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Sample records for ring rolling process

  1. Ring rolling process simulation for geometry optimization

    Science.gov (United States)

    Franchi, Rodolfo; Del Prete, Antonio; Donatiello, Iolanda; Calabrese, Maurizio

    2017-10-01

    Ring Rolling is a complex hot forming process where different rolls are involved in the production of seamless rings. Since each roll must be independently controlled, different speed laws must be set; usually, in the industrial environment, a milling curve is introduced to monitor the shape of the workpiece during the deformation in order to ensure the correct ring production. In the present paper a ring rolling process has been studied and optimized in order to obtain anular components to be used in aerospace applications. In particular, the influence of process input parameters (feed rate of the mandrel and angular speed of main roll) on geometrical features of the final ring has been evaluated. For this purpose, a three-dimensional finite element model for HRR (Hot Ring Rolling) has been implemented in SFTC DEFORM V11. The FEM model has been used to formulate a proper optimization problem. The optimization procedure has been implemented in the commercial software DS ISight in order to find the combination of process parameters which allows to minimize the percentage error of each obtained dimension with respect to its nominal value. The software allows to find the relationship between input and output parameters applying Response Surface Methodology (RSM), by using the exact values of output parameters in the control points of the design space explored through FEM simulation. Once this relationship is known, the values of the output parameters can be calculated for each combination of the input parameters. After the calculation of the response surfaces for the selected output parameters, an optimization procedure based on Genetic Algorithms has been applied. At the end, the error between each obtained dimension and its nominal value has been minimized. The constraints imposed were the maximum values of standard deviations of the dimensions obtained for the final ring.

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

    Science.gov (United States)

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

    2018-05-01

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

  3. Finite element modelling of process-integrated powder coating by radial axial rolling of rings

    International Nuclear Information System (INIS)

    Frischkorn, J.; Kebriaei, R.; Reese, S.; Moll, H.; Theisen, W.; Husmann, T.; Meier, H.

    2011-01-01

    The process-integrated powder coating by radial axial rolling of rings represents a new hybrid production technique applied in the manufacturing of large ring-shaped work pieces with functional layers. It is thought to break some limitations that come along with the hot isostatic pressing (HIP) which is used nowadays to apply the powdery layer material onto the rolled substrate ring. Within the new process the compaction of the layer material is integrated into the ring rolling and HIP becomes dispensable. Following this approach the rolling of such compound rings brings up some new challenges. The volume of a solid ring stays nearly constant during the rolling. This behaviour can be exploited to determine the infeed of the rollers needed to reach the desired ring shape. Since volume consistency cannot be guaranteed for the rolling of a compound ring the choice of appropriate infeed of the rollers is still an open question. This paper deals with the finite element (FE) simulation of this new process. First, the material model that is used to describe the compaction of the layer material is shortly reviewed. The main focus of the paper is then put on a parameterized FE ring rolling model that incorporates a control system in order to stabilize the process. Also the differences in the behaviour during the rolling stage between a compound and a solid ring will be discussed by means of simulation results.

  4. Optimization and Simulation of Machining Parameters in Radial-axial Ring Rolling Process

    Directory of Open Access Journals (Sweden)

    Shuiyuan Tang

    2011-05-01

    Full Text Available Ring rolling is a complicated process, in which rolling parameters influence directly the quality of ring. It is a process method with high productivity and few waste of material, widely used in transportation industry including automotive, shipbuilding, aerospace etc. During the rolling process of large-sized parts, crinkle and hollows often appear on surface, due to inconsistence of rolling motions with the deformation of ring part. Based on radial-axial ring rolling system configuration, motions and forces in rolling process are analyzed, and a dynamic model is formulated. Error of ring's end flatness and roundness are defined as the characteristic parameters of ring quality. The relationship between core roller feed speed, drive roller speed, the upper taper roller feed speed, and quality of ring part are analyzed. The stress and strain of the part are simulated in the Finite Element Method by DEFORM software. The simulation results provide a reference for the definition of ring rolling process parameters. It is able to make the deformation of the part be consistent with the process parameters, and improve product quality considerably.

  5. A Feeding Strategy in Inner L-Shape Ring Hot Rolling Process

    Directory of Open Access Journals (Sweden)

    Wen Meng

    2017-01-01

    Full Text Available In order to make the inner L-shape ring polling process with a closed die structure (ILRRCDS on the top and bottom of the driven roll stable, at first, this paper established the mathematical model for ILRRCDS. Then, the plastic penetration and biting-in conditions for ILRRCDS were deduced based on plain ring rolling theory. Moreover, a feeding strategy that can realize a constant growth of the ring’s outer radius was proposed and the reasonable value ranges of the feed rate of the mandrel were determined. The numerical simulation model for ILRRCDS is established based on ABAQUS software. Finally, the equivalent plastic strain (PEEQ and temperature distributions of rolled ring were obtained. The results indicated that the proposed feeding strategy can realize a stable ILRRCDS. At the end of ILRRCDS, the PEEQ at the inner radius surface of the ring is maximum, the PEEQ at the outer radius surface of the ring takes the second place, and the PEEQ at the middle part of ring is minimum. With the increase of rolling time, the higher temperature zone of the rolled ring gradually moves from the center part of the ring to the “inner corner zone” of the ring.

  6. Optimization on cooperative feed strategy for radial–axial ring rolling process of Inco718 alloy by RSM and FEM

    Directory of Open Access Journals (Sweden)

    Zhu Xinglin

    2016-06-01

    Full Text Available During radial–axial ring rolling process, cooperative strategy of the radial–axial feed is critical for dimensional accuracy and thermo mechanical parameters distribution of the formed ring. In order to improve the comprehensive quality of the ring parts, response surface method (RSM is employed for the first time to optimize the cooperative feed strategy for radial–axial ring rolling process by combining it with an improved and verified 3D coupled thermo-mechanical finite element model. The feed trajectory is put forward to describe cooperative relationship of the radial–axial feed and three variables are designed based on the feed trajectory. In order to achieve multi-objective optimization, four responses including thermo mechanical parameters distribution and rolling force are proposed. Based on the FEM results, RSM is used to establish a response model to depict the function relationship between the objective response and design variables. Through this approximate model, effects of different variables on ring rolling process are analyzed connectedly and optimal feed strategy is obtained by resorting to the optimal chart specific to a constraint condition.

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

    NARCIS (Netherlands)

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

    2015-01-01

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

  8. Influence of feed rate on damage development in hot ring rolling

    NARCIS (Netherlands)

    Wang, Chao; van den Boogaard, Antonius H.; Omerspahic, E.; Recina, V.; Geijselaers, Hubertus J.M.; Ishikawa, T.; Mori, K.-I.

    2014-01-01

    As an incremental forming process of bulk metal, 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. Under some process conditions, defects such as

  9. Ring rolling of AW5083 large rings for the external cylinder of CMS

    CERN Multimedia

    S. Sgobba / EST

    2001-01-01

    Picture 1: The forged cylinder is engaged in the ring rolling plant. Picture 2: Vertical rolls allow for the reduction in the axial direction. Rolling is carried out at approx. 400 degrees C. Horizontal rolls (not shown) allow for the reduction in the radial direction. Picture 3: Handling of the ring, rolled at the internal diameter of approx. 7m, and transfer to the quenching both. All pictures have been taken during the visit of Mr. Sgobba at Dembiermont, Mobeuge (Bruxelles).

  10. Precision ring rolling technique and application in high-performance bearing manufacturing

    Directory of Open Access Journals (Sweden)

    Hua Lin

    2015-01-01

    Full Text Available High-performance bearing has significant application in many important industry fields, like automobile, precision machine tool, wind power, etc. Precision ring rolling is an advanced rotary forming technique to manufacture high-performance seamless bearing ring thus can improve the working life of bearing. In this paper, three kinds of precision ring rolling techniques adapt to different dimensional ranges of bearings are introduced, which are cold ring rolling for small-scale bearing, hot radial ring rolling for medium-scale bearing and hot radial-axial ring rolling for large-scale bearing. The forming principles, technological features and forming equipments for three kinds of precision ring rolling techniques are summarized, the technological development and industrial application in China are introduced, and the main technological development trend is described.

  11. 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.

  12. 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).

  13. Self-(Un)rolling Biopolymer Microstructures: Rings, Tubules, and Helical Tubules from the Same Material.

    Science.gov (United States)

    Ye, Chunhong; Nikolov, Svetoslav V; Calabrese, Rossella; Dindar, Amir; Alexeev, Alexander; Kippelen, Bernard; Kaplan, David L; Tsukruk, Vladimir V

    2015-07-13

    We have demonstrated the facile formation of reversible and fast self-rolling biopolymer microstructures from sandwiched active-passive, silk-on-silk materials. Both experimental and modeling results confirmed that the shape of individual sheets effectively controls biaxial stresses within these sheets, which can self-roll into distinct 3D structures including microscopic rings, tubules, and helical tubules. This is a unique example of tailoring self-rolled 3D geometries through shape design without changing the inner morphology of active bimorph biomaterials. In contrast to traditional organic-soluble synthetic materials, we utilized a biocompatible and biodegradable biopolymer that underwent a facile aqueous layer-by-layer (LbL) assembly process for the fabrication of 2D films. The resulting films can undergo reversible pH-triggered rolling/unrolling, with a variety of 3D structures forming from biopolymer structures that have identical morphology and composition. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. The effect of roll with passive segment on the planetary rolling process

    Directory of Open Access Journals (Sweden)

    Qing-Ling Zeng

    2015-03-01

    Full Text Available In three-roll planetary rolling process, there is secondary torsion phenomenon that may lead to rolling instability. This article proposed a new idea to alleviate the secondary torsion phenomenon by dividing the secondary torsion segment out of the roll as an independent and passive one. To study the performance of the roll with passive segment, the three-dimensional finite element models of planetary rolling process using actual roll or new roll with passive segment involving elastic–plastic and thermal–mechanical coupling were established by the software ABAQUS/Explicit, and a series of analysis had been done successfully. The rolling temperature and rolling force of planetary mill were in good agreement with the measured results, which indicated that the finite element method would supply important reference merit for three-dimensional thermo-mechanical simulation of the three-roll planetary rolling process. Comparing the simulation results of the two models, the results indicated that the change in the roll structure had just a little influence on the metal deformation, temperature, and rolling force, but it lessened the secondary torsion deformation effectively and improved the outside roundness of the rolled tube slightly. The research provided a new idea for the roll design of three-roll planetary mill (PSW.

  15. Electron ring diagnostics with magnetic probes during roll-out and acceleration

    International Nuclear Information System (INIS)

    Schumacher, U.; Ulrich, M.

    1976-03-01

    Different methods using magnetic field probes to determine the properties of electron rings during their compression, roll-out and acceleration are presented. The results of the measurements of the electron number and the axial velocity and acceleration of the rings, as obtained with the various diagnostic devices, are discussed and compared. (orig.) [de

  16. Rolling contact fatigue of low hardness steel for slewing ring application

    Science.gov (United States)

    Knuth, Jason A.

    This thesis discusses the rolling contact fatigue of steel utilized in anti-friction bearings, also referred to as slewing bearings. These slewing bearings are utilized in cranes, excavators, wind turbines and other similar applications. Five materials composed of two different material types were tested. The two material types were high carbon steel and medium carbon alloy steel. The test specimens were processed from forged rolled rings. Two machines were evaluated a ZF-RCF and 3-Ball test machine. The evaluation was to determine which machine can best simulate the application in which the slewing bearing is utilized. Initially, each specimen will be pretested to determine the appropriate testing direction from within the forged rolled rings. Pretesting is needed in order to establish consistent failure modes between samples. The primary goal of the test is to understand the life differences and failure modes between high carbon steel and medium carbon alloy steel. The high carbon steel ring was cut into two sections, one of which was stress relieved and the other was quenched and tempered. The medium carbon alloy steel was cut into three sections, all of which were quenched and tempered to different hardness levels. The test program was dynamically adjusted based upon the previous sample's life and load. An S-N curve was then established from the 5 materials tested at two target loads. The samples were run until the first sign of a crack was detected by an eddy current. At the completion of the rolling contact test, select sample's microstructure was evaluated for crack initiation location. The selected samples were divided into four groups which represent different maximum shear stress levels. These samples displayed indications of material deformation in which the high carbon steel experienced an increased amount of cold work when compared to medium carbon alloy steel. The life of the high carbon steel was nearly equivalent to the expected life of the medium

  17. Interlayer adhesion in roll-to-roll processed flexible inverted polymer solar cells

    KAUST Repository

    Dupont, Stephanie R.; Oliver, Mark; Krebs, Frederik C.; Dauskardt, Reinhold H.

    2012-01-01

    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

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

    DEFF Research Database (Denmark)

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

    2010-01-01

    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...... 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...

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

    DEFF Research Database (Denmark)

    Larsen-Olsen, Thue Trofod; Andersen, Thomas Rieks; Andreasen, Birgitta

    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...

  20. 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.

  1. Annuitants Added to the Annuity Roll Processing System (ARPS)

    Data.gov (United States)

    Office of Personnel Management — Small table showing the total Civil Service Retirement System (CSRS) and Federal Employees Retirement System (FERS) Annuitants added to the Annuity Roll Processing...

  2. Influences of rolling method on deformation force in cold roll-beating forming process

    Science.gov (United States)

    Su, Yongxiang; Cui, Fengkui; Liang, Xiaoming; Li, Yan

    2018-03-01

    In process, the research object, the gear rack was selected to study the influence law of rolling method on the deformation force. By the mean of the cold roll forming finite element simulation, the variation regularity of radial and tangential deformation was analysed under different rolling methods. The variation of deformation force of the complete forming racks and the single roll during the steady state under different rolling modes was analyzed. The results show: when upbeating and down beating, radial single point average force is similar, the tangential single point average force gap is bigger, the gap of tangential single point average force is relatively large. Add itionally, the tangential force at the time of direct beating is large, and the dire ction is opposite with down beating. With directly beating, deformation force loading fast and uninstall slow. Correspondingly, with down beating, deformat ion force loading slow and uninstall fast.

  3. Spring-back of flexible roll forming bending process

    International Nuclear Information System (INIS)

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

    2015-01-01

    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 be well described by the simulation software and guide the actual machine. (paper)

  4. 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...... ion mass spectrometry, attenuated total reflectance infrared, and transmission/reflection UV−vis techniques....

  5. 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.

    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...

  6. 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.

  7. Study of rolled uranium annealing process

    International Nuclear Information System (INIS)

    Cabane, G.

    1954-06-01

    The dilatometric study of rolled uranium clearly shows not only the expansions or contractions induced by stress relief or diffusion of vacancies, but also the slope variations of the cooling curves, which are the best evidence of a texture change. Under the microscope, hard-rolled sheets appear as a mixture of two distinct structures; it is also possible by intermediate annealing to prepare homogeneous sheets of either structure, i.e. twinned or untwinned. All these sheets which have similar textures, undergo at first a primary recrystallization beginning at 320 deg C, then a texture change without any apparent crystal growth, at about 430 deg C. (author) [fr

  8. Interlayer adhesion in roll-to-roll processed flexible inverted polymer solar cells

    DEFF Research Database (Denmark)

    Dupont, Stephanie R.; Oliver, Mark; Krebs, Frederik C

    2012-01-01

    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......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...... energies was observed....

  9. 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.

  10. 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 µm layer-to-layer registration, which is usually a challenge in high-speed R2R environments as the standard registration methods are limited to the millimeter range—or, at best, to tens of µm 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 methods—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.

  11. Mathematical modeling of a process the rolling delivery

    Science.gov (United States)

    Stepanov, Mikhail A.; Korolev, Andrey A.

    2018-03-01

    An adduced analysis of the scientific researches in a domain of the rolling equipments, also research of properties the working material. A one of perspective direction of scientific research this is mathematical modeling. That is broadly used in many scientific disciplines and especially at the technical, applied sciences. With the aid of mathematical modeling it can be study of physical properties of the researching objects and systems. A research of the rolling delivery and transporting devices realized with the aid of a construction of mathematical model of appropriate process. To be described the basic principles and conditions of a construction of mathematical models of the real objects. For example to be consider a construction of mathematical model the rolling delivery device. For a construction that is model used system of the equations, which consist of: Lagrange’s equation of a motion, describing of the law conservation of energy of a mechanical system, and the Navier - Stokes equations, which characterize of the flow of a continuous non-compressed fluid. A construction of mathematical model the rolling deliver to let determined of a total energy of device, and therefore to got the dependence upon the power of drive to a gap between of rolls. A corroborate the hypothesis about laminar the flow of a material into the rolling gap of deliver.

  12. 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 ±5μm on a 500 mm-wide film was achieved at a σ level of 2.4 and 2.8 (x and y directions, respectively) in a continuous R2R printing process. This paper presents the components and mechanisms used in reverse offset printing based on a R2R system and the printing results including positioning accuracy and overlay alignment accuracy.

  13. 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

    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...

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

    DEFF Research Database (Denmark)

    Carlé, 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....... 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...

  15. Simulation of Bimetallic Bush Hot Rolling Bonding Process

    Directory of Open Access Journals (Sweden)

    Yaqin Tian

    2015-01-01

    Full Text Available Three-dimensional model of bimetallic bush was established including the drive roller and the core roller. The model adopted the appropriate interface assumptions. Based on the bonding properties of bimetallic bush the hot rolling process was analyzed. The optimum reduction ratio of 28% is obtained by using the finite element simulation software MARC on the assumption of the bonding conditions. The stress-strain distribution of three dimensions was research assumptions to interface deformation of rolling. At the same time, based on the numerical simulation, the minimum reduction ratio 20% is obtained by using a double metal composite bush rolling new technology from the experiment research. The simulation error is not more than 8%.

  16. Application research of ferrous matrix composites in roller ring used in high-speed wire/bar rolling mill

    International Nuclear Information System (INIS)

    Song Yanpei; Li Xiuqing; Bi Shuangxu

    2010-01-01

    Research highlights: → A composite structure roller rings was fabricated by centrifugal casting. → The roller rings consisted of outer WCP/Fe-C composites layer and inner Fe-C alloy matrix. → Hardness attained to HRA80-85 in the composites layer, and HRA73-76 in inner Fe-C alloy matrix where the toughness was over 8 J/cm 2 . → The wear resistance of the roller rings excelled that of high-speed steel, and approached to that of the WC hard alloy roll. → The production cost of the WCP/Fe-C composites roller ring decreased by 50%. - Abstract: Tungsten carbide particle (WC P ) reinforced ferrous matrix composites roller rings were fabricated by centrifugal casting. The microstructures, properties and application effect of the composites roller rings were investigated by SEM, TEM and various property testers. The experimental results show that the WC P were uniformly distributed in outer reinforced-layer (working-layer) of 20-50 mm in thickness and their volume fraction reached 60-80 vol.%; there was a good interface bonding between WC P and Fe-C alloy without any reaction products; hardness attained to HRA80-85 in working-layer, and HRA73-76 in inner ferrous matrix where the toughness was over 8 J/cm 2 ; the wear resistance of the composites roller rings excels that of high-speed steel; service life of the composites parts approached to that of the WC hard alloy roll when the same WC P -volume-fraction in working-layer were obtained for both of them, but the production cost of the WC P /Fe-C composites roller ring decreased by 50%.

  17. 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

    2015-10-22

    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.

  18. Flow behavior of polymers during the roll-to-roll hot embossing process

    International Nuclear Information System (INIS)

    Deng, Yujun; Yi, Peiyun; Peng, Linfa; Lai, Xinmin; Lin, Zhongqin

    2015-01-01

    The roll-to-roll (R2R) hot embossing process is a recent advancement in the micro hot embossing process and is capable of continuously fabricating micro/nano-structures on polymers, with a high efficiency and a high throughput. However, the fast forming of the R2R hot embossing process limits the time for material flow and results in complicated flow behavior in the polymers. This study presents a fundamental investigation into the flow behavior of polymers and aims towards the comprehensive understanding of the R2R hot embossing process. A three-dimensional (3D) finite element (FE) model based on the viscoelastic model of polymers is established and validated for the fabrication of micro-pyramids using the R2R hot embossing process. The deformation and recovery of micro-pyramids on poly(vinyl chloride) (PVC) film are analyzed in the filling stage and the demolding stage, respectively. Firstly, in the analysis of the filling stage, the temperature distribution on the PVC film is discussed. A large temperature gradient is observed along the thickness direction of the PVC film and the temperature of the top surface is found to be higher than that of the bottom surface, due to the poor thermal conductivity of PVC. In addition, creep strains are demonstrated to depend highly on the temperature and are also observed to concentrate on the top layer of the PVC film because of high local temperature. In the demolding stage, the recovery of the embossed micro-pyramids is obvious. The cooling process is shown to be efficient for the reduction of recovery, especially when the mold temperature is high. In conclusion, this research advances the understanding of the flow behavior of polymers in the R2R hot embossing process and might help in the development of the highly accurate and highly efficient fabrication of microstructures on polymers. (paper)

  19. 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.

    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...... edges. The edge sealing rim was 10 mm wide. Cell modules were characterized by periodic measurements of IV curves over extended periods in a variety of conditions, as well as by a variety of spatial imaging techniques. Data show significant stability benefits of the edge sealing process. The results...

  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. © 2011 Elsevier B.V.

  1. Roll-to-roll atomic layer deposition process for flexible electronics encapsulation applications

    International Nuclear Information System (INIS)

    Maydannik, Philipp S.; Kääriäinen, Tommi O.; Lahtinen, Kimmo; Cameron, David C.; Söderlund, Mikko; Soininen, Pekka; Johansson, Petri; Kuusipalo, Jurkka; Moro, Lorenza; Zeng, Xianghui

    2014-01-01

    At present flexible electronic devices are under extensive development and, among them, flexible organic light-emitting diode displays are the closest to a large market deployment. One of the remaining unsolved challenges is high throughput production of impermeable flexible transparent barrier layers that protect sensitive light-emitting materials against ambient moisture. The present studies deal with the adaptation of the atomic layer deposition (ALD) process to high-throughput roll-to-roll production using the spatial ALD concept. We report the development of such a process for the deposition of 20 nm thickness Al 2 O 3 diffusion barrier layers on 500 mm wide polymer webs. The process uses trimethylaluminum and water as precursors at a substrate temperature of 105 °C. The observation of self-limiting film growth behavior and uniformity of thickness confirms the ALD growth mechanism. Water vapor transmission rates for 20 nm Al 2 O 3 films deposited on polyethylene naphthalate (PEN) substrates were measured as a function of substrate residence time, that is, time of exposure of the substrate to one precursor zone. Moisture permeation levels measured at 38 °C/90% relative humidity by coulometric isostatic–isobaric method were below the detection limit of the instrument ( −4  g/m 2 day) for films coated at web moving speed of 0.25 m/min. Measurements using the Ca test indicated water vapor transmission rates ∼5 × 10 −6 g/m 2 day. Optical measurements on the coated web showed minimum transmission of 80% in the visible range that is the same as the original PEN substrate

  2. Roll-to-roll atomic layer deposition process for flexible electronics encapsulation applications

    Energy Technology Data Exchange (ETDEWEB)

    Maydannik, Philipp S., E-mail: philipp.maydannik@lut.fi; Kääriäinen, Tommi O.; Lahtinen, Kimmo; Cameron, David C. [Advanced Surface Technology Research Laboratory, Lappeenranta University of Technology, Sammonkatu 12, 50130 Mikkeli (Finland); Söderlund, Mikko; Soininen, Pekka [Beneq Oy, P.O. Box 262, 01511 Vantaa (Finland); Johansson, Petri; Kuusipalo, Jurkka [Tampere University of Technology, Paper Converting and Packaging Technology, P.O. Box 589, 33101 Tampere (Finland); Moro, Lorenza; Zeng, Xianghui [Samsung Cheil Industries, San Jose R and D Center, 2186 Bering Drive, San Jose, California 95131 (United States)

    2014-09-01

    At present flexible electronic devices are under extensive development and, among them, flexible organic light-emitting diode displays are the closest to a large market deployment. One of the remaining unsolved challenges is high throughput production of impermeable flexible transparent barrier layers that protect sensitive light-emitting materials against ambient moisture. The present studies deal with the adaptation of the atomic layer deposition (ALD) process to high-throughput roll-to-roll production using the spatial ALD concept. We report the development of such a process for the deposition of 20 nm thickness Al{sub 2}O{sub 3} diffusion barrier layers on 500 mm wide polymer webs. The process uses trimethylaluminum and water as precursors at a substrate temperature of 105 °C. The observation of self-limiting film growth behavior and uniformity of thickness confirms the ALD growth mechanism. Water vapor transmission rates for 20 nm Al{sub 2}O{sub 3} films deposited on polyethylene naphthalate (PEN) substrates were measured as a function of substrate residence time, that is, time of exposure of the substrate to one precursor zone. Moisture permeation levels measured at 38 °C/90% relative humidity by coulometric isostatic–isobaric method were below the detection limit of the instrument (<5 × 10{sup −4} g/m{sup 2} day) for films coated at web moving speed of 0.25 m/min. Measurements using the Ca test indicated water vapor transmission rates ∼5 × 10{sup −6} g/m{sup 2} day. Optical measurements on the coated web showed minimum transmission of 80% in the visible range that is the same as the original PEN substrate.

  3. Characterization of printed planar electromagnetic coils using digital extrusion and roll-to-roll flexographic processes

    Science.gov (United States)

    Rickard, Scott

    Electromagnets are a crucial component in a wide range of more complex electrical devices due to their ability to turn electrical energy into mechanical energy and vice versa. The trend for electronics becoming smaller and lighter has led to increased interest in using flat, planar electromagnetic coils, which have been shown to perform better at scaled down sizes. The two-dimensional geometry of a planar electromagnetic coil yields itself to be produced by a roll-to-roll additive manufacturing process. The emergence of the printed electronics field, which uses traditional printing processes to pattern functional inks, has led to new methods of mass-producing basic electrical components. The ability to print a planar electromagnetic coil using printed electronics could rival the traditional subtractive and semi-subtractive PCB process of manufacturing. The ability to print lightweight planar electromagnetic coils on flexible substrates could lead to their inclusion into intelligent packaging applications and could have specific use in actuating devices, transformers, and electromagnetic induction applications such as energy harvesting or wireless charging. In attempts to better understand the limitations of printing planar electromagnetic coils, the effect that the design parameters of the planar coils have on the achievable magnetic field strength were researched. A comparison between prototyping methods of digital extrusion and manufacturing scale flexographic printing are presented, discussing consistency in the printed coils and their performance in generating magnetic fields. A method to predict the performance of these planar coils is introduced to allow for design within required needs of an application. Results from the research include a demonstration of a printed coil being used in a flat speaker design, working off of actuating principles.

  4. Hot-rolled Process of Multilayered Composite Metal Plate

    Directory of Open Access Journals (Sweden)

    YU Wei

    2017-02-01

    Full Text Available For multi-layer plate, it is a difficult problem to increase product yield rate and improve bonding interface quality. A high yield hot-rolled method of multilayered plate was proposed. The raw strips and plate were fixed by argon arc welding. The combined billet was put into a metal box and vacuum pumped, and then heated and rolled by multi passes at the temperature of 1000-1200℃. The 67 layered plate with the thickness of 2.5mm was successfully produced. The interfacial microstructures and diffusion behavior were investigated and analyzed by optical microscopy and scan electronic microscopy. The tensile and shear strength were tested,and the shear fractures were analyzed. The results show that the multilayered plate yield rate is more than 90% by two steps billet combination method and rolling process optimization. The good bonding interface quality is obtained, the shear strength of multilayered plate reaches 241 MPa. Nickel interlayer between 9Cr18 and 1Cr17 can not only prevent the diffusion of carbon, but also improve the microstructure characteristics.

  5. Material-Process-Performance Relationships for Roll-to-Roll Coated PEM Electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Mauger, Scott; Neyerlin, K.C.; Stickel, Jonathan; Ulsh, Michael; More, Karren; Wood, David

    2017-04-26

    Roll-to-roll (R2R) coating is the most economical and highest throughput method for producing fuel cell electrodes. R2R coating encompasses many different methodologies to create uniform films on a moving web substrate. Here we explore two coating methods, gravure and slot die, to understand the impacts of each on film uniformity and performance.

  6. Research on the rolling moment in the symmetrical and asymmetrical rolling process

    Science.gov (United States)

    Alexa, V.; Raţiu, S. A.; Kiss, I.; Cioată, C. G.

    2017-01-01

    Research distribution the rolling moments symmetrical and asymmetrical report presents great importance both in theory and to introduce clarifications to the calculation of rolling resistance line assemblies. Clarifying individuals of metallic material deformation between the rolls single cylinder diameters act of any difference of work and analysis of advance and delay phenomena. Torque drive value for each of the rolling cylinders was done by reducing the thickness of the laminate samples, an experimental facility located in the laboratory of plastic deformation of the Faculty of Engineering Hunedoara. The analysis of research results show that in terms of power consumption for deformation and safety equipment in operation is rational for mills which require such a difference between the work rolls to execute about one cylinder operated.

  7. Measurement of Normal and Friction Forces in a Rolling Process

    DEFF Research Database (Denmark)

    Henningsen, Poul; Arentoft, Mogens; Wanheim, Tarras

    2004-01-01

    by the fric-tion conditions. To achieve this important informa-tion, measurements of the normal pressure and friction stresses in the deformation zone are re-quested. The direction of the friction stresses is changing during the rolling gap. At the entrance of the de-formation zone, the peripherical velocity...... of the roll is higher than for the incoming material, which causes frictional stresses at the material acting in the rolling direction. At the outlet of the rolling gap, the velocity of the deformed material exceeds the velocity of the roll, generating frictional stresses contrary to the direction of rolling....... In a narrow area in the deformation zone, the velocity of the de-formed material is equal to the velocity of the rolls. This area or line is named “neutral line”. The posi-tion of the neutral line depends on friction, reduc-tion ratio, diameter of the rolls, and width of the sheet....

  8. A numerical approach to robust in-line control of roll forming processes

    NARCIS (Netherlands)

    Wiebenga, J.H.; Weiss, M.; Rolfe, B.; van den Boogaard, A.H.

    2012-01-01

    The quality of roll formed products is known to be highly sensitive and dependent on the process parameters and thus the unavoidable variations of these parameters during mass production. To maintain a constant high product quality, a new roll former with an adjustable final roll forming stand is

  9. Highly flexible indium zinc oxide electrode grown on PET substrate by cost efficient roll-to-roll sputtering process

    International Nuclear Information System (INIS)

    Park, Yong-Seok; Kim, Han-Ki; Jeong, Soon-Wook; Cho, Woon-Jo

    2010-01-01

    We have investigated the characteristics of flexible indium zinc oxide (IZO) electrode grown on polyethylene terephthalate (PET) substrates using a specially designed roll-to-roll (RTR) sputtering system for use in flexible optoelectronics. It was found that both electrical and optical properties of the flexible IZO electrode were critically dependent on the DC power and Ar/O 2 flow ratio during the roll-to-roll sputtering process. At optimized conditions (constant working pressure of 3 mTorr, Ar/O 2 flow ratio of Ar at only 30 sccm, DC power 800 W and rolling speed at 0.1 cm/s) the flexible IZO electrode exhibits a sheet resistance of 17.25 Ω/sq and an optical transmittance of 89.45% at 550 nm wavelength. Due to the low PET substrate temperature, which is effectively maintained by cooling drum system, all IZO electrodes showed an amorphous structure regardless of the DC power and Ar/O 2 flow ratio. Furthermore, the IZO electrodes grown at optimized condition exhibited superior flexibility than the conventional amorphous ITO electrodes due to its stable amorphous structure. This indicates that the RTR sputter grown IZO electrode is a promising flexible electrode that can substitute for the conventional ITO electrode, due to its low resistance, high transparency, superior flexibility and fast preparation by the RTR process.

  10. Roll-to-Roll Printed Silver Nanowire Semitransparent Electrodes for Fully Ambient Solution-Processed Tandem Polymer Solar Cells

    DEFF Research Database (Denmark)

    Angmo, Dechan; Andersen, Thomas Rieks; Bentzen, Janet Jonna

    2015-01-01

    Silver nanowires (AgNWs) and zinc oxide (ZnO) are deposited on flexible substrates using fast roll-to-roll (R2R) processing. The AgNW film on polyethylene terephthalate (PET) shows >80% uniform optical transmission in the range of 550-900 nm. This electrode is compared to the previously reported...... spectrum reaching up to 40% increased transmission at 750 nm in comparison to Flextrode. The functionality of AgNW electrodes is demonstrated in single and tandem polymer solar cells and compared with parallel devices on traditional Flextrode. All layers, apart from the semitransparent electrodes which...... are large-scale R2R produced, are fabricated in ambient conditions on a laboratory roll-coater using printing and coating methods which are directly transferrable to large-scale R2R processing upon availability of materials. In a single cell structure, Flextrode is preferable with active layers based...

  11. Mathematical simulation of bearing ring grinding process

    Science.gov (United States)

    Koltunov, I. I.; Gorbunova, T. N.; Tumanova, M. B.

    2018-03-01

    The paper suggests the method of forming a solid finite element model of the bearing ring. Implementation of the model allowed one to evaluate the influence of the inner cylindrical surface grinding scheme on the ring shape error.

  12. Influence exerted by the shape of the surfaces of working roll barrels upon the course of the MEFASS (Metal Forming Aided by Shear Stresses rolling process

    Directory of Open Access Journals (Sweden)

    Świątoniowski A.

    2017-03-01

    Full Text Available The essential aspect of the MEFASS rolling process is introducing the cyclic axial counter movement of the rolls transverse to the direction of rolling in the course of a band pass through a rolling gap. The effect of a change in the way of deformation obtained in this manner makes it possible to set in one roll pass a deformation several times larger than it is possible in a conventional process. In this paper, upon the basis of the computer model of the MES process, supported by experimental research, the analysis of the influence exerted by the shape of the surface of roll barrels upon the distribution of the intensity of stresses σi and deformations εi in the section of the band being rolled, and also upon the kinematic and force parameters of the process.

  13. Effects of the process temperature and rolling speed on the thermal roll-to-roll imprint lithography of flexible polycarbonate film

    International Nuclear Information System (INIS)

    Sohn, Ki-Ju; Lee, Woo Il; Park, Jae Hong; Jang, Hyun-Ik; Lee, Dong-Eon

    2013-01-01

    Thermal roll-to-roll imprint lithography (R2RIL) is a simple and low-cost process for the mass production of micro/nanopatterns. However, in that it relies on highly viscous thermoplastic resists, it is limited in its ability to imprint precise patterns at a high speed. Moreover, the concentrated imprint force applied in R2RIL can damage the resist material which is structurally vulnerable at high process temperatures. Therefore, it is important to understand the temperature- and time-dependent characteristics of the resist material as well as the imprinting mechanism when using thermal R2RIL. In this work, the effects of the process temperature and rolling speed on thermal R2RIL of polycarbonate (PC) films were investigated to improve the process efficiency. Micro-scale line patterns were successfully transferred onto PC films from nickel (Ni) mold stamps. Consequently, line patterns with widths in the range of 5–80 µm were achieved at a traveling speed of 28.6 mm s –1 and process temperature of 150 °C, which is just above the glass transition temperature (T g ). In addition, the patterning performance was investigated for different temperatures, rolling speeds and pattern sizes. The imprinted pattern profiles were measured by an alpha-step surface profiler to investigate the patterning performance. The results show that a much better imprint performance was achieved at 150 °C, compared to the result at temperatures below T g . The physical mechanisms of thermal R2RIL on a PC film were studied by a finite-element analysis and the patterning process was successfully demonstrated by a visco-plastic deformation model. (paper)

  14. Theoretical Analysis of Unit Friction Force Working on the Metal Contact Surface with the Roll Change during Feedstock with Non-Uniform Temperature Distribution Rolling Process

    Directory of Open Access Journals (Sweden)

    Sygut P.

    2016-06-01

    Full Text Available The paper presents the results of theoretical studies influence of non-uniform temperature distribution along the feedstock length to the unit friction force working on the metal contact surface with the roll change during the round bars 70 mm in diameter continuous rolling process. This value is one of the major factors affecting the grooves wear during the rolling process. The studies were carried out based on the actual engineering data for 160 × 160 mm square cross-section feedstock of steel S355J0. Numerical modelling of the rolling process was performed using Forge2008®, a finite-element based computer program.

  15. 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; Jørgensen, 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 ......HT:[70]PCBM. The solar cell modules were used to demonstrate the complete manufacture of a small lamp entirely using techniques of flexible electronics. The solar cell module was used to charge a polymer lithium ion battery through a blocking diode. The entire process was fully automated...

  16. Experimental and numerical study of the effect of rolling parameters on shaft deformation during the longitudinal rolling process

    Science.gov (United States)

    Kowalik, Marek; Trzepiecinski, Tomasz

    2018-05-01

    This paper presents the characteristics of the process of longitudinal rolling of shafts and the geometry of the working section of forming rollers with a secant profile. In addition, the analytical formulae defining the geometry of a roller profile were determined. The experiments were carried out on shafts made of S235JR and C45 structural steels and the MSC.Marc + Mentat program was used for the numerical analysis of the rolling process based on the finite element method. The paper analyses the effect of roller geometry on the changes in value of the widening coefficient and the diameter reduction coefficient for the first forming passage. It was found that the mechanical properties of the shaft material have a slight influence on the widening coefficient. The value of the widening coefficient of the shaft increases with increase in the initial diameter of the shaft. Increasing shaft diameter causes an increase of strain gradient on the cross-section of the shaft.

  17. Microstructure and mechanical properties of nickel processed by accumulative roll bonding

    DEFF Research Database (Denmark)

    Zhang, Yubin; Mishin, Oleg; Kamikawa, N.

    2013-01-01

    rolling to an identical nominal strain, the microstructure after ARB is more refined and contains a greater fraction of high angle boundaries. This enhanced refinement is attributed to the geometric accumulation of shear-strain influenced volumes as a result of the ARB process and large-draught rolling...

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

    International Nuclear Information System (INIS)

    Chen Shaojie; Xu Jianzhong; Liu Xianghua; Wang Guodong

    2000-01-01

    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)

  19. Aluminum and stainless steel tubes joined by simple ring and welding process

    Science.gov (United States)

    Townhill, A.

    1967-01-01

    Duranel ring is used to join aluminum and stainless steel tubing. Duranel is a bimetal made up of roll-bonded aluminum and stainless steel. This method of joining the tubing requires only two welding operations.

  20. Process Monitoring and Fault Diagnosis for Shell Rolling Production of Seamless Tube

    Directory of Open Access Journals (Sweden)

    Dong Xiao

    2015-01-01

    Full Text Available Continuous rolling production process of seamless tube has many characteristics, including multiperiod and strong nonlinearity, and quickly changing dynamic characteristics. It is difficult to build its mechanism model. In this paper we divide production data into several subperiods by K-means clustering algorithm combined with production process; then we establish a continuous rolling production monitoring and fault diagnosis model based on multistage MPCA method. Simulation experiments show that the rolling production process monitoring and fault diagnosis model based on multistage MPCA method is effective, and it has a good real-time performance, high reliability, and precision.

  1. NORMAL PRESSURE AND FRICTION STRESS MEASUREMENT IN ROLLING PROCESSES

    DEFF Research Database (Denmark)

    Henningsen, Poul; Arentoft, Mogens; Lagergren, Jonas

    2005-01-01

    the 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...

  2. Closure behavior of spherical void in slab during hot rolling process

    Science.gov (United States)

    Cheng, Rong; Zhang, Jiongming; Wang, Bo

    2018-04-01

    The mechanical properties of steels are heavily deteriorated by voids. The influence of voids on the product quality should be eliminated through rolling processes. The study on the void closure during hot rolling processes is necessary. In present work, the closure behavior of voids at the center of a slab at 800 °C during hot rolling processes has been simulated with a 3D finite element model. The shape of the void and the plastic strain distribution of the slab are obtained by this model. The void decreases along the slab thickness direction and spreads along the rolling direction but hardly changes along the strip width direction. The relationship between closure behavior of voids and the plastic strain at the center of the slab is analyzed. The effects of rolling reduction, slab thickness and roller diameter on the closure behavior of voids are discussed. The larger reduction, thinner slab and larger roller diameter all improve the closure of voids during hot rolling processes. Experimental results of the closure behavior of a void in the slab during hot rolling process mostly agree with the simulation results..

  3. Mechanical Behaviour of 304 Austenitic Stainless Steel Processed by Room Temperature Rolling

    Science.gov (United States)

    Singh, Rahul; Goel, Sunkulp; Verma, Raviraj; Jayaganthan, R.; Kumar, Abhishek

    2018-03-01

    To study the effect of room temperature rolling on mechanical properties of 304 Austenitic Stainless Steel, the as received 304 ASS was rolled at room temperature for different percentage of plastic deformation (i.e. 30, 50, 70 and 90 %). Microstructural study, tensile and hardness tests were performed in accordance with ASTM standards to study the effect of rolling. The ultimate tensile strength (UTS) and hardness of a rolled specimen have enhanced with rolling. The UTS has increased from 693 MPa (as received) to 1700 MPa (after 90% deformation). The improvement in UTS of processed samples is due to combined effect of grain refinement and stress induced martensitic phase transformation. The hardness values also increases from 206 VHN (as received) to 499 VHN (after 90% deformation). Magnetic measurements were also conducted to confirm the formation of martensitic phase.

  4. 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

    2015-01-01

    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...

  5. Effective application of statistical process control (SPC) on the lengthwise tonsure rolled plates process

    OpenAIRE

    Noskievičová, Darja; Kucharczyk, Radim

    2012-01-01

    This paper deals with the eff ective application of SPC on the lengthwise tonsure rolled plates process on double side scissors. After explanation of the SPC fundamentals, goals and mistakes during the SPC implementation, the methodical framework for the eff ective SPC application is defi ned. In the next part of the paper the description of practical application of SPC and its analysis from the point of view of this framework is accomplished. Ovaj članak opisuje djelotvornu primj...

  6. Combination process of diamond machining and roll-to-roll UV-replication for thin film micro- and nanostructures

    Science.gov (United States)

    Väyrynen, J.; Mönkkönen, K.; Siitonen, S.

    2016-09-01

    Roll-to-roll (R2R) ultraviolet (UV) curable embossing replication process is a highly accurate and cost effective way to replicate large quantities of thin film polymer parts. These structures can be used for microfluidics, LED-optics, light guides, displays, cameras, diffusers, decorative, laser sensing and measuring devices. In the R2R UV-process, plastic thin film coated with UV-curable lacquer, passes through an imprinting embossing drum and is then hardened by an UV-lamp. One key element for mastering this process is the ability to manufacture a rotating drum containing micro- and nanostructures. Depending on the pattern shapes, the drum can be directly machined by diamond machining or it can be done through wafer level lithographical process. Due to the shrinkage of UV-curable lacquer, the R2R drum pattern process needs to be prototyped few times, in order to get the desired performance and shape from the R2R produced part. To speed up the prototyping and overall process we have developed a combination process where planar diamond machining patterns are being turned into a drum roller. Initially diamond machined patterns from a planar surface are replicated on a polymer sheet using UV-replication. Secondly, a nickel stamper shim is grown form the polymer sheet and at the end the stamper is turned into a roller and used in the R2R process. This process allows various micro milled, turned, grooved and ruled structures to be made at thin film products through the R2R process. In this paper, the process flow and examples of fabricating R2R embossed UVcurable thin film micro- and nanostructures from planar diamond machined patterns, is reported.

  7. The Relationship Between Protein Fractions of Wheat Gluten and the Quality of Ring-Shaped Rolls Evaluated by the Echolocation Method

    Directory of Open Access Journals (Sweden)

    Grazina Juodeikiene

    2005-01-01

    Full Text Available This paper presents the results of the relationship between separate protein fractions and the quality of baked ring-shaped rolls. The qualitative and quantitative protein composition of flour derived from some wheat varieties grown in Lithuania has been determined. The protein properties are evaluated by SDS-PAGE. A new method of the analysis of swelling, based on the principle of echolocation, has been used to determine the quality of this specific kind of baked goods. For the application of this method the wheat flour, which is most suitable for the production of ring-shaped rolls, made from the wheat variety Portal (Pasvalys PVRS, has been selected. This flour has the following quality parameters: proteins 10.5 %, gluten 22.0 %, gluten index 47 r.u. Correlation between the flour quality parameters and the quality of the final bread product shows that γ-gliadins (r=–0.63, LMM glutenins (r=0.55, HMM glutenins (r=0.63 and the content of gluten (r=0.87 have the greatest influence on the quality of the ring-shaped rolls.

  8. Rolling Stock Planning at DSB S-tog - Processes, Cost Structures and Requirements

    DEFF Research Database (Denmark)

    Thorlacius, Per

    A central issue for operators of suburban passenger train transport systems is providing sufficient number of seats for the passengers while at the same time minimising operating costs. The process of providing this is called rolling stock planning. This technical report documents the terminology......, the processes, the cost structures and the requirements for rolling stock planning at DSB S-tog, the suburban passenger train operator of the City of Copenhagen. The focus of the technical report is directed at practical train operator oriented issues. The technical report is thought to serve as a basis...... for investigating better methods to perform the rolling stock planning (to be the topic of later papers). This technical report is produced as a part of the current industrial Ph. D. project to improve the rolling stock planning process of DSB S-tog....

  9. Process Development And Simulation For Cold Fabrication Of Doubly Curved Metal Plate By Using Line Array Roll Set

    International Nuclear Information System (INIS)

    Shim, D. S.; Jung, C. G.; Seong, D. Y.; Yang, D. Y.; Han, J. M.; Han, M. S.

    2007-01-01

    For effective manufacturing of a doubly curved sheet metal, a novel sheet metal forming process is proposed. The suggested process uses a Line Array Roll Set (LARS) composed of a pair of upper and lower roll assemblies in a symmetric manner. The process offers flexibility as compared with the conventional manufacturing processes, because it does not require any complex-shaped die and loss of material by blank-holding is minimized. LARS allows flexibility of the incremental forming process and adopts the principle of bending deformation, resulting in a slight deformation in thickness. Rolls composed of line array roll sets are divided into a driving roll row and two idle roll rows. The arrayed rolls in the central lines of the upper and lower roll assemblies are motor-driven so that they deform and transfer the sheet metal using friction between the rolls and the sheet metal. The remaining rolls are idle rolls, generating bending deformation with driving rolls. Furthermore, all the rolls are movable in any direction so that they are adaptable to any size or shape of the desired three-dimensional configuration. In the process, the sheet is deformed incrementally as deformation proceeds simultaneously in rolling and transverse directions step by step. Consequently, it can be applied to the fabrication of doubly curved ship hull plates by undergoing several passes. In this work, FEM simulations are carried out for verification of the proposed incremental forming system using the chosen design parameters. Based on the results of the simulation, the relationship between the roll set configuration and the curvature of a sheet metal is determined. The process information such as the forming loads and torques acting on every roll is analyzed as important data for the design and development of the manufacturing system

  10. Linear signal processing using silicon micro-ring resonators

    DEFF Research Database (Denmark)

    Peucheret, Christophe; Ding, Yunhong; Ou, Haiyan

    2012-01-01

    We review our recent achievements on the use of silicon micro-ring resonators for linear optical signal processing applications, including modulation format conversion, phase-to-intensity modulation conversion and waveform shaping.......We review our recent achievements on the use of silicon micro-ring resonators for linear optical signal processing applications, including modulation format conversion, phase-to-intensity modulation conversion and waveform shaping....

  11. Development of a new forming process with vertical rolls for electric-resistance-welded pipes

    Energy Technology Data Exchange (ETDEWEB)

    Mizutani, W; Nakajima, K

    1981-01-01

    The features of a new process (VRF process) for forming pipes by constraining the strip edges with undriven vertical rolls are described. The equipment characteristics and forming characteristics are compared with conventional processes. The VRF process can reduce edge stretch, forming energy, equipment and energy costs. 27 refs.

  12. Vertically aligned carbon nanotubes black coatings from roll-to-roll deposition process

    Science.gov (United States)

    Goislard de Monsabert, Thomas; Papciak, L.; Sangar, A.; Descarpentries, J.; Vignal, T.; de Longiviere, Xavier; Porterat, D.; Mestre, Q.; Hauf, H.

    2017-09-01

    Vertically aligned carbon nanotubes (VACNTs) have recently attracted growing interest as a very efficient light absorbing material over a broad spectral range making them a superior coating in space optics applications such as radiometry, optical calibration, and stray light elimination. However, VACNT coatings available to-date most often result from batch-to-batch deposition processes thus potentially limiting the manufacturing repeatability, substrate size and cost efficiency of this material.

  13. Numerical simulation study on rolling-chemical milling process of aluminum-lithium alloy skin panel

    Science.gov (United States)

    Huang, Z. B.; Sun, Z. G.; Sun, X. F.; Li, X. Q.

    2017-09-01

    Single curvature parts such as aircraft fuselage skin panels are usually manufactured by rolling-chemical milling process, which is usually faced with the problem of geometric accuracy caused by springback. In most cases, the methods of manual adjustment and multiple roll bending are used to control or eliminate the springback. However, these methods can cause the increase of product cost and cycle, and lead to material performance degradation. Therefore, it is of significance to precisely control the springback of rolling-chemical milling process. In this paper, using the method of experiment and numerical simulation on rolling-chemical milling process, the simulation model for rolling-chemical milling process of 2060-T8 aluminum-lithium alloy skin was established and testified by the comparison between numerical simulation and experiment results for the validity. Then, based on the numerical simulation model, the relative technological parameters which influence on the curvature of the skin panel were analyzed. Finally, the prediction of springback and the compensation can be realized by controlling the process parameters.

  14. Impact of imitation processes on the effectiveness of ring vaccination.

    Science.gov (United States)

    Wells, Chad R; Tchuenche, Jean M; Meyers, Lauren Ancel; Galvani, Alison P; Bauch, Chris T

    2011-11-01

    Ring vaccination can be a highly effective control strategy for an emerging disease or in the final phase of disease eradication, as witnessed in the eradication of smallpox. However, the impact of behavioural dynamics on the effectiveness of ring vaccination has not been explored in mathematical models. Here, we analyze a series of stochastic models of voluntary ring vaccination. Contacts of an index case base vaccinating decisions on their own individual payoffs to vaccinate or not vaccinate, and they can also imitate the behaviour of other contacts of the index case. We find that including imitation changes the probability of containment through ring vaccination considerably. Imitation can cause a strong majority of contacts to choose vaccination in some cases, or to choose non-vaccination in other cases-even when the equivalent solution under perfectly rational (non-imitative) behaviour yields mixed choices. Moreover, imitation processes can result in very different outcomes in different stochastic realizations sampled from the same parameter distributions, by magnifying moderate tendencies toward one behaviour or the other: in some realizations, imitation causes a strong majority of contacts not to vaccinate, while in others, imitation promotes vaccination and reduces the number of secondary infections. Hence, the effectiveness of ring vaccination can depend significantly and unpredictably on imitation processes. Therefore, our results suggest that risk communication efforts should be initiated early in an outbreak when ring vaccination is to be applied, especially among subpopulations that are heavily influenced by peer opinions.

  15. Mechanics-driven patterning of CVD graphene for roll-based manufacturing process

    Science.gov (United States)

    Kim, Sang-Min; Jang, Bongkyun; Jo, Kyungmin; Kim, Donghyuk; Lee, Jihye; Kim, Kyung-Shik; Lee, Seung-Mo; Lee, Hak-Joo; Han, Seung Min; Kim, Jae-Hyun

    2017-06-01

    Graphene is considered as a promising material for flexible and transparent electrodes due to its outstanding electrical, optical, and mechanical properties. Efforts to mass-produce graphene electrodes led to the development of roll-to-roll chemical vapor deposition (CVD) graphene growth and transfer, and the only remaining obstacle to the mass-production of CVD graphene electrodes is a cost-effective patterning technique that is compatible with the roll-to-roll manufacturing. Herein, we propose a mechanics-driven technique for patterning graphene synthesized on copper foil (commonly used in roll-to-roll manufacturing). The copper foil is exposed to high temperature for a prolonged period during the CVD growth of graphene, and thus can result in recrystallization and grain growth of the copper foil and thereby reducing to the yield strength. This softening behavior of the copper was carefully controlled to allow simple stamp patterning of the graphene. The strength of the underlying substrate was controlled for the accuracy of the residual patterns. The proposed stamp patterning technique is mask-less and photoresist-free, and can be performed at room temperature without high-energy sources such as lasers or plasma. To demonstrate the capability of this process to produce a continuous electrode, a transparent in-plane supercapacitor was fabricated using the proposed patterning technique.

  16. Develop Roll-to-Roll Manufacturing Process of ZrO2 Nanocrystals/Acrylic Nanocomposites for High Refractive Index Applications

    Energy Technology Data Exchange (ETDEWEB)

    Joshi, Pooran C [ORNL; Compton, Brett G [ORNL; Li, Jianlin [ORNL; Jellison Jr, Gerald Earle [ORNL; Duty, Chad E [ORNL

    2015-04-01

    The purpose of this Cooperative Research and Development Agreement (CRADA) was to develop and evaluate ZrO2/acrylic nanocomposite coatings for integrated optoelectronic applications. The formulations engineered to be compatible with roll-to-roll process were evaluated in terms of optical and dielectric properties. The uniform distribution of the ZrO2 nanocrystals in the polymer matrix resulted in highly tunable refractive index and dielectric response suitable for advanced photonic and electronic device applications.

  17. Research on Continuous Injection Direct Rolling Process for PMMA Optical Plate

    Directory of Open Access Journals (Sweden)

    HaiXiong Wang

    2014-06-01

    Full Text Available Continuous injection direct rolling (CIDR combined intermittent injection and rolling process is a new technology for molding optical polymer plates with microstructured patterns; research on forming PMMA optical plates is an aspect of it in this paper. The equipment of CIDR process consists of plastic injection module, precision rolling module, and automatic coiling module. Based on the establishing mathematical CIDR models, numerical analysis was used to explode the distribution of velocity, temperature, and pressure in injection-rolling zone. The simulation results show that it is feasible to control the temperature, velocity, and injection-rolling force, so it can form polymer plate under certain process condition. CIDR experiment equipment has been designed and produced. PMMA optical plate was obtained by CIDR experiments, longitudinal thickness difference is 0.005 mm/200 mm, horizontal thickness difference is 0.02/200 mm, transmittance is 86.3%, Haze is 0.61%, and the difference is little compared with optical glasses. So it can be confirmed that CIDR process is practical to produce PMMA optical plates.

  18. Motion characteristic between die and workpiece in spline rolling process with round dies

    Directory of Open Access Journals (Sweden)

    Da-Wei Zhang

    2016-06-01

    Full Text Available In the spline rolling process with round dies, additional kinematic compensation is an essential mechanism for improving the division of teeth and pitch accuracy as well as surface quality. The motion characteristic between the die and workpiece under varied center distance in the spline rolling process was investigated. Mathematical models of the instantaneous center of rotation, transmission ratio, and centrodes in the rolling process were established. The models were used to analyze the rolling process of the involute spline with circular dedendum, and the results indicated that (1 with the reduction in the center distance, the instantaneous center moves toward workpiece, and the transmission ratio increases at first and then decreases; (2 the variations in the instantaneous center and transmission ratio are discontinuous, presenting an interruption when the involute flank begins to be formed; (3 the change in transmission ratio at the forming stage of the workpiece with the involute flank can be negligible; and (4 the centrode of the workpiece is an Archimedes line whose polar radius reduces, and the centrode of the rolling die is similar to Archimedes line when the workpiece is with the involute flank.

  19. Analysis of factors influencing the bond strength in roll bonding processes

    Science.gov (United States)

    Khaledi, Kavan; Wulfinghoff, Stephan; Reese, Stefanie

    2018-05-01

    Cold Roll Bonding (CRB) is recognized as an industrial technique in which the metal sheets are joined together in order to produce laminate metal composites. In this technique, a metallurgical bond resulting from severe plastic deformation is formed between the rolled metallic layers. The main objective of this paper is to analyse different factors which may affect the bond formation in rolling processes. To achieve this goal, first, an interface model is employed which describes both the bonding and debonding. In this model, the bond strength evolution between the metallic layers is calculated based on the film theory of bonding. On the other hand, the debonding process is modelled by means of a bilinear cohesive zone model. In the numerical section, different scenarios are taken into account to model the roll bonding process of metal sheets. The numerical simulation includes the modelling of joining during the roll bonding process followed by debonding in a Double Cantilever Beam (DCB) peeling test. In all simulations, the metallic layers are regarded as elastoplastic materials subjected to large plastic deformations. Finally, the effects of some important factors on the bond formation are numerically investigated.

  20. The effect of post-processing treatments on inflection points in current–voltage curves of roll-to-roll processed polymer photovoltaics

    DEFF Research Database (Denmark)

    Lilliedal, Mathilde Raad; Medford, Andrew James; Vesterager Madsen, Morten

    2010-01-01

    Inflection point behaviour is often observed in the current–voltage (IV) curve of polymer solar cells. This phenomenon is examined in the context of flexible roll-to-roll (R2R) processed polymer solar cells in a large series of devices with a layer structure of: PET–ITO–ZnO–P3HT...... characterization of device interfaces was carried out in order to identify possible chemical processes that are related to photo-annealing. A possible mechanism based on ZnO photoconductivity, photooxidation and redistribution of oxygen inside the cell is proposed, and it is anticipated that the findings......:PCBM–PEDOT:PSS–Ag. The devices were manufactured using a combination of slot-die coating and screen printing; they were then encapsulated by lamination using a polymer based barrier material. All manufacturing steps were carried out in ambient air. The freshly prepared devices showed a consistent inflection point in the IV...

  1. 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

    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 (Risø DTU) followed b...

  2. Heating Processes Of The Axle-Boxes Of Rolling-Stock On Railway Track Curves

    Directory of Open Access Journals (Sweden)

    Olegas Lunys

    2013-12-01

    Full Text Available The article deals with the heating process of the axle-boxes ofrolling stock when the train is in motion and discusses the forcesacting on the wheel-set when rolling stock moves along the trackcurves. The paper analyses scientific publications relevant tothe forces acting on the wheel-set of rolling stock and focuseson the axle-box heating process. The article also discusses theresults of theoretical studies on wheel-set forces that affect theheat exchange process of axle-boxes for a railway vehicle. Theresearch has determined a change in heating temperatures ofdifferent axle-boxes of rolling stock and reasons for their variationsand tendencies. The paper has estimated an effect of thetrain running along the track curves on the heating intensity ofthe axle-box. Finally, valid conclusions and recommendationshave been provided.

  3. Analysis of Startup Process and Its Optimization for a Two-Stand Reversible Cold Rolling Mill

    Directory of Open Access Journals (Sweden)

    Guangming Liu

    2017-01-01

    Full Text Available Dynamic characteristic analysis of a two-stand reversible cold rolling mill in the startup process was carried out. The delay algorithm of the interstand thickness was proposed. A new method combined with the accelerated secant and the tangent methods was established to solve the simultaneous equations. The thickness and interstand tension transition processes with different static tension establishing processes were analyzed. Both mills were operated under constant rolling force control mode in the above process. The results show that the strip thickness in the rolling gap reduces in the static mill screwdown process. The entry stand runs inversely to establish the static interstand tension. This area becomes an abnormal thickness reduction area of the incoming strip. It results in several abnormal interstand tension increases in the subsequent startup process. The tension increase leads to an impact force on the strip that is the main reason of the strip breakage in the startup process. So the static tension establishing process was optimized, and the interstand tension fluctuation and the strip breakage accidents both reduced significantly. The results are beneficial to the startup process of the two-stand reversible cold rolling mill.

  4. Microstructure based procedure for process parameter control in rolling of aluminum thin foils

    Science.gov (United States)

    Johannes, Kronsteiner; Kabliman, Evgeniya; Klimek, Philipp-Christoph

    2018-05-01

    In present work, a microstructure based procedure is used for a numerical prediction of strength properties for Al-Mg-Sc thin foils during a hot rolling process. For this purpose, the following techniques were developed and implemented. At first, a toolkit for a numerical analysis of experimental stress-strain curves obtained during a hot compression testing by a deformation dilatometer was developed. The implemented techniques allow for the correction of a temperature increase in samples due to adiabatic heating and for the determination of a yield strength needed for the separation of the elastic and plastic deformation regimes during numerical simulation of multi-pass hot rolling. At the next step, an asymmetric Hot Rolling Simulator (adjustable table inlet/outlet height as well as separate roll infeed) was developed in order to match the exact processing conditions of a semi-industrial rolling procedure. At each element of a finite element mesh the total strength is calculated by in-house Flow Stress Model based on evolution of mean dislocation density. The strength values obtained by numerical modelling were found in a reasonable agreement with results of tensile tests for thin Al-Mg-Sc foils. Thus, the proposed simulation procedure might allow to optimize the processing parameters with respect to the microstructure development.

  5. Transmission Electron Microscopy of Amorphous Tandem Thin-Film Silicon Modules Produced by A Roll-to-Roll Process on Plastic Foil

    DEFF Research Database (Denmark)

    Couty, P.; Duchamp, Martial; Söderström, K.

    2011-01-01

    An improvement of the photo-current is expected when amorphous silicon solar cells are grown on a ZnO texture. A full understanding of the relationship between cell structure and electrical performance is essential for the rapid development of high efficiency VHF-tandem cells on textured substrates...... a control-lost of shape fidelity is used to smooth the texture and make it compatible with subsequent layer growth. Then, we present the electrical performances of the most promising reference solar cell single junction which was obtained on a roll-to-roll foil. Finally, a tandem amorphous/amorphous Si....... At first, we present the systematic study where amorphous cells are grown on ZnO based textures. For varying the texture, the same original master LPCVD ZnO was successively transferred to nickel molds and finally transferred to the plastic foil by roll-to-roll process. From TEM images, we show how...

  6. Physical Analysis of Cross-Wedge Rolling Process of a Stepped Shaft

    Directory of Open Access Journals (Sweden)

    Łukasz Wójcik

    2017-12-01

    Full Text Available The paper presents experimental- model research results on the process of cross-wedge rolling of an axially-symmetrical element (stepped shaft. During research was used plastic mass on the basis of waxes in black and white colour. The aim of this experimental research was to determine the best option of forming in terms of values obtained and the course of forces. Physical examination was carried out using specialist machines, that is model and laboratory cross-wedge rolling mill. Experimental analysis was carried out using billets with the temperature of 15°C, whereas the actual process was carried out for billet from C45 carbon steel of temperature 1150°C. The study compared the dimensions of the components obtained during rolling tests and forming forces obtained in the result of physical modeling with forces obtained during real tests.

  7. Asymmetric Rolling Process Simulations by Dynamic Explicit Crystallographic Homogenized Finite Element Method

    International Nuclear Information System (INIS)

    Ngoc Tam, Nguyen; Nakamura, Yasunori; Terao, Toshihiro; Kuramae, Hiroyuki; Nakamachi, Eiji; Sakamoto, Hidetoshi; Morimoto, Hideo

    2007-01-01

    Recently, the asymmetric rolling (ASR) has been applied to the material processing of aluminum alloy sheet to control micro-crystal structure and texture in order to improve the mechanical properties. Previously, several studies aimed at high formability sheet generation have been carried out experimentally, but finite element simulations to predict the deformation induced texture evolution of the asymmetrically rolled sheet metals have not been investigated rigorously. In this study, crystallographic homogenized finite element (FE) codes are developed and applied to analyze the asymmetrical rolling processes. The textures of sheet metals were measured by electron back scattering diffraction (EBSD), and compared with FE simulations. The results from the dynamic explicit type Crystallographic homogenization FEM code shows that this type of simulation is a comprehensive tool to predict the plastic induced texture evolution

  8. A mesh density study for application to large deformation rolling process evaluation

    International Nuclear Information System (INIS)

    Martin, J.A.

    1997-12-01

    When addressing large deformation through an elastic-plastic analysis the mesh density is paramount in determining the accuracy of the solution. However, given the nonlinear nature of the problem, a highly-refined mesh will generally require a prohibitive amount of computer resources. This paper addresses finite element mesh optimization studies considering accuracy of results and computer resource needs as applied to large deformation rolling processes. In particular, the simulation of the thread rolling manufacturing process is considered using the MARC software package and a Cray C90 supercomputer. Both mesh density and adaptive meshing on final results for both indentation of a rigid body to a specified depth and contact rolling along a predetermined length are evaluated

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

    Energy Technology Data Exchange (ETDEWEB)

    Zabihi, Majed, E-mail: m.zabihi@ma.iut.ac.ir [Department of Materials Engineering, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of); Toroghinejad, Mohammad Reza, E-mail: toroghi@cc.iut.ac.ir [Department of Materials Engineering, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of); Shafyei, Ali, E-mail: shafyei@cc.iut.ac.ir [Department of Materials Engineering, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of)

    2013-01-10

    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% Al{sub 2}O{sub 3} were fractured whereas strip composites with 2 and 4 wt% Al{sub 2}O{sub 3} 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% Al{sub 2}O{sub 3} composite strips is a typical ductile fracture, while the failure mode was shear ductile fracture with more flat surfaces in Al-4 wt% Al{sub 2}O{sub 3} strips.

  10. Continuous and scalable fabrication of bioinspired dry adhesives via a roll-to-roll process with modulated ultraviolet-curable resin.

    Science.gov (United States)

    Yi, Hoon; Hwang, Insol; Lee, Jeong Hyeon; Lee, Dael; Lim, Haneol; Tahk, Dongha; Sung, Minho; Bae, Won-Gyu; Choi, Se-Jin; Kwak, Moon Kyu; Jeong, Hoon Eui

    2014-08-27

    A simple yet scalable strategy for fabricating dry adhesives with mushroom-shaped micropillars is achieved by a combination of the roll-to-roll process and modulated UV-curable elastic poly(urethane acrylate) (e-PUA) resin. The e-PUA combines the major benefits of commercial PUA and poly(dimethylsiloxane) (PDMS). It not only can be cured within a few seconds like commercial PUA but also possesses good mechanical properties comparable to those of PDMS. A roll-type fabrication system equipped with a rollable mold and a UV exposure unit is also developed for the continuous process. By integrating the roll-to-roll process with the e-PUA, dry adhesives with spatulate tips in the form of a thin flexible film can be generated in a highly continuous and scalable manner. The fabricated dry adhesives with mushroom-shaped microstructures exhibit a strong pull-off strength of up to ∼38.7 N cm(-2) on the glass surface as well as high durability without any noticeable degradation. Furthermore, an automated substrate transportation system equipped with the dry adhesives can transport a 300 mm Si wafer over 10,000 repeating cycles with high accuracy.

  11. Connecting ring and process to fix heaters in a pressure vessel by means of these rings

    International Nuclear Information System (INIS)

    Bailleul, G.; Caloine, P.; Coville, P.

    1984-01-01

    The invention can applies to the installation of heaters for nuclear reactor pressurizer or to the installation of any kind of reheaters by means of electric resistances when these reheaters have to work under important pressures. The connecting ring is made of a single metallic piece, two coaxial tubes joined each other by a skirt nearly radial; the skirt joins an end of the outer cylindrical tube and an intermediate zone of the inner cylindrical tube. The invention concerns also a heater provided with such a connecting ring, substituted for a part of its metallic envelope, and a process of fastening of these heaters on a pressure vessel. The description given in the frame of a pressurizer applies to the case of a gas reheater or to a reheater for liquid under pressure such as liquid sodium in a tank [fr

  12. Structure and hot-rolled reinforcement rods properties evolution in the process of long service life

    International Nuclear Information System (INIS)

    Mikryukov, V.R.; Syomin, A.P.; Konovalov, S.V.; Ivanov, Yu.F.; Gromov, V.E.

    2006-01-01

    The physical nature of mechanical properties of hot-rolled reinforcement rods degradation during long-life operation is established by methods of transmission diffraction electron microscopy. It is shown that strength and plasticity properties decrease is due to cementite plates cutting and dissolution, microcracks formation process as a result of interstitial phase inclusions creation in the near-surface layer of material

  13. Structure and hot-rolled reinforcement rods properties evolution in the process of long service life

    Energy Technology Data Exchange (ETDEWEB)

    Mikryukov, V R [Siberian State Industrial University, Kirov str., 42. 654007, Novokuznetsk (Russian Federation); Syomin, A P [Siberian State Industrial University, Kirov str., 42. 654007, Novokuznetsk (Russian Federation); Konovalov, S V [Siberian State Industrial University, Kirov str., 42. 654007, Novokuznetsk (Russian Federation); Ivanov, Yu F [Siberian State Industrial University, Kirov str., 42. 654007, Novokuznetsk (Russian Federation); Gromov, V E [Siberian State Industrial University, Kirov str., 42. 654007, Novokuznetsk (Russian Federation)

    2006-08-25

    The physical nature of mechanical properties of hot-rolled reinforcement rods degradation during long-life operation is established by methods of transmission diffraction electron microscopy. It is shown that strength and plasticity properties decrease is due to cementite plates cutting and dissolution, microcracks formation process as a result of interstitial phase inclusions creation in the near-surface layer of material.

  14. THERMO-MECHANICALLY PROCESSED ROLLED WIRE FOR HIGH-STRENGTH ON-BOARD WIRE

    Directory of Open Access Journals (Sweden)

    V. A. Lutsenko

    2011-01-01

    Full Text Available It is shown that at twisting of wire of diameter 1,83 mm, produced by direct wire drawing of thermomechanically processed rolled wire of diameter 5,5 mm of steel 90, metal stratification is completely eliminated at decrease of carbon, manganese and an additional alloying of chrome.

  15. The influence of multiscale heterogeneity on recrystallization in nickel processed by accumulative roll bonding

    DEFF Research Database (Denmark)

    Mishin, Oleg; Zhang, Yubin; Godfrey, A.

    2017-01-01

    Microscopic and sample-scale heterogeneities have been characterized in nickel processed by accumulative roll bonding (ARB) to a von Mises strain of 4.8, and their influence on recrystallization have been analyzed. The microscopic deformation heterogeneities in this material are mostly associated...

  16. High‐Volume Processed, ITO‐Free Superstrates and Substrates for Roll‐to‐Roll Development of Organic Electronics

    DEFF Research Database (Denmark)

    Hösel, Markus; Angmo, Dechan; Søndergaard, Roar R.

    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...

  17. Roll splitting as an alternative intermediate process for wood fuel

    Science.gov (United States)

    Paul E. Barnett; Donald L. Sirois

    1985-01-01

    In an effort to develop mobile equipment for harvesting and processing woody biomass from power line rights-of-way and precommerial thinnings, numerous alternative concepts were evaluated by Tennessee Valley Authority's Timber Harvesting Project.

  18. STUDY ON ENERGY EXCHANGE PROCESSES IN NORMAL OPERATION OF METRO ROLLING STOCK WITH REGENERATIVE BRAKING SYSTEMS

    Directory of Open Access Journals (Sweden)

    A. O. Sulym

    2017-10-01

    Full Text Available Purpose. The analysis of the existing studies showed that the increasing of energy efficiency of metro rolling stock becomes especially important and requires timely solutions. It is known that the implementation of regenerative braking systems on rolling stock will allow significantly solving this problem. It was proved that one of the key issues regarding the introduction of the above-mentioned systems is research on efficient use of electric energy of regenerative braking. The purpose of the work is to evaluate the amount of excessive electric power of regenerative braking under normal operation conditions of the rolling stock with regenerative braking systems for the analysis of the energy saving reserves. Methodology. Quantifiable values of electrical energy consumed for traction, returned to the contact line and dissipated in braking resistors (excessive energy are determined using results of experimental studies of energy exchange processes under normal operating conditions of metro rolling stock with regenerative systems. Statistical methods of data processing were applied as well. Findings. Results of the studies analysis of metro rolling stock operation under specified conditions in Sviatoshinsko-Brovarskaia line of KP «Kyiv Metro system» stipulate the following: 1 introduction of regenerative braking systems into the rolling stock allows to return about 17.9-23.2% of electrical energy consumed for traction to the contact line; 2 there are reserves for improving of energy efficiency of rolling stock with regenerative systems at the level of 20.2–29.9 % of electrical energy consumed for traction. Originality. For the first time, it is proved that the most significant factor that influences the quantifiable values of the electrical energy regeneration is a track profile. It is suggested to use coefficients which indicate the amount and reserves of unused (excessive electrical energy for quantitative evaluation. Studies on

  19. On the use of accumulative roll bonding process to develop nanostructured aluminum alloy 5083

    Energy Technology Data Exchange (ETDEWEB)

    Reza Toroghinejad, Mohammad; Ashrafizadeh, Fakhreddin [Department of Materials Engineering, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of); Jamaati, Roohollah, E-mail: r.jamaatikenari@ma.iut.ac.ir [Department of Materials Engineering, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of); Young Researchers Club, Ayatollah Amoli Branch, Islamic Azad University, Amol (Iran, Islamic Republic of)

    2013-01-20

    In the present study, the effect of accumulative roll bonding (ARB) process at room temperature on the microstructure and mechanical properties of AA5083 strip was investigated. Microstructural observations were done by transmission electron microscopy (TEM) and scanning electron microscopy (SEM). Also, mechanical properties were performed by tensile, hardness, and microhardness tests. It was observed that accumulative roll bonding is a promising process for production of nanostructured (80 nm) AA5083 strips. Nano shear bands were formed in the microstructure after the fourth cycles. When the number of cycles increased, the tensile strength and hardness of the accumulatively roll bonded strips increased. However, by increasing the number of cycles, the elongation value decreased except for the last (sixth) cycle. It was found that when the number of cycles increased, the distribution of microhardness values became more uniform. After the tensile test, debonding can be observed especially in the interface formed in the last cycle. Observations revealed that the failure mode in the accumulatively roll bonded AA5083 strip was a shear ductile rupture with elongated shallow shear dimples.

  20. Slot-die Coating of a High Performance Copolymer in a Readily Scalable Roll Process for Polymer Solar Cells

    DEFF Research Database (Denmark)

    Helgesen, Martin; Carlé, Jon Eggert; Krebs, Frederik C

    2013-01-01

    reported compact coating/printing machine, which enables the preparation of PSCs that are directly scalable with full roll-to-roll processing. The positioning of the side-chains on the thiophene units proves to be very significant in terms of solubility of the polymers and consequently has a major impact...... on the device yield and process control. The most successful processing is accomplished with the polymer, PDTSTTz-4, that has the side-chains situated in the 4-position on the thiophene units. Inverted PSCs based on PDTSTTz-4 demonstrate high fill factors, up to 59%, even with active layer thicknesses well...... above 200 nm. Power conversion efficiencies of up to 3.5% can be reached with the roll-coated PDTSTTz-4:PCBM solar cells that, together with good process control and high device yield, designate PDTSTTz-4 as a convincing candidate for high-throughput roll-to-roll production of PSCs....

  1. Observation and investigation of a dynamic inflection point in current-voltage curves for roll-to-roll processed polymer photovoltaics

    DEFF Research Database (Denmark)

    Medford, Andrew James; Lilliedal, Mathilde Raad

    2010-01-01

    Inflection point behaviour is often observed in the current-voltage (IV) curve of polymer and organic solar cells. This phenomenon is examined in the context of flexible roll-to-roll (R2R) processed polymer solar cells in a large series of devices with a layer structure of: PET-ITO-ZnO-P3HT...... of this “photo-annealing” behaviour was further investigated by studying the effects of several key factors: temperature, illumination, and atmosphere. The results consistently showed that the inflection point is a dynamic interface phenomenon which can be removed under specific conditions. Subsequently...

  2. Influence of inductive heating on microstructure and material properties in roll forming processes

    Science.gov (United States)

    Guk, Anna; Kunke, Andreas; Kräusel, Verena; Landgrebe, Dirk

    2017-10-01

    The increasing demand for sheet metal parts and profiles with enhanced mechanical properties by using high and ultra-high-strength (UHS) steels for the automotive industry must be covered by increasing flexibility of tools and machines. This can be achieved by applying innovative technologies such as roll forming with integrated inductive heating. This process is similar to indirect press hardening and can be used for the production of hardened profiles and profiles with graded properties in longitudinal and traverse direction. The advantage is that the production of hardened components takes place in a continuous process and the integration of heating and quenching units in the profiling system increases flexibility, accompanied by shortening of the entire process chain and minimizing the springback risk. The features of the mentioned process consists of the combination of inhomogeneous strain distribution over the stripe width by roll forming and inhomogeneity of microstructure by accelerated inductive heating to austenitizing temperature. Therefore, these two features have a direct influence on the mechanical properties of the material during forming and hardening. The aim of this work is the investigation of the influence of heating rates on microstructure evolution and mechanical properties to determine the process window. The results showed that heating rate should be set at 110 K/s for economic integration of inductive heating into the roll forming process.

  3. Nanograined Ti–Nb microalloy steel achieved by Accumulative Roll Bonding (ARB) process

    International Nuclear Information System (INIS)

    Tohidi, A.A.; Ketabchi, M.; Hasannia, A.

    2013-01-01

    Over the last decade, nanocrystalline and ultra-fine grained (UFG) materials with grain size less than 1 μm have aroused considerable interest due to their superior mechanical properties compared to conventionally grained materials. In this work Ti–Nb microalloy steel was processed by the severe plastic deformation (SPD) technique called Accumulative Roll Bonding (ARB) in order to produce an ultra-fine grained microstructure and improve the mechanical properties. After initial preparation to achieve good sheet bonding, 8 cycles of ARB at 550 °C were successfully performed. Observation of optical microstructure, scanning electron microscopy (SEM) micrographs, and X-Ray Diffraction (XRD) peak broadening analysis were used for the characterization of grain structure of the ARB processed sample. The mechanical attributes after rolling and cooling were examined. It was calculated that metal's yield and tensile strength increased by 334% and 215% respectively, while the ductility dropped from as-received value of 34% to 2.9%. Microhardness of the material was studied at room temperature. There was a continuous enhancement of hardness by increasing the pass number of the ARB process. At the 8th pass, the hardness values increased by 230%. The rolling process was stopped at 8th cycle when cracking of the edge became pronounced

  4. Instrumented roll technology for the design space development of roller compaction process.

    Science.gov (United States)

    Nesarikar, Vishwas V; Vatsaraj, Nipa; Patel, Chandrakant; Early, William; Pandey, Preetanshu; Sprockel, Omar; Gao, Zhihui; Jerzewski, Robert; Miller, Ronald; Levin, Michael

    2012-04-15

    Instrumented roll technology on Alexanderwerk WP120 roller compactor was developed and utilized successfully for the measurement of normal stress on ribbon during the process. The effects of process parameters such as roll speed (4-12 rpm), feed screw speed (19-53 rpm), and hydraulic roll pressure (40-70 bar) on normal stress and ribbon density were studied using placebo and active pre-blends. The placebo blend consisted of 1:1 ratio of microcrystalline cellulose PH102 and anhydrous lactose with sodium croscarmellose, colloidal silicon dioxide, and magnesium stearate. The active pre-blends were prepared using various combinations of one active ingredient (3-17%, w/w) and lubricant (0.1-0.9%, w/w) levels with remaining excipients same as placebo. Three force transducers (load cells) were installed linearly along the width of the roll, equidistant from each other with one transducer located in the center. Normal stress values recorded by side sensors and were lower than normal stress values recorded by middle sensor and showed greater variability than middle sensor. Normal stress was found to be directly proportional to hydraulic pressure and inversely to screw to roll speed ratio. For active pre-blends, normal stress was also a function of compressibility. For placebo pre-blends, ribbon density increased as normal stress increased. For active pre-blends, in addition to normal stress, ribbon density was also a function of gap. Models developed using placebo were found to predict ribbon densities of active blends with good accuracy and the prediction error decreased as the drug concentration of active blend decreased. Effective angle of internal friction and compressibility properties of active pre blend may be used as key indicators for predicting ribbon densities of active blend using placebo ribbon density model. Feasibility of on-line prediction of ribbon density during roller compaction was demonstrated using porosity-pressure data of pre-blend and normal stress

  5. Numerical simulation research on rolling process of monolithic nuclear fuel plate

    International Nuclear Information System (INIS)

    Wan Jibo; Kong Xiangzhe; Ding Shurong; Xu Hongbin; Huo Yongzhong

    2015-01-01

    For the strain-rate-dependent constitutive relation of zircaloy cladding in UMo monolithic nuclear fuel plates, the three-dimensional stress updating algorithm was derived out, and the corresponding VUMAT subroutine to define its constitutive relation was developed and validated; the finite element model was built to simulate the frame rolling process of UMo monolithic nuclear fuel plates; with the explicit dynamic finite element method, the evolution rules of the deformation and contact pressure during the rolling process within the composite slab were obtained and analyzed. The research results indicate that it is convenient and efficient to define the strain-rate- dependent constitutive relations of materials with the user-defined material subroutine VUMAT; the rolling-induced contact pressure between the fuel meat and the covers varies with time, and the maximum pressure exits at the symmetric plane along the plate width direction. This study supplies a foundation and a computation method for optimizing the processing parameters to manufacture UMo monolithic nuclear fuel plates. (authors)

  6. Analysis of reforming process of large distorted ring in final enlarging forging

    International Nuclear Information System (INIS)

    Miyazawa, Takeshi; Murai, Etsuo

    2002-01-01

    In the construction of reactors or pressure vessels for oil chemical plants and nuclear power stations, mono block open-die forging rings are often utilized. Generally, a large forged ring is manufactured by means of enlarging forging with reductions of the wall thickness. During the enlarging process the circular ring is often distorted and becomes an ellipse in shape. However the shape control of the ring is a complicated work. This phenomenon makes the matter still worse in forging of larger rings. In order to make precision forging of large rings, we have developed the forging method using a v-shape anvil. The v-shape anvil is geometrically adjusted to fit the distorted ring in the final circle and reform automatically the shape of the ring during enlarging forging. This paper has analyzed the reforming process of distorted ring by computer program based on F.E.M. and examined the effect on the precision of ring forging. (author)

  7. A jelly-roll process for high temperature superconducting tapes and wires

    International Nuclear Information System (INIS)

    Tsuei, C.C.; Chi, C.C.; Frey, T.; Mitzi, D.B.; Kazyaka, T.; Haugan, T.; Ye, J.; Patel, S.; Shaw, D.T.; Wu, M.K.

    1992-01-01

    As an alternative to the powder-in-tube method, a new technique called the jelly-roll process is proposed for making high-T c superconducting tapes and wires. A normal-metal sheet coated with high-T c cuprate is configured in a jelly-roll fashion and cold worked into tapes or wires made of alternating cuprate superconductor and normal metal layers. The feasibility of this new process is demonstrated for both the YBa 2 Cu 3 O 7 /Ag and Bi 2 Sr 2 CaCu 2 O 8 /Ag composite systems. The role of reduction in the cross-sectional area by cold-rolling, heat treatment and oxygenation in optimizing T c and J c has been studied. Preliminary results indicate that partialmelt texturing, in the Bi 2 Sr 2 CaCu 2 O 8 /Ag system, results in a relatively field independent J c (H c (H = 0) ∝5 X 10 4 A cm -2 at 4.2 K

  8. A jelly-roll process for high temperature superconducting tapes and wires

    Energy Technology Data Exchange (ETDEWEB)

    Tsuei, C C; Chi, C C; Frey, T; Mitzi, D B; Kazyaka, T [IBM Thomas J. Watson Research Center, Yorktown Heights, NY (United States); Haugan, T; Ye, J; Patel, S; Shaw, D T [New York State Inst. on Superconductivity, SUNY, Buffalo, Amherst, NY (United States); Wu, M K [Dept. of Physics, National Tsing Hua Univ., Hsinchu (Taiwan)

    1992-07-01

    As an alternative to the powder-in-tube method, a new technique called the jelly-roll process is proposed for making high-T[sub c] superconducting tapes and wires. A normal-metal sheet coated with high-T[sub c] cuprate is configured in a jelly-roll fashion and cold worked into tapes or wires made of alternating cuprate superconductor and normal metal layers. The feasibility of this new process is demonstrated for both the YBa[sub 2]Cu[sub 3]O[sub 7]/Ag and Bi[sub 2]Sr[sub 2]CaCu[sub 2]O[sub 8]/Ag composite systems. The role of reduction in the cross-sectional area by cold-rolling, heat treatment and oxygenation in optimizing T[sub c] and J[sub c] has been studied. Preliminary results indicate that partialmelt texturing, in the Bi[sub 2]Sr[sub 2]CaCu[sub 2]O[sub 8]/Ag system, results in a relatively field independent J[sub c] (H< or approx.7T) with J[sub c](H = 0) [proportional to]5 X 10[sup 4] A cm[sup -2] at 4.2 K.

  9. Evolution of Oxide Inclusions in Si-Mn Killed Steels During Hot-Rolling Process

    Science.gov (United States)

    Yang, Wen; Guo, Changbo; Zhang, Lifeng; Ling, Haitao; Li, Chao

    2017-10-01

    The evolution of oxide inclusions in Si-Mn killed steels refined by slags of different basicity during a four-pass industrial hot-rolling process was investigated using an automated microscopy system. High-basicity refining slag induced the formation of CaO- and Al2O3-containing inclusions, while refining slag with 0.8 basicity induced dominant inclusions of SiO2 and MnO-SiO2. CaO-SiO2-Al2O3 inclusions mainly formed endogenously during solidification and cooling of Ca-containing steels, where Ca originated from slag-steel reactions. However, the larger-sized higher-CaO inclusions originated from slag entrainment. Different inclusions presented different hot-rolling behaviors. The inclusion composition changed by deformation and new phase formation. The dominant oxide types were unchanged under refinement by low-basicity slag; however, they changed under refinement with high-basicity slag. The deformation index of inclusions decreased with increasing accumulated reduction (AR) of the steel. The difference in deformation index between different inclusion types was the largest in the first rolling stage and decreased in subsequent stages. SiO2-CaO and SiO2-MnO-CaO inclusions had larger deformation indices during hot rolling but smaller indices in the last two stages. High-basicity slag increased inclusion complexity; from the perspective of cold-drawing performance, low-basicity refining slag is better for the industrial production of tire-cord steels.

  10. Texture and magnetic properties of non-oriented electrical steels processed by an unconventional cold rolling scheme

    Energy Technology Data Exchange (ETDEWEB)

    He, Youliang, E-mail: youliang.he@canada.ca [CanmetMATERIALS, Natural Resources Canada, Hamilton, ON (Canada); Hilinski, Erik J. [Formerly Research and Technology Centre, United States Steel Corporation, Munhall, PA (United States); Now Tempel Steel Co., Chicago, IL (United States)

    2016-05-01

    Two non-oriented electrical steels containing 0.9 wt% and 2.8 wt% of silicon were processed using an unconventional cold rolling scheme, i.e. the cold rolling direction (CRD) was intentionally inclined at an angle to the hot rolling direction (HRD) so that the initial texture before cold rolling and the rotation paths of crystals during cold deformation were both altered as compared to conventional cold rolling along the original HRD. The cold-rolled steel strips were then annealed, skin-pass rolled and final annealed. The texture and microstructure of the materials were characterized by X-ray diffraction (XRD), electron backscatter diffraction (EBSD) and optical microscopy, and considerable differences in average grain size and texture were observed at different inclination angles. The magnetic properties of the steel strips were measured at 400 Hz and 1.0 T/1.5 T using a specially designed Epstein frame, and apparent differences were also noticed at various angles. The magnetic quality of texture was evaluated using different texture factors/parameters and compared to the measured magnetic properties. Although apparent improvement on the magnetic quality of texture can be noted by inclining the CRD to HRD, the trend does not match the measured magnetic properties at 400 Hz, which may have been affected by other parameters in addition to crystallographic texture. - Highlights: • The cold rolling direction is inclined an angle to the hot rolling direction. • The deformation and annealing textures are both changed by the inclined rolling. • Magnetic quality of texture is improved at specific inclination angles. • Low silicon steel is more sensitive in texture change than high silicon steel. • High frequency core loss does not follow the computed magnetic quality of texture.

  11. Combined process "helical rolling-pressing" and its effect on the microstructure of ferrous and non-ferrous materials

    Science.gov (United States)

    Naizabekov, Abdrakhman; Lezhnev, Sergey; Arbuz, Alexandr; Panin, Evgeniy

    2018-02-01

    Ultrafine-grained materials are one of the most promising structural and functional materials. However, the known methods of obtaining them are not enough powerful and technologically advanced for profitable industrial applications. Development of the combined process "helical rolling-pressing" is an attempt to bring technology to produce ultrafine-grained materials to the industry. The combination of intense processing of the surface by helical rolling and the entire cross section of workpiece in equal channel angular matrix, with intense deformation by torsion between rolls and matrix will increase the degree of deformation per pass and allows to mutually compensate disadvantages of these methods in the case of their separate use. This paper describes the development of a laboratory stand and study of influence of combined process "helical rolling-pressing"on the microstructure of tool steel, technical copper and high alloy stainless high-temperature steel.

  12. Large critical current density improvement in Bi-2212 wires through the groove-rolling process

    International Nuclear Information System (INIS)

    Malagoli, A; Bernini, C; Braccini, V; Romano, G; Putti, M; Chaud, X; Debray, F

    2013-01-01

    Recently there has been a growing interest in Bi-2212 superconductor round wire for high magnetic field use despite the fact that an increase of the critical current is still needed to boost its successful use in such applications. Recent studies have demonstrated that the main obstacle to current flow, especially in long wires, is the residual porosity inside these powder-in-tube processed conductors that develops from bubble agglomeration when the Bi-2212 melts. In this work we tried to overcome this issue affecting the wire densification by changing the deformation process. Here we show the effects of groove rolling versus the drawing process on the critical current density J C and on the microstructure. In particular, groove-rolled multifilamentary wires show a J C increased by a factor of about 3 with respect to drawn wires prepared with the same Bi-2212 powder and architecture. We think that this approach in the deformation process is able to produce the required improvements both because the superconducting properties are enhanced and because it makes the fabrication process faster and cheaper. (paper)

  13. Linking heterometallic rings for quantum information processing and amusement.

    Science.gov (United States)

    Timco, Grigore A; Faust, Thomas B; Tuna, Floriana; Winpenny, Richard E P

    2011-06-01

    Linking polymetallic cages can be a method for creating new structures and new properties. In this tutorial review we use heterometallic anti-ferromagnetically coupled rings (AF-rings) as exemplars for three approaches that can be used to link cage compounds. The first of three routes involves an ion-pair interaction supported by hydrogen-bonding interactions, which allows the synthesis of hybrid rotaxanes among other materials. The second route involves functionalising the exterior of the AF-ring so that it will act as a Lewis base; complexes involving coordination of pyridine to bridging monometallic and dimetallic fragments are discussed. The third route involves creating a vacancy on one site of the AF-ring, and then using the ring as a Lewis acid. Di-imine ligands can then be used to link the AF-rings into dimers. A brief discussion of the physical properties of these systems is also included.

  14. Analysis of the deep rolling process on turbine blades using the FEM/BEM-coupling

    International Nuclear Information System (INIS)

    Baecker, V; Klocke, F; Wegner, H; Timmer, A; Grzhibovskis, R; Rjasanow, S

    2010-01-01

    Highly stressed components of aircraft engines, like turbine blades, have to satisfy stringent requirements regarding durability and reliability. The induction of compressive stresses and strain hardening in their surface layer has proven as a promising method to significantly increase their fatigue resistance. The required surface layer properties can be achieved by deep rolling. The determination of optimal process parameters still requires elaborate experimental set-up and subsequent time- and cost-extensive measurements. In previous works the application of the Finite Element Method (FEM) was proposed as an effective and cost reducing alternative to predict the surface layer state for given process parameters. However, FEM requires very fine mesh in the surface layer to resolve the high stress gradients with sufficient accuracy. The hereby caused high time and memory requirements render an efficient simulation of complete turbine components as impossible. In this article a solution is offered by coupling the FEM with the Boundary Elements Method (BEM). It enables the computing of large scale models at low computational cost and high result accuracy. Different approaches of the FEM/BEM-coupling for the simulation of deep rolling are examined with regard to their stability and required computing time.

  15. Effect of Carbon Content on the Properties of Iron-Based Powder Metallurgical Parts Produced by the Surface Rolling Process

    Directory of Open Access Journals (Sweden)

    Yan Zhao

    2018-01-01

    Full Text Available In recent years, the rolling densification process has become increasingly widely used to strengthen powder metallurgy parts. The original composition of the rolled powder metallurgy blank has a significant effect on the rolling densification technology. The present work investigated the effects of different carbon contents (0 wt. %, 0.2 wt. %, 0.45 wt. %, and 0.8 wt. % on the rolling densification. The selection of the raw materials in the surface rolling densification process was analyzed based on the pore condition, structure, hardness, and friction performance of the materials. The results show that the 0.8 wt. % carbon content of the surface rolling material can effectively improve the properties of iron-based powder metallurgy parts. The samples with 0.8 wt. % carbon have the highest surface hardness (340 HV0.1 and the lowest surface friction coefficient (0.35. Even if the dense layer depth is 1.13 mm, which is thinner than other samples with low carbon content, it also meets the requirements for powder metallurgy parts such as gears used in the auto industry.

  16. Silver front electrode grids for ITO-free all printed polymer solar cells with embedded and raised topographies, prepared by thermal imprint, flexographic and inkjet roll-to-roll processes

    DEFF Research Database (Denmark)

    Yu, Jong-Su; Kim, Inyoung; Kim, Jung-Su

    2012-01-01

    Semitransparent front electrodes for polymer solar cells, that are printable and roll-to-roll processable under ambient conditions using different approaches, are explored in this report. The excellent smoothness of indium-tin-oxide (ITO) electrodes has traditionally been believed to be difficult...

  17. Feasibility Study on Flexibly Reconfigurable Roll Forming Process for Sheet Metal and Its Implementation

    Directory of Open Access Journals (Sweden)

    Jun-Seok Yoon

    2014-06-01

    Full Text Available A multicurved sheet metal surface for a skin structure has usually been manufactured using a conventional die forming process involving the use of both a die and a press machine in accordance with the product shape. However, such processes are economically inefficient because additional production costs are incurred for the development and management of forming tools. To overcome this drawback, many alternative processes have been developed; however, these still suffer from problems due to defects such as dimples and wrinkles occurring in the sheet. In this study, a new sheet metal forming process called the flexibly reconfigurable roll forming (FRRF process is proposed as an alternative to existing processes. Unlike existing processes, FRRF can reduce additional production costs resulting from material loss and significantly reduce forming errors. Furthermore, it involves the use of a smaller apparatus. The methodology and applicable procedure of the FRRF process are described. Numerical forming simulations of representative multicurved sheet surfaces are conducted using FEM. In addition, a simple apparatus is developed for verifying the feasibility of this process, and a doubly curved metal is formed to verify the applicability of the reconfigurable roller, a critical component in this forming process.

  18. Roll-to-Roll Processing of Inverted Polymer Solar Cells using Hydrated Vanadium(V)Oxide as a PEDOT:PSS Replacement.

    Science.gov (United States)

    Espinosa, Nieves; Dam, Henrik Friis; Tanenbaum, David M; Andreasen, Jens W; Jørgensen, Mikkel; Krebs, Frederik C

    2011-01-11

    The use of hydrated vanadium(V)oxide as a replacement of the commonly employed hole transporting material PEDOT:PSS was explored in this work. Polymer solar cells were prepared by spin coating on glass. Polymer solar cells and modules comprising 16 serially connected cells were prepared using full roll-to-roll (R2R) processing of all layers. The devices were prepared on flexible polyethyleneterphthalate (PET) and had the structure PET/ITO/ZnO/P3HT:PCBM/V₂O₅·(H₂O) n /Ag. The ITO and silver electrodes were processed and patterned by use of screen printing. The zinc oxide, P3HT:PCBM and vanadium(V)oxide layers were processed by slot-die coating. The hydrated vanadium(V)oxide layer was slot-die coated using an isopropanol solution of vanadyl-triisopropoxide (VTIP). Coating experiments were carried out to establish the critical thickness of the hydrated vanadium(V)oxide layer by varying the concentration of the VTIP precursor over two orders of magnitude. Hydrated vanadium(V)oxide layers were characterized by profilometry, scanning electron microscopy, energy dispersive X-ray spectroscopy, and grazing incidence wide angle X-ray scattering. The power conversion efficiency (PCE) for completed modules was up to 0.18%, in contrast to single cells where efficiencies of 0.4% were achieved. Stability tests under indoor and outdoor conditions were accomplished over three weeks on a solar tracker.

  19. Roll-to-Roll Processing of Inverted Polymer Solar Cells using Hydrated Vanadium(VOxide as a PEDOT:PSS Replacement

    Directory of Open Access Journals (Sweden)

    Frederik C. Krebs

    2011-01-01

    Full Text Available The use of hydrated vanadium(Voxide as a replacement of the commonly employed hole transporting material PEDOT:PSS was explored in this work. Polymer solar cells were prepared by spin coating on glass. Polymer solar cells and modules comprising 16 serially connected cells were prepared using full roll-to-roll (R2R processing of all layers. The devices were prepared on flexible polyethyleneterphthalate (PET and had the structure PET/ITO/ZnO/P3HT:PCBM/V2O5·(H2On/Ag. The ITO and silver electrodes were processed and patterned by use of screen printing. The zinc oxide, P3HT:PCBM and vanadium(Voxide layers were processed by slot-die coating. The hydrated vanadium(Voxide layer was slot-die coated using an isopropanol solution of vanadyl-triisopropoxide (VTIP. Coating experiments were carried out to establish the critical thickness of the hydrated vanadium(Voxide layer by varying the concentration of the VTIP precursor over two orders of magnitude. Hydrated vanadium(Voxide layers were characterized by profilometry, scanning electron microscopy, energy dispersive X-ray spectroscopy, and grazing incidence wide angle X-ray scattering. The power conversion efficiency (PCE for completed modules was up to 0.18%, in contrast to single cells where efficiencies of 0.4% were achieved. Stability tests under indoor and outdoor conditions were accomplished over three weeks on a solar tracker.

  20. Roll-to-Roll Processing of Inverted Polymer Solar Cells using Hydrated Vanadium(V)Oxide as a PEDOT:PSS Replacement

    DEFF Research Database (Denmark)

    Martinez, Nieves Espinosa; Dam, Henrik Friis; Tanenbaum, David M.

    2011-01-01

    roll-to-roll (R2R) processing of all layers. The devices were prepared on flexible polyethyleneterphthalate (PET) and had the structure PET/ITO/ZnO/P3HT:PCBM/V2O5·(H2O)n/Ag. The ITO and silver electrodes were processed and patterned by use of screen printing. The zinc oxide, P3HT:PCBM and vanadium(V)oxide......The use of hydrated vanadium(V)oxide as a replacement of the commonly employed hole transporting material PEDOT:PSS was explored in this work. Polymer solar cells were prepared by spin coating on glass. Polymer solar cells and modules comprising 16 serially connected cells were prepared using full...... layers were processed by slot-die coating. The hydrated vanadium(V)oxide layer was slot-die coated using an isopropanol solution of vanadyl-triisopropoxide (VTIP). Coating experiments were carried out to establish the critical thickness of the hydrated vanadium(V)oxide layer by varying the concentration...

  1. Fabrication of a metallic roll stamp with low internal stress and high hardness for large area display applications by a pulse reverse current electroforming process

    International Nuclear Information System (INIS)

    Kim, Joongeok; Han, Jungjin; Kim, Taekyung; Kang, Shinill

    2014-01-01

    With the increasing demand for large scale micro/nano components in the fields of display, energy and electrical devices, etc, the establishment of a roll imprinting process has become a priority. The fabrication of a roll stamp with high dimensional accuracy and uniformity is one of the key issues in the roll imprinting process, because the roll stamp determines the properties of the replicated micro/nano structures. In this study, a method to fabricate a metallic roll stamp with low internal stress, high flatness, and high hardness was proposed by a pulse reverse current (PRC) electroforming process. The effects of PRC electroforming processes on the internal stress, hardness, and grain size of the electroformed stamp were examined, and the optimum process conditions were suggested. As a practical example of the proposed method, various micro-patterns for electronic circuits were fabricated via the roll imprinting process using a PRC electroformed stamp. (paper)

  2. Silver front electrode grids for ITO-free all printed polymer solar cells with embedded and raised topographies, prepared by thermal imprint, flexographic and inkjet roll-to-roll processes.

    Science.gov (United States)

    Yu, Jong-Su; Kim, Inyoung; Kim, Jung-Su; Jo, Jeongdai; Larsen-Olsen, Thue T; Søndergaard, Roar R; Hösel, Markus; Angmo, Dechan; Jørgensen, Mikkel; Krebs, Frederik C

    2012-09-28

    Semitransparent front electrodes for polymer solar cells, that are printable and roll-to-roll processable under ambient conditions using different approaches, are explored in this report. The excellent smoothness of indium-tin-oxide (ITO) electrodes has traditionally been believed to be difficult to achieve using printed front grids, as surface topographies accumulate when processing subsequent layers, leading to shunts between the top and bottom printed metallic electrodes. Here we demonstrate how aqueous nanoparticle based silver inks can be employed as printed front electrodes using several different roll-to-roll techniques. We thus compare hexagonal silver grids prepared using either roll-to-roll inkjet or roll-to-roll flexographic printing. Both inkjet and flexo grids present a raised topography and were found to perform differently due to only the conductivity of the obtained silver grid. The raised topographies were compared with a roll-to-roll thermally imprinted grid that was filled with silver in a roll-to-roll process, thus presenting an embedded topography. The embedded grid and the flexo grid were found to perform equally well, with the flexographic technique currently presenting the fastest processing and the lowest silver use, whereas the embedded grid presents the maximally achievable optical transparency and conductivity. Polymer solar cells were prepared in the same step, using roll-to-roll slot-die coating of zinc oxide as the electron transport layer, poly-3-hexylthiophene:phenyl-C(61)-butyric acid methyl ester (P3HT:PCBM) as the active layer and poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) as the top electrode, along with a flat bed screen printed silver grid. The power conversion efficiency (PCE) obtained for large area devices (6 cm(2)) was 1.84%, 0.79% and 1.72%, respectively, for thermally imprinted, inkjet and flexographic silver grids, tested outside under the real sun. Central to all three approaches was that they

  3. Roll force prediction of high strength steel using foil rolling theory in cold skin pass rolling

    International Nuclear Information System (INIS)

    Song, Gil Ho; Jung, Jae Chook

    2013-01-01

    Skin pass rolling is a very important process for applying a certain elongation to a strip in the cold rolling and annealing processes, which play an important role in preventing the stretching of the yield point when the material is processed. The exact prediction of the rolling force is essential for obtaining a given elongation with the steel grade and strip size. Unlike hot rolling and cold rolling, skin pass rolling is used to apply an elongation of within 2% to the strip. Under a small reduction, it is difficult to predict the rolling force because the elastic deformation behavior of the rolls is complicated and a model for predicting the rolling force has not yet been established. Nevertheless, the exact prediction of the rolling force in skin pass rolling has gained increasing importance in recent times with the rapid development of high strength steels for use in automobiles. In this study, the possibility of predicting the rolling force in skin pass rolling for producing various steel grades was examined using foil rolling theory, which is known to have similar elastic deformation behavior of rolls in the roll bite. It was found that a noncircular arc model is more accurate than a circular model in predicting the roll force of high strength steel below TS 980 MPa in skin pass rolling

  4. Impact of tool wear on cross wedge rolling process stability and on product quality

    Science.gov (United States)

    Gutierrez, Catalina; Langlois, Laurent; Baudouin, Cyrille; Bigot, Régis; Fremeaux, Eric

    2017-10-01

    Cross wedge rolling (CWR) is a metal forming process used in the automotive industry. One of its applications is in the manufacturing process of connecting rods. CWR transforms a cylindrical billet into a complex axisymmetrical shape with an accurate distribution of material. This preform is forged into shape in a forging die. In order to improve CWR tool lifecycle and product quality it is essential to understand tool wear evolution and the physical phenomena that change on the CWR process due to the resulting geometry of the tool when undergoing tool wear. In order to understand CWR tool wear behavior, numerical simulations are necessary. Nevertheless, if the simulations are performed with the CAD geometry of the tool, results are limited. To solve this difficulty, two numerical simulations with FORGE® were performed using the real geometry of the tools (both up and lower roll) at two different states: (1) before starting lifecycle and (2) end of lifecycle. The tools were 3D measured with ATOS triple scan by GOM® using optical 3D measuring techniques. The result was a high-resolution point cloud of the entire geometry of the tool. Each 3D point cloud was digitalized and converted into a STL format. The geometry of the tools in a STL format was input for the 3D simulations. Both simulations were compared. Defects of products obtained in simulation were compared to main defects of products found industrially. Two main defects are: (a) surface defects on the preform that are not fixed in the die forging operation; and (b) Preform bent (no longer straight), with two possible impacts: on the one hand that the robot cannot grab it to take it to the forging stage; on the other hand, an unfilled section in the forging operation.

  5. Black rings and the physical process version of the first law of thermodynamics

    International Nuclear Information System (INIS)

    Rogatko, Marek

    2005-01-01

    We consider the problem of the physical process version of the first law of black ring thermodynamics in n-dimensional Einstein gravity with additional (p+1)-form field strength and dilaton fields. The first order variations of mass, angular momentum and local charge for black ring are derived. From them we prove the physical process version of the first law of thermodynamic for stationary black rings

  6. The process parameters effect of ovality in cross wedge rolling for hollow valve without mandril

    Directory of Open Access Journals (Sweden)

    Ji Hongchao

    2016-01-01

    Full Text Available This paper presents the experimental and numerical results of the effect process parameters on ovality in cross wedge rolling (CWR for hollow engine valve without mandrel. Numerical simulation model for ovality was established by means of the rigid-plastic finite element modeling (FEM method for hollow engine valve. The experiments and numerical analyses suggest that the following parameters represent the best conditions for CWR of hollow engine valve: 30°-34° for the forming angle(α, 5°-7° for the stretching angle(β, 0.2-0.3mm for the mold void width(L, and 65%-70% for the area reduction(Ψ.

  7. Nano grained AZ31 alloy achieved by equal channel angular rolling process

    International Nuclear Information System (INIS)

    Hassani, F.Z.; Ketabchi, M.

    2011-01-01

    Equal channel angular rolling (ECAR) is a severe plastic deformation process which is carried out on large, thin sheets. The grain size could be significantly decreased by this process. The main purpose of this study is to investigate the possibility of grain refinement of AZ31 magnesium alloy sheet by this process to nanometer. The effect of the number of ECAR passes on texture evolution of AZ31 magnesium alloy was investigated. ECAR temperature was controlled to maximize the grain refinement efficiency along with preventing cracking. The initial microstructure of as-received AZ31 sheet showed an average grain size of about 21 μm. The amount of grain refinement increased with increasing the pass number. After 10 passes of the process, significant grain refinement occurred and the field emission scanning electron microscopic (FESEM) micrographs showed that the size of grains were decreased significantly to about 14-70 nm. These grains were formed at the grain boundaries and inside some of the previous larger micrometer grains. Observation of optical microstructures and X-ray diffraction patterns (XRD) showed the formation of twins after ECAR process. Micro-hardness of material was studied at room temperature. There was a continuous enhancement of hardness by increasing the pass number of ECAR process. At the 8th pass, hardness values increased by 53%. At final passes hardness reduced slightly, which was attributed to saturation of strain in high number of passes.

  8. Grain refinement and mechanical properties of CP-Ti processed by warm accumulative roll bonding

    International Nuclear Information System (INIS)

    Milner, Justin L.; Abu-Farha, Fadi; Bunget, Cristina; Kurfess, Thomas; Hammond, Vincent H.

    2013-01-01

    Accumulative roll bonding (ARB), a severe plastic deformation technique, was used in this study to process commercially pure titanium (CP-Ti) at 450 °C. Sheet samples were processed by seven consecutive ARB cycles, with an overall equivalent strain of 5.6. Mechanical characterization and microstructural examination were carried out on the processed material to track their changes and relationships with regard to one another. Electron microscopy, TEM in particular, revealed significant grain refinement in the material, with submicron microstructure achieved even after one cycle of warm processing. Further processing was shown to progressively fragment the highly elongated grains, ultimately producing a predominantly-equiaxed ultrafine grain structure with an average grain size of ∼100 nm. Tensile strength and microhardness of the material increased with the number of ARB cycles; the strength–grain size relationship followed the Hall–Petch equation. The overall grain refinement and strengthening levels observed here are close to those reported in the literature for ARB processing of CP-Ti at ambient temperatures. This demonstrates the ability of warm ARB can be as effective as cold ARB, while offering several advantages for industrial utilization.

  9. Effect of Surface Densification on the Microstructure and Mechanical Properties of Powder Metallurgical Gears by Using a Surface Rolling Process

    Directory of Open Access Journals (Sweden)

    Jingguang Peng

    2016-10-01

    Full Text Available Powder metallurgy (PM components are widely used in the auto industry due to the advantage of net-shape forming, low cost, and high efficiency. Still, usage of PM components is limited in the auto industry when encountering rigorous situations, like heavy load, due to lower strength, hardness, wear resistance, and other properties compared to wrought components due to the existence of massive pores in the PM components. In this study, through combining the powder metallurgy process and rolling process, the pores in the PM components were decreased and a homogenous densified layer was formed on the surface, which resulted in the enhancement of the strength, hardness, wear resistance, and other properties, which can expand its range of application. In this paper, we study the impact of different rolling feeds on the performance of the components’ surfaces. We found that with the increase of the rolling feed, the depth of the densified layer increased.

  10. Application of continual annealing and roll bonding (CAR) process for manufacturing Al–Zn multilayered composites

    International Nuclear Information System (INIS)

    Dehsorkhi, Reza Nasiri; Qods, Fathallah; Tajally, Mohammad

    2012-01-01

    Highlights: ► CAR process was performed on Al–Zn composite. ► Good bonding between layers was achieved by increasing the number of CAR cycles. ► With increasing number of cycles, a good distribution of Zn fragmentations was achieved. ► The composites which were produced by CAR process, possess a higher tensile strength and elongation than ARB process. ► By EDX analysis it is proved that Al and Zn atoms would diffuse with each other. - Abstract: In this study, an aluminium–zinc composite was produced for the first time by using a continual annealing and roll-bonding (CAR) process. A composite with homogeneous distribution of fragmented zinc layers in aluminium matrix was produced after ten CAR cycles. The results demonstrate that tensile strength of the final composites increases up to 410 MPa, which is about 4 times higher than those of initial aluminium and zinc sheets. However, elongation of the composite reduced down to 4% after ten CAR cycles. The fracture surfaces of the tensile samples were observed by scanning electron microscope (SEM) to evaluate the failure mode. Observations reveal that the failure mode in CAR-processed composites is a typical ductile fracture which shows deep dimples in samples with few CAR cycles, while the failure mode was shear ductile fracture with shallow and elongated dimples in samples with ten CAR cycles.

  11. 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.

  12. Experimental and numerical investigation on cold flat rolling processes of DC04 sheets with special focus on residual stresses

    International Nuclear Information System (INIS)

    Bauer, A; Binotsch, C; Awiszus, B; Mehner, T; Sieber, M; Lampke, T

    2016-01-01

    The process of cold flat rolling is a widespread industrial technique to manufacture semi-finished products, e.g., for the automotive or homewares industry. Basic knowledge of the process regarding dimensioning and adjustment of defined characteristics is already state of the art. However, a detailed consideration and analysis with respect to local inhomogeneous residual stresses in several process steps mostly remains disregarded. A broad understanding of the process due to the distribution of residual stresses in the workpiece and the direction of the stress tensors allows for a definition of the characteristics of the workpiece even before the actual manufacturing process. For that purpose, it is necessary to perform numerical investigations by means of the finite element analysis (FEA) of cold flat rolling processes. Within this contribution, several approaches for the calibration of the FEA with the real flat rolling process will be addressed and discussed. To ensure that the numerical consideration provides realistic results, this calibration is indispensable. General parameters such as geometry, height reduction, rolling temperature, process time, and the rolling speed are considered as well as a photogrammetric survey, and calculated residual stresses with results of X-ray diffraction (XRD) will be compared. In the course of the experiments, a good agreement between the stress results of the FEA and the XRD was found in the center of the specimen. In combination with the allocation of the stress orientations, the agreement close to the edges is also fine. Some issues that cause differences between the FEA and the experiment are dis-cussed. (paper)

  13. Study on the Surface Integrity of a Thin-Walled Aluminum Alloy Structure after a Bilateral Slid Rolling Process

    Directory of Open Access Journals (Sweden)

    Laixiao Lu

    2016-04-01

    Full Text Available For studying the influence of a bilateral slid rolling process (BSRP on the surface integrity of a thin-walled aluminum alloy structure, and revealing the generation mechanism of residual stresses, a self-designed BSRP appliance was used to conduct rolling experiments. With the aid of a surface optical profiler, an X-ray stress analyzer, and a scanning electron microscope (SEM, the differences in surface integrity before and after BSRP were explored. The internal changing mechanism of physical as well as mechanical properties was probed. The results show that surface roughness (Ra is reduced by 23.7%, microhardness is increased by 21.6%, and the depth of the hardening layer is about 100 μm. Serious plastic deformation was observed within the subsurface of the rolled region. The residual stress distributions along the depth of the rolling surface and milling surface were tested respectively. Residual stresses with deep and high amplitudes were generated via the BSRP. Based on the analysis of the microstructure, the generation mechanism of the residual stresses was probed. The residual stress of the rolling area consisted of two sections: microscopic stresses caused by local plastic deformation and macroscopic stresses caused by overall non-uniform deformation.

  14. All solution roll-to-roll processed polymer solar cells free from indium-tin-oxide and vacuum coating steps

    DEFF Research Database (Denmark)

    Krebs, Frederik C

    2009-01-01

    of a bottom electrode comprising silver nanoparticles on a 130 micron thick polyethyleneternaphthalate (PEN) substrate. Subsequently an electron transporting layer of zinc oxide nanoparticles was applied from solution followed by an active layer of P3HT-PCBM and a hole transporting layer of PEDOT......, 3 and 8 stripes. All five layers in the device were processed from solution in air and no vacuum steps were employed. An additional advantage is that the use of indium-tin-oxide (ITO) is avoided in this process. The devices were tested under simulated sunlight (1000 W m−2, AM1.5G) and gave a typical...

  15. Rapid flash annealing of thermally reactive copolymers in a roll-to-roll process for polymer solar cells

    DEFF Research Database (Denmark)

    Helgesen, Martin; Carlé, Jon Eggert; Andreasen, Birgitta

    2012-01-01

    intensity pulsed light, delivered by a commercial photonic sintering system. Thermally labile ester groups are positioned on the DTZ unit of the copolymer that can be eliminated thermally for enhanced photochemical stability and advantages in terms of processing (solubility/insolubility switching...

  16. The Critical Choice of PEDOT: PSS Additives for Long Term Stability of Roll‐to‐Roll Processed OPVs

    DEFF Research Database (Denmark)

    Roth, Bérenger; Benatto, Gisele Alves dos Reis; Corazza, Michael

    2015-01-01

    The impact of additives mixed with poly(3,4-ethylenedioxythiophene):polystyrenesulfonate (PEDOT:PSS) on the stability of organic photovoltaic modules is investigated for fully ambient roll-to-roll (R2R) processed indium tin oxide free modules. Four different PEDOT:PSS inks from two different...... on organic photovoltaic stability (ISOS). For the harsh indoor test (ISOS-L-3) only a slight difference in stability is observed between the different modules. During both ISOS-L-3 and ISOS-D-3 one new failure mode is observed as a result of tiny air inclusions in the barrier foil and a R2R method...

  17. Design of Experiment as a powerful tool when applying Finite Element Method: a case study on prediction of hot rolling process parameters

    Directory of Open Access Journals (Sweden)

    Giancarlo G. Bordonaro

    2018-04-01

    Full Text Available The ultimate goal in hot roll pass design is to manufacture a rolled product with the required dimensional accuracy, defect free surface, and mechanical properties. The proper selection of process parameters is crucial to meet increasing requirements for desired quality and geometrical properties of rolled products. Due to the complex behavior of the metal flow at high temperatures and the severe plastic deformations in shape rolling, most efforts that have been made so far only rely upon the practical experience gained by operators. The large number of variables involved and the difficulty in investigating the process characteristics, make the use of finite element (FE tools an effective and attractive opportunity towards a thorough understanding of the rolling process. In this work, Design of Experiment (DOE is proposed as a powerful and viable method for the prediction of rolling process parameters while reducing the computational effort. Nonlinear 3D FE models of the hot rolling process are developed for a large set of complex cross-section shapes and validated against experimental evidences provided by real plant products at each stage of the deformation sequence. Based on the accuracy of the validated FE models, DOE is applied to investigate the flat rolling process under a series of many parameters and scenarios. Effects of main roll forming variables are analyzed on material flow behavior and geometrical features of a rolled product. The selected DOE factors are the workpiece temperature, diameter size, diameter reduction (draught, and rolls angular velocity. The selected DOE responses are workpiece spread, effective stresses, contact stresses, and rolls reaction loads. Eventually, the application of Pareto optimality (a Multi-Criteria Decision Making method allows to detect an optimal combination of design factors which respect desired target requirements for the responses.

  18. The influence of post-processing on creep and microstructure of rolled Cu-8Cr-4Nb

    Energy Technology Data Exchange (ETDEWEB)

    Walley, J.L.; Heelan, J.L.; Vettraino, L.G.; Groza, J.R. [Department of Chemical Engineering and Materials Science, University of California, One Shields Ave., Davis, CA 95616 (United States); Gibeling, J.C., E-mail: jcgibeling@ucdavis.edu [Department of Chemical Engineering and Materials Science, University of California, One Shields Ave., Davis, CA 95616 (United States)

    2010-10-15

    Research highlights: {yields} A simulated-life heat treatment anneal of 24 h at 773 K reduced the steady-state creep rate and increased the creep life of a rolled powder metallurgy Cu-8Cr-4Nb alloy. {yields} The primary microstructural difference between the rolled form and the annealed form of Cu-8Cr-4Nb is the development of annealing twins during heat treatment causing a decrease in the intensity of the texture. {yields} Friction stir welding of rolled Cu-8Cr-4Nb negatively affected creep ductility, thereby decreasing creep life at the temperature tested. Strain localization in the soft heat-affected zone of the weld is hypothesized to be the cause of the decreased creep ductility. - Abstract: Previous work has shown that rolling of an extruded Cu-8Cr-4Nb (GRCop-84) alloy results in higher steady-state creep rates over a range of stresses, leading to concern that other post-processing methods could have substantial deleterious effects on creep properties. To explore that possibility, constant-stress creep tests were conducted at 773 K on rolled GRCop-84 after it was subjected to either friction stir welding (FSW) or a 24 h 1073 K simulated-life heat treatment. The FSW had no measurable effect on the creep rate of the rolled material, but did have detrimental effects on the creep ductility caused by softening, and thus strain localization, in the heat-affected zone of the weld. The simulated-life heat treatment decreased the steady-state creep rate by approximately 45% as compared to the rolled material, leading to longer creep life at a particular applied stress. Electron backscatter diffraction methods were used to compare the microstructural features of extruded, rolled and annealed material forms. It was determined that the rolling procedure decreased the grain size, and decreased the intensity of the texture as compared to the extruded form. The simulated-life heat treatment allowed for the substantial development of twins along with minor grain growth, and

  19. The influence of post-processing on creep and microstructure of rolled Cu-8Cr-4Nb

    International Nuclear Information System (INIS)

    Walley, J.L.; Heelan, J.L.; Vettraino, L.G.; Groza, J.R.; Gibeling, J.C.

    2010-01-01

    Research highlights: → A simulated-life heat treatment anneal of 24 h at 773 K reduced the steady-state creep rate and increased the creep life of a rolled powder metallurgy Cu-8Cr-4Nb alloy. → The primary microstructural difference between the rolled form and the annealed form of Cu-8Cr-4Nb is the development of annealing twins during heat treatment causing a decrease in the intensity of the texture. → Friction stir welding of rolled Cu-8Cr-4Nb negatively affected creep ductility, thereby decreasing creep life at the temperature tested. Strain localization in the soft heat-affected zone of the weld is hypothesized to be the cause of the decreased creep ductility. - Abstract: Previous work has shown that rolling of an extruded Cu-8Cr-4Nb (GRCop-84) alloy results in higher steady-state creep rates over a range of stresses, leading to concern that other post-processing methods could have substantial deleterious effects on creep properties. To explore that possibility, constant-stress creep tests were conducted at 773 K on rolled GRCop-84 after it was subjected to either friction stir welding (FSW) or a 24 h 1073 K simulated-life heat treatment. The FSW had no measurable effect on the creep rate of the rolled material, but did have detrimental effects on the creep ductility caused by softening, and thus strain localization, in the heat-affected zone of the weld. The simulated-life heat treatment decreased the steady-state creep rate by approximately 45% as compared to the rolled material, leading to longer creep life at a particular applied stress. Electron backscatter diffraction methods were used to compare the microstructural features of extruded, rolled and annealed material forms. It was determined that the rolling procedure decreased the grain size, and decreased the intensity of the texture as compared to the extruded form. The simulated-life heat treatment allowed for the substantial development of twins along with minor grain growth, and a substantial

  20. Semi-solid twin-roll casting process of magnesium alloy sheets

    International Nuclear Information System (INIS)

    Watari, H.; Davey, K.; Rasgado, M.T. Alonso; Haga, T.; Koga, N.

    2004-01-01

    An experimental approach has been performed to ascertain the effectiveness of semi-solid strip casting using a horizontal twin roll caster. The demand for light-weight products with high strength has grown recently due to the rapid development of automobile and aircraft technology. One key to such development has been utilization of magnesium alloys, which can potentially reduce the total product weight. However, the problems of utilizing magnesium alloys are still mainly related to high manufacturing cost. One of the solutions to this problem is to develop magnesium casting-rolling technology in order to produce magnesium sheet products at competitive cost for commercial applications. In this experiment, magnesium alloy AZ31B was used to ascertain the effectiveness of semi-solid roll strip casting for producing magnesium alloy sheets. The temperature of the molten magnesium, and the roll speeds of the upper and lower rolls, (which could be changed independently), were varied to find an appropriate manufacturing condition. Rolling and heat treatment conditions were changed to examine which condition would be appropriate for producing wrought magnesium alloys with good formability. Microscopic observation of the crystals of the manufactured wrought magnesium alloys was performed. It has been found that a limiting drawing ratio of 2.7 was possible in a warm deep drawing test of the cast magnesium alloy sheets after being hot rolled

  1. ITO-free flexible polymer solar cells: From small model devices to roll-to-roll processed large modules

    DEFF Research Database (Denmark)

    Manceau, Matthieu; Angmo, Dechan; Jørgensen, Mikkel

    2011-01-01

    and the resultant performances compared. Modules comprising 16 serially connected cells gave total area efficiencies up to 0.5% (235 cm2 – 1% on the active area) while the best monolithic ones gave 0.35% (100 cm2 – 0.4% on the active area). The freshly prepared devices consistently showed an inflection point......) monolithic modules (to achieve high geometric fill factor and increase the flexibility of the process). For this second concept, the only layer that needs to be patterned is the silver grid electrode and the grid pattern design can then be readily tuned. As an example, four different patterns were used...

  2. Process cubes : slicing, dicing, rolling up and drilling down event data for process mining

    NARCIS (Netherlands)

    Aalst, van der W.M.P.

    2013-01-01

    Recent breakthroughs in process mining research make it possible to discover, analyze, and improve business processes based on event data. The growth of event data provides many opportunities but also imposes new challenges. Process mining is typically done for an isolated well-defined process in

  3. OPV for mobile applications: an evaluation of roll-to-roll processed indium and silver free polymer solar cells through analysis of life cycle, cost and layer quality using inline optical and functional inspection tools

    DEFF Research Database (Denmark)

    Espinosa Martinez, Nieves; Lenzmann, Frank O.; Ryley, Stephen

    2013-01-01

    Organic photovoltaic modules have been evaluated for their integration in mobile electronic applications such as a laser pointer. An evaluation of roll-to-roll processed indium and silver free polymer solar cells has been carried out from different perspectives: life cycle assessment, cost analysis...... and layer quality evaluation using inline optical and functional inspection tools. The polymer solar cells were fabricated in credit card sized modules by three routes, and several encapsulation alternatives have been explored, with the aim to provide the simplest but functional protection against moisture...... a low carbon footprint. From the economic perspective there is a huge reduction in the cost of the ITO- and silver-free options, reaching as low as 0.25 V for the OPV module. We used inspection tools such as a roll-to-roll inspection system to evaluate all processing steps during the fabrication...

  4. Roll-to-roll suitable short-pulsed laser scribing of organic photovoltaics and close-to-process characterization

    Science.gov (United States)

    Kuntze, Thomas; Wollmann, Philipp; Klotzbach, Udo; Fledderus, Henri

    2017-03-01

    The proper long term operation of organic electronic devices like organic photovoltaics OPV depends on their resistance to environmental influences such as permeation of water vapor. Major efforts are spent to encapsulate OPV. State of the art is sandwich-like encapsulation between two ultra-barrier foils. Sandwich encapsulation faces two major disadvantages: high costs ( 1/3 of total costs) and parasitic intrinsic water (sponge effects of the substrate foil). To fight these drawbacks, a promising approach is to use the OPV substrate itself as barrier by integration of an ultra-barrier coating, followed by alternating deposition and structuring of OPV functional layers. In effect, more functionality will be integrated into less material, and production steps are reduced in number. All processing steps must not influence the underneath barrier functionality, while all electrical functionalities must be maintained. As most reasonable structuring tool, short and ultrashort pulsed lasers USP are used. Laser machining applies to three layers: bottom electrode made of transparent conductive materials (P1), organic photovoltaic operative stack (P2) and top electrode (P3). In this paper, the machining of functional 110…250 nm layers of flexible OPV by USP laser systems is presented. Main focus is on structuring without damaging the underneath ultra-barrier layer. The close-to-process machining quality characterization is performed with the analysis tool "hyperspectral imaging" (HSI), which is checked crosswise with the "gold standard" Ca-test. It is shown, that both laser machining and quality controlling, are well suitable for R2R production of OPV.

  5. Synergy Between Plasma-Assisted ALD and Roll-to-Roll Atmospheric Pressure PE-CVD Processing of Moisture Barrier Films on Polymers

    NARCIS (Netherlands)

    Starostin, S. A.; Keuning, W.; Schalken, J.; Creatore, M.; Kessels, W. M. M.; Bouwstra, J. B.; van de Sanden, M. C. M.; de Vries, H. W.

    2016-01-01

    The synergy between fast (1600 nm · min−1), roll-to-roll plasma-enhanced chemical vapor deposited (PE-CVD) SiO2 layers and plasma-assisted atomic layer deposited (PA-ALD) ultra-thin Al2O3 films has been investigated in terms of moisture permeation barrier properties. The effective and intrinsic

  6. Synergy between plasma-assisted ALD and roll-to-roll atmospheric pressure PE-CVD processing of moisture barrier films on polymers

    NARCIS (Netherlands)

    Starostin, S.A.; Keuning, W.; Schalken, J.R.G.; Creatore, M.; Kessels, W.M.M.; Bouwstra, J.B.; Sanden, van de M.C.M.; Vries, de H.W.

    2016-01-01

    The synergy between fast (1600 nm · min−1), roll-to-roll plasma-enhanced chemical vapor deposited (PE-CVD) SiO2 layers and plasma-assisted atomic layer deposited (PA-ALD) ultra-thin Al2O3 films has been investigated in terms of moisture permeation barrier properties. The effective and intrinsic

  7. High strain rate superplasticity in an Al–Mg–Sc–Zr alloy processed via simple rolling

    Energy Technology Data Exchange (ETDEWEB)

    Li, Mengjia [School of Materials Science and Engineering, Central South University, Changsha 410083 (China); Pan, Qinglin, E-mail: csupql@163.com [Nonferrous Metal Oriented Advanced Structural Materials and Manufacturing Cooperative Innovation Center, Central South University, Changsha 410083 (China); Shi, Yunjia; Sun, Xue; Xiang, Hao [School of Materials Science and Engineering, Central South University, Changsha 410083 (China)

    2017-02-27

    The superplastic behavior of Al–Mg–Sc–Zr samples with standard gauge size (18 mm by 6 mm) were prepared using simple rolling and were tested in the temperature range from 450 °C to 525 °C at strain rates ranging from 1.67×10{sup –3} s{sup −1} to 1×10{sup –1} s{sup −1}. With proper deformation parameters, the Al–Mg–Sc–Zr alloy has an elongation to failure much higher than 300% and the maximum elongation is 740%. The Microstructure and dislocation substructure investigation using optical microscopy (OM) and transmission electron microscopy (TEM) revealed a dynamic recrystallization in it. The grain size and activation energy on the deformation mechanisms of superplastic is discussed. Results also show that these nano-scale Al{sub 3}(Sc{sub 1−x}Zr{sub x}) particles play an important role in the superplastic process. Al{sub 6}FeMn particles were found to induce the formation and growth of cavities, which can lead to the fracture of specimens.

  8. Studies of the AA2519 Alloy Hot Rolling Process and Cladding with EN AW-1050A Alloy

    Directory of Open Access Journals (Sweden)

    Płonka B.

    2016-03-01

    Full Text Available The objective of the study was to determine the feasibility of plastic forming by hot rolling of the AA2519 aluminium alloy sheets and cladding these sheets with a layer of the EN AW-1050A alloy. Numerous hot-rolling tests were carried out on the slab ingots to define the parameters of the AA2519 alloy rolling process. It has been established that rolling of the AA2519 alloy should be carried out in the temperature range of 400-440°C. Depending on the required final thickness of the sheet metal, appropriate thickness of the EN AW-1050A alloy sheet, used as a cladding layer, was selected. As a next step, structure and mechanical properties of the resulting AA2519 alloy sheets clad with EN AW-1050A alloy was examined. The thickness of the coating layer was established at 0,3÷0,5mm. Studies covered alloy grain size and the core alloy-cladding material bond strength.

  9. Real-time track-less Cherenkov ring fitting trigger system based on Graphics Processing Units

    Science.gov (United States)

    Ammendola, R.; Biagioni, A.; Chiozzi, S.; Cretaro, P.; Cotta Ramusino, A.; Di Lorenzo, S.; Fantechi, R.; Fiorini, M.; Frezza, O.; Gianoli, A.; Lamanna, G.; Lo Cicero, F.; Lonardo, A.; Martinelli, M.; Neri, I.; Paolucci, P. S.; Pastorelli, E.; Piandani, R.; Piccini, M.; Pontisso, L.; Rossetti, D.; Simula, F.; Sozzi, M.; Vicini, P.

    2017-12-01

    The parallel computing power of commercial Graphics Processing Units (GPUs) is exploited to perform real-time ring fitting at the lowest trigger level using information coming from the Ring Imaging Cherenkov (RICH) detector of the NA62 experiment at CERN. To this purpose, direct GPU communication with a custom FPGA-based board has been used to reduce the data transmission latency. The GPU-based trigger system is currently integrated in the experimental setup of the RICH detector of the NA62 experiment, in order to reconstruct ring-shaped hit patterns. The ring-fitting algorithm running on GPU is fed with raw RICH data only, with no information coming from other detectors, and is able to provide more complex trigger primitives with respect to the simple photodetector hit multiplicity, resulting in a higher selection efficiency. The performance of the system for multi-ring Cherenkov online reconstruction obtained during the NA62 physics run is presented.

  10. Controlled rolling process for dual phase steels and application to rod, wire, sheet and other shapes

    Science.gov (United States)

    Thomas, Gareth; Ahn, Jae-Hwan; Kim, Nack-Joon

    1986-01-01

    An improved, energy efficient, hot rolling method for direct production of cold formable dual-phase steel is provided. The steel is heated to completely austenitize it and then continuously hot rolled and cooled down into the ferrite-austenite two phase region to a temperature which is just below the effective Ar.sub.3 temperature. The hot rolled steel is then rapidly quenched to provide an alloy containing strong, tough lath martensite (fibers) in a ductile soft ferrite matrix. The method is particularly useful for providing rods in which form the alloy is capable of being drawn into high strength wire or the like in a cold drawing operation without any intermediate annealing or patenting, and has excellent strength, ductility and fatigue characteristics.

  11. Surface Improvement of Shafts by Turn-Assisted Deep Cold Rolling Process

    Directory of Open Access Journals (Sweden)

    Prabhu Raghavendra

    2016-01-01

    Full Text Available It is well recognized that mechanical surface enhancement methods can significantly improve the characteristics of highly-stressed metallic components. Deep cold rolling is one of such technique which is particularly attractive since it is possible to generate, near the surface, deep compressive residual stresses and work hardened layers while retaining a relatively smooth surface finish. In this paper, the effect of turn-assisted deep cold rolling on AISI 4140 steel is examined, with emphasis on the residual stress state. Based on the X-ray diffraction measurements, it is found that turn-assisted deep cold rolling can be quite effective in retarding the initiation and initial propagation of fatigue cracks in AISI 4140 steel.

  12. NUMERICAL EVALUATION OF TEMPERATURE DISTRIBUTION IN THE ROLLING MILL ROLLS

    Directory of Open Access Journals (Sweden)

    José Claudino de Lira Júnior

    2013-06-01

    Full Text Available In hot rolling processes occur changes in the profile of the rolling mill rolls (expansion and contraction and constant wear due to mechanical stress and continuous thermal cycles of heating/cooling caused by contact rolled material- working roll and the cooling system by water jets in their surface, decreasing their lifetime. This paper presents a computational model to simulate the thermal performance of rolling mill rolls. The model was developed using the finite volume method for a transient two-dimensional system and allows calculating the temperature distribution of the rolling mill rolls under various conditions of service. Here it is investigated the influence of flow rate and temperature of the cooling water on the temperature distribution. The results show that the water temperature has greater influence than the water flow to control the surface temperature of the cylinders.

  13. Additional grain refinement in recrystallization controlled rolling of Ti-microalloyed steels processed by near-net-shape casting technology

    International Nuclear Information System (INIS)

    Arribas, M.; Lopez, B.; Rodriguez-Ibabe, J.M.

    2008-01-01

    This paper analyzes the recrystallization kinetics in Ti-microalloyed steels processed using 'beam blank' casting technology. The faster solidification rates associated with this technology brings a finer precipitation of TiN particles which are very effective in controlling austenite grain growth during hot working. Furthermore, these small precipitates have been shown to delay static and dynamic recrystallization. The finer the precipitates the higher the delay in recrystallization. Nevertheless, beyond particle size and distribution, the level of delay is very dependent on microstructure (above all austenite grain size) and deformation conditions (strain and temperature). This paper studies the effects of this recrystallization delay on the microstructure evolution during hot rolling. Special attention was paid to the study of the occurrence of partial recrystallization during the final stages of rolling, which could lead to the presence of mixed microstructures before transformation. The possibility of achieving an additional austenite grain size refinement prior to transformation was evaluated

  14. Video processing of remote sensor data applied to uranium exploration in Wyoming. [Roll-front U deposits

    Energy Technology Data Exchange (ETDEWEB)

    Levinson, R.A.; Marrs, R.W.; Crockell, F.

    1979-06-30

    LANDSAT satellite imagery and aerial photography can be used to map areas of altered sandstone associated with roll-front uranium deposits. Image data must be enhanced so that alteration spectral contrasts can be seen, and video image processing is a fast, low-cost, and efficient tool. For LANDSAT data, the 7/4 ratio produces the best enhancement of altered sandstone. The 6/4 ratio is most effective for color infrared aerial photography. Geochemical and mineralogical associations occur in unaltered, altered, and ore roll-front zones. Samples from Pumpkin Buttes show that iron is the primary coloring agent which makes alteration visually detectable. Eh and pH changes associated with passage of a roll front cause oxidation of magnetite and pyrite to hematite, goethite, and limonite in the host sandstone, thereby producing the alteration. Statistical analysis show that the detectability of geochemical and color zonation in host sands is weakened by soil-forming processes. Alteration can only be mapped in areas of thin soil cover and moderate to sparse vegetative cover.

  15. Making Ends Meet: Flow Synthesis as the Answer to Reproducible High-Performance Conjugated Polymers on the Scale that Roll-to-Roll Processing Demands

    DEFF Research Database (Denmark)

    Helgesen, Martin; Carlé, Jon Eggert; Benatto, Gisele Alves dos Reis

    2015-01-01

    reaction times down to 10 min afforded PBDTTTz-4 with high molecular weight and a constant quality. The flow method enables full control of the molecular weight via tuning of the flow speed, catalyst loading, and temperature and avoids variation in materials’ quality associated with conventional batch......Continuous flow methods are employed for the controlled polymerization of the roll-to-roll (R2R) compatible polymer PBDTTTz-4 including optimization and upscaling experiments. The polymerization rate and materials’ quality can be increased significantly with the continuous fl ow method where...

  16. Roll-to-roll compatible organic thin film transistor manufacturing technique by printing, lamination, and laser ablation

    International Nuclear Information System (INIS)

    Hassinen, Tomi; Ruotsalainen, Teemu; Laakso, Petri; Penttilä, Raimo; Sandberg, Henrik G.O.

    2014-01-01

    We present roll-to-roll printing compatible techniques for manufacturing organic thin film transistors using two separately processed foils that are laminated together. The introduction of heat-assisted lamination opens up possibilities for material and processing combinations. The lamination of two separately processed substrates together will allow usage of pre-patterned electrodes on both substrates and materials with non-compatible solvents. Also, the surface microstructure is formed differently when laminating dry films together compared to film formation from liquid phase. Demonstrator transistors, inverters and ring oscillators were produced using lamination techniques. Finally, a roll-to-roll compatible lamination concept is proposed where also the source and drain electrodes are patterned by laser ablation. The demonstrator transistors have shown very good lifetime in air, which is contributed partly to the good material combination and partly to the enhanced interface formation in heat-assisted lamination process. - Highlights: • A roll-to-roll compatible lamination technique for printed electronics is proposed. • Laser ablation allows highly defined metal top and bottom electrodes. • Method opens up processing possibilities for incompatible materials and solvents. • Shearing forces may enhance molecular orientation and packing. • An air stable polymer transistor is demonstrated with a lifetime of years

  17. Quality Parameters Defined by Chebyshev Polynomials in Cold Rolling Process Chain

    International Nuclear Information System (INIS)

    Judin, Mika; Nylander, Jari; Larkiola, Jari; Verho, Martti

    2011-01-01

    The thickness profile of hot strip is of importance to profile, flatness and shape of the final cold rolled product. In this work, strip thickness and flatness profiles are decomposed into independent components by solving Chebyshev polynomials coefficients using matrix calculation. Four terms are used to characterize most common shapes of thickness and flatness profile. The calculated Chebyshev coefficients from different line measurements are combined together and analysed using neural network tools. The most common types of shapes are classified.

  18. daptive Filter Used as a Dynamic Compensator in Automatic Gauge Control of Strip Rolling Processes

    Directory of Open Access Journals (Sweden)

    N. ROMAN

    2010-12-01

    Full Text Available The paper deals with a control structure of the strip thickness in a rolling mill of quarto type (AGC – Automatic Gauge Control. It performs two functions: the compensation of errors induced by unideal dynamics of the tracking systems lead by AGC system and the control adaptation to the change of dynamic properties of the tracking systems. The compensation of dynamical errors is achieved through inverse models of the tracking system, implemented as adaptive filters.

  19. Texture Analysis using The Neutron Diffraction Method on The Non Standardized Austenitic Steel Process by Machining,Annealing, and Rolling

    Directory of Open Access Journals (Sweden)

    Tri Hardi Priyanto

    2016-04-01

    Full Text Available Austenitic steel is one type of stainless steel which is widely used in the industry. Many studies on  austenitic stainless steel have been performed to determine the physicalproperties using various types of equipment and methods. In this study, the neutron diffraction method is used to characterize the materials which have been made from  minerals extracted from the mines in Indonesia. The materials consist of a granular ferro-scrap, nickel, ferro-chrome, ferro-manganese, and ferro-silicon added with a little titanium. Characterization of the materials was carried out in threeprocesses, namely: machining, annealing, and rolling. Experimental results obtained from the machining process generally produces a texture in the 〈100〉direction. From the machining to annealing process, the texture index decreases from 3.0164 to 2.434.Texture strength in the machining process (BA2N sample is  8.13 mrd and it then decreases to 6.99 in the annealing process (A2DO sample. In the annealing process the three-component texture appears, cube-on-edge type texture{110}〈001〉, cube-type texture {001}〈100〉, and brass-type {110}〈112〉. The texture is very strong leading to the direction of orientation {100}〈001〉, while the {011}〈100〉is weaker than that of the {001}, and texture withorientation {110}〈112〉is weak. In the annealing process stress release occurred, and this was shown by more randomly pole compared to stress release by the machining process. In the rolling process a brass-type texture{110}〈112〉with a spread towards the goss-type texture {110}〈001〉 appeared,  and  the  brass  component  is markedly  reinforced  compared  to  the undeformed state (before rolling. Moreover, the presence of an additional {110} component was observed at the center of the (110 pole figure. The pole density of three components increases withthe increasing degree of thickness reduction. By increasing degrees

  20. Manufacturing of Nanostructured Rings from Previously ECAE-Processed AA5083 Alloy by Isothermal Forging

    Directory of Open Access Journals (Sweden)

    C. J. Luis

    2013-01-01

    Full Text Available The manufacturing of a functional hollow mechanical element or ring of the AA5083 alloy previously equal channel angular extrusion (ECAE processed, which presents a submicrometric microstructure, is dealt with. For this purpose, the design of two isothermal forging dies (preform and final shape is carried out using the design of experiments (DOE methodology. Moreover, after manufacturing the dies and carrying out tests so as to achieve real rings, the mechanical properties of these rings are analysed as well as their microstructure. Furthermore, a comparison between the different forged rings is made from ECAE-processed material subjected to different heat treatments, previous to the forging stage. On the other hand, the ring forging process is modelled through the use of finite element simulation in order to improve the die design and to study the force required for the isothermal forging, the damage value, and the strain the material predeformed by ECAE has undergone. With this present research work, it is intended to improve the knowledge about the mechanical properties of nanostructured material and the applicability of this material to industrial processes that allow the manufacturing of functional parts.

  1. On the performance of micro injection moulding process simulations of TPE micro rings

    DEFF Research Database (Denmark)

    Baruffi, Federico; Calaon, Matteo; Tosello, Guido

    , a case study based on the micro injection moulding process of thermoplastic elastomer (TPE) micro rings (volume: 1.5 mm3, mass: 2.2 mg) for sensors application is treated. Injection moulding process simulations using Autodesk Moldflow Insight 2016® were applied with the aim of accomplishing two main...

  2. OPV for mobile applications. An evaluation of roll-to-roll processed indium and silver free polymer solar cells through analysis of life cycle, cost and layer quality using inline optical and functional inspection tools

    Energy Technology Data Exchange (ETDEWEB)

    Espinos, N.; Angmo, D.; Hoesel, M.; Soendergaard, R.R.; Joergensen, M.; Krebs, F.C. [Department of Energy Conversion and Storage, Technical University of Denmark, Frederiksborgvej 399, DK-4000 Roskilde (Denmark); Lenzmann, F.O. [ECN Solar Energy, P.O. Box 1, 1755 ZG Petten (Netherlands); Ryley, S. [UK Materials Technology Research Institute, Nottingham Road, Melton Mowbray (United Kingdom); Huss, D.; Dafinger, S.; Gritsch, S. [Dr. Schenk GmbH Industriemesstechnik, Einsteinstrasse 37, D-82152 Planegg (Germany); Kroon, J.M. [ECN Solar Energy, High Tech Campus 5 P-61, 5656 AE Eindhoven (Netherlands)

    2013-05-08

    Organic photovoltaic modules have been evaluated for their integration in mobile electronic applications such as a laser pointer. An evaluation of roll-to-roll processed indium and silver free polymer solar cells has been carried out from different perspectives: life cycle assessment, cost analysis and layer quality evaluation using inline optical and functional inspection tools. The polymer solar cells were fabricated in credit card sized modules by three routes, and several encapsulation alternatives have been explored, with the aim to provide the simplest but functional protection against moisture and oxygen, which could deteriorate the performance of the cells. The analysis shows that ITO- and silver-free options are clearly advantageous in terms of energy embedded over the traditional modules, and that encapsulation must balance satisfying the protection requirements while having at the same time a low carbon footprint. From the economic perspective there is a huge reduction in the cost of the ITO- and silver-free options, reaching as low as 0.25 euro for the OPV module. We used inspection tools such as a roll-to-roll inspection system to evaluate all processing steps during the fabrication and analyse the layers' quality and forecast whether a module will work or not and establish any misalignment of the printed pattern or defects in the layers that can affect the performance of the devices. This has been found to be a good tool to control the process and to increase the yield.

  3. Application of MMC model on simulation of shearing process of thick hot-rolled high strength steel plate

    Energy Technology Data Exchange (ETDEWEB)

    Dong, Liang; Li, Shuhui [Shanghai Key Laboratory of Digital Manufacture for Thin-walled Structures, Shanghai Jiao Tong University, Shanghai 200240 (China); Yang, Bing; Gao, Yongsheng [Automotive Steel Research Institute, R and D Center, BaoShan Iron and Steel Co.,Ltd, Shanghai 201900 (China)

    2013-12-16

    Shear operation is widely used as the first step in sheet metal forming to cut the sheet or plate into the required size. The shear of thick hot-rolled High Strength Steel (HSS) requires large shearing force and the sheared edge quality is relatively poor because of the large thickness and high strength compared with the traditional low carbon steel. Bad sheared edge quality will easily lead to edge cracking during the post-forming process. This study investigates the shearing process of thick hot-rolled HSS plate metal, which is generally exploited as the beam of heavy trucks. The Modified Mohr-Coulomb fracture criterion (MMC) is employed in numerical simulation to calculate the initiation and propagation of cracks during the process evolution. Tensile specimens are designed to obtain various stress states in tension. Equivalent fracture strains are measured with Digital Image Correlation (DIC) equipment to constitute the fracture locus. Simulation of the tension test is carried out to check the fracture model. Then the MMC model is applied to the simulation of the shearing process, and the simulation results show that the MMC model predicts the ductile fracture successfully.

  4. Application of MMC model on simulation of shearing process of thick hot-rolled high strength steel plate

    International Nuclear Information System (INIS)

    Dong, Liang; Li, Shuhui; Yang, Bing; Gao, Yongsheng

    2013-01-01

    Shear operation is widely used as the first step in sheet metal forming to cut the sheet or plate into the required size. The shear of thick hot-rolled High Strength Steel (HSS) requires large shearing force and the sheared edge quality is relatively poor because of the large thickness and high strength compared with the traditional low carbon steel. Bad sheared edge quality will easily lead to edge cracking during the post-forming process. This study investigates the shearing process of thick hot-rolled HSS plate metal, which is generally exploited as the beam of heavy trucks. The Modified Mohr-Coulomb fracture criterion (MMC) is employed in numerical simulation to calculate the initiation and propagation of cracks during the process evolution. Tensile specimens are designed to obtain various stress states in tension. Equivalent fracture strains are measured with Digital Image Correlation (DIC) equipment to constitute the fracture locus. Simulation of the tension test is carried out to check the fracture model. Then the MMC model is applied to the simulation of the shearing process, and the simulation results show that the MMC model predicts the ductile fracture successfully

  5. Micro injection moulding process validation for high precision manufacture of thermoplastic elastomer micro suspension rings

    DEFF Research Database (Denmark)

    Calaon, M.; Tosello, G.; Elsborg Hansen, R.

    Micro injection moulding (μIM) is one of the most suitable micro manufacturing processes for flexible mass-production of multi-material functional micro components. The technology was employed in this research used to produce thermoplastic elastomer (TPE) micro suspension rings identified...... main μIM process parameters (melt temperature, injection speed, packing pressure) using the Design of Experiment statistical technique. Measurements results demonstrated the importance of calibrating mould´s master geometries to ensure correct part production and effective quality conformance...... on the frequency in order to improve the signal quality and assure acoustic reproduction fidelity. Production quality of the TPE rings drastically influence the product functionality. In the present study, a procedure for μIM TPE micro rings production optimization has been established. The procedure entail using...

  6. Study of rolled uranium annealing process; Etude du recuit de l'uranium lamine

    Energy Technology Data Exchange (ETDEWEB)

    Cabane, G [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1954-06-15

    The dilatometric study of rolled uranium clearly shows not only the expansions or contractions induced by stress relief or diffusion of vacancies, but also the slope variations of the cooling curves, which are the best evidence of a texture change. Under the microscope, hard-rolled sheets appear as a mixture of two distinct structures; it is also possible by intermediate annealing to prepare homogeneous sheets of either structure, i.e. twinned or untwinned. All these sheets which have similar textures, undergo at first a primary recrystallization beginning at 320 deg C, then a texture change without any apparent crystal growth, at about 430 deg C. (author) [French] L'anisotropie de l'uranium {alpha} se manifeste fortement dans les coefficients de dilatation. Aussi la dilatometrie permet lle de reperer facilement les expansions ou contractions dues a des relachements de tensions ou a des disparitions de lacunes, ainsi que les variations de pente des courbes de refroidissement, qui constituent la plus importante manifestation d'un changement de texture. Au microscope, les toles fortement ecrouies apparaissent generalement formees d'un melange de deux structures differentes; on a pu aussi preparer des toles de structure homogene: les unes formees de cristaux macles, les autres apparemment depourvues de macles. Ces toles, qui ont toutes a peu pres la meme texture, subissent d'abord une recristallisation primaire a partir de 320 deg C, puis a 430 deg C environ, un changement de texture sans grossissement apparent de cristaux. (auteur)

  7. Preliminary results for the Co-Rolling process fabrication of plate-type nuclear fuel based in U-10Mo monolithic meat and zircaloy-4 cladding

    International Nuclear Information System (INIS)

    Pedrosa, Tercio A.; Brina, Jose Giovanni M.; Paula, Joao Bosco de; Lameiras, Fernando S.; Ferraz, Wilmar B.

    2013-01-01

    The fabrication process of plate-type nuclear fuel with monolithic meat is under development at CDTN. The U-10Mo alloy was chosen as the meat material due to its high density, corrosion resistance and the higher dimensional stability proportioned by the metastable gamma phase, which presents a lesser extension of the breakaway swelling phenomena occurrence during irradiation tests. The monolithic meat was cut from an U-10Mo ingot, that was induction melted at CDTN. The co-rolling process was adopted due to the higher mechanical properties and melting point of the Zircalloy-4 cladding material, which presents a lesser discrepancy in relation to the meat material properties, when compared to the aluminum 6061 alloy. Preliminary plates were obtained by means of the co-rolling process, performed at 650, 800, 950 deg C with total thickness reduction of 80%, followed by a pickling step and cold co-rolling passes. The plates were characterized through bending tests, optical microscopy and radiography. The co-rolling temperature of 800 deg C presented the best results, with a homogeneous distribution of the total thickness reduction between the cover plates and the meat, and the absence of delamination in the bending test samples. It was observed the occurrence of meat thickening in its ends, according to its longitudinal axle, parallel to the rolling direction, that is known as the d og bone , for the three co-rolling temperatures. (author)

  8. Process for producing curved surface of membrane rings for large containers, particulary for prestressed concrete pressure vessels of nuclear reactors

    International Nuclear Information System (INIS)

    Kumpf, H.

    1977-01-01

    Membrane rings for large pressure vessels, particularly for prestressed-concrete pressure vessels, often have curved surfaces. The invention describes a process of producing these at site, which is particularly advantageous as the forming and installation of the vessel component coincide. According to the invention, the originally flat membrane ring is set in a predetermined position, is then pressed in sections by a forming tool (with a preformed support ring as opposite tool), and shaped. After this, the shaped parts are welded to the ring-shaped wall parts of the large vessel. The manufacture of single and double membrane rings arrangements is described. (HP) [de

  9. Linear all-optical signal processing using silicon micro-ring resonators

    DEFF Research Database (Denmark)

    Ding, Yunhong; Ou, Haiyan; Xu, Jing

    2016-01-01

    Silicon micro-ring resonators (MRRs) are compact and versatile devices whose periodic frequency response can be exploited for a wide range of applications. In this paper, we review our recent work on linear all-optical signal processing applications using silicon MRRs as passive filters. We focus...

  10. Preparation of functional layers for anode-supported solid oxide fuel cells by the reverse roll coating process

    Science.gov (United States)

    Mücke, R.; Büchler, O.; Bram, M.; Leonide, A.; Ivers-Tiffée, E.; Buchkremer, H. P.

    The roll coating technique represents a novel method for applying functional layers to solid oxide fuel cells (SOFCs). This fast process is already used for mass production in other branches of industry and offers a high degree of automation. It was utilized for coating specially developed anode (NiO + 8YSZ, 8YSZ: 8 mol% yttria-stabilized zirconia) and electrolyte (8YSZ) suspensions on green and pre-sintered tape-cast anode supports (NiO + 8YSZ). The layers formed were co-fired in a single step at 1400 °C for 5 h. As a result, the electrolyte exhibited a thickness of 14-18 μm and sufficient gas tightness. Complete cells with a screen-printed and sintered La 0.65Sr 0.3MnO 3- δ (LSM)/8YSZ cathode yielded a current density of 0.9-1.1 A cm -2 at 800 °C and 0.7 V, which is lower than the performance of non-co-fired slip-cast or screen-printed Jülich standard cells with thinner anode and electrolyte layers. The contribution of the cell components to the total area-specific resistance (ASR) was calculated by analyzing the distribution function of the relaxation times (DRTs) of measured electrochemical impedance spectra (EIS) and indicates the potential improvement in the cell performance achievable by reducing the thickness of the roll-coated layers. The results show that the anode-supported planar half-cells can be fabricated cost-effectively by combining roll coating with subsequent co-firing.

  11. EBSD characterization of an IF steel processed by Accumulative Roll Bonding

    International Nuclear Information System (INIS)

    Cruz-Gandarilla, F; Salcedo-Garrido, A M; Avalos, M; Bolmaro, R; Baudin, T; Cabañas-Moreno, J G; Dorantes-Rosales, H J

    2015-01-01

    The objective of this work is to study the texture and microstructure evolution of an IF steel deformed by Accumulative Roll Bonding (ARB) using Electron Backscatter Diffraction. Texture changes occur with increasing number of ARB cycles. For the early cycles, the main components are the α and γ fiber components characteristic of steels. With increasing the number of ARB cycles a tendency towards a random texture is obtained. In the initial state, the mean grain size is 30 μm and after 5 cycles it decreases to 1.2 μm. For the first ARB cycles, the fraction of high angle grain boundary is low but it increases with the number of cycles to about 80% for 5 cycles. The Kernel Average Misorientation (KAM) has no appreciable changes with the number of ARB cycles for all the texture components. (paper)

  12. Spray rolling aluminum alloy strip

    Energy Technology Data Exchange (ETDEWEB)

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

    2004-10-10

    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.

  13. Texture and mechanical properties of Al-0.5Mg-1.0Si-0.5Cu alloy sheets manufactured via a cross rolling method

    Science.gov (United States)

    Jeon, Jae-Yeol; Son, Hyeon-Taek; Woo, Kee-Do; Lee, Kwang-Jin

    2012-04-01

    The relationship between the texture and mechanical properties of 6xxx aluminum alloy sheets processed via cross rolling was investigated. The microstructures of the conventional rolled and cross rolled sheets after annealing were analyzed using optical micrographs (OM). The texture distribution across the thickness in the Al-Mg-Si-Cu alloy, conventional rolled sheets, and cross rolled sheets both before and after annealing was investigated via X-ray texture measurements. The texture was analyzed in three layers from the surface to the center of the sheet. The β-fiber texture of the conventional rolled sheet was typical of the texture obtained using aluminumoll ring. After annealing, the typical β-fiber orientations were changed to recrystallization textures: cube{001} and normal direction (ND)-rotated cubes. However, the texture of the cross rolled sheet was composed of an asymmetrical, rolling direction (RD)-rotated cubes. After annealing, the asymmetrical orientations in the cross rolled sheet were changed to a randomized texture. The average R-value of the annealed cross rolled sheets was higher than that of the conventional rolled sheets. The limit dome height (LDH) test results demonstrated that cross rolling is effective in improving the formability of the Al-Mg-Si-Cu alloy sheets.

  14. Microstructural evolution, mechanical properties, and strain hardening behavior of ultrafine grained commercial pure copper during the accumulative roll bonding process

    Energy Technology Data Exchange (ETDEWEB)

    Fattah-alhosseini, A. [Department of Materials Engineering, Bu-Ali Sina University, Hamedan 65178-38695 (Iran, Islamic Republic of); Imantalab, O., E-mail: o.imantalab@gmail.com [Department of Materials Engineering, Bu-Ali Sina University, Hamedan 65178-38695 (Iran, Islamic Republic of); Mazaheri, Y. [Department of Materials Engineering, Bu-Ali Sina University, Hamedan 65178-38695 (Iran, Islamic Republic of); Keshavarz, M.K. [Department of Engineering Physics, Polytechnique Montreal, Montreal (Canada)

    2016-01-05

    In this study, the microstructural evolution, mechanical properties, and strain hardening behavior of commercial pure copper processed by the accumulative roll bonding (ARB) were investigated. Transmission electron microscopy (TEM) micrographs and atomic force microscopy (AFM) images indicated that with increasing the number of ARB cycles, the grain size of samples decreased. An Ultrafine grained (UFG) structure with an average grain size of about 200 nm was achieved after four cycles of ARB. The yield and ultimate tensile strength of pure copper with the UFG microstructure was reached about 360 MPa and 396 MPa (about 400% and 100% higher than that of the annealed state), respectively. All ARB-processed copper samples showed lower strain hardening exponent in comparison with the annealed state. Moreover, the strain hardening rate increased with increasing ARB cycles up to 3 cycles and then decreased.

  15. Microstructural evolution, mechanical properties, and strain hardening behavior of ultrafine grained commercial pure copper during the accumulative roll bonding process

    International Nuclear Information System (INIS)

    Fattah-alhosseini, A.; Imantalab, O.; Mazaheri, Y.; Keshavarz, M.K.

    2016-01-01

    In this study, the microstructural evolution, mechanical properties, and strain hardening behavior of commercial pure copper processed by the accumulative roll bonding (ARB) were investigated. Transmission electron microscopy (TEM) micrographs and atomic force microscopy (AFM) images indicated that with increasing the number of ARB cycles, the grain size of samples decreased. An Ultrafine grained (UFG) structure with an average grain size of about 200 nm was achieved after four cycles of ARB. The yield and ultimate tensile strength of pure copper with the UFG microstructure was reached about 360 MPa and 396 MPa (about 400% and 100% higher than that of the annealed state), respectively. All ARB-processed copper samples showed lower strain hardening exponent in comparison with the annealed state. Moreover, the strain hardening rate increased with increasing ARB cycles up to 3 cycles and then decreased.

  16. Process based model sheds light on climate sensitivity of Mediterranean tree-ring width

    Directory of Open Access Journals (Sweden)

    R. Touchan

    2012-03-01

    Full Text Available We use the process-based VS (Vaganov-Shashkin model to investigate whether a regional Pinus halepensis tree-ring chronology from Tunisia can be simulated as a function of climate alone by employing a biological model linking day length and daily temperature and precipitation (AD 1959–2004 from a climate station to ring-width variations. We check performance of the model on independent data by a validation exercise in which the model's parameters are tuned using data for 1982–2004 and the model is applied to generate tree-ring indices for 1959–1981. The validation exercise yields a highly significant positive correlation between the residual chronology and estimated growth curve (r=0.76 p<0.0001, n=23. The model shows that the average duration of the growing season is 191 days, with considerable variation from year to year. On average, soil moisture limits tree-ring growth for 128 days and temperature for 63 days. Model results depend on chosen values of parameters, in particular a parameter specifying a balance ratio between soil moisture and precipitation. Future work in the Mediterranean region should include multi-year natural experiments to verify patterns of cambial-growth variation suggested by the VS model.

  17. Tailoring structures through two-step annealing process in nanostructured aluminum produced by accumulative roll-bonding

    DEFF Research Database (Denmark)

    Kamikawa, Naoya; Huang, Xiaoxu; Hansen, Niels

    2008-01-01

    temperature before annealing at high temperature. By this two-step process, the structure is homogenized and the stored energy is reduced significantly during the first annealing step. As an example, high-purity aluminum has been deformed to a total reduction of 98.4% (equivalent strain of 4.......8) by accumulative roll-bonding at room temperature. Isochronal annealing for 0.5 h of the deformed samples shows the occurrence of recrystallization at 200 °C and above. However, when introducing an annealing step for 6 h at 175 °C, no significant recrystallization is observed and relatively homogeneous structures...... are obtained when the samples afterwards are annealed at higher temperatures up to 300 °C. To underpin these observations, the structural evolution has been characterized by transmission electron microscopy, showing that significant annihilation of high-angle boundaries, low-angle dislocation boundaries...

  18. Analysis of residual stresses due to roll-expansion process: Finite element computation and validation by experimental tests

    International Nuclear Information System (INIS)

    Aufaure, M.; Boudot, R.; Zacharie, G.; Proix, J.M.

    1987-01-01

    The steam generator heat exchangers of pressurized water reactors are made of U-shaped tubes, both ends of them being fixed to a plate by roll-expansion. This process consists in increasing the tube section by means of a rotating tool in order to apply its outer side to the surface of the hole through the plate. As reported by de Keroulas (1986), in service cracks appeared on these tubes in the transition from expanded to nonexpanded portions. So we developed a program to compute residual stresses at the surface of the tubes, which caused their cracking, and to endeavour to lower their level by acting on some parameters. This program was validated by experimental tests. (orig.)

  19. RELATIONSHIP BETWEEN ROLLING AND SLIP RESISTANCE IN ROLLING BEARINGS

    Directory of Open Access Journals (Sweden)

    L. M. Bondarenko

    2016-06-01

    Full Text Available Purpose. About one of the causes of slip rolling is known from the second half of the 19th century, it was believed that the slip resistance appears at the place of contact due to different speeds on the arc of contact. Only in the mid-20th century it was proved that this resistance is negligible in rolling resistance. However (for some unknown reason it is ignored the fact that in practice in rolling bearings may rotate both the inner ring with a stationary outer one, and vice versa almost in equal relations. It is not taken into account the fact that the ball or roller in the rolling bearings runs the different distance along the roller path of the outer and inner bearing cages in one revolution. This fact is not taken into account in determining the calculated values for the friction coefficient of a rolling bearing reduced to the shaft. Therefore, the aim of this work is to determine the influence of path length on the track riding the outer and inner race of the bearing on the determination of the calculated value of the coefficient of friction of rolling bearings is given to the shaft. Methodology. The solution technique is based on the theory of plane motion of a rigid body, the theory of Hertzian contact deformation and the analytical dependencies for determination of coefficient of rolling friction. Findings. The obtained dependences on determination of rolling resistance of the balls or rollers along the bearing tracks of inner and outer bearing cages as well as path difference metering of the rolling on them allows to analytically obtain the rolling resistance and slipping for any size of bearings and different devices of bearing units. It is also possible at the design stage of rolling nodes to handle not only the design but also the content of the node. Originality. Using the analytical dependences for determination of the rolling resistance of bodies at point and line contacts, and also account for the difference in the path of the

  20. Glow discharge processing vs bakeout for aluminum storage ring vacuum chambers

    International Nuclear Information System (INIS)

    Dean, N.R.; Hoyt, E.W.; Palrang, M.T.; Walker, B.G.

    1977-11-01

    Experiments were carried out on laboratory and prototype scale systems in order to establish the feasibility of argon discharge processing the PEP storage ring aluminum vacuum chambers. Electron-induced desorption rates showed significant reductions following bakeout and/or argon glow discharge treatment (>10 19 ions cm -1 ). Data are presented and discussed in relation to advantages and problems associated with: water removal, argon trapping and subsequent release, electron energy dependence, discharge distribution, and surface plasma chemical effects

  1. Hot rolling of thick uranium molybdenum alloys

    Science.gov (United States)

    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.

  2. Rolling at small scales

    DEFF Research Database (Denmark)

    Nielsen, Kim L.; Niordson, Christian F.; Hutchinson, John W.

    2016-01-01

    The rolling process is widely used in the metal forming industry and has been so for many years. However, the process has attracted renewed interest as it recently has been adapted to very small scales where conventional plasticity theory cannot accurately predict the material response. It is well....... Metals are known to be stronger when large strain gradients appear over a few microns; hence, the forces involved in the rolling process are expected to increase relatively at these smaller scales. In the present numerical analysis, a steady-state modeling technique that enables convergence without...

  3. Kulturens rolle

    DEFF Research Database (Denmark)

    Hasse, Cathrine

    2007-01-01

    Kulturens rolle. Herunder kulturens betydning for psykologisk teori og forskning set i lyset af den stigende globalisering og væksten i kulturmøder. Der gives eksempler fra hverdagssituationer, den pædagogiske praksis, fra indvandrerforskning, turister men også fra avisernes referater af kulturmø......Kulturens rolle. Herunder kulturens betydning for psykologisk teori og forskning set i lyset af den stigende globalisering og væksten i kulturmøder. Der gives eksempler fra hverdagssituationer, den pædagogiske praksis, fra indvandrerforskning, turister men også fra avisernes referater af...

  4. Use of a ring-shaped, passively stable, superconducting magnetic bearing in the ring spinning process; Einsatz eines ringfoermigen, passiv stabilen, supraleitenden Magnetlagers im Ringspinnprozess

    Energy Technology Data Exchange (ETDEWEB)

    Berger, Anne; Sparing, Maria; Berger, Dietmar; Fuchs, Guenter; Schultz, Ludwig [IFW Dresden (Germany). Inst. fuer Metallische Werkstoffe; Hossain, Mahmud; Abdkader, Anwar; Cherif, Chokri [TU Dresden (Germany). ITM

    2015-07-01

    For the integration of a superconducting magnetic bearing in a ring spinning machine a LN{sub 2} continuous flow cryostat was developed, which is needed to cool the superconductor below its transition temperature of ∝91 K and simultaneously ensures that the spinning process takes place at room temperature. The ring spinning process is the most widely used process for spinning yarn. In this case, a loose fiber connection is first stretched in a roller system, then twisted by the so-called spinning ring-ring traveler system, and finally wound on a spindle. The spinning ring is a circular guide, which is mounted around the spindle. On this the ring traveler rotates as yarn guide. The yarn is driven by the rotation of the spindle and there is a balloon-shaped movement of the yarn which results the twist. The productivity of the process is limited by the systematic frictional heat between the yarn, spinning ring and ring travelers. This leads at high speeds to yarn breakage and limits the maximum spindle speed depending on the type of fiber to a maximum of 25,000 U/min. To increase the speed and thus the productivity of the process, the conventional spinning ring-ring rotor system is replaced by a superconducting magnetic bearing. Here floats a NdFeB permanent magnet passively stable over the LN{sub 2} cooled ceramic high-temperature superconductor YBa{sub 2}Cu{sub 3}O{sub 7-x}. Driven by the yarn the permanent magnet rotates, thus ensuring the necessary balloon-shaped yarn movement to twist. Such a bearing has been successfully tested in a ring spinning machine. Preliminary results show a similar yarn quality. [German] Fuer die Integration eines supraleitenden Magnetlagers in eine Ringspinnmaschine wurde ein LN{sub 2}-Durchflusskryostat entwickelt, der noetig ist, um den Supraleiter unter seine Sprungtemperatur von ∝91 K zu kuehlen und gleichzeitig dafuer sorgt, dass der Spinnprozess bei Raumtemperatur ablaeuft. Der Ringspinnprozess ist der am weitesten verbreitete

  5. Round-Robin Studies on Roll-Processed ITO-free Organic Tandem Solar Cells Combined with Inter-Laboratory Stability Studies

    DEFF Research Database (Denmark)

    Livi, Francesco; Søndergaard, Roar R.; Andersen, Thomas Rieks

    2015-01-01

    Roll-processed, indium tin oxide (ITO)-free, flexible, organic tandem solar cells and modules have been realized and used in round-robin studies as well as in parallel inter-laboratory stability studies. The tandem cells/modules show no significant difference in comparison to their single...

  6. A rational method for developing and testing stable flexible indium- and vacuum-free multilayer tandem polymer solar cells comprising up to twelve roll processed layers

    DEFF Research Database (Denmark)

    Andersen, Thomas Rieks; Dam, Henrik Friis; Andreasen, Birgitta

    2014-01-01

    and to efficiently identify layers and interfaces that are not robust we developed a double sided illumination method and demonstrate how layer thicknesses can be optimized with respect to the roll processing in the aim of achieving functional tandem devices. The devices were prepared directly on barrier foil...

  7. Microstructure and partitioning behavior characteristics in low carbon steels treated by hot-rolling direct quenching and dynamical partitioning processes

    International Nuclear Information System (INIS)

    Li, Yun-jie; Li, Xiao-lei; Yuan, Guo; Kang, Jian; Chen, Dong; Wang, Guo-dong

    2016-01-01

    In this work, a new process and composition design are proposed for “quenching and partitioning” or Q&P treatment. Three low carbon steels were treated by hot-rolling direct quenching and dynamical partitioning processes (DQ&P). The effects of proeutectoid ferrite and carbon concentration on microstructure evolution and mechanical properties were investigated. The present work obtained DQ&P prototype steels with good mechanical properties and established a new notion on compositions for Q&P processing. Microstructures were characterized by means of electro probe microanalyzer (EPMA), scanning electron microscopy (SEM), electron backscatter diffraction (EBSD), transmission electron microscopy (TEM) and X-ray diffraction (XRD), especially the morphology and size of retained austenite. Mechanical properties were measured by uniaxial tensile tests. The results indicated that introducing proeutectoid ferrite can increase the volume fraction of retained austenite and thus improve mechanical properties. TEM observation showed that retained austenite included the film-like inter-lath austenite and blocky austenite located in martensite/ferrite interfaces or surrounded by ferrites. It was interesting that when the carbon concentration is as low as ~ 0.078%, the film-like inter-lath untransformed austenite cannot be stabilized to room temperature and almost all of them transformed into twin martensite. The blocky retained austenite strengthened the interfaces and transformed into twin martensite during the tensile deformation process. The PSEs of specimens all exceeded 20 GPa.%. - Highlights: •This study focused on a new process: Q&P process applying dynamical partitioning. •Ferrite can increase the volume fraction of retained austenite. •The film-like austenite and the blocky austenite were observed. •The low carbon steels treated by new process reached PSEs higher than 20 GPa.%.

  8. LEDs are on a roll

    NARCIS (Netherlands)

    Blom, P.W.M.; Mol, A.M.B. van

    2011-01-01

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

  9. Rudder roll stabilization for ships

    NARCIS (Netherlands)

    van Amerongen, J.; van der Klugt, P.G.M.; van Nauta lemke, H.R.

    1990-01-01

    This paper describes the design of an autopilot for rudder roll stabilization for ships. This autopilot uses the rudder not only for course keeping but also for reduction of the roll. The system has a series of properties which make the controller design far from straightforward: the process has

  10. Simulation of collisional transport processes and the stability of planetary rings

    Science.gov (United States)

    Brophy, Thomas G.; Esposito, Larry W.

    1989-01-01

    The utility of the phase-space fluid method for the study of planetary ring dynamics is presently demonstrated through the numerical solution of a model kinetic equation for a flattened Keplerian disk. Attention is given to ringlets composed of single-sized particles, as well as to ringlets composed of two different-sized particles; in the latter case, the ringlets evolve in such a way that the lighter particles are confined by the heavier ones. The results obtained indicate that some natural process may sharpen the optical depth profile of edges even without an external forcing mechanism, and that intermediate optical depths are dynamically preferred in some cases.

  11. Microstructure analysis of AISI 304 stainless steel produced by twin-roll thin strip casting process

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The microstructure of AISI 304 austenite stainless steel fabricated by the thin strip casting process were investigated using optical microscope, scanning electron microscope (SEM), transmission electron microscope (TEM), and X-ray diffraction (XRD).The microstructures of the casting strips show a duplex structure consisting of delta ferrite and austenite. The volume fraction of the delta ferrite is about 9.74vol% at the center and 6.77vol% at the surface of the casting thin strip, in vermicular and band shapes. On account of rapid cooling and solidification in the continuous casting process, many kinds of inclusions and precipitates have been found. Most of the inclusions and precipitates are spherical complex compounds consisting of oxides, such as, SiO2, MnO, Al2O3,Cr2O3,and FeO or their multiplicity oxides of MnO·Al2O3,2FeO·SiO2, and 2MnO·SiO2. Many defects including dislocations and stacking faults have also formed during the rapid cooling and solidification process, which is helpful to improve the mechanical properties of the casting strips.

  12. Whole through processing understanding of rolling and recrystallization textures in low carbon steels

    International Nuclear Information System (INIS)

    Roatta, A; Fourty, A; Bolmaro, R.E

    2008-01-01

    Processing steels to achieve particular useful properties is a science as well as an art. Many of the properties of modern steels are a successful combination of empiric and scientific knowledge. Deep drawing low carbon steels have been used and improved through many decades of research and technological advance. However the micro mechanisms involved in the development of particular microstructures and properties are still under discussion. The current paper shows an integrated attempt to obtain consistent microscopical data from micromechanical simulations coupled with recrystallization and phase transformation codes. The simulations are performed in a way such that the information obtained from certain temperature, level or process is used in the next step to proceed further. The goal is not avoiding experiments but having a whole through scale and time integration for judging the validity of similar parameters and assumptions during the different processing steps. The simulations include high and low temperature deformation and recrystallization in the austenite region, phase transformation to room temperature, low temperature deformation and recrystallization in the ferrite phase region. The results are compared with experiments available in the literature

  13. Effect of electropulsing on surface mechanical properties and microstructure of AISI 304 stainless steel during ultrasonic surface rolling process

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Haibo [Advanced Materials Institute, Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055 (China); Key Laboratory of Advanced Materials, Tsinghua University, Beijing 100084 (China); Song, Guolin [Advanced Materials Institute, Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055 (China); Tang, Guoyi, E-mail: tanggy@mail.tsinghua.edu.cn [Advanced Materials Institute, Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055 (China); Key Laboratory of Advanced Materials, Tsinghua University, Beijing 100084 (China)

    2016-04-26

    The present work integrates 3D digital optical microscopy (OM), nano-indentation, X-ray diffraction (XRD), scanning electron microscopy (SEM) with electron backscatter diffraction (EBSD) and transmission electron microscopy (TEM) to systematically investigate the effect of electropulsing on the surface mechanical properties and microstructure of AISI 304 stainless steel during the ultrasonic surface rolling process (USRP). Compared with the original USRP, the introduction of electropulsing with optimal parameters can effectively facilitate surface crack healing and improve surface hardness and wear resistance dramatically, and the residual compressive stress is further enhanced. Meanwhile, more martensite phase and fewer deformation twins can be found in the strengthened layer. Rapid improvement of the surface mechanical properties should be attributed to the ultra-refined grains, accelerated martensitic phase transformation and suppressed deformation twining induced by the coupling effect of USRP and electropulsing. The high strain rate given by USRP, increased stacking fault energy and accelerated dislocation mobility caused by electropulsing are likely the primary intrinsic reasons for the observed phenomena.

  14. Interfacial layers evolution during annealing in Ti-Al multi-laminated composite processed using hot press and roll bonding

    Science.gov (United States)

    Assari, A. H.; Eghbali, B.

    2016-09-01

    Ti-Al multi-laminated composites have great potential in high strength and low weight structures. In the present study, tri-layer Ti-Al composite was synthesized by hot press bonding under 40 MPa at 570 °C for 1 h and subsequent hot roll bonding at about 450 °C. This process was conducted in two accumulative passes to 30% and to 67% thickness reduction in initial and final passes, respectively. Then, the final annealing treatments were done at 550, 600, 650, 700 and 750 °C for 2, 4 and 6 h. Investigations on microstructural evolution and thickening of interfacial layers were performed by scanning electron microscopes, energy dispersive spectrometer, X-ray diffraction and micro-hardness tests. The results showed that the thickening of diffusion layers corresponds to amount of deformation. In addition to thickening of the diffusion layers, the thickness of aluminum layers decreased and after annealing treatment at 750 °C for 6 h the aluminum layers were consumed entirely, which occurred because of the enhanced interdiffusion of Ti and Al elements. Scanning electron microscope equipped with energy dispersive spectrometer showed that the sequence of interfacial layers as Ti3Al-TiAl-TiAl2-TiAl3 which are believed to be the result of thermodynamic and kinetic of phase formation. Micro-hardness results presented the variation profile in accordance with the sequence of intermetallic phases and their different structures.

  15. Cliché fabrication method using precise roll printing process with 5 um pattern width

    Science.gov (United States)

    Shin, Yejin; Kim, Inyoung; Oh, Dong-Ho; Lee, Taik-Min

    2016-09-01

    Among the printing processes for printed electronic devices, gravure offset and reverse offset method have drawn attention for its fine pattern printing possibility. These printing methods use cliché, which has critical effect on the final product precision and quality. In this research, a novel precise cliché replica method is proposed. It consists of copper sputtering, precise mask pattern printing with 5 um width using reverse offset printing, Ni electroplating, lift-off, etching, and DLC coating. We finally compare the fabricated replica cliché with the original one and print out precise patterns using the replica cliché.

  16. Impact of food processing and simulated gastrointestinal digestion on gliadin immunoreactivity in rolls.

    Science.gov (United States)

    Brzozowski, Bartosz

    2018-07-01

    The enzymatic modification of wheat proteins during dough fermentation and its digestion as supported by peptidases of microbiological origin can result in the degradation of important peptides in the pathogenesis of coeliac disease. However, baking bread and the high temperature associated with this could change the physicochemical and immunological properties of proteins. Thermal changes in the spatial structure of proteins and their hydrolysis can lead to a masking or degrading of immunoreactive peptides. The addition of prolyl endopeptidase (PEP), comprising peptidases isolated from Lactobacillus acidophilus 5e2 (LA) or transglutaminase (TG) in the course of fermentation, decreases its immunoreactivity by 83.9%, 51.9% and 18.5%, respectively. An analysis of the fractional composition of gliadins revealed that γ- and ω-gliadins are the proteins most susceptible to enzymatic modification. Hydrolysis of wheat storage proteins with PEP and LA reduces the content of αβ-, γ- and ω-gliadins by 13.7%, 60.2% and 41.9% for PEP and by 22.1%, 43.5% and 36.9% for LA, respectively. Cross-linking of proteins with TG or their hydrolysis by PEP and LA peptidases during the process of forming wheat dough, followed by digesting bread samples with PEP and LA peptidases, decreases the immunoreactivity of bread hydrolysates from 2.4% to 0.02%. The content of peptide detected in polypeptide sequences is 263.4 ± 3.3, 30.9 ± 1.5 and 7.9 ± 0.4 mg kg -1 in samples of hydrolysates of bread digested with PEP, as produced from dough modified by TG, PEP and LA, respectively. Enzymatic pre-modification of proteins during the process of dough fermentation decreases their immunoreactive potential, such that fewer peptides recognised by R5 antibodies are released during the digestion process from the bread matrix. Immunoreactive peptides are degraded more effectively when digestive enzymes are supported by the addition of PEP. © 2017 Society of Chemical Industry. © 2017

  17. Project of Economically Profitable Technological Process of Production of Rotor and Stator Plates of Inductive Position Sensor by Blanking and Roll Bending

    Directory of Open Access Journals (Sweden)

    Radek ČADA

    2013-12-01

    Full Text Available Paper concerns innovation of production of rotor and stator plates of inductive position sensors which are used at automatization of production processes. Authors analyse possibility of efficiency improvement of production of these devices in joint-stock company TES VSETÍN and suggest concrete solving of new production technology. Composition of production line for blanking and roll bending of rotor and stator plates of inductive position sensor from individual technological devices was suggested: decoiler, straightening device, actuating belt feeder, pneumatic shears with inclined tools, belt conveyer and four cylinders bending rolls. Construction of production line was projected in order to its operation can be secured by one production workman, which controls and chooses operation of CNC programme, takes separate roll bended rotor and stator plates of inductive position sensor from bending rolls and according to required technological procedure he composes them to rotor and stator complexes. Construction of production line was projected so that it is possible to move it by crane without necessity to dismantle and subsequently to put together and adjust the line.

  18. Influence of Solution and Aging Treatment Conditions on the Formation of Ultrafine-Grained Structure of CuFe2 Alloy Processed by Rolling with Cyclic Movement of Rolls

    Directory of Open Access Journals (Sweden)

    Urbańczyk-Gucwa A.

    2016-06-01

    Full Text Available The effect of second phase particles on grain refinement in CuFe2 alloy has been investigated by using rolling with the cyclic movement of rolls (RCMR method. Two different population of second phase particles of Fe: coherent, about 10 nm in diameter and about 100 nm in size were obtained by applying aging treatment followed at 500°C for 2 h and at 700°C for 24 h respectively. In addition, solution treated samples were deformed by RCMR method at the same parameters. The microstructures of the CuFe2 alloy were analyzed using light microscope (LM, electron backscattered diffraction (EBSD microscope technique and scanning transmission electron microscope (STEM. The presence of high-density of coherent Fe particles in the matrix inhibits recovery process and in the result obtained grain/subgrain boundaries have diffused character and are weakly visible. The largest particles which are not coherent with the matrix act as an effective barrier against the boundary motion.

  19. Phase locked multiple rings in the radiation pressure ion acceleration process

    Science.gov (United States)

    Wan, Y.; Hua, J. F.; Pai, C.-H.; Li, F.; Wu, Y. P.; Lu, W.; Zhang, C. J.; Xu, X. L.; Joshi, C.; Mori, W. B.

    2018-04-01

    Laser contrast plays a crucial role for obtaining high quality ion beams in the radiation pressure ion acceleration (RPA) process. Through one- and two-dimensional particle-in-cell (PIC) simulations, we show that a plasma with a bi-peak density profile can be produced from a thin foil on the effects of a picosecond prepulse, and it can then lead to distinctive modulations in the ion phase space (phase locked double rings) when the main pulse interacts with the target. These fascinating ion dynamics are mainly due to the trapping effect from the ponderomotive potential well of a formed moving standing wave (i.e. the interference between the incoming pulse and the pulse reflected by a slowly moving surface) at nodes, quite different from the standard RPA process. A theoretical model is derived to explain the underlying mechanism, and good agreements have been achieved with PIC simulations.

  20. Experimental Study of Shock Generated Compressible Vortex Ring

    Science.gov (United States)

    Das, Debopam; Arakeri, Jaywant H.; Krothapalli, Anjaneyulu

    2000-11-01

    Formation of a compressible vortex ring and generation of sound associated with it is studied experimentally. Impulse of a shock wave is used to generate a vortex ring from the open end of a shock-tube. Vortex ring formation process has been studied in details using particle image Velocimetry (PIV). As the shock wave exits the tube it diffracts and expands. A circular vortex sheet forms at the edge and rolls up into a vortex ring. Far field microphone measurement shows that the acoustic pressure consists of a spike due to shock wave followed by a low frequency pressure wave of decaying nature, superimposed with high frequency pressure wave. Acoustic waves consist of waves due to expansion, waves formed in the tube during diaphragm breakage and waves associated with the vortex ring and shear-layer vortices. Unsteady evolution of the vortex ring and shear-layer vortices in the jet behind the ring is studied by measuring the velocity field using PIV. Corresponding vorticity field, circulation around the vortex core and growth rate of the vortex core is calculated from the measured velocity field. The velocity field in a compressible vortex ring differs from that of an incompressible ring due to the contribution from both shock and vortex ring.

  1. The influence of deformation path on strain characteristics of AA1050 aluminium processed by equal-channel angular pressing followed by rolling

    Energy Technology Data Exchange (ETDEWEB)

    Vega, M.C.V. [Department of Materials Engineering – Universidade Federal de São Carlos, (SP) Rod. Washington Luis km 235, 13565-905 São Carlos (Brazil); Bolmaro, R.E. [Instituto de Física Rosario (IFIR) FCEIA-UNR-CONICET, Bv. 27 de Febrero 210 bis, S2000EZP Rosario (Argentina); Ferrante, M.; Sordi, V.L. [Department of Materials Engineering – Universidade Federal de São Carlos, (SP) Rod. Washington Luis km 235, 13565-905 São Carlos (Brazil); Kliauga, A.M., E-mail: kliauga@ufscar.br [Department of Materials Engineering – Universidade Federal de São Carlos, (SP) Rod. Washington Luis km 235, 13565-905 São Carlos (Brazil)

    2015-10-14

    The present investigation reports on the microstructure evolution, texture development, the nature of the grain boundaries and the tensile and deep drawing behaviour of commercial AA1050 Al processed by Equal Channel Angular Pressing (ECAP) plus rolling. Although in terms of final mechanical strength ECAP and rolling are indistinguishable, the deformation path is substantially different, and this has important consequences on both microstructure and texture. From the spatial distribution of high angle grain boundaries (HAGB) and low angle grain boundaries (LAGB), the fine microstructure and the crystallographic texture, it was concluded that the microstructure is oriented according to the external imposed flow: a spin movement in the ECAP process, which promotes the rotation of the cells inside the original grain, followed by a sliding movement caused by the rolling, leading to grain elongation. The ECAP process is more suitable to promote a higher fraction of HAGBs, and the same time as it reduces the intensity of the bulk crystallographic texture. As a consequence an increase of the penetration depth and deformation strain, as measured by the Erichsen test, was observed in samples processed by 8 ECAP passes, characterized by low texture intensity and a high degree of dynamic recrystallization.

  2. Intra-rater repeatability of the Oxford foot model in healthy children in different stages of the foot roll over process during gait

    DEFF Research Database (Denmark)

    Curtis, D J; Bencke, J; Stebbins, J A

    2009-01-01

    BACKGROUND: The repeatability of the Oxford foot model has been reported, but possible variations in the repeatability during the foot roll over process have not been examined. The aim of this study was to determine the relative and absolute repeatability of the model for each stage of the foot...... roll over process during gait and to compare foot kinematic data from this study with that from another centre as a preliminary examination of the model's inter-centre repeatability and validity. METHOD: Eight healthy children were tested twice at the gait laboratory. Foot kinematics from this study...... were plotted against those from an earlier repeatability study and repeatability statistics calculated for the three rockers of stance phase and swing phase. RESULTS: Foot kinematics from this study and an earlier repeatability study produced similar kinematic patterns and joint angle ranges...

  3. Impact parameter sensitive study of inner-shell atomic processes in the experimental storage ring

    Science.gov (United States)

    Gumberidze, A.; Kozhuharov, C.; Zhang, R. T.; Trotsenko, S.; Kozhedub, Y. S.; DuBois, R. D.; Beyer, H. F.; Blumenhagen, K.-H.; Brandau, C.; Bräuning-Demian, A.; Chen, W.; Forstner, O.; Gao, B.; Gassner, T.; Grisenti, R. E.; Hagmann, S.; Hillenbrand, P.-M.; Indelicato, P.; Kumar, A.; Lestinsky, M.; Litvinov, Yu. A.; Petridis, N.; Schury, D.; Spillmann, U.; Trageser, C.; Trassinelli, M.; Tu, X.; Stöhlker, Th.

    2017-10-01

    In this work, we present a pilot experiment in the experimental storage ring (ESR) at GSI devoted to impact parameter sensitive studies of inner shell atomic processes for low-energy (heavy-) ion-atom collisions. The experiment was performed with bare and He-like xenon ions (Xe54+, Xe52+) colliding with neutral xenon gas atoms, resulting in a symmetric collision system. This choice of the projectile charge states was made in order to compare the effect of a filled K-shell with the empty one. The projectile and target X-rays have been measured at different observation angles for all impact parameters as well as for the impact parameter range of ∼35-70 fm.

  4. A pilot-scale nonwoven roll goods manufacturing process reduces microbial burden to pharmacopeia acceptance levels for nonsterile hygiene applications

    Science.gov (United States)

    A total of seven source fiber types were selected for use in the manufacturing of nonwoven roll goods: polyester; polypropylene; rayon; greige cotton from two sources; mechanically cleaned greige cotton; and scoured and bleached cotton. The microbial burden of each source fiber was measured as a pr...

  5. Mass production of volume holographic optical elements (vHOEs) using Bayfol® HX photopolymer film in a roll-to-roll copy process

    Science.gov (United States)

    Bruder, Friedrich-Karl; Fäcke, Thomas; Grote, Fabian; Hagen, Rainer; Hönel, Dennis; Koch, Eberhard; Rewitz, Christian; Walze, Günther; Wewer, Brita

    2017-03-01

    Volume Holographic Optical Elements (vHOEs) gained wide attention as optical combiners for the use in augmented and virtual reality (AR and VR, respectively) consumer electronics and automotive head-up display applications. The unique characteristics of these diffractive grating structures - being lightweight, thin and flat - make them perfectly suitable for use in integrated optical components like spectacle lenses and car windshields. While being transparent in Off-Bragg condition, they provide full color capability and adjustable diffraction efficiency. The instant developing photopolymer Bayfol® HX film provides an ideal technology platform to optimize the performance of vHOEs in a wide range of applications. Important for any commercialization are simple and robust mass production schemes. In this paper, we present an efficient and easy to control one-beam recording scheme to copy a so-called master vHOE in a step-and-repeat process. In this contact-copy scheme, Bayfol® HX film is laminated to a master stack before being exposed by a scanning laser line. Subsequently, the film is delaminated in a controlled fashion and bleached. We explain working principles of the one-beam copy concept and discuss the mechanical construction of the installed vHOE replication line. Moreover, we treat aspects like master design, effects of vibration and suppression of noise gratings. Furthermore, digital vHOEs are introduced as master holograms. They enable new ways of optical design and paths to large scale vHOEs.

  6. 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, Bérenger; Corazza, Michael

    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...

  7. Stress and accidental defect detection on rolling mill rolls

    International Nuclear Information System (INIS)

    Auzas, J.-D.

    1999-01-01

    During the rolling mill process, rolls are submitted to high pressures that can lead to local decohesion or metallurgical changes. Both these cracks or softened areas must be detected as soon as they appear because of the risk of spalling, marks on the product, and mill wreck. These defects can be detected using the eddy current method, and particularly sensors specially developed for micro-defects detection. These sensors must be adapted to the environment of a roll grinding machine on which they must be installed. Users' schedule of conditions also require them to be attached to a wide range of eddy current generator and automatic computerized interpretation. Mill requirements for new high tech roll grades and quality lead to continuous development and improvement of the tools that will provide immediate 'go - no go' information. This paper is an update of these developments. (author)

  8. Polycrystalline silicon ring resonator photodiodes in a bulk complementary metal-oxide-semiconductor process.

    Science.gov (United States)

    Mehta, Karan K; Orcutt, Jason S; Shainline, Jeffrey M; Tehar-Zahav, Ofer; Sternberg, Zvi; Meade, Roy; Popović, Miloš A; Ram, Rajeev J

    2014-02-15

    We present measurements on resonant photodetectors utilizing sub-bandgap absorption in polycrystalline silicon ring resonators, in which light is localized in the intrinsic region of a p+/p/i/n/n+ diode. The devices, operating both at λ=1280 and λ=1550  nm and fabricated in a complementary metal-oxide-semiconductor (CMOS) dynamic random-access memory emulation process, exhibit detection quantum efficiencies around 20% and few-gigahertz response bandwidths. We observe this performance at low reverse biases in the range of a few volts and in devices with dark currents below 50 pA at 10 V. These results demonstrate that such photodetector behavior, previously reported by Preston et al. [Opt. Lett. 36, 52 (2011)], is achievable in bulk CMOS processes, with significant improvements with respect to the previous work in quantum efficiency, dark current, linearity, bandwidth, and operating bias due to additional midlevel doping implants and different material deposition. The present work thus offers a robust realization of a fully CMOS-fabricated all-silicon photodetector functional across a wide wavelength range.

  9. Ring Theory

    CERN Document Server

    Jara, Pascual; Torrecillas, Blas

    1988-01-01

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

  10. Systematics of constant roll inflation

    Science.gov (United States)

    Anguelova, Lilia; Suranyi, Peter; Wijewardhana, L. C. R.

    2018-02-01

    We study constant roll inflation systematically. This is a regime, in which the slow roll approximation can be violated. It has long been thought that this approximation is necessary for agreement with observations. However, recently it was understood that there can be inflationary models with a constant, and not necessarily small, rate of roll that are both stable and compatible with the observational constraint ns ≈ 1. We investigate systematically the condition for such a constant-roll regime. In the process, we find a whole new class of inflationary models, in addition to the known solutions. We show that the new models are stable under scalar perturbations. Finally, we find a part of their parameter space, in which they produce a nearly scale-invariant scalar power spectrum, as needed for observational viability.

  11. {open_quotes}O{close_quotes} ring sealed process tube, Phase II, test project

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, R.E.

    1951-04-09

    The {open_quotes}O{close_quotes} ring seal has been proposed to replace the van stone flange and the bellows thermal expansion assembly currently used on the existing Hanford piles to achieve water and gas seals, respectively. Possible advantages of the {open_quotes}O{close_quotes} ring seal are: (1) simplification of component parts and elimination of van stone corrosion; (2) simplification of maintenance; (3) lower costs of initial erection; (4) increased strength. This test supplements Test Project No. 27 (a preliminary thermal cycling test) in applying the {open_quotes}O{close_quotes} ring seal assembly to actual pile operating conditions.

  12. Perturbation of a slowly rotating black hole by a stationary axisymmetric ring of matter. II. Penrose processes, circular orbits, and differential mass formulae

    International Nuclear Information System (INIS)

    Will, C.M.

    1975-01-01

    We present a detailed description of the phenomenon of energy extraction (''Penrose'') from a slowly rotating black hole perturbed by a stationary axisymmetric ring of matter, and show that the gravitational interaction between the ring and the particles used in the Penrose process must be taken into account. For the case of a black-hole-ring configuration of ''minimum enregy'' we show that a Penrose process can extract further energy, but that by measns of their gravitational forces, the particles used in the process cause the radius of the ring to change, releasing precisely sufficient gravitational potential energy to make up for that extracted. By analyzing the properties of circular test-particle orbits in black-hole-ring spacetimes, we show quantitatively how this change in radius is produced. A ''differential mass formula'' relating the total masses of neighboring black-hole-ring configurations is also derived

  13. Deformation induced dynamic recrystallization and precipitation strengthening in an Mg−Zn−Mn alloy processed by high strain rate rolling

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Jimiao; Song, Min [State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083 (China); Yan, Hongge [School of Materials Science and Engineering, Hunan University, Changsha 410082 (China); Yang, Chao [State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083 (China); Ni, Song, E-mail: song.ni@csu.edu.cn [State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083 (China)

    2016-11-15

    The microstructure of a high strain-rate rolled Mg−Zn−Mn alloy was investigated by transmission electron microscopy to understand the relationship between the microstructure and mechanical properties. The results indicate that: (1) a bimodal microstructure consisting of the fine dynamic recrystallized grains and the largely deformed grains was formed; (2) a large number of dynamic precipitates including plate-like MgZn{sub 2} phase, spherical MgZn{sub 2} phase and spherical Mn particles distribute uniformly in the grains; (3) the major facets of many plate-like MgZn{sub 2} precipitates deviated several to tens of degrees (3°–30°) from the matrix basal plane. It has been shown that the high strength of the alloy is attributed to the formation of the bimodal microstructure, dynamic precipitation, and the interaction between the dislocations and the dynamic precipitates. - Highlights: •A bimodal microstructure was formed in a high strain-rate rolled Mg−Zn−Mn alloy. •Plate-like MgZn{sub 2}, spherical MgZn{sub 2} and spherical Mn phases were observed. •The major facet of the plate-like MgZn{sub 2} deviated from the matrix basal plane.

  14. Effect of strain path on microstructure, deformation texture and mechanical properties of nano/ultrafine grained AA1050 processed by accumulative roll bonding (ARB)

    Energy Technology Data Exchange (ETDEWEB)

    Naseri, M.; Reihanian, M. [Department of Materials Science and Engineering, Faculty of Engineering, Shahid Chamran University of Ahvaz, Ahvaz (Iran, Islamic Republic of); Borhani, E., E-mail: e.borhani@semnan.ac.ir [Department of Nano Technology, Nano Materials Group, Semnan University, Semnan (Iran, Islamic Republic of)

    2016-09-15

    Commercial pure Al sheets were severe plastically deformed at room temperature by accumulative roll bonding (ARB) and cross accumulative roll bonding (CARB). Change in strain path was imposed during CARB by rotating the sheets with 90° around the normal direction axis between each cycle. Microstructural evolution of processed sheets was studied by electron back scattered diffraction (EBSD) analysis and revealed that nano/ultrafine grains (NG/UFG) with the average grain size of 380 nm and 155 nm were formed by both processing routes after eight cycles, respectively. The fraction of high angle grain boundaries and mean misorientation angle of the boundaries in the CARB were 49% and 40.20°, respectively, in comparison to that of ARB sample (41% and 37.37°). Deformation texture evolution demonstrated that the change in strain path leads to the formation of strong orientation along the β-fiber. The major texture components for ARB specimens were Brass {011}<211> and S {123}<634> while those for CARB were Brass {011}<211> and Goss {011}<100>. The CARB processed specimen exhibited the tensile strength, microhardness and elongation of about 230 MPa, 92 HV and 13% compared with ARB sample (180 MPa, 80 HV and 10.5%) after eight cycles. Scanning electron microscopy (SEM) observations of tensile fracture surface of specimens revealed ductile type fracture.

  15. Processing of fine grained AISI 304L austenitic stainless steel by cold rolling and high-temperature short-term annealing

    Science.gov (United States)

    Naghizadeh, Meysam; Mirzadeh, Hamed

    2018-05-01

    An advanced thermomechanical process based on the formation and reversion of deformation-induced martensite was used to refine the grain size and enhance the hardness of an AISI 304L austenitic stainless steel. Both low and high reversion annealing temperatures and also the repetition of the whole thermomechanical cycle were considered. While a microstructure with average austenite grain size of a few micrometers was achieved based on cold rolling and high-temperature short-term annealing, an extreme grain refinement up to submicrometer regime was obtained by cold rolling followed by low-temperature long-term annealing. However, the required annealing time was found to be much longer, which negates its appropriateness for industrial production. While a magnificent grain refinement was achieved by one pass of the high-temperature thermomechanical process, the reduction in grain size was negligible by the repetition of the whole cycle. It was found that the hardness of the thermomechanically processed material is much higher than that of the as-received material. The results of the present work were shown to be compatible with the general trend of grain size dependence of hardness for AISI 304L stainless steel based on the Hall-Petch relationship. The results were also discussed based on the X-ray evaluation of dislocation density by modified Williamson-Hall plots.

  16. The Coagulant Type Influence on Removal Efficiency of 5- and 6-Ring Pahs During Water Coagulation Process

    Directory of Open Access Journals (Sweden)

    Nowacka Anna

    2014-12-01

    Full Text Available The article presents results on investigation of the removal efficiency of selected 5- and 6-ring polycyclic aromatic hydrocarbons (benzo[a]pyrene, benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[j]fluoranthene, benzo[g,h,i]perylene, indeno[1,2,3-cd]pyrene, dibenzo[a,h]anthracene from water during coagulation and sedimentation process. Two pre-hydrolyzed aluminum coagulants: PAX XL 19H and FLOKOR 105V were chosen for research. Process was carried out at optimum process parameters: rapid-mixing - 3 min at the rotational speed of 200 rpm, slow mixing - 10 min at 30 rpm, sedimentation - 60 min. The removal effectiveness was dependant on coagulant type and its composition. Better results in the removal of 5-and 6-ring PAHs were obtained after application of FLOKOR 105V (lower aluminum content than after using PAX XL 19H.

  17. Novel manufacturing process of nanoparticle/Al composite filler metals of tungsten inert gas welding by accumulative roll bonding

    Energy Technology Data Exchange (ETDEWEB)

    Fattahi, M., E-mail: fattahi.put@gmail.com [Technical Inspection Engineering Department, Petroleum University of Technology, Abadan (Iran, Islamic Republic of); Noei Aghaei, V. [Aerospace Engineering Department, Sharif University of Technology, Tehran (Iran, Islamic Republic of); Dabiri, A.R. [Technical Inspection Engineering Department, Petroleum University of Technology, Abadan (Iran, Islamic Republic of); Amirkhanlou, S. [Young Researchers and Elite Club, Najafabad Branch, Islamic Azad University, Najafabad (Iran, Islamic Republic of); Akhavan, S.; Fattahi, Y. [Materials Engineering Department, Isfahan University of Technology, Isfahan (Iran, Islamic Republic of)

    2015-11-11

    In the present work, accumulative roll bonding (ARB) was used as an effective method for manufacturing nanoparticle/Al composite filler metals of tungsten inert gas (TIG) welding. After welding, the distribution of ceramic nanoparticles and mechanical properties of welds were investigated. By applying ARB, ceramic nanoparticles were uniformly dispersed in the composite filler metals. Consequently, the welds produced by these filler metals had a uniform dispersion of ceramic nanoparticles in their compositions. The test results showed that the yield strength of welds was greatly increased when using the nanoparticle/Al composite filler metals. The improvement in the yield strength was attributed to the coefficient of thermal expansion mismatch and Orowan strengthening mechanisms. Therefore, according to the results presented in this paper, it can be concluded that the nanoparticle/Al composite filler metals can serve as a novel filler metal for TIG welding of aluminum and its alloys.

  18. Upscaling of Perovskite Solar Cells: Fully Ambient Roll Processing of Flexible Perovskite Solar Cells with Printed Back Electrodes

    DEFF Research Database (Denmark)

    Schmidt, Thomas Mikael; Larsen-Olsen, Thue Trofod; Carlé, Jon Eggert

    2015-01-01

    A scaling effort on perovskite solar cells is presented where the device manufacture is progressed onto fl exible substrates using scalable techniques such as slot-die roll coating under ambient conditions. The printing of the back electrode using both carbon and silver is essential to the scaling...... effort. Both normal and inverted device geometries are explored and it is found that the formation of the correct morphology for the perovskite layer depends heavily on the surface upon which it is coated and this has signifi cant implications for manufacture. The time it takes to form the desired layer...... morphology falls in the range of 5–45 min depending on the perovskite precursor, where the former timescale is compatible with mass production and the latter is best suited for laboratory work. A signifi cant loss in solar cell performance of around 50% is found when progressing to using a fully scalable...

  19. Analysis of bearing steel exposed to rolling contact fatigue

    DEFF Research Database (Denmark)

    Hansen, K. T.; Fæster, Søren; Natarajan, Anand

    2017-01-01

    The objective of this work is to characterize fatigue damage in roller bearings under conditions of high load and slippage. A test rig constructed for rolling contact fatigue tests of rings is described, and test results are presented for rings taken from two spherical roller bearings. The prepar...

  20. Self-assembly of the yeast actomyosin contractile ring as an aggregation process: kinetics of formation and instability regimes

    Science.gov (United States)

    Ojkic, Nikola; Vavylonis, Dimitrios

    2009-03-01

    Fission yeast cells assemble an equatorial contractile ring for cytokinesis, the last step of mitosis. The ring assembles from ˜ 65 membrane-bound ``nodes''' containing myosin motors and other proteins. Actin filaments that grow out from the nodes establish transient connections among the nodes and aid in pulling them together in a process that appears as pair-wise attraction (Vavylonis et al. Science 97:319, 2008). We used scaling arguments, coarse grained stability analysis of homogeneous states, and Monte Carlo simulations of simple models, to explore the conditions that yield fast and efficient ring formation, as opposed to formation of isolated clumps. We described our results as a function of: number of nodes, rate of establishing connections, range of node interaction, distance traveled per node interaction and broad band width, w. Uniform cortical 2d distributions of nodes are stable over short times due to randomness of connections among nodes, but become unstable over long times due to fluctuations in the initial node distribution. Successful condensation of nodes into a ring requires sufficiently small w such that lateral contraction occurs faster then clump formation.

  1. An acetone microsensor with a ring oscillator circuit fabricated using the commercial 0.18 μm CMOS process.

    Science.gov (United States)

    Yang, Ming-Zhi; Dai, Ching-Liang; Shih, Po-Jen

    2014-07-17

    This study investigates the fabrication and characterization of an acetone microsensor with a ring oscillator circuit using the commercial 0.18 μm complementary metal oxide semiconductor (CMOS) process. The acetone microsensor contains a sensitive material, interdigitated electrodes and a polysilicon heater. The sensitive material is α-Fe2O3 synthesized by the hydrothermal method. The sensor requires a post-process to remove the sacrificial oxide layer between the interdigitated electrodes and to coat the α-Fe2O3 on the electrodes. When the sensitive material adsorbs acetone vapor, the sensor produces a change in capacitance. The ring oscillator circuit converts the capacitance of the sensor into the oscillation frequency output. The experimental results show that the output frequency of the acetone sensor changes from 128 to 100 MHz as the acetone concentration increases 1 to 70 ppm.

  2. Manufacturing processes of S-shaped temple rings from Vrbno, Central Bohemia

    Czech Academy of Sciences Publication Activity Database

    Ottenwelter, Estelle; Hošek, Jiří; Děd, J.; Štefan, I.

    2012-01-01

    Roč. 64, č. 3 (2012), s. 525-533 ISSN 0323-1267 Institutional research plan: CEZ:AV0Z80020508 Keywords : S-shaped temple rings * Early Middle Ages * Vrbno * tinning * gilding * silver plating Subject RIV: AC - Archeology, Anthropology, Ethnology

  3. Chaos in coherent two-photon processes in a ring cavity

    Energy Technology Data Exchange (ETDEWEB)

    Singh, S; Agarwal, G S

    1983-08-01

    The output of a ring cavity containing a resonant medium undergoing two photon transitions is shown to become chaotic, after following a series of bifurcations involving 2 to the nth cycles, as the strength of the driving field is increased. The chaotic regime is followed by a sequence of period doubling bifurcations in reverse order. 14 references.

  4. 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%.

  5. From process to proxy: Ecological challenges and opportunities of tree-ring based environmental reconstructions

    Science.gov (United States)

    Wilmking, Martin; Buras, Allan; Heinrich, Ingo; Scharnweber, Tobias; Simard, Sonia; Smiljanic, Marko; van der Maaten, Ernst; van der Maaten-Theunissen, Marieke

    2014-05-01

    Trees are sessile, long-living organisms and as such constantly need to adapt to changing environmental conditions. Accordingly, they often show high phenotypic plasticity (the ability to change phenotypic traits, such as allocation of resources) in response to environmental change. This high phenotypic plasticity is generally considered as one of the main ingredients for a sessile organism to survive and reach high ages. Precisely because of the ability of trees to reach old age and their in-ability to simply run away when conditions get worse, growth information recorded in tree rings has long been used as a major environmental proxy, covering time scales from decades to millennia. Past environmental conditions (e.g. climate) are recorded in i.e. annual tree-ring width, early- and latewood width, wood density, isotopic concentrations, cell anatomy or wood chemistry. One prerequisite for a reconstruction is that the relationship between the environmental variable influencing tree growth and the tree-growth variable itself is stable through time. This, however, might contrast the ecological theory of high plasticity and the trees ability to adapt to change. To untangle possible mechanisms leading to stable or unstable relationships between tree growth and environmental variables, it is helpful to have exact site information and several proxy variables of each tree-ring series available. Although we gain insight into the environmental history of a sampling site when sampling today, this is extremely difficult when using archeological wood. In this latter case, we face the additional challenge of unknown origin, provenance and (or) site conditions, making it even more important to use multiple proxy time-series from the same sample. Here, we review typical examples, where the relationship between tree growth and environmental variables seems 1) stable and 2) instable through time, and relate these two cases to ecological theory. Based on ecological theory, we then

  6. Token Ring Project

    Directory of Open Access Journals (Sweden)

    Adela Ionescu

    2007-01-01

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

  7. Microstructure Evolution and Mechanical Properties of Al-TiB2/TiC In Situ Aluminum-Based Composites during Accumulative Roll Bonding (ARB Process

    Directory of Open Access Journals (Sweden)

    Jinfeng Nie

    2017-01-01

    Full Text Available In this study, a kind of Al-TiB2/TiC in situ composite was successfully prepared using the melt reaction method and the accumulative roll-bonding (ARB technique. The microstructure evolution of the composites with different deformation treatments was characterized using field emission scanning electron microscopy (FESEM and a transmission electron microscope (TEM. The mechanical properties of the Al-TiB2/TiC in situ composite were also studied with tensile and microhardness tests. It was found that the distribution of reinforcement particles becomes more homogenous with an increasing ARB cycle. Meanwhile, the mechanical properties showed great improvement during the ARB process. The ultimate tensile strength (UTS and microhardness of the composites were increased to 173.1 MPa and 63.3 Hv after two ARB cycles, respectively. Furthermore, the strengthening mechanism of the composite was analyzed based on its fracture morphologies.

  8. Cold rolling precision forming of shaft parts theory and technologies

    CERN Document Server

    Song, Jianli; Li, Yongtang

    2017-01-01

    This book presents in detail the theory, processes and equipment involved in cold rolling precision forming technologies, focusing on spline and thread shaft parts. The main topics discussed include the status quo of research on cold rolling precision forming technologies; the design and calculation of process parameters; the numerical simulation of cold rolling forming processes; and the equipment used in cold rolling forming. The mechanism of cold rolling forming is extremely complex, and research on the processes, theory and mechanical analysis of spline cold rolling forming has remained very limited to date. In practice, the forming processes and production methods used are mainly chosen on the basis of individual experience. As such, there is a marked lack of both systematic, theory-based guidelines, and of specialized books covering theoretical analysis, numerical simulation, experiments and equipment used in spline cold rolling forming processes – all key points that are included in this book and ill...

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

    Science.gov (United States)

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

    2014-01-01

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

  10. Rolling of molybdenum and niobium tubes on cold-rolling mill with high stiff stand

    Energy Technology Data Exchange (ETDEWEB)

    Potapov, I N; Shejkh-Ali, A D; Filimonov, G V; Lunev, A G

    1984-03-01

    To develop the technique of tube production the process of rolling is studied and comparative evaluation of the structure formed is carried out. It is shown that billets of rods deformed by screw rolling have the improved plastic properties and are deformed on cold-rolling mill (CRM) with a high degree of reduction without defect formation. High stiff stand of the CRM permits to produce high-quality molybdenum tubes.

  11. Loss pattern of Pb ions with charge changing processes in the LEIR ring

    CERN Document Server

    Pasternak, J

    2004-01-01

    Avalanche like pressure rise and an associated decrease of the beam lifetime, caused by (i) beam loss due to charge exchange interactions with rest gas molecules and (ii) ion impact induced outgassing, is a potential limitation for heavy ion accelerators. The vacuum system of the LEIR ring has to be upgraded carefully to avoid that these phenomena prevent the machine from reaching design performance. The loss pattern of Pb ions having captured an electron presented in this report allows to estimate whether the low dynamic pressure needed for LEIR is reachable. Efficient interception of lost ions with low beam loss induced outgassing absorber blocks, installed at appropriate locations is promising.

  12. Lubrication in cold rolling : Numerical simulation using multigrid techniques

    NARCIS (Netherlands)

    Lugt, Pieter Martin

    1992-01-01

    In the cold rolling process a lubricant is applied on the rolls and/or the strip mate­rial. Due to the velocities of the rolls and the strip, part of the lubricant is sheared into the contact causing, amongst others, a reduction of the friction. In this thesis a physical-mathematical model is

  13. Method and an apparatus to control the lateral motion of a long metal bar being formed by a mechanical process such as rolling or drawing

    Science.gov (United States)

    Chang, Tzyy-Shuh; Huang, Hsun-Hau; Lin, Chang-Hung

    2007-10-02

    An adjustable guide, includes two or more mechanisms each having a rotatable retaining element containing a retaining groove with a variable radius in its perimeter surface. The grooves form a guidance path to control the lateral, i.e. non-axial, motion of a long bar moving along a longitudinal axis during a production process.The diameter of the guidance path varies according to the variable radii of the grooves. The guidance path increases in size at a predetermined rate, from a point of origin to an end point on the retaining groove. Rotating the retaining elements causes the diameter of the retaining grooves to change so that the size of the guidance path can be changed to match the diameter of the bar being rolled, size of the guidance path can be changed to fit the diameter of a new bar rolled without having to exchange the guide for a different sized guide, reduce fiction between the bar and the guide, a media, such as compressed air, can be injected between the retaining elements via orifices.Each retaining element is attached to a mounting apparatus. The mounting apparatus can be fixed or flexible. The flexible mounting apparatus includes one or more springs and one or more shock absorbers. A force neutral position of the flexible mounting apparatus is designed to be located on the predetermined ideal bar path line. The flexible mounting apparatus dissipates kinetic energy from the bar thereby reducing the bar's lateral motion relative to the ideal bar path line.The damping ratio of the mounting apparatus can be adjustable to alter the product's vibration mode to enable better control of the bar's lateral motion.

  14. Properties of the AZ31 Magnesium Alloy Round Bars Obtained in Different Rolling Processes / Własności Prętów Okrągłych Ze Stopu Magnezu AZ31 Otrzymanych W Różnych Procesach Walcowania

    Directory of Open Access Journals (Sweden)

    Stefanik A.

    2015-12-01

    Full Text Available Currently magnesium alloy bars are manufactured mainly in the extrusion process. This method has some drawbacks, which include: low process capacity, considerable energy demand, small length of finished products. Therefore it is purposeful to develop efficient methods for manufacturing of Mg alloy products in the form of bars, such methods include groove rolling and three-high skew rolling processes. Modified stretching passes provide change in material plastic flow, which contributes to the occurrence of the better distribution of stress and strain state than in the case of rolling in classical stretching passes. One of the modern method of Mg alloy bars production is rolling in a three-high skew rolling mill, which allows to set in a single pass a larger deformation compared to the rolling in the stretching passes.

  15. Saturation of the laser-induced narrowband coherent synchrotron radiation process: Experimental observation at a storage ring

    Science.gov (United States)

    Hosaka, M.; Yamamoto, N.; Takashima, Y.; Szwaj, C.; Le Parquier, M.; Evain, C.; Bielawski, S.; Adachi, M.; Zen, H.; Tanikawa, T.; Kimura, S.; Katoh, M.; Shimada, M.; Takahashi, T.

    2013-02-01

    We study the efficiency limitation affecting laser-induced coherent synchrotron radiation (CSR) at high laser power. Experiments are made on the UVSOR-II storage ring in conditions of narrowband terahertz CSR emission. While, at moderate power, CSR power increases quadratically with laser power, a noticeable decrease in efficiency and eventually a decrease in CSR power is observed experimentally at high power. Details of the underlying process are analyzed numerically. As the saturation effect depends almost instantaneously on the laser intensity, the saturation occurs locally in longitudinal space. This has important consequences on the modulation pattern induced on the electron bunch.

  16. 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

    2014-01-01

    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...

  17. Black rings

    International Nuclear Information System (INIS)

    Emparan, Roberto; Reall, Harvey S

    2006-01-01

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

  18. 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 algorithms 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.

  19. 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)

    Yi-Wen Cheng; Patrick Purtscher

    1999-01-01

    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

  20. White Ring; White ring

    Energy Technology Data Exchange (ETDEWEB)

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

    1998-01-05

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

  1. Prediction of flux loss in a Nd-Fe-B ring magnet considering magnetizing process

    International Nuclear Information System (INIS)

    Fukunaga, H; Koreeda, H; Yanai, T; Nakano, M; Yamashita, F

    2010-01-01

    We developed a technique to predict flux loss of a magnet with a complicated magnetization pattern using the finite element method. The developed method consists of four steps. At first, the distribution of magnetization under magnetizing field is analyzed (Step 1), and a demagnetization curve of each element is deduced from the result of the first step (Step 2). After removing the magnetizing field, the distributions of magnetization at room and elevated temperatures are analyzed by using demagnetization curves determined in Step 2 (Step 3). Based on a physical model, the distribution of flux loss due to exposure at the elevated temperature is predicted by using the result obtained in Step 3 (Step 4). We applied this technique to a ring magnet with 10 poles, and large flux loss values were predicted at the transition regions between magnetic poles.

  2. Microstructure, mechanical properties and stretch formability of Mg-3Al-0.5Ca-0.2Gd alloy processed at various finish rolling temperatures

    Science.gov (United States)

    Kang, Qiang; Jiang, Haitao; Zhang, Yun

    2018-04-01

    Effects of various finish rolling temperatures on the microstructure, texture, mechanical properties and stretch formability of rolled and annealed Mg-3Al-0.5Ca-0.2Gd (wt%) alloy were investigated in this paper, and it was found that compared with grain size and second phase particles, the basal textures, tensile properties and stretch formability Mg-3Al-0.5Ca-0.2Gd alloy are more sensitive to the increasing finishing rolling temperature. For the rolled and annealed Mg-3Al-0.5Ca-0.2Gd alloy, their grains barely grow up and second phase particles are slightly coarsened, while their basal poles are obviously weakened and tilted with increasing finish rolling temperature. Consequently, the weakened and RD-tilted basal textures are beneficial to the gradually improved elongation and stretch formability of Mg-3Al-0.5Ca-0.2Gd alloy. It is investigated that the gradually activated non-basal slips, e. g. 〈c 〉, 〈c + a〉 dislocations due to the increasing finish rolling temperature could contribute to the weakened RD-tilted textures in rolled and annealed Mg-3Al-0.5Ca-0.2Gd alloy.

  3. Dominant root locus in state estimator design for material flow processes: A case study of hot strip rolling.

    Science.gov (United States)

    Fišer, Jaromír; Zítek, Pavel; Skopec, Pavel; Knobloch, Jan; Vyhlídal, Tomáš

    2017-05-01

    The purpose of the paper is to achieve a constrained estimation of process state variables using the anisochronic state observer tuned by the dominant root locus technique. The anisochronic state observer is based on the state-space time delay model of the process. Moreover the process model is identified not only as delayed but also as non-linear. This model is developed to describe a material flow process. The root locus technique combined with the magnitude optimum method is utilized to investigate the estimation process. Resulting dominant roots location serves as a measure of estimation process performance. The higher the dominant (natural) frequency in the leftmost position of the complex plane the more enhanced performance with good robustness is achieved. Also the model based observer control methodology for material flow processes is provided by means of the separation principle. For demonstration purposes, the computer-based anisochronic state observer is applied to the strip temperatures estimation in the hot strip finishing mill composed of seven stands. This application was the original motivation to the presented research. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

  4. Preorganization of Nanostructured Inks for Roll-to-Roll-Coated Polymer Solar Cells

    DEFF Research Database (Denmark)

    Krebs, Frederik C; Senkovskyy, Volodymyr; Kiriy, Anton

    2010-01-01

    , 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...

  5. Technology development for roll-to-roll production of organic photovoltaics

    NARCIS (Netherlands)

    Galagan, Y.O.; Vries, I.G. de; Langen, A.P.; Andriessen, H.A.J.M.; Verhees, W.J.H.; Veenstra, S.C.; Kroon, J.M.

    2011-01-01

    In order to reach the objective of low-cost, large area organic photovoltaic systems, we build up a knowledge base concerning the influence of process conditions on the performance of polymer solar cells. A large area solar cell module, with roll-to-roll coated PEDOT:PSS and photoactive layers

  6. Roll-to-roll paper sensors (ROPAS); Wireless communicating sensors on paper in the logistic chain

    NARCIS (Netherlands)

    Rentrop, C.; Rubingh, J.E.J.M.; Lelieveld, R.; Sandberg, H.

    2014-01-01

    The ROPAS project (Roll-to-roll paper sensors) combines high end electronics and wireless sensors with low cost paper substrates and processing techniques that can be applied on a large scale. Paper is the next step in the printed electronics roadmap of utilising cheaper substrate materials as a

  7. Ship Roll Damping Control

    DEFF Research Database (Denmark)

    Perez, Tristan; Blanke, Mogens

    2012-01-01

    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 together with the challenges associated with their design. It discusses the assessment of performance...

  8. Cosmology with rolling tachyon

    Indian Academy of Sciences (India)

    Email: sami@iucaa.ernet.in. Abstract. We examine the possibility of rolling tachyon to play the dual role of inflaton at early epochs and dark matter at late times. We argue that enough inflation can be generated with the rolling tachyon either by invoking the large number of branes or brane world assisted inflation. However ...

  9. Origins of Rolling Friction

    Science.gov (United States)

    Cross, Rod

    2017-01-01

    When a hard object rolls on a soft surface, or vice versa, rolling friction arises from deformation of the soft object or the soft surface. The friction force can be described in terms of an offset in the normal reaction force or in terms of energy loss arising from the deformation. The origin of the friction force itself is not entirely clear. It…

  10. Finite-element model to predict roll-separation force and defects during rolling of U-10Mo alloys

    Science.gov (United States)

    Soulami, Ayoub; Burkes, Douglas E.; Joshi, Vineet V.; Lavender, Curt A.; Paxton, Dean

    2017-10-01

    A major goal of the Convert Program of the U.S. Department of Energy's National Nuclear Security Administration (DOE/NNSA) is to enable high-performance research reactors to operate with low-enriched uranium rather than the high-enriched uranium currently used. To this end, uranium alloyed with 10 wt% molybdenum (U-10Mo) represents an ideal candidate because of its stable gamma phase, low neutron caption cross section, acceptable swelling response, and predictable irradiation behavior. However, because of the complexities of the fuel design and the need for rolled monolithic U-10Mo foils, new developments in processing and fabrication are necessary. This study used a finite-element code, LS-DYNA, as a predictive tool to optimize the rolling process. Simulations of the hot rolling of U-10Mo coupons encapsulated in low-carbon steel were 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. The study reported here discussed various attributes of the rolled coupons revealed by the model (e.g., waviness and thickness non-uniformity like dog-boning). To investigate the influence of the cladding material on these rolling defects, other cases were simulated: hot rolling with alternative can materials, namely, 304 stainless steel and Zircaloy-2, and bare-rolling. Simulation results demonstrated that reducing the mismatch in strength between the coupon and can material improves the quality of the rolled sheet. Bare-rolling simulation results showed a defect-free rolled coupon. The finite-element model developed and presented in this study can be used to conduct parametric studies of several process parameters (e.g., rolling speed, roll diameter, can material, and reduction).

  11. Decision Support for the Rolling Stock Dispatcher

    DEFF Research Database (Denmark)

    Groth, Julie Jespersen

    Real-time recovery is receiving a fast growing interest in an increasingly competitive railway operation market. This thesis considers the area of rolling stock dispatching which is one of the typical real-time railway dispatching problems. All work of the thesis is based on the network...... and planning processes of the railway operator DSB S-tog a/s. In the thesis the problems existing in the railway planning process from the strategic to real-time level are briefly sketched. Network planning, line planning, timetabling, crew and rolling stock planning is outlined and relevant references...... are given. Specifically the thesis references the operation research studies based on the railway operation of DSB S-tog a/s. Subsequently the process of dispatching is outlined with a specific emphasis on rolling stock. The rolling stock recovery problem is the problem of assigning train units to train...

  12. Perovskite solar cells for roll-to-roll fabrication

    Directory of Open Access Journals (Sweden)

    Uddin Ashraf

    2017-01-01

    Full Text Available Perovskite solar cell (PSCs is considered as the game changer in emerging photovoltaics technology. The highest certified efficiency is 22% with high temperature processed (∼500 °C TiO2 based electron transport layer (ETL. High temperature process is a rudimentary hindrance towards roll-to-roll processing of PSCs on flexible substrates. Low temperature solution process (<150 °C ZnO based ETL is one of the most promising candidate for large scale roll-to-roll fabrication of cells as it has nearly identical electron affinity (4.2 eV of TiO2. The mixed organic perovskite (MA0.6FA0.4PbI3 devices with Al doped ZnO (AZO ETL demonstrate average cell efficiency over 16%, which is the highest ever reported efficiency for this device configuration. The energy level alignment and related interfacial charge transport dynamics at the interface of ZnO and perovskite films and the adjacent charge transport layers are investigated. Significantly improved device stability, hysteresis free device photocurrent have been observed in MA0.6FA0.4PbI3 cells. A systematic electrochemical impedance spectroscopy, frequency dependent capacitance spectra, surface morphology and topography characterization have been conducted to understand the role of interfacial electronic properties between perovskite and neighbouring layers in perovskite device. A standardized degradation study, interfacial electronic property and capacitive spectra analysis of aged device, have been measured to understand the enhanced device stability in mixed MA0.6FA0.4PbI3 cells. Slow perovskite material decomposition rate and augmented device lifetime with AZO based devices have been found to be correlated with the more hydrophobic and acidic nature of AZO surface compared to pristine ZnO film.

  13. Dimensional ranges and rolling efficiency in a tandem cold rolling mill

    Energy Technology Data Exchange (ETDEWEB)

    Larkiola, J.

    1997-12-31

    In this work, physical models and a neural network theory have been combined in order to predict the properties of a steel strip and to optimise the process parameters in cold rolling. The prediction of the deformation resistance of the material and the friction parameter is based on the physical model presented by Bland, Ford and Ellis and artificial neural network computing (ANN). The accuracy of these models has been tested and proved by using a large amount of the measured data. With the aid of these models it has been shown that (a) the small change to the relative reduction distribution can have a clear effect upon the rolling efficiency, (b) the dimensional ranges of the tandem cold roll mill can be determined and optimised and (c) the possibility to cold roll a new product of new width, strength or thickness can be determined and the parameters of the tandem cold rolling process can be optimised. (orig.) 43 refs.

  14. Vortex rings

    CERN Document Server

    Akhmetov, D G

    2009-01-01

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

  15. STUDY OF THE flat die pellet mills kinematic diagram with active cylindrical press rolLS

    Directory of Open Access Journals (Sweden)

    Osokin Anton Vladislavovich

    2017-03-01

    Full Text Available Though being widely spread, the designs of such machines as flat die pellet mills have hardly been comprehensively theoretically studied. At the same time, the kinematic motion of the ring die pellet mill executive parts have been studied quite thoroughly. The machine executive parts kinematics determines the nature of their motion and velocity parameters, as well as the energy costs for the unit operation of the assembly. In addition, a detailed analysis of the facility kinematic diagram enables a rational approach to the design process for a new equipment. In view of this, this paper proposes a classification of flat matrix granulators over the kinematic diagrams of the executive parts interactions. We performed an analytical study of the kinematic diagram flat matrix granulator with active cylindrical press rolls. We considered the forces acting on the press roll during its operation. We determined the kinematic parameters and their interrelation with the design parameters of the press roll. We obtained the analytical equations for the of the neutral cross-section determination - the most characteristic section of the press-roll granulator

  16. Towards roll-to-roll manufacturing of polymer photonic devices

    Science.gov (United States)

    Subbaraman, Harish; Lin, Xiaohui; Ling, Tao; Guo, L. Jay; Chen, Ray T.

    2014-03-01

    Traditionally, polymer photonic devices are fabricated using clean-room processes such as photolithography, e-beam lithography, reactive ion etching (RIE) and lift-off methods etc, which leads to long fabrication time, low throughput and high cost. We have utilized a novel process for fabricating polymer photonic devices using a combination of imprinting and ink jet printing methods, which provides high throughput on a variety of rigid and flexible substrates with low cost. We discuss the manufacturing challenges that need to be overcome in order to realize true implementation of roll-to-roll manufacturing of flexible polymer photonic systems. Several metrology and instrumentation challenges involved such as availability of particulate-free high quality substrate, development and implementation of high-speed in-line and off-line inspection and diagnostic tools with adaptive control for patterned and unpatterned material films, development of reliable hardware, etc need to be addressed and overcome in order to realize a successful manufacturing process. Due to extreme resolution requirements compared to print media, the burden of software and hardware tools on the throughput also needs to be carefully determined. Moreover, the effect of web wander and variations in web speed need to accurately be determined in the design of the system hardware and software. In this paper, we show the realization of solutions for few challenges, and utilizing these solutions for developing a high-rate R2R dual stage ink-jet printer that can provide alignment accuracy of web speed of 5m/min. The development of a roll-to-roll manufacturing system for polymer photonic systems opens limitless possibilities for the deployment of high performance components in a variety of applications including communication, sensing, medicine, agriculture, energy, lighting etc.

  17. Design and analysis of roll cage

    Science.gov (United States)

    Angadi, Gurusangappa; Chetan, S.

    2018-04-01

    Wildlife fire fighting vehicles are used to extinguish fires in forests, in this process vehicles face falling objects like rocks, tree branches and other objects. Also due to uneven conditions of the terrain like cliff edges, uneven surfaces etc. makes the vehicle to roll over and these can cause injuries to both the driver and the operator. Roll over of a vehicle is a common incident which makes fatal injuries to the operator and also stands next to the crash accidents. In order to reduce the injury level and continuous roll over of the vehicle it is necessary to equip suitable roll cage according to standards of vehicle. In this present work roll cage for pump operator in wildfire fighting vehicle is designed and analysis is carried out in computer simulated environment when seating position of operator seated outside of the cabin. According to NFPA 1906 standards wildlife fire apparatus, Design and Test procedures that are carried out in Hyperworks maintaining SAE J1194.1983 standards. G load case, roof crush analysis and pendulum impact analysis tests are carried out on roll cage to ensure the saftey of design. These load cases are considerd to satisfy the situation faced in forest terrain. In these test procedures roll cage is analysed for stresses and deformation in various load cases. After recording results these are compared with standards mentioned in SAE J1194.1983.

  18. Physics of quantum rings

    International Nuclear Information System (INIS)

    Fomin, Vladimir M.

    2014-01-01

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

  19. Experimental investigation of thermal processes in the multi-ring Couette system with counter rotation of cylinders

    Science.gov (United States)

    Mamonov, V. N.; Nazarov, A. D.; Serov, A. F.; Terekhov, V. I.

    2016-01-01

    The effect of parameters of the multi-ring Couette system with counter rotating coaxial cylinders on the process of thermal energy release in a viscous liquid filling this system is considered with regard to the problem of determining the possibility of creating the high-performance wind heat generator. The multi-cylinder rotor design allows directly conversion of the mechanical power of a device consisting of two "rotor" wind turbines with a common axis normal to the air flow into the thermal energy in a wide range of rotational speed of the cylinders. Experimental results on the measurement of thermal power released in the pilot heat generator at different relative angular speeds of cylinder rotation are presented.

  20. Monte Carlo simulation for thermal assisted reversal process of micro-magnetic torus ring with bistable closure domain structure

    Energy Technology Data Exchange (ETDEWEB)

    Terashima, Kenichi; Suzuki, Kenji; Yamaguchi, Katsuhiko, E-mail: yama@sss.fukushima-u.ac.jp

    2016-04-01

    Monte Carlo simulations were performed for temperature dependences of closure domain parameter for a magnetic micro-torus ring cluster under magnetic field on limited temperature regions. Simulation results show that magnetic field on tiny limited temperature region can reverse magnetic closure domain structures when the magnetic field is applied at a threshold temperature corresponding to intensity of applied magnetic field. This is one of thermally assisted switching phenomena through a self-organization process. The results show the way to find non-wasteful pairs between intensity of magnetic field and temperature region for reversing closure domain structure by temperature dependence of the fluctuation of closure domain parameter. Monte Carlo method for this simulation is very valuable to optimize the design of thermally assisted switching devices.

  1. EBT ring physics

    International Nuclear Information System (INIS)

    Uckan, N.A.

    1980-04-01

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

  2. Reforging the Wedding Ring: Exploring a Semi-Artificial Model of Population for the United Kingdom with Gaussian process emulators

    Directory of Open Access Journals (Sweden)

    Viet Dung Cao

    2013-10-01

    Full Text Available Background: We extend the "Wedding Ring‟ agent-based model of marriage formation to include some empirical information on the natural population change for the United Kingdom together with behavioural explanations that drive the observed nuptiality trends. Objective: We propose a method to explore statistical properties of agent-based demographic models. By coupling rule-based explanations driving the agent-based model with observed data we wish to bring agent-based modelling and demographic analysis closer together. Methods: We present a Semi-Artificial Model of Population, which aims to bridge demographic micro-simulation and agent-based traditions. We then utilise a Gaussian process emulator - a statistical model of the base model - to analyse the impact of selected model parameters on two key model outputs: population size and share of married agents. A sensitivity analysis is attempted, aiming to assess the relative importance of different inputs. Results: The resulting multi-state model of population dynamics has enhanced predictive capacity as compared to the original specification of the Wedding Ring, but there are some trade-offs between the outputs considered. The sensitivity analysis allows identification of the most important parameters in the modelled marriage formation process. Conclusions: The proposed methods allow for generating coherent, multi-level agent-based scenarios aligned with some aspects of empirical demographic reality. Emulators permit a statistical analysis of their properties and help select plausible parameter values. Comments: Given non-linearities in agent-based models such as the Wedding Ring, and the presence of feedback loops, the uncertainty in the model may not be directly computable by using traditional statistical methods. The use of statistical emulators offers a way forward.

  3. Tests of an environmental and personnel safe cleaning process for BNL accelerator and storage ring components

    International Nuclear Information System (INIS)

    Foerster, C.L.; Lanni, C.; Lee, R.; Mitchell, G.; Quade, W.

    1996-10-01

    A large measure of the successful operation of the National Synchrotron Light Source (NSLS) at Brookhaven National Laboratory (BNL) for over a decade can be attributed to the cleaning of its UHV components during and after construction. A new UHV cleaning process, which had to be environmentally and personnel safe, was needed to replace the harsh, unfriendly process which was still in use. Dow Advanced Cleaning Systems was contracted to develop a replacement process without the use of harsh chemicals and which must clean vacuum surfaces as well as the existing process. Acceptance of the replacement process was primarily based on Photon Stimulated Desorption (PSD) measurements of beam tube samples run on NSLS beam line U10B. One meter long beam tube samples were fabricated from aluminum, 304 stainless steel and oxygen free copper. Initially, coupon samples were cleaned and passed preliminary testing for the proposed process. Next, beam tube samples of each material were cleaned, and the PSD measured on beam line U10B using white light with a critical energy of 487 ev. Prior to cleaning, the samples were contaminated with a mixture of cutting oils, lubricants, vacuum oils and vacuum grease. The contaminated samples were then baked. Samples of each material were also cleaned with the existing process after the same preparation. Beam tube samples were exposed to between 10 22 and 10 23 photons per meter for a PSD measurement. Desorption yields for H 2 , CO, CO 2 , CH 4 and H 2 O are reported for both the existing cleaning and for the replacement cleaning process. Preliminary data, residual gas scans, and PSD results are given and discussed. The new process is also compared with new cleaning methods developed in other laboratories

  4. Replication of nanopits and nanopillars by roll-to-roll extrusion coating using a structured cooling roll

    DEFF Research Database (Denmark)

    Murthy, Swathi; Pranov, Henrik; Pedersen, Henrik Chresten

    2016-01-01

    This paper investigates a novel, very high throughput, roll-to-roll (R2R) process for nanostructuring of polymer foils, called R2R extrusion coating. It has the potential to accelerate the integration of nanostructured materials in consumer products for a variety of applications, including optical....../height of 100 nm. The best replication was achieved in polypropylene, by running at high roller line-speed of 60 m/min, and high cooling roller temperature of 70°C. Replication in other common polymers like polyethylene and polystyrene was not possible for the parameter range used for the investigation......., technical, and functional surfaces and devices. In roll-to-roll extrusion coating, a molten polymer film is extruded through a flat die forming a melt curtain, and then laminated onto a carrier foil. The lamination occurs as the melt curtain is pressed between a cooling roller and a counter roller...

  5. Setup of a Parameterized FE Model for the Die Roll Prediction in Fine Blanking using Artificial Neural Networks

    Science.gov (United States)

    Stanke, J.; Trauth, D.; Feuerhack, A.; Klocke, F.

    2017-09-01

    Die roll is a morphological feature of fine blanked sheared edges. The die roll reduces the functional part of the sheared edge. To compensate for the die roll thicker sheet metal strips and secondary machining must be used. However, in order to avoid this, the influence of various fine blanking process parameters on the die roll has been experimentally and numerically studied, but there is still a lack of knowledge on the effects of some factors and especially factor interactions on the die roll. Recent changes in the field of artificial intelligence motivate the hybrid use of the finite element method and artificial neural networks to account for these non-considered parameters. Therefore, a set of simulations using a validated finite element model of fine blanking is firstly used to train an artificial neural network. Then the artificial neural network is trained with thousands of experimental trials. Thus, the objective of this contribution is to develop an artificial neural network that reliably predicts the die roll. Therefore, in this contribution, the setup of a fully parameterized 2D FE model is presented that will be used for batch training of an artificial neural network. The FE model enables an automatic variation of the edge radii of blank punch and die plate, the counter and blank holder force, the sheet metal thickness and part diameter, V-ring height and position, cutting velocity as well as material parameters covered by the Hensel-Spittel model for 16MnCr5 (1.7131, AISI/SAE 5115). The FE model is validated using experimental trails. The results of this contribution is a FE model suitable to perform 9.623 simulations and to pass the simulated die roll width and height automatically to an artificial neural network.

  6. New Numerical Solution of von Karman Equation of Lengthwise Rolling

    Directory of Open Access Journals (Sweden)

    Rudolf Pernis

    2015-01-01

    Full Text Available The calculation of average material contact pressure to rolls base on mathematical theory of rolling process given by Karman equation was solved by many authors. The solutions reported by authors are used simplifications for solution of Karman equation. The simplifications are based on two cases for approximation of the circular arch: (a by polygonal curve and (b by parabola. The contribution of the present paper for solution of two-dimensional differential equation of rolling is based on description of the circular arch by equation of a circle. The new term relative stress as nondimensional variable was defined. The result from derived mathematical models can be calculated following variables: normal contact stress distribution, front and back tensions, angle of neutral point, coefficient of the arm of rolling force, rolling force, and rolling torque during rolling process. Laboratory cold rolled experiment of CuZn30 brass material was performed. Work hardening during brass processing was calculated. Comparison of theoretical values of normal contact stress with values of normal contact stress obtained from cold rolling experiment was performed. The calculations were not concluded with roll flattening.

  7. Sealing Failure Analysis on V-Shaped Sealing Rings of an Inserted Sealing Tool Used for Multistage Fracturing Processes

    Directory of Open Access Journals (Sweden)

    Gang Hu

    2018-06-01

    Full Text Available The inserted sealing tool is a critical downhole implement that is used to balance the downhole pressure in multistage fracturing operations and prevent fracturing fluid from overflow and/or backward flow. The sealing ring of an inserted sealing tool plays an important role in downhole sealing since a sealing failure would ail the fracturing operation. In order to improve the sealing performance and reduce the potential fracturing failures, this research aims to investigate the influence of V-shaped sealing ring geometries on sealing performance. Constitutive experiments of rubber materials were carried out and the parameters of the constitutive relationship of rubber materials were obtained. A two-dimensional axisymmetric model considering the sealing ring has been established and influences are investigated with considerations of various system parameters and operating conditions. It is found that the stresses concentrated at the shoulder and inner vertex of the sealing ring have direct impact on the damage of the sealing rings under operational conditions. Moreover, the sealing interference, among several other factors, greatly affects the life of the sealing ring. A new design of the sealing ring is suggested with optimized geometric parameters. Its geometric parameters are the edge height of 5 mm, the vertex angle of 90°–100°, and the interference of 0.1 mm, which show a better performance and prolonged operation life of the sealing ring.

  8. Aperiodic signals processing via parameter-tuning stochastic resonance in a photorefractive ring cavity

    Directory of Open Access Journals (Sweden)

    Xuefeng Li

    2014-04-01

    Full Text Available Based on solving numerically the generalized nonlinear Langevin equation describing the nonlinear dynamics of stochastic resonance by Fourth-order Runge-Kutta method, an aperiodic stochastic resonance based on an optical bistable system is numerically investigated. The numerical results show that a parameter-tuning stochastic resonance system can be realized by choosing the appropriate optical bistable parameters, which performs well in reconstructing aperiodic signals from a very high level of noise background. The influences of optical bistable parameters on the stochastic resonance effect are numerically analyzed via cross-correlation, and a maximum cross-correlation gain of 8 is obtained by optimizing optical bistable parameters. This provides a prospective method for reconstructing noise-hidden weak signals in all-optical signal processing systems.

  9. Multi response optimization of internal grinding process parameters for outer ring using Taguchi method and PCR-TOPSIS

    Science.gov (United States)

    Wisnuadi, Alief Regyan; Damayanti, Retno Wulan; Pujiyanto, Eko

    2018-02-01

    Bearing is one of the most widely used parts in automotive industry. One of the leading bearing manufacturing companies in the world is SKF Indonesia. This company must produce bearing with international standard. SKF Indonesia must do continuous improvement in order to face competition. During this time, SKF Indonesia is only performing quality control at its Quality Assurance department. In other words, quality improvement at SKF Indonesia has not been done thoroughly. The purpose of this research is to improve quality of outer ring product at SKF Indonesia by conducting an internal grinding process experiment about setting speed ratio, fine position, and spark out grinding time. The specific purpose of this experiment is to optimize some quality responses such as roughness, roundness, and cycle time. All of the response in this experiment were smaller the better. Taguchi method and PCR-TOPSIS are used for the optimization process. The result of this research shows that by using Taguchi method and PCR-TOPSIS, the optimum condition occurs on speed ratio 36, fine position 18 µm/s and spark out 0.5 s. The optimum conditions result were roughness 0.398 µm, roundness 1.78 µm and cycle time 8.1 s. This results have been better than the previous results and meet the standards. The roughness of 0.523 µm decrease to 0.398 µm and the average cycle time of 8.5 s decrease to 8.1 s.

  10. PECULIARITIES OF INFLUENCE OF THERMO-MECHANICAL PROCESSING IN PRODUCTION LINE OF MILL 150 OF THE BELARUSIAN METALLURGICAL WORKS ON QUALITATIVE CHARACTERISTICS OF HIGH-CARBON ROLLED WIRE

    Directory of Open Access Journals (Sweden)

    V. A. Lutsenko

    2012-01-01

    Full Text Available Using of new arrangement of finishing train of block structure with divisibility of deformation and system of inter-block control of the semi-finished rolled products temperature enables to decrease disorder of mechanical properties, to reduce the depth of the decarbonized layer.

  11. 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.

  12. Entry Strategies to Indonesian Market Case: MoveaRoll

    OpenAIRE

    Islam, Zahedul

    2013-01-01

    MoveRoll Oy, an internationally growing and expanding Finnish company located in Porvoo, has invented a unique technology to produce a paper roll conveyor which the company believes will revolutionise the paper roll handling industry. Moreover, after establishing itself in the Finnish market, the company has started expanding its business to countries like Sweden, USA, and China. Likewise, the process of expanding to the Russian market is currently underway and the company has recently launch...

  13. METHOD OF ROLLING URANIUM

    Science.gov (United States)

    Smith, C.S.

    1959-08-01

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

  14. Fluid management in roll-to-roll nanoimprint lithography

    Science.gov (United States)

    Jain, A.; Bonnecaze, R. T.

    2013-06-01

    The key process parameters of UV roll-to-roll nanoimprint lithography are identified from an analysis of the fluid, curing, and peeling dynamics. The process includes merging of droplets of imprint material, curing of the imprint material from a viscous liquid to elastic solid resist, and pattern replication and detachment of the resist from template. The time and distances on the web or rigid substrate over which these processes occur are determined as function of the physical properties of the uncured liquid, the cured solid, and the roller configuration. The upper convected Maxwell equation is used to model the viscoelastic liquid and to calculate the force on the substrate and the torque on the roller. The available exposure time is found to be the rate limiting parameter and it is O(√Rho /uo), where R is the radius of the roller, ho is minimum gap between the roller and web, and uo is the velocity of the web. The residual layer thickness of the resist should be larger than the gap between the roller and the substrate to ensure complete feature filling and optimal pattern replication. For lower residual layer thickness, the droplets may not merge to form a continuous film for pattern transfer.

  15. All-Solution-Processed, Ambient Method for ITO-Free, Roll-Coated Tandem Polymer Solar Cells using Solution- Processed Metal Films

    DEFF Research Database (Denmark)

    Angmo, Dechan; Dam, Henrik Friis; Andersen, Thomas Rieks

    2014-01-01

    A solution-processed silver film is employed in the processing of top-illuminated indium-tin-oxide (ITO)-free polymer solar cells in single- and double-junction (tandem) structures. The nontransparent silver film fully covers the substrate and serves as the bottom electrode whereas a PEDOT...... in terms of surface morphological and topographical properties and to ITO in terms of flexibility. The slot–die coated Ag film demonstrates extremely low roughness (a root-meansquare roughness of 3 nm was measured over 240_320 mm2 area), is highly conductive (

  16. Analysis of Residual Stress and Deformation of Rolling Strengthen Crankshaft Fillet

    Directory of Open Access Journals (Sweden)

    Han Shaojun

    2016-01-01

    Full Text Available Based on the analysis of crankshaft fillet rolling process, used ANSYS finite element analysis software to conduct the elastic-plastic mechanical simulation of crankshaft rolling process, and gained the variation law of the residual stress and plastic deformation in the radial path of the fillet under different rolling laps and rolling pressure. Established the relationship between the rolling pressure and the plastic deformation and residual stress of the fillet, and provided theoretical support for the evaluation and detection of the crankshaft rolling quality.

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

    DEFF Research Database (Denmark)

    Søndergaard, 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...... research fields such as organic photovoltaics, organic thin film transistors, light-emitting diodes, polymer electrolyte membrane fuel cells, and electrochromic devices. © 2012 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 000: 000–000, 2012...

  18. Interpolation of final geometry and result fields in process parameter space

    NARCIS (Netherlands)

    Misiun, Grzegorz Stefan; Wang, Chao; Geijselaers, Hubertus J.M.; van den Boogaard, Antonius H.; Saanouni, K.

    2016-01-01

    Different routes to produce a product in a bulk forming process can be described by a limited set of process parameters. The parameters determine the final geometry as well as the distribution of state variables in the final shape. Ring rolling has been simulated using different parameter settings.

  19. Statistical prediction of parametric roll using FORM

    DEFF Research Database (Denmark)

    Jensen, Jørgen Juncher; Choi, Ju-hyuck; Nielsen, Ulrik Dam

    2017-01-01

    Previous research has shown that the First Order Reliability Method (FORM) can be an efficient method for estimation of outcrossing rates and extreme value statistics for stationary stochastic processes. This is so also for bifurcation type of processes like parametric roll of ships. The present...

  20. Plastic anisotropy of straight and cross rolled molybdenum sheets

    International Nuclear Information System (INIS)

    Oertel, C.-G.; Huensche, I.; Skrotzki, W.; Knabl, W.; Lorich, A.; Resch, J.

    2008-01-01

    The microstructure, texture and mechanical properties of molybdenum sheets produced by different rolling processes were investigated by orientation imaging in the scanning electron microscope, X-ray diffraction and tensile tests, respectively. For comparable recrystallization degree of the sheets investigated, straight rolling with low reduction ratio produces α-fiber textures with a maximum at {100} . At higher rolling degrees the maximum shifts to {112} . Cross rolling increases the rotated cube component {100} . The strong differences in the texture measured are reflected in the plastic anisotropy characterized by differences in the yield stress and Lankford parameter which were measured along directions in the rolling plane at angles of 0 deg., 45 deg. and 90 deg. with the rolling direction. The Taylor-Bishop-Hill theory is used successfully to qualitatively explain the plastic anisotropy

  1. Person og Rolle

    DEFF Research Database (Denmark)

    Szatkowski, Janek

    2011-01-01

    Distinktionen mellem person og rolle forslås som grundlag for et præcist og anlytisk anvendeligt begreb om performativitet. Begrebet tager sigte på at beskrive enkeltindividers og gruppers kommunikation med henblik på hvordan kommunikation etableres. Performativitet gør det muligt at iagttage den...

  2. Ship Roll Motion Control

    DEFF Research Database (Denmark)

    Perez, Tristan; Blanke, Mogens

    2010-01-01

    . 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....

  3. Rolling Cylinder Phase 1

    DEFF Research Database (Denmark)

    Margheritini, Lucia; Taraborrelli, Valeria Taraborrelli

    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...

  4. Rolled-up nanotechnology: 3D photonic materials by design

    International Nuclear Information System (INIS)

    Böttner, Stefan; Jorgensen, Matthew R.; Schmidt, Oliver G.

    2016-01-01

    Rolled-up nanotechnology involves the deposition of strained material layers for subsequent release and relaxation into functional structures with applications spanning several disciplines. Originally developed for use with semiconductor materials, over the last decade the processes involved in rolled-up nanotechnology have been applied across a wide palette of materials resulting in applications (among others) in micro robotics, energy storage, electronics, and photonics. Here we highlight the key advancements and future directions in rolled-up photonics, focusing on the diverse demonstrations of rolled-up three-dimensional microresonators which enable integrated sensing, micro-lasing, and out-of-plane routing of light.

  5. Adaptive attenuation of aliased ground roll using the shearlet transform

    Science.gov (United States)

    Hosseini, Seyed Abolfazl; Javaherian, Abdolrahim; Hassani, Hossien; Torabi, Siyavash; Sadri, Maryam

    2015-01-01

    Attenuation of ground roll is an essential step in seismic data processing. Spatial aliasing of the ground roll may cause the overlap of the ground roll with reflections in the f-k domain. The shearlet transform is a directional and multidimensional transform that separates the events with different dips and generates subimages in different scales and directions. In this study, the shearlet transform was used adaptively to attenuate aliased and non-aliased ground roll. After defining a filtering zone, an input shot record is divided into segments. Each segment overlaps adjacent segments. To apply the shearlet transform on each segment, the subimages containing aliased and non-aliased ground roll, the locations of these events on each subimage are selected adaptively. Based on these locations, mute is applied on the selected subimages. The filtered segments are merged together, using the Hanning function, after applying the inverse shearlet transform. This adaptive process of ground roll attenuation was tested on synthetic data, and field shot records from west of Iran. Analysis of the results using the f-k spectra revealed that the non-aliased and most of the aliased ground roll were attenuated using the proposed adaptive attenuation procedure. Also, we applied this method on shot records of a 2D land survey, and the data sets before and after ground roll attenuation were stacked and compared. The stacked section after ground roll attenuation contained less linear ground roll noise and more continuous reflections in comparison with the stacked section before the ground roll attenuation. The proposed method has some drawbacks such as more run time in comparison with traditional methods such as f-k filtering and reduced performance when the dip and frequency content of aliased ground roll are the same as those of the reflections.

  6. Fabrication of Superhydrophobic Metallic Surface by Wire Electrical Discharge Machining for Seamless Roll-to-Roll Printing

    Directory of Open Access Journals (Sweden)

    Jin-Young So

    2018-04-01

    Full Text Available This paper presents a proposal of a direct one-step method to fabricate a multi-scale superhydrophobic metallic seamless roll mold. The mold was fabricated using the wire electrical discharge machining (WEDM technique for a roll-to-roll imprinting application to produce a large superhydrophobic surface. Taking advantage of the exfoliating characteristic of the metallic surface, nano-sized surface roughness was spontaneously formed while manufacturing the micro-sized structure: that is, a dual-scale hierarchical structure was easily produced in a simple one-step fabrication with a large area on the aluminum metal surface. This hierarchical structure showed superhydrophobicity without chemical coating. A roll-type seamless mold for the roll-to-roll process was fabricated through engraving the patterns on the cylindrical substrate, thereby enabling to make a continuous film with superhydrophobicity.

  7. ring system

    African Journals Online (AJOL)

    1,3,2-DIAZABORACYCLOALKANE. RING SYSTEM. Negussie Retta" and Robert H. Neilson. 'Department of Chemistry, Addis Ababa University, P.O. Box 1176, Addis Ababa, Ethiopia. Department of Chemistry, Texas Christian University.

  8. Lengthening the lifetime of roll-to-roll produced polymer solar cells

    DEFF Research Database (Denmark)

    Madsen, Morten Vesterager

    the knowledge of the degradation mechanisms involved in roll-to-roll coated polymer solar cells. While only a part of the experiments have directly involved roll-to-roll coated devices, most of the work is applicable to coated devices. The first part of the dissertation is devoted to the study of in......The field of polymer solar cells is a field with an exponential growth in the number of published papers. It is a field defined by a set of challenges including; efficiency, stability and processability. Before all of these challenges have been addressed; polymer solar cells...... will not be a commercial success. This dissertation is devoted primarily to the study of the stability of polymer solar cells, and more specifically to designing and verifying experimental techniques, procedures, and automated solutions to stability tests and characterization. The goal of the project was to expand...

  9. Planetary Rings

    Science.gov (United States)

    Nicholson, P. D.

    2001-11-01

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

  10. Finite-element model to predict roll-separation force and defects during rolling of U-10Mo alloys

    Energy Technology Data Exchange (ETDEWEB)

    Soulami, Ayoub; Burkes, Douglas E.; Joshi, Vineet V.; Lavender, Curt A.; Paxton, Dean

    2017-10-01

    This study used a finite element code, LSDYNA, as a predictive tool to optimize the rolling process. Simulations of the hot rolling of U-10Mo coupons encapsulated in low-carbon steel were 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. The study reported here discussed various attributes of the rolled coupons revealed by the model (e.g., waviness and thickness non-uniformity like dog boning). To investigate the influence of the cladding material on these rolling defects, other cases were simulated:  hot rolling with alternative can materials, namely, 304 stainless steel and Zircaloy-2, and bare-rolling.

  11. Virus-specific proteins in cells infected with tomato black ring nepovirus: evidence for proteolytic processing in vivo.

    Science.gov (United States)

    Demangeat, G; Hemmer, O; Reinbolt, J; Mayo, M A; Fritsch, C

    1992-07-01

    The synthesis of proteins encoded by the RNA of tomato black ring virus (TBRV) in vivo was studied in protoplasts by direct labelling with [35S]methionine, and in protoplasts and plants by immunoblotting experiments with specific antisera. Comparison of the proteins synthesized in infected and mock-inoculated protoplasts suggested that proteins of M(r) 120K, 90K, 80K, 57K and 46K were virus-specific. The proteins derived from the RNA-1-encoded polyprotein detected by immunoblotting were a stable 120K protein and, only in protoplasts, small amounts of a 90K protein which contains the C-terminal part of the 120K protein and the polymerase domain. The results suggest that the polymerase and the adjacent protease function in vivo largely or solely when combined in a 120K protein. The proteins derived from the RNA-2-encoded polyprotein detected by immunoblotting were 59K and 57K proteins, which reacted with antiserum to TBRV particles, and a 46K protein. In extracts of infected Nicotiana clevelandii and Chenopodium quinoa made soon after inoculation, the 59K protein was more abundant than the 57K protein; later samples contained similar quantities of each protein. The 57K protein comigrated with protein extracted from virus particles. The results of amino acid sequencing suggested that the 57K protein is derived from the 59K protein by the loss of nine C-terminal amino acids. Antiserum to a peptide adjacent to the 57K protein in the 150K polyprotein detected a 46K protein in protoplasts and plant tissue. The results support the processing scheme for TBRV polyproteins proposed after analysis of the products of in vitro translation.

  12. Rolling Force Prediction in Heavy Plate Rolling Based on Uniform Differential Neural Network

    Directory of Open Access Journals (Sweden)

    Fei Zhang

    2016-01-01

    Full Text Available Accurate prediction of the rolling force is critical to assuring the quality of the final product in steel manufacturing. Exit thickness of plate for each pass is calculated from roll gap, mill spring, and predicted roll force. Ideal pass scheduling is dependent on a precise prediction of the roll force in each pass. This paper will introduce a concept that allows obtaining the material model parameters directly from the rolling process on an industrial scale by the uniform differential neural network. On the basis of the characteristics that the uniform distribution can fully characterize the solution space and enhance the diversity of the population, uniformity research on differential evolution operator is made to get improved crossover with uniform distribution. When its original function is transferred with a transfer function, the uniform differential evolution algorithms can quickly solve complex optimization problems. Neural network structure and weights threshold are optimized by uniform differential evolution algorithm, and a uniform differential neural network is formed to improve rolling force prediction accuracy in process control system.

  13. Roll-to-Roll Nanoforming of Metals Using Laser-Induced Superplasticity.

    Science.gov (United States)

    Goswami, Debkalpa; Munera, Juan C; Pal, Aniket; Sadri, Behnam; Scarpetti, Caio Lui P G; Martinez, Ramses V

    2018-05-24

    This Letter describes a low-cost, scalable nanomanufacturing process that enables the continuous forming of thin metallic layers with nanoscale accuracy using roll-to-roll, laser-induced superplasticity (R2RLIS). R2RLIS uses a laser shock to induce the ultrahigh-strain-rate deformation of metallic films at room temperature into low-cost polymeric nanomolds, independently of the original grain size of the metal. This simple and inexpensive nanoforming method does not require access to cleanrooms and associated facilities, and can be easily implemented on conventional CO 2 lasers, enabling laser systems commonly used for rapid prototyping or industrial cutting and engraving to fabricate uniform and three-dimensional crystalline metallic nanostructures over large areas. Tuning the laser power during the R2RLIS process enables the control of the aspect ratio and the mechanical and optical properties of the fabricated nanostructures. This roll-to-roll technique successfully fabricates mechanically strengthened gold plasmonic nanostructures with aspect ratios as high as 5 that exhibit high oxidation resistance and strong optical field enhancements. The CO 2 laser used in R2RLIS can also integrate the fabricated nanostructures on transparent flexible substrates with robust interfacial contact. The ability to fabricate ultrasmooth metallic nanostructures using roll-to-roll manufacturing enables the large scale production, at a relatively low-cost, of flexible plasmonic devices toward emerging applications.

  14. New progress of FEM simulation and AI application in rolling at RAL

    International Nuclear Information System (INIS)

    Liu Xianghua; Wang Guodong; Zhao Kun

    2000-01-01

    New progresses on FEM simulation and AI application in rolling have been achieved at RAL recently. The existence and uniqueness of the extreme point of total functional for rolling problem has been proved. Different rolling processes, such as H-beam rolling, ribbing strip rolling, slab sizing, have been solved by our in-house FEM software package. The simulation results have been put into production use to improve the precision of math models. The Artificial Neural Network has been used to predict rolling force, coiling temperature, microstructure and properties of the rolled products. An expert system for deviation diagnoses of strip thickness has been developed for industry use. Synergetic Artificial Intelligence has also been applied to rolling scheduling. We are making continuous efforts to develop AI applications for rolling line co-operating in China steel industry. (author)

  15. Hot-rolling metals in vacuum. Information circular

    International Nuclear Information System (INIS)

    Beall, R.A.; Worthington, R.B.; Blickensderfer, R.

    1979-01-01

    The process of hot-rolling metals, alloys, and composites in vacuum is studied. First, a comprehensive review of the literature is presented, including the advantages and disadvantages of using vacuum. Next, details of hot-rolling titanium, chromium, and molybdenum-iron bimetal are given. Finally, the design of new equipment is described

  16. Finite element method analysis of surface roughness transfer in micro flexible rolling

    OpenAIRE

    Qu Feijun; Xie Haibo; Jiang Zhengyi

    2016-01-01

    Micro flexible rolling aims to fabricate submillimeter thick strips with varying thickness profile, where the surface quality of products is mainly determined by initial workpiece surface roughness and subsequent surface asperity flattening process, which is affected by process parameters during rolling. This paper shows a 3D finite element model for flexible rolling of a 250 μm thick workpiece with reduction of 20 to 50%, and rolling phase with thinner thickness indicates a better ability to...

  17. An advanced dissymmetric rolling model for online regulation

    Science.gov (United States)

    Cao, Trong-Son

    2017-10-01

    Roll-bite model is employed to predict the rolling force, torque as well as to estimate the forward slip for preset or online regulation at industrial rolling mills. The rolling process is often dissymmetric in terms of work-rolls rotation speeds and diameters as well as the friction conditions at upper and lower contact surfaces between work-rolls and the strip. The roll-bite model thus must be able to account for these dissymmetries and in the same time has to be accurate and fast enough for online applications. In the present study, a new method, namely Adapted Discretization Slab Method (ADSM) is proposed to obtain a robust roll-bite model, which can take into account the aforementioned dissymmetries and has a very short response time, lower than one millisecond. This model is based on the slab method, with an adaptive discretization and a global Newton-Raphson procedure to improve the convergence speed. The model was validated by comparing with other dissymmetric models proposed in the literature, as well as Finite Element simulations and industrial pilot trials. Furthermore, back-calculation tool was also constructed for friction management for both offline and online applications. With very short CPU time, the ADSM-based model is thus attractive for all online applications, both for cold and hot rolling.

  18. Enhancement in transport critical current density of ex situ PIT Ag/(Ba, K)Fe2As2 tapes achieved by applying a combined process of flat rolling and uniaxial pressing

    Science.gov (United States)

    Togano, Kazumasa; Gao, Zhaoshun; Matsumoto, Akiyoshi; Kumakura, Hiroaki

    2013-11-01

    We report that the transport critical current density Jc of ex situ powder-in-tube (PIT) processed (Ba, K)Fe2As2 (Ba-122) tapes can be significantly enhanced by applying uniaxial cold pressing at the final stage of deformation. The tapes were prepared by packing high quality precursor powder into a Ag tube, cycles of rolling and intermediate annealing, and pressing followed by the final heat treatment for sintering. The Jc values in applied magnetic fields were increased by almost one order of magnitude compared to the tapes processed without pressing, exceeding 104 A cm-2 at 4.2 K. We achieved the highest Jc (at 4.2 K and 10 T) of 2.1×104 A cm-2 among PIT-processed Fe-based wires and tapes reported so far. The Jc-H curves measured at higher temperatures maintain small field dependence up to around 20 K, suggesting that these tapes are promising for applications at higher temperatures as well as at liquid helium temperature. The microstructure investigations reveal that there are two possible causes of the large Jc enhancement by pressing: one is densification and the other is the change of crack structure. Optimization of processing parameters such as the reduction ratio of rolling and pressing is expected to yield further Jc enhancement.

  19. Rolling bearing analysis

    CERN Document Server

    Harris, Tedric A

    2001-01-01

    One of the most well-known experts in the field brings cutting-edge research to practitioners in the new edition of this important reference. Covers the improved mathematical calculations for rolling bearing endurance developed by the American Society of Mechanical Engineers and the Society of Lubrication and Tribology Engineers. Updated with new material on Condition-Based Maintenance, new testing methods, and new bearing materials.

  20. Roll of honour

    Energy Technology Data Exchange (ETDEWEB)

    Moxon, Suzanne

    1999-07-01

    This article gives details of the design and construction of dams selected by members of the dam construction industry for praise as feats of construction. The dams covered in the roll of honour include the dam at the Guri hydroelectric power station in Venezuela on the Caroni river, the Contra dam on the Verzrasca river in Switzerland, and the double curvature arc Ertan dam on the Yalong river in China. (UK)

  1. Shear Roll Mill Reactivation

    Science.gov (United States)

    2012-09-13

    pneumatically operated paste dumper and belt conveyor system, the loss in weight feeder system, the hydraulically operated shear roll mill, the pellet...out feed belt conveyor , and the pack out system comprised of the metal detector, scale, and pack out empty and full drum roller conveyors . Page | 4...feed hopper and conveyor supplying the loss in weight feeder were turned on, and it was verified that these items functioned as designed . The

  2. The Appropriate Welding Process of Repairing Crack of Converter Supporting Ring%转炉托圈裂纹修复的焊接工艺

    Institute of Scientific and Technical Information of China (English)

    马海超; 刘子龙

    2014-01-01

    The present paper introduces the process for repairing crack of converter supporting ring. Perfect result has been gained by analysing the weldability, selecting the suitable welding material, and making the appropriate welding process. It offers the practical experience for repairing crack of converter supporting ring.%本文介绍了转炉托圈裂纹的焊接修复过程。通过分析材料的焊接性,选择合适的焊接材料并且制定了合适的焊接工艺,取得了比较满意的结果,为托圈裂纹的焊接修复提供了实践经验。

  3. Experimental study of the stabilization process of a non-premixed flame via the destabilization analysis of the blue ring flame

    Energy Technology Data Exchange (ETDEWEB)

    Pinguet, Guillaume; Escudie, Dany [Centre de Thermique de Lyon (CETHIL) UMR 5008 CNRS-INSA-UCBL, INSA de Lyon, 20 av. A. Einstein, 69621 Villeurbanne cedex (France)

    2007-04-15

    The flame stabilization phenomenon remains a crucial issue. The experimental study of flame stabilization behind a tulip-shaped flame-holder is addressed in this paper. The process leading to the transition between specific modes - the blue ring flame and the instable ring - of a non-premixed flame stabilized on a tulip-shaped bluff-body is detailed. The aim of this study is to provide an accurate description of the destabilization of specific combustion modes, which enables a further understanding of the entire stabilization mechanism. The aerodynamic and mixing fields are described by laser Doppler anemometry and concentration measurements by sampling probe respectively. The behaviour of shear layers developing at the wake and jet boundaries are characterized by means of a spectral analysis of the fluctuating radial velocity. Results show that the destabilization process is related to the intensification of hot gas recirculation, inducing an upheaval of the dynamical condition of stabilization and a transition of mixing phenomena. (author)

  4. Atmospheric spatial atomic-layer-deposition of Zn(O, S) buffer layer for flexible Cu(In, Ga)Se2 solar cells: From lab-scale to large area roll to roll processing

    NARCIS (Netherlands)

    Frijters, C.H.; Bolt, P.J.; Poodt, P.W.G.; Knaapen, R.; Brink, J. van den; Ruth, M.; Bremaud, D.; Illiberi, A.

    2016-01-01

    In this manuscript we present the first successful application of a spatial atomic-layer-deposition process to thin film solar cells. Zn(O,S) has been grown by spatial atomic layer deposition (S-ALD) at atmospheric pressure and applied as buffer layer in rigid and flexible CIGS cells by a lab-scale

  5. The influence of additives on the morphology and stability of roll-to-roll processed polymer solar cells studied through ex situ and in situ X-ray scattering

    DEFF Research Database (Denmark)

    Zawacka, Natalia Klaudia; Andersen, Thomas Rieks; Andreasen, Jens Wenzel

    2014-01-01

    -Vis Spectroscopy and Small Angle X-ray Scattering (SAXS) for cells prepared with 1-chloronaphthalene (CN), N-methyl-2-pyrrolidone (NMP) and 1,3-dimethyl-barbituric acid (BARB) as processing additives. The studies suggested that the use of these additives resulted in films with improved morphology and electrical...

  6. The superiority of silver nanoellipsoids synthesized via a new approach in suppressing the coffee-ring effect during drying and film formation processes

    International Nuclear Information System (INIS)

    Tang, Yao; He, Wei; Wang, Shouxu; Tao, Zhihua; Cheng, Lijuan

    2014-01-01

    Silver nanoellipsoids (Ag NEs) with about 40 nm diameter minor axis and 100 nm major axis were prepared by a typical polyol process in the presence of poly(vinyl pyrrolidone), using Cl − as etching agent at the early stage of synthesis and poly(ethylene glycol) at the later stage to control the size. A suspension of these kinds of Ag NEs can resist the coffee-ring effect and deposit uniform films after drying. By contrast, suspensions of spherical silver nanoparticles suffer the coffee-ring effect badly, always leaving a ring on the edge of patterns after evaporation is complete. The reasons behind these phenomena can be mainly attributed to the long-ranged interparticle attraction between Ag NEs that preserves them from being transported by Marangoni flows during the drying process. These Ag NEs will be very useful in the preparation of conductive inks. They can perform well in the solidification process of printed patterns, forming uniform and smooth films, greatly enhancing the printing efficiency. (paper)

  7. Storage Rings

    International Nuclear Information System (INIS)

    Fischer, W.

    2010-01-01

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

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

    Science.gov (United States)

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

    2014-03-01

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

  9. Investigation of transient processes at the DELTA electron storage ring using a digital bunch-by-bunch feedback system

    Energy Technology Data Exchange (ETDEWEB)

    Hoener, Markus

    2015-07-01

    At the 1.5-GeV synchrotron radiation source DELTA, operated by the TU Dortmund University, intensive synchrotron radiation in the spectral range from hard X-rays to THz radiation is generated by the circular deflection of highly relativistic electron bunches. Interacting with the vacuum chamber wall, the electron bunches create electric fields, which can act back on subsequent bunches. With increasing beam current, the excitation is enhanced so that the electron beam is unstable, which means that the electron bunches oscillate longitudinally or transversely relative to their reference position. The oscillations reduce the quality of the synchrotron radiation and limit the maximum storable beam current. Within the scope of this thesis, the beam instabilities at the storage ring were systematically investigated. A digital bunch-by-bunch feedback system was installed and commissioned, which allows to detect and digitize the position of each electron bunch at each turn. Based on the input signal, a correction signal is calculated in order to suppress transverse and longitudinal oscillation of the bunches. In addition, it is possible to excite dedicated bunches. The systematic excitation of all coupled-bunch modes allowed for the first time to determine the damping rates of all 192 eigenmodes of the electron beam. The current dependence of the damping rates was investigated and an instability threshold was found. Besides the investigation of multibunch instabilities, single-bunch instabilities are discussed. In addition, the acquisition unit of the digital feedback system can be triggered on external events. This was used to investigate the injection process and beam losses. It was shown that the transverse feedback system increases the injection efficiency. Another aspect of this thesis is the improvement of the signal quality of ultrashort coherent synchrotron radiation pulses, which are generated by the short-pulse facility at DELTA. The short-pulse facility is based

  10. Topological rings

    CERN Document Server

    Warner, S

    1993-01-01

    This text brings the reader to the frontiers of current research in topological rings. The exercises illustrate many results and theorems while a comprehensive bibliography is also included. The book is aimed at those readers acquainted with some very basic point-set topology and algebra, as normally presented in semester courses at the beginning graduate level or even at the advanced undergraduate level. Familiarity with Hausdorff, metric, compact and locally compact spaces and basic properties of continuous functions, also with groups, rings, fields, vector spaces and modules, and with Zorn''s Lemma, is also expected.

  11. Ring accelerators

    International Nuclear Information System (INIS)

    Gisler, G.; Faehl, R.

    1983-01-01

    We present two-dimensional simulations in (r-z) and r-theta) cylinderical geometries of imploding-liner-driven accelerators of rings of charged particles. We address issues of azimuthal and longitudinal stability of the rings. We discuss self-trapping designs in which beam injection and extraction is aided by means of external cusp fields. Our simulations are done with the 2-1/2-D particle-in-cell plasma simulation code CLINER, which combines collisionless, electromagnetic PIC capabilities with a quasi-MHD finite element package

  12. Deformation mechanisms of pure Mg materials fabricated by using pre-rolled powders

    Energy Technology Data Exchange (ETDEWEB)

    Shen, J., E-mail: shen-j@jwri.osaka-u.ac.jp [Joining and Welding Research Institute, Osaka University (Japan); Imai, H. [Joining and Welding Research Institute, Osaka University (Japan); Chen, B. [Graduate School of Engineering, Osaka University (Japan); Ye, X.; Umeda, J.; Kondoh, K. [Joining and Welding Research Institute, Osaka University (Japan)

    2016-03-21

    In the present work, a powder rolling process was utilized in the fabrication of fine grained pure Mg via powder metallurgy. Mg flakes were obtained after each rolling process, and broken into pieces for further rolling or sintering. Mg samples of experiencing 0, 5 and 10 rolling passes were obtained following spark plasma sintering (SPS) and hot extrusion. Microstructural results from electron backscatter diffraction (EBSD) revealed that, without experiencing powder rolling, the specimen contained a great number of residual tensile twins; in contrast, after powder rolling the specimen showed uniform and equiaxed grain structures. In addition, the average grain size was measured to be around 9.2, 2.9 and 2.1 µm for the samples subjected to 0, 5 and 10 rolling passes. The powder rolled specimens were found superior in mechanical properties. Post-loading microstructure examinations were also performed for the samples and a discussion regarding the relationship between their mechanical behavior and microstructures was provided.

  13. Deformation mechanisms of pure Mg materials fabricated by using pre-rolled powders

    International Nuclear Information System (INIS)

    Shen, J.; Imai, H.; Chen, B.; Ye, X.; Umeda, J.; Kondoh, K.

    2016-01-01

    In the present work, a powder rolling process was utilized in the fabrication of fine grained pure Mg via powder metallurgy. Mg flakes were obtained after each rolling process, and broken into pieces for further rolling or sintering. Mg samples of experiencing 0, 5 and 10 rolling passes were obtained following spark plasma sintering (SPS) and hot extrusion. Microstructural results from electron backscatter diffraction (EBSD) revealed that, without experiencing powder rolling, the specimen contained a great number of residual tensile twins; in contrast, after powder rolling the specimen showed uniform and equiaxed grain structures. In addition, the average grain size was measured to be around 9.2, 2.9 and 2.1 µm for the samples subjected to 0, 5 and 10 rolling passes. The powder rolled specimens were found superior in mechanical properties. Post-loading microstructure examinations were also performed for the samples and a discussion regarding the relationship between their mechanical behavior and microstructures was provided.

  14. Influence of different kinds of rolling on the crystallographic texture and magnetic induction of a NOG 3 wt% Si steel

    Science.gov (United States)

    Silva, J. M.; Baêta Júnior, E. S.; Moraes, N. R. D. C.; Botelho, R. A.; Felix, R. A. C.; Brandao, L.

    2017-01-01

    The purpose of this work was to study the influence of different kinds of rolling on the magnetic properties of NOG steel, an electric steel widely used in electrical motors. These properties are highly correlated with the crystallographic texture of the material, which can be changed by rolling. Three kinds of rolling were examined: conventional rolling, cross-rolling and asymmetrical rolling. The crystallographic texture was determined by X-ray diffraction and the magnetic properties were calculated from a theoretical model that related the magnetic induction to crystallographic texture through the anisotropy energy. The results show that cross-rolling yields higher values of magnetic induction than the other processes.

  15. RESEARCH OF INFLUENCE OF FRONT TENSION AT ROLLING OF PERIODIC PROFILE IN NON-DRIVE ROLLERS

    Directory of Open Access Journals (Sweden)

    L. A. Isayevich

    2012-01-01

    Full Text Available Influence of a forward tension is theoretically investigated at a rolling of the periodic profiles used as elastic elements of spring suspension brackets. The power balance of rolling process with a tension is analyzed. Dependences for definition of a critical corner and size of its increment are received at a rolling with a forward tension.

  16. Simulating the DISAMATIC process using the discrete element method — a dynamical study of granular flow

    DEFF Research Database (Denmark)

    Hovad, Emil; Spangenberg, Jon; Larsen, P.

    2016-01-01

    . The DEM parameters describing the static friction coefficients are obtained using a ring shear tester and the rolling resistance and cohesion value is subsequently calibrated with a sand pile experiment. The calibrated DEM model is used to model the sand shot in the DISAMATIC process for three different...

  17. Development of high-speed reactive processing system for carbon fiber-reinforced polyamide-6 composite: In-situ anionic ring-opening polymerization

    International Nuclear Information System (INIS)

    Kim, Sang-Woo; Seong, Dong Gi; Yi, Jin-Woo; Um, Moon-Kwang

    2016-01-01

    In order to manufacture carbon fiber-reinforced polyamide-6 (PA-6) composite, we optimized the reactive processing system. The in-situ anionic ring-opening polymerization of ε-caprolactam was utilized with proper catalyst and initiator for PA-6 matrix. The mechanical properties such as tensile strength, inter-laminar shear strength and compressive strength of the produced carbon fiber-reinforced PA-6 composite were measured, which were compared with the corresponding scanning electron microscope (SEM) images to investigate the polymer properties as well as the interfacial interaction between fiber and polymer matrix. Furthermore, kinetics of in-situ anionic ring-opening polymerization of ε-caprolactam will be discussed in the viewpoint of increasing manufacturing speed and interfacial bonding between PA-6 matrix and carbon fiber during polymerization.

  18. Development of high-speed reactive processing system for carbon fiber-reinforced polyamide-6 composite: In-situ anionic ring-opening polymerization

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sang-Woo; Seong, Dong Gi; Yi, Jin-Woo; Um, Moon-Kwang [Composites Research Division, Korea Institute of Materials Science (KIMS), Changwon, Gyeongnam, 642–831 (Korea, Republic of)

    2016-05-18

    In order to manufacture carbon fiber-reinforced polyamide-6 (PA-6) composite, we optimized the reactive processing system. The in-situ anionic ring-opening polymerization of ε-caprolactam was utilized with proper catalyst and initiator for PA-6 matrix. The mechanical properties such as tensile strength, inter-laminar shear strength and compressive strength of the produced carbon fiber-reinforced PA-6 composite were measured, which were compared with the corresponding scanning electron microscope (SEM) images to investigate the polymer properties as well as the interfacial interaction between fiber and polymer matrix. Furthermore, kinetics of in-situ anionic ring-opening polymerization of ε-caprolactam will be discussed in the viewpoint of increasing manufacturing speed and interfacial bonding between PA-6 matrix and carbon fiber during polymerization.

  19. Ring interferometry

    CERN Document Server

    Malykin, Grigorii B; Zhurov, Alexei

    2013-01-01

    This monograph is devoted to the creation of a comprehensive formalism for quantitative description of polarized modes' linear interaction in modern single-mode optic fibers. The theory of random connections between polarized modes, developed in the monograph, allows calculations of the zero shift deviations for a fiber ring interferometer. The monograph addresses also the

  20. Superhydrophobic Properties of Nanotextured Polypropylene Foils Fabricated by Roll-to-Roll Extrusion Coating

    DEFF Research Database (Denmark)

    Telecka, Agnieszka; Murthy, Swathi; Sun, Ling

    2016-01-01

    etching with different processing gas flow rates. We provide a systematic study of the wetting properties for the fabricated surfaces and show that a controlled texture stretching effect in the R2R-EC process is instrumental to yield the superhydrophobic surfaces with water contact angles approaching 160......° and droplet roll-off angles below 10°....

  1. 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...... as the nanoparticles are already sintered. The advantage of single exposure is the ability to produce higher R2R processing speeds without overlapping, which is shown in the form of theoretical calculations....

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

    International Nuclear Information System (INIS)

    Abdollahi, H.; Dehghani, K.

    2007-01-01

    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

  3. Evolution of fuel plate parameters during deformation in rolling

    Energy Technology Data Exchange (ETDEWEB)

    Durazzo, M., E-mail: mdurazzo@ipen.br [Nuclear and Energy Research Institute – IPEN/CNEN-SP, São Paulo (Brazil); Vieira, E.; Urano de Carvalho, E.F. [Nuclear and Energy Research Institute – IPEN/CNEN-SP, São Paulo (Brazil); Riella, H.G. [Nuclear and Energy Research Institute – IPEN/CNEN-SP, São Paulo (Brazil); Chemical Engineering Department, Santa Catarina Federal University, Florianópolis (Brazil)

    2017-07-15

    The Nuclear and Energy Research Institute – IPEN/CNEN-SP routinely produces the nuclear fuel necessary for operating its research reactor, IEA-R1. This fuel consists of fuel plates containing U{sub 3}Si{sub 2}-Al composites as the meat, which are fabricated by rolling. The rolling process currently deployed was developed based on information obtained from literature, which was used as a premise for defining the current manufacturing procedures, according to a methodology with an essentially empirical character. Despite the current rolling process being perfectly stable and highly reproducible, it is not well characterized and is therefore not fully known. The objective of this work is to characterize the rolling process for producing dispersion fuel plates. Results regarding the evolution of the main parameters of technological interest, after each rolling pass, are presented. Some defects that originated along the fuel plate deformation during the rolling process were characterized and discussed. The fabrication procedures for manufacturing the fuel plates are also presented. - Highlights: •Evolution of defects when manufacturing dispersion fuel plates. •Aspects of dispersion fuel plates fabrication. •What happen during the manufacturing of dispersion fuel plates? •Clarifying the deformation of fuel plates by rolling.

  4. 3-dimensional numerical modelling of rolling of superconducting Ag/BSCCO tape

    DEFF Research Database (Denmark)

    Eriksen, Morten; Bech, Jakob Ilsted; Seifi, Behrouz

    2000-01-01

    and Ø126 mm) have been investigated. It is found that it is possible to perform numerical simulation with 3D models of flat rolling of multifilament wire. Two 3D models have been used; 3D pressing with rolls and 3D rolling. 3D pressing with rolls have the advance that the simulation time is lower than...... in the 3D rolling. The 3D models have the advantage compared to 2D pressing that they can predict the 3 dimensional flow in the flat rolling, which has been showed to be very imported for the super conduction properties......Numerical simulation of the deformation process during flat rolling of multifilament HTS tapes has been investigated using a commercial FEM program, ELFEN. The numerical models were built up in 2D and 3D using a Drucker-Prager/Cap model for the powder. Three different roll diameters (Ø24 mm, Ø85 mm...

  5. Voltage and Thermally Driven Roll-to-Roll Organic Printed Transistor Made in Ambient Air Conditions

    DEFF Research Database (Denmark)

    Pastorelli, Francesco

    of the organic semiconductor poly3hexylthiophene and the dielectric material polyvinylphenol before the gate was applied by screen printing. All the processing was realized in ambient air on a PET flexible substrate. We explore the footprint and the practically accessible geometry of such devices with a special......Resume: Organic thin film transistors offer great potential for use in flexible electronics. Much of this potential lies in the solution processability of the organic polymers enabling both roll coating and printing on flexible substrates and thus greatly reducing the material and fabrication costs....... We present flexible organic power transistors prepared by fast (20 m min−1) roll-to-roll flexographic printing of the drain and source electrode structures, with an interspace below 50 um, directly on polyester foil[1]. The devices have top gate architecture and were completed by slotdie coating...

  6. Roll back malaria update.

    Science.gov (United States)

    1999-10-01

    This article presents the activities under WHO's Roll Back Malaria (RBM) program in Asia, particularly in Nepal, Indonesia, India, Bangladesh, Sri Lanka and the Philippines. In India, the RBM program will start in 5 districts with a major malaria problem. A national committee has been formed by researchers, which will be able to provide operational and strategic support and research expertise in relation to malaria. In Bangladesh, the RBM program was initiated in the sparsely populated hill tract areas of Banderban and Chittagong where access to health care is very poor. At the district level, effective partnerships with private practitioners, politicians, community leaders, school teachers, the press and district Ministry of Health officials are operating to plan for rolling back malaria. In Myanmar, Cambodia, Lao People's Democratic Republic, Yunnan province of China, Vietnam, and Thailand, the focus of the RBM program was to move health care closer to the malaria-infected communities. WHO¿s Global Health Leadership Fellowship Programme, supported by the UN Foundation and Rockefeller Foundation, enables potential leaders to experience the work of UN agencies and contribute to the work of the organization for 2 years. Three out of four persons appointed to the RBM program received prestigious awards: Dr. Paola Marchesini of Brazil; Dr. Tieman Diarra of Mali; and Dr. Bob Taylor of the UK.

  7. Roll-to-roll UV imprint lithography for flexible electronics

    NARCIS (Netherlands)

    Maury, P.; Turkenburg, D.H.; Stroeks, N.; Giesen, P.; Barbu, I.; Meinders, E.R.; Bremen, A. van; Iosad, N.; Werf, R. van der; Onvlee, H.

    2011-01-01

    We propose a roll-to-roll UV imprint lithography tool as a way to pattern flexible PET foil with µm-resolution. As a way to overcome dimensional instability of the foil and its effect on overlay, a self-align approach was investigated, that permits to make several layers in a single lithography

  8. A computer system to aid in the planning of steel rolls cuts

    Directory of Open Access Journals (Sweden)

    Nelson Maculan

    2007-03-01

    Full Text Available The planning of cuts in steel rolls is a combinatory optimization problem. Some companies of the metallurgical industry use the steel cold lamination process so that it acquires the necessary physical properties. In this case, the cutting patterns should consist of compartments of items compatible with the lamination process, hindering the task of cuts planning. A compartment represents an intermediate roll to be laminated, so that it is possible to combine intermediate rolls with different lamination needs in the same roll of the stock. In this work the prototype of the RollCut System will be presented to aid with the cuts planning.

  9. Virus-specific proteins in cells infected with tomato black ring nepovirus: evidence for proteolytic processing in vivo.

    OpenAIRE

    Demangeat, Gerard; Hemmer, O; Reinbolt, J; Mayo, M A; Fritsch, Coralie

    1992-01-01

    The synthesis of proteins encoded by the RNA of tomato black ring virus (TBRV) in vivo was studied in protoplasts by direct labelling with [35S]methionine, and in protoplasts and plants by immunoblotting experiments with specific antisera. Comparison of the proteins synthesized in infected and mock-inoculated protoplasts suggested that proteins of M(r) 120K, 90K, 80K, 57K and 46K were virus-specific. The proteins derived from the RNA-1-encoded polyprotein detected by immunoblotting were a sta...

  10. The Saturnian rings

    International Nuclear Information System (INIS)

    Alfven, H.

    1975-09-01

    The structure of the Saturnian rings is traditionally believed to be due to resonances caused by Mimas (and possibly other satellites). It is shown that both theoretical and observational evidence rule out this interpretation. The increased observational accuracy on one hand and the increased understanding of the cosmogonic processes on the other makes it possible to explain the structure of the ring system as a product of condensation from a partially corotating plasma. In certain respects the agreement between theory and observations is about 1%. (Auth.)

  11. RINGED ACCRETION DISKS: INSTABILITIES

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-04-01

    We analyze the possibility that several instability points may be formed, due to the Paczyński mechanism of violation of mechanical equilibrium, in the orbiting matter around a supermassive Kerr black hole. We consider a recently proposed model of a ringed accretion disk, made up by several tori (rings) that can be corotating or counter-rotating relative to the Kerr attractor due to the history of the accretion process. Each torus is governed by the general relativistic hydrodynamic Boyer condition of equilibrium configurations of rotating perfect fluids. We prove that the number of the instability points is generally limited and depends on the dimensionless spin of the rotating attractor.

  12. Anisotropic constant-roll inflation

    Energy Technology Data Exchange (ETDEWEB)

    Ito, Asuka; Soda, Jiro [Kobe University, Department of Physics, Kobe (Japan)

    2018-01-15

    We study constant-roll inflation in the presence of a gauge field coupled to an inflaton. By imposing the constant anisotropy condition, we find new exact anisotropic constant-roll inflationary solutions which include anisotropic power-law inflation as a special case. We also numerically show that the new anisotropic solutions are attractors in the phase space. (orig.)

  13. Rolling up a Graphene Sheet

    NARCIS (Netherlands)

    Calvaresi, Matteo; Quintana, Mildred; Rudolf, Petra; Zerbetto, Francesco; Prato, Maurizio

    2013-01-01

    Carbon Nanotubes, CNTs, have been described as rolled-up graphene layers. Matching this concept to experiments has been a great experimental challenge for it requires a method to exfoliate graphite, generate ordered and stable dangling carbon bonds, and roll up the layer without affecting the

  14. Compressible Vortex Ring

    Science.gov (United States)

    Elavarasan, Ramasamy; Arakeri, Jayawant; Krothapalli, Anjaneyulu

    1999-11-01

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

  15. Computational design of rolling bearings

    CERN Document Server

    Nguyen-Schäfer, Hung

    2016-01-01

    This book comprehensively presents the computational design of rolling bearings dealing with many interdisciplinary difficult working fields. They encompass elastohydrodynamics (EHD), Hertzian contact theory, oil-film thickness in elastohydrodynamic lubrication (EHL), bearing dynamics, tribology of surface textures, fatigue failure mechanisms, fatigue lifetimes of rolling bearings and lubricating greases, Weibull distribution, rotor balancing, and airborne noises (NVH) in the rolling bearings. Furthermore, the readers are provided with hands-on essential formulas based on the up-to-date DIN ISO norms and helpful examples for computational design of rolling bearings. The topics are intended for undergraduate and graduate students in mechanical and material engineering, research scientists, and practicing engineers who want to understand the interactions between these working fields and to know how to design the rolling bearings for automotive industry and many other industries.

  16. The Rings of Saturn

    Science.gov (United States)

    Cuzzi, J. N.; Filacchione, G.; Marouf, E. A.

    2018-03-01

    One could become an expert on Saturn's iconic rings pretty easily in the early 1970s, as very little was known about them beyond the distinction between the A, B, and C rings, and the Cassini Division or "gap" between rings A and B (Alexander, 1962; Bobrov, 1970). Water ice was discovered spectroscopically on the ring particle surfaces, and radar and microwave emission observations proved that the particles must be centimeters to meters in size, consisting primarily, not just superficially, of water ice (Pollack, 1975). While a 2:1 orbital resonance with Mimas had long been suspected of having something to do with the Cassini Division, computers of the time were unable to model the subtle dynamical effects that we now know to dominate ring structure. This innocent state of affairs was exploded by the Voyager 1 and 2 encounters in 1980 and 1981. Spectacular images revealed filigree structure and odd regional color variations, and exquisitely detailed radial profiles of fluctuating particle abundance were obtained from the first stellar and radio occultations, having resolution almost at the scale of single particles. Voyager-era understanding was reviewed by Cuzzi et al. (1984) and Esposito et al. (1984). While the Voyager data kept ring scientists busy for decades, planning which led to the monumentally successful NASA-ESA-ASI Cassini mission, which arrived in 2004, had been under way even before Voyager got to Saturn. A review of pre-Cassini knowledge of Saturn's Rings can be found in Orton et al. (2009). This chapter will build on recent topical and process-specific reviews that treat the gamut of ring phenomena and its underlying physics in considerable detail (Colwell et al., 2009; Cuzzi et al., 2009; Horányi et al., 2009; Schmidt et al., 2009; Esposito, 2010; Tiscareno, 2013b; Esposito, 2014). We will follow and extend the general organization of Cuzzi et al. (2010), the most recent general discussion of Saturn's rings. For brevity and the benefit of the

  17. DESIGN OF PARTICULATE MATERIAL COMPACTOR ROLLS DIAMETER

    Directory of Open Access Journals (Sweden)

    Peter Peciar

    2017-09-01

    Full Text Available At present, in a period of an industrial expansion great emphasis is placed on the environment. That means aiming for a reduced energy consumption, and also lessening dustiness from very fine powder material. This category also includes particulate material agglomeration processes. Because this process is very energy-intensive, it is necessary to correctly design these devices. The aim of this paper is to focus on a theoretical design of a production compactor with the rolls diameter for an experimental particulate material, based on Johanson’s theory and experimentally measured material properties. The material used for experimental measurements was an NPK-based industrial fertilizer consisting of several components. The results of this paper is the dependence of the ratio of the maximum compression pressure to the initial compression pressure from the rolls diameter of the proposed compactor.

  18. Multi-field coupling finite element analysis for determining the influence of temperature field on die service life during precision-forming process of steel synchronizer ring

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Jun; Luo, Shan-Ming; Li, Feng-Qiang; Xu, Chen-Bing [Xiamen University of Technology, Xiamen (China)

    2017-07-15

    Failure analysis shows that increased die temperature caused by severe plastic deformation of material and heat conduction between hot billet and cavity significantly affects the distortion of gear cavity in steel synchronizer ring forging process. The forging process of steel synchronizer ring and die temperature distribution under different forging conditions are analyzed through finite element method. Simulation results show that severe plastic deformation occurs in the gear cavity. The improvement of lubrication condition results in decreased die temperature. When the initial billet temperature is high, the die temperature is also high. Increasing forging speed in a certain range facilitates the die temperature decrease. The distribution of die temperature in synthetic forming technology is more reasonable than that of one step forging. The synthetic forming technology is adopted in production to reduce the effects of severe plastic deformation caused by die temperature. The ejection mechanism and control system of the double disc friction press are improved to reduce the contact time between the hot billet and cavity. Experimental results show that synthetic forming technology is reasonable, and that the die service life is prolonged.

  19. Multi-field coupling finite element analysis for determining the influence of temperature field on die service life during precision-forming process of steel synchronizer ring

    International Nuclear Information System (INIS)

    Zhao, Jun; Luo, Shan-Ming; Li, Feng-Qiang; Xu, Chen-Bing

    2017-01-01

    Failure analysis shows that increased die temperature caused by severe plastic deformation of material and heat conduction between hot billet and cavity significantly affects the distortion of gear cavity in steel synchronizer ring forging process. The forging process of steel synchronizer ring and die temperature distribution under different forging conditions are analyzed through finite element method. Simulation results show that severe plastic deformation occurs in the gear cavity. The improvement of lubrication condition results in decreased die temperature. When the initial billet temperature is high, the die temperature is also high. Increasing forging speed in a certain range facilitates the die temperature decrease. The distribution of die temperature in synthetic forming technology is more reasonable than that of one step forging. The synthetic forming technology is adopted in production to reduce the effects of severe plastic deformation caused by die temperature. The ejection mechanism and control system of the double disc friction press are improved to reduce the contact time between the hot billet and cavity. Experimental results show that synthetic forming technology is reasonable, and that the die service life is prolonged.

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

    International Nuclear Information System (INIS)

    Kurokawa, Hiroyuki; Nakasuji, Kazuyuki; Kajimura, Haruhiko; Nagai, Takayuki; Takeda, Seiichiro.

    1997-01-01

    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)

  1. Transient thermal stresses of work roll by coupled thermoelasticity

    Science.gov (United States)

    Lai, W. B.; Chen, T. C.; Weng, C. I.

    1991-01-01

    A numerical method, based on a two-dimensional plane strain model, is developed to predict the transient responses (that include distributions of temperature, thermal deformation, and thermal stress) of work roll during strip rolling by coupled thermoelasticity. The method consists of discretizing the space domain of the problem by finite element method first, and then treating the time domain by implicit time integration techniques. In order to avoid the difficulty in analysis due to relative movement between work roll and its thermal boundary, the energy equation is formulated with respect to a fixed Eulerian reference frame. The effect of thermoelastic coupling term, that is generally disregarded in strip rolling, can be considered and assessed. The influences of some important process parameters, such as rotational speed of the roll and intensity of heat flux, on transient solutions are also included and discussed. Furthermore, since the stress history at any point of the roll in both transient and steady state could be accurately evaluated, it is available to perform the analysis of thermal fatigue for the roll by means of previous data.

  2. Roll bonding of strained aluminium

    DEFF Research Database (Denmark)

    Staun, Jakob M.

    2003-01-01

    This report investigates roll bonding of pre-strained (å ~ 4) aluminium sheets to produce high strain material from high purity aluminium (99.996%) and commercial pure aluminium (99.6%). The degree of bonding is investigated by optical microscopy and ultrasonic scanning. Under the right...... of the 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...

  3. What impact do Global Health Initiatives have on human resources for antiretroviral treatment roll-out? A qualitative policy analysis of implementation processes in Zambia

    Directory of Open Access Journals (Sweden)

    Hanefeld Johanna

    2009-02-01

    Full Text Available Abstract Background Since the beginning of the 21st century, development assistance for HIV/AIDS has increasingly been provided through Global Health Initiatives, specifically the United States Presidential Emergency Plan for AIDS Relief, the Global Fund to Fight HIV, TB and Malaria and the World Bank Multi-country AIDS Programme. Zambia, like many of the countries heavily affected by HIV/AIDS in southern Africa, also faces a shortage of human resources for health. The country receives significant amounts of funding from GHIs for the large-scale provision of antiretroviral treatment through the public and private sector. This paper examines the impact of GHIs on human resources for ART roll-out in Zambia, at national level, in one province and two districts. Methods It is a qualitative policy analysis relying on in-depth interviews with more than 90 policy-makers and implementers at all levels. Results Findings show that while GHIs do not provide significant funding for additional human resources, their interventions have significant impact on human resources for health at all levels. While GHIs successfully retrain a large number of health workers, evidence suggests that GHIs actively deplete the pool of skilled human resources for health by recruiting public sector staff to work for GHI-funded nongovernmental implementing agencies. The secondment of GHI staff into public sector facilities may help alleviate immediate staff shortages, but this practice risks undermining sustainability of programmes. GHI-supported programmes and initiatives add significantly to the workload of existing public sector staff at all levels, while incentives including salary top-ups and overtime payments mean that ART programmes are more popular among staff than services for non-focal diseases. Conclusion Research findings suggest that GHIs need to actively mediate against the potentially negative consequences of their funding on human resources for health. Evidence

  4. Inkjet printing as a roll-to-roll compatible technology for the production of large area electronic devices on a pre-industrial scale

    NARCIS (Netherlands)

    Teunissen, P.; Rubingh, E.; Lammeren, T. van; Abbel, R.J.; Groen, P.

    2014-01-01

    Inkjet printing is a promising approach towards the solution processing of electronic devices on an industrial scale. Of particular interest is the production of high-end applications such as large area OLEDs on flexible substrates. Roll-to-roll (R2R) processing technologies involving inkjet

  5. USE OF HIGH SPEED STEEL WORK ROLLS (HSS ON APERAM STECKEL MILL

    Directory of Open Access Journals (Sweden)

    Arísio de Abreu Barbosa

    2013-12-01

    Full Text Available This paper outlines the main actions taken to reinforce the decision to use HSS work rolls on the Aperam Steckel Mill. These are: work roll cooling improvements, systematically analyzing Eddy Current and Ultrasonic non destructive tests, mechanical adjustment of work roll crown and critically examining the rolling process. These actions applied together have contributed to the success of HSS rolls state of the art application, and provide the Steckel Mill with a much improved performance. Significant results have been achieved, such as: increasing of work roll change intervals, increasing of the available production time, a yield gain, a product quality improvement, less working hours needed for the roll grinding operation, etc

  6. A NOVEL ROLLING BASED DNA CRYPTOGRAPHY

    Directory of Open Access Journals (Sweden)

    Rejwana Haque

    2017-05-01

    Full Text Available DNA Cryptography can be defined as a hiding data in terms of DNA Sequence. In this paper we propose a new DNA Encryption Technique where three different types of ordering is use to make binary data into cipher text. The main stages of this encryption technique are: Key Analysis, Data and Key Arrangement, Roll in encoding, Secondary Arrangement and Shifting. Decryption process has six main steps to obtain the original binary data from the encrypted data and key. Decryption steps are: Key Analysis, Shifting, Secondary Arrangement, Key Arrangement, Roll-out decoding, Data Arrangement. Here key size is half of binary data and the key is varies from data to data so key are used as one time pad. In this paper we also discuss about the implementation from sample data and security analysis for this given method.

  7. 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

  8. Rolling Resistance Measurement and Model Development

    DEFF Research Database (Denmark)

    Andersen, Lasse Grinderslev; Larsen, Jesper; Fraser, Elsje Sophia

    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, s......, surface and texture modeling, contact models, tire models, and macro-modeling of rolling resistance...

  9. Multi-level Quantum Mechanics and Molecular Mechanics Study of Ring Opening Process of Guanine Damage by Hydroxyl Radical in Aqueous Solution.

    Science.gov (United States)

    Liu, Peng; Wang, Qiong; Niu, Meixing; Wang, Dunyou

    2017-08-10

    Combining multi-level quantum mechanics theories and molecular mechanics with an explicit water model, we investigated the ring opening process of guanine damage by hydroxyl radical in aqueous solution. The detailed, atomic-level ring-opening mechanism along the reaction pathway was revealed in aqueous solution at the CCSD(T)/MM levels of theory. The potentials of mean force in aqueous solution were calculated at both the DFT/MM and CCSD(T)/MM levels of the theory. Our study found that the aqueous solution has a significant effect on this reaction in solution. In particular, by comparing the geometries of the stationary points between in gas phase and in aqueous solution, we found that the aqueous solution has a tremendous impact on the torsion angles much more than on the bond lengths and bending angles. Our calculated free-energy barrier height 31.6 kcal/mol at the CCSD(T)/MM level of theory agrees well with the one obtained based on gas-phase reaction profile and free energies of solvation. In addition, the reaction path in gas phase was also mapped using multi-level quantum mechanics theories, which shows a reaction barrier at 19.2 kcal/mol at the CCSD(T) level of theory, agreeing very well with a recent ab initio calculation result at 20.8 kcal/mol.

  10. A struggle for knowledge. An analysis of the process related to changes in water regulation for Suldalsl#Latin Small Letter A With Ring Above#gen

    Energy Technology Data Exchange (ETDEWEB)

    Egeland, Helene [Sintef Energy, Trondheim (Norway)

    2012-07-01

    This report is part of the project GOVREP (Governance for Renewable Electricity Production) whose purpose is to produce research that can create a better understanding of how to reconcile energy and environmental policy considerations in renewable electricity production. To illustrate the challenges of the national framework (Knudsen and Ruud 2011), it is important to look at how such considerations into practice are integrated through looking at specific hydropower issues. In this report, we look at the process related to the change of the rules of operation for Suldalsl#Latin Small Letter A With Ring Above#gen focusing on knowledge documents' role. The knowledge base is crucial to how energy and environmental considerations integrated into hydropower management. The analysis shows that there are significant governance challenges m#Latin Small Letter A With Ring Above#lavklaring and organization of knowledge production. Moreover, the lack of trust between the actors concerned determines whether the knowledge base is perceived as adequate and sturdy enough to serve as a legitimate basis for decision making.(author)

  11. Relation Between Residual and Hoop Stresses and Rolling Bearing Fatigue Life

    Science.gov (United States)

    Oswald, Fred B.; Zaretsky, Erwin V.; Poplawski, Joseph V.

    2015-01-01

    Rolling-element bearings operated at high speed or high vibration may require a tight interference fit between the bore of the bearing and shaft to prevent rotation of the bearing bore around the shaft and fretting damage at the interfaces. Previous work showed that the hoop stresses resulting from tight interference fits can reduce bearing lives by as much as 65 percent. Where tight interference fits are required, case-carburized steel such as AISI 9310 or M50 NiL is often used because the compressive residual stresses inhibit subsurface crack formation and the ductile core inhibits inner-ring fracture. The presence of compressive residual stress and its combination with hoop stress also modifies the Hertz stress-life relation. This paper analyzes the beneficial effect of residual stresses on rolling-element bearing fatigue life in the presence of high hoop stresses for three bearing steels. These additional stresses were superimposed on Hertzian principal stresses to calculate the inner-race maximum shearing stress and the resulting fatigue life of the bearing. The load-life exponent p and Hertz stress-life exponent n increase in the presence of compressive residual stress, which yields increased life, particularly at lower stress levels. The Zaretsky life equation is described and is shown to predict longer bearing lives and greater load- and stress-life exponents, which better predicts observed life of bearings made from vacuum-processed steel.

  12. Influence of different kinds of rolling on the crystallographic texture and magnetic induction of a NOG 3 wt% Si steel

    Energy Technology Data Exchange (ETDEWEB)

    Silva, J.M.; Baêta Júnior, E.S.; Moraes, N.R.D.C.; Botelho, R.A. [Department of Mechanical and Materials Engineering, Military Institute of Engineering (IME), Praça General Tibúrcio, 80,Urca, Rio de Janeiro/RJ (Brazil); Felix, R.A.C. [Scientific Instrumentation and Mechanical Technology Laboratory, Brazilian Center for Physics Research (CBPF), Rua Dr. Xavier Sigaud, 150-Urca, Rio de Janeiro-RJ (Brazil); Brandao, L., E-mail: brandao@ime.eb.br [Department of Mechanical and Materials Engineering, Military Institute of Engineering (IME), Praça General Tibúrcio, 80,Urca, Rio de Janeiro/RJ (Brazil)

    2017-01-01

    The purpose of this work was to study the influence of different kinds of rolling on the magnetic properties of NOG steel, an electric steel widely used in electrical motors. These properties are highly correlated with the crystallographic texture of the material, which can be changed by rolling. Three kinds of rolling were examined: conventional rolling, cross-rolling and asymmetrical rolling. The crystallographic texture was determined by X-ray diffraction and the magnetic properties were calculated from a theoretical model that related the magnetic induction to crystallographic texture through the anisotropy energy. The results show that cross-rolling yields higher values of magnetic induction than the other processes. - Highlights: • The B{sub 50} of NOG steels was evaluated via texture for different rolling processes. • On comparison to all processes used, the cross-rolling led to highest average B{sub 50}. • Cross-rolling enhances Goss and γ-fiber after annealing. • The better B{sub 50} values were obtained for symmetrical and cross-rolling processes. • For asymmetric rolling process, cylinder diameter ratio changed slightly the texture.

  13. Planetary ring systems properties, structures, and evolution

    CERN Document Server

    Murray, Carl D

    2018-01-01

    Planetary rings are among the most intriguing structures of our solar system and have fascinated generations of astronomers. Collating emerging knowledge in the field, this volume reviews our current understanding of ring systems with reference to the rings of Saturn, Uranus, Neptune, and more. Written by leading experts, the history of ring research and the basics of ring–particle orbits is followed by a review of the known planetary ring systems. All aspects of ring system science are described in detail, including specific dynamical processes, types of structures, thermal properties and their origins, and investigations using computer simulations and laboratory experiments. The concluding chapters discuss the prospects of future missions to planetary rings, the ways in which ring science informs and is informed by the study of other astrophysical disks, and a perspective on the field's future. Researchers of all levels will benefit from this thorough and engaging presentation.

  14. Multispectral processing of ERTS-A (LANDSAT) data for uranium exploration in the Wind River Basin, Wyoming: a visible region ratio to enhance surface alteration associated with roll-type uraium deposits. Final report, June 1974--July 1975

    International Nuclear Information System (INIS)

    Salmon, B.C.; Pillars, W.W.

    1975-07-01

    The purpose of this report is to document possible detection capabilities of the LANDSAT multispectral scanner data for use in exploration for uranium roll-type deposits. Spectral reflectivity, mineralogy, iron content, and color paramenters were measured for twenty natural surface samples collected from a semiarid region. The relationships of these properties to LANDSAT response-weighted reflectances and to reflectance ratios are discussed. It was found that the single ratio technique of multispectral processing is likely to be sensitive enough to separate hematitic stain, but not limonitic. A combination of the LANDSAT R/sub 5,4/ and R/sub 7,6/ ratios, and a processing technique sensitive to vegetative cover is recommended for detecting areas of limonitic stain. Digital level slicing of LANDSAT R/sub 5,4/ over the Wind River Basin, after geometric correction, resulted in adequate enhancement of Triassic redbeds and lighter red materials, but not for limonitic areas. No recommendations for prospects in the area were made. Information pertaining to techniques of evaluating laboratory reflectance spectra for remote sensing applications, ratio processing, and planimetric correction of LANDSAT data is presented qualitatively

  15. 浅谈超白压延光伏玻璃常见的成形缺陷%Causes and Solutions of Common Defects in Low- iron Photovoltaic Glass Produced by Rolled Process

    Institute of Scientific and Technical Information of China (English)

    冯贵明; 赵海雪; 魏会元; 张建萍:

    2011-01-01

    The high speed development of solar energy industry brings the rapid growth of photovoltaic glass . Ultra-clear photovoltaic glass used as the cover material for solar energy setup is more popular and worldwide . The production of PV-glass is high in technological content and the manufacture process is difficult to control . Any little defect will affect the quality and processed performance. Therefore the causes of defect in low-iron photovoltaic glass produced by rolled process and the corresponding steps were described in this paper.%太阳能产业的高速发展带来光伏玻璃的快速增长,超白压延玻璃作为太阳能装置首选的盖板材料越发潮流化。超白压延玻璃生产科技含量高、生产难度大,任何一个细微的成型缺陷都有可能影响玻璃的质量等级与加工性能,本文对超白压延玻璃成形缺陷产生的原因进行了分析,并提出了合理的解决措施。

  16. Diagnosis of faults in rolling element bearings by using directional spectra of vibration signals

    International Nuclear Information System (INIS)

    Park, Jong Po; Lee, Chong Won

    1999-01-01

    Backward and forward defect frequencies of rolling element bearing are experimentally investigated utilizing the two-sided directional spectra of the complex-valued vibration signals measured from the outer ring of defective bearings. The experimental results show that the directional zoom spectrum is superior to the conventional spectrum in identification of bearing defect frequencies, in particular the inner race defect frequencies

  17. Finite element method analysis of surface roughness transfer in micro flexible rolling

    Directory of Open Access Journals (Sweden)

    Qu Feijun

    2016-01-01

    Full Text Available Micro flexible rolling aims to fabricate submillimeter thick strips with varying thickness profile, where the surface quality of products is mainly determined by initial workpiece surface roughness and subsequent surface asperity flattening process, which is affected by process parameters during rolling. This paper shows a 3D finite element model for flexible rolling of a 250 μm thick workpiece with reduction of 20 to 50%, and rolling phase with thinner thickness indicates a better ability to decrease the surface roughness. Four types of initial workpiece surface roughness are studied in the simulation, and the influences of process parameters, such as friction coefficient, rolling speed and roll gap adjusting speed, on surface asperity flattening of workpieces with different initial surface roughness have been numerically investigated and analysed.

  18. Modelling of drawing and rolling of high carbon flat wires

    International Nuclear Information System (INIS)

    Bobadilla, C.; Persem, N.; Foissey, S.

    2007-01-01

    In order to meet customer requirements, it is necessary to develop new flat wires with a high tensile strength and a high width/thickness ratio. These products are manufactured from wire rod. The first step is to draw the wire until we have the required mechanical properties and required surface area of the section. After this, the wire is rolled from a round to a rectangular section. During the flat rolling process it can be reduced by more than 50%. Then the wire is exposed to a high level of stress during this process. Modelling allows us to predetermine this stress level, taking into account the final dimensions and the mechanical properties, thus optimising both rolling and drawing process. Forge2005 was used in order to simulate these processes. The aim of this study is to determine the value of residual stresses after drawing and so to optimise rolling. Indeed, the highest stress values are reached at this step of the process by changing the section of the wire from a round to a rectangular one. In order to evaluate the stress value accuracy for high strain levels, a behaviour law has been identified. This is a result of tensile tests carried out at each step of the drawing process. Finally, a multi-axial damage criterion was implemented using Forge2005. The optimisation of the rolling is directly linked to the minimisation of this criterion

  19. MATHEMATICAL MODELING OF TRANSIENT EMERGENCY ELECTROMAGNETIC PROCESSES IN THE SYSTEM OF THE ELECTROMAGNETIC TRACTION DC. 2. SHORT CIRCUIT WITH ELECTRIC ROLLING STOCK

    Directory of Open Access Journals (Sweden)

    P. E. Mihalichenko

    2010-04-01

    Full Text Available The article deals with the description of mathematical model of the system of traction electric power supply with load in the short circuit condition as well as the calculation results of this emergency process. The transition values as well as the character of their change, which can be used for detection of emergency processes, have been determined.

  20. Kayser-Fleischer Rings

    Science.gov (United States)

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

  1. Polarized particles in storage rings

    International Nuclear Information System (INIS)

    Derbenev, Ya.S.; Kondratenko, A.M.; Serednyakov, S.I.; Skrinskij, A.N.; Tumajkin, G.M.; Shatunov, Yu.M.

    1977-01-01

    Experiments with polarized beams on the VEPP-2M and SPEAK storage rings are described. Possible methods of producing polarized particle beams in storage rings as well as method of polarization monitoring are counted. Considered are the processes of radiation polarization of electrons and positrons. It is shown, that to preserve radiation polarization the introduction of regions with a strong sign-variable magnetic field is recommended. Methods of polarization measurement are counted. It is suggested for high energies to use dependence of synchrotron radiation power on transverse polarization of electrons and positrons. Examples of using polarizability of colliding beams in storage rings are presented

  2. In vitro processing of the RNA-2-encoded polyprotein of two nepoviruses: tomato black ring virus and grapevine chrome mosaic virus.

    Science.gov (United States)

    Demangeat, G; Hemmer, O; Fritsch, C; Le Gall, O; Candresse, T

    1991-02-01

    In vitro translation of RNA-2 of each of two closely related nepoviruses, tomato black ring virus (TBRV) and grapevine chrome mosaic virus (GCMV), in a rabbit reticulocyte lysate resulted in the synthesis of single polypeptides of 150K and 146K respectively. Processing of these polyproteins occurred after the addition of translation products of homologous RNA-1. The positions of the cleavage products within the polyproteins were determined. From the N to the C terminus, Mr values for the proteins were 50K, 46K and 59K for TBRV and 44K, 46K and 56K for GCMV. TBRV RNA-1 translation products also cleaved the polyproteins encoded by GCMV RNA-2 which suggests that the cleavage sites in the two polyproteins are similar.

  3. A model for prediction of profile and flatness of hot and cold rolled flat products in four-high mills

    Science.gov (United States)

    Overhagen, Christian; Mauk, Paul Josef

    2018-05-01

    For flat rolled products, the thickness profile in the transversal direction is one of the most important product properties. For further processing, a defined crown of the product is necessary. In the rolling process, several mechanical and thermal influences interact with each other to form the strip shape at the roll gap exit. In the present analysis, a process model for rolling of strip and sheet is presented. The core feature of the process model is a two-dimensional stress distribution model based on von Karman's differential equation. Sub models for the mechanical influences of work roll flattening as well as work and backup roll deflection and the thermal influence of work roll expansion have been developed or extended. The two-dimensional stress distribution serves as an input parameter for the roll deformation models. For work roll flattening, a three-dimensional model based on the Boussinesq problem is adopted, while the work and backup roll deflection, including contact flattening is calculated by means of finite beam elements. The thermal work roll crown is calculated with help of an axisymmetric numerical solution of the heat equation for the work roll, considering azimuthal averaging for the boundary conditions at the work roll surface. Results are presented for hot rolling of a strip in a seven-stand finishing train of a hot strip mill, showing the calculated evolution of the strip profile. A variation of the strip profile from the first to the 20th rolled strip is shown. This variation is addressed to the progressive increase of work roll temperature during the first 20 strips. It is shown that a CVC® system can lead to improvements in strip profile and therefore flatness.

  4. Roll-to-Roll Fabricated Polymer Solar Cells: Towards Low Environmental Impact and Reporting Consensus

    DEFF Research Database (Denmark)

    Larsen-Olsen, Thue Trofod

    The sun is by far the largest source of renewable energy available; consequently solar cells, which are able to convert light into electricity, have the technical potential to cover the global energy needs. Polymer solar cells (PSCs) on flexible plastic substrate have a low embodied energy and can...... be processed by fast roll-to-roll (R2R) methods, using earth abundant materials, and thus deliver the prospects to fulfil this potential. A strong polarization in PSC research efforts have led to diverging and non-comparable results: While very high power conversion efficiencies (PCEs) above 10% have been......, through R2R processing of tandem PSCs. A final focus area of the thesis is the investigation into the extrinsic variability in standard J-V characterizations done on PSCs, and towards ways to minimize it. Organic solvents are predominant process solvents used for fabricating the active layer of a PSC...

  5. Tests of an environmental and personnel safe cleaning process for Brookhaven National Laboratory accelerator and storage ring components

    International Nuclear Information System (INIS)

    Foerster, C.L.; Lanni, C.; Lee, R.; Mitchell, G.; Quade, W.

    1997-01-01

    A large measure of the successful operation of the National Synchrotron Light Source (NSLS) at Brookhaven National Laboratory (BNL) for over a decade can be attributed to the cleaning of its ultrahigh vacuum (UHV) components during and after construction. A new UHV cleaning process, which has to be environmentally and personnel safe, is needed to replace the harsh, unfriendly process which is still in use. Dow Advanced Cleaning Systems was contracted to develop a replacement process without the use of harsh chemicals and which must clean vacuum surfaces as well as the existing process. Acceptance of the replacement process was primarily based on photon stimulated desorption (PSD) measurements of beam tube samples run on NSLS beam line U10B. One meter long beam tube samples were fabricated from aluminum, 304 stainless steel, and oxygen-free copper. Initially, coupon samples were cleaned and passed preliminary testing for the proposed process. Next, beam tube samples of each material were cleaned, and the PSD measured on beam line U10B using white light with a critical energy of 487 eV. Prior to cleaning, the samples were contaminated with a mixture of cutting oils, lubricants, vacuum oils, and vacuum grease. The contaminated samples were then baked. Samples of each material were also cleaned with the existing process after the same preparation. Beam tube samples were exposed to between 10 22 and 10 23 photons per meter for a PSD measurement. Desorption yields for H 2 , CO, CO 2 , CH 4 , and H 2 O are reported for both the existing cleaning and for the replacement cleaning process. Preliminary data, residual gas scans, and PSD results are given and discussed. The new process is also compared with new cleaning methods developed in other laboratories. After modification, the new UHV cleaning process was accepted by BNL

  6. ASSOCIATIVE RINGS SOLVED AS LIE RINGS

    Directory of Open Access Journals (Sweden)

    M. B. Smirnov

    2011-01-01

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

  7. 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.

  8. Deep surface rolling for fatigue life enhancement of laser clad aircraft aluminium alloy

    Energy Technology Data Exchange (ETDEWEB)

    Zhuang, W., E-mail: wyman.zhuang@dsto.defence.gov.au [Aerospace Division, Defence Science and Technology Organisation, 506 Lorimer Street, Fishermans Bend, Victoria 3207 (Australia); Liu, Q.; Djugum, R.; Sharp, P.K. [Aerospace Division, Defence Science and Technology Organisation, 506 Lorimer Street, Fishermans Bend, Victoria 3207 (Australia); Paradowska, A. [Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW 2232 (Australia)

    2014-11-30

    Highlights: • Deep surface rolling as a post-repair enhancement technology was applied to the laser cladded 7075-T651 aluminium alloy specimens that simulated corrosion damage blend-out repair. • The residual stresses induced by the deep surface rolling process were measured. • The deep surface rolling process can introduce deep and high magnitude compressive residual stresses beyond the laser clad and substrate interface. • Spectrum fatigue test showed the fatigue life was significantly increased by deep surface rolling. - Abstract: Deep surface rolling can introduce deep compressive residual stresses into the surface of aircraft metallic structure to extend its fatigue life. To develop cost-effective aircraft structural repair technologies such as laser cladding, deep surface rolling was considered as an advanced post-repair surface enhancement technology. In this study, aluminium alloy 7075-T651 specimens with a blend-out region were first repaired using laser cladding technology. The surface of the laser cladding region was then treated by deep surface rolling. Fatigue testing was subsequently conducted for the laser clad, deep surface rolled and post-heat treated laser clad specimens. It was found that deep surface rolling can significantly improve the fatigue life in comparison with the laser clad baseline repair. In addition, three dimensional residual stresses were measured using neutron diffraction techniques. The results demonstrate that beneficial compressive residual stresses induced by deep surface rolling can reach considerable depths (more than 1.0 mm) below the laser clad surface.

  9. Deep surface rolling for fatigue life enhancement of laser clad aircraft aluminium alloy

    International Nuclear Information System (INIS)

    Zhuang, W.; Liu, Q.; Djugum, R.; Sharp, P.K.; Paradowska, A.

    2014-01-01

    Highlights: • Deep surface rolling as a post-repair enhancement technology was applied to the laser cladded 7075-T651 aluminium alloy specimens that simulated corrosion damage blend-out repair. • The residual stresses induced by the deep surface rolling process were measured. • The deep surface rolling process can introduce deep and high magnitude compressive residual stresses beyond the laser clad and substrate interface. • Spectrum fatigue test showed the fatigue life was significantly increased by deep surface rolling. - Abstract: Deep surface rolling can introduce deep compressive residual stresses into the surface of aircraft metallic structure to extend its fatigue life. To develop cost-effective aircraft structural repair technologies such as laser cladding, deep surface rolling was considered as an advanced post-repair surface enhancement technology. In this study, aluminium alloy 7075-T651 specimens with a blend-out region were first repaired using laser cladding technology. The surface of the laser cladding region was then treated by deep surface rolling. Fatigue testing was subsequently conducted for the laser clad, deep surface rolled and post-heat treated laser clad specimens. It was found that deep surface rolling can significantly improve the fatigue life in comparison with the laser clad baseline repair. In addition, three dimensional residual stresses were measured using neutron diffraction techniques. The results demonstrate that beneficial compressive residual stresses induced by deep surface rolling can reach considerable depths (more than 1.0 mm) below the laser clad surface

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

    DEFF Research Database (Denmark)

    Mishin, Oleg; Bay, B.; Winther, G.

    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 tex......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...... 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...

  11. Numerical aspects of U-Mo core covered by Zry-4 miniplates co-rolling

    International Nuclear Information System (INIS)

    Picchetti, B.; Moscarda, M.V.; Taboada, H.

    2013-01-01

    The aim of this work is to support through adequate modeling the development of the co-rolling process of miniplates and plates starting with compacts including a monolithic U-Mo core with Zry-4 frame and cladding, Through relevant parameter identification and specific variables calculation a co rolling process model was set. The goal is to design a co-rolling optimal strategy related to the expected results through the use of such model. To that end the rolling process is depicted and some elements of strain stress theory on metals are employed. Plastic strain depends on deviator components of the stress tensor but no on the hydrostatic one. Metal sheet co-rolling is a plastic strain by planar compression at constant volume. During the co-rolling process the width constancy is assumed, being the piece of metal free to flow along its length. In this work the relationship between constitutive materials shield stresses U-Mo core and Zry-4 cladding under T= 650°C co-rolling is determined. This allows to modeling the reduction that exist in each co-rolling step for each one of phases present, which enables the design of a loop control lace optimizing the co rolling process. (author)

  12. Adição de grafite na conformação de substratos cerâmicos porosos processados por rolos a frio Addition of graphite in the conformation of ceramic porous substrates processed by cold roll pressing

    Directory of Open Access Journals (Sweden)

    L. Koshimizu

    2012-12-01

    Full Text Available O desenvolvimento de substratos cerâmicos porosos de fina espessura (The development of porous ceramic substrates with thickness less than 1 mm presents a great technology interesting for electro-electronic or catalytic applications. Among all the techniques of ceramic conformation, the viscoplastic processing shows great advantages decreasing the amount of liquids and the particles agglomeration from an intensive shearing of the ceramic paste. This process allows the conformation of ceramic samples in a simple way and without toxic additives, the opposite of tape casting, which is the method often applied. The substrates were conformed by cold roll pressing in a thickness between 400 and 700 µm, and with the rotation of rollers of 15 rpm. Theses were dried before the firing at 1600 ºC for 1 h. As a pore-forming agent it was studied the graphite powder which was added to the alumina plastic paste in two different concentrations, 9 and 18 wt%, which results in an apparent porosity of 21 and 52%, respectively.

  13. Near-infrared chemical imaging (NIR-CI) as a process monitoring solution for a production line of roll compaction and tableting

    DEFF Research Database (Denmark)

    Khorasani, Milad Rouhi; Amigo Rubio, Jose Manuel; Sun, Changquan Calvin

    2015-01-01

    In the present study the application of near-infrared chemical imaging (NIR-CI) supported by chemometric modeling as non-destructive tool for monitoring and assessing the roller compaction and tableting processes was investigated. Based on preliminary risk-assessment, discussion with experts...... compound for both roller compacted ribbons and corresponding tablets. In order to select the optimal process, setting the standard deviation of tablet tensile strength and tablet weight for each tablet batch was considered. Strong linear correlation between tablet tensile strength and amount of fines...... and granule size was established, respectively. These approaches are considered to have a potentially large impact on quality monitoring and control of continuously operating manufacturing lines, such as roller compaction and tableting processes....

  14. Microstructure formation via roll-to-roll UV embossing using a flexible mould made from a laminated polymer–copper film

    International Nuclear Information System (INIS)

    Zhong, Z W; Shan, X C

    2012-01-01

    Roll-to-roll large format UV embossing processes aim to revolutionize the manufacturing of functional films, with the ability to process a large area at one time, resulting in high throughput and cost reduction. In this paper, we present the experimental results obtained during the process development for roll-to-roll large format UV embossing. Flexible moulds were fabricated from a hybrid film substrate made of a liquid crystal polymer with clad copper foils laminated on both sides of it. The effective pattern area of the fabricated flexible mould was 400 mm × 300 mm with a minimal feature size of 50 µm. The results show that the roll-to-roll embossing processes are capable of producing micro-scale structures and functional devices over a large area at one time. Large-area roll-to-roll embossing was demonstrated by using the hybrid flexible mould, and micro-features and structures such as micro-channels and dot arrays were replicated on thermoplastic substrates. In addition to its ease and low cost in fabrication, the hybrid flexible moulds demonstrated to have acceptable fidelity and durability. The hybrid flexible mould is a novel solution for large-area embossing. (paper)

  15. In situ monitoring of structure formation in the active layer of polymer solar cells during roll-to-roll coating

    DEFF Research Database (Denmark)

    Rossander, Lea Hildebrandt; Zawacka, Natalia Klaudia; Dam, Henrik Friis

    2014-01-01

    The active layer crystallization during roll-to-roll coating of organic solar cells is studied in situ. We developed an X-ray setup where the coater unit is an integrated part of the small angle X-ray scattering instrument, making it possible to control the coating process while recording...

  16. Ring-like size segregation in vibrated cylinder with a bottleneck

    International Nuclear Information System (INIS)

    Kong Xiangzhao; Hu Maobin; Wu Qingsong; Wu Yonghong

    2005-01-01

    In this Letter, a ring-like segregation pattern of bi-dispersed granular material in a vibrated bottleneck-cylinder is presented. The driving frequency can greatly affect the strength and structure of the convection roll and segregation pattern. The position and height of the ring (cluster of big beads) can be adjusted by altering the vibration frequency. And a heuristic theory is developed to interpret the ring's position dependence on driving frequency

  17. A rolling-gliding wear simulator for the investigation of tribological material pairings for application in total knee arthroplasty

    OpenAIRE

    Richter, Berna I; Ostermeier, Sven; Turger, Anke; Denkena, Berend; Hurschler, Christof

    2010-01-01

    Abstract Background Material wear testing is an important technique in the development and evaluation of materials for use in implant for total knee arthroplasty. Since a knee joint induces a complex rolling-gliding movement, standardised material wear testing devices such as Pin-on-Disc or Ring-on-Disc testers are suitable to only a limited extent because they generate pure gliding motion only. Methods A rolling-gliding wear simulator was thus designed, constructed and implemented, which sim...

  18. Engineering of rolled constructional microalloyed steel products

    International Nuclear Information System (INIS)

    Adamczyk, J.

    2003-01-01

    Flexibility of the microalloyed steels on manufacturing of products with high mechanical and technological properties at not exaggerated production costs, it caused of their application for different constructions and machines in many branches of economy. It is a reason of the big interest of this steel group and the improvement of metallurgical and technological processing. In the work the examples of applications of C-Mn microalloyed steels with V and N microadditions for production of long shape products of R p0.2 > 650 MPa and KCU2 > 57 Jcm -2 are presented. They are manufactured in the controlled rolling process. Moreover this work presents liquid metal treatment in ladlemann process and influence of ingots solidification conditions, controlled rolling of weldable plates with Nb, Ti, V and B microadditions which after quenching and tempering have R p0.2 > 870 MPa, KV -50 o C > 27 J and plastic strain ratio equals 1.2. This work also presents the energy saving rolling technology with controlled recrystallization (method of thermomechanical treatment) of improved Weldox 960 steel plates with Mb, Ti, V and B microadditions which have after high-temperature tempering R p0.2 > 100 MPa, KV -50 o C >90 J and plastic strain ratio is less than 1.2. The introduction of microalloyed constructional steels and the appropriate technology in the domestic industry will contribute to high-processed products with properties competitive to products manufactured in high-industrialized countries. Thanks to that it will be possible to increase the technical level as well as to reduce production costs and import. (author)

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

    Science.gov (United States)

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

    2014-12-01

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

  20. Zurek–Kibble Symmetry Breaking Process in Superconducting Rings; Spontaneous Fluxon Formation in Annular Josephson Tunnel Junctions

    DEFF Research Database (Denmark)

    Aarøe, Morten; Monaco, Roberto; Dmitriev, P

    2007-01-01

    We report on new investigations of spontaneous symmetry breaking in non-adiabatic phase transitions. This Zurek-Kibble (ZK) process is mimicked in solid state systems by trapping of magnetic flux quanta, fluxons, in a long annular Josephson tunnel junction quenched through the normal-superconducting...

  1. Study of deformation texture in an AZ31 magnesium alloy rolled at wide range of rolling speed and reductions

    International Nuclear Information System (INIS)

    Sanjari, M; Su, J; Kabir, A S; Yue, S; Tamimi, S; Hara, K; Utsunomiya, H; Petrov, R; Kestens, L

    2015-01-01

    The plasticity of Mg is restricted at low temperatures because: (a) only a small number of deformation mechanisms can be activated, and (b) a preferred crystallographic orientation (texture) develops in wrought alloys, especially in flat-rolled sheets. This causes problems in thin sheet processing as well as component manufacturing from the sheet. In this study, different rolling speeds from 15 to 1000 m/min were employed to warm-roll AZ31B magnesium alloy to different reductions. The results show that AZ31B sheets rolled at 15 m/min and 100 °C has fractured for reductions of more than 30% per pass. However, by increasing the rolling speed to 1000 m/min the rollability was improved significantly and the material can be rolled to reductions of more than 70% per pass. The results show that with increasing strain rate at 100°C, the splitting of basal poles was observed, indicating the activation of more contraction twins and secondary twins. (paper)

  2. Robust Rudder Roll Damping Control

    DEFF Research Database (Denmark)

    Yang, C.

    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...

  3. Stirling engine piston ring

    Science.gov (United States)

    Howarth, Roy B.

    1983-01-01

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

  4. Analysis of roll-stamped light guide plate fabricated with laser-ablated stamper

    Science.gov (United States)

    Na, Hyunjun; Hong, Seokkwan; Kim, Jongsun; Hwang, Jeongho; Joo, Byungyun; Yoon, Kyunghwan; Kang, Jeongjin

    2017-12-01

    LGP (light guide plate) is one of the major components of LCD (liquid crystal display), and it makes surface illumination for LCD backlit. LGP is a transparent plastic plate usually produced by injection molding process. On the back of LGP there are micron size patterns for extraction of light. Recently a roll-stamping process has achieved the high mass productivity of thinner LGPs. In order to fabricate optical patterns on LGPs, a fabricating tool called as a stamper is used. Micro patterns on metallic stampers are made by several micro machining processes such as chemical etching, LIGA-reflow, and laser ablation. In this study, a roll-stamping process by using a laser ablated metallic stamper was dealt with in consideration of the compatibility with the roll-stamping process. LGP fabricating tests were performed using a roll-stamping process with four different roll pressures. Pattern shapes on the stamper fabricated by laser ablation and transcription ratios of the roll-stamping process were analyzed, and LGP luminance was evaluated. Based on the evaluation, optical simulation model for LGP was made and simulation accuracy was evaluated. Simulation results showed good agreements with optical performance of LGPs in the brightness and uniformity. It was also shown that the roll-stamped LGP has the possibility of better optical performance than the conventional injection molded LGP. It was also shown that the roll-stamped LGP with the laser ablated stamper is potential to have better optical performance than the conventional injection molded LGP.

  5. Ring Confidential Transactions

    Directory of Open Access Journals (Sweden)

    Shen Noether

    2016-12-01

    Full Text Available This article introduces a method of hiding transaction amounts in the strongly decentralized anonymous cryptocurrency Monero. Similar to Bitcoin, Monero is a cryptocurrency which is distributed through a proof-of-work “mining” process having no central party or trusted setup. The original Monero protocol was based on CryptoNote, which uses ring signatures and one-time keys to hide the destination and origin of transactions. Recently the technique of using a commitment scheme to hide the amount of a transaction has been discussed and implemented by Bitcoin Core developer Gregory Maxwell. In this article, a new type of ring signature, A Multilayered Linkable Spontaneous Anonymous Group signature is described which allows one to include a Pedersen Commitment in a ring signature. This construction results in a digital currency with hidden amounts, origins and destinations of transactions with reasonable efficiency and verifiable, trustless coin generation. The author would like to note that early drafts of this were publicized in the Monero Community and on the #bitcoin-wizards IRC channel. Blockchain hashed drafts are available showing that this work was started in Summer 2015, and completed in early October 2015. An eprint is also available at http://eprint.iacr.org/2015/1098.

  6. Alternative loop rings

    CERN Document Server

    Goodaire, EG; Polcino Milies, C

    1996-01-01

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

  7. Researches on the Piston Ring

    Science.gov (United States)

    Ehihara, Keikiti

    1944-01-01

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

  8. Including asphalt cooling and rolling regimes in laboratory compaction procedures

    NARCIS (Netherlands)

    Bijleveld, Frank; Doree, Andries G.; Kim,

    2014-01-01

    Given the various changes occurring in the asphalt construction industry, improved process and quality control is becoming essential. The significance of appropriate rolling and compaction for the quality of asphalt is widely acknowledged and vital for improved process control. But what constitutes

  9. Rolling motion in moving droplets

    Indian Academy of Sciences (India)

    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 .... rigid body rotation. The solid body rotation makes sense in the context of small Reynolds. (Re) number flows ...

  10. Effect of Reduction in Thickness and Rolling Conditions on Mechanical Properties and Microstructure of Rolled Mg-8Al-1Zn-1Ca Alloy

    Directory of Open Access Journals (Sweden)

    Yuta Fukuda

    2017-01-01

    Full Text Available A cast Mg-8Al-1Zn-1Ca magnesium alloy was multipass hot rolled at different sample and roll temperatures. The effect of the rolling conditions and reduction in thickness on the microstructure and mechanical properties was investigated. The optimal combination of the ultimate tensile strength, 351 MPa, yield strength, 304 MPa, and ductility, 12.2%, was obtained with the 3 mm thick Mg-8Al-1Zn-1Ca rolled sheet, which was produced with a roll temperature of 80°C and sample temperature of 430°C. This rolling process resulted in the formation of a bimodal structure in the α-Mg matrix, which consequently led to good ductility and high strength, exclusively by the hot rolling process. The 3 mm thick rolled sheet exhibited fine (mean grain size of 2.7 μm and coarse grain regions (mean grain size of 13.6 μm with area fractions of 29% and 71%, respectively. In summary, the balance between the strength and ductility was enhanced by the grain refinement of the α-Mg matrix and by controlling the frequency and orientation of the grains.

  11. Microstructure and properties of hot roll bonding layer of dissimilar metals. 2. Bonding interface microstructure of Zr/stainless steel by hot roll bonding and its controlling

    International Nuclear Information System (INIS)

    Yasuyama, Masanori; Ogawa, Kazuhiro; Taka, Takao; Nakasuji, Kazuyuki; Nakao, Yoshikuni; Nishimoto, Kazutoshi.

    1996-01-01

    The hot roll bonding of zirconium and stainless steel inserted with tantalium was investigated using the newly developed rolling mill. The effect of hot rolling temperatures of zirconium/stainless steel joints on bonding interface structure was evaluated. Intermetallic compound layer containing cracks was observed at the bonding interface between stainless steel and tantalium when the rolling temperature was above 1373K. The hardness of the bonding layer of zirconium and tantalium bonded above 1273K was higher than tantalium or zirconium base metal in spite of absence of intermetallic compound. The growth of reaction layer at the stainless steel and tantalium interface and at the tantalium and zirconium interface was conforming a parabolic low when that was isothermally heated after hot roll bonding, and the growth rate was almost same as that of static diffusion bonding without using hot roll bonding process. It is estimated that the strain caused by hot roll bonding gives no effect on the growth of reaction layer. It was confirmed that the dissimilar joint of zirconium and stainless steel with insert of tantalium having the sound bonding interface were obtained at the suitable bonding temperature of 1173K by the usage of the newly developed hot roll bonding process. (author)

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

    DEFF Research Database (Denmark)

    Bundgaard, Eva; Hagemann, Ole; Manceau, Matthieu

    2010-01-01

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

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

    International Nuclear Information System (INIS)

    Leppäniemi, Jaakko; Mattila, Tomi; Suhonen, Mika; Alastalo, Ari; Kololuoma, Terho

    2012-01-01

    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)

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

    Science.gov (United States)

    Leppäniemi, Jaakko; Mattila, Tomi; Kololuoma, Terho; Suhonen, Mika; Alastalo, Ari

    2012-08-01

    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 (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.

  15. Leapfrogging of multiple coaxial viscous vortex rings

    International Nuclear Information System (INIS)

    Cheng, M.; Lou, J.; Lim, T. T.

    2015-01-01

    A recent theoretical study [Borisov, Kilin, and Mamaev, “The dynamics of vortex rings: Leapfrogging, choreographies and the stability problem,” Regular Chaotic Dyn. 18, 33 (2013); Borisov et al., “The dynamics of vortex rings: Leapfrogging in an ideal and viscous fluid,” Fluid Dyn. Res. 46, 031415 (2014)] shows that when three coaxial vortex rings travel in the same direction in an incompressible ideal fluid, each of the vortex rings alternately slips through (or leapfrogs) the other two ahead. Here, we use a lattice Boltzmann method to simulate viscous vortex rings with an identical initial circulation, radius, and separation distance with the aim of studying how viscous effect influences the outcomes of the leapfrogging process. For the case of two identical vortex rings, our computation shows that leapfrogging can be achieved only under certain favorable conditions, which depend on Reynolds number, vortex core size, and initial separation distance between the two rings. For the case of three coaxial vortex rings, the result differs from the inviscid model and shows that the second vortex ring always slips through the leading ring first, followed by the third ring slipping through the other two ahead. A simple physical model is proposed to explain the observed behavior

  16. THE METHOD OF ROLL SURFACE QUALITY MEASUREMENT FOR CONTINUOUS HOT DIP ZINC COATED STEEL SHEET PRODUCTION LINE

    Directory of Open Access Journals (Sweden)

    Ki Yong Choi

    2015-01-01

    Full Text Available The present paper describes a developed analyzing system of roll surface during the process of continuous hot dip zinc coated steel sheet production line, in particular, adhering problem by transferred inclusions from roll to steel sheet surface during annealing process so called the pickup. The simulated test machine for coated roll surface in processing line has been designed and performed. The system makes it possible to analyze roll surface condition according to pickup phenomena from various roll coatings concerning operating conditions of hearth rolls in annealing furnace. The algorithm of fast pickup detection on surface is developed on the base of processing of several optical images of surface. The parameters for quality estimation of surface with pickups were developed. The optical system for images registration and image processing electronics may be used in real time and embed in processing line.

  17. Maintenance Appointments in Railway Rolling Stock Rescheduling

    NARCIS (Netherlands)

    J.C. Wagenaar (Joris); L.G. Kroon (Leo); M.E. Schmidt (Marie)

    2016-01-01

    textabstractThis paper addresses the Rolling Stock Rescheduling Problem (RSRP), while taking maintenance appointments into account. After a disruption, the rolling stock of the disrupted passenger trains has to be rescheduled in order to restore a feasible rolling stock circulation. Usually, a

  18. Rolling block mazes are PSPACE-complete

    NARCIS (Netherlands)

    Buchin, K.; Buchin, M.

    2012-01-01

    In a rolling block maze, one or more blocks lie on a rectangular board with square cells. In most mazes, the blocks have size k × m × n where k, m, n are integers that determine the size of the block in terms of units of the size of the board cells. The task of a rolling block maze is to roll a

  19. Efficient Circulation of Railway Rolling Stock

    NARCIS (Netherlands)

    Alfieri, A.; Groot, R.; Kroon, L.G.; Schrijver, A.

    2006-01-01

    Railway rolling stock (locomotives, carriages, and train units) is one of the most significant cost sources for operatorsof passenger trains, both public and private. Rolling stock costsare due to material acquisition, power supply, and material maintenance. The efficient circulation of rolling

  20. Proton storage rings

    International Nuclear Information System (INIS)

    Rau, R.R.

    1978-04-01

    A discussion is given of proton storage ring beam dynamic characteristics. Topics considered include: (1) beam energy; (2) beam luminosity; (3) limits on beam current; (4) beam site; (5) crossing angle; (6) beam--beam interaction; (7) longitudinal instability; (8) effects of scattering processes; (9) beam production; and (10) high magnetic fields. Much of the discussion is related to the design parameters of ISABELLE, a 400 x 400 GeV proton---proton intersecting storage accelerator to be built at Brookhaven National Laboratory

  1. Design of a Small Scale Roll to Roll Device

    OpenAIRE

    Pereira, Amon A; White, Edward; Kramer, Rebecca Krone

    2014-01-01

    In the soft robotics field, hyperelastic polymer films are used in conjunction with eutectic gallium indium to create flexible strain gages. However, rapid large scale manufacturing methods of such sensors have yet to be developed. Developing new manufacturing methods will allow for researchers to build and test new soft sensor concepts faster but also pave the way for future mass-production of these sensors for consumer or industrial consumption. One of those methods would be a Roll to...

  2. Mechanism and the origins of stereospecificity in copper-catalyzed ring expansion of vinyl oxiranes: a traceless dual transition-metal-mediated process.

    Science.gov (United States)

    Mustard, Thomas J L; Mack, Daniel J; Njardarson, Jon T; Cheong, Paul Ha-Yeon

    2013-01-30

    Density functional theory computations of the Cu-catalyzed ring expansion of vinyloxiranes is mediated by a traceless dual Cu(I)-catalyst mechanism. Overall, the reaction involves a monomeric Cu(I)-catalyst, but a single key step, the Cu migration, requires two Cu(I)-catalysts for the transformation. This dual-Cu step is found to be a true double Cu(I) transition state rather than a single Cu(I) transition state in the presence of an adventitious, spectator Cu(I). Both Cu(I) catalysts are involved in the bond forming and breaking process. The single Cu(I) transition state is not a stationary point on the potential energy surface. Interestingly, the reductive elimination is rate-determining for the major diastereomeric product, while the Cu(I) migration step is rate-determining for the minor. Thus, while the reaction requires dual Cu(I) activation to proceed, kinetically, the presence of the dual-Cu(I) step is untraceable. The diastereospecificity of this reaction is controlled by the Cu migration step. Suprafacial migration is favored over antarafacial migration due to the distorted Cu π-allyl in the latter.

  3. Progress in cold roll bonding of metals

    International Nuclear Information System (INIS)

    Li Long; Nagai, Kotobu; Yin Fuxing

    2008-01-01

    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)

  4. Comparison of additive amount used in spin-coated and roll-coated organic solar cells

    DEFF Research Database (Denmark)

    Cheng, Pei; Lin, Yuze; Zawacka, Natalia Klaudia

    2014-01-01

    All-polymer and polymer/fullerene inverted solar cells were fabricated by spin-coating and roll-coating processes. The spin-coated small-area (0.04 cm(2)) devices were fabricated on indium tin oxide (ITO) coated glass substrates in nitrogen. The roll-coated large-area (1.0 cm(2)) devices were...

  5. COMPUTER MODELING OF THE ROLLING TECHNOLOGICAL REGIMES INFLUENCE ON MICROSTRUCTURE OF EUTECTOID COLONIES OF ROD PEARLITE

    Directory of Open Access Journals (Sweden)

    A. N. Chichko

    2010-01-01

    Full Text Available Interconnection between the parameters of the rolled wire production technology and characteristics of its microstructure is shown. The correlation interconnections between the characteristics of the rolled wire microstructure, calculated by method of image processing, and technology of its receipt in conditions of RUP «BMZ» are determined. 

  6. SOFTWARE FOR COMPUTER-AIDED DESIGN OF CROSS-WEDGE ROLLING

    OpenAIRE

    A. A. Abramov; S. V. Medvedev

    2013-01-01

    The issues of computer technology creation of 3D-design and engineering analysis of metal forming processes using cross wedge rolling methods (CWR) are considered. The developed software for computer-aided design and simulation of cross-wedge rolling is described.

  7. Analysis of through-thickness heterogeneities of microstructure and texture in nickel after accumulative roll bonding

    DEFF Research Database (Denmark)

    Zhang, Yubin; Mishin, Oleg; Godfrey, A.

    2014-01-01

    with the summed fraction of the rolling texture components. The observed microstructural and textural variations are discussed and compared with literature data, taking into account the influence of large-draught rolling and lubrication on the distribution of strain imposed during the ARB process....

  8. An isoindigo containing donor-acceptor polymer: synthesis and photovoltaic properties of all-solution-processed ITO- and vacuum-free large area roll-coated single junction and tandem solar cells

    DEFF Research Database (Denmark)

    Brandt, Rasmus Guldbæk; Yue, Wei; Andersen, Thomas Rieks

    2015-01-01

    In this work, the design, synthesis, and characterization of a donor-acceptor polymer from dithieno[3,2-b:2',3'-d]pyrrole and isoindigo (i-ID) are presented. The synthesized polymer has been applied in large area ITO-free organic photovoltaics, both as spin coated and roll coated devices; the lat......In this work, the design, synthesis, and characterization of a donor-acceptor polymer from dithieno[3,2-b:2',3'-d]pyrrole and isoindigo (i-ID) are presented. The synthesized polymer has been applied in large area ITO-free organic photovoltaics, both as spin coated and roll coated devices...

  9. On the constant-roll inflation

    Science.gov (United States)

    Yi, Zhu; Gong, Yungui

    2018-03-01

    The primordial power spectra of scalar and tensor perturbations during slow-roll inflation are usually calculated with the method of Bessel function approximation. For constant-roll or ultra slow-roll inflation, the method of Bessel function approximation may be invalid. We compare the numerical results with the analytical results derived from the Bessel function approximation, and we find that they differ significantly on super-horizon scales if the constant slow-roll parameter ηH is not small. More accurate method is needed for calculating the primordial power spectrum for constant-roll inflation.

  10. Berth Allocation Problem with Quay Crane Assignment for Container Terminals Based on Rolling-Horizon Strategy

    Directory of Open Access Journals (Sweden)

    Ling Xiao

    2014-01-01

    Full Text Available In order to solve the large-scale integral dynamic scheduling of continuous berths and quay cranes problem, a method based on rolling-horizon strategy is proposed. A multiobjective optimization model that is established minimizes the total penalty costs considering vessels’ deviations to their preferred berthing positions, delayed times for berthing comparing to their estimated arrival times, and delayed times for departure comparing to their estimated departure times. Then, the scheduling process was divided into a set of continual scheduling interval according to the dynamic arrival sequences. Meanwhile, rolling-horizon strategies for setting rolling and frozen windows and the parameter updating strategy are designed. The input parameters of the model in the next rolling window are updated according to the optimal results of each time window which have been obtained. The model is solved by choosing appropriate rolling and freezing window lengths that represents the numbers of adjacent vessels in the sequence of calling vessels. The holistic optimal solution is obtained by gradually rolling and combining the results of each window. Finally, a case study indicated that the rolling schedule can solve large-scale scheduling problems, and the efficiency of the proposed approach relates to the size of rolling window, freeze ship quantity, and rolling frequency.

  11. Pre-treatment of Biomass By Rolling - A Combined Experimental and Numerical Analysis

    DEFF Research Database (Denmark)

    Hansen, Klaus Schütt; Ravn, Christian; Nielsen, Emil Krabbe

    2017-01-01

    Pre-treatment of bulk straw material by rolling is studied as a possible method to prepare for subsequent biogas production. A combined experimental and theoretical study is presented. A pilot rolling mill with a double screw feeder is designed and constructed for crushing of bulk straw. Experime...... process window for pre-treatment of wheat straw by roll pressing varying the feed, the roll gap, the roll speed and the moisture content of the bulk straw.......Pre-treatment of bulk straw material by rolling is studied as a possible method to prepare for subsequent biogas production. A combined experimental and theoretical study is presented. A pilot rolling mill with a double screw feeder is designed and constructed for crushing of bulk straw....... Experiments show that the roll speed and the roll reduction should be chosen within a specific range depending on the injection screw speed to avoid blocking or insufficient compaction. A mechanical testing procedure of the bulk straw material including closed die compaction testing as well as simple...

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

    International Nuclear Information System (INIS)

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

    1986-01-01

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

  13. Improved Dutch Roll Approximation for Hypersonic Vehicle

    Directory of Open Access Journals (Sweden)

    Liang-Liang Yin

    2014-06-01

    Full Text Available An improved dutch roll approximation for hypersonic vehicle is presented. From the new approximations, the dutch roll frequency is shown to be a function of the stability axis yaw stability and the dutch roll damping is mainly effected by the roll damping ratio. In additional, an important parameter called roll-to-yaw ratio is obtained to describe the dutch roll mode. Solution shows that large-roll-to-yaw ratio is the generate character of hypersonic vehicle, which results the large error for the practical approximation. Predictions from the literal approximations derived in this paper are compared with actual numerical values for s example hypersonic vehicle, results show the approximations work well and the error is below 10 %.

  14. Observation of radio frequency ring-shaped hollow cathode discharge plasma with MgO and Al electrodes for plasma processing

    International Nuclear Information System (INIS)

    Ohtsu, Yasunori; Matsumoto, Naoki

    2014-01-01

    Various high-density plasma sources have been proposed for plasma processing. Especially, the hollow cathode discharge is one of the powerful ones. In this work, radio-frequency (RF) driven ring-shaped hollow cathode discharges with high secondary-electron emission have been investigated, using an aluminum (Al) cathode, coated or not with magnesium oxide (MgO). The thickness of MgO thin film is approximately 200 nm. The RF discharge voltage for the coated cathode is almost the same as that for the uncoated one, in a wide range of Ar gas pressure, from 5.3 to 53.2 Pa. The results reveal that the plasma density has a peak at an Ar gas pressure of 10.6 Pa for both cathodes. The plasma density for the coated cathode is about 1.5–3 times higher than that for the uncoated one, at various gas pressures. To the contrary, the electron temperature for the coated cathode is lower than temperature obtained with the uncoated cathode, at various gas pressures. Radial profiles of electron saturation current, which is proportional to plasma flux, are also examined for a wide range of gas pressure. Radial profiles of electron temperature at various axial positions are almost uniform for both cathodes so that the diffusion process due to density gradient is dominant for plasma transport. The secondary electrons emitted from the coated cathode contribute to the improvement of the plasma flux radial profile obtained using the uncoated cathode

  15. Bubble departure diameter in narrow rectangular channel under rolling condition

    Energy Technology Data Exchange (ETDEWEB)

    Xie, T.; Chen, B.; Yan, X.; Xu, J.; Huang, Y.; Xiao, Z. [Nuclear Power Inst. of China, Chengdu, Sichuan (China)

    2014-07-01

    Forced convective subcooled boiling flow experiments were conducted in a vertical upward narrow rectangular channel under rolling motion. A high-speed digital video camera was used to capture the dynamics of the bubble nucleation process. Bubble departure diameters were obtained from the images. A bubble departure model based on force balance analysis was proposed to predict the bubble departure size under rolling condition by considering the additional centrifugal, tangential and Coriolis force. The proposed model agreed well with the experimental data within the averaged relative deviation of 5%. (author)

  16. The study and fabrication of DLC micropattern on roll mold

    Science.gov (United States)

    Kwon, Young Woo; Lee, Tae Dong; Park, Yeong Min; Cho, Hyun; Kim, Jin Kon; Kim, Tae Gyu

    2015-03-01

    Diamond-like carbon (DLC) coating is becoming a promising protective coating layers due to its superior properties. In this study, instead of protective coating, DLC film was applied as the only component for micropattern then etched with lithography and lift-off process selectively. Furthermore, DLC film has been fabricated on aluminum roll mold. Then UV curing resin was applied to form the pattern on the polyethylene terephthalate (PET) film. The dimension and formation of the DLC micropattern on roll mold were analyzed. Moreover, the Raman spectroscopic of nitrogen-doped DLC film was analyzed.

  17. Rings in drugs.

    Science.gov (United States)

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

    2014-07-24

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

  18. Birth Control Ring

    Science.gov (United States)

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

  19. Effects of Changing Hot Rolling Direction on Microstructure, Texture and Mechanical Properties of Cu-2.7Be Sheets

    Science.gov (United States)

    Zhu, Daibo; Liu, Chuming; Yu, Haijun; Han, Tan

    2018-03-01

    A hot rolling scheme (cross-rolling and unidirectional rolling) was adopted to process Cu-2.7Be sheets used as multiplier dynodes in photomultiplier. The effects of changing rolling direction on microstructure, texture and mechanical properties were studied by a combination of XRD, EBSD and TEM. It was found that higher copper-type texture and lower brass texture intensity were obtained in the ultimately cross-rolling (CR) sheet compared with the unidirectional rolling (UR) sheet.The EBSD results indicated that the grain orientation from mainly for UR sample turns to random for CR sample. Great enhancements in YS and UTS after unidirectional rolling were attributed to the massive and polygonal γ precipitates. The CR sample exhibited lower anisotropy, because of the increase of S and γ precipitates with spherical and tiny shape.

  20. Tachyon constant-roll inflation

    Science.gov (United States)

    Mohammadi, A.; Saaidi, Kh.; Golanbari, T.

    2018-04-01

    The constant-roll inflation is studied where the inflaton is taken as a tachyon field. Based on this approach, the second slow-roll parameter is taken as a constant which leads to a differential equation for the Hubble parameter. Finding an exact solution for the Hubble parameter is difficult and leads us to a numerical solution for the Hubble parameter. On the other hand, since in this formalism the slow-roll parameter η is constant and could not be assumed to be necessarily small, the perturbation parameters should be reconsidered again which, in turn, results in new terms appearing in the amplitude of scalar perturbations and the scalar spectral index. Utilizing the numerical solution for the Hubble parameter, we estimate the perturbation parameter at the horizon exit time and compare it with observational data. The results show that, for specific values of the constant parameter η , we could have an almost scale-invariant amplitude of scalar perturbations. Finally, the attractor behavior for the solution of the model is presented, and we determine that the feature could be properly satisfied.

  1. 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; García-Valverde, Rafael; Urbina, Antonio

    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 ...... photovoltaic technologies. The results showed that an Energy Pay-Back Time (EPBT) of 2.02 years can be achieved for an organic solar module of 2% efficiency, which could be reduced to 1.35 years, if the efficiency was 3%.......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...... printed. Finally the polymer solar modules were encapsulated, using a polyester barrier material. All operations except the application of ITO were carried out under ambient conditions. The life cycle analysis delivered a material inventory of the full process for a module production...

  2. Groups, rings, modules

    CERN Document Server

    Auslander, Maurice

    2014-01-01

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

  3. Enhanced friction modeling for steady-state rolling tires

    NARCIS (Netherlands)

    Steen, van der R.

    2010-01-01

    Tire modeling is nowadays a necessary tool in the tire industry. Car manufacturers, governments and consumers demand better traction under all circumstances, less wear and more recently less noise and a lower rolling resistance. Therefore finite element analysis is adopted in the design process of

  4. Strategic flat rolling of Ag/BSCCO-2223 tapes

    DEFF Research Database (Denmark)

    Nielsen, Morten Storgård; Bech, Jakob Ilsted; Eriksen, Morten

    2002-01-01

    In the process of single-step flat rolling of multifilament Ag/BSCCO-2223 wire to tape previous work has shown the optimum strategy giving maximum critical current density to be it balance between the length and width strain, so they are of equal size i.e. so, that the logarithmic strain ratio, L...

  5. MODELING OF THE TRACK AND ROLLING STOCK INTERACTION

    Directory of Open Access Journals (Sweden)

    N. V. Khalipova

    2013-09-01

    Full Text Available Purpose. Interaction of system’s elements of "carriage–track" modelling requires consideration of various criteria, it also requires analysis of many uncertainty and randomness factors’ influence on the basic parameters to ensure optimal or rational parameters of the system. The researching of interactions’ process requires new theoretical approaches to formulation of objectives, based on a generalization of existing modeling approaches. The purpose of this work is development of interaction models between track and rolling stock based on multiple structures of objects. Methodology. Dedicated and formed the main evaluation criteria of dynamic interaction between track and rolling stock optimization - quality assurance and safety of transportation process, improving of their efficiency and reducing of prime cost’s. Based on vector optimization methods, proposed model of rolling stock and track’s elements interaction. For the synthesis of the model used mathematical machine of multiple objects structures. Findings. Generalized approaches to modeling in the interaction of rolling stock and track for different structural elements of the system under different exploitation conditions. This theoretical approach demonstrated on the examples of modeling of passenger and freight cars with track under different exploitation conditions. Originality. Proposed theoretical approach to the problem of track and rolling stock interaction, based on a synthesis of existing models by using of multiple objects structures. Practical value. Using of proposed model allows to structure key data and rational parameters of rolling stock and track interaction’s modeling and to formulate optimal and rational parameters of the system, to determine the effective exploitation parameters and measurement system for rational use of infrastructure.

  6. Accretion in Saturn's F Ring

    Science.gov (United States)

    Meinke, B. K.; Esposito, L. W.; Stewart, G.

    2012-12-01

    Saturn's F ring is the solar system's principal natural laboratory for direct observation of accretion and disruption processes. The ring resides in the Roche zone, where tidal disruption competes with self-gravity, which allows us to observe the lifecycle of moonlets. Just as nearby moons create structure at the B ring edge (Esposito et al. 2012) and the Keeler gap (Murray 2007), the F ring "shepherding" moons Prometheus and Pandora stir up ring material and create observably changing structures on timescales of days to decades. In fact, Beurle et al (2010) show that Prometheus makes it possible for "distended, yet gravitationally coherent clumps" to form in the F ring, and Barbara and Esposito (2002) predicted a population of ~1 km bodies in the ring. In addition to the observations over the last three decades, the Cassini Ultraviolet Imaging Spectrograph (UVIS) has detected 27 statistically significant features in 101 occultations by Saturn's F ring since July 2004. Seventeen of those 27 features are associated with clumps of ring material. Two features are opaque in occultation, which makes them candidates for solid objects, which we refer to as Moonlets. The 15 other features partially block stellar signal for 22 m to just over 3.7 km along the radial expanse of the occultation. Upon visual inspection of the occultation profile, these features resemble Icicles, thus we will refer to them as such here. The density enhancements responsible for such signal attenuations are likely due to transient clumping of material, evidence that aggregations of material are ubiquitous in the F ring. Our lengthy observing campaign reveals that Icicles are likely transient clumps, while Moonlets are possible solid objects. Optical depth is an indicator of clumping because more-densely aggregated material blocks more light; therefore, it is natural to imagine moonlets as later evolutionary stage of icicle, when looser clumps of material compact to form a feature that appears

  7. Multilayer Steel Materials Deformation Resistance and Roll Force Measurement

    Directory of Open Access Journals (Sweden)

    A. G. Kolesnikov

    2014-01-01

    Full Text Available To create new types of cars, raise their reliability, gain operational life, and decrease in metal consumption of products it is necessary to improve mechanical, physical, and also special properties of the constructional materials applied in mechanical engineering. Presently, there are intensive researches and developments under way to create materials with ultrafine-grained structure (the sizes of grains in their crystal lattice make less than 1 micron in one of the measurements.BMSTU developed a manufacturing technology of multilayer steel sheets with steady ultrafine-grained structure based on the multiple hot rolling of billet as a composition consisting of the alternating metal sheets. A principled condition for implementation of such technology is existence of different crystallographic modifications in the adjoining sheets of the composition at specified temperature of rolling.Power parameters of rolling are important technical characteristics of the process. Usually, to determine a deformation resistance value when rolling the diverse multilayer materials, is used the actual resistance value averaging in relation to the components of the composition. The aim of this work is a comparative analysis of known calculated dependences with experimental data when rolling the 100-layer samples. Objects of research were the 100-layer compositions based on the alternating layers of steel 08H18N10 and U8.Experimental samples represented the vacuumized capsules with height, width, and length of 53 mm x 53 mm x 200 mm, respectively, in which there were the 100-layer packs from sheets, each of 0.5 mm, based on the composition of steels (U8+08H18N10. Rolling was made on the double-high mill with rolls of 160 mm in diameter during 19 passes to the thickness of 7 mm with the speed of 0,1 m/s. Relative sinking in each pass was accepted to be equal 10±2,5%. Rolling forces were measured by the strain-gauging method using the measuring cells, located under

  8. Dynamical Evolution of Ring-Satellite Systems

    Science.gov (United States)

    Ohtsuki, Keiji

    2005-01-01

    The goal of this research was to understand dynamical processes related to the evolution of size distribution of particles in planetary rings and application of theoretical results to explain features in the present rings of giant planets. We studied velocity evolution and accretion rates of ring particles in the Roche zone. We developed a new numerical code for the evolution of ring particle size distribution, which takes into account the above results for particle velocity evolution and accretion rates. We also studied radial diffusion rate of ring particles due to inelastic collisions and gravitational encounters. Many of these results can be also applied to dynamical evolution of a planetesimal disk. Finally, we studied rotation rates of moonlets and particles in planetary rings, which would influence the accretional evolution of these bodies. We describe our key accomplishments during the past three years in more detail in the following.

  9. Validation of the finite element simulation to estimate the rolling resistance of a non-driving wheel with experimental tests

    Directory of Open Access Journals (Sweden)

    N Dibagar

    2015-09-01

    rubber materials for the tire. Tire model consisted of three components: tread, rubber and ring. Using a soil bin and one wheel tester with their related equipment, experimental tests were carried out in the workstation of mechanics of bio system engineering department of the Urmia University. This system includes various sections such as soil storage in dimensions of 22×2×1 meter, tools carrier or tracker, soil processing equipment, dynamic system, evaluation tools and controlling systems. In order to launch the collection and supply required power for wheel carrier, an industrial three phase electromotor with 22 kW (30 hp was used. Both numerical and experimental tests were done at three levels of wheel dynamic load (1, 2, 3, 4 and 5 kN, tire inflation pressure (100, 200 and 300 kPa and four levels of speed (0.25, 0.45, 0.65, 0.9 and 1.15 m s-1 to obtain the rolling resistance of the tire. Results and discussion: In order to evaluate the performance of final non driving tire-soil model to estimate the rolling resistance, numerical results were compared with preliminary experimental data obtained from the soil-bin tests. The comparison showed reasonably good agreement between the computed and measured general pattern of the rolling resistance at the tire-soil interface under different speeds, vertical loads and inflation pressures. In both tests, a specified relation was not seen between tire velocity and its rolling resistance, as it was not seen in empirical models such as Wismar and Luce. Correlation coefficient between experimental and numerical data, in the minimum and maximum value of tire inflation pressure was computed to be 0.06 and 0.016 percent, respectively. The amount of tire rolling resistance significantly increased with increase of tire vertical load. Correlation coefficient between experimental and numerical data, in the minimum and maximum vertical loads was computed to be 80 and 87 percent, respectively. Gent and Walter obtained the same results

  10. Laboratory Simulation of Rolling Contact Fatigue Cracks in Wind Turbine Bearings Using Hydrogen Infused 100Cr6 Bearing Steel

    DEFF Research Database (Denmark)

    Janakiraman, Shravan; West, Ole; Klit, Peder

    Premature fatigue failure is observed in rolling element bearings used in wind turbine components. It is believed that decomposed hydrogen from the lubricant diffuses into the surface of the bearing inner ring making it susceptible to failure. An attempt is made to simulate the formation of these...

  11. The influence of physical properties of materials used for slide rings on the process of heat transfer in the non-contacting face seals

    Directory of Open Access Journals (Sweden)

    Blasiak Slawomir

    2017-01-01

    Full Text Available The paper presents the results of analytical solution of the model of heat transfer for non-contacting face seals. Comparative analyses were performed for various physical properties of materials used for slide rings. A mathematical model includes a series of differential equations of partial derivatives with generally used boundary conditions, i.e. the Reynold’s equation, energy equation and heat transfer equations, which describe the heat transfer in sealing rings with surrounding medium. Heat transfer equation is written in the Cartesian coordinate system and solved using the Green’s functions method. Theoretical studies made it possible to draw a number of practical conclusions on the phenomena of heat transfer in the node seal. The presented model will allow more accurate identification of the heat transfer mechanism in the node seal. The results will help to select appropriate materials for sealing rings, depending on operating conditions of non-contacting face seals.

  12. Global coupling and decoupling of the APS storage ring

    Energy Technology Data Exchange (ETDEWEB)

    Chae, Y.C.; Liu, J.; Teng, L.C.

    1993-07-01

    This paper describes a study of controlling the coupling between the horizontal and the vertical betatron oscillations in the 7-GeV Advanced Photon Source (APS) storage ring. First, we investigate the strengthening of coupling using two families of skew quadrupoles. Twenty skew quadrupoles are arranged in the 40 sectors of the storage ring and powered in such a way so as to generate both quadrature components of the required 21st harmonic. The numerical results from tracking a single particle are presented for the various configurations of skew quadrupoles. Second, we describe the global decoupling procedure to minimize the unwanted coupling effects. These are mainly due to the random roll errors of normal quadruples. It is shown that even with the rather large rms roll error of 2 mrad, the coupling effects can be compensated for with 20 skew quadrupoles each having maximum strength one order of magnitude lower than the typical normal quadrupole strength.

  13. Theoretical study of the process of chelate ring scission in β-diketonates of metals. Basic state of lithium β-diketonates

    International Nuclear Information System (INIS)

    Sirenko, N.S.; L'vov, I.B.; Vovna, V.I.

    2000-01-01

    By the methods of Mndo and ab initio with configuration interaction (CI) accounting among them two variants of torsion scission of chelate ring in lithium malonodialdeginate and acetylacetonate are investigated. Effect of used approximation and optimization on calculated barriers of rotation and scission energies of metallocycle is estimated. It is shown that value of rotation barrier in ab initio approximation (2.0-2.5 eV) is for 30-100 % more then in MNDO approximation. Accounting of CI leads to insignificant changes of chelate ring scission energies and energy barriers as in direction of increase so in decrease one [ru

  14. Interfacial fatigue stress in PVD TiN coated tool steels under rolling contact fatigue conditions

    OpenAIRE

    Carvalho, N.J.M.; Huis in ’t Veld, A.J.; Hosson, J.Th. De

    1998-01-01

    Titanium–nitrogen (TiN) films were Physical Vapour Deposited (PVD) on tool steel substrates with different hardness and surface roughness, in a Bai 640R unit using a triode ion plating (e-gun) with a high plasma density. The coated substrates were submitted to a rolling contact fatigue test technique (modified pin-on-ring test) to obtain some clarifications of the mechanism of interfacial failure. Tests were run using PVD-coated rings finished by polishing or grinding to produce different sur...

  15. Deformation in Micro Roll Forming of Bipolar Plate

    Science.gov (United States)

    Zhang, P.; Pereira, M.; Rolfe, B.; Daniel, W.; Weiss, M.

    2017-09-01

    Micro roll forming is a new processing technology to produce bipolar plates for Proton Exchange Membrane Fuel Cells (PEMFC) from thin stainless steel foil. To gain a better understanding of the deformation of the material in this process, numerical studies are necessary before experimental implementation. In general, solid elements with several layers through the material thickness are required to analyse material thinning in processes where the deformation mode is that of bending combined with tension, but this results in high computational costs. This pure solid element approach is especially time-consuming when analysing roll forming processes which generally involves feeding a long strip through a number of successive roll stands. In an attempt to develop a more efficient modelling approach without sacrificing accuracy, two solutions are numerically analysed with ABAQUS/Explicit in this paper. In the first, a small patch of solid elements over the strip width and in the centre of the “pre-cut” sheet is coupled with shell elements while in the second approach pure shell elements are used to discretize the full sheet. In the first approach, the shell element enables accounting for the effect of material being held in the roll stands on material flow while solid elements can be applied to analyse material thinning in a small discrete area of the sheet. Experimental micro roll forming trials are performed to prove that the coupling of solid and shell elements can give acceptable model accuracy while using shell elements alone is shown to result in major deviations between numerical and experimental results.

  16. Progress on low emittance tuning for the CLIC Damping Rings

    CERN Document Server

    Alabau-Gonzalvo, J; Papaphilippou, Y

    2014-01-01

    In the frame of the CLIC main Damping Ring a study on the sensitivity of the lattice to different sources of misalignment is presented. The minimum equilibrium emittance is simulated and analytically estimated under dipole and quadrupole rolls, and quadrupole and sextupole vertical offsets. The result of this study establishes alignment tolerances to preserve the vertical emittance below the design value (1 pmrad). Non-linear dynamics studies have been done to determine the dynamic aperture in the presence of misalignments.

  17. Microstructure and mechanical properties of Mg-Al-Mn-Ca alloy sheet produced by twin roll casting and sequential warm rolling

    International Nuclear Information System (INIS)

    Wang Yinong; Kang, Suk Bong; Cho, Jaehyung

    2011-01-01

    Research highlights: → This work, taking AM30 + 0.2Ca alloy as experimental material, will provide some new information as follows: one is microstructural difference between twin roll cast and ingot cast AM31-0.2Ca alloy. The other is the comparison of tensile properties after warm rolling and annealing. Suggesting the possibility of the development of wrought magnesium alloy sheets by strip casting. - Abstract: Microstructural evolution and mechanical properties of twin roll cast (TRC) Mg-3.3 wt.%Al-0.8 wt.%Mn-0.2 wt.%Ca (AM31 + 0.2Ca) alloy strip during warm rolling and subsequent annealing were investigated in this paper. The as-TRC alloy strip shows columnar dendrites in surface and equiaxed dendrites in center regions, as well as finely dispersed primary Al 8 Mn 5 particles on interdendritic boundaries which result in the beneficial effect on microstructural refinement of strip casting. The warm rolled sheets show intensively deformed band or shear band structures, as well as finely and homogeneously dispersed Al-Mn particles. No evident dynamic recrystallization (DRX) takes place during warm rolling process, which is more likely attributed to the finely dispersed particle and high solid solution of Al and Mn atoms in α-Mg matrix. After annealing at 350 deg. C for 1 h, the warm rolled TRC sheets show fine equiaxed grains around 7.8 μm in average size. It has been shown that the present TRC alloy sheet has superior tensile strength and comparative elongation compared to commercial ingot cast (IC) one, suggesting the possibility of the development of wrought magnesium alloy sheets by twin roll strip casting processing. The microstructural evolution during warm rolling and subsequent annealing as well as the resulting tensile properties were analyzed and discussed.

  18. The real time rolling shutter

    OpenAIRE

    Monaghan, David; O'Connor, Noel E.; Cleary, Anne; Connolly, Denis

    2015-01-01

    From an early age children are often told either, you are creative you should do art but stay away from science and maths. Or that you are mathematical you should do science but you're not that creative. Compounding this there also exist some traditional barriers of artistic rhetoric that say, "don't touch, don't think and don't be creative, we've already done that for you, you can just look...". The Real Time Rolling Shutter is part of a collaborative Art/Science partnership whose core tenet...

  19. Grooved tube plug rolls in

    International Nuclear Information System (INIS)

    Krausser, P.

    1991-01-01

    The removable plugs used to date by the Power Generation Group (KWU) of Siemens to seal defective steam generator tubes have a good track record. Their sealing principle is based on the elastic tensioning of three seal disks against the inside wall of the tube. Now a further removable plug is available -a roll-in plug with a metal-coated surface. It is particularly suitable for use in the roller-expanded zone of the tubes at the tube sheet. The plugs can be used in both Siemens-KWU steam generators and in steam generators manufactured in compliance with the guidelines of the ASME Code. (author)

  20. 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 ...

  1. Missile rolling tail brake torque system. [simulating bearing friction on canard controlled missiles

    Science.gov (United States)

    Davis, W. T. (Inventor)

    1984-01-01

    Apparatus for simulating varying levels of friction in the bearings of a free rolling tail afterbody on a canard-controlled missile to determine friction effects on aerodynamic control characteristics is described. A ring located between the missile body and the afterbody is utilized in a servo system to create varying levels of friction between the missile body and the afterbody to simulate bearing friction.

  2. Radiometric study of creep in ingot rolling

    International Nuclear Information System (INIS)

    Kubicek, P.; Zamyslovsky, Z.; Uherek, J.

    The radiometric study of creep during ingot rolling performed in the rolling mill of the Vitkovice Iron and Steel Works and the first results are described. Selected sites in 3 to 8 ton ingots were labelled with 2 to 3.7x10 5 Bq of 60 Co and after rolling into blocks, the transposition of the labelled sites of the ingots was investigated. The results indicate creep during rolling, local extension in certain sites under study and help to determine the inevitable bottom crop incurred in the forming. Finally, the requirements put on the radiometric apparatus for the next stages of technological research are presented. (author)

  3. METHOD OF HOT ROLLING URANIUM METAL

    Science.gov (United States)

    Kaufmann, A.R.

    1959-03-10

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

  4. Photophysical property of rhodamine-cored poly(amidoamine) dendrimers: Simultaneous effect of spirolactam ring-opening and PET process on sensing trivalent chromium ion

    International Nuclear Information System (INIS)

    Lei Yonglin; Su Yuanqiang; Huo Jichuan

    2011-01-01

    Two novel poly(amidoamine) (PAMAM) dendrimers, comprising rhodamine B unit in the core and 1-phenyl-3-methyl-5-pyrazolone unit at the periphery, have been synthesized and characterized. Both dendrimers displayed high selectivity and sensitivity towards Cr 3+ ion. As considering the potential of being applied as fluorescent sensors for Cr 3+ ion, we studied the complexes formed between the dendrimers and Cr 3+ ion. Different PAMAM dendrimers had different recognition mechanism towards Cr 3+ ion. For dendrimer G2, the recognition of Cr 3+ was mainly due to the ring-opening of spirolactam. However, it significantly depended on the simultaneous effect of ring-opening of spirolactam and photoinduced electron transfer (PET) in the case of dendrimer G3. - Highlights: → First synthesize two novel PAMAM simultaneously containing rhodamine and pyrazolone. → Novel dendrimer show high selectivity and sensitivity towards Cr 3+ . → Recognition Cr 3+ of dendrimer G2 is dominantly due to the ring-opening mechanism. → Sensing Cr 3+ of dendrimer G3 is dependent on simultaneous mechanisms of ring-opening and PET.

  5. Fabrication of cold-rolled bands of the alloy-ehi 702 in rolls

    International Nuclear Information System (INIS)

    Zhuchin, V.N.; Gindin, A.Sh.; Shaburov, V.E.; Vladimirov, S.M.; Sokolov, V.A.; Shavkun, V.V.; Perepelitsa, I.V.; Markov, V.V.; Naymov, E.P.; Evstaf'ev, P.P.

    1977-01-01

    The questions are discussed, connected with the manufacture of cold-rolled strip of alloy EI702 in reels from strip blanks. It has been established that in the manufacture of hot-rolled stock from EI702 slabs it is necessary to use powerful rolling equipment because of high resistance to deformation. The reel method for manufacturing EI702 alloy improves the rolled stock and increases percentage of serviceable stock, as well as the output

  6. Rolling into spatial disorientation: Simulator demonstration of the post-roll (Gillingham) illusion

    NARCIS (Netherlands)

    Nooij, S.A.E.; Groen, E.L.

    2011-01-01

    Introduction: Spatial disorientation (SD) is still a contributing factor in many aviation accidents, stressing the need for adequate SD training scenarios. In this article we focused on the post-roll effect (the sensation of rolling back after a roll maneuver, such as an entry of a coordinated turn)

  7. Roll-to-roll fabrication of a low-reflectance transparent conducting oxide film with subwavelength structures

    Science.gov (United States)

    Chou, Ta-Hsin; Cheng, Kuei-Yuan; Hsieh, Chih-Wei; Takaya, Yasuhiro

    2012-04-01

    The transparent conducting oxide (TCO) film is a significant component in flat panel display, e-paper and touch panel. The tin-doped indium oxide (ITO) material is one of the most popular TCOs. However, ITO has high refractive index, so the phenomenon of high-reflectance limits the wide use of ITO. In this study, the structure and mass production process of new low-reflectance TCO film is verified. Laser interference lithography and the roll-to-roll UV embossing process are used to fabricate subwavelength structures on PET film; then ITO was deposited on structures by roll-to-roll sputtering. When the dimension of structures reaches 300 nm pitch, the optical reflectance and electrical performance of film are reduced to 8.1% at wavelength 550 nm and its transmittance rate is 84.3% at the same wavelength, and the sheet resistance of this film is 50.44 Ω/□. This result indicates that the new TCO proposed in this study is suitable for touch panel and other display applications.

  8. Token ring technology report

    CERN Document Server

    2013-01-01

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

  9. Radioactive gold ring dermatitis

    International Nuclear Information System (INIS)

    Miller, R.A.; Aldrich, J.E.

    1990-01-01

    A superficial squamous cell carcinoma developed in a woman who wore a radioactive gold ring for more than 30 years. Only part of the ring was radioactive. Radiation dose measurements indicated that the dose to basal skin layer was 2.4 Gy (240 rad) per week. If it is assumed that the woman continually wore her wedding ring for 37 years since purchase, she would have received a maximum dose of approximately 4600 Gy

  10. Self-assembly of concentric quantum double rings.

    Science.gov (United States)

    Mano, Takaaki; Kuroda, Takashi; Sanguinetti, Stefano; Ochiai, Tetsuyuki; Tateno, Takahiro; Kim, Jongsu; Noda, Takeshi; Kawabe, Mitsuo; Sakoda, Kazuaki; Kido, Giyuu; Koguchi, Nobuyuki

    2005-03-01

    We demonstrate the self-assembled formation of concentric quantum double rings with high uniformity and excellent rotational symmetry using the droplet epitaxy technique. Varying the growth process conditions can control each ring's size. Photoluminescence spectra emitted from an individual quantum ring complex show peculiar quantized levels that are specified by the carriers' orbital trajectories.

  11. Dynamical black rings with a positive cosmological constant

    International Nuclear Information System (INIS)

    Kimura, Masashi

    2009-01-01

    We construct dynamical black ring solutions in the five-dimensional Einstein-Maxwell system with a positive cosmological constant and investigate the geometrical structure. The solutions describe the physical process such that a thin black ring at early time shrinks and changes into a single black hole as time increases. We also discuss the multiblack rings and the coalescence of them.

  12. A new solution method for wheel/rail rolling contact.

    Science.gov (United States)

    Yang, Jian; Song, Hua; Fu, Lihua; Wang, Meng; Li, Wei

    2016-01-01

    To solve the problem of wheel/rail rolling contact of nonlinear steady-state curving, a three-dimensional transient finite element (FE) model is developed by the explicit software ANSYS/LS-DYNA. To improve the solving speed and efficiency, an explicit-explicit order solution method is put forward based on analysis of the features of implicit and explicit algorithm. The solution method was first applied to calculate the pre-loading of wheel/rail rolling contact with explicit algorithm, and then the results became the initial conditions in solving the dynamic process of wheel/rail rolling contact with explicit algorithm as well. Simultaneously, the common implicit-explicit order solution method is used to solve the FE model. Results show that the explicit-explicit order solution method has faster operation speed and higher efficiency than the implicit-explicit order solution method while the solution accuracy is almost the same. Hence, the explicit-explicit order solution method is more suitable for the wheel/rail rolling contact model with large scale and high nonlinearity.

  13. Roll-to-roll embedded conductive structures integrated into organic photovoltaic devices

    International Nuclear Information System (INIS)

    Van de Wiel, H J; Galagan, Y; Van Lammeren, T J; De Riet, J F J; Gilot, J; Nagelkerke, M G M; Lelieveld, R H C A T; Shanmugam, S; Pagudala, A; Groen, W A; Hui, D

    2013-01-01

    Highly conductive screen printed metallic (silver) structures (current collecting grids) combined with poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) are a viable replacement for indium tin oxide (ITO) and inkjet printed silver as transparent electrode materials. To provide successful integration into organic photovoltaic (OPV) devices, screen printed silver current collecting grids should be embedded into a substrate to avoid topology issues. In this study micron-thick conductive structures are embedded and integrated into OPV devices. The embedded structures are produced roll-to-roll with optimized process settings and materials. Topology measurements show that the embedded grids are well suited for integration into OPV devices since the surface is almost without spikes and has low surface roughness. JV measurements of OPV devices with embedded structures on a polyethylene terephthalate/silicon nitride (PET/SiN) substrate show an efficiency of 2.15%, which is significantly higher than identical flexible devices with ITO (1.02%) and inkjet printed silver (1.48%). The use of embedded screen printed silver instead of ITO and inkjet printed silver in OPV devices will allow for higher efficiency devices which can be produced with larger design and process freedom. (paper)

  14. 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.

  15. Investigation of mechanical properties of bimetallic square tubes produced by shape rolling of Al/Cu circular pipes

    International Nuclear Information System (INIS)

    Tajyar, Ali; Masoumi, Abolfazi

    2016-01-01

    We investigated the effect of shape rolling process on the bond strength and mechanical properties of Al/Cu bimetal pipes. A bimetal circular pipe was fabricated by the explosive welding process. Then, the bimetal explosive-welded circular pipe was reshaped to a square tube by means of the shape rolling process. The mechanical properties of explosive welded pipes and shape-rolled tubes at the various stages of the rolling process were experimentally investigated by using the shear testing, micro hardness testing along the thicknesses and measurement of yield. The obtained results show that with the increase of roll gap reduction during the various stages, the hardness increases, while the shear strength decreases. However, their effects on hardness increase are not the same for both materials. Yield stress measurement results indicate that the average yield stress increases during explosive welding and also shape rolling process, but the rate of increase is more intensive in the explosive welding process. Moreover, the morphology of the interface before and after the Shape rolling was examined by Optical microscope (OM) and the presence of the intermetallic compounds at the interface was investigated by the electron microscope (SEM) and EDS analysis. Examination of the interfaces morphology revealed that, due to the brittle nature of the intermetallic compounds at the joining interface, the nucleation and propagation of micro cracks accelerated during the shape rolling process and the amount of micro cracks increases which makes the shear strength decrease

  16. Investigation of mechanical properties of bimetallic square tubes produced by shape rolling of Al/Cu circular pipes

    Energy Technology Data Exchange (ETDEWEB)

    Tajyar, Ali; Masoumi, Abolfazi [School of Mechanical Engineering, College of Engineering, University of Tehran, Tehran (Iran, Islamic Republic of)

    2016-09-15

    We investigated the effect of shape rolling process on the bond strength and mechanical properties of Al/Cu bimetal pipes. A bimetal circular pipe was fabricated by the explosive welding process. Then, the bimetal explosive-welded circular pipe was reshaped to a square tube by means of the shape rolling process. The mechanical properties of explosive welded pipes and shape-rolled tubes at the various stages of the rolling process were experimentally investigated by using the shear testing, micro hardness testing along the thicknesses and measurement of yield. The obtained results show that with the increase of roll gap reduction during the various stages, the hardness increases, while the shear strength decreases. However, their effects on hardness increase are not the same for both materials. Yield stress measurement results indicate that the average yield stress increases during explosive welding and also shape rolling process, but the rate of increase is more intensive in the explosive welding process. Moreover, the morphology of the interface before and after the Shape rolling was examined by Optical microscope (OM) and the presence of the intermetallic compounds at the interface was investigated by the electron microscope (SEM) and EDS analysis. Examination of the interfaces morphology revealed that, due to the brittle nature of the intermetallic compounds at the joining interface, the nucleation and propagation of micro cracks accelerated during the shape rolling process and the amount of micro cracks increases which makes the shear strength decrease.

  17. The Effect of Cold Rolling on the Hydrogen Susceptibility of 5083 Aluminum Alloy

    Directory of Open Access Journals (Sweden)

    E.P. Georgiou

    2017-10-01

    Full Text Available This work focuses in investigating the effect of cold deformation on the cathodic hydrogen charging of 5083 aluminum alloy. The aluminium alloy was submitted to a cold rolling process, until the average thickness of the specimens was reduced by 7% and 15%, respectively. A study of the structure, microhardness, and tensile properties of the hydrogen charged aluminium specimens, with and without cold rolling, indicated that the cold deformation process led to an increase of hydrogen susceptibility of this aluminum alloy.

  18. Pipe Rolling from Continuous Cast Metal

    International Nuclear Information System (INIS)

    Zhordania, I.; Chkhartishvili, I.; Lordkipanidze, J.; Melashvili, Z.; Papava, K.; Khundadze, K.

    2007-01-01

    The approach to manufacturing of high quality pipes as a result of solid and hollow billet rolling from continuous cast metal is shown. Optimal parameters of piercing, temperature of piercing and piercing rolling mill rollers speed have been experimentally established. (author)

  19. Numerical analysis of Swiss roll metamaterials

    International Nuclear Information System (INIS)

    Demetriadou, A; Pendry, J B

    2009-01-01

    A Swiss roll metamaterial is a resonant magnetic medium, with a negative magnetic permeability for a range of frequencies, due to its self-inductance and self-capacitance components. In this paper, we discuss the band structure, S-parameters and effective electromagnetic parameters of Swiss roll metamaterials, with both analytical and numerical results, which show an exceptional convergence.

  20. Efficient Circulation of Railway Rolling Stock

    NARCIS (Netherlands)

    A. Alfieri (Arianna); R. Groot (Rutger); L.G. Kroon (Leo); A. Schrijver (Lex)

    2002-01-01

    textabstractRailway rolling stock (locomotives, carriages, and train units) is one of the most significant cost sources for operatorsof passenger trains, both public and private. Rolling stock costsare due to material acquisition, power supply, and material maintenance. The efficient circulation of

  1. Validation of single ball rolling contact fatigue machine dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Allison, Bryan [SKF Aeroengine, Falconer (United States)

    2017-01-15

    Single ball test machines are a common method for accelerated rolling contact fatigue testing of bearing materials. Historically, it has always been assumed that the force applied by the retaining bars is negligible, without any data to support this claim. In this study, strain gauges were placed on the retaining bars to determine the load experienced by the retaining bars. This value was then compared to the applied load. It was found that a load of approximately 4 N was transferred to the retainer by the test ball during steady state operation, when a 8385 N load was applied to the ball via the rings. A simulation of the system was also created and successfully predicted the expected loads with reasonable accuracy. This information, as well as the technique of strain gauging the retaining bars, may be useful in the development of similar testing machinery.

  2. Storage ring development at the National Synchrotron Light Source

    International Nuclear Information System (INIS)

    Krinsky, S.; Bittner, J.; Fauchet, A.M.; Johnson, E.D.; Keane, J.; Murphy, J.; Nawrocky, R.J.; Rogers, J.; Singh, O.V.; Yu, L.H.

    1991-09-01

    This report contains papers on the following topics: Transverse Beam Profile Monitor; Bunch Length Measurements in the VUV Storage Ring; Photoelectric Effect Photon Beam Position Monitors; RF Receivers for Processing Electron Beam Pick-up Electrode Signals; Real-Time Global Orbit Feedback Systems; Local Orbit Feedback; Active Interlock System for High Power Insertion Devices in the X-ray Ring; Bunch Lengthening Cavity for the VUV Ring; SXLS Storage Ring Design

  3. Constant-roll (quasi-)linear inflation

    Science.gov (United States)

    Karam, A.; Marzola, L.; Pappas, T.; Racioppi, A.; Tamvakis, K.

    2018-05-01

    In constant-roll inflation, the scalar field that drives the accelerated expansion of the Universe is rolling down its potential at a constant rate. Within this framework, we highlight the relations between the Hubble slow-roll parameters and the potential ones, studying in detail the case of a single-field Coleman-Weinberg model characterised by a non-minimal coupling of the inflaton to gravity. With respect to the exact constant-roll predictions, we find that assuming an approximate slow-roll behaviour yields a difference of Δ r = 0.001 in the tensor-to-scalar ratio prediction. Such a discrepancy is in principle testable by future satellite missions. As for the scalar spectral index ns, we find that the existing 2-σ bound constrains the value of the non-minimal coupling to ξphi ~ 0.29–0.31 in the model under consideration.

  4. Analytical method for establishing indentation rolling resistance

    Directory of Open Access Journals (Sweden)

    Gładysiewicz Lech

    2018-01-01

    Full Text Available Belt conveyors are highly reliable machines able to work in special operating conditions. Harsh environment, long distance of transporting and great mass of transported martials are cause of high energy usage. That is why research in the field of belt conveyor transportation nowadays focuses on reducing the power consumption without lowering their efficiency. In this paper, previous methods for testing rolling resistance are described, and new method designed by authors was presented. New method of testing rolling resistance is quite simple and inexpensive. Moreover it allows to conduct the experimental tests of the impact of different parameters on the value of indentation rolling resistance such as core design, cover thickness, ambient temperature, idler travel frequency, or load value as well. Finally results of tests of relationship between rolling resistance and idler travel frequency and between rolling resistance and idler travel speed was presented.

  5. Analytical method for establishing indentation rolling resistance

    Science.gov (United States)

    Gładysiewicz, Lech; Konieczna, Martyna

    2018-01-01

    Belt conveyors are highly reliable machines able to work in special operating conditions. Harsh environment, long distance of transporting and great mass of transported martials are cause of high energy usage. That is why research in the field of belt conveyor transportation nowadays focuses on reducing the power consumption without lowering their efficiency. In this paper, previous methods for testing rolling resistance are described, and new method designed by authors was presented. New method of testing rolling resistance is quite simple and inexpensive. Moreover it allows to conduct the experimental tests of the impact of different parameters on the value of indentation rolling resistance such as core design, cover thickness, ambient temperature, idler travel frequency, or load value as well. Finally results of tests of relationship between rolling resistance and idler travel frequency and between rolling resistance and idler travel speed was presented.

  6. New perspectives on constant-roll inflation

    Science.gov (United States)

    Cicciarella, Francesco; Mabillard, Joel; Pieroni, Mauro

    2018-01-01

    We study constant-roll inflation using the β-function formalism. We show that the constant rate of the inflaton roll is translated into a first order differential equation for the β-function which can be solved easily. The solutions to this equation correspond to the usual constant-roll models. We then construct, by perturbing these exact solutions, more general classes of models that satisfy the constant-roll equation asymptotically. In the case of an asymptotic power law solution, these corrections naturally provide an end to the inflationary phase. Interestingly, while from a theoretical point of view (in particular in terms of the holographic interpretation) these models are intrinsically different from standard slow-roll inflation, they may have phenomenological predictions in good agreement with present cosmological data.

  7. Effects of microalloying on hot-rolled and cold-rolled Q&P steels

    Science.gov (United States)

    Azevedo de Araujo, Ana Luiza

    Third generation advanced high strength steels (AHSS) have been a major focus in steel development over the last decade. The premise of these types of steel is based on the potential to obtain excellent combinations of strength and ductility with low-alloy compositions by forming mixed microstructures containing retained austenite (RA). The development of heat treatments able to achieve the desired structures and properties, such as quenching and partitioning (Q&P) steels, is driven by new requirements to increase vehicle fuel economy by reducing overall weight while maintaining safety and crashworthiness. Microalloying additions of niobium (Nb) and vanadium (V) in sheet products are known to provide strengthening via grain refinement and precipitation hardening and may influence RA volume fraction and transformation behavior. Additions of microalloying elements in Q&P steels have not been extensively studied to date, however. The objective of the present study was to begin to understand the potential roles of Nb and V in hot-rolled and cold-rolled Q&P steel. For that, a common Q&P steel composition was selected as a Base alloy with 0.2C-1.5Si-2.0Mn (wt. %). Two alloys with an addition of Nb (0.02 and 0.04 wt. %) and one with an addition of V (0.06 wt. %) to the Base alloy were investigated. Both hot-rolled and cold-rolled/annealed Q&P simulations were conducted. In the hot-rolled Q&P study, thermomechanical processing was simulated via hot torsion testing in a GleebleRTM 3500, and four coiling temperatures (CT) were chosen. Microstructural evaluation (including RA measurements via electron backscattered diffraction - EBSD) and hardness measurements were performed for all alloys and coiling conditions. The analysis showed that Nb additions led to overall refinement of the prior microstructure. Maximum RA fractions were measured at the 375 °C CT, and microalloying was associated with increased RA in this condition when compared to the Base alloy. A change in

  8. Evolution of the texture, mechanical properties, and microstructure of Cu-2.7Be alloys during hot cross-rolling

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Daibo; Liu, Chuming; Liu, Yadi; Gao, Yonghao; Jiang, Shunong [Central South University, School of Materials Science and Engineering, Changsha (China); Han, Tan [Suzhou Kinkou Copper Industry Limited Liability Company, Taicang (China)

    2015-09-15

    The evolution of the microstructure and texture of Cu-2.7Be alloys during hot rolling was investigated and related to the mechanical properties of the resulting sheets. Hot cross-rolling is shown to be an effective way to refine the hard and brittle secondary-phase particles in Cu-2.7Be alloys. The Cu- and brass-type textures increase and decrease in prevalence, respectively, during the rolling process. The yield strengths along the first and second rolling directions, and 45 to the former, are all enhanced because the corresponding Schmid factors decrease as the sheets are rolled thinner. The ductility anisotropy of the as-rolled sheets is related to the distribution and shape of the secondary-phase particles therein. (orig.)

  9. Experiment and simulation analysis of roll-bonded Q235 steel plate

    International Nuclear Information System (INIS)

    Zhao, G.; Huang, Q.; Zhou, C.; Zhang, Z.; Ma, L.; Wang, X.

    2016-01-01

    Heavy-gauge Q235 steel plate was roll bonded, and the process was simulated using MARC software. Ultrasonic testing results revealed the presence of cracks and lamination defects in an 80-mm clad steel sheet, especially at the head and tail of the steel plate. There were non-uniform ferrite + pearlite microstructures and unbound areas at a bond interface. Through scanning electron microscopy analysis, long cracks and additional inclusions in the cracks were observed at the interface. A fracture analysis revealed non-uniform inclusions that pervaded the interface. Moreover, MARC simulations demonstrated that there was little equivalent strain at the centre of the slab during the first rolling pass. The equivalent centre increased to 0.5 by the fourth rolling pass. Prior to the final pass, the equivalent strain was not consistent across the thickness direction, preventing bonding interfaces from forming consistent deformation and decreasing the residual stress. The initial rolling reduction rate should not be very small (e.g. 5%) as it is averse to the coordination of rolling deformation. Such rolling processes are averse to the rolling bond. (Author)

  10. Effect of surface shear on cube texture formation in heavy cold-rolled Cu-45 at%Ni alloy substrates

    DEFF Research Database (Denmark)

    Tian, Hui; Suo, Hongli; Liang, Yaru

    2015-01-01

    Two types of Cu-45 at%Ni alloy thin tapes with and without surface shear were obtained by different heavy cold rolling processes. The deformation and recrystallization textures of the two tapes were thoroughly investigated by electron back scattering diffraction technique. The results showed...... that a shear texture mainly covered the surface of the heavy deformed tapes because of the fraction between the surface of rolling mills and the thin tapes when the rolling force strongly reduced at high strain, which significantly reduced the fraction of rolling texture on the surface of the Cu-45at %Ni alloy...

  11. Metal-assisted exfoliation (MAE): green, roll-to-roll compatible method for transferring graphene to flexible substrates

    International Nuclear Information System (INIS)

    Zaretski, Aliaksandr V; Moetazedi, Herad; Kong, Casey; Sawyer, Eric J; Savagatrup, Suchol; Valle, Eduardo; O’Connor, Timothy F; Printz, Adam D; Lipomi, Darren J

    2015-01-01

    Graphene is expected to play a significant role in future technologies that span a range from consumer electronics, to devices for the conversion and storage of energy, to conformable biomedical devices for healthcare. To realize these applications, however, a low-cost method of synthesizing large areas of high-quality graphene is required. Currently, the only method to generate large-area single-layer graphene that is compatible with roll-to-roll manufacturing destroys approximately 300 kg of copper foil (thickness = 25 μm) for every 1 g of graphene produced. This paper describes a new environmentally benign and scalable process of transferring graphene to flexible substrates. The process is based on the preferential adhesion of certain thin metallic films to graphene; separation of the graphene from the catalytic copper foil is followed by lamination to a flexible target substrate in a process that is compatible with roll-to-roll manufacturing. The copper substrate is indefinitely reusable and the method is substantially greener than the current process that uses relatively large amounts of corrosive etchants to remove the copper. The sheet resistance of the graphene produced by this new process is unoptimized but should be comparable in principle to that produced by the standard method, given the defects observable by Raman spectroscopy and the presence of process-induced cracks. With further improvements, this green, inexpensive synthesis of single-layer graphene could enable applications in flexible, stretchable, and disposable electronics, low-profile and lightweight barrier materials, and in large-area displays and photovoltaic modules. (paper)

  12. Metal-assisted exfoliation (MAE): green, roll-to-roll compatible method for transferring graphene to flexible substrates

    Science.gov (United States)

    Zaretski, Aliaksandr V.; Moetazedi, Herad; Kong, Casey; Sawyer, Eric J.; Savagatrup, Suchol; Valle, Eduardo; O'Connor, Timothy F.; Printz, Adam D.; Lipomi, Darren J.

    2015-01-01

    Graphene is expected to play a significant role in future technologies that span a range from consumer electronics, to devices for the conversion and storage of energy, to conformable biomedical devices for healthcare. To realize these applications, however, a low-cost method of synthesizing large areas of high-quality graphene is required. Currently, the only method to generate large-area single-layer graphene that is compatible with roll-to-roll manufacturing destroys approximately 300 kg of copper foil (thickness = 25 μm) for every 1 g of graphene produced. This paper describes a new environmentally benign and scalable process of transferring graphene to flexible substrates. The process is based on the preferential adhesion of certain thin metallic films to graphene; separation of the graphene from the catalytic copper foil is followed by lamination to a flexible target substrate in a process that is compatible with roll-to-roll manufacturing. The copper substrate is indefinitely reusable and the method is substantially greener than the current process that uses relatively large amounts of corrosive etchants to remove the copper. The sheet resistance of the graphene produced by this new process is unoptimized but should be comparable in principle to that produced by the standard method, given the defects observable by Raman spectroscopy and the presence of process-induced cracks. With further improvements, this green, inexpensive synthesis of single-layer graphene could enable applications in flexible, stretchable, and disposable electronics, low-profile and lightweight barrier materials, and in large-area displays and photovoltaic modules.

  13. Inflation with a constant rate of roll

    International Nuclear Information System (INIS)

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

    2015-01-01

    We consider an inflationary scenario where the rate of inflaton roll defined by ·· φ/H φ-dot 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

  14. Prediction of deformation textures in asymmetric rolling of aluminium alloys

    OpenAIRE

    Shore, Diarmuid; Nguyen-Minh, Tuan; Kestens, Leo; Van Bael, Albert

    2015-01-01

    Asymmetric cold rolling (ASR) has been shown to have potential to improve the formability of aluminium sheet alloys in deep drawing by increasing the normal plastic anisotropy, mainly as a result of the additional shear strains it imposes and the consequent alteration of the crystallographic texture. It is generally found that the process produces shear strains that vary across the sheet thickness, resulting in heterogeneity of the texture and related properties. While it may be a typical des...

  15. Inflationary dynamics with a smooth slow-roll to constant-roll era transition

    Energy Technology Data Exchange (ETDEWEB)

    Odintsov, S.D. [ICREA, Passeig Luis Companys, 23, 08010 Barcelona (Spain); Oikonomou, V.K., E-mail: odintsov@ieec.uab.es, E-mail: v.k.oikonomou1979@gmail.com [Laboratory for Theoretical Cosmology, Tomsk State University of Control Systems and Radioelectronics (TUSUR), Lenin Avenue 40, 634050 Tomsk (Russian Federation)

    2017-04-01

    In this paper we investigate the implications of having a varying second slow-roll index on the canonical scalar field inflationary dynamics. We shall be interested in cases that the second slow-roll can take small values and correspondingly large values, for limiting cases of the function that quantifies the variation of the second slow-roll index. As we demonstrate, this can naturally introduce a smooth transition between slow-roll and constant-roll eras. We discuss the theoretical implications of the mechanism we introduce and we use various illustrative examples in order to better understand the new features that the varying second slow-roll index introduces. In the examples we will present, the second slow-roll index has exponential dependence on the scalar field, and in one of these cases, the slow-roll era corresponds to a type of α-attractor inflation. Finally, we briefly discuss how the combination of slow-roll and constant-roll may lead to non-Gaussianities in the primordial perturbations.

  16. On the Laurent polynomial rings

    International Nuclear Information System (INIS)

    Stefanescu, D.

    1985-02-01

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

  17. Analysis of flat rolling of superconducting silver/ceramic composites

    DEFF Research Database (Denmark)

    Bech, Jakob Ilsted; Nielsen, Morten Storgård; Eriksen, Morten

    2001-01-01

    The flat rolling process from wire to tape is presumably the most crucial link in the chain of mechanical processes leading from loose powder and silver tubes to the final superconducting Ag/BSCCO tape. In order to improve the critical current density of the superconducting filaments, one must...... process these to the highest possible density without at the same time introducing failures as large cracks and macroscopic shear bands. In order to analyse and optimise the process, the interaction between the involved materials and their very different mechanical properties must be taken into account...

  18. Look! It's Rock'n'roll!

    DEFF Research Database (Denmark)

    Lindelof, Anja

    2007-01-01

    , and dates. Consult your library or click here for more information on citing sources. -------------------------------------------------------------------------------- Anja Mølle Lindelof. (2007). Look! it's rock'n'roll! how television participated in shaping the visual genre conventions of popular music...... to personal names, capitalization, and dates. Consult your library or click here for more information on citing sources. -------------------------------------------------------------------------------- Anja Mølle Lindelof. "Look! It's Rock'n'roll! How television participated in shaping the visual genre....... Pay special attention to personal names, capitalization, and dates. Consult your library or click here for more information on citing sources. -------------------------------------------------------------------------------- TY - JOUR T1 - Look! It's Rock'n'roll! How television participated in shaping...

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

    Science.gov (United States)

    Huang, Chen-Guang; Zhou, You-He

    2018-03-01

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

  20. A Scalable Route to Nanoporous Large-Area Atomically Thin Graphene Membranes by Roll-to-Roll Chemical Vapor Deposition and Polymer Support Casting.

    Science.gov (United States)

    Kidambi, Piran R; Mariappan, Dhanushkodi D; Dee, Nicholas T; Vyatskikh, Andrey; Zhang, Sui; Karnik, Rohit; Hart, A John

    2018-03-28

    Scalable, cost-effective synthesis and integration of graphene is imperative to realize large-area applications such as nanoporous atomically thin membranes (NATMs). Here, we report a scalable route to the production of NATMs via high-speed, continuous synthesis of large-area graphene by roll-to-roll chemical vapor deposition (CVD), combined with casting of a hierarchically porous polymer support. To begin, we designed and built a two zone roll-to-roll graphene CVD reactor, which sequentially exposes the moving foil substrate to annealing and growth atmospheres, with a sharp, isothermal transition between the zones. The configurational flexibility of the reactor design allows for a detailed evaluation of key parameters affecting graphene quality and trade-offs to be considered for high-rate roll-to-roll graphene manufacturing. With this system, we achieve synthesis of uniform high-quality monolayer graphene ( I D / I G casting and postprocessing, show size-selective molecular transport with performance comparable to that of membranes made from conventionally synthesized graphene. Therefore, this work establishes the feasibility of a scalable manufacturing process of NATMs, for applications including protein desalting and small-molecule separations.

  1. Large Area 2D and 3D Colloidal Photonic Crystals Fabricated by a Roll-to-Roll Langmuir-Blodgett Method.

    Science.gov (United States)

    Parchine, Mikhail; McGrath, Joe; Bardosova, Maria; Pemble, Martyn E

    2016-06-14

    We present our results on the fabrication of large area colloidal photonic crystals on flexible poly(ethylene terephthalate) (PET) film using a roll-to-roll Langmuir-Blodgett technique. Two-dimensional (2D) and three-dimensional (3D) colloidal photonic crystals from silica nanospheres (250 and 550 nm diameter) with a total area of up to 340 cm(2) have been fabricated in a continuous manner compatible with high volume manufacturing. In addition, the antireflective properties and structural integrity of the films have been enhanced via the use of a second roll-to-roll process, employing a slot-die coating of an optical adhesive over the photonic crystal films. Scanning electron microscopy images, atomic force microscopy images, and UV-vis optical transmission and reflection spectra of the fabricated photonic crystals are analyzed. This analysis confirms the high quality of the 2D and 3D photonic crystals fabricated by the roll-to-roll LB technique. Potential device applications of the large area 2D and 3D colloidal photonic crystals on flexible PET film are briefly reviewed.

  2. Heavy ion storage rings

    International Nuclear Information System (INIS)

    Schuch, R.

    1987-01-01

    A brief overview of synchrotron storage rings for heavy ions, which are presently under construction in different accelerator laboratories is given. Ions ranging from protons up to uranium ions at MeV/nucleon energies will be injected into these rings using multiturn injection from the accelerators available or being built in these laboratories. After injection, it is planned to cool the phase space distribution of the ions by merging them with cold electron beams or laser beams, or by using stochastic cooling. Some atomic physics experiments planned for these rings are presented. 35 refs

  3. Faithfully quadratic rings

    CERN Document Server

    Dickmann, M

    2015-01-01

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

  4. Depreciation of bearing blocks of rollers of roller conveyers of rolling mills

    Science.gov (United States)

    Artiukh, Viktor; Belyaev, Michael; Ignatovich, Igor; Miloradova, Nadezda

    2017-10-01

    Essential increase in functional durability of a node of a roller of the roller conveyer of the rolling mill by the rational choice of parameters of the small-size shock-absorber (buffer adapter) is shown. At the same time dimensions of a node don’t change, costs of reconstruction are small. The possibility of management of loadings in a bearing node without change of technology parameters of the process which is carried out by the rolling mill is confirmed.

  5. Effects of cellulose fiber with different fiber length on rheological properties of wheat dough and quality of baked rolls.

    Science.gov (United States)

    Lauková, Michaela; Kohajdová, Zlatica; Karovičová, Jolana; Kuchtová, Veronika; Minarovičová, Lucia; Tomášiková, Lenka

    2017-09-01

    Powdered cellulose is often used in cereal processing industry. The effects of partial replacement (0.5%, 1%, 2% and 5%) of wheat flour by cellulose fiber with different fiber length (80, 120 and 220 µm) on rheological properties of wheat dough and qualitative parameters of baked rolls were studied. Sensory evaluation of baked products was also performed. Mixing and pasting properties of dough were determined by Mixolab. Generally, cellulose-enriched dough was characterized with higher water absorption, dough stability and parameters C2 and C3. Moreover, it was found that parameters C4 and C5 increased with increasing cellulose fiber length. From the results, it was also concluded that the physical parameters of baked rolls containing cellulose were reduced. It was also observed that the incorporation of cellulose fiber with shorter fiber length concluded in lower rolls volume compared to cellulose fiber with long fiber length. Texture analyses showed that the firmness of rolls containing cellulose at the substitution level 5% was significantly higher than those of the control, whereas the springiness of wheat rolls was not significantly affected. It was also recorded that the firmness and cohesiveness of baked rolls were higher after the addition of cellulose fiber with shorter fiber length. Sensory evaluation indicated that baked rolls with cellulose addition up to 1% were comparable with control rolls. Results also showed that higher levels of cellulose significantly decreased crust, taste, color and porosity of rolls.

  6. Study of the influence between the strength of antibending of working rolls on the widening during hot rolling of thin sheet metal

    Directory of Open Access Journals (Sweden)

    U. Muhin

    2016-07-01

    Full Text Available Based on the variation principle of Jourdan was developed a mathematical model of the process of widening freely in hot rolling of thin sheet metal. The principle applies to rigid-plastic materials and for the cinematically admissible area of speeds. The developed model allows to study the distribution of the widening on the length of the deformation zone depending on the parameters of the rolling process and sheet metal. Results are obtained, characterizing the size of the widening and effectiveness of the process control on tension at the entrance and exit from the stand. The widening is dependent on the strength of anti bending.

  7. Roll paper pilot. [mathematical model for predicting pilot rating of aircraft in roll task

    Science.gov (United States)

    Naylor, F. R.; Dillow, J. D.; Hannen, R. A.

    1973-01-01

    A mathematical model for predicting the pilot rating of an aircraft in a roll task is described. The model includes: (1) the lateral-directional aircraft equations of motion; (2) a stochastic gust model; (3) a pilot model with two free parameters; and (4) a pilot rating expression that is a function of rms roll angle and the pilot lead time constant. The pilot gain and lead time constant are selected to minimize the pilot rating expression. The pilot parameters are then adjusted to provide a 20% stability margin and the adjusted pilot parameters are used to compute a roll paper pilot rating of the aircraft/gust configuration. The roll paper pilot rating was computed for 25 aircraft/gust configurations. A range of actual ratings from 2 to 9 were encountered and the roll paper pilot ratings agree quite well with the actual ratings. In addition there is good correlation between predicted and measured rms roll angle.

  8. Plasmonic color metasurfaces fabricated by a high speed roll-to-roll method

    DEFF Research Database (Denmark)

    Murthy, Swathi; Pranov, Henrik; Feidenhans'l, Nikolaj Agentoft

    2017-01-01

    Lab-scale plasmonic color printing using nano-structured and subsequently metallized surfaces have been demonstrated to provide vivid colors. However, upscaling these structures for large area manufacturing is extremely challenging due to the requirement of nanometer precision of metal thickness....... In this study, we have investigated a plasmonic color meta-surface design that can be easily upscaled. We have demonstrated the feasibility of fabrication of these plasmonic color surfaces by a high-speed roll-to-roll method, comprising roll-to-roll extrusion coating at 10 m min-1 creating a polymer foil having...... 100 nm deep pits of varying sub-wavelength diameter and pitch length. Subsequently this polymer foil was metallized and coated also by high-speed roll-to-roll methods. The perceived colors have high tolerance towards the thickness of the metal layer, when this thickness exceeds the depths of the pits...

  9. Improved Fatigue Performance of Threaded Drillstring Connections by Cold Rolling

    Energy Technology Data Exchange (ETDEWEB)

    Kristoffersen, Steinar

    2002-01-01

    The research work presented in this thesis is concerned with analytical, numerical and experimental studies of the effect of cold rolling on the fatigue behaviour of threaded drillstring connections. A comprehensive literature study is made of the various effects on the fatigue behaviour of residual stresses introduced by mechanical deformation of notched components. Some of the effects studied are cyclic hardening behaviour after prestraining, cyclic creep, fatigue initiation in prestrained materials, short cracks and crack growth models including crack closure. Residual stresses were introduced in the surface of a smooth pipe by a rolling device to simulate a cold rolling process and verify the calculated residual stresses by measurements. Strain hardening and contact algorithm of the two bodies were incorporated in the FE analyses. Two significant errors were found in the commercial software package for residual stress evaluation, Restran v. 3.3.2a also called SINT, when using the Schajer method. The Schajer algorithm is the only hole-drilling algorithm without theoretical shortcomings, and is recommended when measuring large residual stress gradients in the depth direction. Using the Schajer method solved by in-house Matlab-routines good agreement between measured residual stress gradients and residual stress gradients from FE analyses was found. Full scale fatigue tests were performed on pipes cut from used drillstrings with notches of similar geometry as threads used in drillstring connections. The simulated threads consisted of four full depth helix notches with runouts at the surface. The pipe threads were cold rolled and fatigue tested in a full-scale four-point rotating bending fatigue testing rig. The test results showed that cold rolling had an effect on the crack initiation period. A major part of the fatigue life was with cracks observed at the notch root, but due to the increased fatigue crack propagation resistance the final fracture initiated at

  10. Is the bell ringing?

    CERN Multimedia

    Francesco Poppi

    2010-01-01

    During the Nobel prize-winning UA1 experiment, scientists in the control room used to ring a bell if a particularly interesting event had occurred. Today, the “CMS Exotica hotline” routine produces a daily report that lists the exotic events that were recorded the day before.   Display of an event selected by the Exotica routine. Take just a very small fraction of the available data (max. 5%); define the events that you want to keep and set the parameters accordingly; run the Exotica routine and only look at the very few images that the system has selected for you. This is the recipe that a small team of CMS researchers has developed to identify the signals coming from possible new physics processes. “This approach does not replace the accurate data analysis on the whole set of data. However, it is a very fast and effective way to focus on just a few events that are potentially very interesting”, explains Maurizio Pierini (CERN), who developed the...

  11. Integral finite element analysis of turntable bearing with flexible rings

    Science.gov (United States)

    Deng, Biao; Liu, Yunfei; Guo, Yuan; Tang, Shengjin; Su, Wenbin; Lei, Zhufeng; Wang, Pengcheng

    2018-03-01

    This paper suggests a method to calculate the internal load distribution and contact stress of the thrust angular contact ball turntable bearing by FEA. The influence of the stiffness of the bearing structure and the plastic deformation of contact area on the internal load distribution and contact stress of the bearing is considered. In this method, the load-deformation relationship of the rolling elements is determined by the finite element contact analysis of a single rolling element and the raceway. Based on this, the nonlinear contact between the rolling elements and the inner and outer ring raceways is same as a nonlinear compression spring and bearing integral finite element analysis model including support structure was established. The effects of structural deformation and plastic deformation on the built-in stress distribution of slewing bearing are investigated on basis of comparing the consequences of load distribution, inner and outer ring stress, contact stress and other finite element analysis results with the traditional bearing theory, which has guiding function for improving the design of slewing bearing.

  12. The Effect of Rolling As-Cast and Homogenized U-10Mo Samples on the Microstructure Development and Recovery Curves

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-07-30

    Over the past several years Pacific Northwest National Laboratory (PNNL) has been actively involved in supporting the U.S. Department of Energy National Nuclear Security Administration Office of Material Management and Minimization (formerly Global Threat Reduction Initiative). The U.S. High- Power Research Reactor (USHPRR) project is developing alternatives to existing highly enriched uranium alloy fuel to reduce the proliferation threat. One option for a high-density metal fuel is uranium alloyed with 10 wt% molybdenum (U-10Mo). Forming the U-10Mo fuel plates/foils via rolling is an effective technique and is actively being pursued as part of the baseline manufacturing process. The processing of these fuel plates requires systematic investigation/understanding of the pre- and post-rolling microstructure, end-state mechanical properties, residual stresses, and defects, their effect on the mill during processing, and eventually, their in-reactor performance. In the work documented herein, studies were conducted to determine the effect of cold and hot rolling the as-cast and homogenized U-10Mo on its microstructure and hardness. The samples were homogenized at 900°C for 48 h, then later annealed for several durations and temperatures to investigate the effect on the material’s microstructure and hardness. The rolling of the as-cast plate, both hot and cold, was observed to form a molybdenum-rich and -lean banded structure. The cold rolling was ineffective, and in some cases exacerbated the as-cast defects. The grains elongated along the rolling direction and formed a pancake shape, while the carbides fractured perpendicularly to the rolling direction and left porosity between fractured particles of UC. The subsequent annealing of these samples at sub-eutectoid temperatures led to rapid precipitation of the ' lamellar phase, mainly in the molybdenum-lean regions. Annealing the samples above the eutectoid temperature did not refine the grain size or the banded

  13. On arbitrarily graded rings

    Indian Academy of Sciences (India)

    58

    paper is devoted to the study of arbitrary rings graded through arbitrary sets. .... which recover certain multiplicative relations among the homogeneous components ... instance the case in which the grading set A is an Abelian group, where the ...

  14. The g-2 ring

    CERN Multimedia

    1974-01-01

    The precise measurement of "g-2", the anomalous magnetic moment of the muon, required a special muon storage ring with electrostatic focussing and very accurate knowledge of the magnetic bending field. For more details see under photo 7405430.

  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. Vortex Ring Dynamics in Radially Confined Domains

    Science.gov (United States)

    Stewart, Kelley; Niebel, Casandra; Jung, Sunghwan; Vlachos, Pavlos

    2010-11-01

    Vortex ring dynamics have been studied extensively in semi-infinite quiescent volumes. However, very little is known about vortex-ring formation in wall-bounded domains where vortex wall interaction will affect both the vortex ring pinch-off and propagation velocity. This study addresses this limitation and studies vortex formation in radially confined domains to analyze the affect of vortex-ring wall interaction on the formation and propagation of the vortex ring. Vortex rings were produced using a pneumatically driven piston cylinder arrangement and were ejected into a long cylindrical tube which defined the confined downstream domain. A range of confinement domains were studied with varying confinement diameters Velocity field measurements were performed using planar Time Resolved Digital Particle Image Velocimetry (TRDPIV) and were processed using an in-house developed cross-correlation PIV algorithm. The experimental analysis was used to facilitate the development of a theoretical model to predict the variations in vortex ring circulation over time within confined domains.

  17. [Liesegang's rings resembling helminthiasis].

    Science.gov (United States)

    Zámecník, M; Riedl, I

    1996-12-01

    So called Liesegang's rings are lamellar corpuscles which develop after periodical precipitation of oversaturated solutions in gel medium. They can occur in cysts, closed cavities, inflammatory exudates and necroses. They resemble parasitic eggs, larvae or adult forms. A case of 28-year-old woman is presented with many Liesegang's rings in a stuff from dilated renal calyx. Their preliminary evaluation considered helminths, especially Dioctophyma renale.

  18. Storage ring group summary

    International Nuclear Information System (INIS)

    King, N.M.

    1980-01-01

    The Storage Ring Group set out to identify and pursue salient problems in accelerator physics for heavy ion fusion, divorced from any particular reference design concept. However, it became apparent that some basic parameter framework was required to correlate the different study topics. As the Workshop progressed, ring parameters were modified and updated. Consequently, the accompanying papers on individual topics will be found to refer to slightly varied parameters, according to the stage at which the different problems were tackled

  19. The rings of Uranus

    Science.gov (United States)

    Elliot, J. L.; Dunham, E.; Mink, D.

    1977-01-01

    A description is given of the observation of five brief occultations of the star SAO 158687 which occurred both before and after its occultation by Uranus on March 10, 1977. The events were observed with a three-channel occultation photometer, attached to a 91-cm telescope. The observations indicate that at least five rings encircle the planet Uranus. Possible reasons for the narrowness of the Uranus rings are discussed.

  20. Texture evolution of experimental silicon steel grades. Part I: Hot rolling

    Energy Technology Data Exchange (ETDEWEB)

    Sandoval Robles, J.A., E-mail: jsandoval.uanl@yahoo.com [Universidad Autónoma de Nuevo León, Facultad de Ingeniería Mecánica y Eléctrica, Ave. Universidad S/N, Cd. Universitaria, San Nicolás de los Garza, Nuevo León C.P. 66450 (Mexico); Salas Zamarripa, A.; Guerrero Mata, M.P. [Universidad Autónoma de Nuevo León, Facultad de Ingeniería Mecánica y Eléctrica, Ave. Universidad S/N, Cd. Universitaria, San Nicolás de los Garza, Nuevo León C.P. 66450 (Mexico); Cabrera, J. [Universitat Politècnica de Catalunya, Departament de Ciència dels Materials I Enginyeria Metal-lúrgica, Av. Diagonal 647, Barcelona 08028 (Spain)

    2017-05-01

    The metallurgical understanding of the deformation processes during the fabrication of non-oriented electrical steels plays a key role in improving their final properties. Texture control and optimization is critical in these steels for the enhancement of their magnetic properties. The aim of the present work is to study the texture evolution of six non-oriented experimental silicon steel grades during hot rolling. These steels were low carbon steel with a silicon content from 0.5 to 3.0 wt%. The first rolling schedule was performed in the austenitic (γ-Fe) region for the steel with a 0.5 wt% of silicon content, while the 1.0 wt% silicon steel was rolled in the two-phase (α+γ) region. Steels with higher silicon content were rolled in the ferritic (α-Fe) region. The second rolling schedule was performed in the α-Fe region. Samples of each stage were analyzed by means of Electron Backscatter Diffraction (EBSD). Findings showed that the texture was random and heterogeneous in all samples after 60% of rolling reduction, which is due to the low deformation applied during rolling. After the second rolling program, localized deformation and substructured grains near to surface were observed in all samples. The Goss {110}<001>texture-component was found in the 0.5 and 1.0 wt.-%silicon steels. This is due to the thermomechanical conditions and the corresponding hot band microstructure obtained after the first program. Moreover, the α<110>//RD and the γ <111>//ND fiber components of the texture presented a considerable increment as the silicon content increases. Future research to be published soon will be related to the texture evolution during the cold-work rolling process. - Highlights: • We analyze six silicon steel experimental grades alloys trough the rolling process. • Material was subjected to a hot deformation process in the α-γ region. • No recrystalization was observed during-after the rolling schedules. • Rise of the magnetic texture components