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1

Novel tube-rolling process using the 3-roll planetary mill (PSW)  

Energy Technology Data Exchange (ETDEWEB)

A high-reduction, 3-roll planetary mill for the production of seamless tube is described and compared with conventional methods. Advantages include continuous rolling, close wall tolerance, increased yield and energy savings.

Bretschneider, E.J.F.E.

1981-10-01

2

WIPER BLADE FOR A ROLLING MILL  

UK PubMed Central (United Kingdom)

The invention relates to a wiper blade system for wiping a product from a roller in a rolling mill, particularly at the last roller in a five-roller mill, comprising a cutter bar, a cutter holder, and a wiper blade (1), which rests against the roller comprising the product to be wiped off. The cutter holder has a spring-loaded blade clamping system.

HOEHENER MANUEL

3

Cost effectiveness of automatic ultrasonics in mill roll testing  

Energy Technology Data Exchange (ETDEWEB)

Roll inspection is necessary to ensure that rolls being returned to the mill are free from defects that may cause the premature failure of the roll, whilst in service. This paper describes the use of an Automatic Ultrasonic system for the inspection of Caster Rolls, up to 140 in. long and 30 in. diameter and its benefits to the user. Roll inspection has been found to be paramount in today`s quality and cost conscious mill operations. Inspection leads to: (1) improved product quality; (2) reduced mill down time; (3) improved roll life; and (4) reduced plant operating costs.

Willcox, M. [DeW Systems Ltd., Hereford (United Kingdom)

1996-12-31

4

Recent technical developments in rolling mill rolls. Atsuen roru ni kansuru saikin no gijutsu doko  

Energy Technology Data Exchange (ETDEWEB)

To meet recent rapid advances in rolling technology, there have been increasing needs for high-performance rolls with longer life and higher reliability. In the field of rolling mill rolls, corresponding to these rolling needs, not only the improvement of existing materials such as high-alloy grain cast iron, etc., but also the development and application of new material rolls such as high-chromium system and tool steel system (high speed steel) have been conducted. Also, in manufacturing processes, in addition to the conventional centrifugal casting process, etc., special manufacturing processes such as the continuous pouring process for cladding (CPC) and the hot isostatic pressing (HIP) process and so forth are adopted. Accordingly, In this report, the transitions and current status of rolling mill rolls' materials were outlined for respective rolling mills in the first half section and the features, operating conditions, etc., of newly developed rolls either in the material or in the manufacturing process which have excellent performance were described in the second half section, centering around those of the rolls developed by Nippon Steel Corp., Plant and Machinery Division. 35 refs., 5 figs., 3 tabs.

Hashimoto, M.; Ishibashi, S.; Kawai, T.; Iboshi, S.; Ayagaki, M.; Kimura, K.; Yamamoto, Y. (Nippon Steel Corp., Tokyo (Japan))

1992-11-30

5

Structural causes of defects in a cast iron mill roll  

Directory of Open Access Journals (Sweden)

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

J. Krawczyk

2008-01-01

6

Analysis of roll stack deflection in a hot strip mill  

Scientific Electronic Library Online (English)

Full Text Available Abstract in english Predictive models are required to provide the bending set point for bending for the flatness control devices at rolling stands of finishing mill of Hot Strip Mill (HSM). A simple model for roll stack deflection at the finishing mill has been illustrated where a modified Misaka?s equation has been used to obtain mean flow-stress. Investigation has been performed to understand the effect of width of roll on roll stack deflection. The bending on the deflection has been foun (more) d to have a positive effect to reduce the amount of the stack deflection. The results from the sensitivity analysis of the roll width on roll deflection are also described.

Sikdar, Sudipta; John, Shylu; Pandit, Ashwin; Dasu, Raju

2007-09-01

7

Analysis of roll stack deflection in a hot strip mill  

Directory of Open Access Journals (Sweden)

Full Text Available Predictive models are required to provide the bending set point for bending for the flatness control devices at rolling stands of finishing mill of Hot Strip Mill (HSM). A simple model for roll stack deflection at the finishing mill has been illustrated where a modified Misaka’s equation has been used to obtain mean flow-stress. Investigation has been performed to understand the effect of width of roll on roll stack deflection. The bending on the deflection has been found to have a positive effect to reduce the amount of the stack deflection. The results from the sensitivity analysis of the roll width on roll deflection are also described.

Sudipta Sikdar; Shylu John; Ashwin Pandit; Raju Dasu

2007-01-01

8

Dimensional ranges and rolling efficiency in a tandem cold rolling mill  

Energy Technology Data Exchange (ETDEWEB)

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.

Larkiola, J.

1997-12-31

9

Characterization of round@flat bar and wire rolling by 2-roll and 3-roll mills. 1. ; Application of computational rolling mill. Round@flat 2 roll oyobi 3 roll hoshiki ni yoru boter dot senzai atsuen no henkater dot fuka tokusei. 1. ; Suchi atsuenki no oyo gijutsu ni kansuru kenkyu  

Energy Technology Data Exchange (ETDEWEB)

Analyses were given on round{approximately} flat bar and wire rolling by 2-roll and 3-roll mills using the computational rolling mill CORMILL system based on the three-dimensional rigid-plastic FEM, and a description is given on the difference of plastic deformation characteristics caused from the rolling of both types of mill. The result obtained from setting the exclusion sectional area ratio (ratio of sectional area excluded by the roll to the initial sectional area of rolled material) in four levels from 10% to 40% may be summarized as follows: (i) A 3-roll mill can roll a material at higher rolling efficiency with lower rolling load than a 2-roll mill can; (ii) a 3-roll mill generates smaller equivalent strain (strain when an extinction rate is identical) after a material is rolled than a 2-roll mill does, and causes a region with small equivalent strain to appear on the center of a rolled material. 11 refs., 13 figs., 2 tabs.

Yanagimoto, J.; Kiuchi, M.; Inoue, Y. (The Univ. of Tokyo, Tokyo (Japan). Inst. of Industrial Science)

1991-09-01

10

[Occupational skin diseases in rolling-mill workers in aluminum mills  

UK PubMed Central (United Kingdom)

Some data on frequency and nature of occupational dermatological diseases and stigmata, as well as the results of epicutaneous allergy tests done with occupational allergens with 234 rollers in the rolling mills of the aluminum mill in Razine, near Sibenik are presented. We have recorded occupational dermatose in 44 rollers (18.8%). In the hot rolling mill, sixty rollers have undergone the test and there was 16 recorded cases of occupational dermatose (26.6%). In the cold rolling mill, 174 rollers have undergone the test, and the occupational dematose was recorded in 28 rollers (16.1%). Positive epicutaneous allergic reaction on occupational allergens was found in 5 (2.1%) rollers. Occupational stigmata are somewhat more frequent in the hot rolling mill and their ratio is from 48-100%, whereas in the cold rolling mill they are somewhat less frequent ranging between 40.3 and 97.0% of rollers.

Bali? J; Klarica J

1989-04-01

11

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

International Nuclear Information System (INIS)

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

2011-05-04

12

Development of rolling mill for rectangular orthodontic wires production  

Directory of Open Access Journals (Sweden)

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

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

2007-01-01

13

A Cold Rolling Mill Model for Unwinding Diagnosis  

UK PubMed Central (United Kingdom)

A model is presented which describes the uncoiling process of a rolling mill in fault-less andin faulty situations. This model is implemented in the DYMOLA modelling and simulation environment.It is used for two purposes: first for the simulation of the unwinding process and second for model-basedfault diagnosis. For the latter diagnostic task, a simplified model is derived. Results of the successfuldiagnosis, in simulation, concludes the paper.

Lehrstuhl Fr Automatisierungstechnik; Und Prozessinformatik; P. Planchon; J. Lunze; Ruhr-universitat Bochum; M. Rode; M. Schneider; Asea Brown Boveri (abb

14

Modelling and control of a hot rolling mill  

Scientific Electronic Library Online (English)

Full Text Available Abstract in english In this paper, a real application of optimal control of a hot rolling mill is presented. It is used the state space model formulation in the minimization of the strip thickness variations. It is presented the simulation results of the control model, which is compared with industrial real data from process controled by traditional techniques. The results of the simulations lead to a less output thickness variations compared with the real industrial data.

Rossomando, F. G.; Denti Filho, J.

2006-07-01

15

Rolling mill optimization using an accurate and rapid new model for mill deflection and strip thickness profile  

Science.gov (United States)

This work presents improved technology for attaining high-quality rolled metal strip. The new technology is based on an innovative method to model both the static and dynamic characteristics of rolling mill deflection, and it applies equally to both cluster-type and non cluster-type rolling mill configurations. By effectively combining numerical Finite Element Analysis (FEA) with analytical solid mechanics, the devised approach delivers a rapid, accurate, flexible, high-fidelity model useful for optimizing many important rolling parameters. The associated static deflection model enables computation of the thickness profile and corresponding flatness of the rolled strip. Accurate methods of predicting the strip thickness profile and strip flatness are important in rolling mill design, rolling schedule set-up, control of mill flatness actuators, and optimization of ground roll profiles. The corresponding dynamic deflection model enables solution of the standard eigenvalue problem to determine natural frequencies and modes of vibration. The presented method for solving the roll-stack deflection problem offers several important advantages over traditional methods. In particular, it includes continuity of elastic foundations, non-iterative solution when using pre-determined elastic foundation moduli, continuous third-order displacement fields, simple stress-field determination, the ability to calculate dynamic characteristics, and a comparatively faster solution time. Consistent with the most advanced existing methods, the presented method accommodates loading conditions that represent roll crowning, roll bending, roll shifting, and roll crossing mechanisms. Validation of the static model is provided by comparing results and solution time with large-scale, commercial finite element simulations. In addition to examples with the common 4-high vertical stand rolling mill, application of the presented method to the most complex of rolling mill configurations is demonstrated with an optimization example involving the 20-high Sendzimir mill.

Malik, Arif Sultan

16

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

Directory of Open Access Journals (Sweden)

Full Text Available The development of a possible slip line field (slf) for theoretical calculations of the deforming pressure (load) in a second pass of a lubricated cold rolling sheet mill and validation using values from an aluminium sheet rolling mill was done in this work. This will be relevant in the manufacturing industries providing an easy method for determining necessary applied rolling load. Experimental rolling was carried out to observe the shear lines in the deformation field. Construction of possible slip line field model was developed adhering strictly to assumptions of rigid plastic model. Calculation of the deforming force/load was achieved using Hencky’s equation. Results showed that the load calculations for constructed slip line field using aluminium sheet rolling as an example tallied with values obtained from Tower Aluminium rolling mill. Slip line fields constructed for the second pass described adequately the rolling pressure in the cold rolling process, giving a valid solution of the exact load estimates on comparison with the industrial load values. Roll pressure along the arc of contact rose fairly linearly from the entrance to a maximum at the exit point. This work showed that slf for the first pass in a cold rolling mill cannot be used for subsequent passes; it requires construction of slfs for each pass in the cold rolling process.

Oluleke O. Oluwole; Olayinka Olaogun

2011-01-01

17

Optimization of a Heavy Continuous Rolling Mill System Via Simulation  

Directory of Open Access Journals (Sweden)

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

Ali Azadeh; Farid Ghaderi

2006-01-01

18

Design of Rolling State Observers for Application to Control of Thickness and Tension in Rolling Mills  

Directory of Open Access Journals (Sweden)

Full Text Available This study focuses on the necessity of designing state observers to be used in controller synthesis for rolling processes. This is motivated by the fact that using several kinds of sensors for measuring all of process variables is technically and economically avoided. On the other hand, using exact measurement in feedback control systems could considerably improve the quality of products. In other word, there is a trade-off between high quality and the implementation limitations, managed here by developing rolling state observers. The proposed observers estimate the states not measured directly by the installed sensors. This technique is applicable to both hot rolling and cold rolling processes. Simulation results demonstrate the performance of the proposed estimation algorithm.

Hamid R. Koofigar; Shahab Amelian

2011-01-01

19

Research upon the quality assurance of the rolling-mill rolls and the variation boundaries of the chemical composition  

Directory of Open Access Journals (Sweden)

Full Text Available The cast-iron rolls must present higher hardness at the rolling surface and lower in the core and the necks, adequate with mechanical resistance and in the high work temperature. If in the zone of the rolling surface, the hardness is guarantied by the irons structure, through the cementite quantities, the core of rolls must contain graphite, to assure this property. Starting from the lamination equipments aspects, from the form of rolls, of the technological interest zones and the structure, which assures the exploitation property, it was establish, through modeling, to the mathematical description of a direct influences, and in final, through successive determinations, to an optimum. One of the parameters, which are determined the structure of the irons destined for rolls casting, is the chemical composition, which guaranties the exploitation properties of the each roll in the stand of rolling mill. The realization of optimum chemical compositions of the cast-iron can constitute a technical efficient way to assure the exploitation properties, the material from which the rolling mills rolls are manufactured having an important role in this sense. Although the manufacture of rolls is in continuously perfecting, the requirements for superior quality rolls are not yet completely satisfied, in many cases, the absence of quality rolls preventing the realization of quality laminates or the realization of productivities of which rolling mills are capable. This paper presents an analysis of the main alloying elements from chemical composition, the influences upon the mechanical properties of the cast-iron rolls, and presents also some graphical addenda. Using the Matlab calculation and graphical programs we determinate some correlations between the hardness (on the working surface and on necks) and the chemical composition. Using the double and triple correlations is really helpful in the foundry practice, as it allows us to determine variation boundaries for the chemical composition, in view the obtaining the desired and optimal values of the hardness of this very important metallurgical equipments. The enunciation of some mathematically modeling results, described through a number of multi-component equations determined for the spaces with 3 the and 4 dimensions, as well as the generation of some regression surfaces, of some curves of levels and volumes of variation, can be represented and interpreted by technologists and can be considerate diagrams of correlation between the analyzed variables. From this point of view the research is inscribes in context of scientific capitalization of the process and the industrial technologies optimizations, on the way of the analysis and the mathematical experiment.Los cilindros o rodillos de laminación de función deben presentar una dureza más alta en su superficie y menor en el núcleo y el cuello del cilindro, adecuados a la resistencia mecánica y a la alta temperatura de trabajo. Si en la zona de la superficie de rodillo, la dureza se garantiza por las cementita existente en la estructura, el núcleo del cilindro debe tener grafito para asegurar la característica deseada. A partir de consideraciones sobre los equipos de la laminación, forma de los cilindros de laminación, zonas tecnológicas del interés y de la estructura, que asegura la característica de la explotación, se estableció un modelo que da una descripción matemática de las influencias directas y, finalmente, mediante determinaciones sucesivas, permite establecer un óptimo. Uno de los parámetros, que determinan la estructura del material de los cilindros de laminación es su composición química, que garantiza las características de la explotación de cada cilindro en el laminador. El empleo de las composiciones químicas de colada, óptimas, puede ser una manera técnicamente eficiente de asegurar las características de la explotación; el material de fabricación de los cilindros juega un papel importante. Aunque la fabricación de cilindros es objeto de una mejora continua, los requis

Kiss, I.

2008-01-01

20

Study on the improved accuracy of strip profile using numerical formula model in continuous cold rolling with 6-high mill  

International Nuclear Information System (INIS)

The quality requirements for thickness accuracy in cold rolling continue to become more stringent. In cold rolling mill, it is very important that the rolling force calculation considers rolling conditions. The rolled strip thickness was predicted using calculated rolling force. However, the prediction of strip thickness in cold rolling is very difficult; in particular, for 6-high mill with shifted intermediate roll (IMR), the accuracy of thickness is not good. In this study, to improve the accuracy of rolled strip thickness, the roll gap flattening can be given based on Hertz contact theory, with contact between rolls and the smooth cylindrical rolls for the rolling elastic deformation. Also, the distribution of the roll gap flattening may be calculated using the contact force of unit transverse length. The strip profile at the continuous cold rolling is calculated by using the numerical analysis model considering the initial strip profile before cold rolling. Hence, we propose that the numerical model can predict the rolled strip profile more quickly and accurately and be applicable to the field. The results of the proposed numerical model were verified by FE-simulation and cold rolling experiments of 6-high mill with five stands

2011-01-01

 
 
 
 
21

Force prediction in cold rolling mills by polynomial methods  

Directory of Open Access Journals (Sweden)

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

Nicu ROMAN; Bogdan IONITA; Dorel AIORDACHIOAE; Emil CEANGA; Ion BIVOL

2007-01-01

22

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

Energy Technology Data Exchange (ETDEWEB)

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

Huang, C.Q.; Yuan, J.G. [Hot Strip Mill Department, Shanghai Baosteel Group, Baoshan District, Shanghai (China); Lian, J.C. [Yuanshan Univ., Qinhuangdao City, Hebei Province (China)

2000-07-01

23

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

International Nuclear Information System (INIS)

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

2000-01-01

24

Optimization of cold rolling procedure using reversing mill  

International Nuclear Information System (INIS)

Optimum procedures of the band cold rolling of the 12Kh18N9T steel and 7KhNM alloy are calculated according to the developed algorithm. Results of calculations of optimum procedures of rolling are given. It is shown that realization of optimum procedure will permit to produce a plotting band with minimum cross section different-thickness at simultaneous reduction of a number of gaps

1980-01-01

25

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

Scientific Electronic Library Online (English)

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

Gálvez, J. M.; Zárate, Luis E.; Helman, H.

2003-03-01

26

INVESTIGATION OF THE MAINTENANCE ORGANISATION FOR HOT ROLLING MILLS  

Directory of Open Access Journals (Sweden)

Full Text Available ENGLISH ABSTRACT: Production systems have undergone dramatic changes in recent years. Many companies have implemented new technologies such as flexible manufacturing systems. There is therefore a shift in focus to maintenance and the effective management thereof. Maintenance is a dynamic activity and is comprised of a large number of interacting variables. An effective maintenance organisation is required to control these variables .This paper discusses the building of a maintenance organisation and the aspects that should be considered during the design. The way in which five companies that operate hot rolling mills apptoached the problem of building an effective maintenance organisation was investigated.AFRIKAANSE OPSOMMING: y eryaardigingstelsels het drastiese veranderinge ondergaan die afgelope aantal jaar. Verskeie Il1~atskappyemaak nou gebruik van nuwe tegnologiee, soas byvoorbeeld aanpasbare vervaardigingstelsels. Daar is gevolglik 'n verskuiwing in fokus na instandhouding en die effektiewe bestuur daarvan. lnstandhouding is 'n dinamiese aktiwiteit en behels 'n groot aantal ' gekoppelde veranderlikes. 'n Effektiewe instandhoudingsorganisasie word benodig om hierdie v'eranderlikes te beheer.Hierdie artikel bespreek die daarstelling van die instandhoudingsorganisasie en die parameters V~toorweeg moet word tydens die ontwerp. Die wyse waarop vyf maatskappye wat }V~rIl1walse bedryf die ontwikkeling van 'neffektiewe organisasie vir instandhouding benader hc(is ondersoek .

P.K. Pretorius; J.K. Visser

2012-01-01

27

Regulated rolling of thick-sheet steel using 2800 mill  

International Nuclear Information System (INIS)

A study was made on possibility of thermal strengthening of sheet low-alloy steel of up to 16 mm thickness, using heat of rolling heat and cooling in the system of automatic controlling temperature of rolling termination (SACTRT). It was recommended to produce 10KhSND steel sheets of 14 mm and less thickness with 0.46 and more factor of chemical composition according to the following technology: to terminate rolling in finishing stand at 870...900 deg.C and then to cool them in SACT RT down to 650...750 deg.C. The developed technology provides the complex of mechanical properties in accordance with requirements of 19282-73 All Union State Standard for 90% of metal. Sheets with unsatisfactory properties are subjected to heat treatment, beginning from special heating

1988-01-01

28

Latest technologies for process control in hot rolling mill; Netsukanatsuen miru ni okeru saishin no purosesu seigyo gijutsu  

Energy Technology Data Exchange (ETDEWEB)

The most recently developed control technologies in a hot strip mill are described. Preview AGC has been developed with a preview control synthesis. It controls roll gaps by using the previous information of disturbances. The disturbances which are concerned are derived from the rolling force, the roll gap and the thickness of a previous stand. The thickness accuracy and the availability of mill have been improved by this technology. An on-line roll grinding (ORG) system with an on-line roll profile meter (OPM) has been developed for the purpose of achieving schedule-free rolling. The ORG smooths the worn and roughed surface of a work roll and OPM can measure the profile of a revolving roll without contact. The data obtained by the OPM are given as feedback information to the ORG. As a result, grinding accuracy has been improved and rolling restriction on width has been relaxed widely. (author)

Urano, A.; Okada, M. [Kawasaki Steel Corporation, Tokyo (Japan). Mizushima Works; Yanagino, K. [Kawasaki Steel Corporation, Tokyo (Japan). Chiba Works

1999-12-01

29

Rolling process simulation of a pair-crossed hot strip mill  

Energy Technology Data Exchange (ETDEWEB)

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)

Chen Shaojie; Xu Jianzhong; Liu Xianghua; Wang Guodong [Northeastern Univ., State Key Lab of Rolling and Automation, Shenyang City (China)

2000-07-01

30

Rolling process simulation of a pair-crossed hot strip mill  

International Nuclear Information System (INIS)

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

2000-01-01

31

Regulation of the Heating Furnace in Tube Rolling Mill  

Directory of Open Access Journals (Sweden)

Full Text Available The rolling of tube requires homogeneous heating along the tube. In steel work the difference along tube was sometimes 80 °C. The reasons for bad homogeneousness of heating were analyzed by a simulation model of heating furnace. Then the proposal was made for a new control system and also the proposal for reconstruction of furnace. In this contribution also a description of some ways for improvement of heating was made. The main contribution is the proposal of an adaptive system

Kostúr, K.

2006-01-01

32

Fine grinding of coal in a two-stage high-pressure roll mill/ball mill hybrid mode  

Energy Technology Data Exchange (ETDEWEB)

Because of its pronounced tendency to undergo visco-plastic flow, coal ground in the energy-efficient high-pressure roll mill invariably comes out as a briquetted product which must be disintegrated in a conventional type of grinding device such as the ball mill. The aggregates comprise comminuted coal particles that are apparently extensively cracked and weakened during passage of the coal through the high-pressure rolls. Their desegregation in a ball mill in the second stage is accompanied by further grinding of the coal with a relatively small expenditure of energy. Thus in spite of energy dissipation in briquetting in the roll mill and in disintegrating the briquettes in the ball mill, significant energy savings are possible in the fine grinding of coal in a two-stage serial grinding mode, as compared to ball mill grinding stages must be apportioned in a n optimal manner; the energy consumption in the ball milling step is comparable to, even in excess of, the energy spent in the high-pressure roll mill; and 20 to 50 percent energy savings might be possible grinding coal to minus 200-mesh size by this two-step process, as compared to conventional milling.

Fuerstenau, D.W.; De, A.; Diao, J.; Kapur, P.C. [Univ. of California, Berkeley, CA (United States). Dept. of Materials Science and Mineral Engineering

1995-10-01

33

High Temperature Thermal Expansion and Elastic Modulus of Steels Used in Mill Rolls  

Science.gov (United States)

The high temperature thermal expansion coefficient (TEC) and elastic modulus of five steels used in mill rolls production were investigated by dilatometer and impulse excitation techniques (IET). The measurements were provided at heating from room temperature till temperatures of about 1000 °C and subsequent cooling. The obtained data were attributed to the properties of predominating phases (austenite, martensite, pearlite, and bainite). The TEC and elastic modulus of corresponding phases were similar for all investigated steels despite the difference in their chemical composition. The steels with a chromium content of 2.95 wt.% and more show enhanced ability to quench hardening. This is an important prerequisite for production of high quality mill rolls.

Laptev, Alexander; Baufeld, Bernd; Swarnakar, Akhilesh Kumar; Zakharchuk, Stanislav; van der Biest, Omer

2012-02-01

34

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

International Nuclear Information System (INIS)

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

2008-06-12

35

Rheology of coal-water slurries prepared by the HP roll mill grinding of coal  

Energy Technology Data Exchange (ETDEWEB)

The objective of the research is the development of improved technology for the preparation of coal-water slurries, which have potential for replacing fuel oil in direct combustion. The fine grinding of coal is a crucial step in the manufacture of coal-water slurries. In this context, currently available grinding mills exhibit poor energy efficiency for size reduction and non-optimum packing characteristics of the ground coal. The first increases the cost of manufacture of coal-water slurries and the second adversely affects their rheological properties. The newly invented choke-fed, high-pressure roll mill is up to 50% more energy efficient and, moreover, there are reasons to believe that it produces a size distribution of ground particles which is closer to the dense packing composition. The high-pressure roll mill (which is perhaps the only really significant innovation in industrial comminution in this century) has lower capital cost, occupies less floor space, shows negligible wear rate, accepts feed with a wide range of moisture contents and, of particular importance, it can be scaled up to grind hundreds of tons of solids per hour. The high-pressure roll mill provides a unique opportunity to develop an improved technology for preparing coal-water slurries. Our research group in the University of California at Berkeley not only has a fully instrumented, laboratory-scale, choke-fed. high-pressure roll mill (the only one of its kind in the United States) but also fully instrumented laboratory ball mills for comparative fine coal preparation purposes. In this research program, our plans are to systematically investigate comminution energy consumption, deagglomeration procedures, and the stability and rheology of coal-water slurry fuel prepared with high-pressure roll mill, and to compare the results with slurry prepared with ball-milled coal.

Fuerstenau, D.W.

1992-12-01

36

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

Directory of Open Access Journals (Sweden)

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

J. Krawczyk; J. Pacyna

2010-01-01

37

Merging of advices from multiple advisory systems - with evaluation on rolling mill data.  

Czech Academy of Sciences Publication Activity Database

multiple-participant decision-makingKód oboru RIV: BC - Teorie a systémy ?ízení http://library.utia.cas.cz/separaty/2009/AS/andrysek-merging of advices from multiple advisory systems-with evaluation on rolling mill data.pdf

Ettler, P.; Andrýsek, JosefG; Šmídl, Václav; Kárný, Miroslav

38

Self-Tuning Controller for Rolling Mill Processes. Interim Progress Report.  

Science.gov (United States)

This report presents an adaptive self-tuning controller for the control of the rolling mill. This controller is designed on the basis of a time-series model (AR model) in which the parameters are estimated recursively on the basis of the available informa...

I. Papapanagiotou G. Maliotis A. J. Koivo

1984-01-01

39

Strip/Foil Rolling Mill Stochastic Excitation Model and Its Stability  

Directory of Open Access Journals (Sweden)

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

Baoyu Xu; Xudong Wang; Yilun Liu; Haichao Feng

2012-01-01

40

The Modelling and Control of Interst and Coolling of Rolled Steell in Billet Mills  

Directory of Open Access Journals (Sweden)

Full Text Available A generalized approach to the modelling of transient heat flow in rolled steel during air-cooling in billet mills is presented. The mathematical development starting with the relevant differential equations and their modelling using the Hills’ integral profile method give polynomial functions which characterize the transient heat flow in the workpiece and establishes an optimal control law for static cooling conditions. An experimental validation test enabled the final model to be obtained as a function of the rolling speed and shows that a good functional correspondence exists between the model and the data reported in the literature.

E.C. Obinabo

2008-01-01

 
 
 
 
41

Performance and Application of a Multiphase Thyristor Motor with a DC Link for Metal-Rolling Mills.  

Science.gov (United States)

Recent demand for reduced power consumption, higher performance, and greater freedom from maintenance requirements has stimulated the replacement of DC motors by AC motors in metal-rolling mills. A multiphase thyristor motor with a DC link has been develo...

T. Asaeda T. Matsuura Y. Tominaga Y. Hosokawa M. Tominaga

1983-01-01

42

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

Science.gov (United States)

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

Imanari, Hiroyuki; Koshinuma, Kazuyoshi

43

Rolling of U-shaped and H-shaped wires by the satellite mill; Satellite mill ni yoru U kei oyobi H kei ikeisen no atsuen  

Energy Technology Data Exchange (ETDEWEB)

Authors have developed a compact continuous mill named the satellite mill. This mill had characteristics in which the elongation of materials was controlled and the transverse metal flow was promoted. In this study, the rolling properties and the product properties were investigated in the formation of U-shaped and H-shape profiled wires by the rolling of the satellite mill using the closed passes. The following results were obtained: By using the satellite mill rolling, the transverse rib heights for both U-shaped and H-shaped profiled wires were much higher than those by the conventional rolling, for significant decreasing of elongation and promotion of the transverse metal flow. In the satellite mill rolling, the material speed for both U-shaped and H-shaped profiled wires was controlled by the rotation speed of the central roll groove, and was almost the same with the rotation speed of the central roll groove in the middle part. The transverse hardness peaks of U-shaped and H-shaped profiled wires existed at the corner and two sides of webs, and the hardness was lower at the tip parts of ribs. 4 refs., 10 figs.

Kawamoto, T. Utsunomiya, H.; Saito, Y. [Osaka Univ., Osaka (Japan). Gaduate School

1998-04-01

44

Investigation of rolling pressure on metallic uranium rod  

Energy Technology Data Exchange (ETDEWEB)

The rolling pressure on metallic uranium rod was investigated. By considering the behavior of the uranium metal in a rolling mill as a viscous flow, the differential equation for the rolling pressure was established. A formula for calculating the rolling pressure was derived and the theoretical calculation method was given. The rolling pressure, the coefficient of contact friction, and the lateral expansion of uranium rod were measured. The measured rolling pressure was compared to the calculated value. Rolling is an important forming technique for uranium. A study of the rolling parameters of uranium serves as a basis for rolling mill design, engineering calculation, and rolling mill strength calibration.

Zhang, M.

1984-06-01

45

Automation system for heat treatment furnaces of roll mill rolls; Sistema de automacao dos fornos para tratamento termico de cilindros de laminacao de Acos Villares  

Energy Technology Data Exchange (ETDEWEB)

the heat treatment process of roll mill rolls operates with very closely controlled thermal cycles and very tight temperature tolerances, and this is fundamental for the good quality and future performance of the product. Albeit our furnaces already coped with the basic conditions for doing this, the roll mill rolls market is each day more demanding and more competitive, making a necessity the modernization of this equipment. The project consisted basically in changing the heat source from the light fuel oil C4 and the manual control of the equipment to a new concept of operation, using pulsating natural gas burners and automation. This was made installing in each of our 11 furnaces, ten pulsating gas burners with full automation. The project uses thirty three process controllers, eleven temperature programmers, linked to a data collection station and two P C supervising workstations. This equipment are all installed in a control room, making possible a good control of the furnaces. The supervisory systems are now being linked with our production planning and scheduling systems, integrating our shop-floor in real time with our administrative needs. This work presents the principal characteristics of this automated heat treatment system, the supervising and ata administration system, and the mean benefits obtained with this project. (author) 2 refs., 7 figs.

Malere, Ernesto P.; Silva, Sergio P.; Correa, Nicolas I.B. [Acos Villares SA, Sao Caetano do Sul, SP (Brazil)

1996-12-31

46

Validation of a 3-D, Thermo-Mechanically Coupled Model for Multi-Pass Rolling in a Reversing Mill  

Energy Technology Data Exchange (ETDEWEB)

A three dimensional numerical model simulating multi-pass, hot rolling on a reversing mill has been developed to analyze deformation patterns and shape changes of a rolled ingot. Validation simulations through 15 passes with an 86% reduction have been performed using the thermo-mechanically coupled model to track the evolution of the deformed ingot geometry. The heat transfer coefficient for thermal conduction between the rolls and slab has been estimated in accordance with experimental data, and heat transfer to the air and coolant outside of the roll bite is included. A hyperbolic sine model using the Zener-Hollomon parameter is used to capture the temperature and strain rate dependence of the aluminum alloy. A Coulomb friction model with a flow strength dependent maximum limit on the interfacial shear stress was employed between the rolls and ingot. Results of validation simulations and comparisons with experiments focusing on the ingot shape evolution are discussed.

Rhee, M; Wang, P; Li, M; Becker, R

2004-01-30

47

A Simple Method of Designing Dual loop Controller for Cold Rolling Mill  

Directory of Open Access Journals (Sweden)

Full Text Available The mathematical model (Interval Plant) of the web guide in rolling mill is controlled using PID controller. The given interval plant is approximated to first order plus time delay with integrator (FOPTDI) system. The dual loop control (DLC) method proposed by Jacob and chidambaram for design PID controllers is extended for FOPTD+I systems. The performance of the closed loop system is evaluated for both the original and the approximated model. The controllers are also tuned using Internal Model Control (IMC) and the performance is compared by simulation.

S. Umamaheswari,; V.Palanisamy,; M.Chidambaram

2010-01-01

48

Understanding Rolle's Theorem  

Directory of Open Access Journals (Sweden)

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

REVATHY PARAMESWARAN

2009-01-01

49

Special technique for cleaning the lubrication system of rolling mill roll grinder slide way; Tecnica especial para limpeza em sistema de lubrificacao de barramento de retificadoras de cilindros da laminacao  

Energy Technology Data Exchange (ETDEWEB)

This paper describes the abnormalities found prior to the application of a special technique for cleaning the lubrication system of rolling mill roll grinder slide waw, the explanation on the technical procedure developed by Companhia Siderurgica Nacional and the outstanding results obtained after the implementation aforesaid technique 3 figs.

Kaneko, J.T.; Dib Junior, A.; Dias, L.C.G. [Companhia Siderurgica Nacional, Volta Redonda, RJ (Brazil)

1995-12-31

50

Numerical Simulations of the Flow of Dilute Polymer Solutions in a Four-Roll Mill  

Science.gov (United States)

We study the startup flow of dilute polymer solutions in a four-roll mill by using FENE dumbbell models. The first objective of the paper is to examine the behavior of the Chilcott-Rallison version of the FENE model (FENE-CR) with varying parameters c, De and L. The coupling between flow and polymer stretching is exhibited by concerted flow suppression and reduction of polymer extension. In particular, the model predicts double-humped velocity and strain rate profiles across the outflow axis, in qualitative agreement with experiments. The second objective of the paper is to study the effects of other features that can be added to the basic FENE-CR model, including conformation-dependent friction (CDF), shear-thinning and an extra viscous stress term. The FENE-CDF model is specially interesting because of its relevance to the phenomenon of birefringence pipe. For the range of parameters studied, the FENE-CDF model does produce more severe flow suppression than the FENE-CR model, but not sufficiently so that the polymer collapses to the coiled state. The shear-thinning in the FENE-P model and the extra viscous stress do not have a significant effect on the startup flow in the four-roll mill.

Feng, J.; Leal, L. G.

1996-11-01

51

Analysis of rolling characteristics in a continuous billet mill with drive-free vertical rolls. Mukudo suichoku roll wo yusuru renzoku billet atsuenki ni okeru atsuen tokusei no kaiseki  

Energy Technology Data Exchange (ETDEWEB)

Based on the rolling data obtained from a rolling experiment using five-stand continuous steel rolling machines as have been reported previously, analyses were made on rolling loads on driven and non-driven stands, rolling torque in the driven stand, and inter-stand tension. In analyzing the rolling load variation, it was revealed that the variation can be explained by use of the inference equation for hole type rolling load by Yanagimoto that takes fore and rear tension into account. In analyzing the rolling torque variation, equations to express torque arm coefficients accounting for the fore and rear tension, and inter-stand tension were introduced. For the analysis of rolling material width variation, an equation that considers the fore and rear tension was introduced. This equation indicates a width spread being affected largely by rear tension, which agrees also with experimental facts. Forced rolling was analyzed theoretically. Compressive stress calculations using the resultant equations agreed approximately well with the measurements. Rolling loads were inferred in a similar manner, of which result was verified capable of inferring the loads within an error range of [plus minus]10% of the measured values. The inference on the required rolling torque corresponded also well with the measurements. 12 refs., 12 figs., 1 tab.

Shikano, H. (Sumitomo Metal Industries, Ltd., Osaka (Japan))

1992-12-01

52

Recent trends in shape mills. ; Hyper beam rolling mill. Katako atsuen setsubi no saikin no doko. ; Haipa bimu no atsuen setsubi ni tsuite  

Energy Technology Data Exchange (ETDEWEB)

'HYPER BEAM' is an advanced type of H-shapes for structural purposes, featuring high fabrication efficiency due to the uniformity of web height and light weight due to thinner webs. The HYPER BEAM manufacturing technology has been established by developing a new type of skew roll mill for high-precision width-spreading and a finishing mill with variable barrel-width rolls for finishing the width-spread material to a desired width. To produce webs far thinner than flanges, a flange cooling equipment which can effectively cool the flanges only with water has been developed. Moreover, a new type of roller straightening machine with an automatic in-line roller barrel-width changing function has been developed to strengthen the shapes as appropriate depending on the inside width of the web. In this report, the skew roll mill, the finishing mill with variable barrel-width rolls, the flange cooling equipment and the roller straightening machine with an automatic in-line roller barrel-width changing function which are core hardwares for realizing HYPER BEAM rolling were described particularly. 5 refs., 20 figs., 1 tab.

Kitamura, T.; Hioki, T.; Nakano, Y.; Ikezaki, T.; Haji, T.; Fujita, K.; Teramae, A. (Nippon Steel Corp., Tokyo (Japan))

1992-11-30

53

The production of aligned short fibre ceramic matrix composites using a twin rolling mill  

Energy Technology Data Exchange (ETDEWEB)

A novel powder processing route for short fibre ceramic matrix composites (CMCs), based on using a twin rolling mill, has been developed. This has been seen to be an efficient and easy way of mixing the composite constituents while obtaining a high degree of fibre alignment. The production of the green composites by this method has taken an average of ten minutes. In this report a system of Nicalon fibres in silicon, subsequently reaction bonded to form a matrix of reaction bonded silicon nitride, has been emphasised. Composites with fibre loading of up to 34% fibre volume fraction have been produced, microscopically analysed, and mechanically tested. A novel way of introducing fibres into the ceramic matrix has removed the problems associated with chopping and handling the fibres. This technique will be developed so that prospective ceramic matrix composite can be efficiently produced in prototype quantities for further appraisal of their properties. (orig.)

Philpott, E. [DRA, Farnborough (United Kingdom). Struct. Mater. Center; Shatwell, R. [DRA, Farnborough (United Kingdom). Struct. Mater. Center; Kendall, K. [Keele Univ. (United Kingdom). Dept. of Chem.

1997-06-01

54

Self-tuning controller for rolling mill processes. Interim progress report  

Energy Technology Data Exchange (ETDEWEB)

This report presents an adaptive self-tuning controller for the control of the rolling mill. This controller is designed on the basis of a time-series model (AR model) in which the parameters are estimated recursively on the basis of the available information (on-line). The controller gains are determined at each sampling instant so that the outputs follow the desired values as closely as possible. The self-tuning controller is thus in the form of a feedback controller, whose gains are calculated continuously on-line. The basic time-series model which relates the inputs to the outputs of the system will be described first, then the controller algorithm. Simulation studies on the resulting system are presented to demonstrate the applicability of the approach.

Papapanagiotou, I.; Maliotis, G.; Koivo, A.J.

1984-01-01

55

Transport, mixing and stretching in a chaotic Stokes flow: The two-roll mill  

International Nuclear Information System (INIS)

We present the outline and preliminary results of an analytical and numerical study of transport, mixing, and stretching in a chaotic Stokes' flow in a two-roll mill apparatus. We use the theory of dynamical systems to describe the rich behavior and structure exhibited by these flows. The main features are the homoclinic tangle which functions as the backbone of the chaotic mixing region, the Smale horseshoe, and the island chains. We then use our detailed knowledge of these structures to develop a theory of transport and stretching of fluid in the chaotic regime. In particular, we show how a specific set of tools for adiabatic chaos- the adiabatic Melnikov function lobe area and flux computations and the adiabatic switching method is ideally suited to develop this theory of transport, mixing and stretching in time-dependent two-dimensional Stokes' flows. 19 refs., 8 figs

1989-01-01

56

Internal roll compression system  

Energy Technology Data Exchange (ETDEWEB)

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

Anderson, Graydon E. (850 Latonka Dr., R.D. 4, Mercer, PA 16137)

1985-01-01

57

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

Directory of Open Access Journals (Sweden)

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

Vijay Gautam

2013-01-01

58

Roll force, torque, lever arm coefficient, and strain distribution in edge rolling  

Science.gov (United States)

Due to the growing importance of width control in strip and plate mills, edge rolling is currently an im-portant process in hot rolling mills. Research in edge rolling has been carried out, and in the present ar-ticle, models for roll force, torque, and lever arm coefficient are derived using the upper bound method. A simple, kinematically admissible deformation zone and velocity field, independent of friction in the roll gap, is proposed, and the energy dissipation rate is derived. The formula for energy dissipation rate has, in practice, no limitation because all edge rolling geometries are safely in the area where the formula is valid. Roll force and torque are derived by means of two independent integrals. Thus, the lever arm coef-ficient is evaluated from the expressions for roll force and torque using conventional rolling theory. Roll-ing trials report good agreement with theory. Measured roll forces are similar to calculated forces. Furthermore, the shape of the dogbone that arises during edge rolling is in fairly good agreement with the calculated dogbone shape. Deviations are due to the deviation from ideally plastic material in the ex-periments. Also, the strain distribution over the dogbone is similar to the proposed deformation zone. Thus, a new formula has been developed to a stage that it can be implemented in width control systems for edge rolling stands in hot strip and plate mills.

Lundberg, S.-E.; Gustafsson, T.

1993-12-01

59

Rolling friction and bistability of rolling motion  

CERN Multimedia

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

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

2005-01-01

60

The Physical Flow of Materials and the Associated Costs in the Production Process of a Rolling Mill  

Directory of Open Access Journals (Sweden)

Full Text Available Efficiency of resources use is, in a large extent, determined by the organization of production flow and the way of their control. The optimization of materials flow in the production process requires the identification of physical flows of goods and it cost. In the article the physical flow process of materials stream in the production process in one of Polish rolling mill and also its logistics analysis and cost analysis are presented.

Holisz-Burzy?ska, J.; Staniewska, E.; Budzik, R.

2007-01-01

 
 
 
 
61

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

Energy Technology Data Exchange (ETDEWEB)

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

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

1990-07-01

62

Evaluation of residual uranium contamination in the dirt floor of an abandoned metal rolling mill.  

UK PubMed Central (United Kingdom)

A single, large, bulk sample of uranium-contaminated material from the dirt floor of an abandoned metal rolling mill was separated into different types and sizes of aliquots to simulate samples that would be collected during site remediation. The facility rolled approximately 11,000 tons of hot-forged ingots of uranium metal approximately 60 y ago, and it has not been used since that time. Thirty small mass (? 0.7 g) and 15 large mass (? 70 g) samples were prepared from the heterogeneously contaminated bulk material to determine how measurements of the uranium contamination vary with sample size. Aliquots of bulk material were also resuspended in an exposure chamber to produce six samples of respirable particles that were obtained using a cascade impactor. Samples of removable surface contamination were collected by wiping 100 cm of the interior surfaces of the exposure chamber with 47-mm-diameter fiber filters. Uranium contamination in each of the samples was measured directly using high-resolution gamma ray spectrometry. As expected, results for isotopic uranium (i.e., U and U) measured with the large-mass and small-mass samples are significantly different (p < 0.001), and the coefficient of variation (COV) for the small-mass samples was greater than for the large-mass samples. The uranium isotopic concentrations measured in the air and on the wipe samples were not significantly different and were also not significantly different (p > 0.05) from results for the large- or small-mass samples. Large-mass samples are more reliable for characterizing heterogeneously distributed radiological contamination than small-mass samples since they exhibit the least variation compared to the mean. Thus, samples should be sufficiently large in mass to insure that the results are truly representative of the heterogeneously distributed uranium contamination present at the facility. Monitoring exposure of workers and the public as a result of uranium contamination resuspended during site remediation should be evaluated using samples of sufficient size and type to accommodate the heterogeneous distribution of uranium in the bulk material.

Glassford E; Spitz H; Lobaugh M; Spitler G; Succop P; Rice C

2013-02-01

63

Feeding roll presses for stable roll operation  

Energy Technology Data Exchange (ETDEWEB)

Roll presses are used to agglomerate bulk solids ranging from extremely fine magnesium oxide, salt, potash, and coal, to very coarse metal turnings. It is easy to see that a given press will work differently with a fine powder such as magnesium oxide, than with coarse metal turnings. It is less obvious that subtle changes in size-consist of the same material may also significantly modify the effectiveness of the press. Such changes must be compensated for if the press is to consistently produce good agglomerates. This paper discusses the various material properties affecting press operation, and suggests methods of operating a roll press system for correcting for these changes.

Johanson, J.R.

1984-06-01

64

Understanding Rolle's Theorem  

Science.gov (United States)

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

Parameswaran, Revathy

2009-01-01

65

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

Energy Technology Data Exchange (ETDEWEB)

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

Karimi Taheri, A.; Serajzadeh, S. [Sharif University of Technology, Dept. of Material Science and Engineering, Tehran (Iran, Islamic Republic of); Shahriari, M.A.; Izadi, J.; Fattahi, M. [Mobarake Steel Complex, Isfehan (Iran, Islamic Republic of)

2000-07-01

66

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

International Nuclear Information System (INIS)

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

2000-01-01

67

Power quality at Gerdau MRM Steel : a rolling mill`s perspective  

Energy Technology Data Exchange (ETDEWEB)

Power quality issues facing Gerdau MRM Steel, a steel mill operation in Selkirk, Manitoba were discussed. It was noted that power interruptions in various process equipment result in production loss, but the effects of harmonics and surges are harder to quantify. Some equipment, such as DC drives, variable-speed AC drives, computers and solid state equipment are sensitive to short term drop-outs and harmonic distortion. This type of equipment can also cause harmonic distortion. Some causes of sags, drop-outs and interruptions such as weather, switching, faults, accidents and human error were also reviewed. It was concluded that power quality problems at the plant can be resolved with support from the electric utility as well as from plant operations.

Shymanski, W.T. [Gerdau MRM Steel, Selkirk, MB (Canada)

1998-12-31

68

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

International Nuclear Information System (INIS)

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

2013-01-01

69

Spray Rolling Aluminum Strip for Transportation Applications  

Energy Technology Data Exchange (ETDEWEB)

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

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

2005-02-01

70

Pilot-industrial technology of sintered tungsten bar section rolling  

International Nuclear Information System (INIS)

Results of development and industrial introduction of new technology for rolling of bar sections from sintered tungsten on specialized rolling mill MK-380 with four-high passes of the Chelyabinsk Polytechnical Institute design are given. The rolling mill design is described and recommendations are given as to the working roll materials. The new technology is characterized by a higher output and quality of produced sections in comparison with existing methods of processing

1984-01-01

71

Pilot-industrial technology of sintered tungsten bar section rolling  

Energy Technology Data Exchange (ETDEWEB)

Results of development and industrial introduction of new technology for rolling of bar sections from sintered tungsten on specialized rolling mill MK-380 with four-high passes of the Chelyabinsk Polytechnical Institute design are given. The rolling mill design is described and recommendations are given as to the working roll materials. The new technology is characterized by a higher output and quality of produced sections in comparison with existing methods of processing.

Vydrin, V.N.; Barkov, L.A.; Pastukhov, V.V.; Matveev, V.A.; Mebel' , V.S. (Chelyabinskij Politekhnicheskij Inst. (USSR))

1984-12-01

72

Rolling shutter device condom  

UK PubMed Central (United Kingdom)

The utility model relates to a rolling machine safety cover, belonging to the safety device on the role of the rolling machine shaft. The utility model provides a rolling machine safety cover which prevents the role of the rolling machine from hurting. The utility model comprises an upper semi circular cover and a lower semi circular cover wherein the upper semi circular cover has two connecting boards respectively positioned at the two sides and the lower semi circular cover has two connecting boards respectively positioned at the two sides as well. The structure points of the utility model lie in that: the upper semi circular cover and the lower semi circular cover respectively have a semi circular shell which has the corresponding axis diameter as the rolling machine, a semi circular shell which has the corresponding outer role diameter as the two shaft of the rolling machine two role through holes are arranged on the shaft of the semi circular shell which has the corresponding outer diameter of the upper semi circular cover the through holes are arranged on the routing direction of the role and are provided with an extendable pipe which consists of a thick pipe and a thin pipe wherein the thick pipe has the same inner diameter as the outer diameter of the through hole and the thin pipe has the same inner diameter as the through hole moreover, the extendable pipe can be arranged on the through hole.

GUOJI WANG

73

Spray Rolling Aluminum Strip  

Energy Technology Data Exchange (ETDEWEB)

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

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

2006-05-10

74

Rheology of coal-water slurries prepared by the HP roll mill grinding of coal. Quarterly technical progress report No. 1, September 1--November 30, 1992  

Energy Technology Data Exchange (ETDEWEB)

The objective of the research is the development of improved technology for the preparation of coal-water slurries, which have potential for replacing fuel oil in direct combustion. The fine grinding of coal is a crucial step in the manufacture of coal-water slurries. In this context, currently available grinding mills exhibit poor energy efficiency for size reduction and non-optimum packing characteristics of the ground coal. The first increases the cost of manufacture of coal-water slurries and the second adversely affects their rheological properties. The newly invented choke-fed, high-pressure roll mill is up to 50% more energy efficient and, moreover, there are reasons to believe that it produces a size distribution of ground particles which is closer to the dense packing composition. The high-pressure roll mill (which is perhaps the only really significant innovation in industrial comminution in this century) has lower capital cost, occupies less floor space, shows negligible wear rate, accepts feed with a wide range of moisture contents and, of particular importance, it can be scaled up to grind hundreds of tons of solids per hour. The high-pressure roll mill provides a unique opportunity to develop an improved technology for preparing coal-water slurries. Our research group in the University of California at Berkeley not only has a fully instrumented, laboratory-scale, choke-fed. high-pressure roll mill (the only one of its kind in the United States) but also fully instrumented laboratory ball mills for comparative fine coal preparation purposes. In this research program, our plans are to systematically investigate comminution energy consumption, deagglomeration procedures, and the stability and rheology of coal-water slurry fuel prepared with high-pressure roll mill, and to compare the results with slurry prepared with ball-milled coal.

Fuerstenau, D.W.

1992-12-01

75

Calucaltion of waste heat from hot rolled steel coils at SSAB and its recovery  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Hot rolling process is heat input process. The heat energy in hot rolled steel coils can be utilized. At SSAB Strip Product Borlänge when the hot rolled steel coils came out of the hot rolling mill they are at the temperature range of 500°C to 800°C. Heat energy contained by the one hot rolled steel...

Yousaf, Naeem

76

Ship Roll Damping Control  

DEFF Research Database (Denmark)

The technical feasibility of roll motion control devices has been amply demonstrated for over 100 years. Performance, however, can still fall short of expectations because of diculties associated with control system designs, which have proven to be far from trivial due to fundamental performance limitations and large variations of the spectral characteristics of wave-induced roll motion. This tutorial paper presents an account of the development of various ship roll motion control systems together with the challenges associated with their design. It discusses the assessment of performance and the applicability of dierent mathematical models, and it surveys the control methods that have been implemented and validated with full scale experiments. The paper also presents an outlook on what are believed to be potential areas of research within this topic.

Perez, Tristan; Blanke, Mogens

2012-01-01

77

Automatic food rolling machine  

UK PubMed Central (United Kingdom)

The invention discloses an automatic food rolling machine, comprising a box body (1), and further comprising a base plate (2) that is flat and fixedly mounted on the bottom surface inside the box body (1) at least two moving members mounted in the box body (1), arranged above the base plate (2) oppositely, connected with a power member (4) and controlled by the power member (4) to move above the base plate (2) and a control device (5) electrically connected to the power member (4) and controlling the movement parameters of the power member (4). The automatic food rolling machine has simple structure and stable performance, is used and maintained conveniently, and can adequately ensure safety and sanitation of foods such as sushi and rice and vegetable roll in the manufacturing process, and ensure the manufactured finished products to have stable taste. Thus, the invention can well satisfy the household use of people.

ZAOYAN LIU

78

Expert system for diagnosis of strip thickness accuracy in cold rolling tandem mill. Reikan tandem mill itaatsu seido shindan expert system  

Energy Technology Data Exchange (ETDEWEB)

In order to maintain a quality and to support a control system maintenance, the realtime diagnostic eepert system for fully continuous cold rolling tandem ills was developed to detect the anomaly of strip thickness and to infer its cause in an automatic gauge control system and hydraulic push-up roll gap control system. The system was composed of a conventional procedural programmed system and knowledge base system. The data for inference were formed on the basis of information from the equipment diagnosis system and mill control PLC (programmable logic controller), and the cause was inferred of the coil anomaly detected at two rolling points, an intermediate point with top-speed and a shear cut point of coils. The prototype method was adopted in system development to utilize the merit of the knowledge base enough while tuning it. In real operations, a fast response within 8 sec was achieved through distributed functions for rapid gathering, processing and editing of operation data, and realtime inference. 3 refs., 8 figs., 2 tabs.

Iguchi, H.; Kitao, N.; Sano, K.; Iritsuki, K.; Karasawa, N.; Komatsu, T. (Kawasaki Steel Corp., Kobe (Japan))

1991-11-01

79

METHOD OF ROLLING URANIUM  

Science.gov (United States)

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.

Smith, C.S.

1959-08-01

80

Ship Roll Motion Control  

DEFF Research Database (Denmark)

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

Perez, Tristan School of Engineering,, The University of Newcastle

2010-01-01

 
 
 
 
81

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

Scientific Electronic Library Online (English)

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

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

2013-02-01

82

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

Directory of Open Access Journals (Sweden)

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

Ricardo Floriano; Daniel Rodrigo Leiva; Stefano Deledda; Bjørn Christian Hauback; Walter José Botta

2012-01-01

83

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

Directory of Open Access Journals (Sweden)

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

Ricardo Floriano; Daniel Rodrigo Leiva; Stefano Deledda; Bjørn Christian Hauback; Walter José Botta

2013-01-01

84

Inflation Without Slow Roll.  

Science.gov (United States)

We draw attention to the possibility that inflation (i.e. accelerated expansion) might continue after the end of slow roll, during a period of fast oscillations of the inflation field Mu. This phenomenon takes place when a mild non-convexity inequality is...

T. Damour V. F. Mukhanov

1997-01-01

85

Rotary tillage rolling apparatus  

UK PubMed Central (United Kingdom)

The utility model relates to a rotary tillage calamus rolling device comprising rotary tillage knives and a central round tube. The rotary tillage knives are in the shape of arch knife blades and are fixed at the tangent position of the round tube. The longitudinal distances of each row of rotary tillage knife blades are equal, every two adjacent knife blades in the circumference of the round tube are rotated by from 10 DEG to 20 DEG, 3 to 5 rows of rotary tillage knives distributed in spiral lines are fixed on the round tube, a flat iron bar is welded on each row of rotary tillage knives, and the iron bar is fixed in a sloping line at the middle of each rotary tillage knife in the row. The rotary tillage calamus rolling device is characterized in that four running blades in the shape of a crisscross are fixed at one end of the round tube, which is farther from a running wheel, the height of the running blades equals to the radius of the rotary tillage calamus rolling device, the cross section of the running blades is of a sink shape, and openings of the four blades face the direction towards which a tillage calamus ship moves. When the rotary tillage calamus rolling device works, the running blades at the end part are inserted in mud, play the role of assisting a running drive, and enable the tillage calamus ship to have more balanced running.

SHENGHAO HE

86

Endless hot strip rolling at No.3 hot strip mill in China works; Chiba seitetsusho dai 3 netsuen kojo ni okeru endless atsuen gijutsu  

Energy Technology Data Exchange (ETDEWEB)

Development of the technology and the operation of the mill are outlined. Endless hot strip rolling is adopted to improve on sheet quality at its leading and trailing edges and on smoothness in sheet feeding during the rolling process, to manufacture thin and wide,or very thin, steel sheets, and to realize lubricated rolling throughout the sheet length. For the implementation of endless rolling, a sheet bar coiler, joining unit, deburring device, and strip shear are installed. Thanks to the newly developed joining technology making use of induced heating and upsetting, sheet bars can be joined in about 5 seconds. Bars were joined by the real mill and the joint was examined, when it was found that the joint was as strong as the parent material. No break occurred in the joint during the finishing process. The endless rolling process achieved a sheet thickness precision of {plus_minus} 25{mu}m throughout the sheet length. It is now possible to produce with stability 1.2mm-thick, 1600mm-wide sheets, and sheets so thin as 0.8-1.2mm. 11 refs., 10 figs., 2 tabs.

Nikaido, H.; Isoyama, S.; Nomura, N. [Kawasaki Steel Corp., Tokyo (Japan); Hayashi, K.; Morimoto, K.; Sakamoto, H. [Mitsubishi Heavy Industries, Ltd., Tokyo (Japan)

1997-03-01

87

The rolling tachyon as a matrix model  

International Nuclear Information System (INIS)

We express all correlation functions in timelike boundary Liouville theory as unitary matrix integrals and develop efficient techniques to evaluate these integrals. We compute large classes of correlation functions explicitly, including an infinite number of terms in the boundary state of the rolling tachyon. The matrix integrals arising here also determine the correlation functions of gauge invariant operators in two dimensional Yang-Mills theory, suggesting an equivalence between the rolling tachyon and QCD2. (author)

2003-01-01

88

Improvements in the manufacturing of rolling mill rolls through a new system of production planning, scheduling and control; Melhorias na manufatura de cilindros de laminacao atraves de um novo sistema de planejamento, programacao e controle da producao  

Energy Technology Data Exchange (ETDEWEB)

This work presents the implementation of new system for production planning, scheduling and control in the rolling mill rolls unit, at Acos Villares, the occurred changes and the attained results. This system provided automation steps for the planning and has modules for the production simulation and real-time shop-floor control. It is operated with a computer network linking the plants at Pindamonhangaba and Sao Caetano do Sul tpo the sales and product areas in Sao Paulo. The culture changing are commented, involving the planning area relationship with other areas, and how personnel commitment with company global objectives. The results show both the improvements in indexes related to productivity and cost reductions, and the better customer services, with more agile and accurate information. (author) 2 refs., 4 figs., 1 tab.

Malere, Ernesto P.; Amaral Carvalho, Sinvaldo do; Correa, Nicolas I.B. [Acos Villares SA, Sao Caetano do Sul, SP (Brazil)

1996-12-31

89

Rolling Stone Rock Guide  

Science.gov (United States)

_Rolling Stone_ magazine and Magellan have teamed up to create this Internet rock resource directory. Whether you want to find out about an artist or a genre of music, obtain tickets for a show, or even gather information on starting your own music career, this site is an excellent starting point. Content for the site is contributed by _Rolling Stone_, but the structure is very similar to Magellan (discussed in the September 1, 1995 Scout Report). The Rock Guide consists of Internet resources that are categorized, reviewed, and rated. Users can browse by genre or search the directory. There are sections on artists, music genres, magazines, books, merchandise, musical instruction, the music business, performances, clubs, online chat and discussion and more.

1996-01-01

90

Roll of honour  

Energy Technology Data Exchange (ETDEWEB)

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)

Moxon, Suzanne

1999-07-01

91

Hot rolling joining process  

International Nuclear Information System (INIS)

In the case of incorporating nonferrous metal equipment in fuel reprocessing processes, from the viewpoint of reducing maintenance works for the piping connection to peripheral equipments, it is desirable to adopt the pipe joints of joining the materials of different kinds, which have the high reliability against leakage. In order to meet this demand, the development of the manufacturing technology of the pipe joints by hot rolling process has been carried out. As for the structure of this pipe joint, a small diameter nonferrous metal pipe and a large diameter stainless steel pipe are joined by hot rolling by using an inserted material. The materials are Ti-5% Ta, Ti and Zr for the nonferrous metals, SUS 304L for the stainless steel, and Ta foil for the inserted material. The merits and demerits of this pipe joints are shown. The control of the interface structure in the joining of different materials was carried out by using the inserted material. The method of manufacturing the pipe joints and the proper conditions of the rolling joining are explained. As for the performance of the pipe joints, the evaluations of the defects in the joining interface, the strength of the joining, the corrosion resistance and the susceptibility to stress corrosion cracking are reported. (K.I.)

1996-01-01

92

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

International Nuclear Information System (INIS)

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

1976-01-01

93

Winding roll and splicing type winding roll assembly parts  

UK PubMed Central (United Kingdom)

The utility mode provides a winding roll and a spliced winding roll assembly, wherein the winding roll comprises a winding wheel which is used for winding a fish wire and a box body which is matched with the winding wheel the winding wheel is arranged inside the box body and a device for fixing the fish wire is arranged on the box body. The winding roll can also comprise a cover body, and the device for fixing the fish wire is converted to be arranged on the cover body. The spliced winding roll assembly is formed by splicing winding rolls. The winding roll can provide convenience for a user to quickly draw off the fish wire, has good holding function on the fish wire and overcomes the defect that the fish wire is winded with other articles after loosened simultaneously because the box body and the cover body are correspondingly provided with a first clamping part and a second clamping part which are used for clamping, a plurality of winding rolls can be spliced so as to be favorable for storage and transportation and the spliced winding roll assembly has the characteristics of simple structure, small shape, beautiful appearance and so on and has certain economic value and industrial value.

YUEBIN LOU

94

Rolling as a continuing collision  

CERN Multimedia

We show that two basic mechanical processes, the collision of particles and rolling motion of a sphere on a plane, are intimately related. According to our recent findings, the restitution coefficient for colliding spherical particles \\epsilon, which characterizes the energy loss upon collision, is directly related to the rolling friction coefficient \\mu_{roll} for a viscous sphere on a hard plane. We quantify both coefficients in terms of material constants which allow to determine either of them provided the other is known. This relation between the coefficients may give rise to a novel experimental technique to determine alternatively the coefficient of restitution or the coefficient of rolling friction.

Brilliantov, N V; Brilliantov, Nikolai V.; Poeschel, Thorsten

1999-01-01

95

G-MG Toilet Roll  

Science.gov (United States)

This is a task from the Illustrative Mathematics website that is one part of a complete illustration of the standard to which it is aligned. Each task has at least one solution and some commentary that addresses important asects of the task and its potential use. Here are the first few lines of the commentary for this task: Picture a roll of toilet paper; assume that the paper in the roll is very tightly rolled. Assuming that the paper in the roll is very thin, find a rela...

96

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

Directory of Open Access Journals (Sweden)

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

J. Krawczyk

2008-01-01

97

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

DEFF Research Database (Denmark)

Background/purpose The only way to establish the true rolling pressure and the true friction condition in cold rolling is to conduct measurements in the roll bite. A new transducer design is therefore proposed, this to overcome problems in previous measurements in the past 70 years. Method The new idea is to increase the contact surface of the transducer, to be larger than the arc of contact. This is in the opposite way, compared to the smaller and smaller contact pin design that has been prevailing. Results The measurements where conducted during cold dry rolling of both copper strips and stainless steel strips in a pilot mill. The recordings were selected from a steady state with no disturbance from the material flow. The transducer was able to simultaneously measure both the normal pressure and the friction stress. An estimation of the coefficient of friction was accordingly performed. Conclusions The new transducer works very well, it was seen to be robust and able to avoid signal disturbance. The pressure and friction stress distribution results was as expected by the authors and a good reproducibility, together with a proven agreement between recorded signals and signals simulated. Keywords Friction stress, normal pressure distribution, roll bite measurements, cold flat rolling of metals

Lagergren, Jonas; Wanheim, Tarras

2005-01-01

98

Rolling cuff flexible bellows  

Energy Technology Data Exchange (ETDEWEB)

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

Lambert, Donald R. (Livermore, CA)

1985-01-01

99

Rolling cuff flexible bellows  

Energy Technology Data Exchange (ETDEWEB)

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

Lambert, D. R.

1985-09-10

100

Influence of wheat milling on low-hydration bread quality developed by sheeting rolls.  

Science.gov (United States)

It is well known that milling influences the characteristics of flour and products made from it. This article analyzed the influence of milling on the quality of low-hydration bread. In general, milling influenced the quality of these products more than the type of wheat selected. Among the various mill streams, the last break and reduction streams produced lower quality bread and must be eliminated in milling. These streams had a higher protein and ash content, showing the presence of components of the outer layers of the grain. The flour was able to absorb more water, but had less extensibility in kneading and the dough generated was weaker due the poorer quality of its proteins and the influence of elements from the outer layers. Thus, bread made from these streams had smaller volume, had a firmer texture and had both darker crumb and crust. These differences, along with the effect of the kind of flour on the flavor and aroma of the bread, made it less acceptable than flour from the rest of the streams studied. PMID:21551227

Gómez, M; Ruiz-París, E; Oliete, B

2011-05-06

 
 
 
 
101

Numerical simulation of a hot rolling process  

Energy Technology Data Exchange (ETDEWEB)

This paper presents the findings of the effects of rolling parameters on the work roll undergoing thermal cycles through numerical simulation using the finite element method. The rolling parameters investigated are the location of the spray nozzle, the coolant spray flux, and the initial work roll temperature. The findings show that the spray nozzle is best placed near the exit of the roll bite for minimum fatigue stress. Firecracking can be eliminated by providing a large cooling flux through spraying. The initial temperature of the work roll have little effect on the roll life, but does have some influence on the quality of the rolled product.

Tso, C.P.; Tan, F.L.

1999-07-01

102

Manufacturing of molybdenum tubes by pressing and skew rolling  

Energy Technology Data Exchange (ETDEWEB)

A study was made on the quality of tube billets and molybdenum cast tubes, manufactured by pressing and the following skew rolling. The structure of the device for increasing the stability of exit side of screw rolling vacuum mill is suggested.

Kozeradskij, S.A.; Kravchenko, S.G.; Pravikov, V.A.

1982-04-01

103

Characterization of roll bite heat transfers in hot steel strip rolling and their influence on roll thermal fatigue degradation  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A temperature sensor with a thermocouple placed at ~0.5 mm from roll surface is used in hot rolling conditions to evaluate by inverse calculation heat transfers in the roll bite. Simulation analysis under industrial hot rolling conditions with short contact lengths (e.g. short contact times) and hig...

LEGRAND, Nicolas; Weisz-Patrault, Daniel; Horsky, Jaroslav; Luks, Tomas; Labbe, Nathalie; Picard, Michel; Ehrlacher, Alain

104

Analysis of roll gap heat transfers in hot steel strip rolling through roll temperature sensors and heat transfer models  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This paper presents an analysis of roll bite heat transfers during pilot hot steel strip rolling. Two types of temperature sensors (drilled and slot sensors) implemented near roll surface are used with heat transfer models to identify interfacial heat flux, roll surface temperature and Heat Transfer...

Weisz-Patrault, Daniel; Ehrlacher, Alain; LEGRAND, Nicolas; Labbe, Nathalie; Horsky, Jaroslav; Luks, Tomas

105

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

Directory of Open Access Journals (Sweden)

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

Walter Mora Perdomo; John Sandro Rivas Murillo; John Jairo Coronado Marín

2005-01-01

106

"AMINAT" ROLL PRESERVE PREPARATION METHOD  

UK PubMed Central (United Kingdom)

FIELD: food production process. ^ SUBSTANCE: preserves are prepared by cutting and freezing cilantro, grating brynza and mixing of the listed components with cooking salt, khmeli-suneli and red hot pepper to obtain mince, beating chicken fillet, putting on it mince and rolling them to prepare rolls, cutting and freezing green onion and mixing without oxygen access with cooking salt and calcium ascorbate to prepare garnish, packing rolls, garnish and chicken stock, sealing and sterilising. ^ EFFECT: diversification of available food products improved digestibility of preserve foods as compared to standard analogues.

KVASENKOV OLEG IVANOVICH

107

Roll Damping at Forward Speed.  

Science.gov (United States)

Three dimensional body theories indicate a significant effect of forward speed on the linear roll damping coefficient, whereas two dimensional and strip-slender body theories indicate that the effect is small. Model tests, carried out many years ago, demo...

M. A. Abkowitz

1983-01-01

108

A mould for bread rolls  

UK PubMed Central (United Kingdom)

Mould of an array of moulds for making bread rolls comprises two parts, one of which contains a cavity 7 and the other of which contains a cap 3 with a former 4 extending therefrom. In use, a quantity of dough is placed in the cavity 7 and the cap 3 put over the open end with the former 4 extending into the cavity 7. The dough is then allowed to prove around the former, and the entire mould is then baked in an oven. The bread rolls made in this way are shaped according to the shape of the cavity and are penetrated by a hole. Since the hole is baked into the roll the entire interior surface of the hole, as well as the entire exterior of the roll, are crusted.

RYAN LAWRENCE JOHN

109

NORMAL PRESSURE AND FRICTION STRESS MEASUREMENT IN ROLLING PROCESSES  

DEFF Research Database (Denmark)

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

Henningsen, Poul; Arentoft, Mogens

2005-01-01

110

Multi-stage FE simulation of hot ring rolling  

Science.gov (United States)

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

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

2013-05-01

111

Grease lubrication in rolling bearings  

CERN Multimedia

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

Lugt, Piet M

2012-01-01

112

Effects of hot-rolling temperature and reduction ratio on edge cracking of hot-rolled boron-stainless steel  

International Nuclear Information System (INIS)

[en] The effects of hot-rolling temperature and reduction ratio on edge cracking in hot-rolled stainless steel containing 1.1% boron were investigated by using a hot-mill simulator. The main results are as follows: (1) The temperature at the side of hot-rolled steel sheets (Ts) during hot-rolling was significantly lower than at the center of hot-rolled steel sheets (Tp) just before hot rolling. (2) Ts at the start of edge cracking was not constant and increased with increasing reduction per pass. (3) The total reduction until the start of edge cracking was constant and was not dependent on Ts or the reduction per pass. (4) It is concluded that total reduction is the main factor in edge cracking due to rapid work hardening of the matrix (?phase), and owing to cavities occurring at the interface of the matrix and boride under constant strain conditions. (author)

1998-01-01

113

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

Energy Technology Data Exchange (ETDEWEB)

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.

Yi-Wen Cheng; Patrick Purtscher

1999-07-30

114

"ONAR" ROLLS PRESERVE PREPARATION METHOD  

UK PubMed Central (United Kingdom)

FIELD: food production process. ^ SUBSTANCE: porcini mushrooms are sliced and blanched, garlic is blanched and minced, pork fat is minced the above-mentioned ingredients are mixed with culinary salt and hot black pepper for a homogenous farce formation. Pork is cut and beaten. The prepared farce is placed on the meat slices thus tenderised. The slices are rolled up and the rolls thus produced are fried in cooking fat. Potatoes are sliced, blanched and strained. Onions are cut and sautéed in margarine. Fresh green peas are frozen. Wheat flour is sautéed in margarine. The potatoes, onions, peas, wheat flour, milk, culinary salt and hot black pepper are mixed under oxygen-free conditions to produce the garnish. The rolls, garnish and mushroom broth are packaged, vacuum-sealed and sterilised. ^ EFFECT: diversification of available food products improved digestibility of preserve foods as compared to standard analogues (digestibility value increased from 2,1.105 to 2,5.105).

KVASENKOV OLEG IVANOVICH

115

"AMINAT" ROLL PRESERVE PREPARATION METHOD  

UK PubMed Central (United Kingdom)

FIELD: food production process. ^ SUBSTANCE: pre-processed cilantro is chopped and frozen, preferably - at a slow rate. Pre-processed brinsen cheese is grated. The above-mentioned ingredients are mixed with culinary salt, khmeli suneli spicy mixture and hot chili pepper under oxygen-free conditions for a homogenous farce formation. Pre-processed chicken fillet is beaten. The prepared farce is placed on the meat slices that are rolled up to produce rolls. Pre-processed cucumbers and tomatoes are sliced and blanched. Pre-processed lettuce is chopped and frozen, preferably - at a fast rate. The above-mentioned ingredients are mixed with culinary salt and calcium ascorbate under oxygen-free conditions to produce the garnish. The rolls, garnish and chicken broth are packaged, vacuum-sealed and sterilised which finally yields the target finished product. ^ EFFECT: pre-cooked food digestibility improvement.

KVASENKOV OLEG IVANOVICH

116

Robust Rudder Roll Damping Control  

DEFF Research Database (Denmark)

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, two kinds of ship model have been obtained: linear ship model used for designing the controller and nonlinear model used for simulation. The ship model uncertainty is discussed in this chapter and so is a wave model because the ship's roll motion is caused by waves. Using an unstructured model of uncertainty, three controllers with different kind of control schemes are designed by the mixed sensitivity method in Chapter 5. Sea-way simulation results show that each of these controllers have good robust stability and performance. The roll damping reduction is above 35% for all of these controllers. Roll reduction of near 70% has been obtained by the cascade controller. Using structured model of uncertainty, a m controller is designed in Chapter 6. The good robust performance has been recognized in the simulation results. It is shown that the m controller has the best robust characteristics with respect to model uncertainty and the roll reduction is near 50% with an envelope of model perturbations.

Yang, C.

1998-01-01

117

Production method of seasoning laminaria roll  

UK PubMed Central (United Kingdom)

The invention relates to a production mthod of seasoning laminaria roll, which comprises the following steps that: dry laminaria roll is arranged inside clean water to be re-hydrated then the laminaria roll is put into baking soda solution to be soaked after being washed by clean water to be neutral, the laminaria roll is naturally drained the drained laminaria roll is put into a mixed sugar liquid consisting of maltitol solution and sorbose to be soaked seasoning material is added into the mixed sugar liquid to be uniformly mixed, and the laminaria roll is continuously soaked and the seasoning steeping liquid which steeps the laminaria roll is heated, heat-preserved, vacuum packed and sterilized in counter pressure. The seasoning laminaria roll which is produced with the method conforms to the taste of the public, has high nutrition value, is riched in minerals which are beneficial to the human body, and also enriches the types of the laminaria product.

RICHUN CHEN; XIUJUAN HUANG

118

Cell sorting by deterministic cell rolling†‡  

Science.gov (United States)

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

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

2012-01-01

119

Cell sorting by deterministic cell rolling.  

UK PubMed Central (United Kingdom)

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

Choi S; Karp JM; Karnik R

2012-04-01

120

Development of dissimilar metal transition joint by hot bond rolling  

International Nuclear Information System (INIS)

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

1997-01-01

 
 
 
 
121

Rolling Tachyon in Nonlocal Cosmology  

CERN Document Server

Nonlocal cosmological models derived from String Field Theory are considered. A new method for constructing rolling tachyon solutions in the FRW metric in two field configuration is proposed and solutions of the Friedman equations with nonlocal operator are presented. The cosmological properties of these solutions are discussed.

Joukovskaya, L

2007-01-01

122

Evaluation on some important force models for cold strip rolling  

Energy Technology Data Exchange (ETDEWEB)

To improve the accuracy of rolling force prediction, some important force models were evaluated through applied computation for cold rolling of low carbon steel and aluminum alloy according to measured data on lab mill. The effects of model structure and three important variables - flow stress, contact length and friction coefficient - on the precision of computed force were quantitatively studied. Flow stress was measured with plane-strain compression test, contact length was based on elastic flattening of work-roll by Hitchcock, and friction-coefficient was determined by rolling strain and numerical iteration. In steel rolling Bland and Ford integration model and Bryant and Osborn algebraic equation are better in accuracy than Ekelund and Parkins. In aluminum rolling all the models produce large deviations {delta}F{sub R} = 10-20% if flow stress, contact length and friction coefficient are determined with the same method as steel rolling. The elastic deformation of aluminum strip is now taken into account for its low elastic modulus. An effective method to determine plastic and elastic contact has been developed in this investigation. The accuracy of force computation is obviously improved for aluminum rolling. (orig.)

Li Guangying; Lagergren, J. [Royal Inst. of Tech. (KTH), Stockholm (Sweden). Dept. of Material Processing

2000-11-01

123

The Heat Conditions of the Cold Pilger Rolling  

Directory of Open Access Journals (Sweden)

Full Text Available The influence of technological factors and constructive parameters of the cold pilger rolling mill to the warm conditions of deformation is observed. The dependences of the heat conditions of pilger rolling on deformation mode and preheating temperature are shown. There was a conclusion drawn about the expediency of combination of warming and cooling of the metal for keeping the deformation zone temperature within limit, which corresponds to the minimal intensity of the metal strengthening.

Frolov, Ya. V.; Mamuzi?, I.; Danchenko, V. N.

2006-01-01

124

Device for covering roofing with rolled material  

Energy Technology Data Exchange (ETDEWEB)

The device for covering roof with rolled material installed on a tunneling combine includes a frame, stand, drum with rolled material installed on the axis, cantilevers and attachment for pressing the drum with the rolled material to the roofing. In order to increase the output of the device by expanding the range of width of the rolled material depending on the width of coverage and the design of the working mechanism of the combine, the frame is made with a through longitudinal slit and the length can be adjusted by axial movement to accommodate longer rolls of material.

Rubis, V.K.; Borovikov, A.Ye.; Kemerov, V.A.; Sarin, P.G.

1981-01-01

125

Improving energy efficiency of reheating furnace of sheet ingot plant and rolling mill Calibers of Gecamines / Lubumbashi by the recovery of waste heat of smoke  

International Nuclear Information System (INIS)

The economic management of energy is an important topic in industrial processes to the extent that it ensures the competitiveness of any firm and ensures its survival. Within this framework we plan to improve the energy efficiency of the powerful furnace for reheating lingots Rolling Mills and Cable Factory (of which the fuel is diesel) where we propose to install a head recovery exchanger between the hot fumes out of the oven (60 C) and combustion air taken initially at room temperature (250C). Without recovery the oven consumes on the average 101 liters of diesel per hour for its operation and yields a thermal efficiency of 68,6%. Whereas with recovery, it can reach a thermal efficiency of 86% on one of recoverers that we have proposed, and save up to 15,8 liters of diesel on its hourly consumption

2010-01-01

126

Almost rolling motion: An investigation of rolling grooved cylinders  

CERN Document Server

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

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

1998-01-01

127

Rubber rolling over a sphere  

Science.gov (United States)

“Rubber” coated bodies rolling over a surface satisfy a no-twist condition in addition to the no slip condition satisfied by “marble” coated bodies [1]. Rubber rolling has an interesting differential geometric appeal because the geodesic curvatures of the curves on the surfaces at corresponding points are equal. The associated distribution in the 5 dimensional configuration space has 2 3 5 growth (these distributions were first studied by Cartan; he showed that the maximal symmetries occurs for rubber rolling of spheres with 3:1 diameters ratio and materialize the exceptional group G 2). The 2 3 5 nonholonomic geometries are classified in a companion paper [2] via Cartan’s equivalence method [3]. Rubber rolling of a convex body over a sphere defines a generalized Chaplygin system [4 8] with SO(3) symmetry group, total space Q = SO(3) × S 2 and base S 2, that can be reduced to an almost Hamiltonian system in T* S 2 with a non-closed 2-form ?NH. In this paper we present some basic results on the sphere-sphere problem: a dynamically asymmetric but balanced sphere of radius b (unequal moments of inertia I j but with center of gravity at the geometric center), rubber rolling over another sphere of radius a. In this example ?NH is conformally symplectic [9]: the reduced system becomes Hamiltonian after a coordinate dependent change of time. In particular there is an invariant measure, whose density is the determinant of the reduced Legendre transform, to the power p = 1/2( b/a - 1). Using sphero-conical coordinates we verify the result by Borisov and Mamaev [10] that the system is integrable for p = -1/2 (ball over a plane). They have found another integrable case [11] corresponding to p = -3/2 (rolling ball with twice the radius of a fixed internal ball). Strikingly, a different set of sphero-conical coordinates separates the Hamiltonian in this case. No other integrable cases with different I j are known.

Koiller, J.; Ehlers, K.

2007-04-01

128

Finite element analysis of roll bit behaviors in cold foil rolling process  

Science.gov (United States)

To investigate roll bite behaviors in cold foil rolling process, a 2D elasto-plastic finite model is established using FEM software ABAQUS. Contact pressure distribution and roll contour in roll bite are also presented, which demonstrate that foil rolling process is different from conventional strip rolling process. The contact area is composed of entry elastic zone, entry plastic zone, an extensive neutral zone, exit plastic zone and exit elastic zone. It conforms to the results of Fleck foil rolling theory. Elastic deformation and work hardening of foil in roll bite are taken into account. The effect of rolling parameters, such as friction coefficient, entry thickness and reduction rate on distribution of contact pressure and vertical displacement are also discussed.

Hao, Liang; Jiang, Zhengyi; Wei, Dongbin; Chen, Xiawei

2013-05-01

129

Increased roll stability suspension system  

Energy Technology Data Exchange (ETDEWEB)

A suspension system is described for suspending an elongated chassis of a vehicle, such as a heavy duty truck, above the front axle and rear axle of a transversely extending tandem axle combination. The suspension system comprises: means for locating the roll center of the vehicle at an elevation below the elevation of the axles; and a stabilizer unit for providing roll stability to the vehicle. The stabilizer unit is mounted to the vehicle chassis at a pivot point longitudinally intermediate the front axle and the rear axle of the tandem axle combination for rotation in a generally horizontal plane. The stabilizer unit includes a pair of linkage members, each linkage member extending generally longitudinally outward from the pivot point in a direction opposite from the other linkage member and toward a corresponding axle.

Giese, L.

1987-05-26

130

Rolling tachyons and decaying branes  

International Nuclear Information System (INIS)

[en] We present new rolling tachyon solutions describing the classical decay of D-branes. Our methods are simpler than those appearing in recent works, yet our results are exact in classical string theory. The role of pressure in the decay is studied using tachyon profiles with spatial variation. In this case the final state involves an array of codimension one D-branes rather than static, pressureless tachyon matter. (author)

2003-01-01

131

Rolling Contact Fatigue of Ceramics  

Energy Technology Data Exchange (ETDEWEB)

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

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

2006-09-01

132

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

DEFF Research Database (Denmark)

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

Lagergren, J.; Wanheim, Tarras

2006-01-01

133

Rolling tooth-like axle harrow  

UK PubMed Central (United Kingdom)

The utility model discloses a rolling tooth-like axle harrow, particularly the technical field of ordinary agricultural machinery. The aim of the utility model is to provide a new harrow for agriculture in order to solve the existing problems of the prior art. The principles of scrolling, rolling and thrust work are used, and steel pipes or the angle iron is connected to form a rectangular frame. An iron roller with a plurality of thorns is arranged in the frame, the iron roller is parallel with two long sides of a rectangle, and both ends are connected with two short sides with the rolling method. The middle parts of the two long sides are provided with traction frames to form the rolling tooth-like axle harrow. More specifically, the rolling tooth-like axle harrow is composed of a tooth-like axle harrow frame, the traction frames and a rolling tooth-like axle, wherein the rolling tooth-like axle comprises the iron roller, rolling thorns and a rolling axle, and the rolling tooth-like axle is arranged in the tooth-like axle harrow frame. The rolling thorns are arranged on the outer surface of a cylinder of the iron roller, the rolling axle is arranged on both ends of the iron roller, and the rolling axle is connected with a left and a right harrow tips through flanges and connecting screws. The utility model is used for leveling soil and preserving the soil moisture of broken soil for agriculture and relevant industries.

WEI HUAWU

134

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

Science.gov (United States)

At Bethlehem Steel Burns Harbor Plate Division (now ISG Burns Harbor Plate Inc.)'s annealing furnace, new nickel aluminide intermetallic alloy rolls provide greater high-temperature strength and wear resistance compared to the conventional H series cast a...

J. Mengel A. Martocci L. Fabina R. Petrusha R. Chango P. Angelini V. Sikka

2003-01-01

135

Continuous Double-Sided Roll-to-Roll Imprinting of Polymer Film  

Science.gov (United States)

Roll-to-roll imprinting of two-sided structures on thermoplastic polymer film have been studied. Two continuous roll-to-roll approaches to producing structures on both sides of a web have been developed. In the sequential method, two separate printing units are used to the pattern upper and bottom surfaces of the film. In simultaneous roll-to-roll imprinting, two patterned rolls are used in one imprinting unit to pattern both sides simultaneously. In both experiments, flexible Ni-masters with submicron patterns wrapped on supporting metal rolls are used as stamps. The cellulose acetate film 95 ?m thick and 50 mm wide has been used as the imprint material in the experiments. Patterned films were studied with an optical microscope and an atomic force microscope (AFM). The results indicate that both methods can be used for double-sided imprinting. However, in sequential imprinting, the first printed pattern is slightly damaged during the second printing phase.

Mäkelä, Tapio; Haatainen, Tomi; Majander, Päivi; Ahopelto, Jouni; Lambertini, Vito

2008-06-01

136

ROLLING PIN FOR STORING COOKIE CUTTERS  

UK PubMed Central (United Kingdom)

The preferred form of the present invention is a rolling pin having a hollow center portion that is sized and configured to receive and store one or more cooking implements such as a plurality of cookie cutters. The cookie cutters are configured to fit within the interior of the rolling pin. The rolling pin includes two handles, and one or both of the handles is removable to allow the cookie cutters or other implements to be either stored or removed for use.

CURTIN HEATHER; MARKS JACOB A

137

ROLLED FOOD ITEM AND METHOD FOR FORMATION OF SAME  

UK PubMed Central (United Kingdom)

A rolled food product and method for making the same is disclosed. The rolle d food product comprises a plurality of individual strands that are joined together and rolled to form a rolled food product having multiple strands th at can be peeled individually from the rolled food product. The structure has enhanced play value and appeal to consumers.

SCHONAUER SYLVIA; REIFSTECK BRIAN; YANG GUOSHEN

138

ROLLED FOOD ITEM AND METHOD FOR FORMATION OF SAME.  

UK PubMed Central (United Kingdom)

A rolled food product and method for making the same is disclosed. The rolled food product comprises a plurality of individual strands that are joined together and rolled to form a rolled food product having multiple strands that can be peeled individually from the rolled food product. The structure has enhanced play value and appeal to consumers.

YANG GUOSHEN; SCHONAUER SYLVIA; REIFSTECK BRIAN

139

ROLLED FOOD ITEM AND METHOD FOR FORMATION OF SAME  

UK PubMed Central (United Kingdom)

A rolled food product and method for making the same is disclosed. The rolled food product comprises a plurality of individual strands that are joined together and rolled to form a rolled food product having multiple strands that can be peeled individually from the rolled food product. The structure has enhanced play value and appeal to consumers.

SCHONAUER Sylvia; REIFSTECK Brian

140

Rolled food item and method for formation of same  

UK PubMed Central (United Kingdom)

A rolled food product and method for making the same is disclosed. The rolled food product comprises a plurality of individual strands that are joined together and rolled to form a rolled food product having multiple strands that can be peeled individually from the rolled food product. The structure has enhanced play value and appeal to consumers.

SCHONAUER SYLVIA; REIFSTECK BRIAN

 
 
 
 
141

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

Energy Technology Data Exchange (ETDEWEB)

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

Mengel, J.

2003-12-16

142

Interactions Between Stably Rolling Leukocytes In Vivo  

CERN Multimedia

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

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

2003-01-01

143

Whirlwind Rolling Process of Slender Shaft  

Directory of Open Access Journals (Sweden)

Full Text Available In order to solve the problem of slender shaft which is easy bended and deformed for its big slenderness ration and poor rigidity, the method of whirlwind rolling with Tri-tools is designed. This paper introduces the principle and the process of stress analysis. With the help of ABAQUS finite element simulation software, the 3D model of whirling rolling is established. The rolling process is simulated by the software and summarizes the influence of quality factors during the whirlwind rolling process.

Zhang Hong; Deng ZhiPing; Jin Long; Long Jun; Zhang Zhengyi

2013-01-01

144

Strip shape analysis in unsymmetrical rolling; Sayu hitaisho atsuen no keijo seigyo kaiseki  

Energy Technology Data Exchange (ETDEWEB)

Model for analyzing unsymmetrical rolling based on a matrix model is built for a 6-stage rolling mill (UC mill) known for its excellent performance in correcting unsymmetrical shapes. The shape controlling properties of the UC mill in unsymmetrical rolling are examined by use of this analysis model. An experiment of unsymmetrical rolling is conducted in which the differentiated loads and the intermediate roll shift are changed, and it is found that there is good agreement between the calculated values and the values obtained from the experiment and that this analysis model works accurately in the analysis of unsymmetrical rolling. There holds a linear relationship between the unsymmetrical component involving the plate edge and quarter section inlet side plate crown and the unsymmetrical component involving the outlet side plate shape, and the effect of the inlet side plate crown can be quantified. When the work roll diameter is large, the scope of unsymmetrical shape control application is small because the controlling properties of the unsymmetrical shape controlling means are alike. When the work roll diameter is small, however, the unsymmetrical shape may be effectively controlled because the controlling properties are greatly dependent on the combination of the unsymmetrical intermediate roll shift with differentiated loads or with the unsymmetrical intermediate roll bender. 5 refs., 14 figs., 4 tabs.

Aizawa, A.; Hara, K.; Nakamoto, K. [Nippon Seiko K.K., Tokyo (Japan)

1997-09-30

145

Rolling-cuff flexible bellows  

Science.gov (United States)

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

Lambert, D.R.

1982-09-27

146

FEM Analysis of Effect of Rolling Parameters on Cold Rolling Process  

Directory of Open Access Journals (Sweden)

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

K. Devarajan

2012-01-01

147

A lubricant for cold rolling  

Energy Technology Data Exchange (ETDEWEB)

In the composition of a lubricant (Sm) for cold rolling based on glycerin ethers of wastes from the production of sebacic acid (OSK), in order to increase the antifriction and antiscuff properties of the lubricant and to increase the quality of the processed surface, aminoparaffin fluoride (FA) is additionally introduced with the following component content in percent: aminoparaffin fluoride, 5 to 15; glycerin ether of waste from the production of sebacic acid, 85 to 95. The aminoparaffin fluoride additive, having high surface active properties, promotes an improvement in the conditions for cleaning the surface of pipes after deformation before heat treatment. The proposed lubricant is not aggressive with respect to corrosion, since the aminoparaffin fluoride is a corrosion inhibitor. Tests of the proposed lubricants in extracting samples from OKh18N10G brand steel showed that unlike the known lubricant, they have better antifriction properties. The proposed lubricant may be used in more rigid conditions of deformation when rolling pipes from corrosion resistant steel and alloys without under lubricant coatings.

Markov, V.I. Breskina, A.I.; Bychkova, N.F.; Frolova, L.M.; Gudz, L.A.; Kolesnikov, V.N.; Pedan, V.P.; Shcherbak, R.Ya.; Solovyev, V.M.; Tarasenko, V.A.

1982-01-01

148

Load-signature analysis for pack rolling of near-gamma titanium aluminide alloys  

Energy Technology Data Exchange (ETDEWEB)

The objective of the present work was to demonstrate the sensitivity of rolling-load signature analysis as a means to monitor hot-pack-rolling processes for the fabrication of sheet of near-gamma titanium-aluminide alloy sand other difficult-to-work materials. In previous work, a simple method was developed for the prediction of temperature transients during two steps in the pack-rolling process: the transfer of the pack from the furnace to the rolling mill and the actual rolling operation itself. The accuracy of the temperature-transient calculations was established through load-signature data obtained during trials for Ti-48Al (atomic percent) rolled at a single nominal (furnace) temperature. In the present work, additional results are presented and discussed for hot pack rolling at various nominal temperatures and for a range of near-gamma titanium-aluminide alloys.

Semiatin, S.L. (Wright Lab. Materials Directorate, Wright-Patterson AFB, OH (United States). Metals and Ceramics Division); Seetharaman, V. (UES, Inc., Dayton, OH (United States))

1994-11-01

149

Effect of roll-heave coupling on roll response of a floating body  

Energy Technology Data Exchange (ETDEWEB)

The effect of roll-heave coupling on the responses of floating bodies is investigated by comparing the free-oscillation behavior of a coupled roll-heave model to that of an uncoupled model. It is found that an important coupling effect is the additional roll damping due to the energy dissipation of the accompanying heave motion. The additional roll damping ratio depends mainly on the roll response, draught-to-beam ratio and the location of the mass center of the floating body.

Xie, Q.; Liaw, C.Y.; Cheong, H.F. [National Univ. of Singapore (Singapore). Dept. of Civil Engineering

1993-12-31

150

Roll casting of 5182 aluminium alloy  

Directory of Open Access Journals (Sweden)

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

T. Haga; M. Mtsuo; D. Kunigo; Y. Hatanaka; R. Nakamuta; H. Watari; S. Kumai

2009-01-01

151

Numerical analysis of Swiss roll metamaterials  

Energy Technology Data Exchange (ETDEWEB)

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.

Demetriadou, A; Pendry, J B, E-mail: ademetri@imperial.ac.u, E-mail: j.pendry@imperial.ac.u [Blackett Laboratory, Imperial College London, London SW7 2AZ (United Kingdom)

2009-08-12

152

Numerical analysis of Swiss roll metamaterials.  

UK PubMed Central (United Kingdom)

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.

Demetriadou A; Pendry JB

2009-08-01

153

Numerical analysis of Swiss roll metamaterials  

Science.gov (United States)

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.

Demetriadou, A.; Pendry, J. B.

2009-08-01

154

Power roll 2007: A five year summary  

Science.gov (United States)

The powered roll gin stand (PRT – Powered Roll Technology) was first tested in a field application on seed cotton during the 2002 ginning season at Servico, Inc., Courtland Alabama. During the 2003 season, Servico installed and operated PRT stands in all three lines. In subsequent years, mechanical ...

155

Advances in roll-to-roll imprint lithography for display applications  

Science.gov (United States)

A solution to the problems of roll-to-roll lithography on flexible substrates is presented. We have developed a roll-toroll imprint lithography technique to fabricate active matrix transistor backplanes on flexible webs of polyimide that have a blanket material stack of metals, dielectrics, and semiconductors. Imprint lithography produces a multi-level 3- dimensional mask that is then successively etched to pattern the underlying layers into the desired structures. This process, Self-Aligned Imprint Lithography (SAIL), solves the layer-to-layer alignment problem because all masking levels are created with one imprint step. The processes and equipment required for complete roll-to-roll SAIL fabrication will be described. Emphasis will be placed on the advances in the roll-to-roll imprint process which have enabled us to produce working transistor arrays.

Jeans, Albert; Almanza-Workman, Marcia; Cobene, Robert; Elder, Richard; Garcia, Robert; Gomez-Pancorbo, Fernando; Jackson, Warren; Jam, Mehrban; Kim, Han-Jun; Kwon, Ohseung; Luo, Hao; Maltabes, John; Mei, Ping; Perlov, Craig; Smith, Mark; Taussig, Carl; Jeffrey, Frank; Braymen, Steve; Hauschildt, Jason; Junge, Kelly; Larson, Don; Stieler, Dan

2010-03-01

156

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

Directory of Open Access Journals (Sweden)

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

Rafiei Masoud; Gadgil Alaka; Ghole Vikram; Gore Sharad; Jaafarzadeh Neemat; Mirkazemi Roksana

2009-01-01

157

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

International Nuclear Information System (INIS)

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

1040-01-00

158

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

Energy Technology Data Exchange (ETDEWEB)

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

Hoshino, Jumpei [Materials Science and Engineering Programme and Nanotec Center of Excellence at Mahidol University, Faculty of Science, Mahidol University, Rajathavee, Bangkok 10400 (Thailand); Limpanart, Sarintorn; Khunthon, Srichalai [Metallurgy and Materials Research Institute, Chulalongkorn University, Phayathai, Bangkok 10330 (Thailand); Osotchan, Tanakorn [Materials Science and Engineering Programme and Nanotec Center of Excellence at Mahidol University, Faculty of Science, Mahidol University, Rajathavee, Bangkok 10400 (Thailand); Physics Department, Faculty of Science, Mahidol University, Rajathavee, Bangkok 10400 (Thailand); Traiphol, Rakchart [Laboratory of Advanced Polymers and Nanomaterials, Department of Chemistry and Center for Innovation in Chemistry, Faculty of Science, Naresuan University, Phitsanulok 65000 (Thailand); Srikhirin, Toemsak, E-mail: sctsk@mahidol.ac.th [Materials Science and Engineering Programme and Nanotec Center of Excellence at Mahidol University, Faculty of Science, Mahidol University, Rajathavee, Bangkok 10400 (Thailand); Physics Department, Faculty of Science, Mahidol University, Rajathavee, Bangkok 10400 (Thailand)

2010-10-01

159

Geometric Models of Rolling-Shutter Cameras  

CERN Multimedia

Cameras with rolling shutters are becoming more common as low-power, low-cost CMOS sensors are being used more frequently in cameras. The rolling shutter means that not all scanlines are exposed over the same time interval. The effects of a rolling shutter are noticeable when either the camera or objects in the scene are moving and can lead to systematic biases in projection estimation. We develop a general projection equation for a rolling shutter camera and show how it is affected by different types of camera motion. In the case of fronto-parallel motion, we show how that camera can be modeled as an X-slit camera. We also develop approximate projection equations for a non-zero angular velocity about the optical axis and approximate the projection equation for a constant velocity screw motion. We demonstrate how the rolling shutter effects the projective geometry of the camera and in turn the structure-from-motion.

Meingast, M; Sastry, S; Meingast, Marci; Geyer, Christopher; Sastry, Shankar

2005-01-01

160

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

Science.gov (United States)

...Flat-Rolled Carbon-Quality Steel Products From Brazil, Japan, and Russia AGENCY: United States...products (``hot-rolled steel'') from Brazil, the antidumping duty orders on hot-rolled steel from Brazil and Japan, and the suspended...

2010-04-01

 
 
 
 
161

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

Science.gov (United States)

...Flat-Rolled Carbon-Quality Steel Products From Brazil, Japan, and Russia AGENCY: United States...products (``hot-rolled steel'') from Brazil, the antidumping duty orders on hot-rolled steel from Brazil and Japan, and the suspended...

2010-07-22

162

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

Science.gov (United States)

...Flat-Rolled Carbon-Quality Steel Products From Brazil, Japan, and Russia AGENCY: United States...products (``hot-rolled steel'') from Brazil, the antidumping duty orders on hot-rolled steel from Brazil and Japan, and the suspended...

2010-10-12

163

Production of powder Ti-alloy rings by means of compaction and radial-rolling  

Energy Technology Data Exchange (ETDEWEB)

Combined-die-compaction (MVV) and rolling is used to produce rings from Ti-6Al-4V powder. The influence of deformation and of heat treatment on the microstructure of Ti-alloy rings was investigated. Plastic deformation of phi/sub v/=0,615 when rolling in a ring rolling mill at 900/sup 0/C and annealing at 925/sup 0/C for 0,5 h results in the required homogenous globular microstructure.

Szczepanik, S.; Kopp, R.; Wiegels, H.

1988-12-01

164

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

Directory of Open Access Journals (Sweden)

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

T. Haga; H. Watari; S. Kumai

2006-01-01

165

Multi-scale modelling of hot rolled dual-phase steels for process design  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This thesis investigates and models the austenite to ferrite transformation in the hot rolling of two different dual phase steels. The investigation has been carried out in a deformation dilatometer as well as a 4-stand pilot rolling mill. Three different modelling approaches were employed to give d...

Suwanpinij, Piyada

166

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

International Nuclear Information System (INIS)

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

2000-01-01

167

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

Energy Technology Data Exchange (ETDEWEB)

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

Huang, C.Q.; Yuan, J.G. [Hot Strip Mill Dept., Shanghai Baosteel Group, Shanghai (China)

2000-07-01

168

Ensilage harvester variable speed feed roll drive  

UK PubMed Central (United Kingdom)

A drive transmission for the feed rolls of a forage harvester includes a planetary gear set arranged such that an input shaft drives the sun gear while a further input shaft is provided by a reversible, variable speed motor that is connected to the ring gear of the planetary gear set so as to effect speed and direction changes in the output of the planetary gear set that is defined by the planet carrier. Thus, the length of cut of crop products fed to the cutterhead by the feed rolls is controlled by varying the speed of the motor in order to vary the delivery speed of the feed rolls.

KEMPF BERND

169

Twin roll casting of magnesium alloys with high aluminum contents  

Directory of Open Access Journals (Sweden)

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

H. Watari; T. Haga; Y. Shibue; K. Davey; N. Koga

2006-01-01

170

Evaluation of roll compaction as a preparation method for hydroxypropyl cellulose-based matrix tablets.  

UK PubMed Central (United Kingdom)

Roll compaction was applied for the preparation of hydroxypropyl cellulose (HPC)-based sustained-release matrix tablets. Matrix tablets made via roll compaction exhibited higher dosage uniformity and faster drug release than direct-compacted tablets. HPC viscosity grade, roll pressure, and milling speed affected tablet properties significantly. Roll compaction seems to be an adequate granulation method for the preparation of HPC-based matrix tablets due to the simplicity of the process, less handling difficulty from HPC tackiness as well as easier particle size targeting. Selecting the optimum ratio of plastic excipients and the particle size of starting materials can however be critical issues in this method.

Jeon I; Gilli T; Betz G

2011-04-01

171

Thermal modeling of roll and strip interfaces in rolling processes. Part 2: Simulation  

Energy Technology Data Exchange (ETDEWEB)

Part 1 of this paper reviewed the modeling approaches and correlations used to study the interface heat transfer phenomena of the roll-strip contact region in rolling processes. The thermal contact conductance approach was recommended for modeling the interface phenomena. To illustrate, the recommended approach and selected correlations are adopted in the present study for modeling of the roll-strip interface region. The specific values of the parameters used to correlate the corresponding thermal contact conductance for the typical cold and hot rolling of steels are first estimated. The influence of thermal contact resistance on the temperature distributions of the roll and strip is then studied. Comparing the present simulation results with previously published experimental and analytical results shows that the thermal contact conductance approach and numerical models used can reliably simulate the heat transfer behavior of the rolling process.

Tseng, A.A. [Arizona State Univ., Tempe, AZ (United States). Mfg. Inst.

1999-02-12

172

Hot rolling of intermetallics FeAl phase based alloys  

Directory of Open Access Journals (Sweden)

Full Text Available Purpose: The one of major problem restricting universal employment of intermetallic phase base alloy istheir low plasticity which leads to hampering their development as construction materials. The following workconcentrates on possibilities to form through rolling process the alloys with various aluminium content.Design/methodology/approach: After casting and annealing, alloy specimens were subjected to axialsymmetriccompression at temperatures ranging from 900 to 1200°C at 10 s-1 strain rates. In order to analyse theprocesses which take place during deformation, the specimens after deformation were intensely cooled with water.Structural examination was carried out using light microscopy. The process was conducted on the K -350 quartorolling mill used for hot rolling of flat products. The process was conducted in some stages in at temperaturesranging from 1200-900°C:Findings: The research carried out enabled the understanding of the phenomena taking place during hot rolling ofthe investigated alloy. An alloy with 38%at. aluminium concentration can be plastically formed at a temperature of upto 900°C, which has been also confirmed in plastometric studies conducted in the form of hot compression tests.Research limitations/implications:Practical implications: The obtained sheets can be used as constructional elements working in complex stressfields, at a high temperature and corrosive environmentsOriginality/value: The tests have shown that it is possible to form the investigated alloys through rolling processingonly where shields are applied. Rolling of the alloys without shields led to the occurrence of a grid of cracks.

G. Niewielski; D. Kuc; I. Schindler; I. Bednarczyk

2008-01-01

173

Rolling tachyon in NS string field theory  

International Nuclear Information System (INIS)

A brief review of studing rolling solutions to equations of motion for the tachyon field living on an unstable D-brane in the level truncated string field theory is given. (Abstract Copyright [2003], Wiley Periodicals, Inc.)

2003-01-01

174

Rahvusvaheline bussiliiklus täna ja selle roll tulevikus  

Index Scriptorium Estoniae

MootorReisi Aktsiaseltsi kümne aastaseks saamise puhul korraldati konverents "Rahvusvaheline bussiliiklus täna ja selle roll tulevikus". MootorReisi AS-i tekkimisest. Vt. samas: Intervjuu MootorReisi AS-i juhatuse esimees Hugo Osulaga

2004-01-01

175

Process for producing Moldavian preserved stuffed rolls  

UK PubMed Central (United Kingdom)

The invention refers to the food industry and can be used for the production of sealed food jars. The process for producing Moldavian preserved stuffed rolls in vine leaves, according to the invention, includes the preliminary treatment of vegetables, cornmeal, which preliminarily is mixed with 5...7% of vegetable oil, are browned, blanched in boiling water in the ratio of 1:3,5, respectively, with permanent mixing, are washed under water jet with the temperature of 50...60?C up to the complete removal of the sediment and it is separated the water, cutting and frying in vegetable oil of the carrot, onion, parsley and celery roots, mixing of the enumerated components with salt, greens and black pepper, obtaining the stuffing, preparation of the vine leaves, rolling therein of the stuffing, obtaining the stuffed rolls, preparation of the filling, prepacking in jars of the rolls and of the filling, sealing and sterilization. Claims: 7

DICHINA ALLA; TERENTIEVA GALINA; CARAGIA VAVIL; IUSAN LARISA

176

Effect of Metacentric Height on Roll Damping.  

Science.gov (United States)

Experiments were conducted on a floating circular cylinder to determine the effect on roll damping of changes in transverse metacentric height GM. The relationship between log decrement (delta) and GM is defined, both graphically and by means of an empiri...

A. Gersten

1969-01-01

177

Roll measurement of Tevatron dipoles and quadrupoles  

Energy Technology Data Exchange (ETDEWEB)

In 2003 a simple digital level system was developed to allow for rapid roll measurements of all dipoles and quadrupoles in the Tevatron. The system uses a Mitutoyo digital level and a PC running MS WINDOWS XP and LAB VIEW to acquire data on the upstream and downstream roll of each magnet. The system is sufficiently simple that all 1,000 magnets in the Tevatron can be measured in less than 3 days. The data can be quickly processed allowing for correction of rolled magnets by the Fermilab alignment group. Data will be presented showing the state of the Tevatron in 2003 and the changes in rolls as measured in each shutdown since then.

Volk, J.T.; Elementi, L.; Gollwitzer, K.; Jostlein, H.; Nobrega, F.; Shiltsev, V.; Stefanski, R.; /Fermilab

2006-09-01

178

Roll measurement of Tevatron dipoles and quadrupoles  

International Nuclear Information System (INIS)

In 2003 a simple digital level system was developed to allow for rapid roll measurements of all dipoles and quadrupoles in the Tevatron. The system uses a Mitutoyo digital level and a PC running MS WINDOWS XP and LAB VIEW to acquire data on the upstream and downstream roll of each magnet. The system is sufficiently simple that all 1,000 magnets in the Tevatron can be measured in less than 3 days. The data can be quickly processed allowing for correction of rolled magnets by the Fermilab alignment group. Data will be presented showing the state of the Tevatron in 2003 and the changes in rolls as measured in each shutdown since then.

2006-01-01

179

The rolling and skidding of automobile tyres  

Science.gov (United States)

This article deals in simple terms with the rolling and skidding of automobile tyres. It shows that skid resistance on slippery road surfaces may be significantly increased by using tyre treads of high hysteresis loss.

Tabor, D.

1994-09-01

180

Pilot roll-to-roll PECVD system for fabrication of thin film Si solar cells  

Energy Technology Data Exchange (ETDEWEB)

Our aim is the development of high-throughput production technology for high efficiency, amorphous and microcrystalline thin film silicon solar cells on flexible substrates. A roll-to-roll system, the FLEXICOAT300, is developed with three deposition chambers for the continuous deposition of, respectively, n-type Si, intrinsic Si and p-type Si. Novel RF and MW sources for plasma enhanced chemical vapour deposition (PECVD) are introduced in the roll-to-roll coater. The first trial depositions of a-Si solar cells show a promising efficiency of > 4%.

Van Aken, B.B.; Devilee, C.; Doerenkaemper, M.S.; Heijna, M.; Loeffler, J.; Soppe, W.J. [ECN Solar Energy, Petten (Netherlands)

2008-03-15

 
 
 
 
181

Rolling Deformations and Residual Stresses of Large Circular Saw Body  

Directory of Open Access Journals (Sweden)

Full Text Available Rolling path squeezes and rolling residual stresses of large diameter circular saw body for wood, generated by rolling pressure from 10 up to 120 bar were examined. X-ray diffraction, Barkhausen noise (BN) and Full Width of the peak at a Half Maximum (FWHM) (o) methods for evaluation of residual stresses were used. Dependencies of a tangential rolling residual stresses inside rolling paths upon rolling pressure p (bar) and rolling area A (mm2) were evaluated. The rolling pressure, as large as 60 bar, resulting in the rolling squeeze as high as 0.04 mm2, and, tangential residual compression stresses inside a rolling path, as large as ?TI = ?822 MPa, was considered to be the largest for the practical application.

Boles?aw Porankiewicz; Jari Parantainen; Karolina Ostrowska

2010-01-01

182

Heat treatment in hot strip rolling of steel  

Energy Technology Data Exchange (ETDEWEB)

Heat treatment aims at optimal properties by control of metallurgical mechanisms during a controlled temperature-time cycle. This can be combined with deformation during this cycle. During hot rolling of steel in a hot strip mill all the metallurgical aspects play an important role, often in such a way that they even influence the control of the process of rolling and cooling itself. The installation is designed for bulk production. Due to market development however the specifications of the final product change very frequently. This makes control of process and material properties very difficult. To obtain a good process control all the metallurgical processes have to be known and quantified during the specific rolling cycle, including the interactions with the process. To solve this problem we have chosen at Hoogovens an approach with physical mathematical models, where the metallurgical models are integrated with the process models. In such a way a practical and economical solution can be found for the production of high quality coils. This approach will be dealt with and illustrated with results from rolling experiments in the Hot Strip Mill. (orig.)

Hoogendoorn, T.M. (HOOGOVENS GROEP BV, Applied Physical Metallurgy Dept. (Netherlands)); Hoogen, A.J. van den (HOOGOVENS GROEP BV, Applied Physical Metallurgy Dept. (Netherlands))

1994-01-01

183

Disk Partition Function and Oscillatory Rolling Tachyons  

CERN Multimedia

An exact cubic open string field theory rolling tachyon solution was recently found by Kiermaier et. al. and Schnabl. This oscillatory solution has been argued to be related by a field redefinition to the simple exponential rolling tachyon deformation of boundary conformal theory. In the latter approach, the disk partition function takes a simple form. Out of curiosity, we compute the disk partition function for an oscillatory tachyon profile, and find that the result is nevertheless almost the same.

Jokela, Niko; Keski-Vakkuri, Esko; Majumder, Jaydeep

2007-01-01

184

Characteristics of cold rolled stainless steel sheets  

International Nuclear Information System (INIS)

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

1976-07-10

185

Outlook of work rolls in hot strip finisher for steel rolling. Netsukan obiita atsuen'yo sagyo roll no gaikyo  

Energy Technology Data Exchange (ETDEWEB)

This review article elucidates the material properties used for finisher rolls of hot strip continuous rolling machines. The work roll in finisher for rolling slides relatively against the strip at the temperature ranging from 900 to 1,100 centigrade under the pressure condition ranging from 200 to 500 MPa. This paper summarizes the properties of material applied to the work roll, which is subjected by such load and thermal load. From the balance between thermal resistance and economic rationality, and from the balance between strength and toughness, iron base materials have been selected as the roll material. In the former stage of finishing, the high speed steel roll has been recently apt to be used in addition to the adamite roll and high-Cr cast iron roll. While, also in the latter stage of finishing, the high speed steel roll has been recently apt to be used in addition to the high-Ni cast iron roll and high-Cr cast iron roll. For the high speed steel roll with an excellent wear resisting property, effects of the resistance of temper softening of matrix and the protection of falling of carbonaceous material can be expected. 8 refs., 2 figs., 3 tabs.

Kihara, J. (The University of Tokyo, Tokyo (Japan). Faculty of Engineering)

1994-07-01

186

Discomfort caused by low-frequency lateral oscillation, roll oscillation and roll-compensated lateral oscillation.  

UK PubMed Central (United Kingdom)

UNLABELLED: Roll compensation during cornering (aligning the feet-to-head axis of the body with the resultant force) reduces lateral acceleration, but how any improvement in comfort depends on the frequency of the acceleration has not previously been investigated. Seated subjects judged the discomfort caused by lateral oscillation, roll oscillation and fully roll-compensated lateral oscillation at each of seven frequencies (0.25-1.0 Hz). Irrespective of whether it was caused by pure lateral acceleration or gravitational acceleration due to pure roll, acceleration in the plane of the seat caused similar discomfort at frequencies less than 0.4 Hz. From 0.4 to 1.0 Hz, with the same lateral acceleration in the plane of the seat, there was greater discomfort from roll oscillation than from lateral acceleration. With fully roll-compensated lateral oscillation, discomfort was less than with either the lateral component or the roll component of the motion from 0.2 to 0.5 Hz, but discomfort increased with increasing frequency and caused similar discomfort to pure roll oscillation at 1.0 Hz. PRACTITIONER SUMMARY: Tilting can reduce passenger exposure to vehicle lateral acceleration when cornering, but how comfort depends on the frequency of motion was unknown. This study shows 'tilt-compensation' only improves comfort at frequencies less than 0.5 Hz. The findings affect tilting vehicles and the prediction of discomfort caused by low-frequency motions.

Beard GF; Griffin MJ

2013-01-01

187

Rolle’s Theorem and Negligibility of Points in Infinite Dimensional Banach Spaces  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In this note we prove that if a differentiable function oscillates between y« and « on the boundary of the unit ball then there exists a point in the interior of the ball in which the differential of the function has norm equal or less than« . This kind of approximate Rolle’s theorem is interesting ...

Azagra Rueda, Daniel; Gómez Gíl, Javier; Jaramillo Aguado, Jesus Angel

188

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

DEFF Research Database (Denmark)

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

Vig, Asger Laurberg; Mäkelä, Tapio

2011-01-01

189

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

Science.gov (United States)

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

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

2011-03-01

190

Decision Support for the Rolling Stock Dispatcher  

DEFF Research Database (Denmark)

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 departures in a disrupted rolling stock schedule so that operation returns quickly to the originally planned schedule. Different network structures and mathematical formulations for the problem are discussed. Based on prior work on network structures a decomposed approach for the rolling stock recovery problem is put forward. The main contributions of the thesis are contained in four papers included as appendices. The papers deal with respectively an analysis of robustness in timetables, the mathematical model behind a decision support tool for reinsertion of a train line, a survey on the dispatching problems of passenger railway transportation and the decomposed solution process of the rolling stock recovery problem. The paper on the robustness analysis has been accepted for submission in the International Journal of Operations Research. Two of the papers have been submitted to journals and are being reviewed. The last paper will be submitted. Furthermore, the work of the two papers on the robustness analysis respectively the reinsertion model have formed the basis of practical projects in DSB S-tog. The applicability of the decomposed process will be further investigated in the future.

Groth, Julie Jespersen

2009-01-01

191

Applying contextual interference to the Pawlata roll.  

UK PubMed Central (United Kingdom)

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

Smith PJ; Davies M

1995-12-01

192

Surface finishing and levelling of thermomechanically hardened rolled steel  

International Nuclear Information System (INIS)

The finishing of high-strength merchant shapes from alloy steel was tried out under industrial conditions with the equipment of metallurgical plants. After thermomechanical hardening in the production line of the rolling mill, 30KhGSN2A and 40Kh1NVA steel rounds 32 and 31 mm in diameter were straightened on a two-roller straightening machine designed by the All-Union Scientific Research Institute for Metallurgical Machinery (VNII Metmash). This made possible subsequent turning and grinding of the rods. The conditions of straightening, turning and grinding have been worked so as to obtain thermomechanically strengthened and ground rolled products approximating the gauged and ground metal in shape geometry and surface finish. It is shown that the labour-consuming operation of turning can be eliminated by reducing the machining pass of the rolled product, and this lowers the labour required for the finishing operations by 75%. After grinding with 40- and 25-grain abrasive wheels, high strength rolled shapes were obtained with a diameter of 30-0.20 mm and a surface finish of class 6-5 satisfying the technical specifications. (author)

1975-01-01

193

Commercial bakery sandwich breads and rolls products  

UK PubMed Central (United Kingdom)

An improvement to a variety of sandwich-based bakery products to prevent "leakage" of food from the sandwich while eating, due to the open sides of present sandwich bakery products. Leakage is avoided by using separate baking-pan molds to create top and bottom parts of a variety of sandwich-like products (e.g., hamburger rolls, English muffins, submarine rolls, and soft taco/burrito shells). The top and bottom parts of most of the products contain outside walls that have a crust layer created by the baking molds that prevents food from falling or squirting out of the sandwich product due to gravity or pressure from biting or squeezing the sandwich product during eating. The one-piece burrito product has "wings" which, when folded properly, prevents leakage of the contents during eating and reduces the multiple end layers created when "rolling up" a conventional burrito.

SCHOEN NEIL CHARLES

194

Study of rolled uranium annealing process  

International Nuclear Information System (INIS)

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)

1954-01-01

195

Wear phenomena of spinning rolls for stone wool production  

Directory of Open Access Journals (Sweden)

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

A. Klimpel; L.A. Dobrza?ski; A. Lisiecki; D. Janicki

2006-01-01

196

Cold roll forming process energy efficiency optimization ?????????????? ??? ??????????? ?????????????? ??? ?????????? ??????????? ?? ???????????????? ??????????  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The objective of the current study is the development of an optimization methodology for the energy efficiency of the cold roll forming process. Towards that target, a hybrid modeling approach, utilizing analytical and computational models, is proposed and developed. The energy efficiency indicato...

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

197

Hot rolling of gamma titanium aluminide foil  

Energy Technology Data Exchange (ETDEWEB)

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

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

2010-08-15

198

Hot rolling of gamma titanium aluminide foil  

International Nuclear Information System (INIS)

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

2010-01-01

199

The riddles of rock and roll  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Rock and roll has often been equated with rebellion. The genre, though, is just a form of popular music and many of the important players in the game of promoting it were, like the saying goes, only in it for the money. As a rule, music like that will be supportive of the social order rather than in...

Anjou, L.J.M. d'

200

Twinning of fcc-structure at rolling (calculation and construction)  

International Nuclear Information System (INIS)

Formation of crystallographic texture in rolled sheets of fcc-metals is calculated using atomic-shear model. Rolling textures formed both under conditions of plane strain and under action of shear stresses are studied. Crystallography of twin systems is determined. Theoretical straight polar figures (220) for nonreversing rolling are plotted.

1994-01-01

 
 
 
 
201

Yield strength anisotropy for cold-rolled beryllium  

International Nuclear Information System (INIS)

[en] The change of beryllium foil anisotropy during cold rolling is investigated. It is shown that anisotropic yield strengths under testing for static tension of beryllium foil samples, oriented at similar angles in the rolling plane, are described by a simple elliptical locus. Therefore, anisotropic deformation strengthening mathematical model, developed for moderately anisotropic materials is applicable for cold-rolled beryllium under investigation

1987-01-01

202

Roll Damping by Free Surface Tanks with Partially Raised Bottom.  

Science.gov (United States)

The influence of free surface tanks with partially raised bottom on ship roll damping was discussed. The purpose of the introduction of a cambered shoal in the rectangular free surface tank was explained. The effect of a roll damping tank on the rolling m...

J. J. Vandenbosch A. P. Dezwaan

1974-01-01

203

Roll compaction and granulation system for nuclear fuel material  

Energy Technology Data Exchange (ETDEWEB)

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

Goldmann, L.H. Jr.; Holley, C.C.

1981-07-29

204

Roll compaction and granulation system for nuclear fuel material  

International Nuclear Information System (INIS)

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

1981-09-02

205

Structure and Motion Estimation from Rolling Shutter Video  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The majority of consumer quality cameras sold today have CMOS sensors with rolling shutters. In a rolling shutter camera, images are read out row by row, and thus each row is exposed during a different time interval. A rolling-shutter exposure causes geometric image distortions when either the camer...

Hedborg, Johan; Ringaby, Erik; Forssén, Per-Erik; Felsberg, Michael

206

Rolling Deformations and Residual Stresses of Large Circular Saw Body  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Rolling path squeezes and rolling residual stresses of large diameter circular saw body for wood, generated by rolling pressure from 10 up to 120 bar were examined. X-ray diffraction, Barkhausen noise (BN) and Full Width of the peak at a Half Maximum (FWHM) (o) methods for evaluation of residual str...

Boles?aw Porankiewicz; Jari Parantainen; Karolina Ostrowska

207

Low band gap polymers for roll-to-roll coated organic photovoltaics. Design, synthesis and characterization  

Energy Technology Data Exchange (ETDEWEB)

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

Bundgaard, Eva; Hagemann, Ole; Joergensen, Mikkel; Krebs, Frederik C. [Technical Univ. of Denmark, Roskilde (Denmark). Risoe National Lab. for Sustainable Energy

2011-07-01

208

Development of high-toughness roll by CPC process. CPC process ni yoru kyojin roll no kahatsu  

Energy Technology Data Exchange (ETDEWEB)

the requirements for the quality of rolling rolls have become increasingly stringent with the recent advance in rolling technology, and remarkable improvement of toughness and wear-resistance of rolls becomes indispensable. This paper describes the development of a high-toughness roll by CPC (Continuous Pouring process for Cladding) process which is expected to meet the requirements. The CPC process is designed to manufacture a composite material by continuous casting a wear-resisting shell material to a solid core material, and improves the toughness of the core material and facilitates high alloying of the shell material. The new technique adapting CPC process was applied to the equipment at the roll shop of the Plant and Machinery Division, Nippon Steel Corp. Roll material of wear-resistance type has been developed by utilizing the characteristics of this new technique. This paper presents the outline of this equipment and the features of the newly developed roll. 8 refs., 11 figs., 2 tabs.

Hashimoto, M.; Otomo, S.; Yoshida, K.; Kurahashi, R. (Nippon Steel Corp., Tokyo (Japan))

1990-07-19

209

Scalability on roll-to-roll gravure printed dielectric layers for printed thin film transistors.  

UK PubMed Central (United Kingdom)

The manufacture of thin film transistors with reliable electrical properties, via full-printing on plastic foils, is a key step for the realization of costless and flexible electronics. To reach this goal, the dielectric layers should be smooth and free from failure while maintaining a high capacitance. In this paper, the parameters, affecting the film quality and capacitance of dielectric layers in a roll-to-roll gravure process, were investigated and some parameters were optimized.

Yi M; Yeom D; Lee W; Jang S; Cho G

2013-08-01

210

Investigation into the causes of cracking of 2024 aluminium alloy during rolling operation  

International Nuclear Information System (INIS)

[en] Aluminium alloy 2024 bars cracked during cold rolling to produce strips conforming to T-3 temper designation. The specimens had reduced to 10 mm X 10 mm size by hot rolling rectangular ingots of size 25 mm X 25 mm in 3 passes using the rolling mill. Microscopic studies of the cracked specimens revealed the presence of inclusions on the grain boundaries and in the fracture valleys. Energy dispersive X-ray analysis (EDAX) indicated that inclusions were rich in iron. Fractrogapy of fracture specimens were carried out using both optical scanning electron microscopy which indicated brittle fracture due to the presence of iron inclusions. (author)

1993-01-01

211

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

Science.gov (United States)

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

Petrzelka, Joseph E.; Hardt, David E.

2013-03-01

212

Deformation behaviour of duplex stainless steel during industrial hot rolling  

Energy Technology Data Exchange (ETDEWEB)

Industrially processed duplex stainless steel sheet was investigated after the reheating, the roughing mill and the finishing rolling. Light optical microscopy revealed that the cast structure that existed before rolling was removed and changed into a banded microstructure. During the process, the ferrite-austenite volume fraction ratio changed from 72%{alpha} + 28%{gamma} to 48%{alpha} + 52%{gamma}. The microhardness was measured for both phases after each process step. Texture measurements were executed by means of the electron backscattering diffraction technique (EBSD). These measurements revealed that extensive static recrystallisation of the austenite occurred during the roughing but that recrystallisation was inhibited during the finishing. Transmission electron microscopy (TEM) on the finish rolled material indicated that the ferrite softened efficiently by extended dynamic recovery. The dislocations in ferrite grains with rotated cube orientation were often found to be straight screw dislocations which were inclined 55 Cto the surface of the sheet. The importance of the partitioning of the alloying elements and the strain partitioning on the deformation behaviour is highlighted. (orig.)

Duprez, L.; Cooman, B.C. de [Lab. for Iron and Steelmaking (LISm), Ghent Univ., Ghent (Belgium); Akdut, N. [Ocas N.V., Research Center of the Sidmar Group, Zelzate (Belgium)

2002-12-01

213

Calculation and Analysis of Temperature Distribution in Hot Rolling Strip  

Directory of Open Access Journals (Sweden)

Full Text Available Modern steel grades require constant and reproducible production conditions both in the hot strip mill and in the cooling section to achieve constant material properties along the entire strip length and from strip to strip. Calculation of the temperature in final rolling process always utilizes factors such as the work piece's inner organizational structure, plastic deformation, and it's variations of properties and so on, also as well as the physical parameters such as gauge, shape, etc. In this paper, a finite element model is constructed for the temperature field in a rolling process. The temperature field of strip steel is modeled with a 3-D finite element analysis (FEA) structure, simultaneously considering the distribution of the work roll temperature. Then the distribution of field is simulated numerically. From the model, the temperature contours can be obtained by analysis of the temperature distribution of contact area. At the same time, the distribution of temperature in any position at any time can be acquired. These efforts provide the reliable parameters for the later finishing temperature and shape control.  

Kaixiang Peng

2013-01-01

214

Solid lubricants in rolling-contact bearings  

Energy Technology Data Exchange (ETDEWEB)

This article points out that in the application of solid lubricant coatings to the frictional surfaces in rolling-contact bearings, little use has been made of the technique of applying the coatings to the individual parts before assembly. Presents data from the literature on the life of solid lubricant coatings and self-lubricated separators in 204 bearings of the normal and high class of tolerances, respectively, these bearings having also been tested in a TsKB-72 tester. Notes that the rolling-contact bearings packed after assembly with the solid lubricant gave longer lives than the bearings with the solid lubricant coating or with the self-lubricated separator, even though the test conditions were more severe.

Glodin, Yu.N.; Eliseenko, A.G.

1982-09-01

215

Loop quantum cosmology and slow roll inflation  

International Nuclear Information System (INIS)

In loop quantum cosmology (LQC) the big bang is replaced by a quantum bounce which is followed by a robust phase of super-inflation. Rather than growing unboundedly in the past, the Hubble parameter vanishes at the bounce and attains a finite universal maximum at the end of super-inflation. These novel features lead to an unforeseen implication: in presence of suitable potentials all LQC dynamical trajectories are funneled to conditions which virtually guarantee slow roll inflation with more than 68 e-foldings, without any input from the pre-big bang regime. This is in striking contrast to certain results in general relativity, where it is argued that the a priori probability of obtaining a slow roll with 68 or more e-foldings is suppressed by a factor e-204.

2010-11-01

216

Establishing rolling resistance of mine vehicles  

Energy Technology Data Exchange (ETDEWEB)

After briefly reviewing history of introduction of large-capacity, tipping vehicles into Czechoslovak coal mining industry, uses the VSV 5,3 vehicle as an example to explain mathematics involved in determining rolling resistance engendered by the vehicle itself and by rail tracks. Discusses resistance measurements made at 1 Maj coal mine using VSV 5,3 vehicles in 1987. Measurements were made using an 8LS-1 dynamic tensiometer and a Brueel and Kjaer 7005 tape recorder. Results are presented in tabular form and are said to represent an initial assessment of rolling resistance of this most modern vehicle. Comparison of actual measurements with theoretical values indicates important influence of track condition and also reveals that actual values are higher than expected, particularly for empty vehicles, in relation to speed. 10 refs.

Polak, J. (Vysoka Skola Banska, Ostrava (Czechoslovakia))

1989-01-01

217

Slipping and Rolling on an Inclined Plane  

CERN Document Server

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

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

2011-01-01

218

Slipping and rolling on an inclined plane  

Energy Technology Data Exchange (ETDEWEB)

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

Aghamohammadi, Cina [Department of Electrical Engineering, Sharif University of Technology, PO Box 11365-11155, Tehran (Iran, Islamic Republic of); Aghamohammadi, Amir, E-mail: mohamadi@alzahra.ac.ir [Department of Physics, Alzahra University, Tehran 19938-91176 (Iran, Islamic Republic of)

2011-07-15

219

Slipping and rolling on an inclined plane  

International Nuclear Information System (INIS)

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

2011-01-01

220

Rolling circle amplification of metazoan mitochondrialgenomes  

Energy Technology Data Exchange (ETDEWEB)

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

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

2005-07-31

 
 
 
 
221

Influence of Surge on Extreme Roll Amplitudes  

DEFF Research Database (Denmark)

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

Vidic-Perunovic, Jelena; Rognebakke, Olav

2008-01-01

222

Theory of rolling contact heat transfer  

Energy Technology Data Exchange (ETDEWEB)

This paper addresses the fundamentals of the phenomenon of steady heat transfer by rolling contact between two bodies at different temperatures. The contact region is modeled according to the classical Hertz theory, by which the bodies undergo elastic deformation and the contact area has the shape of an ellipse. In the first part of the study it is shown that when the two bodies make contact continuously over the elliptical area, the overall heat transfer rate is proportional to the square root of the Peclet number based on the ellipse semiaxis parallel to the tangential (rolling) velocity. In the same case the heat transfer rate increases as the square root of the normal force (F) between the two bodies. The second part of the study treats the case when the rolling contact is made through a large number of asperities (contact sites) distributed over the elliptical contact area. The heat transfer rate is again proportional to the square root of the Peclet number. When the asperities are distributed randomly, the heat transfer rate increases as F{sup 5/6}. In the case of regularly distributed asperities that undergo elastic deformation, the heat transfer rate is proporitonal to F{sup 13/18}. The high Peclet number domain covered by this study is discussed in the closing section of the paper.

Bejan, A. (Duke Univ., Durham, NC (United States))

1989-05-01

223

Determination of the energy and power parameters during groove-rolling  

Directory of Open Access Journals (Sweden)

Full Text Available Purpose: In order to correctly design the process of bar rolling in grooves it is required that several limitations affecting the rolling process be considered. When developing a technology, energy and force parameters, among others, are needed to be taken into account. Therefore, it is purposeful to examine variations in the energy and force parameters during the rolling of bars.Design/methodology/approach: Using FEM-based computer programs for solving the problems of the theory of plasticity enables determining the energy and force parameters in complex plastic working processes and also accounting for a number of process specificities, which are not provided for by the empirical formula.Findings: The theoretical values of the rolling torque and power during the rolling of band in the grooves, as determined using the Forge3® software and the engineering method proposed by Chekmarev, were compared with the experimental values obtained from the measurements of current loads in a plant manufacturing bars. The current loads of the main drive of the continuous rolling mill for rolling bars were measured in one of the Polish steelworks.Practical implications: Change in the band temperature over its length influences the variations in the magnitudes of widening and advance. Its variations lead to a change in energy–force parameters.Originality/value: Using the FE programs for the computation of the values of the energy–force parameters can take into account the distribution of temperature over the band length.

S. Mróz; K. Jagie?a; H. Dyja

2007-01-01

224

Troll, a Language for specifying Dice-rolls  

DEFF Research Database (Denmark)

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

Mogensen, Torben Ægidius

2009-01-01

225

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

Directory of Open Access Journals (Sweden)

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

Juliana de Paula Martins; André Luis Moreira de Carvalho; Angelo Fernando Padilha

2012-01-01

226

Rolls-Royce digital Rod Control System  

Energy Technology Data Exchange (ETDEWEB)

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

Pouillot, M. [Rolls-Royce Civil Nuclear SAS (France)

2010-07-01

227

Development of a twin roll caster for light metals  

Directory of Open Access Journals (Sweden)

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

T. Haga

2010-01-01

228

Flexible thin-film polymer waveguides fabricated in an industrial roll-to-roll process.  

UK PubMed Central (United Kingdom)

The fabrication of flexible low-loss, thin-film, foil-based polymer waveguides with grating couplers employing a high-volume industrial roll-to-roll process is demonstrated. The embossed waveguides feature propagation losses of less than 1 dB/cm (633 nm, TE polarization), bending losses of 0.4-0.8 dB/360° for bending radii as small as 2 mm, and grating coupling efficiencies of up to 25%. In addition, the waveguides possess a thermo-optic coefficient of -1.58×10(-4) 1/°C. The fabricated waveguides are promising candidates for short-distance data communication as well as for sensing applications.

Bruck R; Muellner P; Kataeva N; Koeck A; Trassl S; Rinnerbauer V; Schmidegg K; Hainberger R

2013-07-01

229

Multilayer roll bonded aluminium foil: processing, microstructure and flow stress  

International Nuclear Information System (INIS)

Bulk aluminium has been produced by warm-rolling followed by cold-rolling of commercial purity (99% purity) aluminium foil. The bonding appeared perfect from observation with the naked eye, light and transmission electron microscopy. By comparison with bulk aluminium of similar purity (AA1200) rolled to a similar strain (90%RA), the roll-bonded metal showed a much higher density of high-angle grain boundaries, similar strength and improved thermal stability. This study has implications for a number of applications in relation to the processing of aluminium. Roll bonding is of interest as a method for grain size refinement; oxide-containing materials have increased strength, enhanced work-hardening behaviour, and exhibit alterations in recrystallisation behaviour. The behaviour of the hard oxide film is of interest in aluminium processing, and has been investigated by characterising the size and distribution of oxide particles in the roll-bonded samples.

2004-08-02

230

Estimation of Parametric Roll in a Stochastic Seaway  

DEFF Research Database (Denmark)

The present paper describes a model for prediction of parametric roll which is sufficiently fast to give predictions in real time for the probability of different levels of parametric roll angles in given long crested sea states. The procedure is based on an extension of a simplified two-degree of freedom (roll and heave) time domain model [10]. In the present paper the effect of the increased added resistance when the bow heaves and pitches down in a wave crest is introduced. Due to the resulting forward speed variation the roll resonance condition will be changed. The influence of ship speed on roll angle has in the past been noted by e.g. [6], where large roll angles in combination with the ship speed reduction can be seen from time traces from model tests.

Jensen, JØrgen Juncher; Pedersen, Preben Terndrup

2008-01-01

231

Cis-trans isomerization of polyacetylene induced by mechanical rolling  

Energy Technology Data Exchange (ETDEWEB)

The influence of mechanical rolling on the ESR spectrum of originally cis-rich polyacetylene is investigated. Rolling decreases the peak-to-peak ESR linewidth, ..delta..H/sub pp/. This phenomenon is supposed to be related to cis-trans isomerization. However, rolling increases only slightly the trans content and the spin susceptibility of the polymer. These observations can be explained by assuming that the rolling induced isomerization preferentially increases the length of the trans segments with unpaired spins. Rolling is less effective than heating in giving rise to isomerization within all-cis segments or in lengthening trans segments with no stable unpaired spins. The behavior of ..delta..H/sub pp/ as a function of trans content in the case of rolling induced isomerization is different from the thermally activated process. The ESR linewidth gives information only about the trans macroradicals and not about the total cis-trans isomer ratio, that used to be employed.

Vancso, G.; Pekker, S.; Egyed, O.; Janossy, A.

1981-01-01

232

Influences Of Size Effects On The Rolling Of Micro Strip  

International Nuclear Information System (INIS)

[en] Comparison between down-scaled flat rolling experiments of thin round wire and numerical simulation of those experiments have shown that the production process of manufacturing micro strip out of thin round wire is influenced by size effects. From plane strain compression tests, used as a physical simulation of the rolling process it is concluded that second order size effects of mechanical strength cause decreasing resistance to forming with decreasing wire diameters for rolling experiments with 25% and 50% reduction

2007-04-07

233

Quantitative Analysis and Design of a Rudder Roll Damping Controller  

DEFF Research Database (Denmark)

A rudder roll damping controller is designed using Quantitative feedback theory to be robust for changes in the ships metacentric height. The analytical constraint due to the non-minimum phase behaviour of the rudder to roll is analysed using the Poisson Integral Formula and it is shown how the design tradeoffs in closed-loop roll reduction can be approximated using this formula before a controller is designed. The robust roll and course keeping controllers designed are then tested using a nonlinear simulation.

Hearns, G.; Blanke, M.

1998-01-01

234

Qantitative Analysis and Design of a Rudder Roll Damping Controller  

DEFF Research Database (Denmark)

A rudder roll damping controller is designed using Quantitative Feedback Theory to be robust for changes in the ships metacentric height. The analytical constraint due to the non-minimum phase behaviour of the rudder to roll is analysed using the Poisson Integral Formula and it is shown how the design tradeoffs in closed-loop roll reduction can be approximated using this formula before a controller is designed. The robust roll and course keeping controllers designed are then evaluated using a nonlinear simulation.

Hearns, G.; Blanke, M.

1998-01-01

235

Directional Roll-up of Nanomembranes Mediated by Wrinkling  

CERN Document Server

We investigate the relaxation of rectangular wrinkled thin films intrinsically containing an initial strain gradient. A preferential rolling direction, depending on wrinkle geometry and strain gradient, is theoretically predicted and experimentally verified. In contrast to typical rolled-up nanomembranes, which bend perpendicular to the longer edge of rectangular patterns, we find a regime where rolling parallel to the long edge of the wrinkled film is favorable. A non-uniform radius of the rolled-up film is well reproduced by elasticity theory and simulations of the film relaxation using a finite element method.

Cendula, P; Mönch, I; Schumann, J; Schmidt, O G

2010-01-01

236

Study on warm caliber rolling of magnesium alloy  

Energy Technology Data Exchange (ETDEWEB)

The warm caliber rolling was experimented using the AZ31 magnesium alloy round bar of 20 mm in diameter machined from cast ingot materials. In warm caliber rolling in final size of 10 mm in diameter at 623 K via 8passes, each width-spreading, the change of each microstructure, X-ray analysis of final texture and final mechanical properties were investigated. Microstructure, texture and mechanical properties of warm caliber rolled round bar at 473 K via latter 4passes were compared with those at 623 K consistently. Obtained results are as follows: (1) The width-spreading in caliber rolling of round bar is relatively large, compared with that in flat rolling of the flat bar. The largeness of width-spreading of round bar makes the shape control of cross section difficult, and causes the cracks around the free surface. (2) Finer microstructure and inclined c axis of hexagonal lattice of 10 degrees to vertical direction of the rolled surface are obtained in warm caliber rolling at 473 K via latter 4 passes. (3) The process of warm caliber rolling at 473 K via latter 4 passes is more useful for strengthening of rolled round bar than that at 623 K consistently. (orig.)

Tanno, Y.; Mukai, T.; Asakawa, M. [Dept. of Mechanical Engineering, Waseda Univ., Japan, Tokyo (Japan); Kobayashi, M. [Nagaoka Univ. of Technology, Japan, Nagaoka, Niigata (Japan)

2003-07-01

237

Recrystallization behavior of cold-rolled Zr 702  

Science.gov (United States)

Using the hardness test, we determined the recrystallization kinetics of cold-rolled Zr 702. The rate of the recrystallization process increased with increasing annealing temperature and rolling reduction. The Johnson-Mehl-Avrami-Kolmogorov (JMAK) exponent obtained was less than 1, which also increased with increasing annealing temperature and rolling reduction. The activation energies for the recrystallization of the 38.9% and 71.0% cold-rolled sheets were 232 kJ/mol and 251 kJ/mol, respectively.

Li, M. H.; Ma, M.; Liu, W. C.; Yang, F. Q.

2013-02-01

238

Weak rolling adhesion enhances bacterial surface colonization.  

Science.gov (United States)

Bacterial adhesion to and subsequent colonization of surfaces are the first steps toward forming biofilms, which are a major concern for implanted medical devices and in many diseases. It has generally been assumed that strong irreversible adhesion is a necessary step for biofilm formation. However, some bacteria, such as Escherichia coli when binding to mannosylated surfaces via the adhesive protein FimH, adhere weakly in a mode that allows them to roll across the surface. Since single-point mutations or even increased shear stress can switch this FimH-mediated adhesion to a strong stationary mode, the FimH system offers a unique opportunity to investigate the role of the strength of adhesion independently from the many other factors that may affect surface colonization. Here we compare levels of surface colonization by E. coli strains that differ in the strength of adhesion as a result of flow conditions or point mutations in FimH. We show that the weak rolling mode of surface adhesion can allow a more rapid spreading during growth on a surface in the presence of fluid flow. Indeed, an attempt to inhibit the adhesion of strongly adherent bacteria by blocking mannose receptors with a soluble inhibitor actually increased the rate of surface colonization by allowing the bacteria to roll. This work suggests that (i) a physiological advantage to the weak adhesion demonstrated by commensal variants of FimH bacteria may be to allow rapid surface colonization and (ii) antiadhesive therapies intended to prevent biofilm formation can have the unintended effect of enhancing the rate of surface colonization. PMID:17189376

Anderson, Brett N; Ding, Albert M; Nilsson, Lina M; Kusuma, Kaoru; Tchesnokova, Veronika; Vogel, Viola; Sokurenko, Evgeni V; Thomas, Wendy E

2006-12-22

239

Rolled edges and phasing of segmented telescopes.  

UK PubMed Central (United Kingdom)

To achieve the diffraction limit, the segments in a segmented telescope must be correctly aligned to a fraction of a wavelength. This alignment is performed via optical measurements using starlight. We investigate the piston degree of freedom or phasing of the segments and the impact of rolled segment edges on the accuracy of the optical alignment. Three models for edge profiles are developed and fit to data from optic manufacturers. These profiles are then used, along with a simplified model of a Shack-Hartmann optical sensor, to determine their impact on phasing accuracy. The results can help estimate the residual phasing error and set requirements on segment polishing.

Yaitskova N; Troy M

2011-02-01

240

Pastry rolling machine with a variable transmission  

UK PubMed Central (United Kingdom)

A pastry rolling machine in which dough passes from an incoming conveyor (1) through the nip of opposing rollers (4a, 4b) to an outgoing conveyor (2), and the conveyors (1, 2) are coupled to a common drive (3) via a gear system with variable transmission, the gear system having a plurality of transmission chains (14-20, 16-20) which can be engaged separately from each other, between the drive and the incoming conveyor, these chains being designed with different speed transmissions.

Bernhardt Udo

 
 
 
 
241

Lightweight Roll-Up Drag Litter  

UK PubMed Central (United Kingdom)

A flexible, portable light-weight drag litter is disclosed capable of being compactly rolled for transportation and storage, having a generally planar base dimensioned to underlie a reclining individual's head, torso, legs, and feet. A torso harness is attached to the base along with groin and leg connectors are attached to the base. A dragline is attached to a head end portion of the base. When a user tugs on the dragline, the base creates a concave surface that supports and protects the patient's head.

BOWLING F; JOHNSON ROSS

242

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

UK PubMed Central (United Kingdom)

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

Yu H; Lu C; Tieu AK; Godbole A; Su L; Sun Y; Liu M; Tang D; Kong C

2013-08-01

243

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

Science.gov (United States)

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

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

2013-08-01

244

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

DEFF Research Database (Denmark)

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

Blanke, M.; Christensen, A.C.

1993-01-01

245

Thermal study on possibility of direct rolling between the continuous casting and hot rolling processes  

Energy Technology Data Exchange (ETDEWEB)

The possibility of unification between the continuous casting and hot rolling porcesses has been investigated from a point of view of a slab temperature. In the casting unit the cast slab temperature at a crater-end is required as higher as possible, and in the hot rolling process the exit temperature of hot rolling stand is required as lower as possible. To obtain the high temperature cast slab in the continuous casting, following matters are desirable to carry out. (1) In the secondary cooling zone, the ratio of the cooling width to the slab width is set to 85 % and above, and make the casting speed slow by shortening the cooling length. (2) In the casting line after the sizing point, higher temperature insulating cover is installed. As the result, the average slab temperature of 1,250/sup 0/C and above at the crater-end can be obtained, and the corner temperature of about 950/sup 0/C is maintained. To obtain the low entrance temperature in the hot rolling process, it is effective to set up thick bar on the delay-table. (9 figs, 2 tabs, 12 refs)

Kokado, Jun' ichi; Hatta, Natsuo; Takuda, Hirohiko; Kitagawa, Ryozo

1988-07-01

246

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

Energy Technology Data Exchange (ETDEWEB)

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

Izu, M.; Ovshinsky, H.C.; Deng, X.; Krisko, A.J.; Narasimhan, K.L.; Crucet, R.; Laarman, T.; Myatt, A.; Ovshinsky, S.R. [Energy Conversion Devices, Inc., Troy, MI (United States)

1994-12-31

247

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

Science.gov (United States)

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

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

2010-06-01

248

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

UK PubMed Central (United Kingdom)

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

Krebs FC; Tromholt T; Jørgensen M

2010-06-01

249

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

DEFF Research Database (Denmark)

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

Krebs, Frederik C; Tromholt, Thomas

2010-01-01

250

Rotational and Rolling Motion Conceptual Survey  

Science.gov (United States)

This 30-question research-based multiple-choice test is designed to evaluate studentsâ conceptual understanding of rotational and rolling motion. The survey is based on investigations of studentsâ difficulties in introductory- and junior-level physics courses and should be given in a 50-minute period. Statistical results have shown the survey to be reliable and valid. A summary of the construction and analysis of the survey is available in Student understanding of rotational and rolling motion, Phys. Rev ST-PER 1 (1), 010102 (2005). This assessment is free for use by instructors in their classroom. However, as it takes years of development effort to create and validate reliable assessment instruments, the file is password-protected. Furthermore, the author requests that 1. students are not given copies following examination; and 2. none of the questions are incorporated into web-based question delivery systems without adequate security to prevent printing or unauthorized access by students. To obtain the password, please send a request with your name, email, institution, and a link to a page at your institution that confirms you are an instructor.

Singh, Chandralekha; Rimoldini, Lorenzo G.

2012-05-03

251

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

International Nuclear Information System (INIS)

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

2007-05-17

252

76 FR 46852 - Panasonic Corporation of North America, Business Operations Group, Rolling Meadows, IL; Panasonic...  

Science.gov (United States)

...Business Operations Group, Rolling Meadows, IL; Panasonic Corporation of North...Financial Services Organization, Rolling Meadows, IL; Amended Certification Regarding...Business Operations Group, Rolling Meadows, Illinois. The workers provide...

2011-08-03

253

The influence of tandem rolling process parameters on the texture and earing behaviour of AA1050  

Energy Technology Data Exchange (ETDEWEB)

A novel combination of techniques, namely hot plane-strain compression (PSC) tests and laboratory cold rolling, was successfully applied to simulate the industrial practice for producing AA1050 sheets. Starting material for testing was taken from a hot rolled plate at transfer gauge between the breakdown and tandem mill. Three-stand hot tandem-rolling was simulated by means of hot plane-strain compression tests using a thermal mechanical treatment simulator (TMTS). Coil-cooling was simulated by means of a controlled cooling in a furnace. The hot deformed material was subsequently cold rolled on a laboratory mill. The influence of tandem rolling process parameters, such as entry temperature and strain rate on textures in different conditions and on the earing in the final annealed condition was investigated. A good agreement in the texture and earing values was found between the PSC-material and the production material, which makes this combination of techniques as a valuable way to evaluate the influences of industrial processing parameters on the final properties. It was found that the entry temperature has a stronger effect on the texture and earing than the strain rate. (orig.)

Liu, C.; Zhuang, L.; Winden, M.R. van der; Hurd, T.J. [Corus Research, Development and Technology, Ijmuiden (Netherlands)

2002-07-01

254

THE STUDY OF SCALE FORMATION ON HOT ROLLED INGOTS AND BILLETS  

Directory of Open Access Journals (Sweden)

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

GHEORGHE VLAICU; IULIAN BANCUTA; CLAUDIA STIHI; GABRIEL STATE; ANCA GHEBOIANU

2010-01-01

255

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

Energy Technology Data Exchange (ETDEWEB)

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

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

1997-12-31

256

Troll, a Language for specifying Dice-rolls  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Dice are used in many games, and often in fairly complex ways that make it difficult to unambiguously describe the dice-roll mechanism in plain language. Many role-playing games, such as Dungeons & Dragons, use a formalised notation for some instances of dice-rolls. This notation, once explained, ma...

Mogensen, Torben Ægidius

257

Student Understanding of Rotational and Rolling Motion Concepts  

Science.gov (United States)

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

Rimoldini, Lorenzo G.; Singh, Chandralekha

2005-01-01

258

Continuum modelling of granular rocks in high pressure rolls crushers  

Energy Technology Data Exchange (ETDEWEB)

In a high pressure rolls crusher two force components: the pressurising thrust and the rolling force can be measured experimentally. Computer analyses have revealed regular patterns of stress distribution in the confined material between the rollers. Based on the computer analyses and experimental results a one-dimensional comminution model has been developed. 14 refs., 12 figs.

Alehossein, H. [CSIRO, Kenmore, Qld. (Australia). Division of Exploration and Mining

1995-12-31

259

Development and Fabrication of Pineapple Rolled Tart Machine  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

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

260

Disruption Management of Rolling Stock in Passenger Railway Transportation  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This paper deals with real-time disruption management of rolling stock in passenger railway transportation. We present a generic framework for modeling disruptions in railway rolling stock schedules. The framework is presented as an online combinatorial decision problem where the uncertainty of a di...

Nielsen, L.K.; Maroti, G.

 
 
 
 
261

Early Detection of Parametric Roll Resonance on Container Ships  

DEFF Research Database (Denmark)

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

Galeazzi, Roberto; Blanke, Mogens

2013-01-01

262

Numerical analysis of the 45 mm reinforcement bar rolling process  

Directory of Open Access Journals (Sweden)

Full Text Available Purpose: The paper presents the results of theoretical investigations of the process of rolling reinforcement bars designed for concrete reinforcement. In the investigation. particular consideration was given to the analysis of the effect of pre-finished band shape on the formation of ribs on the finished bar in the finished pass.Design/methodology/approach: Using the numerical modelling to rolling process of the reinforcement bars in a finished pass to define rolling parameters. The simulations of the ribbed bar rolling were carried out using the Forge2005® software.Findings: It has been performed in order to define the specific features of the mode of metal flow in the roll gap and to determine the effect of the shape and dimensions of the feedstock oval on the height of the ribs and on the thickness of surface layer of the finished bar.Research limitations/implications: The use of commercial software applications in the design of process technologies will allow for the development of reinforcement bars rolling technology with a minimum number of laboratory and industrial trials.Practical implications: Reinforcement bars are chiefly used in the building industry at production of reinforced concrete constructions. and as working elements in bridge building.Originality/value: Production of the reinforcement bars is very difficult. One from many problems during production the bars is rolling in the finished pass. In this paper the computer simulation of the rolling reinforcement bar is presented.

P. Szota

2008-01-01

263

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

The rise of an autonomous youth culture is one of the most remarkable events of the fifties not in the least because of the noisy advent of its music: rock-'n-roll. This music shocked society and has been associated with rebellion and protest ever since. Rock-'n-roll acquired a meaning that went bey...

Anjou, L.J.M. d'

264

Method and apparatus for mechanically classifying rolling bodies  

International Nuclear Information System (INIS)

A bowl feeder for separating damaged rolling bodies, for example nuclear fuel pellets, from sound ones includes a bowl having a central conical section for distributing the bodies radially outwardly towards a V-shaped circular channel which ensures that the bodies are arranged end-to-end with the rolling axes orientated lengthwise of the channel. The channel discharges the bodies onto an outer sloping section to allow bodies with asymmetrical defects to resist rolling while allowing defect free bodies to roll radially outwardly down the slope. A system of rails with gaps serves to separate defective bodies from those which are defect free, the latter being allowed to roll to the outer periphery of the bowl and eventually to feed track while the former are routed to a reject outlet. (author).

1985-02-21

265

AI technology in steel rolling. Atsuen ni okeru AI gijutsu  

Energy Technology Data Exchange (ETDEWEB)

Examples of knowledge engineering methods applied to a rolling process are explained. When the examples of application of knowledge engineering methods in the steel industry are viewed by process, about 50% of the applications is accounted for by rolling process including transportation. When viewed by method, the expert system is the most in number, followed by the fuzzy and neural networks. Examples of specific applications of the expert system can be classified as follows: Interpretations and diagnostics fall under facility failure diagnostics, product quality diagnostics, and acceptance determination. Monitoring and control are applied to rolling pitch control and non-steady state control in heating furnace combustion control, or transportation control in a product yard. Planning and design include applications to rolling sequence set-up and material design support. The AI technology applied to the rolling process contains many problems, including knoeledge acquisition in an expert system, stability in fuzzy control, and convergence in a neural network. 3 figs., 1 tab.

Yokoi, T. (Sumitomo Metal Industries, Ltd., Osaka (Japan))

1991-02-01

266

Rolling Bearing Diagnosis Based on LMD and Neural Network  

Directory of Open Access Journals (Sweden)

Full Text Available Inner ring pitting, the outer indentation and rolling element wear are typical faults of rolling bearing. In order to diagnose these faults rapidly and accurately, the paper proposes a novel diagnosis method of rolling bearing based on the energy characteristics of PF component and neural network by the vibration signal of local mean decomposition(Local mean decomposition, LMD). The vibration signal is decomposed into several PF components by the local mean decomposition, the calculated energy characteristics of the PF component are inputted to the neural network to identify the type of rolling bearing faults. At the same time, the genetic algorithm is introduced to optimize the structure parameters of neural network, which improves diagnostic rate and accuracy of faults. The results show that this method has a higher diagnosis and recognition rate for the typical faults of rolling bearing.

Baoshan Huang; Baoshan Huang; Wei; Wei Xu; Xinfeng Zou

2013-01-01

267

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

Science.gov (United States)

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

Yi, Hou Hui

268

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

Index Scriptorium Estoniae

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

Pärnits, Kadi, 1965-

2009-01-01

269

High speed twin roll casting of 6016 aluminium alloy strip  

Directory of Open Access Journals (Sweden)

Full Text Available Purpose: of this paper is to clear the possibility of high speed roll casting of aluminum alloy strip. In the bodyof the automobiles, a sheet of 6016 aluminum alloy is adopted for the outer panel. Therefore, casting of 6016was tried in this study. Characteristics of roll cast 6016 were investigated.Design/methodology/approach: was a high speed twin roll caster. The high speed twin roll caster was designedto overcome the low castability of the twin roll caster.Findings: are as below. 6016 alloy could be cast into the strip continuously at the speed of 60m/min. Thethickness of the strip was 3.4 mm. The microstructure at as-cast and after T4 heat treatment was shown. Themicrostructure was very fine. The mechanical properties were investigated by the tensile test and 180 degreesvending test. The as-cast strip could be cold rolled without homogenization to 1mm. Result of tensile test wastensile strength was 230MPa, 0.2% proof stress was 118MPa and elongation was 33%. 6016 strip of T4 heattreatment could be bent 180 degrees without occurrence of crack at the outer surface or breaking.Research limitations/implications: is the width of the strip was 100 mm. It is necessary to test twin roll casterequipped wide rolls.Practical implications: are as below. The mechanical properties of the roll-cast 6016 were enough for the sheetmetal for the automobile. The low productivity of the twin roll caster could be improved.Originality/value: is that 6016 strip could be cast continuously at speed 60 m/min and this strip had goodmechanical properties.

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

2007-01-01

270

In-Roll Stress Analysis Considering Air-Entrainment at the Roll-Inlet with the Effect of Grooves on Nip Roll Surface  

Science.gov (United States)

High-speed winding of paper web sometimes leads the winding system into unstable states, interlayer slippage of wound roll, paper breakage and so on, due to the excessive air-entrainment at the roll-inlet of nip contact region. These phenomena are more frequently observed on coated paper or plastic film comparing with newspaper, because the former allows little permeation of air and their surface roughness is small. Therefore, it is of vital importance to clarify the in-roll stress of wound roll considering the effect of air-entrainment. Generally, it is known that the amount of air-entrainment is affected by grooving shape of nip roll surface. In this paper, we focused on the grooving shape and investigated the relationship with the air-entrainment into two rolls being pressed each other and the grooving shape in order to achieve stable winding at high speed. We conducted experiments using small sized test machine. Entrained air-film thickness was evaluated applying the solution of the elasto-hydrodynamic lubrication for foil bearing with the consideration of nip profile at the grooved area. Air film thickness was measured to ensure the applicability of the above theory. Consequently, we found that the air film thickness can be estimated considering the effect of grooves on the nip roll surface, and that the validity of the above estimations was ensured from experimental investigations. Furthermore, it became to be able to propose the optimal shape of grooves on nip roll surface to maintain the stable winding at high speed and at large-diameter in reel.

Sasaki, Masashi; Tanimoto, Koshi; Kohno, Kazukiyo; Takahashi, Sadamu; Kometani, Hideo; Hashimoto, Hiromu

271

M3A1 Hyundai Container Roll-In/Roll-Out Platform (CROP) TP-94-01, Transportability Testing Procedures.  

Science.gov (United States)

The U.S. Army Defense Ammunition Center (DAC), Validation Engineering Division (SMAAC-DEV), was tasked by the U.S. Army Tank- automotive and Armaments Command to conduct a First Article Test (FAT) on the Container Roll-in-Roll-Out Platform (CROP) manufact...

2000-01-01

272

Flexible IZO/Ag/IZO/Ag multilayer electrode grown on a polyethylene terephthalate substrate using roll-to-roll sputtering  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We investigated the optical, electrical, structural, and surface properties of roll-to-roll [R2R] sputter-grown flexible IZO/Ag/IZO/Ag [IAIA] multilayer films on polyethylene terephthalate substrates as a function of the top indium zinc oxide [IZO] thickness. It was found that the optical transmitta...

Kim, Han-Ki; Lim, Jong-Wook

273

Roll-to-Roll Microimprinting Process for Indium Tin Oxide Layer Patterning  

Science.gov (United States)

Conventional indium tin oxide (ITO) layer patterning processes are problematic because they have limited efficiency. Many applications demand large-area, continuous processing with low costs and a high throughput. In order to overcome these problems, a continuous roll-to-roll (R2R) microimprinting process is proposed and demonstrated for the purpose of ITO layer patterning. Additionally, a series of experiments were conducted to investigate the influence of process parameters, i.e., the operating speed, the nip pressure and the tension of substrate, and the geometry, i.e., the width and height of the master patterns, on the imprinted patterns of ITO-coated polyethylene terephthalate substrates. The proper imprinting conditions are investigated and the mechanism of ITO patterning by imprinting process was suggested. It was found that the ITO-coated area can be electrically isolated through the imprinting process, by the accumulation of microcracks on ITO induced by the deformation.

Ahn, Byoung-Joon; Kim, Ji-Youp; Ko, Sung-Lim

2013-05-01

274

Material for hot rolling of high boron content austenite stainless steel, and hot rolling method  

International Nuclear Information System (INIS)

[en] A hot rolling material made of a high boron content austenite stainless steel of the present invention comprises a slab made of an austenite stainless steel containing from 0.6 to 2.0% by weight of B and a pad-welded metal layer formed on the side surface of the slab. The pad-welded metal layer has ? ferrite amount of from 3 to 12% by volume, B content up to 0.3% by weight, a thickness of 3mm or greater, and is subjected to hot rolling after heated to a temperature of from 1100 to 1200degC. This can prevent occurrence of peripheral cracking and the material can be industrially manufactured stably at a low cost. (T.M.)

1996-03-29

275

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

DEFF Research Database (Denmark)

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

Larsen-Olsen, Thue Trofod; Andersen, Thomas Rieks

2012-01-01

276

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

DEFF Research Database (Denmark)

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

Rösch, R.; Krebs, Frederik C

2012-01-01

277

Large-scale roll-to-roll fabrication of vertically oriented block copolymer thin films.  

UK PubMed Central (United Kingdom)

Large-scale roll-to-roll (R2R) fabrication of vertically oriented nanostructures via directed self-assembly of cylindrical block copolymer (c-BCP) thin films is reported. Nearly 100% vertical orientation of cylinders in sub-100 nm c-BCP films under optimized processing via a dynamic sharp temperature gradient field termed Cold Zone Annealing-Sharp or 'CZA-S' is achieved, with successful scale-up on a prototype custom-built 70 ft × 1 ft R2R platform moving at 25 ?m/s, with 9 consecutive CZA units. Static thermal annealing of identical films in a conventional vacuum oven fails to produce comparable results. As a potential for applications, we fabricate high-density silicon oxide nanodot arrays from the CZA-S annealed BCP thin film template.

Singh G; Batra S; Zhang R; Yuan H; Yager KG; Cakmak M; Berry B; Karim A

2013-06-01

278

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

DEFF Research Database (Denmark)

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

SØndergaard, Roar R.; Hösel, Markus

2013-01-01

279

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

DEFF Research Database (Denmark)

We report on the use of intense visible light with a narrow spectral distribution matched to the region where the conjugated polymer material absorbs to selectively heat the active material and induce thermocleavage. We show a full roll-to-roll process, leading to complete large-area polymer solar cell modules using light-induced thermocleavage. The process employs full solution processing in air for all five layers in the device and does not employ indium?tin oxide or vacuum processing. The process steps were carefully analyzed using X-ray photoelectron spectroscopy, time-of-flight secondary ion mass spectrometry, attenuated total reflectance infrared, and transmission/reflection UV?vis techniques.

Krebs, Frederik C; Norrman, Kion

2010-01-01

280

Control rolling and cooling for on-line production of strong, tough steels  

Energy Technology Data Exchange (ETDEWEB)

Strong tough steels have been designed to produce microcomposite structures of fine grained auto-tempered lath martensite with untransformed austenite films between the laths. Such structures can be produced on-line in a hot mill by controlled rolling and cooling. The steels are based on Fe/Cr/Mn/C compositions which can be air hardenable, or for lean compositions, water quench hardened with Nb microalloying. The steels have excellent mechanical properties that are superior to current HSLA steels and require no subsequent heat treatment following rolling and cooling. Successful commercial plate trials have occurred. 18 refs., 11 figs., 1 tab.

Thomas, G.

1988-11-01

 
 
 
 
281

Rheological effects in roll coating of paints  

Directory of Open Access Journals (Sweden)

Full Text Available the aim of this work is the study of the problems that arise during roll coating application of paints on steel sheets. We put in evidence the particular effects due to the non-Newtonian properties of these fluids. At speeds above a certain critical value, the flow of paint through the applicator suffers a hydrodynamical instability called ribbing, which generates a patterned interface on the film applied. Threshold of instability as well as waveform of the pattern is function of rheological properties of paints as well as surface tension. Thixotropy of paints as well as shear-thinning behaviour has been determined for several industrial paints used in the steel industry, and correlated with levelling performance after application.

F. Varela López; M. Rosen

2002-01-01

282

G_2 and the "Rolling Distribution"  

CERN Multimedia

Associated to the problem of rolling one surface along another there is a five-manifold M with a rank two distribution. If the two surfaces are spheres then M is the product of the rotation group SO_3 with the two-sphere and its distribution enjoys an obvious symmetry group; the product of two SO_3's, one for each sphere. But if the ratio of radii of the spheres is 1:3 and if the distribution is lifted to the universal cover S^3 \\times S^2 of M, then the symmetry group becomes much larger: the split real form of the Lie group G_2. This fact goes back to Cartan in a sense, and can be found in a paper by Bryant and Hsu. We prove this fact through two explicit constructions, relying on the theory of roots and weights for the Lie algebra of G_2, and on its 7-dimensional representation.

Bor, G; Bor, Gil; Montgomery, Richard

2006-01-01

283

Roll up nanowire battery from silicon chips.  

Science.gov (United States)

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

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

2012-09-04

284

Periodically fighting shake, rattle and roll  

CERN Multimedia

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

Brun, M; Jones, I S

2011-01-01

285

Mechanical spectroscopy of rolling oil thin films on cold-rolled steel sheets  

International Nuclear Information System (INIS)

Fine traces of lubricating oil can be discovered in the form of fine debris left on the surface of cold-rolled steel sheets. High resolution mechanical spectroscopy is a sensitive technique for detecting such extremely fine oil traces. It is shown that a characteristic mechanical loss spectrum occurs in the low temperature range (from 180K up to 280K) only in the two following cases, namely (i) if traces of the rolling oil are left on the surface of sheets and (ii) if the clean sheets are covered with a thin film of the rolling oil (or any other natural or mineral oil). It is clearly demonstrated that similar mechanical spectra induced by the presence of oil can be observed in the sub-resonant mechanical spectroscopy if the oil film is deposited on a very soft cellulose neutral substrate. Therefore the behaviour of the oil alone can be obtained with a high resolution. It will be demonstrated that it is possible to assign the mechanical loss phenomena to the steel sheet (like the Snoek-Koster effect above 500K) and oil separately. In particular, it is shown that the low temperature relaxation phenomena do not originate from a specific interaction of the steel surface with oil, as frequently reported in the literature.

2009-01-01

286

Man power driving rolling cutter type straw cutter  

UK PubMed Central (United Kingdom)

The utility model relates to a man power driving rolling cutter type mower, which is composed of a traveling wheel which is connected to be frame-shaped, a bracket, a handle support, and a mower. The inner ring of the traveling wheel is provided with a gear wheel the mower mechanism is composed of a rolling cutter and a fixed cutter the shaft frame of the rolling cutter is arranged on the bracket the two ends of the shaft are respectively provided with the pinion of the planetary gear train which is engaged with the inner ring gear wheel of the traveling wheel the fixed knife is fixed onto the bracket, and the cutting part of the fixed cutter is tangential with the cutting part of the rolling cutter. The man power driving rolling cutter type mower which needs no energy has compact structure and easy usage the man power driving rolling cutter type mower which has no vibration, noise, and air pollution has no tear action while cutting the lawn grass, and the man power driving rolling cutter type mower is more beneficial to the lawn.

LI LINGFENG

287

Tea fine-rolling machine and unmanned tea processing machine  

UK PubMed Central (United Kingdom)

The invention discloses a tea fine-rolling machine and an unmanned tea processing machine. The tea fine-rolling machine comprises rolling devices A and B, wherein A comprises an upper layer guide trough plate and a lower layer guide trough plate which are arranged horizontally and evenly provided with edge bones in a band manner tea is propelled between the two layers of guide trough plates, rolled into strips and then conveyed to B for further rolling and B comprises a rolling cylinder with changeable working direction and a head cover and a base plate thereof. The fine-rolling machine leads the tea to be fast formed and the flow process of tea primary processing to be possible, and can obtain the unmanned tea processing machine when being combined with a fixing machine, a drying machine, a transmitting device and a control system. The whole set of tea processing machine can be operated by one person in a central control room, and the unmanned production workshop is clean and sanitary, thus avoiding the secondary man-made pollution. The quality of the produced tea is improved by more than one grade, the refining rate is improved by 10-15 percent, the energy consumption is reduced by 20 percent, the labor force is saved by 96 percent, each set of tea processing machine can produce 2.5 tons of dried tea each day, and incomes increasing while expenses decreasing of 6 months isnearly 2,000,000 Yuan.

YISHENG LIN; CHENGZHI LIN; TIANDUO DING; FENG LIN; ZHONG LIN; QUAN LIN

288

Determining asymmetry of roll-over shapes in prosthetic walking  

Directory of Open Access Journals (Sweden)

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

Carolin Curtze, MSc; Bert Otten, PhD; At L. Hof, PhD; Klaas Postema, MD, PhD

2011-01-01

289

Deep-drawing quality of cold rolled sheet made of ferritically rolled hot strip  

Energy Technology Data Exchange (ETDEWEB)

In the so-called ferritic rolling the finishing is shifted down into the temperature region of ferrite, which enables a production of thinner hot strips (compared to the conventional hot rolling in austenite) with a changed texture development. The present study is focused on the effect of the process parameters of such initial warm rolled hot strips on the texture formation and hence on the deep-drawing quality of the final cold strips. A special attention is given to the transmission of the hot strip texture to the cold strip. The investigation was carried out on commercial IF- and ELC-steels by a laboratory simulation with the hot deformation simulator Wumsi (rolling simulated by the plane strain compression test). It was possible to optimize cold rolling and subsequent annealing by means of the measurements of the texture development during the ferritic (warm) deformation as well as the parameters of the processing route of such special production of cold strips by means of the calculation of r-values. If compared with the conventional processing route, a considerable improvement of deep-drawability with a diminished earing is achievable especially with the IF-steel. (orig.) [German] Beim sogenannten ferritischen Walzen werden die Endwalzstiche zu tieferen Temperaturen in das Temperaturfeld des Ferrits verlagert, wodurch sich, im Vergleich zum konventionellen Warmwalzen im Austenitgebiet, duennere Warmbaender mit geaenderten Texturen herstellen lassen. In der vorliegenden Arbeit wurden die Auswirkungen der Prozessparameter dieser halbwarm gewalzten Warmbaender auf die Texturentwicklung und damit auf die erzielbare Tiefziehfaehigkeit in hieraus gefertigten Kaltbaendern untersucht. Besonderes interesse lag hierbei in der Vererbung der Warmbandtextur auf das resultierende Kaltband. Die Untersuchungen wurden mittels Laborsimulationen mit Hilfe des Warmumformsimulators Wumsi an einem typischen IF- und ELC-Stahl durchgefuehrt. Mittels der Bestimmung der Texturentwicklung im Warmband ueber das Kaltwalzen und das abschliessende Gluehen und durch die Berechnung der hieraus resultierenden r-Werte konnten die Prozessparameter fuer das ferritische Walzen und fuer den Kaltwalzprozess optimiert werden. Im Vergleich zur konventionellen Fertigung koennen somit, besonders beim IF-Stahl, nachdrueckliche Verbesserungen der Tiefzieheigenschaften der Kaltbaender und eine verminderte Zipfelbildung erwartet werden. (orig.)

Tomitz, A.; Kaspar, R. [Max-Planck-Institut fuer Eisenforschung GmbH, Duesseldorf (Germany)

2000-12-01

290

Visually guided adjustments of body posture in the roll plane.  

UK PubMed Central (United Kingdom)

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

Tarnutzer AA; Bockisch CJ; Straumann D

2013-05-01

291

Visually guided adjustments of body posture in the roll plane.  

Science.gov (United States)

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

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

2013-03-28

292

Access to the Commonwealth electoral roll for medical research.  

UK PubMed Central (United Kingdom)

In the 2010-11 financial 2013, there was a dramatic reduction in the approvals granted by the Australian Electoral Commission for access to samples of the adult population derived from the electoral roll for the purposes of public health research. Much time and effort has been expended in making applications without success. Researchers refused access to electoral roll samples must rely on sampling methods that are not as robust and that may produce less reliable data. We outline a set of recommendations that, if adopted, will result in a fairer system for obtaining access to the electoral roll for public health research.

Loff B; Campbell EA; Glass DC; Kelsall HL; Slegers C; Zion DR; Brown NJ; Fritschi L

2013-01-01

293

A coupled fluid flow, deformation and heat transfer model for a twin roll caster  

Energy Technology Data Exchange (ETDEWEB)

A numerical model of coupled fluid flow, solidification and plastic deformation for the twin roll casting process has been developed. Non-orthogonal curvilinear coordinates are used to provide a more realistic description of the roll bite geometry while a variable heat transfer coefficient based on the normal pressure at the strip/roll interface, is incorporated through the roll bite.

Bradbury, P.J.; Hunt, J.D. [Univ. of Oxford (United Kingdom). Dept. of Materials

1995-12-31

294

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

A simple and low cost thin film solution processing system comprising a single roll coating machine has been developed to allow direct investigation of variable parameter effects in roll-to-roll processing. We present roll coating of the active layers in polymer solar cells and validate the instrume...

Dam, Henrik Friis; Krebs, Frederik C

295

The condition for classical slow rolling in new inflation  

International Nuclear Information System (INIS)

By means of the stochastic description of inflation, we investigate the dynamics of a fixed comoving domain in a continuously inflating universe on the global scale, both analytically and numerically. A particular attention is paid to the condition for a domain to enter the classical slow rolling phase. New inflationary universe models with the potential form, V(?) ? V0 - c?2n at ? ? 0 are considered. The critical value of the scalar field beyond which the field slowly rolls down the potential hill is estimated. We find, for all models under consideration, the condition for classical slow rolling is a sufficient condition for the expected amplitude of density perturbations to be smaller than unity. In other words, the density perturbation amplitude at the later Friedmann stage is always smaller than unity if the universe experienced the classical slow roll-over phase. (author)

1988-01-01

296

Cold rolling textures in AZ31 wrought magnesium alloy  

International Nuclear Information System (INIS)

[en] Samples of the magnesium alloy AZ31 (3 wt% Al, 1 wt% Zn, balance Mg) with two microstructures, recrystallized and squeeze cast, were rolled at room temperature. The initial texture and the final cold rolling texture were investigated by X-ray diffraction. The cold rolling texture of both examined initial microstructures consists of two fibres, representing the familiar double peak in the basal pole tilted ±15 deg. from the normal direction to the rolling direction. A systematic texture modelling was performed using a viscoplastic Taylor model, based on different combinations of four slip modes and one twinning mode. The best agreement with experiment can be achieved for a combination of -basal, -prismatic, -pyramidal slip systems together with the {0 1 1-bar 2} twinning system

2004-01-01

297

Prediction of Parametric Roll Resonance by Multilayer Perceptron Neural Network  

DEFF Research Database (Denmark)

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

Míguez González, M; López Peña, F.

2011-01-01

298

Dynamic Effect of Rolling Massage on Blood Flow  

International Nuclear Information System (INIS)

The Chinese traditional medical massage has been used as a natural therapy to eliminate some diseases. Here, the effect of the rolling massage frequency to the blood flow in the blood vessels under the rolling massage manipulation is studied by the lattice Boltzmann simulation. The simulation results show that when the frequency is smaller than or comparable to the pulsatile frequency of the blood flow, the effect on the blood flux by the rolling massage is small. On the contrast, if the frequency is twice or more times of the pulsatile frequency of the blood flow, the blood flux is greatly enhanced and increases linearly with respect to the frequency. Similar behavior has also been observed on the shear stress on the blood vessel walls. The result is helpful for understanding that the rolling massage has the function of promoting the blood circulation and removing the blood stasis.

2009-02-15

299

Parallel Estimation Respecting Constraints of Parametric Models of Cold Rolling.  

Czech Academy of Sciences Publication Activity Database

steel industryKód oboru RIV: BB - Aplikovaná statistika, opera?ní výzkum http://library.utia.cas.cz/separaty/2010/AS/karny-parallel estimation respecting constraints of parametric models of cold rolling.pdf

Ettler, P.; Kárný, MiroslavG

300

Wheel rolling constraints and slip in mobile robots  

Energy Technology Data Exchange (ETDEWEB)

It is widely accepted that dead reckoning based on the rolling with no slip condition on wheels is not a reliable method to ascertain the position and orientation of a mobile robot for any reasonable distance. We establish that wheel slip is inevitable under the dynamic model of motion using classical results on the accessibility and controllability in nonlinear control theory and an analytical model of rolling of two linearly elastic bodies.

Shekhar, S.

1997-03-01

 
 
 
 
301

Wheel rolling constraints and slip in mobile robots  

Energy Technology Data Exchange (ETDEWEB)

It is widely accepted that dead reckoning based on the rolling with no slip condition on wheels is not a reliable method to ascertain the position and orientation of a mobile robot for any reasonable distance. The author establishes that wheel slip is inevitable under the dynamic model of motion using classical results on the accessibility and controllability in nonlinear control theory and an analytical model of rolling of two linearly elastic bodies.

Shekhar, S.

1997-03-01

302

Wheel rolling constraints and slip in mobile robots  

Energy Technology Data Exchange (ETDEWEB)

It is widely accepted that dead-reckoning based on the rolling with no-slip condition on the wheels is not a reliable method to ascertain the position and orientation of a mobile robot for any reasonable distance. The authors establish that wheel slip is inevitable under the dynamic model of motion using classical results on the accessibility and controllability in nonlinear control theory and an analytical model of rolling of two linearly elastic bodies.

Shekhar, S. [Oak Ridge National Lab., TN (United States). Robotics and Process Systems Div.

1996-06-01

303

High speed twin roll casting of 6016 strip  

Directory of Open Access Journals (Sweden)

Full Text Available Purpose: of this paper is to clear the possibility of high speed roll casting of thin aluminum alloy strip. 6016aluminum alloy is used for sheet metal of the automobile. Therefore, casting of 6016 was tried in this study.Castability and characteristics of roll cast 6016 strip were investigated.Design/methodology/approach: was a high speed twin roll caster. The high speed twin roll caster was designedto overcome the low castability of the twin roll caster.Findings: are as below. The 6016 could be cast at speed of 60 m/min. The thickness of the 6016 was 3 mm.The microstructure at as-cast and after T6 heat treatment was shown. The microstructure was very fine by theeffect of the rapid solidification. The mechanical properties were investigated by the tension test and 180 degreesbending test. The as-cast strip could be cold rolled down to 1 mm without homogenization. The result of tensiontest (gage length 50mm) of T4 strip was as below, tensile stress was 242 MPa, proof stress was 123 MPa andelongation was 26%. There was no crack at the outer surface of 180-degree-bent strip until contact. This showsthe strip endure the hem forming.Research limitations/implications: is the width of the strip was 100 mm. The test using a large scale twin rollcaster must be operated.Practical implications: are as below. The mechanical properties of the roll-cast 6016 were enough for the sheetmetal for the automobile. The low productivity of the twin roll caster could be improved, and economy 6016strip was able to produce.Originality/value: is that 6016 strip could be cast at speed 60 m/min and this strip had good mechanicalproperties.

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

2006-01-01

304

Technical aspects of the linkage of the processing steps of the cold rolling steel plants; Aspectos tecnicos ligados ao acoplamento de linhas de processo na laminacao de tiras a frio  

Energy Technology Data Exchange (ETDEWEB)

Several industries have made efforts to attain an actual link between processing lines. In special, at cold rolling steel plants. This link have been made involving continuous pickling lines, cold tandem mill, annealing lines and temper mill. Design aspects and data simulation of this new tendency in cold rolling processing lines are discussed in this paper. 2 figs., 4 tabs., 6 refs.

Oliveira, Generoso N.; Massuda, Marcelo S. [COBRAPI, Belo Horizonte, MG (Brazil)

1990-12-31

305

A mechanism for ramified rolling circle amplification  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Amplification of single-stranded DNA circles has wide utility for a variety of applications. The two-primer ramified rolling circle amplification (RAM) reaction provides exponential DNA amplification under isothermal conditions, creating a regular laddered series of double-stranded DNA products. However, the molecular mechanism of the RAM reaction remains unexplained. Results A RAM reaction model predicts exponential accumulation of a double-stranded DNA product size series, and product-size ratios, that are consistent with observed RAM reaction products. The mechanism involves generation of a series of increasing size intermediate templates; those templates produce RAM products and recursively generate smaller intermediate templates. The model allows prediction of the number of rounds of circular template replication. Real-time RAM reaction data are consistent with the model. Analysis of RAM reaction products shows exponential growth limitation consistent with the model's predictions. Conclusions The model provides a rationale for the observed products of the RAM reaction, and the molecular yield among those products. Experimental results are consistent with the model.

Beals Thomas P; Smith James H; Nietupski Raymond M; Lane David J

2010-01-01

306

Rolling horizon appointment scheduling: a simulation study.  

UK PubMed Central (United Kingdom)

Health-care consumers continue to be frustrated with long waits, especially when an appointment has been made. However, providers who book appointments are under increasing pressure to maximize utilization so that revenues will be increased and costs reduced. Thus, scheduling appointments involves opposing forces that are difficult to manage. This challenge is addressed in a rolling-horizon environment with fluctuating demand loads. These two issues have not been explored previously in the appointment-scheduling research. Two management policies are considered: overload rules (OLR) and rule delay (RD). The former considers different scheduling methods (overtime, double booking) when demand loads are high, and the rule delay policy considers when to implement the overload rules. These methods are explored for six different demand patterns/loads and evaluated with a variety of client and server-oriented measures. The results show that managers of appointment scheduling systems must carefully consider which measures are most important to them since the best choices of OLR and RD vary substantially by measure. Good choices also depend on the general type of client demand pattern. Thus, to consider the various tradeoffs between client and server measures a matrix is developed that outlines good choices for each scenario.

Rohleder TR; Klassen KJ

2002-08-01

307

Magnetically capped rolled-up nanomembranes.  

UK PubMed Central (United Kingdom)

Modifying the curvature in magnetic nanostructures is a novel and elegant way toward tailoring physical phenomena at the nanoscale, allowing one to overcome limitations apparent in planar counterparts. Here, we address curvature-driven changes of static magnetic properties in cylindrically curved magnetic segments with different radii of curvature. The curved architectures are prepared by capping nonmagnetic micrometer- and nanometer-sized rolled-up membranes with a soft-magnetic 20 nm thick permalloy (Ni(80)Fe(20)) film. A quantitative comparison between the magnetization reversal processes in caps with different diameters is given. The phase diagrams of magnetic equilibrium domain patterns (diameter versus length) are generated. For this, joint experimental, including X-ray magnetic circular dichroism photoelectron emission microscopy (XMCD-PEEM), and theoretical studies are carried out. The anisotropic magnetostatic interaction in cylindrically curved architectures originating from the thickness gradient reduces substantially the magnetostatic interaction between closely packed curved nanowires. This feature is beneficial for racetrack memory devices, since a much higher areal density might be achieved than possible with planar counterparts.

Streubel R; Thurmer DJ; Makarov D; Kronast F; Kosub T; Kravchuk V; Sheka DD; Gaididei Y; Schäfer R; Schmidt OG

2012-08-01

308

Communication using eye roll reflective signalling  

Science.gov (United States)

Body reflections in the ultraviolet (UV) are a common occurrence in nature. Despite the abundance of such signals and the presence of UV cones in the retinas of many vertebrates, the function of UV cones in the majority of taxa remains unclear. Here, we report on an unusual communication system in the razorback sucker, Xyrauchen texanus, that involves flash signals produced by quick eye rolls. Behavioural experiments and field observations indicate that this form of communication is used to signal territorial presence between males. The flash signal shows highest contrast in the UV region of fhe visual spectrum (??max???380 nm), corresponding to the maximum wavelength of absorption of the UV cone mechanism in suckers. Furthermore, these cones are restricted to the dorsal retina of the animal and the upwelling light background is such that their relative sensitivity would be enhanced by chromatic adaptation of the other cone mechanisms. Thus, the UV cones in the sucker have optimal characteristics (both in terms of absorbance and retinal topography) to constitute the main detectors of the flash signal. Our findings provide the first ecological evidence for restricted distribution of UV cones in the retina of a vertebrate. ?? 2007 The Royal Society.

Flamarique, I. N.; Mueller, G. A.; Cheng, C. L.; Figiel, C. R.

2007-01-01

309

An improved rolled strip pulse forming line.  

UK PubMed Central (United Kingdom)

The rolled strip pulse forming line (RSPFL) has advantages of compactness, portability, and long pulse achievability which could well meet the requirements of industrial application of the pulse power technology. In this paper, an improved RSPFL with an additional insulator between the grounded conductors is investigated numerically and experimentally. Results demonstrate that the jitter on the flat-top of the output voltage waveform is reduced to 3.8% due to the improved structure. Theoretical analysis shows that the electromagnetic coupling between the conductors of the RSPFL strongly influences the output voltage waveform. Therefore, the new structure was designed to minimize the detrimental effect of the electromagnetic coupling. Simulation results show that the electromagnetic coupling can be efficiently reduced in the improved RSPFL. Experimental results illustrate that the improved RSPFL, with dimensions and weight of ? 290 × 250 mm and 16 kg, when used as a simple pulse forming line, could generate a well shaped quasi-square pulse with output power of hundreds of MW and pulse duration of 250 ns. Importantly, the improved RSPFL was successfully used as a Blumlein pulse forming line, and a 10.8 kV, 260 ns quasi-square pulse was obtained on a 2 ? dummy load. Experiments show reasonable agreement with numerical analysis.

Li S; Qian BL; Yang HW; Gao JM; Liu ZX

2013-06-01

310

Rolling in the Higgs Model and Elliptic Functions  

CERN Document Server

Asymptotic methods in nonlinear dynamics are used usually to improve perturbation theory results in the oscillations regime. However, for some problems of nonlinear dynamics, particularly in the case of Higgs (Duffing) equation and the Friedmann cosmological equations, not only small oscillations regime is of interest but also the regime of rolling (claiming), more precisely the rolling from a top (claiming to the top). In the Friedman cosmology, where the slow rolling regime is often used, the rolling from a top (not necessary slow) is of interest too. In the present work a method for approximate solution to the Higgs equation in the rolling regime is presented. It is shown that in order to improve perturbation theory in the rolling regime it turns out to be effective not to use an expansion in trigonometric functions as it is done in case of small oscillations but use expansions in hyperbolic functions instead. This regime is investigated using the representation of the solution in terms of elliptic functio...

Arefeva, I Ya; Volovich, I V

2012-01-01

311

Sticking Phenomenon Occurring during Hot Rolling of Ferritic Stainless Steels  

Energy Technology Data Exchange (ETDEWEB)

Sticking phenomenon occurring during hot rolling of two ferritic stainless steels, STS 430J1L and STS 436L, was investigated in this study. A hot rolling simulation test was carried out using a high-temperature wear tester capable of controlling rolling speed, load, and temperature. The simulation test results at 900 .deg. C and 1000 .deg. C revealed that the sticking process proceeded with three stages, i.e., nucleation, growth, and saturation, for the both stainless steels, and that STS 430J1L had a smaller number of sticking nucleation sites than the STS436L because of higher high-temperature hardness, thereby leading to a smaller amount of the sticking. When the test temperature was 1070 .deg. C, the sticking hardly occurred in both stainless steels as Fe-Cr oxide layers were formed on the surface of the rolled materials. These findings suggested that the improvement of high-temperature properties of stainless steels and the appropriate rolling conditions for readily forming oxide layers on the rolled material surface were required in order to prevent or minimize the sticking.

Son, Chang Young; Kim, Chang Kyu; Ha, Dae Jin; Lee, Sung Hak [Pohang Univ. of Institute of Science and Technology, Pohang (Korea, Republic of); Lee, Jong Seog; Kim, Kwang Tae; Lee, Yong Deuk [POSCO Technical Research Lab., Gwangyang (Korea, Republic of)

2007-01-15

312

Effects of pitching and rolling on reactor power  

International Nuclear Information System (INIS)

Present report is described about the effect of pitching and rolling on 'MUTSU' reactor power. Using the vertical gyro and the acceleration detectors, we measured pitching and rolling in addition to physical quantities from the nuclear reactor instrumentations on a voyage for N.S.'MUTSU' Power-Up Tests. This data was used to apply a multivariable autoregressive model to analyze the correlations between pitching-angle, rolling-angle, steam flow (load), neutron flux (power) and primary coolant temperature. Concerning reactor kinetics, we got a result that the pitching and rolling have no effect on primary coolant temperature and neutron flux. It is found that the frequencies at high coherence between load and power is lower and separate from the frequencies at the pitching and rolling. The pitching and rolling mainly depend on the size, weight and position of center of gravity of the ship, on the other hand the load-follow characteristics depend on the load and heat capacities of primary loop and secondary loop of the reactor. For this reason we interpret that the design of reactor and ship of N.S.'MUTSU' match well each other. (author)

1991-01-01

313

Numerical modelling of the bimetallic reinforcement bar rolling process  

Directory of Open Access Journals (Sweden)

Full Text Available Purpose: New kind of reinforcement bars are bimetallic reinforcement bars which has a higher corrosion resistance and mechanical properties, than the standard bars. The bimetallic bars are more and more often applied to building of concrete construction. This kind of application decides about high requirements imposed upon their performance characteristics and mechanical properties.Design/methodology/approach: Using the numerical modelling to rolling process of the bimetallic reinforcement bars in a finished pass to define rolling parameters. The simulations of the ribbed bar rolling were carried out using the Forge2005® commercial program.Findings: It has been performed in order to define the specific features of the mode of metal flow in the roll gap and to determine the effect of the shape and dimensions of the feedstock oval on the height of the ribs and on the thickness of surface layer of the finished bar.Practical implications: Reinforcement bars are chiefly used in the building industry at production of reinforced concrete constructions, and as working elements in bridge building.Originality/value: Production of bimetallic reinforcement bars is very difficult. One from many problems during production bimetallic bars is rolling in the finished passes. In this paper the computer simulation of the rolling bimetallic reinforcement bar is presented.

P. Szota; H. Dyja

2007-01-01

314

Prediction of mechanical properties of hot rolled steel products  

Directory of Open Access Journals (Sweden)

Full Text Available Purpose: Model for prediction of mechanical properties of rolled steel products after final cooling from exitrolling temperature is one of the basic component of any software for complex computer simulation of rollingtechnologies. Theoretical background and implementation of such software tool is described.Design/methodology/approach: After calculation of cooling curves by any technology dependent Shell thesoftware tool MECHP can be called to predict CCT Diagram from current chemical composition of steel andinitial properties of deformed austenite first than structure shares (percentage of ferrite, pearlite, bainite andmartensite) resulting from austenite decomposition process for given cooling curve and finally mechanicalproperties of final product after cooling (hardness, yield stress, tensile strength) are calculated. Implementationof MECHP tool into the software RollFEM3D for 3D Finite Elements Method simulation of rolling processesis presented.Findings: Comparison of MECHP calculations with measured process data (water cooling and subsequent aircooling of hot rolled narrow plate and wire) shows correspondence that is satisfactory for using in control ofprocess cooling technology.Practical implications: Results of verification showed that the software tool MECHP is implementable asa postprocessor into off-line rolling process simulation software or can be used as a mechanical propertiespredictor in software for on-line control of cooling.Originality/value: Developing of technology independent Library solving the problem of final mechanicalproperties prediction for various kinds of rolling technologies.

P. Šime?ek; D. Hajduk

2007-01-01

315

Just Roll with It? Rolling Volumes vs. Discrete Issues in Open Access Library and Information Science Journals  

Directory of Open Access Journals (Sweden)

Full Text Available INTRODUCTION Articles in open access (OA) journals can be published on a rolling basis, as they become ready, or in complete, discrete issues. This study examines the prevalence of and reasons for rolling volumes vs. discrete issues among scholarly OA library and information science (LIS) journals based in the United States. METHODS A survey was distributed to journal editors, asking them about their publication model and their reasons for and satisfaction with that model. RESULTS Of the 21 responding journals, 12 publish in discrete issues, eight publish in rolling volumes, and one publishes in rolling volumes with an occasional special issue. Almost all editors, regardless of model, cited ease of workflow as a justification for their chosen publication model, suggesting that there is no single best workflow for all journals. However, while all rolling-volume editors reported being satisfied with their model, satisfaction was less universal among discrete-issue editors. DISCUSSION The unexpectedly high number of rolling-volume journals suggests that LIS journal editors are making forward-looking choices about publication models even though the topic has not been much addressed in the library literature. Further research is warranted; possibilities include expanding the study’s geographic scope, broadening the study to other disciplines, and investigating publication model trends across the entire scholarly OA universe. CONCLUSION Both because satisfaction is high among editors of rolling-volume journals and because readers and authors appreciate quick publication times, the rolling-volume model will likely become even more prevalent in coming years.

Jill Cirasella; Sally Bowdoin

2013-01-01

316

Roll-to-Roll Inkjet Printing and Photonic Sintering of Electrodes for ITO Free Polymer Solar Cell Modules and Facile Product Integration  

DEFF Research Database (Denmark)

Small polymer solar cell modules that are manufactured without indium-tin-oxide using only roll-to-roll printing and coating techniques under ambient conditions enable facile integration into a simple demonstrator (for example a laser pointer). Semitransparent front electrode grid structures prepared by roll-to-roll inkjet printing in conjunction with photonic sintering enabled preparation of complete modules on flexible substrates and subsequent integration of the modules into a laser pointer demonstrator.

Angmo, Dechan; Larsen-Olsen, Thue Trofod

2013-01-01

317

Roll-to-Roll Screen Printed Radio Frequency Identification Transponder Antennas for Vehicle Tracking Systems  

Science.gov (United States)

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.

Zichner, Ralf; Baumann, Reinhard R.

2013-05-01

318

Patterned immobilization of antibodies within roll-to-roll hot embossed polymeric microfluidic channels.  

UK PubMed Central (United Kingdom)

This paper describes a method for the patterned immobilization of capture antibodies into a microfluidic platform fabricated by roll-to-roll (R2R) hot embossing on poly (methyl methacrylate) (PMMA). Covalent attachment of antibodies was achieved by two sequential inkjet printing steps. First, a polyethyleneimine (PEI) layer was deposited onto oxygen plasma activated PMMA foil and further cross-linked with glutaraldehyde (GA) to provide an amine-reactive aldehyde surface (PEI-GA). This step was followed by a second deposition of antibody by overprinting on the PEI-GA patterned PMMA foil. The PEI polymer ink was first formulated to ensure stable drop formation in inkjet printing and the printed films were characterized using atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS). Anti-CRP antibody was patterned on PMMA foil by the developed method and bonded permanently with R2R hot embossed PMMA microchannels by solvent bonding lamination. The functionality of the immobilized antibody inside the microfluidic channel was evaluated by fluorescence-based sandwich immunoassay for detection of C-reactive protein (CRP). The antibody-antigen assay exhibited a good level of linearity over the range of 10 ng/ml to 500 ng/ml (R(2)?=?0.991) with a calculated detection limit of 5.2 ng/ml. The developed patterning method is straightforward, rapid and provides a versatile approach for creating multiple protein patterns in a single microfluidic channel for multiplexed immunoassays.

Feyssa B; Liedert C; Kivimaki L; Johansson LS; Jantunen H; Hakalahti L

2013-01-01

319

Patterned Immobilization of Antibodies within Roll-to-Roll Hot Embossed Polymeric Microfluidic Channels  

Science.gov (United States)

This paper describes a method for the patterned immobilization of capture antibodies into a microfluidic platform fabricated by roll-to-roll (R2R) hot embossing on poly (methyl methacrylate) (PMMA). Covalent attachment of antibodies was achieved by two sequential inkjet printing steps. First, a polyethyleneimine (PEI) layer was deposited onto oxygen plasma activated PMMA foil and further cross-linked with glutaraldehyde (GA) to provide an amine-reactive aldehyde surface (PEI-GA). This step was followed by a second deposition of antibody by overprinting on the PEI-GA patterned PMMA foil. The PEI polymer ink was first formulated to ensure stable drop formation in inkjet printing and the printed films were characterized using atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS). Anti-CRP antibody was patterned on PMMA foil by the developed method and bonded permanently with R2R hot embossed PMMA microchannels by solvent bonding lamination. The functionality of the immobilized antibody inside the microfluidic channel was evaluated by fluorescence-based sandwich immunoassay for detection of C-reactive protein (CRP). The antibody-antigen assay exhibited a good level of linearity over the range of 10 ng/ml to 500 ng/ml (R2?=?0.991) with a calculated detection limit of 5.2 ng/ml. The developed patterning method is straightforward, rapid and provides a versatile approach for creating multiple protein patterns in a single microfluidic channel for multiplexed immunoassays.

Feyssa, Belachew; Liedert, Christina; Kivimaki, Liisa; Johansson, Leena-Sisko; Jantunen, Heli; Hakalahti, Leena

2013-01-01

320

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

DEFF Research Database (Denmark)

In this report we employ static and roll-to-roll (R2R) photonic sintering processes on flexo printed silver nanoparticle-based electrode structures with a heat-sensitive 60 mm thin barrier foil as a substrate. We use large area electrode structures to visualize the increased optical footprint of single and quadruple flashes, and the R2R challenges in the form of overlapping exposures. It is shown that single flash exposure is enough to significantly increase the conductivity and adhesion without damaging the foil or build-up of cracks in the silver layer. Additional flash exposures or increased energies above the threshold level have only minor impact on the conductivity but lead to cracks and substrate deformation. A second silver nanoparticle ink was printed, which was already optimized for lowtemperature drying. Here we show that photonic sintering has only a minor impact on the conductivity 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.

Hösel, Markus; Krebs, Frederik C

2012-01-01

 
 
 
 
321

Multivariable passive RFID vapor sensors: roll-to-roll fabrication on a flexible substrate.  

UK PubMed Central (United Kingdom)

We demonstrate roll-to-roll (R2R) fabrication of highly selective, battery-free radio frequency identification (RFID) sensors on a flexible polyethylene terephthalate (PET) polymeric substrate. Selectivity of our developed RFID sensors is provided by measurements of their resonance impedance spectra, followed by the multivariate analysis of spectral features, and correlation of these spectral features to the concentrations of vapors of interest. The multivariate analysis of spectral features also provides the ability for the rejection of ambient interferences. As a demonstration of our R2R fabrication process, we employed polyetherurethane (PEUT) as a "classic" sensing material, extruded this sensing material as 25, 75, and 125-?m thick films, and thermally laminated the films onto RFID inlays, rapidly producing approximately 5000 vapor sensors. We further tested these RFID vapor sensors for their response selectivity toward several model vapors such as toluene, acetone, and ethanol as well as water vapor as an abundant interferent. Our RFID sensing concept features 16-bit resolution provided by the sensor reader, granting a highly desired independence from costly proprietary RFID memory chips with a low-resolution analog input. Future steps are being planned for field-testing of these sensors in numerous conditions.

Potyrailo RA; Burns A; Surman C; Lee DJ; McGinniss E

2012-06-01

322

Roll-to-Roll Solution-Processible Small-Molecule OLEDs  

Energy Technology Data Exchange (ETDEWEB)

The objective of this program is to develop key knowledge and make critical connections between technologies needed to enable low-cost manufacturing of OLED lighting products. In particular, the program was intended to demonstrate the feasibility of making high performance Small-Molecule OLEDs (SM-OLED) using a roll-to-roll (R2R) wet-coating technique by addressing the following technical risks (1) Whether the wet-coating technique can provide high performance OLEDs, (2) Whether SM-OLED can be made in a R2R manner, (3) What are the requirements for coating equipment, and (4) Whether R2R OLEDs can have the same performance as the lab controls. The program has been managed and executed according to the Program Management Plan (PMP) that was first developed at the beginning of the program and further revised accordingly as the program progressed. Significant progress and risk reductions have been accomplished by the end of the program. Specific achievements include: (1) Demonstrated that wet-coating can provide OLEDs with high LPW and long lifetime; (2) Demonstrated R2R OLEDs can be as efficient as batch controls (Figure 1) (3) Developed & validated basic designs for key equipment necessary for R2R SM-OLEDs; (4) Developed know-hows & specifications on materials & ink formulations critical to wetcoating; (5) Developed key R2R processes for each OLED layer (6) Identified key materials and components such as flexible barrier substrates necessary for R2R OLEDs.

Liu, Jie Jerry

2012-07-31

323

Função de afilamento para Virola surinamensis (Roll.) Warb Tapering function for Virola surinamensis (Roll.) Warb  

Directory of Open Access Journals (Sweden)

Full Text Available Este estudo foi conduzido com o propósito de gerar equação de afilamento para Virola surinamensis (Roll.) Warb, que está entre as espécies mais exportadas pela indústria madeireira do estuário amazônico. Foram testados os modelos de Kozak (1969), Baldwin (1991), Demaerschalk (1972) e Garay (1979). Todos esses modelos estimaram o diâmetro comercial com precisão, porém os três primeiros resultaram em inconsistência ao estimar a altura comercial. O modelo de Garay foi selecionado e utilizado para gerar uma curva de cubagem para a espécie.This study was carried out with the aim of generating a taper equation for Virola surinamensis (Roll.) Warb, which is among the main exported species by the wood industries from the Amazonian estuary. The Kozak (1969), Baldwin (1991), Demaerschalk (1972) and Garay (1979) mathematical models were tested. All the tested models estimated the diameter with good precision, however, the first three models resulted in inconsistency while estimating commercial height. The Garay model was chosen and used to generate a cubage curve for the species.

Helio Garcia Leite; João Ricardo Vasconcellos Gama; Jovane Pereira da Cruz; Agostinho Lopes de Souza

2006-01-01

324

Função de afilamento para Virola surinamensis (Roll.) Warb/ Tapering function for Virola surinamensis (Roll.) Warb  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese Este estudo foi conduzido com o propósito de gerar equação de afilamento para Virola surinamensis (Roll.) Warb, que está entre as espécies mais exportadas pela indústria madeireira do estuário amazônico. Foram testados os modelos de Kozak (1969), Baldwin (1991), Demaerschalk (1972) e Garay (1979). Todos esses modelos estimaram o diâmetro comercial com precisão, porém os três primeiros resultaram em inconsistência ao estimar a altura comercial. O modelo de Garay foi selecionado e utilizado para gerar uma curva de cubagem para a espécie. Abstract in english This study was carried out with the aim of generating a taper equation for Virola surinamensis (Roll.) Warb, which is among the main exported species by the wood industries from the Amazonian estuary. The Kozak (1969), Baldwin (1991), Demaerschalk (1972) and Garay (1979) mathematical models were tested. All the tested models estimated the diameter with good precision, however, the first three models resulted in inconsistency while estimating commercial height. The Garay model was chosen and used to generate a cubage curve for the species.

Leite, Helio Garcia; Gama, João Ricardo Vasconcellos; Cruz, Jovane Pereira da; Souza, Agostinho Lopes de

2006-02-01

325

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

DEFF Research Database (Denmark)

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.

Dupont, Stephanie R.; Oliver, Mark

2012-01-01

326

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

DEFF Research Database (Denmark)

We show that it is possible to perform ellipsometry on large area roll-to-roll (R2R) coated solar cells on flexible substrates and further demonstrate that the slot-die coating technique employed yields the same bulk heterojunction (BHJ) film morphology and vertical phase separation as laboratory samples prepared by the spin coating technique. The solar cell device geometry was Kapton/Al/Cr/P3HT:PCBM/PEDOT:PSS/Ag. Variable angle ellipsometry was used to determine the optical dispersions of the pure phases of P3HT and PCBM allowing an effective medium approximation model to be employed. It was found that a top layer phase separation of P3HT and a vertical linear gradient of P3HT and PCBM best described the BHJ layer. The model was tested for samples of varying thickness and blend composition, model parameters including thickness (AFM), vertical composition (XPS depth profiling), and optical transmission (optical simulation and UV–visible spectroscopy comparisons) was confirmed to comply with the model. A meansof quality testing and optimization of the coating procedure line scans across a R2R slot-die-coated sample over large distances (8 cm) was made giving insight into thickness and composition uniformity.

Vesterager Madsen, Morten; Sylvester-Hvid, Kristian O.

2011-01-01

327

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

DEFF Research Database (Denmark)

The challenges associated with obtaining the desired nanomorphology of the active layer in polymer solar cells were addressed through preparation of conjugated polymer chains grown from the surface of seed nanoparticles with a well-defined size. Poly-3-hexylthiophene (P3HT) was thus polymerized using a quasi-living chain polymerization method initiated by surface-modified silica nanoparticles. The nanoparticles with a silica core and a P3HT-corona exhibited excellent solubility and optical properties similar to native P3HT. Upon mixing with phenyl-C61-butyric acid methyl ester in solution, a preorganized ink was obtained that was used to make polymer solar cell modules in a full roll-to-roll coating and printing process operating in ambient air. The polymer solar cells were thus prepared by a mixture of slot die and flat-bed screen printing. Various polymer solar cell modules were prepared ranging from single cells to two, three, and eight serially connected cells. The power conversion efficiency for the polymer solar cell modules were in the range of 0.8%-1.2% with an active area of up to 120 cm.

Krebs, Frederik C; Senkovskyy, Volodymyr

2010-01-01

328

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

DEFF Research Database (Denmark)

A life cycle analysis was performed on a full roll-to-roll coating procedure used for the manufacture of flexible polymer solar cell modules. The process known as ProcessOne employs a polyester substrate with a sputtered layer of the transparent conductor indium-tin-oxide (ITO). The ITO film was processed into the required pattern using a full roll-to-roll process, employing screen printing of an etch resist and then applying etching, stripping, washing and drying procedures. The three subsequent layers; ZnO, P3HT:PCBM and PEDOT:PSS were slot-die coated and the silver back electrode was screen 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, and an accountability of the energy embedded both in the input materials and in the production processes. Finally, upon assumption of power conversion efficiencies and lifetime for the modules, a calculation of energy pay-back time allowed us to compare this roll-to-roll manufacturing with other organic and hybrid 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%.

Espinosa Martinez, Nieves; García-Valverde, Rafael

2011-01-01

329

Using CCT diagrams to optimize the composition of an As-rolled dual-phase steel  

Energy Technology Data Exchange (ETDEWEB)

A continuous-cooling transformation (CCT) diagram study was conducted for the purpose of optimizing the composition of an Mn-Si-Cr-Mo as-rolled dual-phase (ARDP) steel. The individual effects of chromium, molybdenum, and silicon on the allowable cooling rates were determined. On the basis of the CCT diagram study and other available information, an optimum composition was selected. Data from recent mill trials at three steel companies, involving steels with compositions in or near the newly recommended range, are presented and compared with earlier mill trial data. The comparison shows that the optimized composition is highly effective in making the steel's properties more uniform and reproducible in the as-rolled condition.

Coldren, A.P.; Eldis, G.T.

1980-03-01

330

Mathematical simulation of controlled cooling for high speed rolled wire in Stelmor process  

International Nuclear Information System (INIS)

Mathematical models have been developed to predict the temperature distribution and austenite - pearlite transformation kinetics during the processing of high carbon steel wire in a stelmor machine. For a given rod radius there are three critical fans whose mechanical efficiency should be periodically reviewed to maintain constant cooling condition. These models are currently being applied for rod production control at the transformation at the conveyor of Tangshan Iron and Steel Co. Ltd., High Speed Wire Rod Rolling Mill, China. (author)

2000-01-01

331

Mathematical simulation of controlled cooling for high speed rolled wire in Stelmor process  

Energy Technology Data Exchange (ETDEWEB)

Mathematical models have been developed to predict the temperature distribution and austenite - pearlite transformation kinetics during the processing of high carbon steel wire in a stelmor machine. For a given rod radius there are three critical fans whose mechanical efficiency should be periodically reviewed to maintain constant cooling condition. These models are currently being applied for rod production control at the transformation at the conveyor of Tangshan Iron and Steel Co. Ltd., High Speed Wire Rod Rolling Mill, China. (author)

Feng, H.; Chu, J.; Li, K.; Liu, M. [Tangshan Iron and Steel Co. Ltd., High Speed Wire Rolling Mill, Tangshan, Hebei (China)

2000-07-01

332

Dimethylsulfoxide exposure modulates HL-60 cell rolling interactions  

Directory of Open Access Journals (Sweden)

Full Text Available Human leukaemic HL-60 cells are widely used for studying interactions involving adhesion molecules [e.g. P-selectin and PSGL-1 (P-selectin glycoprotein ligand-1)] since their rolling behaviour has been shown to mimic the dynamics of leucocyte rolling in vitro. HL-60 cells are neutrophilic promyelocytes that can undergo granulocytic differentiation upon exposure to compounds such as DMSO (dimethylsulfoxide). Using a parallel plate flow chamber functionalized with recombinant P-selectin–Fc chimaera, undifferentiated and DMSO-induced (48, 72 and 96 h) HL-60 cells were assayed for rolling behaviour. We found that depending on P-selectin incubation concentration, undifferentiated cells incurred up to a 6-fold increase in rolling velocity while subjected to an approximately 10-fold increase in biologically relevant shear stress. HL-60 cells exposed to DMSO for up to 72 h incurred up to a 3-fold increase in rolling velocity over the same shear stress range. Significantly, cells exposed for up to 96 h incurred up to a 9-fold decrease in rolling velocity, compared with undifferentiated HL-60 cells. Although cell surface and nuclear morphological changes were evident upon exposure to DMSO, flow cytometric analysis revealed that PSGL-1 expression was unchanged, irrespective of treatment duration. The results suggest that DMSO-treated HL-60 cells may be problematic as a substitute for neutrophils for trafficking studies during advanced stages of the LAC (leucocyte adhesion cascade). We suggest that remodelling of the cell surface during differentiation may affect rolling behaviour and that DMSO-treated HL-60 cells would behave differently from the normal leucocytes during inflammatory response in vivo.

David J. Gee; L. Kate Wright; Jonathan Zimmermann; Kayla Cole; Karen Soule; Michelle Ubowski

2012-01-01

333

High speed twin roll casting of 6061 alloy strips  

Directory of Open Access Journals (Sweden)

Full Text Available Purpose: of this paper is to clear the possibility of high speed roll casting of thin strips of two aluminum alloys:6061 and recycled 6061. Mechanical properties of the roll cast 6061 and recycled 6061 strips were investigated inthe frame of this purpose.Design/methodology/approach: Methods used in the present study were high speed twin roll caster and lowtemperature casting. These methods were used to realize rapid solidification and increase the casting speed.Findings: are that 6061 and recycled 6061 could be cast at speed of 60 m/min. Casted strips were about 3 mmthick. As cast strip could be cold-rolled down to sheet of 1 mm thick. 180 degrees bending test was operated on thesheet after T4 heat treatment and crack was not worse than 6022 which is typical aluminum alloy for sheet of theautomobile. This result means the roll cast 6061 can be used as a sheet for body of the automobile instead of 6022.Research limitations/implications: Research limitation is that the width of the strip was 100 mm andinvestigation of the properties were enough for practical use. Wider strip must be cast using the twin roll caster ofthe size for production.Originality/value: The economy sheet of the 6061 for the auto mobile can be produced by the high speed twinroll caster. 6061 is typical wrought aluminum alloy of 6000 series. Therefore, the sheet of 6061 will becomeeconomy. 6061 can be recycled at two times when the 6061 is cast into strip by the high speed roll casting.

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

2008-01-01

334

Rolling bearing life models and steel internal cleanliness  

Energy Technology Data Exchange (ETDEWEB)

The most widely used steel grade for rolling bearings is based on a steel composition first used almost a hundred years ago, the so-called 1C-1.5Cr steel. This steel is used either in a selective surface induction hardened conditions or in a through hardened heat treated condition, both yielding exceptional structural and contact fatigue properties. The Lundberg and Palmgren rolling bearing life prediction model, published in 1947, was the first analytical approach to bearing performance prediction, subsequently becoming a widely accepted basis for rolling bearing life calculations. At that time the fatigue life of rolling bearings was dominated by the classical sub-surface initiated failure mode. This mode results from the accumulation of micro-plastic strain at the depth of maximum Hertzian stress and is accelerated by the stress concentrations occurring at the micro internal defects. In common with all fatigue processes, rolling bearing failure is a statistical process: the failures of bearings with high inclusion content tested at high stress levels belong to the well-known family of Weibull distributions. Steady improvements in bearing steel cleanliness due, amongst other things, to the introduction of secondary metallurgy steel making techniques, have resulted in a significantly increased rolling bearing life and load carrying capacity. In recognition of this, in 1985 Ioannides and Harris introduced a new fatigue life model for rolling bearings, comprising a more widely applicable approach to the modeling of bearing life based on the relevant failure mode. Subsequently this has been extended to include effects of hardness and of micro-inclusion distributions in state-of-the-art clean bearing steel.

Beswick, J.; Gabelli, A.; Ioannides, S.; Tripp, J.H.; Voskamp, A.P.

1999-07-01

335

Rheology of coal-water slurries prepared by the HP roll mill grinding of coal. Quarterly technical report No. 7, March 1, 1994--May 31, 1994  

Energy Technology Data Exchange (ETDEWEB)

The objective of this research is the development of improved technology for the preparation of coal-water slurries that have potential for replacing fuel oil in direct combustion. This should be of major importance to the United States in its efforts to reduce dependence on imported oil and to rely more on its enormous low-cost coal resources. According to this objective, Quarterly Report No. 1 presented preliminary results on the rheological behavior of coal-water slurries prepared from Pittsburgh No. 8 coal that had been ground in a ball mill under various conditions. Quarterly Report No. 2 summarized the results of studies on the effects of solids content and water immobilization on the rheological behavior of coal-water slurries, including the role of different viscometers, such as the Haake Rotovisco RV-12 and Brookfield Synchro-Lectric LVT on the measured results. In Quarterly Report No. 3, the authors compared the rheological behavior of Pittsburgh No. 8 coal-water slurries using different sensor system. In Quarterly Report No. 4, studies on the role of the initial mixing procedure in the preparation of coal-water slurries were summarized. In Quarterly Report No. 5, the evaluation of the effect of a cationic surfactant (TMAE) and an anionic surfactant (2-TEPA) on the rheological behavior and the aggregative stability of Pittsburgh No. 8 coal-water slurries was presented. In Quarterly Report No. 6, the effect of nonionic surfactants (Triton X series) on the aggregative stability of coal-water slurries was studied by measuring the relative sedimentation volume and floc size distribution.

Fuerstenau, D.W.

1994-06-01

336

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

Energy Technology Data Exchange (ETDEWEB)

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)

Liu Xianghua; Wang Guodong [Northeastern Univ., State Key Lab. of Rolling and Automation, Shenyang City (China); Zhao Kun [Shanghai Baosteel Yichang Steel Strip Co. Ltd., Shanghai (China)

2000-07-01

337

Finite-element modeling of soft tissue rolling indentation.  

UK PubMed Central (United Kingdom)

We describe a finite-element (FE) model for simulating wheel-rolling tissue deformations using a rolling FE model (RFEM). A wheeled probe performing rolling tissue indentation has proven to be a promising approach for compensating for the loss of haptic and tactile feedback experienced during robotic-assisted minimally invasive surgery (H. Liu, D. P. Noonan, B. J. Challacombe, P. Dasgupta, L. D. Seneviratne, and K. Althoefer, "Rolling mechanical imaging for tissue abnormality localization during minimally invasive surgery, " IEEE Trans. Biomed. Eng., vol. 57, no. 2, pp. 404-414, Feb. 2010; K. Sangpradit, H. Liu, L. Seneviratne, and K. Althoefer, "Tissue identification using inverse finite element analysis of rolling indentation," in Proc. IEEE Int. Conf. Robot. Autom. , Kobe, Japan, 2009, pp. 1250-1255; H. Liu, D. Noonan, K. Althoefer, and L. Seneviratne, "The rolling approach for soft tissue modeling and mechanical imaging during robot-assisted minimally invasive surgery," in Proc. IEEE Int. Conf. Robot. Autom., May 2008, pp. 845-850; H. Liu, P. Puangmali, D. Zbyszewski, O. Elhage, P. Dasgupta, J. S. Dai, L. Seneviratne, and K. Althoefer, "An indentation depth-force sensing wheeled probe for abnormality identification during minimally invasive surgery," Proc. Inst. Mech. Eng., H, vol. 224, no. 6, pp. 751-63, 2010; D. Noonan, H. Liu, Y. Zweiri, K. Althoefer, and L. Seneviratne, "A dual-function wheeled probe for tissue viscoelastic property identification during minimally invasive surgery," in Proc. IEEE Int. Conf. Robot. Autom. , 2008, pp. 2629-2634; H. Liu, J. Li, Q. I. Poon, L. D. Seneviratne, and K. Althoefer, "Miniaturized force indentation-depth sensor for tissue abnormality identification," IEEE Int. Conf. Robot. Autom., May 2010, pp. 3654-3659). A sound understanding of wheel-tissue rolling interaction dynamics will facilitate the evaluation of signals from rolling indentation. In this paper, we model the dynamic interactions between a wheeled probe and a soft tissue sample using the ABAQUS FE software package. The aim of this work is to more precisely locate abnormalities within soft tissue organs using RFEM and hence aid surgeons to improve diagnostic ability. The soft tissue is modeled as a nonlinear hyperelastic material with geometrical nonlinearity. The proposed RFEM was validated on a silicone phantom and a porcine kidney sample. The results show that the proposed method can predict the wheel-tissue interaction forces of rolling indentation with good accuracy and can also accurately identify the location and depth of simulated tumors.

Sangpradit K; Liu H; Dasgupta P; Althoefer K; Seneviratne LD

2011-12-01

338

Finite-element modeling of soft tissue rolling indentation.  

Science.gov (United States)

We describe a finite-element (FE) model for simulating wheel-rolling tissue deformations using a rolling FE model (RFEM). A wheeled probe performing rolling tissue indentation has proven to be a promising approach for compensating for the loss of haptic and tactile feedback experienced during robotic-assisted minimally invasive surgery (H. Liu, D. P. Noonan, B. J. Challacombe, P. Dasgupta, L. D. Seneviratne, and K. Althoefer, "Rolling mechanical imaging for tissue abnormality localization during minimally invasive surgery, " IEEE Trans. Biomed. Eng., vol. 57, no. 2, pp. 404-414, Feb. 2010; K. Sangpradit, H. Liu, L. Seneviratne, and K. Althoefer, "Tissue identification using inverse finite element analysis of rolling indentation," in Proc. IEEE Int. Conf. Robot. Autom. , Kobe, Japan, 2009, pp. 1250-1255; H. Liu, D. Noonan, K. Althoefer, and L. Seneviratne, "The rolling approach for soft tissue modeling and mechanical imaging during robot-assisted minimally invasive surgery," in Proc. IEEE Int. Conf. Robot. Autom., May 2008, pp. 845-850; H. Liu, P. Puangmali, D. Zbyszewski, O. Elhage, P. Dasgupta, J. S. Dai, L. Seneviratne, and K. Althoefer, "An indentation depth-force sensing wheeled probe for abnormality identification during minimally invasive surgery," Proc. Inst. Mech. Eng., H, vol. 224, no. 6, pp. 751-63, 2010; D. Noonan, H. Liu, Y. Zweiri, K. Althoefer, and L. Seneviratne, "A dual-function wheeled probe for tissue viscoelastic property identification during minimally invasive surgery," in Proc. IEEE Int. Conf. Robot. Autom. , 2008, pp. 2629-2634; H. Liu, J. Li, Q. I. Poon, L. D. Seneviratne, and K. Althoefer, "Miniaturized force indentation-depth sensor for tissue abnormality identification," IEEE Int. Conf. Robot. Autom., May 2010, pp. 3654-3659). A sound understanding of wheel-tissue rolling interaction dynamics will facilitate the evaluation of signals from rolling indentation. In this paper, we model the dynamic interactions between a wheeled probe and a soft tissue sample using the ABAQUS FE software package. The aim of this work is to more precisely locate abnormalities within soft tissue organs using RFEM and hence aid surgeons to improve diagnostic ability. The soft tissue is modeled as a nonlinear hyperelastic material with geometrical nonlinearity. The proposed RFEM was validated on a silicone phantom and a porcine kidney sample. The results show that the proposed method can predict the wheel-tissue interaction forces of rolling indentation with good accuracy and can also accurately identify the location and depth of simulated tumors. PMID:21257372

Sangpradit, Kiattisak; Liu, Hongbin; Dasgupta, Prokar; Althoefer, Kaspar; Seneviratne, Lakmal D

2011-01-20

339

On the sound radiation of a rolling tyre  

Science.gov (United States)

The sound radiation from rolling tyres is still not very well understood. Although details such as horn effect or directivity during rolling have been investigated, it is not clear which vibrational modes of the tyre structure are responsible for the radiated sound power. In this work an advanced tyre model based on Wave Guide Finite Elements is used in connection with a contact model validated in previous work. With these tools the tyre vibrations during rolling on an ISO surface are simulated. Starting from the calculated contact forces in time the amplitudes of the modes excited during rolling are determined as function of frequency. A boundary element model also validated in previous work is applied to predict the sound pressure level on a reference surface around a tyre placed on rigid ground as function of the modal composition of the tyre vibrations. Taking into account different modes when calculating the vibrational field as input into the boundary element calculations, it is possible to identify individual modes or groups of modes of special relevance for the radiated sound power. The results show that mainly low-order modes with relative low amplitudes but high radiation efficiency in the frequency range around 1 kHz are responsible for the radiated sound power at these frequencies, while those modes which are most strongly excited in that frequency range during rolling are irrelevant for the radiated sound power. This fact is very essential when focusing on the design of quieter tyres.

Kropp, Wolfgang; Sabiniarz, Patrick; Brick, Haike; Beckenbauer, Thomas

2012-04-01

340

Do Liquid Drops on Inclined Surfaces Slide or Roll?  

Science.gov (United States)

A solid sphere is likely to roll, while a rectangular box is likely to slide, on an inclined surface. Instead, a liquid drop can exhibit a variety of shapes and complex but interesting dynamics. We obtain global minimum energy static shapes first, for two realistic bases of potential energy, front and back-pinned. We find that the free end always assumes Young's equilibrium angle. Using this clue, simple equations describing the angles and the maximum volume may be derived. Combining the lattice Boltzmann method for hydrodynamics and method of lines for a Cahn-Hilliard equation, a hybrid numerical scheme is developed to study the dynamics of binary fluids on an inclined plate. The contribution of pure translation, and the vorticities associated with rolling and shearing motion are distinguished, using which the motion of the drop can be split into roll and slip. Surprisingly, as gravity increases, the fraction of motion due to roll decreases significantly for certain contact angles. The rolling motion is strongly dependent on the slip length which is in contrast to predictions by the lubrication approximation, where all dependence on the slip length is generally logarithamic.

Pt, Sumesh; Pagonabarraga, Ignacio; Adhikari, Ronojoy; Govindarajan, Rama

2011-11-01

 
 
 
 
341

Innovation in pressure tube rolled joint sampling  

International Nuclear Information System (INIS)

AECL has been developing pressure tube (PT) sampling technology for the past eighteen years to take material from a PT for hydrogen and deuterium analysis. Hitherto, more than 2500 samples have been successfully taken from CANDU PTs by this proven technology. The hydrogen and deuterium content in the body of a PT is a key parameter in assessing the remaining service life of a PT. Sampling is a process of taking material (oxide and sample chips) from a PT by using specialized tools. AECL has successfully deployed several such tools: damp sampling tool (DST), single head sampling tool (SHST or wet), multi-head sampling tool (MHST), and circumferential sampling tool (CST) at CANDU stations around the world. The tools are delivered to fuel channels (FCs) either manually or by available delivery machines. The CST is a specialized tool, developed to take material samples from the rolled joint (RJ) region of a pressure tube for hydrogen isotope concentration analysis. The tool obtains a circumferentially-oriented sample from the inside surface of the PT in the region of a RJ. The Mark I (damp) CST has been successfully used on-reactor for the past eight years. Part of the CST development included qualification of post-sampling PT to end fitting RJs for leak tightness and pull-out strength. In order to take advantage of the availability of current delivery machines, reduce the time, cost and dose associated with damp sampling activities, AECL has adapted its Mark I (damp) CST to develop the Mark II system. The new Mark II (wet) CST makes use of key components of the original design. However, the updated design may be operated with either of the new delivery systems used at CANDU reactors (the Advance Delivery Machine or the Universal Delivery Machine). Hence reduction in radiation dosage to field personnel and outage time result. Simple changes are made to re-configure the tool for use with either delivery system. A laboratory prototype tool has been produced and successfully demonstrated, including testing with the ADM. This paper discusses this new sampling innovation. (author)

2006-01-01

342

Parametric roll due to hull instantaneous volumetric changes and speed variations  

DEFF Research Database (Denmark)

Parametric roll of a containership in head sea condition has been studied in the paper. A time domain routine for GZ righting arm calculation based on exact underwater hull geometry has been implemented into a two-degree-of-freedom procedure for roll response calculation. The speed variation due to e.g. added resistance has been accounted for in the model by the surge velocity. The ship roll motion due to a regular wave critical for parametric roll occurrence has been simulated, as well as the ship roll response in a severe stochastic sea. The present method has been compared with other existing methods for parametric roll prediction.

Vidic-Perunovic, Jelena; Jensen, JØrgen Juncher

2009-01-01

343

Research for rolling effects on flow pattern of gas-water flow in horizontal tubes  

International Nuclear Information System (INIS)

The flow pattern transition of two-phase flow is caused by the inertial force resulted from rolling and incline of horizontal tubes under rolling state. an experimental study on the flow patterns of gas-water flow was carried out in horizontal tubes under rolling state, which rolling period is 15 second and rolling angle is 10 degrees, and a pattern flow picture is shown. It was found that there are two flow patterns in one rolling period under some gas flux and water flux. (authors)

2007-01-01

344

Roll-to-roll coated PBI membranes for high temperature PEM fuel cells  

DEFF Research Database (Denmark)

We employed roll-to-roll coating in the preparation of 40 ?m thick poly[2,2?(m-phenylene)-5,5?bibenzimidazole] (PBI) films for fuel cells using both knife-coating (KC) and slot-die (SD) coating. The films were coated directly from a 9% (w/w) solution of PBI in dimethylacetamide onto a sacrificial low cost paper or plastic based carrier substrate and dried using a hot air oven with a length of 1 m at 140 °C. A web width of 305 mm, a working width of 250 mm and a web speed of 0.2 m min?1 were explored to ensure efficient drying of the thick wet film. A large air flow was found to efficiently avoid skinning. Films were prepared by a single coating step and by two subsequent coating steps in order to explore whether two coating steps gave films with fewer defects. A significant development towards upscaling the PEM fuel cell technology was that the PBI membrane was coated onto a sacrificial carrier substrate allowing for easy recoating on top of the firstly prepared film. It was thus possible to prepare free-standing films by a simple coating procedure followed by delamination from the carrier substrate post-film formation and drying. We finally carried out systematic membrane characterization with respect to solubility, phosphoric acid doping and fuel cell performance. Our results showed that the PBI membranes prepared in this work have identical properties compared to traditionally cast membranes while enabling an increase of a factor of 100 in manufacturing speed.

Steenberg, Thomas; Hjuler, Hans Aage

2012-01-01

345

An improved gradient and Newton algorithm for fast rolling problem  

Science.gov (United States)

Finite element method (FEM) is an efficient computational algorithm and has been widely applied to strip rolling process. For on-line application, two key issues, i.e. calculating speed and calculating precious, have to be achieved to the industrial requirements. In this paper, we present an algorithm named improved gradient and Newton method that combines Cholesky factorization method and Newton method to solve the strip rolling problem. In the proposed algorithm, Cholesky factorization method is used to search descend direction (gradient), while Newton method mainly focuses on searching step factor. Due to the excellent ability of Cholesky factorization method in solving the decomposed equations of FEM, the calculating speed is absolutely improved. Accordingly, the ability of Newton method in finding exact step factor improves the calculating precious. The global convergence of proposed algorithm can be proved according to the convergence proof of Newton method. Computational experiments demonstrate that the proposed algorithm is efficient and steady in strip rolling.

Song, Shuni; Liu, Jingyi

2013-05-01

346

Recrystallization and texture development in hot rolled 1050 aluminum  

Energy Technology Data Exchange (ETDEWEB)

The evolution of texture as a function of recrystallization has been characterized for hot-rolled AA1050. Samples prepared from hot rolled sheet were annealed isothermally for sufficient time to allow complete recrystallization. The microstructural variation and texture evolution in the samples was observed by automatic indexing of electron back scatter diffraction (EBSD) patterns in a scanning electron microscope (SEM). The spatial orientation variation within the deformed microstructure of nucleation, growth and orientations of recrystallized grains was examined. The orientation spread within grains was found to be a useful quantity for partitioning recrystallized and unrecrystallized regions. Also the effect of deformation texture on the evolution and growth of various recrystallization texture components was analyzed. The analysis is aimed at obtaining a correlation between the deformation microstructure, texture development and recrystallization kinetics in the hot-rolled condition. Preliminary results suggest only a weak correlation between the rate of recrystallization and the deformation texture component. (orig.)

Alvi, M.H.; Rollett, A.D. [Dept. of Material Science and Engineering, Carnegie Mellon Univ. (United States); Cheong, S.; Weiland, H. [Alcoa Technical Center, Alcoa Center, PA (United States)

2004-07-01

347

Student understanding of rotational and rolling motion concepts  

Directory of Open Access Journals (Sweden)

Full Text Available We investigated the common difficulties that students have with concepts related to rotational and rolling motion covered in the introductory physics courses. We compared the performance of calculus- and algebra-based introductory physics students with physics juniors who had learned rotational and rolling motion concepts in an intermediate level mechanics course. Interviews were conducted with six physics juniors and ten introductory students using demonstration-based tasks. We also administered free-response and multiple-choice questions to a large number of students enrolled in introductory physics courses, and interviewed six additional introductory students on the test questions (during the test design phase). All students showed similar difficulties regardless of their background, and higher mathematical sophistication did not seem to help acquire a deeper understanding. We found that some difficulties were due to related difficulties with linear motion, while others were tied specifically to the more intricate nature of rotational and rolling motion.

Lorenzo G. Rimoldini; Chandralekha Singh

2005-01-01

348

Stability of Benard multi-rolls in a rarefied gas  

Energy Technology Data Exchange (ETDEWEB)

This is the third of the series of the author's papers that deals with the two-dimensional Benard problem for a rarefied gas in a rectangular domain on the basis of kinetic theory. To be more specific, the stability of multi-rolls of the Benard flow is studied numerically by a finite-difference analysis of the Boltzmann-Krook-Welander equation (the so-called BGK model) with the diffuse reflection condition on the top (cooled) and bottom (heated) boundaries and the specular reflection condition on the various multi-roll solutions with respect to the aspect ratio of the domain under consideration. The existence range of the Benard convection of two to six rolls, the number of possible types of flow, which on the whole increases with the aspect ratio of the domain, and various transition processes are clarified. (authors)

Sone, Y.; Aoki, K.; Sugimoto, H. [Kyoto Univ., Dept. of Aeronautics and Astronautics, Graduate School of Engineering, Kyoto (Japan)

1999-07-01

349

Improved Fatigue Performance of Threaded Drillstring Connections by Cold Rolling  

Energy Technology Data Exchange (ETDEWEB)

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 pits inside the pipe. Therefore, an optimisation of the roll geometry and rolling parameters was not possible. However, a significant fatigue life improvement was achieved. Based on experiments, a roller with similar profile as the thread root is recommended. A rolling force of maximum 20 kN is recommended to minimise the possibility of damaging the thread profile. Shallow cracks were observed typically when 5% of the fatigue life had expired. Re-rolling after 50% of expected improved fatigue life, when also short cracks were observed in the notch roots further increased the fatigue improvement. Pretensioned small steel specimens with a notch were used to simulate cold rolled threads. The specimens were fatigue tested in tension with minimum load close to zero. Pretensioning increased the fatigue life from approximately 50 000 cycles to an infinite number of cycles. In these tests non-propagating cracks of typically 0.4 mm length were found. The benefit from pretensioning gradually disappeared with increasing mean stress. FE analyses indicated that an almost instant relaxation of residual stresses to a level with no monotonic strain hardening from preloading would take place when cycled at moderate mean stress. Cycled at low mean stress, an instant relaxation of the surface layer was found in analysis. All observations from notched pretensioned fatigue specimens were in good agreement with the available literature. However, preloading was found to be strain rate dependent in tests where a pretension load held for 2 minutes gave a longer fatigue life than a sinusoidal loading-unloading cycle performed over a one minute interval. Strain hardening was found not contributing to the fatigue life improvement, whereas the polishing effect from improved surface quality after cold rolling increased the fatigue initiation period. However, residual stress and subsequent early crack closure was the dominating effect at moderate cyclic mean loads. The material data required to perform FE fatigue simulation studies of a full threaded cold rolled coupling incorporating make-up

Kristoffersen, Steinar

2002-01-01

350

Method and compositions for efficient and specific rolling circle amplification  

UK PubMed Central (United Kingdom)

Disclosed are compositions and methods for nucleic acid amplification reactions that reduce, prevent, or eliminate artifacts; increase efficiency; increase specificity; and/or increase consistency. The disclosed method can combine, for example, the use of open circle probes that can form intramolecular stem structures; the use of matched open circle probe sets in the same amplification reaction; the use of detection primers and detection during the amplification reaction; the use of a plurality of detection rolling circle replication primer, a secondary DNA strand displacement primer and a common rolling circle replication primer in the same amplification reaction; and/or the use of peptide nucleic acid quenchers associated with detection rolling circle replication primers. Such combinations can produce, in the same amplification reaction, the benefits of each of the combined components.

ALSMADI OSAMA A; DRISCOLL MARK D; EGHOLM MICHAEL; ABARZUA PATRICIO

351

Tribological characteristics of sputtered thin films in rolling Hertzian contacts  

Energy Technology Data Exchange (ETDEWEB)

The results of tribological studies carried out on hardened steel test bodies coated with solid lubricants are reported. The tests were carried out to assess the suitability of solid lubricant films in rolling hertzian contacts. A specially constructed concentrated contact simulator was used to determine the traction (frictional) characteristics of sputtered MoS/sub 2/ and WSe/sub 2/-In-Ga films. Test results obtained show that sputtered solid lubricant films are satisfactory for heavily loaded rolling contact applications as long as the slide-roll ratio is not very much larger than 0.02. Comparative tests show that burnished films yield lower traction coefficients than sputtered films indicating that there is room to improve sputtering practice further in order to enhance the tribological characteristics of sputtered solid lubricant films.

Ramalingam, S.; Winer, W.O.; Bair, S.

1981-10-16

352

Microstructural development during warm rolling of an IF steel  

Energy Technology Data Exchange (ETDEWEB)

Wedge-shaped slab rolling was employed to investigate the microstructural evolution of an interstitial-free (IF) steel during warm working in the temperature range 500--800 C. Mean flow stress-strain curves calculated from load-time data of rolling tests reasonably correspond to work hardening and dynamic recovery behavior. The development of substructures in the deformed material was investigated using optical and electron microscopy. A close correlation was observed between mechanical behavior and microstructural development during deformation. Microbands in directions of {+-} 35{degree} with respect to the rolling direction, independent of strain, temperature and initial grain orientations are the most noticeable features in the microstructural observations. The sequences of substructural changes from the appearance of early microbands at very low strains, their development with strain, to the formation of equiaxed subgrains at higher strains and temperatures were followed by TEM.

Akbari, G.H.; Sellars, C.M.; Whiteman, J.A. [Univ. of Sheffield (United Kingdom). Dept. of Engineering Materials

1997-12-01

353

Micro Crack of Aluminum Sheet During Cold Rolling  

Directory of Open Access Journals (Sweden)

Full Text Available The micro crack of aluminum sheet during cold rolling lubricated with emulsions is investigated. Experi-ments show that micro cracks occur after cold rolling process and this is attributed to various parameters, for instance, the thin oxide film formed at the sheet surface. The micro crack spacing thus becomes an important parameter which deserves more concerns. The aspect ratio of these micro cracks is then analyzed theoreti-cally, which takes into consideration of the oxide fracture process. The good agreement between the obser-vations and the theoretical predictions validates the analysis. The approach can shed some new lights on the mechanical process of aluminium sheet during cold rolling.

Chaohui Zhang; Sisi Liu; Chenhui Zhang

2011-01-01

354

Atomic Scale Sliding and Rolling of Carbon Nanotubes  

CERN Document Server

A carbon nanotube is an ideal object for understanding the atomic scale aspects of interface interaction and friction. Using molecular statics and dynamics methods different types of motion of nanotubes on a graphite surface are investigated. We found that each nanotube has unique equilibrium orientations with sharp potential energy minima. This leads to atomic scale locking of the nanotube. The effective contact area and the total interaction energy scale with the square root of the radius. Sliding and rolling of nanotubes have different characters. The potential energy barriers for sliding nanotubes are higher than that for perfect rolling. When the nanotube is pushed, we observe a combination of atomic scale spinning and sliding motion. The result is rolling with the friction force comparable to sliding.

Buldum, A; Lu, Jian Ping

1999-01-01

355

Roll-up of validation results to a target application.  

Energy Technology Data Exchange (ETDEWEB)

Suites of experiments are preformed over a validation hierarchy to test computational simulation models for complex applications. Experiments within the hierarchy can be performed at different conditions and configurations than those for an intended application, with each experiment testing only part of the physics relevant for the application. The purpose of the present work is to develop methodology to roll-up validation results to an application, and to assess the impact the validation hierarchy design has on the roll-up results. The roll-up is accomplished through the development of a meta-model that relates validation measurements throughout a hierarchy to the desired response quantities for the target application. The meta-model is developed using the computation simulation models for the experiments and the application. The meta-model approach is applied to a series of example transport problems that represent complete and incomplete coverage of the physics of the target application by the validation experiments.

Hills, Richard Guy

2013-09-01

356

Novel Modeling of Correlation between Two-Dimensional Registers in Large-Area Multilayered Roll-to-Roll Printed Electronics  

Science.gov (United States)

For the adaption of a roll-to-roll printing method to printed electronics, it is mandatory to increase the register control resolution. Therefore, it is necessary to derive a mathematical model of the register and to develop a controller to reduce register error. A correlation between the machine-direction (MD) and cross-direction (CD) registers was derived by considering both the lateral motion of a moving substrate and the transverse position of a printing roll. By the analysis of the correlation between MD and CD registers, a novel mathematical model of an oblique-machine-direction (OMD) register was derived. The OMD register is more critical in large-area roll-to-roll printing, as the OMD register error is proportional to the width of the substrate. The proposed model can be used to design an effective two-dimensional (2D) register controller that reduces the correlation between MD and CD registers. The proposed mathematical model was validated by numerical simulations and experimental verifications under various operation conditions using a multilayered direct gravure printing machine. The results show that the proposed OMD register model reasonably exposes the MD--CD register correlation.

Kang, Hyun-Kyoo; Lee, Chang-Woo; Shin, Kee-Hyun

2011-01-01

357

Asymmetric Rolling of Interstitial-Free Steel Using Differential Roll Diameters. Part I: Mechanical Properties and Deformation Textures  

Science.gov (United States)

IF steel sheets were processed by conventional symmetric and asymmetric rolling (ASR) at ambient temperature. The asymmetry was introduced in a geometric way using differential roll diameters with a number of different ratios. The material strength was measured by tensile testing and the microstructure was analyzed by optical and transmission electron microscopy as well as electron backscatter diffraction (EBSD) analysis. Texture was also successfully measured by EBSD using large surface areas. Finite element (FE) simulations were carried out for multiple passes to obtain the strain distribution after rolling. From the FE results, the velocity gradient along selected flow lines was extracted and the evolution of the texture was simulated using polycrystal plasticity modeling. The best mechanical properties were obtained after ASR using a roll diameter ratio of 2. The textures appeared to be tilted up to 12 deg around the transverse direction, which were simulated with the FE-combined polycrystal plasticity modeling in good agreement with measurements. The simulation work revealed that the shear component introduced by ASR was about the same magnitude as the normal component of the rolling strain tensor.

Orlov, Dmitry; Pougis, Arnaud; Lapovok, Rimma; Toth, Laszlo S.; Timokhina, Ilana B.; Hodgson, Peter D.; Haldar, Arunansu; Bhattacharjee, Debashish

2013-09-01

358

77 FR 69790 - Certain Hot-Rolled Carbon Steel Flat Products From the People's Republic of China: Final Results...  

Science.gov (United States)

...Trade Administration [A-570-865] Certain Hot-Rolled Carbon Steel Flat Products From the People's...review of the antidumping duty order on certain hot- rolled carbon steel flat products (``hot-rolled steel'') from the People's...

2012-11-21

359

78 FR 40428 - Certain Hot-Rolled Carbon Steel Flat Products from India: Rescission of Antidumping Duty...  

Science.gov (United States)

...Trade Administration [A-533-820] Certain Hot-Rolled Carbon Steel Flat Products from India...review of the antidumping duty order on certain hot- rolled carbon steel flat products (hot rolled steel) from India for the period...

2013-07-05

360

Continuous roll casting of aluminium alloys – casting parameters analysis  

Directory of Open Access Journals (Sweden)

Full Text Available The main goal of the paper was to present the influence of casting parameters on casting conditions and interference of casting parameters on the final strip characteristics such as constant strip thickness, surface quality and roughness of aluminum alloys sheet 6,30 to 6,50 mm thick. The study shows that casting speed, roll force and roll gap should have the greatest influence on the final strip thickness, and that the examined parameters agree well with the theoretical standpoints.

E. Krsti? Vukelja; I. Duplan?i?; B. Lela

2010-01-01

 
 
 
 
361

PRODUCTION METHOD OF PRESERVED FOOD "SPICY EGGPLANT ROLLS"  

UK PubMed Central (United Kingdom)

FIELD: food production process. ^ SUBSTANCE: preserves are produced by blanching and mincing garlic, cutting and freezing basil greens, parsley and dill, mincing walnut nucleuses and tofu. The listed ingredients are mixed with mayonnaise, culinary salt and hot black pepper under oxygen-free conditions to produce farce. Eggplants are cut, covered in soy flour and fried in vegetable oil. Farce is laid on it and twisted to obtain rolls. The rolls and vegetable oil are packaged, vacuum-sealed and sterilised. ^ EFFECT: enhanced digestibility.

KVASENKOV OLEG IVANOVICH; KOROVKIN VIKTOR NIKOLAEVICH

362

Rudder-Roll Damping Controller Design using Mu Synthesis  

DEFF Research Database (Denmark)

The effectiveness of rudder roll damping control is very sensitive to uncertainty in ship dynamic parameters. In this paper, an H-infinity controller is designed using mu synthesis and an uncertainty model for roll and yaw that was identified earlier from experiments at sea. The properties of the resulting controller are discussed and seaway simulations with linear and non-linear models of a container ship illustrate the controller performance. The simulation results show that the mu synthesis controller is able to obtain robust performance over an envelope of operational conditions.

Yang, C.; Blanke, M.

1998-01-01

363

Hybrid bearing technology for advanced turbomachinery: Rolling contact fatigue testing  

Energy Technology Data Exchange (ETDEWEB)

The purpose of this paper is to describe the basic structure and results to date of a major ARPA funded effort to provide a tribological performance database on ceramic bearing materials and their interaction with standard bearing steels. Program efforts include studies of material physical properties, machining characteristics, and tribological performance. The majority of the testing completed to date focuses on rolling contact fatigue testing of the ceramic materials, including efforts to arrive at optimum approaches to evaluating ceramic/steel hybrid combinations in rolling contact fatigue.

Dill, J.F. [Mechanical Technology Inc., Latham, NY (United States)

1996-01-01

364

Plain and Rolled Images from Paired Fingerprint Cards  

Science.gov (United States)

NIST Plain and Rolled Images from Paired Fingerprint Cards (PC database for purchase)   NIST Special Database 29 is being distributed for use in development and testing fingerprint matching systems. The data consist of 216 ten-print fingerprint card pairs with both the rolled and plains (from a bottom of the fingerprint card) scanned at 19.7 pixels per mm. A newer version of the compression/decompression software on the CDROM can be found at the website http://www.nist.gov/itl/iad/ig/nigos.cfm as part of the NBIS package.

365

Comparative roll-over analysis of prosthetic feet.  

Science.gov (United States)

A prosthetic foot is a key element of a prosthetic leg, literally forming the basis for a stable and efficient amputee gait. We determined the roll-over characteristics of a broad range of prosthetic feet and examined the effect of a variety of shoes on these characteristics. The body weight of a person acting on a prosthetic foot during roll-over was emulated by means of an inverted pendulum-like apparatus. Parameters measured were the effective radius of curvature, the forward travel of the center of pressure, and the instantaneous radius of curvature of the prosthetic feet. Finally, we discuss how these parameters relate to amputee gait. PMID:19446814

Curtze, Carolin; Hof, At L; van Keeken, Helco G; Halbertsma, Jan P K; Postema, Klaas; Otten, Bert

2009-05-15

366

Comparative roll-over analysis of prosthetic feet.  

UK PubMed Central (United Kingdom)

A prosthetic foot is a key element of a prosthetic leg, literally forming the basis for a stable and efficient amputee gait. We determined the roll-over characteristics of a broad range of prosthetic feet and examined the effect of a variety of shoes on these characteristics. The body weight of a person acting on a prosthetic foot during roll-over was emulated by means of an inverted pendulum-like apparatus. Parameters measured were the effective radius of curvature, the forward travel of the center of pressure, and the instantaneous radius of curvature of the prosthetic feet. Finally, we discuss how these parameters relate to amputee gait.

Curtze C; Hof AL; van Keeken HG; Halbertsma JP; Postema K; Otten B

2009-08-01

367

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

DEFF Research Database (Denmark)

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 of the imaging experiments show that the ingress of atmospheric reactants from the edges leads to degradation. In the case of edge sealed devices the same effects are observed but significantly slowed down. In particular, the fast nonlinear degradation is eliminated.

Tanenbaum, David M.; Dam, Henrik Friis

2012-01-01

368

Fatigue acceptance test limit criteria for larger diameter rolled thread fasteners  

Energy Technology Data Exchange (ETDEWEB)

This document describes a fatigue lifetime acceptance test criterion by which studs having rolled threads, larger than 1.0 inches (25 mm) in diameter, can be assured to meet minimum quality attributes associated with a controlled rolling process.

Kephart, A.R.

1999-05-19

369

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

DEFF Research Database (Denmark)

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 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

Eriksen, Morten; Bech, Jakob Ilsted

2000-01-01

370

Speed reducing gearing mechanism employing trochoidally formed gear surfaces for rolling torque transmission  

Energy Technology Data Exchange (ETDEWEB)

This patent describes a speed reducing transmission, comprising: an input; an output; a stator; an intermediate member between the stator and the output; means for orbitally driving the intermediate member; rolling torque transmitting elements arranged between the intermediate member and the output, and between the intermediate member and the stator. The intermediate member is provided with first and second race members on either side thereof in rolling contact with the rolling elements. The stator is provided with a race member complementary to the confronting race member of the intermediate member and upon which the rolling elements therebetween bear as they roll. The complementary race members are formed with substantially trochoidal curvature such that the rolling elements travel along a substantially trochoidal path. The complementary race members are further formed such that all of the rolling elements disposed therebetween are maintained in substantially constant rolling contact with both of the complementary race members.

Distin, R.; Shaffer, J.

1987-02-17

371

Effect of skin-pass rolling direction on magnetic properties of semiprocessed nonoriented electrical steel sheets  

Energy Technology Data Exchange (ETDEWEB)

Effect of skin-pass rolling direction on magnetic properties and directionality in semiprocessed nonoriented electrical steel sheets produced by skin-pass rolling process was studied. Skin-pass rolling direction greatly affects magnetic properties and directionality. By control of skin-pass rolling direction, the value of B{sub 50} in the required directions such as 0{degree}, 90{degree} and circumferential direction can be adjusted and the value of B{sub 50} is higher than that of the usual skin-pass rolling direction of 0{degree}. The textures of the steel sheets developed after batch annealing varied with the skin-pass rolling directions and this result indicates that the residual strain energy by skin-pass rolling varies with skin-pass rolling directions.

Kurosaki, Y.; Shimazu, T.; Shiozaki, M.

1999-09-01

372

Rheological model for simulation of hot rolling of new generation steel strips for automotive applications  

Energy Technology Data Exchange (ETDEWEB)

The main objective of this paper is the development of a rheological model for automotive steels for the conditions of hot strip rolling and implementation of this model in a finite element program is. Three types of steels were investigated, IF, dual phase and TRIP steel. Plastometric tests were performed on a Gleeble 3800 simulator for the temperature range 850-1200 C and strain rates 3-150 s{sup -1}. Inverse analysis was applied to eliminate the influence of disturbances occurring in the plastometric tests and to determine the real flow stress of the material. The coefficients in the flow stress equation were evaluated and this equation was implemented in the FEM code as the constitutive law. The model was validated by comparison of measured and calculated loads in the compression tests and by strip rolling experiments conducted in the laboratory mill. Validation confirmed a good predictive capability of the rheological model. (orig.)

Hadasik, E.; Adamczyk, M. [Silesian Univ. of Tech., Katowice (Poland); Kuziak, R. [Inst. for Ferrous Metallurgy, Gliwice (Poland); Kawalla, R. [TU-Bergakademie Freiberg (Germany); Pietrzyk, M. [Akademia Gorniczo Hutnicza, Krakow (Poland)

2006-12-15

373

Leavened dough cooking method for baking industry, involves introducing leavened dough rolls inside enclosure to cook leavened dough rolls, and injecting vapor inside enclosure after time period to cook leavened dough rolls  

UK PubMed Central (United Kingdom)

The method involves providing an enclosure (12) presenting a base plate (14), and providing overheated water vapor to inject the vapor inside the enclosure. Leavened dough rolls (26) are introduced inside the enclosure to cook the leavened dough rolls, and are placed in contact with the base plate during determined time period when the dough rolls are introduced inside the enclosure and the water vapor flow inside the enclosure is prohibited. The vapor is injected inside the enclosure after the time period to cook the leavened dough rolls.

SOMMIER ALAIN; ROCCA POLIMENI RICHARD; TRYSTRAM GILLES

374

The preparation of self-supporting metallic targets with rolling  

International Nuclear Information System (INIS)

[en] The Procedure of making metal targets with rolling is described. The technique of preparing soft metal targets of Pb, Sn, In, Al, Au and Ag and the procedure of intermediate annealing for some elements such as Mo, W, Hf, Co and Rh are discussed. The method for controlling and measuring of target thickness is mentioned

1988-01-01

375

Rolling contact fatigue testing of peek based composites  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Rolling contact fatigue phenomenon was investigated on unfilled PEEK and on three different PEEK composites: 10% carbon micro-fiber, graphite and PTFE filled matrix, 30% carbon micro-fiber filled matrix, 30% glass micro-fiber filled matrix. For this aim, roller-shaped specimens were machined fr...

Avanzini A.; Donzella G.; Gallina D.; Pandini S.; Petrogalli C.

376

Improved Ensemble Empirical Mode Decomposition for Rolling Bearing Fault Diagnosis  

Directory of Open Access Journals (Sweden)

Full Text Available Rolling bearing is an important part in mechanical system and faults occur frequently with vibration noise. Empirical mode decomposition (EMD) is a tool for nonlinear and non-stationary signals analysis. However, the major drawbacks of EMD is mode mixing problem, ensemble empirical mode decomposition (EEMD) provides a new tool for signal analysis, and it is an improved technique of EMD. In order to alleviate the mode mixing problem and choose useful IMFs, a method called EEMD and distributing fitting testing is proposed in this paper, and it is used in rolling bearing fault diagnosis. Firstly, using it for rolling bearing fault diagnosis, the fault signal is decomposed by EEMD. Then applying distributing fitting testing to choose components with truly physical meaning and the de-noised signal can be obtained. Finally, utilizing envelope spectrum to distinguish different faults. The results demonstrate the proposed method can sift useful IMFs and diagnose faults effectively, such as inner race fault, outer race fault. The advantage of the proposed method is suitable for rolling bearing diagnosis.

Youpeng Zhang; Ting Zhang; Jie Teng; Hongsheng Su

2013-01-01

377

In-situ conditioning of a strip casting roll  

Science.gov (United States)

A strip caster (10) for producing a continuous strip (24) has a tundish (12) for containing a melt (14) and a pair of horizontally disposed water cooled casting rolls (22). The casting rolls are juxtaposed relative to one another for forming a pouring basin (18) for receiving the melt through a teeming tube (16) thereby establishing a meniscus (20) between the rolls for forming a strip (24). The melt is protected from the outside air by a non-oxidizing gas passed through a supply line (28) to a sealing chamber (26). Devices (29) for conditioning the outer peripheral chill surfaces of the casting rolls includes grit blasting nozzles (30A, 30B, 30C, 30D), a collection trough (32) for gathering the grit, a line (34) for recycling the grit to a bag house (36), a feeder (38) and a pressurized distributor (40) for delivering the grit to the nozzles. The conditioning nozzles remove dirt, metal oxides and surface imperfections providing a clean surface readily wetted by the melt.

Williams, R.S.; Campbell, S.L.

1997-07-29

378

Fatigue Strength and Residual Stress Analysis of Deep Rolled Crankshafts  

Directory of Open Access Journals (Sweden)

Full Text Available The endurance life of an engine crankshaft is closely related to its fatigue strength, in addition to other material properties and shape parameters. Deep rolling, moreover, enhances the fatigue limit by applying compressive residual stress within the fillet radius area as a major surface hardening technique. The objective of this paper isto maximize fatigue life of engine through crankshaft design optimization by quantifying fatigue strength for microalloyed steels versus Cr-Mo alloy steel, and to examine the effects of deep rolling load and rolled fillet geometry. Fatigue tests have been made with standard rotary bending test samples from both bar and forged blanks. Rig tests for actual crankshafts have been made to show how the fatigue strength correlates with different sample types. A correlation of stress distribution with bending moment was demonstrated by applying a strain gauging technique on crankshaft specimens. Therefore, an analysis of combined stresses could be made by considering the effect of static residual stress in addition to the applied dynamic bending stress. Optimum conditions for rolling load, fillet geometry and material were identified. Consequently, these results will be adapted to CAE analysis database to enable an optimization of safety factors.

Imran M Quraishi; Mrs Madhavi S Harne

2012-01-01

379

Acoustic trauma from rock-and-roll music.  

UK PubMed Central (United Kingdom)

Analysis of certain measurements of noise levels and frequency distributions in two rock-and-roll music establishments indicated that this program material can produce temporary auditory threshold shifts and is of an order that has been recognized as entailing risk of permanent ear damage.

Lebo CP; Oliphant KS; Garrett J

1967-11-01

380

Magnetoresistance of rolled-up Fe3Si nanomembranes  

International Nuclear Information System (INIS)

Magnetotransport of individual rolled-up Fe3Si nanomembranes is investigated in a broad temperature range from 4.2 K up to 300 K in pulsed magnetic fields up to 55 T. The observed magnetoresistance (MR) has the following pronounced features: (i) MR is negative in the investigated intervals of temperature and magnetic field; (ii) its magnitude increases linearly with the magnetic field in a low-field region and reveals a gradual trend to saturation when the magnetic field increases; (iii) the MR effect becomes more pronounced with increasing temperature. These dependences of MR on the magnetic field and temperature are in line with predictions of the spin-disorder model of the spin-flip s–d interaction assisted with creation or annihilation of magnons, which is expected above a certain critical temperature. Comparison of the MR features in rolled-up and planar samples reveals a substantial increase of the critical temperature in the rolled-up tube, which is attributed to a new geometry and internal strain arising in the rolled-up nanomembranes, influencing the electronic and magnetic properties of the material. (paper)

2012-06-29

 
 
 
 
381

A survey of potential vectors of apricot chlorotic leaf roll  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A comparative survey was done in leafhopper populations captured in apricot orchards in two areas of Valencia, one with considerable natural spread of apricot chlorotic leaf roll (ACLR), and the other where such natural spread is virtually nonexistent. An identification of the leafhopper species fou...

Llácer Ill, Gerardo; Medina Piles, Vicente; Archelós, Dolores

382

Roll-waves in bi-layer flows  

CERN Multimedia

In this paper, we derive consistent shallow water equations for bi-layer flows of Newtonian fluids flowing down a ramp. We carry out a complete spectral analysis of steady flows in the low frequency regime and show the occurence of hydrodynamic instabilities, so called roll-waves, when steady flows are unstable.

Boutounet, Marc; Vila, Jean-Paul

2011-01-01

383

VNR (b-roll) ICTR-PHE 2012  

CERN Multimedia

Video News Release (B-roll)accompanying the press release announcing the ICTR-PHE 2012 conference (International Conference on Translational Research in Radio-Oncology and Physics for Health in Europe)organized by CERN from Feb 27 to March 2, 2012 at the International Conference Centre Geneva (CICG).

CERN Visual Media Office; Paola Catapano

2012-01-01

384

Deep Drawing of Continuously Cast and Rolled Zinc Sheet.  

Science.gov (United States)

Zinc sheets were deformed by a rotary symmetric deep drawing tool with variable geometry (diameter and radius of die and die plate, drawing gap). Sheets consisted of two continuously rolled ZnCuTi alloys. The effect of holding down drawing speed and lubri...

K. Drefahl H. J. Henrich A. Stradmann

1983-01-01

385

Precision and accuracy of the subjective haptic vertical in the roll plane  

Digital Repository Infrastructure Vision for European Research (DRIVER)

ABSTRACT: BACKGROUND: When roll-tilted, the subjective visual vertical (SVV) deviates up to 40degrees from earth-vertical and trial-to-trial variability increases with head roll. Imperfections in the central processing of visual information were postulated to explain these roll-angle dependent error...

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

386

Inflationary Hubble Parameter from the Gravitational Wave Spectrum in the General Slow-roll Approximation  

CERN Multimedia

Improved general slow-roll formulae giving the primordial gravitational wave spectrum are derived in the present work. Also the first and second order general slow-roll inverse formulae giving the Hubble parameter $H$ in terms of the gravitational wave spectrum are derived. Moreover, the general slow-roll consistency condition relating the scalar and tensor spectra is obtained.

Joy, Minu

2007-01-01

387

The model of laminar pulsatile flow in tubes in rolling motion  

International Nuclear Information System (INIS)

[en] The laminar pulsatile flow in tubes in rolling motion is investigated theoretically. The theoretical model of laminar flow in rolling motion is developed and the velocity correlation is also derived. The effect of rolling motion on velocity and frictional resistance factor is analyzed. The rolling motion mainly affects on the laminar flow by the tangential force. The centrifugal force does not affect on the flow. The tangential force affects on the flow in axial direction, its radial effect is very weak and could be omitted. There are two critical rolling points in rolling motion. After the first critical rolling point, the flowing velocity next to the wall reverses. Moreover, the flow rate at the tube cross-section becomes negative after the second critical rolling point. The buoyancy force is only one part of the effects that affects on the average velocity of a natural circulation system in rolling motion. The effect of Womersley number on the velocity is significant, which can not only affect on the average velocity but also on the oscillating period and velocity amplitude. The rolling motion does not affect on the average frictional resistance of laminar pulsatile flow. If the rolling motion is very serious, the flow is at a transitional or turbulent flow state, in this case the effect of rolling motion on the average frictional resistance is considerable.

2008-10-01

388

Development of an O/W emulsion with high viscosity and fine droplet size in cold rolling of stainless steels; Konendo bisairyukeigata stainless yo reikanatsuenyu no kaihatsu  

Energy Technology Data Exchange (ETDEWEB)

For a steel kind required to high surface gloss which is representative of stainless steel sheet, the development of rolling oil to make possible to obtain high surface gross even under the rolling condition of large diameter roller and to protect heat scratch formation in high speed rolling was conducted. When the production of rolling oil using tandem mills, it is necessary to reduce the amount of bring in oil under a condition of high speed rolling using large diameter roller. However, with the decrease of the amount of bring in oil, interfacial temperature on a roll bite increases, and heat scratch is apt to occur. In this study, a high viscosity and fine droplet size emulsion oil was proposed for the rolling oil fulfil these conflicting requirements. It is on a base of a concept to make to reduce the amount of bring in oil by the comminution of emulsion particle size and to secure the oil film strength in a wide range by the viscosity increase of base oil, and was confirmed the effectiveness in a laboratory experiment as well as in actual tandem mills machine. 15 refs., 8 figs., 4 tabs.

Kimura, Y.; Masuda, S.; Miyake, M. [NKK Corp., Yamaguchi (Japan). Materials and Processing Research Center; Yagi, R.; Mihara, Y. [NKK Corp., Tokyo (Japan); Yamakawa, M. [Nippon Quaker Chemical, Osaka (Japan)

1998-03-01

389

Pitch, roll, and yaw variations in patient positioning  

International Nuclear Information System (INIS)

Purpose: To use pretreatment megavoltage-computed tomography (MVCT) scans to evaluate positioning variations in pitch, roll, and yaw for patients treated with helical tomotherapy. Methods and Materials: Twenty prostate and 15 head-and-neck cancer patients were selected. Pretreatment MVCT scans were performed before every treatment fraction and automatically registered to planning kilovoltage CT (KVCT) scans by bony landmarks. Image registration data were used to adjust patient setups before treatment. Corrections for pitch, roll, and yaw were recorded after bone registration, and data from fractions 1-5 and 16-20 were used to analyze mean rotational corrections. Results: For prostate patients, the means and standard deviations (in degrees) for pitch, roll, and yaw corrections were -0.60 ± 1.42, 0.66 ± 1.22, and -0.33 ± 0.83. In head-and-neck patients, the means and standard deviations (in degrees) were -0.24 ± 1.19, -0.12 ± 1.53, and 0.25 ± 1.42 for pitch, roll, and yaw, respectively. No significant difference in rotational variations was observed between Weeks 1 and 4 of treatment. Head-and-neck patients had significantly smaller pitch variation, but significantly larger yaw variation, than prostate patients. No difference was found in roll corrections between the two groups. Overall, 96.6% of the rotational corrections were less than 4 deg. Conclusions: The initial rotational setup errors for prostate and head-and-neck patients were all small in magnitude, statistically significant, but did not vary considerably during the course of radiotherapy. The data are relevant to couch hardware design for correcting rotational setup variations. There should be no theoretical difference between these data and data collected using cone beam KVCT on conventional linacs.

2006-11-01

390

Dynamics of in silico leukocyte rolling, activation, and adhesion  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background We present a multilevel, agent based, in silico model that represents the dynamics of rolling, activation, and adhesion of individual leukocytes in vitro. Object-oriented software components were designed, verified, plugged together, and then operated in ways that represent the molecular and cellular mechanisms believed responsible for leukocyte rolling and adhesion. The result is an in silico analogue of an experimental in vitro system. The experimentally measured, phenotypic attributes of the analogue were compared and contrasted to those of leukocytes in vitro from three different experimental conditions. Results The individual in silico dynamics of "rolling" on simulated P-selectin, and separately on simulated VCAM-1, were an acceptable match to individual in vitro distance-time and velocity-time measurements. The analogues are also able to represent the transition from rolling to adhesion on P-selectin and VCAM-1 in the presence of GRO-? chemokine. The individual in silico and in vitro behavioral similarities translated successfully to population level measures. These behavioral similarities were enabled in part by subdividing the functionality of the analogue's surface into 600 independent, "cell"-controlled, equally capable modules of comparable functionality. Conclusion The overlap in phenotypic attributes of our analogue with those of leukocytes in vitro confirm the considerable potential of our model for studying the key events that determine the behavioral outcome of individual leukocytes during rolling, activation, and adhesion. Our results provide an important foundation and framework for future in silico research into plausible causal links between well-documented, subcellular molecular level events and the variety of systemic phenotypic attributes that distinguish normal leukocyte adhesion from abnormal disease-associated adhesion.

Tang Jonathan; Ley Klaus F; Hunt C Anthony

2007-01-01

391

Analysis of market possibilities for development of pipe-rolling production on PJSC «Sumy Frunze MNPO»  

Directory of Open Access Journals (Sweden)

Full Text Available The aim of the article. The aim of this article is analysis and evaluation of market opportunities and the potential of innovative development of Public Joint Stock Company Sumy Frunze Machine-Building Science-and-Production Association, concerning to the production and upgrading of cold-rolling of the tubes with the incomplete certainty of the environment.The results of the analysis. The results of the analysis show that in recent years there is the need to increase services for modernization of cold-rolling tubes in markets of foreign countries. Main factors that contribute to the intensive development and growth of the world market for the modernization of cold-rolling tubes are revealed.It is substantiated that 543 rolling mills, which were produced in the countries of the former Soviet republics, have to be modernized. Their total mass is estimated of 4090-10895 tons. Considering the prices of modernization services which are calculated by weight, market capacity in value terms makes $49,08-130,74 million. About 75% of this capacity is the markets of the former Soviet republics.Their tube companies cannot get new mills so they will upgrade existing ones, because of the unstable financial situation.It is revealed that despite the economic crisis, in the market of production of new pipe-rolling mills their sales are growing in China, India, South Korea and Japan. Also growth of sales of the unique specialized pipe-rolling equipment is observed. Potential consumers of new rolling mills concrete enterprises of the foreign and neighboring countries are defined.The comparative analysis of main producers of new rolling mills, and also services in modernization of the available ones is carried out. As the result, their strengths, weaknesses and prospects of development in the market are defined.The authors made the analysis of market opportunities of innovative development ofPJSC Sumy Frunze MNPO in the market of production and modernization of mills of cold rolling of pipes. The analysis was made with consecutive specification of market prospects ofPJSC Sumy Frunze MNPO. Methods of SWOT-analysis, PEST-analysis and SNW-analysis were used. Features formation of the innovative strategy development of PJSC are defined as result of the analysis. They will allow to get the balance between external and internal possibilities of development and to increase chances of PJSC to reach the success.The main external (of direct and indirect action) and internal risk factors of the innovative project of production and modernization of cold-rolling pipes are revealed. The quantitative assessment of extent of their influence is executed with the method of expert evaluations. It is established that at this combination of factors the enterprise is in zone of the increased risk, generally because owing to adverse influence of external factors.The assessment of financial stability of innovative project showed its absolute stability and absence of investment risk, generally because of alleged financing of the project only at the expense of own means of PJSC.The identified multiple-factor quantitative assessment of risk allowed establishing value termsof possible losses (for separate stages and for innovative project as a whole) at worst-case scenarios. Comparison of possible losses (taking into account probability of their emergence) with the expected income of the project and PJSC as a whole testifies about the acceptable size of risk (even for the pessimistic type of behavior of the person making the decision) at implementation of the innovative project of production and modernization of cold-rolling of pipes.Detailed analysis of innovative development potential of PJSC (including the analysis of its separate components: market, innovative, production and marketing potentials) concerning production and modernization of pipe-rolling camps which testifies about high chances of implementation of the considered innovative project is made.The received results testify about high chances of realization of one of the most perspecti

P.M. Bolharyn; S.M. Illiashenko

2013-01-01

392

Pechiney Rolled Products: Plant-Wide Energy Assessment Identifies Opportunities to Optimize Aluminum Casting and Rolling Operations  

Energy Technology Data Exchange (ETDEWEB)

A Pechiney Rolled Products plant focused on various aluminum casting processes during a PWA. The assessment revealed potential annual savings of 460,000 MMBtu in natural gas, 9.6 million kWh in electricity, 69 million pounds in CO2, and $2.5 million.

2004-07-01

393

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

Science.gov (United States)

...Steel Products From Brazil, Japan, and Russia Determinations On the basis of the record...flat-rolled carbon-quality steel products from Russia would be likely to lead to continuation...Steel Products from Brazil, Japan, and Russia: Investigation Nos. 701-TA-384...

2011-06-10

394

Waveguide slot-excited long racetrack electron cyclotron resonance plasma source for roll-to-roll (scanning) processing  

Science.gov (United States)

We present a SLot-excited ANtenna (SLAN) long racetrack ECR plasma source that is utilized for roll-to-roll plasma processing such as thin film encapsulation of large-area OLED (organic light emitting diode) panel or modification of fabric surfaces. This source is designed to be long, and to operate under high density uniform plasma with sub-milli-torr pressures. The above features are accomplished by a slot-excited long racetrack resonator with a toroidal geometry of magnetic field ECR configuration, and reinforced microwave electric distributions along the central region of plasma chamber. Also, a new feature has been added to the source. This is to employ a tail plunger, which allows the microwave electric field and the uniformity of the plasma profile to be easily adjustable. We have successfully generated Ar plasmas operating with the microwave power of 0.5-3 kW in the pressure range of 0.2-10 mTorr. The plasma is uniform (<10%) in the direction of the straight track and has a Gaussian profile in the roll-to-roll (scanning) direction. In addition, it is shown that the tail plunger could adjust the plasma profile in order to obtain plasma uniformity. Furthermore, based on the results, we suggest a newly designed up-scaled racetrack-SLAN source.

You, H.-J.

2013-07-01

395

Design of roll-to-roll printing equipment with multiple printing methods for multi-layer printing  

Science.gov (United States)

In this paper, a novel design concept for roll-to-roll printing equipment used for manufacturing printed electronic devices by multi-layer printing is presented. The roll-to-roll printing system mainly consists of printing units for patterning the circuits, tension control components such as feeders, dancers, load cells, register measurement and control units, and the drying units. It has three printing units which allow switching among the gravure, gravure-offset, and flexo printing methods by changing the web path and the placements of the cylinders. Therefore, depending on the application devices and the corresponding inks used, each printing unit can be easily adjusted to the required printing method. The appropriate printing method can be chosen depending on the desired printing properties such as thickness, roughness, and printing quality. To provide an example of the application of the designed printing equipment, we present the results of printing tests showing the variations in the printing properties of the ink for different printing methods.

Kim, Chung Hwan; Jo, Jeongdai; Lee, Seung-Hyun

2012-06-01

396

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

DEFF Research Database (Denmark)

Synchrotron-based X-rays were used to probe active materials for polymer solar cells on flexible polyester foil. The active material was coated onto a flexible 130 micron thick polyester foil using roll-to-roll differentially pumped slot-die coating and presented variation in composition, thickness, and additives. The coated foil was passed through a synchrotron X-ray beam on a small unit comprising unwinder and winder for the foil, an X-ray probe station, and a barcode reader for sample registration. Foil lengths of 10 meters were probed and yielded X-ray scattering data for approximately every 1 cm, probing linear variations in processing and coating parameters along the foil. The demonstration shows that real-time structural characterization of roll-to-roll coating at realistic web-speeds is feasible using synchrotron radiation. Off-line characterization with lower spatial resolution would be possible with dedicated laboratory instruments. We found that poly(3-hexyl)thiophene (P3HT) only crystallizes at a ratio above 1 : 2 with phenyl-C61-butyric acid methyl ester (PCBM) and that an optimum addition of 2 vol% chloronaphthalene (CN) as a processing additive significantly improves polymer crystallinity and crystallite size. In coated films thinner than 275 nm, textured poly(3-hexyl)thiophene crystallites with the lamellar stack aligned with the substrate dominate, similar to what is observed for spin-coated films.

Böttiger, Arvid P.L.; JØrgensen, Mikkel

2012-01-01

397

Waveguide slot-excited long racetrack electron cyclotron resonance plasma source for roll-to-roll (scanning) processing.  

Science.gov (United States)

We present a SLot-excited ANtenna (SLAN) long racetrack ECR plasma source that is utilized for roll-to-roll plasma processing such as thin film encapsulation of large-area OLED (organic light emitting diode) panel or modification of fabric surfaces. This source is designed to be long, and to operate under high density uniform plasma with sub-milli-torr pressures. The above features are accomplished by a slot-excited long racetrack resonator with a toroidal geometry of magnetic field ECR configuration, and reinforced microwave electric distributions along the central region of plasma chamber. Also, a new feature has been added to the source. This is to employ a tail plunger, which allows the microwave electric field and the uniformity of the plasma profile to be easily adjustable. We have successfully generated Ar plasmas operating with the microwave power of 0.5-3 kW in the pressure range of 0.2-10 mTorr. The plasma is uniform (<10%) in the direction of the straight track and has a Gaussian profile in the roll-to-roll (scanning) direction. In addition, it is shown that the tail plunger could adjust the plasma profile in order to obtain plasma uniformity. Furthermore, based on the results, we suggest a newly designed up-scaled racetrack-SLAN source. PMID:23902069

You, H-J

2013-07-01

398

Waveguide slot-excited long racetrack electron cyclotron resonance plasma source for roll-to-roll (scanning) processing.  

UK PubMed Central (United Kingdom)

We present a SLot-excited ANtenna (SLAN) long racetrack ECR plasma source that is utilized for roll-to-roll plasma processing such as thin film encapsulation of large-area OLED (organic light emitting diode) panel or modification of fabric surfaces. This source is designed to be long, and to operate under high density uniform plasma with sub-milli-torr pressures. The above features are accomplished by a slot-excited long racetrack resonator with a toroidal geometry of magnetic field ECR configuration, and reinforced microwave electric distributions along the central region of plasma chamber. Also, a new feature has been added to the source. This is to employ a tail plunger, which allows the microwave electric field and the uniformity of the plasma profile to be easily adjustable. We have successfully generated Ar plasmas operating with the microwave power of 0.5-3 kW in the pressure range of 0.2-10 mTorr. The plasma is uniform (<10%) in the direction of the straight track and has a Gaussian profile in the roll-to-roll (scanning) direction. In addition, it is shown that the tail plunger could adjust the plasma profile in order to obtain plasma uniformity. Furthermore, based on the results, we suggest a newly designed up-scaled racetrack-SLAN source.

You HJ

2013-07-01

399

Design of roll-to-roll printing equipment with multiple printing methods for multi-layer printing.  

UK PubMed Central (United Kingdom)

In this paper, a novel design concept for roll-to-roll printing equipment used for manufacturing printed electronic devices by multi-layer printing is presented. The roll-to-roll printing system mainly consists of printing units for patterning the circuits, tension control components such as feeders, dancers, load cells, register measurement and control units, and the drying units. It has three printing units which allow switching among the gravure, gravure-offset, and flexo printing methods by changing the web path and the placements of the cylinders. Therefore, depending on the application devices and the corresponding inks used, each printing unit can be easily adjusted to the required printing method. The appropriate printing method can be chosen depending on the desired printing properties such as thickness, roughness, and printing quality. To provide an example of the application of the designed printing equipment, we present the results of printing tests showing the variations in the printing properties of the ink for different printing methods.

Kim CH; Jo J; Lee SH

2012-06-01

400

On the Feasibility of Stabilizing Parametric Roll with Active Bifurcation Control  

DEFF Research Database (Denmark)

When parametric resonance occurs on a ship, large roll motion develops rapidly and severe damage on cargo is likely. Some vessels have even capsized in moderate seas for reasons believed to be parametric resonance. This paper revisits the analysis of parametric resonance and assess the possibility to dynamically modify the instability region where parametric roll can occur. It is shown how a control strategy for roll stabilization could be modi…ed to change a bifurcation in roll motion and stabilize the motion, even after parametric resonance has started. The paper addresses issues of achievable performance and demonstrates the approach on a yaw-sway-roll-surge model of a containership.

Galeazzi, Roberto; Blanke, Mogens

2007-01-01

 
 
 
 
401

Theoretical research on flowing characteristics in rolling motion with fractional Maxwell model  

International Nuclear Information System (INIS)

The flowing characteristics of the flow with no initial velocity in a tube in rolling motion are investigated theoretically, with the fractional Maxwell method. The velocity in rolling motion is derived. The effect of rolling motion on the flowing velocity of Newtonian fluids and Non-Newtonian fluids is analyzed. The variation of peak velocity and velocity gradient in the wall is also investigated. Compared with the non-Newtonian fluid, the effect of rolling motion on Newtonian fluid is more averaged. The oscillation of velocity gradient at the wall is similar to that of velocity. And their oscillation period is half of the rolling period. (authors)

2010-01-01

402

Theoretical peculiarities regarding the definition and representation of the rolling surfaces  

Directory of Open Access Journals (Sweden)

Full Text Available This paper presents the matrix-vector calculus of the rolling surfaces of a bevel worm gear with inverted conicity. By this gear the worm gear is situated on the inner side of the crown taper. It is to remark that in this case both rolling surfaces cannot be tangent. Keeping the worm’s rolling surface conical, it is necessary to calculate the profile of the crown’s rolling surface that becomes a hyperboloid. Using a numerical approach, the best approximating cone of the crown wheel’s rolling surface will be calculated.

Bogdan Bucur; Márton Máté

2011-01-01

403

Stabilization of Parametric Roll Resonance with Active U-Tanks via Lyapunov Control Design  

DEFF Research Database (Denmark)

Parametric ship roll resonance is a phenomenon where a ship can rapidly develop high roll motion while sailing in longitudinal waves. This effect can be described mathematically by periodic changes of the parameters of the equations of motion, which lead to a bifurcation. In this paper, the control design of an active u-tank stabilizer is carried out using Lyapunov theory. A nonlinear backstepping controller is developed to provide global exponential stability of roll. An extension of commonly used u-tank models is presented to account for large roll angles, and the control design is tested via simulation on a high-fidelity model of a vessel under parametric roll resonance.

Holden, Christian; Galeazzi, Roberto

2009-01-01

404

Development and verification of variogram models in roll front type uranium deposits  

International Nuclear Information System (INIS)

This paper illustrates the application of geostatistics to a roll front type uranium deposit located in Wyoming. The steps involved in calculation of experimental variograms, variogram modeling, and verification of the resulting models are described in detail. The resulting spherical variogram models for grade thickness and thickness show strong geometrical anisotropies. The major axis of anisotropy for both variables is approximately parallel to the axis of the roll front and the minor axis perpendicular to the roll. This model confirms the technique of drilling ''fences'' across the roll front, where the drilling is much closer together than the fences along the roll. 9 refs

1979-01-01

405

3104????????????????? A Earing Control Method for 3104 Aluminum Alloy Sheet through Cold Rolling Texture Modification  

Directory of Open Access Journals (Sweden)

Full Text Available 3104?????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????The earing of the deep drawing 3104 aluminum alloy depends on the texture of the sheet. This re-search found that increasing the number of rolling passes in the first cold rolling can enhance the intensity of the cold rolling texture components. After annealing, the strong cold rolling texture form the strong recrystal-lization texture. This strong recrystallization texture is largely retained after the finishing cold rolling, which effectively lowers the anisotropy of the alloy and finally reduces the earing tendency.

???; ???; ??; ??

2011-01-01

406

Roller compaction process development and scale up using Johanson model calibrated with instrumented roll data.  

UK PubMed Central (United Kingdom)

Roller compaction is a dry granulation process used to convert powder blends into free flowing agglomerates. During scale up or transfer of roller compaction process, it is critical to maintain comparable ribbon densities at each scale in order to achieve similar tensile strengths and subsequently similar particle size distribution of milled material. Similar ribbon densities can be reached by maintaining analogous normal stress applied by the rolls on ribbon for a given gap between rolls. Johanson (1965) developed a model to predict normal stress based on material properties and roll diameter. However, the practical application of Johanson model to estimate normal stress on the ribbon is limited due to its requirement of accurate estimate of nip pressure i.e. pressure at the nip angle. Another weakness of Johanson model is the assumption of a fixed angle of wall friction that leads to use of a fixed nip angle in the model. To overcome the above mentioned limitations, we developed a novel approach using roll force equations based on a modified Johanson model in which the requirement of pressure value at nip angle was eliminated. An instrumented roll on WP120 roller compactor was used to collect normal stress data measured at three locations across the width of a roll (P1, P2, P3), as well as gap and nip angle data on ribbon for placebo and various active blends along with corresponding process parameters. The nip angles were estimated directly using experimental pressure profile data of each run. The roll force equation of Johanson model was validated using normal stress, gap, and nip angle data of the placebo runs. The calculated roll force values compared well with those determined from the roll force equation provided for the Alexanderwerk(®) WP120 roller compactor. Subsequently, the calculation was reversed to estimate normal stress and corresponding ribbon densities as a function of gap and RFU (roll force per unit roll width). A placebo model was developed and calibrated using a subset of placebo run data obtained on WP120. The roll force values were calculated using vendor supplied equation. The nip angle was expressed as a function of gap and RFU. The nip angle, gap and RFU were used in a new roll force equation to estimate normal stress P2 at the center of the ribbon. Using ratios P1/P2 and P3/P2 from the calibration data set, P1 and P2 were estimated. The ribbon width over which P1, P2, and P3 are effective was determined by minimizing sum square error between the model predicted vs. experimental ribbon densities of the calibration set. The model predicted ribbon densities of the placebo runs compared well with the experimental data. The placebo model also predicted with reasonable accuracy the ribbon densities of active A, B, and C blends prepared at various combinations of process parameters. The placebo model was then used to calculate scale up parameters from WP120 to WP200 roller compactor. While WP120 has a single screw speed, WP200 is equipped with a twin feed screw system. A limited number of roller compaction runs on WP200 was used as a calibration set to determine normal stress profile across ribbon width. The nip angle equation derived from instrumented roll data collected on WP120 was applied to estimate nip angles on WP200 at various processing conditions. The roll force values calculated from vendor supplied equation and the nip angle values were used in roll force equation to estimate normal stress P2 at the tip of the feed screws. Based on feed screw design, it was assumed that the normal stress at the center of the ribbon was equal to those calculated at the tip of the feed screws. The ratio of normal stress at the edge of the ribbon Pe to the normal stress P2 at the feed screw tip was optimized to minimize sum square error between model predicted vs. experimental ribbon densities of the calibration set. The model predicted ribbon densities of the batches prepared on WP200 compared well with the experimental data thus indicating success of the scale up procedure. For the demonstration purpose,

Nesarikar VV; Patel C; Early W; Vatsaraj N; Sprockel O; Jerzweski R

2012-10-01

407

Study on the natural circulation characteristics of a marine reactor during rolling motion  

Energy Technology Data Exchange (ETDEWEB)

A series of natural circulation tests with a physical model of a marine reactor mounted on a rolling apparatus were performed in order to clarify the natural circulation characteristics during rolling motion. Prior to the test, two types of preliminary tests were conducted to investigate two factors, natural circulation driving force and cyclic acceleration change derived from rolling motion, which affect on the thermohydraulic behavior of the natural circulation during rolling motion. It was observed that the flow rates at hot legs and cold legs fluctuate with the change of rolling angle. The manners of these flow rate fluctuations change with the rolling period. It was found that the loop flow rate fluctuations are mainly caused by the acceleration change due to rolling motion. The core flow rate does not change with time, while it changes with the rolling period. Its change is well correlated with the Reynolds number for rolling motion. A simple analytical model was proposed, and the numerical calculation was performed. The computed result agrees well with the experimental result, and it was verified that the change of the core flow rate with rolling period is induced by the change of the natural circulation driving force and flow resistance due to rolling motion. (author).

Murata, Hiroyuki; Kobayashi, Michiyuki

1989-01-01

408

Design And Development Of Roll Cage For An All-Terrain Vehicle  

Directory of Open Access Journals (Sweden)

Full Text Available The study aims to design, develop and fabricate a roll cage for an All-Terrain Vehicle (ATV) in accordance with the rulebook of BAJA 2013 given by SAE. A roll cage is a skeleton of an ATV. The roll cage not only forms the structural base but also a 3-D shell surrounding the occupant which protects the occupant in case of impact and roll over incidents. The roll cage also adds to the aesthetics of a vehicle. The design and development comprises of material selection, chassis and frame design, cross section determination, determining strength requirements of roll cage, stress analysis and simulations to test the ATV against failure. Finally the roll cage is fabricated as per the tools and techniques available in the workshop.

Khelan Chaudhari; Amogh Joshi; Ranjit Kunte; Kushal Nair

2013-01-01

409

Lattice Boltzmann Simulation of Blood Flow in Blood Vessels with the Rolling Massage  

Science.gov (United States)

The rolling massage manipulation is a classic Chinese massage, which is expected to improve the circulation by pushing, pulling and kneading of the muscle. A model for the rolling massage manipulation is proposed and the lattice Boltzmann method is applied to study the blood flow in the blood vessels. The simulation results show that the blood flux is considerably modified by the rolling massage and the explicit value depends on the rolling frequency, the rolling depth, and the diameter of the vessel. The smaller the diameter of the blood vessel, the larger the enhancement of the blood flux by the rolling massage. The model, together with the simulation results, is expected to be helpful to understand the mechanism and further development of rolling massage techniques.

Yi, Hou-Hui; Xu, Shi-Xiong; Qian, Yue-Hong; Fang, Hai-Ping

2005-12-01

410

Effect of niobium and rolling parameters on the mechanical properties and microstructure of dual phase steels  

International Nuclear Information System (INIS)

[en] In this study, the effect of hot rolling parameters such as reduction percentage, rolling and coiling temperature on the microstructure and mechanical properties of dual phase (DP) steels with and without niobium was investigated. Melting process was carried out in an induction furnace. The casted products were forged and homogenized before rolling process. Three different reduction percentages (i.e., 15, 30 and 50%), two different rolling temperatures (950 and 850 deg. C) and two coiling temperatures (550 and 400 deg. C) were used. The results showed that rolling in dual phase region and coiling at low temperature led to the elongated grains in the rolling direction. Such elongated grains were not observed as coiling temperature increased. At a constant rolling and coiling temperature, increasing the reduction percentage increased the yield and tensile strength and decreased the total elongation. Additionally, specimens containing Nb had greater yield and tensile strength, higher martensite fraction, and lower elongation and ferrite grain size.

2010-08-20

411

Nonlinear Rudder-Roll Damping Of Non-Minimum Phase Ships Using Sliding Mode Control  

UK PubMed Central (United Kingdom)

A non-minimum phase nonlinear ship model from rudderangle to roll angle is used to design a stable controllerfor simultaneous roll damping and course keeping. Thecontroller is stable in presence of 1st-order wave disturbancesand modeling errors provided that the magnitudeof the model errors and disturbances are known. Stabilityis proved using Lyapunov theory. The simulation resultsshow excellent performance and robustness.1 IntroductionBesides controlling the heading of a ship it is often desirableto reduce the wave-induced roll motion. The mainreasons for introducing a roll damping system are to preventcargo damage and to increase crew effectiveness andpassenger comfort. Criteria for the maximum roll angleare given in [4], and they suggest that the root meansquare of the roll angle should be less than 6 degrees forlight manual work and 3 degrees for intellectual work.There are several approaches that can be used to reducethe roll motion, e.g. bilge keels, anti-rolli...

Trygve Lauvdal; Thor I. Fossen

412

Effects of production parameters on characteristics of magnesium alloy sheets manufactured by twin-roll casting  

Directory of Open Access Journals (Sweden)

Full Text Available Purpose: : The purpose of the work is to establish a manufacturing process and technology to facilitate the economical manufacture of high-quality magnesium sheet alloys.Design/methodology/approach: Magnesium alloy AZ31B was used to investigate the appropriate manufacturing conditions for use in twin-roll strip casting. Temperatures of the molten materials and roll speeds were varied to find the appropriate manufacturing conditions. The effects of manufacturing conditions on possible forming were clarified in terms of roll speeds and roll gaps between upper and lower rolls.Findings: In the hot-rolling process, a temperature exceeding 200°C was chosen to keep cast products from cracking. An appropriate annealing temperature was effective for homogenizing the microstructure of the rolled cast sheets after the strip casting process. The grain size of the manufactured wrought magnesium alloys sheet was less than 10 micrometers. The obtained magnesium alloy sheet exhibited an equivalent limiting drawing ratio in a warm-drawing test.Research limitations/implications: AZ31 were used to investigate the appropriate manufacturing conditions for use in twin-roll strip casting. Casting temperatures were varied from 630°C to 670°C to find the best casting conditions. Roll casting speeds were varied from 5m/min to 30 m/min in order to examine which roll speed was appropriate for solidifying the molten magnesium.Practical implications: It was found that the cast magnesium sheet manufactured by roll strip casting could be used for plastic forming if the appropriate magnesium sheets were produced after the roll casting process.Originality/value: This paper showed the effectiveness of twin roll casting for magnesium alloys by a horizontal roll caster.

H. Watari; T. Haga; K. Davey; N. Koga; T. Yamazaki

2006-01-01

413

Modelling the microstructural evolution during hot rolling  

Directory of Open Access Journals (Sweden)

Full Text Available A metallurgical model that describes the microstructural evolution of C-Mn steels in the hot strip mill, and that predicts the yield strength and the ultimate tensile strength based on the steel chemistry and the processing conditions is presented. The model comprises the microstructural evolution during hot deformation in the austenitic range (taking into account the effects recrystallization and grain growth), and the austenite decomposition during cooling (formation of ferrite, perlite and/or bainite). A comparison between calculated and measured yield strength and ultimate tensile strength values for several steels and processing conditions is also included.

G.R. Gómez; T. Pérez

2002-01-01

414

Modelling the microstructural evolution during hot rolling  

Scientific Electronic Library Online (English)

Full Text Available Abstract in english A metallurgical model that describes the microstructural evolution of C-Mn steels in the hot strip mill, and that predicts the yield strength and the ultimate tensile strength based on the steel chemistry and the processing conditions is presented. The model comprises the microstructural evolution during hot deformation in the austenitic range (taking into account the effects recrystallization and grain growth), and the austenite decomposition during cooling (formation of (more) ferrite, perlite and/or bainite). A comparison between calculated and measured yield strength and ultimate tensile strength values for several steels and processing conditions is also included.

Gómez, G.R.; Pérez, T.

2002-07-01

415

Effect of surface rolling on fatigue strength as influenced by the strain hardening rate  

Energy Technology Data Exchange (ETDEWEB)

In this study, the authors examine the role of strain hardening during surface rolling and its effect on the direct stress fatigue strength. A thermomechanically mill treated (TMT) high strength low alloy (HSLA) steel with the weight percent alloy composition of: 0.10 C, 1.55 Mn, 0.014 P, 0.006 S, 0.27 Si, 0.040 Nb, 0.035 V, and 0.034 Al was selected and its strain hardening characteristics were manipulated by intercritically annealing in the dual phase (DP) region. This produced two steels with the same composition but different microstructures and strain hardening characteristics as follows: the TMT steel having a high yield strength and a low strain hardening rate, and the DP steel having a low yield strength and a high rate of strain hardening. After characterizing the mechanical properties of both steels, the authors quantified the surface rolling process using penetration depth of work hardening and magnitude of the compressive surface residual stress. Noting that yield strength can be a strong indicator of fatigue strength, the authors then investigated whether the low yield strength DP steel when compensated with a high strain hardening rate could achieve a greater increase in fatigue strength because of surface rolling in comparison to that of the high yield strength TMT steel.

Rebinsky, D.A.; Vitovec, F.H. (Univ. of Alberta, Edmonton, Alberta (Canada). Dept. of Mechanical Engineering)

1994-02-15

416

Effect of cold rolling and annealing on mechanical properties of HSLA steel  

Directory of Open Access Journals (Sweden)

Full Text Available Purpose: was to examine effect of the parameters of cold deformation and recrystallization annealing on mechanical properties of a Nb-microalloyed HSLA steel.Design/methodology/approach: Research of strip steel QStE 420 was based on a combination of laboratory cold rolling, recrystallization annealing in vacuum furnace, mechanical (particularly tensile) tests and metallographic analyses.Findings: It was validated that by a sophisticated combination of size of previous cold reduction size and parameters of the following annealing it is possible to impact markedly a set of final properties of particular strips. Formability of the studied HSLA steel rises and vice versa strength properties fall with an increasing temperature of annealing.Research limitations/implications: The experiment should be supplemented by additional TEM analyses explaining the behaviour and role of precipitates.Practical implications: The experimentally obtained particular trends of mechanical properties may be utilized for optimization of conditions of heat treatment of the investigated HLSA steel in a cold strip rolling mill, reflecting the specific requirements for a relation between strength and plastic properties.Originality/value: Experimental potentialities of the Institute of Modelling and Control of Forming Processes in the sphere of cold rolling and heat treatment were introduced in their integrity for the first time.

I. Schindler; M. Janošec; E. Místecký; M. R?ži?ka; ??ižek; L.A. Dobrza?ski; S. Rusz; P. Suchánek

2009-01-01

417

Experimental testing of the double-roll crusher for breaking silicon carbide coatings on unirradiated Ft. St. Vrain fuel particles  

International Nuclear Information System (INIS)

Testing of a 4-inch diameter double-roll crusher for crushing Ft. St. Vrain TRISO particles has been completed. The effect of feed rate, roll speed, roll clearance, and carbon particle interference on crushing efficiency and crushed particle size distribution was determined. Wear rates of the rolls were not determined. (U.S.)

1975-01-01

418

Evaluation of the Frictional Characteristics of Rolling Emulsions  

Directory of Open Access Journals (Sweden)

Full Text Available A series of ring compression tests were carried out in samples machined from hot- rolled steel slabs to determine the frictional characteristics of various emulsions used for lubrication in cold rolling of steel strip; additional tests were conducted without lubrication or using polytetrafluorethylene (PTFE) tape. The material was tested at different velocities in a servo-hydraulic computer driven testing machine. The friction factor (m) was evaluated from the dimensional change of the ring samples. It was found that the increase of testing speed produces a reduction in the value of m in liquid lubricants; m was found to be independent of speed when testing without lubrication or with PTFE tape.

Vicente Espinoza-Cantú; Martha P. Guerrero-Mata; Tomás Lozano; Rafael Colás

2008-01-01

419

Press and Dryer Roll Surfaces and Web Transfer Systems  

Energy Technology Data Exchange (ETDEWEB)

The objective of the project is to provide fundamental knowledge and diagnostic tools needed to design new technologies that will allow ultra high speed web transfer from press rolls and dryer cylinders. From a fundamental standpoint, we expect that roll surface performance depends on the composition of contaminants that deposit on those surfaces during use, as well as the materials and finishing techniques used in manufacturing these surfaces. We need to understand; the contamination process, the influence of contamination on work of adhesion, the roles of surface topology, film splitting, and process conditions on web transfer. The purpose of this quarterly report is to provide an overview of the project including key tasks, schedules for completion of tasks and to document accomplishments.

Patterson, T.F.

2000-05-01

420