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Sample records for rolling mill rolls

  1. Tribology; Cold rolling mill roll; Hard chrome; Surface texturing.

    Directory of Open Access Journals (Sweden)

    José Lucio Gonēalves Junior

    2012-12-01

    Full Text Available The present work analyzes the tribological behavior of surface modifications often used in cold rolling mill rolls. Different surface modifications were carried out on samples produced from a fragment of the rolling mill roll: i texturing; ii chromium plating; iii texturing with subsequent hard chrome plating; iv and hard chrome plating with subsequent texturing. Before the surface modifications the samples were heat treated and ground on both faces. Wear tests were performed using a reciprocating movement of a ball over flat configuration under a load of 9.8 N. It is observed that there is no significant change in the coefficient of friction as a function of surface modification. Surface texturing increases the wear of the counter body, while the hard chromium coating reduces it. The addition of hard chromium coating promotes the formation of a tribolayer on the counter body consisting of chromium and oxygen. On the other hand, for the samples without hard chrome coating, the tribolayer consists of iron and oxygen

  2. Metallurgical analysis of spalled work roll of hot strip mill

    International Nuclear Information System (INIS)

    In this study failure analysis of four work roll of the Hot Strip Mill is carried out. The microstructure is correlated with the chemical composition of shell and roll-life. It was concluded that for the longer service of the roll, cementite, graphite and martensite should be balanced (as per working requirement of the mill). (author)

  3. Structural causes of defects in a cast iron mill roll

    Directory of Open Access Journals (Sweden)

    J. Krawczyk

    2008-07-01

    Full Text Available This paper describes an analysis of a defective microstructure of a mill roll. For this purpose, a piece of a broken roll was collected. That roll was made of mottled cast iron. Its microstructure consisted of modular graphite, transformed ledeburite and a matrix composed of bainite and martensite. Metallographic investigations were performed nearby the fracture in the roll. Observations were conducted on polished sections, first not etched, and then etched, which allowed us to trace carefully the propagation of the fracture. There was found a strict correlation between the microstructure of the roll and the progress occurring in the crack. It was ascertained that the basic reason for the damage to the roll was banded precipitations of ledeburitic cementite. In addition, cementite formed a continuous network. Another microstructure defects of that roll are also precipitations of secondary carbides on the boundaries of former grain of austenite as well as the occurrence of upper bainite in its matrix. The results obtained hereunder allow broadening the data base relative to the genesis of damages to mill rolls, which in future will permit one to design a proper microstructure of cast iron mill rolls. Proper microstructure of cast iron mill roll should be shaped at the stage of designing the chemical composition, conditions of crystallization or heat treatment if any.

  4. Theoretical And Experimental Analysis Of Aluminium Bars Rolling Process In Three-High Skew Rolling Mill

    Directory of Open Access Journals (Sweden)

    Stefanik A.

    2015-06-01

    Full Text Available Technology of round bars rolling on a three-high skew rolling mills allows rolling of standard materials such as steel and aluminum, as well as new materials, especially hard deformable materials. The paper presents the results of theoretical and experimental rolling process of aluminum bars with a diameter of 20 mm. As the stock round bars with a diameter of 25 mm made of aluminum grade 1050A and aluminum alloy grade 2017A were used. The rolling process of aluminum bars has been carried out in a single pass. The numerical analysis was carried out by using computer program Forge2011®. On the basis of theoretical research it has been determined the state of deformation, stress and temperature distribution during rolling of aluminum bars. In addition, the results of theoretical research allowed to determine the schema of the metal plastic flow in the roll gap. Verification of the theoretical research was carried out during the rolling of aluminum bars on the RSP 40/14 laboratory three-high skew rolling mill. From the finished bars were taken the samples to set the shape and compared with the results of theoretical research. Finished aluminum round bars were characterized by low ovality and good surface quality.

  5. Failure analysis of work rolls of a thin hot strip mill

    OpenAIRE

    Piyas Palit; Hrishikesh R. Jugade; Arvind Kumar Jha; Souvik Das; Goutam Mukhopadhyay

    2015-01-01

    In hot rolling mills, premature failure of rolls is a major concern as it adversely affects the mill operation as well as production. Analysis of failed roll materials and actual rolling conditions in service are therefore necessary to understand the roll failure mechanism and thereby improve the wear resistance and extend the service life of rolls. The hot strip mill referred here consists of six stands wherein high chromium (Hi-Cr) iron rolls and Indefinite Chilled Double Poured (ICDP) c...

  6. Digital technology for radiometric thickness gages in rolling mills

    International Nuclear Information System (INIS)

    In this paper a nuclear (Am-241, Sr-90) computer-controlled thicknessgerge is described, utilizing the digital technologies additionally for transmission and filtration of signals of the receiver for automatic computation of the calibration curves, automatic standardization over the gauge range and on-line digital diagnosis. This device works without contact and can be used in cold and hot rolling mills. (orig.)

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

    International Nuclear Information System (INIS)

    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.

  8. Development of rolling mill for rectangular orthodontic wires production

    Directory of Open Access Journals (Sweden)

    G.E. Totten

    2007-09-01

    Full Text Available Purpose: In orthodontic treatments, wires of different metallic alloys are used for alignment, leveling, correction of the molar position, space closing, finish and retention. The purpose of the paper is the characteristics of austenitic stainless steel wires, with a square traverse section, which were produced using a rolling mill built for this purpose, are presented hereDesign/methodology/approach: With respect to finish and retention, these wires are responsible for adequate positioning of the upper teeth on the lower teeth. Wires that are subjected to incisor torque require high resistance and stiffness. For this, wires of rectangular austenitic stainless steel are used due to high modulus of elasticity and good corrosion resistance in the oral environment. Because of the rectangular geometry, wire production requires process development suitable for industrial scale manufacture with geometric characteristics and mechanical properties better adapted to the use conditions.Findings: To obtain wires with such characteristics, a rolling mill was developed for the production of rectangular wires by a rolling process with the objective of reducing cost of the cold drawing process that is currently used which utilize complex and expensive wire-drawing dies. In addition to the rolling process itself, wire deformation, microhardness, tension and bend tests were also performed.Research limitations/implications: A rolling-mill was built that successfully produced dental wires within acceptable tolerances and physical/mechanical properties.These wires exhibited excellent hardness and tensile strength, although slightly less than analogous commercial wires. It is expected that this problem are corrected by using initial wires with a higher hardness, since this property is directly related with the tensile strength.Originality/value: In these tests, wire geometry, surface finish and mechanical properties were successfully adapted for use in orthodontic treatments.

  9. Optimization of a Heavy Continuous Rolling Mill System Via Simulation

    OpenAIRE

    Ali Azadeh; Farid Ghaderi

    2006-01-01

    The objective of this study was to develop an integrated simulation model, which generates a set of optimizing alternatives for a heavy continuous rolling mill system in a full-scale steelmaking factory. The simulation approach enabled us to evaluate the performance of the existing system and pinpointed existing bottlenecks in workstations and production flow. Consequently, it generated a set of optimum production alternatives. Data related to process and operation times, repairs, maintenance...

  10. Development of rolling mill for rectangular orthodontic wires production

    OpenAIRE

    Totten, G.E.; A.I. Filho; C.A.R. Gouvéa; Neto, A.; L.C. Casteletti

    2007-01-01

    Purpose: In orthodontic treatments, wires of different metallic alloys are used for alignment, leveling, correction of the molar position, space closing, finish and retention. The purpose of the paper is the characteristics of austenitic stainless steel wires, with a square traverse section, which were produced using a rolling mill built for this purpose, are presented hereDesign/methodology/approach: With respect to finish and retention, these wires are responsible for adequate positioning o...

  11. Influence of a matrix on properties of mottled cast iron applied for mill rolls

    OpenAIRE

    Krawczyk, J; J. Pacyna

    2010-01-01

    Mill rolls are ones of the most expensive tools applied in plastic working processes and have to satisfy several criteria, which allow them to be used. Cast iron mill rolls, due to their fracture toughness and tribological properties, are the most often applied at hot-rolling in the last rolling stands. This results from the smallest dynamic loads of such rolling stands and the decisive influence of the surface quality of these tools on the surface quality of the rolled product. An improper m...

  12. Slip Line Field Solution for Second Pass in Lubricated 4-High Reversing Cold Rolling Sheet Mill

    OpenAIRE

    Oluleke O. Oluwole; Olayinka Olaogun

    2011-01-01

    The development of a possible slip line field (slf) for theoretical calculations of the deforming pressure (load) in a second pass of a lubricated cold rolling sheet mill and validation using values from an aluminium sheet rolling mill was done in this work. This will be relevant in the manufacturing industries providing an easy method for determining necessary applied rolling load. Experimental rolling was carried out to observe the shear lines in the deformation field. Construction of possi...

  13. Numerical And Experimental Study On Producing Aluminum Alloy 6061 Shafts By Cross Wedge Rolling Using A Universal Rolling Mill

    Directory of Open Access Journals (Sweden)

    Tofil A.

    2015-06-01

    Full Text Available The paper presents a selection of numerical and theoretical results of the cross wedge rolling process for producing stepped shafts made of aluminum alloy 6061. The numerical modeling was performed using the FEM-based Simufact Forming simulation software. In the simulations, we examined the kinematics of metal flow and determined the distribution patterns of effective strains, temperatures, axial stresses and the Cockroft-Latham damage criterion. Variations in the rolling forces were determined, too. The numerical results were verified experimentally using a universal rolling mill designed and constructed by the present authors. This machine can be used to perform such processes as cross wedge rolling, longitudinal rolling and round bar cropping. During the experiments, we examined process stability and finished product geometry and recorded the torques. The experimental results confirm that axisymmetric aluminum alloy shafts can be produced by cross wedge rolling with two rolls. Last but not least, the experiments served to evaluate the technological potential of the rolling mill used.

  14. Bayesian model mixing for cold rolling mills: Test results.

    Czech Academy of Sciences Publication Activity Database

    Ettler, P.; Puchr, I.; Dedecius, Kamil

    Slovensko : Slovak University of Technology, 2013, s. 359-364. ISBN 978-1-4799-0926-1. [19th International Conference on Process Control. Štrbské Pleso (SK), 18.06.2013-21.06.2013] R&D Projects: GA MŠk(CZ) 7D09008; GA MŠk 7D12004 Keywords : Bayesian statistics * model mixing * process control Subject RIV: BC - Control Systems Theory http://library.utia.cas.cz/separaty/2013/AS/dedecius-bayesian model mixing for cold rolling mills test results.pdf

  15. Optimization of a Heavy Continuous Rolling Mill System Via Simulation

    Directory of Open Access Journals (Sweden)

    Ali Azadeh

    2006-01-01

    Full Text Available The objective of this study was to develop an integrated simulation model, which generates a set of optimizing alternatives for a heavy continuous rolling mill system in a full-scale steelmaking factory. The simulation approach enabled us to evaluate the performance of the existing system and pinpointed existing bottlenecks in workstations and production flow. Consequently, it generated a set of optimum production alternatives. Data related to process and operation times, repairs, maintenance and quality control were collected and analyzed systematically. The simulation model was modeled by Visual SLAM and Awesim simulation language. The results and structure of the computer simulation model were validated and verified against the actual system. Also, the results of the models were discussed and approved by the production managers. The distinct feature of the simulation model is three fold. First, it is integrated and considers detailed operations and activities of the Rolling Mill system. Furthermore, it is designed to be integrated with other workshops of the factory. Second, it locates the optimum solutions by a rule-based methodology. Finally, the model considers the Just-in-Time configuration of the line and is capable of answering all production and inventory issues.

  16. Hot sheet rolling on continuous mill under plastic fluid friction conditions

    International Nuclear Information System (INIS)

    A technique for hot sheet rolling in plastic fluid friction conditions of sheets of the 12Kh18N10T and carbon 10 sp steels is developed and tested. A new lubricant ''Silicatherm'' constitutes the basis of the technique. The advantages of the given technique as compared to the rolling with liquid lubricants of mineral and vegetative origin as well as the prospects of its introduction during hot rolling on continuous mills are shown

  17. Force prediction in cold rolling mills by polynomial methods

    Directory of Open Access Journals (Sweden)

    Nicu ROMAN

    2007-12-01

    Full Text Available A method for steel and aluminium strip thickness control is provided including a new technique for predictive rolling force estimation method by statistic model based on polynomial techniques.

  18. Research on roll wear of 2050mm hot strip finishing train (CVC Mill) of Baosteel

    International Nuclear Information System (INIS)

    In this paper, the general characteristics and affecting factors of work and backup rolls wear of finishing train were analyzed. Taking the CVC finishing mills of 2050mm hot strip mill of Baosteel as an example, the roll wear magnitude and contour were calculated in theory, and measured by the present grinding machine in experiment. The calculated results agree well with the measured data in distribution, and also in general characteristics. Based on the calculated and measured results, an on-line prediction model by which the roll wear distribution characteristics of a CVC mill can be revealed more accurately was proposed. (author)

  19. IMPROVEMENT PROCESS FOR ROLLING MILL THROUGH THE DMAIC SIX SIGMA APPROACH

    Directory of Open Access Journals (Sweden)

    Kunal Ganguly

    2012-09-01

    Full Text Available This project aims to address the problems that are facing a large aluminum company in a Developing Hot Rolling Mill Capabilities for Wider Widths Hard Alloys Rolling and b Eliminate down time due to strip /coil slippage during hard alloys 5xxx rolling at Hot Mill. The challenge for the company was to cater the fast changing export demand for Flat Rolled products with its existing resources. By applying Six Sigma principles, the team identified the current situation that the rolling mills operations were in. Si x Sigma DMAIC methodologies were use d in the project to determine the project's CTQ characteristics, defining the possible causes, Identifying the variation sources, establishing variable relationships and Implementing Control Plans. The project can be useful for any company that needs to fi nd the most cost efficient way to improve and utilize its resources.

  20. Drop deformation in two-roll mills considering wall effects

    Science.gov (United States)

    Escalante-Velįzquez, C. A.; Huesca-Reyes, M. A.; Yescas Rosas, I.; Geffroy, E.

    2015-01-01

    Experimental, theoretical and numerical results of dynamics of drop deformation in strong flows generated by a co-rotating two-roll mill and considering the influence of near rigid walls are presented. The drop dynamics is altered, with respect to a drop free of wall effects, by the proximity of the rigid boundaries as well as caused by a non-linear and non-uniform flow due to gradients of flow-type parameter and shear rate. Simulations were carried out using the Boundary Element Method (BEM). Since the inclusion of the whole boundaries (drop and rollers surfaces) is not an easy and trivial task, bi-dimensional numerical simulations was performed as a first approach. The experimental and numerical results were obtained for a flow type of ? = 0.03 and two values of viscosity ratio ? = 0.012 and 16. In general, numerical results for the stationary deformation parameters, up to intermediate confinements, are in agreement with the experiments, with and without wall effects. Since the case of drops with a high viscosity ratio did not match existing theoretical models, the wall-effect theory of Shapira and Haber was modified, considering Cox's second-order theory as the converging theory without wall effects. From low to intermediate confinements, the new Cox-Shapira-Haber model fitted the observed experimental deformations.

  1. Drop deformation in two-roll mills considering wall effects

    International Nuclear Information System (INIS)

    Experimental, theoretical and numerical results of dynamics of drop deformation in strong flows generated by a co-rotating two-roll mill and considering the influence of near rigid walls are presented. The drop dynamics is altered, with respect to a drop free of wall effects, by the proximity of the rigid boundaries as well as caused by a non-linear and non-uniform flow due to gradients of flow-type parameter and shear rate. Simulations were carried out using the Boundary Element Method (BEM). Since the inclusion of the whole boundaries (drop and rollers surfaces) is not an easy and trivial task, bi-dimensional numerical simulations was performed as a first approach. The experimental and numerical results were obtained for a flow type of ? = 0.03 and two values of viscosity ratio ? = 0.012 and 16. In general, numerical results for the stationary deformation parameters, up to intermediate confinements, are in agreement with the experiments, with and without wall effects. Since the case of drops with a high viscosity ratio did not match existing theoretical models, the wall-effect theory of Shapira and Haber was modified, considering Cox's second-order theory as the converging theory without wall effects. From low to intermediate confinements, the new Cox-Shapira-Haber model fitted the observed experimental deformations

  2. A small economical rolling mill for producing foils used as nuclear targets

    Energy Technology Data Exchange (ETDEWEB)

    Greene, J.P.; Thomas, G.E.

    1996-11-01

    A small, economical rolling mill has found extensive use in the Physics Division Target Development Laboratory for producing foils used in atomic and nuclear physics experiments. This apparatus is quite versatile for its size and enables a large fraction of our target foil requirements to be realized in-house. A description of the rolling mill and some examples of targets produced will be given.

  3. A model-based predictive control scheme for steal rolling mills using neural networks

    Scientific Electronic Library Online (English)

    J. M., Gįlvez; Luis E., Zįrate; H., Helman.

    2003-03-01

    Full Text Available A capital issue in roll-gap control for rolling mill plants is the difficulty to measure the output thickness without including time delays in the control loop. Time delays are a consequence of the possible locations for the output thickness sensor, which usually is located some distance away from t [...] he roll gap. In this work, a new model-based predictive control law is proposed. The new scheme is a neural network based predictive control structure which is applied to roll-gap control with outstanding results. It is shown that the neural network based predictive control permits to overcome the existing time delays in the system dynamics. The proposed scheme implements a virtual thickness sensor, which releases an accurate estimate of the actual output thickness. It is shown that the dynamic response of the rolling mill system can be substantially improved by using the proposed controller. Simulation results are presented to illustrate the controller performance.

  4. Fuzzy-Neural Control of Hot-Rolling Mill

    Directory of Open Access Journals (Sweden)

    Khearia Mohamad

    2010-12-01

    Full Text Available This paper deals with the application of Fuzzy-Neural Networks (FNNs in multi-machine system control applied on hot steel rolling. The electrical drives that used in rolling system are a set of three-phase induction motors (IM controlled by indirect field-oriented control (IFO. The fundamental goal of this type of control is to eliminate the coupling influence though the coordinate transformation in order to make the AC motor behaves like a separately excited DC motor. Then use Fuzzy-Neural Network in control the IM speed and the rolling plant. In this work MATLAB/SIMULINK models are proposed and implemented for the entire structures. Simulation results are presented to verify the effectiveness of the proposed control schemes. It is found that the proposed system is robust in that it eliminates the disturbances considerably.

  5. Rolling process simulation of a pair-crossed hot strip mill

    International Nuclear Information System (INIS)

    Process simulation can help optimize the operating parameters aiming to improve the quality of rolled products. In this paper, software in Visual Basic language is developed to simulate the hot rolling process of a pair-crossed mill. The strip temperature is calculated by considering air cooling, water cooling, heat generation and conduction.The production parameters including rolling speeds, resistance to deformation, rolling forces, drive torques and powers are evaluated by mathematical models and their parameter identification support tools. The deformation of roll stack is calculated by influential function method. The roll temperature and expansion are calculated by finite differential method, and the roll wear is described by empirical formula. Based on these calculations as well as the effect of heredity is taken into account, the strip crown and flatness then can be obtained. The results show that the simulation software has friendly user interface, high accuracy and practicability. It can be served as a basis for the mill design and optimization of process parameters to acquire high quality of hot rolled strip. (author)

  6. Metal rolling - Asymmetrical rolling process

    Science.gov (United States)

    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.

  7. FEM SIMULATION OF THE TUBE ROLLING PROCESS IN DIESCHER’S MILL

    Directory of Open Access Journals (Sweden)

    Zbigniew Pater

    2014-06-01

    Full Text Available This paper deals with the issue of numerical modelling of the piercing process of a thick–walled bush in a two-rolled skew rolling mill, equipped with guiding devices of Diescher’s type. After a short characteristic of the subject matter, the developed geometric model of the process was discussed, with taking kinematics of tools movement and thermal phenomena present in metal during forming into consideration. Next, the results of calculations were presented in a form of fields of strain, damage criterion and temperature. Distributions of force parameters acting on particular tools during the process of bush rolling were also given.

  8. Wireless Remote Monitoring System for the Agc Svibration Fault of Rolling Mill

    OpenAIRE

    Yan Gao; Baoquan Jin; Hongjuan Zhang

    2013-01-01

    The rolling mill screw down AGC system sets several subsystems of machinery, electronics, hydraulics, controls in one. Under the action of responding extreme frequency or external disturbances, the non design objective coupling between the subsystems may be excited, and causing the most serious vibration, seriously impact product quality or even cause great destruction. Aiming at the defects in fault diagnosis and control system of the traditional rolling m...

  9. Advanced Soft Sensor Technology to be Used for Cold Rolling Mills.

    Czech Academy of Sciences Publication Activity Database

    Ettler, P.; Dedecius, Kamil; Juri?i?, D.; Preglej, A.

    Toulouse : IEEE, 2011, s. 1-4. ISBN 978-1-4577-0016-3. [16th IEEE International Conference on Emerging Technologies and Factory Automation ETFA'2011. Toulouse (FR), 05.09.2011-09.09.2011] R&D Projects: GA MŠk(CZ) 7D09008 Institutional research plan: CEZ:AV0Z10750506 Keywords : soft sensor * rolling mill Subject RIV: IN - Informatics, Computer Science http://library.utia.cas.cz/separaty/2011/AS/dedecius-advanced soft sensor technology to be used for cold rolling mills.pdf

  10. Extended Kalman Filter Based Neural Networks Controller For Hot Strip Rolling mill

    International Nuclear Information System (INIS)

    The present paper deals with the application of an Extended Kalman filter based adaptive Neural-Network control scheme to improve the performance of a hot strip rolling mill. The suggested Neural Network model was implemented using Bayesian Evidence based training algorithm. The control input was estimated iteratively by an on-line extended Kalman filter updating scheme basing on the inversion of the learned neural networks model. The performance of the controller is evaluated using an accurate model estimated from real rolling mill input/output data, and the usefulness of the suggested method is proved

  11. Influence of a matrix on properties of mottled cast iron applied for mill rolls

    Directory of Open Access Journals (Sweden)

    J. Krawczyk

    2010-07-01

    Full Text Available Mill rolls are ones of the most expensive tools applied in plastic working processes and have to satisfy several criteria, which allow them to be used. Cast iron mill rolls, due to their fracture toughness and tribological properties, are the most often applied at hot-rolling in the last rolling stands. This results from the smallest dynamic loads of such rolling stands and the decisive influence of the surface quality of these tools on the surface quality of the rolled product. An improper microstructure of rolls can lead to their premature wearing, e.g. broken flanges, pivots twisting off etc. By means of the heat treatment the matrix microstructure and morphology of carbide precipitationscan be modified and this in-turn can influence cast iron properties.Determination of the influence of microstructure changes, caused by the heat treatment, on the properties of EN-GJN-HV300 low-alloycast iron, after its modification and spheroidization – is the aim of the present paper. Those changes are based on the formation pearlitic or bainitic matrices at the similar morphology of graphite and ledeburitic cementite precipitations. The performed investigations should enable designing the heat treatment of cast iron metallurgical rolls in such a way as to obtain the optimal microstructures for functional parameters of these type of tools. The influence of changing the pearlitic matrix into the bainitic one on such properties as: hardness, impact strength, tensile strength, creep limit, bending strength and a stress intensity factor KIc was investigated in this study. Samples for testing, the listed above mechanical properties, were taken from an industrial casting with care to have pieces of very similar crystallization conditions.

  12. Rolling reloaded

    International Nuclear Information System (INIS)

    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. 17 353-6). We provide a detailed experimental verification of this observation, collecting 3D data from a rolling wheel with a commercially available optical tracking system. We also extend the observation to a generalized form: for a rolling wheel, there is a set of points with instantaneous velocities directed at or away from any point P; these points form a circle whose diameter connects the point P to the wheel's point of contact with the ground. This generalization is also verified experimentally

  13. Strip/Foil Rolling Mill Stochastic Excitation Model and Its Stability

    Directory of Open Access Journals (Sweden)

    Baoyu Xu

    2012-06-01

    Full Text Available Based on the stochastic rolling force data from aluminum hot strip tandem mill, the ARMA time series model and the stochastic excitation power spectral density (PSD model are established, and the stochastic rolling forces excitation model is established by utilizing Levenberg-Marquardt combined with generalized global planning algorithm. A two dimensional stochastic nonlinear dynamical model of rolls is presented considering the stochastic factor of the rolling force. The Hamilton function is also described as one dimension diffusion process by using stochastic average method, the singular boundary theory was taken for analyzing the global stochastic stability of the system, and the system’s stochastic stability was researched by solving the Fokker-Planck-Kolmogorov (FPK equation. The results show that the stochastic excitation model obtained has significance for analyzing and researching stochastic dynamics characteristics to the system, and also generalized energy H in the range of 0.02 to 0.4, the system’s response has the minimum transition probability density, and the system state is not easy to change, therefore the system generalized energy H should be to limit in this range in the design and operation of the rolling mill.

  14. Lubricant for clean rolling: Escapee oil particles keep cold rolling steel mills lubricated:

    OpenAIRE

    Graaf, A., van de

    2002-01-01

    One of the unique selling points of the Corus steel mills at IJmuiden is the quality of the steel they produce. The lubrication used during the last production stage is one of the factors that determine how clean and smooth the steel will emerge from the mill. The usual lubricant consists of an emulsion of oil in water. Until recently, little was known about the physical principles underlying the action of lubricant emulsions in steel mills. The only way to test new lubricants was by...

  15. Wireless Remote Monitoring System for the Agc Svibration Fault of Rolling Mill

    Directory of Open Access Journals (Sweden)

    Yan Gao

    2013-01-01

    Full Text Available The rolling mill screw down AGC system sets several subsystems of machinery, electronics, hydraulics, controls in one. Under the action of responding extreme frequency or external disturbances, the non design objective coupling between the subsystems may be excited, and causing the most serious vibration, seriously impact product quality or even cause great destruction. Aiming at the defects in fault diagnosis and control system of the traditional rolling mill, the wireless remote monitoring system for the rolling mill AGC system vibration fault is designed in this paper. Using the advanced sensor technology, PLC and configuration software, GPRS network technology, the parallel distributed data acquisition and data processing for the key servo element and the hydraulic parameters which can characterize the fault characteristics of the system can be done. The monitoring software system platform on line of the hydraulic AGC system based on Kingview is set up for centralized real-time monitoring. According to the collected multidisciplinary parameter the fault identification and location is done by using the fault diagnosis expert system based on Web, thus to make the preliminary evaluation for the operation and fault of hydraulic AGC system and provide advanced prediction and exclude strategy.

  16. Effect of powder milling on mechanical properties of hot-pressed and hot-rolled Cu–Cr–Nb alloy

    Energy Technology Data Exchange (ETDEWEB)

    Shukla, A.K.; Narayana Murty, S.V.S.; Suresh Kumar, R. [Materials and Metallurgy Group, Vikram Sarabhai Space Centre, Trivandrum 695 022 (India); Mondal, K., E-mail: kallol@iitk.ac.in [Department of Materials Science and Engineering, Indian Institute of Technology Kanpur, Kanpur 208 016 (India)

    2013-12-15

    Highlights: •Milled powder enhances sintering and mechanical properties after hot pressing. •Hot-rolling of hot-pressed samples made from milled powder enhances ductility. •Pore size and number of pores decreases after hot-rolling. -- Abstract: The present study is on the effect of mechanical milling of gas-atomized powders on mechanical properties of the hot-pressed and subsequently hot-rolled Cu–8 at% Cr–4 at% Nb alloy with a microstructure consisting of pure copper matrix hardened by intermetallic Cr{sub 2}Nb precipitates. The mechanically milled powders result in lower sintering temperature during hot pressing compared to the atomized powders. The hot-pressed samples made from the milled powder exhibit significantly higher hardness and tensile strength, but lower ductility and electrical conductivity compared to that made from the un-milled gas-atomized powders. The hot rolling results in marginal increase in strength, but significant increase in ductility compared to the hot-pressed alloy for both the milled and atomized powders and it is attributed to the decrease in size of the pores and amount of porosities after hot rolling.

  17. Finite elements method (FEM simulation based prediction of deformation and temperature at rolling of tubes on a pilgrim mill

    Directory of Open Access Journals (Sweden)

    R. Kocich

    2009-10-01

    Full Text Available 3D - FEM simulation was used as an efficient tool for description of stress-deformation thermal field at rolling of tubes on a pilgrim mill. The monitored objectives comprised also behaviour of working tools at this rolling. This paper assumes rolling of already pierced thick-walled blank, which passes through the pilgrim stand at simultaneous reduction of thickness of inside and outside diameters at the expense of elongation of initial length. Main attention is focused on the mentioned parameters with respect to various conditions of rolling, such as different heat transfer, different friction or different distance of insertion of the rolled product into the gauge. The input data used at simulation were derived from real conditions of tubemaking.

  18. Failure analysis of work rolls of a thin hot strip mill

    Directory of Open Access Journals (Sweden)

    Piyas Palit

    2015-04-01

    Destructive testing (including metallography and chemical analysis was carried out on the failed roll samples in the first case and gross abnormality in microstructure was observed. Some foreign particle/entrapment was observed after dressing of the working surface of roll at 566 mm diameter (initial diameter of roll was 620 mm and scrap diameter was projected to be 540 mm. The chemical composition of the particle was analyzed by a portable X-Ray Fluorescence (XRF alloy analyzer and it was confirmed that the particle is basically a ferroalloy which was entrapped in the shell of the roll, probably during casting/manufacturing of roll.

  19. Neural compensation and modelling of a hot strip rolling mill using radial basis function

    Scientific Electronic Library Online (English)

    F.G., Rossomando; J., Denti F; A., Vigliocco.

    2011-07-01

    Full Text Available In this paper a Neural Compensation Strategy for a hot rolling mill process is proposed. The target of this work is to built a RBF-NN compensation approximation for the classical force feed forward and speed controller. A strategy based on neural networks is proposed here, because they are capable o [...] f modelling many nonlinear systems and their neural control via RBF-NN approximation. Simulations demonstrate that the proposed solution deals with disturbances and modeling errors in a better way than classic solutions do. The analysis of the RBF-NN approximation error on the control errors is included, and control system performance is verified through simulations.

  20. Customized maximal-overlap multiwavelet denoising with data-driven group threshold for condition monitoring of rolling mill drivetrain

    Science.gov (United States)

    Chen, Jinglong; Wan, Zhiguo; Pan, Jun; Zi, Yanyang; Wang, Yu; Chen, Binqiang; Sun, Hailiang; Yuan, Jing; He, Zhengjia

    2016-02-01

    Fault identification timely of rolling mill drivetrain is significant for guaranteeing product quality and realizing long-term safe operation. So, condition monitoring system of rolling mill drivetrain is designed and developed. However, because compound fault and weak fault feature information is usually sub-merged in heavy background noise, this task still faces challenge. This paper provides a possibility for fault identification of rolling mills drivetrain by proposing customized maximal-overlap multiwavelet denoising method. The effectiveness of wavelet denoising method mainly relies on the appropriate selections of wavelet base, transform strategy and threshold rule. First, in order to realize exact matching and accurate detection of fault feature, customized multiwavelet basis function is constructed via symmetric lifting scheme and then vibration signal is processed by maximal-overlap multiwavelet transform. Next, based on spatial dependency of multiwavelet transform coefficients, spatial neighboring coefficient data-driven group threshold shrinkage strategy is developed for denoising process by choosing the optimal group length and threshold via the minimum of Stein's Unbiased Risk Estimate. The effectiveness of proposed method is first demonstrated through compound fault identification of reduction gearbox on rolling mill. Then it is applied for weak fault identification of dedusting fan bearing on rolling mill and the results support its feasibility.

  1. Finite element analysis of deflection of rolls and its correction by providing camber on rolls

    OpenAIRE

    Vijay Gautam

    2013-01-01

    Rolling process is a key step in the production of flat steel products. Because of automation commonly implemented in flat product rolling mills, the products should meet the requirements of tight tolerances. one of the major defects observed in the rolling process is flatness and lack of attainment of the desired surface profile due to deflection of the rolls. The spatial shape and dimensions of the roll gap are influenced by the elastic deformation of all parts of the rolling stand equipmen...

  2. Fabrication of cold-rolled sheet using 1700 mill in Karaganda metallurgical works

    International Nuclear Information System (INIS)

    Technical specifications are presented and the operation experience is summarized of the continuous five-cage cold rolling stand 1700 KarMK put into operation in 1973. The peculiarities of the technology of fabrication of cold-rolled strips of 0.5-2.0 mm thickness are considered. The factors of rolling various thickness and manufactured strips are analyzed, the optimum cogging conditions are recommended. Data on wearing and on changing of microrelief of shaft surface are given. The equipment available and the technology adopted ensure the fabrication of cold-rolled sheet in conformity with the state standard (GOST) requirements

  3. Rolling-Element Bearings

    Science.gov (United States)

    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.

  4. Spray rolling aluminum alloy strip

    International Nuclear Information System (INIS)

    Spray rolling combines spray forming with twin-roll casting to process metal flat products. It consists of atomizing molten metal with a high velocity inert gas, cooling the resultant droplets in flight and directing the spray between mill rolls. In-flight convection heat transfer from atomized droplets teams with conductive cooling at the rolls to rapidly remove the alloy's latent heat. Hot deformation of the semi-solid material in the rolls results in fully consolidated, rapidly solidified product. While similar in some ways to twin-roll casting, spray rolling has the advantage of being able to process alloys with broad freezing ranges at high production rates. This paper describes the process and summarizes microstructure and tensile properties of spray-rolled 2124 and 7050 aluminum alloy strips. A Lagrangian/Eulerian poly-dispersed spray flight and deposition model is described that provides some insight into the development of the spray rolling process. This spray model follows droplets during flight toward the rolls, through impact and spreading, and includes oxide film formation and breakup when relevant

  5. Rolling and annealing texture in twin roll cast commercial purity aluminium

    Energy Technology Data Exchange (ETDEWEB)

    Benum, S. (SINTEF, Div. of Metallurgy, Trondheim (Norway)); Engler, O. (Inst. fuer Metallkunde und Metallphysik, RWTH Aachen (Germany)); Nes, E. (Norwegian Inst. of Tech., Dept. of Metallurgy, Trondheim (Norway))

    1994-01-01

    The development of cold rolling and annealing texture in twin roll cast commercial aluminium has been studied, varying rolling conditions such as lubricant and rolling speed in laboratory rolling and by comparing laboratory rolled sheets to that from a commercial mill. The tendency to formation of shear texture in the surface of laboratory rolled sheets was promoted by high surface friction and low rolling speeds, while well lubricated rolls and high speeds resulted in a plane strain type texture also in the sheet surface. The latter was also typical of industrial rolling. The effect of the surface deformation mode and texture on the grain structure resulting from the subsequent annealing has also been studied. The shear texture in laboratory rolled sheets were associated with a smaller grain size than industrially rolled sheets. (orig.)

  6. Simulation of two Stands Cold Rolling Mill Process Using a Combination of Neural Networks and Genetic Algorithms to Avoid the Chatter Phenomenon

    Directory of Open Access Journals (Sweden)

    Behzad BahramiNejad

    2015-03-01

    Full Text Available Rolling mill Industry is one of the most profitable industries in the world. Chatter phenomenon is one of the key issues in this industry. Chatter or rolling unwanted vibrations not only has an adverse effect on product quality, but also reduces considerably the efficiency with reduced rolling velocities of rolling lines. This paper is an attempt to simulate the phenomenon of Chatter more accurate than the previous performed simulations. In order to increase the production speed, it needs to avoid parameters which effect on the Chatter and varieties with the rolling lines condition. Actual values of these parameters were determined in the archives of the Mobarakeh two stand cold rolling mills and collected on the 210 case study of real chattering. To simulate the experiment, a neural network is trained and weights and bias values of the neural network with genetic optimization algorithm were used to get an optimal neural network which reduces bugs on the test data. So this model is capable to predict speed of Chatter threshold on rolling process of two stand cold rolling mill with the accuracy less than one percent. So it can be used in rolling process with the building intelligent recognition systems to prevent the creator conditions of the chatter frequency range.

  7. Finite element analysis of deflection of rolls and its correction by providing camber on rolls

    Directory of Open Access Journals (Sweden)

    Vijay Gautam

    2013-10-01

    Full Text Available Rolling process is a key step in the production of flat steel products. Because of automation commonly implemented in flat product rolling mills, the products should meet the requirements of tight tolerances. one of the major defects observed in the rolling process is flatness and lack of attainment of the desired surface profile due to deflection of the rolls. The spatial shape and dimensions of the roll gap are influenced by the elastic deformation of all parts of the rolling stand equipment affected by the roll pressure. The current study aims to determine the variation of the deflection in rolls in a two high mill with varying percentage reduction of the sheet i.e, 20%, 25% and 30% on annealed and non-annealed IF steel sheet and analyzing possible solutions to reduce the elastic deflection of rolls with special emphasis on cambering and modelling of the same in Abaqus CAE.

  8. Rolling friction and bistability of rolling motion

    CERN Document Server

    Pöschel, T; Brilliantov, N; Zaikin, A; Poeschel, Thorsten; Schwager, Thomas; Brilliantov, Nikolai; Zaikin, Alexei

    2005-01-01

    The rolling motion of a rigid cylinder on an inclined flat viscous surface is investigated and the nonlinear resistance force against rolling, $F_R(v)$, is derived. For small velocities $F_R(v)$ increases with velocity due to increasing deformation rate of the surface material. For larger velocity it decreases with velocity due to decreasing contact area between the rolling cylinder and the deformed surface. The cylinder is, moreover, subjected to a viscous drag force and stochastic fluctuations due to a surrounding medium (air). For this system, in a wide range of parameters we observe bistability of the rolling motion. Depending on the material parameters, increasing the noise level may lead to increasing or decreasing average velocity.

  9. Evaluation of Health Consequences of Air Pollution Induced by Beam Rolling Mills Factory (Iran

    Directory of Open Access Journals (Sweden)

    Rafiei Masoud

    2014-10-01

    Full Text Available The increases in air pollution over the metropolitan cities are a threat to human health and environment. An attempt has been made to evaluate the health consequences of indoor air pollution induced by Beam Rolling Mills Factory at Ahwaz (Iran. A questionnaire was prepared to obtain information on health of 481 workers, out of which 200 each were selected from exposed and non-exposed category by stratified randomized method. Fisher exact test and chi-square test were used to calculate the values. The study concludes that more than 80% of the workers have high exposure risk to diseases. Analysis of the health impacts reveals that exposed workers are more prone to various diseases as compared to the non-exposed workers. It is also observed that exposure to air pollutants might be the causative factor for various diseases among the smokers but also nonsmoking workers. The analysis also reveals that there is higher relative risk in occupational fatigue and cardio-vascular disease. Further, the study found that percentage of workers having various diseases is much higher in the indoor environment as compared to the outdoor environment

  10. Grain refinement of magnesium alloy sheets by ARB using high-speed rolling mill

    International Nuclear Information System (INIS)

    Applications of ARB to magnesium alloys were limited due to low deformability. The authors recently found that the rollability of the alloys is significantly improved in highspeed rolling. It is supposed that the severe plastic deformation of magnesium alloy sheets is feasible if rolling in ARB processes is conducted at high speed. In this study, AZ31B and ZK60A sheets are processed by ARB up to five cycles at 423K with a speed of 1000m/min. Vickers hardness increases with increasing number of ARB cycles, while the tensile strength shows the maximum after the second cycle. The grain size is reduced significantly at the first cycle and decreases gradually from the second cycle. The mean grain sizes after five cycles are 1.6?m for AZ31B and 1.8?m for ZK60A. It is concluded that ARB using high-speed rolling is effective for grain refinement of magnesium alloys.

  11. Expert system for flatness control in aluminum foil rolling. Alumi haku mill keijo seigyo expert system

    Energy Technology Data Exchange (ETDEWEB)

    Konishi, M.; Nose, K.; Narazaki, H.; Iwatani, T.; Oshima, H.; Kitagawa, S. (Kobe Steel, Ltd., Kobe (Japan))

    1990-07-01

    This paper reports the application of an expert system for Automatic Flatness Control (AFC) in aluminum foil rolling. The expert system is connected with AFC, and adjusts the target shape pattern according to the material characteristics and the operating conditions. This system is developed on the UNIX work station, and consists of six units, three knowledge bases, and a working memory. It has shown the ability to improve all kinds of aluminum foil throughout an one year adaptation in the operational rolling process. By using this system, the speed of rolling was improved above 10 percent. The algorithm which maintains consistency among multiple control purposes and the adaptive inference method realized in this system proved to be useful as a paradigm of the knowledge base system for the control process. 1 ref., 6 figs.

  12. Improving Thermal Efficiency Of Push Type Furnace In A Hot Re-Rolling Steel Mill By Direct Method : Case Study

    Directory of Open Access Journals (Sweden)

    Jeetendra Mohan Khare

    2013-04-01

    Full Text Available Rolling is the process of reducing the thickness or changing the cross-section of a long work-piece by compressive forces applied through a set of rolls. Rolling accounts for about 90% of all metals produced by metalworking processes. The purpose of Rolling is to convert larger sections into smaller sections, which can be used directly in as rolled state or as stock for working through other processes. As a result of rolling, the coarse structure of cast ingot is converted into a fine grained structure

  13. Improving Thermal Efficiency Of Push Type Furnace In A Hot Re-Rolling Steel Mill By Direct Method : Case Study

    OpenAIRE

    Jeetendra Mohan Khare; Sandip Kumar Mishra; Shashank Shrivastava

    2013-01-01

    Rolling is the process of reducing the thickness or changing the cross-section of a long work-piece by compressive forces applied through a set of rolls. Rolling accounts for about 90% of all metals produced by metalworking processes. The purpose of Rolling is to convert larger sections into smaller sections, which can be used directly in as rolled state or as stock for working through other processes. As a result of rolling, the coarse structure of cast ingot is converted into a fine grained...

  14. Ship Roll Damping Control

    DEFF Research Database (Denmark)

    Perez, Tristan; Blanke, Mogens

    2012-01-01

    The technical feasibility of roll motion control devices has been amply demonstrated for over 100 years. Performance, however, can still fall short of expectations because of difficulties associated with control system designs, which have proven to be far from trivial due to fundamental performance limitations and large variations of the spectral characteristics of wave-induced roll motion. This tutorial paper presents an account of the development of various ship roll motion control systems tog...

  15. Rolling Shutter Motion Deblurring

    KAUST Repository

    Su, Shuochen

    2015-06-07

    Although motion blur and rolling shutter deformations are closely coupled artifacts in images taken with CMOS image sensors, the two phenomena have so far mostly been treated separately, with deblurring algorithms being unable to handle rolling shutter wobble, and rolling shutter algo- rithms being incapable of dealing with motion blur. We propose an approach that delivers sharp and undis torted output given a single rolling shutter motion blurred image. The key to achieving this is a global modeling of the camera motion trajectory, which enables each scanline of the image to be deblurred with the corresponding motion segment. We show the results of the proposed framework through experiments on synthetic and real data.

  16. Finite element analysis of edge fracture of electrical steel strip in reversible cold rolling mill

    International Nuclear Information System (INIS)

    An electrical steel strip is commonly used as a core material in all types of electric transformers and motors. It is produced by a cold rolling process. In this paper, a damage mechanics based approach that predicts the edge fracture of an electrical steel strip during cold rolling is presented. We adopted the normal tensile stress criterion and the fracture energy method as a damage initiation criterion and a damage evolution scheme, respectively. We employed finite element analysis (FEA) to simulate crack initiation and propagation at the initial notch located at the edges of the strip. The material constants required in FEA were experimentally obtained by tensile tests using a standard and a notched sheet type specimen. The results reveal that the edge crack was initiated at the entrance of the roll bite and that it rapidly evolved at the exit. The evolution length of the edge crack increased as the length of the initial notch as well as front tension reel force of the strip increased

  17. The ways of increasing the socket accuracy in the course of broaching on a three-roll mill

    International Nuclear Information System (INIS)

    The results are presented of experimental investigations on the wall thickness variation of sleeves broached on a three-high mill with barrel-shaped rolls. To obtain sleeves with relatively accurate geometrical dimensions it is necessary to ensure a high rigidity of alignment of the sleeve-mandrel-rod system with a 3- to 4-fold safety margin for rod resistance to longitudinal bending with a length equal to that of the sleeve. Broaching is better to accomplish at increased feed angles (14-16 deg.) with partial cooling of the billets

  18. Catalytic surface modification of roll-milled poly({epsilon}-caprolactone) biaxially stretched to ultra-thin dimension

    Energy Technology Data Exchange (ETDEWEB)

    Foo, H.L. [Graduate Programme in Bioengineering, National University of Singapore (Singapore); Bionic Materials Technology Group, Biomaterials Center, National Institute for Materials Science (Japan); Taniguchi, A. [Bionic Materials Technology Group, Biomaterials Center, National Institute for Materials Science (Japan); Yu, H. [Graduate Programme in Bioengineering, National University of Singapore (Singapore); Department of Physiology, National University of Singapore (Singapore); Okano, T. [Bionic Materials Technology Group, Biomaterials Center, National Institute for Materials Science (Japan); Institute of Biomedical Engineering, Tokyo Women' s Medical University (Japan); Teoh, S.H. [Graduate Programme in Bioengineering, National University of Singapore (Singapore) and Department of Mechanical Engineering, National University of Singapore (Singapore)]. E-mail: mpetsh@nus.edu.sg

    2007-03-15

    A novel roll-milling polymer processing technique along with biaxial stretching was used to fabricate 10 {mu}m thick poly({epsilon}-caprolactone) films. A less invasive collagen surface modification was used, involving a reaction between corona-preactivated membranes and ferrous-containing acrylic acid solution at the low temperature of 42 {sup o}C. Successful modified films were characterized by Toluidine Blue O assay and X-ray photoelectron spectroscopy. Human umbilical vein endothelial cells also showed both higher proliferation rate and differentiated cobblestone morphology on these collagen-immobilized substrates.

  19. Catalytic surface modification of roll-milled poly(?-caprolactone) biaxially stretched to ultra-thin dimension

    International Nuclear Information System (INIS)

    A novel roll-milling polymer processing technique along with biaxial stretching was used to fabricate 10 ?m thick poly(?-caprolactone) films. A less invasive collagen surface modification was used, involving a reaction between corona-preactivated membranes and ferrous-containing acrylic acid solution at the low temperature of 42 oC. Successful modified films were characterized by Toluidine Blue O assay and X-ray photoelectron spectroscopy. Human umbilical vein endothelial cells also showed both higher proliferation rate and differentiated cobblestone morphology on these collagen-immobilized substrates

  20. Prediction of work-roll temperature distribution in continuous hot strip rolling process

    International Nuclear Information System (INIS)

    Prediction of temperature distribution within the work-rolls during the hot slab rolling process is of great importance to mill designers. This is because, not only the temperature distribution in rolling material and the dimensional accuracy are depended on work-roll temperature but also the roll life is a function of its temperature distribution. In this paper using the heat transfer equations for moving media and a two dimensional finite element method, the work-roll temperature distribution during continuous hot strip rolling process is predicted. To achieve an accurate temperature field the effects of various factors including the rolling speed, interface heat transfer coefficient, and the amount of slab thickness reduction at each deformation pass are taken into account. Comparison between the predicted and experimental published results depicts the validity of the mathematical model. (author)

  1. Analysis of the bimetallic bars rolling during a skew rolling

    Directory of Open Access Journals (Sweden)

    S. Sawicki

    2008-07-01

    Full Text Available Purpose: Bimetallic bars which possess higher corrosion resistance and mechanical properties, it is the newkind of bimetallic bars which are better than standard bars. The bimetallic bars are more often applied in concreteconstruction. There are few methods which ensure a good strength of bimetallic layer bond. Hydrostatic extrusion,rotary rolling and explosive cladding are most often used methods.Design/methodology/approach: The simulations of the bar rolling in a three-high skew mill were carriedout using the Forge2005® commercial program.Findings: The higher value of yield stress of the cladding layer does not produce the effect of “flowing down” ofthis layer over the core surface and it’s folding between the rolls. The use of non-corrosive steel on plating layerassures receipt on a high durability and esthetics bimetallic bars.Practical implications: Bimetallic bars are chiefly used in the building industry at production of concreteconstructions, and as working elements in bridge building in aggressive environment.Originality/value: Production of bimetallic bars is very difficult. One from many problems during productionbimetallic bars is assurance good strength of bimetallic layer bond. A theoretical analysis of bimetallic bar rollingin a three-high skew mill is presented in the paper and the distributions of stress and strain intensities in thebimetallic bar during skew rolling are shown.

  2. Spray Rolling Aluminum Strip for Transportation Applications

    Energy Technology Data Exchange (ETDEWEB)

    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. Grooved roll for a high speed twin roll caster

    Directory of Open Access Journals (Sweden)

    T. Haga

    2008-04-01

    Full Text Available Purpose: Purpose of this paper is investigation of the effect of roll-surface on the strip-surface. Improvement ofsmall cracks on the strip-surface was tried and effect of groove at the roll surface on the strip surface was shown.Design/methodology/approach: Method used in the present study was high speed twin roll caster withgrooved roll. Two kinds of grooves were used: one was parallel groove and the other was cross groove machinedby knurling and bite attached to a lathe.Findings: Findings of this research are that grooved roll was effective to eliminate the small cracks on the stripsurface. The contact condition between the roll and the melt became uniform by the small groove on the rollsurface. Contact area became small, and heat transfer between the melt and roll became small, too. As the result,chill structure did not become columnar, and crack did not occur. Groove pattern on the strip surface could beerased by the cold rolling.Research limitations/implications: Research limitation is that groove life could not be investigated.Practical implications: Practical implications are as below. The roll load was small and strip was not hot-rolledin a high speed twin roll caster. The grooved roll made strip-surface sound. Grooved 600mm width roll was tested,and usefulness of the grooved roll was shown.Originality/value: In the present study effect of the grooved roll on a high speed twin roll caster was investigated.

  4. Biomechanics of leukocyte rolling

    OpenAIRE

    Sundd, Prithu; POSPIESZALSKA, MARIA K.; Cheung, Luthur Siu-Lun; Konstantopoulos, Konstantinos; Ley, Klaus

    2011-01-01

    Leukocyte rolling on endothelial cells and other P-selectin substrates is mediated by P-selectin binding to P-selectin glycoprotein ligand-1 expressed on the tips of leukocyte microvilli. Leukocyte rolling is a result of rapid, yet balanced formation and dissociation of selectin-ligand bonds in the presence of hydrodynamic shear forces. The hydrodynamic forces acting on the bonds may either increase (catch bonds) or decrease (slip-bonds) their lifetimes. The force-dependent ‘catch-slip’ bond ...

  5. Maintenance strategy for tilting table of rolling mill based on reliability considerations

    International Nuclear Information System (INIS)

    Reliability centred maintenance (RCM) is a new strategic framework for ensuring that any asset continues to perform, as its users want it to perform. RCM is a process used to determine the maintenance requirement of any physical asset in its operating context. RCM process entails asking seven questions about each of the selected assets. It makes use of two documents namely, RCM information worksheet and RCM decision worksheet. RCM decision diagram integrates all the decision processes into a single strategic framework. RCM concept developed by US commercial airlines industry has been successfully implemented by Military, Navy, Nuclear power plants, electric power generation and distribution undertakings and several other sectors. These projects have been carried out in the United Kingdom, The Republic of Ireland, the United States, Hong Kong, Australia, Spain and Singapore. The fact that people has enthusiastically received RCM at all levels and has enabled users to achieve some remarkable successes in all of these countries, suggests that it can be universally employed. Literature review indicates that RCM approach is not conventionally applied in process industries in India. Presently, predictive maintenance (PDM) approach along with conventional preventive maintenance is used in continuous/process industries. This approach if implemented in totality will increase the production cost to a large degree and make the production uneconomical. Similarly breakdown maintenance (BDM) approach cannot be applied in such industries as each breakdown involves huge costs. RCM approach is a compromise between PDM and BDM approach for optimising the cost and ensuring the availability of machine. The RCM approach has been applied to the tilting table system of rolling mill for the research work reported in this paper. In the present study, preventive maintenance tasks suggested for power transmission subsystem, guiding and transportation subsystem and hydraulic subsystem in tilting tables are 14 scheduled on-condition tasks, 10 scheduled on-restoration tasks, seven scheduled discard task. Whereas for 14 failure modes no scheduled maintenance has been proposed. Existing maintenance schedule for tilting tables indicates the maintenance action as and when required. Hence RCM based schedule specifies that additional preventive maintenance tasks need to be executed as compared to none initially. Cost incurred for this can be offset from the savings accrued from reduction in loss of production due to repetitive breakdowns. The methodology of RCM adopted in western industries cannot be applied as it is to Indian industries because of labour oriented nature, partially computerised information systems, non-availability of the information about cost of loss of production due to breakdown and age-reliability pattern of equipment, insufficient maintenance database. These problems can be overcome by development of sound MMIS, formulation of RCM review group and imparting suitable training to acquire the relevant skills in RCM. Thus RCM methodology can be applied to Indian industry for reduction of breakdowns as well as optimisation of preventive maintenance cost. This can further boost up the prospects of Indian industry to offer the products at globally competitive prices

  6. Maintenance strategy for tilting table of rolling mill based on reliability considerations

    Energy Technology Data Exchange (ETDEWEB)

    Deshpande, V.S.; Modak, J.P

    2003-04-01

    Reliability centred maintenance (RCM) is a new strategic framework for ensuring that any asset continues to perform, as its users want it to perform. RCM is a process used to determine the maintenance requirement of any physical asset in its operating context. RCM process entails asking seven questions about each of the selected assets. It makes use of two documents namely, RCM information worksheet and RCM decision worksheet. RCM decision diagram integrates all the decision processes into a single strategic framework. RCM concept developed by US commercial airlines industry has been successfully implemented by Military, Navy, Nuclear power plants, electric power generation and distribution undertakings and several other sectors. These projects have been carried out in the United Kingdom, The Republic of Ireland, the United States, Hong Kong, Australia, Spain and Singapore. The fact that people has enthusiastically received RCM at all levels and has enabled users to achieve some remarkable successes in all of these countries, suggests that it can be universally employed. Literature review indicates that RCM approach is not conventionally applied in process industries in India. Presently, predictive maintenance (PDM) approach along with conventional preventive maintenance is used in continuous/process industries. This approach if implemented in totality will increase the production cost to a large degree and make the production uneconomical. Similarly breakdown maintenance (BDM) approach cannot be applied in such industries as each breakdown involves huge costs. RCM approach is a compromise between PDM and BDM approach for optimising the cost and ensuring the availability of machine. The RCM approach has been applied to the tilting table system of rolling mill for the research work reported in this paper. In the present study, preventive maintenance tasks suggested for power transmission subsystem, guiding and transportation subsystem and hydraulic subsystem in tilting tables are 14 scheduled on-condition tasks, 10 scheduled on-restoration tasks, seven scheduled discard task. Whereas for 14 failure modes no scheduled maintenance has been proposed. Existing maintenance schedule for tilting tables indicates the maintenance action as and when required. Hence RCM based schedule specifies that additional preventive maintenance tasks need to be executed as compared to none initially. Cost incurred for this can be offset from the savings accrued from reduction in loss of production due to repetitive breakdowns. The methodology of RCM adopted in western industries cannot be applied as it is to Indian industries because of labour oriented nature, partially computerised information systems, non-availability of the information about cost of loss of production due to breakdown and age-reliability pattern of equipment, insufficient maintenance database. These problems can be overcome by development of sound MMIS, formulation of RCM review group and imparting suitable training to acquire the relevant skills in RCM. Thus RCM methodology can be applied to Indian industry for reduction of breakdowns as well as optimisation of preventive maintenance cost. This can further boost up the prospects of Indian industry to offer the products at globally competitive prices.

  7. Spray Rolling Aluminum Strip

    Energy Technology Data Exchange (ETDEWEB)

    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.

  8. Computation of Rolling Stand Parameters by Genetic Algorithm

    Directory of Open Access Journals (Sweden)

    František ?urovskż

    2008-05-01

    Full Text Available Mathematical model of rolling process is used at cold mill rolling on tandemmills in metallurgy. The model goal is to analyse rolling process according to process datameasured on the mill and get immeasurable variables necessary for rolling control andoptimal mill pre-set for next rolled coil. The values obtained by model are used asreferences for superimposed technology controllers (thickness, speed, tension, etc. as well.Considering wide steel strip assortment (different initial and final thickness, differenthardness, and fluctuation of tandem mill parameters (change of friction coefficient, workrolls abrasion, temperature fluctuation, etc. the exact analysis of tandem is complicated.The paper deals with an identification of friction coefficient on a single rolling mill standby a genetic algorithm. Mathematical description of tandem mill stand is based on themodified Bland-Ford model. Results are presented in graphical form.

  9. Nanostructured MgH2 obtained by cold rolling combined with short-time high-energy ball milling

    Scientific Electronic Library Online (English)

    Ricardo, Floriano; Daniel Rodrigo, Leiva; Stefano, Deledda; Bjųrn Christian, Hauback; Walter José, Botta.

    2013-02-01

    Full Text Available MgH2 was processed by short time high-energy ball milling (BM) and cold rolling (CR). A new alternative processing route (CR + BM) using the combination of CR followed by short time BM step was also applied. The effects on the final morphology, crystalline structure and H-sorption properties were ev [...] aluated. The CR + BM processing (compared to BM and CR process) resulted in an inhomogeneous particle size distribution and the biggest crystallite size of MgH2, showing that there is a clear dependence between the size/shape of the particles which compose the starting material and the efficiency of crystallite size reduction during the BM process. On the other hand, we observed that a short BM step improved the kinetic properties of the cold rolled material. It shows that the particle size reduction of MgH2 obtained by CR combined with the increase in specific surface area attained by short BM step could be key factors to allow the use of the CR + BM route.

  10. The analysis of the asymmetric plate rolling process

    Directory of Open Access Journals (Sweden)

    A. Kawa?ek

    2007-08-01

    Full Text Available Purpose: The analysis of asymmetric band rolling in the finishing stand of a plate rolling mill has been carried out within the present study with the aim of establishing the effect of the speed asymmetry factor, av, on band bending during the rolling process and determining the strain velocity distributions of the rolled material in the roll bite region.Design/methodology/approach: The simulation of metal flow in the asymmetric roll bite region was performed using the program FORGE 2D. The development of numerous branches of the steelmaking industry imposes increasingly high demands on steel product manufacturers, which can only be met by products manufactured according to the state-of-the-art plastic working technologies. One of the major plastic working technologies is asymmetric rolling.Findings: The analysis shows that the band bends most often toward the lower-speed roll. Increasing the value of the speed asymmetry factor causes an increase in the advance, while the force parameters decrease with increasing asymmetry factor av.Practical implications: Asymmetric rolling is achieved by differentiating working roll diameters, roll rotational speeds, or roll surface roughness. In industrial practice, one or a combination of the above-mentioned parameters is used.Originality/value: In order to improve the asymmetric plate rolling process, the analysis of the following parameters must be carried out: band temperature, the magnitude of rolling reduction, the magnitude of yield stress for particular steel grades, roll rotational speeds and roll diameters.

  11. Sliding and Rolling: The Physics of a Rolling Ball.

    Science.gov (United States)

    Hierrezuelo, J.; Carnero, C.

    1995-01-01

    Presents an approach that provides a simple and adequate procedure for introducing the concept of rolling friction. Discusses some aspects related to rolling motion that are the source of students' misconceptions. Presents several didactic suggestions. (JRH)

  12. Ship Roll Motion Control

    DEFF Research Database (Denmark)

    Perez, Tristan; Blanke, Mogens

    2010-01-01

    The technical feasibility of roll motion control devices has been amply demonstrated for over 100 years. Performance, however, can still fall short of expectations because of deciencies in control system designs, which have proven to be far from trivial due to fundamental performance limitations....... This tutorial paper presents an account of the development of various ship roll motion control systems and the challenges associated with their design. The paper discusses how to assess performance, the applicability of dierent models, and control methods that have been applied in the past....

  13. Texture comparison between cold rolled and cryogenically rolled pure copper

    Science.gov (United States)

    Lapeire, L.; Sidor, J.; Martinez Lombardia, E.; Verbeken, K.; De Graeve, I.; Terryn, H.; Kestens, L. A. I.

    2015-04-01

    Nowadays, there is a considerable scientific interest in bulk ultrafine grained materials, due to their potential for superior mechanical properties. One of the possible formation methods of nano-grained materials is cryogenic rolling. The influence of rolling at cryogenic temperatures has been investigated. Significant differences in the textures and the microstructures can be observed between the cryogenically rolled copper and conventionally cold rolled copper, reduced to the same thickness.

  14. Rolling Stonesi kinokontsert kannab toorest rokiväge / Maris Meiessaar

    Index Scriptorium Estoniae

    Meiessaar, Maris

    2009-01-01

    Martin Scorsese muusikalisest dokumentaalfilmist "Shine a Light - Valgus peale" (USA-Suurbritannia, 2008), mille keskmes on 2006. a. New Yorgi Beaconi teatris toimunud briti ansambli Rolling Stones kontsert

  15. Slitting criterion for various rolling speeds in MSR rolling process

    Directory of Open Access Journals (Sweden)

    A. Stefanik

    2008-03-01

    Full Text Available Purpose: The main idea of MSR technology is the capability of producing two, three, four and even five rods simultaneously from a single strip in a hot rolling process. Correctly separation of the joined strips is the one of the mainly problem in MSR process. Changing the rolling speed may causes easier of the strand division. In this paper results of the computer simulation of the double slitting rolling process were presented.Design/methodology/approach: For numerical modelling of the multi rolling process a computer program Forge 2005, based by the finished element method was used. As a slitting criterion normalised Cockroft ā€“ Latham criterion was used.Findings: For the analysis performed in this study, it was found that increasing of the rolling speed causes of increasing the normalized Cockroft ā€“ Latham criterion. For the small values of rolling velocity the strip separation was easier.Research limitations/implications: Multi Slit Rolling process is applied in ribbed rods rolling. Adjusting of the rolling speed in multi slit rolling process could improve of the slitting band to the separated strips.Originality/value: Incorrect construction or bad gap matching could cause lack of separation propelled slitting rolls. The separation of the band is effected by means of separating rollers, which shape must be properly designed to suit to the slitting pass. Changing of the rolling speed could improve of the separation to the single strips.

  16. Person og Rolle

    DEFF Research Database (Denmark)

    Szatkowski, Janek

    2011-01-01

    Distinktionen mellem person og rolle forslås som grundlag for et pręcist og anlytisk anvendeligt begreb om performativitet. Begrebet tager sigte på at beskrive enkeltindividers og gruppers kommunikation med henblik på hvordan kommunikation etableres. Performativitet gųr det muligt at iagttage den strukturelle kobling mellem psykiske stystemers bevidsthed og sociale systemers kommunikation, og derved åbne for en diskussion af hvordan vęrdier fungerer i en sådan kommunikation.

  17. Lokalpolitikeres rolle og råderum

    DEFF Research Database (Denmark)

    Holm Pedersen, Lene; Houlberg, Kurt

    2013-01-01

    I en ny og omfattende undersųgelse fra KORA og CBS er alle landets lokalpolitikere blevet spurgt om, hvordan de oplever deres rolle og råderum. Undersųgelsen belyser blandt andet, hvordan arbejdsvilkår og indflydelsesmuligheder er i dag, og hvordan vilkår og muligheder er blevet ęndret de senere år.

  18. Walk and roll robot

    Science.gov (United States)

    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.

  19. Possibilities of enhancing the rolling quality in the course of deformation of high-alloy steel ingots on the roughing mill

    International Nuclear Information System (INIS)

    At the Dneprospetsstal' plant the variation in power parameters of rolling, the temperature and plasticity of the metal on deformation of ingots of stainless steels 10Kh23N18, 10Kh17N13M2T, and 12Kh18N10T have been investigated on a 950 mill. Upon combined analysis of the variations in the deformation conditions and the properties of the metal in the course of rolling, one can recommend the ways for improving the quality of the rolled stock and the mill efficiency. In the rolling of 2.8-ton (metric), 540x540 mm ingots, the lowest plasticity , nsub(k) is observed before the pass 15-16 because of the presence of a cast structure in the initial passes and the temperature drop in the subsequent ones. One must reduce compressions in these passes, and increase them in the others. It is also expedient to allow a short overheating (for 15-20 min) of the ingot surface up to 1300 deg C (30-50 deg. above the optimum)

  20. Tenascin Supports Lymphocyte Rolling

    OpenAIRE

    Clark, Rachael A; Erickson, Harold P.; Springer, Timothy A

    1997-01-01

    Tenascin is a large extracellular matrix molecule expressed at specific sites in the adult, including immune system tissues such as the bone marrow, thymus, spleen, and T cell areas of lymph nodes. Tenascin has been reported to have both adhesive and anti-adhesive effects in static assays. We report here that tenascin supports the tethering and rolling of lymphocytes and lymphoblastic cell lines under flow conditions. Binding was calcium dependent and was not inhibited by treatment of ly...

  1. Effect of the microstructure on tribological phenomena occurring on the surface of a mill roll made of SA5T cast iron (GJSL-HV600 - GJSL-330NiMoCr12-8-3

    Directory of Open Access Journals (Sweden)

    J. Krawczyk

    2008-07-01

    Full Text Available This paper deals with the role of the microstructure in the tribological wear processes occurring in a cast iron mill roll. For this purpose, a piece of a broken roll, made in Italy, was collected. Its microstructure consisted of modular graphite, transformed ledeburite and a matrix composed of bainite and martensite. Metallographic investigations were performed on the roll working surface in conjunction with metallographic tests effected within its surface layer. There was established the relation between the microstructure of the roll and the process of its tribological wear. The following was ascertained: micro-shrinkages or graphite precipitations nearby the working area cause cracks between those places and the working area; in the surface layer, cracks occur usually in the zone of ledeburitic cementite. At places of considerable precipitations of ledeburitic cementite, the tribological wear intensity of the roll is lower. A banded layout of precipitations of ledeburitic cementite facilitates a selective spalling of some parts of the roll material. The results of this study allow broadening the data base related to the effect of the microstructure on tribological wear of mill rolls, which in future will permit one to design their proper microstructure of cast iron mill rolls.

  2. Rolling motion in moving droplets

    Indian Academy of Sciences (India)

    Sumesh P Thampi; Rama Govindarajan

    2015-03-01

    Drops moving on a substrate under the action of gravity display both rolling and sliding motions. The two limits of a thin sheet-like drop in sliding motion on a surface, and a spherical drop in roll, have been extensively studied. We are interested in intermediate shapes. We quantify the contribution of rolling motion for any intermediate shape, and recently obtained a universal curve for the amount of roll as a function of a shape parameter using hybrid lattice Boltzmann simulations. In this paper, we discuss the linear relationship which is expected between the Capillary and Bond numbers, and provide detailed confirmation by simulations. We also show that the viscosity of the surrounding medium can qualitatively affect dynamics. Our results provide an answer to a natural question of whether drops roll or slide on a surface and carry implications for various applications where rolling motion may or may not be preferred.

  3. Kinematics of rolling-cutter bit with offset rolling-cutter axes

    Energy Technology Data Exchange (ETDEWEB)

    Abdullin, M.M.; Trushkin, B.N.; Spivak, A.I.

    1981-11-01

    Results of test-bench investigations of kinematic parameters of operation of the equipment of the serially produced rolling-cutter bit, Sh215 9S-GV, are presented. They made it possible to record the mean and ''instantaneous'' frequencies of rotation of milling cutters for any frequency of rotation of the bit. The effect of the bit load on the mean gear ratios of the rolling cutters is established. The degree of nonuniformity of rotation of rolling cutters is shown and a relation is found between the position of teeth of the peripheral rolling cutter rings with respect to the bottom hole and the character of variation of the ''instantaneous'' rolling-cutter gear ratios.

  4. Rolling Cylinder Phase 1

    DEFF Research Database (Denmark)

    Margheritini, Lucia; Taraborrelli, Valeria Taraborrelli

    This report has been prepared under the contract agreement between Aalborg Universitet and Storper Innovation ApS. The report has been written by Lucia Margheritini (lm@civil.aau.dk ) who is also responsible for the data analysis. Laboratory tests in regular waves have been run by Lucia...... Margheritini and Valeria Taraborrelli(valeria.taraborrelli@hotmail.it) with a total of 3 day visit from the developers. Laboratory tests in irregular waves will be performed by Lucia Margheritini. The report is aimed at the first stage testing of the Rolling Cylinder wave energy device. This phase includes...... tests in regular waves and irregular waves, realized in two different set of tests....

  5. Quantifying texture evolution during hot rolling of AZ31 Twin Roll Cast strip

    Science.gov (United States)

    Gorelova, S.; Schaeben, H.

    2015-04-01

    Multi-pass rolling experiments with an AZ31 Twin Roll Cast (TRC) alloy were performed on an industrial scaled four-high rolling mill. Within the rolling with an intermediate annealing the evolution of texture was investigated. To quantify the extent of preferred crystallographic orientation experimental X-ray pole figures were measured after different process steps and analyzed using the free and open Matlab® toolbox MTEX for texture analysis. The development of the fiber texture was observed and analyzed in dependence on rolling conditions. In the initial state the specimen exhibits a texture composed of a weak basal texture and a cast texture with {0001}-planes oriented across the rolling direction. During the following rolling process a fiber texture was developed. The expected strength increment of the fiber texture was quantitatively confirmed in terms of volume portions of the orientation density function around the fiber and in terms of the canonical parameters of fitted pseudo Bingham distributions. On the results of this work a model for prediction of the texture evolution during the strip rolling of magnesium in the examined parameter range was developed.

  6. Textures of molybdenum monocrystal deformation in rolling in profiled rolls

    International Nuclear Information System (INIS)

    The texture of molybdenum monocrystals rolled in profiled rolls with epsilon=6-90% cogging is studied by the method of reverse pole figures in Mo Ksub(?) radiation. The crystallographic directions of and were oriented in the deformation direction. At different orientation of the monocrystal in the rolling plane after epsilon=25-27% in the rolling direction (RD) different crystallographic orientations were formed which is caused by pointing accuracy of the monocrystal in the deformation plane. Rolling of a monocrystal with long RD orientation provokes RD reorientation and formation of the (111) [011] texture at high deformation degree. At average cogging degrees (epsilon=35-60%) the total axial texture long RD is formed transforming into a limited axial one and then into an axial one with the deformation degree increase

  7. Design of two bearings with sealing system for the top roll shaft of sugar cane mill

    Scientific Electronic Library Online (English)

    Walter, Mora Perdomo; John Sandro, Rivas Murillo; John Jairo, Coronado Marķn.

    2005-12-01

    Full Text Available Las chumaceras de bronce utilizadas actualmente en los molinos de cańa de azścar presentan elevado desgaste debido, entre otros factores, a la materia extrańa que ingresa en ella cuando el eje superior se eleva (flota) por efecto del colchón de cańa que pasa entre las mazas y al sobrecalentamiento c [...] ausado por fallas en los sistemas de lubricación y refrigeración. Con el objetivo de solucionar estos problemas dos diseńos de chumaceras fueron realizados: uno con refrigeración en la caja y otro con refrigeración en la teja, ambos usando un sistema de sellado. Anįlisis por Elementos Finitos del comportamiento mecįnico y térmico de los diseńos garantiza un buen desempeńo en operación. Abstract in english The bronze bearings currently used in sugar cane mills undergo an excessive wear due to both, the extraneous matter entering in the bearing gap when the shaft lift by effect of cane passing through the mill and heating caused by failures in both the lubrication and the refrigeration systems. In orde [...] r to solve this problems two bearing were designed: one cooled in the box and other cooled in the roofing tile, both using a sealing system. Finite Elements Analysis of the designs showed that they will have a good mechanical and thermal performance.

  8. 9 CFR 381.159 - Poultry rolls.

    Science.gov (United States)

    2010-01-01

    ...INSPECTION AND CERTIFICATION POULTRY PRODUCTS INSPECTION REGULATIONS...Composition § 381.159 Poultry rolls. (a) Binders...permitted for use as binders in poultry rolls: transglutaminase enzyme...the product; e.g., “Turkey Roll-Gelatin Added.”...

  9. Roll bonding of strained aluminium

    DEFF Research Database (Denmark)

    Staun, Jakob M.

    2003-01-01

    cross rolled volume fraction is found. To further asses this effect, and the anisotropy, it is necessary to acquire knowledge about both texture and microstructure, e.g. by TEM. Roll bonding of pre-strained aluminium is found to be a possible alternative to ARB in the quest for ultra-fine grained...

  10. Rolling friction of adhesive microspheres

    International Nuclear Information System (INIS)

    The rolling friction of adhesive microspheres is an important quantity as it determines the strength and stability of larger aggregates. Current models predict rolling forces that are 1 to 2 orders of magnitude smaller than observed experimentally. Starting from the well-known Johnson–Kendall–Roberts (JKR) contact description, we derive an analytical theory for the rolling friction based on the concept of adhesion hysteresis, e.g. a difference in apparent surface energies for opening/closing cracks. We show how adhesion hysteresis causes the pressure distribution within the contact to become asymmetrical, leading to an opposing torque. Analytical expressions are derived relating the size of the hysteresis, the rolling torque, and the rolling displacement, ?. We confirm the existence of a critical rolling displacement for the onset of rolling, the size of which is set by the amount of adhesion hysteresis and the size of the contact area. We demonstrate how the developed theory is able to explain the large rolling forces and particle-size dependence observed experimentally. Good agreement with experimental results is achieved for adhesion hysteresis values of (??/?) ? 3 for polystyrene, and (??/?) ? 0.5 for silicates, at crack propagation rates of 0.1 µm s?1 and 1–10 µm s?1, respectively. (paper)

  11. Using Variable Perturbation Method to Study the Stability of Torsional Self-Excited Vibration in Main Drive System of Rolling Mill

    Directory of Open Access Journals (Sweden)

    Fenglan Wang

    2013-06-01

    Full Text Available The self-excited vibration of blooming mill is a kind of torsional vibration, which occurs only when the rolling machine slips under appropriate conditions. Once in place, this may cause the larger peak pressure of each component in the main drive system; reduce the service life of the components, cause components? damage directly. A large number of studies have shown that, at present there are not effective methods for diagnosis, monitoring of slipping and take proper measures in time to stop slipping so as to avoid the occurrence of malignant accidents. In this paper, author set out from another angle, take the main drive system of rolling mill as an example, to study stability of self-excited vibration. The conditions of the stable vibration are gained. By combining with the actual working conditions of blooming mill, author has put forward some effective measures to meet the stable conditions in order to make the blooming mill work in the stable state. Practice research has proved that the effective measures can contribute to reduce structural damage directly caused by the torsional vibration when “slipping” phenomenon occurred and to extend the service life of the components.

  12. A new transducer for roll gap measurements of the roll pressure distribution and the friction condition in cold flat rolling

    DEFF Research Database (Denmark)

    Lagergren, Jonas; Wanheim, Tarras; Presz, W.; Henningsen, Poul; Arentoft, Mogens; Jonsson, Nils-Göran

    2005-01-01

    Background/purpose The only way to establish the true rolling pressure and the true friction condition in cold rolling is to conduct measurements in the roll bite. A new transducer design is therefore proposed, this to overcome problems in previous measurements in the past 70 years. Method The new...... stainless steel strips in a pilot mill. The recordings were selected from a steady state with no disturbance from the material flow. The transducer was able to simultaneously measure both the normal pressure and the friction stress. An estimation of the coefficient of friction was accordingly performed....... Conclusions The new transducer works very well, it was seen to be robust and able to avoid signal disturbance. The pressure and friction stress distribution results was as expected by the authors and a good reproducibility, together with a proven agreement between recorded signals and signals simulated...

  13. A new transducer for local load measurements of friction and roll pressure in cold flat rolling

    DEFF Research Database (Denmark)

    Lagergren, J.; Wanheim, Tarras; Precz, W.; Henningsen, Poul; Arentoft, Mogens; Jonsson, N.G.

    2006-01-01

    The only way to establish the true rolling pressure and the true friction condition in cold rolling is to conduct measurements in the roll bite. A new transducer design is therefore proposed, in order to overcome problems in previous measurements in the past 70 years. The new idea is to increase...... recordings were selected from a steady state with no disturbance from the material flow. The transducer was able to simultaneously measure both the normal pressure and the friction stress. An estimation of the coefficient of friction was accordingly performed. The new transducer works very well, it was seen...... the contact surface of the transducer, to be larger than the arc of contact. This is in contrast to the smaller and smaller contact pin design that has been prevailing. The measurements were conducted during cold dry rolling of both copper strips and stainless steel strips in a pilot mill. The...

  14. Roll Control in Fruit Flies

    CERN Document Server

    Beatus, Tsevi; Cohen, Itai

    2014-01-01

    Due to aerodynamic instabilities, stabilizing flapping flight requires ever-present fast corrective actions. Here we investigate how flies control body roll angle, their most susceptible degree of freedom. We glue a magnet to each fly, apply a short magnetic pulse that rolls it in mid-air, and film the corrective maneuver. Flies correct perturbations of up to $100^{\\circ}$ within $30\\pm7\\mathrm{ms}$ by applying a stroke-amplitude asymmetry that is well described by a linear PI controller. The response latency is $\\sim5\\mathrm{ms}$, making the roll correction reflex one of the fastest in the animal kingdom.

  15. Rolling of tungsten base cermet in four-roll grooves

    International Nuclear Information System (INIS)

    The sintered cermet pieces 30 mm in diameter were used to roll square bars sized 32, 16 and 12 mm (the one-pass reduction ratio in the range 1.25-1.80). Studies were made of the contact stresses and energy parameters in the rolling of tungsten bars. The results obtained can be useful in the the design of new equipment and development of industrial technology

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

    Energy Technology Data Exchange (ETDEWEB)

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

    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.

  17. Adaptive Automatic Gauge Control of a Cold Strip Rolling Process

    OpenAIRE

    ROMAN, N.; E. Ceanga; BIVOL, I.; CARAMAN, S.

    2010-01-01

    The paper tackles with thickness control structure of the cold rolled strips. This structure is based on the rolls position control of a reversible quarto rolling mill. The main feature of the system proposed in the paper consists in the compensation of the errors introduced by the deficient dynamics of the hydraulic servo-system used for the rolls positioning, by means of a dynamic compensator that approximates the inverse system of the servo-system. Because the servo-system is considered va...

  18. Steel balls forming by cross rolling with upsetting

    Directory of Open Access Journals (Sweden)

    Z. Pater

    2013-01-01

    Full Text Available The paper describes a process of forming four balls with a diameter of 22 mm by means of cross rolling with upsetting. The paper also presents the tool used to form semi-finished balls. Owing to the application of the finite element method (FEM, the course of the rolling process as well as temperature and strain distributions in the obtained balls could be presented. The rolling tests conducted in laboratory conditions at the Lublin University of Technology have proved that the balls produced with the developed rolling method meet the demands for grinding media used in ball mills.

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

    Energy Technology Data Exchange (ETDEWEB)

    Soulami, Ayoub [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Lavender, Curt A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Paxton, Dean M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Burkes, Douglas [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    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).

  20. Õpetaja muutuv roll / Anneli Kannus

    Index Scriptorium Estoniae

    Kannus, Anneli

    2003-01-01

    Eesti Kutsehariduse Edendamise Ühingu ja haridusministeeriumi koostöös toimus 2003.a. jaanuaris Pühajärvel kutsehariduse talveseminar. Ühes töörühmas arutleti teemal "Õpetaja muutuv roll ja ülesanded" ning tõdeti, et kutseõpetaja ettevalmistus ei vasta koolide ootustele.

  1. Frontal Impact of Rolling Spheres.

    Science.gov (United States)

    Domenech, A.; Casasus, E.

    1991-01-01

    A model of the inelastic collision between two spheres rolling along a horizontal track is presented, taking into account the effects of frictional forces at impact. This experiment makes possible direct estimates of the coefficients of restitution and friction. (Author)

  2. Rolling Resistance Measurement and Model Development

    DEFF Research Database (Denmark)

    Andersen, Lasse Grinderslev; Larsen, Jesper; Fraser, Elsje Sophia; Schmidt, Bjarne; Dyre, J. C.

    2015-01-01

    There is an increased focus worldwide on understanding and modeling rolling resistance because reducing the rolling resistance by just a few percent will lead to substantial energy savings. This paper reviews the state of the art of rolling resistance research, focusing on measuring techniques, surface and texture modeling, contact models, tire models, and macro-modeling of rolling resistance

  3. Grease lubrication in rolling bearings

    CERN Document Server

    Lugt, Piet M

    2012-01-01

    The definitive book on the science of grease lubrication for roller and needle bearings in industrial and vehicle engineering. Grease Lubrication in Rolling Bearings provides an overview of the existing knowledge on the various aspects of grease lubrication (including lubrication systems) and the state of the art models that exist today. The book reviews the physical and chemical aspects of grease lubrication, primarily directed towards lubrication of rolling bearings. The first part of the book covers grease composition, properties and rheology, including thermal

  4. Fundamentals of Rolling Contact Fatigue:

    OpenAIRE

    Grabulov, A.

    2010-01-01

    In the mechanical industry there is a need for continuous development towards increasing performance of various types of machinery. Critical components in such machines are exposed to gradually harsher operating environments involving higher cyclic stresses and operating temperatures. Examples of such fatigue-exposed components are gears, camshafts and rolling element bearings in engines and gearboxes. The components in the bearing industry are always subject to the high cycle rolling contact...

  5. NORMAL PRESSURE AND FRICTION STRESS MEASUREMENT IN ROLLING PROCESSES

    DEFF Research Database (Denmark)

    Henningsen, Poul; Arentoft, Mogens; Lagergren, Jonas; Jonsson, Nils-Göran; Presz, W.

    2005-01-01

    output from the transducer, the friction stress and normal pressure in the contact zone can be determined. The new concept differs from existing pin designs by a lower disturbance of lubricant film and material flow and limited penetration of material between transducer and roll. Aluminum, cupper and......A load transducer has been developed to measure the contact forces in the deformation zone during rolling. The transducer consists of a strain gauge equipped insert, embedded in the surface of the roll. The length of the insert exceeds the contact length between material and roll. By analyzing the...... steel strips with a width of 40 mm was rolled with reduction varying from 2.7% to 29%, in a pilot mill. For evaluating the transducer, the measured contact forces are compared with external measurements of roll separating forces and torque. The determined friction coefficients are compared with values...

  6. Multi-stage FE simulation of hot ring rolling

    Science.gov (United States)

    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.

  7. AISI/DOE Advanced Process Control Program Vol. 3 of 6: MICROSTRUCTURAL ENGINEERING IN HOT-STRIP MILLS Part 2 of 2: Constitutive Behavior Modeling of Steels Under Hot-Rolling Conditions

    Energy Technology Data Exchange (ETDEWEB)

    Yi-Wen Cheng; Patrick Purtscher

    1999-07-30

    This report describes the development of models for predicting (1) constitutive behaviors and (2) mechanical properties of hot-rolled steels as functions of chemical composition, microstructural features, and processing variables. The study includes the following eight steels: A36, DQSK, HSLA-V, HSLA-Nb, HSLA-50/Ti-Nb, and two interstitial-free (IF) grades. These developed models have been integrated into the Hot-Strip Mill Model (HSMM), which simulates the hot strip rolling mills and predicts the mechanical properties of hot-rolled products. The HSMM model has been developed by the University of British Columbia-Canada as a part of project on the microstructural engineering in hot-strip mills.

  8. AISI/DOE Advanced Process Control Program Vol. 3 of 6: MICROSTRUCTURAL ENGINEERING IN HOT-STRIP MILLS Part 2 of 2: Constitutive Behavior Modeling of Steels Under Hot-Rolling Conditions; FINAL

    International Nuclear Information System (INIS)

    This report describes the development of models for predicting (1) constitutive behaviors and (2) mechanical properties of hot-rolled steels as functions of chemical composition, microstructural features, and processing variables. The study includes the following eight steels: A36, DQSK, HSLA-V, HSLA-Nb, HSLA-50/Ti-Nb, and two interstitial-free (IF) grades. These developed models have been integrated into the Hot-Strip Mill Model (HSMM), which simulates the hot strip rolling mills and predicts the mechanical properties of hot-rolled products. The HSMM model has been developed by the University of British Columbia-Canada as a part of project on the microstructural engineering in hot-strip mills

  9. The effect of roll gap geometry on microstructure in cold-rolled aluminum

    DEFF Research Database (Denmark)

    Mishin, Oleg; Bay, B.; Winther, G.; Juul Jensen, D.

    2004-01-01

    Microstructure and texture are analyzed through the thickness of two aluminum plates cold-rolled 40% with different roll gap geometries. It is found that both texture and microstructure are strongly affected by the rolling geometry. After rolling with intermediate-size draughts a rolling-type texture is developed throughout the plate thickness. In this case, grains are subdivided by extended planar dislocation boundaries preferentially aligned at an angle of 40 +/- 15degrees to the rolling direc...

  10. Ambient roll-to-roll fabrication of flexible solar cells based on small molecules

    DEFF Research Database (Denmark)

    Lin, Yuze; Dam, Henrik Friis; Andersen, Thomas Rieks; Bundgaard, Eva; Fu, Weifei; Chen, Hongzheng; Krebs, Frederik C; Zhan, Xiaowei

    2013-01-01

    All solution-processed roll-to-roll flexible solar cells based on a starshaped small molecule donor and PCBMacceptor were fabricated by slot-die coating, as the first successful example reported for small molecule roll-to-roll flexible solar cells.......All solution-processed roll-to-roll flexible solar cells based on a starshaped small molecule donor and PCBMacceptor were fabricated by slot-die coating, as the first successful example reported for small molecule roll-to-roll flexible solar cells....

  11. Hot rolling of thick uranium molybdenum alloys

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    International Nuclear Information System (INIS)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Soulami, Ayoub [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Lavender, Curt A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Paxton, Dean M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Burkes, Douglas [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    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 Administrationā€™s Office of Material Management and Minimization Reactor Conversion Program. This report documents modeling results of PNNLā€™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.

  14. Rolling Stonesi kinokontsert kannab toorest rokivƤge / Maris Meiessaar

    Index Scriptorium Estoniae

    Meiessaar, Maris

    2009-01-01

    Martin Scorsese muusikalisest dokumentaalfilmist "Shine a Light - Valgus peale" (USA-Suurbritannia, 2008), mille keskmes on 2006. a. New Yorgi Beaconi teatris toimunud briti ansambli Rolling Stones kontsert

  15. Cell sorting by deterministic cell rolling†‡

    OpenAIRE

    Choi, Sungyoung; Karp, Jeffrey M.; Karnik, Rohit

    2012-01-01

    This communication presents the concept of “deterministic cell rolling”, which leverages transient cell-surface molecular interactions that mediate cell rolling to sort cells with high purity and efficiency in a single step.

  16. High performance rolling element bearing

    Science.gov (United States)

    Bursey, Jr., Roger W. (Inventor); Olinger, Jr., John B. (Inventor); Owen, Samuel S. (Inventor); Poole, William E. (Inventor); Haluck, David A. (Inventor)

    1993-01-01

    A high performance rolling element bearing (5) which is particularly suitable for use in a cryogenically cooled environment, comprises a composite cage (45) formed from glass fibers disposed in a solid lubricant matrix of a fluorocarbon polymer. The cage includes inserts (50) formed from a mixture of a soft metal and a solid lubricant such as a fluorocarbon polymer.

  17. Rolling Tachyons in String Cosmology

    OpenAIRE

    Kim, Chanju; Kim, Hang Bae; Kim, Yoonbai

    2002-01-01

    We study the role of rolling tachyons in the cosmological model with dilatonic gravity. In the string frame, flat space solutions of both initial-stage and late-time are obtained in closed form. In the Einstein frame, we show that every expanding solution is decelerating.

  18. Rubber rolling over a sphere

    CERN Document Server

    Koiller, J; Koiller, Jair; Ehlers, Kurt M.

    2006-01-01

    ``Rubber'' coated rolling bodies satisfy a no-twist in addition to the no slip satisfied by ``marble'' coated bodies. Rubber rolling has an interesting differential geometric appeal because the geodesic curvatures of the curves on the surfaces at the corresponding points are equal. The associated distribution in the 5 dimensional configuration space has 2-3-5 growth (these distributions were first studied by Cartan; he showed that the maximal symmetries occurs for rubber rolling of spheres with 3:1 diameters ratio and materialize the exceptionalgroup G_2. The 2-3-5 nonholonomic geometries are classified in a companion paper via Cartan's equivalence method. Rubber rolling of a convex body over a sphere defines a generalized Chaplygin system with SO(3) symmetry group, total space Q = SO(3) X S^2 that can be reduced to an almost Hamiltonian system in T^*S^2 with a non-closed 2-form \\omega_{NH}. In this paper we present some basic results on this reduction and as an example we discuss the sphere-sphere problem. I...

  19. Modeling Asymmetric Rolling Process of Mg alloys

    International Nuclear Information System (INIS)

    Asymmetric deformation during rolling can arise in various ways: difference in the radii, speeds, frictions of the top and bottom rolls. Asymmetric warm rolling processes of magnesium alloys were modeled using a lagrangian incremental approach. A constitutive equation representing flow behaviors of AZ31 magnesium alloys during warm deformation was implemented to the modeling. Various roll speed ratios were introduced to investigate deformation behaviors of the magnesium alloys. Bending and texturing of the strips were examined.

  20. Roll-to-roll fabricated lab-on-a-chip devices

    DEFF Research Database (Denmark)

    Vig, Asger Laurberg; Mäkelä, Tapio; Majander, Päivi; Lambertini, Vito; Ahopelto, Jouni; Kristensen, Anders

    2011-01-01

    manufacturing process consists of two steps: (i) roll-to-roll thermal nanoimprint for patterning the microchannels into a CA film and (ii) roll-to-roll lamination for bonding another CA film onto the imprinted film to seal the microchannels. Reverse gravure coating is used to apply an adhesive polymer onto the...

  1. Development of dissimilar metal transition joint by hot bond rolling

    International Nuclear Information System (INIS)

    Metallurgically bonded transition joints which enable to connect reprocessing equipments made of superior corrosion resistant valve metals (Ti-5Ta, Zr or Ti) to stainless steel piping are required for nuclear fuel reprocessing plants. The authors have developed dissimilar transition joints made of stainless steel and Ti-5Ta, Zr or Ti with an insert metal of Ta by the hot bond rolling process of clad bars and clad pipes, using a newly developed mill called 'rotary reduction mill'. This report presents the manufacturing process of dissimilar transition joints produced from the clad pipe with three layers by the hot bond rolling. First, the method of hot bond rolling of clad pipe is proposed. Then, the mechanical and corrosion properties of the dissimilar transition joints are evaluated in detail by carrying out various tests. Finally, the rolling properties in the clad pipe method are discussed. (author)

  2. Fatigue crack growth and fracture mechanics analysis of a working roll surface layer material

    OpenAIRE

    M. Drobne; Vuherer, T.; I. Samardži?; S Glodež

    2014-01-01

    Fatigue crack growth and fracture mechanics analysis of a working roll surface layer material is presented in this paper. The research is done on a hot strip mill working roll where High Chromium Steel is used for roll’s shell material. To obtain corresponding parameters, a rectangular single edge notched bend specimens – SENB, according to standard BS 7448, were used. The fatigue crack growth analysis was done on a resonant testing machine with use of special crack gauges, while for fracture...

  3. Recent developments in semiprocessed cold rolled magnetic lamination steel

    International Nuclear Information System (INIS)

    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

  4. Finite Element Modeling of Roll Wear during Cold Asymmetric Sheet Rolling of Aluminum Alloy 5083

    Directory of Open Access Journals (Sweden)

    Pesin A.

    2015-01-01

    Full Text Available Since the main purpose of asymmetrical rolling is to impose high shear strains on the sheet, in order to obtain ultrafine grain structure, the friction between the rolls and the sheet has to be kept relatively high. This means that asymmetric rolling is performed with dry rolls. The paper presents a numerical analysis of the roll wear during asymmetric cold rolling of 5083 aluminum alloy. The finite element simulation was used to calculate the amount of roll wear by Usui’s equation. FEM simulations were carried out with using software DEFORM 2D. The influence of the friction coefficient on the roll wear and the material flow was discussed. The sliding velocity, interface pressure and temperature were used to calculate the roll wear. The results of simulation can be used to optimize the asymmetric rolling process to improve surface quality of aluminum sheets.

  5. Roll-to-roll fabrication of polymer solar cells

    Directory of Open Access Journals (Sweden)

    Roar Sųndergaard

    2012-01-01

    Full Text Available As the performance in terms of power conversion efficiency and operational stability for polymer and organic solar cells is rapidly approaching the key 10–10 targets (10 % efficiency and 10 years of stability the quest for efficient, scalable, and rational processing methods has begun. The 10–10 targets are being approached through consistent laboratory research efforts, which coupled with early commercial efforts have resulted in a fast moving research field and the dawning of a new industry. We review the roll-to-roll processing techniques required to bring the magnificent 10–10 targets into reality, using quick methods with low environmental impact and low cost. We also highlight some new targets related to processing speed, materials, and environmental impact.

  6. High speed electrical measurement for roll-to-roll nanomanufacturing

    Science.gov (United States)

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

    2015-03-01

    Roll-to-roll processing of nanomaterials can produce high-quality coatings and filaments continuously, enabling materials applications for electronics, fabrics, and wires. These applications often require specific electrical properties that are correlated to the material's nanostructure. While several high-throughput structural characterizations techniques exist, there are relatively few contactless options for quantifying the electrical properties of materials for nanomanufacturing. Here, we demonstrate a microwave method for measuring complex permittivity (or geometry for samples of known dielectric properties) in a millisecond. The demonstrated measurement times are suitable for current industrial needs, allowing real-time materials characterization and in-line control of processing variables without disrupting production. Address correspondence to Dr. Stephan J. Stranick, and Dr. J. Alexander Liddle.

  7. Almost rolling motion: An investigation of rolling grooved cylinders

    CERN Document Server

    Mead, L R; Mead, Lawrence R.; Bentrem, Frank W.

    1998-01-01

    We examine the dynamics of cylinders that are grooved to form N teeth for rolling motion down an inclined plane. The grooved cylinders are experimentally found to reach a terminal velocity. This result can be explained by the inclusion of inelastic processes which occur whenever a tooth hits the surface. The fraction of the angular velocity that is lost during an inelastic collision is phenomenologically found to be proportional to (2*sin^2*pi/N)-(alpha*sin^3*pi/N), and the method of least squares is used to find the constant alpha=0.98. The adjusted theoretical results for the time of rolling as well as for terminal velocity are found to be in good agreement with the experimental results.

  8. Fillet rolled dual phase steel. [1018 steel

    Energy Technology Data Exchange (ETDEWEB)

    Klinard, E.J.; Watt, D.F. (Univ. of Windsor, Ontario (Canada))

    The high strain hardening rates found in dual phase steels makes them a good candidate material for high strength thread rolled fasteners. The strain imposed in the rolling process develops very high residual compressive stresses, providing excellent fatigue resistance. Fillet rolled fatigue specimens have been tested for 1018 steel in the normalized, dual phase, and quenched and tempered conditions. The shape and extent of the plastic zone as a function of roll force has been revealed by etching fillet rolled Fe-Si specimens.

  9. 76 FR 34101 - Hot-Rolled Flat-Rolled Carbon-Quality Steel Products From Brazil, Japan, and Russia

    Science.gov (United States)

    2011-06-10

    ...and 731-TA-806-808 Second Review] Hot-Rolled Flat-Rolled Carbon-Quality...termination of the suspension agreement on hot- rolled flat-rolled carbon-quality...revocation of the countervailing duty order on hot-rolled flat-rolled...

  10. 77 FR 32513 - Hot-Rolled Flat-Rolled Carbon-Quality Steel Products From the Russian Federation; Preliminary...

    Science.gov (United States)

    2012-06-01

    ...International Trade Administration [A-821-809] Hot-Rolled Flat-Rolled Carbon-Quality...Administrative Review of the Suspension Agreement on Hot-Rolled Flat-Rolled Carbon-Quality...Suspending the Antidumping Duty Investigation of Hot-Rolled Flat-Rolled...

  11. Robust Rudder Roll Damping Control

    DEFF Research Database (Denmark)

    Yang, C.

    reduction of near 70% has been obtained by the cascade controller. Using structured model of uncertainty, a m controller is designed in Chapter 6. The good robust performance has been recognized in the simulation results. It is shown that the m controller has the best robust characteristics with respect to......The results of a systematic research to solve a specific ship motion control problem, simultaneous roll damping and course keeping using the rudder are presented in this thesis. The fundamental knowledge a priori is that rudder roll damping is highly sensitive to the model uncertainty, therefore H......-infinity theory is used to deal with the problem. The necessary mathematical tools and the H-Infinity theory as the basis of controller design are presented in Chapter 2 and 3. The mu synthesis and the D-K iteration are introduced in Chapter 3. The ship dynamics and modeling technology are discussed in Chapter 4...

  12. Development of rolling magnetic microrobots

    International Nuclear Information System (INIS)

    This paper reports magnetic microrobots with rolling capability. A magnetic object subjected to an externally rotating magnetic field would be rotated due to the tendency of alignment between its internal magnetization and the field. Based on this principle, a magnetic microrobot in a spherical body with a diameter of several hundred microns was designed and fabricated. To remotely power and control the microrobot, a rotating magnet was used to generate a rotating magnetic field. Driven by this field, the microrobot can freely roll on three-dimensional surfaces. These surfaces can be in air, water or silicon oil. In a dry environment, a microrobot with a diameter of 440 µm achieved a maximum linear speed of 13.2 mm s?1.

  13. Generalized Slow Roll for Tensors

    OpenAIRE

    Hu, Wayne

    2014-01-01

    The recent BICEP2 detection of degree scale CMB B-mode polarization, coupled with a deficit of observed power in large angle temperature anisotropy, suggest that the slow-roll parameter $\\epsilon_H$, the fractional variation in the Hubble rate per efold, is both relatively large and may evolve from an even larger value on scales greater than the horizon at recombination. The relatively large tensor contribution implied also requires finite matching features in the tensor pow...

  14. Micromagnetic testing for rolled steel

    OpenAIRE

    Wolter, B.; Dobmann, G.

    2006-01-01

    In forming of steel by hot and cold rolling a broad range of semi-finished and final products can be produced with very specific, custom-tailored technological properties. Here, the characteristics of mechanical-technological tests (tensile, hardness, creep, fatigue test) are often of central importance. Obviously the traditionally process orientated steel industry has a strong interest to replace timeconsuming and expensive destructive mechanical tests by non-destructive (nd) methods, which ...

  15. Rolling-Friction Robotic Gripper

    Science.gov (United States)

    Vranish, John M.

    1992-01-01

    Robotic gripper using rolling-friction fingers closes in on object with interface designed to mate with rollers somewhat misaligned initially, aligns object with respect to itself, then holds object securely in uniquely determined position and orientation. Operation of gripper causes minimal wear and burring of gripper and object. Exerts minimal friction forces on object when grasping and releasing. Releases object easily and reliably even when side forces and torques are between itself and object.

  16. Rolling Cylinder Phase 1bis

    DEFF Research Database (Denmark)

    Margheritini, Lucia

    This report has been prepared under the contract agreement between Aalborg Universitet and Storper Innovation ApS. The report has been written by Lucia Margheritini (lm@civil.aau.dk) who is also responsible for the data analysis. This report is the continuation of the previous report ā€œRolling...... optimized), by mean of physical tests in irregular waves. Several difficulties have been encountered during the testing, the biggest of witch being the extremely unfriendly torque measuring system....

  17. The effect of roll gap geometry on microstructure in cold-rolled aluminum

    DEFF Research Database (Denmark)

    Mishin, Oleg; Bay, B.

    2004-01-01

    Microstructure and texture are analyzed through the thickness of two aluminum plates cold-rolled 40% with different roll gap geometries. It is found that both texture and microstructure are strongly affected by the rolling geometry. After rolling with intermediate-size draughts a rolling-type texture is developed throughout the plate thickness. In this case, grains are subdivided by extended planar dislocation boundaries preferentially aligned at an angle of 40 +/- 15degrees to the rolling direction. In the plate rolled with small draughts, shear texture components appear in the intermediate layers. In these layers, extended planar dislocation boundaries are frequently found to be inclined closely to the rolling direction. The subsurface and central layers of this plate exhibit microstructures similar to those in the plate rolled with intermediate draughts. It is suggested that the development of different textures and microstructures at different depths is related to the activation of different slip systems due to through-thickness strain gradients.

  18. Generalized Slow Roll for Tensors

    CERN Document Server

    Hu, Wayne

    2014-01-01

    The recent BICEP2 detection of degree scale CMB B-mode polarization, coupled with a deficit of observed power in large angle temperature anisotropy, suggest that the slow-roll parameter $\\epsilon_H$, the fractional variation in the Hubble rate per efold, is both relatively large and may evolve from an even larger value on scales greater than the horizon at recombination. The relatively large tensor contribution implied also requires finite matching features in the tensor power spectrum for any scalar power spectrum feature proposed to explain anomalies in the temperature data. We extend the generalized slow-roll approach for computing power spectra, appropriate for such models where the slow-roll parameters vary, to tensor features where scalar features are large. This approach also generalizes the tensor-scalar consistency relation to be between the ratio of tensor and scalar sources and features in the two power spectra. Features in the tensor spectrum are generically suppressed by $\\epsilon_H$ relative tho...

  19. Mechanisms of rolling contact spalling

    Science.gov (United States)

    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.

  20. Rolling Contact Fatigue of Ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Wereszczak, Andrew A [ORNL; Wang, W. [Bournemouth University, Bournemouth, United Kingdom; Wang, Y. [Bournemouth University, Bournemouth, United Kingdom; Hadfield, M. [Bournemouth University, Bournemouth, United Kingdom; Kanematsu, W. [National Institute of Advanced Industrial Science and Technology, Japan; Kirkland, Timothy Philip [ORNL; Jadaan, Osama M. [University of Wisconsin, Platteville

    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.

  1. Study Friction Distribution during the Cold Rolling of Material by Matroll Software

    International Nuclear Information System (INIS)

    Rolling process is one of the most important ways of metal forming. Since the results of this process are almost finished product, therefore controlling the parameters affecting this process is very important in order to have cold rolling products with high quality. Among the parameters knowing the coefficient of friction within the roll gap is known as the most significant one. That is because other rolling parameters such as rolling force, pressure in the roll gap, forward slip, surface quality of sheet, and the life of work rolls are directly influenced by friction. On the other hand, in rolling calculation due to lake of a true amount for coefficient of friction a supposed value is considered for it. In this study, a new software (Matroll), is introduced which can determine the coefficient of friction (COF) and plot the friction hills for an industrial mill. Besides, based on rolling equations, it offers about 30 rolling parameters as outputs. Having the rolling characteristics as inputs, the software is able to calculate the coefficient of friction. Many rolling passes were performed on real industrial aluminum mill. The coefficient of friction was obtained for all passes. The results are in good agreement with the findings of the other researchers

  2. Roll-to-roll fabricated lab-on-a-chip devices

    DEFF Research Database (Denmark)

    Vig, Asger Laurberg; Mäkelä, Tapio; Majander, Päivi; Lambertini, Vito; Ahopelto, Jouni; Kristensen, Anders

    2011-01-01

    We present a high-volume fabrication technique for making polymer lab-on-a-chip devices. Microfluidic separation devices, relying on pinched flow fraction, are roll-to-roll fabricated in a cellulose acetate (CA) film at a volume of 360 devices h?1 for a cost of approximately 0.5 euro/device. The manufacturing process consists of two steps: (i) roll-to-roll thermal nanoimprint for patterning the microchannels into a CA film and (ii) roll-to-roll lamination for bonding another CA film onto the imp...

  3. Roll-to-roll fabricated lab-on-a-chip devices

    OpenAIRE

    Vig, Asger Laurberg; Mäkelä, Tapio; Majander, Päivi; Lambertini, Vito; Ahopelto, Jouni; Kristensen, Andrs

    2011-01-01

    We present a high-volume fabrication technique for making polymer lab-on-a-chip devices. Microfluidic separation devices, relying on pinched flow fraction, are roll-to-roll fabricated in a cellulose acetate (CA) film at a volume of 360 devices h?1 for a cost of approximately 0.5 euro/device. The manufacturing process consists of two steps: (i) roll-to-roll thermal nanoimprint for patterning the microchannels into a CA film and (ii) roll-to-roll lamination for bonding another CA film onto the ...

  4. Large-scale Evaluation of Nickel Aluminide Rolls in a Heat-Treat Furnace at Bethelehem Steel's (Now ISG) Burns Harbor Plate Mill

    Energy Technology Data Exchange (ETDEWEB)

    Mengel, J.

    2003-12-16

    At Bethlehem Steel Burns Harbor Plate Division (now ISG Burns Harbor Plate Inc.)'s annealing furnace, new nickel aluminide intermetallic alloy rolls provide greater high-temperature strength and wear resistance compared to the conventional H series cast austenitic alloys currently used in the industry. Oak Ridge National Laboratory and Bethlehem (ISG) partnered under a U.S. Department of Energy, Office of Industrial Technology's Emerging Technology Deployment Program to demonstrate and evaluate the nickel aluminide intermetallic alloy rolls as part of an updated energy efficient large commercial annealing furnace system. Many challenges were involved in this project, including developing welding procedures for joining nickel aluminide intermetallic alloys with H-series austenitic alloys, developing commercial cast roll manufacturing specifications, working with several commercial suppliers to produce a quantity of high quality, reproducible nickel aluminide rolls for a large steel industrial annealing furnace, installing and demonstrating the capability of the rolls in this furnace, performing processing trials to evaluate the benefits of new equipment and processes, and documenting the findings. Updated furnace equipment including twenty-five new automated furnace control dampers have been installed replacing older design, less effective units. These dampers, along with upgraded flame-safety control equipment and new AC motors and roll-speed control equipment, are providing improved furnace control and additional energy efficiency. Energy data shows up to a 34% energy reduction from baseline after the installation of upgraded furnace damper controls along with up to a 34% reduction in greenhouse gases, potential for an additional 3 to 6% energy reduction per campaign of light-up and shutdown, and a 46% energy reduction from baseline for limited trials of a combination of improved damper control and straight-through plate processing. The straight-through processing is now possible because of the nickel aluminide rolls which also provided plate product surface quality improvement that will allow the additional processing of surface critical material. Benefits also include associated large reductions in maintenance, reduction in spare rolls and associated component costs, and potential for greater through-put and productivity. Estimated project fuel cost reductions alone for processing 100,000 tons/yr through this furnace are almost $0.5 million/yr with the new dampers, and more than $600,000/yr with straight-through processing and new damper control, assuming natural gas prices of $6.00/MMBtu. The nickel aluminide rolls are competitively priced with conventional H series alloy rolls.

  5. Adaptive Automatic Gauge Control of a Cold Strip Rolling Process

    Directory of Open Access Journals (Sweden)

    ROMAN, N.

    2010-02-01

    Full Text Available The paper tackles with thickness control structure of the cold rolled strips. This structure is based on the rolls position control of a reversible quarto rolling mill. The main feature of the system proposed in the paper consists in the compensation of the errors introduced by the deficient dynamics of the hydraulic servo-system used for the rolls positioning, by means of a dynamic compensator that approximates the inverse system of the servo-system. Because the servo-system is considered variant over time, an on-line identification of the servo-system and parameter adapting of the compensator are achieved. The results obtained by numerical simulation are presented together with the data taken from real process. These results illustrate the efficiency of the proposed solutions.

  6. Study of reissner beam under rolling disk

    OpenAIRE

    Jursinovi?, Boštjan

    2011-01-01

    For this degree paper we developed two-dimensional mathematical model of a rigid body rolling motion on deformable surface. Rigid body was modeled as a disk and deformable surface with geometrically non-linear beam. We derived equations of the rolling disk on know curve line, equations of dynamical response of Reissner beam under point load and equations of coupled rolling of disk on geometrical non-linear beam. Equations are discretized first with respect to the length of the beam followin...

  7. Rolling textures of niobium and molybdenum

    International Nuclear Information System (INIS)

    Niobium and molybdenum were rolled at ambient temperature. The crystallographic orientation distribution of the 50%, 60% and 70% deformed samples was investigated by means of quantitative texture analysis. Simulations of the rolling textures were performed using the Relaxed Constraints Taylor Theory. It was shown that dislocation movement took place on {110} and {112} glide planes. After 70% rolling deformation additional glide on {123} planes occurred in case of niobium. (orig.)

  8. ROLL OUT THE TALENT : Final project report

    OpenAIRE

    Eerola, Tuomas; Tuominen, Pirjo; Hakkarainen, Riitta-Liisa; Laurikainen, Marja; Mero, Niina

    2014-01-01

    The ROLL OUT THE TALENT project was born out of the desire to recognise and support the strengths of vocational students and to develop new and innovative operating models. ROLL OUT THE TALENT promoted regional cooperation between institutes and companies. The project produced operating and study path models that take into consideration the individual strengths of vocational students and the principles of lifelong learning. This is the final report of the ROLL OUT THE TALENT project, and ...

  9. Cold roll forming process energy efficiency optimization

    OpenAIRE

    ?????????, ???????

    2012-01-01

    The objective of the current study is the development of an optimization methodology for the energy efficiency of the cold roll forming process. Towards that target, a hybrid modeling approach, utilizing analytical and computational models, is proposed and developed. The energy efficiency indicator for the cold roll forming process is defined, as taking into account the cold roll forming process as a system with energy inputs and outputs. An analytical model was proposed and analyzed fo...

  10. Simulations of Gear Rolling by Flat Tools

    OpenAIRE

    Saleem, Adil

    2013-01-01

    Gear rolling is one of the latest techniques being used in gear manufacturing. As compared to traditional gear manufacturing techniques, gear rolling can add benefits like improved surface finish, increased flank strength, increased load capacity and less material usage. After initial research initiatives in USA, Germany and China, efforts are underway to make this technique industrially viable for production of both low and high module gears. There are two methods for gear rolling one uses r...

  11. Large-area, continuous roll-to-roll nanoimprinting with PFPE composite molds

    International Nuclear Information System (INIS)

    Successful implementation of a high-speed roll-to-roll nanoimprinting technique for continuous manufacturing of electronic devices has been hindered due to lack of simple substrate preparation steps, as well as lack of durable and long lasting molds that can faithfully replicate nanofeatures with high fidelity over hundreds of imprinting cycles. In this work, we demonstrate large-area high-speed continuous roll-to-roll nanoimprinting of 1D and 2D micron to sub-100 nm features on flexible substrate using perfluoropolyether (PFPE) composite molds on a custom designed roll-to-roll nanoimprinter. The efficiency and reliability of the PFPE based mold for the dynamic roll-to-roll patterning process was investigated. The PFPE composite mold replicated nanofeatures with high fidelity and maintained superb mold performance in terms of dimensional integrity of the nanofeatures, nearly defect free pattern transfer and exceptional mold recovering capability throughout hundreds of imprinting cycles. (paper)

  12. Interactions Between Stably Rolling Leukocytes In Vivo

    CERN Document Server

    King, M R; Kim, M B; Sarelius, I H; King, Michael R.; Ruscio, Aimee D.; Kim, Michael B.; Sarelius, Ingrid H.

    2003-01-01

    We have characterized the two-dimensional spatial dependence of the hydrodynamic interactions between two adhesively rolling leukocytes in a live venule in the mouse cremaster muscle. Two rolling leukocytes were observed to slow each other down when rolling together in close proximity, due to mutual sheltering from the external blood flow in the vessel lumen. These results are in agreement with a previous study of leukocyte rolling interactions using carbohydrate-coated beads in a parallel-plate flow chamber and a detailed computer model of adhesion in a multicellular environment.

  13. A Framework for Rolling Stock Rescheduling

    DEFF Research Database (Denmark)

    Haahr, JŲrgen Thorlund; Lusby, Richard Martin

    Rolling Stock schedules are typically made months or weeks prior to the date of execution. It is, however, rare that everything goes exactly as planned due to internal and external factors on the day of operation. If the magnitude of the disturbances is small then the problems may be absorbed by network buffer times. However, if the problems are more severe, changes must be made to the rolling stock schedule. In this talk we will discuss the Rolling Stock Rescheduling problem and Disruption Management. We will present our current work and planned future work on a framework for solving the Rolling Stock in a disruption context.

  14. A Framework for Rolling Stock Rescheduling

    DEFF Research Database (Denmark)

    Haahr, JĆørgen Thorlund; Lusby, Richard Martin

    Rolling Stock schedules are typically made months or weeks prior to the date of execution. It is, however, rare that everything goes exactly as planned due to internal and external factors on the day of operation. If the magnitude of the disturbances is small then the problems may be absorbed by...... network buffer times. However, if the problems are more severe, changes must be made to the rolling stock schedule. In this talk we will discuss the Rolling Stock Rescheduling problem and Disruption Management. We will present our current work and planned future work on a framework for solving the Rolling...

  15. Terras: NATO õppuste roll Euroopas kasvab

    Index Scriptorium Estoniae

    2013-01-01

    Kaitseväe juhataja kindralmajor Riho Terrase sõnul suureneb lähiaastatel NATO õppuste roll Euroopas, sest Afganistanis sõdides saadud kogemust on vaja säilitada ning kasutada seda kollektiivkaitse tugevdamiseks

  16. Europarlamendi roll põllumajanduspoliitika kujundamisel / Andres Tarand

    Index Scriptorium Estoniae

    Tarand, Andres, 1940-

    2006-01-01

    Euroopa Parlamendi roll Euroopa Liidu ühtse põllumajandus- ja energiapoliitika kujundamisel. Põllumajanduslik aspekt energeetikas: energiasektori varustamine omamaa bioenergiaga, Venemaa energeetika välispoliitika teenistuses

  17. Simple model of microscopic rolling friction.

    Science.gov (United States)

    Braun, O M

    2005-09-16

    Rolling friction at a microscopic scale is studied with the help of a simple two-dimensional model. Molecular dynamics simulations show that rolling of spherical lubricant molecules exists only for concentrations lower than the concentration of a close-packed layer. At concentrations higher than a critical one due to jamming of lubricant molecules the rolling of nearest neighboring molecules is hindered. An optimal concentration exists which provides the minimum of kinetic friction. Methods for avoiding jamming and increasing the range of operation of rolling mechanism of friction are discussed. PMID:16197089

  18. Roll pass design for improved flexibility and quality in wire rod rolling

    OpenAIRE

    Eriksson, Conny

    2004-01-01

    The thesis treats roll pass design in wire rod rolling of stainless steel for sequences and series built up by two-symmetrical grooves. It is focused on predicting rolling flexibility, also called working range, as well as product quality. For analysing the flexibility a computer program has been developed. The minimum and maximum roll gap and corresponding bar areas for series of grooves including "oval", "round", "false round", "square" and "diamond" shapes are calculated. Six pass designs ...

  19. Assessment of air pollution and its effects on the health status of the workers in beam rolling mills factory (Iran National Steel Industrial Group from Ahvaz-Iran

    Directory of Open Access Journals (Sweden)

    Rafiei Masoud

    2009-01-01

    Full Text Available Background: Air pollutants of iron- and steel-making operations have historically been an environmental and health hazard. These pollutants include gaseous substances such as sulfur oxide, nitrogen dioxide, and carbon monoxide. The Iran National Steel Industrial Group beam rolling mills factory has two production lines viz. line 630 and line 650, with different beam production capabilities and is capable of producing different types of beams. Materials and Methods: A retrospective cross-sectional study on 400 workers in different exposure levels to environmental pollution was performed during 2005 to determine the mean value of respirable particulate matter (RPM concentrations and its effects on the health status of workers. To elicit information regarding the health status of the worker, the National Institute for Occupational Safety and Health standard questionnaire was used. Fisher?s exact test was performed to assess the relative risk (RR of exposure to air pollution on cardiovascular diseases, chest tightness, cough, difficulty in retention, i.e. loss of memory, tension, occupational fatigue, and occupational stress in exposed workers. Results: There was significant difference in RPM pollution level between two product lines. The RR of exposure to air pollution on cardiovascular diseases, chest tightness, cough, difficulty in retention, i.e. loss of memory, tension, occupational fatigue, and occupational stress in exposed workers were 2.78, 2.44, 2.15, 1.92, 1.57, 3.90, and 2.09, respectively.

  20. Adsorption of single-strand alkylammonium salts on bentonite, surface properties of the modified clay and polymer nanocomposites formation by a two-roll mill

    International Nuclear Information System (INIS)

    The adsorption of tallow alkylammonium salts onto bentonite from the Lopburi province in Thailand, and the effect of surface wettability on the formation of polymer-clay nanocomposites are reported. We looked specifically at octadecyltrimethyl ammonium chloride (S18), a popular member of the tallow alkylammonium salt family. The adsorption of S18 onto the bentonite interlayer can be divided into three distinct stages depending upon the initial concentration of S18. These stages are (a) monolayer formation, (b) intermediate state of double layer formation and (c) double layer formation. A decrease in surface energy driven by drops in the values of the polar and dispersive components was observed as the amount of surfactant surface coverage increased. Using thermal gravimetric analysis (TGA), the critical surface energy (CSE) of organoclay was found to decrease as the amount of absorbed S18 increased. S18 organoclay with different degrees of surface coverage was used in a two-roll mill to prepare high-density polyetheylene (HDPE)-clay nanocomposites. The oxidized polyethylene wax (OWax) was used as a dispersing agent to promote the delamination of the organoclay platelets. The results from X-ray diffraction (XRD) and transmission electron microscope (TEM) indicated a difference in the dispersing capability of the organoclay.

  1. Dynamics of Entangled Polymeric Fluids in Two-roll Mill studied via Dynamic Light Scattering and Two-color flow Birefringence; 1, Steady flow

    CERN Document Server

    Sanyal, S; Leal, L C; Sanyal, Subrata; Yavich, Dmitry

    2000-01-01

    We present the experimental results on a series of high molecular weight, entangled polystyrene solutions subjected to a ``mixed'' shear and elongational flow-type generated in a co-rotating two-roll mill. For steady-flows as well as for start-up of flows from rest, we used two different optical methods to study the dynamics of entangled polymeric fluids: two-color flow birefringence (TCFB) and dynamic light scattering (DLS). Using the TCFB method, we measured the birefringence, $\\Delta n$, and the orientation angle, $\\chi$, of the optic axes in the solution and thereby the generalized viscosity function, $\\eta$ (with the use of stress-optical relations). The DLS method was applied to measure the velocity-gradient, \\gdot, and the flow-type parameter $\\lambda$ for the polymer solutions under flow conditions identical to the TCFB measurements. For low deformation rates the symmetry of the flow-field was reduced with the use of polymeric fluids compared to that seen with a Newtonian fluid. A molecular constituti...

  2. FEM Analysis of Effect of Rolling Parameters on Cold Rolling Process

    Directory of Open Access Journals (Sweden)

    K. Devarajan

    2012-03-01

    Full Text Available A FEM simulation study was carried out to investigate the influence of the rolling parameters on the rolling process. Using commercial FEM software, ABAQUS, a number of cases were studied. In this paper, a two-dimensional Elastic-plastic finite element model to simulate the cold rolling of thick strip with different roll angular velocity and roll diameter models is described. The angular velocity of the rigid rolls ranged from 30 to 480 revolutions per minute (r.p.m. and the rigid roll diameter ranged from 100 to 300 mm. The initial feeding speed of the plate and friction was kept constant, thus causing a slip between the plate and the roll surfaces. The main interest of this study is to see whether the speed of the rolls and the diameter of the rolls have any influence on the contact pressure and the residual stress in cold rolling process. The roll speed is an easily controlled operational parameter which may be used to enhance the process and the quality of the final products by changing the roller diameter and see the effect of stress and contact pressure on the thick plates strip is new one.

  3. Finite Element Analysis of Symmetric and Asymmetric Three-roll Rolling Process

    Directory of Open Access Journals (Sweden)

    Pesin A.

    2015-01-01

    Full Text Available A three-roll process is a significant technique in the production of wire rod, round bars and hexagonal profiles for structural applications. Better mechanical properties of wire rod, round bars and hexagonal profiles can be achieved due to large plastic deformation by the three-roll process. Asymmetric rolling is a novel technique characterised by a kinematic asymmetry linked to the difference in peripheral speed of the rolls, able to introduce additional shear strains through the bar thickness. In order to achieve this, asymmetrical three-roll rolling process was investigated to better control the deformation compared to the conventional three-roll rolling process in a stand with two three-roll calibers located very close to each other. Simulation of round-triangle-triangle pass rolling was performed. FEM simulations were carried out with using software DEFORM 3D. The influence of the friction coefficient and speed asymmetry on the shear strain and material flow was discussed. The results of simulation can be used to optimize the asymmetric three-roll rolling process to improve the mechanical properties of wire rod, round bars and hexagonal profiles.

  4. 75 FR 16504 - Hot-Rolled Flat-Rolled Carbon-Quality Steel Products From Brazil, Japan, and Russia

    Science.gov (United States)

    2010-04-01

    ...731-TA-806-808 (Second Review)] Hot-Rolled Flat-Rolled Carbon-Quality Steel...the countervailing duty order on certain hot-rolled flat-rolled carbon-quality steel products (``hot-rolled steel'') from Brazil, the...

  5. 75 FR 62566 - Hot-Rolled Flat-Rolled Carbon-Quality Steel Products From Brazil, Japan, and Russia

    Science.gov (United States)

    2010-10-12

    ...731-TA-806-808 (Second Review)] Hot-Rolled Flat-Rolled Carbon-Quality Steel...concerning the countervailing duty order on hot-rolled flat-rolled carbon-quality steel products (``hot-rolled steel'') from Brazil, the...

  6. 75 FR 42782 - Hot-Rolled Flat-Rolled Carbon-Quality Steel Products From Brazil, Japan, and Russia

    Science.gov (United States)

    2010-07-22

    ...731-TA-806-808 (Second Review)] Hot-Rolled Flat-Rolled Carbon-Quality Steel...the countervailing duty order on certain hot-rolled flat-rolled carbon-quality steel products (``hot-rolled steel'') from Brazil, the...

  7. High speed roll casting of Mg alloy strip by a vertical type twin roll caster

    OpenAIRE

    Watari, H; S.Kumai; Haga, T

    2006-01-01

    Purpose: The possibility of high speed roll casting of AZ31, AM60 and AZ91 was investigated. Warm deep drawing of roll cast magnesium alloy was operated. and formability of roll cast magnesium strip was cleared.Design/methodology/approach: A vertical type high speed twin roll caster was used. The roll casting was operated in the air atmosphere. The casting speed was from 60 m/min up to 180 m/min. Low temperature casting was adopted to realize high speed casting.Findings: Strip thinner 3 mm wi...

  8. Roll forming of eco-friendly stud

    Science.gov (United States)

    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%.

  9. Roll casting of 5182 aluminium alloy

    Directory of Open Access Journals (Sweden)

    T. Haga

    2009-06-01

    Full Text Available Purpose: of this paper is investigation of the ability of the high speed roll casting of 5182 aluminium alloy. Appropriate twin roll caster to cast the 5182 strip was researched.Design/methodology/approach: Method used in the present study was an unequal diameter twin roll caster and a vertical type high speed twin roll caster equipped with mild steel rolls without parting material.Findings: are that the vertical type high speed twin roll caster was effective to cast 5182 strip at high speed. 5182 could be cast at 10 times higher speed than a conventional twin roll caster for aluminium alloy. 5182 could be cast by the mild steel roll using no-parting material without sticking.Research limitations/implications: is that ability of casting of the wide strip, that is wider than 600 mm, could not be investigated.Practical implications: 600 mm-width 5182 strip could be cast and this width is enough for some structural parts. 5182 could be cast into the strip at high productivity and low energy using the economy equipment and no-consumable good.Originality/value: The method to make economy sheet metal of aluminium alloy is imported. The economy alloy and economy process are essential to get economy aluminium alloy sheet.

  10. CRITICAL WAVE EPISODES FOR ASSESSMENT OF ROLL

    DEFF Research Database (Denmark)

    Jensen, JĆørgen Juncher; Pedersen, Preben Terndrup

    time-varying restoring moment and the heave acceleration. The result is the mean outcrossing rate of the roll angle together with corresponding most probable wave scenarios (critical wave episodes), leading to specific maximum roll angles. The procedure is computationally very effective and can thus be...

  11. Lubrication of rolling-element bearings

    Science.gov (United States)

    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. Steels For Rolling-Element Bearings

    Science.gov (United States)

    Zaretsky, Erwin V.

    1988-01-01

    Bearing lives increased by attention to details of processing and applications. NASA technical memorandum discusses selection of steels for long-life rolling-element bearings. After brief review of advances in manufacturing, report discusses effect of cleanliness of bearing material on fatigue in rolling element. Also discusses fracture toughnesses of through-hardened and case-hardened materials.

  13. New versions of the rolling double cone

    Science.gov (United States)

    Balta, Nuri

    2002-03-01

    Rolling a double cone upward is interesting but oscillating it on a track having an elevated centre is fascinating. You can design three different arrangements of a pair of cones each requiring different tracks to roll up and oscillate on a track of elevated centre.

  14. Molecular rolling friction: the cogwheel model

    International Nuclear Information System (INIS)

    With the help of a two-dimensional (2D) model we study rolling lubrication by circular ('2D fullerenes') molecules for a wide range of parameters. The conditions under which microscopic rolling friction may be effective are identified and related to the relative ingraining between substrate and molecule, the latter behaving as a nanosized cogwheel

  15. Effect of Pavement Conditions on Rolling Resistance

    Directory of Open Access Journals (Sweden)

    Mr.Dipanjan Mukherjee

    2014-07-01

    Full Text Available Rolling resistance is the force acting on a vehicle over a full journey. It is generated by the hysteresis of tyre and pavement. Rolling resistance, sometimes called rolling friction or rolling drag, is the force resisting the motion when a body (such as a ball, tire, or wheel rolls on a surface. It is mainly caused by non-elastic effects; that is, not all the energy needed for deformation (or movement of the wheel, roadbed, etc. is recovered when the pressure is removed. A hysteresis phenomenon can be observed when viscoelastic materials undergo a load-then-unload process. A typical hysteresis curve of viscoelastic material can be found. The shadow area enclosed by the hysteresis loop represents energy loss. A characteristic of a deformable material such that the energy of deformation is greater than the energy of recovery. The rubber compound in a tire exhibits hysteresis. As the tire rotates under the weight of the vehicle, it experiences repeated cycles of deformation and recovery, and it dissipates the hysteresis energy loss as heat. Hysteresis is the main cause of energy loss associated with rolling resistance and is attributed to the viscoelastic characteristics of the rubber. Materials that have a large hysteresis effect, such as rubber, which bounce back slowly, exhibit more rolling resistance than materials with a small hysteresis effect that bounce back more quickly and more completely, such as steel or silica. Low rolling resistance tires typically incorporate silica in place of carbon black in their tread compounds to reduce low-frequency hysteresis without compromising traction. Note that railroads also have hysteresis in the roadbed structure. Like the fuel consumption, rolling resistance also has a significant relationship with velocity. experiment has shown that, for a 32-tonn goods vehicle, rolling resistance contributes about 70% of total drag when driven at 50km/h and about 37% at 100km/h. An important issue which should not be overlooked is that rolling resistance is affected by the characteristics of the pavement surface. Rolling resistance varies between different pavement surfaces. Hard and smooth surfaces produce lower rolling resistance than soft and rough surfaces. Rolling resistance is affected by both tyre and ambient temperature.

  16. Rolling of 316L Stainless Steel with Rough Rolls to Potentially Obtain Superficial Nanograins

    Science.gov (United States)

    Camurri, Carlos; Gallegos, Alejo; Carrasco, Claudia

    2014-06-01

    316L stainless steel plates of 5-mm thickness, normalized at 900 °C, were cold rolled with different reductions and number of passes using rolls with three different surface roughnesses: grain heights of 0.17 and 0.33 mm and rhomboid-shaped grains of 1.5-mm height. Subsequently, the rolled samples were annealed at 275 °C for 1 h in an effort to achieve superficial nanograins. The plates laminated using low-roughness rolls had continuous superficial microcrystallization when they were rolled for at least 26 passes. For samples made with rougher rolls, the recrystallized superficial grains formed on the surface (sized ~10-15 ?m) were smaller than those below the surface; this behavior was caused by the major deformation induced by repeated indentations. The superficial recrystallization of the sample also tended to be more continuous for higher number of passes; micrographs of the penetration profiles of indentation in the samples rolled with high-roughness rolls revealed that a sample rolled 24 times had not yet reached the steady surface topology. As a conclusion, in order to successfully form superficial nanograins, very low-roughness rolls must be used as well as a small absolute reduction per pass, followed by annealing. These rolling conditions generate a continuous field of highly superficial deformations, which act as nucleation centers for nanograins during annealing.

  17. How to make a cylinder roll uphill

    CERN Document Server

    Hore, Dipabali; Mondal, Subrata; Roy, Abhijit; Ghatak, Animangsu

    2015-01-01

    Slithering, crawling, slipping, gliding are various modes of limbless locomotion that have been mimicked for micro-manipulation of soft, slender and sessile objects. A lesser known mode is rolling which involves periodic, asymmetric and lateral muscular deformations. Here we enable an elastomeric cylinder of poly(dimethylsiloxane) to roll on a substrate by releasing small quantity of a solvent like chloroform, toluene, hexane, heptane and so on, which swells differentially a portion of the cylinder, but evaporates from portion of it which remains exposed to the atmosphere. In a dynamic situation, this asymmetric swelling-shrinking cycle generates a torque which drives the cylinder to roll. The driving torque is strong enough that the cylinder can roll up an inclined plane, within a range of inclination, its velocity even increases. The cylinder can even drag a dead weight significantly larger, ~8-10 times its own weight. A scaling law is derived for optimizing the rolling velocity.

  18. Surface defects on austenitic rolled steel

    International Nuclear Information System (INIS)

    A study was made on the nature of surface defects of 12Kh2N4A, Kh18N10T, Kh23N18 and other rolled steels, the reasons of their formation and the methods for their prevention. It is shown that main types of surface defects are presented by fissures and cracks. The fissures are related to low metal plasticity, as well as to steel rolling at the temperature lower than recrystallization temperature. The use of differentiated conditions of heating ingots for rolling excludes completely these defects. Cracks are of different nature: the single ones form during rolling on ingots, casted carelessly; the grouped cracks are located along two antipodar rolling generatrices. They are characteristic for intermediate oval profile with low mechanical properties

  19. Automated Procedure for Roll Pass Design

    Science.gov (United States)

    Lambiase, F.; Langella, A.

    2009-04-01

    The aim of this work has been to develop an automatic roll pass design method, capable of minimizing the number of roll passes. The adoption of artificial intelligence technologies, particularly expert systems, and a hybrid model for the surface profile evaluation of rolled bars, has allowed us to model the search for the minimal sequence with a tree path search. This approach permitted a geometrical optimization of roll passes while allowing automation of the roll pass design process. Moreover, the heuristic nature of the inferential engine contributes a great deal toward reducing search time, thus allowing such a system to be employed for industrial purposes. Finally, this new approach was compared with other recently developed automatic systems to validate and measure possible improvements among them.

  20. TR-I rocket roll control system

    Science.gov (United States)

    Kouchiyama, Jiro; Funo, Yasuhiro; Ogawa, Shigeyuki; Fujiwara, Teruo; Nishida, Megumu; Hasegawa, Kazuo

    A test rocket designated as TR-I was launched to acquire engineering design data for H-II, the Japanese next-generation satellite launcher, which has been under development by NASDA. A simple roll control system has been installed to the TR-I in order to maintain roll angle and roll rate within a limitation during the flight for assuring complete downlink of the telemetry system and for simulating flight conditions of the H-II. Major components of the roll control system, such as the Electronics Package (E-PACK), Inertial Sensor Package (ISP), Solid Motor Roll Control Unit (SMRC), and their hardware-in-the-loop (HWIL) simulation are discussed, referring to the actual flight data.

  1. Effect of Warm Rolling on Microstructure and Mechanical Properties of Twin-roll Casted ZK60 Alloy Sheets

    Scientific Electronic Library Online (English)

    Xibing, Gong; Wentao, Gong; Suk Bong, Kang; Jae Hyung, Cho.

    2015-04-01

    Full Text Available In this study, ZK60 magnesium alloy strips were produced by twin roll casting (TRC) and then subjected to warm rolling at the temperature of 300 °C and 350 °C. Rolled sheets related to different rolling reductions were prepared after sequential warm rolling with the rolling speed of 5 m/min. Microst [...] ructures, texture, hardness, tensile properties of the rolled sheets with different rolling reductions were studied experimentally. It has been found that grain refinement occurs actively during the warm rolling. Also, high density of shear bands were observed in the rolled sheets. The warm rolling sheet presents strong (0002) basal texture. In addition, the increase of the rolling reduction results in the improvement of the mechanical properties.

  2. The Evolution of the Surface Morphologies and Microstructures of an Unleveled Hot-Rolled Steel Strip During Cold Rolling After Hydrogen Reduction

    Science.gov (United States)

    Jing, Yu-An; Shang, Qiuyue; Zang, Xiaoming; Zhang, Lei; Peng, Xingdong; Jia, Pinfeng

    2015-10-01

    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 were subjected to leveling prior to reduction.

  3. Tensile mechanical behavior and fracture toughness of MWCNT and DWCNT modified vinyl-ester/polyester hybrid nanocomposites produced by 3-roll milling

    International Nuclear Information System (INIS)

    This study aims to investigate the tensile mechanical behavior and fracture toughness of vinyl-ester/polyester hybrid nanocomposites containing various types of nanofillers, including multi- and double-walled carbon nanotubes with and without amine functional groups (MWCNTs, DWCNTs, MWCNT-NH2 and DWCNT-NH2). To prepare the resin suspensions, very low contents (0.05, 0.1 and 0.3 wt.%) of carbon nanotubes (CNTs) were dispersed within a specially synthesized styrene-free polyester resin, conducting 3-roll milling technique. The collected resin stuff was subsequently blended with vinyl-ester via mechanical stirring to achieve final suspensions prior to polymerization. Nanocomposites containing MWCNTs and MWCNT-NH2 were found to exhibit higher tensile strength and modulus as well as larger fracture toughness and fracture energy compared to neat hybrid polymer. However, incorporation of similar contents of DWCNTs and DWCNT-NH2 into the hybrid resin did not reflect the same improvement in the corresponding mechanical properties. Furthermore, experimentally measured elastic moduli of the nanocomposites containing DWCNTs, DWCNT-NH2, MWCNTs and MWCNT-NH2 were fitted to Halphin-Tsai model. Regardless of amine functional groups or content of carbon nanotubes, MWCNT modified nanocomposites exhibited better agreement between the predicted and the measured elastic moduli values compared to nanocomposites with DWCNTs. Furthermore, Transmission Electron Microscopy (TEM) and Scanning Electron Microscopy (SEM) were used to reveal dispersion state of the carbon nanotubes within the hybrid polymer and to examine the CNT induced failure modes that occurred under mechanical loading, respectively. Based on the experimental findings obtained, it was emphasized that the types of CNTs and presence of amine functional groups on the surface of CNTs affects substantially the chemical interactions at the interface, thus tuning the ultimate mechanical performance of the resulting nanocomposites.

  4. High speed roll casting of Mg alloy strip by a vertical type twin roll caster

    Directory of Open Access Journals (Sweden)

    H. Watari

    2006-02-01

    Full Text Available Purpose: The possibility of high speed roll casting of AZ31, AM60 and AZ91 was investigated. Warm deep drawing of roll cast magnesium alloy was operated. and formability of roll cast magnesium strip was cleared.Design/methodology/approach: A vertical type high speed twin roll caster was used. The roll casting was operated in the air atmosphere. The casting speed was from 60 m/min up to 180 m/min. Low temperature casting was adopted to realize high speed casting.Findings: Strip thinner 3 mm with 100 width could be cast continuously. The casting ability became better with increasing content of Al. Roll cast Mg alloy strips could be hot-rolled down to 0.5 mm. AZ31 as-cast strip could be thinner down to 0.5 mm only by three times of hot rolling. Deep drawing was operated with three kinds of Mg alloy at 250°C, and LDR value was larger than 2.0. It was shown that deep drawing of AZ91 alloy for casting was possible.Research limitations/implications: There was tendency that cracks occurred at the center in the thickness direction as Al content increased.Practical implications: Sheet metal forming of magnesium alloy with high content Al can be realized.Originality/value: It was shown that possibility of high speed roll casting of magnesium alloy, and warm deep drawing of roll cast AZ91 strip.

  5. CANDU 3 rolled joint development program

    International Nuclear Information System (INIS)

    The CANDU 3 reactor will use shop-assembled fuel channel assemblies installed in the reactor as single modules. These modules will consist of two dissimilar end fitting assemblies connected to a pressure tube by means of conventional rolled joints, two dissimilar calandria tube extensions attached to a calandria tube by sandwich-type rolled joints, and four spacers installed in the annular gap between the pressure tube and calandria tube. The introduction of the modular fuel channel assembly has resulted in a fuel channel assembly design that incorporates four new or different designs of rolled joints. Because of space limitations, the pressure tube/end fitting rolled joint assemblies have significantly thinner hub wall thicknesses than normal on CANDU reactors, while the calandria tube/calandria tube extension rolled joint assemblies incorporate thin-walled CTX hubs rather than the more usual rigid tubesheets in current CANDU reactors. These changes have necessitated the introduction of some unusual fabrication techniques and procedures to achieve acceptable rolled joint assemblies. The fabrication and testing of a limited quantity of each type of joint has demonstrated the feasibility of producing joints that will meet their design requirements. This paper reports on the extensive development program carried out to optimize the fabrication parameters in terms of rolled joint integrity and leak tightness, and to establish practical production tolerance ranges. (Author) 8 figs

  6. Inflation with a constant rate of roll

    Science.gov (United States)

    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.

  7. Minimizing the edge buckling of the cold roll-forming process

    International Nuclear Information System (INIS)

    In this work, the cold roll-forming process was numerically simulated by MSC SuperForm 2002 software based on finite element method. The strips were modelled with U-profile and a pre-punched hole located at the web zone was introduced. Two different configurations of the roll-forming mills were simulated, named as the Conventional and Curved. The conventional roll-forming mill was obtained by using the same diameters of the bottom rolls. The downhill roll-forming mill was achieved by increasing the diameters of the bottom rolls. This study investigated the occurrence of edge buckling in the hole lateral edge of the pre-punched sheet during the forming process. It could be concluded that, during the cold roll-forming process, reducing or even eliminating the compression stress in the web zone by the downhill roll-forming mill is possible to minimize occurrence of the edge buckling in the hole lateral edge of the pre-punched sheet during the forming process.

  8. Minimizing the edge buckling of the cold roll-forming process

    Science.gov (United States)

    Cavaguti, M.; Ferreira, J. V.

    2010-06-01

    In this work, the cold roll-forming process was numerically simulated by MSC SuperForm 2002 software based on finite element method. The strips were modelled with U-profile and a pre-punched hole located at the web zone was introduced. Two different configurations of the roll-forming mills were simulated, named as the Conventional and Curved. The conventional roll-forming mill was obtained by using the same diameters of the bottom rolls. The downhill roll-forming mill was achieved by increasing the diameters of the bottom rolls. This study investigated the occurrence of edge buckling in the hole lateral edge of the pre-punched sheet during the forming process. It could be concluded that, during the cold roll-forming process, reducing or even eliminating the compression stress in the web zone by the downhill roll-forming mill is possible to minimize occurrence of the edge buckling in the hole lateral edge of the pre-punched sheet during the forming process.

  9. ROLLING NOISE SIMULATION OF A RAILWAY VEHICLE

    Directory of Open Access Journals (Sweden)

    Traian MAZILU

    2013-05-01

    Full Text Available Rolling noise of the railway vehicles is occurred by the wheel/rail vibration excited bythe rolling surfaces roughness. This paper presents an acoustic model able to predict the rollingnoise level of a railway vehicle. The acoustic model is based on a wheel/rail vibration modelwhich takes into account the structural wheel vibration (Remington model and the bendingvertical waves of the rail. To this, the track model with an infinite Euler Bernoulli beam elasticallysupported on two layers is applied to simulate the effect of the ballasted track. The influence of therolling surfaces roughness and vehicle velocity on the rolling noise is investigated.

  10. FINITE ELEMENT ANALYSIS OF SAE ROLL CAGE

    OpenAIRE

    Vidyadhar Biswal*, Shubham Singhmar, Mohit Kumar, Shubham Sharma

    2015-01-01

    The objective of this thesis is to analyze the design of the Formula SAE roll cage. This work describes how a common model of the roll cage is developed using solid works Finite Element Analysis to be performed by Ansys 16 software. In this paper Front impact, back impact or side impact of roll cage is performed. This paper’s sole focus is the design and analysis for a chassis which has to sustain the racing environment. As chassis plays a vital role in a race car but ...

  11. FINITE ELEMENT ANALYSIS OF SAE ROLL CAGE

    Directory of Open Access Journals (Sweden)

    Vidyadhar Biswal*, Shubham Singhmar, Mohit Kumar, Shubham Sharma

    2015-06-01

    Full Text Available The objective of this thesis is to analyze the design of the Formula SAE roll cage. This work describes how a common model of the roll cage is developed using solid works Finite Element Analysis to be performed by Ansys 16 software. In this paper Front impact, back impact or side impact of roll cage is performed. This paper’s sole focus is the design and analysis for a chassis which has to sustain the racing environment. As chassis plays a vital role in a race car but can be called as the back bone of a good race car.

  12. Off-line calculation of pass schedule for hot rolling stainless steel strip and establishment of model parameters for on-line set up calculation

    International Nuclear Information System (INIS)

    In this paper, the method to calculate the roughing and finishing rolling forces is described. The way to establish the model parameters for on-line process set up calculation during developing hot rolling stainless steel strip in 2050mm hot rolling mill of Baosteel, is also introduced. Rolling test shows that the rolling forces calculated by on-line process set up model agree well with measured data. (author)

  13. Twin roll casting of magnesium alloys with high aluminum contents

    Directory of Open Access Journals (Sweden)

    H. Watari

    2006-08-01

    Full Text Available Purpose: The purpose of the work is to establish a manufacturing process and technology to facilitate theeconomical manufacture of high-quality magnesium sheet alloys with high aluminum contents, such as AZ61and AZ91. The aim of the work is to establish a twin roll casting technology to facilitate the manufacture ofAZ61 and AZ91 magnesium sheet alloys economically whilst maintaining high quality.Design/methodology/approach: A horizontal type twin roll caster was used to manufacture thin magnesium alloysheets of AZ61 and AZ91. Pair of copper alloy roll and pure copper roll was used for the horizontal type twin roll caster.A closed type tundish was set to the roll caster to keep stable contact of molten magnesium with upper and lower rolls.Findings: The experiment results clarified that AZ61 and AZ91 sheets can be manufactured by twin roll castingprocess. The product sheet thickness in the present experiment is 2.0 to 4.5 mm for AZ91, 2.5 to 5.0mm forAZ61. Mill stiffness and a method of predicting the cast sheet’s thickness were investigated to determine theappropriate manufacturing conditions. The microstructure of AZ61 cast strips was equiaxed structure and thecrystal sizes are different depending on cross section observed. The dendric and equiaxed microstructure wereseen in the microstructure of AZ91 cross section. The intermetllic Mg17Al12 was seen in the grain boundary inAZ91 when roll speed was very slow. The grain size of the manufactured wrought magnesium alloys sheet wasless than 10 micrometers. The obtained magnesium alloy sheet exhibited an equivalent limiting drawing ratio ina warm-drawing test. The limiting drawing ratio of AZ61 was 2.6 and 2.4 for AZ91.Research limitations/implications: The suitable roll speed was from 9m/min to 15m/min in manufacturingAZ91 and AZ61 strip using copper alloy rolls. When in use of pure copper roll, strips were cast between 6m/minand 20m/min for manufacturing AZ61 and AZ91. The superheats in the experiment were 15ŗC and 30ŗC. Thecast strips should be hot rolled at 300ŗC.Originality/value: value In this experiment, it is clarified that AZ61, AZ91 sheets can be manufactured by twinroll casting. These cast sheet can be hot rolled and the manufacturing process by twin roll casting enable tomanufacure thin magnesium sheet alloys with high aluminum contents. It has been found that the manufacturedcast AZ61 and AZ91 have good formability by a warm deep drawing test.

  14. Fatigue crack growth and fracture mechanics analysis of a working roll surface layer material

    Directory of Open Access Journals (Sweden)

    M. Drobne

    2014-10-01

    Full Text Available Fatigue crack growth and fracture mechanics analysis of a working roll surface layer material is presented in this paper. The research is done on a hot strip mill working roll where High Chromium Steel is used for roll’s shell material. To obtain corresponding parameters, a rectangular single edge notched bend specimens – SENB, according to standard BS 7448, were used. The fatigue crack growth analysis was done on a resonant testing machine with use of special crack gauges, while for fracture mechanics parameters the electro–mechanical testing machine was used.

  15. Transparent conductive film by large area roll-to-roll processing

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Linda Y.L., E-mail: ylwu@simtech.a-star.edu.sg [Singapore Institute of Manufacturing Technology, 71 Nanyang Drive, Singapore 638075 (Singapore); Kerk, W.T. [Singapore Institute of Manufacturing Technology, 71 Nanyang Drive, Singapore 638075 (Singapore); Wong, C.C. [School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798 (Singapore)

    2013-10-01

    Sputtered indium tin oxide (ITO) coating on polyethylene terephthalate film has been used as the substrate for roll-to-roll fabrication of large area printed electronics devices, but it is expensive and could be cracked when bending, limiting its applications. Transparent conductive (TC) electrode made by roll-to-roll coating of transparent conductive ink on flexible substrate is an alternative, but both the ink material and the control of the coating quality are very crucial. The major challenges are the coating performance, coating uniformity and defect control during roll-to-roll processing. In this paper, we report the chemical synthesis of silver nanowires in preferred shape and size, the surface modification of the Ag nanowires for better dispersion into the commercial Poly(3,4-ethylenedioxythiophene) Poly(styrenesulfonate) (PEDOT:PSS) conductive polymer ink, and the controlled roll-to-roll coating process on flexible polyethylene terephthalate substrate by a one meter web-width roll-to-roll slot die coating system. We obtained high uniformity PEDOT:PSS coating with optical transmission higher than 80% and sheet resistance lower than 100 ?/square, and silver containing coating with sheet resistance below 40 ?/square and maintained optical transmittance. The slot die coating mechanism is investigated and the influencing factors for coating uniformity and defect are defined. The coated transparent conductive film has the same properties as the sputtered ITO and has been used as the TC electrode for printed lighting, whose performance has been proven by standard weathering test for 1000 h. - Highlight: • Controlled synthesis of silver nanowires using trace amount of Cl{sup ?} ions • Large area roll-to-roll processed transparent conductive (TC) coatings • TC film has light transmission > 80% and sheet resistance < 100 ?/sq. • Silver containing ink achieved better property than conductive polymer ink. • Used as the TC electrode for printed lighting device with proven performance.

  16. Transparent conductive film by large area roll-to-roll processing

    International Nuclear Information System (INIS)

    Sputtered indium tin oxide (ITO) coating on polyethylene terephthalate film has been used as the substrate for roll-to-roll fabrication of large area printed electronics devices, but it is expensive and could be cracked when bending, limiting its applications. Transparent conductive (TC) electrode made by roll-to-roll coating of transparent conductive ink on flexible substrate is an alternative, but both the ink material and the control of the coating quality are very crucial. The major challenges are the coating performance, coating uniformity and defect control during roll-to-roll processing. In this paper, we report the chemical synthesis of silver nanowires in preferred shape and size, the surface modification of the Ag nanowires for better dispersion into the commercial Poly(3,4-ethylenedioxythiophene) Poly(styrenesulfonate) (PEDOT:PSS) conductive polymer ink, and the controlled roll-to-roll coating process on flexible polyethylene terephthalate substrate by a one meter web-width roll-to-roll slot die coating system. We obtained high uniformity PEDOT:PSS coating with optical transmission higher than 80% and sheet resistance lower than 100 ?/square, and silver containing coating with sheet resistance below 40 ?/square and maintained optical transmittance. The slot die coating mechanism is investigated and the influencing factors for coating uniformity and defect are defined. The coated transparent conductive film has the same properties as the sputtered ITO and has been used as the TC electrode for printed lighting, whose performance has been proven by standard weathering test for 1000 h. - Highlight: • Controlled synthesis of silver nanowires using trace amount of Cl? ions • Large area roll-to-roll processed transparent conductive (TC) coatings • TC film has light transmission > 80% and sheet resistance < 100 ?/sq. • Silver containing ink achieved better property than conductive polymer ink. • Used as the TC electrode for printed lighting device with proven performance

  17. Designing Rolling-Element Bearings

    Science.gov (United States)

    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.

  18. Plasmid Rolling-Circle Replication.

    Science.gov (United States)

    Ruiz-Masó, J A; MachóN, C; Bordanaba-Ruiseco, L; Espinosa, M; Coll, M; Del Solar, G

    2015-02-01

    Plasmids are DNA entities that undergo controlled replication independent of the chromosomal DNA, a crucial step that guarantees the prevalence of the plasmid in its host. DNA replication has to cope with the incapacity of the DNA polymerases to start de novo DNA synthesis, and different replication mechanisms offer diverse solutions to this problem. Rolling-circle replication (RCR) is a mechanism adopted by certain plasmids, among other genetic elements, that represents one of the simplest initiation strategies, that is, the nicking by a replication initiator protein on one parental strand to generate the primer for leading-strand initiation and a single priming site for lagging-strand synthesis. All RCR plasmid genomes consist of a number of basic elements: leading strand initiation and control, lagging strand origin, phenotypic determinants, and mobilization, generally in that order of frequency. RCR has been mainly characterized in Gram-positive bacterial plasmids, although it has also been described in Gram-negative bacterial or archaeal plasmids. Here we aim to provide an overview of the RCR plasmids' lifestyle, with emphasis on their characteristic traits, promiscuity, stability, utility as vectors, etc. While RCR is one of the best-characterized plasmid replication mechanisms, there are still many questions left unanswered, which will be pointed out along the way in this review. PMID:26104557

  19. Rolling-Contact Spalling In Bearings

    Science.gov (United States)

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

    1990-01-01

    Report describes experimental and theoretical studies of effects of thermal and mechanical contact stresses and attendant plastic deformations responsible for rolling-contact spalling of the 440C-steel bearings in high-pressure-oxygen turbopump.

  20. 9 CFR 381.159 - Poultry rolls.

    Science.gov (United States)

    2010-01-01

    ... 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...

  1. An oil for cold rolling of metal

    Energy Technology Data Exchange (ETDEWEB)

    Ito, K.; Kendzi, K.; Onisi, M.

    1982-08-27

    The oil for cold rolling of metals (MKhI) is made by adding 0.01 to 10 percent of one or several salts of fatty acids (ZhK) to a base oil (BM). The base oil is either petroleum or vegetable oil, fatty acids, synthetic ethers and so on. Laurates, palmitates, oleates and stearates of beryllium, sodium, magnesium, aluminum, calcium, manganese, iron, copper, zinc and barium are used as the salts. The oil for cold rolling of metal may contain salts of fatty acids obtained with the break down of vegetable oils and fats, saturated and unsaturated fatty acids, polymerized fatty acids, anion active and nonanion active emulsifiers and additives which improve the load capacity of the oil, antioxidants and so on. The oil for cold rolling of metal prevents the adhesion of the steel sheets rolled by a cold method in the process of annealing without the loss of the surface properties of the sheel sheet.

  2. Why Low Bounce Balls Exhibit High Rolling Resistance

    Science.gov (United States)

    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…

  3. Quality control of roll-to-roll processed polymer solar modules by complementary imaging methods

    DEFF Research Database (Denmark)

    Rösch, R.; Krebs, Frederik C; Tanenbaum, D.M.; Hoppe, H.

    2012-01-01

    We applied complementary imaging methods to investigate processing failures of roll-to-roll solution processed polymer solar modules based on polymer:fullerene bulk heterojunctions. For investigation of processing deficiencies in solar modules we employed dark lock-in thermography (DLIT), electro......We applied complementary imaging methods to investigate processing failures of roll-to-roll solution processed polymer solar modules based on polymer:fullerene bulk heterojunctions. For investigation of processing deficiencies in solar modules we employed dark lock-in thermography (DLIT...

  4. Texture comparison between room temperature rolled and cryogenically rolled pure copper

    International Nuclear Information System (INIS)

    Nowadays, due to their potential for superior mechanical properties, a considerable interest in bulk ultrafine grained metals exists. One of the possible formation methods for this ultrafine grained material is cryogenic rolling. In this work, the influence of cryogenic rolling on the texture and the microstructure of pure copper is investigated by electron backscatter diffraction (EBSD), both in the deformed and the annealed state. This is done by comparing cryogenically rolled copper with room temperature rolled copper, rolled to the same thickness reductions. A texture difference between the room temperature rolled and cryogenically rolled copper is seen in the deformed state, although the largest texture difference is observed after annealing. These texture differences are mainly attributed to the presence of shear bands in the microstructure of the cryogenically rolled copper. In order to obtain a better understanding of the influence of shear bands on the texture evolution, the grain orientations inside the shear bands are analyzed both experimentally and numerically by applying the visco plastic self-consistent (VPSC) model. A number of shear band specific orientations, which are not observed in the conventional rolling texture of fcc materials, could be identified both in the experimental observations and in the simulations

  5. Compaction Behavior of Isomalt after Roll Compaction

    OpenAIRE

    Peter Kleinebudde; Johanna Mosig; Julian Quodbach

    2012-01-01

    The suitability of the new isomalt grade galenIQ™ 801 for dry granulation and following tableting is evaluated in this study. Isomalt alone, as well as a blend of equal parts with dibasic calcium phosphate, is roll compacted and tableted. Particle size distribution and flowability of the granules and friability and disintegration time of the tablets are determined. Tensile strength of tablets is related to the specific compaction force during roll compaction and the tableting force....

  6. Characteristics of cold rolled stainless steel sheets

    International Nuclear Information System (INIS)

    The cold rolling of sheets of austenitic stainless steel was investigated for different temperatures and percentages of reduction. It was also established under which conditions are the mechanical strenght and the ductility improved. It was found that this improvement is related to the characteristics of martensitic transformation taking place during rolling and through the tensile tests performed in stainless steels with different degree of martensitic transformation. The results are explained on the basis of martensite participation in the stained structure. (Author)

  7. Rolling and sliding dynamics in centrifugal spreading

    OpenAIRE

    Rioual, F.; Piron, E.; Tijskens, E.

    2007-01-01

    Centrifugal forcing is a usual method to spread a granular material. The dynamics of a particle in this system appears to change spectacularly according to the shape of the particle. The authors present a dynamical transition between rolling and sliding regime and a purely sliding regime as a function of the friction coefficient and the elongation of the particle. This rolling/sliding motion is indeed observed, in situ, for real particles. This simple effect of shape gives a physical interpre...

  8. ROLLING NOISE SIMULATION OF A RAILWAY VEHICLE

    OpenAIRE

    Traian MAZILU

    2013-01-01

    Rolling noise of the railway vehicles is occurred by the wheel/rail vibration excited bythe rolling surfaces roughness. This paper presents an acoustic model able to predict the rollingnoise level of a railway vehicle. The acoustic model is based on a wheel/rail vibration modelwhich takes into account the structural wheel vibration (Remington model) and the bendingvertical waves of the rail. To this, the track model with an infinite Euler Bernoulli beam elasticallysupported on two layers is a...

  9. Contact conditions in skin-pass rolling

    DEFF Research Database (Denmark)

    Kijima, Hideo; Bay, Niels

    2007-01-01

    The special contact conditions in skin-pass rolling of steel strip is analysed by studying plane strain upsetting of thin sheet with low reduction applying long narrow tools and dry friction conditions. An extended sticking region is estimated by an elasto-plastic FEM analysis of the plane strain upsetting. This sticking region causes a highly inhomogeneous elasto-plastic deformation with large influence of work-hardening and friction. A numerical analysis of skin-pass rolling shows the same con...

  10. Partition Decomposition for Roll Call Data

    CERN Document Server

    Leibon, Greg; Rockmore, Daniel N; Savell, Robert

    2011-01-01

    In this paper we bring to bear some new tools from statistical learning on the analysis of roll call data. We present a new data-driven model for roll call voting that is geometric in nature. We construct the model by adapting the "Partition Decoupling Method," an unsupervised learning technique originally developed for the analysis of families of time series, to produce a multiscale geometric description of a weighted network associated to a set of roll call votes. Central to this approach is the quantitative notion of a "motivation," a cluster-based and learned basis element that serves as a building block in the representation of roll call data. Motivations enable the formulation of a quantitative description of ideology and their data-dependent nature makes possible a quantitative analysis of the evolution of ideological factors. This approach is generally applicable to roll call data and we apply it in particular to the historical roll call voting of the U.S. House and Senate. This methodology provides a...

  11. Strip edge cracking simulation in cold rolling

    International Nuclear Information System (INIS)

    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.

  12. Roll bonding of 6061 aluminum alloy plates

    International Nuclear Information System (INIS)

    The roll bonding process is an important application of the solid state welding . in principle, two or more slabs of the materials to be bonded are placed in contact and welded around the edges. then, this assembled set is heated and rolled until the required thickness is obtained. this process is applied to clad the nuclear fuel, with high strength aluminum alloys during fabrication of plate type nuclear fuel elements for research reactors, or to produce many new constructions which have special uses in industrial applications. in the present work, the steps of the hot roll bonding of 6061 aluminum alloy plates were studies by using both microscopic examination and mechanical test namely singe lap shear strength test. also the effect of reduction degree in thickness, the sequence of hot rolling , surface roughness, degassing opening length and holding time on roll bonding process were studied. the results obtained due to variations in the above parameters are discussed with respect to their effects on the roll bonding of 6061 aluminum alloy plates as well as their effects on the specifications of the fuel plates

  13. Microstructure evolution during spray rolling and heat treatment of 2124 Al

    International Nuclear Information System (INIS)

    Spray rolling is a strip-casting technology that combines elements of spray forming and twin-roll casting. It consists of atomizing molten metal with a high velocity inert gas, quenching the resultant droplets in flight, and directing the spray between mill rolls. In-flight convection heat transfer from atomized droplets and conduction heat transfer at the rolls rapidly remove the metal's latent heat. Hot deformation of the semi-solid material in the rolls results in fully consolidated, rapidly-solidified strip. Spray rolling operates at a higher solidification rate than conventional twin-roll casting and is able to process a broader range of alloys at high production rates. A laboratory-scale strip caster was constructed and used to evaluate the interplay of processing parameters and strip quality for strips up to 200 mm wide and 1.6-6.4 mm thick. This paper examines microstructure evolution during spray rolling and explores how gas-to-metal mass flow ratio influences the microstructure and mechanical properties of spray-rolled 2124 Al. The influences of solution heat treatment and cold rolling on grain structure and constituent particle spheroidization are also examined

  14. Microstructure evolution during spray rolling and heat treatment of 2124 Al

    Energy Technology Data Exchange (ETDEWEB)

    McHugh, K.M. [Industrial Technology Department, Idaho National Laboratory, Idaho Falls, ID 83415-2050 (United States)], E-mail: kevin.mchugh@inl.gov; Lin, Y.; Zhou, Y.; Johnson, S.B.; Delplanque, J.-P.; Lavernia, E.J. [Department of Chemical Engineering and Materials Science, University of California, Davis, CA 95616 (United States)

    2008-03-25

    Spray rolling is a strip-casting technology that combines elements of spray forming and twin-roll casting. It consists of atomizing molten metal with a high velocity inert gas, quenching the resultant droplets in flight, and directing the spray between mill rolls. In-flight convection heat transfer from atomized droplets and conduction heat transfer at the rolls rapidly remove the metal's latent heat. Hot deformation of the semi-solid material in the rolls results in fully consolidated, rapidly-solidified strip. Spray rolling operates at a higher solidification rate than conventional twin-roll casting and is able to process a broader range of alloys at high production rates. A laboratory-scale strip caster was constructed and used to evaluate the interplay of processing parameters and strip quality for strips up to 200 mm wide and 1.6-6.4 mm thick. This paper examines microstructure evolution during spray rolling and explores how gas-to-metal mass flow ratio influences the microstructure and mechanical properties of spray-rolled 2124 Al. The influences of solution heat treatment and cold rolling on grain structure and constituent particle spheroidization are also examined.

  15. 49 CFR 393.134 - What are the rules for securing roll-on/roll-off or hook lift containers?

    Science.gov (United States)

    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...

  16. 78 FR 69316 - Airworthiness Directives; Rolls-Royce Deutschland Ltd & Co KG (Formerly Rolls-Royce Deutschland...

    Science.gov (United States)

    2013-11-19

    ...Airworthiness Directives; Rolls-Royce Deutschland Ltd & Co KG (Formerly Rolls-Royce Deutschland GmbH, Formerly BMW Rolls-Royce GmbH...2012-26-14 that applies to all Rolls-Royce Deutschland Ltd & Co KG (RRD)...

  17. An Influence Function Method Analysis of Cold Strip Rolling

    Science.gov (United States)

    Jiang, Z. Y.; Wei, D. W.; Tieu, A. K.

    An influence function method has been developed to simulate the asymmetric cold rolling of thin strip with work roll kiss at edges. The numerical simulation model was obtained based on the deformation compatibility of the roll system in rolling and lateral directions. The strip plastic deformation has been considered in the formulation, which is significantly different from the traditional theory of metal rolling. The rolling mechanics and crown of the strip with work roll edge kiss, which are new findings for cold rolling of thin strip, are obtained. A comparison of the rolling force, roll edge kiss force and the strip crown after rolling has been conducted for various cross shear regions in the roll bite. Results show that the calculated strip crown is in good agreement with Ameasured value, and the rolling force and strip crown decrease with an increase of cross shear regions, as well as the work roll edge kiss force and edge wear decrease. The friction also has an influence on the profile of the rolled thin strip.

  18. Roll and roll-to-roll process scaling through development of a compact flexo unit for printing of back electrodes

    DEFF Research Database (Denmark)

    Dam, Henrik Friis; Andersen, Thomas Rieks

    2015-01-01

    We report manufacture of fully printed and coated polymer solar cells on a small scale roll-to-roll coater representing the intermediate scale between laboratory and pilot scale. We highlight the enormous span in scale between the laboratory scale and the intended industrial scale by a factor of >100.000 and detail how this enormous scale must be covered by equipment that follow the scale. Especially the intermediate scale between equipment that can fit inside a fume cupboard and the typical pilot equipment with a footprint having the size of a large room presents a challenge that comprises some of the most critical steps in the scaling process. We describe the development of such a machine that comprise web guiding, tension control and surface treatment in a compact desk size that is easily moved around and also detail the development of a small cassette based flexographic unit for back electrode printing that is parsimonious in terms of ink usage and more gentle than laboratory scale flexo units where the foil transport is either driven by the flexo unit or the flexo unit is driven by the foil transport. We demonstrate fully operational flexible polymer solar cell manufacture using this new roll and roll-to-roll (R3) approach and compare with the existing methods.

  19. Roll-to-roll fabricated lab-on-a-chip devices

    DEFF Research Database (Denmark)

    Vig, Asger Laurberg; Mäkelä, Tapio

    2011-01-01

    We present a high-volume fabrication technique for making polymer lab-on-a-chip devices. Microfluidic separation devices, relying on pinched flow fraction, are roll-to-roll fabricated in a cellulose acetate (CA) film at a volume of 360 devices h?1 for a cost of approximately 0.5 euro/device. The manufacturing process consists of two steps: (i) roll-to-roll thermal nanoimprint for patterning the microchannels into a CA film and (ii) roll-to-roll lamination for bonding another CA film onto the imprinted film to seal the microchannels. Reverse gravure coating is used to apply an adhesive polymer onto the CA lid film before roll-to-roll lamination in order to increase the bonding strength. The fabricated devices are compared with planar imprinted devices with regard to the cross-sectional profile of the imprinted channels and their separation functionality. The separation functionality is characterized using fluorescent polystyrene microspheres with diameters ranging from 0.5 to 5 µm.

  20. Roll-to-roll fabricated lab-on-a-chip devices

    International Nuclear Information System (INIS)

    We present a high-volume fabrication technique for making polymer lab-on-a-chip devices. Microfluidic separation devices, relying on pinched flow fraction, are roll-to-roll fabricated in a cellulose acetate (CA) film at a volume of 360 devices h?1 for a cost of approximately 0.5 euro/device. The manufacturing process consists of two steps: (i) roll-to-roll thermal nanoimprint for patterning the microchannels into a CA film and (ii) roll-to-roll lamination for bonding another CA film onto the imprinted film to seal the microchannels. Reverse gravure coating is used to apply an adhesive polymer onto the CA lid film before roll-to-roll lamination in order to increase the bonding strength. The fabricated devices are compared with planar imprinted devices with regard to the cross-sectional profile of the imprinted channels and their separation functionality. The separation functionality is characterized using fluorescent polystyrene microspheres with diameters ranging from 0.5 to 5 µm.

  1. Hardening mechanism of Cr5 backup roll material induced by rolling contact fatigue

    International Nuclear Information System (INIS)

    The hardening mechanism of Cr5 backup roll material induced by rolling contact fatigue was studied. X-ray diffraction, Optical microscopy (OM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were employed to investigate the effect of microstructure alternations induced by fatigue on the hardness change. Remarkable change was observed at the half value breadth of X-ray diffraction under microstructure alternates which resulted from rolling contact fatigue. The OM photos showed obvious white etching areas (WEAs) in the layer influenced by fatigue, reflecting that some kind of content or structure with high etching resistance was generated in the layer influenced by fatigue. Microstructure changes such as nano-sized carbides precipitation and nanocrystalline formation induced by fatigue were observed in the site where the peak of half value breadth of X-ray located. These changes of microstructure should be considered in the mechanism for hardening of Cr5 backup roll material due to rolling contact fatigue

  2. 75 FR 47541 - Hot-Rolled Flat-Rolled Carbon-Quality Steel Products from Brazil and Japan: Final Results of...

    Science.gov (United States)

    2010-08-06

    ...Administration [A-351-828, A-588-846] Hot-Rolled Flat-Rolled Carbon-Quality...reviews of the antidumping duty orders on hot-rolled flat-rolled carbon-quality...reviews of the antidumping duty orders on hot- rolled flat-rolled...

  3. 77 FR 72820 - Hot-Rolled Flat-Rolled Carbon-Quality Steel Products From the Russian Federation; 2010-2011...

    Science.gov (United States)

    2012-12-06

    ...International Trade Administration [A-821-809] Hot-Rolled Flat-Rolled Carbon-Quality...Antidumping Duty Investigation on Certain Hot-Rolled Flat-Rolled Carbon-Quality...July 1, 2010 through June 30, 2011. See Hot-Rolled Flat-Rolled [[Page...

  4. Autonomous Supervision and Control of Parametric Roll Resonance

    DEFF Research Database (Denmark)

    Galeazzi, Roberto

    thesis has therefore two objectives. The first is to develop methods for detection of the inception of parametric roll resonance. The second is to develop control strategies to stabilize the motion after parametric roll has started. Stabilisation of parametric roll resonance points to two possible...... methods. The two control strategies are then combined to stabilise parametric roll resonance within few roll cycles. Limitations on the maximum stabilisable roll angle are analysed and linked to the ii slew rate saturation and hydrodynamic stall characteristics of the fin stabilisers. The study on maximum...... model in heave-pitch-roll of a container ship suitable for parametric roll resonance study is proposed. The model, which has been developed in collaboration with other researchers, provides a benchmark for the study and simulation of parametric roll over a large range of ship speeds and sea states. The...

  5. Microstructural heterogeneity of forged rolled rings

    Directory of Open Access Journals (Sweden)

    J. Herian

    2007-04-01

    Full Text Available Purpose: The paper presents the processes which condition the quality of steel cast strands and properties of rolled products. It touches upon the technology of small-size rings manufacture from the 42CrMo4 steel used for the production of rolling bearings and toothed rings.Design/methodology/approach: Investigations were made on the 42CrMo4 steel based process of small-size rings manufacture of weight not exceeding 100 kg and the internal diameter up to 600 mm.Findings: Microstructure heterogeneity has been proven on the cross section of rods and rings under hot rolling and thermal treatment. Non-uniformity in hardness distribution was found on the hot rolled rings’ face surface and cross section. Final products made from rings with heterogeneous properties characterize: difficulties with machining, cracking during surface hardening and decrease of life time. After the process modification, the rings’ microstructure homogeneity and advantageous hardness distribution were obtained.Practical implications: A good quality of final rings after heat treatment is obtained in the case of charge characterized by a uniform pearlitic/ferritic microstructure. After the process technology modification, the rings’ microstructure homogeneity and advantageous hardness distribution were obtained.Originality/value: The minimum processing degree in the rolling of rod products should guarantee obtaining a homogeneous microstructure on the rings cross section and properties which would ensure a good quality and the required functional properties of the final products.

  6. Roll and roll-to-roll process scaling through development of a compact flexo unit for printing of back electrodes

    DEFF Research Database (Denmark)

    Dam, Henrik Friis; Andersen, Thomas Rieks; Madsen, Morten Vesterager; Mortensen, Thomas K.; Pedersen, Mads F.; Nielsen, Uffe; Krebs, Frederik C

    2015-01-01

    We report manufacture of fully printed and coated polymer solar cells on a small scale roll-to-roll coater representing the intermediate scale between laboratory and pilot scale. We highlight the enormous span in scale between the laboratory scale and the intended industrial scale by a factor of >100.000 and detail how this enormous scale must be covered by equipment that follow the scale. Especially the intermediate scale between equipment that can fit inside a fume cupboard and the typical pil...

  7. Microstructure Evolution During Spray Rolling and Heat Treatment of 2124 Al

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-09-01

    Spray rolling is a strip casting technology that combines elements of spray forming and twin-roll casting. It consists of atomizing molten metal with a high velocity inert gas, quenching the resultant droplets in flight, and directing the spray between mill rolls. In-flight convection heat transfer from atomized droplets and conduction heat transfer at the rolls rapidly move an alloy’s latent heat. Hot deformation of the semi-solid material in the rolls results in fully consolidated, rapidly-solidified product. While similar in many ways to twin-roll casting, spray rolling is able to process a broader range of alloys and operates at a higher production rate. A laboratory-scale strip caster has been constructed at INL and used to evaluate the interplay of processing parameters and strip quality while producing strips up to 200 mm wide and 1.6 – 6.4 mm thick. Plans are underway to scale to 600 mm width and demonstrate steady-state operation. As-spray-rolled strip is characterized by a flat, uniformly thick profile with minimal porosity or segregation. This paper examines how processing parameters influence the microstructure transformations that take place during spray rolling and post-deposition heat treatment of 2124 Al.

  8. Development of a twin roll caster for light metals

    OpenAIRE

    Haga, T.

    2010-01-01

    Purpose: Purpose of this paper is to show the development of a twin roll caster for aluminium alloy. One of the developments was the increase of the roll speed. The increase of the roll speed was essential to improve the low productivity of the twin roll caster. Limitation of the alloys, which can be cast into the strip, could be enlarged by the method to increase the roll speed. The method to increase the roll speed was useful to increase the cooling rate of the cast strip. The devices to in...

  9. Detection of Parametric Roll on Ships

    DEFF Research Database (Denmark)

    Galeazzi, Roberto; Blanke, Mogens; Poulsen, Niels KjĆølstad

    phenomenon could make the navigator change shipā€™s speed and heading, and these remedial actions could make the vessel escape the bifurcation. This chapter proposes non-parametric methods to detect the onset of parametric roll resonance. Theoretical conditions for parametric resonance are re-visited and......Recent years have shown several incidents with dramatic damage on container vessels caused by parametric resonance. When the resonance starts, the roll oscillation at a sub-harmonic frequency of the wave excitation may be completely unexpected. Timely warning about the onset of the resonance...... signal-based methods are developed to detect its onset. Hypothesis testing is derived for the particular distribution of the indicators for resonance. Robustness is investigated by analyzing forced roll and disturbances in real weather conditions. The performance of the novel methods is demonstrated on...

  10. Rolling Element Bearing Stiffness Matrix Determination (Presentation)

    Energy Technology Data Exchange (ETDEWEB)

    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.

  11. Controlling roll perturbations in fruit flies.

    Science.gov (United States)

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

    2015-04-01

    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

  12. Enhanced roll-angle measurement interferometer

    Science.gov (United States)

    Ju, Aisong; Hou, Wenmei; Le, Yanfen

    2015-03-01

    A roll-angle measurement interferometer with good stability and high sensitivity is presented. In the system, two sets of spatial parallel beams with different frequencies are formed with the help of a Koster prism, a corner cube, a quarter-wave plate, a wedge prism, and a wedge mirror. The wedge prism is used for the roll-angle sensing component, the roll of which will cause the changes of the optical path of the two beams with different frequencies. This interferometer complies with the principle of common path which minimizes the dead path; the cross talk of straightness, pitch, and yaw errors are avoided in this specific structure which enhances the stability and precision of the measurement. The experimental result fits well with the theoretical analysis and a measurement resolution of 2 ?rad is achieved with an electronic interpolation of 2?/512.

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

    DEFF Research Database (Denmark)

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

    2010-01-01

    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......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...... 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...

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

    Science.gov (United States)

    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.

  15. Generalized slow roll for noncanonical kinetic terms

    International Nuclear Information System (INIS)

    We show that the generalized slow roll approach for calculating the power spectrum where the inflationary slow roll parameters are neither small nor slowly varying can be readily extended to models with noncanonical kinetic terms in the inflaton action. For example, rapid sound speed variations can arise in Dirac-Born-Infeld models with features in the warp factor leading to features in the power spectrum. Nonetheless there remains a single source function for deviations that is simply related to the power spectrum. Empirical constraints on this source function can be readily interpreted in the context of features in the inflaton potential or sound speed.

  16. Generalized slow roll for noncanonical kinetic terms

    Science.gov (United States)

    Hu, Wayne

    2011-07-01

    We show that the generalized slow roll approach for calculating the power spectrum where the inflationary slow roll parameters are neither small nor slowly varying can be readily extended to models with noncanonical kinetic terms in the inflaton action. For example, rapid sound speed variations can arise in Dirac-Born-Infeld models with features in the warp factor leading to features in the power spectrum. Nonetheless there remains a single source function for deviations that is simply related to the power spectrum. Empirical constraints on this source function can be readily interpreted in the context of features in the inflaton potential or sound speed.

  17. Rolling friction on a granular medium.

    Science.gov (United States)

    De Blasio, Fabio Vittorio; Saeter, May-Britt

    2009-02-01

    We present experimental results for the rolling of spheres on a granular bed. We use two sets of glass and steel spheres with varying diameters and a high-speed camera to follow the motion of the spheres. Despite the complex phenomena occurring during the rolling, the results show a friction coefficient nearly independent of the velocity (0.45-0.5 for glass and 0.6-0.65 for steel). It is found that for a given sphere density, the large spheres reach a longer distance, a result that may also help explain the rock sorting along natural stone accumulations at the foot of mountain slopes. PMID:19391789

  18. Stress evaluations under rolling/sliding contacts

    Science.gov (United States)

    Kannel, J. W.; Tevaarwerk, J. L.

    1981-01-01

    The state of stress beneath traction drive type of contacts were analyzed. Computing stresses and stress reversals on various planes for points beneath the surface were examined. The effect of tangential and axial friction under gross slip conditions is evaluated with the models. Evaluations were performed on an RC (rolling contact) tester configuration and it is indicated that the classical fatigue stresses are not altered by friction forces typical of lubricated contact. Higher values of friction can result in surface shear reversal that exceeds the stresses at the depth of maximum shear reversal under rolling contact.

  19. Slow Roll Inflation: A Somehow Different Perspective

    CERN Document Server

    Germani, Cristiano

    2011-01-01

    In this note we point out that, contrary to the standard point of view, slow roll inflation is due to high gravitational friction. We show that the requirement of slow roll coincides with the requirement of a flat scalar field potential in the case of minimally coupled scalar field. In this sense, the search for a successful inflationary theory may be more fruitful by shifting the focus on models with high gravitational friction. We review then a gravitational mechanism, the so called "Gravitationally Enhanced Friction" mechanism, such that high gravitational friction is dynamically generated during inflation allowing even steep (i.e. non-flat) scalar potential to inflate.

  20. Fluidic emergency roll control system. [for emergency aircraft control following failure of primary roll control system

    Science.gov (United States)

    Haefner, K. B.; Honda, T. S.

    1973-01-01

    A fluidic emergency roll control system for aircraft stabilization in the event of primary flight control failure was evaluated. The fluidic roll control units were designed to provide roll torque proportional to an electrical command as operated by two diametrically opposed thrust nozzles located in the wing tips. The control package consists of a solid propellant gas generator, two diametrically opposed vortex valve modulated thrust nozzles, and an electromagnetic torque motor. The procedures for the design, development, and performance testing of the system are described.

  1. Modeling, simulation and identification for control of tandem cold metal rolling

    Scientific Electronic Library Online (English)

    Péricles Guedes, Alves; José Adilson de, Castro; Luciano Pessanha, Moreira; Elder Moreira, Hemerly.

    2012-12-01

    Full Text Available This paper describes a modeling procedure for tandem cold metal rolling, including the linearization step and system identification for control. The tandem cold rolling process is described by a mathematical model based on algebraic equations developed for control purposes and empirical relations. A [...] state-space model is derived and detailed analyses in open loop are presented, concerning the sensitivity with regard to the variations in process parameters and results for the application of a new subspace identification method are compared with classical methodologies. Therefore, this work intents to be a contribution for developments in new control strategies for tandem cold rolling process that offer the potential to reduce the design efforts, the commissioning time and maintenance in rolling mills. The preliminary results obtained with this model have shown reasonable agreement with operational data presented at literature for industrial cold rolling process.

  2. Wear phenomena of spinning rolls for stone wool production

    Directory of Open Access Journals (Sweden)

    A. Klimpel

    2006-04-01

    Full Text Available Purpose: Purpose of this paper: Results of the study of wear phenomena of cascade spinning rolls during stone wool production process are described.Design/methodology/approach: The study were based on direct process observations, chemical analysis and temperature measurements of basalt lava, metallographic examinations of the spinning rolls deposits.Findings: It was showed that the deposits of spinning rolls are worn in very different way, depending on the roll position in rolls cascade. Predominant wear phenomena are high temperature erosion, molten basalt lava (molten salt corrosion, high temperature corrosion-oxidation, high temperature metal-ceramic abrasion wear, thermal fatigue of the working surface of spinning rolls.Research limitations/implications: The mechanisms of high temperature erosion demands further investigations and detailed studies.Practical implications: The wear resistance of basalt lava spinning rolls can be increased.Originality/value: The mechanisms of surface layer wear of basalt lava spinning rolls were determined.

  3. Youth, Rock 'n' Roll, and Electronic Media.

    Science.gov (United States)

    Snow, Robert P.

    1987-01-01

    Rock 'n' Roll as a form of electronic communication is central to youth culture. There are procedural rules similar to grammatical structures which allow meaningful interpretation of this musical experience. As new forms of communication appear both youth culture and the meaning of music are altered to encompass the changes. (VM)

  4. Roll diffusion bonding of titanium alloy panels

    Science.gov (United States)

    Bennett, J.; De Witt, T. E.; Jones, A. G.; Koeller, F.; Muser, C.

    1968-01-01

    Roll diffusion bonding technique is used for fabricating T-stiffened panel assemblies from titanium alloy. The single unit fabrication exhibits excellent strength characteristics under tensile and compressive loads. This program is applied to structures in which weight/strength ratio and integral construction are important considerations.

  5. Cosmological constraints on rapid roll inflation

    International Nuclear Information System (INIS)

    We obtain cosmological constraints on models of inflation which exhibit rapid roll solutions. Rapid roll attractors exist for potentials with large mass terms and are thus of interest for inflationary model building within string theory. We constrain a general ansatz for the power spectrum arising from rapid roll inflation that, in the small field limit, can be associated with tree level hybrid potentials with variable mass terms and nonminimal gravitational coupling ?R?2. We consider perturbations generated through modulated reheating and/or curvaton mechanisms in place of the observationally unacceptable primary spectra generated by inflaton fluctuations in these models. The lack of a hierarchy amongst higher-order k-dependencies of the power spectrum results in models with potentially large runnings, allowing us to impose tight constraints on such models using CMB and LSS data. In particular, we find ns < 1 and |?| < 0.01. We conclude with a concrete realization of rapid roll inflation within warped throat brane inflation that is in good agreement with current data

  6. Vananemise ilu ehk restaureerimisarhitekti roll / Ove Hidemark

    Index Scriptorium Estoniae

    Hidemark, Ove

    1997-01-01

    Restaureerimisarhitekti ülesannetest - ta ei pea otsustama üksnes tehniliste küsimuste üle, vaid arvestama ka sajandite vältel muutunud maitset, vana käsitöö erilist atmosfääri, toetama ehitisse koondatud ajaloolist elamust, nähes selles aja ja muutumise tervikut ning inimkäe mõju ja ajaloo sünteesi. Artikkel "Att behärska åldrandets skönhet eller om restaureringsarkitektens roll" rootsi ajakirjast "Kulturmiljövård", 1990, nr.4, lk.13-16

  7. Hot rolling of gamma titanium aluminide foil

    International Nuclear Information System (INIS)

    Metal flow and microstructure evolution during the thermomechanical processing of thin-gage foil of a near-gamma titanium aluminide alloy, Ti-45.5Al-2Cr-2Nb, with an equiaxed-gamma microstructure was investigated experimentally and theoretically. Foils of thickness of 200-250 ?m were fabricated via hot rolling of sheet in a can of proprietary design. The variation in gage of the rolled foils was ±15 ?m except in very sporadic (local) areas, with variations of approximately 60 ?m relative to the mean. Metallography revealed that the larger thickness variations were associated with large remnant colonies lying in a hard orientation for deformation. To rationalize these observations, a self-consistent model was used to estimate the strain partitioning between the softer (equiaxed-gamma) matrix and the remnant colonies. Furthermore, the efficacy of pre- or post-rolling heat treatment in eliminating remnant colonies was demonstrated and quantified using a static-spheroidization model. The elimination of remnant colonies via spheroidization prior to foil rolling gave rise to improved gage control.

  8. Hot rolling of gamma titanium aluminide foil

    Energy Technology Data Exchange (ETDEWEB)

    Semiatin, S.L., E-mail: lee.semiatin@wpafb.af.mil [Air Force Research Laboratory, Materials and Manufacturing Directorate, Wright-Patterson Air Force Base, OH 45433 (United States); Shanahan, B.W. [University of Dayton, 300 College Park, Dayton, OH 45409 (United States); Meisenkothen, F. [UES, Inc., 4401 Dayton-Xenia Road, Dayton, OH 45432 (United States)

    2010-08-15

    Metal flow and microstructure evolution during the thermomechanical processing of thin-gage foil of a near-gamma titanium aluminide alloy, Ti-45.5Al-2Cr-2Nb, with an equiaxed-gamma microstructure was investigated experimentally and theoretically. Foils of thickness of 200-250 {mu}m were fabricated via hot rolling of sheet in a can of proprietary design. The variation in gage of the rolled foils was {+-}15 {mu}m except in very sporadic (local) areas, with variations of approximately 60 {mu}m relative to the mean. Metallography revealed that the larger thickness variations were associated with large remnant colonies lying in a hard orientation for deformation. To rationalize these observations, a self-consistent model was used to estimate the strain partitioning between the softer (equiaxed-gamma) matrix and the remnant colonies. Furthermore, the efficacy of pre- or post-rolling heat treatment in eliminating remnant colonies was demonstrated and quantified using a static-spheroidization model. The elimination of remnant colonies via spheroidization prior to foil rolling gave rise to improved gage control.

  9. Cosmological rolling solutions of nonlocal theories

    CERN Document Server

    Calcagni, Gianluca

    2009-01-01

    We find cosmological solutions of a nonlocal scalar field equation with cubic or exponential potential. The former case corresponds to the lowest-level effective tachyon action of cubic string field theory. While the well-known Minkowski solution is wildly oscillating, due to Hubble friction its cosmological counterpart describes smooth rolling towards the local minimum of the potential.

  10. Rolling Friction on a Wheeled Laboratory Cart

    Science.gov (United States)

    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…

  11. Large Scale Evaluation fo Nickel Aluminide Rolls

    Energy Technology Data Exchange (ETDEWEB)

    None

    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.

  12. 33 CFR 159.107 - Rolling test.

    Science.gov (United States)

    2010-07-01

    ... MARINE SANITATION DEVICES Design, Construction, and Testing § 159.107 Rolling test. (a) The device, with... cycles with the axis of rotation 4 feet from the centerline of the device, no more than 6 inches below the plane of the bottom of the device, and parallel to any tank baffles. The device must then...

  13. The role of internal communication in the rolling forecast process

    OpenAIRE

    Sorvari, Jiri

    2010-01-01

    Objective of the Study The objective of the study was to examine the role of internal communication in the rolling forecast process. The study analysed the role of internal communication through four research questions: 1) What communication practices are connected with the rolling forecast process? 2) Which organisational attributes influence the internal communication climate in the rolling forecast process? 3) How is management and strategic communication incorporated in the rolling fo...

  14. Rolling induced size effects in elastic–viscoplastic sheet metals

    DEFF Research Database (Denmark)

    Nielsen, Kim Lau

    2015-01-01

    Rolling processes for which the characteristic length scale reaches into the range where size effects become important are receiving increased interest. In particularly, this is owed to the roll-molding process under development for high-throughput of micron-scale surface features. The study presented revolves around the rolling induced effect of visco-plasticity (ranging hot and cold rolling) in combination with strain gradient hardening – including both dissipative and energetic contributions....

  15. Design, Analysis and Optimization of Anti-Roll Bar

    OpenAIRE

    Pravin Bharane; Kshitijit Tanpure

    2014-01-01

    Vehicle anti-roll bar is part of an automobile suspension system which limits body roll angle. This U-shaped metal bar connects opposite wheels together through short lever arms and is clamped to the vehicle chassis with rubber bushes. Its function is to reduce body roll while cornering, also while travelling on uneven road which enhances safety and comfort during driving. Design changes of anti-roll bars are quite common at various steps of vehicle production and a design ana...

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  17. 21 CFR 136.160 - Raisin bread, rolls, and buns.

    Science.gov (United States)

    2010-04-01

    ...2010-04-01 2010-04-01 false Raisin bread, rolls, and buns. 136.160 Section...Standardized Bakery Products § 136.160 Raisin bread, rolls, and buns. (a) Each of the foods raisin bread, raisin rolls, and raisin buns...

  18. Development and Fabrication of Pineapple Rolled Tart Machine

    Directory of Open Access Journals (Sweden)

    Azman Hamzah

    2011-01-01

    Full Text Available A pineapple rolled tart machine is required in the manufacturing of pineapple rolled tart. In this research, a machine that would reduce processing time and operating cost and that would be affordable for small-scale industries was designed. The machine was tested at different screw rotating speeds and dough formulations. The rolled tart throughput rates were significantly increased (p-1.

  19. Development and Fabrication of Pineapple Rolled Tart Machine

    OpenAIRE

    Azman Hamzah; Rosnah Shamsudin; Pua Ming Yee; Johari Endan

    2011-01-01

    A pineapple rolled tart machine is required in the manufacturing of pineapple rolled tart. In this research, a machine that would reduce processing time and operating cost and that would be affordable for small-scale industries was designed. The machine was tested at different screw rotating speeds and dough formulations. The rolled tart throughput rates were significantly increased (p

  20. 14 CFR 23.493 - Braked roll conditions.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Braked roll conditions. 23.493 Section 23....493 Braked roll conditions. Under braked roll conditions, with the shock absorbers and tires in their... to the vertical reaction at the wheel multiplied by a coefficient of friction of 0.8 must be...

  1. Roll compaction and granulation system for nuclear fuel material

    International Nuclear Information System (INIS)

    A roll compaction and roll granulation system has been designed and fabricated to replace conventional preslugging and crushing operations typically used in the fabrication of mixed oxide nuclear fuel pellets. This equipment will be of maintenance advantage with only the compaction and granulation rolls inside containment. The prototype is being tested and the results will be reported within a year

  2. Wavelength Scanning Interferometery for large area roll to roll metrology applications in photovoltaic manufacturing environment

    OpenAIRE

    Elrawemi, Mohamed; Blunt, Liam; Fleming, Leigh; Muhamedsalih, Hussam

    2014-01-01

    The wavelength scanning interferometer is currently being applied as a core metrology technology as part of the EU project NanoMend - Nanoscale Defect Detection, Cleaning and Repair for Large Area Substrates ?500 mm width. NanoMend Project aims to develop technologies that are able to detect and correct micro and nano-scale defects in roll-to-roll produced films in order to improve product performance, yield and lifetime.

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

    Science.gov (United States)

    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 predictable production.

  4. Micro-Plasto-Hydrodynamic Lubrication a Fundamental Mechanism in Cold Rolling

    DEFF Research Database (Denmark)

    Laugier, Maxime; Boman, Romain

    2014-01-01

    This paper presents recent investigations in Micro-Plasto-Hydrodynamic (MPH) lubrication. Industrial evidences of the existence of MPH lubrication mechanism for cold rolling processes are presented. A new lubrication model developed for strip drawing processes is then applied to predict the MPH lubrication initiation and MPH lubrication extension along the tool-piece solid contacts initially in boundary lubrication regime. Finally, it is shown how this new MPH lubrication model can be implemented in a cold rolling model to maximize mills capabilities, determine optimum rolling oils properties and predict roughness transfer.

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

    Science.gov (United States)

    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

  6. Coupled rolling motion: considering rolling friction in non-holonomic mechanics

    International Nuclear Information System (INIS)

    This paper enlarges an undergraduate student project in non-holonomic mechanics (Janova et al 2009 Eur. J. Phys. 30 1257-69) by considering rolling friction. In the original problem of coupled rolling motion, the agreement of theory and experiment was demonstrated for the initial part of motion with rolling friction being neglected. As expected, the reality is that rolling friction plays a decisive role during the whole experiment. Extending the correspondence of the model to reality by considering rolling friction, in this paper it is demonstrated that the model satisfactorily explains not only the initial part but also the whole period of the motion observed. Together with the original problem, this paper is an interesting demonstration of the influence of rolling friction and its physical modelling for undergraduate physics education. It also demonstrates that a relatively simple theoretical background can be used for describing realistic situations in mechanics and for explaining experimental results. Moreover, this paper itself can be used by physics teachers as an interesting project in theoretical mechanics that may be solved both separately from and as a follow-up project to Janova et al (2009).

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

    Science.gov (United States)

    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. PMID:25607497

  8. Improved Billet Shape Modeling in Optimization of the Hot Rod and Wire Rolling Process

    OpenAIRE

    Betshammar, Jan

    2006-01-01

    The hot rod and wire rolling process is widely used to produce rolled iron alloys in different shapes and dimensions. This industry has been under a constant development during the last decades. Today, complex geometries are produced at a high speed since it is possible to use several stands in each mill at the same time. A reason for the development is rising demands from customers. The most important demands are to save energy, to get better material properties and higher dimension accuracy...

  9. Scalable, ambient atmosphere roll-to-roll manufacture of encapsulated large area, flexible organic tandem solar cell modules

    DEFF Research Database (Denmark)

    Andersen, Thomas Rieks; Dam, Henrik Friis; Hösel, Markus; Helgesen, Martin; Carlé, Jon Eggert; Larsen-Olsen, Thue Trofod; Gevorgyan, Suren; Andreasen, Jens Wenzel; Adams, Jens; Li, Ning; Machui, Florian; Spyropoulos, George D.; Ameri, Tayebeh; Lema?tre, Noella; Legros, Mathilde; Scheel, Arnulf; Gaiser, Detlef; Kreul, Kilian; Berny, Stephane; Lozman, Owen R.; Nordman, Sirpa; Välimäki, Marja; Vilkman, Marja; Sųndergaard, Roar R.; Jųrgensen, Mikkel; Brabec, Christoph J.; Krebs, Frederik C

    2014-01-01

    Inline printing and coating methods have been demonstrated to enable a high technical yield of fully roll-to-roll processed polymer tandem solar cell modules. We demonstrate generality by employing different material sets and also describe how the ink systems must be carefully co-developed in order to reach the ambitious objective of a fully printed and coated 14-layer flexible tandem solar cell stack. The roll-to-roll methodologies involved are flexographic printing, rotary screen printing, slo...

  10. 77 FR 32513 - Hot-Rolled Flat-Rolled Carbon-Quality Steel Products From the Russian Federation; Preliminary...

    Science.gov (United States)

    2012-06-01

    ... Carbon-Quality Steel Products From the Russian Federation, 64 FR 38626 (July 19, 1999). Likewise, the...-Rolled Flat-Rolled Carbon-Quality Steel Products from the Russian Federation, 77 FR 19619 (April 2, 2012... reference price of $408.32/metric ton for A36 hot-rolled steel applicable to the second quarter of 2012...

  11. Edge sealing for low cost stability enhancement of roll-to-roll processed flexible polymer solar cell modules

    DEFF Research Database (Denmark)

    Tanenbaum, David M.; Dam, Henrik Friis; Rösch, R.; Jųrgensen, Mikkel; Hoppe, Harald; Krebs, Frederik C

    2012-01-01

    Fully roll-to-roll processed polymer solar cell modules were prepared, characterized, and laminated. Cell modules were cut from the roll and matched pairs were selected, one module with exposed cut edges, the other laminated again with the same materials and adhesive sealing fully around the cut...

  12. Densification behavior of titanium in direct powder rolling process

    International Nuclear Information System (INIS)

    The densification behavior of titanium powder in the direct powder rolling process was investigated. An analytical model for the roll backlash phenomenon during this process was proposed to conduct a realistic finite element analysis. Furthermore, the roll backlash was quantitatively analyzed, and the relative densities of the green strip along the rolling direction were precisely estimated. Finally, the slip and nip phenomena were identified by calculating the contact pressure and shear stress between the titanium powder and the roller in order to understand the densification behavior of the powder during the rolling process

  13. Densification behavior of titanium in direct powder rolling process

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Dong Hwan; Kim, Tae Won [Hanyang Univ., Seoul (Korea, Republic of); Hong, Jae Keun; Park, Nho Kwang [Korea Institute of Materials Science, Changwon (Korea, Republic of)

    2012-10-15

    The densification behavior of titanium powder in the direct powder rolling process was investigated. An analytical model for the roll backlash phenomenon during this process was proposed to conduct a realistic finite element analysis. Furthermore, the roll backlash was quantitatively analyzed, and the relative densities of the green strip along the rolling direction were precisely estimated. Finally, the slip and nip phenomena were identified by calculating the contact pressure and shear stress between the titanium powder and the roller in order to understand the densification behavior of the powder during the rolling process.

  14. High speed twin roll casting of 6016 strip

    OpenAIRE

    T. Haga; Ikawa, M.; H. Watari; S. Kumai

    2006-01-01

    Purpose: of this paper is to clear the possibility of high speed roll casting of thin aluminum alloy strip. 6016aluminum alloy is used for sheet metal of the automobile. Therefore, casting of 6016 was tried in this study.Castability and characteristics of roll cast 6016 strip were investigated.Design/methodology/approach: was a high speed twin roll caster. The high speed twin roll caster was designedto overcome the low castability of the twin roll caster.Findings: are as below. The 6016 could...

  15. Numerical analysis of the skew rolling process for main shafts

    Directory of Open Access Journals (Sweden)

    Z. Pater

    2015-10-01

    Full Text Available The paper discusses a new technique of skew rolling with three tapered rolls and its application to the production of long main shafts of steel that are used in light trucks. First, the design of this forming technique is described. Then the paper stresses the universality of this process, as the skew rolling technique enables forming various products using one set of rolls. The reported numerical results (workpiece shape change during rolling, maps of effective strains and temperatures as well as loads and torques confirm that the discussed technique is suitable for producing long shafts.

  16. 76 FR 36081 - Hot-Rolled Flat-Rolled Carbon-Quality Steel Products From Brazil and Japan: Revocation of the...

    Science.gov (United States)

    2011-06-21

    ...A-351-828, A-588-846, C-351-829] Hot-Rolled Flat-Rolled Carbon-Quality Steel...antidumping duty (``AD'') orders on certain hot-rolled flat-rolled carbon-quality steel products (``hot-rolled steel'') from Brazil and...

  17. ROLLING PROCESS WITH OHSAS AND TEXTURE FORMATION– A REVIEW

    Directory of Open Access Journals (Sweden)

    P. CHANDRAMOHAN

    2009-03-01

    Full Text Available Rolling is a mechanical treatment, which plays an important part in the processing of ferrous and nonferrous alloys. Texturing is an important phenomenon that occurs after rolling process. Preferred orientation increases the strength of the material enormously. Hence the research is focused on the rolling studies and the texture formation, which occurs after rolling process. This review mainly focuses on rolling process carried out in different alloys. It also highlights the analysis made on various rolling parameters for improving the mechanical properties. Texture studies carried on various ferrous and non-ferrous alloys; particularly in nitrogen alloyed duplex stainless steel is discussed. Finally the need for implementation of occupational health and safety during a thermomechanical treatment is also discussed. The state of art in this field is encouraging and showing positive signs of commercializing rolled nitrogen alloyed duplex stainless steel after proper texture control.

  18. Effects of rolling on laminar frictional resistance in tubes

    International Nuclear Information System (INIS)

    The laminar velocity distribution in tubes in rolling motion is obtained by properly simplifying the laminar flow equations. The method of for analyzing the effect of periodic pressure on laminar flow is partly adopted. The influence of initial velocity on the velocity in rolling motion fades away quickly, while the periodic pressure due to rolling motion controls the velocity variation gradually. The effects of several parameters on the velocity profile in the cross-section are investigated. The rolling radius and amplitude only affect the velocity in a specified proportion, and the velocity profile shape remains unchanged. The tube radius, rolling period and fluid viscosity not only affect the velocity peak, but also the profile shape. The tube radius and fluid viscosity could limit the effect of rolling motion on the flow. The laminar friction coefficient in rolling motion is also obtained. The laminar friction resistance and factor for two special cases are investigated.

  19. Rolling friction for hard cylinder and sphere on viscoelastic solid.

    Science.gov (United States)

    Persson, B N J

    2010-12-01

    We calculate the friction force acting on a hard cylinder or spherical ball rolling on a flat surface of a viscoelastic solid. The rolling-friction coefficient depends non-linearly on the normal load and the rolling velocity. For a cylinder rolling on a viscoelastic solid characterized by a single relaxation time Hunter has obtained an exact result for the rolling friction, and our result is in very good agreement with his result for this limiting case. The theoretical results are also in good agreement with experiments of Greenwood and Tabor. We suggest that measurements of rolling friction over a wide range of rolling velocities and temperatures may constitute a useful way to determine the viscoelastic modulus of rubber-like materials. PMID:21107881

  20. Microstructure evolution and grain refinement in asymmetrically rolled aluminium

    International Nuclear Information System (INIS)

    Aluminium alloy sheets were asymmetrically rolled and annealed. Asymmetric rolling was applied by imposing different velocity ratios between the top and bottom rolls, from 1 to 1.5. After cold rolling, the microstructures of various samples were analysed by electron back scatter diffraction, whereas the mechanical properties were characterized by stress–strain curves and microhardness measurements. The asymmetrical rolling process was examined as an alternative method to obtain fine- or even ultrafine-grained aluminium. The main purpose of this paper is to describe, qualitatively and quantitatively, the influence of asymmetrical rolling on microstructure evolution. Grain size, misorientation, image quality factor and other parameters were characterized and analysed in some detail. In the present study, a unique approach has been used for the first time to examine the possibility of applying the asymmetric rolling process in the preparation of materials with controlled heterogeneity

  1. Rotordynamic Influence on Rolling ELement Bearing Selection and Operation

    Science.gov (United States)

    Queitzsch, Gilbert K., Jr.; Fleming, David P.

    2001-01-01

    Three case studies are presented that illustrate the importance of dynamic considerations in the design of machinery supported by rolling element bearings. The first case concerns a milling spindle that experienced internal rubs and high bearing loads, and required retrofit of an additional . damped bearing. The second case deals with a small high-speed generator that suffered high vibration due to flexible mounting. The third case is a propulsion fan simulator rig whose bearings failed catastrophically due to improper bearing installation (which resulted in inadequate dynamic bearing stiffness) and lack of health monitoring instrumentation.

  2. Investigations upon the indefinite rolls quality assurance in multiple regression analysis

    International Nuclear Information System (INIS)

    The rolling rolls quality has been enhanced mainly due to the improvements of the chemical compositions of rolls materials. The realization of an optimal chemical composition can constitute a technical efficient mode to assure the exploitation properties, the material from which the rolling mills rolls are manufactured having a higher importance in this sense. This paper continues to present the scientifically results of our experimental research in the area of the rolling rolls. The basic research contains concrete elements of immediate practical utilities in the metallurgical enterprises, for the quality improvements of rolls, having in last as the aim the durability growth and the safety in exploitation. This paper presents an analysis of the chemical composition, the influences upon the mechanical properties of the indefinite cast iron rolls. We present some mathematical correlations and graphical interpretations between the hardness (on the working surface and on necks) and the chemical composition. Using the double and triple correlations which is really helpful in the foundry practice, as it allows us to determine variation boundaries for the chemical composition, in view the obtaining the optimal values of the hardness. We suggest a mathematical interpretation of the influence of the chemical composition over the hardness of these indefinite rolling rolls. In this sense we use the multiple regression analysis which can be an important statistical tool for the investigation of relationships between variables. The enunciation of some mathematically modeling results can be described through a number of multi-component equations determined for the spaces with 3 and 4 dimensions. Also, the regression surfaces, curves of levels and volumes of variations can be represented and interpreted by technologists considering these as correlation diagrams between the analyzed variables. In this sense, these researches results can be used in the engineers collectives of the foundries and the rolling mills sectors, for quality assurances of rolls as far back as phase of production, as well as in exploitation of these, what lead to, inevitably, to the quality assurance of produced laminates. (Author) 16 refs.

  3. Numerical simulation of wear of basalt lava spinning rolls

    Directory of Open Access Journals (Sweden)

    A. Lisiecki

    2006-08-01

    Full Text Available Purpose: of this paper: Results of the study of wear phenomena of cascade spinning rolls during stone woolproduction process are described.Design/methodology/approach: The study was based on direct process observations, chemical analysis andtemperature measurements of basalt lava, metallographic examinations of the spinning rolls deposits. It was showedthat the deposits of spinning rolls are worn in very different way, depending on the roll position in rolls cascade.Findings: Predominant wear phenomena of the fully austenitic Grade 310 deposit of spinning roll no 1 is moltenbasalt lava corrosion-oxidation accompanied by low and high cycle thermal fatigue, high temperature basalt lavaerosion at low velocity of basalt lava stream impinging the working surface at high angle. Predominant wearphenomena of the austenitic-ferritic Grade S32304 deposit of spinning roll no 2 is high temperature basalt lava erosionat very high velocity of lava stream impinging the working surface at high angle what is the cause of much faster wearof then spinning roll no 1. High temperature erosion wear is accompanied by molten basalt lava corrosion-oxidationand low and high cycle thermal fatigue processes. Predominant wear phenomena of the austenitic-ferritic GradeS32304 deposits spinning roll no 3 and roll no 4 is high temperature basalt lava abrasion as sprayed by rolls no 1 andno 2 fibers of solidifying basalt lava impinge the working surface of spinning rolls no 3 and no 4.Research limitations/implications: The mechanisms of high temperature erosion demands further investigationsand detailed studies.Practical implications: The wear resistance of basalt lava spinning rolls can be increased.Originality/value: The mechanisms of surface layer wear of basalt lava spinning rolls were determined.

  4. Dynamics and Stability of Rolling Viscoelastic Tires

    Energy Technology Data Exchange (ETDEWEB)

    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.

  5. Contact conditions in skin-pass rolling

    DEFF Research Database (Denmark)

    Kijima, Hideo; Bay, Niels

    2007-01-01

    The special contact conditions in skin-pass rolling of steel strip is analysed by studying plane strain upsetting of thin sheet with low reduction applying long narrow tools and dry friction conditions. An extended sticking region is estimated by an elasto-plastic FEM analysis of the plane strain...... upsetting. This sticking region causes a highly inhomogeneous elasto-plastic deformation with large influence of work-hardening and friction. A numerical analysis of skin-pass rolling shows the same contact conditions, i.e. an extended sticking region around the center of the contact zone. The calculated...... size of the sticking region with varying contact length and pressure/reduction is experimentally verified by plane strain upsetting tests measuring the local surface deformation of the work pieces after unloading....

  6. Slipping and Rolling on an Inclined Plane

    CERN Document Server

    Aghamohammadi, Cina; 10.1088/0143-0807/32/4/017

    2011-01-01

    In the first part of the article using a direct calculation two-dimensional motion of a particle sliding on an inclined plane is investigated for general values of friction coefficient ($\\mu$). A parametric equation for the trajectory of the particle is also obtained. In the second part of the article the motion of a sphere on the inclined plane is studied. It is shown that the evolution equation for the contact point of a sliding sphere is similar to that of a point particle sliding on an inclined plane whose friction coefficient is $2/7}\\ \\mu$. If $\\mu> 2/7 \\tan\\theta$, for any arbitrary initial velocity and angular velocity the sphere will roll on the inclined plane after some finite time. In other cases, it will slip on the inclined plane. In the case of rolling center of the sphere moves on a parabola. Finally the velocity and angular velocity of the sphere are exactly computed.

  7. Slipping and rolling on an inclined plane

    International Nuclear Information System (INIS)

    In the first part of the paper, using a direct calculation two-dimensional motion of a particle sliding on an inclined plane is investigated for general values of friction coefficient (?). A parametric equation for the trajectory of the particle is also obtained. In the second part of the paper, the motion of a sphere on the inclined plane is studied. It is shown that the evolution equation for the contact point of a sliding sphere is similar to that of a point particle sliding on an inclined plane whose friction coefficient is 7/2 ?. If ? > 2/7 tan ?, for any arbitrary initial velocity and angular velocity, the sphere will roll on the inclined plane after some finite time. In other cases, it will slip on the inclined plane. In the case of rolling, the centre of the sphere moves on a parabola. Finally the velocity and angular velocity of the sphere are exactly computed.

  8. A Model of Active Roll Vehicle Suspension

    Directory of Open Access Journals (Sweden)

    I. ?ech

    2010-01-01

    Full Text Available This paper describes active suspension with active roll for four-wheel vehicle (bus by means of an in-series pump actuator with doubled hydropneumatic springs. It also gives full control law with no sky-craping. Lateral stiffness and solid axle geometry in the mechanical model are not neglected. Responses to lateral input as well as responses to statistical unevennesses show considerable improvement of passengers comfort and safety when cornering.

  9. Roll up nanowire battery from silicon chips

    OpenAIRE

    Vlad, Alexandru; Reddy, Arava Leela Mohana; Ajayan, Anakha; Singh, Neelam; Gohy, Jean-FranƧois; 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 stab...

  10. Boundary Friction on Molecular Lubricants: Rolling Mode?

    CERN Document Server

    Loktev, V M; Pogorelov, Yu.G.

    2003-01-01

    A theoretical model is proposed for low temperature friction between two smooth rigid solid surfaces separated by lubricant molecules, admitting their deformations and rotations. Appearance of different modes of energy dissipation (by ''rocking'' or ''rolling'' of lubricants) at slow relative displacement of the surfaces is shown to be accompanied by the stick-and-slip features and reveals a non-monotonic (mean) friction force {\\it vs} external load

  11. Boundary friction on molecular lubricants: rolling mode?

    International Nuclear Information System (INIS)

    A theoretical model is proposed for low-temperature friction between two smooth rigid solid surfaces separated by lubricant molecules, admitting their deformations and rotations. The appearance of different modes of energy dissipation (by 'rocking' or 'rolling' of lubricants) at slow relative displacement of the surfaces is shown to be accompanied by stick-and-slip features and reveals a nonmonotonic (mean) friction force vs external load

  12. Rolling circle amplification of metazoan mitochondrialgenomes

    Energy Technology Data Exchange (ETDEWEB)

    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.

  13. Electromagnetic String Fluid in Rolling Tachyon

    OpenAIRE

    Kim, Chanju; Kim, Hang Bae; Kim, Yoonbai; Kwon, O-Kab

    2003-01-01

    We study Born-Infeld type effective action for unstable D3-brane system including a tachyon and an Abelian gauge field, and find the rolling tachyon with constant electric and magnetic fields as the most general homogeneous solution. Tachyonic vacua are characterized by magnitudes of the electric and magnetic fields and the angle between them. Analysis of small fluctuations in this background shows that the obtained configuration may be interpreted as a fluid consisting of s...

  14. Rolling Bearing Life Prediction, Theory, and Application

    Science.gov (United States)

    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.

  15. Influence of Surge on Extreme Roll Amplitudes

    DEFF Research Database (Denmark)

    Vidic-Perunovic, Jelena; Rognebakke, Olav

    2008-01-01

    Interference of the wave-induced ship surge motion with roll dynamics has been studied. The surge motion has been included in a previously derived hydrodynamic roll prediction model in order to account for the ship speed variation due to the longitudinal incident wave pressure force. Depending on the position of the wave crest relatively to the ship, the ship will be slowed down when she meets the wave. In this paper attempts are made to accurately account for added resistance and additional thrust, applied in order to maintain the ship speed. The surge equilibrium equation has been longitudinally balanced in order to determine the added thrust term that would represent actions to maintain speed The resulting forward speed variation affects the frequency of encounter and the parametric roll resonant condition is directly influenced by this speed variation. The analysis procedure is demonstrated for an example containership sailing mainly in head sea condition and higher sea states. Sensitivity of the results to the added thrust model and vertical motion calculation is discussed.

  16. Vibration Analysis of Rolling Element Bearings Defects

    Scientific Electronic Library Online (English)

    H., Saruhan; S., Saridemir; A., Qicek; I., Uygur.

    Full Text Available In this work, vibration analysis of rolling element bearings (REBs) defects is studied. The REBs are the most widely used mechanical parts in rotating machinery under high load and high rotational speeds. When the defect in a rolling element comes into contact with another element surface, an impact [...] force is generated which is resulting in an impulsive response of the bearing. A defect at any element of the REB transmits to all other elements such as outer race, inner race, ball and, train cage of the bearing. The defect in rolling elements may lead to serious catastrophic consequences resulting in costly downtime. For this purpose, the vibration analysis technique which is a reliable and accurately detecting defect in the bearing elements is used. The vibration data captured and used for determination and validation is composed from four different defects states of the REB -outer raceway defect, inner raceway defect, ball defect, and combination of the bearing elements defect- and one representing normal state of the bearing for four different running speeds with two load levels. The results obtained from the experiments have illustrated and explained.

  17. Rapid roll inflation with conformal coupling

    International Nuclear Information System (INIS)

    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. S3 of Klebanov-Strassler (KS) geometry) have solutions identical to conformally coupled modes and also cannot be responsible for cosmological fluctuations. We discuss other possibilities

  18. Asymmetric Rolling of Interstitial-Free Steel Using One Idle Roll

    Science.gov (United States)

    Lapovok, R.; Orlov, D.; Timokhina, I. B.; Pougis, A.; Toth, L. S.; Hodgson, P. D.; Haldar, A.; Bhattacharjee, D.

    2012-04-01

    The effect of additional shear on the asymmetric rolling (ASR) of an interstitial-free (IF) steel was studied by modeling and experiments. The asymmetry was introduced by making one roll idle. A 66 pct of total thickness reduction was performed in 6 passes with less than 16 pct reduction per pass. ASR was performed in two ways: monotonically and by rotating the sheet between passes by 180 deg around the rolling direction (RD). Better grain fragmentation was obtained in the near surface layers. The results of monotonic asymmetric rolling are similar to symmetric rolling in terms of misorientation and cell size with the difference that the volume fraction of grains containing shear bands (SB) is larger for monotonic ASR. ASR with the sheet rotated 180 deg around the RD direction between passes showed the most promising results in terms of grain refinement, depth of the highly deformed layer, texture, and properties. The grain fragmentation process was also simulated with a recent grain refinement polycrystal model for strain hardening, texture development, grain size distribution, and grain misorientation distribution. The obtained simulation results showed strong agreement with the experiments.

  19. ANALYSIS OF HEAT TRANSFER OF WORK ROLL COOLING IN HOT ROLLING

    Directory of Open Access Journals (Sweden)

    Marcio Rodrigo Solimani

    2013-10-01

    Full Text Available The roll cooling in Hot Rolling of flats directly affects two fundamental characteristics of the rolls:.the durability due to surface degradation. The other is the thermal expansion, which affects the shape and dimensions of the strip. Cooling is done by water jets that need to be properly adjusted. The determination of heat transfer coefficients is essential to optimize the process and thus increase its durability and quality of the strip. Results of experimental and numerical effects of cooling using a water jet fan-shaped on a prototype roll at temperatures between 50°C and 350°C are performed. Water pressure, nozzle type and the position along the length of the fan-shaped (center and edge influence the efficiency of roll cooling. The maximum value found in the coefficient of heat transfer was 6.0 kW/m2°C, and a 14.3% difference between the center and end of the jet fan-shaped is observed.

  20. Texture Evolution of a Non-oriented Electrical Steel Cold Rolled at Directions Different from the Hot Rolling Direction

    Science.gov (United States)

    He, Youliang; Hilinski, Erik; Li, Jian

    2015-09-01

    With the objective of optimizing the crystallographic texture of non-oriented electrical steel, i.e., reducing the //ND and //RD fibers and promoting the //ND texture, a new rolling scheme was proposed and tested, in which the cold rolling direction (CRD) was intentionally inclined at an angle to the hot rolling direction (HRD) in order to change the orientation flow paths during cold rolling and alter the final texture of the annealed sheets. A non-oriented electrical steel containing 0.88 wt pct Si was hot rolled using conventional routes and annealed, and a number of rectangular plates were cut from the hot band with the longitudinal directions inclined at various angles, i.e., 0, 15, 30, 45, 60, 75, and 90 deg, to the HRD. These plates were then cold rolled along the longitudinal directions with a thickness reduction of 72 pct. The cold-rolled samples were annealed, temper rolled and annealed again (final annealing). The texture evolution during hot rolling, hot band annealing, cold rolling, and final annealing was characterized by electron backscatter diffraction and X-ray diffraction techniques. By changing the CRD with respect to the HRD, the initial texture and the orientation flow paths were altered, which resulted in apparent differences in the textures as compared to conventional cold rolling. After temper rolling and final annealing, the recrystallization textures consisted of mainly a //ND fiber and there was almost no //ND fiber. The sample cold rolled at an angle of 60 deg to the HRD had the strongest texture (intensity almost 2× of conventional rolling) with a maximum at the cube {001} orientation—a magnetically favorable orientation for non-oriented electrical steels.

  1. Texture Evolution of a Non-oriented Electrical Steel Cold Rolled at Directions Different from the Hot Rolling Direction

    Science.gov (United States)

    He, Youliang; Hilinski, Erik; Li, Jian

    2015-11-01

    With the objective of optimizing the crystallographic texture of non-oriented electrical steel, i.e., reducing the //ND and //RD fibers and promoting the //ND texture, a new rolling scheme was proposed and tested, in which the cold rolling direction (CRD) was intentionally inclined at an angle to the hot rolling direction (HRD) in order to change the orientation flow paths during cold rolling and alter the final texture of the annealed sheets. A non-oriented electrical steel containing 0.88 wt pct Si was hot rolled using conventional routes and annealed, and a number of rectangular plates were cut from the hot band with the longitudinal directions inclined at various angles, i.e., 0, 15, 30, 45, 60, 75, and 90 deg, to the HRD. These plates were then cold rolled along the longitudinal directions with a thickness reduction of 72 pct. The cold-rolled samples were annealed, temper rolled and annealed again (final annealing). The texture evolution during hot rolling, hot band annealing, cold rolling, and final annealing was characterized by electron backscatter diffraction and X-ray diffraction techniques. By changing the CRD with respect to the HRD, the initial texture and the orientation flow paths were altered, which resulted in apparent differences in the textures as compared to conventional cold rolling. After temper rolling and final annealing, the recrystallization textures consisted of mainly a //ND fiber and there was almost no //ND fiber. The sample cold rolled at an angle of 60 deg to the HRD had the strongest texture (intensity almost 2× of conventional rolling) with a maximum at the cube {001} orientation—a magnetically favorable orientation for non-oriented electrical steels.

  2. Boundary layer roll circulations during FIRE

    Science.gov (United States)

    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 clear air case are that the pure inflection point mode is not possible and the pure thermal mode was oriented 35 degrees to the right of the mean wind direction. The origin of this unacceptably large discrepancy between the observed and modeled results will be investigated further and the conclusions reported at the next FIRE workshop.

  3. Troll, a Language for specifying Dice-rolls

    DEFF Research Database (Denmark)

    Mogensen, Torben Ęgidius

    2009-01-01

    Dice are used in many games, and often in fairly complex ways that make it difficult to unambiguously describe the dice-roll mechanism in plain language. Many role-playing games, such as Dungeons & Dragons, use a formalised notation for some instances of dice-rolls. This notation, once explained, make dice-roll descriptions concise and unambiguous. Furthermore, the notation has been used in automated tools for pseudo-random dice-rolling (typically used when playing over the Internet). This notation is, however, fairly limited in the types of dice-rolls it can describe, so most games still use natural language to describe rolls. Even Dungeons & Dragons use formal notation only for some of the dice-roll methods used in the game. Hence, a more complete notation is in this paper proposed, and a tool for pseudo-random rolls and (nearly) exact probability calculations is described. The notation is called "Troll", combining the initial of the Danish word for dice ("terninger") with the English word "roll". It is a development of the language Roll described in an earlier paper. The present paper describes the most important features of Troll and its implementation.

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

    International Nuclear Information System (INIS)

    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. (paper)

  5. Rolls-Royce digital Rod Control System

    International Nuclear Information System (INIS)

    Full text of publication follows: Rolls-Royce has developed a new generation of Rod Control System, based on 40 years of experience. The fifth-generation Rod Control System (RCS) from Rolls-Royce offers a reliable, modular design with adaptability to your preferred platform, for modernization projects or new reactors. Flexible implementation provides the option for you to keep existing cabinets, which permits you to optimize installation approach. Main features for the power part: - Control Rod Drive Mechanism (CRDM) type: 3-coil. - Independent control of each sub-bank. - Each sub-bank is controlled by a cycler unit and 3 identical power racks, each including 4 identical power modules and a common power-supply module. - Coil-per-coil digital control: each power module embeds power-conversion, current-control, and current-monitoring functions for one coil. Control and monitoring are carried out by separate electronics in the module. Current is digitized and fully monitored by means of min-max templates. - A double-hold function is included: a power module assigned to a gripper will activate its coil if a fault risking to cause a reactor trip occurs. - Power modules are standardized, hot-pluggable and self-configured: a power module includes a set of parameters for each type of coil SG, MG, LC. The module recognizes the rack it is plugged in, and chooses automatically parameters to be used. Main benefits: - Reduced operational, maintenance, training, and inventory costs: standardization of power modules and integration of control and monitoring on the same PC-card lead to a drastic reduction of spare part types, and simplification of the system. - Easy maintenance: - Replacement of a power module solves nearly all failures due to current control or monitoring for a coil. It is done instantly thanks to hot-plug capability. - On the front plate of power-modules, LEDs provide useful information for diagnostic: current setpoint from cycler, output current bar-graph representing min-max monitoring thresholds, and grouped faults. Plugs allow output current checking per coil. - From the cycler, the output current can be forced on a rack for test, while ensuring that rods are held by another available gripper rack. - Low power dissipation: no need for multiplexing or LC-inhibition thyristors - Commissioning: 3-thyristor well-tried half bridges (no energy storage), fuses for protection of feed-through penetrations. The paper will present in details the technical features of the Rolls-Royce Rod Control System and the main benefits to use it. About Rolls-Royce Rolls-Royce is a global business providing integrated power systems for use on land, at sea and in the air. The Group has a balanced business portfolio with leading market positions. Rolls-Royce has a broad range of civil nuclear expertise, including work related to licensing and safety reviews, engineering design, supply chain management, manufacturing, installation and commissioning of the nuclear island systems and equipments, as well as operational management and through life support. Rolls-Royce benefits of a strong reputation worldwide and of a unique experience in the nuclear market. (author)

  6. A roll-to-roll welding process for planarized silver nanowire electrodes.

    Science.gov (United States)

    Lee, Seong Jun; Kim, Young-Hoon; Kim, Jung Kyu; Baik, Hionsuck; Park, Jae Hoon; Lee, Jaeki; Nam, Jaewook; Park, Jong Hyeok; Lee, Tae-Woo; Yi, Gi-Ra; Cho, Jeong Ho

    2014-10-21

    We demonstrate continuous roll-to-roll production of highly conductive silver network films on a plastic substrate via mechanical and chemical welding processes. This process included three essential steps: (i) solvent spraying, (ii) roll compression, and (iii) salt treatment and washing. The sheet resistance of the resulting AgNW film was 5 ? sq(-1) at 92% transmittance, which was the lowest sheet resistance and the highest transparency among the values reported previously for solution-processed AgNW electrodes. Moreover, the strong contacts among the AgNWs dramatically enhanced the mechanical stability of the network film. The resulting AgNW film was successfully applied to various organic electronic devices, such as organic field-effect transistors (OFETs), organic light-emitting diodes (OLEDs), and organic solar cells (OSCs). PMID:25169643

  7. Texture analysis of cold rolled and annealed aluminum alloy produced by twin-roll casting

    Directory of Open Access Journals (Sweden)

    Juliana de Paula Martins

    2012-02-01

    Full Text Available A 7.4 mm thick strip of 3003 aluminum alloy produced by the industrial twin-roll casting (TRC process was homogenized at 500 °C for 12 hours, after which it was cold rolled in two conditions: 1 to reduce the strip's thickness by 67%, and 2 to reduce it by 91%. The alloy was annealed at 400 °C for 1 hour in both conditions. The results revealed that a rotated cube texture, the {001} component, predominated in the as-cast condition and was transformed into brass, copper and S type textures during the cold rolling process. There was practically no difference between the deformation textures at the two thickness reductions.

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

    DEFF Research Database (Denmark)

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

    2010-01-01

    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...... 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...... 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...

  9. Low Band Gap Polymers for Roll-to-Roll Coated Organic Photovoltaics – Design, Synthesis and Characterization

    DEFF Research Database (Denmark)

    Bundgaard, Eva; Hagemann, Ole

    2011-01-01

    In this paper we present the design and synthesis of 25 new low band gap polymers. The polymers were characterized by UV-vis spectroscopy which showed optical band gaps of 2.0–0.9 eV. The polymers which were soluble enough were applied in organic photovoltaics, both small area devices with a spin coated active layer and in large area modules where all layers including the active layer were either roll-to-roll coated or printed. These experiments showed that the design of polymers compatible with roll-toroll coating is not straightforward and that there are various issues such as donor/acceptor fitting within the polymer, side chains to ensure solubility and HOMO/LUMO level alignment with the acceptor (e.g. [60]PCBM) to take into consideration.

  10. Towards Realizing High-Throughput, Roll-to-Roll Manufacturing of Flexible Electronic Systems

    Directory of Open Access Journals (Sweden)

    Xiaohui Lin

    2014-11-01

    Full Text Available High-rate roll-to-roll (R2R tracker systems are utilized for large volume flexible electronic device manufacturing, and the current alignment mechanism between layers is mainly achieved by relying on passive techniques. In this paper, we present a machine vision based alignment strategy that is used to achieve precise registration for stacking multilayers. Based on this strategy, we demonstrate two-layer printing with alignment accuracy better than 100 ?m in web moving direction and 200 ?m in lateral direction at a web rate of 5 m/min.

  11. Roll-to-Roll fabrication of large area functional organic materials

    DEFF Research Database (Denmark)

    SĆøndergaard, Roar R.; Hƶsel, Markus; Krebs, Frederik C

    2013-01-01

    With the prospect of extremely fast manufacture of very low cost devices, organic electronics prepared by thin film processing techniques that are compatible with roll-to-roll (R2R) methods are presently receiving an increasing interest. Several technologies using organic thin films are at the...... research fields such as organic photovoltaics, organic thin film transistors, light-emitting diodes, polymer electrolyte membrane fuel cells, and electrochromic devices. Ā© 2012 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 000: 000ā€“000, 2012...

  12. Using Light-Induced Thermocleavage in a Roll-to-Roll Process for Polymer Solar Cells

    DEFF Research Database (Denmark)

    Krebs, Frederik C; Norrman, Kion

    2010-01-01

    We report on the use of intense visible light with a narrow spectral distribution matched to the region where the conjugated polymer material absorbs to selectively heat the active material and induce thermocleavage. We show a full roll-to-roll process, leading to complete large-area polymer solar cell modules using light-induced thermocleavage. The process employs full solution processing in air for all five layers in the device and does not employ indium?tin oxide or vacuum processing. The pro...

  13. Ellipsometry as a Nondestructive Depth Profiling Tool for Roll-to-Roll Manufactured Flexible Solar Cells

    DEFF Research Database (Denmark)

    Vesterager Madsen, Morten; Sylvester-Hvid, Kristian O.; Dastmalchi, Babak; Hingerl, Kurt; Norrman, Kion; Tromholt, Thomas; Manceau, Matthieu; Angmo, Dechan; Krebs, Frederik C

    2011-01-01

    We show that it is possible to perform ellipsometry on large area roll-to-roll (R2R) coated solar cells on flexible substrates and further demonstrate that the slot-die coating technique employed yields the same bulk heterojunction (BHJ) film morphology and vertical phase separation as laboratory...... transmission (optical simulation and UV–visible spectroscopy comparisons) was confirmed to comply with the model. A means of quality testing and optimization of the coating procedure line scans across a R2R slot-die-coated sample over large distances (8 cm) was made giving insight into thickness and...

  14. Roll Rotation Cues Influence Roll Tilt Perception Assayed Using a Somatosensory Technique

    OpenAIRE

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

    2006-01-01

    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 20Ā°. During this paradigm, subjects experienced a sinusoidal variation of interaural gravitational force with a peak of 0.34 g. The second mot...

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

    Science.gov (United States)

    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

  16. Large-scale roll-to-roll photonic sintering of flexo printed silver nanoparticle electrodes

    OpenAIRE

    Hösel, Markus; Krebs, Frederik C.

    2012-01-01

    In this report we employ static and roll-to-roll (R2R) photonic sintering processes on flexo printed silver nanoparticle-based electrode structures with a heat-sensitive 60 mm thin barrier foil as a substrate.We use large area electrode structures to visualize the increased optical footprint of single and quadruple flashes, and the R2R challenges in the form of overlapping exposures. It is shown that single flash exposure is enough to significantly increase the conductivity and adhesion witho...

  17. Large-scale roll-to-roll photonic sintering of flexo printed silver nanoparticle electrodes

    DEFF Research Database (Denmark)

    Hösel, Markus; Krebs, Frederik C

    2012-01-01

    In this report we employ static and roll-to-roll (R2R) photonic sintering processes on flexo printed silver nanoparticle-based electrode structures with a heat-sensitive 60 mm thin barrier foil as a substrate. We use large area electrode structures to visualize the increased optical footprint of...... energies above the threshold level have only minor impact on the conductivity but lead to cracks and substrate deformation. A second silver nanoparticle ink was printed, which was already optimized for lowtemperature drying. Here we show that photonic sintering has only a minor impact on the conductivity...

  18. Ellipsometry as a Nondestructive Depth Profiling Tool for Roll-to-Roll Manufactured Flexible Solar Cells

    DEFF Research Database (Denmark)

    Vesterager Madsen, Morten; Sylvester-Hvid, Kristian O.; Dastmalchi, Babak; Hingerl, Kurt; Norrman, Kion; Tromholt, Thomas; Manceau, Matthieu; Angmo, Dechan; Krebs, Frederik C

    2011-01-01

    We show that it is possible to perform ellipsometry on large area roll-to-roll (R2R) coated solar cells on flexible substrates and further demonstrate that the slot-die coating technique employed yields the same bulk heterojunction (BHJ) film morphology and vertical phase separation as laboratory samples prepared by the spin coating technique. The solar cell device geometry was Kapton/Al/Cr/P3HT:PCBM/PEDOT:PSS/Ag. Variable angle ellipsometry was used to determine the optical dispersions of the p...

  19. Low Band Gap Polymers for Roll-to-Roll Coated Polymer Solar Cells

    DEFF Research Database (Denmark)

    2010-01-01

    We present the synthesis of a low band gap copolymer based on dithienothiophene and dialkoxybenzothiadiazole (poly(dithienothiophene-co-dialkoxybenzothiadiazole), PDTTDABT). The optical properties of the polymer showed a band gap of 1.6 eV and a sky-blue color in solid films. The polymer was explored in roll-to-roll coating experiments and was optimized with respect to the manufacturing process and mixing ratio with [60]PCBM through a series of experiments with variation of the composition in st...

  20. Roll-to-Roll fabrication of large area functional organic materials

    DEFF Research Database (Denmark)

    Sųndergaard, Roar R.; Hösel, Markus; Krebs, Frederik C

    2013-01-01

    With the prospect of extremely fast manufacture of very low cost devices, organic electronics prepared by thin film processing techniques that are compatible with roll-to-roll (R2R) methods are presently receiving an increasing interest. Several technologies using organic thin films are at the point, where transfer from the laboratory to a more production-oriented environment is within reach. In this review, we aim at giving an overview of some of the R2R-compatible techniques that can be used i...

  1. Development of a twin roll caster for light metals

    Directory of Open Access Journals (Sweden)

    T. Haga

    2010-11-01

    Full Text Available Purpose: Purpose of this paper is to show the development of a twin roll caster for aluminium alloy. One of the developments was the increase of the roll speed. The increase of the roll speed was essential to improve the low productivity of the twin roll caster. Limitation of the alloys, which can be cast into the strip, could be enlarged by the method to increase the roll speed. The method to increase the roll speed was useful to increase the cooling rate of the cast strip. The devices to increase the roll speed were shown in this paper. Other development was invention of the twin roll caster to cast clad strip. The twin roll casters to cast two layers clad strip, three layers clad strip and five layers clad strip were invented.Design/methodology/approach: Increase of roll speed was attained by the use of a copper roll and a nozzle, operation of the low temperature casting and non-use of parting material. A scraper was adopted to the twin roll caster for clad strip to prevent the mixture of the molten metals and to control the surface condition. The devices to increase the roll speed were useful for the roll caster to cast clad strip.Findings: The aluminium alloy strip could be cast at the speeds up to 90 m/min. The aluminium alloy which has wide freezing zone like Al-25%Si could be cast into the strip. Two layers, three layers and five layers of clad strips could be cast.Research limitations/implications: The roll casters were laboratory size. Therefore, it was not clear of the ability of the casting of the long size and wide size strips.Practical implications: The productivity of aluminium alloy strip is increased. The property of the aluminium alloy strip is improved. The aluminium alloy, which was too brittle to be formed into the plate, will be cast into strip directly from melt. The process and energy to make the brazing sheet will be saved by the roll caster of the present study.Originality/value: The invented roll casters, devices for casting and properties of the cast strips are original.

  2. High resolution UV roll-to-roll nanoimprinting of resin moulds and subsequent replication via thermal nanoimprint lithography

    International Nuclear Information System (INIS)

    UV roll-to-roll nanoimprinting at high resolution is still a relatively unexplored field of study with far-reaching application potential. One enabling technology that is particularly worthy of attention is mass production of high resolution resin moulds via UV roll-to-roll nanoimprinting at such high throughput and low cost that they can be used only once and disposed of or recycled economically. Low cost, high resolution resin moulds can greatly improve the production cost profile for a number of applications in biomedicine, nanofluidics, data storage and electronics with relatively low unit values but which require one or more nanoscale lithography steps. In this report, UV roll-to-roll nanoimprinting was employed to fabricate high fidelity resin moulds with nanoscale as well as mixed micro- and nanoscale features down to 50 nm feature diameter, at up to 120 cm2 area and at 10 m min?1 throughput. UV roll-to-roll nanoimprinted resin moulds were subsequently segmented out, employed in a batch mode thermal nanoimprinting process, and characterized to study performance and demonstrate viability. The results show that high resolution mixed nanostructures can be faithfully replicated in PMMA on silicon substrates with minimal volumetric shrinkage. Process details and challenges specific to roll-to-roll fabrication of resin moulds are discussed at length, particularly with respect to the curvature uniformity of the imprint roller. (paper)

  3. Numerical and experimental analysis of lubrication in strip cold rolling

    Scientific Electronic Library Online (English)

    Sérgio Tonini, Button.

    2011-06-01

    Full Text Available In this work an analytical model based on the slab method was built to analyze the lubrication during cold rolling of aluminum strips. Some process variables were studied like the rolling speed, the cross-section reduction, and lubricant viscosity. Numerical results are presented for pressure variat [...] ion and film thickness at the inlet and work zones. The loads necessary to separate the rolls are also estimated. Some experimental results are shown for the surface roughness of the rolled products. It is shown that analytical results are in good accordance to experimental results, and that rolling pressure, lubricant film thickness and surface roughness are strongly influenced by rolling conditions, especially the lubricant viscosity and the area reduction.

  4. Rolling test of turbine generator by non-nuclear steam

    International Nuclear Information System (INIS)

    The object and procedure of rolling turbine generator test by non-nuclear steam in Qinshan NPP are presented. The steam source of rolling test is compared and chosen. The steam quantity during the rolling test is simply calculated. The limits of parameters of the test and the preparing for rolling of turbine generator are introduced. Procedures of rolling test are divided into three stage of speed: 600 r/min, 1200 r/min, 3000 r/min. Parameters measured as a result of rolling test, such as absolute vibration of axle, metal temperature of bearings, temperature of oil from the exit of bearings and vacuity of condenser etc, show that the design, manufacture, installation and speed control of turbine generator are satisfactory

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

    Science.gov (United States)

    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.

  6. A review on hot direct rolling of hsla steel

    International Nuclear Information System (INIS)

    The evolution of economically viable high strength low alloy structural steels (HSLA) with a good weld ability is probably the most significant metallurgical achievement of the steel industry in the last few decades. In these developments during thermo mechanical processing grain refinement is achieved by refining the as rolled austenite phase prior to transformation and introducing a high density of ferrite nucleation sites during rolling. A current trend in thermo mechanical processing of steel is to integrate the rolling process with continuous casting process. The development of a direct linkage between the continuous casting machine and hot working processes is suggested by economic considerations. However, hot charge rolling (HCR) and hot direct rolling (HDR) of micro alloyed steels affect mechanical properties significantly compared with conventional controlled rolling(CCR). (author)

  7. Semisolid strip casting using a vertical type twin roll caster

    Energy Technology Data Exchange (ETDEWEB)

    Haga, T. [Osaka Inst. of Tech., Osaka (Japan); Takahashi, K. [Graduate School of Osaka, Inst. of Tech., Osaka (Japan); Watari, H. [Oyama National Coll. of Technology (Japan)

    2003-07-01

    Semisolid strip casting of A356 alloy was tried using a vertical type twin roll caster equipped with a nozzle and a cooling slope. Molten metal was poured on the cooling slope and the molten metal became semisolid slurry. Solidification rate of the semisolid slurry was lower than 5%. Low solidification rate roll casting was carried out. Roll speed was from 60 m/min to 180 m/min. Strip thickness, which was thinner than 3 mm, could be cast. Microstructure was not columnar but equiaxed structure. Eutectic Si became very fine and globular. Ductility of the strip after homogenization was enough for cold rolling. The strip could be cold rolled until 0.5 mm. Mechanical properties were investigated after homogenization, cold rolling and T6 heat treatment. The elongation was improved and better than 15%. The strip, that thickness was 0.5 mm and was annealed, was not broken after 180 degrees bending. (orig.)

  8. THEORETICAL INVESTIGATIONS OF STRAW PARTICLES MOTION WHEN LEVELING HAY ROLLS

    Directory of Open Access Journals (Sweden)

    Teterin V. S.

    2015-10-01

    Full Text Available One can see some density irregularity within the roll in the baler with a chamber of constant volume. We have found out that the maximum density of hay roll width (the baler width is observed in the middle part. This is due to the shape of the hay roll entering the baler. To even the hay rolls they have mounted some rotating disks having some inclined spring pins above the baler. To improve the roller distribution the disks above the baler have been pushed forward forming a tapering gap. The evening discs rotating above the moving roll will cause some relative motion of hay particles. The interaction of the evening disks with the hay roll in the vertical plane will be determined by the elasticity of the hay roll and the weight of the frame with the disks. We have studied the trajectories of hay particles motion with the help of MathCad program. We have had the following initial parameters: the degree of compaction (decrease of the roll height when evening, the friction coefficient, the angle rate of the evening disks, the number of pins and the speed of the hay roll. As a result we have got the trajectories of the hay particles motion when the evening disks functioning. The analysis of the trajectories has allowed to establish some basic parameters of the evening device such as the distance of 0.15…0.2 m between the pins; the degree of compression while evening 20...25 %, the angle rate of the evening discs 23...30 rad / s and the diameter of the evening disc 0.74 m. The application of the evening device in the form of the disks with pins provides a uniform distribution of hay particles edgewise of the baler ensuring preliminary hay roll seal press before passing to the baler pressure chamber that contributes to getting the rolls with larger mass and a uniform distribution of hay density inside the roll

  9. Rolling up Ge microtube from bare-Ge substrate

    International Nuclear Information System (INIS)

    Highlights: • We propose a new way to fabricate rolled up solid state Ge microtubes by ion implantation. • The strain for rolling up microtube comes from proton implantation damage. • This method can be applied any position of Ge substrate. - Abstract: We show Ge microtubes can be rolled-up from bare-Ge wafer at almost any position, once these films are released from its substrate

  10. High speed twin roll casting of 6061 alloy strips

    OpenAIRE

    Haga, T.; Sakaguchi, H.; Watari, H; S.Kumai

    2008-01-01

    Purpose: of this paper is to clear the possibility of high speed roll casting of thin strips of two aluminum alloys:6061 and recycled 6061. Mechanical properties of the roll cast 6061 and recycled 6061 strips were investigated inthe frame of this purpose.Design/methodology/approach: Methods used in the present study were high speed twin roll caster and lowtemperature casting. These methods were used to realize rapid solidification and increase the casting speed.Findings: are that 6061 and rec...

  11. Models of frictional resistance for circular tubes in rolling motion

    International Nuclear Information System (INIS)

    The forces affected on the laminar and turbulent flows in rolling motion were analyzed. The flowing models of laminar and turbulent flows were established on the basis of Navier-Stokes equation. The correlations of velocity and frictional resistance coefficient of laminar and turbulent flows in rolling motion were derived. The influence mechanism of rolling motion on the flowing characteristics of these flows was also investigated. The theoretical models were validated with experimental results. The theoretical results are consistent with experimental results. (authors)

  12. High speed twin roll caste for aluminum alloy thin strip

    OpenAIRE

    Haga, T; H. Inui; Sakaguchi, H.(Hiroshima University, Hiroshima, Japan); Watari, H; S. Kumaic

    2007-01-01

    Purpose: In the present study, effectiveness of a high-speed twin roll caster for recycling aluminum alloy was investigated.Design/methodology/approach: The effects of the high-speed twin roll caster on alleviating the deterioration of mechanical properties by impurities were investigated. Properties of the cast strip were investigated by metalography, a tension test, and a bending test.Findings: A vertical type twin roll caster for strip casting of aluminum alloys was devised. The strip, whi...

  13. Advanced hot rolling strategies for IF and TRIP steels:

    OpenAIRE

    Elsner, A

    2005-01-01

    Steel producers are forced to reduce the production cost on the one hand and increase the performances of the products on the other hand, to maintain or even increase their market share. A likely method to save on production costs is to cut down the rather long production chain for conventional cold rolled strip, and to substitute certain cold rolled steel grades by hot rolled steel. Certainly this can rarely be achieved for exposed parts, requiring a perfect surface finish, whereas for unexp...

  14. Rolling contact deformation of 1100 aluminum disks

    Science.gov (United States)

    Hahn, G. T.; Huang, Q.

    1986-09-01

    The plastic deformation produced by pure, two dimensional, rolling contacts has been studied by subjecting 1100 aluminum disks to repeated contacts with well-defined relative peak contact pressures in the range 2 ? P 0/ k c ? 6.8. Two microstructural conditions are examined: as-received (warm worked) and annealed, displaying cyclic softening and cyclic hardening, respectively. Measurements of the distortion of wire markers imbedded in the rims, microhardness values of the plastically deformed layer, and changes in disk radius and width are reported. These are used to evaluate the plastic circumferential, radial, and axial displacements of the rim surface and the depth of the plastically deformed layer. These features are compared with the classical, elastic-quasi plastic analysis of rolling, and with recent elastic-plastic finite element calculations. The results show that the rim deformation state approaches plane strain when the disk width-to-Hertzian half contact width-ratio B/w ? 200. The presence of a solid lubricant has no detectable influence on the character of the plane strain deformation. The measurements of the per cycle forward (circumferential) displacements for the two conditions are self-consistent and agree with the finite element calculations when the resistance to plastic deformation is attributed to the instantaneous cyclic yield stress, but not when the resistance is identified with the initial monotonie yield stress. At the same time, the extent of the plastic zone is 5× greater than predicted by the analyses. These and other results can be rationalized by drawing on the special features of the resistance to cyclic deformation. They support the view that the deformation produced by the N th rolling contact is governed by the shape of the stress-strain hysteresis loop after the corresponding number of stress-strain cycles which depends on the cycle strain amplitude, degree of reversibility, and the strain path imposed by the contact loading at different depths.

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

    Science.gov (United States)

    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 ±5?m on a 500 mm-wide film was achieved at a ? 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.

  16. Bayesian Soft Sensing in Cold Sheet Rolling.

    Czech Academy of Sciences Publication Activity Database

    Dedecius, Kamil; Jirsa, Ladislav

    Praha : ŚTIA AV ?R, v.v.i, 2010. s. 45-45. [6th International Workshop on Data–Algorithms–Decision Making. 2.12.2010-4.12.2010, Jind?ich?v Hradec] R&D Projects: GA MŠk(CZ) 7D09008 Institutional research plan: CEZ:AV0Z10750506 Keywords : soft sensor * bayesian statistics * bayesian model averaging Subject RIV: BB - Applied Statistics, Operational Research http://library.utia.cas.cz/separaty/2010/AS/dedecius-bayesian soft sensing in cold sheet rolling.pdf

  17. Equity valuation : Rolls-Royce PLC

    OpenAIRE

    Fonseca, Mafalda Filipa Sousa

    2014-01-01

    The purpose of this thesis is to evaluate Rolls-Royce PLC. In order to do so, two valuation methodologies will be presented. The first one regards the Discount Cash Flow – WACC methodology, where each sector of the company is valued. By doing so, it is possible to reach a price per share of 1369 pence. Therefore, when using this methodology, the company is presented as a buying opportunity (the market yields a price of 1112 pence.) The second valuation presented and which is introduced ...

  18. Spoilers for roll control of light airplanes

    Science.gov (United States)

    Roskam, J.; Kohlman, D. L.; Wentz, W. H.

    1974-01-01

    The paper presents an overview of the state-of-the-art of roll control spoilers for light airplanes. Reasons for using spoilers on light airplanes are presented. Several classical objections to the use of spoilers of such airplanes are critically examined. It is shown that mechanically driven spoiler systems can be designed. Flight test results of a new mechanically driven spoiler on the Redhawk airplane are discussed. Tunnel data of spoilers on the new general aviation airfoil GA(W)-1 are presented. Finally, a bibliography on spoiler data is included.

  19. Corrosion behaviour of different hot rolled steels

    OpenAIRE

    Perez, F. J.; Martinez, L.; Hierro, M. P.; Gomez, C.; Portela, A. L.; G.N. Pucci; Duday, D.; Lecomte-Beckers, Jacqueline; Greday, Y.

    2006-01-01

    The oxidation-corrosion behaviour of hot rolled alloys was examined by electrochemical impedance spectroscopy. The corrosion behaviour of the non-oxidised alloys was first determined in order to have a reference behaviour. Then, each alloy was oxidised for 1 and 3 days at 650 degrees C in air and its corrosion behaviour was also determined. For all the alloys, Fe2O3 was formed at the scale-gas interface. However, the Fe2O3 crystallographic structures varied as a function of the alloy composit...

  20. Convex functions and the rolling circle criterion

    Directory of Open Access Journals (Sweden)

    G. P. Kapoor

    1995-12-01

    Full Text Available Given 0Ć¢Ā‰Ā¤R1Ć¢Ā‰Ā¤R2Ć¢Ā‰Ā¤Ć¢ĀˆĀž, CVG(R1,R2 denotes the class of normalized convex functions f in the unit disc U, for which Ć¢ĀˆĀ‚f(U satisfies a Blaschke Rolling Circles Criterion with radii R1 and R2. Necessary and sufficient conditions for R1=R2, growth and distortion theorems for CVG(R1,R2 and rotation theorem for the class of convex functions of bounded type, are found.

  1. Convex functions and the rolling circle criterion

    OpenAIRE

    Kapoor, G. P.; O. P. Juneja; V.Srinivas

    1995-01-01

    Given 0Ć¢Ā‰Ā¤R1Ć¢Ā‰Ā¤R2Ć¢Ā‰Ā¤Ć¢ĀˆĀž, CVG(R1,R2) denotes the class of normalized convex functions f in the unit disc U, for which Ć¢ĀˆĀ‚f(U) satisfies a Blaschke Rolling Circles Criterion with radii R1 and R2. Necessary and sufficient conditions for R1=R2, growth and distortion theorems for CVG(R1,R2) and rotation theorem for the class of convex functions of bounded type, are found.

  2. Early Detection of Parametric Roll Resonance on Container Ships

    DEFF Research Database (Denmark)

    Galeazzi, Roberto; Blanke, Mogens; Poulsen, Niels KjĆølstad

    2013-01-01

    ship's speed and course, to escape from the bifurcation condition. This paper proposes nonparametric methods to detect the onset of roll resonance and demonstrates their performance. Theoretical conditions for parametric resonance are revisited and are used to develop efficient methods to detect its......Parametric roll resonance on ships is a nonlinear phenomenon where waves encountered at twice the natural roll frequency can bring the vessel dynamics into a bifurcation mode and lead to extreme values of roll. Recent years have seen several incidents with dramatic damage to container vessels. The...... experimental data from model tests and on data from a container ship crossing the Atlantic during a storm....

  3. Rolling induced size effects in elastic–viscoplastic sheet metals

    DEFF Research Database (Denmark)

    Nielsen, Kim Lau

    2015-01-01

    presented revolves around the rolling induced effect of visco-plasticity (ranging hot and cold rolling) in combination with strain gradient hardening – including both dissipative and energetic contributions. To bring out first order effects on rolling at small scale, the modeling efforts are limited to flat...... sheet rolling, where a non-homogeneous material deformation takes place between the rollers. Large strain gradients develop where the rollers first come in contact with the sheet, and a higher order plasticity model is employed to illustrate their influence at small scales. The study reveals that the...

  4. Troll, a Language for specifying Dice-rolls

    DEFF Research Database (Denmark)

    Mogensen, Torben Ęgidius

    2009-01-01

    Dice are used in many games, and often in fairly complex ways that make it difficult to unambiguously describe the dice-roll mechanism in plain language. Many role-playing games, such as Dungeons & Dragons, use a formalised notation for some instances of dice-rolls. This notation, once explained, make dice-roll descriptions concise and unambiguous. Furthermore, the notation has been used in automated tools for pseudo-random dice-rolling (typically used when playing over the Internet). This notat...

  5. Arvuti roll elementaarmatemaatika õppimisel ja õpetamisel / Margo Kikas

    Index Scriptorium Estoniae

    Kikas, Margo, 1974-

    1998-01-01

    Juuni algul toimus TPÜ-s kolmepäevane kursus "Arvuti roll elementaarmatemaatika õppimisel ja õpetamisel", kus põhiesinejaks oli The Royal Danish School of Educational Studies (Taani) õppejõud Viggo Sadolin

  6. Development and validation of thermal hydraulic code in rolling motion

    International Nuclear Information System (INIS)

    The RELAP5/MOD3.3 code was modified by adding a module calculating the effect of rolling motion and introducing new flow and heat transfer models. The thermal hydraulic code in rolling motion was developed. The experimental data were used to validate the theoretical models and calculation results. It is shown that the new flow and heat transfer models can correctly calculate the frictional resistance and heat transfer coefficients in rolling motion. The developed thermal hydraulic code can be used to simulate the thermal hydraulic system in rolling motion. (authors)

  7. Roll caster for the three-layer clad-strip

    Directory of Open Access Journals (Sweden)

    R. Nakamura

    2010-02-01

    Full Text Available Purpose: of this paper is to show the characteristics of two kinds of roll casters for three-layer clad strip of aluminium alloys. Moreover, the characteristics of these twin roll casters were compeered with the early type of roll casters for clad strip.Design/methodology/approach: Design was tried to attain the fabrication of the roll casters to cast the three-layers-clad-strip. One caster was an unequal diameter roll caster equipped with a scraper. The scraper was adopted to prevent the mixture of different kinds of melts of the alloys. The scraper was used to cast the clad strip with clear interfaces between each strip. The other caster was a tandem type roll caster assembled from two vertical type twin roll casters. A vertical type of twin roll was mounted on the other vertical type of a twin roll caster.Findings: Three layers of clad strips could be cast by two kinds of the roll casters developed in the present study. The casting speed was 20 m/min. This speed was much higher at the conventional twin roll caster for the aluminium alloys. Each strip of three layers clad strip was connected strictly. The element of clad strip did not peel at the interface by continuous bending. The as-cast clad strip could be cold-rolled. The element of alloys did not mix at the connecting interface of the strips. The casting conditions which affected the connecting of the strips and condition of interface were investigated and shown in this paper.Research limitations/implications: The width of the strip was from 30 mm to 50 mm. The casting of the wide strip was not investigated. The alloy used in the present study was only aluminium alloys. The length of the cast strip was 3 m. The thickness of element strip was from 0.8 mm to 1.5 mm. The difference of the melting temperature of the alloys was within 50°C. The number of the layers was less than three layers.Practical implications: The roll caster invented in the present study can be used for the fabrication of the clad strip. The clad strip is, for example, used for the brazing sheet of the radiator for the automotive industry.Originality/value: There was not a report concerning the roll caster for three layers clad strip. The roll casters for clad strips shown in this paper were of an original process. Especially, the use of the scraper in the roll casting was original.

  8. Rudder-Roll Damping Autopilot Robustness to Sway-Yaw-Roll Couplings

    DEFF Research Database (Denmark)

    Blanke, M.; Christensen, A.C.

    1993-01-01

    Contributions of the paper are to advise ways to access the effects of coupling term changes on RRD control, to show the changes in robustness, including roll reduction capability for various parameters, and to provide a complete, parameterized model that can be used for comparison of methodology in RRD design

  9. Self-Aligned Metal Electrodes in Fully Roll-to-Roll Processed Organic Transistors

    Directory of Open Access Journals (Sweden)

    Marja Vilkman

    2016-01-01

    Full Text Available We demonstrate the production of organic bottom gate transistors with self-aligned electrodes, using only continuous roll-to-roll (R2R techniques. The self-alignment allows accurate <5 Āµm layer-to-layer registration, which is usually a challenge in high-speed R2R environments as the standard registration methods are limited to the millimeter rangeā€”or, at best, to tens of Āµm if online cameras and automatic web control are utilized. The improved registration enables minimizing the overlap between the source/drain electrodes and the gate electrode, which is essential for minimizing the parasitic capacitance. The complete process is a combination of several techniques, including evaporation, reverse gravure, flexography, lift-off, UV exposure and development methodsā€”all transferred to a continuous R2R pilot line. Altogether, approximately 80 meters of devices consisting of thousands of transistors were manufactured in a roll-to-roll fashion. Finally, a cost analysis is presented in order to ascertain the main costs and to predict whether the process would be feasible for the industrial production of organic transistors.

  10. Register Control of Roll-to-Roll Printing System Based on Statistical Approach

    Science.gov (United States)

    Kim, Chung Hwan; You, Ha-Il; Jo, Jeongdai

    2013-05-01

    One of the most important requirements when using roll-to-roll printing equipment for multilayer printing is register control. Because multilayer printing requires a printing accuracy of several microns to several tens of microns, depending on the devices and their sizes, precise register control is required. In general, the register errors vary with time, even for one revolution of the plate cylinder. Therefore, more information about the register errors in one revolution of the plate cylinder is required for more precise register control, which is achieved by using multiple register marks in a single revolution of the plate cylinder. By using a larger number of register marks, we can define the value of the register error as a statistical value rather than a single one. The register errors measured from an actual roll-to-roll printing system consist of a linearly varying term, a static offset term, and small fluctuations. The register errors resulting from the linearly varying term and the offset term are compensated for by the velocity and phase control of the plate cylinders, based on the calculated slope and offset of the register errors, which are obtained by the curve-fitting of the data set of register errors. We show that even with the slope and offset compensation of the register errors, a register control performance of within 20 µm can be achieved.

  11. Low Band Gap Polymers for Roll-to-Roll Coated Polymer Solar Cells

    DEFF Research Database (Denmark)

    Bundgaard, Eva; Hagemann, Ole

    2010-01-01

    We present the synthesis of a low band gap copolymer based on dithienothiophene and dialkoxybenzothiadiazole (poly(dithienothiophene-co-dialkoxybenzothiadiazole), PDTTDABT). The optical properties of the polymer showed a band gap of 1.6 eV and a sky-blue color in solid films. The polymer was explored in roll-to-roll coating experiments and was optimized with respect to the manufacturing process and mixing ratio with [60]PCBM through a series of experiments with variation of the composition in steps of 1% w/w of respectively PDTTDABT and [60]PCBM and a relatively broad optimimum was found around a 1:2 mixing ratio. Roll-to-roll coated polymer solar cell devices were prepared under ambient conditions employing solution processing in all steps including the metallic back electrode that was printed as a grid giving semitransparent solar cell devices. Solar cell modules comprising 16 serially connected cells were prepared with a total module active area of 96 cm2. The devices were tested for operational stability under simulated sunlight (AM1.5G) and natural sunlight, and the photochemical stability of the polymer was examined using a combination of UV?vis and IR spectroscopy.

  12. Roll bonding steps of 6061 aluminum alloy plates during hot rolling of nuclear fuel plates

    International Nuclear Information System (INIS)

    Roll Bonding process is applied to clad the core plate (U3O8+Al), with high strength aluminum alloys during fabrication of plate type nuclear fuel elements for research reactors, and to produce many new constructions which have special uses in industrial applications. In the present work, the steps of the hot roll bonding process were studied using both microscopic examination and mechanical testing. It was found that, there is a threshold of reduction, at which the metallic bond initiates. After this point, the increasing of degree of reduction leads to increase in the bond strength. This reduction threshold was found to be 30%. The final bond strength was about 0.87 of the strength of the base 6061 aluminum alloy at the same conditions of hot working and thermal treatments. The present results showed that at least 81% reduction in thickness is required to produce the required bond between the cladding and both core plate and frame for roll bonded plates with the standard roll bonding method. (author)

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

    Science.gov (United States)

    Krebs, Frederik C; Tromholt, Thomas; Jųrgensen, 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 technologies due to the inferior operational lifetime. The presented devices are thus competitive for consumer electronics but ill-suited for on-grid electricity production in their current form. PMID:20648282

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

    DEFF Research Database (Denmark)

    Krebs, Frederik C; Tromholt, Thomas

    2010-01-01

    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 m-2 and an electricity cost of 8.1 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 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 technologies due to the inferior operational lifetime. The presented devices are thus competitive for consumer electronics but ill-suited for on-grid electricity production in their current form.

  15. Scalable, ambient atmosphere roll-to-roll manufacture of encapsulated large area, flexible organic tandem solar cell modules

    DEFF Research Database (Denmark)

    Andersen, Thomas Rieks; Dam, Henrik Friis

    2014-01-01

    Inline printing and coating methods have been demonstrated to enable a high technical yield of fully roll-to-roll processed polymer tandem solar cell modules. We demonstrate generality by employing different material sets and also describe how the ink systems must be carefully co-developed in order to reach the ambitious objective of a fully printed and coated 14-layer flexible tandem solar cell stack. The roll-to-roll methodologies involved are flexographic printing, rotary screen printing, slot-die coating, X-ray scattering, electrical testing and UV-lamination. Their combination enables the manufacture of completely functional devices in exceptionally high yields. Critical to the ink and process development is a carefully chosen technology transfer to industry method where first a roll coater is employed enabling contactless stack build up, followed by a small roll-to-roll coater fitted to an X-ray machine enabling in situ studies of wet ink deposition and drying mechanisms, ultimately elucidating how a robust inline processed recombination layer is key to a high technical yield. Finally, the transfer to full roll-to-roll processing is demonstrated.

  16. Roll-to-roll printed silver nanowires for increased stability of flexible ITO-free organic solar cell modules

    DEFF Research Database (Denmark)

    Benatto, Gisele Alves dos Reis; Roth, BĆ©renger; Corazza, Michael; SĆøndergaard, Roar R.; Gevorgyan, Suren A.; JĆørgensen, Mikkel; Krebs, Frederik C

    2016-01-01

    We report the use of roll-to-roll printed silver nanowire networks as front electrodes for fully roll-to-roll processed flexible indium-tin-oxide (ITO) free OPV modules. We prepared devices with two types of back electrodes, a simple PEDOT:PSS back electrode and a PEDOT:PSS back electrode with a...... printed silver grid in order to simultaneously explore the influence of the back electrode structure on the operational stability of the modules that did not include any UV-protection. We subjected the devices to stability testing under a number of protocols recommended by the international summit on OPV...

  17. A life cycle analysis of polymer solar cell modules prepared using roll-to-roll methods under ambient conditions

    DEFF Research Database (Denmark)

    Espinosa Martinez, Nieves; Garcķa-Valverde, Rafael; Urbina, Antonio; Krebs, Frederik C

    2011-01-01

    A life cycle analysis was performed on a full roll-to-roll coating procedure used for the manufacture of flexible polymer solar cell modules. The process known as ProcessOne employs a polyester substrate with a sputtered layer of the transparent conductor indium-tin-oxide (ITO). The ITO film was processed into the required pattern using a full roll-to-roll process, employing screen printing of an etch resist and then applying etching, stripping, washing and drying procedures. The three subsequen...

  18. Terminal retrograde turn of rolling rings

    Science.gov (United States)

    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.

  19. Time-symmetric rolling tachyon profile

    Science.gov (United States)

    Longton, Matheson

    2015-09-01

    We investigate the tachyon profile of a time-symmetric rolling tachyon solution to open string field theory. We algebraically construct the solution of [1] at 6th order in the marginal parameter, and numerically evaluate the corresponding tachyon profile as well as the action and several correlation functions containing the equation of motion. We find that the marginal operator's singular self-OPE is properly regularized and all quantities we examine are finite. In contrast to the widely studied time-asymmetric case, the solution depends nontrivially on the strength of the deformation parameter. For example, we find that the number and period of oscillations of the tachyon field changes as the strength of the marginal deformation is increased. We use the recent renormalization scheme of [2], which contains two free parameters. At finite deformation parameter the tachyon profile depends on these parameters, while when the deformation parameter is small, the solution becomes insensitive to them and behaves like previously studied time-asymmetric rolling tachyon solutions. We also show that convergence of perturbation series is not as straightforward as in the time-asymmetric case with regular OPE, and find evidence that it may depend on the renormalization constants.

  20. Wear of rolling element bearings in sodium

    International Nuclear Information System (INIS)

    Rolling element bearings and related mechanisms are attractive for service in liquid sodium but it is not clear what minimum wear rate can be anticipated. For axially loaded angular contact bearings rotation is incompatible with pure rolling on both races and wear arises from the resulting ball spin. The initial pressure distributions and sizes of the contact ellipses can be calculated but will change with bearing wear. However, the most effective distribution for producing wear would be for the full loads to be borne on the tips of the contact areas, whose maximum length is given by examination of the race wear tracks. A calculation on such a basis should set a lower limit for the wear coefficient. Both the torque and instantaneous wear rate of a bearing will be similar functions of the integral over the contact areas of the product of contact pressure and radius from the ball spin axis. A better estimate of wear coefficient should be obtained by relating the average torque, the average wear, the initial torque and the initial wear where the conditions are known. Analysis of tests in sodium at 4000C of high speed steel and Stellite bearings by these methods indicates specific wear rates of the order of 10-15m3/N-m, not unduly out of line with the range of values found in conventional sliding tests

  1. Precision instrumentation for rolling element bearing characterization.

    Science.gov (United States)

    Marsh, Eric R; Vigliano, Vincent C; Weiss, Jeffrey R; Moerlein, Alex W; Vallance, R Ryan

    2007-03-01

    This article describes an instrument to measure the error motion of rolling element bearings. This challenge is met by simultaneously satisfying four requirements. First, an axial preload must be applied to seat the rolling elements in the bearing races. Second, one of the races must spin under the influence of an applied torque. Third, rotation of the remaining race must be prevented in a way that leaves the radial, axial/face, and tilt displacements free to move. Finally, the bearing must be fixtured and measured without introducing off-axis loading or other distorting influences. In the design presented here, an air bearing reference spindle with error motion of less than 10 nm rotates the inner race of the bearing under test. Noninfluencing couplings are used to prevent rotation of the bearing outer race and apply an axial preload without distorting the bearing or influencing the measurement. Capacitive displacement sensors with 2 nm resolution target the nonrotating outer race. The error motion measurement repeatability is shown to be less than 25 nm. The article closes with a discussion of how the instrument may be used to gather data with sufficient resolution to accurately estimate the contact angle of deep groove ball bearings. PMID:17411223

  2. Zentrale Rolle des Hausarztes bei der Diabetesprävention

    Directory of Open Access Journals (Sweden)

    Sarnighausen HE

    2010-01-01

    Full Text Available Kurzfassung: Im Leitfaden ?Prävention Diabetes mellitus Typ 2? des ?Nationalen Aktionsforums Diabetes mellitus? (NAFDM spielt der Arzt (Hausarzt bei der Rekrutierung und Führung der noch nicht erkrankten ?Kunden? mit erhöhtem Risiko für die Entwicklung eines Typ-2-Diabetes, welches anhand des ?FindRisk-Bogens? (www.diabetesrisiko. de ermittelt werden kann, eine untergeordnete Rolle. Die Ursache hierfür liegt im Wesentlichen darin, dass nach Ansicht der beteiligten Gesellschaften der Hausarzt im Bereich der Kuration von Krankheiten tätig ist und nicht für präventive Aufgaben im Bereich des Gesundheitswesens ausgebildet wurde. Die ?Deutsche Gesellschaft für Allgemein- und Familienmedizin? hat ihre Mitwirkung aus diesem Grund versagt. Um die Umsetzung des ?Leitfadens Prävention Diabetes mellitus Typ 2? zu initiieren und voranzutreiben, ist eine Änderung in der Prozessstruktur zu diskutieren, in der der Arzt (Hausarzt eine zentrale Rolle einnimmt. Hiermit soll erreicht werden, dass Diabetesprävention zu einer Kernaufgabe hausärztlicher Tätigkeit wird, da der Hausarzt seit Langem Erfahrungen in der Prävention von Stoffwechsel- und Gefäßerkrankungen (Gesundheitscheck 35 und Krebserkrankungen (Krebsvorsorgeuntersuchung hat.

  3. Advanced cold rolled steels for automotive applications

    Energy Technology Data Exchange (ETDEWEB)

    Hofmann, Harald; Mattissen, Dorothea; Schaumann, Thomas Wilhelm [ThyssenKrupp Steel AG, Center of Materials Excellence, Dortmund (Germany)

    2009-01-15

    Advanced high-strength steels offer a great potential for the further development of automobile bodies-in-white due to their combined mechanical properties of high formability and strength. They represent the first choice in material selection for strength and crash-relevant parts with challenging geometries. The intensive development of multiphase steels by ThyssenKrupp Steel has led to hot dip galvanizing concepts with an outstanding forming potential. Hot rolled, hot dip galvanized complex-phase steels are currently produced in addition to cold rolled dual phase (DP) and retained austenite (RA) or transformation induced plasticity (TRIP) steels. New continuously annealed grades of steel are being developed with tensile strength levels of up to 1000 MPa in combination with sufficient ductility for the high demands of structural automobile components. These steels make use of the classic advantages of microalloying as well as the principles of DP steels and RA / TRIP steels. Further improvement of properties will be reached by the new class of high manganese alloyed steels. (orig.)

  4. Curious terminal turn of rolling rings

    CERN Document Server

    Jalali, Mir Abbas; Alam, Reza

    2014-01-01

    We report an unexpected reverse spiral turn in the final stage of the motion of rolling rings. It is well known that spinning disks have definite centers of rotation until they stop. While a spinning ring starts its motion with a similar kinematics, moving along a cycloidal path prograde with the direction of its rigid body rotation, the mean trajectory of its center of mass 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.

  5. Progress in cold roll bonding of metals

    International Nuclear Information System (INIS)

    Layered composite materials have become an increasingly interesting topic in industrial development. Cold roll bonding (CRB), as a solid phase method of bonding same or different metals by rolling at room temperature, has been widely used in manufacturing large layered composite sheets and foils. In this paper, we provide a brief overview of a technology using layered composite materials produced by CRB and discuss the suitability of this technology in the fabrication of layered composite materials. The effects of process parameters on bonding, mainly including process and surface preparation conditions, have been analyzed. Bonding between two sheets can be realized when deformation reduction reaches a threshold value. However, it is essential to remove surface contamination layers to produce a satisfactory bond in CRB. It has been suggested that the degreasing and then scratch brushing of surfaces create a strong bonding between the layers. Bonding mechanisms, in which the film theory is expressed as the major mechanism in CRB, as well as bonding theoretical models, have also been reviewed. It has also been showed that it is easy for fcc structure metals to bond compared with bcc and hcp structure metals. In addition, hardness on bonding same metals plays an important part in CRB. Applications of composites produced by CRB in industrial fields are briefly reviewed and possible developments of CRB in the future are also described. Corrections were made to the abstract and conclusion of this article on 18 June 2008. The corrected electronic version is identical to the print version. (topical review)

  6. Precision instrumentation for rolling element bearing characterization

    International Nuclear Information System (INIS)

    This article describes an instrument to measure the error motion of rolling element bearings. This challenge is met by simultaneously satisfying four requirements. First, an axial preload must be applied to seat the rolling elements in the bearing races. Second, one of the races must spin under the influence of an applied torque. Third, rotation of the remaining race must be prevented in a way that leaves the radial, axial/face, and tilt displacements free to move. Finally, the bearing must be fixtured and measured without introducing off-axis loading or other distorting influences. In the design presented here, an air bearing reference spindle with error motion of less than 10 nm rotates the inner race of the bearing under test. Noninfluencing couplings are used to prevent rotation of the bearing outer race and apply an axial preload without distorting the bearing or influencing the measurement. Capacitive displacement sensors with 2 nm resolution target the nonrotating outer race. The error motion measurement repeatability is shown to be less than 25 nm. The article closes with a discussion of how the instrument may be used to gather data with sufficient resolution to accurately estimate the contact angle of deep groove ball bearings

  7. High speed twin roll caste for aluminum alloy thin strip

    Directory of Open Access Journals (Sweden)

    T. Haga

    2007-09-01

    Full Text Available Purpose: In the present study, effectiveness of a high-speed twin roll caster for recycling aluminum alloy was investigated.Design/methodology/approach: The effects of the high-speed twin roll caster on alleviating the deterioration of mechanical properties by impurities were investigated. Properties of the cast strip were investigated by metalography, a tension test, and a bending test.Findings: A vertical type twin roll caster for strip casting of aluminum alloys was devised. The strip, which was thinner than 3 mm, could be cast at speeds higher than 60 m/min. Features of the twin roll casters are as below. Copper rolls were used and lubricant was not used in order to increase the casting speed. A casting nozzle was used to set the solidification length precisely. Heat transfer between melt and the roll was improved by hydrostatic pressure of the melt. Separating force was very small in order to prevent sticking of the strip to the roll. Low superheat casting was carried out in order to improve microstructure of the strip. In the present study, effectiveness of a high-speed and high-cooling rate twin roll caster of the present study for recycling aluminum alloy was investigated. Fe was added as impurity to 6063 and A356. The roll caster of the present study was useful to decrease the influence of impurity of Fe.Research limitations/implications: A high-speed twin roll caster of vertical type was designed and assembled to cast aluminum alloy thin strip.Originality/value: The results demonstrate that the high-speed twin roll caster can improve the deterioration by impurities.

  8. High-precision thickness setting models for titanium alloy plate cold rolling without tension

    Science.gov (United States)

    Wang, Xiaochen; Yang, Quan; He, Fei; Sun, Youzhao; Xiao, Huifang

    2015-03-01

    Due to its highly favorable physical and chemical properties, titanium and titanium alloy are widely used in a variety of industries. Because of the low output of a single batch, plate cold rolling without tension is the most common rolling production method for titanium alloy. This method is lack of on-line thickness closed-loop control, with carefully thickness setting models for precision. A set of high-precision thickness setting models are proposed to suit the production method. Because of frequent variations in rolling specification, a model structural for the combination of analytical models and statistical models is adopted to replace the traditional self-learning method. The deformation resistance and friction factor, the primary factors which affect model precision, are considered as the objectives of statistical modeling. Firstly, the coefficient fitting of deformation resistance analytical model based on over-determined equations set is adopted. Additionally, a support vector machine(SVM) is applied to the modeling of the deformation resistance and friction factor. The setting models are applied to a 1450 plate-coiling mill for titanium alloy plate rolling, and then thickness precision is found consistently to be within 3%, exceeding the precision of traditional setting models with a self-learning method based on a large number of stable rolling data. Excellent application performance is obtained. The proposed research provides a set of high-precision thickness setting models which are well adapted to the characteristics of titanium alloy plate cold rolling without tension.

  9. EVOLUTION OF THE AUSTENITE GRAIN SIZE DURING HOT STRIP ROLLING OF NIOBIUM MICROALLOYED STEELS

    OpenAIRE

    Antonio Augusto Gorni; Marcos Roberto Soares da Silva

    2015-01-01

    The occurrence of dynamic recrystallization in the intermediate stands of the Finishing Mill of a Hot Strip Mill promotes substantial softening of the rolling stock, a situation that can cause operational problems and even scrapping of the strip. The aim of this work was to identify the specific process conditions that can lead to this situation, which was carried out through the application of a microstructural evolution model. It was verified, for the specific conditions of the ...

  10. THE STUDY OF SCALE FORMATION ON HOT ROLLED INGOTS AND BILLETS

    Directory of Open Access Journals (Sweden)

    GHEORGHE VLAICU

    2010-06-01

    Full Text Available During the heating for rolling, ingots and billets are affected by the chemical action of the heating atmosphere. Between the heating environment elements and steel components there are taking place chemical reactions initiated at the separation surface that may affect a layer in metal of about a few microns to a few millimeters. The thickness of the affected layer is a function of the environment nature, heated material composition, chemical reaction’s type and kinetics, heating rate and temperature. The aim of this paper is to correlate the oxidation and the decarburization processes during the heating of ingots and billets for rolling. The study was made on ingots and billets rolled at the breakdown mill of the Special Steel Complex, Physics Laboratories from MECHEL Targoviste, Romania. The scope of the study is the analysis of the scale obtained from the rolling mill train in order to obtain specific information that will be used in adjusting the rolling parameters for diminishing the oxidation and decarburization and for recycling the scale in electric furnaces.

  11. The influence of the shape of grooves on the behavior of internal material discontinuities in continuous S355J2G3 steel strands during rolling

    Directory of Open Access Journals (Sweden)

    H. Dyja

    2014-10-01

    Full Text Available The article discusses problems related to the influence of rolling processes on the process of closing of internal discontinuities in continuous castings during rolling in shape grooves. Numerical modelling of the process of rolling 160 × 160 mm continuous S355J2G3 steel strands was carried out using the Forge 2008R software program. The experimental studies were conducted in a D150 laboratory rolling mill. Holes simulating material discontinuities were examined. In numerical and experimental studies, in steel samples after rolling in the third rolling stand, the defects were closing in 100 % on average. It was stated that the speed of closing of material discontinuities in feedstock is strongly influenced by the shape of the rolling groove.

  12. 40 CFR 426.30 - Applicability; description of the rolled glass manufacturing subcategory.

    Science.gov (United States)

    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 Ā§ 426.30 Applicability; description of the rolled...

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

    International Nuclear Information System (INIS)

    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

  14. 40 CFR 426.30 - Applicability; description of the rolled glass manufacturing subcategory.

    Science.gov (United States)

    2010-07-01

    ...POINT SOURCE CATEGORY Rolled Glass Manufacturing Subcategory ...Applicability; description of the rolled glass manufacturing subcategory...ingredients) are mixed, melted in a furnace, and cooled by rollers to form rolled...

  15. 14 CFR 25.491 - Taxi, takeoff and landing roll.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Taxi, takeoff and landing roll. 25.491..., 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...

  16. 21 CFR 136.130 - Milk bread, rolls, and buns.

    Science.gov (United States)

    2010-04-01

    ...HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION BAKERY PRODUCTS...rolls, and buns. (a) Each of the foods milk bread, milk rolls, and milk...preparation of the dough is milk or, as an alternative, a combination of dairy products...whey, cheese whey product, or milk protein is used. (b) The name of the food is “milk bread”, “milk...

  17. Effects of Foam Rolling on Vertical Jump Performance

    Directory of Open Access Journals (Sweden)

    Andrew Jones

    2015-07-01

    Full Text Available Background: Foam rolling is a popular activity utilized by strength and conditioning coaches as it is believed to increase muscle length and break up fibrous adhesions located in connective tissue. However, there is little research investigating the effects of foam rolling on athletic performance. Objective: The purpose of this study was to investigate the effects of lower body foam rolling on vertical jump performance. Methods: Twenty males (age 24.05 ± 2.02 years; height 177.43 ± 6.31 cm; mass 81.41 ± 8.76 kg volunteered to participate. Subjects completed three days of testing, separated by at least twenty-four hours. Day one consisted of baseline vertical jumps on a force plate, followed by familiarization with foam rolling and control protocols. Subjects returned on days two and three and performed 30-second bouts of lower body foam rolling or mimicked foam rolling movements on a skateboard followed by vertical jumps on a force plate. The highest jump from each day was used for statistical analyses. Results: Repeated measures ANOVAs revealed no significant differences in Jump height, impulse, relative ground reaction force, or take-off velocity between conditions. Conclusion: 30-second bouts of lower body foam rolling do not improve vertical jump performance.Keywords: Dynamic Warm-Up, Foam Rolling, Vertical Jump

  18. Early Detection of Parametric Roll Resonance on Container Ships

    DEFF Research Database (Denmark)

    Galeazzi, Roberto; Blanke, Mogens

    2013-01-01

    Parametric roll resonance on ships is a nonlinear phenomenon where waves encountered at twice the natural roll frequency can bring the vessel dynamics into a bifurcation mode and lead to extreme values of roll. Recent years have seen several incidents with dramatic damage to container vessels. The roll oscillation, which is subharmonic with respect to the wave excitation, may be completely unexpected and a system for detection of the onset of such resonance could warn the navigators before roll angles reach serious levels. Timely warning could make remedial actions possible, such as change the ship's speed and course, to escape from the bifurcation condition. This paper proposes nonparametric methods to detect the onset of roll resonance and demonstrates their performance. Theoretical conditions for parametric resonance are revisited and are used to develop efficient methods to detect its onset. Spectral and temporal correlations of the square of roll with pitch (or heave) are demonstrated to be of particularinterest as indicators. Properties of the indicators are scrutinized, and a change detector is designed for the Weibull-type of distributions that were observed from a time-domain indicator for phase correlation. Hypothesis testing for resonance is developed using a combination of detectors to obtain robustness. Conditions of forced roll and disturbances in real weather conditions are analyzed and robust detection techniques are suggested. The efficacy of the methodology is shown on experimental data from model tests and on data from a container ship crossing the Atlantic during a storm.

  19. Influence of the GZ calculation method on parametric roll prediction

    DEFF Research Database (Denmark)

    Vidic-Perunovic, Jelena

    order of magnitude. Calculations have been made for different sea states and operational conditions leading to parametric roll resonance and for relevant maximum pre-defined roll angles. The outcome of this comparative study could be useful for the decisions in an early design phase or for application...

  20. High speed twin roll casters for aluminum alloy strips

    Energy Technology Data Exchange (ETDEWEB)

    Haga, T. [Osaka Inst. of Tech. (Japan); Suzuki, S. [Technical Univ. Berlin (Germany)

    2002-07-01

    Two kinds of twin roll caster for aluminum alloys were devised in the present study. Vertical type was adopted. The strip, which was thinner than 3 mm, could be cast at speeds higher than 60 m/min. Aluminum alloy, which freezing zone is very wide like A5182, could be cast using the twin roll caster of the present study at speeds up to 150 m/min. Features of the twin roll casters are as below. Copper rolls were used and lubricant was not used in order to increase the casting speed. Heat transfer between melt and the roll was improved by hydrostatic pressure of the melt. Separating force was very small in order to prevent sticking of the strip to the roll. Low superheat casting was carried out in order to improve microstructure of the strip. A5182 strip, which had equiaxed structure, could be cast. Some heat treatment was tried and tested in order to improve the mechanical property of A5182 strip. A3003 strip was cast by low superheat strip casting. A3003 strip showed thermo-softening resistance. Semisolid strip casting of A356 alloy was tried using a twin roll caster equipped with a cooling slope. Mechanical property, especially elongation, was improved. Result of 180 degrees bending test was improved, too. Semisolid strip casting was useful for high speed roll casting, and the casting speed increased up to 180 m/min. (orig.)

  1. Cold-rolled steel strip X-ray thickness gauge

    International Nuclear Information System (INIS)

    This paper introduces a cold-rolled steel strip X-ray thickness gauge. This gauge uses two-detector construction including penetrating ionization chamber and measuring ionization chamber. Standard magazine box is composed of three rotating plates driving by stepper motor, including 13 pieces of standard sample to build up 154 thickness value, obtaining standard sample curve covering thickness range of 0.1 mm to 5 mm. Automation system include Siemens S7-200 PLC as key controlling unit, embedded controlling system for data acquisition and computing, and PC as man-machine interface, and employ Ethernet (TCP/IP) or RS485/232 as communication protocol. Reversing Cold mill AGC closed-loop control operation test demonstrates that the gauge can adapt to the severe production environment, operate stably and reliably, measurement precision can reached to ±0.19%, reproducibility to ±0.09%, and stability to ±0.06%, response time range from 4 ms to 200 ms and be adjustable. So it can meet the high demanding of cold-rolled plate/strip production. (authors)

  2. Production of normalized steel plate through normalizing rolling; Producao de chapas grossas normalizadas diretamente do calor de laminacao

    Energy Technology Data Exchange (ETDEWEB)

    Gorni, Antonio Augusto; Cavalcanti, Celso Gomes; Reis, Jackson Soares de Souza; Silveira, Jose Herbert Dolabela da [Companhia Siderurgica Paulista (COSIPA), SP (Brazil)

    1997-12-31

    Normalized plates can be got directly from the rolling heat through the use of a normalizing rolling process. In such way, an additional step of the conventional process of production of normalized plates - the normalizing heat treatment - can be suppressed, reducing the manufacturing cost of the product and shortening its production time. This relatively new production route is being used in several steelworks all over the world for many years. This work describes the implementation trials of normalizing rolling at COSIPA`s plate mill, using an alternative process of controlled rolling called recrystallization controlled rolling. The results got with new technique were successful, as it was able to produce plates with properties very similar to the conventionally normalized material, attending the requirements of the DIN 17100 RR 52-3N standard. This is one of many standards that permit the use of this new route of normalized steel plate production. (author) 14 refs., 8 figs., 2 tabs.

  3. Spring-back of flexible roll forming bending process

    Science.gov (United States)

    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.

  4. Ground roll attenuation using non-stationary matching filtering

    Science.gov (United States)

    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.

  5. COLD ROLLING ORTHODONTIC WIRES OF AUSTENITIC STAINLESS STEEL AISI 304

    Directory of Open Access Journals (Sweden)

    Rodrigo Santos Messner

    2013-03-01

    Full Text Available Austenitic stainless steels wires are widely used in the final stages of orthodontic treatment. The objective of this paper is to study the process of conformation of rectangular wires from round wires commercial austenitic stainless steel AISI 304 by the process of cold rolling. The wire quality is evaluated by means of dimensional analysis, microhardness measurements, tensile strength and fractographic analysis of the wires subjected to tensile tests. Also a study on the application of finite element method to simulate the process, comparing the force and rolling stress obtained in the rolling is done. The simulation results are consistent with those obtained in the actual process and the rolled wires show ductile fracture, tensile strength and dimensional variations appropriate to orthodontic standards. The fracture morphology shows the model cup-cone type besides the high deformation and hardness inherent in the cold rolling process.

  6. Controlling the microstructure of magnesium alloy sheet during rolling

    International Nuclear Information System (INIS)

    A hot rolled magnesium alloy sheet embedded in a steel block was rolled together with 3% thickness reduction at room temperature, 373 K, and 673 K. Tensile twins were observed after the rolling, which could not be found when the magnesium alloy sheet was rolled without the steel block. The twin fraction was the highest at 373 K because of thermal expansion and activating non-basal slip systems at high temperature. Electron back-scattered diffraction analysis and finite element simulations confirmed that the steel block with higher strength played an important role in generating compressive stress along the transverse direction in the magnesium alloy sheet. The compressive stress could increase owing to suppression of thermal expansion in the magnesium alloy sheet at 373 K. The yield stress and the tensile stress became higher in the rolled specimen with the steel block at 373 K than in the specimen without it owing to grain refinement caused by tensile twins

  7. Chaotic travelling rolls in Rayleighā€“BĆ©nard convection

    Indian Academy of Sciences (India)

    Supriyo Paul; Krishna Kumar; Mahendra K Verma; Daniele Carati; Arnab K De; Vinayak Eswaran

    2010-01-01

    In this paper we investigate two-dimensional (2D) Rayleighā€“B Ģenard convection using direct numerical simulation in Boussinesq fluids with Prandtl number $P = 6.8$ confined between thermally conducting plates. We show through the simulation that in a small range of reduced Rayleigh number $r (770 < r < 890)$ the 2D rolls move chaotically in a direction normal to the roll axis. The lateral shift of the rolls may lead to a global flow reversal of the convective motion. The chaotic travelling rolls are observed in simulations with free-slip as well as no-slip boundary conditions on the velocity field. We show that the travelling rolls and the flow reversal are due to an interplay between the real and imaginary parts of the critical modes.

  8. Controlling the microstructure of magnesium alloy sheet during rolling

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Se-Jong, E-mail: ksj1009@kims.re.kr; Yim, Chang Dong; Lee, Young-Seon; Yoon, Jong-Hun; Lee, Jung Hwan

    2014-02-24

    A hot rolled magnesium alloy sheet embedded in a steel block was rolled together with 3% thickness reduction at room temperature, 373 K, and 673 K. Tensile twins were observed after the rolling, which could not be found when the magnesium alloy sheet was rolled without the steel block. The twin fraction was the highest at 373 K because of thermal expansion and activating non-basal slip systems at high temperature. Electron back-scattered diffraction analysis and finite element simulations confirmed that the steel block with higher strength played an important role in generating compressive stress along the transverse direction in the magnesium alloy sheet. The compressive stress could increase owing to suppression of thermal expansion in the magnesium alloy sheet at 373 K. The yield stress and the tensile stress became higher in the rolled specimen with the steel block at 373 K than in the specimen without it owing to grain refinement caused by tensile twins.

  9. Deformation microstructures and textures of some cold rolled Mg alloys

    International Nuclear Information System (INIS)

    Electron Backscatter Diffraction (EBSD) is employed to characterize the deformation microstructures and textures established during the cold rolling of pure Mg, Mg-0.2Ce and Mg-3Al-1Zn (also known as AZ31). The maximum cold rolling reductions achievable in these alloys prior to failure were ?30, >90 and ?15%, respectively. The dominant features of the microstructure were twins and shear bands. The frequency of the former decreased while that of the latter increased with rolling reduction. Each alloy displayed a fibre texture in which the c-axis was closely aligned with the sheet normal direction. There was little change to the rolling textures with increasing rolling reduction beyond ?10%. Much of the deformation appeared to be concentrated in the shear bands. It is speculated that the striking effect of alloying addition on cold rollability can be understood in terms of differences in severity, frequency and lifetime of shear bands

  10. Deformation microstructures and textures of some cold rolled Mg alloys

    Energy Technology Data Exchange (ETDEWEB)

    Barnett, M.R. [School of Engineering and Technology, Deakin University, Pigdons Road, Geelong, VIC 3217 (Australia)]. E-mail: barnettm@deakin.edu.au; Nave, M.D. [School of Engineering and Technology, Deakin University, Pigdons Road, Geelong, VIC 3217 (Australia); Bettles, C.J. [CSIRO Manufacturing and Infrastructure Technology, Private Bag 33, Clayton South, VIC 3169 (Australia)

    2004-11-25

    Electron Backscatter Diffraction (EBSD) is employed to characterize the deformation microstructures and textures established during the cold rolling of pure Mg, Mg-0.2Ce and Mg-3Al-1Zn (also known as AZ31). The maximum cold rolling reductions achievable in these alloys prior to failure were {approx}30, >90 and {approx}15%, respectively. The dominant features of the microstructure were twins and shear bands. The frequency of the former decreased while that of the latter increased with rolling reduction. Each alloy displayed a fibre texture in which the c-axis was closely aligned with the sheet normal direction. There was little change to the rolling textures with increasing rolling reduction beyond {approx}10%. Much of the deformation appeared to be concentrated in the shear bands. It is speculated that the striking effect of alloying addition on cold rollability can be understood in terms of differences in severity, frequency and lifetime of shear bands.

  11. Simple roll coater with variable coating and temperature control for printed polymer solar cells

    DEFF Research Database (Denmark)

    Dam, Henrik Friis; Krebs, Frederik C

    2012-01-01

    A simple and low cost thin film solution processing system comprising a single roll coating machine has been developed to allow direct investigation of variable parameter effects in roll-to-roll processing. We present roll coating of the active layers in polymer solar cells and validate the instrument by reinvestigating the well known effect of solvent on performance. We obtained a maximum power conversion efficiency of 1.6% for the reference cells, which compares well with reported roll-to-roll...

  12. A study on the wear of silicon nitride in rolling-sliding contact

    OpenAIRE

    Khader, Iyas; Kürten, Dominik; Kailer, Andreas

    2012-01-01

    The aim of this study is to characterize the wear in silicon nitride rolls undergoing rolling–sliding contact. A rolling contact experiment was proposed and conducted on a twin-disk tribometer. The ceramic rolls were brought into rolling contact with hardened steel disks under water lubrication at a predefined slip ratio. The generated wear on the surface of the rolls was measured and converted into a wear coefficient, which was subsequently implemented in a finite element based simulation to...

  13. Quality control of roll-to-roll processed polymer solar modules by complementary imaging methods

    DEFF Research Database (Denmark)

    Rösch, R.; Krebs, Frederik C

    2012-01-01

    We applied complementary imaging methods to investigate processing failures of roll-to-roll solution processed polymer solar modules based on polymer:fullerene bulk heterojunctions. For investigation of processing deficiencies in solar modules we employed dark lock-in thermography (DLIT), electroluminescence (ELI) and photoluminescence/reflection imaging (PLI/RI) complemented by optical imaging (OI). The combination of all high resolution images allowed us to allocate the origin of processing errors to a specific deposition process, i.e. the insufficient coverage of an electrode interlayer. The investigation can be divided into a fast DLIT overview of the module and a successive more detailed analysis of the suspicious region by all imaging methods.

  14. Roll-to-roll printed resistive WORM memory on a flexible substrate

    International Nuclear Information System (INIS)

    The fabrication process and the operation characteristics of a fully roll-to-roll printed resistive write-once-read-many memory on a flexible substrate are presented. The low-voltage (<10 V) write operation of the memories from a high resistivity ‘0’ state to a low resistivity ‘1’ state is based on the rapid electrical sintering of bits containing silver nanoparticles. The bit ink is formulated by mixing two commercially available silver nanoparticle inks in order to tune the initial square resistance of the bits and to create a self-organized network of percolating paths. The electrical performance of the memories, including read and write characteristics, is described and the long-term stability of the less stable ‘0’ state is studied in different environmental conditions. The memories can find use in low-cost mass printing applications. (paper)

  15. Roll-to-roll processed polymer tandem solar cells partially processed from water

    DEFF Research Database (Denmark)

    Larsen-Olsen, Thue Trofod; Andersen, Thomas Rieks

    2012-01-01

    Large area polymer tandem solar cells completely processed using roll-to-roll (R2R) coating and printing techniques are demonstrated. A stable tandem structure was achieved by the use of orthogonal ink solvents for the coating of all layers, including both active layers. Processing solvents included water, alcohols and chlorobenzene. Open-circuit voltages close to the expected sum of sub cell voltages were achieved, while the overall efficiency of the tandem cells was found to be limited by the low yielding back cell, which was processed from water based ink. Many of the challenges associated with upscaling the multilayer tandem cells were identified giving valuable information for future experiments and development.

  16. Aqueous Processing of Low-Band-Gap Polymer Solar Cells Using Roll-to-Roll Methods

    DEFF Research Database (Denmark)

    Andersen, Thomas Rieks; Larsen-Olsen, Thue Trofod; Andreasen, Birgitta; Böttiger, Arvid P.L.; Carlé, Jon Eggert; Helgesen, Martin; Bundgaard, Eva; Norrman, Kion; Andreasen, Jens Wenzel; Jųrgensen, Mikkel; Krebs, Frederik C

    2011-01-01

    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...

  17. Development of polymers for large scale roll-to-roll processing of polymer solar cells

    DEFF Research Database (Denmark)

    CarlƩ, Jon Eggert

    Development of polymers for large scale roll-to-roll processing of polymer solar cells Conjugated polymers potential to both absorb light and transport current as well as the perspective of low cost and large scale production has made these kinds of material attractive in solar cell research. The...... research field of polymer solar cells (PSCs) is rapidly progressing along three lines: Improvement of efficiency and stability together with the introduction of large scale production methods. All three lines are explored in this work. The thesis describes low band gap polymers and why these are needed...... spectrum can effectively be tuned and a significant broadening of the absorption spectrum is obtained. A focus in this thesis is stabilization of the active layer morphology and the photochemical stability of its components. In terms of stability PSC degrades under illumination and the operational lifetime...

  18. Flexible organic tandem solar modules with 6% efficiency: combining roll-to-roll compatible processing with high geometric fill factors

    DEFF Research Database (Denmark)

    Spyropoulos, G. D.; Kubis, P.; Li, Na; Baran, D.; Lucera, L.; Salvador, M.; Ameri, T.; Voigt, M. M.; Krebs, Frederik C; Brabec, C. J.

    2014-01-01

    Organic solar cell technology bears the potential for high photovoltaic performance combined with truly low-cost, high-volume processing. Here we demonstrate organic tandem solar modules on flexible substrates fabricated by fully roll-to-roll compatible processing at temperatures

  19. Scalable, ambient atmosphere roll-to-roll manufacture of encapsulated large area, flexible organic tandem solar cell modules

    DEFF Research Database (Denmark)

    Andersen, Thomas Rieks; Dam, Henrik Friis; Hösel, Markus; Helgesen, Martin; Carlé, Jon Eggert; Larsen-Olsen, Thue Trofod; Gevorgyan, Suren; Andreasen, Jens Wenzel; Adams, Jens; Li, Ning; Machui, Florian; Spyropoulos, George D.; Ameri, Tayebeh; Lema?tre, Noella; Legros, Mathilde; Scheel, Arnulf; Gaiser, Detlef; Kreul, Kilian; Berny, Stephane; Lozman, Owen R.; Nordman, Sirpa; Välimäki, Marja; Vilkman, Marja; Sųndergaard, Roar R.; Jųrgensen, Mikkel; Brabec, Christoph J.; Krebs, Frederik C

    2014-01-01

    Inline printing and coating methods have been demonstrated to enable a high technical yield of fully roll-to-roll processed polymer tandem solar cell modules. We demonstrate generality by employing different material sets and also describe how the ink systems must be carefully co-developed in ord...

  20. Flexible organic tandem solar modules with 6% efficiency: combining roll-to-roll compatible processing with high geometric fill factors

    DEFF Research Database (Denmark)

    Spyropoulos, G. D.; Kubis, P.; Li, Na; Baran, D.; Lucera, L.; Salvador, M.; Ameri, T.; Voigt, M. M.; Krebs, Frederik C; Brabec, C. J.

    2014-01-01

    Organic solar cell technology bears the potential for high photovoltaic performance combined with truly low-cost, high-volume processing. Here we demonstrate organic tandem solar modules on flexible substrates fabricated by fully roll-to-roll compatible processing at temperatures...

  1. All polymer photovoltaics: From small inverted devices to large roll-to-roll coated and printed solar cells

    DEFF Research Database (Denmark)

    Liu, Yao; Larsen-Olsen, Thue Trofod; Zhao, Xingang; Andreasen, Birgitta; Sųndergaard, Roar R.; Helgesen, Martin; Norrman, Kion; Jųrgensen, Mikkel; Krebs, Frederik C; Zhan, Xiaowei

    2013-01-01

    Inverted all polymer solar cells based on a blend of a perylene diimide based polymer acceptor and a dithienosilole based polymer donor were fabricated from small area devices to roll-to-roll (R2R) coated and printed large area modules. The device performance was successfully optimized by using s...

  2. High-throughput roll-to-roll X-ray characterization of polymer solar cell active layers

    DEFF Research Database (Denmark)

    Bƶttiger, Arvid P.L.; JĆørgensen, Mikkel; Menzel, Andreas; Krebs, Frederik C; Andreasen, Jens Wenzel

    2012-01-01

    Synchrotron-based X-rays were used to probe active materials for polymer solar cells on flexible polyester foil. The active material was coated onto a flexible 130 micron thick polyester foil using roll-to-roll differentially pumped slot-die coating and presented variation in composition, thickne...

  3. Interlaboratory outdoor stability studies of flexible roll-to-roll coated organic photovoltaic modules: Stability over 10,000 h

    DEFF Research Database (Denmark)

    Gevorgyan, Suren; Madsen, Morten Vesterager; Dam, Henrik Friis; JĆørgensen, Mikkel; Fell, Christopher J.; Anderson, Kenrick F.; Duck, Benjamin C.; Mescheloff, Asaf; Katz, Eugene A.; Elschner, Andreas; Roesch, Roland; Hoppe, Harald; Hermenau, Martin; Riede, Moritz; Krebs, Frederik C

    2013-01-01

    This work attempts to reveal the comparability issues related to outdoor testing procedures of organic photovoltaic (OPV) modules via studies of inter-laboratory long-term outdoor measurements of roll-to-roll coated flexible OPV modules (P3HT:PCBM, inverted architecture) in different geographic...

  4. A life cycle analysis of polymer solar cell modules prepared using roll-to-roll methods under ambient conditions

    DEFF Research Database (Denmark)

    Espinosa Martinez, Nieves; Garcķa-Valverde, Rafael; Urbina, Antonio; Krebs, Frederik C

    2011-01-01

    processed into the required pattern using a full roll-to-roll process, employing screen printing of an etch resist and then applying etching, stripping, washing and drying procedures. The three subsequent layers; ZnO, P3HT:PCBM and PEDOT:PSS were slot-die coated and the silver back electrode was screen...

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

    Science.gov (United States)

    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. A round robin study of flexible large-area roll-to-roll processed polymer solar cell modules

    DEFF Research Database (Denmark)

    Krebs, Frederik C; Gevorgyan, Suren; Gholamkhass, Bobak; Holdcraft, Steven; Schlenker, Cody; Thompson, Mark E.; Thompson, Barry C.; Olsson, Dana; Ginley, David S.; Shaheen, Sean E.; Alshareef, Husam N.; Murphy, John W.; Youngblood, W. Justin; Heston, Nathan C.; Reynolds, John R.; Jia, Shijun; Laird, Darin; Tuladhar, Sachetan M.; Dane, Justin G.A.; Atienzar, Pedro; Nelson, Jenny; Kroon, Jan M.; Wienk, Martijn M.; Janssen, René A.J.; Tvingstedt, Kristofer; Zhang, Fengling; Andersson, Mattias; Inganäs, Olle; Lira-Cantu, Monica; Bettignies, Rémi de; Guillerez, Stéphane; Aernouts, Tom; Cheyns, David; Lutsen, Laurence; Zimmermann, Birger; Würfel, Uli; Niggemann, Michael; Schleiermacher, Hans-Frieder; Liska, Paul; Grätzel, Michael; Lianos, Panagiotis; Katz, Eugene A.; Lohwasser, Wolfgang; Jannon, Bertrand

    2009-01-01

    A round robin for the performance of roll-to-roll coated flexible large-area polymer solar-cell modules involving 18 different laboratories in Northern America, Europe and Middle East is presented. The study involved the performance measurement of the devices at one location (Risų DTU) followed b...

  7. Rolling of high nitrogen steel - texture analysis

    International Nuclear Information System (INIS)

    In polycrystalline materials plastic deformation leads to incompatibilities at grain boundaries, and in the case of duplex steels additionally at phase boundaries. These deformation inhomogeneities influence also the texture development of each phase. The more ductile a material is the easier it can fulfill the imposed deformation. Thereby, if possible, the orientations of all grains try to rotate, for instance by slip of twinning, towards the 'most suitable' orientation. But with increasing nitrogen content dislocation glide, which is the most important deformation mechanism, is progressively hindered. Furthermore all the mechanisms, which influence texture development, i.e. dislocation glide, stacking fault energy, structure and energy of grain and phase boundaries, the precipitation of nitrides ..., are also influenced by the nitrogen content. In the following the rolling texture development at room temperature of two nitrogen alloyed duplex stainless steels and the high nitrogen alloyed austenite P900 will be presented and compared. (author). 27 refs., 9 figs

  8. Inhomogeneous fragmentation of the rolling tachyon

    International Nuclear Information System (INIS)

    Dirac-Born-Infeld type effective actions reproduce many aspects of string theory classical tachyon dynamics of unstable Dp-branes. The inhomogeneous tachyon field rolling from the top of its potential forms topological defects of lower codimensions. In between them, as we show, the tachyon energy density fragments into a p-dimensional web-like high density network evolving with time. We present an analytic asymptotic series solution of the nonlinear equations for the inhomogeneous tachyon and its stress energy. The generic solution for a tachyon field with a runaway potential in arbitrary dimensions is described by the free streaming of noninteracting massive particles whose initial velocities are defined by the gradients of the initial tachyon profile. Thus, relativistic particle mechanics is a dual picture of the tachyon field effective action. Implications of this picture for inflationary models with a decaying tachyon field are discussed

  9. Micro-miniature roll rate sensor

    Science.gov (United States)

    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.

  10. Modeling of rolling element bearing mechanics

    Science.gov (United States)

    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.

  11. Annealing texture of rolled nickel alloys

    International Nuclear Information System (INIS)

    A texture of pure nickel and binary alloys after the 95% rolling and annealing has been studied. Insoluble additives (Mg, Zr) slacken the cubic texture in nickel and neral slackening of the texture (Zr). In the case of alloying with silicium (up to 2%) the texture practically coinsides with that of a technical-grade nickel. The remaining soluble additives either do not change the texture of pure nickel (C, Nb) or enhance the sharpness and intensity of the cubic compontnt (Al, Cu, Mn, Cr, Mo, W, Co -at their content 0.5 to 2.0%). A model is proposed by which variation of the annealing texture upon alloying is caused by dissimilar effect of the alloying elements on the mobility of high- and low-angle grain boundaries

  12. Periodically fighting shake, rattle and roll

    CERN Document Server

    Brun, M; Jones, I S

    2011-01-01

    How easy is it to suppress shake, rattle and roll in a long bridge or a skyscraper? Most practical structures are designed so that long wave resonance vibrations can be avoided. However, there are recent examples, such as the Millennium Bridge in London or the Volga Bridge in Volgograd, which show that unexpected external forces may result in large scale unwanted shake and rattle. Full scale alteration of a bridge (or a skyscraper) would not be considered as an acceptable option, unless the structure has collapsed. Can we fix this by examining a representative part of the structure only and making small lightweight changes? We will do it here and illustrate an idea linking the engineering analysis to elastic waveguides.

  13. Thermal stability of warm-rolled tungsten

    DEFF Research Database (Denmark)

    Alfonso Lopez, Angel

    Pure tungsten is considered as armor material for the most critical parts of fusion reactors (thedivertor and the blanket first wall), mainly due to its high melting point (3422 °C). This is becauseboth the divertor and the first wall have to withstand high temperatures during service which...... recrystallization occur in tungsten, and quantifying the kinetics and microstructuralaspects of these restoration processes. Two warm-rolled tungsten plates are annealed attemperatures between 1100 °C and 1350 °C, under vacuum conditions or argon atmosphere. Theeffects of annealing on the microstructure are...... recrystallization kinetics (based on these activation energies) to lower annealingtemperatures allows predicting the lifespan of these tungsten plates under fusion reactor conditions.A much longer lifetime at normal operating temperatures was found for the plate W67 (e.g. at least1 million years at 800 °C) as...

  14. Kollektiivlepingu roll töösuhete regulatsioonis pärast uue töölepingu seaduse vastuvõtmist / Kadi Pärnits

    Index Scriptorium Estoniae

    Pärnits, Kadi, 1965-

    2009-01-01

    Kollektiivlepingu roll töösuhete reguleerimisel Eesti kehtivate seaduste ja uue töölepingu seaduse järgi. Kollektiivlepingu roll Soomes, Taanis, Prantsusmaal, Saksamaal, Ungaris, Tšehhis, Poolas jt. riikides

  15. Effect of Rolling Massage on the Vortex Flow in Blood Vessels with Lattice Boltzmann Simulation

    Science.gov (United States)

    Yi, Hou Hui

    The rolling massage manipulation is a classic Chinese Medical Massage, which is a nature therapy in eliminating many diseases. Here, the effect of the rolling massage on the cavity flows in blood vessel under the rolling manipulation is studied by the lattice Boltzmann simulation. The simulation results show that the vortex flows are fully disturbed by the rolling massage. The flow behavior depends on the rolling velocity and the rolling depth. Rolling massage has a better effect on the flows in the cavity than that of the flows in a planar blood vessel. The result is helpful to understand the mechanism of the massage and develop the rolling techniques.

  16. Advanced cold rolled steels for automotive applications

    Energy Technology Data Exchange (ETDEWEB)

    Hofmann, H. [ThyssenKrupp Steel AG, Eberhardstrasse 12, 44145 Dortmund (Germany); Mattissen, D.; Schaumann, T.W. [ThyssenKrupp Steel AG, Duisburg (Germany)

    2006-09-15

    Advanced multiphase steels offer a great potential for bodies-in-white through their combination of formability and achievable component strength levels. They are first choice for strength and crash-relevant parts of challenging geometry. The intensive development of high-strength multiphase steels by ThyssenKrupp has led to hot dip galvanizing concepts with an outstanding forming potential. Hot rolled, hot dip galvanized complex phase steels are currently produced in addition to cold rolled DP and RA steels. New continuously annealed grades with tensile strength levels of up to 1000 MPa in combination with sufficient ductility for applications mainly in the field of structural automobile elements make use of the classic advantages of microalloying as well as the principles of DP and TRIP steels. Further improvement of properties will be reached by the new class of high manganese alloyed steels. (Abstract Copyright [2006], Wiley Periodicals, Inc.) [German] Fortschrittliche Multiphasen-Staehle eroeffnen wegen der inzwischen erreichbaren Kombination aus Umformbarkeit und Bauteilfestigkeit ein enormes Potenzial fuer Rohkarosserien. Sie stellen eine erste Wahl dar, wenn es um Festigkeit und um Crashsicherheit geht und besondere Anforderungen an die Bauteilgeometrien gestellt werden. Bei ThyssenKrupp hat die Entwicklung hochfester Multiphasen-Staehle in Verbindung mit dem Feuerverzinken zur Realisierung von Blechhalbzeugen gefuehrt, die hervorragend formbar sind. Es werden heute feuerverzinkte Komplexphasenstaehle neben den bewaehrten kaltgewalzten Dualphasen(DP) - und Retained Austenit(RA)-Staehlen produziert. Die neuen kontinuierlich gegluehten Stahlvarianten mit Festigkeiten bis zu 1000 MPa in Kombination mit der bei Strukturbauteilen im Automobilbau geforderten Duktilitaet nutzen sowohl die klassischen Vorteile des Mikrolegierens aus und dazu die Prinzipien, die man bei DP- und TRIP-Staehlen anwendet. Eine weitere Verbesserung des Eigenschaftsprofils wird mit dem neuen Stahltypus hochmanganhaltiger Staehle erreicht. (Abstract Copyright [2006], Wiley Periodicals, Inc.)

  17. Autonomous Supervision and Control of Parametric Roll Resonance

    DEFF Research Database (Denmark)

    Galeazzi, Roberto

    2010-01-01

    When ships sail in longitudinal waves, and the encounter frequency and wave length satisfy certain conditions, passage of wave crest and wave trough along the hull continuously amplifies the roll motion at half the frequency of encounter. This gives the onset of a resonance condition. The phenomenon can induce a rapid increase in roll motion that can reach 40 degrees or more. Recent incidents have shown that modern container ships and some fishing vessels are particularly prone to this due to their hull shape. Such incidents can result in damages counting to millions of USD. Theoretically, the resonance behaviour is well understood and it can be reproduced by quasi-periodic changes in parameters of nonlinear differential equations that describe ship motion. Practically, the challenge is whether detection and stabilization can be achieved in time to avoid damage. The research in this thesis has therefore two objectives. The first is to develop methods for detection of the inception of parametric roll resonance. The second is to develop control strategies to stabilize the motion after parametric roll has started. Stabilisation of parametric roll resonance points to two possible courses of action. One is a direct stabilisation through an increase of damping in roll, which increases the threshold that triggers the resonant motion. A second is to obtain a change in wave encounter frequency by means of changes in ship forward speed and/or heading. As direct stabilisation, this thesis considers the increase of roll damping by using fin stabilisers, which are controlled using integrator backstepping methods. As indirect stabilisation, a shift in the encounter frequency is considered by varying the ship forward speed. The speed controller is designed using nonlinear Lyapunov methods. The two control strategies are then combined to stabilise parametric roll resonance within few roll cycles. Limitations on the maximum stabilisable roll angle are analysed and linked to the ii slew rate saturation and hydrodynamic stall characteristics of the fin stabilisers. The study on maximum stabilisable roll angle leads to the requirements for early detection. Two novel detectors are proposed, which work within a shorttime prediction horizon, and issue early warnings of parametric roll inception within few roll cycles from its onset. The main idea behind these detection schemes is that of exploiting the link between the second harmonic of roll angle and the first harmonic of heave or pitch motions. A nonlinear energy flow indicator, which measures the transfer of energy from the first harmonic of heave or pitch into the second harmonic of roll, is at the core of the first detector. The second detector relies on a driving signal that carries information about the phase correlation between either pitch or heave and roll. A generalised likelihood ratio test is designed to detect a change in distribution of the driving signal. The detectors are validated against experimental data of tests of a 1:45 scale model of a container ship. The validation shows excellent performance in terms of time to detect and false-alarm rate for both the proposed detectors. The detectors are the main contribution of this research. The thesis also offers a contribution regarding modeling. A 3 degree-offreedom nonlinear model in heave-pitch-roll of a container ship suitable for parametric roll resonance study is proposed. The model, which has been developed in collaboration with other researchers, provides a benchmark for the study and simulation of parametric roll over a large range of ship speeds and sea states. The results of this research have been published in articles enclosed in this dissertation and in an international patent application.

  18. Synthesis and Characterization of Hot-Roll and Cold-Roll Byproduct-Derived Strontium Hard Ferrites

    Directory of Open Access Journals (Sweden)

    H. S. Woon

    2009-01-01

    Full Text Available Problem statement: Ceramic permanent magnets or more commonly known as strontium hexagonal ferrites have been widely used in permanent magnetic materials as they provide high remanence, high coercivity, relatively high energy product and good chemical stability. In this study, we treated factory byproduct from hot-roll and cold-roll steel industry was used as raw material in synthesis of strontium hexagonal hard ferrites. Approach: X-Ray Diffraction (XRD was employed to confirm the formation of strontium hard ferrite compound. Vibrating Sample Magnetometer (VSM was used to analyze the magnetic properties of samples prepared. Results: The magnetic properties, namely remanence and coercivity of factory byproduct-derived strontium hard ferrites were compared. The cold-roll-derived strontium hard ferrite showed higher remanence in this study. Conclusion: This implied that cold-roll byproduct was a better candidate to replace hematite in preparation of strontium hard ferrites compared to hot-roll byproduct.

  19. Numerical Treatments of Slipping/No-Slip Zones in Cold Rolling of Thin Sheets with Heavy Roll Deformation

    Directory of Open Access Journals (Sweden)

    Yukio Shigaki

    2015-04-01

    Full Text Available In the thin sheet cold rolling manufacturing process, a major issue is roll elastic deformation and its impact on roll load, torque and contact stresses. As in many systems implying mechanical contact under high loading, a central part is under “sticking friction” (no slip while both extremities do slip to accommodate the material acceleration of the rolled metal sheet. This is a crucial point for modeling of such rolling processes and the numerical treatment of contact and friction (“regularized” or not, of the transition between these zones, does have an impact on the results. Two ways to deal with it are compared (regularization of the stick/slip transition, direct imposition of a no-slip condition and recommendations are given.

  20. Improving the quality of rolled pipe steel products by minimizing the bending of the ends of plates

    Science.gov (United States)

    Salganik, V. M.; Chikishev, D. N.; Denisov, S. V.; Stekanov, P. A.; Shmakov, A. V.; Fomichev, A. V.

    2013-11-01

    The causes of the vertical bending of the front ends of plates during hot rolling are revealed. A finite-element mathematical model is developed to describe the state of stress of the metal in an asymmetric deformation zone with allowance for solving a temperature problem, and the model is adapted to the conditions of the 5000 rolling mill in OAO MMK. It is found that, in rolling with mismatched work roll speeds, the direction of bending of the front strip end is determined by the strip thickness and the deformation zone shape. The main cause of the bending of the front plate end at the stage of finishing stage of rolling is shown to be the difference between the roller bed level and the rolling line. New asymmetric deformation regimes are developed with allowance for the effect of the deformation zone shape on the direction of bending of the front strip end. The developed technological regimes of asymmetric rolling make it possible to decrease the mill downtime because of the bending of the breakdown bar ends and to reduce the metal volume rejected because of violated temperature regimes of the thermomechanical treatment of plates.

  1. Research on automatic loading & unloading technology for vertical hot ring rolling process

    Directory of Open Access Journals (Sweden)

    Xiaokai Wang

    2015-01-01

    Full Text Available The automatic loading & unloading technology is the key to the automatic ring production line. In this paper, the automatic vertical hot ring rolling (VHRR process is taken as the target, the method of the loading & unloading for VHRR is proposed, and the mechanical structure of loading & unloading system is designed, The virtual prototype model of VHRR mill and loading & unloading mechanism is established, and the coordinated control method of VHRR mill and loading & unloading auxiliaries is studied, the movement trace and dynamic characteristic of the critical components are obtained. Finally, a series of hot ring rolling tests are conducted on the VHRR mill, and the production rhythm and the formed rings' geometric precision are analysed. The tests results show that the loading & unloading technology can meet the high quality and high efficiency ring production requirement. The research conclusions have practical significance for the large-scale automatic ring production.

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

    Science.gov (United States)

    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. PMID:25774448

  3. Determining asymmetry of roll-over shapes in prosthetic walking

    Directory of Open Access Journals (Sweden)

    Carolin Curtze, MSc

    2011-12-01

    Full Text Available How does the inherent asymmetry of the locomotor system in people with lower-limb amputation affect the ankle-foot roll-over shape of prosthetic walking? In a single-case design, we evaluated the walking patterns of six people with lower-limb amputation (3 transtibial and 3 transfemoral and three matched nondisabled controls. We analyzed the walking patterns in terms of roll-over characteristics and spatial and temporal factors. We determined the level of asymmetry by roll-over shape comparison (root-mean-square distance as well as differences in radius of curvature. In addition, we calculated ratios to determine spatial and temporal asymmetries and described different aspects of asymmetry of roll-over shapes. All participants showed some level of asymmetry in roll-over shape, even the nondisabled controls. Furthermore, we found good intralimb reproducibility for the group as a whole. With respect to spatial and temporal factors, the participants with transtibial amputation had a quite symmetrical gait pattern, while the gait in the participants with transfemoral amputation was more asymmetrical. The individual ankle-foot roll-over shapes provide additional insight into the marked individual adjustments occurring during the stance phase of the nondisabled limb. The two methods we present are suitable for determining asymmetry of roll-over shapes; both methods should be used complementarily.

  4. Rolling induced size effects in elastic–viscoplastic sheet metals

    DEFF Research Database (Denmark)

    Nielsen, Kim Lau

    2015-01-01

    Rolling processes for which the characteristic length scale reaches into the range where size effects become important are receiving increased interest. In particularly, this is owed to the roll-molding process under development for high-throughput of micron-scale surface features. The study presented revolves around the rolling induced effect of visco-plasticity (ranging hot and cold rolling) in combination with strain gradient hardening – including both dissipative and energetic contributions. To bring out first order effects on rolling at small scale, the modeling efforts are limited to flat sheet rolling, where a non-homogeneous material deformation takes place between the rollers. Large strain gradients develop where the rollers first come in contact with the sheet, and a higher order plasticity model is employed to illustrate their influence at small scales. The study reveals that the energetic length parameter has negligible effect on the rolling quantities of interest, while the contribution coming from the dissipative length parameter can be dominant. Considering a slow and a fast moving sheet, respectively, convergence towards the rate independent limit is demonstrated, and a characteristic velocity is identified, for which the torque and punch force applied to the roller becomes independent of the material rate-sensitivity.

  5. Rolling and annealing texture of 3004 aluminium alloy

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, D.F.; Jiang, X.P.; Hu, Z.C.; Wang, F.; Zuo, L. [School of Materials and Metallurgy, Northeastern Univ., Shenyang (China)

    2002-07-01

    The 3004 aluminium alloy used for beverage cans, require stringent material properties and earing behavior of the final sheet is of great importance. Final texture and thereby earing is controlled by deformation and heating processes in a most complicated manner where hot rolling, cold rolling and recrystallization are key issues. The hot rolling, cold rolling and annealing textures of the 3004 aluminium alloys were studied by means of orientation distribution functions (ODFs). The results show that texture in the hot-rolled plate is (100)[uvw] and the rotated cube orientation {l_brace}100{r_brace} left angle 011 right angle is the strongest. The intensity of the rotated cube orientation {l_brace}100{r_brace} left angle 011 right angle increases with the increase of the reduction The cold rolling textures show a typical copper-type feature and the intensity of deformation texture increases with the increase reduction The final cold rolling textures are composed of S-, Cu- and Bs-components. After isothermal annealing for 2 h, the recrystallization textures are different from the deformation ones. The recrystallization textures are mainly composed of Cube-, annealing R/S and copper components. The desired cube texture is the strongest at 400 C. The evolution of texture during recrystallization is described in detail and possible origins of various components are discussed. (orig.)

  6. Studi Eksperimen Pengaruh Lunas Bilga Terhadap Gerakan Rolling

    Directory of Open Access Journals (Sweden)

    Haris Hendratmoko

    2012-09-01

    Full Text Available Gerak roll merupakan parameter penting dalam stabilitas kapal, dimana pada cuaca buruk gerak roll dapat menyebakan capsizing. Di sisi lain, koefisien damping merupakan parameter terpenting untuk meredam gerakan roll. Berbagai Bentuk anti-roll device kemudian digunakan untuk memperbesar koefisien damping dan kemudian mengurangi gerak roll kapal. Salah satu bentuk anti-roll yang popular adalah lunas bilga, karena sejumlah kelebihannya antara lain efektifitas lunas bilga dan sifat lunas bilga yang pasif. Aspek yang perlu diperhatikan dalam pemasangan lunas bilga adalah efektifitas dalam meningkatkan koefisien damping dan respon kapal akibat pemasangan lunas bilga. Tugas akir ini menjelaskan tentang pengaruh panjang lunas bilga (Lbk dan lebar lunas bilga (Bbk terhadap koefisien damping dan respon kapal.Variasi ukuran lunas bilga yang digunakan yaitu B0; B1; B2; B3; B4; B5; B6. Selain itu juga dilakukan variasi periode gelombang 1,2; 1,6; 2; 2,4 dan 2,8 untuk menghitung respon kapal. Semua uji gerak roll berdasakan eksperimen towing tank di laboratorium hidrodinamika. Dari hasil analisa didapatkan penambahan lebar lunas bilga lebih efektif daripada penambahan panjang dan juga pemasangan lunas bilga efektif mengurangi respon puncak kapal apabila dibandingkan dengan barehull.

  7. Design, Analysis and Optimization of Anti-Roll Bar

    Directory of Open Access Journals (Sweden)

    Pravin Bharane

    2014-09-01

    Full Text Available Vehicle anti-roll bar is part of an automobile suspension system which limits body roll angle. This U-shaped metal bar connects opposite wheels together through short lever arms and is clamped to the vehicle chassis with rubber bushes. Its function is to reduce body roll while cornering, also while travelling on uneven road which enhances safety and comfort during driving. Design changes of anti-roll bars are quite common at various steps of vehicle production and a design analysis must be performed for each change. So Finite Element Analysis (FEA can be effectively used in design analysis of anti-roll bars. The finite element analysis is performed by ANSYS. This paper includes pre-processing, analysis, post processing, and analyzing the FEA results by using APDL (Ansys Parametric Design Language. The effects of anti-roll bar design parameters on final anti-roll bar properties are also evaluated by performing sample analyses with the FEA program developed in this project.

  8. Effect of pass schedule and groove design on the metal deformation of 38MnVS6 in the initial passes of hot rolling

    Indian Academy of Sciences (India)

    R S Nalawade; V R Marje; G Balachandran; V Balasubramanian

    2016-01-01

    The deformation behaviour of a hot rolled micro-alloyed steel bar of grade 38MnVS6 was examined using an FEM model during the initial passes in a blooming mill, as a function of three different pass schedules,roll groove depth, collar taper angle and corner radius. The simulations predicted the effective strain penetration,load, torque, fish tail billet end shapes, and metal flow behaviour at a chosen temperature, mill rpm and draft. The model predictions were validated for typical groove geometry and a typical pass schedule. Lower collar taper angle, lower corner radius and higher depth of groove in hot rolling enabled achievement of higher strain penetration, higher mill load and lower fish tail formation. The present study establishes the capability of the model to improve the internal quality of the rolled billet as measured by effective strain which was corroborated to the rolled bar macrostructure and microstructure. The model enables yield improvement by the choice of draft to minimise fish tail losses. The surface quality is improved by the ability to avoid fin formation that occurs at certain conditions of rolling. Thus, the groove geometry, roll pass schedule and rolling mill parameters and temperature can be optimised for best product quality and yield.

  9. Clad strip casting by a twin roll caster

    Directory of Open Access Journals (Sweden)

    T. Haga

    2009-06-01

    Full Text Available Purpose: Of this paper is to realize the casting of the clad strip by only one process. Therefore, the investigation of the ability of the casting of the clad strip by a vertical type twin roll caster was operated. The aim of the use of the twin roll caster to make clad strip was in the reduction of the production-energy of the clad strip.Design/methodology/approach: Used in the present study was a vertical type twin roll caster with the scriber. The scriber was used to prevent the mixture of the two kinds of the melts. The scriber was set at roll-bite, and the scriber contacted to the one of solidification layer. The melt was stopped by the scriber and the only the solidification layer was dragged by the roll.Findings: The clad strip with the clear interface could be by the vertical type twin roll caster with the scriber. The scriber was useful to drag only the solid and semisolid layer. The two kinds of strips were connected strictly at the interface of the clad strip. The clad strip was not broken at the interface by the continuous bending.Research limitations/implications: Are that 100 mm width-strip was cast in the present study. Ability of the clad strip that is wider than 100 mm was not clear. The control of the clad ratio was not investigated.Practical implications: The twin roll caster devised and investigated in this report is useful to cast clad strip like the brazing sheet for the radiator of the automobile.Originality/value: The vertical type twin roll cater to cast clad strip is original process. The scriber was used to prevent the mixture of the two kinds of melts. The scriber was not used in the previous research to cast clad strip at the twin roll caster, and use of the scriber was the first try.

  10. Selection of a decision model for rolling stock maintenance scheduling

    Scientific Electronic Library Online (English)

    O.O., Asekun; C.J., Fourie.

    2015-05-01

    Full Text Available Rolling stock is the most maintenance intensive part of the railway system and therefore, the most vulnerable if maintenance is neglected. It is therefore, essential to have an efficient maintenance schedule for rolling stock components. A decision support model can be used to achieve this. However, [...] selecting the appropriate model to achieve this is vital to the success of the decision support model. In this paper a practical way of selecting the appropriate model to develop a decision support for scheduling of rolling stock maintenance, is presented. A case study is used as a numerical example for the proposed framework.

  11. Numerical evaluation of uniform magnetic field within superconducting Swiss roll

    Science.gov (United States)

    Tsuchimoto, M.; Demachi, K.; Itoh, I.

    2004-10-01

    Uniform and high magnetic field is required for medical apparatus such as magnetic resonance imaging. The homogeneous magnetic field in a solenoid magnet can be enhanced with superconducting Swiss roll, where NbTi/Nb/Cu multilayer sheet is rolled inside the magnet. Experimental magnetic field measurement is evaluated with a numerical simulation code based on the finite element circuit method. Shielding current distribution in the superconductor is obtained by using the critical state model. Numerical results agree well with experimental results. Uniformity of the field is discussed from the shielding current distribution of the superconducting Swiss roll.

  12. Correcting Quadrupole Roll in Magnetic Lenses with Skew Quadrupoles

    Energy Technology Data Exchange (ETDEWEB)

    Walstrom, Peter Lowell [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    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 roll angle or placing skew quadrupole correctors in the bores of main quadrupoles).

  13. Fast-roll solutions from two scalar field inflation

    CERN Document Server

    Santos, J R L

    2015-01-01

    The cosmological equations of motion of scalar fields are commonly not easy to be analytically solved, which makes necessary to use approximation methods, as the {\\it slow-roll} regime. In such an approximation one considers the scalar field potentials to be nearly flat. On the other hand, the so called {\\it fast-roll} regime considers exactly flat potentials. Our purpose in this work is to obtain solutions for a two scalar field quintessence model in the fast-roll regime. Cosmological interpretations for such solutions are also presented.

  14. Optimization of Contact Point Trajectory for a Spherical Rolling Robot

    Science.gov (United States)

    Urakubo, Takateru; Maekawa, Satoshi; Ueda, Tetsuya; Tamaki, Hisashi

    Recently, various types of spherical robots that can roll and move on the ground have been developed. We are now developing a spherical robot that can roll and, in addition, rotate around the vertical axis simultaneously. By using the added degree of freedom, the attitude of the robot can be changed arbitrarily even when the robot rolls along a specified path on the ground. This paper proposes an optimal trajectory planning method for the robot that moves along a straight line on the ground. The trajectory that connects an initial attitude and a final attitude is obtained by finding the optimal contact point trajectory on a spherical surface.

  15. Effects of Foam Rolling on Vertical Jump Performance

    OpenAIRE

    Andrew Jones; Brown, Lee E.; Coburn, Jared W.; Noffal, Guillermo J.

    2015-01-01

    Background: Foam rolling is a popular activity utilized by strength and conditioning coaches as it is believed to increase muscle length and break up fibrous adhesions located in connective tissue. However, there is little research investigating the effects of foam rolling on athletic performance. Objective: The purpose of this study was to investigate the effects of lower body foam rolling on vertical jump performance. Methods: Twenty males (age 24.05 ± 2.02 years; height 177.43 ± 6.31 cm; m...

  16. Nucleation at hardness indentations in cold rolled Al

    DEFF Research Database (Denmark)

    Xu, C.L.; Zhang, Yubin

    2015-01-01

    Nucleation of recrystallization near hardness indentations has been investigated in slightly cold rolled high purity aluminium. Samples were cold rolled to 12% and 20% reductions in thickness and indentations were done with two different loads (500 g and 2000 g). The samples were annealed at 300 °C for 1 h and nuclei were identified. It is found that the indentations are preferential nucleation sites. With EBSD maps around indentation tips, the orientation relationship between nuclei and matrix is analyzed. Finally, effects of rolling reduction and indentation load on local misorientations and stored energy distributions and thus on nucleation are discussed.

  17. [Rolling friction: a desing of artificial knee joint].

    Science.gov (United States)

    He, Yujue; Yu, Zhongjia; Chen, Ming; Wang, Chengtao

    2005-08-01

    Resorption and osteolysis of periimplant bones resulting from the wear debris of artificial joint will cause long-term loosening. A new type of rolling knee artificial joint without UHMWPE based on the mechanics of rolling friction is designed for alleviating this problem. Because of low friction force, the resistance of extension and flexion is reduced strikingly and the stress on the interface between prosthesis and bone is reduced evidently. In addition, the bio-toxicity caused by the wear debris of UHMWPE will not occur absolutely. In consequence, the rolling artificial joint can prevent the trend of long-term loosening of the prosthesis efficiently. PMID:16156286

  18. Hydrogen effect on cold rolling texture of stable ?-titanium alloy

    International Nuclear Information System (INIS)

    A study was made into microstructure and texture of cold rolled titanium alloy VT-35 with various hydrogen content aimed to reveal hydrogen influence on the mechanism of cold plastic deformation by rolling. Experiments were carried out using sheets 1.2 mm thick hydrogenated up to hydrogen concentrations from 0.06 to 0.554 mass. %. All specimens constituted a single-phase FCC ?-solid solution. It is shown that small hydrogen additions have a plasticizing effect on ?-titanium alloys in their cold rolling. The character of texture is dependent on hydrogen concentration and determined by deformation mechanism. 6 refs.; 5 figs

  19. Flowing Model in Rectangular Tubes at Rolling Motion

    International Nuclear Information System (INIS)

    The laminar flow model in rectangular tubes at rolling motion was developed and the velocity correlation was derived. The effect of rolling motion on laminar flow in rectangular tubes was investigated. The effect of centrifugal force is counteracted in the system. The velocity oscillation is caused by tangential force,so the oscillation period of velocity is the same with the rolling period. However, the tangential force does not effect on the average velocity profile and frictional resistance factor. As to the laminar flow in rectangular tubes, the Richardson effect can also be seen. (authors)

  20. Rock-'n-roll: de sociale constructie van een muziekstijl

    OpenAIRE

    Anjou, Leo

    2001-01-01

    The rise of an autonomous youth culture is one of the most remarkable events of the fifties not in the least because of the noisy advent of its music: rock-'n-roll. This music shocked society and has been associated with rebellion and protest ever since. Rock-'n-roll acquired a meaning that went beyond music itself and the intentions of its producers because of its social construction. This article analyses the construction of rock-'n-roll, particularly the way it was shaped in the social and...

  1. FEM analysis of hollow hub forming in rolling extrusion process

    Directory of Open Access Journals (Sweden)

    J. Bartnicki

    2014-10-01

    Full Text Available In this paper are presented the results of numerical calculations of rolling extrusion process of a hollow hub. As the flanges manufacturing at both sides of the product is required, in the analyzed process of rolling extrusion, a rear bumper was implemented as additional tool limiting axial metal flow. Numerical calculations of the hub forming process were conducted basing on finite element method, applying software Deform3D and Simufact in conditions of three dimensional state of strain. The obtained satisfactory results show that it is possible to conduct the further research works of experimental character, with the application of a modernized aggregate for the rolling extrusion process PO-2.

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

    Science.gov (United States)

    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.

  3. NUMERICAL SIMULATION OF THE FIRST COLD ROLLING PASS OF A C-MN STRIP STEEL

    Directory of Open Access Journals (Sweden)

    Willian Costa do Nascimento

    2013-03-01

    Full Text Available This work presents the modeling by the finite element method of the first cold rolling pass of a four-high mill at the CSN steel plant. For this purpose, a two dimensional model is proposed considering the work-roll as a rigid surface together with the assumptions of plane-strain state for the strip and material isotropy with nonlinear isotropic workhardening. A C-Mn steel strip with initial thickness of 3.5 mm was first characterized by means of uniaxial tensile tests in specimens cut along the rolling direction to evaluate the work-hardening parameters. In the finite element model, the contact is defined by means of the Coulomb’s law to describe the friction between the work-roll and the strip surfaces. Moreover, the industrial back and forward tensions are also taken into account as prescribed conditions in the finite element model. The numerical predictions of the rolling load show a good agreement with the measured data and the forecasted value is determined with the slab-method.

  4. Application of powder metallurgy and hot rolling processes for manufacturing aluminum/alumina composite strips

    International Nuclear Information System (INIS)

    In this study, aluminum matrix composites (AMC) with 2, 4, 6 and 10 wt% alumina were produced using powder metallurgy (PM), mechanical milling (MM) and vacuum hot pressing (VHP) techniques; then, this was followed by the hot-rolling process. During hot rolling, AMCs with 6 and 10 wt% Al2O3 were fractured whereas strip composites with 2 and 4 wt% Al2O3 were produced successfully. Microstructure and mechanical properties of the samples were investigated by optical and scanning electron microscopes and tensile and hardness tests, respectively. Microscopic evaluations of the hot-rolled composites showed a uniform distribution of alumina particles in the aluminum matrix. It was found that with increasing alumina content in the matrix, tensile strength (TS) and hardness increased and the percentage of elongation also decreased. Scanning electron microscope (SEM) was used to investigate aluminum/alumina interfaces and fracture surfaces of the hot rolled specimens after tensile test. SEM observations demonstrated that the failure mode in the hot-rolled Al-2 wt% Al2O3 composite strips is a typical ductile fracture, while the failure mode was shear ductile fracture with more flat surfaces in Al-4 wt% Al2O3 strips.

  5. Product integration of compact roll-to-roll processed polymer solar cell modules: methods and manufacture using flexographic printing, slot-die coating and rotary screen printing

    DEFF Research Database (Denmark)

    Krebs, Frederik C; Fyenbo, Jan; Jųrgensen, Mikkel

    2010-01-01

    The improvement of the performance of roll-to-roll processed polymer solar cell modules through miniaturization of the device outline is described. The devices were prepared using full roll-to-roll processing comprising flexographic printing, slot-die coating and rotary screen printing to create 5 mm wide lines of ZnO, P3HT:[60/70]PCBM, PEDOT:PSS and silver on an ITO-PET substrate. The lines were spaced by 1 mm and the devices were completed by encapsulation using roll-to-roll lamination on both...

  6. Development of polymers for large scale roll-to-roll processing of polymer solar cells

    DEFF Research Database (Denmark)

    Carlé, Jon Eggert

    2013-01-01

    Development of polymers for large scale roll-to-roll processing of polymer solar cells Conjugated polymers potential to both absorb light and transport current as well as the perspective of low cost and large scale production has made these kinds of material attractive in solar cell research. The research field of polymer solar cells (PSCs) is rapidly progressing along three lines: Improvement of efficiency and stability together with the introduction of large scale production methods. All three lines are explored in this work. The thesis describes low band gap polymers and why these are needed. Polymer of this type display broader absorption resulting in better overlap with the solar spectrum and potentially higher current density. Synthesis, characterization and device performance of three series of polymers illustrating how the absorption spectrum of polymers can be manipulated synthetically and how this affects the PSC parameters are presented. It is generally found that it is possible to syntheticallycontrol the absorption spectrum of conjugated polymer systems. One way to alter the spectrum is by incorporating alternating donor-acceptor motifs, resulting in an additional optical absorption band, the charge transfer (CT) band. A second approach is to introduce fused donor systems. A third method is to use several different monomer units in the polymerization hereby creating semirandom polymers with multiple chromophores. By changing the fed ratio of the monomers the absorption spectrum can effectively be tuned and a significant broadening of the absorption spectrum is obtained. A focus in this thesis is stabilization of the active layer morphology and the photochemical stability of its components. In terms of stability PSC degrades under illumination and the operational lifetime are generally limited. A fundamental understanding of the degradation of PSCs allows one to develop improved materials that can increase their lifetime. Synthesis and characterization of polymer materials for improved stability in PSCs is presented. Stabilization of the active layer was accomplished by incorporating different types of crosslinking functionalities into the polymer TQ1. Cross-linking was achieved by UV-light illumination to give solvent resistant films and reduced phase separation and growth of PCBM crystallites in polymer:PCBM films. This study showed that cross-linking can improve morphological stability but that it has little influence on the operational stability of the device. The photochemical stability of a wide range of materials relevant to PSC is presented and compared. General rules relative to the polymer structure–stability relationship are proposed and can be used as a guideline for further development of PSCs. One of the main advantages of PSCs is that they can be produced using printing techniques which allows for large scale roll-to-roll (R2R) production. A laboratory roll coater that enables solution processing of five layers on ITO-free flexible substrates using slot-die coating and flexographic printing is presented. As little as one ml of active material solution is needed to produce more than a hundred devices. This laboratory scale approach to PSCs was found to be directly scalable to the large scale R2R equipment making it suitable as a test platform for polymer development. PSC devices based on PDTSTTz-4 and PCBM were produced using the laboratory roll coater and through optimerization of the processing parameters a PCE of 2.95 % at ambient condition. This efficiency is among the highest obtained on flexible ITO-free substrates using slot-die coating.

  7. Development of a paper based roll-to-roll nanoimprinting machine

    Science.gov (United States)

    Son, Byungwook

    Nanoimprint lithography (NIL) has been developed and studied since 1995. It is a technique where micro- or nanoscale patterns are transferred to soft materials such as polymer through pressing a stamp with certain patterns into this materials and then solidifying it by cooling at lower temperature or curing under ultra violet excitement. High Cost and low throughput of batch mode nanoimprint lithography (NIL) processes are limiting its wide range of applications in meeting industry manufacturing requirements. The roll-to-roll (R2R) nanoimprinting technology is emerged as a solution to this issue. This thesis study presents the design, build and test of an innovative R2R T-NIL process machine for nanofabrication and MEMS fabrication applications, which consists of individual modules of heating, inking, pressuring, and rotational speed control. The system utilizes PDMS as mold material, PMMA as imprinting material, and paper as substrate material. In order to achieve a uniform pressure on PMMA during imprinting process, an innovative air pressure device (APD) was developed and integrated with R2R machine. The APD replaces the conventional 2-roll line contact pressure approach and can cover one third of the surface of the imprinting roller with a uniform pressure (1-3 psi). During the imprinting experiment, a mixture of PMMA (20w %) and 2-Ethoxyethyl acetate is applied on the paper substrate by an inking roller using capillary force and an IR heater is used for pre-heating and drying of polymer layers before it is fed into the imprinting module. Two 500-Watt cartridge heaters are installed on the roller and provide the heat to raise the PMMA film temperature during the imprinting.

  8. Cord blood sampling: Die Rolle des Gynäkologen

    Directory of Open Access Journals (Sweden)

    Imhof M

    2001-01-01

    Full Text Available Sensationsmeldungen über neue medizinische Errungenschaften im Zusammenhang mit Stammzellen gehören beinahe zum Alltag. So erhofft man sich, die Effizienz medizinischer Behandlungstechniken deutlich zu verbessern und somit Lebenserwartung und Lebensqualität des Menschen steigern zu können. Die Anwendung von Stammzellen ist praktisch in jedem Spezialbereich der Medizin denkbar, wie z.B. durch Nachzüchtung von Organgeweben zur Behandlung einer Leberzirrhose ebenso wie eines Diabetes mellitus, und erscheint somit als ein weiterer Schritt im Wandel weg von der klassischen Nachsorge- hin zur Vorsorgemedizin. Stammzellen aus der Nabelschnur können im Vergleich zur Knochenmarkspunktion völlig risikofrei und vergleichsweise günstig gewonnen werden. Sie sind weitgehend frei von Infektionen und teilungspotent. Die Entnahme der Stammzellen findet nach Abnabelung des Kindes durch Punktion der Umbilicalvene statt. Ungefähr 80 (± 25 ml Blut werden, nach virologischer und bakteriologischer Austestung sowie Zellzählung auf ca. minus 190°C abgekühlt und eingelagert. Das Tätigkeitsspektrum des Frauenarztes ist breit. Zunehmend wird er im Zuge der Mutter-Kind-Paß-Untersuchungen mit Fragen der Patienten zum Thema Stammzelleinlagerung und Vorsorgemedizin im allgemeinen konfrontiert. Es obliegt ihm die Koordination von Vorbereitung, Entnahme und Versorgung der Präparate. Auch wenn sich der Vorgang technisch einfach darstellt, ist die Gelegenheit zur Stammzellextraktion einmalig und bedarf einer sorgfältigen Abnahme. Im Bereich der gynäkologischen Basisforschung spielen die Sexualsteroide und ihr Einfluß auf die Stammzellentwicklung eine entscheidende Rolle. Die medizinischen Auswirkungen dieses neuen Verfahrens können heute noch nicht abgeschätzt werden. Dennoch sollte man im Interesse kommender Generationen diese Chance nicht ungenützt lassen.

  9. Time-Symmetric Rolling Tachyon Profile

    CERN Document Server

    Longton, Matheson

    2015-01-01

    We investigate the tachyon profile of a time-symmetric rolling tachyon solution to open string field theory. We algebraically construct the solution of [arXiv:0707.4472] at 6th order in the marginal parameter, and numerically evaluate the corresponding tachyon profile as well as the action and several correlation functions containing the equation of motion. We find that the marginal operator's singular self-OPE is properly regularized and all quantities we examine are finite. In contrast to the widely studied time-asymmetric case, the solution depends nontrivially on the strength of the deformation parameter. For example, we find that the number and period of oscillations of the tachyon field changes as the strength of the marginal deformation is increased. We use the recent renormalization scheme of [arXiv:1412.3466], which contains two free parameters. At finite deformation parameter the tachyon profile depends on these parameters, while when the deformation parameter is small, the solution becomes insensit...

  10. Experiments on Spray from a Rolling Tire

    Science.gov (United States)

    Radovich, Charles; Browand, Fred

    2010-11-01

    A novel laboratory apparatus has been built to understand the mechanisms and statistics of droplet production for spray emerging from a rolling tire. Using high-speed imaging, water passing through a single circumferential groove was observed to leave the tire contact patch in the form of a liquid sheet of non-uniform thickness. The sheet breaks into droplets as a result of several, organized instabilities. Measurements for the breakup length of the liquid sheet showed a dependence on Weber number proportional to We-1/6, for Weber numbers of 2700, 10900 and 24400. A technique to identify and size water droplets was developed and the distribution of droplet sizes was determined as a function of Weber number. At We = 2700, droplet sizes between 80 and 9000?m were detected, with a mean diameter near 800?m. Both the range of droplet sizes and the mean diameter were found to decrease with increasing Weber number as (approximately) We-1/2. Correlation Image Velocimetry (CIV) was used to estimate the distribution of droplet velocities as a function of droplet size. The spread of droplet velocities about the tire peripheral speed is strongly correlated with droplet size. The spread can be estimated by a simple physical model incorporating rigid droplets subject to gravity and drag.

  11. Mesomorphic Lamella Rolling of Au in Vacuum

    Directory of Open Access Journals (Sweden)

    Chen Shuei-Yuan

    2009-01-01

    Full Text Available Abstract Lamellar nanocondensates in partial epitaxy with larger-sized multiply twinned particles (MTPs or alternatively in the form of multiple-walled tubes (MWTs having nothing to do with MTP were produced by the very energetic pulse laser ablation of Au target in vacuum under specified power density and pulses. Transmission electron microscopic observations revealed (111-motif diffraction and low-angle scattering. They correspond to layer interspacing (0.241–0.192 nm and the nearest neighbor distance (ca. 0.74–0.55 nm of atom clusters within the layer, respectively, for the lamella, which shows interspacing contraction with decreasing particle size under the influence of surface stress and rolls up upon electron irradiation. The uncapped MWT has nearly concentric amorphous layers interspaced by 0.458–0.335 nm depending on dislocation distribution and becomes spherical onions for surface-area reduction upon electron dosage. Analogous to graphene-derived tubular materials, the lamella-derived MWT of Au could have pentagon–hexagon pair at its zig-zag junction and useful optoelectronic properties worthy of exploration.

  12. Communication using eye roll reflective signalling

    Science.gov (United States)

    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.

  13. Thermobimetals Mechanical Properties Produced by Explosive Welding with Rolling

    OpenAIRE

    Gulbin, V.; Kobelev, A.; Borissov, D.

    1997-01-01

    We used explosive welding with rolling to produce thermobimetals on the basis of beryllium bronze and alloys of nickel. It gave us possibility to obtain magnetic and non-magnetic thermobimetals possessing high physical and mechanical properties.

  14. On the assessment of parametric roll in random sea

    DEFF Research Database (Denmark)

    Jensen, JĆørgen Juncher; Olsen, Anders SmƦrup

    2006-01-01

    simple non-linear dynamic model for roll including the effect of heave is formulated in the time domain. Closed form expressions are used for the heave motion and for the wave-induced roll moment. The instantaneous GZ curve is derived numerically, but only for one regular wave. Inclu-sion of parametric...... roll in the example has not been possible due to shortcomings in the present model of the GZ curve and the lack of a coupling to pitch. However, provided more accurate hydrostatic and hydrodynamic models are used, parametric roll could be accounted for, too, in the proposed stochastic procedure.......The aim of the present paper is to advocate for a very effective stochastic procedure, based on the First Order Reli-ability Method (FORM) well-known within structural reliability. Due to the efficient optimisation procedures imple-mented in standard FORM codes and the short duration of the time...

  15. Dynamic Effect of Rolling Massage on Blood Flow

    International Nuclear Information System (INIS)

    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.

  16. Dynamic Effect of Rolling Massage on Blood Flow

    Science.gov (United States)

    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.

  17. Elastic Deployable Composite Tubular Roll-Out Boom Project

    Data.gov (United States)

    National Aeronautics and Space Administration ā€” Deployable Space Systems (DSS) has developed an affordable and ultra-lightweight elastically self-deployable Roll-Out Boom technology that provides affordability...

  18. Elastic Deployable Composite Tubular Roll-Out Boom Project

    Data.gov (United States)

    National Aeronautics and Space Administration ā€” DSS's innovative Elastic Deployable Composite Tubular Roll-Out Boom will provide revolutionary performance when compared to conventional state-of-the-art...

  19. Rolling to a stop down an inclined plane

    Science.gov (United States)

    Cross, Rod

    2015-11-01

    Experimental and theoretical results are presented showing that a ball with a high coefficient of rolling friction can roll to a stop when it rolls without slipping down an inclined plane. The rate at which energy is dissipated is directly proportional to the rolling friction force on the ball, despite the fact that the net work done by the friction force is zero. The energy loss arises from internal friction within the ball due to compression and expansion of the ball in the contact region. Since the compression force is larger than the expansion force, an opposing torque arises that reduces the angular velocity of the ball. The work done by the opposing torque is equal to the energy that is dissipated.

  20. Rolling bearing fault diagnosis using an optimization deep belief network

    Science.gov (United States)

    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.

  1. Localized and guided electroluminescence from roll printed organic nanofibres

    DEFF Research Database (Denmark)

    Tavares, Luciana; Kjelstrup-Hansen, Jakob; Rubahn, Horst-Günter

    2012-01-01

    Here, we report localized, polarized, and waveguidedelectroluminescence (EL) from well aligned organic nanofibres integrated via roll printing on transistor platforms. The localized emission is due to the application of an AC voltage to the transistor gate electrodes, which causes sequential...

  2. Adaptive methods, rolling contact, and nonclassical friction laws

    Science.gov (United States)

    Oden, J. T.

    1989-01-01

    Results and methods on three different areas of contemporary research are outlined. These include adaptive methods, the rolling contact problem for finite deformation of a hyperelastic or viscoelastic cylinder, and non-classical friction laws for modeling dynamic friction phenomena.

  3. Theoretical research on effect of rolling motion on turbulent flow

    International Nuclear Information System (INIS)

    The turbulent flow in rectangular tube at rolling motion was investigated theoretically with Fluent code. The effects of several turbulent models and parameters on the flow were analyzed. At rolling motion, the velocity profile in tube center is more averaged. But the velocity gradient and frictional resistance coefficient on the wall increase. The effect of rolling motion on the turbulent flow can be depressed by the tube wall. At pitching motion,the velocity contour in small length-width ratio tube is in a dumbbell shape.As to the turbulent flow in the paper, the frictional resistance coefficient at rolling motion is in inverse ratio with the power of 0.47 of Reynolds number. (authors)

  4. Rolling shutter image compensation based on humanoid robot NAO

    Science.gov (United States)

    Zhao, Shuying; Zhao, Bing; Pan, Feng; Lan, Dongying; Jiang, Longwei; Hu, Xiangliang

    2014-01-01

    According to the requirement of RoboCup Standard Platform League (NAO) Rule Book, the author did some experiments to finish the League's tasks based on the humanoid robot NAO. The image captured by a moving camera will have a distortion which is affected by the so called "rolling shutter". The rolling shutter means that not all scanlines are exposed over the same time interval. This paper presents the model of rolling shutter of cameras and principle of capturing images. Then corrections to image distortion found on the NAO robots is described. At last the cases of reversing the effects of a rolling shutter on the images taken by the robot's moving camera are presented. This approach improves the effectiveness of shape recognition and the accuracy of Tilt rate of field line.

  5. Prediction of Parametric Roll Resonance by Multilayer Perceptron Neural Network

    DEFF Research Database (Denmark)

    Mķguez Gonzįlez, M; López Peńa, F.; Dķaz Casįs, V.; Galeazzi, Roberto; Blanke, Mogens

    acknowledged in the last few years. This work proposes a prediction system based on a multilayer perceptron (MP) neural network. The training and testing of the MP network is accomplished by feeding it with simulated data of a three degrees-of-freedom nonlinear model of a fishing vessel. The neural network is......Parametric roll resonance is a ship stability related phenomenon that generates sudden large amplitude oscillations up to 30-40 degrees of roll. This can cause severe damage, and it can put the crew in serious danger. The need for a parametric rolling real time prediction system has been...... shown to be capable of forecasting the ship’s roll motion in realistic scenarios....

  6. Roll Damping by Rudder Control: A Multi Objective H-infinity Approach

    DEFF Research Database (Denmark)

    Stoustrup, Jakob; Niemann, H.H.; Blanke, M.

    1994-01-01

    Roll damping and simultaneous course steering by rudder control is a challenging problem where a key factor is roll damping performance in waves......Roll damping and simultaneous course steering by rudder control is a challenging problem where a key factor is roll damping performance in waves...

  7. 77 FR 39156 - Airworthiness Directives; Rolls-Royce Deutschland Ltd & Co KG (RRD) Turbofan Engines

    Science.gov (United States)

    2012-07-02

    ...Airworthiness Directives; Rolls-Royce Deutschland Ltd & Co KG (RRD) Turbofan Engines...2009-07-01 R1 Rolls-Royce Deutschland Ltd & Co KG (formerly BMW Rolls-Royce...Applicability This AD applies to Rolls-Royce Deutschland Ltd & Co KG BR700- 715A1-30,...

  8. 77 FR 9869 - Airworthiness Directives; Rolls-Royce Deutschland Ltd & Co KG (RRD) Turbofan Engines

    Science.gov (United States)

    2012-02-21

    ...Airworthiness Directives; Rolls-Royce Deutschland Ltd & Co KG (RRD) Turbofan Engines...March 23, 2009): Rolls-Royce Deutschland Ltd & Co KG (formerly BMW Rolls-Royce...Applicability This AD applies to Rolls-Royce Deutschland Ltd & Co KG BR700- 715A1-30,...

  9. Evaluating the mechanical behavior of hot rolled Al/alumina composite strips using shear punch test

    International Nuclear Information System (INIS)

    The evaluation of mechanical properties, like yield and ultimate shear strengths from shear punch tests, is important when availability of material, is limited. A shear punch test setup was built, and the mechanical properties of different strips of hot rolled pure aluminum, post-rolling annealed pure aluminum, as-milled pure aluminum, and 4 wt% Al2O3 were investigated. The materials were first manufactured using powder metallurgy and then processed by hot rolling procedure. Microstructures of the samples were investigated by optical and scanning electron microscopes. It was found that by increasing alumina content in the matrix, shear strength and hardness were increased; also, the percentage of shear elongation was decreased. The results, also, indicated that by applying mechanical milling on pure aluminum powders before the hot rolling process, shear strength and hardness increased more than other samples. Moreover, shear strength was increased by increasing the amount of alumina particles in composite strips. SEM observations demonstrated that the amount of flat surface in shear failure micrographs increased by increasing the amount of shear strength and hardness

  10. Bioinspired superhydrophobic surfaces, fabricated through simple and scalable roll-to-roll processing

    Science.gov (United States)

    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.

  11. Microstructureā€“mechanical property correlation of cryo rolled Zircaloy-4

    International Nuclear Information System (INIS)

    The evolution of microstructure and the mechanical properties of cryo-rolled Zircaloy-4 were both investigated to understand the origin of the alloyā€™s strength processed at a cryogenic temperature. The correlation of dislocation density, grain size and yield stress of the rolled product indicated that an increase in dislocation density due to the suppression of dynamic recovery is the primary source of strengthening

  12. Microstructureā€“mechanical property correlation of cryo rolled Zircaloy-4

    Energy Technology Data Exchange (ETDEWEB)

    Sarkar, Apu, E-mail: asarkar5@ncsu.edu; Murty, Korukonda L.

    2015-01-15

    The evolution of microstructure and the mechanical properties of cryo-rolled Zircaloy-4 were both investigated to understand the origin of the alloyā€™s strength processed at a cryogenic temperature. The correlation of dislocation density, grain size and yield stress of the rolled product indicated that an increase in dislocation density due to the suppression of dynamic recovery is the primary source of strengthening.

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

    OpenAIRE

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

    2013-01-01

    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,...

  14. Generalized Slow Roll for Non-Canonical Kinetic Terms

    OpenAIRE

    Hu, Wayne

    2011-01-01

    We show that the generalized slow-roll approach for calculating the power spectrum where the inflationary slow roll parameters are neither small nor slowly varying can be readily extended to models with non-canonical kinetic terms in the inflaton action. For example, rapid sound speed variations can arise in DBI models with features in the warp factor leading to features in the power spectrum. Nonetheless there remains a single source function for deviations that is simply r...

  15. Cell and band structures in cold rolled polycrystalline copper

    DEFF Research Database (Denmark)

    Ananthan, V.S.; Leffers, Torben; Hansen, Niels

    1991-01-01

    The effect of plastic strain on the deformation microstructure has been investigated in polycrystalline copper rolled at room temperature to 5, 10, 20, and 30% reduction in thickness equivalent strain 0.06-0.42). Results from transmission electron microscopy (TEM) observations show that dense dislocation walls (DDWs) and cells develop during the initial stages of cold rolling. Grains having a high density of DDWs are described as high wall density (HWD) structures, and grains having a low densit...

  16. Lubricants for the rolling and drawing of metals:

    OpenAIRE

    ?ur?ija, Dušan; Mamuzi?, Ilija

    2005-01-01

    A survey is given over lubricants for rolling and drawing of metals. Emulsions, suspensions, natural fats and oils and synthetic lubricants are presented. Fluid mechanics Reynolds equations are used for the calculation of the lubricant lyer in the entering section of the metals deformation zone. Colloide chemistry is used for the analysis of surface active additions on lubricant properties, lubricant layer thickness and the wetting angle. Lubricants for hot rolling based on suspensions and gl...

  17. Wheel rolling constraints and slip in mobile robots

    Energy Technology Data Exchange (ETDEWEB)

    Shekhar, S. [Oak Ridge National Lab., TN (United States). Robotics and Process Systems Div.

    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.

  18. Smart identification of roll cages through logistics chain

    OpenAIRE

    Kolarovszki, Peter

    2015-01-01

    Article provides research in field of automatic identification of roll cages through radio-frequency identification technology (RFID) in terms of supply chain of particular postal-logistics operators. The ambition of this work is selection of appropriate identifier type and its placement on a roll cage. A special section is dedicated to description of the technical equipment used during measurements as well as their results from MySQL database. Article deals with relationship between the orie...

  19. A theory of sovereign debt roll-over crisis

    OpenAIRE

    Hattori, Masazumi

    2004-01-01

    In this paper, we attempt to provide theoretical investigation to debt roll-over crisis in government bond market. By using the global game techniques, we analyse coordination problem in debt auction. The approach in this paper allows us to have insight on the relation between occurence of soverign debt roll-over crisis and the fundamentals of economy which is not clearly explained in preceding works. This paper also makes it clear how the amount of debt for refinancing affects occurrence of ...

  20. Roll Aftereffects: Influence of tilt and inter-stimulus interval

    OpenAIRE

    Crane, Benjamin T.

    2012-01-01

    A theme in sensory perception it that exposure to a stimulus causes perception of subsequent stimuli to be shifted in the opposite direction. Such phenomenon are known as aftereffects and have 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 effec...

  1. MoirƩ fringe method for roll angular displacement measurement

    Science.gov (United States)

    Yu, Xue; Liu, Chao; Xie, Xian; Lang, Yaopu; Liu, Qinggang

    2015-10-01

    In the three-dimensional angle measurement, yaw and pitch angle can be detected easily by several convention optical devices. While the roll angle is difficult to measure since its rotation axis is parallel to the incident plane. This work is based on the application of the Talbot effect with a Ronchi grating. The period of MoirƩ fringes which generated by two gratings will be changed with small rotation. The roll angle can be calculated by the width change of fringes.

  2. Deuterium ingress at rolled joints in Embalse nuclear power plant

    International Nuclear Information System (INIS)

    Deuterium ingress model at the Rolled Joint has been extensively used for CANDU Nuclear Power Plants Operators in the Life Management of the Pressure Tubes. The importance of understanding the model is vital to avoid delayed hydride cracking at the Rolled Joint. This work reports the first step on develop the model presented on literature to be used in Argentinean CANDU 6, Embalse Nuclear Power Plant. (author)

  3. Effect of Rolling Massage on Particle Moving Behaviour in Blood Vessels

    International Nuclear Information System (INIS)

    The rolling massage manipulation is a classic Chinese massage, which is expected to eliminate many diseases. Here the effect of the rolling massage on the particle moving property in the blood vessels under the rolling massage manipulation is studied by the lattice Boltzmann simulation. The simulation results show that the particle moving behaviour depends on the rolling velocity, the distance between particle position and rolling position. The average values, including particle translational velocity and angular velocity, increase as the rolling velocity increases almost linearly. The result is helpful to understand the mechanism of the massage and develop the rolling techniques. (cross-disciplinary physics and related areas of science and technology)

  4. Computer-aided analysis and design of the shape rolling process for producing turbine engine airfoils

    Science.gov (United States)

    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.

  5. Prediction of mechanical properties of hot rolled steel products

    Directory of Open Access Journals (Sweden)

    P. Šime?ek

    2007-01-01

    Full Text Available Purpose: Model for prediction of mechanical properties of rolled steel products after final cooling from exitrolling temperature is one of the basic component of any software for complex computer simulation of rollingtechnologies. Theoretical background and implementation of such software tool is described.Design/methodology/approach: After calculation of cooling curves by any technology dependent Shell thesoftware tool MECHP can be called to predict CCT Diagram from current chemical composition of steel andinitial properties of deformed austenite first than structure shares (percentage of ferrite, pearlite, bainite andmartensite resulting from austenite decomposition process for given cooling curve and finally mechanicalproperties of final product after cooling (hardness, yield stress, tensile strength are calculated. Implementationof MECHP tool into the software RollFEM3D for 3D Finite Elements Method simulation of rolling processesis presented.Findings: Comparison of MECHP calculations with measured process data (water cooling and subsequent aircooling of hot rolled narrow plate and wire shows correspondence that is satisfactory for using in control ofprocess cooling technology.Practical implications: Results of verification showed that the software tool MECHP is implementable asa postprocessor into off-line rolling process simulation software or can be used as a mechanical propertiespredictor in software for on-line control of cooling.Originality/value: Developing of technology independent Library solving the problem of final mechanicalproperties prediction for various kinds of rolling technologies.

  6. Rolling-Element Fatigue Testing and Data Analysis - A Tutorial

    Science.gov (United States)

    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.

  7. Twisting, Rolling Motions, and Helicity in Prominence Eruptions

    Science.gov (United States)

    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/

  8. Stresses inside a roll in case of higher belt tension ?????????? ? ?????? ??? ?????????????? ????????? ?????

    Directory of Open Access Journals (Sweden)

    Antonov Viktor Ivanovich

    2013-09-01

    Full Text Available The author considers the problem of stresses arising in the roll in case of higher tension value in the roll-forming belt. It is noticed, that if some force is applied to the loose end of the roll-forming belt, outer layers are set in motion — they stretch and slightly slip along lower layers. The slipping surface gradually shifts to the center of the roll and either reaches the surface of the core, or stops at some distance from it. The penetration depth depends on the initial tension, the intensity of the applied force and the belt material properties. Thus, the two zones are formed — the outer zone where the belt slides, and the inner zone, where no relative motion of layers is demonstrated, but where layers compress under a higher pressure produced on the zone boundaries. At some values of influential parameters, the third zone appears near the core area, which is also a slip zone. Stress redistribution occurs here both due to the relative shift of layers, and to the higher pressure produced by the outer part of the roll. The analytical solution to the problem is found assuming that the formed roll is a homogeneous isotropic cylinder.??????????? ?????? ??????????? ??????????, ??????????? ? ?????????????? ?????? ??? ?????????????? ????????? ?????, ?????????? ?????. ????????, ??? ???? ? ?????????? ????? ?????, ?????????? ?????, ????????? ????????? ????, ?? ???????? ???? ???????? ? ???????? ?, ???????????, ????????? ?????????????? ?? ??????????? ?????. ??????????? ??????????????? ?????????? ????????? ? ?????? ?????? ? ???? ????????? ??????????? ??????????, ???? ??????????????? ?? ????????? ???????? ?? ????. ??????? ????????????? ??????? ?? ????????? ??????????, ???????? ??????????? ???? ? ??????? ????????? ?????. ????? ???????, ?????????? ??? ????: ????????, ? ??????? ?????????? ?????????? ?????, ? ??????????, ? ??????? ?????????????? ???????? ????? ?? ??????????, ?? ???? ??????????? ??? ????????? ??????????????? ???????? ?? ???????? ????. ??? ????????? ????????? ???????????? ?????????? ?????? ??????????? ?????????? ????????? ?????? ????, ???????, ??? ? ????????, ???????? ????? ??????????. ????? ????????????????? ?????????? ?????????? ??? ?? ???? ?????????????? ???????? ?????, ??? ? ?? ???? ??????????????? ???????? ?? ??????? ???????? ????? ??????. ???????? ????????????? ??????? ???????????? ?????? ? ?????????????, ??? ?????????????? ????? ???????????? ????? ?????????? ?????????? ???????.

  9. Numerical modelling of the bimetallic reinforcement bar rolling process

    Directory of Open Access Journals (Sweden)

    P. Szota

    2007-11-01

    Full Text Available Purpose: New kind of reinforcement bars are bimetallic reinforcement bars which has a higher corrosion resistance and mechanical properties, than the standard bars. The bimetallic bars are more and more often applied to building of concrete construction. This kind of application decides about high requirements imposed upon their performance characteristics and mechanical properties.Design/methodology/approach: Using the numerical modelling to rolling process of the bimetallic reinforcement bars in a finished pass to define rolling parameters. The simulations of the ribbed bar rolling were carried out using the Forge2005® commercial program.Findings: It has been performed in order to define the specific features of the mode of metal flow in the roll gap and to determine the effect of the shape and dimensions of the feedstock oval on the height of the ribs and on the thickness of surface layer of the finished bar.Practical implications: Reinforcement bars are chiefly used in the building industry at production of reinforced concrete constructions, and as working elements in bridge building.Originality/value: Production of bimetallic reinforcement bars is very difficult. One from many problems during production bimetallic bars is rolling in the finished passes. In this paper the computer simulation of the rolling bimetallic reinforcement bar is presented.

  10. Effects of pitching and rolling on reactor power

    International Nuclear Information System (INIS)

    Present report is described about the effect of pitching and rolling on 'MUTSU' reactor power. Using the vertical gyro and the acceleration detectors, we measured pitching and rolling in addition to physical quantities from the nuclear reactor instrumentations on a voyage for N.S.'MUTSU' Power-Up Tests. This data was used to apply a multivariable autoregressive model to analyze the correlations between pitching-angle, rolling-angle, steam flow (load), neutron flux (power) and primary coolant temperature. Concerning reactor kinetics, we got a result that the pitching and rolling have no effect on primary coolant temperature and neutron flux. It is found that the frequencies at high coherence between load and power is lower and separate from the frequencies at the pitching and rolling. The pitching and rolling mainly depend on the size, weight and position of center of gravity of the ship, on the other hand the load-follow characteristics depend on the load and heat capacities of primary loop and secondary loop of the reactor. For this reason we interpret that the design of reactor and ship of N.S.'MUTSU' match well each other. (author)

  11. The Foam Roll as a Tool to Improve Hamstring Flexibility.

    Science.gov (United States)

    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 stretching method. PMID:25992660

  12. New surface layers with low rolling resistance tested in Denmark

    DEFF Research Database (Denmark)

    Pettinari, Matteo; Schmidt, Bjarne

    2014-01-01

    The project ‘CO2 emission reduction by exploitation of rolling resistance modeling of pavements’ (COOEE) was started in 2011 to establish a scientific background for development of novel pavement types and asset management solutions that minimize the rolling resistance for cars and trucks, the purpose being to reduce CO2 emission from the transport sector. In summer 2012, three different test sections were constructed on a highway located near Vordingborg, Denmark, in order to verify the respective Rolling Resistances; the main purpose was to develop and design new surface layers with reduced Rolling Resistance coefficient that could improve energy efficiency of the roads. In particular, two new types of Split Mastic Asphalt (SMA) were developed and compared to a reference one; both mixtures have a relatively small maximum grain-size, 6 mm and 8 mm, respectively. Surface measurements such as Skid Resistance and Mean Depth Profile were appropriately verified in order to fulfill these essential texture values. Samples were taken and studied in the laboratory to analyze the volumetric characteristics. Rolling resistance measurements have shown that both new SMAs have a reduced Rolling Resistance compared to the traditional one.

  13. High?Volume Processed, ITO?Free Superstrates and Substrates for Roll?to?Roll Development of Organic Electronics

    DEFF Research Database (Denmark)

    Hösel, Markus; Angmo, Dechan

    2014-01-01

    The fabrication of substrates and superstrates prepared by scalable roll-to-roll methods is reviewed. The substrates and superstrates that act as the flexible carrier for the processing of functional organic electronic devices are an essential component, and proposals are made about how the general availability of various forms of these materials is needed to accelerate the development of the field of organic electronics. The initial development of the replacement of indium-tin-oxide (ITO) for the flexible carrier materials is described and a description of how roll-to-roll processing development led to simplification from an initially complex make-up to higher performing materials through a more simple process is also presented. This process intensification through process simplification is viewed as a central strategy for upscaling, increasing throughput, performance, and cost reduction.

  14. Development of manufacturing process of wrought magnesium alloy sheets by twin roll casting

    OpenAIRE

    Watari, H; R. Paisarn; Haga, T; Noda, K.; Davey, K.; N. Koga

    2007-01-01

    Purpose: The purpose of the work is to development of a strip casting technology for manufacturing magnesiumalloy sheets. The aim of the work is to establish a manufacturing process and technology to facilitate theeconomical manufacture of high-strength magnesium sheet alloys.Design/methodology/approach: A horizontal type twin roll caster was used to manufacture magnesium alloysheets. Pair of copper alloy roll, pure copper roll and steel roll was used for the horizontal type twin roll caster....

  15. A review of contemporary solutions for cold rolling that allow quality improvement

    OpenAIRE

    W. Soszy?ski; A. Studnicka

    2012-01-01

    Purpose: of this paper is a literature review on cold rolling of products with tight dimensional tolerances.Design/methodology/approach: In this paper a review on methods of quality improvement of cold rolled products was performed. Main groups of analysed factors, influencing high quality of rolled products are: rolling equipment, rolling technology, used tools.Findings: As a result of literature review it is concluded that the most important element involved in the manufacturing process and...

  16. Roll-to-Roll Screen Printed Radio Frequency Identification Transponder Antennas for Vehicle Tracking Systems

    Science.gov (United States)

    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.

  17. Roll-to-Roll Solution-Processible Small-Molecule OLEDs

    Energy Technology Data Exchange (ETDEWEB)

    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.

  18. Preorganization of Nanostructured Inks for Roll-to-Roll-Coated Polymer Solar Cells

    DEFF Research Database (Denmark)

    Krebs, Frederik C; Senkovskyy, Volodymyr

    2010-01-01

    The challenges associated with obtaining the desired nanomorphology of the active layer in polymer solar cells were addressed through preparation of conjugated polymer chains grown from the surface of seed nanoparticles with a well-defined size. Poly-3-hexylthiophene (P3HT) was thus polymerized using a quasi-living chain polymerization method initiated by surface-modified silica nanoparticles. The nanoparticles with a silica core and a P3HT-corona exhibited excellent solubility and optical properties similar to native P3HT. Upon mixing with phenyl-C61-butyric acid methyl ester in solution, a preorganized ink was obtained that was used to make polymer solar cell modules in a full roll-to-roll coating and printing process operating in ambient air. The polymer solar cells were thus prepared by a mixture of slot die and flat-bed screen printing. Various polymer solar cell modules were prepared ranging from single cells to two, three, and eight serially connected cells. The power conversion efficiency for the polymer solar cell modules were in the range of 0.8%-1.2% with an active area of up to 120 cm.

  19. Roll-to-roll coated PBI membranes for high temperature PEM fuel cells

    DEFF Research Database (Denmark)

    Steenberg, Thomas; Hjuler, Hans Aage; Terkelsen, Carina; Sanchez, Maria Teresa Romero; Cleemann, Lars Nilausen; Krebs, Frederik C

    2012-01-01

    characterization with respect to solubility, phosphoric acid doping and fuel cell performance. Our results showed that the PBI membranes prepared in this work have identical properties compared to traditionally cast membranes while enabling an increase of a factor of 100 in manufacturing speed.......We employed roll-to-roll coating in the preparation of 40 ?m thick poly[2,2?(m-phenylene)-5,5?bibenzimidazole] (PBI) films for fuel cells using both knife-coating (KC) and slot-die (SD) coating. The films were coated directly from a 9% (w/w) solution of PBI in dimethylacetamide onto a sacrificial...... low cost paper or plastic based carrier substrate and dried using a hot air oven with a length of 1 m at 140 °C. A web width of 305 mm, a working width of 250 mm and a web speed of 0.2 m min?1 were explored to ensure efficient drying of the thick wet film. A large air flow was found to efficiently...

  20. Interlayer adhesion in roll-to-roll processed flexible inverted polymer solar cells

    KAUST Repository

    Dupont, Stephanie R.

    2012-02-01

    The interlayer adhesion of roll-to-roll processed flexible inverted P3HT:PCBM bulk heterojunction (BHJ) polymer solar cells is reported. Poor adhesion between adjacent layers may result in loss of device performance from delamination driven by the thermomechanical stresses in the device. We demonstrate how a thin-film adhesion technique can be applied to flexible organic solar cells to obtain quantitative adhesion values. For the P3HT:PCBM-based BHJ polymer solar cells, the interface of the BHJ with the conductive polymer layer PEDOT:PSS was found to be the weakest. The adhesion fracture energy varied from 1.6 J/m2 to 0.1 J/m2 depending on the composition of the P3HT:PCBM layer. Post-deposition annealing time and temperature were shown to increase the adhesion at this interface. Additionally the PEDOT:PSS cells are compared with V2O5 cells whereby adhesive failure marked by high fracture energies was observed. Ā© 2011 Elsevier B.V.