials with lower environmental impacts in both processing and final products. Spray Rolling was developed as a collaborative project between the University of California-Davis, the Colorado School of Mines, the Idaho National Engineering and Environmental Laboratory, and an industry team. The following objectives of this project were achieved: (1) Demonstration of the feasibility of the spray rolling process at the bench-scale level and evaluation of the materials properties of spray rolled aluminum strip alloys; and (2) Demonstration of 2X scalability of the process and documentation of technical hurdles to further scale up and initiate technology transfer to industry for eventual commercialization of the process.

  1. Wear of hot rolling mill rolls: An overview

    NASA Astrophysics Data System (ADS)

    Spuzic, S.; Strafford, K. N.; Subramanian, C.; Savage, G.

    1994-08-01

    Rolling is today one of the most important industrial processes because a greater volume of material is worked by rolling than by any other technique. Roll wear is a multiplex process where mechanical and thermal fatigue combines with impact, abrasion, adhesion and corrosion, which all depend on system interactions rather than material characteristics only. The situation is more complicated in section rolling because of the intricacy of roll geometry. Wear variables and modes are reviewed along with published methods and models used in the study and testing of roll wear. This paper reviews key aspects of roll wear control - roll material properties, roll pass design, and system factors such as temperature, loads and sliding velocity. An overview of roll materials is given including adamites, high Cr materials, high speed tool steels and compound rolls. Non-uniform wear, recognized as the most detrimental phenomenon in section rolling, can be controlled by roll pass design. This can be achieved by computer-aided graphical and statistical analyses of various pass series. Preliminary results obtained from pilot tests conducted using a two-disc hot wear rig and a scratch tester are discussed.

  2. Constitutive Modeling for Flow Behavior of Medium-Carbon Bainitic Steel and Its Processing Maps

    NASA Astrophysics Data System (ADS)

    Yang, Zhinan; Li, Yingnan; Li, Yanguo; Zhang, Fucheng; Zhang, Ming

    2016-09-01

    The hot deformation behavior of a medium-carbon bainitic steel was studied in a temperature range of 900-1100 °C and a strain rate range of 0.01-10 s-1. With increasing strain, the flow stress displays three tendencies: a continuous increase under most conditions and a peak stress with and without a steady-state region. Accurate constitutive modeling was proposed and exhibits a correlation coefficient of 0.984 and an average absolute relative error of 0.063 between the experimental and predicted stress values. The activation energy of the steel increased from 393 to 447 kJ/mol, when the strain increased from 0.1 to 0.4, followed by a slight fluctuation at higher strain. Finally, processing maps under different strains were constructed and exhibit a varied instability region with increasing strain. Microstructural observations show that a mischcrystal structure formed in the specimens that worked on the instability regions, which resulted from the occurrence of flow localization. Some deformation twins were also observed in certain specimens and were responsible for negative m-values. The optimum hot working processing parameters for the studied steel were 989-1012 °C, 0.01-0.02 s-1 and 1034-1066 °C, 0.07-0.22 s-1, and a full dynamic recrystallization structure with fine homogeneous grains could be obtained.

  3. A Unified Constitutive Equation of a Bainite Steel During Hot Deformation

    NASA Astrophysics Data System (ADS)

    Li, Lixin; Ye, Ben; Liu, Sheng; Hu, Shengde; Liao, Hanqing

    2016-10-01

    A constitutive model has been established based on dislocation theory, work hardening and dynamic recovery theory, and softening mechanisms of dynamic recrystallization. The stress-strain curves of a bainite steel have been measured with hot compression experiments at temperatures of 1173, 1273, 1373 and 1473 K with strain rates of 0.01, 0.1, 1 and 10 s-1 on a thermo-mechanical simulator (Gleeble-1500). The material constants involved in the constitutive model have been optimized by an inverse analysis of the stress-strain curves using the method of coordinate rotation, determining the strain-stress relationship or the constitutive equation, the kinetic models of dynamic recovery and dynamic recrystallization, and a few material constants of the investigated steel. Comparison of the calculated flow stress with the experimental data suggests that the relationship between the flow stress and the strain rate, temperature, strain of the steel during hot deformation can be described by the constitutive model, and that the underlying materials science can be captured from the material constants determined by the stress-strain curves.

  4. Effects of Vanadium Addition on Microstructure and Tribological Performance of Bainite Hardfacing Coatings

    NASA Astrophysics Data System (ADS)

    Chen, Jigang; Xing, Xiaolei; Wang, Yajun; Zhou, Yefei; Ren, Xuejun; Yang, Yulin; Yang, Qingxiang

    2015-03-01

    New hardfacing coatings with different vanadium (V) additions were prepared by surfacing technology. The microstructures of the hardfacing coatings were analyzed by field emission scanning electron microscope equipped with energy dispersive X-ray spectrometry and examined by transmission electron microscope. The hardness and wear resistances of the hardfacing coatings were measured. Worn debris were collected at the end of wear test and analyzed. The precipitation temperature of the phases in the hardfacing coatings and the mass fraction of MC carbide were calculated by Jmatpro software. The experimental results show that, the hardfacing coating mainly consists of granular bainite. No significant change in the size of linear martensite-austenite (M-A) islands is observed with the increase of V addition, while the size of massive M-A islands is decreased. The wear resistance of the hardfacing coating reaches a maximum level with V content of 0.14 wt.%. The calculated results show that, the mass fraction of MC carbide is increased with the increase of V content. Based on calculation following two-dimensional mismatch theory, MC carbide is a heterogeneous nucleus of the ferrite resulting refined ferrite in the hardfacing coating.

  5. A Unified Constitutive Equation of a Bainite Steel During Hot Deformation

    NASA Astrophysics Data System (ADS)

    Li, Lixin; Ye, Ben; Liu, Sheng; Hu, Shengde; Liao, Hanqing

    2016-08-01

    A constitutive model has been established based on dislocation theory, work hardening and dynamic recovery theory, and softening mechanisms of dynamic recrystallization. The stress-strain curves of a bainite steel have been measured with hot compression experiments at temperatures of 1173, 1273, 1373 and 1473 K with strain rates of 0.01, 0.1, 1 and 10 s-1 on a thermo-mechanical simulator (Gleeble-1500). The material constants involved in the constitutive model have been optimized by an inverse analysis of the stress-strain curves using the method of coordinate rotation, determining the strain-stress relationship or the constitutive equation, the kinetic models of dynamic recovery and dynamic recrystallization, and a few material constants of the investigated steel. Comparison of the calculated flow stress with the experimental data suggests that the relationship between the flow stress and the strain rate, temperature, strain of the steel during hot deformation can be described by the constitutive model, and that the underlying materials science can be captured from the material constants determined by the stress-strain curves.

  6. 3D analysis of bainite morphologies and kinetics in alloy steels

    SciTech Connect

    Hackenberg, R. E.; Nordstrom, D. P.; Shiflet, G. J.

    2002-01-01

    Serial sectioning and 3D reconstruction of austenite decomposition products were undertaken in bay-forming ternary steels to better understand their true morphologies in the bay region of their TTT diagrams. Jagged growth interfaces are revealed in allotriomorphic bainite formed at the bay in Fe-0.24C-4M0, contrasting with the idealized geometries often assumed when formulating growth models. This also has implications for experimental thickening kinetics measurments. Examination of the so-called 'degenerate' ferrite formed below the bay in Fe-Ox-6.3 W reveals that it is not degenerate at all, but rather has a Widmanstatten rod morphology which gives the appearance of degeneracy due to the multiplicity of ways that they can intersect a randomly-oriented plane of polish. Furthermore, these rods are grouped in packets posessing a common elongation direction, highlighting the crystallographic nature of their formation. The impact of these findings on the understanding of austenite decomposition in bayforming steels will be discussed.

  7. Extended slow-roll conditions and rapid-roll conditions

    SciTech Connect

    Chiba, Takeshi; Yamaguchi, Masahide E-mail: gucci@phys.aoyama.ac.jp

    2008-10-15

    We derive slow-roll conditions for a scalar field which is non-minimally coupled with gravity in a consistent manner and express spectral indices of scalar/tensor perturbations in terms of the slow-roll parameters. The conformal invariance of the curvature perturbation is proved without linear approximations. Rapid-roll conditions are also derived, and the relation with the slow-roll conditions is discussed.

  8. METHOD OF ROLLING URANIUM

    DOEpatents

    Smith, C.S.

    1959-08-01

    A method is described for rolling uranium metal at relatively low temperatures and under non-oxidizing conditions. The method involves the steps of heating the uranium to 200 deg C in an oil bath, withdrawing the uranium and permitting the oil to drain so that only a thin protective coating remains and rolling the oil coated uranium at a temperature of 200 deg C to give about a 15% reduction in thickness at each pass. The operation may be repeated to accomplish about a 90% reduction without edge cracking, checking or any appreciable increase in brittleness.

  9. Research on work roll thermal crown in cold rolling mill

    NASA Astrophysics Data System (ADS)

    Song, Lei; Shen, Mingang; Chen, Xuebo; Wang, Junsheng

    2013-05-01

    The factors which have influence on the work roll thermal crown in cold strip rolling are discussed. The heat transferring in three directions (radial axis and circumference) were considered for calculating the work roll thermal deformation. Therefore, it is a three dimensions unstable system for the work roll temperature calculation. The plastic deformation work and friction heat are calculated by the divided element and digital integration method. The simplified calculation model is built for the heat transferring along work roll. There are four zones for work roll heat transferring: roll gap zone air cooling zone emulsion zone rolls contact zone. The heat transferring between the zones is decided by the temperature difference. The inter temperature field and thermal deformation of work roll can be calculated by two-dimension finite difference method. The work roll temperature and thermal crown of actual application cold rolling mill are analyzed by the model. By the comparison between calculated values and measured values, the work roll thermal calculation model can meet the accuracy requirement of on-line control.

  10. Possibility of wave control of the formation of twinned austenite in the process of the formation of bainitic ferrite

    NASA Astrophysics Data System (ADS)

    Kashchenko, M. P.; Chashchina, V. G.

    2015-04-01

    An analysis has been performed of the elastic fields of the basic dislocation loops of carriers of shear deformation on {558}γ planes close to the habit planes of the basic component of the bimodal distribution of ferrite habits in a bainite macroplate. It has been shown that there are extrema of the elastic field that can be associated with the creation of plates of austenite twins in the wave regime. The formation of an additional component of the distribution of the ferrite habits is mainly associated with the regions of twinned austenite.

  11. GRCop-84 Rolling Parameter Study

    NASA Technical Reports Server (NTRS)

    Loewenthal, William S.; Ellis, David L.

    2008-01-01

    This report is a section of the final report on the GRCop-84 task of the Constellation Program and incorporates the results obtained between October 2000 and September 2005, when the program ended. NASA Glenn Research Center (GRC) has developed a new copper alloy, GRCop-84 (Cu-8 at.% Cr-4 at.% Nb), for rocket engine main combustion chamber components that will improve rocket engine life and performance. This work examines the sensitivity of GRCop-84 mechanical properties to rolling parameters as a means to better define rolling parameters for commercial warm rolling. Experiment variables studied were total reduction, rolling temperature, rolling speed, and post rolling annealing heat treatment. The responses were tensile properties measured at 23 and 500 C, hardness, and creep at three stress-temperature combinations. Understanding these relationships will better define boundaries for a robust commercial warm rolling process. The four processing parameters were varied within limits consistent with typical commercial production processes. Testing revealed that the rolling-related variables selected have a minimal influence on tensile, hardness, and creep properties over the range of values tested. Annealing had the expected result of lowering room temperature hardness and strength while increasing room temperature elongations with 600 C (1112 F) having the most effect. These results indicate that the process conditions to warm roll plate and sheet for these variables can range over wide levels without negatively impacting mechanical properties. Incorporating broader process ranges in future rolling campaigns should lower commercial rolling costs through increased productivity.

  12. Walk and roll robot

    NASA Technical Reports Server (NTRS)

    Wilson, Andrew (Inventor); Punnoose, Andrew (Inventor); Strausser, Katherine (Inventor); Parikh, Neil (Inventor)

    2011-01-01

    A mobile robotic unit features a main body, a plurality of legs for supporting the main body on and moving the main body in forward and reverse directions about a base surface, and a drive assembly. According to an exemplary embodiment each leg includes a respective pivotal hip joint, a pivotal knee joint, and a wheeled foot adapted to roll along the base surface. Also according to an exemplary embodiments the drive assembly includes a motor operatively associated with the hip and knee joints and the wheeled foot for independently driving pivotal movement of the hip joint and the knee joint and rolling motion of the wheeled foot. The hip joint may include a ball-and-socket-type joint interconnecting top portion of the leg to the main body, such that the hip joint is adapted to pivot said leg in a direction transverse to a forward-and-reverse direction.

  13. Continuous roll-to-roll amorphous silicon photovoltaic manufacturing technology

    NASA Astrophysics Data System (ADS)

    Izu, M.; Ovshinsky, S. R.; Deng, X.; Krisko, A.; Ovshinsky, H. C.; Narasimhan, K. L.; Young, R.

    1994-06-01

    Energy Conversion Devices, Inc. (ECD) has designed and constructed a 2 Megawatt (mW) manufacturing line that produces triple-junction spectrum-splitting a-Si alloy solar cells in a continuous roll-to-roll process. This manufacturing line has reliably and consistently produced high efficiency solar cells. We have demonstrated the production of 4ft 2 triple-junction two band-gap a-Si alloy PV production modules with 8% stable aperture area efficiency. The production line has successfully incorporated: 1) a band-gap profiled a-Si-Ge narrow band-gap solar cell deposited in a continuous roll-to-roll process using a proprietary gas distribution manifold and cathode configuration; and 2) a textured Ag/ZnO back-reflector deposited in a continuous roll-to-roll sputtering machine with production subcell yields greater than 99%.

  14. Roll-to-Roll production of carbon nanotubes based supercapacitors

    NASA Astrophysics Data System (ADS)

    Zhu, Jingyi; Childress, Anthony; Karakaya, Mehmet; Roberts, Mark; Arcilla-Velez, Margarita; Podila, Ramakrishna; Rao, Apparao

    2014-03-01

    Carbon nanomaterials provide an excellent platform for electrochemical double layer capacitors (EDLCs). However, current industrial methods for producing carbon nanotubes are expensive and thereby increase the costs of energy storage to more than 10 Wh/kg. In this regard, we developed a facile roll-to-roll production technology for scalable manufacturing of multi-walled carbon nanotubes (MWNTs) with variable density on run-of-the-mill kitchen Al foils. Our method produces MWNTs with diameter (heights) between 50-100 nm (10-100 μm), and a specific capacitance as high as ~ 100 F/g in non-aqueous electrolytes. In this talk, the fundamental challenges involved in EDLC-suitable MWNT growth, roll-to-roll production, and device manufacturing will be discussed along with electrochemical characteristics of roll-to-roll MWNTs. Research supported by NSF CMMI Grant1246800.

  15. Precipitation Behavior and Mechanical Properties of Ti-Mo Medium-Carbon Steel During Austenite to Bainite Transformation

    NASA Astrophysics Data System (ADS)

    Deng, Xiangtao; Wang, Zhaodong; Misra, R. D. K.; Han, Jie; Wang, Guodong

    2015-02-01

    The precipitation behavior and evolution of mechanical properties of Ti-Mo-bearing microalloyed medium-carbon steel during austenite to bainite transformation were studied, and two different cooling rates including ultrafast cooling (~80 °C/s) and accelerated cooling (~15 °C/s) during transformation were also investigated. The results suggest that Ti-Mo-bearing medium-carbon steel yield finer microstructure and nano-precipitates during austenite to bainite transformation during both ultrafast cooling and accelerated cooling processes. Yield strength and tensile strength obtained by ultrafast cooling process were higher than the accelerated cooling process, while the elongation was slightly reduced. Microstructural characterization indicated that grain refinement and precipitation hardening were the primary reasons for the increase in strength. Ultrafast cooling increased the density of dislocations and refined the grain size. Average size of precipitates containing Ti and Mo was 3-6 nm by ultrafast cooling process, while average precipitate size obtained by accelerated cooling process was 6-9 nm.

  16. Alternative backing up pump for turbomolecular pumps

    DOEpatents

    Myneni, Ganapati Rao

    2003-04-22

    As an alternative to the use of a mechanical backing pump in the application of wide range turbomolecular pumps in ultra-high and extra high vacuum applications, palladium oxide is used to convert hydrogen present in the evacuation stream and related volumes to water with the water then being cryo-pumped to a low pressure of below about 1.e.sup.-3 Torr at 150.degree. K. Cryo-pumping is achieved using a low cost Kleemenco cycle cryocooler, a somewhat more expensive thermoelectric cooler, a Venturi cooler or a similar device to achieve the required minimization of hydrogen partial pressure.

  17. VIEW OF HANDOPERATED ROLLING MILLS ROLLING STANDS FROM LEFT TO ...

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

    VIEW OF HAND-OPERATED ROLLING MILLS ROLLING STANDS FROM LEFT TO RIGHT: THREE HIGH; THREE HIGH; THREE HIGH; THREE HIGH (OPERATED AS A TWO-HIGH); TWO HIGH TWO HIGH MANUFACTURED BY BLAW-KNOX THREE HIGH MANUFACTURED BY LEWIS FOUNDRY AND MACHINE CO. - Cambria Iron Company, Gautier Works, 12" Mill, Clinton Street & Little Conemaugh River, Johnstown, Cambria County, PA

  18. Video Analysis of Rolling Cylinders

    ERIC Educational Resources Information Center

    Phommarach, S.; Wattanakasiwich, P.; Johnston, I.

    2012-01-01

    In this work, we studied the rolling motion of solid and hollow cylinders down an inclined plane at different angles. The motions were captured on video at 300 frames s[superscript -1], and the videos were analyzed frame by frame using video analysis software. Data from the real motion were compared with the theory of rolling down an inclined…

  19. LEDs are on a roll

    NASA Astrophysics Data System (ADS)

    Blom, Paul; van Mol, Ton

    2011-11-01

    Light-emitting diodes are more efficient than conventional lighting, but high production costs limit their uptake. Organic versions that can be produced using a cheap newspaper-style "roll-to-roll" printing process are likely to revolutionize our lighting and signage.

  20. Room Temperature Microstructure and Property Evaluation of a Heat Treated Fully Bainitic 20CrMoVTiB410 Steel

    NASA Astrophysics Data System (ADS)

    Srivatsa, Kulkarni; Srinivas, Perla; Balachandran, G.; Balasubramanian, V.

    2016-10-01

    The room temperature mechanical behavior of the fully bainitic steel grade 20CrMoVTiB410 was studied in the as-quenched and tempered conditions. The hardenability response of the steel during heat treatment was assessed. In the as-quenched condition itself, the steel exhibited a good combination of strength, ductility and toughness. Tempering the quenched steel till to 550°C, showed uniform mechanical properties. Tempering at 650°C showed secondary hardening behaviour, where the highest strength and least impact toughness was observed. Tempering at 700°C showed a sharp decrease in strength but with significant enhancement of toughness. The properties obtained were correlated with the microstructure and phase analysis was established using optical, scanning electron microscope, transmission electron microscope and x-ray diffraction techniques.

  1. Room Temperature Microstructure and Property Evaluation of a Heat Treated Fully Bainitic 20CrMoVTiB410 Steel

    NASA Astrophysics Data System (ADS)

    Srivatsa, Kulkarni; Srinivas, Perla; Balachandran, G.; Balasubramanian, V.

    2016-08-01

    The room temperature mechanical behavior of the fully bainitic steel grade 20CrMoVTiB410 was studied in the as-quenched and tempered conditions. The hardenability response of the steel during heat treatment was assessed. In the as-quenched condition itself, the steel exhibited a good combination of strength, ductility and toughness. Tempering the quenched steel till to 550°C, showed uniform mechanical properties. Tempering at 650°C showed secondary hardening behaviour, where the highest strength and least impact toughness was observed. Tempering at 700°C showed a sharp decrease in strength but with significant enhancement of toughness. The properties obtained were correlated with the microstructure and phase analysis was established using optical, scanning electron microscope, transmission electron microscope and x-ray diffraction techniques.

  2. Manufacturing Demonstration Facility: Roll-to-Roll Processing

    SciTech Connect

    Datskos, Panos G; Joshi, Pooran C; List III, Frederick Alyious; Duty, Chad E; Armstrong, Beth L; Ivanov, Ilia N; Jacobs, Christopher B; Graham, David E; Moon, Ji Won

    2015-08-01

    This Manufacturing Demonstration Facility (MDF)e roll-to-roll processing effort described in this report provided an excellent opportunity to investigate a number of advanced manufacturing approaches to achieve a path for low cost devices and sensors. Critical to this effort is the ability to deposit thin films at low temperatures using nanomaterials derived from nanofermentation. The overarching goal of this project was to develop roll-to-roll manufacturing processes of thin film deposition on low-cost flexible substrates for electronics and sensor applications. This project utilized ORNL s unique Pulse Thermal Processing (PTP) technologies coupled with non-vacuum low temperature deposition techniques, ORNL s clean room facility, slot dye coating, drop casting, spin coating, screen printing and several other equipment including a Dimatix ink jet printer and a large-scale Kyocera ink jet printer. The roll-to-roll processing project had three main tasks: 1) develop and demonstrate zinc-Zn based opto-electronic sensors using low cost nanoparticulate structures manufactured in a related MDF Project using nanofermentation techniques, 2) evaluate the use of silver based conductive inks developed by project partner NovaCentrix for electronic device fabrication, and 3) demonstrate a suite of low cost printed sensors developed using non-vacuum deposition techniques which involved the integration of metal and semiconductor layers to establish a diverse sensor platform technology.

  3. Body roll in swimming: a review.

    PubMed

    Psycharakis, Stelios G; Sanders, Ross H

    2010-02-01

    In this article, we present a critical review of the swimming literature on body roll, for the purposes of summarizing and highlighting existing knowledge, identifying the gaps and limitations, and stimulating further research. The main research findings can be summarized as follows: swimmers roll their shoulders significantly more than their hips; swimmers increase hip roll but maintain shoulder roll when fatigued; faster swimmers roll their shoulders less than slower swimmers during a 200-m swim; roll asymmetries, temporal differences in shoulder roll and hip roll, and shoulder roll side dominance exist in front crawl swimming, but there is no evidence to suggest that they affect swimming performance; and buoyancy contributes strongly to generating body roll in front crawl swimming. Based on and stimulated by current knowledge, future research should focus on the following areas: calculation of body roll for female swimmers and for backstroke swimming; differences in body roll between breathing and non-breathing cycles; causes of body roll asymmetries and their relation to motor laterality; body roll analysis across a wide range of velocities and swimming distances; exploration of the association between body roll and the magnitude and direction of propulsive/resistive forces developed during the stroke cycle; and the influence of kicking actions on the generation of body roll. PMID:20131140

  4. Body roll in swimming: a review.

    PubMed

    Psycharakis, Stelios G; Sanders, Ross H

    2010-02-01

    In this article, we present a critical review of the swimming literature on body roll, for the purposes of summarizing and highlighting existing knowledge, identifying the gaps and limitations, and stimulating further research. The main research findings can be summarized as follows: swimmers roll their shoulders significantly more than their hips; swimmers increase hip roll but maintain shoulder roll when fatigued; faster swimmers roll their shoulders less than slower swimmers during a 200-m swim; roll asymmetries, temporal differences in shoulder roll and hip roll, and shoulder roll side dominance exist in front crawl swimming, but there is no evidence to suggest that they affect swimming performance; and buoyancy contributes strongly to generating body roll in front crawl swimming. Based on and stimulated by current knowledge, future research should focus on the following areas: calculation of body roll for female swimmers and for backstroke swimming; differences in body roll between breathing and non-breathing cycles; causes of body roll asymmetries and their relation to motor laterality; body roll analysis across a wide range of velocities and swimming distances; exploration of the association between body roll and the magnitude and direction of propulsive/resistive forces developed during the stroke cycle; and the influence of kicking actions on the generation of body roll.

  5. Rolling Process Modeling Report: Finite-Element Prediction of Roll Separating Force and Rolling Defects

    SciTech Connect

    Soulami, Ayoub; Lavender, Curt A.; Paxton, Dean M.; Burkes, Douglas

    2014-04-23

    Pacific Northwest National Laboratory (PNNL) has been investigating manufacturing processes for the uranium-10% molybdenum (U-10Mo) alloy plate-type fuel for the U.S. high-performance research reactors. This work supports the Convert Program of the U.S. Department of Energy’s National Nuclear Security Administration (DOE/NNSA) Global Threat Reduction Initiative. This report documents modeling results of PNNL’s efforts to perform finite-element simulations to predict roll separating forces and rolling defects. Simulations were performed using a finite-element model developed using the commercial code LS-Dyna. Simulations of the hot rolling of U-10Mo coupons encapsulated in low-carbon steel have been conducted following two different schedules. Model predictions of the roll-separation force and roll-pack thicknesses at different stages of the rolling process were compared with experimental measurements. This report discusses various attributes of the rolled coupons revealed by the model (e.g., dog-boning and thickness non-uniformity).

  6. The influence of fine ferrite formation on the γ/α interface, fine bainite and retained austenite in a thermomechanically-processed transformation induced plasticity steel

    DOE PAGESBeta

    Timokhina, Ilana B.; Miller, Michael K.; Beladi, Hossein; Hodgson, Peter D.

    2016-03-03

    We subjected a Fe–0.26C–1.96Si–2Mn with 0.31Mo (wt%) steel to a novel thermomechanical processing route to produce fine ferrite with different volume fractions, bainite, and retained austenite. In two types of fine ferrites were found to be: (i) formed along prior austenite grain boundaries, and (ii) formed intragranularly in the interior of austenite grains. An increase in the volume fraction of fine ferrite led to the preferential formation of blocky retained austenite with low stability, and to a decrease in the volume fraction of bainite with stable layers of retained austenite. Moreover, the difference in the morphology of the bainitic ferritemore » and the retained austenite after different isothermal ferrite times was found to be responsible for the deterioration of the mechanical properties. The segregation of Mn, Mo, and C at distances of 2–2.5 nm from the ferrite and retained austenite/martensite interface on the retained austenite/martensite site was observed after 2700 s of isothermal hold. Finally, it was suggested that the segregation occurred during the austenite-to-ferrite transformation, and that this would decrease the interface mobility, which affects the austenite-to-ferrite transformation and ferrite grain size.« less

  7. Hot rolling of thick uranium molybdenum alloys

    SciTech Connect

    DeMint, Amy L.; Gooch, Jack G.

    2015-11-17

    Disclosed herein are processes for hot rolling billets of uranium that have been alloyed with about ten weight percent molybdenum to produce cold-rollable sheets that are about one hundred mils thick. In certain embodiments, the billets have a thickness of about 7/8 inch or greater. Disclosed processes typically involve a rolling schedule that includes a light rolling pass and at least one medium rolling pass. Processes may also include reheating the rolling stock and using one or more heavy rolling passes, and may include an annealing step.

  8. 14 CFR 25.349 - Rolling conditions.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...(b): (1) Conditions corresponding to steady rolling velocities must be investigated. In addition... rolling velocity may be assumed in the absence of a rational time history investigation of the...

  9. 14 CFR 23.349 - Rolling conditions.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Rolling conditions. 23.349 Section 23.349... Rolling conditions. The wing and wing bracing must be designed for the following loading conditions: (a..., the rolling accelerations may be obtained by modifying the symmetrical flight conditions in §...

  10. Rolling Wrinkles on Elastic Substrates

    NASA Astrophysics Data System (ADS)

    Imburgia, Michael; Crosby, Alfred

    The mechanics of rolling contact between an elastomer layer and a thin film present unique opportunities for taking advantage of elastic instabilities, such as surface wrinkling, to create patterned surfaces. Here we present a plate-to-roll(P2R) geometry to laminate a thin film onto an elastomer layer in order to induce surface wrinkling. First, a poly(dimethylsiloxane)(PDMS) layer is draped around a roller and pressed into contact with a poly(styrene)(PS) film supported on a plate. Once rolling begins, the PS film preferentially laminates onto the PDMS layer. During this process, the deformation of the PDMS layer can induce wrinkling when the contact load exceeds a critical value. Wrinkle feature size consists of amplitudes of 0 . 2 - 4 μm and wavelengths of 15 - 20 μm . Wrinkle amplitude can be controlled by contact load and roller curvature, as well as the mechanical properties and thickness of the film and elastomer. We develop semi-empirical equations to describe the effect of contact load and roller curvature on the wrinkle aspect ratio. Finite-element modeling of an elastomer layer in rolling contact with a rigid plate is used to support experimental results. Using these models, wrinkle-based technologies such as optoelectronics and enhanced adhesives can be envisioned.

  11. A rolling 3-UPU parallel mechanism

    NASA Astrophysics Data System (ADS)

    Miao, Zhihuai; Yao, Yan'an; Kong, Xianwen

    2013-12-01

    A novel rolling mechanism is proposed based on a 3-UPU parallel mechanism in this paper. The rolling mechanism is composed of two platforms connected by three UPU (universal-prismatic-universal) serial-chain type limbs. The degree-of-freedom of the mechanism is analyzed using screw theory. Gait analysis and stability analysis are presented in detail. Four rolling modes of the mechanism are discussed and simulated. The feasibility of the rolling mechanism is verified by means of a physical prototype. Finally, its terrain adaptability is enhanced through planning the rolling gaits.

  12. [Roll repair of nonconfluent pulmonary artery].

    PubMed

    Komiya, T; Yamazaki, K; Kohchi, K; Kanzaki, Y

    1995-11-01

    We reviewed the repair of nonconfluent pulmonary artery using a roll to clarify indication of this operation, operative technique (especially the material and the size of conduit) and possibility of total correction. Eleven patients (mean age: five years) and 13 operations including two reoperations were reviewed. The material of the roll was xenopericardium in nine and artificial graft in four operations. No operative death and late death occurred. Five patients required reoperations from three occlusion and two severe stenosis of the roll. Three of nine xenopericardial roll needed reoperations and in two reoperated cases, the roll had been placed behind the aorta. In contrast, one artificial graft needed reoperation. The diameter of the roll was compared with that of normal pulmonary artery estimated from the body surface area. If the roll was too large (more than 125% normal) or too small (less than 100% normal), the luminal diameter of the roll became significantly smaller than appropriate-sized roll (p = 0.002). The size of nonconfluent side of the pulmonary artery also affect the result of repair. In occluded or stenotic cases, the unilateral PA index was significantly smaller than good patent cases (p = 0.014). Total correction was possible in eight cases (73%) including four Rastelli operation, two right ventricular outflow patch enlargement, and two modified Fontan operations without operative death. Thus preoperative evaluation of the pulmonary artery size and anatomy, selection of roll material and size matching seemed to be important for successful roll repair of nonconfluent pulmonary artery.

  13. Tribological Testing of Anti-Adhesive coatings for Cold Rolling Mill Rolls--Application to TiN-Coated Rolls

    SciTech Connect

    Ould, Choumad; Montmitonnet, Pierre; Gachon, Yves; Badiche, Xavier

    2011-05-04

    Roll life is a major issue in cold strip rolling. Roll wear may result either in too low roll roughness, bringing friction below the minimum requested for strip entrainment; or it may degrade strip surface quality. On the contrary, adhesive wear and transfer (''roll coating'', ''pick up'') may form a thick metallic deposits on the roll which increases friction excessively and degrades strip surface again [1]. The roll surface, with the help of a materials-adapted lubricant, must therefore possess anti-wear and anti-adhesive properties. Thus, High Speed Steeel (HSS) rolls show superior properties compared with standard Cr-steel rolls due to their high carbide surface coverage. Another way to improve wear and adhesion properties of surfaces is to apply hard metallic (hard-Cr) or ceramic coatings. Chromium is renowned for its excellent anti-wear and anti-adhesive properties and may serve as a reference. Here, as a first step towards alternative, optimised coatings, a PVD TiN coating has been deposited on tool steels, as previous attempts have proved TiN to be rather successful in cold rolling experiments [2,3]. Different tribological tests are reported here, giving insight in both anti-adhesive properties and fatigue life improvement.

  14. Slow-roll thawing quintessence

    SciTech Connect

    Chiba, Takeshi

    2009-04-15

    We derive slow-roll conditions for thawing quintessence. We solve the equation of motion of {phi} for a Taylor expanded potential (up to the quadratic order) in the limit where the equation of state w is close to -1 to derive the equation of state as a function of the scale factor. We find that the evolution of {phi} and hence w are described by only two parameters. The expression for w(a), which can be applied to general thawing models, coincides precisely with that derived recently by Dutta and Scherrer for hilltop quintessence. The consistency conditions of |w+1|<<1 are derived. The slow-roll conditions for freezing quintessence are also derived.

  15. Slow-roll extended quintessence

    SciTech Connect

    Chiba, Takeshi; Siino, Masaru; Yamaguchi, Masahide

    2010-04-15

    We derive the slow-roll conditions for a nonminimally coupled scalar field (extended quintessence) during the radiation/matter dominated era extending our previous results for thawing quintessence. We find that the ratio {phi}e/3H{phi} becomes constant but negative, in sharp contrast to the ratio for the minimally coupled scalar field. We also find that the functional form of the equation of state of the scalar field asymptotically approaches that of the minimally coupled thawing quintessence.

  16. Mechanisms of rolling contact spalling

    NASA Technical Reports Server (NTRS)

    Kumar, A. M.; Kulkarni, S. M.; Bhargava, V.; Hahn, G. T.; Rubin, C. A.

    1987-01-01

    The results of a study aimed at analyzing the mechanical material interactions responsible for rolling contact spalling of the 440 C steel, high pressure oxygen turbopump bearings are presented. A coupled temperature displacement finite element analysis of the effects of friction heating under the contact is presented. The contact is modelled as a stationary, heat generating, 2 dimensional indent in an elastic perfectly plastic half-space with heat fluxes up to 8.6 x 10000 KW/m sq comparable to those generated in the bearing. Local temperatures in excess of 1000 C are treated. The calculations reveal high levels of residual tension after the contact is unloaded and cools. Efforts to promote Mode 2/Mode 3 fatigue crack growth under cyclic torsion in hardened 440 C steel are described. Spalls produced on 440 C steel by a 3 ball/rod rolling contact testing machine were studied with scanning microscopy. The shapes of the cyclic, stress strain hysteresis loops displayed by hardened 440 C steel in cyclic torsion at room temperature are defined for the plastic strain amplitudes encountered in rolling/sliding contact. Results of these analyses are discussed in detail.

  17. Rolling Contact Fatigue of Ceramics

    SciTech Connect

    Wereszczak, Andrew A; Wang, W.; Wang, Y.; Hadfield, M.; Kanematsu, W.; Kirkland, Timothy Philip; Jadaan, Osama M.

    2006-09-01

    High hardness, low coefficient of thermal expansion and high temperature capability are properties also suited to rolling element materials. Silicon nitride (Si{sub 3}N{sub 4}) has been found to have a good combination of properties suitable for these applications. However, much is still not known about rolling contact fatigue (RCF) behavior, which is fundamental information to assess the lifetime of the material. Additionally, there are several test techniques that are employed internationally whose measured RCF performances are often irreconcilable. Due to the lack of such information, some concern for the reliability of ceramic bearings still remains. This report surveys a variety of topics pertaining to RCF. Surface defects (cracks) in Si{sub 3}N{sub 4} and their propagation during RCF are discussed. Five methods to measure RCF are then briefly overviewed. Spalling, delamination, and rolling contact wear are discussed. Lastly, methods to destructively (e.g., C-sphere flexure strength testing) and non-destructively identify potential RCF-limiting flaws in Si{sub 3}N{sub 4} balls are described.

  18. Modeling C-Curves for the Growth Rate of Widmanstätten and Bainitic Ferrite in Fe-C Alloys

    NASA Astrophysics Data System (ADS)

    Leach, Lindsay; Hillert, Mats; Borgenstam, Annika

    2016-01-01

    When Zener formulated his maximum growth rate criterion for predicting the coarseness of various metallographic objects, he simplified the growth rate equations and predicted that the optimum coarseness should be twice the critical value for which all the driving force would be absorbed by interfacial energy. It is now emphasized that a composition dependence of the diffusion coefficient has a considerable influence and can result in a ratio much larger than two. Various approximations have now been removed from the growth rate equation. When applied to acicular ferrite in the Fe-C system, a C-curve for the growth rate is obtained that resembles the unusually wide C-curve obtained experimentally when information on Widmanstätten ferrite and bainite is combined. It is not necessary to explain that shape as a combination of separate curves for Widmanstätten ferrite and bainite. The main reason for the wide C-curve is the direct effect of the composition dependence of the diffusivity of carbon in austenite.

  19. Effects of Austempering Temperature on Strength, Ductility and Toughness of Low-C High-Al/Si Carbide-Free Bainitic Steel

    NASA Astrophysics Data System (ADS)

    Meng, Jiangying; Feng, Ying; Zhou, Qian; Zhao, Leijie; Zhang, Fucheng; Qian, Lihe

    2015-08-01

    The microstructure and the mechanical properties of a low-carbon Al/Si-alloyed carbide-free bainitic steel austempered at temperatures between 300 and 350 °C have been investigated by means of optical microscopy, scanning electron microscopy, transmission electron microscopy, x-ray diffraction analysis, and mechanical property tests. The results show that an excellent combination of tensile strength, ductility, and impact toughness is obtained at the austempering temperature of 320 °C—but neither at the lowest temperature of 300 °C nor at the highest temperature of 350 °C. These results are correlated with the features of the constituent phases of the microstructure, especially the amount and size of retained austenite, which are largely dependent on the austempering temperature. The observations are also due to the inconsistent effects of strain-induced martensitic transformation on strength, ductility, and toughness. The results of the present study suggest that an optimized isothermal temperature may also exist for any other bainitic steel, at which, if austempering treatment is carried out, an improved combination of tensile and impact properties can be obtained.

  20. Helitrons on a roll: eukaryotic rolling-circle transposons.

    PubMed

    Kapitonov, Vladimir V; Jurka, Jerzy

    2007-10-01

    Rolling-circle eukaryotic transposons, known as Helitron transposons, were first discovered in plants (Arabidopsis thaliana and Oryza sativa) and in the nematode Caenorhabditis elegans. To date, Helitrons have been identified in a diverse range of species, from protists to mammals. They represent a major class of eukaryotic transposons and are fundamentally different from classical transposons in terms of their structure and mechanism of transposition. Helitrons seem to have a major role in the evolution of host genomes. They frequently capture diverse host genes, some of which can evolve into novel host genes or become essential for helitron transposition.

  1. How rolling forecasting facilitates dynamic, agile planning.

    PubMed

    Miller, Debra; Allen, Michael; Schnittger, Stephanie; Hackman, Theresa

    2013-11-01

    Rolling forecasting may be used to replace or supplement the annual budget process. The rolling forecast typically builds on the organization's strategic financial plan, focusing on the first three years of plan projections and comparing the strategic financial plan assumptions with the organization's expected trajectory. Leaders can then identify and respond to gaps between the rolling forecast and the strategic financial plan on an ongoing basis.

  2. Spray Rolling Aluminum Strip for Transportation Applications

    SciTech Connect

    Kevin M. McHugh; Y. Lin; Y. Zhou; E. J. Lavernia; J.-P. Delplanque; S. B. Johnson

    2005-02-01

    Spray rolling is a novel strip casting technology in which molten aluminum alloy is atomized and deposited into the roll gap of mill rolls to produce aluminum strip. A combined experimental/modeling approach has been followed in developing this technology with active participation from industry. The feasibility of this technology has been demonstrated at the laboratory scale and it is currently being scaled-up. This paper provides an overview of the process and compares the microstructure and properties of spray-rolled 2124 aluminum alloy with commercial ingot-processed material

  3. METHOD OF HOT ROLLING URANIUM METAL

    DOEpatents

    Kaufmann, A.R.

    1959-03-10

    A method is given for quickly and efficiently hot rolling uranium metal in the upper part of the alpha phase temperature region to obtain sound bars and sheets possessing a good surface finish. The uranium metal billet is heated to a temperature in the range of 1000 deg F to 1220 deg F by immersion iii a molten lead bath. The heated billet is then passed through the rolls. The temperature is restored to the desired range between successive passes through the rolls, and the rolls are turned down approximately 0.050 inch between successive passes.

  4. Effect of temper rolling on final shape defects in a V-section roll forming process

    NASA Astrophysics Data System (ADS)

    Abvabi, Akbar; Rolfe, Bernard; Hodgson, Peter D.; Weiss, Matthias

    2013-12-01

    Roll forming is a continuous process in which a flat strip is shaped to the desired profile by sequential bending in a series of roll stands. Because of the large variety of applications of roll forming in the industry, Finite Element Analysis (FEA) is increasingly utilized for roll forming process design. Bending is the dominant deformation mode in roll forming. Sheet materials used in this process are generally temper rolled, roller- or tension- leveled. These processes introduce residual stresses into the material, and recent studies have shown that those affect the material behavior in bending. In this study a numerical model of the temper rolling (skin passing) process was used to determine a residual stress distribution in a dual phase, DP780, steel strip. A 5-stand roll forming process for the forming of a V-section was modeled, and the effect of various thickness reduction levels in the temper rolling process on the final shape defects was analyzed. The results show that a small thickness reduction in the temper rolling process decreases the maximum bow height but the final springback angle increases. It is also shown that reasonable model accuracy can be achieved by including the residual stress information due to temper rolling as initial condition in the numerical modeling of a roll forming process.

  5. 1. EXTERIOR VIEW OF BUILDING THAT HOUSES THE HOT ROLL ...

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

    1. EXTERIOR VIEW OF BUILDING THAT HOUSES THE HOT ROLL MILL, ALSO KNOWN AS THE NO. 31 HOT ROLL MILL; LOOKING SOUTHWEST - American Brass Company, Kenosha Works, Hot Roll Mill, Kenosha, Kenosha County, WI

  6. Dynamic precipitation of Al-Zn alloy during rolling and accumulative roll bonding

    NASA Astrophysics Data System (ADS)

    Liu, C. Y.; Yu, L.; Ma, M. Z.; Liu, R. P.; Ma, Z. Y.

    2015-11-01

    In this study, cold rolling was performed on a binary Al-20 wt%Zn alloy and dynamic precipitation identified for the first time in Al alloys under cold rolling. Zn clusters formed after application of 0.6 strain, and the Zn phase precipitated upon further increasing strain. Both grain refinement and rolling-induced defects are considered to promote Zn precipitation. The hardness of Al-Zn alloy initially increased with strain up to a strain of 2.9 and then decreased with increasing rolling strain. Dynamic precipitation greatly affects the strengthening mechanism of the rolled Al-Zn alloy under various strains.

  7. 14 CFR 25.349 - Rolling conditions.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... STANDARDS: TRANSPORT CATEGORY AIRPLANES Structure Flight Maneuver and Gust Conditions § 25.349 Rolling conditions. The airplane must be designed for loads resulting from the rolling conditions specified in... deflections may be limited by pilot effort) must be considered in combination with an airplane load factor...

  8. 14 CFR 25.349 - Rolling conditions.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... STANDARDS: TRANSPORT CATEGORY AIRPLANES Structure Flight Maneuver and Gust Conditions § 25.349 Rolling conditions. The airplane must be designed for loads resulting from the rolling conditions specified in... deflections may be limited by pilot effort) must be considered in combination with an airplane load factor...

  9. 14 CFR 25.349 - Rolling conditions.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... STANDARDS: TRANSPORT CATEGORY AIRPLANES Structure Flight Maneuver and Gust Conditions § 25.349 Rolling conditions. The airplane must be designed for loads resulting from the rolling conditions specified in... deflections may be limited by pilot effort) must be considered in combination with an airplane load factor...

  10. 14 CFR 25.349 - Rolling conditions.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... STANDARDS: TRANSPORT CATEGORY AIRPLANES Structure Flight Maneuver and Gust Conditions § 25.349 Rolling conditions. The airplane must be designed for loads resulting from the rolling conditions specified in... deflections may be limited by pilot effort) must be considered in combination with an airplane load factor...

  11. Lubrication of rolling-element bearings

    NASA Technical Reports Server (NTRS)

    Parker, R. J.

    1980-01-01

    The lubrication of rolling element bearings is surveyed. Emphasis is on the critical design aspects related to speed, temperature, and ambient pressure environment. Types of lubrication including grease, jets, mist, wick, and through the race are discussed. The historical development, present state of technology, and the future problems of rolling element bearing lubrication are discussed.

  12. Roll forming of eco-friendly stud

    NASA Astrophysics Data System (ADS)

    Keum, Y. T.; Lee, S. Y.; Lee, T. H.; Sim, J. K.

    2013-12-01

    In order to manufacture an eco-friendly stud, the sheared pattern is designed by the Taguchi method and expanded by the side rolls. The seven geometrical shape of sheared pattern are considered in the structural and thermal analyses to select the best functional one in terms of the durability and fire resistance of dry wall. For optimizing the size of the sheared pattern chosen, the L9 orthogonal array and smaller-the-better characteristics of the Taguchi method are used. As the roll gap causes forming defects when the upper-and-lower roll type is adopted for expanding the sheared pattern, the side roll type is introduced. The stress and strain distributions obtained by the FEM simulation of roll-forming processes are utilized for the design of expanding process. The expanding process by side rolls shortens the length of expanding process and minimizes the cost of dies. Furthermore, the stud manufactured by expanding the sheared pattern of the web is an eco-friend because of the scrapless roll-forming process. In addition, compared to the conventionally roll-formed stud, the material cost is lessened about 13.6% and the weight is lightened about 15.5%.

  13. 42 CFR 21.46 - Merit roll.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Merit roll. 21.46 Section 21.46 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES PERSONNEL COMMISSIONED OFFICERS Appointment § 21.46 Merit roll. Each board appointed pursuant to § 21.30 to consider the qualifications...

  14. Computational Analysis of Ares I Roll Control System Jet Interaction Effects on Rolling Moment

    NASA Technical Reports Server (NTRS)

    Deere, Karen A.; Pao, S. Paul; Abdol-Hamid, Khaled S.

    2011-01-01

    The computational flow solver USM3D was used to investigate the jet interaction effects from the roll control system on the rolling moment of the Ares I full protuberance configuration at wind tunnel Reynolds numbers. Solutions were computed at freestream Mach numbers from M = 0.5 to M = 5 at the angle of attack 0deg, at the angle of attack 3.5deg for a roll angle of 120deg, and at the angle of attack 7deg for roll angles of 120deg and 210deg. Results indicate that the RoCS housing provided a beneficial jet interaction effect on vehicle rolling moment for M > or = 0.9. Most of the components downstream of the roll control system housing contributed to jet interaction penalties on vehicle rolling moment.

  15. Direct Observations of Austenite, Bainite and Martensite Formation During Arc Welding of 1045 Steel using Time Resolved X-Ray Diffraction

    SciTech Connect

    Elmer, J; Palmer, T; Babu, S; Zhang, W; DebRoy, T

    2004-02-17

    In-situ Time Resolved X-Ray Diffraction (TRXRD) experiments were performed during stationary gas tungsten arc (GTA) welding of AISI 1045 C-Mn steel. These synchrotron-based experiments tracked, in real time, phase transformations in the heat-affected zone of the weld under rapid heating and cooling conditions. The diffraction patterns were recorded at 100 ms intervals, and were later analyzed using diffraction peak profile analysis to determine the relative fraction of ferrite ({alpha}) and austenite ({gamma}) phases in each diffraction pattern. Lattice parameters and diffraction peak widths were also measured throughout the heating and cooling cycle of the weld, providing additional information about the phases that were formed. The experimental results were coupled with a thermofluid weld model to calculate the weld temperatures, allowing time-temperature transformation kinetics of the {alpha} {yields} {gamma} phase transformation to be evaluated. During heating, complete austenitization was observed in the heat affected zone of the weld and the kinetics of the {alpha} {yields} {gamma} phase transformation were modeled using a Johnson-Mehl-Avrami (JMA) approach. The results from the 1045 steel weld were compared to those of a 1005 low carbon steel from a previous study. Differences in austenitization rates of the two steels were attributed to differences in the base metal microstructures, particularly the relative amounts of pearlite and the extent of the allotriomorphic ferrite phase. During weld cooling, the austenite transformed to a mixture of bainite and martensite. In situ diffraction was able to distinguish between these two non-equilibrium phases based on differences in their lattice parameters and their transformation rates, resulting in the first real time x-ray diffraction observations of bainite and martensite formation made during welding.

  16. Inflation with a constant rate of roll

    NASA Astrophysics Data System (ADS)

    Motohashi, Hayato; Starobinsky, Alexei A.; Yokoyama, Jun'ichi

    2015-09-01

    We consider an inflationary scenario where the rate of inflaton roll defined by ̈phi/H dot phi remains constant. The rate of roll is small for slow-roll inflation, while a generic rate of roll leads to the interesting case of 'constant-roll' inflation. We find a general exact solution for the inflaton potential required for such inflaton behaviour. In this model, due to non-slow evolution of background, the would-be decaying mode of linear scalar (curvature) perturbations may not be neglected. It can even grow for some values of the model parameter, while the other mode always remains constant. However, this always occurs for unstable solutions which are not attractors for the given potential. The most interesting particular cases of constant-roll inflation remaining viable with the most recent observational data are quadratic hilltop inflation (with cutoff) and natural inflation (with an additional negative cosmological constant). In these cases even-order slow-roll parameters approach non-negligible constants while the odd ones are asymptotically vanishing in the quasi-de Sitter regime.

  17. Signal and power roll ring testing update

    NASA Technical Reports Server (NTRS)

    Smith, Dennis W.

    1989-01-01

    The development of the roll ring as a long-life, low-torque alternative to the slip ring is discussed. A roll ring consists of one or more circular flexures captured by their own spring force in the annular space between two concentric conductors or contact rings. The advantages of roll rings over other types of electrical transfer devices are: extremely low drag torque, high transfer efficiencies in high-power configurations, extremely low wear debris generation, long life, and low weight for high-power applications.

  18. Why Low Bounce Balls Exhibit High Rolling Resistance

    ERIC Educational Resources Information Center

    Cross, Rod

    2015-01-01

    A simple experiment is described to measure the coefficient of rolling friction for a low bounce ball rolling on a horizontal surface. As observed previously by others, the coefficient increased with rolling speed. The energy loss due to rolling friction can be explained in terms of the measured coefficient of restitution for the ball, meaning…

  19. 9 CFR 381.159 - Poultry rolls.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... subchapter, in 9 CFR Chapter III, Subchapter E, or in 21 CFR Chapter I, Subchapter A or Subchapter B. In... use as binders in poultry rolls: transglutaminase enzyme at up to 65 ppm. When binding agents...

  20. Mathematical modeling of deformation during hot rolling

    SciTech Connect

    Jin, D.; Stachowiak, R.G.; Samarasekera, I.V.; Brimacombe, J.K.

    1994-12-31

    The deformation that occurs in the roll bite during the hot rolling of steel, particularly the strain-rate and strain distribution, has been mathematically modeled using finite-element analysis. In this paper three different finite-element models are compared with one another and with industrial measurements. The first model is an Eulerian analysis based on the flow formulation method, while the second utilizes an Updated Lagrangian approach. The third model is based on a commercially available program DEFORM which also utilizes a Lagrangian reference frame. Model predictions of strain and strain-rate distribution, particularly near the surface of the slab, are strongly influenced by the treatment of friction at the boundary and the magnitude of the friction coefficient or shear factor. Roll forces predicted by the model have been compared with industrial rolling loads from a seven-stand hot-strip mill.

  1. Next-Generation Space Ambitions Keep Rolling

    NASA Video Gallery

    As space shuttle Atlantis rolled to its new home at the Kennedy Space Center Visitor Complex earlier this month, NASA and its commercial crew partners reflected on the Space Shuttle Program's treme...

  2. A Simple Modeling of Asymmetric Rolling

    NASA Astrophysics Data System (ADS)

    Halloumi, A.; Desrayaud, Ch.; Montheillet, F.

    2010-06-01

    Two complementary analytical approaches and the finite difference method are proposed for modeling asymmetric rolling (ASR) of metal sheet. The first analytical model is an upper bound method based on a uniform strain field depending on one single optimization parameter, viz. the entry velocity of the sheet. Its results can be straightforwardly used for practical applications. The second model uses a more refined analytical velocity field based on the classical parabolic estimation of the material flow lines in rolling. It involves an additional optimization parameter associated with the precise form of the velocity field. Local values of strain, strain rate and self-heating temperature are easily calculated, as well as the rolling force. Finally, the finite difference method is applied to compute heat transfers between the rolls and the sheet. In conclusion, the respective advantages of the three methods are discussed.

  3. A high sensitive roll angle interferometer

    NASA Astrophysics Data System (ADS)

    Le, Yanfen; Hou, Wenmei; Hu, Kai; Ju, Aisong

    2013-01-01

    A roll angle interferometer with high sensitivity is designed in this paper. Two sets of centrosymmetric beams are used to travel through the measurement and reference arms of the roll angle interferometer which contains two specific optical devices: wedge prism assembly and wedge mirror assembly. The optical path change in both arms caused by roll is converted into phase shift which can be measured by interferometer. Because of the adoption of the centrosymmetric measurement structure, the straightness errors, yaw error and pitch error can be avoided and the dead path is minimized, so that the stability and the accuracy of the measurement can be greatly enhanced. The resolution for the roll measurement is about 0.006″ with the measurement range of ±1°.

  4. Roll motion analysis of deepwater pipelay crane vessel

    NASA Astrophysics Data System (ADS)

    You, Dandan; Sun, Liping; Qu, Zhiguo; Wang, Tao

    2013-12-01

    For a large floating vessel in waves, radiation damping is not an accurate prediction of the degree of roll unlike other degrees of freedom motion. Therefore, to get the knowledge of roll motion performance of deepwater pipelay crane vessels and to keep the vessel working safety, the paper presents the relationship between a series of dimensionless roll damping coefficients and the roll response amplitude operator (RAO). By using two kinds of empirical data, the roll damping is estimated in the calculation flow. After getting the roll damping coefficient from the model test, a prediction of roll motion in regular waves is evaluated. According to the wave condition in the working region, short term statistics of roll motion are presented under different wave parameters. Moreover, the relationship between the maximal roll response level to peak spectral wave period and the roll damping coefficient is investigated. Results may provide some reference to design and improve this kind of vessel.

  5. 75 FR 42782 - Hot-Rolled Flat-Rolled Carbon-Quality Steel Products From Brazil, Japan, and Russia

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-22

    ... party group responses to its notice of institution (75 FR 16504, April 1, 2010) were adequate. A record... COMMISSION Hot-Rolled Flat-Rolled Carbon-Quality Steel Products From Brazil, Japan, and Russia AGENCY: United...-year reviews concerning the countervailing duty order on certain hot-rolled flat-rolled...

  6. 49 CFR 393.134 - What are the rules for securing roll-on/roll-off or hook lift containers?

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... or hook lift containers? 393.134 Section 393.134 Transportation Other Regulations Relating to... for securing roll-on/roll-off or hook lift containers? (a) Applicability. The rules in this section apply to the transportation of roll-on/roll-off or hook lift containers. (b) Securement of a...

  7. 49 CFR 393.134 - What are the rules for securing roll-on/roll-off or hook lift containers?

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... or hook lift containers? 393.134 Section 393.134 Transportation Other Regulations Relating to... for securing roll-on/roll-off or hook lift containers? (a) Applicability. The rules in this section apply to the transportation of roll-on/roll-off or hook lift containers. (b) Securement of a...

  8. 49 CFR 393.134 - What are the rules for securing roll-on/roll-off or hook lift containers?

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... or hook lift containers? 393.134 Section 393.134 Transportation Other Regulations Relating to... for securing roll-on/roll-off or hook lift containers? (a) Applicability. The rules in this section apply to the transportation of roll-on/roll-off or hook lift containers. (b) Securement of a...

  9. 49 CFR 393.134 - What are the rules for securing roll-on/roll-off or hook lift containers?

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... or hook lift containers? 393.134 Section 393.134 Transportation Other Regulations Relating to... for securing roll-on/roll-off or hook lift containers? (a) Applicability. The rules in this section apply to the transportation of roll-on/roll-off or hook lift containers. (b) Securement of a...

  10. 49 CFR 393.134 - What are the rules for securing roll-on/roll-off or hook lift containers?

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... or hook lift containers? 393.134 Section 393.134 Transportation Other Regulations Relating to... for securing roll-on/roll-off or hook lift containers? (a) Applicability. The rules in this section apply to the transportation of roll-on/roll-off or hook lift containers. (b) Securement of a...

  11. Designing Rolling-Element Bearings

    NASA Technical Reports Server (NTRS)

    Moore, James D., Jr.

    2007-01-01

    Bearing Analysis Tool (BAT) is a computer program for designing rolling-element bearings for cryogenic turbomachines. BAT provides a graphical user interface (GUI) that guides the entry of data to develop mathematical models of bearings. The GUI breaks model data into logical subsets that are entered through logic-driven input screens. The software generates a threedimensional graphical model of a bearing as the data are entered. Most dataentry errors become immediately obvious in the graphical model. BAT provides for storage of all the data on a shaft/bearing system, enabling the creation of a library of proven designs. Data from the library can be transferred to subsequent projects by use of simple cut-and-paste routines. BAT includes a library of temperature- dependent cryogenic bearing-material properties for use in the mathematical models. BAT implements algorithms that (1) enable the user to select combinations of design and/or operating-condition parameters, and then (2) automatically optimize the design by performing trade studies over all of the parameter combinations. This feature enables optimization over a large trade space in a fraction of the time taken when using prior bearingmodel software.

  12. Strip edge cracking simulation in cold rolling

    SciTech Connect

    Hubert, C.; Dubar, L.; Dubar, M.; Dubois, A.

    2011-01-17

    This research work focuses on a specific defect which occurs during cold rolling of steel strips: edge-serration. Investigations on the industrial processes have led to the conclusion that this defect is the result of the edge-trimming and cold rolling sequences. The aim of this research work is to analyze the effect of the cutting process and the cold rolling on cracks occurrence, especially on strip edges.This study is performed using an experimental testing stand called Upsetting Rolling Test (URT). It allows to reproduce cold rolling contact parameters such as forward slip, reduction ratio and friction coefficients. Specimens sampled near trimmed industrial strip edges are deformed using the URT stand. Two sets of specimens with different stress states, obtained by annealing, are submitted to two reduction passes with extreme forward slips.Scanning electron microscopy observations added to 3D optical surface profiler topographies show that on one hand, forward slip has a major effect on cracks opening. On the other hand, cracks opening decreases according to high roll strip speed gradient. Concerning the heat-treated specimens, no crack appeared after all reduction passes, showing a large influence of the cutting process and consequently of the local stress state in the vicinity of the burnish and fracture regions.

  13. 40 CFR 1066.225 - Roll runout and diameter verification procedure.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... for roll runout and roll diameter. Roll runout is a measure of the variation in roll radius around the... position of the roll surface relative to the roll centerline as it turns through a complete revolution. The... dial indicator. (4) Slowly turn the roll through a complete rotation and record the maximum and...

  14. 40 CFR 1066.225 - Roll runout and diameter verification procedure.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... for roll runout and roll diameter. Roll runout is a measure of the variation in roll radius around the... position of the roll surface relative to the roll centerline as it turns through a complete revolution. The... dial indicator. (4) Slowly turn the roll through a complete rotation and record the maximum and...

  15. Electromechanical battery design suitable for back-up power applications

    DOEpatents

    Post, Richard F.

    2002-01-01

    The windings that couple energy into and out of the rotor of an electro-mechanical battery are modified. The normal stator windings of the generator/motor have been replaced by two orthogonal sets of windings. Because of their orthogonality, they are decoupled from each other electrically, though each can receive (or deliver) power flows from the rotating field produced by the array of permanent magnets. Due to the orthogonal design of the stator windings and the high mechanical inertia of the flywheel rotor, the resulting power delivered to the computer system is completely insensitive to any and all electrical transients and variabilities of the power from the main power source. This insensitivity includes complete failure for a period determined only by the amount of stored kinetic energy in the E-M battery modules that are supplied. Furthermore there is no need whatsoever for fast-acting, fractional-cycle switches, such as are employed in conventional systems, and which are complicated to implement.

  16. [Team work as the way to back up consciousness].

    PubMed

    Maksakova, O A

    2014-01-01

    Conception of unconsciousness after brain injury had changed considerably due to high technologies. Nowadays some patients considered by clinicians as unconscious are admitted to awareness with neurovisual techniques. Physiologic and neurophysiologic signals' combining brings forward robust quantification of patients' clinical state too. These "Third Person View" approaches leave the question of patient's experience content open because of determined stimuli paradigms. Yet patient's response pattern becomes formed not only with brain deficits but by questions-stimuli, context, and inquiring person. Rehabilitation team work is sourcing of phenomenology knowledge of patient's processes due to "First-Second Person View" approach and chance to real-time change. Restoration of consciousness comes of building-up patients' contacts with their own bodies, other persons and outward things. The basic principle of this approach is feedback assignement to any minimal movement or vegetative signal of the patient. The net of feedbacks with the patient and inter-professional ones builds up the team as Non-linear Complex System. Characteristics of "Team-Patient" system status are energy, entropy, and complexity. Impairment of consciousness as the absence of linear contact with a patient may appear together with a loss of essential functions (low energy), vegetative-visceral fits (excessive energy and low order), motor agitation (excessive energy and order), and etc. Techniques of team work are different in these cases for resulting optimization of the system condition. System complexity rise is a powerful tool to arouse apatient with impairment of consciousness. System self-organization is a key process for awareness formation. Analysis of complex communication process in patient--team system may be useful for creation of the general theory of consciousness.

  17. Cost-benefit analysis of system back-up methodologies

    SciTech Connect

    Not Available

    1982-09-01

    The purpose of this document is to enable the Energy Information Administration (EIA) management to choose between alternative approaches for establishing an emergency backup system for processing as part of our Continuity of Operations Plan (COOP). These alternatives include costs for implementing, testing, and processing critical energy data at an alternative site in the unlikely event of loss of our Forrestal Computer Facility due to disaster.

  18. The Back-Up Brigade: Volunteer Tutors Lend a Hand.

    ERIC Educational Resources Information Center

    Grindstaff, Gordon

    1981-01-01

    Describes three tutoring centers--two in churches, one in an office building--where adults from the community provide voluntary after-school help to children from Chicago's disadvantaged Cabrini Green housing project. (SJL)

  19. Analog Film Images...Back-Up Digital Technology.

    ERIC Educational Resources Information Center

    Brunner, Alex

    1999-01-01

    Examines the role of microfilm in storing information to eliminate digital obsolescence. Discusses the benefits of digital-to-analog microfilm systems; changes in conventional microfilm technology; and the advantages of true hybrid imaging systems that allow retrieval of images from document microfilm, digitally created microfilm or paper scanners…

  20. Data Storage & Management: Backing up to the Future

    ERIC Educational Resources Information Center

    Briggs, Linda L.

    2006-01-01

    "I saved my presentation in my personal drive on the server last night, but now I can't find it. It just seems to be gone. Can you get it back?" "It looks like the mail server is corrupted. When was the last backup?" These sorts of questions, whether from faculty, students, or IT staff, can be an IT nightmare, or they can set in motion a…

  1. Optimization of cold rolling process parameters in order to increasing rolling speed limited by chatter vibrations

    PubMed Central

    Heidari, Ali; Forouzan, Mohammad R.

    2012-01-01

    Chatter has been recognized as major restriction for the increase in productivity of cold rolling processes, limiting the rolling speed for thin steel strips. It is shown that chatter has close relation with rolling conditions. So the main aim of this paper is to attain the optimum set points of rolling to achieve maximum rolling speed, preventing chatter to occur. Two combination methods were used for optimization. First method is done in four steps: providing a simulation program for chatter analysis, preparing data from simulation program based on central composite design of experiment, developing a statistical model to relate system tendency to chatter and rolling parameters by response surface methodology, and finally optimizing the process by genetic algorithm. Second method has analogous stages. But central composite design of experiment is replaced by Taguchi method and response surface methodology is replaced by neural network method. Also a study on the influence of the rolling parameters on system stability has been carried out. By using these combination methods, new set points were determined and significant improvement achieved in rolling speed. PMID:25685398

  2. Optimization of cold rolling process parameters in order to increasing rolling speed limited by chatter vibrations.

    PubMed

    Heidari, Ali; Forouzan, Mohammad R

    2013-01-01

    Chatter has been recognized as major restriction for the increase in productivity of cold rolling processes, limiting the rolling speed for thin steel strips. It is shown that chatter has close relation with rolling conditions. So the main aim of this paper is to attain the optimum set points of rolling to achieve maximum rolling speed, preventing chatter to occur. Two combination methods were used for optimization. First method is done in four steps: providing a simulation program for chatter analysis, preparing data from simulation program based on central composite design of experiment, developing a statistical model to relate system tendency to chatter and rolling parameters by response surface methodology, and finally optimizing the process by genetic algorithm. Second method has analogous stages. But central composite design of experiment is replaced by Taguchi method and response surface methodology is replaced by neural network method. Also a study on the influence of the rolling parameters on system stability has been carried out. By using these combination methods, new set points were determined and significant improvement achieved in rolling speed.

  3. Comparing Acute Bouts of Sagittal Plane Progression Foam Rolling vs. Frontal Plane Progression Foam Rolling.

    PubMed

    Peacock, Corey A; Krein, Darren D; Antonio, Jose; Sanders, Gabriel J; Silver, Tobin A; Colas, Megan

    2015-08-01

    Many strength and conditioning professionals have included the use of foam rolling devices within a warm-up routine prior to both training and competition. Multiple studies have investigated foam rolling in regards to performance, flexibility, and rehabilitation; however, additional research is necessary in supporting the topic. Furthermore, as multiple foam rolling progressions exist, researching differences that may result from each is required. To investigate differences in foam rolling progressions, 16 athletically trained males underwent a 2-condition within-subjects protocol comparing the differences of 2 common foam rolling progressions in regards to performance testing. The 2 conditions included a foam rolling progression targeting the mediolateral axis of the body (FRml) and foam rolling progression targeting the anteroposterior axis (FRap). Each was administered in adjunct with a full-body dynamic warm-up. After each rolling progression, subjects performed National Football League combine drills, flexibility, and subjective scaling measures. The data demonstrated that FRml was effective at improving flexibility (p ≤ 0.05) when compared with FRap. No other differences existed between progressions.

  4. Practice of Improving Roll Deformation Theory in Strip Rolling Process Based on Boundary Integral Equation Method

    NASA Astrophysics Data System (ADS)

    Yuan, Zhengwen; Xiao, Hong; Xie, Hongbiao

    2014-02-01

    Precise strip-shape control theory is significant to improve rolled strip quality, and roll flattening theory is a primary part of the strip-shape theory. To improve the accuracy of roll flattening calculation based on semi-infinite body model, a new and more accurate roll flattening model is proposed in this paper, which is derived based on boundary integral equation method. The displacement fields of the finite length semi-infinite body on left and right sides are simulated by using finite element method (FEM) and displacement decay functions on left and right sides are established. Based on the new roll flattening model, a new 4Hi mill deformation model is established and verified by FEM. The new model is compared with Foppl formula and semi-infinite body model in different strip width, roll shifting value and bending force. The results show that the pressure and flattening between rolls calculated by the new model are more precise than other two models, especially near the two roll barrel edges.

  5. Development of a Rolling Process Design Tool for Use in Improving Hot Roll Slab Recovery

    SciTech Connect

    2001-10-01

    The project goal is to develop a numerical modeling capability to optimize the hot rolling process used to produce aluminum plate. This tool will be used in the forming process so that loss of product will be minimized. Product lost in the rolling process requires the energy-intensive steps of remelting and reforming into an ingot.

  6. Sensitivity analysis of roll load, torque and material properties in the roll forming process

    NASA Astrophysics Data System (ADS)

    Abeyrathna, Buddhika; Rolfe, Bernard; Hodgson, Peter; Weiss, Matthias

    2013-12-01

    Advanced High Strength Steel (AHSS) and Ultra High Strength Steel (UHSS) are increasingly used in the current automotive industry because of their high strength and weight saving potential. As a sheet forming process, roll forming is capable of forming such materials with precise dimensions, however a small change in processing may results in significant change in the material properties such as yield strength and hardening exponent from coil to coil or within the same coil. This paper presents the effect of yield strength and the hardening exponent on roll load, torque of the roll forming process and the longitudinal bow. The roll forming process is numerically simulated, and then the regression analysis and Analysis of Variance (ANOVA) techniques are employed to establish the relationships among the aforementioned parameters and to determine the percentage influence of material properties on longitudinal bow, roll load and torque.

  7. Improvement of vehicle roll stability by varying suspension properties

    NASA Astrophysics Data System (ADS)

    Shim, Taehyun; Velusamy, Pradheep C.

    2011-02-01

    Vehicle roll dynamics are strongly influenced by suspension properties such as roll centre height, roll steer, and roll camber. In this paper, the effects of suspension properties on vehicle roll response have been investigated using a multi-body vehicle dynamics programme. Roll dynamics of a vehicle model with MacPherson (front) and multilink (rear) suspensions were evaluated for the fishhook manoeuvre and variations of its roll response due to changes in the suspension properties were assessed by quantitatively analysing the vehicle response through simulation. Critical suspension design parameters for vehicle roll dynamics were identified and adjusted to improve roll stability of the vehicle model with passive suspension. Design of experiments has been used for identifying critical hardpoints affecting the suspension parameters, and optimisation techniques were employed for parameter optimisation. This approach provides a viable alternative to costlier active control systems for economy-class vehicles.

  8. Applying contextual interference to the Pawlata roll.

    PubMed

    Smith, P J; Davies, M

    1995-12-01

    Contextual interference is manipulated by changing the practice order of a number of similar motor tasks, so that the learning context of each interferes with that of the other. The effect has been found to generalize to baseball batting, badminton serving and volleyball skills. The present study examined whether this practice technique could be applied to a Pawlata roll in a kayak. The study was further motivated by the fact that many instructors in Britain currently advocate learning the Pawlata roll in one direction only to a criterion of accuracy, thereafter transferring to the opposite direction. Contextual interference literature predicts that skill retention would be better served by practising on alternate sides. Accordingly, 16 undergraduate students with no kayaking experience were randomly allocated to either a low contextual interference group, which followed U'ren's (1993) recommendations, or a high contextual interference group, which practised the skill on alternate sides. The high contextual interference group took less time to acquire the skill, and were also quicker to achieve successful performance in retention (full roll) and transfer (half roll) tests, regardless of the direction of the roll, 1 week later. The time savings in practice were not expected, as acquisition under high contextual interference was improved rather than impaired. This finding suggests that bilateral transfer was increased by randomizing practice. These results are worthy of further investigation, in that they suggest that the recommended training methods may not be optimal. PMID:8850571

  9. Applying contextual interference to the Pawlata roll.

    PubMed

    Smith, P J; Davies, M

    1995-12-01

    Contextual interference is manipulated by changing the practice order of a number of similar motor tasks, so that the learning context of each interferes with that of the other. The effect has been found to generalize to baseball batting, badminton serving and volleyball skills. The present study examined whether this practice technique could be applied to a Pawlata roll in a kayak. The study was further motivated by the fact that many instructors in Britain currently advocate learning the Pawlata roll in one direction only to a criterion of accuracy, thereafter transferring to the opposite direction. Contextual interference literature predicts that skill retention would be better served by practising on alternate sides. Accordingly, 16 undergraduate students with no kayaking experience were randomly allocated to either a low contextual interference group, which followed U'ren's (1993) recommendations, or a high contextual interference group, which practised the skill on alternate sides. The high contextual interference group took less time to acquire the skill, and were also quicker to achieve successful performance in retention (full roll) and transfer (half roll) tests, regardless of the direction of the roll, 1 week later. The time savings in practice were not expected, as acquisition under high contextual interference was improved rather than impaired. This finding suggests that bilateral transfer was increased by randomizing practice. These results are worthy of further investigation, in that they suggest that the recommended training methods may not be optimal.

  10. Microstructures and Mechanical Properties of a New As-Hot-Rolled High-Strength DP Steel Subjected to Different Cooling Schedules

    NASA Astrophysics Data System (ADS)

    Hu, Jun; Du, Lin-Xiu; Wang, Jian-Jun; Gao, Cai-Ru; Yang, Tong-Zi; Wang, An-Yang; Misra, R. D. K.

    2013-11-01

    Controlled rolling followed by accelerated cooling was carried out in-house to study the microstructure and mechanical properties of a low carbon dual-phase steel. The objective of the study described here was to explore the effect of cooling schedule, such as air cooling temperature and coiling temperature, on the final microstructure and mechanical properties of dual-phase steels. Furthermore, the precipitation behavior and yield ratio are discussed. The study demonstrates that it is possible to obtain tensile strength and elongation of 780 MPa and 22 pct, respectively, at the two cooling schedules investigated. The microstructure consists of 90 pct ferrite and 10 pct martensite when subjected to moderate air cooling and low temperature coiling, such that the yield ratio is a low 0.69. The microstructure consists of 75 pct ferrite and 25 pct granular bainite with a high yield ratio of 0.84 when the steel is directly cooled to the coiling temperature. Compared to the conventional dual-phase steels, the high yield strength is attributed to precipitation hardening induced by nanoscale TiC particles and solid solution strengthening by high Si content. The interphase precipitates form at a suitable ledge mobility, and the row spacing changes with the rate of ferrite transformation. There are different orientations of the rows in the same grain because of the different growth directions of the ferrite grain boundaries, and the interface of the two colonies is devoid of precipitates because of the competitive mechanisms of the two orientations.

  11. Rolling bearing stiffness in arbitrary direction

    NASA Astrophysics Data System (ADS)

    Luo, Zhusan; Sun, Xinde; Wu, Linfeng

    1992-06-01

    This paper presents a new concept of rolling bearing stiffness in arbitrary direction, which is necessary to the investigation of rotor-bearing dynamics. It includes the axial stiffness and the arbitrary radial stiffness of the rolling bearing. Based on elasticity theory and the geometrical parameters of the bearing, the approximate formulas of the axial stiffness, the arbitrary radial stiffness, and the inner ring displacements are derived. Furthermore, the paper also discusses the effects of the loads, the radial clearance, and the load distribution parameters on the rolling bearing stiffness. In order to verify the model and the computer program, an example of a ball bearing is analyzed in detail. It shows that the model and the program are reliable and the results are consistent with the data supplied by the U.S. Air Force Aeropropulsion Laboratory.

  12. Controlling roll perturbations in fruit flies

    PubMed Central

    Beatus, Tsevi; Guckenheimer, John M.; Cohen, Itai

    2015-01-01

    Owing to aerodynamic instabilities, stable flapping flight requires ever-present fast corrective actions. Here, we investigate how flies control perturbations along their body roll angle, which is unstable and their most sensitive degree of freedom. We glue a magnet to each fly and apply a short magnetic pulse that rolls it in mid-air. Fast video shows flies correct perturbations up to 100° within 30 ± 7 ms by applying a stroke-amplitude asymmetry that is well described by a linear proportional–integral controller. For more aggressive perturbations, we show evidence for nonlinear and hierarchical control mechanisms. Flies respond to roll perturbations within 5 ms, making this correction reflex one of the fastest in the animal kingdom. PMID:25762650

  13. Rolling Element Bearing Stiffness Matrix Determination (Presentation)

    SciTech Connect

    Guo, Y.; Parker, R.

    2014-01-01

    Current theoretical bearing models differ in their stiffness estimates because of different model assumptions. In this study, a finite element/contact mechanics model is developed for rolling element bearings with the focus of obtaining accurate bearing stiffness for a wide range of bearing types and parameters. A combined surface integral and finite element method is used to solve for the contact mechanics between the rolling elements and races. This model captures the time-dependent characteristics of the bearing contact due to the orbital motion of the rolling elements. A numerical method is developed to determine the full bearing stiffness matrix corresponding to two radial, one axial, and two angular coordinates; the rotation about the shaft axis is free by design. This proposed stiffness determination method is validated against experiments in the literature and compared to existing analytical models and widely used advanced computational methods. The fully-populated stiffness matrix demonstrates the coupling between bearing radial, axial, and tilting bearing deflections.

  14. Log-rolling block copolymers cylinders

    NASA Astrophysics Data System (ADS)

    Kim, So Youn; Kim, Ye Chan; Kim, Dong Hyup; Kwon, Na Kyung; Register, Richard A.

    Shear has been the most effective method to create long range order of micro- or nano- structures in soft materials. When shear is applied, soft particles or polymers tend to align along the shear direction to minimize the viscous dissipation, thus transverse (so-called ``log-rolling'') alignment is unfavored. In this study, for the first time we report the transverse alignment of cylinder-forming block copolymers. Poly(styrene-b-methyl methacrylate), PS-PMMA, can form a metastable hemicylinder structure when confined in a thin film, and this hemicylinder structure can align either along the shear direction, or transverse to the shear direction (``log-rolling''), depending on the shearing temperature. This unusual ``log-rolling'' behavior is explained by the different chain mobility of the two blocks in PS-PMMA; the rigidity of core cylinder is the critical parameter determining the direction of shear alignment.

  15. Measurements of canard-induced roll oscillations

    NASA Technical Reports Server (NTRS)

    Katz, J.; Levin, D.

    1985-01-01

    A small canard wing was installed in front of a delta wing which was mounted on a free-to-roll sting balance in a low-speed wind tunnel. The leading edge vortices, originating from the canard, enhanced self-induced roll oscillations at test conditions for which the basic delta wing would otherwise have been stable. Time-dependent roll angle, and normal and side force data recorded during these oscillations are presented along with their phase relations. It was found that the canard increased the range of angle of attack at which self-induced oscillations occurred. Also, at an angle of attack of about 46 deg asymmetric oscillations are observed.

  16. Computer-aided roll pass design in rolling of airfoil shapes

    NASA Technical Reports Server (NTRS)

    Akgerman, N.; Lahoti, G. D.; Altan, T.

    1980-01-01

    This paper describes two computer-aided design (CAD) programs developed for modeling the shape rolling process for airfoil sections. The first program, SHPROL, uses a modular upper-bound method of analysis and predicts the lateral spread, elongation, and roll torque. The second program, ROLPAS, predicts the stresses, roll separating force, the roll torque and the details of metal flow by simulating the rolling process, using the slab method of analysis. ROLPAS is an interactive program; it offers graphic display capabilities and allows the user to interact with the computer via a keyboard, CRT, and a light pen. The accuracy of the computerized models was evaluated by (a) rolling a selected airfoil shape at room temperature from 1018 steel and isothermally at high temperature from Ti-6Al-4V, and (b) comparing the experimental results with computer predictions. The comparisons indicated that the CAD systems, described here, are useful for practical engineering purposes and can be utilized in roll pass design and analysis for airfoil and similar shapes.

  17. Routh symmetry in the Chaplygin's rolling ball

    NASA Astrophysics Data System (ADS)

    Kim, Byungsoo

    2011-12-01

    The Routh integral in the symmetric Chaplygin's rolling ball has been regarded as a mysterious conservation law due to its interesting form of sqrt {I_1 I_3 + m< {I_s ,s} rangle } Ω _3 . In this paper, a new form of the Routh integral is proposed as a Noether's pairing form of a conservation law. An explicit symmetry vector for the Routh integral is proved to associate the conserved quantity with the invariance of the Lagrangian function under the rollingly constrained nonholonomic variation. Then, the form of the Routh symmetry vector is discussed for its origin as the linear combination of the configurational vectors.

  18. Roll ring assemblies for the Space Station

    NASA Technical Reports Server (NTRS)

    Batista, J.; Vise, J.; Young, K.

    1994-01-01

    Space Station Freedom requires the transmission of high power and signals through three different rotational interfaces. Roll ring technology was baselined by NASA for rotary joints to transfer up to 65.5 kW of power for 30 years at greater than 99 percent efficiency. Signal transfer requirements included MIL-STD-1553 data transmission and 4.5 MHz RS250A base and color video. A unique design for each rotary joint was developed and tested to accomplish power and signal transfer. An overview of roll ring technology is presented, followed by design requirements, hardware configuration, and test results.

  19. 40 CFR 467.20 - Applicability; description of the rolling with emulsions subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... rolling with emulsions subcategory. 467.20 Section 467.20 Protection of Environment ENVIRONMENTAL... Rolling With Emulsions Subcategory § 467.20 Applicability; description of the rolling with emulsions... the rolling with emulsions subcategory....

  20. 40 CFR 467.20 - Applicability; description of the rolling with emulsions subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... rolling with emulsions subcategory. 467.20 Section 467.20 Protection of Environment ENVIRONMENTAL... Rolling With Emulsions Subcategory § 467.20 Applicability; description of the rolling with emulsions... the rolling with emulsions subcategory....

  1. Cross-directional interlocking of rolls in an air press of a papermaking machine

    DOEpatents

    Beck, David A.; Gorshe, Thomas

    2003-05-13

    An air press for pressing a paper web is composed of a plurality of rolls including at least a first roll and a second roll. The first roll and the second roll are positioned adjacent one another and form a first nip therebetween. Further, the first roll and the second roll each have a roll end, the roll end of the first roll adjoining the roll end of the second roll. A bevel plate is attached to the roll end of the first roll, the bevel plate having at least a first angled plate face. A seal ring is positioned adjacent the roll end of the second roll, the seal ring being juxtaposed to the bevel plate. The seal ring has at least a first angled ring face, and the first angled ring face mates with the first angled plate face.

  2. 2. AERIAL VIEW OF ROLLING LIFT BRIDGE. DORCHESTER AVENUE IN ...

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

    2. AERIAL VIEW OF ROLLING LIFT BRIDGE. DORCHESTER AVENUE IN BACKGROUND. SOUTH STATION VISIBLE AT TOP LEFT. - New York, New Haven & Hartford Railroad, Fort Point Channel Rolling Lift Bridge, Spanning Fort Point Channel, Boston, Suffolk County, MA

  3. 25 CFR 75.4 - Basic membership roll.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... THE EASTERN BAND OF CHEROKEE INDIANS, NORTH CAROLINA § 75.4 Basic membership roll. All persons whose names appear on the roll of the Eastern Band of Cherokee Indians of North Carolina, prepared...

  4. 25 CFR 75.4 - Basic membership roll.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... THE EASTERN BAND OF CHEROKEE INDIANS, NORTH CAROLINA § 75.4 Basic membership roll. All persons whose names appear on the roll of the Eastern Band of Cherokee Indians of North Carolina, prepared...

  5. T Strip Properties Fabricated by Powder Rolling Method

    NASA Astrophysics Data System (ADS)

    Hong, Jae-Keun; Lee, Chae-Hun; Kim, Jeoung-Han; Yeom, Jong-Taek; Park, Nho-Kwang

    In the present study, the characteristics of the Ti powders fabricated by Hydride-Dehydride (HDH) were analyzed in terms of particle shape, size and size distribution. Ti powders were subjected to roll compaction and their microstructure and green densities were evaluated in terms of particle size, powder morphology, roll gap and rolling speed. Effects of blending elements having different powder sizes on densification properties were analyzed. The strip thickness was proportional to the roll gap up to 0.9 mm and the density of titanium strip was decreased with the increase in roll gap. As the roll speed increased, the strip density and thickness were decreased by using -200 mesh Ti powder. However, the effect of rolling speed for -400 mesh Ti powder was not greater than that of -200 mesh powder. The highest density by 93% was achieved by using -400 mesh Ti powder at 0.1 mm roll gap, however edge cracks and alligator cracks were occurred.

  6. Detail from roadbed showing sprocket teeth in rolling segment and ...

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

    Detail from roadbed showing sprocket teeth in rolling segment and typical lateral bracing. View south - New York, New Haven & Hartford Railroad, Fort Point Channel Rolling Lift Bridge, Spanning Fort Point Channel, Boston, Suffolk County, MA

  7. 46 CFR 28.575 - Severe wind and roll.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 1 2013-10-01 2013-10-01 false Severe wind and roll. 28.575 Section 28.575 Shipping... INDUSTRY VESSELS Stability § 28.575 Severe wind and roll. (a) Each vessel must meet paragraphs (f) and (g) of this section when subjected to the gust wind heeling arm and the angle of roll to windward...

  8. 46 CFR 28.575 - Severe wind and roll.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 1 2014-10-01 2014-10-01 false Severe wind and roll. 28.575 Section 28.575 Shipping... INDUSTRY VESSELS Stability § 28.575 Severe wind and roll. (a) Each vessel must meet paragraphs (f) and (g) of this section when subjected to the gust wind heeling arm and the angle of roll to windward...

  9. 46 CFR 28.575 - Severe wind and roll.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 1 2012-10-01 2012-10-01 false Severe wind and roll. 28.575 Section 28.575 Shipping... INDUSTRY VESSELS Stability § 28.575 Severe wind and roll. (a) Each vessel must meet paragraphs (f) and (g) of this section when subjected to the gust wind heeling arm and the angle of roll to windward...

  10. 46 CFR 56.30-15 - Expanded or rolled joints.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Expanded or rolled joints. 56.30-15 Section 56.30-15... APPURTENANCES Selection and Limitations of Piping Joints § 56.30-15 Expanded or rolled joints. (a) Expanded or rolled joints may be used where experience or test has demonstrated that the joint is suitable for...

  11. 46 CFR 56.30-15 - Expanded or rolled joints.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 2 2014-10-01 2014-10-01 false Expanded or rolled joints. 56.30-15 Section 56.30-15... APPURTENANCES Selection and Limitations of Piping Joints § 56.30-15 Expanded or rolled joints. (a) Expanded or rolled joints may be used where experience or test has demonstrated that the joint is suitable for...

  12. 46 CFR 56.30-15 - Expanded or rolled joints.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 2 2011-10-01 2011-10-01 false Expanded or rolled joints. 56.30-15 Section 56.30-15... APPURTENANCES Selection and Limitations of Piping Joints § 56.30-15 Expanded or rolled joints. (a) Expanded or rolled joints may be used where experience or test has demonstrated that the joint is suitable for...

  13. 25 CFR 75.15 - Current membership roll.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 25 Indians 1 2012-04-01 2011-04-01 true Current membership roll. 75.15 Section 75.15 Indians... THE EASTERN BAND OF CHEROKEE INDIANS, NORTH CAROLINA § 75.15 Current membership roll. The membership roll of the Eastern Band of Cherokee Indians shall be kept current by striking therefrom the names...

  14. 25 CFR 75.15 - Current membership roll.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 25 Indians 1 2011-04-01 2011-04-01 false Current membership roll. 75.15 Section 75.15 Indians... THE EASTERN BAND OF CHEROKEE INDIANS, NORTH CAROLINA § 75.15 Current membership roll. The membership roll of the Eastern Band of Cherokee Indians shall be kept current by striking therefrom the names...

  15. 25 CFR 75.15 - Current membership roll.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 25 Indians 1 2013-04-01 2013-04-01 false Current membership roll. 75.15 Section 75.15 Indians... THE EASTERN BAND OF CHEROKEE INDIANS, NORTH CAROLINA § 75.15 Current membership roll. The membership roll of the Eastern Band of Cherokee Indians shall be kept current by striking therefrom the names...

  16. 25 CFR 75.15 - Current membership roll.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false Current membership roll. 75.15 Section 75.15 Indians... THE EASTERN BAND OF CHEROKEE INDIANS, NORTH CAROLINA § 75.15 Current membership roll. The membership roll of the Eastern Band of Cherokee Indians shall be kept current by striking therefrom the names...

  17. 25 CFR 75.15 - Current membership roll.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 25 Indians 1 2014-04-01 2014-04-01 false Current membership roll. 75.15 Section 75.15 Indians... THE EASTERN BAND OF CHEROKEE INDIANS, NORTH CAROLINA § 75.15 Current membership roll. The membership roll of the Eastern Band of Cherokee Indians shall be kept current by striking therefrom the names...

  18. 25 CFR 75.4 - Basic membership roll.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 25 Indians 1 2013-04-01 2013-04-01 false Basic membership roll. 75.4 Section 75.4 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR TRIBAL GOVERNMENT REVISION OF THE MEMBERSHIP ROLL OF THE EASTERN BAND OF CHEROKEE INDIANS, NORTH CAROLINA § 75.4 Basic membership roll. All persons...

  19. 21 CFR 136.130 - Milk bread, rolls, and buns.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 2 2010-04-01 2010-04-01 false Milk bread, rolls, and buns. 136.130 Section 136....130 Milk bread, rolls, and buns. (a) Each of the foods milk bread, milk rolls, and milk buns conforms... permitted in the preparation of the dough is milk or, as an alternative, a combination of dairy products...

  20. 21 CFR 136.130 - Milk bread, rolls, and buns.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 2 2011-04-01 2011-04-01 false Milk bread, rolls, and buns. 136.130 Section 136....130 Milk bread, rolls, and buns. (a) Each of the foods milk bread, milk rolls, and milk buns conforms... permitted in the preparation of the dough is milk or, as an alternative, a combination of dairy products...

  1. 14. VIEW OF METAL ROLLING OPERATION. THE METALS ARE BEING ...

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

    14. VIEW OF METAL ROLLING OPERATION. THE METALS ARE BEING PREPARED TO BE ROLLED INTO SHEETS OF SPECIFIC THICKNESS. COMPONENT PARTS WERE FABRICATED FROM THE METAL SHEETS. (11/82) - Rocky Flats Plant, Uranium Rolling & Forming Operations, Southeast section of plant, southeast quadrant of intersection of Central Avenue & Eighth Street, Golden, Jefferson County, CO

  2. 15. VIEW OF ROLLING OPERATION. INGOTS AND BAR STOCK WERE ...

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

    15. VIEW OF ROLLING OPERATION. INGOTS AND BAR STOCK WERE ROLLED TO A SPECIFIED THICKNESS IN PREPARATION FOR FURTHER PROCESSING. (11/82) - Rocky Flats Plant, Uranium Rolling & Forming Operations, Southeast section of plant, southeast quadrant of intersection of Central Avenue & Eighth Street, Golden, Jefferson County, CO

  3. Development of a Rolling Process Design Tool for Use in Improving Hot Roll Slab Recovery

    SciTech Connect

    Couch, R; Becker, R; Rhee, M; Li, M

    2004-09-24

    Lawrence Livermore National Laboratory participated in a U. S. Department of Energy/Office of Industrial Technology sponsored research project 'Development of a Rolling Process Design Tool for Use in Improving Hot Roll Slab Recovery', as a Cooperative Agreement TC-02028 with the Alcoa Technical Center (ATC). The objective of the joint project with Alcoa is to develop a numerical modeling capability to optimize the hot rolling process used to produce aluminum plate. Product lost in the rolling process and subsequent recycling, wastes resources consumed in the energy-intensive steps of remelting and reprocessing the ingot. The modeling capability developed by project partners will be used to produce plate more efficiently and with reduced product loss.

  4. 9 CFR 381.159 - Poultry rolls.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... subchapter, in 9 CFR Chapter III, Subchapter E, or in 21 CFR Chapter I, Subchapter A or Subchapter B. In... 9 Animals and Animal Products 2 2013-01-01 2013-01-01 false Poultry rolls. 381.159 Section 381.159... ORGANIZATION AND TERMINOLOGY; MANDATORY MEAT AND POULTRY PRODUCTS INSPECTION AND VOLUNTARY INSPECTION...

  5. 9 CFR 381.159 - Poultry rolls.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... subchapter, in 9 CFR Chapter III, Subchapter E, or in 21 CFR Chapter I, Subchapter A or Subchapter B. In... 9 Animals and Animal Products 2 2011-01-01 2011-01-01 false Poultry rolls. 381.159 Section 381.159... ORGANIZATION AND TERMINOLOGY; MANDATORY MEAT AND POULTRY PRODUCTS INSPECTION AND VOLUNTARY INSPECTION...

  6. 9 CFR 381.159 - Poultry rolls.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... subchapter, in 9 CFR Chapter III, Subchapter E, or in 21 CFR Chapter I, Subchapter A or Subchapter B. In... 9 Animals and Animal Products 2 2014-01-01 2014-01-01 false Poultry rolls. 381.159 Section 381.159... ORGANIZATION AND TERMINOLOGY; MANDATORY MEAT AND POULTRY PRODUCTS INSPECTION AND VOLUNTARY INSPECTION...

  7. 9 CFR 381.159 - Poultry rolls.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... subchapter, in 9 CFR Chapter III, Subchapter E, or in 21 CFR Chapter I, Subchapter A or Subchapter B. In... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Poultry rolls. 381.159 Section 381.159... ORGANIZATION AND TERMINOLOGY; MANDATORY MEAT AND POULTRY PRODUCTS INSPECTION AND VOLUNTARY INSPECTION...

  8. Engineers Test Roll-Off at JPL

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This image taken at JPL shows engineers testing the route by which the Mars Exploration Rover Opportunity will roll off its lander. Opportunity touched down at Meridiani Planum, Mars on Jan. 24, 9:05 p.m. PST, 2004, Earth-received time.

  9. Roll-Off Test at JPL

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This still image illustrates what the Mars Exploration Rover Spirit will look like as it rolls off the northeastern side of the lander on Mars. The image was taken from footage of rover testing at JPL's In-Situ Instruments Laboratory, or 'Testbed.'

  10. Oscillations and Rolling for Duffing's Equation

    NASA Astrophysics Data System (ADS)

    Aref'eva, I. Ya.; Piskovskiy, E. V.; Volovich, I. V.

    2013-01-01

    The Duffing equation has been used to model nonlinear dynamics not only in mechanics and electronics but also in biology and in neurology for the brain process modeling. Van der Pol's method is often used in nonlinear dynamics to improve perturbation theory results when describing small oscillations. However, in some other problems of nonlinear dynamics particularly in case of Duffing-Higgs equation in field theory, for the Einsten-Friedmann equations in cosmology and for relaxation processes in neurology not only small oscillations regime is of interest but also the regime of slow rolling. In the present work a method for approximate solution to nonlinear dynamics equations in the rolling regime is developed. It is shown that in order to improve perturbation theory in the rolling regime it turns out to be effective to use an expansion in hyperbolic functions instead of trigonometric functions as it is done in van der Pol's method in case of small oscillations. In particular the Duffing equation in the rolling regime is investigated using solution expressed in terms of elliptic functions. Accuracy of obtained approximation is estimated. The Duffing equation with dissipation is also considered.

  11. Rolling Friction on a Wheeled Laboratory Cart

    ERIC Educational Resources Information Center

    Mungan, Carl E.

    2012-01-01

    A simple model is developed that predicts the coefficient of rolling friction for an undriven laboratory cart on a track that is approximately independent of the mass loaded onto the cart and of the angle of inclination of the track. The model includes both deformation of the wheels/track and frictional torque at the axles/bearings. The concept of…

  12. 14 CFR 23.349 - Rolling conditions.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... Rolling conditions. The wing and wing bracing must be designed for the following loading conditions: (a) Unsymmetrical wing loads appropriate to the category. Unless the following values result in unrealistic loads... semispan wing airload acts on one side of the plane of symmetry and 60 percent of this load acts on...

  13. 14 CFR 23.349 - Rolling conditions.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... Rolling conditions. The wing and wing bracing must be designed for the following loading conditions: (a) Unsymmetrical wing loads appropriate to the category. Unless the following values result in unrealistic loads... semispan wing airload acts on one side of the plane of symmetry and 60 percent of this load acts on...

  14. 14 CFR 23.349 - Rolling conditions.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Rolling conditions. The wing and wing bracing must be designed for the following loading conditions: (a) Unsymmetrical wing loads appropriate to the category. Unless the following values result in unrealistic loads... semispan wing airload acts on one side of the plane of symmetry and 60 percent of this load acts on...

  15. 14 CFR 23.349 - Rolling conditions.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... Rolling conditions. The wing and wing bracing must be designed for the following loading conditions: (a) Unsymmetrical wing loads appropriate to the category. Unless the following values result in unrealistic loads... semispan wing airload acts on one side of the plane of symmetry and 60 percent of this load acts on...

  16. Antares Rolls Out to Wallops Launch Pad

    NASA Video Gallery

    Orbital Sciences Corporation’s Antares rocket rolls out to the launch pad at NASA’s Wallops Flight Facility on the morning of Oct. 1, 2012. Over the next several months, Orbital plans a hot-fir...

  17. Land rolling increases broadleaf weed emergence

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In the northern Great Plains, annual forage and pulse crops typically are land rolled after planting to push rocks back into the soil to prevent damage to harvest equipment. Packer wheels commonly are used at planting to improve soil-seed contact for more uniform crop emergence and subsequent matur...

  18. Large Scale Evaluation fo Nickel Aluminide Rolls

    SciTech Connect

    2005-09-01

    This completed project was a joint effort between Oak Ridge National Laboratory and Bethlehem Steel (now Mittal Steel) to demonstrate the effectiveness of using nickel aluminide intermetallic alloy rolls as part of an updated, energy-efficient, commercial annealing furnace system.

  19. Conical Euler analysis and active roll suppression for unsteady vortical flows about rolling delta wings

    NASA Technical Reports Server (NTRS)

    Lee-Rausch, Elizabeth M.; Batina, John T.

    1993-01-01

    A conical Euler code was developed to study unsteady vortex-dominated flows about rolling, highly swept delta wings undergoing either forced motions or free-to-roll motions that include active roll suppression. The flow solver of the code involves a multistage, Runge-Kutta time-stepping scheme that uses a cell-centered, finite-volume, spatial discretization of the Euler equations on an unstructured grid of triangles. The code allows for the additional analysis of the free to-roll case by simultaneously integrating in time the rigid-body equation of motion with the governing flow equations. Results are presented for a delta wing with a 75 deg swept, sharp leading edge at a free-stream Mach number of 1.2 and at 10 deg, 20 deg, and 30 deg angle of attack alpha. At the lower angles of attack (10 and 20 deg), forced-harmonic analyses indicate that the rolling-moment coefficients provide a positive damping, which is verified by free-to-roll calculations. In contrast, at the higher angle of attack (30 deg), a forced-harmonic analysis indicates that the rolling-moment coefficient provides negative damping at the small roll amplitudes. A free-to-roll calculation for this case produces an initially divergent response, but as the amplitude of motion grows with time, the response transitions to a wing-rock type of limit cycle oscillation, which is characteristic of highly swept delta wings. This limit cycle oscillation may be actively suppressed through the use of a rate-feedback control law and antisymmetrically deflected leading-edge flaps. Descriptions of the conical Euler flow solver and the free-to roll analysis are included in this report. Results are presented that demonstrate how the systematic analysis of the forced response of the delta wing can be used to predict the stable, neutrally stable, and unstable free response of the delta wing. These results also give insight into the flow physics associated with unsteady vortical flows about delta wings undergoing forced

  20. An integrated optical pickup with roll-to-roll fabricated diffractive components.

    PubMed

    Hsu, Jo-Han; Lee, Chi-Hung; Chen, Rongshun

    2011-07-01

    This work designed and fabricated an optical pickup system based on optical films using the roll-to-roll process. The design combined the advantages of the stacked and planar optical pickup system. Two blazed gratings were used as beam splitters for bending the optical path, while a cylindrical lens was used for astigmatic focus-error detection. The proposed design effectively reduces overall system configuration, component cost, and fabrication complexity.

  1. High-rate, roll-to-roll nanomanufacturing of flexible systems

    NASA Astrophysics Data System (ADS)

    Cooper, Khershed P.; Wachter, Ralph F.

    2012-10-01

    Since the National Nanotechnology Initiative was first announced in 2000, nanotechnology has developed an impressive catalog of nano-scale structures with building-blocks such as nanoparticles, nanotubes, nanorods, nanopillars, and quantum dots. Similarly, there are accompanying materials processes such as, atomic layer deposition, pulsed layer deposition, nanoprinting, nanoimprinting, transfer printing, nanolithography and nanopatterning. One of the challenges of nanomanufacturing is scaling up these processes reliably and affordably. Roll-to-roll manufacturing is a means for scaling up, for increasing throughput. It is high-speed production using a continuous, moving platform such as a web or a flexible substrate. The adoption of roll-to-roll to nanomanufacturing is novel. The goal is to build structures and devices with nano-scale features and specific functionality. The substrate could be a polymer, metal foil, silk, cloth or paper. The materials to build the structures and multi-level devices could be organic, inorganic or biological. Processing could be solution-based, e.g., ink-jet printing, or vacuum-based, e.g., chemical vapor deposition. Products could be electronics, optoelectronics, membranes, catalysts, microfluidics, lab-on-film, filters, etc. By this means, processing of large and conformal areas is achievable. High-throughput translates into low cost, which is the attraction of roll-to-roll nanomanufacturing. There are technical challenges requiring fundamental scientific advances in materials and process development and in manufacturing and system-integration where achieving nano-scale feature size, resolution and accuracy at high speeds can be major hurdles. We will give an overview of roll-to-roll nanomanufacturing with emphasis on the need to understand the material, process and system complexities, the need for instrumentation, measurement, and process control and describe the concept of cyber-enabled nanomanufacturing for reliable and

  2. Laser direct write system for fabricating seamless roll-to-roll lithography tools

    NASA Astrophysics Data System (ADS)

    Petrzelka, Joseph E.; Hardt, David E.

    2013-03-01

    Implementations of roll to roll contact lithography require new approaches towards manufacturing tooling, including stamps for roll to roll nanoimprint lithography (NIL) and soft lithography. Suitable roll based tools must have seamless micro- or nano-scale patterns and must be scalable to roll widths of one meter. The authors have developed a new centrifugal stamp casting process that can produce uniform cylindrical polymer stamps in a scalable manner. The pattern on the resulting polymer tool is replicated against a corresponding master pattern on the inner diameter of a centrifuge drum. This master pattern is created in photoresist using a UV laser direct write system. This paper discusses the design and implementation of a laser direct write system targeting the internal diameter of a rotating drum. The design uses flying optics to focus a laser beam along the axis of the centrifuge drum and to redirect the beam towards the drum surface. Experimental patterning results show uniform coatings of negative photoresist in the centrifuge drum that are effectively patterned with a 405 nm laser diode. Seamless patterns are shown to be replicated in a 50 mm diameter, 60 mm long cylindrical stamp made from polydimethylsiloxane (PDMS). Direct write results show gratings with line widths of 10 microns in negative photoresist. Using an FPGA, the laser can be accurately timed against the centrifuge encoder to create complex patterns.

  3. High resolution patterning for flexible electronics via roll-to-roll nanoimprint lithography

    NASA Astrophysics Data System (ADS)

    Sabik, Sami; de Riet, Joris; Yakimets, Iryna; Smits, Edsger

    2014-03-01

    Flexible electronics is a growing field and is currently maturing in applications such as displays, smart packaging, organic light-emitting diodes and organic photovoltaic cells. In order to process on flexible substrates at high throughput and large areas, novel patterning techniques will be essential. Conventional optical lithography is limited in throughput as well as resolution, and requires several alignment steps to generate multi-layered patterns, required for applications such as thin-film transistors. It therefore remains a complex and expensive process. Nanoimprint lithography is an emerging alternative to optical lithography, demonstrating patterning capabilities over a wide range of resolutions, from several microns down to a few nanometres. For display applications, nanoimprint lithography can be used to pattern various layers. Micron sized thin-film transistors for backplane can be fabricated where a self-aligned geometry is used to decrease the number of alignment steps, and increase the overlay accuracy. In addition, nano-structures can be used for optical applications such as anti-reflective surfaces and nano patterned transparent electrodes. Imprint lithography is a fully roll-to-roll compatible process and enables large area and high throughput fabrication for flexible electronics. In this paper we discuss the possibilities and the challenges of large area patterning by roll-to-roll nanoimprint lithography, reviewing micron and nano sized structures realized on our roll-to-roll equipment. Nano patterned transparent electrodes, moth-eye antireflective coatings, and multilevel structures will be covered.

  4. Roll-to-Roll Nanomanufacturing of Hybrid Nanostructures for Energy Storage Device Design.

    PubMed

    Oakes, Landon; Hanken, Trevor; Carter, Rachel; Yates, William; Pint, Cary L

    2015-07-01

    A key limitation to the practical incorporation of nanostructured materials into emerging applications is the challenge of achieving low-cost, high throughput, and highly replicable scalable nanomanufacturing techniques to produce functional materials. Here, we report a benchtop roll-to-roll technique that builds upon the use of binary solutions of nanomaterials and liquid electrophoretic assembly to rapidly construct hybrid materials for battery design applications. We demonstrate surfactant-free hybrid mixtures of carbon nanotubes, silicon nanoparticles, MoS2 nanosheets, carbon nanohorns, and graphene nanoplatelets. Roll-to-roll electrophoretic assembly from these solutions enables the controlled fabrication of homogeneous coatings of these nanostructures that maintain chemical and physical properties defined by the synergistic combination of nanomaterials utilized without adverse effects of surfactants or impurities that typically limit liquid nanomanufacturing routes. To demonstrate the utility of this nanomanufacturing approach, we employed roll-to-roll electrophoretic processing to fabricate both positive and negative electrodes for lithium ion batteries in less than 30 s. The optimized full-cell battery, containing active materials of prelithiated silicon nanoparticles and MoS2 nanosheets, was assessed to exhibit energy densities of 167 Wh/kgcell(-1) and power densities of 9.6 kW/kgcell(-1). PMID:26053115

  5. Roll rotation cues influence roll tilt perception assayed using a somatosensory technique.

    PubMed

    Park, Sukyung; Gianna-Poulin, Claire; Black, F Owen; Wood, Scott; Merfeld, Daniel M

    2006-07-01

    We investigated how the nervous system processes ambiguous cues from the otolith organs by measuring roll tilt perception elicited by two motion paradigms. In one paradigm (tilt), eight subjects were sinusoidally tilted in roll with the axis of rotation near ear level. Stimulus frequencies ranged from 0.005 to 0.7 Hz, and the peak amplitude of tilt was 20 degrees . During this paradigm, subjects experienced a sinusoidal variation of interaural gravitational force with a peak of 0.34 g. The second motion paradigm (translation) was designed to yield the same sinusoidal variation in interaural force but did not include a roll canal cue. This was achieved by sinusoidally translating the subjects along their interaural axis. For the 0.7-Hz translation trial, the subjects were simply translated from side to side. A centrifuge was used for the 0.005- to 0.5-Hz translation trials; the subjects were rotated in yaw at 250 degrees /s for 5 min before initiating sinusoidal translations yielding an interaural otolith stimulus composed of both centrifugal and radial acceleration. Using a somatosensory task to measure roll tilt perception, we found substantial differences in tilt perception during the two motion paradigms. Because the primary difference between the two motion paradigms was the presence of roll canal cues during roll tilt trials, these perceptual differences suggest that canal cues influence tilt perception. Specifically, rotational cues provided by the semicircular canals help the CNS resolve ambiguous otolith cues during head tilt, yielding more accurate tilt perception.

  6. Roll-to-Roll Nanomanufacturing of Hybrid Nanostructures for Energy Storage Device Design.

    PubMed

    Oakes, Landon; Hanken, Trevor; Carter, Rachel; Yates, William; Pint, Cary L

    2015-07-01

    A key limitation to the practical incorporation of nanostructured materials into emerging applications is the challenge of achieving low-cost, high throughput, and highly replicable scalable nanomanufacturing techniques to produce functional materials. Here, we report a benchtop roll-to-roll technique that builds upon the use of binary solutions of nanomaterials and liquid electrophoretic assembly to rapidly construct hybrid materials for battery design applications. We demonstrate surfactant-free hybrid mixtures of carbon nanotubes, silicon nanoparticles, MoS2 nanosheets, carbon nanohorns, and graphene nanoplatelets. Roll-to-roll electrophoretic assembly from these solutions enables the controlled fabrication of homogeneous coatings of these nanostructures that maintain chemical and physical properties defined by the synergistic combination of nanomaterials utilized without adverse effects of surfactants or impurities that typically limit liquid nanomanufacturing routes. To demonstrate the utility of this nanomanufacturing approach, we employed roll-to-roll electrophoretic processing to fabricate both positive and negative electrodes for lithium ion batteries in less than 30 s. The optimized full-cell battery, containing active materials of prelithiated silicon nanoparticles and MoS2 nanosheets, was assessed to exhibit energy densities of 167 Wh/kgcell(-1) and power densities of 9.6 kW/kgcell(-1).

  7. Flatness Control Using Roll Coolant Based on Predicted Flatness Variation in Cold Rolling Mills

    NASA Astrophysics Data System (ADS)

    Dohmae, Yukihiro; Okamura, Yoshihide

    Flatness control for cold rolling mills is one of the important technologies for improving of product quality and productivity. In particular, poor flatness leads to strip tearing in the extreme case and, moreover, it significantly reduces productivity. Therefore, various flatness control system has been developed. The main actuators for flatness control are classified into two types; one is mechanical equipment such as roll bender, the other is roll coolant, which controls thermal expansion of roll. Flatness variation such as center buckle or edge wave is mainly controlled by mechanical actuator which has high response characteristics. On another front, flatness variation of local zone can be controlled by roll coolant although one's response is lower than the response of mechanical actuator. For accomplishing good flatness accuracy in cold rolling mills, it is important to improve the performance of coolant control moreover. In this paper, a new coolant control method based on flatness variation model is described. In proposed method, the state of coolant spray on or off is selected to minimize the flatness deviation by using predicted flatness variation. The effectiveness of developed system has been demonstrated by application in actual plant.

  8. Roll-to-roll embossing of optical linear Fresnel lens polymer film for solar concentration.

    PubMed

    Zhang, XinQuan; Liu, Kui; Shan, Xuechuan; Liu, Yuchan

    2014-12-15

    Roll-to-roll manufacturing has been proven to be a high-throughput and low-cost technology for continuous fabrication of functional optical polymer films. In this paper, we have firstly studied a complete manufacturing cycle of linear Fresnel lens polymer film for solar concentration in the aspects of ultra-precision diamond machining of metal roller mold, roll-to-roll embossing, and measurement on film profile and functionality. A metal roller mold patterned with linear Fresnel lenses is obtained using single point diamond turning technique. The roller mold is installed onto a self-developed roll-to-roll UV embossing system to realize continuous manufacturing of linear Fresnel lens film. Profile measurement of the machined roller mold and the embossed polymer film, which is conducted using a stylus profilometer, shows good agreement between measured facet angles with designed ones. Functionality test is conducted on a solar simulation system with a reference solar cell, and results show that strong light concentration is realized.

  9. Rolling Moments Due to Rolling and Yaw for Four Wing Models in Rotation

    NASA Technical Reports Server (NTRS)

    Knight, Montgomery; Wenzinger, Carl J

    1932-01-01

    This report presents the results of a series of autorotation and torque tests on four different rotating wing systems at various rates of roll and at several angles of yaw. The investigation covered an angle of attack range up to 90 degrees and angles of yaw of 0 degree, 5 degrees, 10 degrees, and 20 degrees. The tests were made in a 5-foot, closed-throat atmospheric wind tunnel. The object of the tests was primarily to determine the effects of various angles of yaw on the rolling moments of the rotating wings up to large angles of attack. It was found that at angles of attack above that of maximum lift the rolling moments on the wings due to yaw (or side slip) from 5 degrees to 20 degrees were roughly of the same magnitude as those due to rolling. There was a wide variation in magnitude of the rolling moment due to yaw angle. The rates and ranges of stable autorotation for the monoplane models were considerably increased by yaw, whereas for an unstaggered biplane they were little affected. The immediate cause of the rolling moment due to yaw is apparently the building up of large loads on the forward wing tip and the reduction of loads on the rearward wing tip.

  10. Roll to roll fabrication technologies for optoelectronic and electronic devices and sensors

    NASA Astrophysics Data System (ADS)

    Maaninen, A.; Tuomikoski, M.; Kivimäki, L.; Kololuoma, T.; Välimäki, M.; Leinonen, M.; Känsäkoski, M.

    2005-09-01

    Embedding of optoelectrical, optical, and electrical functionalities into low-cost products like product packages and printed matter can be used to increase their information content. For these purposes, components like displays, photodetectors, light sources, solar cells, battery elements, diffractive optical elements, lightguides, electrical conductors, resistors, transistors, switching elements etc. and their integration to functional modules are required. Also the need of rapid and reliable di-agnostic systems for wellness and healthcare applications is apparent. Today the time from sampling to result can take hours or even several days. In future the target is to analyze the sample within a few minutes for further action. Additionally, the price of the components for low-end products and disposable sensors has to be in cent scale or preferably below that. Therefore, new, cost-effective, and volume scale capable manufacturing techniques are required. Recent developments of liquid-phase processable electrical and optical polymeric, inorganic, and hybrid material inks together with biocompatible materials have made it possible to fabricate functional components by conventional roll-to-roll techniques such as gravure printing on flexible paper and plastic like substrates. In this paper, we show our current achievements in the field of roll-to-roll fabricated electronics, optoelec-tronics and biosensors. With examples of light guiding structures, organic light emitting diodes, biocompatible materials etc., we demonstrate the huge potential of roll to roll fabrication as a low cost mass production technology for future low end electronic products.

  11. 75 FR 16504 - Hot-Rolled Flat-Rolled Carbon-Quality Steel Products From Brazil, Japan, and Russia

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-01

    ... (``Commerce'') issued an antidumping duty order on imports of hot- rolled steel from Japan (64 FR 34778... duty order on hot-rolled steel from Brazil (70 FR 30417, May 26, 2005), the antidumping duty orders on hot-rolled steel from Brazil and Japan (70 FR 30413, May 26, 2005), and the suspended investigation...

  12. Investigation on carburizing duplex-microstructures of martensite-bainite, their properties of 430 D2 steel and the application of carburizing and austempering to self-tapping screw dies

    SciTech Connect

    Chuenmei, L.; Jinhua, X.; Xin, C.; Suidong, Z.; Liming, X.

    1995-12-31

    By carburizing, the composition of the case has been greatly changed for 430 D2 steel. The microstructures and properties acquired by the case depends upon the cooling process. This paper deals with comparing the oil quenched structures with the austempered structures of the carburized case. The compared aspects also covered the substructures, relative quantities of several structures, mechanical properties and type of fracture topography. In addition, according to fracture mechanics and the characteristics of fatigue failure of the self-tapping screw dies, how the duplex microstructure of martensite and bainite limited the initiation and propagation of fatigue cracks has been discussed.

  13. Use of sleeved rolls in a blooming mill

    NASA Astrophysics Data System (ADS)

    Kuhn, G.

    1983-03-01

    The use of sleeved rolls in the blooming stand ahead of a continuous semifinishing mill is treated. Two sleeved rolls were produced. One comprises a tough steel arbor and the wear resistant roll sleeve of Cr-Ni-Mo-alloyed spheroidal cast iron with carbide. Both parts were joined together in an unstressed manner by adhesive bonding. Tests show that sleeved rolls can be used in blooming stands, thereby increasing their application possibilities, but porosity in the finishing grooves of the rolls caused during the casting process means that long term behavior can not be assessed.

  14. Toward large-area roll-to-roll printed nanophotonic sensors

    NASA Astrophysics Data System (ADS)

    Karioja, Pentti; Hiltunen, Jussi; Aikio, Sanna M.; Alajoki, Teemu; Tuominen, Jarkko; Hiltunen, Marianne; Siitonen, Samuli; Kontturi, Ville; Böhlen, Karl; Hauser, Rene; Charlton, Martin; Boersma, Arjen; Lieberzeit, Peter; Felder, Thorsten; Eustace, David; Haskal, Eliav

    2014-05-01

    Polymers have become an important material group in fabricating discrete photonic components and integrated optical devices. This is due to their good properties: high optical transmittance, versatile processability at relative low temperatures and potential for low-cost production. Recently, nanoimprinting or nanoimprint lithography (NIL) has obtained a plenty of research interest. In NIL, a mould is pressed against a substrate coated with a moldable material. After deformation of the material, the mold is separated and a replica of the mold is formed. Compared with conventional lithographic methods, imprinting is simple to carry out, requires less-complicated equipment and can provide high-resolution with high throughput. Nanoimprint lithography has shown potential to become a method for low-cost and high-throughput fabrication of nanostructures. We show the development process of nano-structured, large-area multi-parameter sensors using Photonic Crystal (PC) and Surface Enhanced Raman Scattering (SERS) methodologies for environmental and pharmaceutical applications. We address these challenges by developing roll-to-roll (R2R) UV-nanoimprint fabrication methods. Our development steps are the following: Firstly, the proof of concept structures are fabricated by the use of wafer-level processes in Si-based materials. Secondly, the master molds of successful designs are fabricated, and they are used to transfer the nanophotonic structures into polymer materials using sheet-level UV-nanoimprinting. Thirdly, the sheet-level nanoimprinting processes are transferred to roll-to-roll fabrication. In order to enhance roll-to-roll manufacturing capabilities, silicone-based polymer material development was carried out. In the different development phases, Photonic Crystal and SERS sensor structures with increasing complexities were fabricated using polymer materials in order to enhance sheet-level and roll-to-roll manufacturing processes. In addition, chemical and molecular

  15. Rolled fingerprint construction using MRF-based nonrigid image registration.

    PubMed

    Kwon, Dongjin; Yun, Il Dong; Lee, Sang Uk

    2010-12-01

    This paper proposes a new rolled fingerprint construction approach incorporating a state-of-the-art nonrigid image registration method based upon a Markov random field (MRF) energy model. The proposed method finds dense correspondences between images from a rolled fingerprint sequence and warps the entire fingerprint area to synthesize a rolled fingerprint. This method can generate conceptually more accurate rolled fingerprints by preserving the geometric properties of the finger surface as opposed to ink-based rolled impressions and other existing rolled fingerprint construction methods. To verify the accuracy of the proposed method, various comparative experiments were designed to reveal differences among the rolled construction methods. The results show that the proposed method is significantly superior in various aspects compared to previous approaches.

  16. Dynamics and Stability of Rolling Viscoelastic Tires

    SciTech Connect

    Potter, Trevor

    2013-04-30

    Current steady state rolling tire calculations often do not include treads because treads destroy the rotational symmetry of the tire. We describe two methodologies to compute time periodic solutions of a two-dimensional viscoelastic tire with treads: solving a minimization problem and solving a system of equations. We also expand on work by Oden and Lin on free spinning rolling elastic tires in which they disovered a hierachy of N-peak steady state standing wave solutions. In addition to discovering a two-dimensional hierarchy of standing wave solutions that includes their N-peak hiearchy, we consider the eects of viscoelasticity on the standing wave solutions. Finally, a commonplace model of viscoelasticity used in our numerical experiments led to non-physical elastic energy growth for large tire speeds. We show that a viscoelastic model of Govindjee and Reese remedies the problem.

  17. Automatic Flatness Control of Cold Rolling Mill

    NASA Astrophysics Data System (ADS)

    Anbe, Yoshiharu; Sekiguchi, Kunio

    One of the subjects of cold rolling is a flatness of the rolled strip. Conventionally, measured strip flatness was approximated by polynomial (2th, 4th, 6th) equation across the entire strip width. This made it difficult to deal with desired loose edge or any desired flatness across the entire strip width. Also conventional flatness control was done for the entire strip width, so if there is a different flatness error among drive side and work side, conventional flatness control can not control properly. We propose independent strip flatness control among drive side and work side, and also automatic flatness control (AFC) system with arbitrary desired strip flatness. Also some applied results to cold mill are shown.

  18. Rolling Bearing Life Prediction, Theory, and Application

    NASA Technical Reports Server (NTRS)

    Zaretsky, Erwin V.

    2013-01-01

    A tutorial is presented outlining the evolution, theory, and application of rolling-element bearing life prediction from that of A. Palmgren, 1924; W. Weibull, 1939; G. Lundberg and A. Palmgren, 1947 and 1952; E. Ioannides and T. Harris, 1985; and E. Zaretsky, 1987. Comparisons are made between these life models. The Ioannides-Harris model without a fatigue limit is identical to the Lundberg-Palmgren model. The Weibull model is similar to that of Zaretsky if the exponents are chosen to be identical. Both the load-life and Hertz stress-life relations of Weibull, Lundberg and Palmgren, and Ioannides and Harris reflect a strong dependence on the Weibull slope. The Zaretsky model decouples the dependence of the critical shear stress-life relation from the Weibull slope. This results in a nominal variation of the Hertz stress-life exponent. For 9th- and 8th-power Hertz stress-life exponents for ball and roller bearings, respectively, the Lundberg- Palmgren model best predicts life. However, for 12th- and 10th-power relations reflected by modern bearing steels, the Zaretsky model based on the Weibull equation is superior. Under the range of stresses examined, the use of a fatigue limit would suggest that (for most operating conditions under which a rolling-element bearing will operate) the bearing will not fail from classical rolling-element fatigue. Realistically, this is not the case. The use of a fatigue limit will significantly overpredict life over a range of normal operating Hertz stresses. Since the predicted lives of rolling-element bearings are high, the problem can become one of undersizing a bearing for a particular application.

  19. Rolling circle amplification of metazoan mitochondrialgenomes

    SciTech Connect

    Simison, W. Brian; Lindberg, D.R.; Boore, J.L.

    2005-07-31

    Here we report the successful use of rolling circle amplification (RCA) for the amplification of complete metazoan mt genomes to make a product that is amenable to high-throughput genome sequencing techniques. The benefits of RCA over PCR are many and with further development and refinement of RCA, the sequencing of organellar genomics will require far less time and effort than current long PCR approaches.

  20. Rapid roll inflation with conformal coupling

    SciTech Connect

    Kofman, Lev; Mukohyama, Shinji

    2008-02-15

    Usual inflation is realized with a slow rolling scalar field minimally coupled to gravity. In contrast, we consider dynamics of a scalar with a flat effective potential, conformally coupled to gravity. Surprisingly, it contains an attractor inflationary solution with the rapidly rolling inflaton field. We discuss models with the conformal inflaton with a flat potential (including hybrid inflation). There is no generation of cosmological fluctuations from the conformally coupled inflaton. We consider realizations of modulated (inhomogeneous reheating) or curvaton cosmological fluctuations in these models. We also implement these unusual features for the popular string-theoretic warped inflationary scenario, based on the interacting D3-D3 branes. The original warped brane inflation suffers a large inflaton mass due to conformal coupling to 4-dimensional gravity. Instead of considering this as a problem and trying to cure it with extra engineering, we show that warped inflation with the conformally coupled, rapidly rolling inflaton is yet possible with N=37 efoldings, which requires low-energy scales 1-100 TeV of inflation. Coincidentally, the same warping numerology can be responsible for the hierarchy. It is shown that the scalars associated with angular isometries of the warped geometry of compact manifold (e.g. S{sup 3} of Klebanov-Strassler (KS) geometry) have solutions identical to conformally coupled modes and also cannot be responsible for cosmological fluctuations. We discuss other possibilities.

  1. Rolling element fatigue testing of gear materials

    NASA Technical Reports Server (NTRS)

    Nahm, A. H.

    1978-01-01

    Rolling element fatigue lives of nine alloys were evaluated in Rolling Contact (RC) rigs. Test conditions included a Hertzian stress at 4,826 MPa (700 ksi), a rolling speed of 6.23 m/sec (245 in/sec.). Tests were run with a Type I oil (MIL-L-7808G) at room temperature. B-10 lives (10% failure rate) of alloys were compared versus reference alloys, VIM-VAR AISI M-50 and VAR AISI 9310. Six case carburizing alloys (AISI 9310, CBS600, CBS1000M, EX00014, Vasco X-2 and EX00053) and three through-hardening alloys (AISI M-50, VascoMax 350 and Vasco Matrix 2 evaluated, showed RCF performance inferior or equivalent to that of AISI 9310 and AISI M-50. It was also found that the effects of vacuum melting processes, different tempering temperatures, freezing cycle during heat treating, shot peening, gold plating and chrome plating employed in the present investigation did not significantly affect RCF life.

  2. Multi-stage FE simulation of hot ring rolling

    NASA Astrophysics Data System (ADS)

    Wang, C.; Geijselaers, H. J. M.; van den Boogaard, A. H.

    2013-05-01

    As a unique and important member of the metal forming family, ring rolling provides a cost effective process route to manufacture seamless rings. Applications of ring rolling cover a wide range of products in aerospace, automotive and civil engineering industries [1]. Above the recrystallization temperature of the material, hot ring rolling begins with the upsetting of the billet cut from raw stock. Next a punch pierces the hot upset billet to form a hole through the billet. This billet, referred to as preform, is then rolled by the ring rolling mill. For an accurate simulation of hot ring rolling, it is crucial to include the deformations, stresses and strains from the upsetting and piercing process as initial conditions for the rolling stage. In this work, multi-stage FE simulations of hot ring rolling process were performed by mapping the local deformation state of the workpiece from one step to the next one. The simulations of upsetting and piercing stages were carried out by 2D axisymmetric models using adaptive remeshing and element erosion. The workpiece for the ring rolling stage was subsequently obtained after performing a 2D to 3D mapping. The commercial FE package LS-DYNA was used for the study and user defined subroutines were implemented to complete the control algorithm. The simulation results were analyzed and also compared with those from the single-stage FE model of hot ring rolling.

  3. Rolling friction—models and experiment. An undergraduate student project

    NASA Astrophysics Data System (ADS)

    Vozdecký, L.; Bartoš, J.; Musilová, J.

    2014-09-01

    In this paper the rolling friction (rolling resistance) model is studied theoretically and experimentally in undergraduate level fundamental general physics courses. Rolling motions of a cylinder along horizontal or inclined planes are studied by simple experiments, measuring deformations of the underlay or of the rolling body. The rolling of a hard cylinder on a soft underlay as well as of a soft cylinder on a hard underlay is studied. The experimental data are treated by the open source software Tracker, appropriate for use at the undergraduate level of physics. Interpretation of results is based on elementary considerations comprehensible to university students—beginners. It appears that the commonly accepted model of rolling resistance based on the idea of a warp (little bulge) on the underlay in front of the rolling body does not correspond with experimental results even for the soft underlay and hard rolling body. The alternative model of the rolling resistance is suggested in agreement with experiment and the corresponding concept of the rolling resistance coefficient is presented. In addition to the obtained results we can conclude that the project can be used as a task for students in practical exercises of fundamental general physics undergraduate courses. Projects of similar type effectively contribute to the development of the physical thinking of students.

  4. Boundary layer roll circulations during FIRE

    NASA Technical Reports Server (NTRS)

    Shirer, Hampton N.; Haack, Tracy

    1990-01-01

    The probable mechanism underlying the development of boundary layer roll circulations are studied using wind and temperature profiles measured by the National Center for Atmospheric Research (NCAR) Electra during the stratocumulus phase of the First ISCCP Regional Experiment (FIRE). The expected, or preferred, roll orientations, horizontal wavelengths, and propagation periods are determined by finding the minimum values of the dynamic and thermodynamic forcing parameters, which here are the eddy Reynolds number (Re) and moist Rayleigh number (Ra sub m). These minimum values depend on the height z sub T of the capping temperature inversion and on the values of the Fourier coefficients of the background height-dependent vector wind profile. As input to our nonlinear spectral model, descent and ascent runs by the Electra provide for initial estimates of the inversion height and the wind profiles. In the first phase of the investigation presented here, a mechanism is said to be a probable contributor to the development of roll circulations within the stratocumulus-topped boundary layer if the modeled roll orientation and wavelengths agree with their observed values. Preliminary results using the 14-coefficient model of Haack-Hirschberg (1988) are discussed for the 7 July 1987 Electra Mission 188-A (Flight 5). This mission was flown across a sharp cloud boundary that was within a LANDSAT/SPOT scene. The stratocumulus deck was relatively solid in the eastern part of the scene, while there was a rapid decrease in cloud cover to scattered cumulus clouds aligned in streets to the west. These cloud streets were oriented nearly parallel to the mean wind direction in the layer, which was approximately 340 degrees. The hypothesis that roll circulations occurred in both the relatively clear and the cloudy regions is investigated using as model input a descent profile obtained in the relatively clear air and an ascent profile obtained in the cloudy air. Initial results for the

  5. Transparent Conductive AGZO/Ag/AGZO Multilayers on PET Substrate by Roll-to-Roll Sputtering.

    PubMed

    Kim, Taehoon; Park, Kwangwon; Kim, Jongsu

    2016-02-01

    Indium-free Al and Ga-codoped ZnO (AGZO) multilayer films with nanoscale Ag interlayer were deposited by dual target roll-to-roll RF for AGZO and DC sputtering systems for Ag at room temperature for a large scale. The thicknesses of AGZO/Ag/AGZO multilayer were optimized by changing the roll speed: 0.15/1.1/0.15 m/min for AGZO/Ag/AGZO multilayers, respectively. The optimum thicknesses of AGZO/Ag/AGZO multilayer are 9.21, 8.32 and 8.04 nm, respectively. Optimized AGZO/Ag/AGZO multilayer films showed an excellent transparency (84% at 550 nm) and a low sheet resistance (9.2 omega/sq.) on PET substrates for opto-electronic applications. The effects of nanoscale Ag interlayer on optical and electrical properties of AGZO/Ag/AGZO multilayer films were discussed.

  6. Transparent Conductive AGZO/Ag/AGZO Multilayers on PET Substrate by Roll-to-Roll Sputtering.

    PubMed

    Kim, Taehoon; Park, Kwangwon; Kim, Jongsu

    2016-02-01

    Indium-free Al and Ga-codoped ZnO (AGZO) multilayer films with nanoscale Ag interlayer were deposited by dual target roll-to-roll RF for AGZO and DC sputtering systems for Ag at room temperature for a large scale. The thicknesses of AGZO/Ag/AGZO multilayer were optimized by changing the roll speed: 0.15/1.1/0.15 m/min for AGZO/Ag/AGZO multilayers, respectively. The optimum thicknesses of AGZO/Ag/AGZO multilayer are 9.21, 8.32 and 8.04 nm, respectively. Optimized AGZO/Ag/AGZO multilayer films showed an excellent transparency (84% at 550 nm) and a low sheet resistance (9.2 omega/sq.) on PET substrates for opto-electronic applications. The effects of nanoscale Ag interlayer on optical and electrical properties of AGZO/Ag/AGZO multilayer films were discussed. PMID:27433648

  7. SASS Applied to Optimum Work Roll Profile Selection in the Hot Rolling of Wide Steel

    NASA Astrophysics Data System (ADS)

    Nolle, Lars

    The quality of steel strip produced in a wide strip rolling mill depends heavily on the careful selection of initial ground work roll profiles for each of the mill stands in the finishing train. In the past, these profiles were determined by human experts, based on their knowledge and experience. In previous work, the profiles were successfully optimised using a self-organising migration algorithm (SOMA). In this research, SASS, a novel heuristic optimisation algorithm that has only one control parameter, has been used to find the optimum profiles for a simulated rolling mill. The resulting strip quality produced using the profiles found by SASS is compared with results from previous work and the quality produced using the original profile specifications. The best set of profiles found by SASS clearly outperformed the original set and performed equally well as SOMA without the need of finding a suitable set of control parameters.

  8. Roll rotation cues influence roll tilt perception assayed using a somatosensory technique.

    PubMed

    Park, Sukyung; Gianna-Poulin, Claire; Black, F Owen; Wood, Scott; Merfeld, Daniel M

    2006-07-01

    We investigated how the nervous system processes ambiguous cues from the otolith organs by measuring roll tilt perception elicited by two motion paradigms. In one paradigm (tilt), eight subjects were sinusoidally tilted in roll with the axis of rotation near ear level. Stimulus frequencies ranged from 0.005 to 0.7 Hz, and the peak amplitude of tilt was 20 degrees . During this paradigm, subjects experienced a sinusoidal variation of interaural gravitational force with a peak of 0.34 g. The second motion paradigm (translation) was designed to yield the same sinusoidal variation in interaural force but did not include a roll canal cue. This was achieved by sinusoidally translating the subjects along their interaural axis. For the 0.7-Hz translation trial, the subjects were simply translated from side to side. A centrifuge was used for the 0.005- to 0.5-Hz translation trials; the subjects were rotated in yaw at 250 degrees /s for 5 min before initiating sinusoidal translations yielding an interaural otolith stimulus composed of both centrifugal and radial acceleration. Using a somatosensory task to measure roll tilt perception, we found substantial differences in tilt perception during the two motion paradigms. Because the primary difference between the two motion paradigms was the presence of roll canal cues during roll tilt trials, these perceptual differences suggest that canal cues influence tilt perception. Specifically, rotational cues provided by the semicircular canals help the CNS resolve ambiguous otolith cues during head tilt, yielding more accurate tilt perception. PMID:16571732

  9. Tribological Testing of Anti-Adhesive coatings for Cold Rolling Mill Rolls—Application to TiN-Coated Rolls

    NASA Astrophysics Data System (ADS)

    Ould, Choumad; Gachon, Yves; Montmitonnet, Pierre; Badiche, Xavier

    2011-05-01

    Roll life is a major issue in cold strip rolling. Roll wear may result either in too low roll roughness, bringing friction below the minimum requested for strip entrainment; or it may degrade strip surface quality. On the contrary, adhesive wear and transfer ("roll coating", "pick up") may form a thick metallic deposits on the roll which increases friction excessively and degrades strip surface again [1]. The roll surface, with the help of a materials-adapted lubricant, must therefore possess anti-wear and anti-adhesive properties. Thus, High Speed Steeel (HSS) rolls show superior properties compared with standard Cr-steel rolls due to their high carbide surface coverage. Another way to improve wear and adhesion properties of surfaces is to apply hard metallic (hard-Cr) or ceramic coatings. Chromium is renowned for its excellent anti-wear and anti-adhesive properties and may serve as a reference. Here, as a first step towards alternative, optimised coatings, a PVD TiN coating has been deposited on tool steels, as previous attempts have proved TiN to be rather successful in cold rolling experiments [2,3]. Different tribological tests are reported here, giving insight in both anti-adhesive properties and fatigue life improvement.

  10. Roll-to-roll gravure with nanomaterials for printing smart packaging.

    PubMed

    Jung, Minhun; Kim, Junseok; Koo, Hyunmo; Lee, Wookyu; Subramanian, Vivek; Cho, Gyoujin

    2014-02-01

    Roll-to-roll (R2R) gravure is considered one of the highest throughput tools for manufacturing inexpensive and flexible ubiquitous IT devices called "smart packaging" in which NFC (near-field communication) transponder, sensors, ADC (analog-to-digital converter), simple processor and signage are all integrated on paper or plastic foils. In this review, we show R2R gravure can be employed to print smart packaging, starting from printing simple electrodes, dielectrics, capacitors, diodes and thin film transistors with appropriate nanomaterial-based inks on plastic foils. PMID:24749427

  11. Diamond turning of high-precision roll-to-roll imprinting molds for fabricating subwavelength gratings

    NASA Astrophysics Data System (ADS)

    Liu, Chun-Wei; Yan, Jiwang; Lin, Shih-Chieh

    2016-06-01

    Diamond turning of high-precision molds is a vital process for the roll-to-roll-based ultraviolet resin imprinting process in fabricating subwavelength gratings. The effects of the grating shape and grating period on diffraction efficiencies and diffraction angles were simulated. Experiments were then conducted to examine the effects of shape design, grating period, and cutting speed on machinability of the mold. According to the optical measurement results, the performance of the subwavelength gratings matched the design well at various incident angles. The results confirm that diamond turning of high-precision molds is a feasible approach for ensuring the continual mass production of subwavelength gratings.

  12. Roll-to-roll gravure with nanomaterials for printing smart packaging.

    PubMed

    Jung, Minhun; Kim, Junseok; Koo, Hyunmo; Lee, Wookyu; Subramanian, Vivek; Cho, Gyoujin

    2014-02-01

    Roll-to-roll (R2R) gravure is considered one of the highest throughput tools for manufacturing inexpensive and flexible ubiquitous IT devices called "smart packaging" in which NFC (near-field communication) transponder, sensors, ADC (analog-to-digital converter), simple processor and signage are all integrated on paper or plastic foils. In this review, we show R2R gravure can be employed to print smart packaging, starting from printing simple electrodes, dielectrics, capacitors, diodes and thin film transistors with appropriate nanomaterial-based inks on plastic foils.

  13. Modelling of spring roll actuators based on viscoelastic dielectric elastomers

    NASA Astrophysics Data System (ADS)

    Zhang, Junshi; Chen, Hualing; Tang, Liling; Li, Bo; Sheng, Junjie; Liu, Lei

    2015-06-01

    In this article, the effect of viscoelastic deformation is analyzed theoretically to evaluate the performance of spring roll dielectric elastomer (DE) actuators. By patterning the electrodes on the rolls, respectively, two functions are studied: axial elongation and bending. The thermodynamic model of viscoelastic DE spring roll is established, and the governing equation is deduced by the free energy method. It is found that when the applied voltage is static and relatively small, both the axial elongated and bending deformed spring rolls can reach equilibrium after viscoelastic relaxation. The evolutions in different timescales and the final profile are presented. The dynamic response is studied as well, by applying a sinusoidal voltage. For the axial elongated spring roll, viscoelasticity can reduce amplitude and increase mean stretch of the actuator. For the bending deformed spring rolls, the results indicate that the spring stiffness has a more significant impact on dynamic performance compared to the effect of voltage.

  14. Strip casting with fluxing agent applied to casting roll

    DOEpatents

    Williams, Robert S.; O'Malley, Ronald J.; Sussman, Richard C.

    1997-01-01

    A strip caster (10) for producing a continuous strip (24) includes a tundish (12) for containing a melt (14), a pair of horizontally disposed water cooled casting rolls (22) and devices (29) for electrostatically coating the outer peripheral chill surfaces (44) of the casting rolls with a powder flux material (56). The casting rolls are juxtaposed relative to one another for forming a pouting basin (18) for receiving the melt through a teeming tube (16) thereby establishing a meniscus (20) between the rolls for forming the strip. The melt is protected from the outside air by a non-oxidizing gas passed through a supply line (28) to a sealing chamber (26). A preferred flux is boron oxide having a melting point of about 550.degree. C. The flux coating enhances wetting of the steel melt to the casting roll and dissolves any metal oxide formed on the roll.

  15. Strip casting with fluxing agent applied to casting roll

    DOEpatents

    Williams, R.S.; O`Malley, R.J.; Sussman, R.C.

    1997-07-29

    A strip caster for producing a continuous strip includes a tundish for containing a melt, a pair of horizontally disposed water cooled casting rolls and devices for electrostatically coating the outer peripheral chill surfaces of the casting rolls with a powder flux material. The casting rolls are juxtaposed relative to one another for forming a pouting basin for receiving the melt through a teeming tube thereby establishing a meniscus between the rolls for forming the strip. The melt is protected from the outside air by a non-oxidizing gas passed through a supply line to a sealing chamber. A preferred flux is boron oxide having a melting point of about 550 C. The flux coating enhances wetting of the steel melt to the casting roll and dissolves any metal oxide formed on the roll. 3 figs.

  16. Mechanics of Thin Strip Steering in Hot Rolling

    NASA Astrophysics Data System (ADS)

    Jiang, Zhengyi; Tieu, Kiet A.

    2004-06-01

    The hot rolling of thin strip can result in several problems in hot rolling, for instance, the control of strip steering, strip shape and flatness and surface roughness etc. Therefore, the hot rolling of thin strip brings out a requirement of innovative technologies such as the extended control of shape and flatness, steering control and reduction of load by roll gap lubrication. In this paper, the authors focus on the analysis of thin strip snaking movement, as well as solve the related problems such as the shape and flatness due to a larger reduction applied when the strip is thinner. A finite element method was used to simulate this nonsymmetricity rolling considering the non-uniform reduction along the strip width. The calculated spread is compared with the measured values obtained from the rolling mill in laboratory and the friction effect is also discussed.

  17. Therapeutic potential of inhibiting leukocyte rolling in ischemia/reperfusion.

    PubMed Central

    Kubes, P; Jutila, M; Payne, D

    1995-01-01

    Leukocyte rolling has been postulated to be mandatory for subsequent leukocyte adhesion and tissue injury observed during ischemia/reperfusion. The objective of this study was to systematically assess this hypothesis at the microvascular level by examining the effects of various concentrations of a selectin-binding carbohydrate (fucoidin) on the increased rolling and adhesion of leukocytes in postischemic venules. The contribution of L-selectin and/or P-selectin to leukocyte rolling were also assessed in this model. Using intravital microscopy we observed that 60 min of ischemia followed by reperfusion caused a profound increase in leukocyte rolling and adhesion. A high dose of fucoidin (25 mg/kg) reduced leukocyte rolling by > 90% and significantly reduced leukocyte adhesion, whereas a lower dose of fucoidin still reduced leukocyte rolling by 60% but had no effect on leukocyte adhesion. Moreover, despite the profound reduction in leukocyte rolling with fucoidin, the remaining rolling cells were able to firmly adhere via a CD18-dependent mechanism, particularly in those postcapillary venules with reduced (30-50%) shear rates. The increased rolling was also reduced 60% by either an anti-P-selectin antibody, an anti-L-selectin antibody, or a combination of the two antibodies, but this reduction in rolling cells did not translate into significantly reduced leukocyte adhesion. Our data suggest that L-selectin, P-selectin, and a fucoidin-sensitive pathway contribute to the significant increase in reperfusion-induced leukocyte rolling. However, targeting leukocyte rolling as a form of therapy requires very significant efficacy (> 90%) to achieve reasonable (approximately 50%) attenuation in leukocyte adhesion in postischemic venules. Images PMID:7539452

  18. 21 CFR 136.180 - Whole wheat bread, rolls, and buns.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 2 2012-04-01 2012-04-01 false Whole wheat bread, rolls, and buns. 136.180... § 136.180 Whole wheat bread, rolls, and buns. (a) Each of the foods whole wheat bread, graham bread, entire wheat bread, whole wheat rolls, graham rolls, entire wheat rolls, whole wheat buns, graham...

  19. 21 CFR 136.180 - Whole wheat bread, rolls, and buns.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 2 2014-04-01 2014-04-01 false Whole wheat bread, rolls, and buns. 136.180... § 136.180 Whole wheat bread, rolls, and buns. (a) Each of the foods whole wheat bread, graham bread, entire wheat bread, whole wheat rolls, graham rolls, entire wheat rolls, whole wheat buns, graham...

  20. 21 CFR 136.180 - Whole wheat bread, rolls, and buns.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 2 2013-04-01 2013-04-01 false Whole wheat bread, rolls, and buns. 136.180... § 136.180 Whole wheat bread, rolls, and buns. (a) Each of the foods whole wheat bread, graham bread, entire wheat bread, whole wheat rolls, graham rolls, entire wheat rolls, whole wheat buns, graham...

  1. 21 CFR 136.180 - Whole wheat bread, rolls, and buns.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 2 2011-04-01 2011-04-01 false Whole wheat bread, rolls, and buns. 136.180... § 136.180 Whole wheat bread, rolls, and buns. (a) Each of the foods whole wheat bread, graham bread, entire wheat bread, whole wheat rolls, graham rolls, entire wheat rolls, whole wheat buns, graham...

  2. The effects of forming parameters on conical ring rolling process.

    PubMed

    Meng, Wen; Zhao, Guoqun; Guan, Yanjin

    2014-01-01

    The plastic penetration condition and biting-in condition of a radial conical ring rolling process with a closed die structure on the top and bottom of driven roll, simplified as RCRRCDS, were established. The reasonable value range of mandrel feed rate in rolling process was deduced. A coupled thermomechanical 3D FE model of RCRRCDS process was established. The changing laws of equivalent plastic strain (PEEQ) and temperature distributions with rolling time were investigated. The effects of ring's outer radius growth rate and rolls sizes on the uniformities of PEEQ and temperature distributions, average rolling force, and average rolling moment were studied. The results indicate that the PEEQ at the inner layer and outer layer of rolled ring are larger than that at the middle layer of ring; the temperatures at the "obtuse angle zone" of ring's cross-section are higher than those at "acute angle zone"; the temperature at the central part of ring is higher than that at the middle part of ring's outer surfaces. As the ring's outer radius growth rate increases at its reasonable value ranges, the uniformities of PEEQ and temperature distributions increase. Finally, the optimal values of the ring's outer radius growth rate and rolls sizes were obtained.

  3. Prediction of temperature distribution in the hot rolling of slabs

    NASA Astrophysics Data System (ADS)

    Serajzadeh, S.; Karimi Taheri, A.; Mucciardi, F.

    2002-03-01

    In the process of continuous hot slab rolling, it is vital to know the temperature distribution within the slab along the length of the rolling mill because temperature is the dominant parameter controlling the kinetics of metallurgical transformations and the flow stress of the rolled metal. In other words, the microstructural changes, the mechanical properties as well as the final dimensions of the product and roll-force depend on the temperature distribution within the metal being rolled. In this paper, a mathematical model based on the finite element method is utilized to predict the temperature distribution and microstructural changes during the continuous hot slab rolling process. The effects of various parameters such as the heat of deformation, the work-roll temperature, the rolling speed, and the heat transfer coefficient between the work-roll and the metal are all taken into account in the analyses. To verify the validity of the model and the generated computer code, a comparison is carried out between the theoretical and plant-recorded results.

  4. The Effects of Forming Parameters on Conical Ring Rolling Process

    PubMed Central

    Meng, Wen; Zhao, Guoqun; Guan, Yanjin

    2014-01-01

    The plastic penetration condition and biting-in condition of a radial conical ring rolling process with a closed die structure on the top and bottom of driven roll, simplified as RCRRCDS, were established. The reasonable value range of mandrel feed rate in rolling process was deduced. A coupled thermomechanical 3D FE model of RCRRCDS process was established. The changing laws of equivalent plastic strain (PEEQ) and temperature distributions with rolling time were investigated. The effects of ring's outer radius growth rate and rolls sizes on the uniformities of PEEQ and temperature distributions, average rolling force, and average rolling moment were studied. The results indicate that the PEEQ at the inner layer and outer layer of rolled ring are larger than that at the middle layer of ring; the temperatures at the “obtuse angle zone” of ring's cross-section are higher than those at “acute angle zone”; the temperature at the central part of ring is higher than that at the middle part of ring's outer surfaces. As the ring's outer radius growth rate increases at its reasonable value ranges, the uniformities of PEEQ and temperature distributions increase. Finally, the optimal values of the ring's outer radius growth rate and rolls sizes were obtained. PMID:25202716

  5. TECHNICAL NOTE: Multiple-degrees-of-freedom electroelastomer roll actuators

    NASA Astrophysics Data System (ADS)

    Pei, Qibing; Rosenthal, Marcus; Stanford, Scott; Prahlad, Harsha; Pelrine, Ron

    2004-10-01

    Electroelastomers (electroactive elastomers) such as the 3M VHB 4910 acrylic adhesive films have exhibited up to 380% strain in area expansion at 5 6 kV when they are highly prestrained. By rolling highly prestrained electroelastomer films around a compression spring, we have demonstrated multifunctional electroelastomer rolls (MERs, or spring rolls) that combine load bearing, actuation, and sensing functions. We extended the design to two-degree-of-freedom (2-DOF) and 3-DOF spring rolls by patterning the electrodes to align radially on two and four circumferential spans of the rolls, respectively. Multiple-DOF spring rolls retain the linear actuation of 1-DOF spring rolls with additional bending actuation. Mathematical equations are derived to correlate the bending angle and lateral force of the rolls with the actuated stroke in one of the electroded spans. Two-DOF spring rolls with a 1.4 cm outside diameter, 6.8 cm axial length, and 11 g weight have been fabricated; these rolls have a 90° maximum actuation bending angle, 0.7 N maximum lateral force, and up to 15 N blocked axial force. Three-DOF spring rolls with a 2.3 cm outside diameter, 9.0 cm axial length, and 29 g weight exhibit a 35° maximum bending angle and 1.0 N maximum lateral force. These specifications can be modified by variations in roll parameters according to the equations. Multi-DOF spring rolls are easy to fabricate, compact, multifunctional, and mechanically robust. They represent a radically new actuation technology and may enable a number of unique applications. We have demonstrated a small walking robot, MERbot, with one 2-DOF spring roll as each of its six legs. The robot's speed is as high as 13.6 cm s-1 or two-thirds of its length per second. 'Sushi rolls' have also been fabricated: these consist of six 2-DOF springs connected in series and monolithic in structure. The sushi rolls can be driven so as to generate wavelike or serpentine motion.

  6. An FE Based On-line Model for the Prediction of Work Roll Thermal Profile in Hot Strip Rolling

    NASA Astrophysics Data System (ADS)

    Choi, Ji Won; Lee, Jung Hyeung; Sun, Cheng Gang; Hwang, Sang Moo

    2010-06-01

    Prediction and control of the thermal deformation of the work roll is vital for enhancing product quality in hot strip and plate rolling. In this paper, we present an on-line model for the prediction of the work roll thermal profile. The model is developed on the basis of an integrated finite element model for the coupled analysis of heat transfer and deformation occurring at the bite zone, to rigorously take into account the effect of various rolling parameters on the thermal behavior of the work roll. The validity of the model is demonstrated through comparison with measurements made in an industrial hot strip mill. Also, an emphasis is given to the examination the effect of some selected rolling parameters in an actual production environment.

  7. Fabrication of microlens arrays on a glass substrate by roll-to-roll process with PDMS mold

    NASA Astrophysics Data System (ADS)

    Hu, Chia-Nying; Su, Guo-Dung J.

    2009-08-01

    This paper presents a roll-to-roll method to fabricate microlens arrays on a glass substrate by using a cost-effective PDMS (Polydimethylsiloxane) mold. We fabricated microlens arrays mold, which was made by photoresist(AZ4620), on the silicon substrate by thermal reflow process, and transferred the pattern to PDMS film. Roll-to-roll system is a standard printing process whose roller is made of acrylic cylinder surrounded with the PDMS mold. UV resin was chosen to be the material to make microlens in rolling process with UV light curing. We investigated the quality of microlens arrays by changing the parameters, such as embossing pressure and rolling speed, to ensure good quality of microlens arrays.

  8. Overlay accuracy on a flexible web with a roll printing process based on a roll-to-roll system.

    PubMed

    Chang, Jaehyuk; Lee, Sunggun; Lee, Ki Beom; Lee, Seungjun; Cho, Young Tae; Seo, Jungwoo; Lee, Sukwon; Jo, Gugrae; Lee, Ki-yong; Kong, Hyang-Shik; Kwon, Sin

    2015-05-01

    For high-quality flexible devices from printing processes based on Roll-to-Roll (R2R) systems, overlay alignment during the patterning of each functional layer poses a major challenge. The reason is because flexible substrates have a relatively low stiffness compared with rigid substrates, and they are easily deformed during web handling in the R2R system. To achieve a high overlay accuracy for a flexible substrate, it is important not only to develop web handling modules (such as web guiding, tension control, winding, and unwinding) and a precise printing tool but also to control the synchronization of each unit in the total system. A R2R web handling system and reverse offset printing process were developed in this work, and an overlay between the 1st and 2nd layers of ±5μm on a 500 mm-wide film was achieved at a σ level of 2.4 and 2.8 (x and y directions, respectively) in a continuous R2R printing process. This paper presents the components and mechanisms used in reverse offset printing based on a R2R system and the printing results including positioning accuracy and overlay alignment accuracy.

  9. High-speed roll-to-roll manufacturing of graphene using a concentric tube CVD reactor

    PubMed Central

    Polsen, Erik S.; McNerny, Daniel Q.; Viswanath, B.; Pattinson, Sebastian W.; John Hart, A.

    2015-01-01

    We present the design of a concentric tube (CT) reactor for roll-to-roll chemical vapor deposition (CVD) on flexible substrates, and its application to continuous production of graphene on copper foil. In the CTCVD reactor, the thin foil substrate is helically wrapped around the inner tube, and translates through the gap between the concentric tubes. We use a bench-scale prototype machine to synthesize graphene on copper substrates at translation speeds varying from 25 mm/min to 500 mm/min, and investigate the influence of process parameters on the uniformity and coverage of graphene on a continuously moving foil. At lower speeds, high-quality monolayer graphene is formed; at higher speeds, rapid nucleation of small graphene domains is observed, yet coalescence is prevented by the limited residence time in the CTCVD system. We show that a smooth isothermal transition between the reducing and carbon-containing atmospheres, enabled by injection of the carbon feedstock via radial holes in the inner tube, is essential to high-quality roll-to-roll graphene CVD. We discuss how the foil quality and microstructure limit the uniformity of graphene over macroscopic dimensions. We conclude by discussing means of scaling and reconfiguring the CTCVD design based on general requirements for 2-D materials manufacturing. PMID:25997124

  10. Continuous roll-to-roll serpentine deposition for high throughput a-Si PV manufacturing

    SciTech Connect

    Izu, M.; Ovshinsky, H.C.; Deng, X.; Krisko, A.J.; Narasimhan, K.L.; Crucet, R.; Laarman, T.; Myatt, A.; Ovshinsky, S.R.

    1994-12-31

    In order to further improve the economies of scale which are inherent in ECD`s continuous roll-to-roll amorphous silicon alloy solar cell manufacturing process, the authors have developed a concept for a serpentine web plasma CVD deposition process to maximize throughput while keeping the size of the deposition chambers small. When this technique is incorporated into a continuous roll-to-roll PV manufacturing process, it will maximize the throughput for a high volume production plant, reduce the machine cost, improve gas utilization, reduce power consumption, and improve the solar cell stability. To demonstrate the serpentine web deposition concept, the authors have constructed a single loop serpentine deposition chamber to deposit a-Si for n-i-p structure solar cells. During the initial process of optimization, they have produced single-junction a-Si solar cells with 8.6% efficiency, and triple-junction a-Si solar cells with a 9.5% initial efficiency, where the top cell intrinsic layer was deposited in the serpentine deposition chamber.

  11. Fabrication of ultra-thin nanostructured bimetallic foils by Accumulative Roll Bonding and Asymmetric Rolling

    PubMed Central

    Yu, Hailiang; Lu, Cheng; Tieu, A. Kiet; Godbole, Ajit; Su, Lihong; Sun, Yong; Liu, Mao; Tang, Delin; Kong, Charlie

    2013-01-01

    This paper reports a new technique that combines the features of Accumulative Roll Bonding (ARB) and Asymmetric Rolling (AR). This technique has been developed to enable production of ultra-thin bimetallic foils. Initially, 1.5 mm thick AA1050 and AA6061 foils were roll-bonded using ARB at 200°C, with 50% reduction. The resulting 1.5 mm bimetallic foil was subsequently thinned to 0.04 mm through four AR passes at room temperature. The speed ratio between the upper and lower AR rolls was 1:1.3. The tensile strength of the bimetallic foil was seen to increase with reduction in thickness. The ductility of the foil was seen to reduce upon decreasing the foil thickness from 1.5 mm to 0.14 mm, but increase upon further reduction in thickness from 0.14 mm to 0.04 mm. The grain size was about 140 nm for the AA6061 layer and 235 nm for the AA1050 layer, after the third AR pass. PMID:23918002

  12. Vortex-lift roll-control device

    NASA Technical Reports Server (NTRS)

    Lamar, J. E. (Inventor)

    1979-01-01

    A wing is described for aircraft of cropped, arrow-type planform with thin leading and side edges. The wing has a pivotable tip to alter the crop angle of the wing during flight. Increasing the crop angle causes the wing side edge to become a trailing edge which reduces the strength of the side edge vortex flow. Decreasing the crop angle causes opposite results, in particular the side edge is now a leading edge and can generate a leading edge vortex flow. The wing constitutes a roll control device for aircraft of the stated design particularly effective at higher angles of attack.

  13. Rolls-Royce implementing new production system

    NASA Astrophysics Data System (ADS)

    1982-05-01

    An advanced, integrated manufacturing systems system is being implemented in Rolls-Royce production facilities in order to cut unit production costs by reducing lead times, manning levels and inventories. The topics discussed include the program outline, planned subcontracting, the machining operation that includes isothermal forming of wide-chord hollow blades, carbon fiber production of subsystems including thrust reversers, continuous dress creep feed grinding, the directionally solidified casting facility that can produce single-crystal blades without modification to the casting furnaces, and a robot machining line.

  14. Upscaling of polymer solar cell fabrication using full roll-to-roll processing.

    PubMed

    Krebs, Frederik C; Tromholt, Thomas; Jørgensen, Mikkel

    2010-06-01

    Upscaling of the manufacture of polymer solar cells is detailed with emphasis on cost analysis and practical approach. The device modules were prepared using both slot-die coating and screen printing the active layers in the form of stripes that were serially connected. The stripe width was varied and the resultant performance analysed. Wider stripes give access to higher geometric fill factors and lower aperture loss while they also present larger sheet resistive losses. An optimum was found through preparation of serially connected stripes having widths of 9, 13 and 18 mm with nominal geometric fill factors (excluding bus bars) of 50, 67 and 75% respectively. In addition modules with lengths of 6, 10, 20, 22.5 and 25 cm were explored. The devices were prepared by full roll-to-roll solution processing in a web width of 305 mm and roll lengths of up to 200 m. The devices were encapsulated with a barrier material in a full roll-to-roll process using standard adhesives giving the devices excellent stability during storage and operation. The total area of processed polymer solar cell was around 60 m2 per run. The solar cells were characterised using a roll-to-roll system comprising a solar simulator and an IV-curve tracer. After characterisation the solar cell modules were cut into sheets using a sheeting machine and contacted using button contacts applied by crimping. Based on this a detailed cost analysis was made showing that it is possible to prepare complete and contacted polymer solar cell modules on this scale at an area cost of 89 euro m(-2) and an electricity cost of 8.1 euro Wp(-1). The cost analysis was separated into the manufacturing cost, materials cost and also the capital investment required for setting up a complete production plant on this scale. Even though the cost in euro Wp(-1) is comparable to the cost for electricity using existing technologies the levelized cost of electricity (LCOE) is expected to be significantly higher than the existing

  15. 40 CFR 426.30 - Applicability; description of the rolled glass manufacturing subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... rolled glass manufacturing subcategory. 426.30 Section 426.30 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS GLASS MANUFACTURING POINT SOURCE CATEGORY Rolled Glass Manufacturing Subcategory § 426.30 Applicability; description of the rolled...

  16. 40 CFR 426.30 - Applicability; description of the rolled glass manufacturing subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... rolled glass manufacturing subcategory. 426.30 Section 426.30 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS GLASS MANUFACTURING POINT SOURCE CATEGORY Rolled Glass Manufacturing Subcategory § 426.30 Applicability; description of the rolled...

  17. An experimental study for determining human discomfort response to roll vibration

    NASA Technical Reports Server (NTRS)

    Leatherwood, J. D.; Dempsey, T. K.; Clevenson, S. A.

    1976-01-01

    An experimental study using a passenger ride quality apparatus (PRQA) was conducted to determine the subjective reactions of passengers to roll vibrations. The data obtained illustrate the effect upon human comfort of several roll-vibration parameters: namely, roll acceleration level, roll frequency, and seat location (i.e., distance from axis of rotation). Results of an analysis of variance indicated that seat location had no effect on discomfort ratings of roll vibrations. The effect of roll acceleration level was significant, and discomfort ratings increased markedly with increasing roll acceleration level at all roll frequencies investigated. Of particular interest, is the fact that the relationship between discomfort ratings and roll acceleration level was linear in nature. The effect of roll frequency also was significant as was the interaction between roll acceleration level and roll frequency.

  18. Simulation of rolling friction in the working stands of wide-strip mills

    NASA Astrophysics Data System (ADS)

    Garber, E. A.; Samarin, S. N.; Traino, A. I.; Ermilov, V. V.

    2007-04-01

    The energy consumed for rolling friction in the interroll contact area in the working stands of cold-rolling and pinch-pass mils intended for the production of wide steel strips has been analyzed. The coefficients and power of rolling friction are obtained for the first time using the databases of the process control systems of operating mills and simulating these quantities. A statistically reliable regression relation is obtained between the coefficient of rolling friction and the significant parameters of rolling and skin rolling (i.e., the interroll force, the roll speed, and the roll body roughness). The power fraction consumed for rolling friction is found to reach 60 80% of the total power of the main drive of working stands for skin rolling and 30 50% for cold rolling. Therefore, it is necessary to take into account these power losses in designing mills and developing technological cold-rolling conditions.

  19. An Analytical Modified Model of Clad Sheet Bonding by Cold Rolling Using Upper Bond Theorem

    NASA Astrophysics Data System (ADS)

    Pishbin, H.; Parsa, M. H.; Dastvareh, A.

    2010-10-01

    In this paper, clad sheet bonding by cold rolling was investigated using the upper bond theorem. Plastic deformation behavior of the strip at the roll gap was investigated, unlike previous methods; distinctive angular velocities are used for different zones in roll gap in present model and absolute minimum of rolling power function is achieved. Rolling power, rolling force, and thickness ratio of the rolled product affected by various rolling condition such as flow stress of sheets, initial thickness ratio, roller radius, total thickness reduction, coefficient of friction between rollers and metals and between components layer, roll speed, etc., are discussed. It was found that the theoretical prediction of the thickness ratio of the rolled product, rolling force, and rolling power are in good agreement with the experimental measurement.

  20. Study of Titanium Alloy Sheet During H-sectioned Rolling Forming Using the Taguchi Method

    SciTech Connect

    Chen, D.-C.; Gu, W.-S.; Hwang, Y.-M.

    2007-05-17

    This study employs commercial DEFORM three-dimensional finite element code to investigate the plastic deformation behavior of Ti-6Al-4V titanium alloy sheet during the H-sectioned rolling process. The simulations are based on a rigid-plastic model and assume that the upper and lower rolls are rigid bodies and that the temperature rise induced during rolling is sufficiently small that it can be ignored. The effects of the roll profile, the friction factor between the rolls and the titanium alloy, the rolling temperature and the roll radii on the rolling force, the roll torque and the effective strain induced in the rolled product are examined. The Taguchi method is employed to optimize the H-sectioned rolling process parameters. The results confirm the effectiveness of this robust design methodology in optimizing the H-sectioned rolling process parameters for the current Ti-6Al-4V titanium alloy.

  1. Terminal retrograde turn of rolling rings

    NASA Astrophysics Data System (ADS)

    Jalali, Mir Abbas; Sarebangholi, Milad S.; Alam, Mohammad-Reza

    2015-09-01

    We report an unexpected reverse spiral turn in the final stage of the motion of rolling rings. It is well known that spinning disks rotate in the same direction of their initial spin until they stop. While a spinning ring starts its motion with a kinematics similar to disks, i.e., moving along a cycloidal path prograde with the direction of its rigid body rotation, the mean trajectory of its center of mass later develops an inflection point so that the ring makes a spiral turn and revolves in a retrograde direction around a new center. Using high speed imaging and numerical simulations of models featuring a rolling rigid body, we show that the hollow geometry of a ring tunes the rotational air drag resistance so that the frictional force at the contact point with the ground changes its direction at the inflection point and puts the ring on a retrograde spiral trajectory. Our findings have potential applications in designing topologically new surface-effect flying objects capable of performing complex reorientation and translational maneuvers.

  2. Rail roughness and rolling noise in tramways

    NASA Astrophysics Data System (ADS)

    Chiacchiari, L.; Thompson, DJ; Squicciarini, G.; Ntotsios, E.; Loprencipe, G.

    2016-09-01

    Companies which manage railway networks have to cope continually with the problem of operating safety and maintenance intervention issues related to rail surface irregularities. A lot of experience has been gained in recent years in railway applications but the case of tramways is quite different; in this field there are no specific criteria to define any intervention on rail surface restoration. This paper shows measurements carried out on some stretches of a tram network with the CAT equipment (Corrugation Analysis Trolley) for the principal purpose of detecting different states of degradation of the rails and identifying a level of deterioration to be associated with the need for maintenance through rail grinding. The measured roughness is used as an input parameter into prediction models for both rolling noise and ground vibration to show the potential effect that high levels of roughness can have in urban environment. Rolling noise predictions are also compared with noise measurements to illustrate the applicability of the modelling approach. Particular attention is given to the way the contact filter needs to be modelled in the specific case of trams that generally operate at low speed. Finally an empirical approach to assess vibration levels in buildings is presented.

  3. Helicopter roll control effectiveness criteria program summary

    NASA Technical Reports Server (NTRS)

    Heffley, Robert K.; Bourne, Simon M.; Mnich, Marc A.

    1988-01-01

    A study of helicopter roll control effectiveness is summarized for the purpose of defining military helicopter handling qualities requirements. The study is based on an analysis of pilot-in-the-loop task performance of several basic maneuvers. This is extended by a series of piloted simulations using the NASA Ames Vertical Motion Simulator and selected flight data. The main results cover roll control power and short-term response characteristics. In general the handling qualities requirements recommended are set in conjunction with desired levels of flight task and maneuver response which can be directly observed in actual flight. An important aspect of this, however, is that vehicle handling qualities need to be set with regard to some quantitative aspect of mission performance. Specific examples of how this can be accomplished include a lateral unmask/remask maneuver in the presence of a threat and an air tracking maneuver which recognizes the kill probability enhancement connected with decreasing the range to the target. Conclusions and recommendations address not only the handling qualities recommendations, but also the general use of flight simulators and the dependence of mission performance on handling qualities.

  4. Air friction and rolling resistance during cycling.

    PubMed

    de Groot, G; Sargeant, A; Geysel, J

    1995-07-01

    To calculate the power output during actual cycling, the air friction force Fa and rolling resistance Fr have to be known. Instead of wind tunnel experiments or towing experiments at steady speed, in this study these friction forces were measured by coasting down experiments. Towing experiments at constant acceleration (increasing velocity) were also done for comparison. From the equation of motion, the velocity-time curve v(t) was obtained. Curve-fitting procedures on experimental data of the velocity v yielded values of the rolling resistance force Fr and of the air friction coefficient k = Fa/v2. For the coasting down experiments, the group mean values per body mass m (N = 7) were km = k/m = (2.15 +/- 0.32) x 10(-3)m-1 and ar = Fr/m = (3.76 +/- 0.18) x 10(-2)ms-2, close to other values from the literature. The curves in the phase plane (velocity vs acceleration) and the small residual sum of squares indicated the validity of the theory. The towing experiments were not congruent with the coasting down experiments. Higher values of the air friction were found, probably due to turbulence of the air.

  5. Multi-hundred kilowatt roll ring assembly

    NASA Technical Reports Server (NTRS)

    Jacobson, Peter E.

    1985-01-01

    A program was completed to develop an evaluation unit of a high power rotary transfer device for potential application in a space environment. This device was configured around a Roll Ring concept which performs the same function as a slip ring/brush assembly with a rolling instead of sliding interface. An eight circuit Evaluation Unit (EU) and a portable Test Fixture (TF) were designed and fabricated. The EU was designed to transfer currents to 200 amperes at a potential of as high as 500 volts for an ultimate 100 kW/circuit transfer capability. The EU was evaluated in vacuum at dc transfer currents of 50 to 200 amperes at voltages to 10 volts and at 500 volts at 2 amperes. Power transfer to levels of 2 kW through each of the eight circuits was completed. Power transfer in vacuum at levels and efficiencies not previously achieved was demonstrated. The terminal-to-terminal resistance was measured to be greater than 0.42 milliohms which translates to an efficiency at 100 kW of 99.98 percent. The EU and TF have been delivered to the Lewis Research Center and are being prepared tor testing at increased power levels and for life testing, which will include both dc and ac power.

  6. Politics Revisited: Metatextual Implications of Rock and Roll Criticism.

    ERIC Educational Resources Information Center

    McDonald, James R.

    1988-01-01

    By viewing rock lyrics as a vehicle that demands a sociopolitical response, rock and roll critics place in the hands of rock artists a responsibility that is not warranted. Particularly with regard to political messages, rock and roll should be viewed from a more individualized perspective. (BJV)

  7. 14 CFR 25.491 - Taxi, takeoff and landing roll.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ..., takeoff and landing roll. Within the range of appropriate ground speeds and approved weights, the airplane structure and landing gear are assumed to be subjected to loads not less than those obtained when the... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Taxi, takeoff and landing roll....

  8. 14 CFR 25.491 - Taxi, takeoff and landing roll.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ..., takeoff and landing roll. Within the range of appropriate ground speeds and approved weights, the airplane structure and landing gear are assumed to be subjected to loads not less than those obtained when the... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Taxi, takeoff and landing roll....

  9. 14 CFR 25.491 - Taxi, takeoff and landing roll.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Taxi, takeoff and landing roll. 25.491 Section 25.491 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Structure Ground Loads § 25.491 Taxi, takeoff and landing roll. Within the range...

  10. 14 CFR 25.491 - Taxi, takeoff and landing roll.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ..., takeoff and landing roll. Within the range of appropriate ground speeds and approved weights, the airplane structure and landing gear are assumed to be subjected to loads not less than those obtained when the... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Taxi, takeoff and landing roll....

  11. 14 CFR 25.491 - Taxi, takeoff and landing roll.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ..., takeoff and landing roll. Within the range of appropriate ground speeds and approved weights, the airplane structure and landing gear are assumed to be subjected to loads not less than those obtained when the... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Taxi, takeoff and landing roll....

  12. Student Understanding of Rotational and Rolling Motion Concepts

    ERIC Educational Resources Information Center

    Rimoldini, Lorenzo G.; Singh, Chandralekha

    2005-01-01

    We investigated the common difficulties that students have with concepts related to rotational and rolling motion covered in the introductory physics courses. We compared the performance of calculus- and algebra-based introductory physics students with physics juniors who had learned rotational and rolling motion concepts in an intermediate level…

  13. Unsteady Aerodynamics of ``Roll-Tacking'' in Olympic Class Sailboats

    NASA Astrophysics Data System (ADS)

    Schutt, Riley; Williamson, Chk

    2015-11-01

    When tacking a sailboat (turning a boat through the wind during upwind sailing), racers employ a ``roll-tacking'' technique. During a roll-tack, sailors use body weight movements to roll the boat through extreme angles of heel. This contrasts with a flat-tack, where the boat remains upright throughout the turn. The dynamic heeling motion of a roll-tack causes the sail to vigorously sweep through the air, resulting in large-scale vortex shedding and increased propulsion. In this research, we use a characteristic roll-tack motion derived from on-the-water data. On-the-water data is collected from a full-scale Olympic racing boat sailed by a national champion in the Laser sailboat class. Using this data, we run a series of representative experiments in the laboratory. Two dimensional flexible sail extrusions are built using rapid-prototyping and are tested in a three degree-of-freedom (X, Y, and theta) towing tank. Particle Image Velocimetry and force measurements are used to compare vortex dynamics and propulsive forces generated by roll-tacks versus flat-tacks. An increase in thrust observed during roll-tack tests agrees with on-the-water experiments, which show a racing advantage greater than one boatlength when a roll-tack is performed relative to a flat tack.

  14. 10. VIEW OF THE INSTALLATION OF PLUTONIUM FABRICATION ROLLING MILL. ...

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

    10. VIEW OF THE INSTALLATION OF PLUTONIUM FABRICATION ROLLING MILL. THE MILL ROLLED INGOTS INTO SHEETS THAT WERE THEN CUT INTO CIRCLE BLANKS TO BE PASSED THROUGH THE CENTER LINE FOR PRESSING. (2/19/63) - Rocky Flats Plant, Plutonium Fabrication, Central section of Plant, Golden, Jefferson County, CO

  15. Skimming the Surface: Teaching Kayak Support Strokes and Rolls.

    ERIC Educational Resources Information Center

    Higgins, Peter; Morgan, Alastair

    1997-01-01

    Teaching novice kayakers only the biomechanics of a roll and other "closed" (nonadaptable) skills does not create opportunities for flexible skill development. A wider approach teaches support strokes and rolls by focusing on "open" skills that can be transferred or adapted to any situation, including emergency decision making, body movement, and…

  16. 16. VIEW OF A ROLLING MILL THAT WAS USED TO ...

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

    16. VIEW OF A ROLLING MILL THAT WAS USED TO CREATE A METAL SHEET (SHOWN). (4/16/57) - Rocky Flats Plant, Uranium Rolling & Forming Operations, Southeast section of plant, southeast quadrant of intersection of Central Avenue & Eighth Street, Golden, Jefferson County, CO

  17. 5. VIEW OF BERYLLIUM PROCESSING AREA, ROLLING MILL. BERYLLIUM FORMING ...

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

    5. VIEW OF BERYLLIUM PROCESSING AREA, ROLLING MILL. BERYLLIUM FORMING BEGAN IN SIDE A OF THE BUILDING IN 1962. (11/5/73) - Rocky Flats Plant, Uranium Rolling & Forming Operations, Southeast section of plant, southeast quadrant of intersection of Central Avenue & Eighth Street, Golden, Jefferson County, CO

  18. Getting to the Center of a Tootsie Roll Pop

    ERIC Educational Resources Information Center

    Lien, Brian

    2007-01-01

    In this article, the author describes an activity he introduced to his engineering drafting students that involved a Tootsie Roll product. In this particular activity, he assigned his students to find out how many licks are needed to get to the center of a Tootsie Roll Pop. He first asked his students to do some research if an answer exists for…

  19. Spring-back of flexible roll forming bending process

    NASA Astrophysics Data System (ADS)

    Zhang, Y.; Kim, D. H.; Jung, D. W.

    2015-12-01

    Simulations are now widely used in the field of roll forming because of their convenience. Simulations provide a low cost, secure and fast analysis tool. Flexible roll forming provides the desired shapes with a one time forming process. For roll forming, the velocity of the sheet and friction are important factors to attain an ideal shape. Because it is a complicated process, simulations provide a better understanding of the roll forming process. Simulations were peformed using ABAQUS software linked to elastic-plastic modules which we developed taking into account of interactions between these fields [1]. The application of this method makes it possible to highlight the strain-stress and mechanical behaviour laws and the spring-back. Thus, the flexible roll forming and bending process can bewell described by the simulation software and guide the actual machine.

  20. Large transient fault current test of an electrical roll ring

    NASA Technical Reports Server (NTRS)

    Yenni, Edward J.; Birchenough, Arthur G.

    1992-01-01

    The space station uses precision rotary gimbals to provide for sun tracking of its photoelectric arrays. Electrical power, command signals and data are transferred across the gimbals by roll rings. Roll rings have been shown to be capable of highly efficient electrical transmission and long life, through tests conducted at the NASA Lewis Research Center and Honeywell's Satellite and Space Systems Division in Phoenix, AZ. Large potential fault currents inherent to the power system's DC distribution architecture, have brought about the need to evaluate the effects of large transient fault currents on roll rings. A test recently conducted at Lewis subjected a roll ring to a simulated worst case space station electrical fault. The system model used to obtain the fault profile is described, along with details of the reduced order circuit that was used to simulate the fault. Test results comparing roll ring performance before and after the fault are also presented.

  1. Ground roll attenuation using non-stationary matching filtering

    NASA Astrophysics Data System (ADS)

    Jiao, Shebao; Chen, Yangkang; Bai, Min; Yang, Wencheng; Wang, Erying; Gan, Shuwei

    2015-12-01

    Conventional approaches based on adaptive subtraction for ground roll attenuation first predict an initial model for ground rolls and then adaptively subtract it from the original data using a stationary matching filter (MF). Because of the non-stationary property of seismic data and ground rolls, the application of a traditional stationary MF is not physically plausible. Thus, in the case of highly non-stationary seismic reflections and ground rolls, a stationary MF cannot obtain satisfactory results. In this paper, we apply a non-stationary matching filter (NMF) to adaptively subtract the ground rolls. The NMF can be obtained by solving a highly under-determined inversion problem using non-stationary autoregression. We apply the proposed approach to one synthetic example and two field data examples, and demonstrate a much improved performance compared with the traditional MF approach.

  2. Calendering and Rolling of Viscoplastic Materials: Theory and Experiments

    NASA Astrophysics Data System (ADS)

    Mitsoulis, E.; Sofou, S.; Muliawan, E. B.; Hatzikiriakos, S. G.

    2007-04-01

    The calendering and rolling processes are used in a wide variety of industries for the production of rolled sheets or films of specific thickness and final appearance. The acquired final sheet thickness depends mainly on the rheological properties of the material. Materials which have been used in the present study are foodstuff (such as mozzarella cheese and flour-water dough) used in food processing. These materials are rheologically viscoplastic, obeying the Herschel-Bulkley model. The results give the final sheet thickness and the torque as a function of the roll speed. Theoretical analysis based on the Lubrication Approximation Theory (LAT) shows that LAT is a good predictive tool for calendering, where the sheet thickness is very small compared with the roll size. However, in rolling where this is not true, LAT does not hold, and a 2-D analysis is necessary.

  3. Roll waves in two-layer Hele-Shaw flows

    NASA Astrophysics Data System (ADS)

    Stepanova, I. V.; Chesnokov, A. A.; Liapidevskii, V. Yu

    2016-06-01

    In this paper we study the emergence and development of roll waves in two-layer fluid flow in a Hele-Shaw cell. We propose the mathematical model of such flow and define the conditions of transition from stable state to instability in the form of the roll waves. We find out the physical parameters of flows at which the roll waves exist. A linear stability analysis and the Whitham criterion of roll waves existence are used for solving the problem and arrive to identical conclusions on depths of upper and lower layers at which violation of flow stability occurs. The numerical calculations for the obtained mathematical model at found ratios of densities, viscosities and depths of layers are performed. They confirm development of the roll waves of finite amplitude from small oscillations of the interface.

  4. 75 FR 47263 - Certain Hot-Rolled Flat-Rolled Carbon-Quality Steel Products From the Russian Federation; Final...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-05

    ....'' \\1\\ See Initiation of Five-Year (``Sunset'') Review, 75 FR 16437 (April 1, 2010) (Notice of..., 75 FR 16437 (2010). Section 351.218(d)(1)(i) of the Department's regulations provides domestic... International Trade Administration Certain Hot-Rolled Flat-Rolled Carbon-Quality Steel Products From the...

  5. Flexure-based Roll-to-roll Platform: A Practical Solution for Realizing Large-area Microcontact Printing

    PubMed Central

    Zhou, Xi; Xu, Huihua; Cheng, Jiyi; Zhao, Ni; Chen, Shih-Chi

    2015-01-01

    A continuous roll-to-roll microcontact printing (MCP) platform promises large-area nanoscale patterning with significantly improved throughput and a great variety of applications, e.g. precision patterning of metals, bio-molecules, colloidal nanocrystals, etc. Compared with nanoimprint lithography, MCP does not require a thermal imprinting step (which limits the speed and material choices), but instead, extreme precision with multi-axis positioning and misalignment correction capabilities for large area adaptation. In this work, we exploit a flexure-based mechanism that enables continuous MCP with 500 nm precision and 0.05 N force control. The fully automated roll-to-roll platform is coupled with a new backfilling MCP chemistry optimized for high-speed patterning of gold and silver. Gratings of 300, 400, 600 nm line-width at various locations on a 4-inch plastic substrate are fabricated at a speed of 60 cm/min. Our work represents the first example of roll-to-roll MCP with high reproducibility, wafer scale production capability at nanometer resolution. The precision roll-to-roll platform can be readily applied to other material systems. PMID:26037147

  6. Planarization coating for polyimide substrates used in roll-to-roll fabrication of active matrix backplanes for flexible displays

    NASA Astrophysics Data System (ADS)

    Almanza-Workman, A. Marcia; Jeans, Albert; Braymen, Steve; Elder, Richard E.; Garcia, Robert A.; de la Fuente Vornbrock, Alejandro; Hauschildt, Jason; Holland, Edward; Jackson, Warren; Jam, Mehrban; Jeffrey, Frank; Junge, Kelly; Kim, Han-Jun; Kwon, Ohseung; Larson, Don; Luo, Hao; Maltabes, John; Mei, Ping; Perlov, Craig; Smith, Mark; Stieler, Dan; Taussig, Carl P.; Trovinger, Steve; Zhao, Lihua

    2012-03-01

    Good surface quality of plastic substrates is essential to reduce pixel defects during roll-to-roll fabrication of flexible display active matrix backplanes. Standard polyimide substrates have a high density of "bumps" from fillers and belt marks and other defects from dust and surface scratching. Some of these defects could be the source of shunts in dielectrics. The gate dielectric must prevent shorts between the source/drain and the gate in the transistors, resist shorts in the hold capacitor and stop shorts in the data/gate line crossovers in active matrix backplanes fabricated by self-aligned imprint lithography (SAIL) roll-to-roll processes. Otherwise data and gate lines will become shorted creating line or pixel defects. In this paper, we discuss the development of a proprietary UV curable planarization material that can be coated by roll-to-roll processes. This material was engineered to have low shrinkage, excellent adhesion to polyimide, high dry etch resistance, and great chemical and thermal stability. Results from PECVD deposition of an amorphous silicon stack on the planarized polyimide and compatibility with roll-to-roll processes to fabricate active matrix backplanes are also discussed. The effect of the planarization on defects in the stack, shunts in the dielectric and curvature of finished arrays will also be described.

  7. 75 FR 64700 - Certain Hot-Rolled Flat-Rolled Carbon-Quality Steel Products From Brazil: Preliminary Results of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-20

    ... FR 56040 (September 17, 2004) (HRS Order). The order was issued five years after the completion of...-Quality Steel Products from Brazil, 64 FR 38797 (July 19, 1999); see also Final Affirmative Countervailing Duty Determination: Certain Hot-Rolled Flat-Rolled Carbon-Quality Steel Products from Brazil, 64...

  8. Truck Roll Stability Data Collection and Analysis

    SciTech Connect

    Stevens, SS

    2001-07-02

    The principal objective of this project was to collect and analyze vehicle and highway data that are relevant to the problem of truck rollover crashes, and in particular to the subset of rollover crashes that are caused by the driver error of entering a curve at a speed too great to allow safe completion of the turn. The data are of two sorts--vehicle dynamic performance data, and highway geometry data as revealed by vehicle behavior in normal driving. Vehicle dynamic performance data are relevant because the roll stability of a tractor trailer depends both on inherent physical characteristics of the vehicle and on the weight and distribution of the particular cargo that is being carried. Highway geometric data are relevant because the set of crashes of primary interest to this study are caused by lateral acceleration demand in a curve that exceeds the instantaneous roll stability of the vehicle. An analysis of data quality requires an evaluation of the equipment used to collect the data because the reliability and accuracy of both the equipment and the data could profoundly affect the safety of the driver and other highway users. Therefore, a concomitant objective was an evaluation of the performance of the set of data-collection equipment on the truck and trailer. The objective concerning evaluation of the equipment was accomplished, but the results were not entirely positive. Significant engineering apparently remains to be done before a reliable system can be fielded. Problems were identified with the trailer to tractor fiber optic connector used for this test. In an over-the-road environment, the communication between the trailer instrumentation and the tractor must be dependable. In addition, the computer in the truck must be able to withstand the rigors of the road. The major objective--data collection and analysis--was also accomplished. Using data collected by instruments on the truck, a ''bad-curve'' database can be generated. Using this database

  9. Thermoresistive strain sensor and positioning method for roll-to-roll processes.

    PubMed

    Liao, Kuan-Hsun; Lo, Cheng-Yao

    2014-01-01

    This study uses the Joule heating effect-generated temperature difference to monitor in real-time and localize both compressive and tensile strains for the polymer substrates used in the roll-to-roll process. A serpentine gold (Au) line was patterned on a polyethylenenaphthalate (PEN) substrate to form the strain sensor based on thermoresistive behavior. This strain sensor was then subjected to either current or voltage to induce the Joule heating effect on the Au resistor. An infrared (IR) detector was used to monitor the strain-induced temperature difference on the Au and PEN surfaces and the minimal detectable bending radius was 0.9 mm with a gauge factor (GF) of 1.46. The proposed design eliminates the judgment ambiguity from conventional resistive strain sensors where resistance is the only physical quantity monitored. This study precisely and successfully indicated the local strain quantitatively and qualitatively with complete simulations and measurements. PMID:24803196

  10. Investigation of pattern transfer to piezoelectric jetted polymer using roll-to-roll nanoimprint lithography

    NASA Astrophysics Data System (ADS)

    Menezes, Shannon John

    Nanoimprint Lithography (NIL) has existed since the mid 1990s as a proven concept of creating micro- and nanostructures using direct mechanical pattern transfer. Initially seen as a viable option to replace conventional lithography methods, the lack of technology to support large-scale manufacturing using NIL has motivated researchers to explore the application of NIL to create a better, more cost-efficient process with the ability to integrate NIL into a mass manufacturing system. One such method is the roll-to-roll process, similar to that used in printing presses of newspapers and plastics. This thesis is an investigation to characterize polymer deposition using a piezoelectric jetting head and attempt to create micro- and nanostructures on the polymer using R2RNIL technique.

  11. Roll-to-Roll Production of Spray Coated N-doped Carbon Nanotube Electrodes for Supercapacitors

    NASA Astrophysics Data System (ADS)

    Karakaya, Mehmet; Zhu, Jingyi; Raghavendra, Achyut; Podila, Ramakrishna; Parler, Samuel; Kaplan, James; Rao, Apparao; Cornell Dubilier Electronics, Inc. Collaboration

    2015-03-01

    Although nanocarbons are being increasingly used in energy storage, there has been a lack of inexpensive, continuous and scalable synthesis methods. Here we present a scalable roll-to-roll spray coating process for synthesizing supercapacitors from randomly oriented multi-walled carbon nanotubes electrodes on Al foils, which yield high power and energy densities (~ 700 mW/cm3 and 1 mWh/cm3) and cycle stability (>10000 cycles) on par with Li-ion thin film batteries. Our cost analysis shows that the R2R spray coating process can produce supercapacitors with 10 times the energy density of conventional activated carbon devices at ~ 17% lower cost. NSF CMMI SNM Award #1246800.

  12. Roll-to-roll production of spray coated N-doped carbon nanotube electrodes for supercapacitors

    NASA Astrophysics Data System (ADS)

    Karakaya, Mehmet; Zhu, Jingyi; Raghavendra, Achyut J.; Podila, Ramakrishna; Parler, Samuel G.; Kaplan, James P.; Rao, Apparao M.

    2014-12-01

    Although carbon nanomaterials are being increasingly used in energy storage, there has been a lack of inexpensive, continuous, and scalable synthesis methods. Here, we present a scalable roll-to-roll (R2R) spray coating process for synthesizing randomly oriented multi-walled carbon nanotubes electrodes on Al foils. The coin and jellyroll type supercapacitors comprised such electrodes yield high power densities (˜700 mW/cm3) and energy densities (1 mW h/cm3) on par with Li-ion thin film batteries. These devices exhibit excellent cycle stability with no loss in performance over more than a thousand cycles. Our cost analysis shows that the R2R spray coating process can produce supercapacitors with 10 times the energy density of conventional activated carbon devices at ˜17% lower cost.

  13. Cotton-textile-enabled flexible self-sustaining power packs via roll-to-roll fabrication.

    PubMed

    Gao, Zan; Bumgardner, Clifton; Song, Ningning; Zhang, Yunya; Li, Jingjing; Li, Xiaodong

    2016-01-01

    With rising energy concerns, efficient energy conversion and storage devices are required to provide a sustainable, green energy supply. Solar cells hold promise as energy conversion devices due to their utilization of readily accessible solar energy; however, the output of solar cells can be non-continuous and unstable. Therefore, it is necessary to combine solar cells with compatible energy storage devices to realize a stable power supply. To this end, supercapacitors, highly efficient energy storage devices, can be integrated with solar cells to mitigate the power fluctuations. Here, we report on the development of a solar cell-supercapacitor hybrid device as a solution to this energy requirement. A high-performance, cotton-textile-enabled asymmetric supercapacitor is integrated with a flexible solar cell via a scalable roll-to-roll manufacturing approach to fabricate a self-sustaining power pack, demonstrating its potential to continuously power future electronic devices.

  14. Cotton-textile-enabled flexible self-sustaining power packs via roll-to-roll fabrication

    PubMed Central

    Gao, Zan; Bumgardner, Clifton; Song, Ningning; Zhang, Yunya; Li, Jingjing; Li, Xiaodong

    2016-01-01

    With rising energy concerns, efficient energy conversion and storage devices are required to provide a sustainable, green energy supply. Solar cells hold promise as energy conversion devices due to their utilization of readily accessible solar energy; however, the output of solar cells can be non-continuous and unstable. Therefore, it is necessary to combine solar cells with compatible energy storage devices to realize a stable power supply. To this end, supercapacitors, highly efficient energy storage devices, can be integrated with solar cells to mitigate the power fluctuations. Here, we report on the development of a solar cell-supercapacitor hybrid device as a solution to this energy requirement. A high-performance, cotton-textile-enabled asymmetric supercapacitor is integrated with a flexible solar cell via a scalable roll-to-roll manufacturing approach to fabricate a self-sustaining power pack, demonstrating its potential to continuously power future electronic devices. PMID:27189776

  15. Integrated optical interconnection for polymeric planar lightwave circuit device using roll-to-roll ultraviolet imprint

    NASA Astrophysics Data System (ADS)

    Cho, Sang Uk; Kang, Ho Ju; Chang, Sunghwan; Choi, Doo-sun; Kim, Chang-Seok; Jeong, Myung Yung

    2014-08-01

    We propose an integrated structure that combines chip and fiber array blocks for optical interconnection with a polymeric planar lightwave circuit (PLC) device using the roll-to-roll imprint process. The fiber array blocks and PLC chip of the integrated structure are fabricated on the same substrate, and the alignments in the three spatial directions were established with the insertion of an optical fiber. The characteristics of the integrated structure were evaluated by fabricating a 1×2 optical splitter device. The structure had an insertion loss of 3.9 dB, and the optical uniformity of the channel was 0.1 dB, indicating that the same performance for an active alignment can be expected.

  16. Noncontact conductivity and dielectric measurement for high throughput roll-to-roll nanomanufacturing

    PubMed Central

    Orloff, Nathan D.; Long, Christian J.; Obrzut, Jan; Maillaud, Laurent; Mirri, Francesca; Kole, Thomas P.; McMichael, Robert D.; Pasquali, Matteo; Stranick, Stephan J.; Alexander Liddle, J.

    2015-01-01

    Advances in roll-to-roll processing of graphene and carbon nanotubes have at last led to the continuous production of high-quality coatings and filaments, ushering in a wave of applications for flexible and wearable electronics, woven fabrics, and wires. These applications often require specific electrical properties, and hence precise control over material micro- and nanostructure. While such control can be achieved, in principle, by closed-loop processing methods, there are relatively few noncontact and nondestructive options for quantifying the electrical properties of materials on a moving web at the speed required in modern nanomanufacturing. Here, we demonstrate a noncontact microwave method for measuring the dielectric constant and conductivity (or geometry for samples of known dielectric properties) of materials in a millisecond. Such measurement times are compatible with current and future industrial needs, enabling real-time materials characterization and in-line control of processing variables without disrupting production. PMID:26592441

  17. Cotton-textile-enabled flexible self-sustaining power packs via roll-to-roll fabrication

    NASA Astrophysics Data System (ADS)

    Gao, Zan; Bumgardner, Clifton; Song, Ningning; Zhang, Yunya; Li, Jingjing; Li, Xiaodong

    2016-05-01

    With rising energy concerns, efficient energy conversion and storage devices are required to provide a sustainable, green energy supply. Solar cells hold promise as energy conversion devices due to their utilization of readily accessible solar energy; however, the output of solar cells can be non-continuous and unstable. Therefore, it is necessary to combine solar cells with compatible energy storage devices to realize a stable power supply. To this end, supercapacitors, highly efficient energy storage devices, can be integrated with solar cells to mitigate the power fluctuations. Here, we report on the development of a solar cell-supercapacitor hybrid device as a solution to this energy requirement. A high-performance, cotton-textile-enabled asymmetric supercapacitor is integrated with a flexible solar cell via a scalable roll-to-roll manufacturing approach to fabricate a self-sustaining power pack, demonstrating its potential to continuously power future electronic devices.

  18. Noncontact conductivity and dielectric measurement for high throughput roll-to-roll nanomanufacturing.

    PubMed

    Orloff, Nathan D; Long, Christian J; Obrzut, Jan; Maillaud, Laurent; Mirri, Francesca; Kole, Thomas P; McMichael, Robert D; Pasquali, Matteo; Stranick, Stephan J; Liddle, J Alexander

    2015-01-01

    Advances in roll-to-roll processing of graphene and carbon nanotubes have at last led to the continuous production of high-quality coatings and filaments, ushering in a wave of applications for flexible and wearable electronics, woven fabrics, and wires. These applications often require specific electrical properties, and hence precise control over material micro- and nanostructure. While such control can be achieved, in principle, by closed-loop processing methods, there are relatively few noncontact and nondestructive options for quantifying the electrical properties of materials on a moving web at the speed required in modern nanomanufacturing. Here, we demonstrate a noncontact microwave method for measuring the dielectric constant and conductivity (or geometry for samples of known dielectric properties) of materials in a millisecond. Such measurement times are compatible with current and future industrial needs, enabling real-time materials characterization and in-line control of processing variables without disrupting production. PMID:26592441

  19. Noncontact conductivity and dielectric measurement for high throughput roll-to-roll nanomanufacturing

    NASA Astrophysics Data System (ADS)

    Orloff, Nathan D.; Long, Christian J.; Obrzut, Jan; Maillaud, Laurent; Mirri, Francesca; Kole, Thomas P.; McMichael, Robert D.; Pasquali, Matteo; Stranick, Stephan J.; Alexander Liddle, J.

    2015-11-01

    Advances in roll-to-roll processing of graphene and carbon nanotubes have at last led to the continuous production of high-quality coatings and filaments, ushering in a wave of applications for flexible and wearable electronics, woven fabrics, and wires. These applications often require specific electrical properties, and hence precise control over material micro- and nanostructure. While such control can be achieved, in principle, by closed-loop processing methods, there are relatively few noncontact and nondestructive options for quantifying the electrical properties of materials on a moving web at the speed required in modern nanomanufacturing. Here, we demonstrate a noncontact microwave method for measuring the dielectric constant and conductivity (or geometry for samples of known dielectric properties) of materials in a millisecond. Such measurement times are compatible with current and future industrial needs, enabling real-time materials characterization and in-line control of processing variables without disrupting production.

  20. Cotton-textile-enabled flexible self-sustaining power packs via roll-to-roll fabrication.

    PubMed

    Gao, Zan; Bumgardner, Clifton; Song, Ningning; Zhang, Yunya; Li, Jingjing; Li, Xiaodong

    2016-01-01

    With rising energy concerns, efficient energy conversion and storage devices are required to provide a sustainable, green energy supply. Solar cells hold promise as energy conversion devices due to their utilization of readily accessible solar energy; however, the output of solar cells can be non-continuous and unstable. Therefore, it is necessary to combine solar cells with compatible energy storage devices to realize a stable power supply. To this end, supercapacitors, highly efficient energy storage devices, can be integrated with solar cells to mitigate the power fluctuations. Here, we report on the development of a solar cell-supercapacitor hybrid device as a solution to this energy requirement. A high-performance, cotton-textile-enabled asymmetric supercapacitor is integrated with a flexible solar cell via a scalable roll-to-roll manufacturing approach to fabricate a self-sustaining power pack, demonstrating its potential to continuously power future electronic devices. PMID:27189776

  1. Rocking and rolling: A can that appears to rock might actually roll

    NASA Astrophysics Data System (ADS)

    Srinivasan, Manoj; Ruina, Andy

    2008-12-01

    A beer bottle or soda can on a table, when slightly tipped and released, falls to an upright position and then rocks up to a somewhat opposite tilt. Superficially this rocking motion involves a collision when the flat circular base of the container slaps the table before rocking up to the opposite tilt. A keen eye notices that the after-slap rising tilt is not generally just diametrically opposite the initial tilt but is veered to one side or the other. Cushman and Duistermaat [Regular Chaotic Dyn. 11, 31 (2006)] recently noticed such veering when a flat disk with rolling boundary conditions is dropped nearly flat. Here, we generalize these rolling disk results to arbitrary axi-symmetric bodies and to frictionless sliding. More specifically, we study motions that almost but do not quite involve a face-down collision of the round container’s bottom with the tabletop. These motions involve a sudden rapid motion of the contact point around the circular base. Surprisingly, similar to the rolling disk, the net angle of motion of this contact point is nearly independent of initial conditions. This angle of turn depends simply on the geometry and mass distribution but not on the moment of inertia about the symmetry axis. We derive simple asymptotic formulas for this “angle of turn” of the contact point and check the result with numerics and with simple experiments. For tall containers (height much bigger than radius) the angle of turn is just over π and the sudden rolling motion superficially appears as a nearly symmetric collision leading to leaning on an almost diametrically opposite point on the bottom rim.

  2. Cyclic statistics in rolling bearing diagnosis

    NASA Astrophysics Data System (ADS)

    Li, Li; Qu, Liangsheng

    2003-10-01

    Mechanical signals with amplitude modulated are characterized by periodic time-varying ensemble statistics and can be considered as cyclostationary. In this paper, the second order cyclic statistics, i.e. cyclic autocorrelation and cyclic spectrum, are introduced. A method of demodulation based on cyclic autocorrelation is derived from a signal model. The modulators and carrier are exhibited, respectively, in low- and high-frequency band of cyclic frequency domain. The three-dimensional spectral correlation figure, which represents cyclic frequency, frequency and spectral correlation strength simultaneously, is developed to express the demodulation results clearly. The method is tested by simulation signal and applied to diagnose rolling bearing faults. It obtained more information than other conventional methods, such as the frequency domain and the envelop detection. Furthermore, its effect is demonstrated by comparing with the wavelet envelope demodulation.

  3. Adaptive Prognostics for Rolling Element Bearing Condition

    NASA Astrophysics Data System (ADS)

    Li, Y.; Billington, S.; Zhang, C.; Kurfess, T.; Danyluk, S.; Liang, S.

    1999-01-01

    Rolling element bearing failure is one of the foremost causes of breakdown in rotating machinery. This paper proposes a remaining life adaptation methodology based on mechanistic modeling and parameter tuning. Vibration measurement is used to estimate defect severity by monitoring the signals generated from rotating bearings. Through a defect propagation model and defect diagnostic model, an adaptive algorithm is developed to fine tune the parameters involved in the propagation model by comparing predicted and measured defect sizes. In this manner, the instantaneous rate of defect propagation can be captured despite defect growth behavior variation. Therefore, a precise estimation of the remaining life can be determined. Simulations and experimental results are presented to illustrate the implementation principles and to verify the applicability of the adaptive prognostic methodology.

  4. Modeling of rolling element bearing mechanics

    NASA Technical Reports Server (NTRS)

    Greenhill, L. M.

    1991-01-01

    Roller element bearings provide the primary mechanical interface between rotating and nonrotating components in the high performance turbomachinery of the Space Shuttle Main Engine (SSME). Knowledge of bearing behavior under various loading and environmental conditions is essential to predicting and understanding the overall behavior of turbopumps, including rotordynamic stability, critical speeds and bearing life. The objective is to develop mathematical models and computer programs to describe the mechanical behavior of ball and cylinder roller bearings under the loading and environmental conditions encountered in the SSME and future high performance rocket engines. This includes characteristics such as nonlinear load/motion relationships, stiffness and damping, rolling element loads for life prediction, and roller and cage stability.

  5. Controlled Microwave Heating Accelerates Rolling Circle Amplification.

    PubMed

    Yoshimura, Takeo; Suzuki, Takamasa; Mineki, Shigeru; Ohuchi, Shokichi

    2015-01-01

    Rolling circle amplification (RCA) generates single-stranded DNAs or RNA, and the diverse applications of this isothermal technique range from the sensitive detection of nucleic acids to analysis of single nucleotide polymorphisms. Microwave chemistry is widely applied to increase reaction rate as well as product yield and purity. The objectives of the present research were to apply microwave heating to RCA and indicate factors that contribute to the microwave selective heating effect. The microwave reaction temperature was strictly controlled using a microwave applicator optimized for enzymatic-scale reactions. Here, we showed that microwave-assisted RCA reactions catalyzed by either of the four thermostable DNA polymerases were accelerated over 4-folds compared with conventional RCA. Furthermore, the temperatures of the individual buffer components were specifically influenced by microwave heating. We concluded that microwave heating accelerated isothermal RCA of DNA because of the differential heating mechanisms of microwaves on the temperatures of reaction components, although the overall reaction temperatures were the same.

  6. Roll up nanowire battery from silicon chips.

    PubMed

    Vlad, Alexandru; Reddy, Arava Leela Mohana; Ajayan, Anakha; Singh, Neelam; Gohy, Jean-François; Melinte, Sorin; Ajayan, Pulickel M

    2012-09-18

    Here we report an approach to roll out Li-ion battery components from silicon chips by a continuous and repeatable etch-infiltrate-peel cycle. Vertically aligned silicon nanowires etched from recycled silicon wafers are captured in a polymer matrix that operates as Li(+) gel-electrolyte and electrode separator and peeled off to make multiple battery devices out of a single wafer. Porous, electrically interconnected copper nanoshells are conformally deposited around the silicon nanowires to stabilize the electrodes over extended cycles and provide efficient current collection. Using the above developed process we demonstrate an operational full cell 3.4 V lithium-polymer silicon nanowire (LIPOSIL) battery which is mechanically flexible and scalable to large dimensions.

  7. Rolling element fatigue testing of gear materials

    NASA Technical Reports Server (NTRS)

    Nahm, A. H.

    1978-01-01

    Rolling element fatigue lives of eleven alloys were evaluated. The eleven alloys studied were three nitriding alloys (Super Nitralloy, Nitralloy 135, and Nitralloy N), four case carburizing alloys (AISI 9310, CBS 600, CBS 1000M and Vasco X-2), and four throughhardening alloys (Vasco Matrix II,AISI W-1, AISI S-2 and AISI O-2). Several different heat treatments and/or melting processes were studied on the three carburizing alloy steels. Metallurgical analyses were made before and after the RC rig tests. Test data were statistically analyzed using the Weibull distribution function. B-10 lives were compared versus VIM-VAR AISI M-50 and carburized VAR AISI 9310, as reference alloys.

  8. Roll up nanowire battery from silicon chips

    PubMed Central

    Vlad, Alexandru; Reddy, Arava Leela Mohana; Ajayan, Anakha; Singh, Neelam; Gohy, Jean-François; Melinte, Sorin; Ajayan, Pulickel M.

    2012-01-01

    Here we report an approach to roll out Li-ion battery components from silicon chips by a continuous and repeatable etch-infiltrate-peel cycle. Vertically aligned silicon nanowires etched from recycled silicon wafers are captured in a polymer matrix that operates as Li+ gel-electrolyte and electrode separator and peeled off to make multiple battery devices out of a single wafer. Porous, electrically interconnected copper nanoshells are conformally deposited around the silicon nanowires to stabilize the electrodes over extended cycles and provide efficient current collection. Using the above developed process we demonstrate an operational full cell 3.4 V lithium-polymer silicon nanowire (LIPOSIL) battery which is mechanically flexible and scalable to large dimensions. PMID:22949696

  9. Heat pipes made of roll bond panels

    NASA Astrophysics Data System (ADS)

    Moeller, M.; Heil, K.

    1983-06-01

    The use of large surfaced aluminum roll bond panels with an integral flow system as heat pipes is studied. With a suitable flow system e.g., parallel passages with a cross-connection, one single filling procedure is required for the operating medium. Adequate materials for the manufacture of heat pipes are Al 99,3; AlMn1, 5 and AlMn1, 5Sil,5. Peel, creep and burst tests as well as corrosion tests were made on specimens and structural elements of these materials. Results show that the use of such panels for heat pipe manufacturing is appropriate for limited maximum temperature applications. Prototypes of heat pipes and their characteristic features are described in view of their use as absorbers in solar collectors. Good heat exchange performances obtained.

  10. Micro-miniature roll rate sensor

    NASA Astrophysics Data System (ADS)

    Grant, Jonathan; Nelson, Bruce; Garnes, George

    1989-11-01

    The Phase 2 Micro-Miniature Roll Rate Sensor Program developed an optical centripetal accelerometer that can be tailored to work over a wide range of accelerations. A rate sensing device was developed by measuring centripetal acceleration due to rotation with a proof mass loading a photoelastic sensing element. The acceleration is proportional to the amount of birefringence induced by the load. Development of this technology resulted in construction of a prototype rate sensor targeted for use with the Copperhead munition. The sensors developed in this program can be adjusted for the desired range of operation through changes in width of a photoelastic (plastic) sensing element and/or changes in the amount of proof mass used to load the sensing element. Radial location of the sensor can also be used to control the range.

  11. Antireflective surface patterned by rolling mask lithography

    NASA Astrophysics Data System (ADS)

    Seitz, Oliver; Geddes, Joseph B.; Aryal, Mukti; Perez, Joseph; Wassei, Jonathan; McMackin, Ian; Kobrin, Boris

    2014-03-01

    A growing number of commercial products such as displays, solar panels, light emitting diodes (LEDs and OLEDs), automotive and architectural glass are driving demand for glass with high performance surfaces that offer anti-reflective, self-cleaning, and other advanced functions. State-of-the-art coatings do not meet the desired performance characteristics or cannot be applied over large areas in a cost-effective manner. "Rolling Mask Lithography" (RML™) enables highresolution lithographic nano-patterning over large-areas at low-cost and high-throughput. RML is a photolithographic process performed using ultraviolet (UV) illumination transmitted through a soft cylindrical mask as it rolls across a substrate. Subsequent transfer of photoresist patterns into the substrate is achieved using an etching process, which creates a nanostructured surface. The current generation exposure tool is capable of patterning one-meter long substrates with a width of 300 mm. High-throughput and low-cost are achieved using continuous exposure of the resist by the cylindrical photomask. Here, we report on significant improvements in the application of RML™ to fabricate anti-reflective surfaces. Briefly, an optical surface can be made antireflective by "texturing" it with a nano-scale pattern to reduce the discontinuity in the index of refraction between the air and the bulk optical material. An array of cones, similar to the structure of a moth's eye, performs this way. Substrates are patterned using RML™ and etched to produce an array of cones with an aspect ratio of 3:1, which decreases the reflectivity below 0.1%.

  12. Rolling contact fatigue and fracture toughness of rolling element bearing materials

    NASA Astrophysics Data System (ADS)

    Tsushima, Noriyuki

    1993-03-01

    To clarify rolling contact fatigue strength in terms of fracture mechanics, various flaking modes in practical rolling bearings, the relationship between rolling contact fatigue life and fracture toughness in Mode I, and recent studies on crack initiation and propagation through fracture mechanics are reviewed. Surface-origin-type flaking is becoming more important than the traditional subsurface-origin type as nonmetallic inclusion in steels is reduced. A new flaking mechanism wherein tensile residual stress in the radial direction in the subsurface initiates cracking has emerged and was verified by an experiment. Another new type of flaking, referred to as brittle flaking, was reported; here cracks are remarkably numerous, large and deep, accompanied by a new type of microstructural change. The cause of the brittle flaking was assumed to be tribological reaction on the raceway which decomposes the lubricant to cause hydrogen embrittlement. To establish a new bearing life calculation equation, it is necessary to create proper models for the various failure modes and to measure fracture toughness in Mode II.

  13. Semi-Rolled Leaf2 modulates rice leaf rolling by regulating abaxial side cell differentiation.

    PubMed

    Liu, Xiaofei; Li, Ming; Liu, Kai; Tang, Ding; Sun, Mingfa; Li, Yafei; Shen, Yi; Du, Guijie; Cheng, Zhukuan

    2016-04-01

    Moderate leaf rolling maintains the erectness of leaves and minimizes the shadowing between leaves which is helpful to establish ideal plant architecture. Here, we describe asrl2(semi-rolled leaf2) rice mutant, which has incurved leaves due to the presence of defective sclerenchymatous cells on the abaxial side of the leaf and displays narrow leaves and reduced plant height. Map-based cloning revealed that SRL2 encodes a novel plant-specific protein of unknown biochemical function.SRL2 was mainly expressed in the vascular bundles of leaf blades, leaf sheaths, and roots, especially in their sclerenchymatous cells. The transcriptional activities of several leaf development-related YABBY genes were significantly altered in the srl2 mutant. Double mutant analysis suggested that SRL2 and SHALLOT-LIKE1(SLL1)/ROLLED LEAF9(RL9) function in distinct pathways that regulate abaxial-side leaf development. Hence, SRL2 plays an important role in regulating leaf development, particularly during sclerenchymatous cell differentiation.

  14. Semi-Rolled Leaf2 modulates rice leaf rolling by regulating abaxial side cell differentiation

    PubMed Central

    Liu, Xiaofei; Li, Ming; Liu, Kai; Tang, Ding; Sun, Mingfa; Li, Yafei; Shen, Yi; Du, Guijie; Cheng, Zhukuan

    2016-01-01

    Moderate leaf rolling maintains the erectness of leaves and minimizes the shadowing between leaves which is helpful to establish ideal plant architecture. Here, we describe a srl2 (semi-rolled leaf2) rice mutant, which has incurved leaves due to the presence of defective sclerenchymatous cells on the abaxial side of the leaf and displays narrow leaves and reduced plant height. Map-based cloning revealed that SRL2 encodes a novel plant-specific protein of unknown biochemical function. SRL2 was mainly expressed in the vascular bundles of leaf blades, leaf sheaths, and roots, especially in their sclerenchymatous cells. The transcriptional activities of several leaf development-related YABBY genes were significantly altered in the srl2 mutant. Double mutant analysis suggested that SRL2 and SHALLOT-LIKE1 (SLL1)/ROLLED LEAF9 (RL9) function in distinct pathways that regulate abaxial-side leaf development. Hence, SRL2 plays an important role in regulating leaf development, particularly during sclerenchymatous cell differentiation. PMID:26873975

  15. Semi-Rolled Leaf2 modulates rice leaf rolling by regulating abaxial side cell differentiation.

    PubMed

    Liu, Xiaofei; Li, Ming; Liu, Kai; Tang, Ding; Sun, Mingfa; Li, Yafei; Shen, Yi; Du, Guijie; Cheng, Zhukuan

    2016-04-01

    Moderate leaf rolling maintains the erectness of leaves and minimizes the shadowing between leaves which is helpful to establish ideal plant architecture. Here, we describe asrl2(semi-rolled leaf2) rice mutant, which has incurved leaves due to the presence of defective sclerenchymatous cells on the abaxial side of the leaf and displays narrow leaves and reduced plant height. Map-based cloning revealed that SRL2 encodes a novel plant-specific protein of unknown biochemical function.SRL2 was mainly expressed in the vascular bundles of leaf blades, leaf sheaths, and roots, especially in their sclerenchymatous cells. The transcriptional activities of several leaf development-related YABBY genes were significantly altered in the srl2 mutant. Double mutant analysis suggested that SRL2 and SHALLOT-LIKE1(SLL1)/ROLLED LEAF9(RL9) function in distinct pathways that regulate abaxial-side leaf development. Hence, SRL2 plays an important role in regulating leaf development, particularly during sclerenchymatous cell differentiation. PMID:26873975

  16. Dynamics of neutrophil rolling over stimulated endothelium in vitro.

    PubMed Central

    Goetz, D J; el-Sabban, M E; Pauli, B U; Hammer, D A

    1994-01-01

    Prior to extravasation at sites of acute inflammation, neutrophils roll over activated endothelium. Neutrophil rolling is often characterized by the average rolling velocity. An additional dynamic feature of rolling that has been identified but not extensively studied is the fluctuation in the rolling velocity about the average. To analyze this characteristic further, we have measured the instantaneous velocity of bovine neutrophils interacting with lipopolysaccharide-stimulated bovine aortic endothelium at shear stresses of 1, 2, 3, and 4 dynes/cm2. The average velocities are quantitatively similar to those reported for human neutrophils rolling over reconstituted P-selectin at a surface density of 400 sites/microns 2. At all shear stresses tested, the population average variance in the instantaneous velocity is at least 2 orders of magnitude higher than the theoretical variance generated from experimental error, indicating that the neutrophils translate with a nonconstant velocity. Possible sources of the variance are discussed. These include "macroscopic" sources such as topological heterogeneity in the endothelium and microscopic sources, such as inherent stochastic formation and breakage of the receptor-ligand bonds that mediate the rolling. Regardless of the ultimate source of the variance, these results justify the use of mathematical models that incorporate stochastic processes to describe bond formation and breakage between the neutrophil and the endothelium and hence are able to generate variable velocity trajectories. Images FIGURE 3 PMID:7521229

  17. Rolling behavior of a micro-cylinder in adhesional contact

    PubMed Central

    Saito, Shigeki; Ochiai, Toshihiro; Yoshizawa, Fumikazu; Dao, Ming

    2016-01-01

    Understanding the rolling behavior of a micro-object is essential to establish the techniques of micro-manipulation and micro-assembly by mechanical means. Using a combined theoretical/computational approach, we studied the critical conditions of rolling resistance of an elastic cylindrical micro-object in adhesional contact with a rigid surface. Closed-form dimensionless expressions for the critical rolling moment, the initial rolling contact area, and the initial rolling angle were extracted after a systematic parametric study using finite element method (FEM) simulations. The total energy of this system is defined as the sum of three terms: the elastic energy stored in the deformed micro-cylinder, the interfacial energy within the contact area, and the mechanical potential energy that depends on the external moment applied to the cylindrical micro-object. A careful examination of the energy balance of the system surprisingly revealed that the rolling resistance per unit cylindrical length can be simply expressed by “work of adhesion times cylindrical radius” independent of the Young’s modulus. In addition, extending a linear elastic fracture mechanics based approach in the literature, we obtained the exact closed-form asymptotic solutions for the critical conditions for initial rolling; these asymptotic solutions were found in excellent agreement with the full-field FEM results. PMID:27677706

  18. Engineering nanoscale surface features to sustain microparticle rolling in flow.

    PubMed

    Kalasin, Surachate; Santore, Maria M

    2015-05-26

    Nanoscopic features of channel walls are often engineered to facilitate microfluidic transport, for instance when surface charge enables electro-osmosis or when grooves drive mixing. The dynamic or rolling adhesion of flowing microparticles on a channel wall holds potential to accomplish particle sorting or to selectively transfer reactive species or signals between the wall and flowing particles. Inspired by cell rolling under the direction of adhesion molecules called selectins, we present an engineered platform in which the rolling of flowing microparticles is sustained through the incorporation of entirely synthetic, discrete, nanoscale, attractive features into the nonadhesive (electrostatically repulsive) surface of a flow channel. Focusing on one example or type of nanoscale feature and probing the impact of broad systematic variations in surface feature loading and processing parameters, this study demonstrates how relatively flat, weakly adhesive nanoscale features, positioned with average spacings on the order of tens of nanometers, can produce sustained microparticle rolling. We further demonstrate how the rolling velocity and travel distance depend on flow and surface design. We identify classes of related surfaces that fail to support rolling and present a state space that identifies combinations of surface and processing variables corresponding to transitions between rolling, free particle motion, and arrest. Finally we identify combinations of parameters (surface length scales, particle size, flow rates) where particles can be manipulated with size-selectivity.

  19. Characteristics of electrohydrodynamic roll structures in laminar planar Couette flow

    NASA Astrophysics Data System (ADS)

    Kourmatzis, Agisilaos; Shrimpton, John S.

    2016-02-01

    The behaviour of an incompressible dielectric liquid subjected to a laminar planar Couette flow with unipolar charge injection is investigated numerically in two dimensions. The computations show new morphological characteristics of roll structures that arise in this forced electro-convection problem. The charge and velocity magnitude distributions between the two parallel electrodes are discussed as a function of the top wall velocity and the EHD Rayleigh number, T for the case of strong charge injection. A wide enough parametric space is investigated such that the observed EHD roll structures progress through three regimes. These regimes are defined by the presence of a single or double-roll free convective structure as observed elsewhere (Vazquez et al 2008 J. Phys. D 41 175303), a sheared or stretched roll structure, and finally by a regime where the perpendicular velocity gradient is sufficient to prevent the generation of a roll. These three regimes have been delineated as a function of the wall to ionic drift velocity {{U}\\text{W}}/κ E , and the T number. In the stretched regime, an increase in {{U}\\text{W}}/κ E can reduce charge and momentum fluctuations whilst in parallel de-stratify charge in the region between the two electrodes. The stretched roll regime is also characterised by a substantial influence of {{U}\\text{W}}/κ E on the steady development time, however in the traditional non-stretched roll structure regime, no influence of {{U}\\text{W}}/κ E on the development time is noted.

  20. Optimization of Resilient Wheels for Rolling Noise Control

    NASA Astrophysics Data System (ADS)

    BOUVET, PASCAL; VINCENT, NICOLAS; COBLENTZ, ARNAUD; DEMILLY, FRANÇOIS

    2000-03-01

    Resilient wheels are currently used on light rail systems such as tramways to prevent squealing noise and to reduce impact noise. On the other hand, they are rarely found on main lines (passenger rolling stock and freight rolling stock). Although manufacturers often claim that resilient wheels are favourable for rolling noise control, no extensive theoretical investigation confirming this statement has been published to date. In this paper, it is shown how resilient wheels can be effectively optimised in order to reduce rolling noise emission, compared to a conventional monobloc wheel. A preliminary analysis of the physical phenomena accounting for rolling noise generation emphasizes the key design parameters affecting both wheel and radiation. These parameters are the radial dynamic stiffness and damping loss factor of the rubber layer. The tread mass is also relevant. The influence of these design parameters is then qualified by a parametric study performed with the TWINS software. An optimum radial dynamic stiffness of the resilient layer is found which depends on operating conditions. Reductions in overall rolling noise up to 3 dB(A) are calculated for the configurations investigated. However, poor selection of the design parameters can lead to a noise increase compared to a standard monobloc wheel. It is also shown that a proper design for rolling noise control will not affect wheel efficiency with regard to squeal noise.

  1. Visually guided adjustments of body posture in the roll plane.

    PubMed

    Tarnutzer, A A; Bockisch, C J; Straumann, D

    2013-05-01

    Body position relative to gravity is continuously updated to prevent falls. Therefore, the brain integrates input from the otoliths, truncal graviceptors, proprioception and vision. Without visual cues estimated direction of gravity mainly depends on otolith input and becomes more variable with increasing roll-tilt. Contrary, the discrimination threshold for object orientation shows little modulation with varying roll orientation of the visual stimulus. Providing earth-stationary visual cues, this retinal input may be sufficient to perform self-adjustment tasks successfully, with resulting variability being independent of whole-body roll orientation. We compared conditions with informative (earth-fixed) and non-informative (body-fixed) visual cues. If the brain uses exclusively retinal input (if earth-stationary) to solve the task, trial-to-trial variability will be independent from the subject's roll orientation. Alternatively, central integration of both retinal (earth-fixed) and extra-retinal inputs will lead to increasing variability when roll-tilted. Subjects, seated on a motorized chair, were instructed to (1) align themselves parallel to an earth-fixed line oriented earth-vertical or roll-tilted 75° clockwise; (2) move a body-fixed line (aligned with the body-longitudinal axis or roll-tilted 75° counter-clockwise to it) by adjusting their body position until the line was perceived earth-vertical. At 75° right-ear-down position, variability increased significantly (p < 0.05) compared to upright in both paradigms, suggesting that, despite the earth-stationary retinal cues, extra-retinal input is integrated. Self-adjustments in the roll-tilted position were significantly (p < 0.01) more precise for earth-fixed cues than for body-fixed cues, underlining the importance of earth-stable visual cues when estimates of gravity become more variable with increasing whole-body roll. PMID:23535837

  2. Visually guided adjustments of body posture in the roll plane.

    PubMed

    Tarnutzer, A A; Bockisch, C J; Straumann, D

    2013-05-01

    Body position relative to gravity is continuously updated to prevent falls. Therefore, the brain integrates input from the otoliths, truncal graviceptors, proprioception and vision. Without visual cues estimated direction of gravity mainly depends on otolith input and becomes more variable with increasing roll-tilt. Contrary, the discrimination threshold for object orientation shows little modulation with varying roll orientation of the visual stimulus. Providing earth-stationary visual cues, this retinal input may be sufficient to perform self-adjustment tasks successfully, with resulting variability being independent of whole-body roll orientation. We compared conditions with informative (earth-fixed) and non-informative (body-fixed) visual cues. If the brain uses exclusively retinal input (if earth-stationary) to solve the task, trial-to-trial variability will be independent from the subject's roll orientation. Alternatively, central integration of both retinal (earth-fixed) and extra-retinal inputs will lead to increasing variability when roll-tilted. Subjects, seated on a motorized chair, were instructed to (1) align themselves parallel to an earth-fixed line oriented earth-vertical or roll-tilted 75° clockwise; (2) move a body-fixed line (aligned with the body-longitudinal axis or roll-tilted 75° counter-clockwise to it) by adjusting their body position until the line was perceived earth-vertical. At 75° right-ear-down position, variability increased significantly (p < 0.05) compared to upright in both paradigms, suggesting that, despite the earth-stationary retinal cues, extra-retinal input is integrated. Self-adjustments in the roll-tilted position were significantly (p < 0.01) more precise for earth-fixed cues than for body-fixed cues, underlining the importance of earth-stable visual cues when estimates of gravity become more variable with increasing whole-body roll.

  3. Modulation of high quality factors in rolled-up microcavities

    NASA Astrophysics Data System (ADS)

    Fang, Yangfu; Li, Shilong; Mei, Yongfeng

    2016-09-01

    We systematically investigate the evolution of resonant modes in a rolled-up microcavity as the overlap length between structural notches increases, which presents a modulation behavior for high Q factors. The resonant modes in the rolled-up microcavity display a deterministic mode chirality, which is well correlated to the Q factor. We derive a two-mode non-Hermitian Hamiltonian to clarify these unusual findings. It reveals that strong resonant interactions of scattered waves between the structural notches are responsible for the high mode chirality (thus high Q factor) and its modulation behavior in rolled-up microcavities.

  4. Correcting Quadrupole Roll in Magnetic Lenses with Skew Quadrupoles

    SciTech Connect

    Walstrom, Peter Lowell

    2014-11-10

    Quadrupole rolls (i.e. rotation around the magnet axis) are known to be a significant source of image blurring in magnetic quadrupole lenses. These rolls may be caused by errors in mechanical mounting of quadrupoles, by uneven radiation-induced demagnetization of permanent-magnet quadrupoles, etc. Here a four-quadrupole ×10 lens with so-called ”Russian” or A -B B-A symmetry is used as a model problem. Existing SLAC 1/2 in. bore high-gradient quadrupoles are used in the design. The dominant quadrupole roll effect is changes in the first-order part of the transfer map (the R matrix) from the object to the image plane (Note effects on the R matrix can be of first order in rotation angle for some R-matrix elements and second order in rotation angle for other elements, as shown below). It is possible to correct roll-induced image blur by mechanically adjusting the roll angle of one or more of the quadrupoles. Usually, rotation of one quadrupole is sufficient to correct most of the combined effect of rolls in all four quadrupoles. There are drawbacks to this approach, however, since mechanical roll correction requires multiple entries into experimental area to make the adjustments, which are made according to their effect on images. An alternative is to use a single electromagnetic skew quadrupole corrector placed either between two of the quadrupoles or after the fourth quadrupole (so-called “non-local” correction). The basic feasibility of skew quadrupole correction of quadrupole roll effects is demonstrated here. Rolls of the third lens quadrupole of up to about 1 milliradian can be corrected with a 15 cm long skew quadrupole with a gradient of up to 1 T/m. Since the effect of rolls of the remaining three lens quadrupoles are lower, a weaker skew quadrupole can be used to correct them. Non-local correction of quadrupole roll effects by skew quadrupoles is shown to be about one-half as effective as local correction (i.e. rotating individual quadrupoles to zero

  5. Recent developments in semiprocessed cold rolled magnetic lamination steel

    NASA Astrophysics Data System (ADS)

    Hilinski, E. J.

    2006-09-01

    Over the past 10 years the magnetic property performance of semi-processed cold rolled magnetic lamination steels in North America have approached those of nonoriented, semi-processed silicon steel. This improvement was accomplished via higher alloy levels in conjunction with hot band annealing. New temper rolling strategies can produce weakly oriented steels tailored to specific applications, such as small transformers used in fluorescent lighting ballasts. Recently, production trials for 0.0138 in product cold rolled on tin mills has been undertaken. Efforts to further improve properties through a better understanding of texture control and via implementation of new production processes, such as thin slab or strip casting, continue.

  6. Roll-Tilt Perception Using a Somatosensory Bar Task

    NASA Technical Reports Server (NTRS)

    Black, F. O.; Wade, S. W.; Arshi, A.

    1999-01-01

    Visual estimates of roll-tilt perception during static roll-tilt are confounded by an offset due to the ocular counterroll that simultaneously occurs. An alternative, non-visual ('somatosensory') measure of roll-tilt perception was developed which is not contaminated by this offset. The aims of this study were to determine: 1) inter-subject variability of somatosensory settings across test session in normal subjects and patients with unilateral or bilateral vestibular loss and 2) intra-subject variability of settings across test session in normal subjects.

  7. Effect of biomimetic coupling units' morphologies on rolling contact fatigue wear resistance of steel from machine tool rolling tracks

    NASA Astrophysics Data System (ADS)

    Yang, Wanshi; Zhou, Hong; Sun, Liang; Wang, Chuanwei; Chen, Zhikai

    2014-04-01

    The rolling contact fatigue wear resistance plays an important role on ensuring machining precision of machine tool using rolling tracks. Bio-inspired wearable surfaces with the alternated hardness were prepared on the specimen of steel material from machine tool rolling tracks by biomimetic coupling laser remelting method to imitate biological coupling principle. The microstructures and micromorphologies of bionic units in different sizes were characterized by optical microscope. The specimens with bionic units in different sizes and distributions were tested for rolling contact fatigue wear resistance. Combining the finite element analysis and the results of wear tests, a discussion on rolling contact fatigue wear was had. The specimens with bionic units had better rolling contact fatigue wear resistance than the untreated one, while the specimens with bionic units in the alternative depth's distributions present a better rolling contact fatigue wear resistance than the ones with bionic units in the single depth's distribution. It attributed to the alternative distribution made further improvement on the dispersion of depth of stress concentration.

  8. Multilength Scale Patterning of Functional Layers by Roll-to-Roll Ultraviolet-Light-Assisted Nanoimprint Lithography.

    PubMed

    Leitgeb, Markus; Nees, Dieter; Ruttloff, Stephan; Palfinger, Ursula; Götz, Johannes; Liska, Robert; Belegratis, Maria R; Stadlober, Barbara

    2016-05-24

    Top-down fabrication of nanostructures with high throughput is still a challenge. We demonstrate the fast (>10 m/min) and continuous fabrication of multilength scale structures by roll-to-roll UV-nanoimprint lithography on a 250 mm wide web. The large-area nanopatterning is enabled by a multicomponent UV-curable resist system (JRcure) with viscous, mechanical, and surface properties that are tunable over a wide range to either allow for usage as polymer stamp material or as imprint resist. The adjustable elasticity and surface chemistry of the resist system enable multistep self-replication of structured resist layers. Decisive for defect-free UV-nanoimprinting in roll-to-roll is the minimization of the surface energies of stamp and resist, and the stepwise reduction of the stiffness from one layer to the next is essential for optimizing the reproduction fidelity especially for nanoscale features. Accordingly, we demonstrate the continuous replication of 3D nanostructures and the high-throughput fabrication of multilength scale resist structures resulting in flexible polyethylenetherephtalate film rolls with superhydrophobic properties. Moreover, a water-soluble UV-imprint resist (JRlift) is introduced that enables residue-free nanoimprinting in roll-to-roll. Thereby we could demonstrate high-throughput fabrication of metallic patterns with only 200 nm line width.

  9. Rolling Process Modeling Report. Finite-Element Model Validation and Parametric Study on various Rolling Process parameters

    SciTech Connect

    Soulami, Ayoub; Lavender, Curt A.; Paxton, Dean M.; Burkes, Douglas

    2015-06-15

    Pacific Northwest National Laboratory (PNNL) has been investigating manufacturing processes for the uranium-10% molybdenum alloy plate-type fuel for high-performance research reactors in the United States. This work supports the U.S. Department of Energy National Nuclear Security Administration’s Office of Material Management and Minimization Reactor Conversion Program. This report documents modeling results of PNNL’s efforts to perform finite-element simulations to predict roll-separating forces for various rolling mill geometries for PNNL, Babcock & Wilcox Co., Y-12 National Security Complex, Los Alamos National Laboratory, and Idaho National Laboratory. The model developed and presented in a previous report has been subjected to further validation study using new sets of experimental data generated from a rolling mill at PNNL. Simulation results of both hot rolling and cold rolling of uranium-10% molybdenum coupons have been compared with experimental results. The model was used to predict roll-separating forces at different temperatures and reductions for five rolling mills within the National Nuclear Security Administration Fuel Fabrication Capability project. This report also presents initial results of a finite-element model microstructure-based approach to study the surface roughness at the interface between zirconium and uranium-10% molybdenum.

  10. Multilength Scale Patterning of Functional Layers by Roll-to-Roll Ultraviolet-Light-Assisted Nanoimprint Lithography.

    PubMed

    Leitgeb, Markus; Nees, Dieter; Ruttloff, Stephan; Palfinger, Ursula; Götz, Johannes; Liska, Robert; Belegratis, Maria R; Stadlober, Barbara

    2016-05-24

    Top-down fabrication of nanostructures with high throughput is still a challenge. We demonstrate the fast (>10 m/min) and continuous fabrication of multilength scale structures by roll-to-roll UV-nanoimprint lithography on a 250 mm wide web. The large-area nanopatterning is enabled by a multicomponent UV-curable resist system (JRcure) with viscous, mechanical, and surface properties that are tunable over a wide range to either allow for usage as polymer stamp material or as imprint resist. The adjustable elasticity and surface chemistry of the resist system enable multistep self-replication of structured resist layers. Decisive for defect-free UV-nanoimprinting in roll-to-roll is the minimization of the surface energies of stamp and resist, and the stepwise reduction of the stiffness from one layer to the next is essential for optimizing the reproduction fidelity especially for nanoscale features. Accordingly, we demonstrate the continuous replication of 3D nanostructures and the high-throughput fabrication of multilength scale resist structures resulting in flexible polyethylenetherephtalate film rolls with superhydrophobic properties. Moreover, a water-soluble UV-imprint resist (JRlift) is introduced that enables residue-free nanoimprinting in roll-to-roll. Thereby we could demonstrate high-throughput fabrication of metallic patterns with only 200 nm line width. PMID:27023664

  11. The Six Track Scherzer Rolling Lift Bridge…Two double track spans ...

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

    The Six Track Scherzer Rolling Lift Bridge…Two double track spans closed. One double-track span open. Photocopy of plate xvi in Scherzer Rolling Lift Bridge Company, Scherzer Rolling Lift Bridges. - New York, New Haven & Hartford Railroad, Fort Point Channel Rolling Lift Bridge, Spanning Fort Point Channel, Boston, Suffolk County, MA

  12. 21 CFR 136.180 - Whole wheat bread, rolls, and buns.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... § 136.180 Whole wheat bread, rolls, and buns. (a) Each of the foods whole wheat bread, graham bread, entire wheat bread, whole wheat rolls, graham rolls, entire wheat rolls, whole wheat buns, graham buns...”, “graham bread”, “entire wheat bread”, “whole wheat rolls”, “graham rolls”, “entire wheat rolls”,...

  13. 40 CFR 1066.225 - Roll runout and diameter verification procedure.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... for roll runout and roll diameter. Roll runout is a measure of the variation in roll radius around the... turns through a complete revolution. The indicator must have some means of being securely mounted... measurement from the weight of a person standing on or near the mounted dial indicator. (4) Slowly turn...

  14. 25 CFR 67.14 - Preparation of a per capita payment roll.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false Preparation of a per capita payment roll. 67.14 Section... ROLL OF INDEPENDENT SEMINOLE INDIANS OF FLORIDA § 67.14 Preparation of a per capita payment roll. (a) The Superintendent shall, based on the roll approved under § 67.12(c), prepare a per capita...

  15. 25 CFR 67.14 - Preparation of a per capita payment roll.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 25 Indians 1 2014-04-01 2014-04-01 false Preparation of a per capita payment roll. 67.14 Section... ROLL OF INDEPENDENT SEMINOLE INDIANS OF FLORIDA § 67.14 Preparation of a per capita payment roll. (a) The Superintendent shall, based on the roll approved under § 67.12(c), prepare a per capita...

  16. 25 CFR 67.14 - Preparation of a per capita payment roll.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 25 Indians 1 2011-04-01 2011-04-01 false Preparation of a per capita payment roll. 67.14 Section... ROLL OF INDEPENDENT SEMINOLE INDIANS OF FLORIDA § 67.14 Preparation of a per capita payment roll. (a) The Superintendent shall, based on the roll approved under § 67.12(c), prepare a per capita...

  17. 25 CFR 67.14 - Preparation of a per capita payment roll.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 25 Indians 1 2013-04-01 2013-04-01 false Preparation of a per capita payment roll. 67.14 Section... ROLL OF INDEPENDENT SEMINOLE INDIANS OF FLORIDA § 67.14 Preparation of a per capita payment roll. (a) The Superintendent shall, based on the roll approved under § 67.12(c), prepare a per capita...

  18. 25 CFR 67.14 - Preparation of a per capita payment roll.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 25 Indians 1 2012-04-01 2011-04-01 true Preparation of a per capita payment roll. 67.14 Section 67... ROLL OF INDEPENDENT SEMINOLE INDIANS OF FLORIDA § 67.14 Preparation of a per capita payment roll. (a) The Superintendent shall, based on the roll approved under § 67.12(c), prepare a per capita...

  19. Rolling element bearing diagnostics—A tutorial

    NASA Astrophysics Data System (ADS)

    Randall, Robert B.; Antoni, Jérôme

    2011-02-01

    This tutorial is intended to guide the reader in the diagnostic analysis of acceleration signals from rolling element bearings, in particular in the presence of strong masking signals from other machine components such as gears. Rather than being a review of all the current literature on bearing diagnostics, its purpose is to explain the background for a very powerful procedure which is successful in the majority of cases. The latter contention is illustrated by the application to a number of very different case histories, from very low speed to very high speed machines. The specific characteristics of rolling element bearing signals are explained in great detail, in particular the fact that they are not periodic, but stochastic, a fact which allows them to be separated from deterministic signals such as from gears. They can be modelled as cyclostationary for some purposes, but are in fact not strictly cyclostationary (at least for localised defects) so the term pseudo-cyclostationary has been coined. An appendix on cyclostationarity is included. A number of techniques are described for the separation, of which the discrete/random separation (DRS) method is usually most efficient. This sometimes requires the effects of small speed fluctuations to be removed in advance, which can be achieved by order tracking, and so this topic is also amplified in an appendix. Signals from localised faults in bearings are impulsive, at least at the source, so techniques are described to identify the frequency bands in which this impulsivity is most marked, using spectral kurtosis. For very high speed bearings, the impulse responses elicited by the sharp impacts in the bearings may have a comparable length to their separation, and the minimum entropy deconvolution technique may be found useful to remove the smearing effects of the (unknown) transmission path. The final diagnosis is based on "envelope analysis" of the optimally filtered signal, but despite the fact that this

  20. DETAIL OF CUTTING ROLLS ON #72 BRASS MILL SLITTER, ONE ...

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

    DETAIL OF CUTTING ROLLS ON #72 BRASS MILL SLITTER, ONE OF THREE CURRENTLY IN OPERATION. BRASS STRIP IS CUT TO CUSTOMER ORDER; COPPER STRIP IS PRODUCED IN STANDARD SIZES. - American Brass Foundry, 70 Sayre Street, Buffalo, Erie County, NY

  1. 46 CFR 56.30-15 - Expanded or rolled joints.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... rolled joints may be used where experience or test has demonstrated that the joint is suitable for the design conditions and where adequate provisions are made to prevent separation of the joint....

  2. 46 CFR 56.30-15 - Expanded or rolled joints.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... rolled joints may be used where experience or test has demonstrated that the joint is suitable for the design conditions and where adequate provisions are made to prevent separation of the joint....

  3. 2. BARN. VIEW LOOKING NORTHWEST. THE ROLLING DOOR PROBABLY REPLACES ...

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

    2. BARN. VIEW LOOKING NORTHWEST. THE ROLLING DOOR PROBABLY REPLACES AN ORIGINAL 4/4 DOUBLE-HUNG WINDOW. - Tonto Ranger Station, Barn, Forest Service Road 65 at Tonto Wash, Skull Valley, Yavapai County, AZ

  4. 11. DETAIL SHOWING ROLLING ENGINE DECK AND NORTHEAST TRUSS OF ...

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

    11. DETAIL SHOWING ROLLING ENGINE DECK AND NORTHEAST TRUSS OF SUPERSTRUCTURE. Looking northeast. - Edwards Air Force Base, Air Force Rocket Propulsion Laboratory, Test Stand 1-A, Test Area 1-120, north end of Jupiter Boulevard, Boron, Kern County, CA

  5. MAIN DRIVE MOTOR FOR BLISS #43 HOT ROLL. THIS WESTINGHOUSE ...

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

    MAIN DRIVE MOTOR FOR BLISS #43 HOT ROLL. THIS WESTINGHOUSE UNIT HAS SINCE BEEN REPLACED BY A 5000 HP TOSHIBA MOTOR. REHEAT FURNACES ARE SHOWN BEHIND MILL MOTOR. - American Brass Foundry, 70 Sayre Street, Buffalo, Erie County, NY

  6. Orbital Rolls to Launch Pad at Wallops for Station Flight

    NASA Video Gallery

    An Orbital Sciences Corporation Antares rolled out to launch Pad-0A at NASA's Wallops Flight Facility, Sunday, January 5, 2014, in advance of a planned Wednesday, Jan. 8th, 1:32 p.m. EST launch. Th...

  7. Rolling bearing fault diagnosis using an optimization deep belief network

    NASA Astrophysics Data System (ADS)

    Shao, Haidong; Jiang, Hongkai; Zhang, Xun; Niu, Maogui

    2015-11-01

    The vibration signals measured from a rolling bearing are usually affected by the variable operating conditions and background noise which lead to the diversity and complexity of the vibration signal characteristics, and it is a challenge to effectively identify the rolling bearing faults from such vibration signals with no further fault information. In this paper, a novel optimization deep belief network (DBN) is proposed for rolling bearing fault diagnosis. Stochastic gradient descent is used to efficiently fine-tune all the connection weights after the pre-training of restricted Boltzmann machines (RBMs) based on the energy functions, and the classification accuracy of the DBN is improved. Particle swarm is further used to decide the optimal structure of the trained DBN, and the optimization DBN is designed. The proposed method is applied to analyze the simulation signal and experimental signal of a rolling bearing. The results confirm that the proposed method is more accurate and robust than other intelligent methods.

  8. 9. DETAIL VIEW OF ROLLING EXPANSION JOINT, NORTHEAST BASE OF ...

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

    9. DETAIL VIEW OF ROLLING EXPANSION JOINT, NORTHEAST BASE OF SECOND CLOSED SPANDREL ARCH AT JUNCTION OF OPEN SPANDREL ARCH, LOOKING EAST - Virgin River Bridge, Spanning Virgin River on State Highway 9, Hurricane, Washington County, UT

  9. A contact-type tensionmeter for hot rolling mills

    NASA Astrophysics Data System (ADS)

    Zhao, Xiaoyan; Zhang, Zhaohui; Sun, Yikang; Wang, Jun; Que, Cheng

    2008-12-01

    To improve the hot rolled strip quality and operational stability, a novel tensionmeter based on lever principle is developed which inspects latent waves and provides real references for flatness control in hot rolling process. The contact-type tensionmeter including two segmented rolls can get the transverse tension distribution along the strip width. Tension profile is deduced by different ratio of four force values from the embedded force sensors in tensionmeter system. The compact mechanical structure ensures the tensionmeter's robust stability in hot rolling process, standard hardware and software for data acquisition make the system easy to operate and maintain. The trails have proven tensionmeter successful in improving both strip flatness and mill performance.

  10. Numerical simulations supporting the process design of ring rolling processes

    NASA Astrophysics Data System (ADS)

    Jenkouk, V.; Hirt, G.; Seitz, J.

    2013-05-01

    In conventional Finite Element Analysis (FEA) of radial-axial ring rolling (RAR) the motions of all tools are usually defined prior to simulation in the preprocessing step. However, the real process holds up to 8 degrees of freedom (DOF) that are controlled by industrial control systems according to actual sensor values and preselected control strategies. Since the histories of the motions are unknown before the experiment and are dependent on sensor data, the conventional FEA cannot represent the process before experiment. In order to enable the usage of FEA in the process design stage, this approach integrates the industrially applied control algorithms of the real process including all relevant sensors and actuators into the FE model of ring rolling. Additionally, the process design of a novel process 'the axial profiling', in which a profiled roll is used for rolling axially profiled rings, is supported by FEA. Using this approach suitable control strategies can be tested in virtual environment before processing.

  11. Dynamic Effect of Rolling Massage on Blood Flow

    NASA Astrophysics Data System (ADS)

    Chen, Yan-Yan; Yi, Hou-Hui; Li, Hua-Bing; Fang, Hai-Ping

    2009-02-01

    The Chinese traditional medical massage has been used as a natural therapy to eliminate some diseases. Here, the effect of the rolling massage frequency to the blood flow in the blood vessels under the rolling massage manipulation is studied by the lattice Boltzmann simulation. The simulation results show that when the frequency is smaller than or comparable to the pulsatile frequency of the blood flow, the effect on the blood flux by the rolling massage is small. On the contrast, if the frequency is twice or more times of the pulsatile frequency of the blood flow, the blood flux is greatly enhanced and increases linearly with respect to the frequency. Similar behavior has also been observed on the shear stress on the blood vessel walls. The result is helpful for understanding that the rolling massage has the function of promoting the blood circulation and removing the blood stasis.

  12. Facility No. 175, interior detail showing rolling doors, trusses, and ...

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

    Facility No. 175, interior detail showing rolling doors, trusses, and angled monitor roof - U.S. Naval Base, Pearl Harbor, Landplane Hangar Type, Wasp Boulevard and Gambier Bay Street, Pearl City, Honolulu County, HI

  13. 18. DETAIL OF ROLLING DOORS AND CANOPY AT SOUTH SIDE ...

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

    18. DETAIL OF ROLLING DOORS AND CANOPY AT SOUTH SIDE ENTRANCE, ALSO SEEN FROM A DISTANCE IN VIEW NO. CA-295-A-15. - United Engineering Company Shipyard, Inspection & Repair Shops, 2900 Main Street, Alameda, Alameda County, CA

  14. Corrosion analysis of accumulative roll bonded aluminum 6016

    NASA Astrophysics Data System (ADS)

    Searcy, Jacquelyn Alisha

    Accumulative Roll Bonding is a Severe Plastic Deformation Process that is used to strengthen a material and promote grain refinement. Accumulative Roll Bonded Aluminum 6016 samples were investigated to determine their corrosion properties. The tests performed consisted of standard techniques including Cyclic Polarization Potentials, Exfoliation Corrosion (EXCO), Electrochemical Impedance Spectroscopy (EIS), Light Microscopy, and Electron Microprobe Analysis. From these tests, it was determined that for Al 6016, the Ultra Fine Grained samples obtained by Accumulative Roll Bonding are in general more susceptible to corrosion than the coarse grained sample. The higher corrosion rate was caused by the additional cold work, which increased the number of grain boundaries and rolled-in debris. The advantage however was that the corrosion was parallel to the surface and rather than deep into the sample as with the as-received 6016.

  15. Worm drive detail, roller hoist mechanism, rolling crest roller gate ...

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

    Worm drive detail, roller hoist mechanism, rolling crest roller gate - plan and sections - Grand Valley Diversion Dam, Half a mile north of intersection of I-70 & Colorado State Route 65, Cameo, Mesa County, CO

  16. SMALL DIAMETER STENCILING, ROLLING OVER STAMP. United States Pipe ...

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

    SMALL DIAMETER STENCILING, ROLLING OVER STAMP. - United States Pipe & Foundry Company Plant, Coating, Painting, Lining & Packaging Building, 2023 St. Louis Avenue at I-20/59, Bessemer, Jefferson County, AL

  17. a Numerical Simulation of Strip Profile in a 6-HIGH Cold Rolling Mill

    NASA Astrophysics Data System (ADS)

    Du, Xiaozhong; Yang, Quan; Lu, Cheng; Tieu, Anh Kiet; Kim, Shinil

    Shape control is always a key issue in the six-high rolling mill, in which the shifting of the intermediate roll and the work roll have been used to enhance the shape control capability. In this paper, a finite element method (FEM) model has been developed to simultaneously simulate the strip deformation and the roll stack deformation for the six-high rolling mill. The effects of the work-roll bending, the shifting of the intermediate roll and the work roll on the strip crown and edge drop are discussed in details. Results have shown that both higher bending force and more roll shifting will significantly reduce the strip crown. The edge drop is also reduced with the bending force and the roll shifting.

  18. Computer-aided analysis and design of the shape rolling process for producing turbine engine airfoils

    NASA Technical Reports Server (NTRS)

    Lahoti, G. D.; Akgerman, N.; Altan, T.

    1978-01-01

    Mild steel (AISI 1018) was selected as model cold rolling material and Ti-6A1-4V and Inconel 718 were selected as typical hot rolling and cold rolling alloys, respectively. The flow stress and workability of these alloys were characterized and friction factor at the roll/workpiece interface was determined at their respective working conditions by conducting ring tests. Computer-aided mathematical models for predicting metal flow and stresses, and for simulating the shape rolling process were developed. These models utilized the upper bound and the slab methods of analysis, and were capable of predicting the lateral spread, roll separating force, roll torque, and local stresses, strains and strain rates. This computer-aided design system was also capable of simulating the actual rolling process, and thereby designing the roll pass schedule in rolling of an airfoil or a similar shape.

  19. Effects of microalloying on hot-rolled and cold-rolled Q&P steels

    NASA Astrophysics Data System (ADS)

    Azevedo de Araujo, Ana Luiza

    Third generation advanced high strength steels (AHSS) have been a major focus in steel development over the last decade. The premise of these types of steel is based on the potential to obtain excellent combinations of strength and ductility with low-alloy compositions by forming mixed microstructures containing retained austenite (RA). The development of heat treatments able to achieve the desired structures and properties, such as quenching and partitioning (Q&P) steels, is driven by new requirements to increase vehicle fuel economy by reducing overall weight while maintaining safety and crashworthiness. Microalloying additions of niobium (Nb) and vanadium (V) in sheet products are known to provide strengthening via grain refinement and precipitation hardening and may influence RA volume fraction and transformation behavior. Additions of microalloying elements in Q&P steels have not been extensively studied to date, however. The objective of the present study was to begin to understand the potential roles of Nb and V in hot-rolled and cold-rolled Q&P steel. For that, a common Q&P steel composition was selected as a Base alloy with 0.2C-1.5Si-2.0Mn (wt. %). Two alloys with an addition of Nb (0.02 and 0.04 wt. %) and one with an addition of V (0.06 wt. %) to the Base alloy were investigated. Both hot-rolled and cold-rolled/annealed Q&P simulations were conducted. In the hot-rolled Q&P study, thermomechanical processing was simulated via hot torsion testing in a GleebleRTM 3500, and four coiling temperatures (CT) were chosen. Microstructural evaluation (including RA measurements via electron backscattered diffraction - EBSD) and hardness measurements were performed for all alloys and coiling conditions. The analysis showed that Nb additions led to overall refinement of the prior microstructure. Maximum RA fractions were measured at the 375 °C CT, and microalloying was associated with increased RA in this condition when compared to the Base alloy. A change in

  20. Roll aftereffects: influence of tilt and inter-stimulus interval.

    PubMed

    Crane, Benjamin T

    2012-11-01

    A theme in sensory perception is that exposure to a stimulus causes perception of subsequent stimuli to be shifted in the opposite direction. Such phenomenon is known as aftereffect and has been extensively described in the visual system as well as recently described for the vestibular system during translation. It is known from aviation studies that after a maneuver in roll, pilots can experience a false perception of roll in the opposite direction. The magnitude and duration of this effect as well as the potential influence of the gravity vector have not previously been defined. In the current paper this roll aftereffect (RAE) is examined in response to whole-body roll about an earth-horizontal axis in eight healthy human subjects. The peak velocity of a 0.5-s-duration roll was varied based on previous responses to find the point where subjects perceived no motion. Without a preceding stimulus, the starting position (upright, 9° left, or 9° right) did not influence roll perception. The RAE was measured in a completely dark room using an adapting (first interval) stimulus consisting of 9° of roll over 1.5 s (peak velocity, 12°/s), delivered 0.5, 3, or 6 s prior to test (second interval) stimulus. A significant RAE was seen in all subjects. Half a second after the adapting stimulus, a test stimulus had to be on average 1.5 ± 0.4°/s in the opposite direction to be perceived as stationary. When the subject remained upright after the adapting stimulus, the RAE diminished with time, although it remained significantly larger at 3 and 6 s when the subject remained tilted after the adapting stimulus. These data demonstrate that roll perception can be influenced by small preceding stimuli and tilt causes a persistence of the RAE.

  1. Heat storage capability of a rolling cylinder using Glauber's salt

    NASA Technical Reports Server (NTRS)

    Herrick, C. S.; Zarnoch, K. P.

    1980-01-01

    The rolling cylinder phase change heat storage concept was developed to the point where a prototype design is completed and a cost analysis is prepared. A series of experimental and analytical tasks are defined to establish the thermal, mechanical, and materials behavior of rolling cylinder devices. These tasks include: analyses of internal and external heat transfer; performance and lifetime testing of the phase change materials; corrosion evaluation; development of a mathematical model; and design of a prototype and associated test equipment.

  2. Wheel rolling constraints and slip in mobile robots

    SciTech Connect

    Shekhar, S.

    1997-03-01

    It is widely accepted that dead reckoning based on the rolling with no slip condition on wheels is not a reliable method to ascertain the position and orientation of a mobile robot for any reasonable distance. We establish that wheel slip is inevitable under the dynamic model of motion using classical results on the accessibility and controllability in nonlinear control theory and an analytical model of rolling of two linearly elastic bodies.

  3. Wheel rolling constraints and slip in mobile robots

    SciTech Connect

    Shekhar, S.

    1996-06-01

    It is widely accepted that dead-reckoning based on the rolling with no-slip condition on the wheels is not a reliable method to ascertain the position and orientation of a mobile robot for any reasonable distance. The authors establish that wheel slip is inevitable under the dynamic model of motion using classical results on the accessibility and controllability in nonlinear control theory and an analytical model of rolling of two linearly elastic bodies.

  4. Roll-to-roll nanopatterning using jet and flash imprint lithography

    NASA Astrophysics Data System (ADS)

    Ahn, Sean; Ganapathisubramanian, Maha; Miller, Mike; Yang, Jack; Choi, Jin; Xu, Frank; Resnick, Douglas J.; Sreenivasan, S. V.

    2012-03-01

    The ability to pattern materials at the nanoscale can enable a variety of applications ranging from high density data storage, displays, photonic devices and CMOS integrated circuits to emerging applications in the biomedical and energy sectors. These applications require varying levels of pattern control, short and long range order, and have varying cost tolerances. Extremely large area R2R manufacturing on flexible substrates is ubiquitous for applications such as paper and plastic processing. It combines the benefits of high speed and inexpensive substrates to deliver a commodity product at low cost. The challenge is to extend this approach to the realm of nanopatterning and realize similar benefits. The cost of manufacturing is typically driven by speed (or throughput), tool complexity, cost of consumables (materials used, mold or master cost, etc.), substrate cost, and the downstream processing required (annealing, deposition, etching, etc.). In order to achieve low cost nanopatterning, it is imperative to move towards high speed imprinting, less complex tools, near zero waste of consumables and low cost substrates. The Jet and Flash Imprint Lithography (J-FILTM) process uses drop dispensing of UV curable resists to assist high resolution patterning for subsequent dry etch pattern transfer. The technology is actively being used to develop solutions for memory markets including Flash memory and patterned media for hard disk drives. In this paper we address the key challenges for roll based nanopatterning by introducing a novel concept: Ink Jet based Roll-to-Roll Nanopatterning. To address this challenge, we have introduced a J-FIL based demonstrator product, the LithoFlex 100. Topics that are discussed in the paper include tool design and process performance. In addition, we have used the LithoFlex 100 to fabricate high performance wire grid polarizers on flexible polycarbonate (PC) films. Transmission of better than 80% and extinction ratios on the order of

  5. Bioinspired superhydrophobic surfaces, fabricated through simple and scalable roll-to-roll processing

    NASA Astrophysics Data System (ADS)

    Park, Sung-Hoon; Lee, Sangeui; Moreira, David; Bandaru, Prabhakar R.; Han, Intaek; Yun, Dong-Jin

    2015-10-01

    A simple, scalable, non-lithographic, technique for fabricating durable superhydrophobic (SH) surfaces, based on the fingering instabilities associated with non-Newtonian flow and shear tearing, has been developed. The high viscosity of the nanotube/elastomer paste has been exploited for the fabrication. The fabricated SH surfaces had the appearance of bristled shark skin and were robust with respect to mechanical forces. While flow instability is regarded as adverse to roll-coating processes for fabricating uniform films, we especially use the effect to create the SH surface. Along with their durability and self-cleaning capabilities, we have demonstrated drag reduction effects of the fabricated films through dynamic flow measurements.

  6. Controlled Microwave Heating Accelerates Rolling Circle Amplification.

    PubMed

    Yoshimura, Takeo; Suzuki, Takamasa; Mineki, Shigeru; Ohuchi, Shokichi

    2015-01-01

    Rolling circle amplification (RCA) generates single-stranded DNAs or RNA, and the diverse applications of this isothermal technique range from the sensitive detection of nucleic acids to analysis of single nucleotide polymorphisms. Microwave chemistry is widely applied to increase reaction rate as well as product yield and purity. The objectives of the present research were to apply microwave heating to RCA and indicate factors that contribute to the microwave selective heating effect. The microwave reaction temperature was strictly controlled using a microwave applicator optimized for enzymatic-scale reactions. Here, we showed that microwave-assisted RCA reactions catalyzed by either of the four thermostable DNA polymerases were accelerated over 4-folds compared with conventional RCA. Furthermore, the temperatures of the individual buffer components were specifically influenced by microwave heating. We concluded that microwave heating accelerated isothermal RCA of DNA because of the differential heating mechanisms of microwaves on the temperatures of reaction components, although the overall reaction temperatures were the same. PMID:26348227

  7. Magnetically capped rolled-up nanomembranes.

    PubMed

    Streubel, Robert; Thurmer, Dominic J; Makarov, Denys; Kronast, Florian; Kosub, Tobias; Kravchuk, Volodymyr; Sheka, Denis D; Gaididei, Yuri; Schäfer, Rudolf; Schmidt, Oliver G

    2012-08-01

    Modifying the curvature in magnetic nanostructures is a novel and elegant way toward tailoring physical phenomena at the nanoscale, allowing one to overcome limitations apparent in planar counterparts. Here, we address curvature-driven changes of static magnetic properties in cylindrically curved magnetic segments with different radii of curvature. The curved architectures are prepared by capping nonmagnetic micrometer- and nanometer-sized rolled-up membranes with a soft-magnetic 20 nm thick permalloy (Ni(80)Fe(20)) film. A quantitative comparison between the magnetization reversal processes in caps with different diameters is given. The phase diagrams of magnetic equilibrium domain patterns (diameter versus length) are generated. For this, joint experimental, including X-ray magnetic circular dichroism photoelectron emission microscopy (XMCD-PEEM), and theoretical studies are carried out. The anisotropic magnetostatic interaction in cylindrically curved architectures originating from the thickness gradient reduces substantially the magnetostatic interaction between closely packed curved nanowires. This feature is beneficial for racetrack memory devices, since a much higher areal density might be achieved than possible with planar counterparts.

  8. Communication using eye roll reflective signalling

    USGS Publications Warehouse

    Flamarique, I.N.; Mueller, G.A.; Cheng, C.L.; Figiel, C.R.

    2007-01-01

    Body reflections in the ultraviolet (UV) are a common occurrence in nature. Despite the abundance of such signals and the presence of UV cones in the retinas of many vertebrates, the function of UV cones in the majority of taxa remains unclear. Here, we report on an unusual communication system in the razorback sucker, Xyrauchen texanus, that involves flash signals produced by quick eye rolls. Behavioural experiments and field observations indicate that this form of communication is used to signal territorial presence between males. The flash signal shows highest contrast in the UV region of fhe visual spectrum (??max???380 nm), corresponding to the maximum wavelength of absorption of the UV cone mechanism in suckers. Furthermore, these cones are restricted to the dorsal retina of the animal and the upwelling light background is such that their relative sensitivity would be enhanced by chromatic adaptation of the other cone mechanisms. Thus, the UV cones in the sucker have optimal characteristics (both in terms of absorbance and retinal topography) to constitute the main detectors of the flash signal. Our findings provide the first ecological evidence for restricted distribution of UV cones in the retina of a vertebrate. ?? 2007 The Royal Society.

  9. An improved rolled strip pulse forming line

    NASA Astrophysics Data System (ADS)

    Li, Song; Qian, Bao-Liang; Yang, Han-Wu; Gao, Jing-Ming; Liu, Zhao-Xi

    2013-06-01

    The rolled strip pulse forming line (RSPFL) has advantages of compactness, portability, and long pulse achievability which could well meet the requirements of industrial application of the pulse power technology. In this paper, an improved RSPFL with an additional insulator between the grounded conductors is investigated numerically and experimentally. Results demonstrate that the jitter on the flat-top of the output voltage waveform is reduced to 3.8% due to the improved structure. Theoretical analysis shows that the electromagnetic coupling between the conductors of the RSPFL strongly influences the output voltage waveform. Therefore, the new structure was designed to minimize the detrimental effect of the electromagnetic coupling. Simulation results show that the electromagnetic coupling can be efficiently reduced in the improved RSPFL. Experimental results illustrate that the improved RSPFL, with dimensions and weight of Φ 290 × 250 mm and 16 kg, when used as a simple pulse forming line, could generate a well shaped quasi-square pulse with output power of hundreds of MW and pulse duration of 250 ns. Importantly, the improved RSPFL was successfully used as a Blumlein pulse forming line, and a 10.8 kV, 260 ns quasi-square pulse was obtained on a 2 Ω dummy load. Experiments show reasonable agreement with numerical analysis.

  10. SOFC technology development at Rolls-Royce

    NASA Astrophysics Data System (ADS)

    Gardner, F. J.; Day, M. J.; Brandon, N. P.; Pashley, M. N.; Cassidy, M.

    Fuel cells have the prospect for exploiting fossil fuels more benignly and more efficiently than alternatives. The various types represent quite different technologies, with no clear winner, yet. Nevertheless, the high temperature MCFC and solid oxide fuel cell (SOFC) types seem better suited to power generation in a hydrocarbon fuel economy. Presently, the costs of MCFCs and SOFCs are too high to compete directly with contemporary power generation plant. Seeking to overcome the drawbacks of first generation fuel cells, over the past 7 years an innovative second generation SOFC concept has been evolved in the Rolls-Royce Strategic Research Centre, with encouraging results. It is distinguished from other types by the name: Integrated Planar Solid Oxide Fuel Cell (IP-SOFC). It is a family of integrated system concepts supporting product flexibility with evolutionary stretch potential from a common SOFC module. Fabrication of the key component of the IP-SOFC, the "multi-cell membrane electrode assembly (multi-cell MEA) module" carrying many series connected cells with supported electrolyte membranes only 10 to 20 μm thick, has been proved. Development of the internal reforming subsystem, the next big hurdle, is now in hand. Following an outline of its salient features and test results, the methodology and results of recent IP-SOFC stack costing studies are presented, and the continuing research and development programme indicated.

  11. Slow-roll k-essence

    SciTech Connect

    Chiba, Takeshi; Dutta, Sourish; Scherrer, Robert J.

    2009-08-15

    We derive slow-roll conditions for thawing k-essence with a separable Lagrangian p(X,{phi})=F(X)V({phi}). We examine the evolution of the equation of state parameter, w, as a function of the scale factor a, for the case where w is close to -1. We find two distinct cases, corresponding to X{approx_equal}0 and F{sub X}{approx_equal}0, respectively. For the case where X{approx_equal}0 the evolution of {phi} and hence w is described by only two parameters, and w(a) is model independent and coincides with similar behavior seen in thawing quintessence models. This result also extends to nonseparable Lagrangians where X{approx_equal}0. For the case F{sub X}{approx_equal}0, an expression is derived for w(a), but this expression depends on the potential V({phi}), so there is no model-independent limiting behavior. For the X{approx_equal}0 case, we derive observational constraints on the two parameters of the model, w{sub 0} (the present-day value of w), and the K, which parametrizes the curvature of the potential. We find that the observations sharply constrain w{sub 0} to be close to -1, but provide very poor constraints on K.

  12. Communication using eye roll reflective signalling

    PubMed Central

    Novales Flamarique, I; Mueller, G.A; Cheng, C.L; Figiel, C.R

    2007-01-01

    Body reflections in the ultraviolet (UV) are a common occurrence in nature. Despite the abundance of such signals and the presence of UV cones in the retinas of many vertebrates, the function of UV cones in the majority of taxa remains unclear. Here, we report on an unusual communication system in the razorback sucker, Xyrauchen texanus, that involves flash signals produced by quick eye rolls. Behavioural experiments and field observations indicate that this form of communication is used to signal territorial presence between males. The flash signal shows highest contrast in the UV region of the visual spectrum (λmax∼380 nm), corresponding to the maximum wavelength of absorption of the UV cone mechanism in suckers. Furthermore, these cones are restricted to the dorsal retina of the animal and the upwelling light background is such that their relative sensitivity would be enhanced by chromatic adaptation of the other cone mechanisms. Thus, the UV cones in the sucker have optimal characteristics (both in terms of absorbance and retinal topography) to constitute the main detectors of the flash signal. Our findings provide the first ecological evidence for restricted distribution of UV cones in the retina of a vertebrate. PMID:17251115

  13. Rolling-circle replication of bacterial plasmids.

    PubMed Central

    Khan, S A

    1997-01-01

    Many bacterial plasmids replicate by a rolling-circle (RC) mechanism. Their replication properties have many similarities to as well as significant differences from those of single-stranded DNA (ssDNA) coliphages, which also replicate by an RC mechanism. Studies on a large number of RC plasmids have revealed that they fall into several families based on homology in their initiator proteins and leading-strand origins. The leading-strand origins contain distinct sequences that are required for binding and nicking by the Rep proteins. Leading-strand origins also contain domains that are required for the initiation and termination of replication. RC plasmids generate ssDNA intermediates during replication, since their lagging-strand synthesis does not usually initiate until the leading strand has been almost fully synthesized. The leading- and lagging-strand origins are distinct, and the displaced leading-strand DNA is converted to the double-stranded form by using solely the host proteins. The Rep proteins encoded by RC plasmids contain specific domains that are involved in their origin binding and nicking activities. The replication and copy number of RC plasmids, in general, are regulated at the level of synthesis of their Rep proteins, which are usually rate limiting for replication. Some RC Rep proteins are known to be inactivated after supporting one round of replication. A number of in vitro replication systems have been developed for RC plasmids and have provided insight into the mechanism of plasmid RC replication. PMID:9409148

  14. Twisting, Rolling Motions, and Helicity in Prominence Eruptions

    NASA Astrophysics Data System (ADS)

    McKillop, Sean; Miralles, Mari Paz; Murphy, Nicholas A.; McCauley, Patrick; Su, Yingna

    2015-04-01

    Panasenco et al. [1] report observations of several CMEs that display a rolling motion about the axis of the erupting prominence. Murphy et al. [2] present simulations of line-tied asymmetric magnetic reconnection that make a falsifiable prediction regarding the handedness of rolling motions of flux ropes during solar eruptions. Mass motions in prominence eruptions tend to be complicated and characterizing these motions is a challenge. We use the AIA filament eruption catalog [3] as a source for finding events. If rolling motions are detected then we will investigate the handedness prediction. We use magnetograms from HMI to determine the strength and asymmetric properties of the photospheric magnetic field in the regions of interest and will use AIA observations to determine the handedness of the rolling motions. We then compare the photospheric magnetic information with the handedness to determine if there is a relationship between the two. We also determine the chirality of the prominences to see if there is any interesting relationship to the twist, rolling motion and/or handedness of the roll.[1] O. Panasenco, S. Martin, A. D. Joshi, & N. Srivastava, J. Atmos. Sol.-Terr. Phys., 73, 1129 (2011)[2] N. A. Murphy, M. P. Miralles, C. L. Pope, J. C. Raymond, H. D. Winter, K. K. Reeves, D. B. Seaton, A. A. van Ballegooijen, & J. Lin, ApJ, 751, 56 (2012)[3] http://aia.cfa.harvard.edu/filament/

  15. Analysis of leukocyte rolling in vivo and in vitro.

    PubMed

    Sperandio, Markus; Pickard, John; Unnikrishnan, Sunil; Acton, Scott T; Ley, Klaus

    2006-01-01

    Leukocyte rolling is an important step for the successful recruitment of leukocytes from blood to tissues mediated by a specialized group of glycoproteins termed selectins. Because of the dynamic process of leukocyte rolling, binding of selectins to their respective counter-receptors (selectin ligands) needs to fulfill three major requirements: (1) rapid bond formation, (2) high tensile strength, and (3) fast dissociation rates. These criteria are perfectly met by selectins, which interact with specific carbohydrate determinants on selectin ligands. This chapter describes the theoretical background, technical requirements, and analytical tools needed to quantitatively assess leukocyte rolling in vivo and in vitro. For the in vivo setting, intravital microscopy allows the observation and recording of leukocyte rolling under different physiological and pathological conditions in almost every organ. Real-time and off-line analysis tools help to assess geometric, hemodynamic, and rolling parameters. Under in vitro conditions, flow chamber assays such as parallel plate flow chamber systems have been the mainstay to study interactions between leukocytes and adhesion molecules under flow. In this setting, adhesion molecules are immobilized on plastic, in a lipid monolayer, or presented on cultured endothelial cells on the chamber surface. Microflow chambers are available for studying leukocyte adhesion in the context of whole blood and without blood cell isolation. The microscopic observation of leukocyte rolling in different in vivo and in vitro settings has significantly contributed to our understanding of the molecular mechanisms responsible for the stepwise extravasation of leukocytes into inflamed tissues.

  16. Observations and Modelling of Convective Rolls Over Low Hills

    NASA Astrophysics Data System (ADS)

    Tian, W.; Parker, D. J.; Kilburn, C. A. D.

    Radar and satellite images provide observations of convective rolls and other struc- tures in the convective boundary layer (CBL), but numerical modelling is a neces- sary complement to the observations, to investigate the temporal and spatial evolu- tion of convective rolls. Numerical simulations have been performed to investigate observed convective rolls over the south of England, using BLASIUS, a relatively simple boundary layer code for flow over topography. The principal features of the convective structures can be successfully reproduced by the model, notably the roll orientation and spacing and the basic features of the cloud field. These features are in good agreement for two case studies, one with distinct rolls and the other with more dispersed convective structures and a time-dependent basic state. The presence of low topography (with maximum height of order 30% of the CBL depth) does not significantly change the orientation and spacing, nor the time of initial occurrence of modelled rolls, but local flow anomalies can be related to the hills. These anomalies are related to coherent patterns in the diagnosed cloud fields, with a tendency for more cloud cover upstream and over hills, and cloud clearing in the lee as a result of descent suppressing convective eddies. This kind of control of the shallow convection by the topography is evident in the satellite imagery.

  17. Fault feature extraction of rolling element bearings using sparse representation

    NASA Astrophysics Data System (ADS)

    He, Guolin; Ding, Kang; Lin, Huibin

    2016-03-01

    Influenced by factors such as speed fluctuation, rolling element sliding and periodical variation of load distribution and impact force on the measuring direction of sensor, the impulse response signals caused by defective rolling bearing are non-stationary, and the amplitudes of the impulse may even drop to zero when the fault is out of load zone. The non-stationary characteristic and impulse missing phenomenon reduce the effectiveness of the commonly used demodulation method on rolling element bearing fault diagnosis. Based on sparse representation theories, a new approach for fault diagnosis of rolling element bearing is proposed. The over-complete dictionary is constructed by the unit impulse response function of damped second-order system, whose natural frequencies and relative damping ratios are directly identified from the fault signal by correlation filtering method. It leads to a high similarity between atoms and defect induced impulse, and also a sharply reduction of the redundancy of the dictionary. To improve the matching accuracy and calculation speed of sparse coefficient solving, the fault signal is divided into segments and the matching pursuit algorithm is carried out by segments. After splicing together all the reconstructed signals, the fault feature is extracted successfully. The simulation and experimental results show that the proposed method is effective for the fault diagnosis of rolling element bearing in large rolling element sliding and low signal to noise ratio circumstances.

  18. Micropatterned surfaces for controlling cell adhesion and rolling under flow.

    PubMed

    Nalayanda, Divya D; Kalukanimuttam, Mahendran; Schmidtke, David W

    2007-04-01

    Cell adhesion and rolling on the vascular wall is critical to both inflammation and thrombosis. In this study we demonstrate the feasibility of using microfluidic patterning for controlling cell adhesion and rolling under physiological flow conditions. By controlling the width of the lines (50-1000 microm) and the spacing between them (50-100 microm) we were able to fabricate surfaces with well-defined patterns of adhesion molecules. We demonstrate the versatility of this technique by patterning surfaces with 3 different adhesion molecules (P-selectin, E-selectin, and von Willebrand Factor) and controlling the adhesion and rolling of three different cell types (neutrophils, Chinese Hamster Ovary cells, and platelets). By varying the concentration of the incubating solution we could control the surface ligand density and hence the cell rolling velocity. Finally by patterning surfaces with both P-selectin and von Willebrand Factor we could control the rolling of both leukocytes and platelets simultaneously. The technique described in this paper provides and effective and inexpensive way to fabricate patterned surfaces for use in cell rolling assays under physiologic flow conditions. PMID:17160704

  19. Numerical Study of a Four-Roll Coating System

    NASA Astrophysics Data System (ADS)

    Tsuda, Takeaki

    The characteristics of a four-roll coating system were numerically investigated and compared with experimental data to validate the theoretical models used in this study. In the theoretical models, a film splitting model using a power-law-type equation, a roll-gap model based on elastohydrodynamics, and a flow model from a rotating-cylinder system were applied. The parametric computations for each operational condition revealed the steady and dynamic behaviors of a coating film and liquid films on the coating rolls. The results of the frequency response to the speed disturbances of the coating rolls indicated that the sensitivity of the lowest coating roll to the disturbance was half that of the others; this implies that the requirement for the accuracy of a driving system of the coating roll is not as severe as compared with others. The experimental data and the numerical results at steady state agreed well. Therefore, the theoretical models used in this research were found to be appropriate.

  20. Rolling-Element Fatigue Testing and Data Analysis - A Tutorial

    NASA Technical Reports Server (NTRS)

    Vlcek, Brian L.; Zaretsky, Erwin V.

    2011-01-01

    In order to rank bearing materials, lubricants and other design variables using rolling-element bench type fatigue testing of bearing components and full-scale rolling-element bearing tests, the investigator needs to be cognizant of the variables that affect rolling-element fatigue life and be able to maintain and control them within an acceptable experimental tolerance. Once these variables are controlled, the number of tests and the test conditions must be specified to assure reasonable statistical certainty of the final results. There is a reasonable correlation between the results from elemental test rigs with those results obtained with full-scale bearings. Using the statistical methods of W. Weibull and L. Johnson, the minimum number of tests required can be determined. This paper brings together and discusses the technical aspects of rolling-element fatigue testing and data analysis as well as making recommendations to assure quality and reliable testing of rolling-element specimens and full-scale rolling-element bearings.

  1. Continuous roll-to-roll amorphous silicon photovoltaic manufacturing technology. Semiannual subcontract report, 1 April 1993--30 September 1993

    SciTech Connect

    Izu, M

    1994-06-01

    This report describes work for this reporting period under a 3-year program to advance Energy Conversion Device`s (ECD) roll-to-roll, triple-junction photovoltaic (PV) manufacturing technologies, to reduce the module production costs, to increase the stabilized module performance, and to expand commercial production capacity utilizing ECD technology. The specific 3-year goal is to develop advanced large-scale manufacturing technology incorporating ECD`s earlier research advances with the capability of producing modules with stable 11% efficiency at a cost of approximately $1.00 per peak watt. Major accomplishments during this reporting period include (1) the design, construction. amd testomg of a continuous roll-to-roll multipurpose amorphous silicon alloy solar cell deposition machine that incorporates improvements necessary to obtain higher efficiency solar cells; (2) development of a photothermal deflection spectroscopy (PDS) technique for evaluating back-reflector systems; (3) the development of an improved textured Ag/ZnO back-reflector system demonstrating 25% gain in J{sub sc} over previous textured Al back-reflector systems; and (4) the design of a serpentine web continuous roll-to-roll deposition chamber.

  2. Development of a continuous roll-to-roll processing system for mass production of plastic optical film

    NASA Astrophysics Data System (ADS)

    Chang, Chih-Yuan; Tsai, Meng-Hsun

    2015-12-01

    This paper reports a highly effective method for the mass production of large-area plastic optical films with a microlens array pattern based on a continuous roll-to-roll film extrusion and roller embossing process. In this study, a thin steel mold with a micro-circular hole array pattern is fabricated by photolithography and a wet chemical etching process. The thin steel mold was then wrapped onto a metal cylinder to form an embossing roller mold. During the roll-to-roll process operation, a thermoplastic raw material (polycarbonate grains) was put into the barrel of the plastic extruder with a flat T-die. Then, the molten polymer film was extruded and immediately pressed against the surface of the embossing roller mold. Under the proper processing conditions, the molten polymer will just partially fill the micro-circular holes of the mold and due to surface tension form a convex lens surface. A continuous plastic optical film with a microlens array pattern was obtained. Experiments are carried out to investigate the effect of plastic microlens formation on the roll-to-roll process. Finally, the geometrical and optical properties of the fabricated plastic optical film were measured and proved satisfactory. This technique shows great potential for the mass production of large-area plastic optical films with a microlens array pattern.

  3. Transforming Roving-Rolling Explorer (TRREx) for Planetary Exploration

    NASA Astrophysics Data System (ADS)

    Edwin, Lionel Ernest

    All planetary surface exploration missions thus far have employed traditional rovers with a rocker-bogie suspension. These rovers can navigate moderately rough and flat terrain, but are not designed to traverse rugged terrain with steep slopes. The fact is, however, that many scientifically interesting missions require exploration platforms with capabilities for navigating such types of chaotic terrain. This issue motivates the development of new kinds of rovers that take advantage of the latest advances in robotic technologies to traverse rugged terrain efficiently. This dissertation proposes and analyses one such rover concept called the Transforming Roving-Rolling Explorer (TRREx) that is principally aimed at addressing the above issue. Biologically inspired by the way the armadillo curls up into a ball when threatened, and the way the golden wheel spider uses the dynamic advantages of a sphere to roll down hills when escaping danger, the novel TRREx rover can traverse like a traditional 6-wheeled rover over conventional terrain, but can also transform itself into a sphere, when necessary, to travel down steep inclines, or navigate rough terrain. This work presents the proposed design architecture and capabilities followed by the development of mathematical models and experiments that facilitate the mobility analysis of the TRREx in the rolling mode. The ability of the rover to self-propel in the rolling mode in the absence of a negative gradient increases its versatility and concept value. Therefore, a dynamic model of a planar version of the problem is first used to investigate the feasibility and value of such self-propelled locomotion - 'actuated rolling'. Construction and testing of a prototype Planar/Cylindrical TRREx that is capable of demonstrating actuated rolling is presented, and the results from the planar dynamic model are experimentally validated. This planar model is then built upon to develop a mathematical model of the spherical TRREx in the

  4. Roll-to-Roll Screen Printed Radio Frequency Identification Transponder Antennas for Vehicle Tracking Systems

    NASA Astrophysics Data System (ADS)

    Zichner, Ralf; Baumann, Reinhard R.

    2013-05-01

    Vehicle tracking systems based on ultra high frequency (UHF) radio frequency identification (RFID) technology are already introduced to control the access to car parks and corporate premises. For this field of application so-called Windshield RFID transponder labels are used, which are applied to the inside of the windshield. State of the art for manufacturing these transponder antennas is the traditional lithography/etching approach. Furthermore the performance of these transponders is limited to a reading distance of approximately 5 m which results in car speed limit of 5 km/h for identification. However, to achieve improved performance compared to existing all-purpose transponders and a dramatic cost reduction, an optimized antenna design is needed which takes into account the special dielectric and in particular metallic car environment of the tag and an roll-to-roll (R2R) printing manufacturing process. In this paper we focus on the development of a customized UHF RFID transponder antenna design, which is adopted for vehicle geometry as well as R2R screen printing manufacturing processes.

  5. Roll-to-roll production of 30-inch graphene films for transparent electrodes

    NASA Astrophysics Data System (ADS)

    Hong, Byung Hee

    2011-03-01

    The outstanding electrical1, mechanical and chemical properties of graphene make it attractive for applications in flexible electronics. However, efforts to make transparent conducting films from graphene have been hampered by the lack of efficient methods for the synthesis, transfer and doping of graphene at the scale and quality required for applications. Here, we report the roll-to-roll production and wet-chemical doping of predominantly monolayer 30-inch graphene films grown by chemical vapour deposition onto flexible copper substrates. The films have sheet resistances as low as ~ 125 Ohm/sq with 97.4% optical transmittance, and exhibit the half-integer quantum Hall effect, indicating their high quality. We further use layer-by-layer stacking to fabricate a doped four-layer film and measure its sheet resistance at values as low as ~ 30 Ohm/sq at ~ 90 % transparency, which is superior to commercial transparent electrodes such as indium tin oxides. Graphene electrodes were incorporated into a fully functional touch-screen panel device capable of withstanding high strain. Work done in collaboration with Sukang Bae, Hyeongkeun Kim, Youngbin Lee, and Jong-Hyun Ahn, Sungkyunkwan University.

  6. Patterned immobilization of antibodies within roll-to-roll hot embossed polymeric microfluidic channels.

    PubMed

    Feyssa, Belachew; Liedert, Christina; Kivimaki, Liisa; Johansson, Leena-Sisko; Jantunen, Heli; Hakalahti, Leena

    2013-01-01

    This paper describes a method for the patterned immobilization of capture antibodies into a microfluidic platform fabricated by roll-to-roll (R2R) hot embossing on poly (methyl methacrylate) (PMMA). Covalent attachment of antibodies was achieved by two sequential inkjet printing steps. First, a polyethyleneimine (PEI) layer was deposited onto oxygen plasma activated PMMA foil and further cross-linked with glutaraldehyde (GA) to provide an amine-reactive aldehyde surface (PEI-GA). This step was followed by a second deposition of antibody by overprinting on the PEI-GA patterned PMMA foil. The PEI polymer ink was first formulated to ensure stable drop formation in inkjet printing and the printed films were characterized using atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS). Anti-CRP antibody was patterned on PMMA foil by the developed method and bonded permanently with R2R hot embossed PMMA microchannels by solvent bonding lamination. The functionality of the immobilized antibody inside the microfluidic channel was evaluated by fluorescence-based sandwich immunoassay for detection of C-reactive protein (CRP). The antibody-antigen assay exhibited a good level of linearity over the range of 10 ng/ml to 500 ng/ml (R(2) = 0.991) with a calculated detection limit of 5.2 ng/ml. The developed patterning method is straightforward, rapid and provides a versatile approach for creating multiple protein patterns in a single microfluidic channel for multiplexed immunoassays.

  7. Patterned Immobilization of Antibodies within Roll-to-Roll Hot Embossed Polymeric Microfluidic Channels

    PubMed Central

    Feyssa, Belachew; Liedert, Christina; Kivimaki, Liisa; Johansson, Leena-Sisko; Jantunen, Heli; Hakalahti, Leena

    2013-01-01

    This paper describes a method for the patterned immobilization of capture antibodies into a microfluidic platform fabricated by roll-to-roll (R2R) hot embossing on poly (methyl methacrylate) (PMMA). Covalent attachment of antibodies was achieved by two sequential inkjet printing steps. First, a polyethyleneimine (PEI) layer was deposited onto oxygen plasma activated PMMA foil and further cross-linked with glutaraldehyde (GA) to provide an amine-reactive aldehyde surface (PEI-GA). This step was followed by a second deposition of antibody by overprinting on the PEI-GA patterned PMMA foil. The PEI polymer ink was first formulated to ensure stable drop formation in inkjet printing and the printed films were characterized using atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS). Anti-CRP antibody was patterned on PMMA foil by the developed method and bonded permanently with R2R hot embossed PMMA microchannels by solvent bonding lamination. The functionality of the immobilized antibody inside the microfluidic channel was evaluated by fluorescence-based sandwich immunoassay for detection of C-reactive protein (CRP). The antibody-antigen assay exhibited a good level of linearity over the range of 10 ng/ml to 500 ng/ml (R2 = 0.991) with a calculated detection limit of 5.2 ng/ml. The developed patterning method is straightforward, rapid and provides a versatile approach for creating multiple protein patterns in a single microfluidic channel for multiplexed immunoassays. PMID:23874811

  8. Roll-to-Roll Solution-Processible Small-Molecule OLEDs

    SciTech Connect

    Liu, Jie Jerry

    2012-07-31

    The objective of this program is to develop key knowledge and make critical connections between technologies needed to enable low-cost manufacturing of OLED lighting products. In particular, the program was intended to demonstrate the feasibility of making high performance Small-Molecule OLEDs (SM-OLED) using a roll-to-roll (R2R) wet-coating technique by addressing the following technical risks (1) Whether the wet-coating technique can provide high performance OLEDs, (2) Whether SM-OLED can be made in a R2R manner, (3) What are the requirements for coating equipment, and (4) Whether R2R OLEDs can have the same performance as the lab controls. The program has been managed and executed according to the Program Management Plan (PMP) that was first developed at the beginning of the program and further revised accordingly as the program progressed. Significant progress and risk reductions have been accomplished by the end of the program. Specific achievements include: (1) Demonstrated that wet-coating can provide OLEDs with high LPW and long lifetime; (2) Demonstrated R2R OLEDs can be as efficient as batch controls (Figure 1) (3) Developed & validated basic designs for key equipment necessary for R2R SM-OLEDs; (4) Developed know-hows & specifications on materials & ink formulations critical to wetcoating; (5) Developed key R2R processes for each OLED layer (6) Identified key materials and components such as flexible barrier substrates necessary for R2R OLEDs.

  9. Roll-to-roll embedded conductive structures integrated into organic photovoltaic devices

    NASA Astrophysics Data System (ADS)

    van de Wiel, H. J.; Galagan, Y.; van Lammeren, T. J.; de Riet, J. F. J.; Gilot, J.; Nagelkerke, M. G. M.; Lelieveld, R. H. C. A. T.; Shanmugam, S.; Pagudala, A.; Hui, D.; Groen, W. A.

    2013-12-01

    Highly conductive screen printed metallic (silver) structures (current collecting grids) combined with poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) are a viable replacement for indium tin oxide (ITO) and inkjet printed silver as transparent electrode materials. To provide successful integration into organic photovoltaic (OPV) devices, screen printed silver current collecting grids should be embedded into a substrate to avoid topology issues. In this study micron-thick conductive structures are embedded and integrated into OPV devices. The embedded structures are produced roll-to-roll with optimized process settings and materials. Topology measurements show that the embedded grids are well suited for integration into OPV devices since the surface is almost without spikes and has low surface roughness. JV measurements of OPV devices with embedded structures on a polyethylene terephthalate/silicon nitride (PET/SiN) substrate show an efficiency of 2.15%, which is significantly higher than identical flexible devices with ITO (1.02%) and inkjet printed silver (1.48%). The use of embedded screen printed silver instead of ITO and inkjet printed silver in OPV devices will allow for higher efficiency devices which can be produced with larger design and process freedom.

  10. Reduced Blood Coagulation on Roll-to-Roll, Shrink-Induced Superhydrophobic Plastics.

    PubMed

    Nokes, Jolie M; Liedert, Ralph; Kim, Monica Y; Siddiqui, Ali; Chu, Michael; Lee, Eugene K; Khine, Michelle

    2016-03-01

    The unique antiwetting properties of superhydrophobic (SH) surfaces prevent the adhesion of water and bodily fluids, including blood, urine, and saliva. While typical manufacturable approaches to create SH surfaces rely on chemical and structural modifications, such approaches are expensive, require postprocessing, and are often not biocompatible. By contrast, it is demonstrated that purely structural SH features are easily formed using high throughput roll-to-roll (R2R) manufacturing by shrinking a prestressed thermoplastic with a thin, stiff layer of silver and calcium. These features are subsequently embossed into any commercially available and Food and Drug Administration (FDA)-approved plastic. The R2R SH surfaces have contact angles >150° and contact angle hysteresis <10°. Importantly, the surfaces minimize blood adhesion, leading to reduced blood coagulation without the need for anticoagulants. SH surfaces have >4200× reduction of blood residue area compared to the nonstructured controls of the same material. In addition, blood clotting is reduced >5× using whole blood directly from the patient. Furthermore, these surfaces can be easily configured into 3D shapes, as demonstrated with SH tubes. With the simple scale-up production and the eliminated need for anticoagulants to prevent clotting, the proposed conformable SH surfaces can be impactful for a wide range of medical tools, including catheters and microfluidic channels. PMID:26784916

  11. In-line roll-to-roll metrology for flexible electronics

    NASA Astrophysics Data System (ADS)

    Kimbrough, Brad

    2015-09-01

    The flexible electronics market continues to grow at a rapid pace. Increasing numbers of applications employ the flexible components including displays, biomedical devices, smart apparel, and advanced sensors. To maintain performance and lifetime, many characteristics of the substrate and deposited layers must be monitored. This includes defects, surface roughness, and feature alignment. Ideally, in-situ metrology can be employed in roll-to-roll (R2R) equipment to allow for real-time process control. This presents the necessary three-dimensional metrology system with several challenging requirements: high vertical and transverse resolution, large field-of-view, extremely fast measurement times, and robust vibration immunity. This paper will discuss the design and performance of a compact, low-cost, large-field interferometric probe for in-situ measurement of R2R substrates. Samples with a variety of known and unknown features and roughnesses will be measured to characterize the performance of the system. Static and moving substrates will be measured to examine effects on results. Optimization of processing to allow for on-board analysis will be examined. Lastly, the paper will discuss how such probes may be arrayed to provide a high degree of areal coverage of the flexible substrate under test.

  12. Patterned immobilization of antibodies within roll-to-roll hot embossed polymeric microfluidic channels.

    PubMed

    Feyssa, Belachew; Liedert, Christina; Kivimaki, Liisa; Johansson, Leena-Sisko; Jantunen, Heli; Hakalahti, Leena

    2013-01-01

    This paper describes a method for the patterned immobilization of capture antibodies into a microfluidic platform fabricated by roll-to-roll (R2R) hot embossing on poly (methyl methacrylate) (PMMA). Covalent attachment of antibodies was achieved by two sequential inkjet printing steps. First, a polyethyleneimine (PEI) layer was deposited onto oxygen plasma activated PMMA foil and further cross-linked with glutaraldehyde (GA) to provide an amine-reactive aldehyde surface (PEI-GA). This step was followed by a second deposition of antibody by overprinting on the PEI-GA patterned PMMA foil. The PEI polymer ink was first formulated to ensure stable drop formation in inkjet printing and the printed films were characterized using atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS). Anti-CRP antibody was patterned on PMMA foil by the developed method and bonded permanently with R2R hot embossed PMMA microchannels by solvent bonding lamination. The functionality of the immobilized antibody inside the microfluidic channel was evaluated by fluorescence-based sandwich immunoassay for detection of C-reactive protein (CRP). The antibody-antigen assay exhibited a good level of linearity over the range of 10 ng/ml to 500 ng/ml (R(2) = 0.991) with a calculated detection limit of 5.2 ng/ml. The developed patterning method is straightforward, rapid and provides a versatile approach for creating multiple protein patterns in a single microfluidic channel for multiplexed immunoassays. PMID:23874811

  13. Multivariable passive RFID vapor sensors: roll-to-roll fabrication on a flexible substrate.

    PubMed

    Potyrailo, Radislav A; Burns, Andrew; Surman, Cheryl; Lee, D J; McGinniss, Edward

    2012-06-21

    We demonstrate roll-to-roll (R2R) fabrication of highly selective, battery-free radio frequency identification (RFID) sensors on a flexible polyethylene terephthalate (PET) polymeric substrate. Selectivity of our developed RFID sensors is provided by measurements of their resonance impedance spectra, followed by the multivariate analysis of spectral features, and correlation of these spectral features to the concentrations of vapors of interest. The multivariate analysis of spectral features also provides the ability for the rejection of ambient interferences. As a demonstration of our R2R fabrication process, we employed polyetherurethane (PEUT) as a "classic" sensing material, extruded this sensing material as 25, 75, and 125-μm thick films, and thermally laminated the films onto RFID inlays, rapidly producing approximately 5000 vapor sensors. We further tested these RFID vapor sensors for their response selectivity toward several model vapors such as toluene, acetone, and ethanol as well as water vapor as an abundant interferent. Our RFID sensing concept features 16-bit resolution provided by the sensor reader, granting a highly desired independence from costly proprietary RFID memory chips with a low-resolution analog input. Future steps are being planned for field-testing of these sensors in numerous conditions.

  14. 75 FR 64246 - Certain Hot-Rolled Flat-Rolled Carbon-Quality Steel Products From Brazil: Correction to Notice of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-19

    ... Japan, 64 FR 34778 (June 29, 1999). Hot-rolled steel coil which meets the following chemical, physical... Products From Brazil, 67 FR 11093 (March 12, 2002) (``Order''). The Order states incorrectly that ``certain... International Trade Administration Certain Hot-Rolled Flat-Rolled Carbon-Quality Steel Products From...

  15. Experiments on spray from a rolling tire

    NASA Astrophysics Data System (ADS)

    Radovich, Charles Anthony

    A novel laboratory apparatus has been built to understand the key mechanisms behind spray emerging from a rolling tire. Several researchers have assessed the performance of spray suppression devices; however, there are no known efforts that address the question "what needs to be suppressed?" This investigation into how water in a tire groove evolves into a droplet field will ultimately contribute to driver safety. Using high-speed imaging, water passing through a single circumferential groove was observed to leave the tire patch in the form of a thin liquid sheet, connecting the roadway and the tire. The sheet disintegrates into a droplet field and the breakup modes associated with this decay were identified with respect to Weber number. Weber numbers based on the properties of water, tire speed and tire groove width were tested at 2700, 10900 and 24400. Measurements for the breakup length of the liquid sheet showed a dependence on Weber number proportional to We-1/6. The lateral displacement of the water exiting the tire patch was also measured. These tests showed the overall size of the spray field grows with We; however, the maximum water volume for all We's was delivered to the same distance from the road. Downstream from the tire patch, a determination of the droplet field was performed. From this study, the distribution of droplet sizes was determined as a function of Weber number. At We = 2,700, droplet sizes between 80 and 9000 microm were detected, with a mean diameter near 800 microm. Both the range of droplet sizes and the mean diameter were found to decrease with Weber number by approximately We-1/2. Based on these size distributions, Correlation Image Velocimetry (CIV) was used to estimate the distribution of droplet velocities as function of their size. These results reveal a strong correlation between droplet diameter and velocity which is comparable to that predicted for a simple sphere.

  16. Photogrammetric Accuracy and Modeling of Rolling Shutter Cameras

    NASA Astrophysics Data System (ADS)

    Vautherin, Jonas; Rutishauser, Simon; Schneider-Zapp, Klaus; Choi, Hon Fai; Chovancova, Venera; Glass, Alexis; Strecha, Christoph

    2016-06-01

    Unmanned aerial vehicles (UAVs) are becoming increasingly popular in professional mapping for stockpile analysis, construction site monitoring, and many other applications. Due to their robustness and competitive pricing, consumer UAVs are used more and more for these applications, but they are usually equipped with rolling shutter cameras. This is a significant obstacle when it comes to extracting high accuracy measurements using available photogrammetry software packages. In this paper, we evaluate the impact of the rolling shutter cameras of typical consumer UAVs on the accuracy of a 3D reconstruction. Hereto, we use a beta-version of the Pix4Dmapper 2.1 software to compare traditional (non rolling shutter) camera models against a newly implemented rolling shutter model with respect to both the accuracy of geo-referenced validation points and to the quality of the motion estimation. Multiple datasets have been acquired using popular quadrocopters (DJI Phantom 2 Vision+, DJI Inspire 1 and 3DR Solo) following a grid flight plan. For comparison, we acquired a dataset using a professional mapping drone (senseFly eBee) equipped with a global shutter camera. The bundle block adjustment of each dataset shows a significant accuracy improvement on validation ground control points when applying the new rolling shutter camera model for flights at higher speed (8m=s). Competitive accuracies can be obtained by using the rolling shutter model, although global shutter cameras are still superior. Furthermore, we are able to show that the speed of the drone (and its direction) can be solely estimated from the rolling shutter effect of the camera.

  17. The Foam Roll as a Tool to Improve Hamstring Flexibility.

    PubMed

    Junker, Daniel H; Stöggl, Thomas L

    2015-12-01

    Although foam rolling is a common myofascial therapy used to increase range of motion (ROM), research is limited on the effectiveness of foam rolling on soft tissue extensibility. The aim of this study was to determine the effect of a 4-week training period of the foam roll method on hamstring flexibility. Furthermore, the study was designed to compare the effectiveness of the foam roll myofascial release with a conventional contract-relax proprioceptive neuromuscular facilitation (PNF) stretching method and a control group. Forty healthy males (age: 17-47 years) were randomly assigned to a foam roll group (FOAM, n = 13), a contract-relax PNF stretching group (CRPNF, n = 14), or a control group (CG, n = 13). The FOAM group massaged their hamstring muscles with the foam roll 3 times per week for 4 weeks (12 training sessions). The CRPNF group was assigned to 12 sessions of contract-relax PNF stretching. The CG underwent no intervention. Hamstring flexibility (ROM) was measured by a stand-and-reach test before and after the intervention period. Two-way repeated-measures analysis of variance showed a significant global time effect (p < 0.001) and an interaction effect for time × treatment (p = 0.004), demonstrating greater improvements in the FOAM and CRPNF compared with the CG, but no difference between the former. Delta changes from baseline to postintervention in ROM were not related to baseline ROM. The foam roll can be seen as an effective tool to increase hamstring flexibility within 4 weeks. The effects are comparable with the scientifically proven contract-relax PNF stretching method.

  18. The Foam Roll as a Tool to Improve Hamstring Flexibility.

    PubMed

    Junker, Daniel H; Stöggl, Thomas L

    2015-12-01

    Although foam rolling is a common myofascial therapy used to increase range of motion (ROM), research is limited on the effectiveness of foam rolling on soft tissue extensibility. The aim of this study was to determine the effect of a 4-week training period of the foam roll method on hamstring flexibility. Furthermore, the study was designed to compare the effectiveness of the foam roll myofascial release with a conventional contract-relax proprioceptive neuromuscular facilitation (PNF) stretching method and a control group. Forty healthy males (age: 17-47 years) were randomly assigned to a foam roll group (FOAM, n = 13), a contract-relax PNF stretching group (CRPNF, n = 14), or a control group (CG, n = 13). The FOAM group massaged their hamstring muscles with the foam roll 3 times per week for 4 weeks (12 training sessions). The CRPNF group was assigned to 12 sessions of contract-relax PNF stretching. The CG underwent no intervention. Hamstring flexibility (ROM) was measured by a stand-and-reach test before and after the intervention period. Two-way repeated-measures analysis of variance showed a significant global time effect (p < 0.001) and an interaction effect for time × treatment (p = 0.004), demonstrating greater improvements in the FOAM and CRPNF compared with the CG, but no difference between the former. Delta changes from baseline to postintervention in ROM were not related to baseline ROM. The foam roll can be seen as an effective tool to increase hamstring flexibility within 4 weeks. The effects are comparable with the scientifically proven contract-relax PNF stretching method. PMID:25992660

  19. Experimental and Theoretical Study on Minimum Achievable Foil Thickness during Asymmetric Rolling

    PubMed Central

    Tang, Delin; Liu, Xianghua; Song, Meng; Yu, Hailiang

    2014-01-01

    Parts produced by microforming are becoming ever smaller. Similarly, the foils required in micro-machines are becoming ever thinner. The asymmetric rolling technique is capable of producing foils that are thinner than those produced by the conventional rolling technique. The difference between asymmetric rolling and conventional rolling is the ‘cross-shear’ zone. However, the influence of the cross-shear zone on the minimum achievable foil thickness during asymmetric rolling is still uncertain. In this paper, we report experiments designed to understand this critical influencing factor on the minimum achievable thickness in asymmetric rolling. Results showed that the minimum achievable thickness of rolled foils produced by asymmetric rolling with a rolling speed ratio of 1.3 can be reduced to about 30% of that possible by conventional rolling technique. Furthermore, the minimum achievable thickness during asymmetric rolling could be correlated to the cross-shear ratio, which, in turn, could be related to the rolling speed ratio. From the experimental results, a formula to calculate the minimum achievable thickness was established, considering the parameters cross-shear ratio, friction coefficient, work roll radius, etc. in asymmetric rolling. PMID:25203265

  20. Rolling Motions During Solar Prominence Eruptions in Asymmetric Magnetic Environments

    NASA Astrophysics Data System (ADS)

    McKillop, Sean; Miralles, Mari Paz; Murphy, Nicholas Arnold; McCauley, Patrick

    2014-06-01

    Panasenco et al. [1] report observations of several CMEs that display a rolling motion about the axis of the erupting prominence. Murphy et al. [2] present simulations of line-tied asymmetric magnetic reconnection that make a falsifiable prediction regarding the handedness of rolling motions of flux ropes during solar eruptions. We will present initial results of our work to investigate this prediction. To determine the strength and any asymmetric properties of the magnetic field in the regions of interest in the photosphere, we use magnetograms from HMI. We use AIA observations to determine if there is any rolling motion and, if so, what handedness the rolling motions have. We then compare the photospheric magnetic information with the handedness information to determine if there is any relationship between the two. Finally, we will discuss prospects for diagnosing rolling motions of erupting prominence using off-limb IRIS observations.[1] O. Panasenco, S. Martin, A. D. Joshi, & N. Srivastava, J. Atmos. Sol.-Terr. Phys., 73, 1129 (2011)[2] N. A. Murphy, M. P. Miralles, C. L. Pope, J. C. Raymond, H. D. Winter, K. K. Reeves, D. B. Seaton, A. A. van Ballegooijen, & J. Lin, ApJ, 751, 56 (2012)

  1. Do Liquid Drops on Inclined Surfaces Slide or Roll?

    NASA Astrophysics Data System (ADS)

    Pt, Sumesh; Pagonabarraga, Ignacio; Adhikari, Ronojoy; Govindarajan, Rama

    2011-11-01

    A solid sphere is likely to roll, while a rectangular box is likely to slide, on an inclined surface. Instead, a liquid drop can exhibit a variety of shapes and complex but interesting dynamics. We obtain global minimum energy static shapes first, for two realistic bases of potential energy, front and back-pinned. We find that the free end always assumes Young's equilibrium angle. Using this clue, simple equations describing the angles and the maximum volume may be derived. Combining the lattice Boltzmann method for hydrodynamics and method of lines for a Cahn-Hilliard equation, a hybrid numerical scheme is developed to study the dynamics of binary fluids on an inclined plate. The contribution of pure translation, and the vorticities associated with rolling and shearing motion are distinguished, using which the motion of the drop can be split into roll and slip. Surprisingly, as gravity increases, the fraction of motion due to roll decreases significantly for certain contact angles. The rolling motion is strongly dependent on the slip length which is in contrast to predictions by the lubrication approximation, where all dependence on the slip length is generally logarithamic.

  2. A MIP Model for Rolling Horizon Surgery Scheduling.

    PubMed

    Luo, Li; Luo, Yong; You, Yang; Cheng, Yuanjun; Shi, Yingkang; Gong, Renrong

    2016-05-01

    Most surgery scheduling is done 1 day in advance. Caused by lack of overall planning, this scheduling scheme often results in unbalanced occupancy time of the operating rooms. So we put forward a rolling horizon mixed integer programming model for the scheduling. Rolling horizon scheduling refers to a scheduling scheme in which cyclic surgical requests are taken into account. Surgical requests are updated daily. The completed surgeries are eliminated, and new surgeries are added to the scheduling list. Considering day-to-day demand for surgery, we develop a non-rolling scheduling model (NRSM) and a rolling horizon scheduling model (RSM). By comparing the two, we find that the quality of surgery scheduling is significantly influenced by the variation in demand from day to day. A rolling horizon scheduling will enable a more flexible planning of the pool of surgeries that have not been scheduled into this main blocks, and hence minimize the idle time of operating rooms. The strategy of the RSM helps balance the occupancy time among operating rooms. Using surgical data from five departments of the West China Hospital (WCH), we generate surgical demands randomly to compare the NRSM and the RSM. The results show the operating rooms' average utilization rate using RSM is significantly higher than when applying NRSM.

  3. Twisting/Rolling Motions and Chirality in Filament Eruptions

    NASA Astrophysics Data System (ADS)

    McKillop, S.; Murphy, N. A.; Miralles, M. P.; McCauley, P.; Su, Y.

    2015-12-01

    Panasenco et al. [1] report observations of several CMEs that display a rolling motion about the axis of the erupting prominence. Murphy et al. [2] present simulations of line-tied asymmetric magnetic reconnection that make a falsifiable prediction regarding the handedness of rolling motions of flux ropes during solar eruptions. Mass motions in prominence eruptions tend to be complicated, and characterizing these motions is a challenge. We use the AIA filament eruption catalog [3] as a source for finding events. If rolling motions are detected then we will investigate the handedness prediction. We use magnetograms from HMI to determine the strength and asymmetric properties of the photospheric magnetic field in the regions of interest and will use AIA observations to determine the handedness of the rolling motions. We then compare the photospheric magnetic information with the handedness to determine if there is a relationship between the two. The AIA filament eruption catalog is a great source for finding events, but it lacks a chirality determination. We aim to add these determinations and then compare the chirality with the directionality of the twisting/rolling motions. [1] O. Panasenco, S. Martin, A. D. Joshi, & N. Srivastava, J. Atmos. Sol.-Terr. Phys., 73, 1129 (2011) [2] N. A. Murphy, M. P. Miralles, C. L. Pope, J. C. Raymond, H. D. Winter, K. K. Reeves, D. B. Seaton, A. A. van Ballegooijen, & J. Lin, ApJ, 751, 56 (2012) [3] http://aia.cfa.harvard.edu/filament/

  4. Towards identifying the roll motion parameters of a motorcycle simulator.

    PubMed

    Shahar, Amit; Dagonneau, Virginie; Caro, Séphane; Israël, Isabelle; Lobjois, Régis

    2014-05-01

    This study aimed at identifying the roll motion parameters of a motorcycle simulator prototype. Experienced motorcyclists tuned the angular physical movement of the mock-up and that of the visual scene to achieve an optimal riding experience during curves. The participants exceeded the rolling angles that would be required in real-world riding, while avoiding leaning the mock-up beyond 10°. In addition, they were more influenced by the speed of the virtual motorcycle than by road curvature, especially in a wide field of view. Heterogeneity was found in the roll applied to the visual scene. The overall patterns suggest that at least when washout is not applied to remove the side forces that in real-world riding are compensated by a centrifugal force, greater roll of the visual at the expense of the mock-up is mandatory to avoid performance biases that might be enhanced due to fear of falling off the simulator. Future roll motion models must take into consideration factors such as riding postures, which might not only influence the forces operating on the rider-motorcycle system, but also how motorcyclists perceive the visual world.

  5. On the sound radiation of a rolling tyre

    NASA Astrophysics Data System (ADS)

    Kropp, Wolfgang; Sabiniarz, Patrick; Brick, Haike; Beckenbauer, Thomas

    2012-04-01

    The sound radiation from rolling tyres is still not very well understood. Although details such as horn effect or directivity during rolling have been investigated, it is not clear which vibrational modes of the tyre structure are responsible for the radiated sound power. In this work an advanced tyre model based on Wave Guide Finite Elements is used in connection with a contact model validated in previous work. With these tools the tyre vibrations during rolling on an ISO surface are simulated. Starting from the calculated contact forces in time the amplitudes of the modes excited during rolling are determined as function of frequency. A boundary element model also validated in previous work is applied to predict the sound pressure level on a reference surface around a tyre placed on rigid ground as function of the modal composition of the tyre vibrations. Taking into account different modes when calculating the vibrational field as input into the boundary element calculations, it is possible to identify individual modes or groups of modes of special relevance for the radiated sound power. The results show that mainly low-order modes with relative low amplitudes but high radiation efficiency in the frequency range around 1 kHz are responsible for the radiated sound power at these frequencies, while those modes which are most strongly excited in that frequency range during rolling are irrelevant for the radiated sound power. This fact is very essential when focusing on the design of quieter tyres.

  6. Geometrical accuracy improvement in flexible roll forming lines

    NASA Astrophysics Data System (ADS)

    Larrañaga, J.; Berner, S.; Galdos, L.; Groche, P.

    2011-01-01

    The general interest to produce profiles with variable cross section in a cost-effective way has increased in the last few years. The flexible roll forming process allows producing profiles with variable cross section lengthwise in a continuous way. Until now, only a few flexible roll forming lines were developed and built up. Apart from the flange wrinkling along the transition zone of u-profiles with variable cross section, the process limits have not been investigated and solutions for shape deviations are unknown. During the PROFOM project a flexible roll forming machine has been developed with the objective of producing high technological components for automotive body structures. In order to investigate the limits of the process, different profile geometries and steel grades including high strength steels have been applied. During the first experimental tests, several errors have been identified, as a result of the complex stress states generated during the forming process. In order to improve the accuracy of the target profiles and to meet the tolerance demands of the automotive industry, a thermo-mechanical solution has been proposed. Additional mechanical devices, supporting flexible the roll forming process, have been implemented in the roll forming line together with local heating techniques. The combination of both methods shows a significant increase of the accuracy. In the present investigation, the experimental results of the validation process are presented.

  7. Dissipative descent: rocking and rolling down an incline

    NASA Astrophysics Data System (ADS)

    Balmforth, N. J.; Bush, J. W. M.; Vener, D.; Young, W. R.

    We consider the dynamics of a hollow cylindrical shell that is filled with viscous fluid and another, nested solid cylinder, and allowed to roll down an inclined plane. A mathematical model is compared to simple experiments. Two types of behaviour are observed experimentally: on steeper slopes, the device accelerates; on shallower inclines, the cylinders rock and roll unsteadily downhill, with a speed that is constant on average. The theory also predicts runaway and unsteady rolling motions. For the rolling solutions, however, the inner cylinder cannot be suspended in the fluid by the motion of the outer cylinder, and instead falls inexorably toward the outer cylinder. Whilst only occurs after an infinite time, the system slows progressively as the gap between the cylinders narrows, owing to heightened viscous dissipation. Such a deceleration is not observed in the experiments, suggesting that some mechanism limits the approach to contact. Coating the surface of the inner cylinder with sandpaper of different grades changes the rolling speed, consistent with the notion that surface roughness is responsible for limiting the acceleration.

  8. Formalizing the slow-roll approximation in inflation

    NASA Astrophysics Data System (ADS)

    Liddle, Andrew R.; Parsons, Paul; Barrow, John D.

    1994-12-01

    The meaning of the inflationary slow-roll approximation is formalized. Comparisons are made between an approach based on the Hamilton-Jacobi equations, governing the evolution of the Hubble parameter, and the usual scenario based on the evolution of the potential energy density. The vital role of the inflationary attractor solution is emphasized, and some of its properties described. We propose a new measure of inflation, based upon contraction of the comoving Hubble length as opposed to the usual e-foldings of physical expansion, and derive relevant formulas. We introduce an infinite hierarchy of slow-roll parameters, and show that only a finite number of them are required to produce results to a given order. The extension of the slow-roll approximation into an analytic slow-roll expansion, converging on the exact solution, is provided. Its role in calculations of inflationary dynamics is discussed. We explore rational approximants as a method of extending the range of convergence of the slow-roll expansion up to, and beyond, the end of inflation.

  9. CMB quadrupole suppression. II. The early fast roll stage

    SciTech Connect

    Boyanovsky, D.; Vega, H. J. de; Sanchez, N. G.

    2006-12-15

    Within the effective field theory of inflation, an initialization of the classical dynamics of the inflaton with approximate equipartition between the kinetic and potential energy of the inflaton leads to a brief fast roll stage that precedes the slow roll regime. The fast roll stage leads to an attractive potential in the wave equations for the mode functions of curvature and tensor perturbations. The evolution of the inflationary perturbations is equivalent to the scattering by this potential and a useful dictionary between the scattering data and observables is established. Implementing methods from scattering theory we prove that this attractive potential leads to a suppression of the quadrupole moment for CMB and B-mode angular power spectra. The scale of the potential is determined by the Hubble parameter during slow roll. Within the effective field theory of inflation at the grand unification (GUT) energy scale we find that if inflation lasts a total number of e-folds N{sub tot}{approx}59, there is a 10%-20% suppression of the CMB quadrupole and about 2%-4% suppression of the tensor quadrupole. The suppression of higher multipoles is smaller, falling off as 1/l{sup 2}. The suppression is much smaller for N{sub tot}>59, therefore if the observable suppression originates in the fast roll stage, there is the upper bound N{sub tot}{approx}59.

  10. Bioinspired superhydrophobic surfaces, fabricated through simple and scalable roll-to-roll processing

    PubMed Central

    Park, Sung-Hoon; Lee, Sangeui; Moreira, David; Bandaru, Prabhakar R.; Han, InTaek; Yun, Dong-Jin

    2015-01-01

    A simple, scalable, non-lithographic, technique for fabricating durable superhydrophobic (SH) surfaces, based on the fingering instabilities associated with non-Newtonian flow and shear tearing, has been developed. The high viscosity of the nanotube/elastomer paste has been exploited for the fabrication. The fabricated SH surfaces had the appearance of bristled shark skin and were robust with respect to mechanical forces. While flow instability is regarded as adverse to roll-coating processes for fabricating uniform films, we especially use the effect to create the SH surface. Along with their durability and self-cleaning capabilities, we have demonstrated drag reduction effects of the fabricated films through dynamic flow measurements. PMID:26490133

  11. Characterization of printed planar electromagnetic coils using digital extrusion and roll-to-roll flexographic processes

    NASA Astrophysics Data System (ADS)

    Rickard, Scott

    Electromagnets are a crucial component in a wide range of more complex electrical devices due to their ability to turn electrical energy into mechanical energy and vice versa. The trend for electronics becoming smaller and lighter has led to increased interest in using flat, planar electromagnetic coils, which have been shown to perform better at scaled down sizes. The two-dimensional geometry of a planar electromagnetic coil yields itself to be produced by a roll-to-roll additive manufacturing process. The emergence of the printed electronics field, which uses traditional printing processes to pattern functional inks, has led to new methods of mass-producing basic electrical components. The ability to print a planar electromagnetic coil using printed electronics could rival the traditional subtractive and semi-subtractive PCB process of manufacturing. The ability to print lightweight planar electromagnetic coils on flexible substrates could lead to their inclusion into intelligent packaging applications and could have specific use in actuating devices, transformers, and electromagnetic induction applications such as energy harvesting or wireless charging. In attempts to better understand the limitations of printing planar electromagnetic coils, the effect that the design parameters of the planar coils have on the achievable magnetic field strength were researched. A comparison between prototyping methods of digital extrusion and manufacturing scale flexographic printing are presented, discussing consistency in the printed coils and their performance in generating magnetic fields. A method to predict the performance of these planar coils is introduced to allow for design within required needs of an application. Results from the research include a demonstration of a printed coil being used in a flat speaker design, working off of actuating principles.

  12. Roll-to-roll atomic layer deposition process for flexible electronics encapsulation applications

    SciTech Connect

    Maydannik, Philipp S. Kääriäinen, Tommi O.; Lahtinen, Kimmo; Cameron, David C.; Söderlund, Mikko; Soininen, Pekka; Johansson, Petri; Kuusipalo, Jurkka; Moro, Lorenza; Zeng, Xianghui

    2014-09-01

    At present flexible electronic devices are under extensive development and, among them, flexible organic light-emitting diode displays are the closest to a large market deployment. One of the remaining unsolved challenges is high throughput production of impermeable flexible transparent barrier layers that protect sensitive light-emitting materials against ambient moisture. The present studies deal with the adaptation of the atomic layer deposition (ALD) process to high-throughput roll-to-roll production using the spatial ALD concept. We report the development of such a process for the deposition of 20 nm thickness Al{sub 2}O{sub 3} diffusion barrier layers on 500 mm wide polymer webs. The process uses trimethylaluminum and water as precursors at a substrate temperature of 105 °C. The observation of self-limiting film growth behavior and uniformity of thickness confirms the ALD growth mechanism. Water vapor transmission rates for 20 nm Al{sub 2}O{sub 3} films deposited on polyethylene naphthalate (PEN) substrates were measured as a function of substrate residence time, that is, time of exposure of the substrate to one precursor zone. Moisture permeation levels measured at 38 °C/90% relative humidity by coulometric isostatic–isobaric method were below the detection limit of the instrument (<5 × 10{sup −4} g/m{sup 2} day) for films coated at web moving speed of 0.25 m/min. Measurements using the Ca test indicated water vapor transmission rates ∼5 × 10{sup −6} g/m{sup 2} day. Optical measurements on the coated web showed minimum transmission of 80% in the visible range that is the same as the original PEN substrate.

  13. Laser processing of organic photovoltaic cells with a roll-to-roll manufacturing process

    NASA Astrophysics Data System (ADS)

    Petsch, Tino; Haenel, Jens; Clair, Maurice; Keiper, Bernd; Scholz, Christian

    2011-03-01

    Flexible large area organic photovoltaic (OPV) is currently one of the fastest developing areas of organic electronics. New light absorbing polymer blends combined with new transparent conductive materials provide higher power conversion efficiencies while new and improved production methods are developed to achieve higher throughput at reduced cost. A typical OPV is formed by TCO layers as the transparent front contact and polymers as active layer as well as interface layer between active layer and front contact. The several materials have to be patterned in order to allow for a row connection of the solar cell. 3D-Micromac used ultra-short pulsed lasers to evaluate the applicability of various wavelengths for the selective ablation of the indium tin oxide (ITO) layer and the selective ablation of the bulk hetero junction (BHJ) consisting of poly(3-hexylthiophene):phenyl-C61-butyric acid methyl ester (P3HT:PCBM) on top of a Poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate) (PEDOT:PSS) without damaging the ITO. These lasers in combination with high performance galvanometer scanning systems achieve superior scribing quality without damaging the substrate. With scribing speeds of 10 m/s and up it is possible to integrate this technology into a roll-to-roll manufacturing tool. The functionality of an OPV usually also requires an annealing step, especially when using a BHJ for the active layer consisting of P3HT:PCBM, to optimize the layers structure and therewith the efficiency of the solar cell (typically by thermal treatment, e.g. oven). The process of laser annealing was investigated using a short-pulsed laser with a wavelength close to the absorption maximum of the BHJ.

  14. Modeling of rolling element bearing mechanics. Theoretical manual

    NASA Astrophysics Data System (ADS)

    Merchant, David H.; Greenhill, Lyn M.

    1994-10-01

    This report documents the theoretical basis for the Rolling Element Bearing Analysis System (REBANS) analysis code which determines the quasistatic response to external loads or displacement of three types of high-speed rolling element bearings: angular contact ball bearings; duplex angular contact ball bearings; and cylindrical roller bearings. The model includes the effects of bearing ring and support structure flexibility. It is comprised of two main programs: the Preprocessor for Bearing Analysis (PREBAN) which creates the input files for the main analysis program; and Flexibility Enhanced Rolling Element Bearing Analysis (FEREBA), the main analysis program. A companion report addresses the input instructions for and features of the computer codes. REBANS extends the capabilities of the SHABERTH (Shaft and Bearing Thermal Analysis) code to include race and housing flexibility, including such effects as dead band and preload springs.

  15. Modeling of rolling element bearing mechanics. Computer program user's manual

    NASA Astrophysics Data System (ADS)

    Greenhill, Lyn M.; Merchant, David H.

    1994-10-01

    This report provides the user's manual for the Rolling Element Bearing Analysis System (REBANS) analysis code which determines the quasistatic response to external loads or displacement of three types of high-speed rolling element bearings: angular contact ball bearings, duplex angular contact ball bearings, and cylindrical roller bearings. The model includes the defects of bearing ring and support structure flexibility. It is comprised of two main programs: the Preprocessor for Bearing Analysis (PREBAN) which creates the input files for the main analysis program, and Flexibility Enhanced Rolling Element Bearing Analysis (FEREBA), the main analysis program. This report addresses input instructions for and features of the computer codes. A companion report addresses the theoretical basis for the computer codes. REBANS extends the capabilities of the SHABERTH (Shaft and Bearing Thermal Analysis) code to include race and housing flexibility, including such effects as dead band and preload springs.

  16. Student understanding of rotational and rolling motion concepts

    NASA Astrophysics Data System (ADS)

    Rimoldini, Lorenzo G.; Singh, Chandralekha

    2005-12-01

    We investigated the common difficulties that students have with concepts related to rotational and rolling motion covered in the introductory physics courses. We compared the performance of calculus- and algebra-based introductory physics students with physics juniors who had learned rotational and rolling motion concepts in an intermediate level mechanics course. Interviews were conducted with six physics juniors and ten introductory students using demonstration-based tasks. We also administered free-response and multiple-choice questions to a large number of students enrolled in introductory physics courses, and interviewed six additional introductory students on the test questions (during the test design phase). All students showed similar difficulties regardless of their background, and higher mathematical sophistication did not seem to help acquire a deeper understanding. We found that some difficulties were due to related difficulties with linear motion, while others were tied specifically to the more intricate nature of rotational and rolling motion.

  17. Flow Stress Evaluation in Hot Rolling of Steel

    NASA Astrophysics Data System (ADS)

    Aghasafari, P.; Salimi, M.; Daraei, A.

    2014-08-01

    In this paper, an inverse analysis technique is used to obtain the flow curve of materials in a hot rolling finishing mill. This technique is based on minimization of the differences between the experimental and computed values. The flow curves and the friction coefficients at roll/work-piece interface are derived from two different models. Model I is based on simple slab method of analysis. Model II is based on a modified slab method in which the effect of shear stress in calculating the rolling force and torque is taken into account. It is shown that the developed inverse analysis technique is reliable and can simultaneously determine a more accurate flow stress for the material as well as a better estimation for the interface friction factors.

  18. Main roll for an air press of a papermaking machine

    DOEpatents

    Beck, David A.

    2004-03-09

    A roll for use in an air press assembly of a papermaking machine has a pair of ends associated therewith. The roll includes a pair of edge portions with each edge portion extending to one of the pair of ends. Each edge portion has an edge surface portion composed of a first material, the first material having a first hardness. The roll further includes a middle portion located between the pair of edge portions, the middle portion having a middle surface portion composed of a second material. The second material has a second hardness, the second material being harder than the first material. The first material is preferably a soft, seal material which promotes reduced air leakage from the air press assembly.

  19. Roll-up of validation results to a target application.

    SciTech Connect

    Hills, Richard Guy

    2013-09-01

    Suites of experiments are preformed over a validation hierarchy to test computational simulation models for complex applications. Experiments within the hierarchy can be performed at different conditions and configurations than those for an intended application, with each experiment testing only part of the physics relevant for the application. The purpose of the present work is to develop methodology to roll-up validation results to an application, and to assess the impact the validation hierarchy design has on the roll-up results. The roll-up is accomplished through the development of a meta-model that relates validation measurements throughout a hierarchy to the desired response quantities for the target application. The meta-model is developed using the computation simulation models for the experiments and the application. The meta-model approach is applied to a series of example transport problems that represent complete and incomplete coverage of the physics of the target application by the validation experiments.

  20. Modeling of rolling element bearing mechanics. Theoretical manual

    NASA Technical Reports Server (NTRS)

    Merchant, David H.; Greenhill, Lyn M.

    1994-01-01

    This report documents the theoretical basis for the Rolling Element Bearing Analysis System (REBANS) analysis code which determines the quasistatic response to external loads or displacement of three types of high-speed rolling element bearings: angular contact ball bearings; duplex angular contact ball bearings; and cylindrical roller bearings. The model includes the effects of bearing ring and support structure flexibility. It is comprised of two main programs: the Preprocessor for Bearing Analysis (PREBAN) which creates the input files for the main analysis program; and Flexibility Enhanced Rolling Element Bearing Analysis (FEREBA), the main analysis program. A companion report addresses the input instructions for and features of the computer codes. REBANS extends the capabilities of the SHABERTH (Shaft and Bearing Thermal Analysis) code to include race and housing flexibility, including such effects as dead band and preload springs.

  1. Elliptic inflation: generating the curvature perturbation without slow-roll

    NASA Astrophysics Data System (ADS)

    Matsuda, Tomohiro

    2006-09-01

    There are many inflationary models in which the inflaton field does not satisfy the slow-roll condition. However, in such models, it is always difficult to generate the curvature perturbation during inflation. Thus, to generate the curvature perturbation, one must introduce another component into the theory. To cite a case, curvatons may generate the dominant part of the curvature perturbation after inflation. However, we question whether it is realistic to consider the generation of the curvature perturbation during inflation without slow-roll. Assuming multifield inflation, we encounter the generation of curvature perturbation during inflation without slow-roll. The potential along the equipotential surface is flat by definition and thus we do not have to worry about symmetry. We also discuss KKLT (Kachru Kallosh Linde Trivedi) models, in which corrections lifting the inflationary direction may not become a serious problem if there is a symmetry enhancement at the tip (not at the moving brane) of the inflationary throat.

  2. Dynamical states in the sensorimotor loop of a rolling robot

    NASA Astrophysics Data System (ADS)

    Sándor, Bulcsú; Jahn, Tim; Martin, Laura; Echeveste, Rodrigo; Gros, Claudius

    We investigate the closed sensorimotor loop of a simple rolling robot as a dynamical system. Using the LpzRobots simulation package, we construct robots with cylindrical body, controlled by a single proprioceptual neuron with a time dependent threshold. Despite its simplicity, we obtain a rich set of rolling modes, as a result of the self-organizing processes arising through the feedback within the sensorimotor loop. These rolling modes are robust against environmental noise, since they correspond to stable limit cycle attractors. However, for certain parameters they also allow for explorative behavior via internal noise induced switching. Furthermore, we also find a region of parameters in which the motion is fully embodied, where, in engineering terms, the engine powering the motion of the robot is turned on dynamically through the feedback of its very motion.

  3. Modeling of rolling element bearing mechanics. Computer program user's manual

    NASA Technical Reports Server (NTRS)

    Greenhill, Lyn M.; Merchant, David H.

    1994-01-01

    This report provides the user's manual for the Rolling Element Bearing Analysis System (REBANS) analysis code which determines the quasistatic response to external loads or displacement of three types of high-speed rolling element bearings: angular contact ball bearings, duplex angular contact ball bearings, and cylindrical roller bearings. The model includes the defects of bearing ring and support structure flexibility. It is comprised of two main programs: the Preprocessor for Bearing Analysis (PREBAN) which creates the input files for the main analysis program, and Flexibility Enhanced Rolling Element Bearing Analysis (FEREBA), the main analysis program. This report addresses input instructions for and features of the computer codes. A companion report addresses the theoretical basis for the computer codes. REBANS extends the capabilities of the SHABERTH (Shaft and Bearing Thermal Analysis) code to include race and housing flexibility, including such effects as dead band and preload springs.

  4. Effects of surface removal on rolling-element fatigue

    NASA Technical Reports Server (NTRS)

    Zaretsky, Erwin V.

    1987-01-01

    The Lundberg-Palmgren equation was modified to show the effect on rolling-element fatigue life of removing by grinding a portion of the stressed volume of the raceways of a rolling-element bearing. Results of this analysis show that depending on the amount of material removed, and depending on the initial running time of the bearing when material removal occurs, the 10-percent life of the reground bearings ranges from 74 to 100 percent of the 10-percent life of a brand new bearing. Three bearing types were selected for testing. A total of 250 bearings were reground. Of this matter, 30 bearings from each type were endurance tested to 1600 hr. No bearing failure occurred related to material removal. Two bearing failures occurred due to defective rolling elements and were typical of those which may occur in new bearings.

  5. Human Ocular Counter-Rolling and Roll Tilt Perception during Off-Vertical Axis Rotation after Spaceflight

    NASA Technical Reports Server (NTRS)

    Clement, Gilles; Denise, Pierre; Reschke, Millard; Wood, Scott J.

    2007-01-01

    Ocular counter-rolling (OCR) induced by whole body tilt in roll has been explored after spaceflight as an indicator of the adaptation of the otolith function to microgravity. It has been claimed that the overall pattern of OCR responses during static body tilt after spaceflight is indicative of a decreased role of the otolith function, but the results of these studies have not been consistent, mostly due to large variations in the OCR within and across individuals. By contrast with static head tilt, off-vertical axis rotation (OVAR) presents the advantage of generating a sinusoidal modulation of OCR, allowing averaged measurements over several cycles, thus improving measurement accuracy. Accordingly, OCR and the sense of roll tilt were evaluated in seven astronauts before and after spaceflight during OVAR at 45 /s in darkness at two angles of tilt (10 and 20 ). There was no significant difference in OCR during OVAR immediately after landing compared to preflight. However, the amplitude of the perceived roll tilt during OVAR was significantly larger immediately postflight, and then returned to control values in the following days. Since the OCR response is predominantly attributed to the shearing force exerted on the utricular macula, the absence of change in OCR postflight suggests that the peripheral otolith organs function normally after short-term spaceflight. However, the increased sense of roll tilt indicates an adaptation in the central processing of gravitational input, presumably related to a re-weigthing of the internal representation of gravitational vertical as a result of adaptation to microgravity.

  6. Static roll-tilt over 5 minutes locally distorts the internal estimate of direction of gravity.

    PubMed

    Tarnutzer, A A; Bockisch, C J; Straumann, D; Marti, S; Bertolini, G

    2014-12-01

    The subjective visual vertical (SVV) indicates perceived direction of gravity. Even in healthy human subjects, roll angle-dependent misestimations, roll overcompensation (A-effect, head-roll > 60° and <135°) and undercompensation (E-effect, head-roll < 60°), occur. Previously, we demonstrated that, after prolonged roll-tilt, SVV estimates when upright are biased toward the preceding roll position, which indicates that perceived vertical (PV) is shifted by the prior tilt (Tarnutzer AA, Bertolini G, Bockisch CJ, Straumann D, Marti S. PLoS One 8: e78079, 2013). Hypothetically, PV in any roll position could be biased toward the previous roll position. We asked whether such a "global" bias occurs or whether the bias is "local". The SVV of healthy human subjects (N = 9) was measured in nine roll positions (-120° to +120°, steps = 30°) after 5 min of roll-tilt in one of two adaptation positions (±90°) and compared with control trials without adaptation. After adapting, adjustments were shifted significantly (P < 0.05) toward the previous adaptation position for nearby roll-tilted positions (±30°, ±60°) and upright only. We computationally simulated errors based on the sum of a monotonically increasing function (producing roll undercompensation) and a mixture of Gaussian functions (representing roll overcompensation centered around PV). In combination, the pattern of A- and E-effects could be generated. By shifting the function representing local overcompensation toward the adaptation position, the experimental postadaptation data could be fitted successfully. We conclude that prolonged roll-tilt locally distorts PV rather than globally shifting it. Short-term adaptation of roll overcompensation may explain these shifts and could reflect the brain's strategy to optimize SVV estimates around recent roll positions. Thus postural stability can be improved by visually-mediated compensatory responses at any sustained body-roll orientation.

  7. Stress analysis of asymmetrical cold rolling of clad sheet using the slab method

    NASA Astrophysics Data System (ADS)

    Hwang, Y. M.; Tzou, G. Y.

    1996-10-01

    An analytical model for general asymmetrical cold rolling of clad sheet bonded before rolling was proposed to explore the plastic deformation behavior of the clad sheet using the slab method. The model allowed easy calculation of the neutral points between the upper and lower rolls and the clad sheet; rolling pressure distribution along the contact interface of the roll, horizontal stresses in the component layers of the clad sheet, shear stresses at the interface of the clad sheet, and rolling force. These characteristics as affected by various rolling conditions (e.g., thickness ratio and shear yield stress ratio of the raw clad sheet, roll speed ratio, reduction, frictional coefficient, roll radius ratio, etc.) were analyzed systematically. This approach yielded complete forms for the rolling pressure distribution, rolling force, and rolling torque. Moreover, the computational time required by this analytical model is about 1/20 to 1/25 of that required by the RUNGE KUTTA numerical method under the same rolling conditions.

  8. Covalent immobilization of p-selectin enhances cell rolling.

    PubMed

    Hong, Seungpyo; Lee, Dooyoung; Zhang, Huanan; Zhang, Jennifer Q; Resvick, Jennifer N; Khademhosseini, Ali; King, Michael R; Langer, Robert; Karp, Jeffrey M

    2007-11-20

    Cell rolling is an important physiological and pathological process that is used to recruit specific cells in the bloodstream to a target tissue. This process may be exploited for biomedical applications to capture and separate specific cell types. One of the most commonly studied proteins that regulate cell rolling is P-selectin. By coating surfaces with this protein, biofunctional surfaces that induce cell rolling can be prepared. Although most immobilization methods have relied on physisorption, chemical immobilization has obvious advantages, including longer functional stability and better control over ligand density and orientation. Here we describe chemical methods to immobilize P-selectin covalently on glass substrates. The chemistry was categorized on the basis of the functional groups on modified glass substrates: amine, aldehyde, and epoxy. The prepared surfaces were first tested in a flow chamber by flowing microspheres functionalized with a cell surface carbohydrate (sialyl Lewis(x)) that binds to P-selectin. Adhesion bonds between P-selectin and sialyl Lewis(x) dissociate readily under shear forces, leading to cell rolling. P-selectin immobilized on the epoxy glass surfaces exhibited enhanced long-term stability of the function and better homogeneity as compared to that for surfaces prepared by other methods and physisorbed controls. The microsphere rolling results were confirmed in vitro with isolated human neutrophils. This work is essential for the future development of devices for isolating specific cell types based on cell rolling, which may be useful for hematologic cancers and certain metastatic cancer cells that are responsive to immobilized selectins.

  9. Scanning sonar of rolling porpoises during prey capture dives.

    PubMed

    Akamatsu, T; Wang, D; Wang, K; Li, S; Dong, S

    2010-01-01

    Dolphins and porpoises have excellent biosonar ability, which they use for navigation, ranging and foraging. However, the role of biosonar in free-ranging small cetaceans has not been fully investigated. The biosonar behaviour and body movements of 15 free-ranging finless porpoises (Neophocaena phocaenoides) were observed using electronic tags attached to the animals. The porpoises often rotated their bodies more than 60 deg., on average, around the body axis in a dive bout. This behaviour occupied 31% of the dive duration during 186 h of effective observation time. Rolling dives were associated with extensive searching effort, and 23% of the rolling dive time was phonated, almost twice the phonation ratio of upright dives. Porpoises used short inter-click interval sonar 4.3 times more frequently during rolling dives than during upright dives. Sudden speed drops, which indicated that an individual turned around, occurred 4.5 times more frequently during rolling dives than during upright dives. Together, these data suggest that the porpoises searched extensively for targets and rolled their bodies to enlarge the search area by changing the narrow beam axis of the biosonar. Once a possible target was detected, porpoises frequently produced short-range sonar sounds. Continuous searching for prey and frequent capture trials appeared to occur during rolling dives of finless porpoises. In contrast, head movements ranging +/-2 cm, which can also change the beam axis, were regularly observed during both dives. Head movements might assist in instant assessment of the arbitrary direction by changing the beam axis rather than prey searching and pursuit.

  10. Hybrid bearing technology for advanced turbomachinery: Rolling contact fatigue testing

    SciTech Connect

    Dill, J.F.

    1996-01-01

    The purpose of this paper is to describe the basic structure and results to date of a major ARPA funded effort to provide a tribological performance database on ceramic bearing materials and their interaction with standard bearing steels. Program efforts include studies of material physical properties, machining characteristics, and tribological performance. The majority of the testing completed to date focuses on rolling contact fatigue testing of the ceramic materials, including efforts to arrive at optimum approaches to evaluating ceramic/steel hybrid combinations in rolling contact fatigue.

  11. Rolling motion: experiments and simulations focusing on sliding friction forces

    NASA Astrophysics Data System (ADS)

    Onorato, Pasquale; Malgieri, Massimiliano; De Ambrosis, Anna

    2016-05-01

    The paper presents an activity sequence aimed at elucidating the role of sliding friction forces in determining/shaping the rolling motion. The sequence is based on experiments and computer simulations and it is devoted both to high school and undergraduate students. Measurements are carried out by using the open source Tracker Video Analysis software, while interactive simulations are realized by means of Algodoo, a freeware 2D-simulation software. Data collected from questionnaires before and after the activities, and from final reports, show the effectiveness of combining simulations and Video Based Analysis experiments in improving students' understanding of rolling motion.

  12. Heat generation in aircraft tires under free rolling conditions

    NASA Technical Reports Server (NTRS)

    Clark, S. K.; Dodge, R. N.

    1982-01-01

    A method was developed for calculating the internal temperature distribution in an aircraft tire while free rolling under load. The method uses an approximate stress analysis of each point in the tire as it rolls through the contact patch, and from this stress change the mechanical work done on each volume element may be obtained and converted into a heat release rate through a knowledge of material characteristics. The tire cross-section is then considered as a body with internal heat generation, and the diffusion equation is solved numerically with appropriate boundary conditions of the wheel and runway surface. Comparison with data obtained with buried thermocouples in tires shows good agreement.

  13. Kinematic stability of roller pairs in free rolling contact

    NASA Technical Reports Server (NTRS)

    Savage, M.; Loewenthal, S. H.

    1976-01-01

    A set of generalized stability equations was developed for roller pairs in free rolling contact. A symmetric, dual contact model was used. Four possible external contact profiles that possess continuous contacting surfaces were studied. It was found that kinematic stability would be insured if the larger radius of transverse curvature, in absolute value, and the smaller rolling radius both exist on the roller that has the apex of its conical surface outboard of its main body. The stability criteria developed are considered to be useful for assessing axial restraint requirements for a variety of roller mechanisms and in the selection of roller contact geometry for traction drive devices.

  14. Teager Energy Spectrum for Fault Diagnosis of Rolling Element Bearings

    NASA Astrophysics Data System (ADS)

    Feng, Zhipeng; Wang, Tianjin; Zuo, Ming J.; Chu, Fulei; Yan, Shaoze

    2011-07-01

    Localized damage of rolling element bearings generates periodic impulses during running. The repeating frequency of impulses is a key indicator for diagnosing the localized damage of bearings. A new method, called Teager energy spectrum, is proposed to diagnose the faults of rolling element bearings. It exploits the unique advantages of Teager energy operator in detecting transient components in signals to extract periodic impulses of bearing faults, and uses the Fourier spectrum of Teager energy to identify the characteristic frequency of bearing faults. The effectiveness of the proposed method is validated by analyzing the experimental bearing vibration signals.

  15. The study and fabrication of DLC micropattern on roll mold

    NASA Astrophysics Data System (ADS)

    Kwon, Young Woo; Lee, Tae Dong; Park, Yeong Min; Cho, Hyun; Kim, Jin Kon; Kim, Tae Gyu

    2015-03-01

    Diamond-like carbon (DLC) coating is becoming a promising protective coating layers due to its superior properties. In this study, instead of protective coating, DLC film was applied as the only component for micropattern then etched with lithography and lift-off process selectively. Furthermore, DLC film has been fabricated on aluminum roll mold. Then UV curing resin was applied to form the pattern on the polyethylene terephthalate (PET) film. The dimension and formation of the DLC micropattern on roll mold were analyzed. Moreover, the Raman spectroscopic of nitrogen-doped DLC film was analyzed.

  16. The evaluation of the rolling moments induced by wraparound fins

    NASA Technical Reports Server (NTRS)

    Seginer, A.; Bar-Haim, B.

    1983-01-01

    A possible reason is suggested for the induced rolling moments occurring on wraparound-fin configurations in subsonic flight at zero angle of attack. The subsonic potential flow over the configuration at zero incidence is solved numerically. The body is simulated by a distribution of sources along its axis, and the fins are described by a vortex-lattice method. It is shown that rolling moments can be induced on the antisymmetric fins by the radial flow generated at the base of the configuration, either over the converging separated wake, or over the diverging plume of a rocket motor.

  17. Pitch and roll hydrodynamics of a pericell hovercraft

    NASA Astrophysics Data System (ADS)

    Moran, David D.

    1986-12-01

    Pitch and roll responses of hovercraft have been extremely difficult to predict due to the complexity of hydrodynamic analyses on one hand and the difficulties of appropriate cushion scale modeling on the other. The paper presents comparisons of pitch and roll stiffness coefficients for overwater and overland operations. Data are presented from model-scale and full-scale trials and analytic-numerical modeling. The effects of model-scale on the cushion dynamics relative to rotational responses are presented and the important characteristics of overwater and overland responses are discussed.

  18. Pitch and roll hydrodynamics of a pericell hovercraft

    NASA Astrophysics Data System (ADS)

    Moran, D. D.

    Pitch and roll responses of hovercraft have been extremely difficult to predict due to the complexity of hydrodynamic analyses on one hand and the difficulties of appropriate cushion scale modeling on the other. The paper presents comparisons of pitch and roll stiffness coefficients for overwater and overland operations. Data are presented from model-scale and full-scale trials and analytic-numerical modeling. The effects of model-scale on the cushion dynamics relative to rotational responses are presented and the important characteristics of overwater and overland responses are discussed.

  19. Scalar perturbations in conformal rolling scenario with intermediate stage

    SciTech Connect

    Libanov, M.; Ramazanov, S.; Rubakov, V. E-mail: sabir@ms2.inr.ac.ru

    2011-06-01

    Scalar cosmological perturbations with nearly flat power spectrum may originate from perturbations of the phase of a scalar field conformally coupled to gravity and rolling down negative quartic potential. We consider a version of this scenario whose specific property is a long intermediate stage between the end of conformal rolling and horizon exit of the phase perturbations. Such a stage is natural, e.g., in cosmologies with ekpyrosis or genesis. Its existence results in small negative scalar tilt, statistical anisotropy of all even multipoles starting from quardupole of general structure (in contrast to the usually discussed single quadrupole of special type) and non-Gaussianity of a peculiar form.

  20. Hamilton-Jacobi approach to non-slow-roll inflation

    NASA Astrophysics Data System (ADS)

    Kinney, William H.

    1997-08-01

    I describe a general approach to characterizing cosmological inflation outside the standard slow-roll approximation, based on the Hamilton-Jacobi formulation of scalar field dynamics. The basic idea is to view the equation of state of the scalar field matter as the fundamental dynamical variable, as opposed to the field value or the expansion rate. I discuss how to formulate the equations of motion for scalar and tensor fluctuations in situations where the assumption of slow roll is not valid. I apply the general results to the simple case of inflation from an ``inverted'' polynomial potential, and to the more complicated case of hybrid inflation.

  1. Plain and Rolled Images from Paired Fingerprint Cards

    National Institute of Standards and Technology Data Gateway

    NIST Plain and Rolled Images from Paired Fingerprint Cards (PC database for purchase)   NIST Special Database 29 is being distributed for use in development and testing fingerprint matching systems. The data consist of 216 ten-print fingerprint card pairs with both the rolled and plains (from a bottom of the fingerprint card) scanned at 19.7 pixels per mm. A newer version of the compression/decompression software on the CDROM can be found at the website http://www.nist.gov/itl/iad/ig/nigos.cfm as part of the NBIS package.

  2. Note: A 1-m Foucault pendulum rolling on a ball.

    PubMed

    Salva, H R; Benavides, R E; Venturino, J A; Cuscueta, D J; Ghilarducci, A A

    2013-10-01

    We have built a short Foucault pendulum of 1-m length. The aim of this work was to increase the sensitivity to elliptical trajectories from other longer pendula. The design was a semi-rigid pendulum that rolls over a small ball. The measurements of the movements (azimuth and elliptical trajectory) were done by an optical method. The resulting pendulum works in a medium satisfactory way due to problems of the correct choice of the mass of the bob together with the diameter of the supporting ball. It is also important to keep the rolling surface very clean.

  3. Note: A 1-m Foucault pendulum rolling on a ball

    NASA Astrophysics Data System (ADS)

    Salva, H. R.; Benavides, R. E.; Venturino, J. A.; Cuscueta, D. J.; Ghilarducci, A. A.

    2013-10-01

    We have built a short Foucault pendulum of 1-m length. The aim of this work was to increase the sensitivity to elliptical trajectories from other longer pendula. The design was a semi-rigid pendulum that rolls over a small ball. The measurements of the movements (azimuth and elliptical trajectory) were done by an optical method. The resulting pendulum works in a medium satisfactory way due to problems of the correct choice of the mass of the bob together with the diameter of the supporting ball. It is also important to keep the rolling surface very clean.

  4. An electrically injected rolled-up semiconductor tube laser

    SciTech Connect

    Dastjerdi, M. H. T.; Djavid, M.; Mi, Z.

    2015-01-12

    We have demonstrated electrically injected rolled-up semiconductor tube lasers, which are formed when a coherently strained InGaAs/InGaAsP quantum well heterostructure is selectively released from the underlying InP substrate. The device exhibits strong coherent emission in the wavelength range of ∼1.5 μm. A lasing threshold of ∼1.05 mA is measured for a rolled-up tube with a diameter of ∼5 μm and wall thickness of ∼140 nm at 80 K. The Purcell factor is estimated to be ∼4.3.

  5. 76 FR 8319 - Special Conditions: Gulfstream Model GVI Airplane; Design Roll Maneuver Requirement for...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-14

    ... Roll Maneuver Requirement for Electronic Flight Controls AGENCY: Federal Aviation Administration (FAA... airplanes. These design features include an electronic flight control system that provides roll control of the airplane through pilot inputs to the flight ] computers. These proposed special conditions...

  6. Fatigue acceptance test limit criteria for larger diameter rolled thread fasteners

    SciTech Connect

    Kephart, A.R.

    1999-05-19

    This document describes a fatigue lifetime acceptance test criterion by which studs having rolled threads, larger than 1.0 inches (25 mm) in diameter, can be assured to meet minimum quality attributes associated with a controlled rolling process.

  7. The effects of cold rolling temperature on corrosion resistance of pure iron

    NASA Astrophysics Data System (ADS)

    Jinlong, Lv; Hongyun, Luo

    2014-10-01

    The effects of cold rolling temperature on grain size and grain orientation of pure iron were investigated. Comparing with sample rolled at room temperature, the grain refinement was facilitated in sample obtained by cryogenic cold rolling at liquid-nitrogen temperature. However, the grain orientation changed little for two samples. It was shown that cathodic hydrogen evolution reaction could govern the corrosion reaction for pure iron in sulfuric acid solution. The grain refinement obtained by rolling improved the corrosion resistance of iron in sulfuric acid solution, borate buffer solution and borate buffer solution with chloride ion. However, comparing with iron rolled at room temperature, the corrosion resistance of iron obtained by cryogenic temperature rolling was lower. Comparing with iron rolled at room temperature, higher dislocation density in iron rolled at cryogenic temperature reduced its corrosion resistance.

  8. Ultrashort-pulsed laser processing and solution based coating in roll-to-roll manufacturing of organic photovoltaics

    NASA Astrophysics Data System (ADS)

    Hördemann, C.; Hirschfelder, K.; Schaefer, M.; Gillner, A.

    2015-09-01

    The breakthrough of flexible organic electronics and especially organic photovoltaics is highly dependent on cost-efficient production technologies. Roll-2-Roll processes show potential for a promising solution in terms of high throughput and low-cost production of thin film organic components. Solution based material deposition and integrated laser patterning processes offer new possibilities for versatile production lines. The use of flexible polymeric substrates brings along challenges in laser patterning which have to be overcome. One main challenge when patterning transparent conductive layers on polymeric substrates are material bulges at the edges of the ablated area. Bulges can lead to short circuits in the layer system leading to device failure. Therefore following layers have to have a sufficient thickness to cover and smooth the ridge. In order to minimize the bulging height, a study has been carried out on transparent conductive ITO layers on flexible PET substrates. Ablation results using different beam shapes, such as Gaussian beam, Top-Hat beam and Donut-shaped beam, as well as multi-pass scribing and double-pulsed ablation are compared. Furthermore, lab scale methods for cleaning the patterned layer and eliminating bulges are contrasted to the use of additional water based sacrificial layers in order to obtain an alternative procedure suitable for large scale Roll-2-Roll manufacturing. Besides progress in research, ongoing transfer of laser processes into a Roll-2-Roll demonstrator is illustrated. By using fixed optical elements in combination with a galvanometric scanner, scribing, variable patterning and edge deletion can be performed individually.

  9. Flexible indium zinc oxide/Ag/indium zinc oxide multilayer electrode grown on polyethersulfone substrate by cost-efficient roll-to-roll sputtering for flexible organic photovoltaics

    SciTech Connect

    Park, Yong-Seok; Kim, Han-Ki

    2010-01-15

    The authors describe the preparation and characteristics of flexible indium zinc oxide (IZO)-Ag-IZO multilayer electrodes grown on flexible polyethersulfone (PES) substrates using a roll-to-roll sputtering system for use in flexible organic photovoltaics. By the continuous roll-to-roll sputtering of the bottom IZO, Ag, and top IZO layers at room temperature, they were able to fabricate a high quality IZO-Ag-IZO multilayer electrode with a sheet resistance of 6.15 {epsilon}/square, optical transmittance of 87.4%, and figure of merit value of 42.03x10{sup -3} {Omega}{sup -1} on the PES substrate. In addition, the IZO-Ag-IZO multilayer electrode exhibited superior flexibility to the roll-to-roll sputter grown single ITO electrode due to the existence of a ductile Ag layer between the IZO layers and stable amorphous structure of the IZO film. Furthermore, the flexible organic solar cells (OSCs) fabricated on the roll-to-roll sputter grown IZO-Ag-IZO electrode showed higher power efficiency (3.51%) than the OSCs fabricated on the roll-to-roll sputter grown single ITO electrode (2.67%).

  10. The Evolution of the Surface Morphologies and Microstructures of an Unleveled Hot-Rolled Steel Strip During Cold Rolling After Hydrogen Reduction

    NASA Astrophysics Data System (ADS)

    Jing, Yu-An; Shang, Qiuyue; Zang, Xiaoming; Zhang, Lei; Peng, Xingdong; Jia, Pinfeng

    2016-01-01

    The removal of oxide scale from a hot-rolled strip surface can completely eliminate environmental pollution if performed by hydrogen-reduction descaling instead of traditional pickling descaling. However, a large number of cracks appear on the surface of a leveled hot-rolled steel strip after hydrogen reduction. This effect is likely to impede the application of reduction descaling to cold-rolled products. Nevertheless, there are almost no cracks on the surface of an unleveled hot-rolled steel strip if the hot-rolled steel strip is not subjected to repeated bending by the leveler machine. The surface quality of a reduced steel strip will be better than that of a pickled steel strip. To investigate the evolution of the surface morphologies, microstructures, and properties of an unleveled strip steel during cold rolling, unleveled strip steel samples were rolled using a four-high mill after hydrogen reduction and after pickling. The surface morphologies and cross-sectional microstructures of the samples were observed by SEM, and the surface-roughness values were measured using a TR200 profilometer before and after cold-rolling deformation. The evolution of the surface morphologies and cross-sectional microstructures of the sample after cold rolling were analyzed. The results show that the oxide scale formed on the surface turns into a metallic iron layer, and a decarburization layer appears between the metallic iron layer and the steel matrix after hydrogen reduction. Few cracks, besides pores, and bubbles, appeared on the surface of the sample after hydrogen reduction. The pores and bubbles were roll-flattened after five passes of cold rolling. The work hardening degree and mechanical properties of the reduced sample are similar to those of the pickled sample after cold rolling. Compared with the rolled sample after pickling, the surface qualities of the reduced samples are better than those of the pickled samples and better than those of the reduced samples that

  11. Use of a finite element method to calculate roll profiles for broad-strip mills

    NASA Astrophysics Data System (ADS)

    Garber, E. A.; Bolobanova, N. L.; Traino, A. I.

    2012-05-01

    A model is proposed to calculate the polishing profiling of rolls in broad-strip mills using a finite element method, and it is applied to develop new roll profiles. The finite element method is used to determine the polishing profiling of a roll with a complex shape, which substantially decreases the nonuniformity of reduction and drawing over the strip width. This profiling can be executed on numerical control roll grinders.

  12. Aqueous processing of low-band-gap polymer solar cells using roll-to-roll methods.

    PubMed

    Andersen, Thomas R; Larsen-Olsen, Thue T; Andreasen, Birgitta; Böttiger, Arvid P L; Carlé, Jon E; Helgesen, Martin; Bundgaard, Eva; Norrman, Kion; Andreasen, Jens W; Jørgensen, Mikkel; Krebs, Frederik C

    2011-05-24

    Aqueous nanoparticle dispersions of a series of three low-band-gap polymers poly[4,8-bis(2-ethylhexyloxy)benzo(1,2-b:4,5-b')dithiophene-alt-5,6-bis(octyloxy)-4,7-di(thiophen-2-yl)(2,1,3-benzothiadiazole)-5,5'-diyl] (P1), poly[(4,4'-bis(2-ethylhexyl)dithieno[3,2-b:2',3'-d]silole)-2,6-diyl-alt-(2,1,3-benzothiadiazole)-4,7-diyl] (P2), and poly[2,3-bis-(3-octyloxyphenyl)quinoxaline-5,8-diyl-alt-thiophene-2,5-diyl] (P3) were prepared using ultrasonic treatment of a chloroform solution of the polymer and [6,6]-phenyl-C(61)-butyric acid methyl ester ([60]PCBM) mixed with an aqueous solution of sodium dodecylsulphate (SDS). The size of the nanoparticles was established using small-angle X-ray scattering (SAXS) of the aqueous dispersions and by both atomic force microscopy (AFM) and using both grazing incidence SAXS (GISAXS) and grazing incidence wide-angle X-ray scattering (GIWAXS) in the solid state as coated films. The aqueous dispersions were dialyzed to remove excess detergent and concentrated to a solid content of approximately 60 mg mL(-1). The formation of films for solar cells using the aqueous dispersion required the addition of the nonionic detergent FSO-100 at a concentration of 5 mg mL(-1). This enabled slot-die coating of high quality films with a dry thickness of 126 ± 19, 500 ± 25, and 612 ± 22 nm P1, P2, and P3, respectively for polymer solar cells. Large area inverted polymer solar cells were thus prepared based on the aqueous inks. The power conversion efficiency (PCE) reached for each of the materials was 0.07, 0.55, and 0.15% for P1, P2, and P3, respectively. The devices were prepared using coating and printing of all layers including the metal back electrodes. All steps were carried out using roll-to-roll (R2R) slot-die and screen printing methods on flexible substrates. All five layers were processed using environmentally friendly methods and solvents. Two of the layers were processed entirely from water (the electron transport layer and the active

  13. Aqueous processing of low-band-gap polymer solar cells using roll-to-roll methods.

    PubMed

    Andersen, Thomas R; Larsen-Olsen, Thue T; Andreasen, Birgitta; Böttiger, Arvid P L; Carlé, Jon E; Helgesen, Martin; Bundgaard, Eva; Norrman, Kion; Andreasen, Jens W; Jørgensen, Mikkel; Krebs, Frederik C

    2011-05-24

    Aqueous nanoparticle dispersions of a series of three low-band-gap polymers poly[4,8-bis(2-ethylhexyloxy)benzo(1,2-b:4,5-b')dithiophene-alt-5,6-bis(octyloxy)-4,7-di(thiophen-2-yl)(2,1,3-benzothiadiazole)-5,5'-diyl] (P1), poly[(4,4'-bis(2-ethylhexyl)dithieno[3,2-b:2',3'-d]silole)-2,6-diyl-alt-(2,1,3-benzothiadiazole)-4,7-diyl] (P2), and poly[2,3-bis-(3-octyloxyphenyl)quinoxaline-5,8-diyl-alt-thiophene-2,5-diyl] (P3) were prepared using ultrasonic treatment of a chloroform solution of the polymer and [6,6]-phenyl-C(61)-butyric acid methyl ester ([60]PCBM) mixed with an aqueous solution of sodium dodecylsulphate (SDS). The size of the nanoparticles was established using small-angle X-ray scattering (SAXS) of the aqueous dispersions and by both atomic force microscopy (AFM) and using both grazing incidence SAXS (GISAXS) and grazing incidence wide-angle X-ray scattering (GIWAXS) in the solid state as coated films. The aqueous dispersions were dialyzed to remove excess detergent and concentrated to a solid content of approximately 60 mg mL(-1). The formation of films for solar cells using the aqueous dispersion required the addition of the nonionic detergent FSO-100 at a concentration of 5 mg mL(-1). This enabled slot-die coating of high quality films with a dry thickness of 126 ± 19, 500 ± 25, and 612 ± 22 nm P1, P2, and P3, respectively for polymer solar cells. Large area inverted polymer solar cells were thus prepared based on the aqueous inks. The power conversion efficiency (PCE) reached for each of the materials was 0.07, 0.55, and 0.15% for P1, P2, and P3, respectively. The devices were prepared using coating and printing of all layers including the metal back electrodes. All steps were carried out using roll-to-roll (R2R) slot-die and screen printing methods on flexible substrates. All five layers were processed using environmentally friendly methods and solvents. Two of the layers were processed entirely from water (the electron transport layer and the active

  14. 40 CFR 426.30 - Applicability; description of the rolled glass manufacturing subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... rolled glass manufacturing subcategory. 426.30 Section 426.30 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) GLASS MANUFACTURING POINT SOURCE CATEGORY Rolled Glass Manufacturing Subcategory § 426.30 Applicability; description of the rolled...

  15. 40 CFR 426.30 - Applicability; description of the rolled glass manufacturing subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... rolled glass manufacturing subcategory. 426.30 Section 426.30 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) GLASS MANUFACTURING POINT SOURCE CATEGORY Rolled Glass Manufacturing Subcategory § 426.30 Applicability; description of the rolled...

  16. 40 CFR 426.30 - Applicability; description of the rolled glass manufacturing subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... rolled glass manufacturing subcategory. 426.30 Section 426.30 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) GLASS MANUFACTURING POINT SOURCE CATEGORY Rolled Glass Manufacturing Subcategory § 426.30 Applicability; description of the rolled...

  17. Simple Model of a Rolling Water-Filled Bottle on an Inclined Ramp

    ERIC Educational Resources Information Center

    Lin, Shihao; Hu, Naiwen; Yao, Tianchen; Chu, Charles; Babb, Simona; Cohen, Jenna; Sangiovanni, Giana; Watt, Summer; Weisman, Danielle; Klep, James; Walecki, Wojciech J.; Walecki, Eve S.; Walecki, Peter S.

    2015-01-01

    We investigate a water-filled bottle rolling down an incline and ask the following question: is a rolling bottle better described by a model ignoring all internal motion where the bottle is approximated by a material point sliding down an incline, or is it better described by a rigid solid cylinder rolling down the incline without skidding? The…

  18. 77 FR 29953 - Application of Buy America Waivers to Rolling Stock Overhauls and Rebuilds

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-21

    ... to apply Buy America to certain end products and components, including rolling stock. 72 FR 53688... parts for rolling stock as well as to manufactured products. 72 FR 53688, 53692, Sept. 20, 2007. The Buy... Federal Transit Administration 49 CFR Part 661 Application of Buy America Waivers to Rolling...

  19. Roll compaction process modeling: transfer between equipment and impact of process parameters.

    PubMed

    Souihi, Nabil; Reynolds, Gavin; Tajarobi, Pirjo; Wikström, Håkan; Haeffler, Gunnar; Josefson, Mats; Trygg, Johan

    2015-04-30

    In this study, the roll compaction of an intermediate drug load formulation was performed using horizontally and vertically force fed roll compactors. The horizontally fed roll compactor was equipped with an instrumented roll technology allowing the direct measurement of normal stress at the roll surface, while the vertically fed roll compactor was equipped with a force gauge between the roll axes. Furthermore, characterization of ribbons, granules and tablets was also performed. Ribbon porosity was primarily found to be a function of normal stress, exhibiting a quadratic relationship thereof. A similar quadratic relationship was also observed between roll force and ribbon porosity of the vertically fed roll compactor. The predicted peak pressure (Pmax) using the Johanson model was found to be higher than the measured normal stress, however, the predicted Pmax correlated well with the ribbon relative density/porosity and the majority of downstream properties of granules and tablets, demonstrating its use as a scale-independent parameter. A latent variable model was developed for both the horizontal and vertical fed roll compactors to express ribbon porosity as a function of geometric and process parameters. The model validation, performed with new data, resulted in overall good predictions. This study successfully demonstrated the scale up/transfer between two different roll compactors and revealed that the combined use of design of experiments, latent variable models and in silico predictions result in better understanding of the critical process parameters in roll compaction.

  20. Autocollimating systems for roll angle measurement of large-scale object deformation

    NASA Astrophysics Data System (ADS)

    Turgalieva, Tatyana V.; Konyakhin, Igor A.

    2015-05-01

    Autocollimating systems for roll angle measurement with tetrahedral reflector, which has the small deviation from 90° in two dihedral angles between reflecting sides is considered. Established that autocollimator scheme with symmetrical track of the beam relative to roll axis with addition re-reflection allow implement precision measurement roll angle.