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Sample records for steel catenary risers

  1. Cross-flow VIV-induced fatigue damage of deepwater steel catenary riser at touch-down point

    NASA Astrophysics Data System (ADS)

    Wang, Kun-peng; Tang, Wen-yong; Xue, Hong-xiang

    2014-03-01

    A prediction model of the deepwater steel catenary riser VIV is proposed based on the forced oscillation test data, taking into account the riser-seafloor interaction for the cross-flow VIV-induced fatigue damage at touch-down point (TDP). The model will give more reasonable simulation of SCR response near TDP than the previous pinned truncation model. In the present model, the hysteretic riser-soil interaction model is simplified as the linear spring and damper to simulate the seafloor, and the damping is obtained according to the dissipative power during one periodic riser-soil interaction. In order to validate the model, the comparison with the field measurement and the results predicted by Shear 7 program of a full-scale steel catenary riser is carried out. The main induced modes, mode frequencies and response amplitude are in a good agreement. Furthermore, the parametric studies are carried out to broaden the understanding of the fatigue damage sensitivity to the upper end in-plane offset and seabed characteristics. In addition, the fatigue stress comparison at TDP between the truncation riser model and the present full riser model shows that the existence of touch-down zones is very important for the fatigue damage assessment of steel catenary riser at TDP.

  2. Experimental investigation on vortex-induced vibration of steel catenary riser

    NASA Astrophysics Data System (ADS)

    Fan, Yu-ting; Mao, Hai-ying; Guo, Hai-yan; Liu, Qing-hai; Li, Xiao-min

    2015-10-01

    Steel catenary riser (SCR) is the transmission device between the seabed and the floating production facilities. As developments move into deeper water, the fatigue life of the riser can become critical to the whole production system, especially due to the vortex-induced vibration (VIV), which is the key factor to operational longevity. As a result, experimental investigation about VIV of the riser was performed in a large plane pool which is 60 m long, 36 m wide and 6.5 m deep. Experiments were developed to study the influence of current speed and seabed on VIV of SCR. The results show that amplitudes of strain and response frequencies increase with the current speed both in cross-flow (CF) and in-line (IL). When the current speed is high, multi-mode response is observed in the VIV motion. The amplitudes of strain in IL direction are not much smaller than those in CF direction. The seabed has influence on the response frequencies of riser and the positions of damage for riser.

  3. Synergetic analysis and possible control of vortex-induced vibrations in a fluid-conveying steel catenary riser

    NASA Astrophysics Data System (ADS)

    Meng, Dan; Zhu, Chongji

    2015-04-01

    This work aimed to demonstrate possibilities for both active and passive control of the vortex-induced vibration and fatigue life of steel catenary risers via an analysis of the self-organization and evolution of the structural vibration based on synergetic theory. An analysis of the complex interrelated and synergistic relationship between the order parameter and the fast variable was performed, and the master equation of the nodal displacements was established as the order parameter for the evolution of the riser's structural vibration. Passive control methods include modifying the structure's elastic modulus, the internal fluid velocity, the top tension and the structural damping ratio, while an active control involves adjusting the external flow rate. Optimized parameters were obtained by analyzing the non-steady state solution of the master equation. The results show that the fatigue life greatly increases as the riser's elastic modulus decreases. In contrast, the fatigue life decreases with an increase of the internal fluid velocity. With an increase of the top tension, the vibration amplitudes and the number of modes may decrease, resulting in fewer bending stress cycles and a longer fatigue life. Furthermore, the structural damping ratio should be as large as possible. Finally, an active and passive control of the riser structure's response to vortex-induced vibration and its fatigue life can be achieved by carefully modifying the parameters mentioned above. The results may provide a theoretical framework for engineering practice concerning the design and control of steel catenary riser structures which are affected by vortex-induced vibration.

  4. Composite hoop wound steel tubes for drilling riser applications

    SciTech Connect

    Grosjean, F.; Odru, P.; Schaeffner, P.; Cassand, G.

    1995-12-31

    The development of very deep offshore drillings outlines the need for mass reduction of the drilling riser. This aim can be achieved, in an interesting way, by decreasing the weight of the two heavy high pressure Kill and Choke lines, fitted on the drilling riser main body. This article presents the work performed by Composites Aquitaine and IFP to develop and qualify new type of lightweight composite hoop wound pipes for this special application. These tubes are made of a steel pipe reinforced by a prestressed winding of unidirectional thermoplastic-aramid composite. The winding parameters are carefully calculated to optimize the distribution of tension/compression stresses in the constitutive materials of the tube.

  5. NASA CPAS Drogue Textile Riser Feasibility Study

    NASA Technical Reports Server (NTRS)

    Hennings, Elsa J.; Petersen, Michael L.; Anderson, Brian; Johnson, Brian

    2015-01-01

    Steel cable was chosen for the lower end of the drogue and main parachute risers on NASA's Orion Multi Purpose Crew Vehicle Parachute Assembly System (CPAS) to protect the risers from extreme temperatures and abrasion should they contact the crew module during deployment, as was done for Apollo. Due to the weight and deployment complexity inherent in steel, there was significant interest in the possibility of substituting textile for steel for the drogue and main parachute risers. However, textile risers could be damaged when subjected to high temperature and abrasion. Investigations were consequently performed by a subset of the authors to determine whether sacrificial, non-load-bearing textile riser covers could be developed to mitigate the thermal and abrasion concerns. Multiple material combinations were tested, resulting in a cover design capable of protecting the riser against severe riser/crew module contact interactions. A feasibility study was then conducted to evaluate the performance of the textile drogue riser cover in relevant abrasive environments. This paper describes the testing performed and documents the results of this feasibility study.

  6. The Catenary as Roulette

    ERIC Educational Resources Information Center

    Sanchez-Reyes, Javier S.

    2012-01-01

    The focus of a parabola rolling without sliding along a straight line traces a catenary. We give some historical notes on this classical kinematical construction, observe that it was rediscovered in a recent article, and give a simpler and more geometric alternative derivation.

  7. The Catenary as Roulette

    ERIC Educational Resources Information Center

    Sanchez-Reyes, Javier S.

    2012-01-01

    The focus of a parabola rolling without sliding along a straight line traces a catenary. We give some historical notes on this classical kinematical construction, observe that it was rediscovered in a recent article, and give a simpler and more geometric alternative derivation.

  8. Orion Parachute Riser Cutter Development

    NASA Technical Reports Server (NTRS)

    Oguz, Sirri; Salazar, Frank

    2011-01-01

    This paper presents the tests and analytical approach used on the development of a steel riser cutter for the CEV Parachute Assembly System (CPAS) used on the Orion crew module. Figure 1 shows the riser cutter and the steel riser bundle which consists of six individual cables. Due to the highly compressed schedule, initial unavailability of the riser material and the Orion Forward Bay mechanical constraints, JSC primarily relied on a combination of internal ballistics analysis and LS-DYNA simulation for this project. Various one dimensional internal ballistics codes that use standard equation of state and conservation of energy have commonly used in the development of CAD devices for initial first order estimates and as an enhancement to the test program. While these codes are very accurate for propellant performance prediction, they usually lack a fully defined kinematic model for dynamic predictions. A simple piston device can easily and accurately be modeled using an equation of motion. However, the accuracy of analytical models is greatly reduced on more complicated devices with complex external loads, nonlinear trajectories or unique unlocking features. A 3D finite element model of CAD device with all critical features included can vastly improve the analytical ballistic predictions when it is used as a supplement to the ballistic code. During this project, LS-DYNA structural 3D model was used to predict the riser resisting load that was needed for the ballistic code. A Lagrangian model with eroding elements shown in Figure 2 was used for the blade, steel riser and the anvil. The riser material failure strain was fine tuned by matching the dent depth on the anvil with the actual test data. LS-DYNA model was also utilized to optimize the blade tip design for the most efficient cut. In parallel, the propellant type and the amount were determined by using CADPROG internal ballistics code. Initial test results showed a good match with LS-DYNA and CADPROG

  9. Catenaries in viscous fluid

    NASA Astrophysics Data System (ADS)

    Hanna, James; Chakrabarti, Brato

    2015-11-01

    Slender structures live in fluid flows across many scales, from towed instruments to plant blades to microfluidic valves. The present work details a simple model of a flexible structure in a uniform flow. We present analytical solutions for the translating, axially flowing equilibria of strings subjected to a uniform body force and linear drag forces. This is an extension of the classical catenaries to a five-parameter family of solutions, represented as trajectories in angle-curvature ``phase space.'' Limiting cases include neutrally buoyant towed cables and freely sedimenting flexible filaments. Now at University of California, San Diego.

  10. Corrosion of stainless steels in the riser during co-processing of bio-oils in a fluid catalytic cracking pilot plant

    DOE PAGES

    Brady, M. P.; Keiser, J. R.; Leonard, D. N.; ...

    2017-01-31

    Co-processing of bio-oils with conventional petroleum-based feedstocks is an attractive initial option to make use of renewable biomass as a fuel source while leveraging existing refinery infrastructures. But, bio-oils and their processing intermediates have high concentrations of organic oxygenates, which, among their other negative qualities, can result in increased corrosion issues. A range of stainless steel alloys (409, 410, 304L, 316L, 317L, and 201) was exposed at the base of the riser in a fluid catalytic cracking pilot plant while co-processing vacuum gas oil with pine-derived pyrolysis bio-oils that had been catalytically hydrodeoxygenated to ~ 2 to 28% oxygen. Wemore » studied the processing using a catalyst temperature of 704 °C, a reaction exit temperature of 520 °C, and total co-processing run times of 57–75 h. External oxide scaling 5–30 μm thick and internal attack 1–5 μm deep were observed in these short-duration exposures. The greatest extent of internal attack was observed for co-processing with the least stabilized bio-oil, and more so for types 409, 410, 304L, 316L, 317L stainless steel than for type 201. Finally, the internal attack involved porous Cr-rich oxide formation, associated with local Ni-metal enrichment and S-rich nanoparticles, primarily containing Cr or Mn. Implications for alloy selection and corrosion are discussed.« less

  11. Reliable Radiographic Inspection of Flexible Risers for the Oil Industry

    NASA Astrophysics Data System (ADS)

    Almeida, Rômulo M.; Rebello, Joao Marcos A.; Vaz, Murilo A.

    2010-02-01

    Flexible risers are composite tubular structures manufactured by the concentric assemblage of cylindrical polymeric and helically wound metallic layers employed to convey pressurized fluids such as oil, gas and water in the ocean environment. The metallic layers account for the flexible risers' structural strength and are dimensioned according to the static and dynamic loads. They are usually installed in a free hanging catenary configuration and are subjected to the direct action of waves and marine currents and wave induced motions from the oil production platform. The fatigue rupture of wire armours in the end fitting or within the riser segment protected by the bend stiffener is an object of major concern. Integrity models have been developed, however inspection techniques are mandatory to ensure that failure is detected. Gammagraphy has been used as a common inspection technique in all regions of the flexible riser, mainly with the single wall-single view method. On the other side, there is not any qualified radiographic procedure to this kind of structure. Radiographic simulation was adopted and its validation with actual gammagraphies and establishment of radiographic parameters to complex radiation geometries were done. Results show the viability of the radiographic inspection analyzing the armour wires' rupture and the displacement between wires.

  12. The Hyperbolic Sine Cardinal and the Catenary

    ERIC Educational Resources Information Center

    Sanchez-Reyes, Javier

    2012-01-01

    The hyperbolic function sinh(x)/x receives scant attention in the literature. We show that it admits a clear geometric interpretation as the ratio between length and chord of a symmetric catenary segment. The inverse, together with the use of dimensionless parameters, furnishes a compact, explicit construction of a general catenary segment of…

  13. The Hyperbolic Sine Cardinal and the Catenary

    ERIC Educational Resources Information Center

    Sanchez-Reyes, Javier

    2012-01-01

    The hyperbolic function sinh(x)/x receives scant attention in the literature. We show that it admits a clear geometric interpretation as the ratio between length and chord of a symmetric catenary segment. The inverse, together with the use of dimensionless parameters, furnishes a compact, explicit construction of a general catenary segment of…

  14. Analysis of Breast Contour using Rotated Catenary

    PubMed Central

    Lee, Juhun; Beahm, Elisabeth K.; Crosby, Melissa A.; Reece, Gregory P.; Markey, Mia K.

    2010-01-01

    Surgical reconstruction of natural-appearing breasts is a challenging task. Currently, surgical planning is limited to the surgeon’s subjective assessment of breast morphology. Therefore, it is useful to develop objective measurements of breast contour. In this paper, a novel quantitative measure of the breast contour based on catenary theory is introduced. A catenary curve is fitted on the breast contour (lateral and inferior) and the key parameter determining the shape of the curve is extracted. The new catenary analysis was applied to pre- and post-operative clinical photographs of women who underwent tissue expander/implant (TE/Implant) reconstruction. A logistic regression model was developed to predict the probability that the observed contour is that of a TE/Implant reconstruction from the catenary parameter, patient age, and patient body mass index. It was demonstrated that the parameters contain useful information for distinguishing TE/Implant reconstructed breasts from pre-operative breasts. PMID:21347015

  15. Analysis of Breast Contour using Rotated Catenary.

    PubMed

    Lee, Juhun; Beahm, Elisabeth K; Crosby, Melissa A; Reece, Gregory P; Markey, Mia K

    2010-11-13

    Surgical reconstruction of natural-appearing breasts is a challenging task. Currently, surgical planning is limited to the surgeon's subjective assessment of breast morphology. Therefore, it is useful to develop objective measurements of breast contour. In this paper, a novel quantitative measure of the breast contour based on catenary theory is introduced. A catenary curve is fitted on the breast contour (lateral and inferior) and the key parameter determining the shape of the curve is extracted. The new catenary analysis was applied to pre- and post-operative clinical photographs of women who underwent tissue expander/implant (TE/Implant) reconstruction. A logistic regression model was developed to predict the probability that the observed contour is that of a TE/Implant reconstruction from the catenary parameter, patient age, and patient body mass index. It was demonstrated that the parameters contain useful information for distinguishing TE/Implant reconstructed breasts from pre-operative breasts.

  16. Presbyopia, accommodation, and the mature catenary.

    PubMed

    Coleman, D J; Fish, S K

    2001-09-01

    To demonstrate a plausible explanation of aging changes and to reduce the controversy relative to accommodation by using a mechanical model of the catenary theory of lens change. MECHANICAL MODELING: A mechanical model was used to simulate a human lens in both the accommodated and unaccommodated state to demonstrate changes in the mechanism of accommodation with age. Fluid-filled latex balloons were supported by a plastic wrap hammock to form a catenary that models the human lens. Increasing volumes were used to simulate that of the aging lens, and variations in curvature were measured. The degree of curvature of a simulated anterior lens surface was measured and compared with mathematical modeling of its optical surface based on the catenary hydraulic suspension theory. The measurements showed that accommodative loss and other features such as mass displacement, reproducible lens surfaces, and zonule support are consistent with the catenary theory of accommodation and an increasing lens volume with age. The catenary theory of accommodation provides a basis for evaluating age changes of the human lens. Variable results with surgical procedures for presbyopia are also predictable with the model. These results can be used to provide a basis for intraocular lens design.

  17. Engineering report for simulated riser installation

    SciTech Connect

    Brevick, C.H., Westinghouse Hanford

    1996-05-09

    The simulated riser installation field tests demonstrated that new access ports (risers) can be installed safely, quickly, and economically in the concrete domes of existing underground single- shell waste storage tanks by utilizing proven rotary drilling equipment and vacuum excavation techniques. The new riser installation will seal against water intrusion, provide as table riser anchored to the tank dome, and be installed in accordance with ALARA principles. The information contained in the report will apply to actual riser installation activity in the future.

  18. A Classroom Investigation into the Catenary

    ERIC Educational Resources Information Center

    Staples, Ed

    2011-01-01

    The quest to find the equation of a catenary makes an ideal investigation for upper secondary students. In the modelling exercise that follows, no knowledge of calculus is required to gain a fairly good understanding of the nature of the curve. This investigation is best described as a scientific investigation--a "hands on" experience…

  19. A fresh look at the catenary

    NASA Astrophysics Data System (ADS)

    Behroozi, F.

    2014-09-01

    A hanging chain takes the familiar form known as the catenary which is one of the most ubiquitous curves students encounter in their daily life. Yet most introductory physics and mathematics texts ignore the subject entirely. In more advanced texts the catenary equation is usually derived as an application of the calculus of variations. Although the variational approach is mathematically elegant, it is suitable for more advanced students. Here we derive the catenary equation in special and rectangular coordinates by considering the equilibrium conditions for an element of the hanging chain and without resorting to the calculus of variations. One advantage of this approach is its simplicity which makes it accessible to undergraduate students; another is the concurrent derivation of a companion equation which gives the tension along the chain. These solutions provide an excellent opportunity for undergraduates to explore the underlying physics. One interesting result is that the shape of a hanging chain does not depend on its linear mass density or on the strength of the gravitational field. Therefore, within a scale factor, all catenaries are copies of the same universal curve. We give the functional dependence of the scale factor on the length and terminal angle of the hanging chain.

  20. Focus on Physics: The Delightful Catenary Curve

    ERIC Educational Resources Information Center

    Hewitt, Paul G.

    2017-01-01

    When teaching how "tension" and "compression" relate to geometrical structures such as bridges, arches, and domes, The author shows a picture of the Notre Dame Cathedral in Paris, completed in the 14th century, and presents a lesson on using the curve called a catenary to explain how he teaches about tension and compression…

  1. TLP rigid riser; A case study

    SciTech Connect

    Rooney, P.P.; Engebretsen, K.B. ); Pettersen, D.J. )

    1992-03-01

    This paper summarizes tension-leg platform (TLP) rigid riser design considerations and presents results of TLP riser analysis for a production/injection riser in the North Sea. Analysis methods, design criteria, and design optimization are addressed. The riser is designed for 300-m water depth in compliance with Norwegian regulations. Emphasis is placed on application of the regulations and quantitative comparison of alternative methods for analysis of fatigue and extremes.

  2. Solar radiation on a catenary collector

    NASA Technical Reports Server (NTRS)

    Crutchik, M.; Appelbaum, J.

    1992-01-01

    A tent-shaped structure with a flexible photovoltaic blanket acting as a catenary collector is presented. The shadow cast by one side of the collector produces a shadow on the other side of the collector. This self-shading effect is analyzed. The direct beam, the diffuse, and the albedo radiation on the collector are determined. An example is given for the insolation on the collector operating on Viking Lander 1 (VL1).

  3. Structural analysis of multiport riser 5A installation on tank 241SY101

    SciTech Connect

    Strehlow, J.P.

    1994-09-16

    The Tank 101-SY multiport riser assembly in the 241-SY-101 waste tank will replace the existing 42 inch riser with four smaller ports. Each smaller port can be used independently to access the tank interior with equipment and instruments needed to mitigate the concentration of hydrogen in the tank. This document provides a design report on the structural evaluation of the multiport riser assembly as well as its anchorage. The multiport riser assembly is a steel structure installed directly above the 42-inch riser and sealed at the existing riser flange. The assembly is structurally supported by the concrete pad placed around the 42 inch riser. The multiport riser assembly will provide two 8-inch penetrations, one 12-inch penetration and one 24-inch penetration. Each penetration will have a shielding plate. These penetrations will be used to insert equipment such as a sonic probe into the tank. In addition to normal loads, non-reactor Safety Class 1 structures, systems and components are to withstand the effects of extreme environmental loads including Design Basis Earthquake (DBE), Design Basis Wind (DBW), Design Basis Flood, Volcanic Eruptions and other abnormal loads considered on a case by case basis. Non-reactor Safety Class 2, 3 and 4 structures, systems and components are those that are not Safety Class 1 and are respectively specified as onsite safety related, occupational safety related and non-safety related items. The 241-SY-101 tank is considered as a non-reactor Safety Class 1 structure. The multiport riser assembly is considered as a non-reactor Safety Class 2 structure since it serves to contain the radioactive and toxic materials under normal operating conditions. However, the pressure relief doors provided on the assembly are considered as Safety Class 1 structures.

  4. Real-time catenary models for the hardware-in-the-loop simulation of the pantograph-catenary interaction

    NASA Astrophysics Data System (ADS)

    Facchinetti, A.; Gasparetto, L.; Bruni, S.

    2013-04-01

    Hardware-in-the-loop (HIL) simulation is a promising technique to study the pantograph-catenary interaction problems by realising the interaction of a physical pantograph with a mathematical model of the overhead equipment (catenary). However, the computing power presently available on real-time CPUs only allows to run simplified models of the overhead equipment. Therefore, it is important to define catenary models that are suitable for real-time simulation and at the same time capable of accurately representing the dynamic behaviour of the catenary. In this paper, the use of a catenary model based on modal superposition is considered, and the effect of changing the number of modelled spans and the number of modal components allocated to the contact and messenger wires is investigated in view of finding the best model compatible with real-time simulation. Comparisons between HIL simulation results and line measurements are presented, to quantify the accuracy of the hybrid simulation method developed.

  5. 20. VIEW OF CATENARY, FEEDER TOWERS AND COS COB POWER ...

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

    20. VIEW OF CATENARY, FEEDER TOWERS AND COS COB POWER PLANT (CENTER BACKGROUND) LOOKING WEST FROM THE NORTH SIDE OF THE MIANUS RIVER BASCULE BRIDGE. NOTE THAT THE CATENARY ENDS AT BRIDGE 313. TRAINS ARE CARRIED ACROSS THE BASCULE BRIDGE BY THEIR OWN MOMENTUM AND PICK UP THE CATENARY ON THE EAST SIDE OF THE RIVER. THE FEEDER LINES CARRY POWER ACROSS THE RIVER ABOVE THE LEVEL OF THE OPENED BASCULE ON THE TOWERS TO THE LEFT AND RIGHT. - New York, New Haven & Hartford Railroad, Cos Cob Power Plant, Sound Shore Drive, Greenwich, Fairfield County, CT

  6. 4. OBLIQUE VIEW, AUTOMATIC BLOCK SIGNAL, EASTBOUND ON CATENARY BRIDGE ...

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

    4. OBLIQUE VIEW, AUTOMATIC BLOCK SIGNAL, EASTBOUND ON CATENARY BRIDGE 486 - New York, New Haven & Hartford Railroad, Automatic Signalization System, Long Island Sound shoreline between Stamford & New Haven, Stamford, Fairfield County, CT

  7. 5. DETAIL, HOME SIGNAL, WESTBOUND ON CATENARY BRIDGE 518, FRONT ...

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

    5. DETAIL, HOME SIGNAL, WESTBOUND ON CATENARY BRIDGE 518, FRONT VIEW - New York, New Haven & Hartford Railroad, Automatic Signalization System, Long Island Sound shoreline between Stamford & New Haven, Stamford, Fairfield County, CT

  8. 1. FRONT VIEW, AUTOMATIC BLOCK SIGNAL, EASTBOUND ON CATENARY BRIDGE ...

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

    1. FRONT VIEW, AUTOMATIC BLOCK SIGNAL, EASTBOUND ON CATENARY BRIDGE 486 - New York, New Haven & Hartford Railroad, Automatic Signalization System, Long Island Sound shoreline between Stamford & New Haven, Stamford, Fairfield County, CT

  9. 3. REAR VIEW, AUTOMATIC BLOCK SIGNAL, EASTBOUND ON CATENARY BRIDGE ...

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

    3. REAR VIEW, AUTOMATIC BLOCK SIGNAL, EASTBOUND ON CATENARY BRIDGE 486 - New York, New Haven & Hartford Railroad, Automatic Signalization System, Long Island Sound shoreline between Stamford & New Haven, Stamford, Fairfield County, CT

  10. 13. OBLIQUE VIEW, THREE DWARF SIGNALS, EAST OF CATENARY BRIDGE ...

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

    13. OBLIQUE VIEW, THREE DWARF SIGNALS, EAST OF CATENARY BRIDGE 522 - New York, New Haven & Hartford Railroad, Automatic Signalization System, Long Island Sound shoreline between Stamford & New Haven, Stamford, Fairfield County, CT

  11. 12. FRONT VIEW, DETAIL, DWARF SIGNAL, EAST ON CATENARY BRIDGE ...

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

    12. FRONT VIEW, DETAIL, DWARF SIGNAL, EAST ON CATENARY BRIDGE 522 - New York, New Haven & Hartford Railroad, Automatic Signalization System, Long Island Sound shoreline between Stamford & New Haven, Stamford, Fairfield County, CT

  12. 28. TOP VIEW OF CIRCUIT BREAKER ADJACENT TO BRIDGE, CATENARY ...

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

    28. TOP VIEW OF CIRCUIT BREAKER ADJACENT TO BRIDGE, CATENARY ANCHOR BRIDGE 310, COS COB POWER PLANT - New York, New Haven & Hartford Railroad, Automatic Signalization System, Long Island Sound shoreline between Stamford & New Haven, Stamford, Fairfield County, CT

  13. 27. CIRCUIT BREAKERS AT SOUTH END OF BRIDGE, CATENARY ANCHOR ...

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

    27. CIRCUIT BREAKERS AT SOUTH END OF BRIDGE, CATENARY ANCHOR BRIDGE 310, COS COB POWER PLANT - New York, New Haven & Hartford Railroad, Automatic Signalization System, Long Island Sound shoreline between Stamford & New Haven, Stamford, Fairfield County, CT

  14. 31. CATENARY BRIDGE 524, NEAR SOUTH NORWALK SWITCH TOWER, LOOKING ...

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

    31. CATENARY BRIDGE 524, NEAR SOUTH NORWALK SWITCH TOWER, LOOKING WESTBOUND - New York, New Haven & Hartford Railroad, Automatic Signalization System, Long Island Sound shoreline between Stamford & New Haven, Stamford, Fairfield County, CT

  15. 11. REAR VIEW, DRAWBRIDGE SIGNAL, EASTBOUND ON CATENARY BRIDGE 522 ...

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

    11. REAR VIEW, DRAWBRIDGE SIGNAL, EASTBOUND ON CATENARY BRIDGE 522 - New York, New Haven & Hartford Railroad, Automatic Signalization System, Long Island Sound shoreline between Stamford & New Haven, Stamford, Fairfield County, CT

  16. 9. FRONT VIEW, TWO DOUBLE DRAWBRIDGE SIGNALS, EASTBOUND ON CATENARY ...

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

    9. FRONT VIEW, TWO DOUBLE DRAWBRIDGE SIGNALS, EASTBOUND ON CATENARY BRIDGE 522 - New York, New Haven & Hartford Railroad, Automatic Signalization System, Long Island Sound shoreline between Stamford & New Haven, Stamford, Fairfield County, CT

  17. 21. CATENARY ANCHOR BRIDGE 310, COS COB POWER PLANT, LOOKING ...

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

    21. CATENARY ANCHOR BRIDGE 310, COS COB POWER PLANT, LOOKING EASTBOUND - New York, New Haven & Hartford Railroad, Automatic Signalization System, Long Island Sound shoreline between Stamford & New Haven, Stamford, Fairfield County, CT

  18. 24. CATENARY ANCHOR BRIDGE 310, COS COB POWER PLANT, NORTH ...

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

    24. CATENARY ANCHOR BRIDGE 310, COS COB POWER PLANT, NORTH TRUSS FOR POWER LEAD-IN WIRES - New York, New Haven & Hartford Railroad, Automatic Signalization System, Long Island Sound shoreline between Stamford & New Haven, Stamford, Fairfield County, CT

  19. 6. FRONT VIEW, TWO DOUBLE HOME SIGNALS, WESTBOUND ON CATENARY ...

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

    6. FRONT VIEW, TWO DOUBLE HOME SIGNALS, WESTBOUND ON CATENARY BRIDGE 518 - New York, New Haven & Hartford Railroad, Automatic Signalization System, Long Island Sound shoreline between Stamford & New Haven, Stamford, Fairfield County, CT

  20. 10. FRONT VIEW, DRAWBRIDGE SIGNAL, EASTBOUND ON CATENARY BRIDGE 522 ...

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

    10. FRONT VIEW, DRAWBRIDGE SIGNAL, EASTBOUND ON CATENARY BRIDGE 522 - New York, New Haven & Hartford Railroad, Automatic Signalization System, Long Island Sound shoreline between Stamford & New Haven, Stamford, Fairfield County, CT

  1. 8. OBLIQUE VIEW, DRAWBRIDGE SIGNAL, EASTBOUND ON CATENARY BRIDGE 522 ...

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

    8. OBLIQUE VIEW, DRAWBRIDGE SIGNAL, EASTBOUND ON CATENARY BRIDGE 522 - New York, New Haven & Hartford Railroad, Automatic Signalization System, Long Island Sound shoreline between Stamford & New Haven, Stamford, Fairfield County, CT

  2. 32. OBLIQUE VIEW SHOWING ASHAPED SUPPORT, CATENARY ANCHOR BRIDGE 524, ...

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

    32. OBLIQUE VIEW SHOWING A-SHAPED SUPPORT, CATENARY ANCHOR BRIDGE 524, NEAR SOUTH NORWALK SWITCH TOWER - New York, New Haven & Hartford Railroad, Automatic Signalization System, Long Island Sound shoreline between Stamford & New Haven, Stamford, Fairfield County, CT

  3. 7. OBLIQUE VIEW, HOME SIGNAL, WESTBOUND ON CATENARY BRIDGE 518 ...

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

    7. OBLIQUE VIEW, HOME SIGNAL, WESTBOUND ON CATENARY BRIDGE 518 - New York, New Haven & Hartford Railroad, Automatic Signalization System, Long Island Sound shoreline between Stamford & New Haven, Stamford, Fairfield County, CT

  4. 30. CATENARY BRIDGE 524, NEAR SOUTH NORWALK SWITCH TOWER, LOOKING ...

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

    30. CATENARY BRIDGE 524, NEAR SOUTH NORWALK SWITCH TOWER, LOOKING EASTBOUND - New York, New Haven & Hartford Railroad, Automatic Signalization System, Long Island Sound shoreline between Stamford & New Haven, Stamford, Fairfield County, CT

  5. 25. CATENARY ANCHOR BRIDGE 310 AND COS COB POWER PLANT ...

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

    25. CATENARY ANCHOR BRIDGE 310 AND COS COB POWER PLANT STRUCTURES, LOOKING WESTBOUND - New York, New Haven & Hartford Railroad, Automatic Signalization System, Long Island Sound shoreline between Stamford & New Haven, Stamford, Fairfield County, CT

  6. 33. VIEW OF ADJACENT SUBSTATION AND TRANSFORMER, CATENARY ANCHOR BRIDGE ...

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

    33. VIEW OF ADJACENT SUBSTATION AND TRANSFORMER, CATENARY ANCHOR BRIDGE 524 - New York, New Haven & Hartford Railroad, Automatic Signalization System, Long Island Sound shoreline between Stamford & New Haven, Stamford, Fairfield County, CT

  7. 23. OBLIQUE VIEW, CATENARY ANCHOR BRIDGE 310, COS COB POWER ...

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

    23. OBLIQUE VIEW, CATENARY ANCHOR BRIDGE 310, COS COB POWER PLANT - New York, New Haven & Hartford Railroad, Automatic Signalization System, Long Island Sound shoreline between Stamford & New Haven, Stamford, Fairfield County, CT

  8. 22. CATENARY ANCHOR BRIDGE 310, COS COB POWER PLANT, LOOKING ...

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

    22. CATENARY ANCHOR BRIDGE 310, COS COB POWER PLANT, LOOKING WESTBOUND - New York, New Haven & Hartford Railroad, Automatic Signalization System, Long Island Sound shoreline between Stamford & New Haven, Stamford, Fairfield County, CT

  9. Four open mammillary and catenary compartment models for pharmacokinetics studies.

    PubMed

    de Biasi, J

    1989-11-01

    A mathematical method is proposed to solve a fourth degree equation which gives the eigenvalues of the matrix connected with a four open compartment model used in pharmacokinetic studies. As examples, the method is applied to mammillary and catenary models.

  10. A Novel Quantitative Measure of Breast Curvature Based on Catenary

    PubMed Central

    Lee, Juhun; Chen, Si; Reece, Gregory P.; Crosby, Melissa A.; Beahm, Elisabeth K.

    2012-01-01

    Quantitative, objective measurements of breast curvature computed from clinical photographs could be used to investigate factors that impact reconstruction and facilitate surgical planning. This paper introduces a novel quantitative measure of breast curvature based on catenary. A catenary curve is used to approximate the overall curvature of the breast contour, and the curvature measure is extracted from the catenary curve. The catenary curve was verified by comparing its length, the area enclosed by the curve, and the curvature measure from the catenary curve to those from manual tracings of the breast contour. The evaluation of the proposed analysis employed untreated and postoperative clinical photographs of women who were undergoing tissue expander/implant (TE/Implant) reconstruction. Logistic regression models were developed to distinguish between the curvature of breasts undergoing TE/Implant reconstruction and that of untreated breasts based on the curvature measure and patient variables (age and body mass index). The relationships between the curvature measures of untreated breasts and patient variables were also investigated. The catenary curve approximates breast curvature reliably. The curvature measure contains useful information for quantifying the curvature differences between breasts undergoing TE/Implant reconstruction and untreated breasts, and identifying the effect of patient variables on the breast shape. PMID:22271826

  11. A novel quantitative measure of breast curvature based on catenary.

    PubMed

    Lee, Juhun; Chen, Si; Reece, Gregory P; Crosby, Melissa A; Beahm, Elisabeth K; Markey, Mia K

    2012-04-01

    Quantitative, objective measurements of breast curvature computed from clinical photographs could be used to investigate factors that impact reconstruction and facilitate surgical planning. This paper introduces a novel quantitative measure of breast curvature based on catenary. A catenary curve is used to approximate the overall curvature of the breast contour, and the curvature measure is extracted from the catenary curve. The catenary curve was verified by comparing its length, the area enclosed by the curve, and the curvature measure from the catenary curve to those from manual tracings of the breast contour. The evaluation of the proposed analysis employed untreated and postoperative clinical photographs of women who were undergoing tissue expander/implant (TE/Implant) reconstruction. Logistic regression models were developed to distinguish between the curvature of breasts undergoing TE/Implant reconstruction and that of untreated breasts based on the curvature measure and patient variables (age and body mass index). The relationships between the curvature measures of untreated breasts and patient variables were also investigated. The catenary curve approximates breast curvature reliably. The curvature measure contains useful information for quantifying the curvature differences between breasts undergoing TE/Implant reconstruction and untreated breasts, and identifying the effect of patient variables on the breast shape.

  12. Experimental investigation of deep sea riser interaction

    SciTech Connect

    Huse, E.

    1996-12-31

    In future deep sea field developments the drag force and corresponding static deflections of the risers due to current can become quite large. The prevention of mechanical contact (collision) between the risers will need more careful evaluation than in moderate water depths. The paper describes a series of model experiments in a Norwegian fjord to determine criteria for on-set of collisions between the risers of a deep sea TLP. The current was modeled using the natural tidal current in the fjord. Results from the tests are summarized and used for verification of numerical calculations of collision criteria.

  13. Dynamic response analysis of the equivalent water depth truncated point of the catenary mooring line

    NASA Astrophysics Data System (ADS)

    Zhang, Huo-ming; Kong, Ling-bin; Guan, Wei-bing; Huang, Sai-hua; Fang, Gui-sheng

    2017-03-01

    The real-time computer-controlled actuators are used to connect the truncated parts of moorings and risers in the active hybrid model testing system. This must be able to work in model-scale real time, based on feedback input from the floater motions. Thus, mooring line dynamics and damping effects are artificially simulated in real time, based on a computer-based model of the problem. In consideration of the nonlinear characteristics of the sea platform catenary mooring line, the equations of the mooring line motion are formulated by using the lumped-mass method and the dynamic response of several points on the mooring line is investigated by the time and frequency domain analysis method. The dynamic response of the representative point on the mooring line is analyzed under the condition of two different corresponding upper endpoint movements namely sine wave excitation and random wave excitation. The corresponding laws of the dynamic response between the equivalent water depth truncated points at different locations and the upper endpoint are obtained, which can provide technical support for further study of the active hybrid model test.

  14. Diffusion of innovations dynamics, biological growth and catenary function

    NASA Astrophysics Data System (ADS)

    Guseo, Renato

    2016-12-01

    The catenary function has a well-known role in determining the shape of chains and cables supported at their ends under the force of gravity. This enables design using a specific static equilibrium over space. Its reflected version, the catenary arch, allows the construction of bridges and arches exploiting the dual equilibrium property under uniform compression. In this paper, we emphasize a further connection with well-known aggregate biological growth models over time and the related diffusion of innovation key paradigms (e.g., logistic and Bass distributions over time) that determine self-sustaining evolutionary growth dynamics in naturalistic and socio-economic contexts. Moreover, we prove that the 'local entropy function', related to a logistic distribution, is a catenary and vice versa. This special invariance may be explained, at a deeper level, through the Verlinde's conjecture on the origin of gravity as an effect of the entropic force.

  15. Catenary optics for achromatic generation of perfect optical angular momentum

    PubMed Central

    Pu, Mingbo; Li, Xiong; Ma, Xiaoliang; Wang, Yanqin; Zhao, Zeyu; Wang, Changtao; Hu, Chenggang; Gao, Ping; Huang, Cheng; Ren, Haoran; Li, Xiangping; Qin, Fei; Yang, Jing; Gu, Min; Hong, Minghui; Luo, Xiangang

    2015-01-01

    The catenary is the curve that a free-hanging chain assumes under its own weight, and thought to be a “true mathematical and mechanical form” in architecture by Robert Hooke in the 1670s, with nevertheless no significant phenomena observed in optics. We show that the optical catenary can serve as a unique building block of metasurfaces to produce continuous and linear phase shift covering [0, 2π], a mission that is extremely difficult if not impossible for state-of-the-art technology. Via catenary arrays, planar optical devices are designed and experimentally characterized to generate various kinds of beams carrying orbital angular momentum (OAM). These devices can operate in an ultra-broadband spectrum because the anisotropic modes associated with the spin-orbit interaction are almost independent of the incident light frequency. By combining the optical and topological characteristics, our approach would allow the complete control of photons within a single nanometric layer. PMID:26601283

  16. Catenary optics for achromatic generation of perfect optical angular momentum.

    PubMed

    Pu, Mingbo; Li, Xiong; Ma, Xiaoliang; Wang, Yanqin; Zhao, Zeyu; Wang, Changtao; Hu, Chenggang; Gao, Ping; Huang, Cheng; Ren, Haoran; Li, Xiangping; Qin, Fei; Yang, Jing; Gu, Min; Hong, Minghui; Luo, Xiangang

    2015-10-01

    The catenary is the curve that a free-hanging chain assumes under its own weight, and thought to be a "true mathematical and mechanical form" in architecture by Robert Hooke in the 1670s, with nevertheless no significant phenomena observed in optics. We show that the optical catenary can serve as a unique building block of metasurfaces to produce continuous and linear phase shift covering [0, 2π], a mission that is extremely difficult if not impossible for state-of-the-art technology. Via catenary arrays, planar optical devices are designed and experimentally characterized to generate various kinds of beams carrying orbital angular momentum (OAM). These devices can operate in an ultra-broadband spectrum because the anisotropic modes associated with the spin-orbit interaction are almost independent of the incident light frequency. By combining the optical and topological characteristics, our approach would allow the complete control of photons within a single nanometric layer.

  17. Reconstruction of Twist Torque in Main Parachute Risers

    NASA Technical Reports Server (NTRS)

    Day, Joshua D.

    2015-01-01

    The reconstruction of twist torque in the Main Parachute Risers of the Capsule Parachute Assembly System (CPAS) has been successfully used to validate CPAS Model Memo conservative twist torque equations. Reconstruction of basic, one degree of freedom drop tests was used to create a functional process for the evaluation of more complex, rigid body simulation. The roll, pitch, and yaw of the body, the fly-out angles of the parachutes, and the relative location of the parachutes to the body are inputs to the torque simulation. The data collected by the Inertial Measurement Unit (IMU) was used to calculate the true torque. The simulation then used photogrammetric and IMU data as inputs into the Model Memo equations. The results were then compared to the true torque results to validate the Model Memo equations. The Model Memo parameters were based off of steel risers and the parameters will need to be re-evaluated for different materials. Photogrammetric data was found to be more accurate than the inertial data in accounting for the relative rotation between payload and cluster. The Model Memo equations were generally a good match and when not matching were generally conservative.

  18. UNIDENTIFIED CATENARY SUSPENSION BRIDGE, SHOWING COMPLETED SINGLE PIPE TOWERS, WOODEN ...

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

    UNIDENTIFIED CATENARY SUSPENSION BRIDGE, SHOWING COMPLETED SINGLE PIPE TOWERS, WOODEN DECK LAID OVER LONGITUDINAL CABLES, AND WIRES READY FOR CABLE SPINNING. NOTE WORKER IN LEFT FOREGROUND STANDING IN ANCHORAGE PIT. BARREL VIEW. - Clear Fork of Brazos River Suspension Bridge, Spanning Clear Fork of Brazos River at County Route 179, Albany, Shackelford County, TX

  19. UNIDENTIFIED CATENARY SUSPENSION BRIDGE WITH TRUSSED OBELISK TOWERS ON STONE ...

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

    UNIDENTIFIED CATENARY SUSPENSION BRIDGE WITH TRUSSED OBELISK TOWERS ON STONE PIERS, SHOWING HOWE PIPE TRUSS RAILING AND TRUSSED DECK BEAMS TYPICAL TO BRIDGES BUILT BY FLINN-MOYER COMPANY. 3/4 VIEW FROM BELOW. - Clear Fork of Brazos River Suspension Bridge, Spanning Clear Fork of Brazos River at County Route 179, Albany, Shackelford County, TX

  20. UNIDENTIFIED CATENARY SUSPENSION BRIDGE WITH SINGLE PIPE TOWERS, SHOWING HOWE ...

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

    UNIDENTIFIED CATENARY SUSPENSION BRIDGE WITH SINGLE PIPE TOWERS, SHOWING HOWE PIPE TRUSS RAILING TYPICAL TO BRIDGES BUILT BY FLINN-MOYER COMPANY. NOTE THAT TRUSS LACKS WOODEN HUB GUARD FOUND ON CLEAR FORK OF THE BRAZOS SUSPENSION BRIDGE. 3/4 VIEW. - Clear Fork of Brazos River Suspension Bridge, Spanning Clear Fork of Brazos River at County Route 179, Albany, Shackelford County, TX

  1. UNIDENTIFIED CATENARY SUSPENSION BRIDGE, SHOWING RIVETED METAL PIERS UNDER CONSTRUCTION. ...

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

    UNIDENTIFIED CATENARY SUSPENSION BRIDGE, SHOWING RIVETED METAL PIERS UNDER CONSTRUCTION. NOTE APPROACH SPANS OF PIPE CONSTRUCTION IN RIGHT BACKGROUND. 3/4 VIEW FROM BELOW. - Clear Fork of Brazos River Suspension Bridge, Spanning Clear Fork of Brazos River at County Route 179, Albany, Shackelford County, TX

  2. Transient wave propagation analysis of a pantograph- catenary system

    NASA Astrophysics Data System (ADS)

    Nagao, Kyohei; Masuda, Arata

    2016-09-01

    This paper proposes a systematic method to analyze the dynamic response of an overhead catenary with pantographs moving at constant speed. The overhead catenary is modeled as a onedimensional infinite-length string, which is periodically supported by hangers. On the other hand, the pantograph is a sub-structure moving at a constant speed, which is modeled as a lumped mass system contacting the catenary. In this study, the whole system is divided into elements in the manner of the transfer matrix method. Then, the relationship among traveling waves in every element is systematically obtained in the Laplace domain following the method of reverberation-ray matrix. Since the governing equation of the system changes periodically with time, the analysis of the temporal evolution of the system can be realized by repeating a single period analysis starting from the instant when the pantograph comes into a unit cell by means of the reverberation-ray matrix analysis followed by the inverse Laplace transform. When the pantograph reaches the opposite hanger, the whole elements are shifted backward, and the catenary response of the forehead element is used as the initial condition of the next period.

  3. Individualized catenary curves: their relationship to arch form and perimeter.

    PubMed

    Battagel, J M

    1996-02-01

    Study casts of the lower arches of 35 children in whom arch alignment was considered acceptable, were examined using a reflex microscope. Arch perimeter was calculated mathematically from a method which required measurement of the mesio-distal widths of the teeth only. This was described as the 'overlap' method. Arch perimeter was also calculated using individualized catenary curves for each subject. Two calculations were made, recording arch width either at the distal contact points of the first permanent molars or between their mesio-buccal cusps. Arch perimeter measured from the length of the catenary curves was consistently shorter than that calculated by the overlap method. The variation ranged from 0.02 to 4.58 mm. The catenary constructed using the distal molar contacts gave a better representation of the actual arch form: the mean discrepancy was 2.36 mm, compared with 2.86 mm with the second method where arch width was measured between mesio-buccal cusps. Both techniques for calculation of arch perimeter were highly reproducible. The catenary curve only approximated arch form well when the arch was relatively narrow across the inter canine region. For square arches this method was unsatisfactory. It is suggested that alternative techniques would be more reliable and the overlap method described here is considered satisfactory.

  4. Modeling and simulation of vortex induced vibration on the subsea riser/pipeline (GRP pipe)

    NASA Astrophysics Data System (ADS)

    Raja Adli, Raja Nor Fauziah bt; Ibrahim, Idris

    2012-06-01

    This paper presents the research work conducted to investigate the dynamics characteristics of the offshore riser pipeline due to vortex flow and to develop a model that could predict its vortex induced responses. Glass-fiber reinforced plastic (GRP) pipe is used for this study which has smaller density from the steel. A two-dimensional finite element computational method is implemented to describe the dynamic behavior of the riser. The governing equation of motion was based on Hamilton's principle, consists of the strain energy due to bending and axial deformation, kinetic energy due to both riser and internal fluid movement and also external force from currents and waves. A direct integration method namely Newmark integration scheme is proposed to solve the equation of motion. A MATLAB program code was developed to obtain the simulation results. The natural frequency and damping ratio are presented for each mode. Dynamic response of riser is shown in time-domain and the numerical results are discussed. Several parameter effects are used to investigate dynamic responses and the results show an agreement with the theory. Vortex shedding phenomenon also has been discussed in this paper. As a conclusion, the simulation results have successfully shown the vortex induced vibration responses for GRP pipeline.

  5. Early Risers. What Works Clearinghouse Intervention Report

    ERIC Educational Resources Information Center

    What Works Clearinghouse, 2012

    2012-01-01

    "Early Risers" is a multi-year prevention program for elementary school children demonstrating early aggressive and disruptive behavior. The intervention model includes two child-focused components and two parent/family components. The Child Skills component is designed to teach skills that enhance children's emotional and behavioral…

  6. Active control strategy on a catenary-pantograph validated model

    NASA Astrophysics Data System (ADS)

    Sanchez-Rebollo, C.; Jimenez-Octavio, J. R.; Carnicero, A.

    2013-04-01

    Dynamic simulation methods have become essential in the design process and control of the catenary-pantograph system, overall since high-speed trains and interoperability criteria are getting very trendy. This paper presents an original hardware-in-the-loop (HIL) strategy aimed at integrating a multicriteria active control within the catenary-pantograph dynamic interaction. The relevance of HIL control systems applied in the frame of the pantograph is undoubtedly increasing due to the recent and more demanding requirements for high-speed railway systems. Since the loss of contact between the catenary and the pantograph leads to arcing and electrical wear, and too high contact forces cause mechanical wear of both the catenary wires and the strips of the pantograph, not only prescribed but also economic and performance criteria ratify such a relevance. Different configurations of the proportional-integral-derivative (PID) controller are proposed and applied to two different plant systems. Since this paper is mainly focused on the control strategy, both plant systems are simulation models though the methodology is suitable for a laboratory bench. The strategy of control involves a multicriteria optimisation of the contact force and the consumption of the energy supplied by the control force, a genetic algorithm has been applied for this purpose. Thus, the PID controller is fitted according to these conflicting objectives and tested within a nonlinear lumped model and a nonlinear finite element model, being the last one validated against the European Standard EN 50318. Finally, certain tests have been accomplished in order to analyse the robustness of the control strategy. Particularly, the relevance or the plant simulation, the running speed and the instrumentation time delay are studied in this paper.

  7. UNIDENTIFIED CATENARY SUSPENSION BRIDGE ON RIVETED METAL PIERS, SHOWING HOWE ...

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

    UNIDENTIFIED CATENARY SUSPENSION BRIDGE ON RIVETED METAL PIERS, SHOWING HOWE PIPE TRUSS RAILING AND TRUSSED DECK BEAMS TYPICAL TO BRIDGES BUILT BY FLINN-MOYER COMPANY. TRIPODAL PIPE TOWERS RESEMBLE CLEAR FORK OF THE BRAZOS SUSPENSION BRIDGE’S TOWERS PRIOR TO ENCASEMENT IN CONCRETE. NOTE COLLAPSED TRUSS IN RIVER. ELEVATION VIEW. - Clear Fork of Brazos River Suspension Bridge, Spanning Clear Fork of Brazos River at County Route 179, Albany, Shackelford County, TX

  8. UNIDENTIFIED CATENARY SUSPENSION BRIDGE WITH TRIPLE PIPE TOWERS, SHOWING HOWE ...

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

    UNIDENTIFIED CATENARY SUSPENSION BRIDGE WITH TRIPLE PIPE TOWERS, SHOWING HOWE PIPE TRUSS RAILING AND TRUSSED DECK BEAMS TYPICAL TO BRIDGES BUILT BY FLINN-MOYER COMPANY. NOTE THAT TOWER PIPES LIE IN ONE PLANE, UNLIKE TRIPODAL ARRANGEMENT AT CLEAR FORK OF THE BRAZOS SUSPENSION BRIDGE. ELEVATION VIEW. - Clear Fork of Brazos River Suspension Bridge, Spanning Clear Fork of Brazos River at County Route 179, Albany, Shackelford County, TX

  9. Concentration of the sun's rays using catenary curves.

    PubMed

    Rottigni, G A

    1978-03-15

    An examination has been carried out of the difficulties a horizontally placed parabola would encounter in concentrating the sun's rays when the angle of incidence between the axis of the parabola and parallel incident rays grows from 0 degrees to 50 degrees . The results obtained with two catenary curves formed by hypothetical reflecting adjustable sheets were compared with the parabola, showing that the concentration can be held at interesting levels as regards technical application.

  10. A photovoltaic catenary-tent array for the Martian surface

    NASA Technical Reports Server (NTRS)

    Colozza, Anthony J.; Appelbaum, J.; Crutchik, M.

    1993-01-01

    To provide electrical power during an exploration mission to Mars, a deployable tent-shaped structure with a flexible photovoltaic (PV) blanket is proposed. The array is designed with a self-deploying mechanism utilizing pressurized gas expansion. The structural design for the array uses a combination of cables, beams, and columns to support and deploy the PV blanket. Under the force of gravity, a cable carrying a uniform load will take the shape of a catenary curve. A catenary-tent collector is self shading which must be taken into account in the solar radiation calculation. The shape and the area of the shadow on the array was calculated and used in the determination of the global irradiance on the array. The PV blanket shape and structure dimensions were optimized to achieve a configuration which maximizes the specific power (W/kg). The optimization was performed for three types of PV blankets (silicon, gallium arsenide over germanium, and amorphous silicon) and two types of structural materials (carbon composite and arimid fiber composite). The results show that the catenary shape of the PV blanket corresponding to zero end angle at the base with respect to the horizontal results in the highest specific power. The tent angle is determined by optimizing the specific mass and the output power for maximum specific power. The combination of carbon fiber structural material and amorphous silicon blanket produces the highest specific power.

  11. J-configured offshore oil production riser

    SciTech Connect

    Wallace, N.R.

    1987-11-03

    This patent describes an apparatus for use in transporting hydrocarbon fluids from subsea wellheads or a manifold to a movable production vessel comprising: a formed-in-place riser of rigid pipe and having a horizontal section, a sag bend section and an upright section. The horizontal section has means for attaching the riser to the subsea manifold. The upper end of the upright section having means for coupling the same to the production vessel. The sag bend section having only a single sag bend and defining a smooth transition between the horizontal section and the upright section. The horizontal section is adapted to frictionally engage the seabed. The sag bend section is free of any structure for connecting it to the seabed. The coupling means is the only means for connecting the upright section to the production vessel.

  12. Selective Withdrawal Riser for Cave Run Lake.

    DTIC Science & Technology

    1986-11-01

    condition. 16. Conditions for vortex formation in the original design of the pro- posed riser are shown in Plates 16, 17, and 18 for the upper, lower, and...all five ports open, respectively. The definition of vortex stages 0 and A-E is shown in Figure 6. The area between the upstream corner of the...the region of most severe vortex activity. Large-scale circulation is present for almost all flow conditions. % 17. Several types of vortex

  13. Riser equipment decontamination engineering task plan

    SciTech Connect

    BOGER, R.M.

    1999-05-12

    On October 15, 1998, two Characterization Project Operations (CPO) employees were found to have contaminated clothing. An operator had 300,000-dpm/100cm2 beta/gamma, no alpha, contamination on his coat sleeve and a Radiation Control Technician (RCT) had 10,000 dpm/100cm2 beta/gamma, no alpha, on his shirt sleeve. The CPO swing shift crew was working in TX tank farm, performing sampling activities at 241-TX-113. TX tank farm is a ''clean farm'' and does not require anti-contamination clothing for entry. The CPO personnel were dressed in normal work clothes. An operator and an RCT were performing a pre-job survey that involved removing bagging around the riser equipment. When the RCT saw that the contamination readings from smear samples of the riser equipment were greater than expected, the job was suspended. Crew members were then directed to areas of lower background radiation for personnel surveys. During personnel surveys, reportable contamination was found on the coat sleeve of the operator who had been involved in the pre-job survey and on the shirt sleeve of the RCT who had been involved in the pre-job survey. No other personnel were found to be contaminated. Because of this off normal event Characterization Engineering was given the following corrective action: Examine the process methodology used for core sampling operations to determine practicality and potential long-term advantages of reducing personnel contact with contaminated equipment. This Engineering Task Plan ensures that LMHC 1998a, Corrective Action No.7 is completely addressed by Characterization Engineering. The deliverable is an Engineering Study that evaluates decontamination of riser equipment components and considers additional engineered features to reduce potential exposure to workers operating the riser equipment. This engineering study shall also address any released design features that have failed to be implemented.

  14. Dynamic analysis of a circulating fluidized bed riser

    SciTech Connect

    Panday, Rupen; Shadle, Lawrence J.; Guenther, Chris

    2012-01-01

    A linear state model is proposed to analyze dynamic behavior of a circulating fluidized bed riser. Different operating regimes were attained with high density polyethylene beads at low and high system inventories. The riser was operated between the classical choking velocity and the upper transport velocity demarcating fast fluidized and transport regimes. At a given riser superficial gas velocity, the aerations fed at the standpipe were modulated resulting in a sinusoidal solids circulation rate that goes into the riser via L-valve. The state model was derived based on the mass balance equation in the riser. It treats the average solids fraction across the entire riser as a state variable. The total riser pressure drop was modeled using Newton’s second law of motion. The momentum balance equation involves contribution from the weight of solids and the wall friction caused by the solids to the riser pressure drop. The weight of solids utilizes the state variable and hence, the riser inventory could be easily calculated. The modeling problem boils down to estimating two parameters including solids friction coefficient and time constant of the riser. It has been shown that the wall friction force acts in the upward direction in fast fluidized regime which indicates that the solids were moving downwards on the average with respect to the riser wall. In transport regimes, the friction acts in the opposite direction. This behavior was quantified based on a sign of Fanning friction factor in the momentum balance equation. The time constant of the riser appears to be much higher in fast fluidized regime than in transport conditions.

  15. Analyzing the effect of integrating riser/mooring line design

    SciTech Connect

    Chakrabarti, P.; Chandwani, R.; Larsen, I.

    1996-12-31

    The design of riser and mooring systems for a floating production system usually assumes uncoupled behavior of the two systems, and each system is analyzed for the effects of the vessel response given as input. In certain situations, such as for a floating production system, the presence of the risers can affect natural periods, damping, and slow drift response of the vessel thereby influencing the system design. This paper discusses a method for analyzing the coupled riser/mooring system with emphasis on the effect of the risers on the total system behavior.

  16. A photovoltaic catenary-tent array for the Martian surface

    NASA Astrophysics Data System (ADS)

    Crutchik, M.; Colozza, Anthony J.; Appelbaum, J.

    1993-08-01

    To provide electrical power during an exploration mission to Mars, a deployable tent-shaped structure with a flexible photovoltaic (PV) blanket is proposed. The array is designed with a self-deploying mechanism utilizing pressurized gas expansion. The structural design for the array uses a combination of cables, beams, and columns to support and deploy the PV blanket. Under the force of gravity a cable carrying a uniform load will take the shape of a catenary curve. A catenary-tent collector is self shadowing which must be taken into account in the solar radiation calculation. The shape and the area of the shadow on the array was calculated and used in the determination of the global radiation on the array. The PV blanket shape and structure dimension were optimized to achieve a configuration which maximizes the specific power (W/kg). The optimization was performed for four types of PV blankets (Si, GaAs/Ge, GaAs CLEFT, and amorphous Si) and four types of structure materials (Carbon composite, Aramid Fiber composite, Aluminum, and Magnesium). The results show that the catenary shape of the PV blanket, which produces the highest specific power, corresponds to zero end angle at the base with respect to the horizontal. The tent angle is determined by the combined effect of the array structure specific mass and the PV blanket output power. The combination of carbon composite structural material and GaAs CLEFT solar cells produce the highest specific power. The study was carried out for two sites on Mars corresponding to the Viking Lander locations. The designs were also compared for summer, winter, and yearly operation.

  17. A photovoltaic catenary-tent array for the Martian surface

    NASA Technical Reports Server (NTRS)

    Crutchik, M.; Colozza, Anthony J.; Appelbaum, J.

    1993-01-01

    To provide electrical power during an exploration mission to Mars, a deployable tent-shaped structure with a flexible photovoltaic (PV) blanket is proposed. The array is designed with a self-deploying mechanism utilizing pressurized gas expansion. The structural design for the array uses a combination of cables, beams, and columns to support and deploy the PV blanket. Under the force of gravity a cable carrying a uniform load will take the shape of a catenary curve. A catenary-tent collector is self shadowing which must be taken into account in the solar radiation calculation. The shape and the area of the shadow on the array was calculated and used in the determination of the global radiation on the array. The PV blanket shape and structure dimension were optimized to achieve a configuration which maximizes the specific power (W/kg). The optimization was performed for four types of PV blankets (Si, GaAs/Ge, GaAs CLEFT, and amorphous Si) and four types of structure materials (Carbon composite, Aramid Fiber composite, Aluminum, and Magnesium). The results show that the catenary shape of the PV blanket, which produces the highest specific power, corresponds to zero end angle at the base with respect to the horizontal. The tent angle is determined by the combined effect of the array structure specific mass and the PV blanket output power. The combination of carbon composite structural material and GaAs CLEFT solar cells produce the highest specific power. The study was carried out for two sites on Mars corresponding to the Viking Lander locations. The designs were also compared for summer, winter, and yearly operation.

  18. Polynomial and catenary curve fits to human dental arches.

    PubMed

    Pepe, S H

    1975-01-01

    Polynomial and catenary equations were fit by least square error methods to the dentitions of seven children with "normal" occlusion. Mean and mean square error were then used to analyze accuracy of curve fits and asymmetries of arches. A lack of congruency for the "lines of occlusion" common to the maxilla and mandible suggest that the defining anatomic landmarks are inaccurate. These analyses show that the coefficients of the sixth degree polynomial equations appear to have potential as clinical indicators of arch form and, perhaps, malocclusion.

  19. Choosing the filter for catenary image enhancement method based on the non-subsampled contourlet transform

    NASA Astrophysics Data System (ADS)

    Wu, Changdong; Liu, Zhigang; Jiang, Hua

    2017-05-01

    The quality of image enhancement plays an important role in the catenary fault diagnosis system based on the image processing technique. It is necessary to enhance the low contrast image of catenary for better detecting the state of catenary part. The Non-subsampled Contourlet transform (NSCT) is the improved Contourlet transform (CT), which can effectively solve the problem of artifact phenomenon in the enhanced catenary image. Besides, choosing the enhancement function and the filter of the NSCT will directly influence the image enhancement effect. In this paper, the proposed method is implemented by combining the NSCT with the nonlinear enhancement function to enhance the catenary image. First, how to choose the filter of the NSCT is discussed. Second, the NSCT is used to decompose the image. Then, the chosen nonlinear enhancement function is used to process the decomposed coefficient of the NSCT. Finally, the NSCT is inversed to obtain the enhanced image. In this paper, we evaluate our algorithm using the lifting wavelet transform, retinex enhancement method, dark channel enhancement method, curvelet transform, and CT method as a comparison to enhance a group of randomly selected low contrast catenary images, respectively. The results of comparative experiments conducted show that the proposed method can effectively enhance the catenary image, the contrast of image is improved, the catenary parts are obvious, and the artifact phenomenon is effectively eliminated, where image details (edges, textures, or smooth areas) are also well preserved. Besides, the values (detail variance-background variance, signal-to-noise ratio, and edge preservation index) of measuring the image enhancement capacity are improved, while the mean squared error value is decreased when compared to the CT method. These indicate that the proposed method is an excellent catenary image enhancement approach.

  20. Choosing the filter for catenary image enhancement method based on the non-subsampled contourlet transform.

    PubMed

    Wu, Changdong; Liu, Zhigang; Jiang, Hua

    2017-05-01

    The quality of image enhancement plays an important role in the catenary fault diagnosis system based on the image processing technique. It is necessary to enhance the low contrast image of catenary for better detecting the state of catenary part. The Non-subsampled Contourlet transform (NSCT) is the improved Contourlet transform (CT), which can effectively solve the problem of artifact phenomenon in the enhanced catenary image. Besides, choosing the enhancement function and the filter of the NSCT will directly influence the image enhancement effect. In this paper, the proposed method is implemented by combining the NSCT with the nonlinear enhancement function to enhance the catenary image. First, how to choose the filter of the NSCT is discussed. Second, the NSCT is used to decompose the image. Then, the chosen nonlinear enhancement function is used to process the decomposed coefficient of the NSCT. Finally, the NSCT is inversed to obtain the enhanced image. In this paper, we evaluate our algorithm using the lifting wavelet transform, retinex enhancement method, dark channel enhancement method, curvelet transform, and CT method as a comparison to enhance a group of randomly selected low contrast catenary images, respectively. The results of comparative experiments conducted show that the proposed method can effectively enhance the catenary image, the contrast of image is improved, the catenary parts are obvious, and the artifact phenomenon is effectively eliminated, where image details (edges, textures, or smooth areas) are also well preserved. Besides, the values (detail variance-background variance, signal-to-noise ratio, and edge preservation index) of measuring the image enhancement capacity are improved, while the mean squared error value is decreased when compared to the CT method. These indicate that the proposed method is an excellent catenary image enhancement approach.

  1. Nonlinear analysis of wind-induced vibration of high-speed railway catenary and its influence on pantograph-catenary interaction

    NASA Astrophysics Data System (ADS)

    Song, Yang; Liu, Zhigang; Wang, Hongrui; Lu, Xiaobing; Zhang, Jing

    2016-06-01

    The wind-induced vibration of the high-speed catenary and the dynamic behaviour of the pantograph-catenary under stochastic wind field are firstly analysed. The catenary model is established based on nonlinear cable and truss elements, which can fully describe the nonlinearity of each wire and the initial configuration. The model of the aerodynamic forces acting on the messenger/contact wire is deduced by considering the effect of the vertical and horizontal fluctuating winds. The vertical and horizontal fluctuating winds are simulated by employing the Davenport and Panofsky spectrums, respectively. The aerodynamic coefficients of the contact/messenger wire are calculated through computational fluid dynamics. The wind-induced vibration response of catenary is analysed with different wind speeds and angles. Its frequency-domain characteristics are discussed using Auto Regression model. Finally, a pantograph model is introduced and the contact force of the pantograph-catenary under stochastic wind is studied. The results show that both the wind speed and the attack angle exert a significant effect on the wind-induced vibration. The existence of the groove on the contact wire cross-section leads to a significant change of the aerodynamic coefficient, which affects largely the aerodynamic forces applied on the catenary wires, as well as the vibration response. The vibration frequency with high spectral power mainly concentrates on the predominant frequency of the fluctuating wind and the natural frequency of catenary. The increase in the wind speed results in a significant deterioration of the current collection. The numerical example shows that a relatively stable current collection can be ensured when the wind flows at the relatively horizontal direction.

  2. Fuzzy Energy Management for a Catenary-Battery-Ultracapacitor based Hybrid Tramway

    NASA Astrophysics Data System (ADS)

    Jibin, Yang; Jiye, Zhang; Pengyun, Song

    2017-05-01

    In this paper, an energy management strategy (EMS) based on fuzzy logic control for a catenary-battery-ultracapacitor powered hybrid modern tramway was presented. The fuzzy logic controller for the catenary zone and catenary-less zone was respectively designed by analyzing the structure and working mode of the hybrid system, then an energy management strategy based on double fuzzy logic control was proposed to enhance the fuel economy. The hybrid modern tramway simulation model was developed based on MATLAB/Simulink environment. The simulation results show that the proposed EMS can satisfy the demand of dynamic performance of the tramway and achieve the power distribution reasonably between the each power source.

  3. Critical design aspects of dynamic titanium alloy risers

    SciTech Connect

    Baxter, C.F.; Schutz, R.W.

    1996-12-01

    Titanium alloys offer a unique, attractive combination of physical, mechanical, and corrosion properties for design of dynamic, compliant offshore risers. The Ti-6Al-4V ELI alloy, in a beta-transformed condition and with minor ruthenium or palladium additions for chloride resistance above 80 C, represent logical base-case metallic materials for compliant risers. All of the technology and components needed to produce a complete, viable titanium alloy compliant riser system, including pipe, termination designs, joining methods, and coatings are available, and are reviewed in this paper.

  4. Vortex shedding induced dynamic response of marine risers

    SciTech Connect

    Rajabi, F.; Mangiavacchi, A.; Zedan, M.F.

    1984-06-01

    An analytical model to predict the dynamic response of a riser in regular waves or in current to vortex shedding-induced lift forces is described. The riser is treated as a continuous beam under tension. A modal superposition scheme is used to solve the linearized equation of motion in the frequency domain. The excitation lift force is represented by a harmonic function with a frequency equal to the dominant vortex shedding frequency. Empirical correlations are used to determine the lift coefficients and shedding frequencies along the riser. Lift amplification is considered at or near the ''lock-in'' conditions. The fluid resistance to riser oscillations is represented by a Morison's equation-type expression.

  5. Vortex-Induced Vibrations of a Riser with Design Variations

    DTIC Science & Technology

    2016-06-19

    the following mechanical concepts of VIV:  How gravity and fluid drag evolves a 3D shape in the riser  How this shape creates specific structural...position. These differences result mostly from gravity acting transverse to pipeline, but longitudinal to the riser. Other comparisons show more...lacks sufficient tension or curvature and can grow to very large values as tension and curvature evolve with transverse displacement. Gravity and

  6. The Effect of a Soap Film on a Catenary: Measurement of Surface Tension from the Triangular Configuration

    ERIC Educational Resources Information Center

    Behroozi, F.; Behroozi, P. S.

    2011-01-01

    A chain assumes the well-known shape known as a catenary when it hangs loosely from two points in a gravitational field. The correct solution of the catenary was one of the early triumphs of the newly invented calculus of variations at the end of the 17th century. Here we revisit the catenary and show that, for a chain hanging from a horizontal…

  7. The Effect of a Soap Film on a Catenary: Measurement of Surface Tension from the Triangular Configuration

    ERIC Educational Resources Information Center

    Behroozi, F.; Behroozi, P. S.

    2011-01-01

    A chain assumes the well-known shape known as a catenary when it hangs loosely from two points in a gravitational field. The correct solution of the catenary was one of the early triumphs of the newly invented calculus of variations at the end of the 17th century. Here we revisit the catenary and show that, for a chain hanging from a horizontal…

  8. Deep water drilling risers in calm and harsh environments

    SciTech Connect

    Olufsen, A.; Nordsve, N.T.

    1994-12-31

    The overall objective of the work presented in this paper is to increase the knowledge regarding application of deep water drilling risers in different environmental conditions. Identification of key parameters and their impact on design and operation of deep water drilling risers are emphasized. Riser systems for two different cases are evaluated. These are: drilling offshore Nigeria in 1,200 m water depth; drilling at the Voering Plateau offshore Northern Norway in 1,500 m water depth. The case studies are mainly referring to requirements related to normal drilling operation of the riser. They are not complete with respect to describe of total riser system design. The objectives of the case studies have been to quantify the important of various parameters and to establish limiting criteria for drilling. Dynamic riser analyses are also performed. For the Nigeria case, results for a design wave with 100 years return period show that the influence of dynamic response is only marginal (but it may of course be significant for fatigue damage/life time estimation). The regularity of the drilling operation is given as the probability that jointly occurring wave heights and current velocities are within the limiting curve.

  9. Computer simulation of FCC riser reactors.

    SciTech Connect

    Chang, S. L.; Golchert, B.; Lottes, S. A.; Petrick, M.; Zhou, C. Q.

    1999-04-20

    A three-dimensional computational fluid dynamics (CFD) code, ICRKFLO, was developed to simulate the multiphase reacting flow system in a fluid catalytic cracking (FCC) riser reactor. The code solve flow properties based on fundamental conservation laws of mass, momentum, and energy for gas, liquid, and solid phases. Useful phenomenological models were developed to represent the controlling FCC processes, including droplet dispersion and evaporation, particle-solid interactions, and interfacial heat transfer between gas, droplets, and particles. Techniques were also developed to facilitate numerical calculations. These techniques include a hybrid flow-kinetic treatment to include detailed kinetic calculations, a time-integral approach to overcome numerical stiffness problems of chemical reactions, and a sectional coupling and blocked-cell technique for handling complex geometry. The copyrighted ICRKFLO software has been validated with experimental data from pilot- and commercial-scale FCC units. The code can be used to evaluate the impacts of design and operating conditions on the production of gasoline and other oil products.

  10. Riser Feeding Evaluation Method for Metal Castings Using Numerical Analysis

    NASA Astrophysics Data System (ADS)

    Ahmad, Nadiah

    One of the design aspects that continues to create a challenge for casting designers is the optimum design of casting feeders (risers). As liquid metal solidifies, the metal shrinks and forms cavities inside the casting. In order to avoid shrinkage cavities, risers are added to the casting shape to supply additional molten metal when shrinkage occurs during solidification. The shrinkage cavities in the casting are compensated by controlling the cooling rate to promote directional solidification. This control can be achieved by designing the casting such that the cooling begins at the sections that are farthest away from the risers and ends at the risers. Therefore, the risers will solidify last and feed the casting with the molten metal. As a result, the shrinkage cavities formed during solidification are in the risers which are later removed from the casting. Since casting designers have to usually go through iterative processes of validating the casting designs which are very costly due to expensive simulation processes or manual trials and errors on actual casting processes, this study investigates more efficient methods that will help casting designers utilize their casting experiences systematically to develop good initial casting designs. The objective is to reduce the casting design method iterations; therefore, reducing the cost involved in that design processes. The aim of this research aims at finding a method that can help casting designers design effective risers used in sand casting process of aluminum-silicon alloys by utilizing the analysis of solidification simulation. The analysis focuses on studying the significance of pressure distribution of the liquid metal at the early stage of casting solidification, when heat transfer and convective fluid flow are taken into account in the solidification simulation. The mathematical model of casting solidification was solved using the finite volume method (FVM). This study focuses to improve our

  11. Waves, modes and properties with a major impact on dynamic pantograph-catenary interaction

    NASA Astrophysics Data System (ADS)

    Vo Van, Olivier; Massat, Jean-Pierre; Balmes, Etienne

    2017-08-01

    Understanding the dynamic behavior of the pantograph-catenary system is crucial for design improvement, but many factors influence the contact force, which is the main design objective. To give a proper understanding of dynamic characteristics, the paper uses a combination of mass drop tests on a catenary, analytic models and parametric finite element model simulations allowing a fine analysis of the influence of train speed. The first contributor to contact force variations is the geometry of the catenary under gravity loading. This parameter is however shown to be insufficient to explain higher frequency effects. The second contributor is the propagation of waves in the contact and messenger wires. The influence of wave dispersion is first demonstrated, which emphasizes the importance of considering the bending stiffness. Wave compensation by droppers and reflections at the mast are then shown to be important. Characteristic times associated with wave group velocities are finally used to explain the series of harmonic contributions visible in spectra in the catenary and pantograph frames. Finally, modes are shown to play a role particularly when their frequencies coincide with other contributions. The notion of mode groups, associated wave velocities and relevant design variables are discussed. Several observations pave the way for future work on catenary design.

  12. Stripwise discrete vortex method for VIV analysis of flexible risers

    NASA Astrophysics Data System (ADS)

    Sun, L.; Zong, Z.; Dong, J.; Dong, G. H.; Liu, C. F.

    2012-11-01

    This paper presents a stripwise discrete vortex method (SDVM) to study the vortex-induced vibration of flexible risers. The discrete vortex method is employed to calculate the vortex-induced vibration (VIV) of each strip, and the finite volume method and increment method are used to compute the 3-D dynamics of the flexible riser. To verify the discrete vortex method for a single cylindrical strip of the entire flexible riser, a cylinder with elastic supports exerted by a 2-D uniform flow with a high Reynolds number is investigated. The 1-D transverse motion, 2-D transverse motion and 2-D stream-wise motion, as well as their influences on the wake shapes, are considered. Comparisons are made between the transverse amplitudes for the single degree of freedom and two degrees of freedom elastic-mounted systems. The relations between the lift coefficients and response amplitudes of the different mass ratios and reduced velocities are further discussed. The characteristics of the motion responses of the cylinder for different mass ratios and degree of freedoms are also discussed. Finally, the present numerical model is employed to calculate a 3-D flexible riser exerted by the uniform current, and the analysis of the numerical results shows the characteristics of the vortex-induced vibration of a flexible riser.

  13. Dynamic Stiffness of a Railway Overhead Wire System and its Effect on Pantograph-Catenary System Dynamics

    NASA Astrophysics Data System (ADS)

    Wu, T. X.; Brennan, M. J.

    1999-01-01

    For an electrical railway overhead wire system there are two main factors which crucially affect the quality of current collection. One is the spatial stiffness variation of the overhead wire along each span and the other is the flexural wave motion in the wire. In this paper a periodically excited single-degree-of-freedom (SDOF) model of a combined pantograph-catenary system is introduced and its basic dynamic behaviour is discussed. To investigate the effect of wave propagation in the overhead wire on vibration of the pantograph the dynamic stiffness of the catenary is introduced into the model. The dynamic stiffness of the catenary is determined by representing the overhead wire system as an infinite periodically spring-supported string. The results show that the dynamic stiffness of the catenary varies with train speed and its effect on the performance of the pantograph-catenary system is discussed.

  14. Dynamic Stiffness of a Railway Overhead Wire System and its Effect on PANTOGRAPH-CATENARY System Dynamics

    NASA Astrophysics Data System (ADS)

    Wu, T. X.; Brennan, M. J.

    1999-01-01

    For an electrical railway overhead wire system there are two main factors which crucially affect the quality of current collection. One is the spatial stiffness variation of the overhead wire along each span and the other is the flexural wave motion in the wire. In this paper a periodically excited single-degree-of-freedom (SDOF) model of a combined pantograph-catenary system is introduced and its basic dynamic behaviour is discussed. To investigate the effect of wave propagation in the overhead wire on vibration of the pantograph the dynamic stiffness of the catenary is introduced into the model. The dynamic stiffness of the catenary is determined by representing the overhead wire system as an infinite periodically spring-supported string. The results show that the dynamic stiffness of the catenary varies with train speed and its effect on the performance of the pantograph-catenary system is discussed.

  15. Post-riser quench improves FCC yields, profitability

    SciTech Connect

    Quinn, G.P.; Silverman, M.A.

    1996-01-15

    Performance tests of a post-riser quench system have shown increases in gasoline yield; reductions in fuel gas, butadienes, and pentadienes; and improved oxidation stability of FCC gasoline. Following commercial trials in six of Amoco Petroleum Products` refineries for some 10 years, the system is now being installed by other refiners. Elimination of post-riser thermal cracking is essential to achieving the most desirable product slate. Most of Amoco`s FCC units (FCCUs) have rough-cut cyclone systems in which there is significant vapor residence time in the disengaging vessel. To overcome this problem Amoco chose to reduce the temperature in the dilute phase. This technology involves quenching the dilute phase, thereby reducing the thermal cracking rates. The approach is very effective and virtually eliminates post-riser cracking. This paper reviews this design.

  16. Multifunctional two-stage riser fluid catalytic cracking process.

    PubMed

    Zhang, Jinhong; Shan, Honghong; Chen, Xiaobo; Li, Chunyi; Yang, Chaohe

    This paper described the discovering process of some shortcomings of the conventional fluid catalytic cracking (FCC) process and the proposed two-stage riser (TSR) FCC process for decreasing dry gas and coke yields and increasing light oil yield, which has been successfully applied in 12 industrial units. Furthermore, the multifunctional two-stage riser (MFT) FCC process proposed on the basis of the TSR FCC process was described, which were carried out by the optimization of reaction conditions for fresh feedstock and cycle oil catalytic cracking, respectively, by the coupling of cycle oil cracking and light FCC naphtha upgrading processes in the second-stage riser, and the specially designed reactor for further reducing the olefin content of gasoline. The pilot test showed that it can further improve the product quality, increase the diesel yield, and enhance the conversion of heavy oil.

  17. Solids flow mapping in gas-solid risers

    NASA Astrophysics Data System (ADS)

    Bhusarapu, Satish Babu

    Gas-solid risers are extensively used in many industrial processes for gas-solid reactions (e.g. coal combustion and gasification) and for solid catalyzed gas phase reactions (e.g. fluid catalytic cracking, butane oxidation to maleic anhydride). Ab initio prediction of the complex multiphase fluid dynamics in risers is not yet possible, which makes reactor modeling difficult. In particular, quantification of solids flow and mixing is important. Almost all the experimental techniques used to characterize solids flow lead to appreciable errors in measured variables in large scale, high mass flux systems. In addition, none of the experimental techniques provide all the relevant data required to develop a satisfactory solids flow model. In this study, non-invasive Computer Automated Radioactive Particle Tracking (CARPT) is employed to visualize and quantify the solids dynamics and mixing in the gas-solid riser of a Circulating Fluidized Bed (CFB). A single radioactive tracer particle is monitored during its multiple visits to the riser and with an assumption of ergodicity, the following flow parameters are estimated: (a) Overall solids mass flux in the CFB loop. (b) Solids residence time distribution in the riser and down-comer. (c) Lagrangian and Eulerian solids velocity fields in a fully-developed section of the riser. This includes velocity fluctuations and components of the diffusivity tensor. The existing CARPT technique is extended to large scale systems. A new algorithm, based on a cross-correlation search, is developed for position rendition from CARPT data. Two dimensional solids holdup profiles are estimated using gamma-ray computed tomography. The image quality from the tomography data is improved by implementing an alternating minimization algorithm. This work establishes for the first time a reliable database for local solids dynamic quantities such as time-averaged velocities, Reynolds stresses, eddy diffusivities and turbulent kinetic energy. In addition

  18. A biomechanical evaluation of staircase riser heights and tread depths during stair-climbing.

    PubMed

    Mital, A; Fard, H F; Khaledi, H

    1987-08-01

    Several different staircase riser heights and tread depths were investigated in order to determine riser height and tread depth that minimized moments acting at the ankle, knee, and hipjoints while walking upstairs. The results indicated that joint moments were minimized when the riser height was 102 mm. For the tread depth, least moments were obtained when the depth was 305 mm.

  19. Pantograph catenary dynamic optimisation based on advanced multibody and finite element co-simulation tools

    NASA Astrophysics Data System (ADS)

    Massat, Jean-Pierre; Laurent, Christophe; Bianchi, Jean-Philippe; Balmès, Etienne

    2014-05-01

    This paper presents recent developments undertaken by SNCF Innovation & Research Department on numerical modelling of pantograph catenary interaction. It aims at describing an efficient co-simulation process between finite element (FE) and multibody (MB) modelling methods. FE catenary models are coupled with a full flexible MB representation with pneumatic actuation of pantograph. These advanced functionalities allow new kind of numerical analyses such as dynamic improvements based on innovative pneumatic suspensions or assessment of crash risks crossing areas that demonstrate the powerful capabilities of this computing approach.

  20. 241-SY-101 mulitport riser acceptance for beneficial use

    SciTech Connect

    Mendoza, R.E.

    1995-10-02

    This document formally demonstrates that the Acceptance for Beneficial USE (ABU) process for the SY tank farm Multiport Riser assembly has been properly completed in accordance with the ABU checklist. For each item required on the ABU checklist, a bibliography of the documentation prepared and released to satisfy the requirement is provided

  1. Design review report for multiport riser final design review

    SciTech Connect

    McWethy, L.M.; Sheen, E.M.

    1994-05-01

    This design review examined the design documents contained in a notebook prepared for the final design review of the multiport riser assembly. This assembly will support the Hydrogen Mitigation Test program for mitigation of safety issues for Hanford Waste Tank 241-SY-101. The purpose of the Multiport Riser is to provide multiple access ports of several diameters in a single 42 inch riser for simultaneous access of test and support equipment. The notebook was titled: {open_quotes}Multiport Riser Final Design Review.{close_quotes} The review was conducted using a database comment registration system whereby the reviewer comments were entered into the database and each comment was given a unique identifier. During the review, each comment was referred to by its identifier. Changes to comments, responses, and actions needed were made with the agreement of the committee and the reviewers at the formal design review meeting held March 1, 1994. When the structural analyses were available, they were distributed for review which allowed closure of all design review comments. Approval of the design was achieved and supporting documents are included in this report.

  2. Evaluating hillslope diffusion and terrace riser degradation in New Zealand and Idaho

    NASA Astrophysics Data System (ADS)

    Clarke, Brian A.; Burbank, Douglas W.

    2010-06-01

    The relationship of sediment flux to surface slope is a predominant control on the evolution of transport-limited hillslopes. Although both linear and nonlinear sediment flux models have been proposed and widely debated, this functional relationship remains one of the outstanding questions in geomorphology. We examine degradation of fluvial terrace risers in New Zealand and Idaho in order to test the linear diffusion model and to better understand the relationship between sediment flux and slope. We implement three techniques based on the linear diffusion model, as well as a geometric scaling method that uses proportional relationships in riser geometry rather than a specific transport equation model, to assess rates of degradation. We show that techniques that utilize the riser midpoint slope as the primary metric of degradation, as opposed to the full scarp profile, offer the simplest and most reliable assessment of riser degradation. Our findings suggest that the linear diffusion model does not accurately describe terrace riser degradation, except for low-angle risers for which linear and nonlinear forms are indistinguishable. Results from the geometric scaling method show that degradation rates in both regions differ by a factor of two between equator- and pole-facing risers and that diffusion ages of Idaho risers are approximately 2 times those of New Zealand risers. Similar geometric trends in riser evolution from both regions reveal that terrace riser degradation is governed by a widely applicable relationship between sediment flux and slope.

  3. Modal analysis of measurements from a large-scale VIV model test of a riser in linearly sheared flow

    NASA Astrophysics Data System (ADS)

    Lie, H.; Kaasen, K. E.

    2006-05-01

    Large-scale model testing of a tensioned steel riser in well-defined sheared current was performed at Hanøytangen outside Bergen, Norway in 1997. The length of the model was 90 m and the diameter was 3 cm. The aim of the present work is to look into this information and try to improve the understanding of vortex-induced vibrations (VIV) for cases with very high order of responding modes, and in particular to study if and under which circumstances the riser motions would be single-mode or multi-mode. The measurement system consisted of 29 biaxial gauges for bending moment. The signals are processed to yield curvature and displacement and further to identify modes of vibration. A modal approach is used successfully employing a combination of signal filtering and least-squares fitting of precalculated mode-shapes. As a part of the modal analysis, it is demonstrated that the equally spaced instrumentation limited the maximum mode number to be extracted to be equal to the number of instrumentation locations. This imposed a constraint on the analysis of in-line (IL) vibration, which occurs at higher frequencies and involves higher modes than cross-flow (CF). The analysis has shown that in general the riser response was irregular (i.e. broad-banded) and that the degree of irregularity increases with the flow speed. In some tests distinct spectral peaks could be seen, corresponding to a dominating mode. No occurrences of single-mode (lock-in) were seen. The IL response is more broad-banded than the CF response and contains higher frequencies. The average value of the displacement r.m.s over the length of the riser is computed to indicate the magnitude of VIV motion during one test. In the CF direction the average displacement is typically 1/4 of the diameter, almost independent of the flow speed. For the IL direction the values are in the range 0.05 0.08 of the diameter. The peak frequency taken from the spectra of the CF displacement at riser midpoint show approximately

  4. ALARA plan for the Old Hydrofracture Facility tanks contents removal project at Oak Ridge National Laboratory, Oak Ridge, Tennessee. Amendment 1 for Appendix B: Install flex-pipe on tank riser spools

    SciTech Connect

    1998-05-13

    This amendment to Appendix B contains the specific ALARA evaluations for installing flex-pipe on riser spools to accommodate ventilation duct connections to the north risers of each tank. The work will be a routine task that is part of the Equipment Installation and Mobilization phase of the project. The dose rates were estimated using the recent Radiological Surveillance Section radiological survey: SAAS-97-063S. Task B-6 has been added to the OHF Project ALARA review process to address a field decision to modify an approach to installing the tank ventilation system. The revised approach will incorporate 12-in. diameter, 36-in. long, stainless steel flex-pipe connected to each north riser spool to address the problem of pipe fitting multiple bends and turns expected with the 12-in. PVC duct. This improved approach will reduce the time necessary to install the duct system between the tanks and the ventilation skid. However, the task includes opening the 12-in. riser spool connections to replace the currently installed blind gaskets. Since a riser spool for each tank will be opened, there is a potential for significant personnel exposure and spread of contamination that will addressed through this ALARA review process.

  5. Use of lift gas in an FCC reactor riser

    SciTech Connect

    Hammershaimb, H. U.; Lomas, D. A.

    1984-10-30

    A process for converting normally liquid hydrocarbons with an active fluid catalytic cracking catalyst which comprises: passing an upflowing suspension of hot regenerated active fluid catalytic cracking catalyst in a lift gas comprising hydrocarbons including not more than 10 mole % C/sub 3/ and heavier hydrocarbons through a lower portion of a vertically orientated riser conversion zone at a velocity of from about 1.8 to less than 12.2 meters per second, and for a residence time from about 0.5 to about 15 seconds, the ratio of catalyst to hydrocarbon in said lift gas being greater than 80; and introducing the normally liquid hydrocarbons into the upflowing suspension at a locus in the riser conversion zone downstream of the lower portion to form a catalyst-hydrocarbon mixture wherein the temperature and residence time are sufficient to effect the desired conversion. The process is particularly useful for the treatment of a heavy residual feedstock.

  6. Promoting stair use: single versus multiple stair-riser messages.

    PubMed

    Webb, Oliver J; Eves, Frank F

    2005-09-01

    Message banners attached to stair risers produced a significant increase in pedestrian stair use, exceeding effects previously reported for conventional posters. Multiple instances of the same message banner, however, were as effective as banners featuring different messages. Therefore, greater visibility, rather than message variety, appears to account for the superiority of the banner format. Our findings indicate the feasibility of simple stair-use promotion campaigns based around the repetition of a single message.

  7. Remote installation of risers on underground nuclear waste storage tanks

    SciTech Connect

    Jackson, J.P.; Gessner, R.F.

    1988-03-01

    The West Valley Demonstration Project was established to solidify 2120 m/sup 3/ (560,000) gallons of high-level nuclear waste generated during six years of commercial nuclear fuel reprocessing. This liquid will be processed to remove radioactive elements which, with the remaining sludge, will be combined with glass formers and be converted into borosilicate glass. Risers were installed on the high-level tank for installation of pumps which will be used to remove the liquid and sludge. The extensive use of remote technology was required to install the risers and to minimize operator exposure to high levels of radiation and contamination. The riser installation required remotely: drilling through two feet of concrete shielding; installing pump access pipes which are welded to the tank top; and cutting holes in tanks located 3658 mm (12) feet below ground. These operations were successfully completed 13 times without exposing personnel to high-level radiation or contamination. Specially designed remote equipment was developed for each step of this operation. Extensive operator training in the use of this equipment was performed on a tank with low radiation prior to work on the high-level tank. This paper discusses the application of remote technology that assured a quality job was safely accomplished. 3 refs., 18 figs., 2 tabs.

  8. A CFD study of gas-solid jet in a CFB riser flow

    SciTech Connect

    Li, Tingwen; Guenther, Chris

    2012-03-01

    Three-dimensional high-resolution numerical simulations of a gas–solid jet in a high-density riser flow were conducted. The impact of gas–solid injection on the riser flow hydrodynamics was investigated with respect to voidage, tracer mass fractions, and solids velocity distribution. The behaviors of a gas–solid jet in the riser crossflow were studied through the unsteady numerical simulations. Substantial separation of the jetting gas and solids in the riser crossflow was observed. Mixing of the injected gas and solids with the riser flow was investigated and backmixing of gas and solids was evaluated. In the current numerical study, both the overall hydrodynamics of riser flow and the characteristics of gas–solid jet were reasonably predicted compared with the experimental measurements made at NETL.

  9. Flow Regime Study in a High Density Circulating Fluidized Bed Riser with an Abrupt Exit

    SciTech Connect

    Mei, J.S.; Shadle, L.J.; Yue, P.C.; Monazam, E.R.

    2007-01-01

    Flow regime study was conducted in a 0.3 m diameter, 15.5 m height circulating fluidized bed (CFB) riser with an abrupt exit at the National Energy Technology Laboratory of the U.S. Department of Energy. Local particle velocities were measured at various radial positions and riser heights using an optical fiber probe. On-line measurement of solid circulating rate was continuously recorded by the Spiral. Glass beads of mean diameter 61 μm and particle density of 2,500 kg/m3 were used as bed material. The CFB riser was operated at various superficial gas velocities ranging from 3 to 7.6 m/s and solid mass flux from 20 to 550 kg/m2-s. At a constant riser gas velocity, transition from fast fluidization to dense suspension upflow (DSU) regime started at the bottom of the riser with increasing solid flux. Except at comparatively low riser gas velocity and solid flux, the apparent solid holdup at the top exit region was higher than the middle section of the riser. The solid fraction at this top region could be much higher than 7% under high riser gas velocity and solid mass flux. The local particle velocity showed downward flow near the wall at the top of the riser due to its abrupt exit. This abrupt geometry reflected the solids and, therefore, caused solid particles traveling downward along the wall. However, at location below, but near, the top of the riser the local particle velocities were observed flowing upward at the wall. Therefore, DSU was identified in the upper region of the riser with an abrupt exit while the fully developed region, lower in the riser, was still exhibiting core-annular flow structure. Our data were compared with the flow regime boundaries proposed by Kim et al. [1] for distinguishing the dilute pneumatic transport, fast fluidization, and DSU.

  10. Buckling of risers in tension due to internal pressure: nonmovable boundaries

    SciTech Connect

    Bernitsas, M.M.; Kokkinis, T.

    1983-01-01

    Open-ended tubular columns may buckle globally as Euler columns due to the action of internal fluid pressure even while they are in tension along their entire length. Hydraulic columns, marine drilling, and production risers are prone to such static instability. This work explains this phenomenon, defines the critical riser length for which this instability may occur, and provides graphs with values of the critical length which can readily be used for design purposes. Risers with nonmovable boundaries are considered. 17 references.

  11. Failure assessment of aluminum liner based filament-wound hybrid riser subjected to internal hydrostatic pressure

    NASA Astrophysics Data System (ADS)

    Dikshit, Vishwesh; Seng, Ong Lin; Maheshwari, Muneesh; Asundi, A.

    2015-03-01

    The present study describes the burst behavior of aluminum liner based prototype filament-wound hybrid riser under internal hydrostatic pressure. The main objective of present study is to developed an internal pressure test rig set-up for filament-wound hybrid riser and investigate the failure modes of filament-wound hybrid riser under internal hydrostatic burst pressure loading. The prototype filament-wound hybrid riser used for burst test consists of an internal aluminum liner and outer composite layer. The carbon-epoxy composites as part of the filament-wound hybrid risers were manufactured with [±55o] lay-up pattern with total composite layer thickness of 1.6 mm using a CNC filament-winding machine. The burst test was monitored by video camera which helps to analyze the failure mechanism of the fractured filament-wound hybrid riser. The Fiber Bragg Grating (FBG) sensor was used to monitor and record the strain changes during burst test of prototype filament-wound hybrid riser. This study shows good improvements in burst strength of filament-wound hybrid riser compared to the monolithic metallic riser. Since, strain measurement using FBG sensors has been testified as a reliable method, we aim to further understand in detail using this technique.

  12. Deep-water riser fatigue monitoring systems based on acoustic telemetry

    NASA Astrophysics Data System (ADS)

    Li, Baojun; Wang, Haiyan; Shen, Xiaohong; Yan, Yongsheng; Yang, Fuzhou; Hua, Fei

    2014-12-01

    Marine risers play a key role in the deep and ultra-deep water oil and gas production. The vortex-induced vibration (VIV) of marine risers constitutes an important problem in deep water oil exploration and production. VIV will result in high rates of structural failure of marine riser due to fatigue damage accumulation and diminishes the riser fatigue life. In-service monitoring or full scale testing is essential to improve our understanding of VIV response and enhance our ability to predict fatigue damage. One marine riser fatigue acoustic telemetry scheme is proposed and an engineering prototype machine has been developed to monitor deep and ultra-deep water risers' fatigue and failure that can diminish the riser fatigue life and lead to economic losses and eco-catastrophe. Many breakthroughs and innovation have been achieved in the process of developing an engineering prototype machine. Sea trials were done on the 6th generation deep-water drilling platform HYSY-981 in the South China Sea. The inclination monitoring results show that the marine riser fatigue acoustic telemetry scheme is feasible and reliable and the engineering prototype machine meets the design criterion and can match the requirements of deep and ultra-deep water riser fatigue monitoring. The rich experience and field data gained in the sea trial which provide much technical support for optimization in the engineering prototype machine in the future.

  13. Guided-waves technique for inspecting the health of wall-covered building risers

    NASA Astrophysics Data System (ADS)

    Tse, Peter W.; Chen, J. M.; Wan, X.

    2015-03-01

    The inspection technique uses guided ultrasonic waves (GW) has been proven effective in detecting pipes' defects. However, as of today, the technique has not attracted much market attention because of insufficient field tests and lack of traceable records with proven results in commercial applications. In this paper, it presents the results obtained by using GW to inspect the defects occurred in real gas risers that are commonly installed in tall buildings. The purpose of having risers is to deliver gas from any building external piping system to each household unit of the building. The risers extend from the external wall of the building, penetrate thorough the concrete wall, into the kitchen or bathroom of each household unit. Similar to in-service pipes, risers are prone to corrosion due to water leaks into the concrete wall. However, the corrosion occurs in the section of riser, which is covered by the concrete wall, is difficult to be inspected by conventional techniques. Hence, GW technique was employed. The effectiveness of GW technique was tested by laboratory and on-site experiments using real risers gathered from tall buildings. The experimental results show that GW can partially penetrate thorough the riser's section that is covered by wall. The integrity of the wall-covered section of a riser can be determined by the reflected wave signals generated by the corroded area that may exit inside the wall-covered section. Based on the reflected wave signal, one can determine the health of the wall-covered riser.

  14. The Stability of the Catenary Shapes for a Hanging Cable of Unspecified Length

    ERIC Educational Resources Information Center

    Mareno, A.; English, L. Q.

    2009-01-01

    It has long been known that when a cable of specified length is hung between two poles, it takes the shape of a catenary--a hyperbolic cosine function. In this paper, we study a variation of this problem. First, we consider a cable hanging between two poles in which one end of the cable is fixed to one pole; the other end of the cable runs over a…

  15. The Stability of the Catenary Shapes for a Hanging Cable of Unspecified Length

    ERIC Educational Resources Information Center

    Mareno, A.; English, L. Q.

    2009-01-01

    It has long been known that when a cable of specified length is hung between two poles, it takes the shape of a catenary--a hyperbolic cosine function. In this paper, we study a variation of this problem. First, we consider a cable hanging between two poles in which one end of the cable is fixed to one pole; the other end of the cable runs over a…

  16. A general method for calculating the mean transit times and distribution rate parameters of catenary metabolites.

    PubMed

    Cheng, H

    1992-04-01

    A general method for calculating the mean transit times and distribution rate parameters is described. The calculations require the AUC, AUMC, and derivatives of the plasma concentration profiles of the metabolites and its precursor. The method is applicable to catenary metabolites with any precursor order and does not require separate administration of the metabolite. The approach is applied to published data for the primary and secondary metabolites of ketamine.

  17. Nonlinear modelling of high-speed catenary based on analytical expressions of cable and truss elements

    NASA Astrophysics Data System (ADS)

    Song, Yang; Liu, Zhigang; Wang, Hongrui; Lu, Xiaobing; Zhang, Jing

    2015-10-01

    Due to the intrinsic nonlinear characteristics and complex structure of the high-speed catenary system, a modelling method is proposed based on the analytical expressions of nonlinear cable and truss elements. The calculation procedure for solving the initial equilibrium state is proposed based on the Newton-Raphson iteration method. The deformed configuration of the catenary system as well as the initial length of each wire can be calculated. Its accuracy and validity of computing the initial equilibrium state are verified by comparison with the separate model method, absolute nodal coordinate formulation and other methods in the previous literatures. Then, the proposed model is combined with a lumped pantograph model and a dynamic simulation procedure is proposed. The accuracy is guaranteed by the multiple iterative calculations in each time step. The dynamic performance of the proposed model is validated by comparison with EN 50318, the results of the finite element method software and SIEMENS simulation report, respectively. At last, the influence of the catenary design parameters (such as the reserved sag and pre-tension) on the dynamic performance is preliminarily analysed by using the proposed model.

  18. Unusual shapes for a catenary under the effects of surface tension and gravity: A variational treatment

    SciTech Connect

    Behroozi, F. ); Mohazzabi, P.; McCrickard, J. )

    1995-02-01

    The familiar catenary is the shape assumed by a chain or string as it hangs from two points. The mathematical equation of the catenary was first published more than three hundred years ago by Leibnitz and Huygen, among others. Here we consider the shapes assumed by a hanging string in the presence of gravity and surface tension. The surface tension is introduced by suspending the string from a thin horizontal rod while the area bounded by the string and the rod is covered with a soap film. The string then assumes new and wonderful shapes depending on the relative strength of the surface tension and the weight per unit length of the string. When surface tension dominates, the string is pulled inward, assuming a convex shape similar to the Greek letter [gamma]. On the other hand, when gravity is dominant the string is pulled outward and assumes a concave shape best described as a distorted catenary. However, when the gravitational force normal to the string matches the surface tension, the string takes a linear configuration similar to the letter [ital V]. Under suitable conditions, the string can be made to assume any of the three configurations by adjusting the separation of its end points. The equations that describe the shape of the string are derived by minimizing the total energy of the system and are presented for the three principal configurations.

  19. An optimized FBG-based fatigue monitoring strategy on deepwater risers

    NASA Astrophysics Data System (ADS)

    Li, Xuan; Ren, Peng; Zhou, Zhi; Ou, Jinping

    2014-11-01

    For the sake of the increasing demands of oil and gas essential, scientists and engineers have exerted great efforts in obtaining natural resources deposited in the deep water. Risers, as the channel between platform and wellhead, play a key role in oil and gas transportation. Subjected to coarse environmental conditions and uncertain loading patterns, risers would display complex dynamic behaviors which could result in severe fatigue damages. Recently, riser response is commonly measured using passive and durable Fiber Bragg Grating (FBG) strain sensors for industry safety, especially for Integrity Management (IM). However, for technique difficulties as well as economical consideration, it is impossible to execute distributed fatigue monitoring on the whole riser, which makes it essential to find out an optimized method utilizing the least number of sensors and reconstruct the global response of risers. This paper propose a method which combines H2 norms and Kalman filter to give optimal state estimation of risers based on limited FBG-based dynamic strain information. The H2 norms are used to give guideline for optimized sensor placement. Meanwhile, Kalman filter realize the global response reconstruction of risers as well as minimize the environmental disturbance. The accuracy and efficiency of the method has been verified by a numerical case. This study provides an FBG-based early warning technique for industry application of deepwater risers in future.

  20. Nonlinear quasi-static analysis of ultra-deep-water top-tension riser

    NASA Astrophysics Data System (ADS)

    Gao, Guanghai; Qiu, Xingqi; Wang, Ke; Liu, Jianjun

    2017-09-01

    In order to analyse the ultra-deep-water top-tension riser deformation in drilling conditions, a nonlinear quasi-static analysis model and equation are established. The riser in this model is regarded as a simply supported beam located in the vertical plane and is subjected to non-uniform axial and lateral forces. The model and the equation are solved by the finite element method. The effects of riser outside diameter, top tension ratio, sea surface current velocity, drag force coefficient, floating system drift distance and water depth on the riser lateral displacement are discussed. Results show that the riser lateral displacement increase with the increase in the sea surface current velocity, drag force coefficient and water depth, whereas decrease with the increase in the riser outside diameter, top tension ratio. The top tension ratio has an important influence on the riser deformation and it should be set reasonably under different circumstances. The drift of the floating system has a complicated influence on the riser deformation and it should avoid a large drift distance in the proceedings of drilling and production.

  1. Camera-based measurement for transverse vibrations of moving catenaries in mine hoists using digital image processing techniques

    NASA Astrophysics Data System (ADS)

    Yao, Jiannan; Xiao, Xingming; Liu, Yao

    2016-03-01

    This paper proposes a novel, non-contact, sensing method to measure the transverse vibrations of hoisting catenaries in mine hoists. Hoisting catenaries are typically moving cables and it is not feasible to use traditional methods to measure their transverse vibrations. In order to obtain the transverse displacements of an arbitrary point in a moving catenary, by superposing a mask image having the predefined reference line perpendicular to the hoisting catenaries on each frame of the processed image sequence, the dynamic intersecting points with a grey value of 0 in the image sequence could be identified. Subsequently, by traversing the coordinates of the pixel with a grey value of 0 and calculating the distance between the identified dynamic points from the reference, the transverse displacements of the selected arbitrary point in the hoisting catenary can be obtained. Furthermore, based on a theoretical model, the reasonability and applicability of the proposed camera-based method were confirmed. Additionally, a laboratory experiment was also carried out, which then validated the accuracy of the proposed method. The research results indicate that the proposed camera-based method is suitable for the measurement of the transverse vibrations of moving cables.

  2. Schools of Authentic and Inclusive Learning. Research Institute on Secondary Education Reform (RISER) for Youth with Disabilities Brief.

    ERIC Educational Resources Information Center

    Hanley-Maxwell, Cheryl; Phelps, L. Allen; Braden, Jeff; Warren, Valli

    This brief provides an overview of the foundation and framework for the Research Institute on Secondary Education Reform (RISER) for Youth with Disabilities. RISER focuses on secondary schools engaged in reform efforts that include students with disabilities and seeks to identify restructuring practices that benefit all students. RISERs goal is to…

  3. Assessment of primary healthcare professionals' management of hypertensive patients with riser pattern.

    PubMed

    Sagarra-Tió, María; Félez-Carrobé, Estel; Baiget, Montserrat; Félez, Jordi

    2015-02-01

    Ambulatory blood pressure monitoring (ABPM) was implemented in our primary care setting four years ago. Since then, 450 ABPMs have been performed and 69 riser subjects identified. The riser pattern is an independent risk factor for both incidence of cardiovascular events and their associated mortality. The purpose of this study was to assess the amount of control of essential hypertension (EH) among riser patients and to evaluate how our health professionals manage therapeutic changes in riser individuals. This retrospective study involved 34,289 inhabitants served in a centre in the Barcelona metropolitan area. EH individuals (450) were recruited and ABPM was performed following guidelines of the MAPAPRES (www.cardiorisc.com/MP/index_MP.asp). Good control of blood pressure was observed in 46% of dipper and non-dipper subjects but only 35% of riser subjects had blood pressures within good control ranges. The measured cardiovascular risk was either high or very high in 35% of riser individuals. Changes in medication were introduced in riser patients with both good and poor blood pressure control. A second follow-up ABPM was done in only 27% of the riser individuals. In these subjects, therapeutic changes successfully modified ABPM patterns in 87% of cases. Therapeutic changes in riser patients were introduced when these subjects were poorly controlled and these changes were highly effective. Additional ABPM to confirm the effectiveness of therapeutic changes was only performed in some individuals. Thus, for management of riser patients, more specific training of health professionals is needed. © The European Society of Cardiology 2013.

  4. Theoretical performance of cross-wind axis turbines with results for a catenary vertical axis configuration

    NASA Technical Reports Server (NTRS)

    Muraca, R. J.; Stephens, M. V.; Dagenhart, J. R.

    1975-01-01

    A general analysis capable of predicting performance characteristics of cross-wind axis turbines was developed, including the effects of airfoil geometry, support struts, blade aspect ratio, windmill solidity, blade interference and curved flow. The results were compared with available wind tunnel results for a catenary blade shape. A theoretical performance curve for an aerodynamically efficient straight blade configuration was also presented. In addition, a linearized analytical solution applicable for straight configurations was developed. A listing of the computer program developed for numerical solutions of the general performance equations is included in the appendix.

  5. Non-metallic optical cable with optical fiber catenary for long span aerial application

    NASA Astrophysics Data System (ADS)

    Hayasaka, E.; Ohtsuk, F.; Monma, M.; Ohira, S.; Horima, H.; Yamashita, K.; Dazai, M.; Abe, H.

    A nonmetallic prehanger type self supporting optical fiber cable with optical fiber catenary was developed and is considered to have a long term operating capability under high tension and abnormal freak weather conditions. The nonmetallic optical fiber cable is intended to be extremely effective for long span aerial cable mounting on all types of overhead poles and power transmission towers. Moreover, this type of cable has particular resistance to the accumulation and forming of ice or snow on the cable sheath which was observed during field test investigations.

  6. A computer program for the analysis of dental arch form using the catenary curve.

    PubMed

    BeGole, E A

    1981-01-01

    This paper presents the logic and details of a FORTRAN computer program which fits a two parameter catenary curve, using the method of least squares, to a set of data points arising from an exact size photograph of a dental model. Error is assessed by evaluating the difference between the observed and fitted y values. Finally, the length of the arc is measured. The program is useful in studies related to dental arch form as a part of orthodontic treatment. The measurement of the arc length provides as assessment of space available in the dental arch, which is an important part of treatment planning for the orthodontic patient.

  7. Resorbable fillers reduce stress risers from empty screw holes.

    PubMed

    Alford, J Winslow; Bradley, Michael P; Fadale, Paul D; Crisco, Joseph J; Moore, Douglas C; Ehrlich, Michael G

    2007-09-01

    Empty screw holes after hardware removal are stress risers that weaken bone and can lead to refracture in an active individual. We sought to reduce these stress risers. We hypothesize that resorbable screws used as hole fillers would (1) provide immediate strength and (2) maintain this strength during resorption. Randomized, prospective controlled animal laboratory study with 75 live New Zealand white rabbits' paired femurs. Single mid-diaphyseal holes were filled with a metal or resorbable screw; contralateral femurs were paired empty hole controls. Main outcome measurements included histologic analysis, torsion to failure, peak torque, energy to failure, and stiffness at baseline, 1 week, and 13 weeks postimplantation. At time baseline, resorbable fillers produced an immediate 30% increase in the peak torque (p = 0.01) and 73% increase in peak energy (p = 0.006). Metal screws produced a 17% increase in peak torque (p = 0.038), and a 58% increase in the amount of energy to failure (p = 0.009). At 1 week, although the resorbable (p = 0.01) but not the metal (p = 0.82) screws increased the peak torque, both metal (p = 0.003) and resorbable (p = 0.050) screws increased the peak energy compared with contralateral empty controls. At 13 weeks, metal and resorbable screw-filled bones were as strong as the healed contralateral femurs. Partial screw resorption and new bone formation without lysis was demonstrated histologically. Resorbable screw hole fillers immediately increase the strength of bones without weakening during early resorption. Placing resorbable fillers in bone defects after hardware removal could reduce the likelihood of refracture.

  8. An optical sensor for the detection of leaks from subsea pipelines and risers

    NASA Astrophysics Data System (ADS)

    McStay, D.; Kerlin, J.; Acheson, R.

    2007-07-01

    An optical sensor for the rapid detection of detect leaks of oil, hydraulic fluids or leak detection chemicals from underwater pipelines and risers is reported. The sensor is designed to be deployed on ROVs or AUVs for the rapid survey of underwater pipelines and risers. The system employs ultra-bright LEDs to project a sensing light beam into the water to allow real time detection of ppm concentration plumes of material leaking from pipelines or riser in real time. Typically the system is deployed on an ROV which inspects a pipeline at a height of 2-3m.

  9. Engineering study - installation of new risers in Single-Shell Tanks

    SciTech Connect

    Magruder, W.J.

    1994-08-01

    A sampling program is being developed to characterize the 149 underground SSTs on the Hanford Site. The sampling effort will require access to the tank interior in a minimum of two locations per tank. Some of the risers suitable for sampling are either unavailable or are not in locations for proper characterization of the tank contents. Additional risers will be required in the SSTs to support the tank characterization sampling program. The purpose of this engineering study is to review alternatives for installation of new riser in the SSTs.

  10. Comparison of optical and electrical measurements of the pantograph-catenary contact force

    NASA Astrophysics Data System (ADS)

    Bocciolone, Marco; Bucca, Giuseppe; Collina, Andrea; Comolli, Lorenzo

    2010-09-01

    In railway engineering the monitoring of contact force between pantograph and catenary gives information about the interaction between the two systems and it is useful to check the status of the overhead line. Indeed the failure of the catenary is one of the main causes of out of order problems. This study was conducted in a test campaign on an underground train instrumented with sensors able to monitor the line status. One of the more important measured quantities is the pantograph contact force, and two measurement systems were implemented: one optical and another electrical. The optical one was based on FBG sensors applied on the pantograph collector strip; the electrical one was based on two load cells positioned at the sides of the collector strip. The in-line measurements show that the optical solution is very promising, providing very reliable results that can be successfully used in the monitoring application, allowing the determination of the critical point in the line. The thermal compensation of any FBG sensors is a known problem and here is no exception: a thermal compensator was used to get also mean value measurements and the results are discussed.

  11. Identifiability and interval identifiability of mammillary and catenary compartmental models with some known rate constants.

    PubMed

    Vicini, P; Su, H; DiStefano, J J

    2000-10-01

    The identifiability problem is addressed for n-compartment linear mammillary and catenary models, for the common case of input and output in the first compartment and prior information about one or more model rate constants. We first define the concept of independent constraints and show that n-compartment linear mammillary or catenary models are uniquely identifiable under n-1 independent constraints. Closed-form algorithms for bounding the constrained parameter space are then developed algebraically, and their validity is confirmed using an independent approach, namely joint estimation of the parameters of all uniquely identifiable submodels of the original multicompartmental model. For the noise-free (deterministic) case, the major effects of additional parameter knowledge are to narrow the bounds of rate constants that remain unidentifiable, as well as to possibly render others identifiable. When noisy data are considered, the means of the bounds of rate constants that remain unidentifiable are also narrowed, but the variances of some of these bound estimates increase. This unexpected result was verified by Monte Carlo simulation of several different models, using both normally and lognormally distributed data assumptions. Extensions and some consequences of this analysis useful for model discrimination and experiment design applications are also noted.

  12. Analysis of dynamic interaction between catenary and pantograph with experimental verification and performance evaluation in new high-speed line

    NASA Astrophysics Data System (ADS)

    Lee, Jin Hee; Park, Tae Won; Oh, Hyuck Keun; Kim, Young Guk

    2015-08-01

    Understanding the dynamic interaction between the catenary and pantograph of a high-speed train is the one of the most important technical issues in the railway industry. This is because the catenary-pantograph system plays a crucial role in providing electric power to the railway vehicle for stable operation. The aim of the present paper is to estimate the current-collection performance of this system by using numerical analysis, in particular, the flexible multibody dynamic analysis technique. To implement large deformable catenary wires, an absolute nodal coordinate formulation is used for the cable element. Additionally, an efficient contact element and an interactive model for the catenary-pantograph system are introduced. Each developed model is then used for analytical and experimental verification. Actual on-line test results of existing high-speed railway vehicles are presented and used to verify the analysis model. Finally, the performance characteristics of a new 400 km/h-class high-speed line are estimated and evaluated on the basis of international standards.

  13. Dynamic responses of a riser under combined excitation of internal waves and background currents

    NASA Astrophysics Data System (ADS)

    Lou, Min; Yu, Chenglong

    2014-09-01

    In this study, the dynamic responses of a riser under the combined excitation of internal waves and background currents are studied. A modified Taylor-Goldstein equation is used to calculate the internal waves vertical structures when background currents exist. By imposing rigid-lid boundary condition, the equation is solved by Thompson-Haskell method. Based on the principle of virtual work, a nonlinear differential equation for riser motions is established combined with the modified Morison formula. Using Newmark-β method, the motion equation is solved in time domain. It is observed that the internal waves without currents exhibit dominated effect on dynamic response of a riser in the first two modes. With the effects of the background currents, the motion displacements of the riser will increase significantly in both cases that wave goes along and against the currents. This phenomenon is most obviously observed at the motions in the first mode

  14. Boundary control design for extensible marine risers in three dimensional space

    NASA Astrophysics Data System (ADS)

    Do, K. D.

    2017-02-01

    A design of boundary controllers is proposed for (practical) exponential stabilization of extensible marine risers in three-dimensional (3D) space under sea loads. The design removes flaws in existing works. Two Lyapunov-type theorems are developed for study of existence and uniqueness, and stability of nonlinear evolution systems in Hilbert space. These theorems have their potential use in control design and stability analysis for flexible systems including marine risers.

  15. Frequency domain response of a parametrically excited riser under random wave forces

    NASA Astrophysics Data System (ADS)

    Lei, Song; Zhang, Wen-Shou; Lin, Jia-Hao; Yue, Qian-Jin; Kennedy, D.; Williams, F. W.

    2014-01-01

    Floating Production, Drilling, Storage and Offloading units represent a new technology with a promising future in the offshore oil industry. An important role is played by risers, which are installed between the subsea wellhead and the Tension Leg Deck located in the middle of the moon-pool in the hull. The inevitable heave motion of the floating hull causes a time-varying axial tension in the riser. This time dependent tension may have an undesirable influence on the lateral deflection response of the riser, with random wave forces in the frequency domain. To investigate this effect, a riser is modeled as a Bernoulli-Euler beam. The axial tension is expressed as a static part, along with a harmonic dynamic part. By linearizing the wave drag force, the riser's lateral deflection is obtained through a partial differential equation containing a time-dependent coefficient. Applying the Galerkin method, the equation is reduced to an ordinary differential equation that can be solved using the pseudo-excitation method in the frequency domain. Moreover, the Floquet-Liapunov theorem is used to estimate the stability of the vibration system in the space of parametric excitation. Finally, stability charts are obtained for some numerical examples, the correctness of the proposed method is verified by comparing with Monte-Carlo simulation and the influence of the parametric excitation on the frequency domain responses of the riser is discussed.

  16. MAMCAT: an expert system for distinguishing between mammillary and catenary compartmental models.

    PubMed

    Kuhn de Chizelle, A N; DiStefano, J J

    1994-05-01

    MAMCAT is a user-friendly, interactive, graphics-based PC program for addressing a common compartmental model discrimination problem in the framework of model indistinguishability theory: can mammillary and catenary models of the same order be distinguished from each other? The software is designed to teach the theory and solve specific problems. The user is guided step-by-step through definitions, examples, theory and problem solution. Topological properties are used first to screen out some distinguishable models and thereby reduce the number of candidates for indistinguishability. Transfer function analysis is then used to explore the remaining candidates. Analytical results for up to 5-compartment models are given and a more general algorithm is induced from these results.

  17. Kennedy Space Center (KSC) Pad B Catenary Capability Analysis and Technical Exchange Meeting (TEM) Support

    NASA Technical Reports Server (NTRS)

    Wilson, Timmy R.; Kichak, Robert; Rakov, Vladimir; Kithil, Richard, Jr.; Sargent, Noel B.

    2009-01-01

    The existing lightning protection system at Pad 39B for the Space Shuttle is an outgrowth of a system that was put in place for the Apollo Program. Dr. Frank Fisher of Lightning Technologies was a key participant in the design and implementation of that system. He conveyed to the NESC team that the catenary wire provision was put in place quickly (as assurance against possible vehicle damage causing critical launch delays) rather than being implemented as a comprehensive system designed to provide a high degree of guaranteed protection. Also, the technology of lightning protection has evolved over time with considerable work being conducted by groups such as the electric utilities companies, aircraft manufacturers, universities, and others. Several accepted present-day methods for analysis of lightning protection were used by Drs. Medelius and Mata to study the expected lightning environment for the Pad 39B facility and to analyze the degree of protection against direct lightning attachment to the Space Shuttle. The specific physical configuration directly affects the vulnerability, so cases that were considered included the RSS next to and rolled back from the Space Shuttle, and the GOx Vent Arm both extended and withdrawn from the ET. Elements of the lightning protection system at Pad 39B are shown in Figure 6.0-1 and consist of an 80 foot insulating mast on top of the Fixed Support Structure (FSS), a catenary wire system that runs from the mast in a North/South direction to grounds 1000 feet away on each side of the mast, the RSS which can either be next to or away from the Space Shuttle, and a GOx vent that can either be extended or retracted from the top of the ET.

  18. Yield Improvement in Steel Casting (Yield II)

    SciTech Connect

    Richard A. Hardin; Christoph Beckermann; Tim Hays

    2002-02-18

    This report presents work conducted on the following main projects tasks undertaken in the Yield Improvement in Steel Casting research program: Improvement of Conventional Feeding and Risering Methods, Use of Unconventional Yield Improvement Techniques, and Case Studies in Yield Improvement. Casting trials were conducted and then simulated using the precise casting conditions as recorded by the participating SFSA foundries. These results present a statistically meaningful set of experimental data on soundness versus feeding length. Comparisons between these casting trials and casting trials performed more than forty years ago by Pellini and the SFSA are quite good and appear reasonable. Comparisons between the current SFSA feeding rules and feeding rules based on the minimum Niyama criterion reveal that the Niyama-based rules are generally less conservative. The niyama-based rules also agree better with both the trials presented here, and the casting trails performed by Pellini an d the SFSA years ago. Furthermore, the use of the Niyama criterion to predict centerline shrinkage for horizontally fed plate sections has a theoretical basis according to the casting literature reviewed here. These results strongly support the use of improved feeding rules for horizontal plate sections based on the Niyama criterion, which can be tailored to the casting conditions for a given alloy and to a desired level of soundness. The reliability and repeatability of ASTM shrinkage x-ray ratings was investigated in a statistical study performed on 128 x-rays, each of which were rated seven different times. A manual ''Feeding and Risering Guidelines for Steel Castings' is given in this final report. Results of casting trials performed to test unconventional techniques for improving casting yield are presented. These use a stacked arrangement of castings and riser pressurization to increase the casting yield. Riser pressurization was demonstrated to feed a casting up to four time s the

  19. Flow Mapping in a Gas-Solid Riser via Computer Automated Radioactive Particle Tracking (CARPT)

    SciTech Connect

    Muthanna Al-Dahhan; Milorad P. Dudukovic; Satish Bhusarapu; Timothy J. O'hern; Steven Trujillo; Michael R. Prairie

    2005-06-04

    Statement of the Problem: Developing and disseminating a general and experimentally validated model for turbulent multiphase fluid dynamics suitable for engineering design purposes in industrial scale applications of riser reactors and pneumatic conveying, require collecting reliable data on solids trajectories, velocities ? averaged and instantaneous, solids holdup distribution and solids fluxes in the riser as a function of operating conditions. Such data are currently not available on the same system. Multiphase Fluid Dynamics Research Consortium (MFDRC) was established to address these issues on a chosen example of circulating fluidized bed (CFB) reactor, which is widely used in petroleum and chemical industry including coal combustion. This project addresses the problem of lacking reliable data to advance CFB technology. Project Objectives: The objective of this project is to advance the understanding of the solids flow pattern and mixing in a well-developed flow region of a gas-solid riser, operated at different gas flow rates and solids loading using the state-of-the-art non-intrusive measurements. This work creates an insight and reliable database for local solids fluid-dynamic quantities in a pilot-plant scale CFB, which can then be used to validate/develop phenomenological models for the riser. This study also attempts to provide benchmark data for validation of Computational Fluid Dynamic (CFD) codes and their current closures. Technical Approach: Non-Invasive Computer Automated Radioactive Particle Tracking (CARPT) technique provides complete Eulerian solids flow field (time average velocity map and various turbulence parameters such as the Reynolds stresses, turbulent kinetic energy, and eddy diffusivities). It also gives directly the Lagrangian information of solids flow and yields the true solids residence time distribution (RTD). Another radiation based technique, Computed Tomography (CT) yields detailed time averaged local holdup profiles at

  20. FEM analysis of deepwater drilling risers under the operability and hang-off working conditions

    NASA Astrophysics Data System (ADS)

    Dai, Wei; Gao, Feng; Bai, Yong

    2009-06-01

    In recent years, numerous exploration activities of oil and gas industry have been conducted in ultra deep water. The global offshore industry is building systems today for drilling in even deeper water, progressively using new technologies, and significantly extending existing technologies. This is the general trend in the offshore oil and gas industry. So the technology of ultra-deepwater risers, which is the main tool in drilling oil, is more and more standard. This paper manly focuses on the global analysis of the drilling risers. And it is divided into two parts, operability analysis and hang-off analysis that are used to check the design of the riser. In this paper, the rotation angle and stress of the riser in the drilling mode are calculated to determine the operability envelop. The number of the buoyancy modules has been determined and according to the API standard, all the worked out values have been checked out. From all the above, it is concluded that the operability envelop is relatively small under harsh condition and the number of the buoyancy modules is a little large. And above all, the design of this riser is successful.

  1. Assessment of a probabilistic approach for design of dynamic flexible risers

    SciTech Connect

    Hanson, T.D.; Nilsen, A.U.

    1994-12-31

    In this work a reliability based method for design of flexible risers is investigated. Two different riser configurations are addressed, one a 6 inch dynamic mud jumper suspended between a semisubmersible support vessel and a jacket. The other is a 15 inch lazy-S gas export riser attached to a floating production unit at approximately 300 meters water depth. ULS failure modes are considered in this study. A finite element analysis of a risers system in the time domain combined with a probabilistic analysis is very cpu consuming. Therefore an approximate method applying response and capacity surfaces in combination with the analytical approximative reliability method FORM is used. An engineering approach was taken regarding the wave loading, where a regular wave with an associated period is applied. Bending failure at the end termination is addressed for the mud jumper. The major load contribution in this case is wave loading and vessel motion. The results show that stiffness of the bending stiffener, standoff position and wave height are the most important parameters contributing to the probability of failure. Tensile failure of the armoring layers is investigated for the gas export riser. For this failure mode environmental loads give only a minor contribution to the probability of failure.

  2. Study and Test of a New Bundle-Structure Riser Stress Monitoring Sensor Based on FBG.

    PubMed

    Xu, Jian; Yang, Dexing; Qin, Chuan; Jiang, Yajun; Sheng, Leixiang; Jia, Xiangyun; Bai, Yang; Shen, Xiaohong; Wang, Haiyan; Deng, Xin; Xu, Liangbin; Jiang, Shiquan

    2015-11-24

    To meet the requirements of riser safety monitoring in offshore oil fields, a new Fiber Bragg Grating (FBG)-based bundle-structure riser stress monitoring sensor has been developed. In cooperation with many departments, a 49-day marine test in water depths of 1365 m and 1252 m was completed on the "HYSY-981" ocean oil drilling platform. No welding and pasting were used when the sensor was installed on risers. Therefore, the installation is convenient, reliable and harmless to risers. The continuous, reasonable, time-consistent data obtained indicates that the sensor worked normally under water. In all detailed working conditions, the test results show that the sensor can do well in reflecting stresses and bending moments both in and in magnitude. The measured maximum stress is 132.7 MPa, which is below the allowable stress. In drilling and testing conditions, the average riser stress was 86.6 MPa, which is within the range of the China National Offshore Oil Corporation (CNOOC) mechanical simulation results.

  3. Study and Test of a New Bundle-Structure Riser Stress Monitoring Sensor Based on FBG

    PubMed Central

    Xu, Jian; Yang, Dexing; Qin, Chuan; Jiang, Yajun; Sheng, Leixiang; Jia, Xiangyun; Bai, Yang; Shen, Xiaohong; Wang, Haiyan; Deng, Xin; Xu, Liangbin; Jiang, Shiquan

    2015-01-01

    To meet the requirements of riser safety monitoring in offshore oil fields, a new Fiber Bragg Grating (FBG)-based bundle-structure riser stress monitoring sensor has been developed. In cooperation with many departments, a 49-day marine test in water depths of 1365 m and 1252 m was completed on the “HYSY-981” ocean oil drilling platform. No welding and pasting were used when the sensor was installed on risers. Therefore, the installation is convenient, reliable and harmless to risers. The continuous, reasonable, time-consistent data obtained indicates that the sensor worked normally under water. In all detailed working conditions, the test results show that the sensor can do well in reflecting stresses and bending moments both in and in magnitude. The measured maximum stress is 132.7 MPa, which is below the allowable stress. In drilling and testing conditions, the average riser stress was 86.6 MPa, which is within the range of the China National Offshore Oil Corporation (CNOOC) mechanical simulation results. PMID:26610517

  4. Analysis of Current Harmonics in 3kV DC Catenary Caused by Specific Current Harmonics of an Asynchronous Motor

    NASA Astrophysics Data System (ADS)

    Lewandowski, Mirosław

    2010-01-01

    The mathematical model of vehicle supply system as well as the mathematical model of main circuit of locomotive with asynchronous motors have been described in this article. The necessity of analysis of disturbances caused by distorted current run of drive motors emerged together with the introduction of high power vehicles with power electronic converters. Analysis of the compatibility of traction high current circuits with circuits of the signal and traffic control systems requires the knowledge of current spectrum in a catenary, which has been taken by a vehicle. The author has described the algebraic method of calculating of the spectrum amplitudes in a catenary. It does not require laborious and time-consuming simulations of a system, which considerably decreases preliminary costs of designation and dimensioning of a vehicle drive system.

  5. Program for catenary-pantograph analysis, PrOSA statement of methods and validation according EN 50318

    NASA Astrophysics Data System (ADS)

    Finner, Lars; Poetsch, Gero; Sarnes, Bernhard; Kolbe, Michael

    2015-03-01

    DB Systemtechnik is a high-performing, customer-driven service provider that, as well as authoritatively serving the Deutsche Bahn Group by dint of its specialist knowledge is also increasingly active on the global railway market. Development and testing of pantograph models and catenary systems have been part of the company's essential activity fields from the beginning. Therefore, an efficient and high-performing simulation tool is indispensable. That is why DB Systemtechnik spent high efforts to develop the program PrOSA in cooperation with the Heinz-Nixdorf-Institut (HNI) of the university Paderborn to simulate the interaction of pantograph and catenary. This article gives an overview of the most relevant properties of PrOSA. Furthermore, it is described how the benchmark requirements were implemented and processed.

  6. Design and implementation of non-contact detection system for catenary based on double linear array cameras

    NASA Astrophysics Data System (ADS)

    Chen, Peng; Xu, Cheng; Li, Zhiqi; Xu, Zisang

    2017-04-01

    The detection of catenary geometric parameters is a very important problem in railway infrastructure measurement. In this paper, a high resolution linear array CCD is used as the photosensitive element, and FPGA is used as the main controller to design the data acquisition system of linear array camera, and a non-contact detection system of catenary geometry parameters based on double linear array cameras is implemented. According to the intensity of linear array CCD output signal, and the adaptive adjustment algorithm of exposure intensity is achieved, so the optical integration time is changed in real time. In order to improve the bandwidth limitation of data transmission, the calibration algorithm of pixel position in the system is completed by FPGA, which improved the response speed of the system. The experimental results show that the scan frequency of linear array camera can reach 6MHz, the measurement error is controlled at mm level, and it has good accuracy and stability.

  7. W3MAMCAT: a world wide web based tool for mammillary and catenary compartmental modeling and expert system distinguishability.

    PubMed

    Russell, Solomon; Distefano, Joseph J

    2006-07-01

    W(3)MAMCAT is a new web-based and interactive system for building and quantifying the parameters or parameter ranges of n-compartment mammillary and catenary model structures, with input and output in the first compartment, from unstructured multiexponential (sum-of-n-exponentials) models. It handles unidentifiable as well as identifiable models and, as such, provides finite parameter interval solutions for unidentifiable models, whereas direct parameter search programs typically do not. It also tutorially develops the theory of model distinguishability for same order mammillary versus catenary models, as did its desktop application predecessor MAMCAT+. This includes expert system analysis for distinguishing mammillary from catenary structures, given input and output in similarly numbered compartments. W(3)MAMCAT provides for universal deployment via the internet and enhanced application error checking. It uses supported Microsoft technologies to form an extensible application framework for maintaining a stable and easily updatable application. Most important, anybody, anywhere, is welcome to access it using Internet Explorer 6.0 over the internet for their teaching or research needs. It is available on the Biocybernetics Laboratory website at UCLA: www.biocyb.cs.ucla.edu.

  8. Experimental study and modelling of overheating of electrical catenary-pantograph interface for trains supplied with power in station

    NASA Astrophysics Data System (ADS)

    Bausseron, Thomas; Baucour, Philippe; Glises, Raynal; Verschelde, Sylvain; Chamagne, Didier

    2015-06-01

    For railroads and trains, there have been many incidents involving catenary overheating at the contact with the pantograph when a train is supplied with power while standing still. The overheating of the catenary-pantograph interface can sometimes cause the contact wire to break. In order to anticipate the occurrence of such costly problems, the FEMTO-ST Institute has carried out theoretical and experimental studies in collaboration with the French National Railway Company (SNCF) to better understand this phenomenon. First, a 2D transient electrical model was developed for the contact wire. This allows the current distribution in the wire to be estimated to obtain an accurate measure of the internal heat generation. The heat produced by the interface was considered and split between the catenary and pantograph with an analytical model. Finally, the heat transfer equation for the wire under particular boundary conditions was solved for the entire finite difference network based on Euler's implicit method. The transient modelling results of the wire heating were compared with earlier experimental values, and a parametric study was performed.

  9. Dynamics of High-Speed Train Pantograph-Catenary Co-Simulation of Finite Element and Multibody Codes

    NASA Astrophysics Data System (ADS)

    Ambrósio, Jorge; Rauter, Frederico; Pombo, João; Pereira, Manuel

    2010-05-01

    The pantograph-catenary system, used for collecting electric energy in high-speed trains should ideally run with low contact forces but without contact loss. Not only defects on the overhead equipment, environmental conditions become more important as the operational speed increases but also the flexibility of the pantograph components may play a role on the overhead contact. In this work a flexible multibody methodology using of the mean-axis conditions, as reference conditions, the mode component synthesis, to reduce the number of generalized coordinates of the system and virtual bodies, to allow using all kinematic joints available for multibody modeling and application of external forces, are used to build flexible multibody pantograph models. The catenary model is build with linear finite elements in a stand-alone code, which is co-simulated with the multibody code to represent the complete system interaction, and the complete nonlinear dynamics of the overhead equipment. A flexible multibody model of the pantograph is described and proposed being the quality of the pantograph-catenary contact analyzed and discussed.

  10. Effect of tension fluctuation on the dynamic behavior of marine risers

    SciTech Connect

    Basu, A.K.

    1996-12-31

    The main purpose of the paper is to show how periodic fluctuation of the top tension affects the dynamic behavior of rigid risers when under the combined action of regular waves, current and vessel motion. The nodal displacements of the riser associated with finite difference discretization are computed in the frequency domain using an iterative procedure which is capable of accurate multi-harmonic treatment of the nonlinear drag load and the load associated with the time dependent component of the tension. This procedure is applicable also to constant tension cases, and is explained in some detail. The example problems included in the paper are designed to illustrate the additional response harmonics generated as a result of interaction of the frequencies of tension fluctuation and riser curvature.

  11. Measuring and modelling of particle-fluid flow in a riser reactor

    NASA Astrophysics Data System (ADS)

    Viitanen, Pekka

    1992-02-01

    An introduction to the basics of fluidization techniques and especially the principle of a Fluidized Catalyst Cracking (FCC) plant is given. The flow in the riser reactor of an FCC plant is essentially a two phase flow with gaseous fluid flow and particulate flow consisting of the cracking catalyst. Experimental results obtained from tracer measurements done in an FCC plant are presented. Measurements indicate that a dilute phase flow is dominating the flow structure of the catalyst in the riser. Different approaches to model two phase flow are reviewed. Axial dispersion model fit is done and a simulation model is constructed in order to calculate the radial distribution of the cracking catalyst on the FCC riser. A satisfactory agreement with the experiments and the model is achieved when the slip velocity between discrete particles and the fluid is described using the Newtonian drag force. The Newtonian drag is argued to be due to turbulent fluid flow.

  12. Moving from Science to Service: Transposing and Sustaining the Early Risers Prevention Program in a Community Service System

    ERIC Educational Resources Information Center

    Bloomquist, Michael L.; August, Gerald J.; Horowitz, Jason L.; Lee, Susanne S.; Jensen, Cheryl

    2008-01-01

    This paper summarizes an effort to transpose and sustain the evidence-based Early Risers "Skills for Success" conduct problems prevention program in a real world community service system. The Early Risers program had previously been implemented by a local agency within the context of research-based operations. In the current initiative,…

  13. Moving from Science to Service: Transposing and Sustaining the Early Risers Prevention Program in a Community Service System

    ERIC Educational Resources Information Center

    Bloomquist, Michael L.; August, Gerald J.; Horowitz, Jason L.; Lee, Susanne S.; Jensen, Cheryl

    2008-01-01

    This paper summarizes an effort to transpose and sustain the evidence-based Early Risers "Skills for Success" conduct problems prevention program in a real world community service system. The Early Risers program had previously been implemented by a local agency within the context of research-based operations. In the current initiative,…

  14. Marine riser protector for use on offshore oil drilling rigs in icy waters

    SciTech Connect

    Yashima, N.

    1985-03-19

    An apparatus for protecting a marine riser extending downwardly from a platform of an offshore station above a sea level toward a sea bottom. A tubular protector is removably mounted on the underside of the platform in surrounding relation to the marine riser in the vicinity of the sea level. According to another embodiment, a tubular protector has an upper portion in the shape of a truncated cone for contact with ice floes and a lower portion shaped as a grid-like truncated cone flaring downwardly for diverting ice floes away from the tubular protector.

  15. Acoustic and Perceptual Measures of SATB Choir Performances on Two Types of Portable Choral Riser Units in Three Singer-Spacing Conditions

    ERIC Educational Resources Information Center

    Daugherty, James F.; Manternach, Jeremy N.; Brunkan, Melissa C.

    2013-01-01

    Under controlled conditions, we assessed acoustically (long-term average spectra) and perceptually (singer survey, listener survey) six performances of an soprano, alto, tenor, and bass (SATB) choir ("N" = 27) as it sang the same musical excerpt on two portable riser units (standard riser step height, taller riser step height) with…

  16. Acoustic and Perceptual Measures of SATB Choir Performances on Two Types of Portable Choral Riser Units in Three Singer-Spacing Conditions

    ERIC Educational Resources Information Center

    Daugherty, James F.; Manternach, Jeremy N.; Brunkan, Melissa C.

    2013-01-01

    Under controlled conditions, we assessed acoustically (long-term average spectra) and perceptually (singer survey, listener survey) six performances of an soprano, alto, tenor, and bass (SATB) choir ("N" = 27) as it sang the same musical excerpt on two portable riser units (standard riser step height, taller riser step height) with…

  17. An analytical solution set for a four-compartment mixed mammillary/catenary model.

    PubMed

    Charkes, N D; Siegel, J A

    1999-06-01

    The purpose of this study was to extract the intercompartmental rate constants analytically from the coefficients and exponents of the exponential sum fitted to tracer data points for a unique four-compartment mixed mammillary/catenary (extended mammillary, radial) model, with losses solely from the central (blood) compartment. This model is useful in estimating myocardial and skeletal blood flow. Using Laplace transforms, the transfer functions of the exponential sum and the differential equations describing the model were obtained and the corresponding coefficients equated sequentially, which yielded the intercompartmental rate constants. Three solution sets of rate constants were found for the model, each of which satisfies both transfer functions. A program written in BASIC is provided, which requires only the coefficients and exponents of the exponential terms as input; the output is the three sets of rate constants. An example is given as an aid in debugging. Only one solution set of the three was physiologically realizable in the example, but the bounds defining these limits are not known. The advantages and limitations of the method are discussed. The method is suitable for initializing a non-linear least-squares fitting program for the rate constants. The appropriate physiological solution set for this model yields fractional and total myocardial or skeletal blood flow in a subject in the steady state.

  18. Promoting stair climbing: stair-riser banners are better than posters... sometimes.

    PubMed

    Olander, Ellinor K; Eves, Frank F; Puig-Ribera, Anna

    2008-04-01

    Stair-riser banners are twice as effective as posters in encouraging stair climbing in shopping centres. This study tested the effectiveness of stair-riser banners in an English train station in 2006-2007. The train station had a 39-step staircase and an adjacent escalator. Baseline observations (3.5 weeks) were followed by 10.5 weeks of a banner intervention supplemented with 3 weeks of a poster intervention. Both poster and banner featured the message 'Stair climbing burns more calories per minute than jogging. Take the stairs'. Ascending escalator and stair users (N=36,239) were coded for gender. Analyses, controlling for effects of gender and pedestrian traffic volume, revealed no significant change in stair climbing between baseline (40.6%) and the banner intervention (40.9%; p=0.98). Addition of the poster increased stair climbing (44.3%; OR=1.36, 95% CIs 1.16-1.60, p<0.001), with the effect reduced at higher pedestrian traffic volumes. While stair-riser banners had no effect, the poster intervention increased stair climbing. The high pedestrian volumes as the wave of disembarking passengers seek to leave the station would have obscured the visibility of the banner for many commuters. Thus stair-riser banners appear unsuitable point-of-choice prompts in stations where pedestrian traffic volume is high.

  19. Riser Pattern: Another Determinant of Heart Failure With Preserved Ejection Fraction.

    PubMed

    Komori, Takahiro; Eguchi, Kazuo; Saito, Toshinobu; Hoshide, Satoshi; Kario, Kazuomi

    2016-10-01

    Paradoxical increase in blood pressure (BP) during sleep, exceeding those of awake BP, is called the "riser" BP pattern, and known as an abnormal circadian BP rhythm, has been reported to be associated with adverse cardiovascular prognoses. However, the significance of ambulatory BP in heart failure patients with preserved ejection fraction (HFpEF) has never been reported. Here, we tested our hypothesis that abnormal circadian BP rhythm is associated with HFpEF. The authors enrolled 508 patients with hospitalized HF (age 68±13 years; 315 men, 193 women). There were 232 cases of HFpEF and 276 cases of heart failure with reduced ejection fraction (HFrEF). The riser BP pattern was significantly more frequent in the HFpEF (28.9%) group compared with the HFrEF group (19.9%). In a multivariable logistic regression analysis, the riser BP pattern was associated with HFpEF (odds ratio, 1.73; 95% confidence interval, 1.02-2.91; P=.041) independent of the other covariates. In conclusion, the riser BP pattern was associated with HFpEF.

  20. The Early Risers Preventive Intervention: Testing for Six-year Outcomes and Mediational Processes

    ERIC Educational Resources Information Center

    Bernat, Debra H.; August, Gerald J.; Hektner, Joel M.; Bloomquist, Michael L.

    2007-01-01

    We examined effects of the Early Risers "Skills for Success" early-age-targeted prevention program on serious conduct problems following 5 years of continuous intervention and one year of follow-up. We also examined if intervention effects on proximally-targeted variables found after 3 years mediated intervention effects on conduct…

  1. Tension and drag forces of flexible risers undergoing vortex-induced vibration

    NASA Astrophysics Data System (ADS)

    Song, Lei-jian; Fu, Shi-xiao; Li, Man; Gao, Yun; Ma, Lei-xin

    2017-03-01

    This paper presents the results of an experimental investigation on the variation in the tension and the distribution of drag force coefficients along flexible risers under vortex-induced vibration (VIV) in a uniform flow for Reynolds numbers ( Re) up to 2.2×105. The results show that the mean tension is proportional to the square of the incoming current speed, and the tension coefficient of a flexible riser undergoing VIV can be up to 12. The mean drag force is uniformly and symmetrically distributed along the axes of the risers undergoing VIV. The corresponding drag coefficient can vary between 1.6 and 2.4 but is not a constant value of 1.2, as it is for a fixed cylinder in the absence of VIV. These experimental results are used to develop a new empirical prediction model to estimate the drag force coefficient for flexible risers undergoing VIV for Reynolds number on the order of 105, which accounts for the effects of the incoming current speed, the VIV dominant modal number and the frequency.

  2. Tools for Inspecting and Sampling Waste in Underground Radioactive Storage Tanks with Small Access Riser Openings

    SciTech Connect

    Nance, T.A.

    1998-12-17

    Underground storage tanks with 2 inches to 3 inches diameter access ports at the Department of Energy's Savannah River Site have been used to store radioactive solvents and sludge. In order to close these tanks, the contents of the tanks need to first be quantified in terms of volume and chemical and radioactive characteristics. To provide information on the volume of waste contained within the tanks, a small remote inspection system was needed. This inspection system was designed to provide lighting and provide pan and tilt capabilities in an inexpensive package with zoom abilities and color video. This system also needed to be utilized inside of a plastic tent built over the access port to contain any contamination exiting from the port. This system had to be build to travel into the small port opening, through the riser pipe, into the tank evacuated space, and out of the riser pipe and access port with no possibility of being caught and blocking the access riser. Long thin plates were found in many access riser pipes that blocked the inspection system from penetrating into the tank interiors. Retrieval tools to clear the plates from the tanks using developed sampling devices while providing safe containment for the samples. This paper will discuss the inspection systems, tools for clearing access pipes, and solvent sampling tools developed to evaluate the tank contents of the underground solvent storage tanks.

  3. Riser Difference Evaluation from Ultrasonic Wall Thickness Inspection of Thirteen Double-Shell Tanks

    SciTech Connect

    Weier, Dennis R.; Pardini, Allan F.

    2010-03-15

    PNNL has performed an analysis of ultrasonic thickness measurements taken on Hanford's double-shell tanks (DSTs) approximately eight years apart. The analysis was performed to determine whether significant differences exist between ultrasonic thickness measurements made in two opposite risers in Hanford DSTs that have been examined twice.

  4. On fatigue damage accumulation from in-line and cross-flow vortex-induced vibrations on risers

    NASA Astrophysics Data System (ADS)

    Baarholm, G. S.; Larsen, C. M.; Lie, H.

    2006-01-01

    Large-scale model tests of a tensioned steel riser were performed at Hanøytangen outside Bergen, Norway in 1997. The length of the model was 90 m and the diameter was 3 cm. The information from these tests consists of measured bending strains, tension, flow speed and all relevant riser data. In this work, this information is reexamined in an attempt to improve our understanding of vortex-induced vibrations (VIV) for cases with very high order of responding modes. The aim is in particular to study the relative importance of in-line (IL) and cross-flow (CF) vibrations for fatigue damage accumulation. It is shown that fatigue damage is proportional to U (U is the flow velocity) when the modes are dominated by tension. When bending controls the modes, the fatigue damage is proportional to U. A linear SN-curve with slope parameter m=3 is used. The Hanøytangen riser fatigue damage goes as U7 for the lowest velocities and U4 for the highest current velocities. Based on the Hanøytangen data, it seems that the transition velocity between the tension and the bending-stiffness-dominated regions is at the current velocity that gives response at a mode number where a tensioned string and an untensioned beam have equal eigenfrequencies. IL response has a significant contribution to fatigue for cases dominated by the lowest modes. The reason is that IL oscillations will take place at double the frequency of those in CF. For a tension-controlled case, this corresponds to a mode with half the wavelength, while a bending-controlled case will tend to have a wavelength ratio of 2. Since the curvature for a given amplitude increases with the inverse modal wavelength squared, fatigue from IL tends to dominate for cases with tension-controlled modes (low current speed), while CF will dominate for bending-controlled modes (high current speed). This tendency is clearly seen in the experimental data for both CF and IL responses. Fatigue damage is calculated directly from the measured

  5. A flexible-segment-model-based dynamics calculation method for free hanging marine risers in re-entry

    NASA Astrophysics Data System (ADS)

    Xu, Xue-song; Wang, Sheng-wei

    2012-03-01

    In re-entry, the drilling riser hanging to the holding vessel takes on a free hanging state, waiting to be moved from the initial random position to the wellhead. For the re-entry, dynamics calculation is often done to predict the riser motion or evaluate the structural safety. A dynamics calculation method based on Flexible Segment Model (FSM) is proposed for free hanging marine risers. In FSM, a riser is discretized into a series of flexible segments. For each flexible segment, its deflection feature and external forces are analyzed independently. For the whole riser, the nonlinear governing equations are listed according to the moment equilibrium at nodes. For the solution of the nonlinear equations, a linearization iteration scheme is provided in the paper. Owing to its flexibility, each segment can match a long part of the riser body, which enables that good results can be obtained even with a small number of segments. Moreover, the linearization iteration scheme can avoid widely used Newton-Rapson iteration scheme in which the calculation stability is influenced by the initial points. The FSM-based dynamics calculation is timesaving and stable, so suitable for the shape prediction or real-time control of free hanging marine risers.

  6. Bench and Riser Soil Water Content on Semiarid Hillslopes with Terracettes

    NASA Astrophysics Data System (ADS)

    Heinse, R.; Corrao, M.; Eitel, J.; Link, T. E.

    2015-12-01

    Microtopographic features known as terracettes are found throughout many semiarid rangelands. These path-like features roughly perpendicular to the slope are frequently traversed by grazing animals on steep hillslopes. The soil properties and hydrologic function, however, are virtually unknown. This research aimed to identify differences in soil properties between terracette bench and riser features, and their influence on soil water content for two terracetted sites and two non-terracetted control sites (grazed and ungrazed) in Eastern Washington State. Measurements of volumetric water content (θ_v), bulk density, soil texture, saturated hydraulic conductivity, pH, and ECa_a were collected along with compaction, vegetative cover and cattle density throughout the 2013 and 2014 field seasons. Results show small but significant volumetric water content differences between terracette benches and risers in the upper 10 cm with benches exhibiting higher mean θ_v than risers throughout the year. Soil bulk density on benches (1600 kg m-3^{-3}) was significantly higher than that of risers (1300 kg m-3^{-3}) with no differences in soil texture. The saturated hydraulic conductivity on benches was roughly half of that for risers. No significant soil differences were noted below 20 cm depth. Terracetted sites showed greater field-averaged θ_v compared to non-terracetted sites suggesting a positive trend with animal stocking rates. Higher water content on terracette benches is attributed to shifts in pore size distribution with compaction, and a reduction in root-water uptake due to plant-root impedance. This increased soil water does not however increase forage production as it is not accessible to plants.

  7. Evaluation of a catenary PBPK model for predicting the in vivo disposition of mAbs engineered for high-affinity binding to FcRn.

    PubMed

    Chen, Yang; Balthasar, Joseph P

    2012-12-01

    Efforts have been made to extend the biological half-life of monoclonal antibody drugs (mAbs) by increasing the affinity of mAb-neonatal Fc receptor (FcRn) binding; however, mixed results have been reported. One possible reason for a poor correlation between the equilibrium affinity of mAb-FcRn binding and mAb systemic pharmacokinetics is that the timecourse of endosomal transit is too brief to allow binding to reach equilibrium. In the present work, a new physiologically based pharmacokinetic (PBPK) model has been developed to approximate the pH and time-dependent endosomal trafficking of immunoglobulin G (IgG). In this model, a catenary sub-model was utilized to describe the endosomal transit of IgG and the time dependencies in IgG-FcRn association and dissociation. The model performs as well as a previously published PBPK model, with assumed equilibrium kinetics of mAb-FcRn binding, in capturing the disposition profile of murine mAb from wild-type and FcRn knockout mice (catenary vs. equilibrium model: r (2), 0.971 vs. 0.978; median prediction error, 3.38% vs. 3.79%). Compared to the PBPK model with equilibrium binding, the present catenary PBPK model predicts much more moderate changes in half-life with altered FcRn binding. For example, for a 10-fold increase in binding affinity, the catenary model predicts <2.5-fold change in half-life compared to an ∼8-fold increase as predicted by the equilibrium model; for a 100-fold increase in binding affinity, the catenary model predicts ∼7-fold change in half-life compared to >70-fold increase as predicted by the equilibrium model. Predictions of the new catenary PBPK model are more consistent with experimental results in the published literature.

  8. A fast rise-rate, adjustable-mass-bit gas puff valve for energetic pulsed plasma experiments.

    PubMed

    Loebner, Keith T K; Underwood, Thomas C; Cappelli, Mark A

    2015-06-01

    A fast rise-rate, variable mass-bit gas puff valve based on the diamagnetic repulsion principle was designed, built, and experimentally characterized. The ability to hold the pressure rise-rate nearly constant while varying the total overall mass bit was achieved via a movable mechanical restrictor that is accessible while the valve is assembled and pressurized. The rise-rates and mass-bits were measured via piezoelectric pressure transducers for plenum pressures between 10 and 40 psig and restrictor positions of 0.02-1.33 cm from the bottom of the linear restrictor travel. The mass-bits were found to vary linearly with the restrictor position at a given plenum pressure, while rise-rates varied linearly with plenum pressure but exhibited low variation over the range of possible restrictor positions. The ability to change the operating regime of a pulsed coaxial plasma deflagration accelerator by means of altering the valve parameters is demonstrated.

  9. A numerical investigation of scale-up effects on coke yields of a thermal cracking Riser reactor

    SciTech Connect

    Chang, S.L.; Lottes, S.A.; Petrick, M.

    1995-05-01

    A validated computational fluid dynamics (CFD) computer code, ICRKFLO, was used to investigate the scale-up effects on the coke yields of thermal cracking riser factors. Comparisons were made for calculated coke yields of pilot- and commercial-scales riser units. Computational results show that the riser aspect ratio, reaction temperature, particle residence time, and particle/oil ratio have major impacts on the coke yield. A computational experiment was conducted to determine optimal operating conditions for a conceptual design of a commercial-scale riser unit. This experiment showed that the performance loss in scale-up from pilot to commercial scale may be almost completely recovered through optimizing the operating conditions after scale-up using the CFD simulations as a guide.

  10. A fast rise-rate, adjustable-mass-bit gas puff valve for energetic pulsed plasma experiments

    SciTech Connect

    Loebner, Keith T. K. Underwood, Thomas C.; Cappelli, Mark A.

    2015-06-15

    A fast rise-rate, variable mass-bit gas puff valve based on the diamagnetic repulsion principle was designed, built, and experimentally characterized. The ability to hold the pressure rise-rate nearly constant while varying the total overall mass bit was achieved via a movable mechanical restrictor that is accessible while the valve is assembled and pressurized. The rise-rates and mass-bits were measured via piezoelectric pressure transducers for plenum pressures between 10 and 40 psig and restrictor positions of 0.02-1.33 cm from the bottom of the linear restrictor travel. The mass-bits were found to vary linearly with the restrictor position at a given plenum pressure, while rise-rates varied linearly with plenum pressure but exhibited low variation over the range of possible restrictor positions. The ability to change the operating regime of a pulsed coaxial plasma deflagration accelerator by means of altering the valve parameters is demonstrated.

  11. A fast rise-rate, adjustable-mass-bit gas puff valve for energetic pulsed plasma experiments

    NASA Astrophysics Data System (ADS)

    Loebner, Keith T. K.; Underwood, Thomas C.; Cappelli, Mark A.

    2015-06-01

    A fast rise-rate, variable mass-bit gas puff valve based on the diamagnetic repulsion principle was designed, built, and experimentally characterized. The ability to hold the pressure rise-rate nearly constant while varying the total overall mass bit was achieved via a movable mechanical restrictor that is accessible while the valve is assembled and pressurized. The rise-rates and mass-bits were measured via piezoelectric pressure transducers for plenum pressures between 10 and 40 psig and restrictor positions of 0.02-1.33 cm from the bottom of the linear restrictor travel. The mass-bits were found to vary linearly with the restrictor position at a given plenum pressure, while rise-rates varied linearly with plenum pressure but exhibited low variation over the range of possible restrictor positions. The ability to change the operating regime of a pulsed coaxial plasma deflagration accelerator by means of altering the valve parameters is demonstrated.

  12. Physical simulation of the response of the Enserch Garden Banks 388 FPF/free standing rigid riser to wind, waves, and current

    SciTech Connect

    Edwards, R.Y.; Johnson, T.L.; Johnson, R.P.

    1995-12-31

    This paper describes large scale hydrodynamic model tests of the Enserch Exploration Garden Banks 388 Floating Production Facility (FPF). This unique facility consists of a semi-submersible connected to a template on the sea floor 2,096 feet below the surface through a buoyant, free standing ``rigid`` riser. The top of the riser and its manifold are located well below the surface to minimize the forces exerted on the riser by waves. Numerous flexible conductors connect the semi-submersible to the manifold on the top of the riser. The emphasis of the model test program was to confirm the estimates of: The structural response of the buoyant, rigid production riser and an adjacent drilling riser; The relative displacements between the semisubmersible and the production riser; The relative displacements between the production riser and drilling riser; and The forces which must be endured by the tensioners and flexible hoses which join the semi-submersible to the production riser. The paper describes the planning and preparation of the model components, the unique aspects of the simulation of the environments and the structural properties of the models, the execution of the experiments and the handling of the large number of measurements necessary to characterize the response of the multi-component system. Finally, the data analysis tools which were employed to provide an understanding of the responses of the system are discussed. 22 figs., 1 tab.

  13. Dynamic fatigue reliability of contact wires based on dynamic simulation of high-speed pantograph-catenary

    NASA Astrophysics Data System (ADS)

    Hu, Ping; Liang, Jie; Fan, Wenli

    2017-05-01

    This paper proposed a dynamic fatigue reliability method of contact wires based on dynamic simulation of high-speed pantograph-catenary. Firstly, the Weibull distribution was adopted to describe the fatigue life of contact wires so as to build the fatigue reliability model of contact wires. And then 10 finite element models of elastic chain type for contact networks were set up with the EN50367 parameter. Thereafter the stress time of the weakest unit on contact wires was calculated through the finite element simulation. Secondly, the mean value and amplitude of each stress cycle were calculated by means of rain flow counting method, and these values were put into the reliability model to draw the changing curve of the fatigue reliability of contact wires with time. The numerical example showed that the fatigue reliability of contact wires would be less than 0.98 when these wires were used for more than 10 years. The method provided in this paper can be used to estimate the fatigue reliability of contact wires more accurately, and it can be used as a reference for the reliability design of the catenary system and the formulation of preventive maintenance plans.

  14. Experimental Study on Gas-Solid Flow Charcteristics in a CFB Riser Of 54M in Height

    NASA Astrophysics Data System (ADS)

    Hu, N.; Yang, H. R.; Zhang, H.; Zhang, R. Q.; Cao, J. N.; Liu, Q.; Lu, J. F.; Yue, G. X.

    Understanding the height effect on the gas-solid flow characteristics in a CFB riser is important as more and more large capacity CFB boilers are used and to be developed. In this study, a cold CFB test rig with a riser of 240mm in LD. and 38m and 54m in height was built. The influences of operating conditions, such as solid inventory and fluidizing gas velocity, on the axial voidage profile along the riser were assessed. When the gas velocity exceeds the transport velocity, the S-shaped profile of voidage in the riser was established. At the same time, the voidage in top-dilute section reached the saturation carrying capacity, and the solids circulation rate did not vary with the height of the riser nor the solids inventory. It was also found the critical solids inventory for the saturation carrying capacity increases as the riser height increases. When the height was changed from 38m to 54m, the critical solids inventory increased about 25% from about 40kg to about 50kg, and pressure drop in the furnace also increased about 25%.

  15. MP-Pic simulation of CFB riser with EMMS-based drag model

    SciTech Connect

    Li, F.; Song, F.; Benyahia, S.; Wang, W.; Li, J.

    2012-01-01

    MP-PIC (multi-phase particle in cell) method combined with the EMMS (energy minimization multi- scale) drag force model was implemented with the open source program MFIX to simulate the gas–solid flows in CFB (circulatingfluidizedbed) risers. Calculated solid flux by the EMMS drag agrees well with the experimental value; while the traditional homogeneous drag over-predicts this value. EMMS drag force model can also predict the macro-and meso-scale structures. Quantitative comparison of the results by the EMMS drag force model and the experimental measurements show high accuracy of the model. The effects of the number of particles per parcel and wall conditions on the simulation results have also been investigated in the paper. This work proved that MP-PIC combined with the EMMS drag model can successfully simulate the fluidized flows in CFB risers and it serves as a candidate to realize real-time simulation of industrial processes in the future.

  16. A general kinetic-flow coupling model for FCC riser flow simulation.

    SciTech Connect

    Chang, S. L.

    1998-05-18

    A computational fluid dynamic (CFD) code has been developed for fluid catalytic cracking (FCC) riser flow simulation. Depending on the application of interest, a specific kinetic model is needed for the FCC flow simulation. This paper describes a method to determine a kinetic model based on limited pilot-scale test data. The kinetic model can then be used with the CFD code as a tool to investigate optimum operating condition ranges for a specific FCC unit.

  17. Time-frequency methods for structural health monitoring of deepwater risers subjected to vortex induced vibrations

    NASA Astrophysics Data System (ADS)

    Huang, Chaojun; Sun, Peng; Nagarajaiah, Satish; Gopalakrishnan, S.

    2013-04-01

    In this paper, an approach based on a new damage index-Distributed Force Change(WDFC), for monitoring the structural health of risers used for production in deep-water floating platforms, is presented. Experiments of a scaled pipe are carried out to validate the vibration based damage identification method. The influences of multiple cracks in the WDFC damage index are studied. Futhermore, this paper demonstrates the effectiveness of wave propagation based structural health monitoring (SHM) strategies within the pipe model. This is realized based on the results of numerical investigation obtained by the use of Finite Element Method(FEM) together with application of Time-of-Flight(FoT) damage identification method in which the damage severity is indicated by Root Mean Square(RMS) of the damage-reflected wave. The influence of crack(s) in the riser/pipe on the wave propagation are studied. The results from the experiments and numerical analysis indicate that both the two damage identification methods can provide information about the estimated crack location(s) and the possible extent of crack. Hence the two methods are suitable for globally and locally monitoring the structural health of deepwater risers respectively.

  18. Experimental investigation for liquid holdup reduction of subsea riser with surfactant

    NASA Astrophysics Data System (ADS)

    Li, C.; Liu, L.; Bao, Q. B.; Zhou, F. D.

    2010-03-01

    The principal pressure drop in a subsea riser is generally the gravitational pressure drop component due to liquid holdup. Surfactant is a kind of Chemical compound related to flow improvement. Gas-liquid two-phase flow in subsea riser with zero and small liquid flow rates was simulated in two vertical tubes with diameters of 40 mm and 65 mm, respectively. Liquid holdup reduction of subsea riser was investigated with surfactant. The simulation was conducted at low pressure, using air as the gas phase and water as the liquid phase. Pressure drop was measured by using differential pressure transducer and holdup was obtained by trapping the liquid in the pipe section. Different trace amounts of surfactant were used in this vertical two-phase flow system. The liquid holdups were measured at different surfactant concentrations and different gas-liquid flow ratios. Liquid holdups with and without surfactant additives are compared and analyzed. How the foamer influences the two-phase flow pattern was observed and the range of foamer concentration corresponding to the best holdup reduction was obtained.

  19. Stress wave propagation analysis on vortex-induced vibration of marine risers

    NASA Astrophysics Data System (ADS)

    Li, Hua-jun; Wang, Chao; Liu, Fu-shun; Hu, Sau-Lon James

    2017-03-01

    To analyze the stress wave propagation associated with the vortex-induced vibration (VIV) of a marine riser, this paper employed a multi-signal complex exponential method. This method is an extension of the classical Prony's method which decomposes a complicated signal into a number of complex exponential components. Because the proposed method processes multiple signals simultaneously, it can estimate the "global" dominating frequencies (poles) shared by those signals. The complex amplitude (residues) corresponding to the estimated frequencies for those signals is also obtained in the process. As the signals were collected at different locations along the axial direction of a marine riser, the phenomena of the stress wave propagation could be analyzed through the obtained residues of those signals. The Norwegian Deepwater Program (NDP) high mode test data were utilized in the numerical studies, including data sets in both the in-line (IL) and cross-flow (CF) directions. It was found that the most dominant component in the IL direction has its stress wave propagation along the riser being dominated by a standing wave, while that in the CF direction dominated by a traveling wave.

  20. Interactions of multiphase hydrodynamics, droplet evaporation, and chemical kinetics in FCC riser reactors.

    SciTech Connect

    Chang, S. L.

    1998-02-17

    A computational fluid dynamics (CFD) computer code, ICRKFLO, has been developed for flow simulation of fluid catalytic cracking (FCC) riser reactors, which convert crude oil into gasoline and other valuable products. The FCC flow, especially in the entry region, is a three-phase reacting flow including hot catalyst particles, inert lift gas, and feed oil droplets. The impact of the hydrodynamics processes of heat transfer, droplet evaporation, and mixing on the chemical kinetics or riser performance can be significant. ICRKFLO was used to evaluate the impact of these processes on the performance of an advanced FCC unit. The code solves for major flow properties of all three phases in an FCC riser, with models governing the transport of catalyst particles and feed oil droplet, the vaporization of the feed oil droplets, the cracking of the oil vapor, and the formation and deposition of coke on particles. First, the code was validated against available test data of a pilot-scale FCC unit. Then, flow calculations for the FCC unit were performed. Computational results indicate that the heat transfer and droplet vaporization processes have a significant impact on the performance of a pilot-scale FCC unit. The impact is expected to be even greater on commercial scale units.

  1. Riser-cable development for ocean-thermal-energy conversion plants. Progress report

    SciTech Connect

    Not Available

    1982-12-01

    Developmental testing and analysis of OTEC riser cables and component materials has been undertaken. Two full-size riser cables have been manufactured and tested, one using cross-linked polyethylene (XLPE) insulation, the other using self-contained, oil filled (SCOF) insulation. These cables and their components have been subjected to testing which simulates handling and insulation prior to OTEC service, as well as the electrical and mechanical loads predicted in service. Results of testing and analyses to date indicate that the XLPE cable has significant potential in the OTEC riser application. The cable has performed well in mechanical and electrical testing. The results for the SCOF cable are mixed. The SCOF cable collapses due to pressure at depths typical of OTEC service; slippage may occur within the insulation or between the conductor and insulation which could result in early cable failure. Particular attention must be paid to alleviating these problems in future cable design efforts. Implications of these findings for cable and system development are presented for use by OTEC platform designers. These findings are subject to change as additional test data are obtained.

  2. Riser-relief valve dynamic interactions (extension to a previous model)

    SciTech Connect

    Botros, K.K.; Dunn, G.H.; Hrycyk, J.A.

    1998-05-01

    Further investigation of the dynamic stability behavior of a typical pilot-operated relief valve is reported. The present study is an extension to Botros et al. (1997) model, which includes mapping of the oscillating frequencies and amplitudes with riser dimensionless length L/D; inclusion of the effects of a wedge-O-ring seal in the model; detailed analyses of the field tests revealing unknown values for model parameters. These model refinements resulted in a better agreement between simulation results and field measurements. Analysis of piston oscillation frequencies and amplitudes indicates that the piston oscillation frequency mirrors the riser`s one-quarter-wave resonance frequency for lower values of L/D. At L/D = 20 and higher, two modes of oscillations started to emerge with two distinct frequencies. Maximum oscillation amplitudes occurred at L/D corresponding to one-quarter wave. Wedge-O-ring seal mechanism helps in suppressing piston oscillations; but it must be used in conjunction with a proper lubricant, otherwise the piston may jam partway during the upward stroke.

  3. Upgrading naphtha in a multiple riser fluid catalytic cracking operation employing a catalyst mixture

    SciTech Connect

    Herbst, J.A.; Owen, H.; Schipper, P.H.

    1989-05-16

    A process is described for producing gasoline comprising contacting a hydrocarbon feed having an initial boiling-point of at least 400/sup 0/F., a 50% boiling of at least 500/sup 0/F. and an end boiling point of at least 600/sup 0/F., in a first riser, with a two component catalyst under fluid catalytic cracking conditions. At least one component of the catalyst is stripped in a stripping unit to remove entrained hydrocarbons, and regenerated wherein the two component catalyst comprises a first catalyst component selected from the group consisting of an amorphous cracking catalyst and a large pore cracking catalyst, whereby a product comprising olefins and naphtha is produced. Ethylene introduced together with the two component catalyst to a second riser, for contacting ethylene with a second catalyst component which is a shape selective medium pore crystalline silicate zeolite to produce products heavier than ethylene and to increase the temperature of the catalyst to an optimum temperature for upgrading naphtha; and naphtha is introduced to the second riser, down stream of the point of ethylene introduction, for contact with the catalyst at the optimum temperature and the naphtha is upgraded to gasoline product.

  4. Helical wire stress analysis of unbonded flexible riser under irregular response

    NASA Astrophysics Data System (ADS)

    Wang, Kunpeng; Ji, Chunyan

    2017-06-01

    A helical wire is a critical component of an unbonded flexible riser prone to fatigue failure. The helical wire has been the focus of much research work in recent years because of the complex multilayer construction of the flexible riser. The present study establishes an analytical model for the axisymmetric and bending analyses of an unbonded flexible riser. The interlayer contact under axisymmetric loads in this model is modeled by setting radial dummy springs between adjacent layers. The contact pressure is constant during the bending response and applied to determine the slipping friction force per unit helical wire. The model tracks the axial stress around the angular position at each time step to calculate the axial force gradient, then compares the axial force gradient with the slipping friction force to judge the helical wire slipping region, which would be applied to determine the bending stiffness for the next time step. The proposed model is verified against the experimental data in the literature. The bending moment-curvature relationship under irregular response is also qualitatively discussed. The stress at the critical point of the helical wire is investigated based on the model by considering the local flexure. The results indicate that the present model can well simulate the bending stiffness variation during irregular response, which has significant effect on the stress of helical wire.

  5. Drilling Fluid Contamination during Riser Drilling Quantified by Chemical and Molecular Tracers

    NASA Astrophysics Data System (ADS)

    Inagaki, F.; Lever, M. A.; Morono, Y.; Hoshino, T.

    2012-12-01

    Stringent contamination controls are essential to any type of microbiological investigation, and are particularly challenging in ocean drilling, where samples are retrieved from hundreds of meters below the seafloor. In summer 2012, Integrated Ocean Drilling Expedition 337 aboard the Japanese vessel Chikyu pioneered the use of chemical tracers in riser drilling while exploring the microbial ecosystem of coalbeds 2 km below the seafloor off Shimokita, Japan. Contamination tests involving a perfluorocarbon tracer that had been successfully used during past riserless drilling expeditions were complemented by DNA-based contamination tests. In the latter, likely microbial contaminants were targeted via quantitative polymerase chain reaction assays using newly designed, group-specific primers. Target groups included potential indicators of (a) drilling mud viscosifiers (Xanthomonas, Halomonas), (b) anthropogenic wastewater (Bifidobacterium, Blautia, Methanobrevibacter), and (c) surface seawater (SAR 11, Marine Group I Archaea). These target groups were selected based on past evidence suggesting viscosifiers, wastewater, and seawater as the main sources of microbial contamination in cores retrieved by ocean drilling. Analyses of chemical and molecular tracers are in good agreement, and indicate microorganisms associated with mud viscosifiers as the main contaminants during riser drilling. These same molecular analyses are then extended to subseafloor samples obtained during riserless drilling operations. General strategies to further reduce the risk of microbial contamination during riser and riserless drilling operations are discussed.

  6. Faulted terrace riser position with respect to meanders constrains late Quaternary slip history of the Honey Lake fault, NE California

    NASA Astrophysics Data System (ADS)

    Gold, R. D.

    2016-12-01

    Faulted terrace risers are prevalent semi-linear features commonly used to constrain Quaternary slip rates along strike-slip faults. Terrace risers are difficult to date directly and therefore the bracketing upper and lower terrace surfaces commonly are used to constrain their ages. However, if there is a significant difference in the age of the upper and lower terrace surfaces, then large uncertainties in slip rate result. Some investigators try to reduce uncertainties by arguing that either the upper- or lower-terrace age closely approximates the age of a terrace riser. To evaluate where this approach is valid, we use 0.25-m airborne lidar data to analyze three sites where terrace risers are laterally offset by the right-lateral Honey Lake fault in NE California. The terrace risers are bracketed by the same sub-horizontal surfaces: an upper surface defined by the bed of abandoned Lake Lahontan having an age of 15.8 ka and a lower fluvial terrace abandoned after 4.7 ka. We estimate a >4x difference in the amount of lateral offset recorded by the risers, ranging from 7 to 30 m. The amount of offset appears to correspond to the riser position relative to modern stream meanders: smaller offsets are in cutbank locations and the largest offset is in the point-bar location. At face value, the results yield slip rates of 0.5 to 6.4 mm/yr. However, in detail, the largest lateral displacement ( 30 m) places a minimum bound on slip rate of 2 mm/yr since 15.8 ka and the smallest displacement ( 7 m) places a maximum bound on slip rate of 1.5 mm/yr since 4.7 ka. This investigation highlights the challenge of correctly determining whether an upper or lower terrace best approximates the age of a faulted terrace riser. To reduce uncertainties, we advocate considering the terrace riser position in the stream system and characterizing numerous faulted and dated landforms.

  7. Catenary cultures of embryonic gastrointestinal tract support organ morphogenesis, motility, neural crest cell migration, and cell differentiation.

    PubMed

    Hearn, C J; Young, H M; Ciampoli, D; Lomax, A E; Newgreen, D

    1999-03-01

    The embryonic gastrointestinal tract develops from a simple tube into a coiled, flexed, and regionalized structure. The changes in gut morphology coincide with the differentiation of multiple cell types in concentric layers, and include colonization by migratory neuron precursors, and the development of gastrointestinal motility. We describe a reliable method for growing embryonic mouse intestine in vitro by the attachment of segments of intestinal tract by their cut ends, with the intervening region suspended in the culture medium. These are termed "catenary cultures." E11-E11.5 mouse midgut, hindgut, or mid- plus hindgut segments were grown in catenary culture for up to 10 days and their growth, morphology, cell differentiation, ability to support neural precursor migration, and contractile activity were assessed. The increase in size of the cultured explants was not large, but morphogenesis proceeded, best exemplified by elongation of the caecum. Cell differentiation also proceeded. In the mucosa, goblet cells differentiated. Muscle layers, characterized by desmin expression, and kit-positive interstitial cells of Cajal differentiated in the correct positions. Where segments initially included neural precursors in a small sub-region, these migrated and proliferated to form uniform neuronal networks throughout the entire explant, and the cells expressed the neuron markers nitric oxide synthase and neuron specific enolase. Gut motility was attained 5-6 days into the culture period, and both contractile- and mixing-type movements were observed. Thus, cell types representative of all three germ layer contributions developed, and in addition, the gut, being mainly free, was able to elongate and bend (unlike on solid support cultures), while retaining its rostrocaudal identity.

  8. Experimental Plan for Crystal Accumulation Studies in the WTP Melter Riser

    SciTech Connect

    Miller, D.; Fowley, M.

    2015-04-28

    This experimental plan defines crystal settling experiments to be in support of the U.S. Department of Energy – Office of River Protection crystal tolerant glass program. The road map for development of crystal-tolerant high level waste glasses recommends that fluid dynamic modeling be used to better understand the accumulation of crystals in the melter riser and mechanisms of removal. A full-scale version of the Hanford Waste Treatment and Immobilization Plant (WTP) melter riser constructed with transparent material will be used to provide data in support of model development. The system will also provide a platform to demonstrate mitigation or recovery strategies in off-normal events where crystal accumulation impedes melter operation. Test conditions and material properties will be chosen to provide results over a variety of parameters, which can be used to guide validation experiments with the Research Scale Melter at the Pacific Northwest National Laboratory, and that will ultimately lead to the development of a process control strategy for the full scale WTP melter. The experiments described in this plan are divided into two phases. Bench scale tests will be used in Phase 1 (using the appropriate solid and fluid simulants to represent molten glass and spinel crystals) to verify the detection methods and analytical measurements prior to their use in a larger scale system. In Phase 2, a full scale, room temperature mockup of the WTP melter riser will be fabricated. The mockup will provide dynamic measurements of flow conditions, including resistance to pouring, as well as allow visual observation of crystal accumulation behavior.

  9. Bed inventory overturn in a circulating fluid bed riser with pant-leg structure

    SciTech Connect

    Jinjing Li; Wei Wang; Hairui Yang; Junfu Lv; Guangxi Yue

    2009-05-15

    The special phenomenon, nominated as bed inventory overturn, in circulating fluid bed (CFB) riser with pant-leg structure was studied with model calculation and experimental work. A compounded pressure drop mathematic model was developed and validated with the experimental data in a cold experimental test rig. The model calculation results agree well with the measured data. In addition, the intensity of bed inventory overturn is directly proportional to the fluidizing velocity and is inversely proportional to the branch point height. The results in the present study provide significant information for the design and operation of a CFB boiler with pant-leg structure. 15 refs., 10 figs., 1 tab.

  10. Strategy for understanding gas-solid riser hydrodynamics and other LANL status items

    SciTech Connect

    Kashiwa, B. A.

    2002-01-01

    The talk presents the status of work in progress in the area of momentum transport theory in turbulent gas-solid multiphase flow. Previous installments have reported details of the theory, and validation results. This talk provides a grand overview of how the details of dynamic simulations in 3D, 2D, 1D and 0D, all fit together to form a consistent strategy for understanding gas-solid riser hydrodynamics. The circulating fluidized bed is the canonical example for showing how the strategy works. Performance of the procedure is shown by comparison to data recently obtained by Sandia National Laboratory. Status of other LANL efforts is also mentioned.

  11. Stress-riser fractures of the hip after sliding screw plate fixation.

    PubMed

    DiMaio, F R; Haher, T R; Splain, S H; Mani, V J

    1992-10-01

    Fractures occurring after fixation of intertrochanteric femur fractures have been described previously in the literature. Terms such as "stress-riser fracture" and "Young's modulus fracture" have been applied. The prevalence of these fracture types has increased, and so has use of the sliding screw plate device for fixation of intertrochanteric hip fractures. The object of this paper is to describe, by case examples, types of stress-related fractures of the proximal femur in association with the sliding screw plate and to define each biomechanical type in review.

  12. Nonlinear Analysis of a Bolted Marine Riser Connector Using NASTRAN Substructuring

    NASA Technical Reports Server (NTRS)

    Fox, G. L.

    1984-01-01

    Results of an investigation of the behavior of a bolted, flange type marine riser connector is reported. The method used to account for the nonlinear effect of connector separation due to bolt preload and axial tension load is described. The automated multilevel substructing capability of COSMIC/NASTRAN was employed at considerable savings in computer run time. Simplified formulas for computer resources, i.e., computer run times for modules SDCOMP, FBS, and MPYAD, as well as disk storage space, are presented. Actual run time data on a VAX-11/780 is compared with the formulas presented.

  13. Offshore North Sea pipeline and riser loss of containment study (PARLOC) -- applications and limitations in the assessment of operating risks

    SciTech Connect

    Robertson, J.L.M.; Smart, D.; Al-Hassan, T.

    1996-05-01

    Since the Piper Alpha disaster in 1988, there has been an urgent requirement to prevent such tragedies occurring by the introduction of higher safety standards and by improving the confidence in the statistical information available for the assessment of the risks of loss of containment associated with operation of North Sea pipelines. In order to achieve the latter, two databases have been compiled: (1) a pipeline database containing details of pipelines and risers installed in the North Sea; (2) an incident database containing details of reported occurrences (covering the period from 1975 to end 1993), which directly resulted or threatened to result in loss of containment from a pipeline or riser, The data has been compiled from information obtained from: U.K., Norwegian, Dutch and Danish Regulatory Authorities; Operators in the U.K., Dutch and Danish Sectors; reports from previous studies made available to the study; published sources. The databases have been used to perform assessments of factors affecting the frequency of incidents, such as: incident cause; part of pipeline or riser affected; pipeline or riser diameter, length, contents, age, type; whether the line is trenched or buried, piggy-backed or not; hydrotest pressure; location of pipeline or riser in the North Sea. The PARLOC study identifies potential hazards and provides an indication of likely loss of containment frequency associated with the operation of North Sea pipelines and risers. Furthermore, PARLOC provides a continually updated key reference for comparative risk assessment and ultimately for the implementation of risk control as part of an overall risk management program.

  14. Evaluation of axial and lateral modal superposition for general 3D drilling riser analysis

    SciTech Connect

    Burgdorf, O. Jr.

    1996-12-31

    A 3D partially non-linear transient fully-coupled riser analysis method is evaluated which uses modal superposition of independently extracted lateral and axial modes. Many lateral modes are combined with a lesser number axial modes to minimize adverse time step requirements typically induced by axial flexibility in direct time integration of beam-column elements. The reduced computer time option enables much faster parametric analysis of hang-off, as well as other connected drilling environments normally examined. Axial-lateral coupling is explicitly enforced and, resonance fidelity is preserved when excitation is near or coincident with axial natural periods. Reasonable correlation is shown with envelopes of test case dynamic responses published by API. Applicability of the method is limited by linearity assumptions indigenous to modal representation of dynamic deflections relative to a mean deflected shape. Sensitivities of incipient buckling during hang-off to axial damping and stiffness are described for an example 6,000 ft. deep composite drilling riser system.

  15. Predictive Model for Particle Residence Time Distributions in Riser Reactors. Part 1: Model Development and Validation

    DOE PAGES

    Foust, Thomas D.; Ziegler, Jack L.; Pannala, Sreekanth; ...

    2017-02-28

    Here in this computational study, we model the mixing of biomass pyrolysis vapor with solid catalyst in circulating riser reactors with a focus on the determination of solid catalyst residence time distributions (RTDs). A comprehensive set of 2D and 3D simulations were conducted for a pilot-scale riser using the Eulerian-Eulerian two-fluid modeling framework with and without sub-grid-scale models for the gas-solids interaction. A validation test case was also simulated and compared to experiments, showing agreement in the pressure gradient and RTD mean and spread. For simulation cases, it was found that for accurate RTD prediction, the Johnson and Jackson partialmore » slip solids boundary condition was required for all models and a sub-grid model is useful so that ultra high resolutions grids that are very computationally intensive are not required. Finally, we discovered a 2/3 scaling relation for the RTD mean and spread when comparing resolved 2D simulations to validated unresolved 3D sub-grid-scale model simulations.« less

  16. Experience with cable-operated ultrasonic pigs for pipeline and riser pipe inspection

    SciTech Connect

    Raad, J.A. de

    1995-10-01

    In order to establish the integrity of ageing pipelines, the use of self contained intelligent pigs has become of increasing interest. For several decades, pigs using magnetic flux leakage (MFL) were the only tools available on the market for this purpose. Over the past decade also ultrasonic pigs have been developed. (Off)loading lines and open risers often only provide single sided access and are not equipped with pig launch and receive traps. For this category of pipelines, RTD developed cable operated ultrasonic pigs. This paper provides an overview of the possibilities of such cable operated pigs. Tools for distances up to 17,000 m, propelled either by reversible wheel-driven crawlers or by differential pressure, are described. These systems are suitable for pipes with diameters between 150 and 1,500 mm. A novel approach for the inspection of gas risers is also mentioned, whereby full circumferential coverage is achieved by means of an oscillating probe ring. In this approach, the pipe has been flooded with a liquid. The first successful field application of such a system has been performed in the autumn of 1992.

  17. Impact Of Particle Agglomeration On Accumulation Rates In The Glass Discharge Riser Of HLW Melter

    SciTech Connect

    Kruger, A. A.; Rodriguez, C. A.; Matyas, J.; Owen, A. T.; Jansik, D. P.; Lang, J. B.

    2012-11-12

    The major factor limiting waste loading in continuous high-level radioactive waste (HLW) melters is an accumulation of particles in the glass discharge riser during a frequent and periodic idling of more than 20 days. An excessive accumulation can produce robust layers a few centimeters thick, which may clog the riser, preventing molten glass from being poured into canisters. Since the accumulation rate is driven by the size of particles we investigated with x-ray microtomography, scanning electron microscopy, and image analysis the impact of spinel forming components, noble metals, and alumina on the size, concentration, and spatial distribution of particles, and on the accumulation rate. Increased concentrations of Fe and Ni in the baseline glass resulted in the formation of large agglomerates that grew over the time to an average size of ~185+-155 {mu}m, and produced >3 mm thick layer after 120 h at 850 deg C. The noble metals decreased the particle size, and therefore significantly slowed down the accumulation rate. Addition of alumina resulted in the formation of a network of spinel dendrites which prevented accumulation of particles into compact layers.

  18. Effect of particle size distribution on the hydrodynamics of dense CFB risers

    NASA Astrophysics Data System (ADS)

    Bakshi, Akhilesh; Khanna, Samir; Venuturumilli, Raj; Altantzis, Christos; Ghoniem, Ahmed

    2015-11-01

    Circulating Fluidized Beds (CFB) are favorable in the energy and chemical industries, due to their high efficiency. While accurate hydrodynamic modeling is essential for optimizing performance, most CFB riser simulations are performed assuming equally-sized solid particles, owing to limited computational resources. Even though this approach yields reasonable predictions, it neglects commonly observed experimental findings suggesting the strong effect of particle size distribution (psd) on the hydrodynamics and chemical conversion. Thus, this study is focused on the inclusion of discrete particle sizes to represent the psd and its effect on fluidization via 2D numerical simulations. The particle sizes and corresponding mass fluxes are obtained using experimental data in dense CFB riser while the modeling framework is described in Bakshi et al 2015. Simulations are conducted at two scales: (a) fine grid to resolve heterogeneous structures and (b) coarse grid using EMMS sub-grid modifications. Using suitable metrics which capture bed dynamics, this study provides insights into segregation and mixing of particles as well as highlights need for improved sub-grid models.

  19. Numerical simulation of thermal-hydraulic processes in the riser chamber of installation for clinker production

    NASA Astrophysics Data System (ADS)

    Borsuk, Grzegorz; Dobrowolski, Bolesław; Nowosielski, Grzegorz; Wydrych, Jacek; Duda, Jerzy

    2016-03-01

    Clinker burning process has a decisive influence on energy consumption and the cost of cement production. A new problem is to use the process of decarbonization of alternative fuels from waste. These issues are particularly important in the introduction of a two-stage combustion of fuel in a rotary kiln without the typical reactor-decarbonizator. This work presents results of numerical studies on thermal-hydraulic phenomena in the riser chamber, which will be designed to burn fuel in the system where combustion air is supplied separately from the clinker cooler. The mathematical model is based on a combination of two methods of motion description: Euler description for the gas phase and Lagrange description for particles. Heat transfer between particles of raw material and gas was added to the numerical calculations. The main aim of the research was finding the correct fractional distribution of particles. For assumed particle distribution on the first stage of work, authors noted that all particles were carried away by the upper outlet to the preheater tower, what is not corresponding to the results of experimental studies. The obtained results of calculations can be the basis for further optimization of the design and operating conditions in the riser chamber with the implementation of the system.

  20. First Riser Logging in Scientific Ocean Drilling: Operational Planning and results/reality

    NASA Astrophysics Data System (ADS)

    Sanada, Yoshinori; Kyaw Thu, Moe; Kido, Yukari; Kawamura, Yoshihisa; Hino, Ryota; Eguchi, Nabuhisa; Toczko, Sean; Takahashi, Kyoma; 319 Science Party, Iodp

    2010-05-01

    The first wireline logging, downhole stress measurement, and two-ship walkaway VSP (Vertical Seismic Profiling) were conducted in the riser drilled hole during IODP Expedition 319 in 2009. The hole C0009 is first riser drilling hole in ODP/IODP history by JAMSTEC D/V Chikyu. The expedition 319 is one of series of NanTroSEIZE Project, which goal is to reveal earthquake mechanism in Nankai trough seismogenic zone in Japan. The hole C0009 is drilled at TD 1603.7mbsf under 2054m sea water. Sampling cores, cutting analysis, gas monitoring, wireline logging, downhole stress measurement, and two-ship walkaway VSP (Vertical Seismic Profiling) were conducted. This presentation report the operational planning, results and reality. IODP standard wireline logging items: natural gamma-ray, resistivity, density, porosity, sonic velocity, resistivity image were measured. The advantages of riser dilled hole against riserless drilled hole for wireline logging are 1) stable hole condition, 2) accurate environmental correction by controlled drilling mud, and 3) large variation of tool selection because of regular hole size instead of slimhole by conventional IODP riser drilling. A couple of new tools were used for new measurement and improvement of the data quality. The SonicScanner (trademark of Schulumberger) successfully measured compressional and share velocity in very low velocities at the soft sediment, where it has been difficult to measure them with conventional DSI tool. The stress and pore pressure in the borehole were measured with the wireline logging tool, (Schlumberger MDT). The single probe tool enable to measure temporal formation fluid pressure. The double packer tool enable to fracture test by sealing and pumping in the borehole. These in-situ measurement and stress experiment data are very important to understand physical properties and mechanism of fault zone. Super long offset walkaway VSP was conducted to reveal detail subsurface structure and velocity

  1. Early Risers

    ERIC Educational Resources Information Center

    Asquith, Chistina

    2002-01-01

    In this article, the author features Bard High School Early College, the first public school in the country to offer a free, full-time college curriculum--and all the credits that go with it--to high schoolers. In Bard's four-year program, students race through high school requirements in 9th and 10th grades, then take college courses in 11th and…

  2. Experimental investigation on the suppression of vortex-induced vibration of long flexible riser by multiple control rods

    NASA Astrophysics Data System (ADS)

    Wu, H.; Sun, D. P.; Lu, L.; Teng, B.; Tang, G. Q.; Song, J. N.

    2012-04-01

    Experimental investigations were conducted to evaluate the vortex-induced vibration (VIV) suppression for slender riser (length to diameter ratio L/D=1750) using multiple control rods. The uniform current was obtained by towing the riser model running in a wave basin, giving the Reynolds numbers ranging from 2400 to 7600. Four control rods with diameter d=0.25D were placed parallel to the riser model with uniform angle interval of 90°. Different spacing ratios δ/D=0.187, 0.375 and 0.562 and coverage rates Lc/L=80%, 60%, 40% and 20% were considered, where δ is the spacing distance, Lc is the covered length. The strain responses in both cross-flow (CF) and in-line (IL) directions were measured by 56 Fiber Bragg Grating sensors. The experimental results show that the multiple control rods perform well in mitigating the VIV. In general the smaller spacing ratio and the larger coverage rates give rise to the better VIV suppression for the CF response, while the IL response is not sensitive to the δ/D and Lc/L. The optimal parameters are suggested to be δ/D≤0.375 and Lc/L≈60%. The monitored end tension of the riser model was observed to increase slightly due to the presence of control rods.

  3. Parent Participation within Community Center or In-Home Outreach Delivery Models of the Early Risers Conduct Problems Prevention Program

    ERIC Educational Resources Information Center

    Bloomquist, Michael L; August, Gerald J.; Lee, Susanne S.; Piehler, Timothy F.; Jensen, Marcia

    2012-01-01

    A variety of predictors of parent participation in prevention programming have been identified in past research, but few studies have investigated how those predictors may vary by implementation context. Patterns of parent participation were examined in the Early Risers Conduct Problems Prevention Program using two family-focused service delivery…

  4. Secondary School Reform, Inclusion, and Authentic Assessment. Research Institute on Secondary Education Reform (RISER) for Youth with Disabilities Brief.

    ERIC Educational Resources Information Center

    Braden, Jeffery P.; Schroeder, Jennifer L.; Buckley, Jacquelyn A.

    The Research Institute on Secondary Education Reform for Youth with Disabilities (RISER) has identified Schools of Authentic and Inclusive Learning (SAIL) to explore whether and how secondary students with disabilities are included in secondary education reform. In this brief, the literature describing the intersection of reform, inclusion, and…

  5. Tibial plateau fracture following gracilis-semitendinosus anterior cruciate ligament reconstruction: The tibial tunnel stress-riser.

    PubMed

    Sundaram, R O; Cohen, D; Barton-Hanson, N

    2006-06-01

    Tibial plateau fractures following anterior cruciate ligament (ACL) reconstruction are extremely rare. This is the first reported case of a tibial plateau fracture following four-strand gracilis-semitendinosus autograft ACL reconstruction. The tibial tunnel alone may behave as a stress riser which can significantly reduce bone strength.

  6. Two cases of malignant hypertension with reversible diffuse leukoencephalopathy exhibiting a reversible nocturnal blood pressure "riser" pattern.

    PubMed

    Eguchi, Kazuo; Kasahara, Kentaro; Nagashima, Akinori; Mor, Tadashi; Nii, Takanobu; Ibaraki, Kazuo; Kario, Kazuomi; Shimada, Kazuyuki

    2002-05-01

    We report two cases of malignant hypertension with reversible diffuse leukoencephalopathy demonstrating a nocturnal blood pressure (BP) rising pattern ("riser" pattern). Case 1 was a 54-year-old man diagnosed with malignant hypertension who presented with diffuse leukoencephalopathy and nocturnal BP rise during the acute phase. These abnormal findings diminished after treatment of hypertension. Case 2 was a 50-year-old woman diagnosed with malignant hypertension in association with leukoencephalopathy, heart failure and acute renal failure. She also presented with a "riser" pattern during the acute phase. In contrast to case 1, the leukoencephalopathy and "riser" pattern in case 2 were not improved even after 1 month of treatment. Following intensive antihypertensive treatment, renal failure was improved in case 1, but renal failure was not improved after 1 month in case 2. In conclusion, a possible explanation of this phenomenon is that a causative volume overload due to renal dysfunction produced the temporal leukoencephalopathy-like brain edema and "riser" pattern in these cases.

  7. IODP Expedition 338: NanTroSEIZE Stage 3: NanTroSEIZE plate boundary deep riser 2

    NASA Astrophysics Data System (ADS)

    Moore, G. F.; Kanagawa, K.; Strasser, M.; Dugan, B.; Maeda, L.; Toczko, S.

    2014-01-01

    The Nankai Trough Seismogenic Zone Experiment (NanTroSEIZE) is designed to investigate fault mechanics and seismogenesis along a subduction megathrust, with objectives that include characterizing fault slip, strain accumulation, fault and wall rock composition, fault architecture, and state variables throughout an active plate boundary system. Integrated Ocean Drilling Program (IODP) Expedition 338 was planned to extend and case riser Hole C0002F from 856 to 3600 meters below the seafloor (m b.s.f.). Riser operations extended the hole to 2005.5 m b.s.f., collecting logging-while-drilling (LWD) and measurement-while-drilling, mud gas, and cuttings data. Results reveal two lithologic units within the inner wedge of the accretionary prism that are separated by a prominent fault zone at ~ 1640 m b.s.f. Due to damage to the riser during unfavorable winds and strong currents, riser operations were suspended, and Hole C0002F left for re-entry during future riser drilling operations. Contingency riserless operations included coring at the forearc basin site (C0002) and at two slope basin sites (C0021 and C0022), and LWD at one input site (C0012) and at three slope basin sites (C0018, C0021 and C0022). Cores and logs from these sites comprehensively characterize the alteration stage of the oceanic basement input to the subduction zone, the early stage of Kumano Basin evolution, gas hydrates in the forearc basin, and recent activity of the shallow megasplay fault zone system and associated submarine landslides.

  8. Pantograph-catenary monitoring by means of fibre Bragg grating sensors: Results from tests in an underground line

    NASA Astrophysics Data System (ADS)

    Bocciolone, Marco; Bucca, Giuseppe; Collina, Andrea; Comolli, Lorenzo

    2013-12-01

    One of the most common way to collect the traction current needed for the underground vehicle operation is by using the pantograph-overhead line system. The periodically check of pantographs and overhead lines is important to assure the correct interaction between the two systems in terms of good current collection quality. The main diagnostic tools are the monitoring of the vertical force between the overhead line and the pantograph head, and the vertical acceleration on the pantograph head. The pantograph system works under high voltage (1500 V, DC, in our tests) and high electromagnetic disturbances are present. For this reason, traditional electrical sensors can be used only with particular precautions that complicate the measurement set up; fibre optic sensors, and in particular fibre Bragg grating (FBG) sensors, are particularly suitable for this application. In this paper, the application of the FBG sensors on a pantograph for the monitoring of underground pantograph-catenary system is presented. FBG sensors are used to measure both the contact force and the vertical acceleration of the pantograph head. The same measurements are also gathered with a traditional electrical system, allowing a comparison. The result is a very good agreement between electrical and optical measurements, except in particular frequency ranges where the different positioning of the sensors influences the output, limiting the comparison. Moreover, some interesting results on the dynamic behaviour of the pantograph and its interaction with the overhead line are presented. Finally, a method to point out the main defects on the overhead line is shown.

  9. Analytical and numerical models to predict the behavior of unbonded flexible risers under torsion

    NASA Astrophysics Data System (ADS)

    Ren, Shao-fei; Xue, Hong-xiang; Tang, Wen-yong

    2016-04-01

    This paper presents analytical and numerical models to predict the behavior of unbonded flexible risers under torsion. The analytical model takes local bending and torsion of tensile armor wires into consideration, and equilibrium equations of forces and displacements of layers are deduced. The numerical model includes lay angle, cross-sectional profiles of carcass, pressure armor layer and contact between layers. Abaqus/Explicit quasi-static simulation and mass scaling are adopted to avoid convergence problem and excessive computation time caused by geometric and contact nonlinearities. Results show that local bending and torsion of helical strips may have great influence on torsional stiffness, but stress related to bending and torsion is negligible; the presentation of anti-friction tapes may have great influence both on torsional stiffness and stress; hysteresis of torsion-twist relationship under cyclic loading is obtained by numerical model, which cannot be predicted by analytical model because of the ignorance of friction between layers.

  10. Design and analysis of tapered stress joint for Top Tensioned Riser system

    NASA Astrophysics Data System (ADS)

    Zhang, Ri-xi; Zhang, Qi; Huang, Yi

    2012-09-01

    Stress Joint (SJ) plays a key role in the Top Tensioned Riser (TTR) system for deep water engineering. A preliminary design method of tapered SJ is proposed in the paper, which could help designers obtain accurate design data. After a further sensitive analysis is carried out, the related parameters choice and control methods are recommended in the engineering practice. By taking the extreme environment conditions into consideration, the effects of bending stress reduction and curve control are analyzed, and the 3-D FE models are established by ABQOUS for numerical evaluation to verify the correctness of design results. At last, dynamic analysis and fatigue analysis, based on actual project, are carried out with designed stress joint. The analysis results prove the feasibility and guidance of this method in the practical engineering applications.

  11. 45-Day safety screening for Tank 241-C-103 push mode sample, riser 2

    SciTech Connect

    Bell, K.E.

    1994-12-16

    This is the 45-Day report for the Tank 241-C-103 (C-103) push-mode core sampling characterization effort. Problems encountered with the push-mode sampling truck following removal of the first segment from riser 2 resulted in a long delay before resumption of sampling, therefore it was decided to begin the 45-day clock and issue a report based on receipt of this first segment. If subsequent segments are removed from tank C-103, a revision of this report or a new report will be issued to include any new data. Included are copies of the differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) scans as requested in Reference 1. Also included is a copy of any immediate notification documentation. Other pertinent documentation will be included in the C-103 216-day report.

  12. Hydrodynamics and catalytic reactions in the riser of a FCC plant

    SciTech Connect

    Derouin, C.; van Landeghem, F.; Turlier, P.; Bernard, J.R.

    1996-12-31

    The hydrodynamic characteristics of the riser of a FCC plants are investigated in a cold pilot plant. The results are checked and completed with measurements made in real operating FCC units. In both cases, tracing of the gas, velocity probes and {gamma}-tomography were used. The gas and solid velocity profiles are described by using a plug flow model with radial dispersion. The gas velocity profile is formally represented by an Ostwald - de Waele type equation; the radial and axial solid concentration profile is fitted to data obtained in the real plant. The kinetics of the reactions occurring during catalytic cracking are investigated in a MAT equipment and are represented by a 19 lumps model including deactivation by coking of the catalyst. A combination of this reaction model with the hydrodynamic model is able to predict with a satisfactory precision the yields of the different product families obtained in an industrial FCC unit. 12 refs., 3 tabs.

  13. Aircraft Steels

    DTIC Science & Technology

    2009-02-19

    NAWCADPAX/TR-2009/ 12 AIRCRAFT STEELS by E. U. Lee R. Taylor C. Lei H. C. Sanders 19 February 2009...MARYLAND NAWCADPAX/TR-2009/ 12 19 February 2009 AIRCRAFT STEELS by E. U. Lee R. Taylor C. Lei H. C. Sanders...Prescribed by ANSI Std. Z39-18 NAWCADPAX/TR-2009/ 12 ii SUMMARY Five high strength and four stainless steels have been studied, identifying their

  14. SEGREGATION IN SMALL STEEL CASTINGS

    DTIC Science & Technology

    Carbon segregation in small castings often occurs near riser necks. Systematic studies were continued to determine effect on segregation of such...intensity of carbon segregation under ’neck-down’ risers varies directly as the neck length and inversely as the neck diameter. The degree of segregation

  15. Yield improvement and defect reduction in steel casting

    SciTech Connect

    Kent Carlson

    2004-03-16

    This research project investigated yield improvement and defect reduction techniques in steel casting. Research and technology development was performed in the following three specific areas: (1) Feeding rules for high alloy steel castings; (2) Unconventional yield improvement and defect reduction techniques--(a) Riser pressurization; and (b) Filling with a tilting mold; and (3) Modeling of reoxidation inclusions during filling of steel castings. During the preparation of the proposal for this project, these areas were identified by the High Alloy Committee and Carbon and Low Alloy Committee of the Steel Founders' Society of America (SFSA) as having the highest research priority to the steel foundry industry. The research in each of the areas involved a combination of foundry experiments, modeling and simulation. Numerous SFSA member steel foundries participated in the project through casting trials and meetings. The technology resulting from this project will result in decreased scrap and rework, casting yield improvement, and higher quality steel castings produced with less iteration. This will result in considerable business benefits to steel foundries, primarily due to reduced energy and labor costs, increased capacity and productivity, reduced lead-time, and wider use and application of steel castings. As estimated using energy data provided by the DOE, the technology produced as a result of this project will result in an energy savings of 2.6 x 10{sup 12} BTU/year. This excludes the savings that were anticipated from the mold tilting research. In addition to the energy savings, and corresponding financial savings this implies, there are substantial environmental benefits as well. The results from each of the research areas listed above are summarized.

  16. Static analysis of offshore risers with a geometrically-exact 3D beam model subjected to unilateral contact

    NASA Astrophysics Data System (ADS)

    Neto, Alfredo Gay; Martins, Clóvis A.; Pimenta, Paulo M.

    2014-01-01

    In offshore applications there are elements that can be modeled as long beams, such as umbilical cables, flexible and rigid pipes and hoses, immersed in the sea water, suspended from the floating unit to the seabed. The suspended part of these elements is named "riser" and is subjected to the ocean environment loads, such as waves and sea current. This work presents a structural geometrically-exact 3D beam model, discretized using the finite element method for riser modeling. An updated Lagrangian framework for the rotation parameterization has been used for the description of the exact kinematics. The goal is to perform a complete static analysis, considering the oceanic loads and the unilateral contact with the seabed, extending the current standard analysis for situations in which very large rotations occurs, in particular, large torsion. Details of the nonlinear 3D model and loads from oceanic environment are discussed, including the contact unilateral constraint.

  17. Evolution of terrace risers along the upper Rhine graben inferred from morphologic dating methods: evidence of climatic and tectonic forcing

    NASA Astrophysics Data System (ADS)

    Nivière, B.; Marquis, Guy

    2000-06-01

    We show that morphologic dating techniques that have been applied successfully in arid and semi-arid areas are also suitable for slowly evolving scarps that are usually found in temperate climate environments. We have attempted two morphologic approaches, based on diffusion, to relate the present-day shape of an abandoned terrace riser to its age. The first assumes a model of scarp degradation based on a diffusive process (the D method). The second evaluates the state of scarp degradation using the slope distribution (the SD method) along a topographic profile. By using a manmade scarp of known age, we have obtained a mass diffusivity close to 1.4m2ka-1 when the area experiences a temperate climate characterized by a continuous vegetation cover. However, this value decreases during glacial episodes, probably on account of the permafrost. Even though the SD method requires an age correction that can be easily computed, only this method reveals that at several profiles a later scarp reactivation event has occurred. Indeed, along several profiles, the slope distribution was best fitted by two offset Gaussian curves, suggesting that some scarps have undergone a complex evolution that cannot be modelled with a single diffusive process. This scarp reactivation may correspond to a new incisive episode and allows one to estimate the vertical incision rate along the terrace riser. Applied to a Wurmian terrace riser of the upper Rhine valley (NE France), this approach reveals that the vertical incision rate ranges from 0.2 to 0.85mmyr-1 between 35 and 15ka and that the terrace bevelling occurred during two episodes related to climatic forcing. Moreover, we can identify a component of tectonic forcing evidenced by an increase to the north of vertical incision rate and Rhine stream-power. Another major result is showing that this terrace riser is not isochronous along its strike and that younger portions result from lateral incision of a 30ka pre-existing scarp.

  18. Faulted terrace risers place new constraints on the late Quaternary slip rate for the central Altyn Tagh fault, northwest Tibet

    USGS Publications Warehouse

    Gold, R.D.; Cowgill, E.; Arrowsmith, J.R.; Chen, X.; Sharp, W.D.; Cooper, K.M.; Wang, X.-F.

    2011-01-01

    The active, left-lateral Altyn Tagh fault defines the northwestern margin of the Tibetan Plateau in western China. To clarify late Quaternary temporal and spatial variations in slip rate along the central portion of this fault system (85??-90??E), we have more than doubled the number of dated offset markers along the central Altyn Tagh fault. In particular, we determined offset-age relations for seven left-laterally faulted terrace risers at three sites (Kelutelage, Yukuang, and Keke Qiapu) spanning a 140-km-long fault reach by integrating surficial geologic mapping, topographic surveys (total station and tripod-light detection and ranging [T-LiDAR]), and geochronology (radiocarbon dating of organic samples, 230Th/U dating of pedogenic carbonate coatings on buried clasts, and terrestrial cosmogenic radionuclide exposure age dating applied to quartz-rich gravels). At Kelutelage, which is the westernmost site (37.72??N, 86.67??E), two faulted terrace risers are offset 58 ?? 3 m and 48 ?? 4 m, and formed at 6.2-6.1 ka and 5.9-3.7 ka, respectively. At the Yukuang site (38.00??N, 87.87??E), four faulted terrace risers are offset 92 ?? 12 m, 68 ?? 6 m, 55 ?? 13 m, and 59 ?? 9 m and formed at 24.2-9.5 ka, 6.4-5.0 ka, 5.1-3.9 ka, and 24.2-6.4 ka, respectively. At the easternmost site, Keke Qiapu (38.08??N, 88.12??E), a faulted terrace riser is offset 33 ?? 6 m and has an age of 17.1-2.2 ka. The displacement-age relationships derived from these markers can be satisfied by an approximately uniform slip rate of 8-12 mm/yr. However, additional analysis is required to test how much temporal variability in slip rate is permitted by this data set. ?? 2011 Geological Society of America.

  19. Can evidence-based prevention programs be sustained in community practice settings? The Early Risers' Advanced-Stage Effectiveness Trial.

    PubMed

    August, Gerald J; Bloomquist, Michael L; Lee, Susanne S; Realmuto, George M; Hektner, Joel M

    2006-06-01

    This study evaluated institutional sustainability of the Early Risers "Skills for Success" conduct problems prevention program. In a previous early-stage effectiveness trial Early Risers had been successfully implemented by a nonprofit community agency with guidance, supervision, technical assistance and fiscal support/oversight provided by program developers. The current advanced-stage effectiveness trial applied a randomized, control group design to determine whether this community agency could replicate earlier positive findings with a new cohort of participants, but with less direct involvement of program developers. An intent-to-intervene strategy was used to compare children randomly assigned to Early Risers or a no-intervention comparison group. Compared to results obtained in an early-stage effectiveness trial, program attendance rates were much lower and only one positive outcome was replicated. Failure to replicate program effects was not attributed to poor program implementation, because data collected pertaining to exposure, adherence and quality of delivery were acceptable, and a participation analysis showed that families who attended at higher levels did benefit. It was difficulties that the community agency experienced in engaging families in program components at recommended levels that primarily accounted for the results. Possible organizational barriers that impeded sustainability included unreliable transportation, poor collaboration between the agency and the local public school system, high staff turnover, agency downsizing, and fiduciary responsibility and accountability. It was concluded that both program developers and program providers need to be proactive in planning for sustainability.

  20. Moving from science to service: transposing and sustaining the Early Risers prevention program in a community service system.

    PubMed

    Bloomquist, Michael L; August, Gerald J; Horowitz, Jason L; Lee, Susanne S; Jensen, Cheryl

    2008-07-01

    This paper summarizes an effort to transpose and sustain the evidence-based Early Risers "Skills for Success" conduct problems prevention program in a real world community service system. The Early Risers program had previously been implemented by a local agency within the context of research-based operations. In the current initiative, responsibility for funding and operating the program was transferred from program developers to a local community agency and county service system. There is a description of how the local community partnership adopted the program and real world program evaluation data pertaining to costs and implementation of the program over 2 years (N = 168 children) is presented. It is demonstrated that the local community system provided ongoing funding and that the agency implemented the program with acceptable exposure and participation. Editors' Strategic Implications: The authors carefully assess multiple elements of fidelity and share important lessons regarding community-based implementation, obstacles, and collaboration. The article should be of interest to anyone considering a replication of the evidence-based Early Risers program and also to a broader audience of researchers and practitioners involved in translational research.

  1. Computational Fluid Dynamics–Discrete Element Method (CFD-DEM) Study of Mass-Transfer Mechanisms in Riser Flow

    PubMed Central

    2017-01-01

    We report a computational fluid dynamics–discrete element method (CFD-DEM) simulation study on the interplay between mass transfer and a heterogeneous catalyzed chemical reaction in cocurrent gas-particle flows as encountered in risers. Slip velocity, axial gas dispersion, gas bypassing, and particle mixing phenomena have been evaluated under riser flow conditions to study the complex system behavior in detail. The most important factors are found to be directly related to particle cluster formation. Low air-to-solids flux ratios lead to more heterogeneous systems, where the cluster formation is more pronounced and mass transfer more influenced. Falling clusters can be partially circumvented by the gas phase, which therefore does not fully interact with the cluster particles, leading to poor gas–solid contact efficiencies. Cluster gas–solid contact efficiencies are quantified at several gas superficial velocities, reaction rates, and dilution factors in order to gain more insight regarding the influence of clustering phenomena on the performance of riser reactors. PMID:28553011

  2. Fracture mechanics correlation of boron/aluminum coupons containing stress risers

    NASA Technical Reports Server (NTRS)

    Adsit, N. R.; Waszczak, J. P.

    1975-01-01

    The mechanical behavior of boron/aluminum near stress risers has been studied and reported. This effort was directed toward defining the tensile behavior of both unidirectional and (0/ plus or minus 45) boron/aluminum using linear elastic fracture mechanics (LEFM). The material used was 5.6-mil boron in 6061 aluminum, consolidated using conventional diffusion bonding techniques. Mechanical properties are reported for both unidirectional and (0/ plus or minus 45) boron/aluminum, which serve as control data for the fracture mechanics predictions. Three different flawed specimen types were studied. In each case the series of specimens remained geometrically similar to eliminate variations in finite size correction factors. The fracture data from these tests were reduced using two techniques. They both used conventional LEFM methods, but the existence of a characteristic flaw was assumed in one case and not the other. Both the data and the physical behavior of the specimens support the characteristic flaw hypothesis. Cracks were observed growing slowly in the (0/ plus or minus 45) laminates, until a critical crack length was reached at which time catastrophic failure occurred.

  3. Fracture mechanics correlation of boron/aluminum coupons containing stress risers

    NASA Technical Reports Server (NTRS)

    Adsit, N. R.; Waszczak, J. P.

    1975-01-01

    The mechanical behavior of boron/aluminum near stress risers has been studied and reported. This effort was directed toward defining the tensile behavior of both unidirectional and (0/ plus or minus 45) boron/aluminum using linear elastic fracture mechanics (LEFM). The material used was 5.6-mil boron in 6061 aluminum, consolidated using conventional diffusion bonding techniques. Mechanical properties are reported for both unidirectional and (0/ plus or minus 45) boron/aluminum, which serve as control data for the fracture mechanics predictions. Three different flawed specimen types were studied. In each case the series of specimens remained geometrically similar to eliminate variations in finite size correction factors. The fracture data from these tests were reduced using two techniques. They both used conventional LEFM methods, but the existence of a characteristic flaw was assumed in one case and not the other. Both the data and the physical behavior of the specimens support the characteristic flaw hypothesis. Cracks were observed growing slowly in the (0/ plus or minus 45) laminates, until a critical crack length was reached at which time catastrophic failure occurred.

  4. Effect of Riser Geometry Structure on Local Flow Pattern in a Rectangular Circulating Fluidized Bed

    NASA Astrophysics Data System (ADS)

    Tian, Chen; Wang, Qinhui; Luo, Zhongyang; Zhang, Ximei; Cheng, Leming; Ni, Mingjiang; Cen, Kefa

    By using a high-speed video camera and particle image velocimetry (PIV) technique, the local flow properties of the solid-gas two phases flow were studied in a plexiglass rectangular CFB cold model with the a riser of 1.5×0.864×4.9m3. Measurements were carried out with transparent spherical glass bead between 0.1-0.425mm as bed materials and cold air as flow medium. The experimental results showed that the secondary air has an important influence on the particle velocity distribution. Because of the secondary air penetrating effect, the particle lateral movement was acute. In the dilute region, the outlet and the comer effect induced the defluxion of the particles movement and the core-annular distribution was broken. The closer to the outlet, the stronger the lateral velocity is. The obstruct of hanging screen reduced the furnace outlet effects between the hanging screen and the front wall, where the particle movement in the area was controlled by the gas flow and the constrain of the wall. High particle concentration areas were formed in the junction between the screen and the front wall and in the comer between the wall and the front wall.

  5. Stainless steel

    SciTech Connect

    Lula, R.A.

    1985-01-01

    This book discusses the stainless steels for high-strength, heat-resistant or corrosion-resistant applications. It is a treatment of the properties and selection of stainless steels. Up-to-date information covers physical, mechanical and chemical properties of all stainless grades, including the new ferritic and duplex grades. The book covers physical metallurgy as well as processing and service characteristics, including service in corrosive environments. It deals with wrought and cast stainless steels and reviews fabrication from cold-forming to powder metallurgy.

  6. Application of a catenary PBPK model to predict the disposition of "catch and release" anti-PCSK9 antibodies.

    PubMed

    Glassman, Patrick M; Balthasar, Joseph P

    2016-05-30

    The development of 'catch and release', or pH-sensitive, monoclonal antibodies (mAb) has become of interest to groups seeking to reduce the influence of target-mediated elimination on pharmacokinetics and pharmacodynamics. In this work, a catenary physiologically-based pharmacokinetic (PBPK) model is described to predict the pharmacokinetic benefit conferred by engineering mAbs for 'catch and release' binding. Our previously published PBPK model was adapted for consideration of the production and elimination of proprotein convertase subtilisin/kexin type 9 (PCSK9) in mice, and the model was then applied to predict the pharmacokinetics of anti-PCSK9 mAb with pH-stable (J10) and pH-sensitive binding (J17). The model was able to generate reasonable predictions of both J10 and J17 plasma pharmacokinetics. For J10, mean (±standard deviation) predicted vs. observed areas under the plasma concentration curve (AUCinf) were: 217 (77.1) vs. 103nMday (1mg/kg), 1.14×10(3) (858) vs. 769nMday (3mg/kg), and 6.60×10(3) (5.58×10(3)) vs. 2.86×10(3)nMday (10mg/kg), and for J17 the values were: 838 (161) vs. 818nMday (1mg/kg), 2.30×10(3) (441) vs. 2.57×10(3)nMday (3mg/kg), and 8.42×10(3) (1.50×10(3)) vs. 9.17×10(3)nMday (10mg/kg). Further simulations with the model predicted that target turnover and the magnitude of change in the complex dissociation rate constant between pH 7.4 and pH 6.0 are key determinants of the improvements in pharmacokinetics associated with 'catch and release' mAbs. The model described here may be useful for prediction of the pharmacokinetics of 'catch and release' mAbs directed against other targets. Copyright © 2016. Published by Elsevier B.V.

  7. Comparative metagenomic analysis of soil microbes along treads and risers of periglacial ground in Glacier National Park, Montana

    NASA Astrophysics Data System (ADS)

    Ricketts, M. K.; Apple, M. E.

    2016-12-01

    The mean annual temperature for Glacier National Park and the surrounding regions has increased 1.33 degrees Celsius since 1900, 1.8 times the global mean increase. Periglacial features created by receding glaciers have created obstacles for endemic native species in Glacier to overcome. In an RM-CESU-funded study at Glacier National Park, a team of researchers from Montana Tech discovered differences in plant species distributions at the edges of snowfields and in periglacial patterned ground. The data from this study showed that on the sloping, green risers of solifluction terraces—periglacial features created by the freeze-thaw cycles of receding glaciers and snowfields at Siyeh Pass, Glacier—just 2% of plant species recorded were considered range-limited and endemic to the region. The team found four rare arctic-alpine species in the flat, rocky tread regions of the terraces, which often face much harsher wind and snow conditions, while only one rare arctic-alpine species was found on the green risers. Soil microbes are known to be important regulators of plant productivity, specifically in nutrient-poor ecosystems with a high abundance of vegetation that relies on symbionts to acquire nutrients. In alpine environments, where weather is harsh and the growing season short, certain species of plants rely on microbial symbionts to mobilize phosphorus and nitrogen within the root system. Research has suggested density of plant populations is linked to soil nutrient availability. In the summer and fall of 2016, comparative metagenomics analysis of soil microbial communities along treads and risers of periglacial ground (moving from the edge of the snowfield out) will be performed. This data will be compared to plant surveys performed in the summers 2014 and 2016 measuring rare alpine plant species dispersal and abundance in order to draw conclusions about how soil microbe distribution affects rare alpine plant species growth and success.

  8. Tibial plateau fracture after anterior cruciate ligament reconstruction: Role of the interference screw resorption in the stress riser effect.

    PubMed

    Thaunat, Mathieu; Nourissat, Geoffroy; Gaudin, Pascal; Beaufils, Philippe

    2006-06-01

    We report a case of tibial plateau fracture after previous anterior cruciate ligament (ACL) reconstruction using patellar tendon autograft and bioabsorbable screws 4 years previously. The fracture occurred through the tibial tunnel. The interference screw had undergone complete resorption and the tunnel widening had increased. The resorption of the interference screw did not simultaneously promote and foster the growth of surrounding bone tissue. Therefore, the area of reactive tissue left by the screw resorption in an enlarged bone tunnel may lead to vulnerability of the tibial plateau. Stress risers would occur following ACL reconstruction if either resorption is not complete or bony integration is not complete.

  9. A study of the spray injection Reynolds number effects on gasoline yields of an FCC riser reactor

    SciTech Connect

    Bowman, B. J.; Zhou, C. Q.; Chang, S. L.; Lottes, S. A.

    2000-04-03

    A computational analysis of the combined effects of feed oil injection parameters in a commercial-scale fluidized catalytic cracking riser reactor was performed using a three-phase, multiple species kinetic cracking computer code. The analysis showed that the injection operating parameters (droplet diameter and injection velocity) had strong impacts on the gasoline yields of the FCC unit. A spray injection Reynolds number combining the two parameters was defined. A correlation between the spray injection Reynolds number and the gasoline product yields for various feed injection conditions was developed. A range of spray injection Reynolds number for the maximum gasoline yield was identified.

  10. IODP Expedition 338: Riser and Riserless Drilling Along the NanTroSEIZE Transect

    NASA Astrophysics Data System (ADS)

    Strasser, M.; Moore, G. F.; Dugan, B.; Kanagawa, K.; Toczko, S.

    2013-12-01

    Integrated Ocean Drilling Program (IODP) Expedition 338 provided new constraints on the Kumano Basin sediments, the accretionary prism inner wedge, the seaward extension of the megasplay fault, the architecture and mechanics of landslides, and the alteration of oceanic basement of the incoming Philippine Sea plate. This was accomplished through riser and riserless drilling, logging while drilling (LWD), and cuttings and core analysis. Cuttings and LWD analyses at Hole C0002F reveal two lithologic units in the prism inner wedge which are separated by a prominent fault zone at ~1640 mbsf. Mud-gases from the inner prism show high concentrations at the top of the wedge that decrease, but become more thermogenic, with depth. These data are from the previously unaccessed deeper part of the Nankai accretionary prism. Riserless coring at Site C0002 provided data across the gas hydrate zone of the Kumano Basin, across the Kumano Basin-accretionary prism unconformity, and in the uppermost accretionary prism. Within the Kumano basin section, gas and porewater geochemistry documents microbial methane gas in hydrates that are disseminated in sandy layers. Multiple penetrations of the Kumano Basin-accretionary prism boundary and 3D seismic data show that the boundary is erosive and complex. LWD (Site C0018) and coring and LWD (Site C0021) augment existing data to better understand submarine landslide dynamics and mass-transport deposit (MTD) emplacement processes. Previous coring at Site C0018 identified six MTDs, but only two MTD intervals were detected in resistivity images that show high angle, randomly oriented bedding. Site C0021, located more proximal to the MTD source, provides constraint on MTD variability. Correlation across the sites reveals a thick MTD with an erosional base characterized by a shear zone in muddy sediments vs. a translational basal surface within coarse volcaniclastic sand in the proximal and distal/lateral areas, respectively. LWD data and cores from

  11. Extreme hydrodynamic load calculations for fixed steel structures

    SciTech Connect

    Jong, P.R. de; Vugts, J.; Gudmestad, O.T.

    1996-12-31

    This paper discusses the expected differences between the planned ISO code for design of offshore structures and the present Standard Norwegian Practice (SNP), concerning the extreme hydrodynamic design load calculation for fixed steel space frame structures. Since the ISO code is expected to be similar to the API RP2A LRFD code, the provisions of API RP2A LRFD are used to represent the ISO standard. It should be noted that the new ISO code may include NewWave theory, in addition to the wave theories recommended by the API. Design loads and associated failure probabilities resulting from the application of the code provisions are compared for a typical North Sea structure, the Europipe riser platform 16/11-E.

  12. Combined action of uniform flow and oscillating flow around marine riser at low Keulegan-Carpenter number

    NASA Astrophysics Data System (ADS)

    Deng, Yue; Huang, Weiping; Zhao, Jingli

    2014-06-01

    With the increase of petroleum and gas production in deep ocean, marine risers of circular cylinder shape are widely used in the offshore oil and gas platform. In order to research the hydrodynamic performance of marine risers, the dynamic mesh technique and User-Defined Function (UDF) are used to simulate the circular cylinder motion. The motion of a transversely oscillating circular cylinder in combination of uniform flow and oscillating flow is simulated. The uniform flow and oscillating flow both are in x direction. SIMPLE algorithm is used to solve the Navier-Stokes equations. The User-Defined Function is used to control the cylinder transverse vibration and the inlet flow. The lift and drag coefficient changing with time and the map of vorticity isolines at different phase angle are obtained. Force time histories are shown for uniform flow at Reynolds number (Re) of 200 and for the combination of uniform and oscillating flows. With the increase of amplitude of oscillating flow in combined flow, the change of lift amplitude is not sensitive to the the change of cylinder oscillating frequency. Lift amplitude increases with the increase of oscillating flow amplitude in the combined flow, but there is no definite periodicity of the lift coefficient. The drag and inertia force coefficients change when the maximum velocity of the oscillating flow increases in the combined flow. The vortex shedding near the circular cylinder shows different characteristics.

  13. Effect of catalyst additives on the production of biofuels from palm oil cracking in a transport riser reactor.

    PubMed

    Chew, Thiam Leng; Bhatia, Subhash

    2009-05-01

    Catalytic cracking of crude palm oil (CPO) and used palm oil (UPO) were studied in a transport riser reactor for the production of biofuels at a reaction temperature of 450 degrees C, with residence time of 20s and catalyst-to-oil ratio (CTO) of 5 gg(-1). The effect of HZSM-5 (different Si/Al ratios), beta zeolite, SBA-15 and AlSBA-15 were studied as physically mixed additives with cracking catalyst Rare earth-Y (REY). REY catalyst alone gave 75.8 wt% conversion with 34.5 wt% of gasoline fraction yield using CPO, whereas with UPO, the conversion was 70.9 wt% with gasoline fraction yield of 33.0 wt%. HZSM-5, beta zeolite, SBA-15 and AlSBA-15 as additives with REY increased the conversion and the yield of organic liquid product. The transport riser reactor can be used for the continuous production of biofuels from cracking of CPO and UPO over REY catalyst.

  14. Maintenance Effects of an Evidence-Based Prevention Innovation for Aggressive Children Living in Culturally Diverse Urban Neighborhoods: The Early Risers Effectiveness Study

    ERIC Educational Resources Information Center

    August, Gerald J.; Lee, Susanne S.; Bloomquist, Michael L.; Realmuto, George M.; Hektner, Joel M.

    2004-01-01

    The present study assessed the ability of the Early Risers' Skills for Success Program to maintain program effects 1 year post intervention. Participants were 327 kindergarten and first-grade children who screened positive for aggressive behavior and who were randomized to program and control conditions. Program children participated in 2…

  15. The Relationship of an Ecological Model of Career Development to Authentic Learning. Research Institute on Secondary Education Reform (RISER) for Youth with Disabilities Brief.

    ERIC Educational Resources Information Center

    Collet-Klingenberg, Lana L.; Hanley-Maxwell, Cheryl; Stuart, Shannon

    This brief discusses how the Research Institute on Secondary Education Reform (RISER) for Youth with Disabilities model, Schools of Authentic Inclusive Learning (SAIL), and career development constructs and processes intersect. The brief provides an overview of SAIL, of authentic and inclusive learning, and of career development theory, while…

  16. Steel Rattler

    NASA Astrophysics Data System (ADS)

    Trudo, Robert A.; Stotts, Larry G.

    1997-07-01

    Steel Rattler is a multi-phased project to determine the feasibility of using commercial off-the-shelf components in an advanced acoustic/seismic unattended ground sensor. This project is supported by the Defense Intelligence Agency through Sandia National Laboratories as the lead development agency. Steel Rattler uses advanced acoustic and seismic detection algorithms to categorize and identify various heavy vehicles down to the number of cylinders in the engine. This detection is accomplished with the capabilities of new, high-speed digital signal processors which analyze both acoustic and seismic data. The resulting analysis is compared against an onboard library of known vehicles and a statistical match is determined. An integrated thermal imager is also employed to capture digital thermal images for subsequent compression and transmission. Information acquired by Steel Rattler in the field is transmitted in small packets by a built-in low-power satellite communication system. The ground station receivers distribute the coded information to multiple analysis sites where the information is reassembled into coherent messages and images.

  17. Development of Millimeter-Wave Velocimetry and Acoustic Time-of-Flight Tomography for Measurements in Densely Loaded Gas-Solid Riser Flow

    SciTech Connect

    Fort, James A.; Pfund, David M.; Sheen, David M.; Pappas, Richard A.; Morgen, Gerald P.

    2007-04-01

    The MFDRC was formed in 1998 to advance the state-of-the-art in simulating multiphase turbulent flows by developing advanced computational models for gas-solid flows that are experimentally validated over a wide range of industrially relevant conditions. The goal was to transfer the resulting validated models to interested US commercial CFD software vendors, who would then propagate the models as part of new code versions to their customers in the US chemical industry. Since the lack of detailed data sets at industrially relevant conditions is the major roadblock to developing and validating multiphase turbulence models, a significant component of the work involved flow measurements on an industrial-scale riser contributed by Westinghouse, which was subsequently installed at SNL. Model comparisons were performed against these datasets by LANL. A parallel Office of Industrial Technology (OIT) project within the consortium made similar comparisons between riser measurements and models at NETL. Measured flow quantities of interest included volume fraction, velocity, and velocity-fluctuation profiles for both gas and solid phases at various locations in the riser. Some additional techniques were required for these measurements beyond what was currently available. PNNL’s role on the project was to work with the SNL experimental team to develop and test two new measurement techniques, acoustic tomography and millimeter-wave velocimetry. Acoustic tomography is a promising technique for gas-solid flow measurements in risers and PNNL has substantial related experience in this area. PNNL is also active in developing millimeter wave imaging techniques, and this technology presents an additional approach to make desired measurements. PNNL supported the advanced diagnostics development part of this project by evaluating these techniques and then by adapting and developing the selected technology to bulk gas-solids flows and by implementing them for testing in the SNL riser

  18. First time real-time mud gas monitoring during riser drilling in the Kumano Basin (IODP Exp 319)

    NASA Astrophysics Data System (ADS)

    Wiersberg, T.; Erzinger, J.; Horiguchi, K.; Saffer, D. M.; Byrne, T. B.; McNeill, L. C.; Araki, E.; Takahashi, K.; Eguchi, N. O.; Toczko, S.

    2009-12-01

    Chikyu Expedition 319 was the first cruise of the Integrated Ocean Drilling Program (IODP) where riser drilling was performed and real-time mud gas monitoring was conducted, because this technique requires drill-mud circulation. In contrast to conventional IODP drilling that uses drill water in combination with lost circulation, during riser drilling the drill mud returns back to the surface through a riser pipe which encases the drill pipe. The dissolved gas is extracted from returning drill mud, analyzed in real time and sampled for noble gas and stable isotopes studies. This technique has been applied in the past on scientific continental drilling projects of e.g. the International Continental Drilling Program. Expedition 319 is part of the NanTroSEIZE project, a multiexpedition, multistage IODP drilling program focused on understanding the mechanics of seismogenesis and ruptures propagation along the Nankai accretionary prism. Riser drilling was carried out on Hole C0009 that intersects the cover sediments of the Kumano Basin and probably penetrates into the accretionary prism below. Site NT2-11 is located approx. 60 km SE of the harbour of Shingu, Japan. Real-time mud gas monitoring was performed in Hole C0009 during drilling from 703 mbsf (meter below sea floor) down to 1594 mbsf and during hole enlargement from 703 mbsf to 1569 mbsf. Both datasets show similar gas distribution at depth. Gas was furthermore extracted, sampled and analyzed from drill cuttings. Drill mud gas is generally composed of air and gases that derive from the formation. The principal formation gas in drill mud from both drilling phases and in cuttings was methane. Up to 14 vol % CH4 was detected during drilling and up to 3 vol % during hole enlargement. Down to 800 mbsf and below 1280 mbsf, the methane concentration in drill mud is lower than in the surrounded interval, where methane peaks at several depths. At 1280 mbsf an unconformity is indicated from lihology, in seismic and

  19. Advances of two-stage riser catalytic cracking of heavy oil for maximizing propylene yield (TMP) process.

    PubMed

    Chaohe, Yang; Xiaobo, Chen; Jinhong, Zhang; Chunyi, Li; Honghong, Shan

    Two-stage riser catalytic cracking of heavy oil for maximizing propylene yield (TMP) process proposed by State Key Laboratory of Heavy oil Processing, China University of Petroleum, can remarkably enhance the propylene yield and minimize the dry gas and coke yields, and obtain high-quality light oils (gasoline and diesel). It has been commercialized since 2006. Up to now, three TMP commercial units have been put into production and other four commercial units are under design and construction. The commercial data showed that taking paraffinic based Daqing (China) atmospheric residue as the feedstock, the propylene yield reached 20.31 wt%, the liquid products yield (the total yield of liquefied petroleum gas, gasoline, and diesel) was 82.66 wt%, and the total yield of dry gas and coke was 14.28 wt%. Moreover, the research octane number of gasoline could be up to 96.

  20. A catenary model to study transport and conjugation of baicalein, a bioactive flavonoid, in the Caco-2 cell monolayer: demonstration of substrate inhibition.

    PubMed

    Sun, Huadong; Zhang, Li; Chow, Edwin Chiu Yuen; Lin, Ge; Zuo, Zhong; Pang, K Sandy

    2008-07-01

    The transport and metabolism of baicalein (Ba) was studied in vitro and in Caco-2 cells. Protein binding of Ba with Caco-2 lysate showed that Ba was bound to two classes of sites: a higher affinity, lower capacity site (K(A1) = 27.6 +/- 4.7 microM(-1), n(1) = 10.6 +/- 0.6 nmol/mg) and lower affinity, higher capacity site (K(A2) = 0.015 +/- 0.0013 microM(-1), n(2) = 413 +/- 21 nmol/mg). Incubation studies of Ba with Caco-2 lysate showed substrate inhibition of both glucuronidation and sulfation, with K(m) values of 0.14 +/- 0.034 and 0.015 +/- 0.0053 microM, and K(I) values of 6.75 +/- 1.70 and 0.37 +/- 0.16 microM, respectively. In the Caco-2 monolayer, Ba (8-47 microM) displayed good apparent permeabilities (P(app)) across the membrane; P(app) was found to be increased with elevated loading concentration in both the absorptive and secretory directions. However, the efflux ratio was less than unity, negating the involvement of apical efflux transporters. The concentration ratios of Ba sulfate (BS) and glucuronide (BG) decreased with increased loading Ba concentration, suggesting that BS and BG are apically excreted via transporters, likely breast cancer resistance protein and multidrug resistance-associated protein 2, respectively. Data fit to the catenary model, composed of basolateral, cellular, and apical compartments, showed a low cellular unbound fraction (0.0019 +/- 0.00018), a high passive diffusion clearance (0.012 +/- 0.00029 ml/min/mg), and substrate inhibition, with sulfation being more readily saturated and inhibited than glucuronidation, as evidenced by smaller K(m) value (0.35 +/- 0.078 versus 1.95 +/- 0.57 microM) and K(I) value (0.58 +/- 0.20 versus 7.90 +/- 1.10 microM); these patterns paralleled those observed in the lysate incubation studies. The results showed that the catenary model aptly predicts substrate inhibition kinetics and offers significant and mechanistic insight into the transport and atypical metabolism of drugs in the Caco-2

  1. Supertough Stainless Bearing Steel

    NASA Technical Reports Server (NTRS)

    Olson, Gregory B.

    1995-01-01

    Composition and processing of supertough stainless bearing steel designed with help of computer-aided thermodynamic modeling. Fracture toughness and hardness of steel exceeds those of other bearing steels like 440C stainless bearing steel. Developed for service in fuel and oxidizer turbopumps on Space Shuttle main engine. Because of strength and toughness, also proves useful in other applications like gears and surgical knives.

  2. Prediction of magnitude of minimum horizontal stress from extended leak-off test conducted by the riser vessel CHIKYU

    NASA Astrophysics Data System (ADS)

    Lin, W.; Masago, H.; Yamamoto, K.; Kawamura, Y.; Saito, S.; Kinoshita, M.

    2007-12-01

    By means of introduction of the drilling vessel 'CHIKYU', riser drilling operations using mud fluid will be carried out in NanTroSEIZE Stage 2 for the first time as an oceanic scientific-drilling. For determining drilling operation parameter such as a mud density, a downhole experiment, leak-off test (LOT) or extended leak-off test (XLOT), is going to be implemented next to casing and cementing at each casing shoe during the drilling process. Data of the downhole experiment aimed for operation can also be used for an important scientific application to obtain in-situ stress information which is necessary for various cases of scientific drillings such as seismogenic zone drillings etc. In order to examine feasibility of the application of the LOT or XLOT data, we analyzed an example of XLOT conducted by the riser vessel CHIKYU during its Shimokita shakedown cruise, 2006; and then estimated magnitude of minimum principal stress in horizontal plane, Shmin. Moreover, we will propose the test procedures to possibly improve the quality of stress result from the applications of LOT or XLOT. The XLOT of Shimokita cruise was conducted under following conditions; 1180 m water depth, 525 mbsf (meter below seafloor) depth, 1030 kg/m3 fluid density (seawater) and 80 litter/min injection flow-rate. Estimated magnitude of the Shmin is equal to 18.3 MPa based on the assumption that fracture closure pressure balances with the minimum principal stress perpendicular to the fracture plane. For comparison, the vertical stress magnitude at the depth was estimated from density profile of core samples retrieved from the same borehole; and was equal to 20 MPa approximately. These two values can be considered to be not disagreement. Therefore, we can say that the XLOT data is valuable and practical for estimating the magnitude of minimum horizontal stress. From the viewpoint of determining stress magnitude, the XLOT is more essential rather than the LOT because it might be hardly to obtain

  3. Modeling of porosity formation and feeding flow during casting of steel and aluminum alloys

    NASA Astrophysics Data System (ADS)

    Lin, Zhiping

    Porosity is one of the most important defects in metal casting. To quantitatively predict the porosity formation during casting two numerical models are developed for steel and aluminum alloys respectively. For steel, a multi-phase model is developed that predicts melt pressure, feeding flow, porosity (both microscopic and macroscopic), and riser pipe formation during casting. The phases included in the model are solid, liquid, porosity, and air. An energy equation is solved to determine solid fraction. A multi-phase momentum equation, which is valid everywhere in the solution domain, is derived. A pressure equation is then derived from this momentum equation and a mixture continuity equation developed that accounts for all phases. The partial pressure of a gas species dissolved in the melt is determined using the species concentration, which is found by solving a species conservation equation that accounts for convection. Porosity forms once the gas pressure exceeds the sum of the melt pressure and the capillary pressure. The amount of porosity that forms is determined from the mixture continuity equation. The riser pipe is determined from an air continuity equation. A pore size model, which considers the effects of the solidifying steel microstructure on pore size, is incorporated into the multi-phase model. The multi-phase model is applied to one-dimensional, two-dimensional, and three-dimensional simulations. The results clearly illustrate the basic physical phenomena involved and predict microporosity and macroporosity distributions, as well as a riser pipe. For aluminum alloys a gas microsegregation model is developed to quantitatively predict porosity, coupled with the calculations of the pressure field, feeding flow, and distribution of dissolved gas species throughout the casting. The effects of dendritic and eutectic microstructure on the pore shape and size are considered in a pore size model. The model is applied to one-dimensional simulations of A319

  4. Ultrahigh carbon steels, Damascus steels, and superplasticity

    SciTech Connect

    Sherby, O.D.; Wadsworth, J.

    1997-04-01

    The processing properties of ultrahigh carbon steels (UHCSs) have been studied at Stanford University over the past twenty years. These studies have shown that such steels (1 to 2.1% C) can be made superplastic at elevated temperature and can have remarkable mechanical properties at room temperature. It was the investigation of these UHCSs that eventually brought us to study the myths, magic, and metallurgy of ancient Damascus steels, which in fact, were also ultrahigh carbon steels. These steels were made in India as castings, known as wootz, possibly as far back as the time of Alexander the Great. The best swords are believed to have been forged in Persia from Indian wootz. This paper centers on recent work on superplastic UHCSs and on their relation to Damascus steels. 32 refs., 6 figs.

  5. A new equation for potential attenuation and anode current output projection for cathodically polarized marine pipelines and risers

    SciTech Connect

    Pierson, P.; Bethune, K.P.; Hartt, W.H.; Anathakrishnan, P.

    2000-04-01

    A first principles based equation for potential attenuation along a marine pipeline or riser that was cathodically polarized by multiple, equally spaced, identical galvanic anodes and that incorporated the electrolyte (anode), coating, and metallic path resistances, as well as the pipe polarization resistance, was derived. Finite different method (FDM) solutions for this equation showed that the potential profile consisted of a relatively abrupt polarization decay within the first several meters of an anode and an essentially constant potential beyond this for cases where anode spacing was {approximately}< 1 km (this distance varied with pipe and anode dimensions, properties, and exposure conditions). For anode spacings greater than this, metallic path resistance became important such that a potential gradient resulted along the entire pipe length. Comparison of the RDM solutions for the case of a pipeline of typical dimensions and marine exposure conditions with results from boundary element modeling (BEM) indicated excellent agreement between the two for situations where the metallic resistance was negligible. For cases where this term was not negligible (relatively large anode spacings), the FDM solutions were more accurate since BEM did not incorporate metallic path resistance. It was concluded that the derived equation has utility for design of pipeline cathodic protection systems and for analysis of data there from, particularly in cases where anode spacing is sufficiently large that metallic path resistance is non-negligible.

  6. Two-year outcomes of the Early Risers prevention trial with formerly homeless families residing in supportive housing.

    PubMed

    Gewirtz, Abigail H; DeGarmo, David S; Lee, Susanne; Morrell, Nicole; August, Gerald

    2015-04-01

    This article reports 2-year outcomes from a cluster randomized, controlled trial of the Early Risers (ER) program implemented as a selective preventive intervention in supportive housing settings for homeless families. Based on the goals of this comprehensive prevention program, we predicted that intervention participants receiving ER services would show improvement in parenting and child outcomes relative to families in treatment-as-usual sites. The sample included 270 children in 161 families, residing in 15 supportive housing sites; multimethod, multi-informant assessments conducted at baseline and yearly thereafter included parent and teacher report of child adjustment, parent report of parenting self-efficacy, and parent-child observations that yielded scores of effective parenting practices. Data were modeled in HLM7 (4-level model accounting for nesting of children within families and families within housing sites). Two years' postbaseline, intent-to-treat (ITT) analyses indicated that parents in the ER group showed significantly improved parenting self-efficacy, and parent report indicated significant reductions in ER group children's depression. No main effects of ITT were shown for observed parenting effectiveness. However, over time, average levels of parenting self-efficacy predicted observed effective parenting practices, and observed effective parenting practices predicted improvements in both teacher- and parent-report of child adjustment. This is the first study to our knowledge to demonstrate prevention effects of a program for homeless families residing in family supportive housing.

  7. Comminuting irradiated ferritic steel

    DOEpatents

    Bauer, Roger E.; Straalsund, Jerry L.; Chin, Bryan A.

    1985-01-01

    Disclosed is a method of comminuting irradiated ferritic steel by placing the steel in a solution of a compound selected from the group consisting of sulfamic acid, bisulfate, and mixtures thereof. The ferritic steel is used as cladding on nuclear fuel rods or other irradiated components.

  8. Welding Rustproof Steels

    NASA Technical Reports Server (NTRS)

    Hoffmann, W

    1929-01-01

    The following experimental results will perhaps increase the knowledge of the process of welding rustproof steels. The experiments were made with two chrome-steel sheets and with two chrome-steel-nickel sheets having the composition shown in Table I.

  9. Measurement of Gas Velocities in the Presence of Solids in the Riser of a Cold Flow Circulating Fluidized Bed

    SciTech Connect

    Spenik, J.; Ludlow, J.C.; Compston, R.; Breault, R.W.

    2007-01-01

    The local gas velocity and the intensity of the gas turbulence in a gas/solid flow are a required measurement in validating the gas and solids flow structure predicted by computational fluid dynamic (CFD) models in fluid bed and transport reactors. The high concentration and velocities of solids, however, make the use of traditional gas velocity measurement devices such as pitot tubes, hot wire anemometers and other such devices difficult. A method of determining these velocities has been devised at the National Energy Technology Laboratory employing tracer gas. The technique developed measures the time average local axial velocity gas component of a gas/solid flow using an injected tracer gas which induces changes in the heat transfer characteristics of the gas mixture. A small amount of helium is injected upstream a known distance from a self-heated thermistor. The thermistor, protected from the solids by means of a filter, is exposed to gases that are continuously extracted from the flow. Changes in the convective heat transfer characteristics of the gas are indicated by voltage variations across a Wheatstone bridge. When pulsed injections of helium are introduced to the riser flow the change in convective heat transfer coefficient of the gas can be rapidly and accurately determined with this instrument. By knowing the separation distance between the helium injection point and the thermistor extraction location as well as the time delay between injection and detection, the gas velocity can easily be calculated. Variations in the measured gas velocities also allow the turbulence intensity of the gas to be estimated.

  10. The steel scrap age.

    PubMed

    Pauliuk, Stefan; Milford, Rachel L; Müller, Daniel B; Allwood, Julian M

    2013-04-02

    Steel production accounts for 25% of industrial carbon emissions. Long-term forecasts of steel demand and scrap supply are needed to develop strategies for how the steel industry could respond to industrialization and urbanization in the developing world while simultaneously reducing its environmental impact, and in particular, its carbon footprint. We developed a dynamic stock model to estimate future final demand for steel and the available scrap for 10 world regions. Based on evidence from developed countries, we assumed that per capita in-use stocks will saturate eventually. We determined the response of the entire steel cycle to stock saturation, in particular the future split between primary and secondary steel production. During the 21st century, steel demand may peak in the developed world, China, the Middle East, Latin America, and India. As China completes its industrialization, global primary steel production may peak between 2020 and 2030 and decline thereafter. We developed a capacity model to show how extensive trade of finished steel could prolong the lifetime of the Chinese steelmaking assets. Secondary steel production will more than double by 2050, and it may surpass primary production between 2050 and 2060: the late 21st century can become the steel scrap age.

  11. Methods of forming steel

    DOEpatents

    Branagan, Daniel J.; Burch, Joseph V.

    2001-01-01

    In one aspect, the invention encompasses a method of forming a steel. A metallic glass is formed and at least a portion of the glass is converted to a crystalline steel material having a nanocrystalline scale grain size. In another aspect, the invention encompasses another method of forming a steel. A molten alloy is formed and cooled the alloy at a rate which forms a metallic glass. The metallic glass is devitrified to convert the glass to a crystalline steel material having a nanocrystalline scale grain size. In yet another aspect, the invention encompasses another method of forming a steel. A first metallic glass steel substrate is provided, and a molten alloy is formed over the first metallic glass steel substrate to heat and devitrify at least some of the underlying metallic glass of the substrate.

  12. Safety Investigation of Liquid-Metal-Cooled Nuclear Systems with Heat Exchanger in the Risers of Simple Flow-Path Pool Design

    SciTech Connect

    Carlsson, Johan; Wider, Hartmut U.

    2005-12-15

    Safety investigations were performed on 600- and 1426-MW(thermal) liquid-metal-cooled reactors with the heat exchangers (HXs) located in the risers of simple flow-path pool designs. This includes both critical reactors and accelerator-driven systems (ADSs) using liquid-metal coolants. For the 600-MW(thermal) ADS, the safety implications were examined for vessel sizes of two heights (11 and 15 m) and two diameters (6 and 10 m). Then, the reference design of 11-m height and 6-m diameter was compared with a similar design, but with the HXs located in the downcomers. The transients investigated were total-loss-of-power (TLOP), unprotected-loss-of-flow (ULOF), protected-loss-of-flow, and unprotected loss-of-heat-sink accidents. The 600-MW(thermal) ADS of 11-m height and 6-m diameter peaks at 1041 K after 29 h during a TLOP accident. If the diameter is increased to 10 m, it will peak after 55 h at a 178 K lower temperature thanks to its larger thermal inertia. The difference between locating the HXs in the risers and the downcomers is insignificant for this accident type. With the HXs in the risers, the temperature peaks at 1045 K after 28 h. During a ULOF accident in an ADS at full power, the core outlet temperature stabilizes at 1010 K, which is 337 K above the nominal outlet temperature. When the vessel height is increased to 15 m, the natural convection is improved, and the core outlet temperature stabilizes at 911 K. A Pb-cooled 1426-MW(thermal) reactor of 11-m height and 12-m diameter is also shown to be sufficiently coolable during a TLOP accident; i.e., it peaks at 1093 K after 49 h. In a pool-type design with a simple flow path, the use of HXs in the risers and flaps at their inlets that prevent a flow reversal will have significant safety advantages in case of HX tube failures. Steam or gas bubbles exiting from the secondary circuit cannot be dragged into the core region by the liquid-metal coolant. Instead, they would rise with the coolant and exit through the

  13. Modeling right-lateral offset of a Late Pleistocene terrace riser along the Polaris fault using ground based LiDAR imagery

    NASA Astrophysics Data System (ADS)

    Howle, J. F.; Bawden, G. W.; Hunter, L. E.; Rose, R. S.

    2009-12-01

    High resolution (centimeter level) three-dimensional point-cloud imagery of offset glacial outwash deposits were collected by using ground based tripod LiDAR (T-LiDAR) to characterize the cumulative fault slip across the recently identified Polaris fault (Hunter et al., 2009) near Truckee, California. The type-section site for the Polaris fault is located 6.5 km east of Truckee where progressive right-lateral displacement of middle to late Pleistocene deposits is evident. Glacial outwash deposits, aggraded during the Tioga glaciation, form a flat lying ‘fill’ terrace on both the north and south sides of the modern Truckee River. During the Tioga deglaciation melt water incised into the terrace producing fluvial scarps or terrace risers (Birkeland, 1964). Subsequently, the terrace risers on both banks have been right-laterally offset by the Polaris fault. By using T-LiDAR on an elevated tripod (4.25 m high), we collected 3D high-resolution (thousands of points per square meter; ± 4 mm) point-cloud imagery of the offset terrace risers. Vegetation was removed from the data using commercial software, and large protruding boulders were manually deleted to generate a bare-earth point-cloud dataset with an average data density of over 240 points per square meter. From the bare-earth point cloud we mathematically reconstructed a pristine terrace/scarp morphology on both sides of the fault, defined coupled sets of piercing points, and extracted a corresponding displacement vector. First, the Polaris fault was approximated as a vertical plane that bisects the offset terrace risers, as well as bisecting linear swales and tectonic depressions in the outwash terrace. Then, piercing points to the vertical fault plane were constructed from the geometry of the geomorphic elements on either side of the fault. On each side of the fault, the best-fit modeled outwash plane is projected laterally and the best-fit modeled terrace riser projected upward to a virtual intersection in

  14. Method and apparatus for production of subsea hydrocarbon formations

    DOEpatents

    Blandford, Joseph W.

    1994-01-01

    A well tender system for controlling, separating, storing and offloading well fluids produced from subsea hydrocarbon formations. The system comprises a vertically aligned series of tethered cylindrical tanks which are torsionally stabilized by flexible catenary production riser and export riser bundles, and serviced by separate catenary pipe bundles. Piles are secured to the seabed, each pile assembly being pivotally connected to a lower rigid tendon, which is in turn connected to tendons arranged about the periphery of the interconnected cylindrical tanks.

  15. Method and apparatus for production of subsea hydrocarbon formations

    DOEpatents

    Blandford, Joseph W.

    1992-01-01

    A well tender system for controlling, separating, storing and offloading well fluids produced from subsea hydrocarbon formations. The system comprises a vertically aligned series of tethered cylindrical tanks which are torsionally stabilized by flexible catenary production riser and expert riser bundles, and serviced by separate catenary pipe bundles. Piles are secured to the seabed, each pile assembly being pivotally connected to a lower rigid tendon, which is in turn connected to tendons arranged about the periphery of the interconnected cylindrical tanks.

  16. Modeling and Measurement of Electromagnetic Fields Near LORAN-C and OMEGA Stations

    DTIC Science & Technology

    1987-06-15

    is called a TIP antenna and is located in Carolina Beach, North Carolina. These extended antennas consist of a series of catenaries and risers...monopole attached to 16 top radials which are anchored 2400 feet from the tower. The Kaneohe, HI, OMEGA antenna is made up of six catenaries spanning a...I’ n calculating coordinates, especially for the 5LT antennas which employ catenary wires. Completed models were then typed into NEC input format

  17. Maraging Steel Machining Improvements

    DTIC Science & Technology

    2007-04-23

    APR 2007 2. REPORT TYPE Technical, Success Story 3. DATES COVERED 01-12-2006 to 23-04-2007 4. TITLE AND SUBTITLE Maraging Steel Machining...consumers of cobalt-strengthened maraging steel . An increase in production requires them to reduce the machining time of certain operations producing... maraging steel ; Success Stories 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT 1 18. NUMBER OF PAGES 1 19a. NAME OF RESPONSIBLE

  18. Welding irradiated stainless steel

    SciTech Connect

    Kanne, W.R. Jr.; Chandler, G.T.; Nelson, D.Z.; Franco-Ferreira, E.A.

    1993-12-31

    Conventional welding processes produced severe underbead cracking in irradiated stainless steel containing 1 to 33 appm helium from n,a reactions. A shallow penetration overlay technique was successfully demonstrated for welding irradiated stainless steel. The technique was applied to irradiated 304 stainless steel that contained 10 appm helium. Surface cracking, present in conventional welds made on the same steel at the same and lower helium concentrations, was eliminated. Underbead cracking was minimal compared to conventional welding methods. However, cracking in the irradiated material was greater than in tritium charged and aged material at the same helium concentrations. The overlay technique provides a potential method for repair or modification of irradiated reactor materials.

  19. Large deflection response of restrained steel beams under fire and explosion loads.

    PubMed

    Xi, Feng

    2016-01-01

    A numerical study on the response of steel beams to fire and explosion is presented in this paper. First, a unified computing model, which can be used to simulate the behaviour of beams under four loading scenarios that involve fire and explosion or impact, is constructed. The proposed technique allows complete transparency of the influence of the various parameters on the structural behaviour. Second, the effects of load level on critical temperature are analyzed for various static and explosion load ratios. Two cases of explosion and fire loading sequences are compared, it is shown that the critical temperature of the beam subjected to fire followed by an explosion is lower than that of the beam subjected to an explosion followed by fire. The influence of temperature on the p-i diagram is investigated, an iso-damage surface is introduced to distinguish safe and unsafe regions. Third, the limiting temperature criteria are further examined. That is, the first and second limiting temperatures can be determined when the dimensional catenary force is equal to zero or to one, which corresponds to the bending or stretching plastic hinge, respectively.

  20. America's fastest risers.

    PubMed

    Deutschman, A

    1991-10-07

    Swift exploiters of change, the 100 companies that make up this new Fortune list attest to an entrepreneurial spirit undiminished by the weak U.S. economy. They owe their success largely to two often-touted but seldom followed managerial practices: putting the customer first and moving with relentless speed and adaptability. Old-line giants had better learn from them--or watch out.

  1. The Steel Band.

    ERIC Educational Resources Information Center

    Weil, Bruce

    1996-01-01

    Describes studying the steel drum, an import from Trinidad, as an instrument of intellectual growth. Describes how developing a steel drum band provided Montessori middle school students the opportunity to experience some important feelings necessary to emotional growth during this difficult age: competence, usefulness, independence, and…

  2. Steel Industry Wastes.

    ERIC Educational Resources Information Center

    Schmidtke, N. W.; Averill, D. W.

    1978-01-01

    Presents a literature review of wastes from steel industry, covering publications of 1976-77. This review covers: (1) coke production; (2) iron and steel production; (3) rolling operations; and (4) surface treatment. A list of 133 references is also presented. (NM)

  3. High Nitrogen Stainless Steel

    DTIC Science & Technology

    2011-07-19

    Hydrogen Embrittlement in Steel by the Increment Loading Technique. Fractography: After the stress-life fatigue tests, the fracture surface morphology...study was conducted to clarify the mechanical properties and stress corrosion cracking (SCC) resistance of high nitrogen stainless steel (HNSS) plates...Corrosion Cracking 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT 18. NUMBER OF PAGES 19a. NAME OF RESPONSIBLE PERSON

  4. Steel Industry Wastes.

    ERIC Educational Resources Information Center

    Schmidtke, N. W.; Averill, D. W.

    1978-01-01

    Presents a literature review of wastes from steel industry, covering publications of 1976-77. This review covers: (1) coke production; (2) iron and steel production; (3) rolling operations; and (4) surface treatment. A list of 133 references is also presented. (NM)

  5. EAST ELEVATION, LTV STEEL (FORMERLY REPUBLIC STEEL), 8" BAR MILL, ...

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

    EAST ELEVATION, LTV STEEL (FORMERLY REPUBLIC STEEL), 8" BAR MILL, BUFFALO PLANT. VIEW LOOKING SOUTHWEST FROM ROLL SHOP. 8" BAR MILL DESIGNED AND BUILT BY DONNER STEEL CO. (PREDECESSOR OF REPUBLIC), 1919-1920. FOR DESCRIPTION OF ORIGINAL MILL SEE "IRON AGE", 116\\4 (23 JULY 1925): 201-204. - LTV Steel, 8-inch Bar Mill, Buffalo Plant, Buffalo, Erie County, NY

  6. Life after High School: Which Postschool Outcomes Matter for Students with and without Disabilities in Restructured High Schools? Research Institute on Secondary Education Reform (RISER) for Youth with Disabilities Brief.

    ERIC Educational Resources Information Center

    Mooney, Marianne; Phelps, L. Allen

    The Research Institute on Secondary Education Reform for Youth with Disabilities (RISER) has been studying three significantly restructured high schools that have included students with disabilities and their parents in the design and/or implementation of school reform efforts. Each of these schools has operated for 3-12 years with its new,…

  7. Vertical Seismic Profiling at riser drilling site in the rupture area of the 1944 Tonankai Earthquake, Japan (Invited)

    NASA Astrophysics Data System (ADS)

    Hino, R.; Kinoshita, M.; Araki, E.; Byrne, T. B.; McNeill, L. C.; Saffer, D. M.; Eguchi, N. O.; Takahashi, K.; Toczko, S.

    2009-12-01

    A series of scientific drilling expeditions is in operation in the Nankai Trough to reveal the faulting mechanism of the magathrust earthquakes, through clarifying composition, fine structure, mechanical behavior, and environmental variables of the seismogenic faults. In the studied area, extensive seismic surveys for site characterization have been made to image detailed geometry of the fault complex in the accretionary prism as well as Vp distribution around the faults. Although these previous surveys provided invaluable information for understanding seismotectonic processes in this subduction zone, more complete knowledge is needed to be acquired to predict dynamic behavior of the faults, such as geometrical irregularities in short wavelength, Vs and seismic attenuation which are sensitive to fluid distribution in and around fault zones. It is expected that estimation of these parameters would be improved considerably by a seismic exploration using a vertical array of seismographs installed in a deep borehole (VSP: vertical seismic profiling). In July 2009, we made a VSP at one of the drilling sites located just above the rupture area of the 1994 Tonankai Earthquake (M 8.1), during the IODP Exp.319. The well site of our VSP was made by the riser drilling of D/V Chikyu. The seismic array, lowered from Chikyu into the hole, was composed of a three-component accelerometer and vertical separation of the array elements was 15.12 m. The VSP was composed of offset VSP and zero-offset VSP. In the offset VSP, a tuned airgun array towed by R/V Kairei was shot along one straight line (walk-away VSP) and another circular line (walk-around VSP) and seismic signals were recorded by an array consisting of 16 elements installed from 907 to 1,135 m in depth from seafloor. The object of the walk-away VSP is to obtain fine image of the faults using reflection arrivals with less attenuation. It is also expected to obtain spatial variation of Vs from arrival time tomography of

  8. Accretion process of sediments below Kumano basin by analyzing cuttings from IODP Exp.319, the first riser drilling

    NASA Astrophysics Data System (ADS)

    Kawabata, K.; Sakaguchi, A.; Kitamura, Y.; Saito, S.

    2012-12-01

    The structure, stress condition and rock properties of accreted sediments in the Nankai Trough have been studied by reflection seismology and deep sea drillings. Accretion processes have been suggested by onland geological studies that the sediments are circulated with undergoing lithification and deformation along thrusts in shallow subduction zone driven by the plate motion. However the process in the modern Nankai Trough has yet to be elucidated. We discuss the accretion process of the shallow Nankai Trough accretionary prism below Kumano basin by clarifying thermal structure and materials by vitrinite measurement and whole rock chemical analyses, respectively, using cuttings samples from IODP The Nankai Trough Seismogenic Zone Experiment (NanTroSEIZE) the first scientific riser drilling Expedition 319 at Site C0009. Cuttings were collected with an interval of every 5 m from 703.9 to 1604 m and cores were recovered from 1509.7 m to 1593.9 m below sea floor (mbsf). Due to poor consolidation of drilled sediments, cuttings samples typically consist of sand and silt floating in a matrix of mixed sedimentary and drilling muds, and solid rock chips were not retrieved above 802.7 mbsf. Visual description based on macro- and micro-scopic observation, XRD and XRF analysis, rocks properties and the age of washed cuttings (i.e. grains without mud) were made throughout the hole, which allowed to establish some indexes to estimate lithology. Four lithologic units (Unit I - IV) were defined at Site C0009 based on compositional and textural variations of cuttings samples, which are believed to closely reflect lithologic changes of drilled sequences, and show good consistency with logging data. Unit IV is believed to be accreted sediment by mainly age and the textural change of sediments. Dissoluble component ratios (TiO2/P2O5) and clay content ratios in the samples analyzed by XRF and XRD are different from that in basin sediment, which might support Unit IV are accreted

  9. Nuclear transmutation in steels

    NASA Astrophysics Data System (ADS)

    Belozerova, A. R.; Shimanskii, G. A.; Belozerov, S. V.

    2009-05-01

    The investigations of the effects of nuclear transmutation in steels that are widely used in nuclear power and research reactors and in steels that are planned for the application in thermonuclear fusion plants, which are employed under the conditions of a prolonged action of neutron irradiation with different spectra, made it possible to study the effects of changes in the isotopic and chemical composition on the tendency of changes in the structural stability of these steels. For the computations of nuclear transmutation in steels, we used a program complex we have previously developed on the basis of algorithms for constructing branched block-type diagrams of nuclide transformations and for locally and globally optimizing these diagrams with the purpose of minimizing systematic errors in the calculation of nuclear transmutation. The dependences obtained were applied onto a Schaeffler diagram for steels used for structural elements of reactors. For the irradiation in fission reactors, we observed only a weak influence of the effects of nuclear transmutation in steels on their structural stability. On the contrary, in the case of irradiation with fusion neutrons, a strong influence of the effects of nuclear transmutation in steels on their structural stability has been noted.

  10. Damascus steel ledeburite class

    NASA Astrophysics Data System (ADS)

    Sukhanov, D. A.; Arkhangelsky, L. B.; Plotnikova, N. V.

    2017-02-01

    Discovered that some of blades Damascus steel has an unusual nature of origin of the excess cementite, which different from the redundant phases of secondary cementite, cementite of ledeburite and primary cementite in iron-carbon alloys. It is revealed that the morphological features of separate particles of cementite in Damascus steels lies in the abnormal size of excess carbides having the shape of irregular prisms. Considered three hypotheses for the formation of excess cementite in the form of faceted prismatic of excess carbides. The first hypothesis is based on thermal fission of cementite of a few isolated grains. The second hypothesis is based on the process of fragmentation cementite during deformation to the separate the pieces. The third hypothesis is based on the transformation of metastable cementite in the stable of angular eutectic carbide. It is shown that the angular carbides are formed within the original metastable colony ledeburite, so they are called “eutectic carbide”. It is established that high-purity white cast iron is converted into of Damascus steel during isothermal soaking at the annealing. It was revealed that some of blades Damascus steel ledeburite class do not contain in its microstructure of crushed ledeburite. It is shown that the pattern of carbide heterogeneity of Damascus steel consists entirely of angular eutectic carbides. Believe that Damascus steel refers to non-heat-resistant steel of ledeburite class, which have similar structural characteristics with semi-heat-resistant die steel or heat-resistant high speed steel, differing from them only in the nature of excess carbide phase.

  11. Experimental Study of the Vortex-Induced Vibration of Drilling Risers under the Shear Flow with the Same Shear Parameter at the Different Reynolds Numbers

    PubMed Central

    Liangjie, Mao; Qingyou, Liu; Shouwei, Zhou

    2014-01-01

    A considerable number of studies for VIV under the uniform flow have been performed. However, research on VIV under shear flow is scarce. An experiment for VIV under the shear flow with the same shear parameter at the two different Reynolds numbers was conducted in a deep-water offshore basin. Various measurements were obtained by the fiber bragg grating strain sensors. Experimental data were analyzed by modal analysis method. Results show several valuable features. First, the corresponding maximum order mode of the natural frequency for shedding frequency is the maximum dominant vibration mode and multi-modal phenomenon is appeared in VIV under the shear flow, and multi-modal phenomenon is more apparent at the same shear parameter with an increasing Reynolds number under the shear flow effect. Secondly, the riser vibrates at the natural frequency and the dominant vibration frequency increases for the effect of the real-time tension amplitude under the shear flow and the IL vibration frequency is the similar with the CF vibration frequency at the Reynolds number of 1105 in our experimental condition and the IL dominant frequency is twice the CF dominant frequency with an increasing Reynolds number. In addition, the displacement trajectories at the different locations of the riser appear the same shape and the shape is changed at the same shear parameter with an increasing Reynolds number under the shear flow. The diagonal displacement trajectories are observed at the low Reynolds number and the crescent-shaped displacement trajectories appear with an increasing Reynolds number under shear flow in the experiment. PMID:25118607

  12. Experimental study of the vortex-induced vibration of drilling risers under the shear flow with the same shear parameter at the different Reynolds numbers.

    PubMed

    Liangjie, Mao; Qingyou, Liu; Shouwei, Zhou

    2014-01-01

    A considerable number of studies for VIV under the uniform flow have been performed. However, research on VIV under shear flow is scarce. An experiment for VIV under the shear flow with the same shear parameter at the two different Reynolds numbers was conducted in a deep-water offshore basin. Various measurements were obtained by the fiber bragg grating strain sensors. Experimental data were analyzed by modal analysis method. Results show several valuable features. First, the corresponding maximum order mode of the natural frequency for shedding frequency is the maximum dominant vibration mode and multi-modal phenomenon is appeared in VIV under the shear flow, and multi-modal phenomenon is more apparent at the same shear parameter with an increasing Reynolds number under the shear flow effect. Secondly, the riser vibrates at the natural frequency and the dominant vibration frequency increases for the effect of the real-time tension amplitude under the shear flow and the IL vibration frequency is the similar with the CF vibration frequency at the Reynolds number of 1105 in our experimental condition and the IL dominant frequency is twice the CF dominant frequency with an increasing Reynolds number. In addition, the displacement trajectories at the different locations of the riser appear the same shape and the shape is changed at the same shear parameter with an increasing Reynolds number under the shear flow. The diagonal displacement trajectories are observed at the low Reynolds number and the crescent-shaped displacement trajectories appear with an increasing Reynolds number under shear flow in the experiment.

  13. Steel Pickling Inspection Checklist

    EPA Pesticide Factsheets

    Checklist to establish whether a facility or operations within a facility are subject to and are in compliance with 40 C.F.R Part 63 Subpart CCC (Steel Pickling—HCl Process Facilities and Hydrochloric Acid Regeneration Plants NESHAP).

  14. Structural Amorphous Steels

    NASA Astrophysics Data System (ADS)

    Lu, Z. P.; Liu, C. T.; Thompson, J. R.; Porter, W. D.

    2004-06-01

    Recent advancement in bulk metallic glasses, whose properties are usually superior to their crystalline counterparts, has stimulated great interest in fabricating bulk amorphous steels. While a great deal of effort has been devoted to this field, the fabrication of structural amorphous steels with large cross sections has remained an alchemist’s dream because of the limited glass-forming ability (GFA) of these materials. Here we report the discovery of structural amorphous steels that can be cast into glasses with large cross-section sizes using conventional drop-casting methods. These new steels showed interesting physical, magnetic, and mechanical properties, along with high thermal stability. The underlying mechanisms for the superior GFA of these materials are discussed.

  15. Cobalt free maraging steel

    SciTech Connect

    Floreen, S.

    1984-04-17

    The subject invention is directed to ferrous-base alloys, particularly to a cobalt-free maraging steel of novel chemistry characterized by a desired combination of strength and toughness, notwithstanding that cobalt is non-essential.

  16. Glass Stronger than Steel

    DOE R&D Accomplishments Database

    Yarris, Lynn

    2011-03-28

    A new type of damage-tolerant metallic glass, demonstrating a strength and toughness beyond that of steel or any other known material, has been developed and tested by a collaboration of researchers from Berkeley Lab and Caltech.

  17. Performance Steel Castings

    DTIC Science & Technology

    2012-09-30

    alloys , foundry, muzzle brake, supply center, tooling, sources Notice Distribution Statement A Format Information Report created in Microsoft Word...Development of Sand Properties 103 Advanced Modeling Dataset.. 105 High Strength Low Alloy (HSLA) Steels 107 Steel Casting and Engineering Support...University, University of Northern Iowa, Non- Ferrous Founders’ Society, QuesTek, buyCASTINGS.com, Spokane Industries, Nova Precision Casting, Waukesha

  18. Life after Steel

    ERIC Educational Resources Information Center

    Mangan, Katherine

    2013-01-01

    Bobby Curran grew up in a working-class neighborhood in Baltimore, finished high school, and followed his grandfather's steel-toed bootprints straight to Sparrows Point, a 3,000-acre sprawl of industry on the Chesapeake Bay. College was not part of the plan. A gritty but well-paying job at the RG Steel plant was Mr. Curran's ticket to a secure…

  19. Joining Steel Armor - Intermix

    DTIC Science & Technology

    1979-03-01

    TARADCOM a d ki Lk A el B~ 0el RWET0 TECHNICAL REPORT NO. 12311 JOINING STEEL ARMOR - INTERMIX March 1979 U U * S* ’ "U .by B. . A.SCEV * U...authorized documents. O "if TECHNICAL REPORT NO. 12311 JOINING STEEL ARMOR - INTERMIX BY B. A. SCHEVO March 1979 AMS: 3197..6D.4329 TARADCOM ARMOR AND...Intermix Process ...... ........ 3 Test Procedures - Intermix Armor ........ ......... 4 Mock Hull ................. ..................... 5 Results

  20. Ferrium M54 Steel

    DTIC Science & Technology

    2015-03-18

    release; distribution is unlimited. 13. SUPPLEMENTARY NOTES 14. ABSTRACT Bare and Zn-14% Ni alloy coated Ferrium M54 steels were studied to...Ni alloy coating appears to provide the steel some protection against hydrogen embrittlement/SCC and corrosion fatigue in aqueous 3.5% NaCl...301-342-8069 Standard Form 298 (Rev. 8-98) Prescribed by ANSI Std. Z39-18 NAWCADPAX/TIM-2014/292 ii SUMMARY Bare and Zn-14% Ni alloy

  1. Life after Steel

    ERIC Educational Resources Information Center

    Mangan, Katherine

    2013-01-01

    Bobby Curran grew up in a working-class neighborhood in Baltimore, finished high school, and followed his grandfather's steel-toed bootprints straight to Sparrows Point, a 3,000-acre sprawl of industry on the Chesapeake Bay. College was not part of the plan. A gritty but well-paying job at the RG Steel plant was Mr. Curran's ticket to a secure…

  2. Articles comprising ferritic stainless steels

    SciTech Connect

    Rakowski, James M.

    2016-06-28

    An article of manufacture comprises a ferritic stainless steel that includes a near-surface region depleted of silicon relative to a remainder of the ferritic stainless steel. The article has a reduced tendency to form an electrically resistive silica layer including silicon derived from the steel when the article is subjected to high temperature oxidizing conditions. The ferritic stainless steel is selected from the group comprising AISI Type 430 stainless steel, AISI Type 439 stainless steel, AISI Type 441 stainless steel, AISI Type 444 stainless steel, and E-BRITE.RTM. alloy, also known as UNS 44627 stainless steel. In certain embodiments, the article of manufacture is a fuel cell interconnect for a solid oxide fuel cell.

  3. Waste product profile: Steel cans

    SciTech Connect

    Miller, C.

    1996-07-01

    Steel cans are made from tinplate steel, which is produced in basic oxygen furnaces. A thin layer of tin is applied to the can`s inner and outer surfaces to prevent rusting and protect food and beverage flavors. As a result, steel cans are often called tin cans. Steel mills are the largest market for steel cans. Integrated mills use the basic oxygen process to manufacture tinplate, appliances, car bodies, and steel framing. Electric arc furnaces use 100% scrap to produce steel shapes such as railroad ties and bridge spans. Electric arc furnaces are more geographically diverse and tend to have smaller capacities than basic oxygen furnaces. Detinners remove the tin from steel cans for resale to tin using industries. Continued decreases in the amount of tin used in steel cans has lessened the importance of this market. Foundries use scrap as a raw material in making castings and molds for industrial users.

  4. Castings, Steel, Homogenization of Steel Castings

    DTIC Science & Technology

    1942-12-05

    diffraction pattern of quenched and tempered steel castings. 2. Calculations based upon known diffusion rates show: A. Practical homogenizing heat ...will be largely eliminated by either the usual heating for nuenching or a homo- genizing treatment. C. Interdendritic segregation of sulfur will...26 Appendix A - History of the Heat Treatment and Composition of Centrifugal Gun Castings at W-tertown Ar- sen-.l. ..... ..................... 2

  5. Fractographic Analysis of Weld Metal and HAZ Regions of API X-80 Steel Subjected to Simulation of the Reel-Lay Method

    NASA Astrophysics Data System (ADS)

    Beltrão, M. A. N.; Bastian, F. L.

    2014-10-01

    The reel-lay method is a process commonly used for rigid riser installation. During this process, riser materials are subjected to high strain levels and associated plastic damage which can affect their structural integrity. The aim of this work was to evaluate the fracture surfaces at weld metal and heat-affected zone regions of API X-80 steel three-point bend specimens, SE(B), subjected to reel-lay method simulations. The pre-existence of circumferential planar defects at 12 o'clock position was considered and the J-integral was used to simulate the reel-lay condition at the defects. Different strain levels considering conditions less and more severe than the real one were also studied. The results showed a great influence of J magnitude on fracture surface morphology. The increase of J magnitude led to a greater local surface damage on the specimens and stable crack growth during reel-lay simulation. High loading conditions should be avoided in the operation in order to prevent further structural damage of the materials.

  6. Profiles in garbage: Steel cans

    SciTech Connect

    Miller, C.

    1998-02-01

    Steel mills are the largest market for steel cans. Integrated mills use the basic oxygen process to manufacture tinplate, appliances, car bodies, and steel framing. Electric arc furnaces use 100% scrap to produce steel shapes such as railroad ties and bridge spans. Electric arc furnaces are more geographically diverse and tend to have smaller capacities than basic oxygen furnaces. Detinners remove the tin from steel cans for resale to tin using industries. With less tin use in steel cans, the importance of the detinning market has declined substantially. Foundries use scrap as a raw material in making castings and molds for industrial users.

  7. View northwest, wharf A, sheet steel bulkhead, steel lift tower ...

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

    View northwest, wharf A, sheet steel bulkhead, steel lift tower - U.S. Coast Guard Sandy Hook Station, Western Docking Structure, West of intersection of Canfield Road & Hartshorne Drive, Highlands, Monmouth County, NJ

  8. Replacement steel windows

    SciTech Connect

    Brown, M.A.; Condren, S.J.

    1999-07-01

    This paper presents the authors experiences in the investigation, design, and installation of replacement steel windows for two renovation projects at a major university in the northeast: a student residential complex and the law school. The authors review the construction of the existing walls (cast-in-place concrete barrier wall at the student residential complex and brick and stone masonry barrier wall at the law school), and the construction and performance of the original steel windows. To maintain the appearance of these architecturally significant buildings, the university elected to install replacement steel windows. The authors discuss special design consideration for steel windows (versus the more prevalent aluminum replacement window), including available window section profiles, corrosion protection, frame fabrication, and glazing design. The authors also review window flashing concepts they employed for the barrier wall construction, which has no drainage cavity. The authors summarize lessons learned during the window selection, design, fabrication, testing, and installation phases of the projects, and present recommendations for improved durability and water penetration resistance of steel windows.

  9. Superclean steel development

    SciTech Connect

    Richman, R.H.; McNaughton, W.P. )

    1989-12-01

    The Electric Power Research Institute has actively encouraged and sponsored a number of research projects to develop a superclean 3.5NiCrMoV steel for low pressure turbine rotors. Such steel is highly resistant to temper embrittlement and will thus facilitate increased efficiency in electricity generation through the use of higher operating temperatures and improvements in design. The objective of this interim report was to integrate the results that have been generated to date worldwide in the pursuit of superclean steel. The report contains detailed findings that enable the interested utility to evaluate how the results affect utility decision making. A companion document has been written to summarize the findings from this technical report. The results indicate that steels with impurity contents typical of the superclean specification can be manufactured for production rotors with properties that equal or exceed those for conventional 3.5NiCrMoV rotors in every detail. Of particular interest are the results that the superclean steels appear to be virtually resistant to temper embrittlement to a temperature of 500 {degrees}C. 109 refs., 51 figs., 9 tabs.

  10. Trends in steel technology. [Dual phase and HSLA steels

    SciTech Connect

    Not Available

    1980-01-01

    Dual phase steels, composite products, and microalloyed steels are making inroads in the automotive industry applications for bumpers, automotive parts, bodies, mechanical parts, suspension and steering equipment and truck bumpers. New steels are also used to support solar mirrors and cells, in corrosive environments in the oil and gas industry, fusion reactors, and pressure vessels in nuclear power plants. (FS)

  11. Continuous steel production and apparatus

    DOEpatents

    Peaslee, Kent D.; Peter, Jorg J.; Robertson, David G. C.; Thomas, Brian G.; Zhang, Lifeng

    2009-11-17

    A process for continuous refining of steel via multiple distinct reaction vessels for melting, oxidation, reduction, and refining for delivery of steel continuously to, for example, a tundish of a continuous caster system, and associated apparatus.

  12. Brazing titanium to stainless steel

    NASA Technical Reports Server (NTRS)

    Batista, R. I.

    1980-01-01

    Titanium and stainless-steel members are usually joined mechanically for lack of any other effective method. New approach using different brazing alloy and plating steel member with nickel resolves problem. Process must be carried out in inert atmosphere.

  13. Stainless steel tanks

    SciTech Connect

    Hagen, T.

    1995-12-31

    There is currently no recognized code or standard for the design, fabrication and construction of atmospheric and low pressure stainless steel tanks. At the present time these tanks are being designed to individual specifications, manufacturers standards or utilizing other codes and standards that may not be entirely applicable. Recognizing the need, the American Petroleum Institute will be publishing a new appendix to the API STD 650 Standard which will cover stainless steel tanks. The new Appendix was put together by a Task Group of selected individuals from the API Subcommittee of Pressure Vessels and Tanks from the Committee on Refinery Equipment. This paper deals with the development and basis of the new appendix. The new appendix will provide a much needed standard to cover the material, design, fabrication, erection and testing requirements for vertical, cylindrical, austenitic stainless steel aboveground tanks in nonrefrigerated service.

  14. A-3 steel work completed

    NASA Technical Reports Server (NTRS)

    2009-01-01

    Stennis Space Center engineers celebrated a key milestone in construction of the A-3 Test Stand on April 9 - completion of structural steel work. Workers with Lafayette (La.) Steel Erector Inc. placed the last structural steel beam atop the stand during a noon ceremony attended by more than 100 workers and guests.

  15. A-3 steel work completed

    NASA Image and Video Library

    2009-04-09

    Stennis Space Center engineers celebrated a key milestone in construction of the A-3 Test Stand on April 9 - completion of structural steel work. Workers with Lafayette (La.) Steel Erector Inc. placed the last structural steel beam atop the stand during a noon ceremony attended by more than 100 workers and guests.

  16. A-3 steel work completed

    NASA Technical Reports Server (NTRS)

    2009-01-01

    Stennis Space Center engineers celebrated a key milestone in construction of the A-3 Test Stand on April 9 - completion of structural steel work. Workers with Lafayette (La.) Steel Erector Inc. placed the last structural steel beam atop the stand during a noon ceremony attended by more than 100 workers and guests.

  17. Thermally Stable Nanocrystalline Steel

    NASA Astrophysics Data System (ADS)

    Hulme-Smith, Christopher Neil; Ooi, Shgh Woei; Bhadeshia, Harshad K. D. H.

    2017-10-01

    Two novel nanocrystalline steels were designed to withstand elevated temperatures without catastrophic microstructural changes. In the most successful alloy, a large quantity of nickel was added to stabilize austenite and allow a reduction in the carbon content. A 50 kg cast of the novel alloy was produced and used to verify the formation of nanocrystalline bainite. Synchrotron X-ray diffractometry using in situ heating showed that austenite was able to survive more than 1 hour at 773 K (500 °C) and subsequent cooling to ambient temperature. This is the first reported nanocrystalline steel with high-temperature capability.

  18. Microbial-Influenced Corrosion of Corten Steel Compared with Carbon Steel and Stainless Steel in Oily Wastewater by Pseudomonas aeruginosa

    NASA Astrophysics Data System (ADS)

    Mansouri, Hamidreza; Alavi, Seyed Abolhasan; Fotovat, Meysam

    2015-07-01

    The microbial corrosion behavior of three important steels (carbon steel, stainless steel, and Corten steel) was investigated in semi petroleum medium. This work was done in modified nutrient broth (2 g nutrient broth in 1 L oily wastewater) in the presence of Pseudomonas aeruginosa and mixed culture (as a biotic media) and an abiotic medium for 2 weeks. The behavior of corrosion was analyzed by spectrophotometric and electrochemical methods and at the end was confirmed by scanning electron microscopy. The results show that the degree of corrosion of Corten steel in mixed culture, unlike carbon steel and stainless steel, is less than P. aeruginosa inoculated medium because some bacteria affect Corten steel less than other steels. According to the experiments, carbon steel had less resistance than Corten steel and stainless steel. Furthermore, biofilm inhibits separated particles of those steels to spread to the medium; in other words, particles get trapped between biofilm and steel.

  19. Braze alloy spreading on steel

    NASA Technical Reports Server (NTRS)

    Siewert, T. A.; Heine, R. W.; Lagally, M. G.

    1978-01-01

    Scanning electron microscopy (SEM) and Auger electron microscopy (AEM) were employed to observe elemental surface decomposition resulting from the brazing of a copper-treated steel. Two types of steel were used for the study, stainless steel (treated with a eutectic silver-copper alloy), and low-carbon steel (treated with pure copper). Attention is given to oxygen partial pressure during the processes; a low enough pressure (8 x 10 to the -5th torr) was found to totally inhibit the spreading of the filler material at a fixed heating cycle. With both types of steel, copper treatment enhanced even spreading at a decreased temperature.

  20. Sensitization of stainless steel

    NASA Technical Reports Server (NTRS)

    Nagy, James P.

    1990-01-01

    The objective of this experiment is to determine the corrosion rates of 18-8 stainless steels that have been sensitized at various temperatures and to show the application of phase diagrams. The laboratory instructor will assign each student a temperature, ranging from 550 C to 1050 C, to which the sample will be heated. Further details of the experimental procedure are detailed.

  1. Active tectonics in southern Xinjiang, China: Analysis of terrace riser and normal fault scarp degradation along the Hotan-Qira fault system

    NASA Technical Reports Server (NTRS)

    Avouac, Jean-Philippe; Peltzer, Gilles

    1993-01-01

    The northern piedmont of the western Kunlun mountains (Xinjiang, China) is marked at its easternmost extremity, south of the Hotan-Qira oases, by a set of normal faults trending N50E for nearly 70 km. Conspicuous on Landsat and SPOT images, these faults follow the southeastern border of a deep flexural basin and may be related to the subsidence of the Tarim platform loaded by the western Kunlun northward overthrust. The Hotan-Qira normal fault system vertically offsets the piedmont slope by 70 m. Highest fault scarps reach 20 m and often display evidence for recent reactivations about 2 m high. Successive stream entrenchments in uplifted footwallls have formed inset terraces. We have leveled topographic profiles across fault scarps and transverse abandoned terrace risers. The state of degradation of each terrace edge has been characterized by a degradation coefficient tau, derived by comparison with analytical erosion models. Edges of highest abandoned terraces yield a degradation coefficient of 33 +/- 4 sq.m. Profiles of cumulative fault scarps have been analyzed in a similar way using synthetic profiles generated with a simple incremental fault scarp model.

  2. Active tectonics in southern Xinjiang, China: Analysis of terrace riser and normal fault scarp degradation along the Hotan-Qira fault system

    NASA Technical Reports Server (NTRS)

    Avouac, Jean-Philippe; Peltzer, Gilles

    1993-01-01

    The northern piedmont of the western Kunlun mountains (Xinjiang, China) is marked at its easternmost extremity, south of the Hotan-Qira oases, by a set of normal faults trending N50E for nearly 70 km. Conspicuous on Landsat and SPOT images, these faults follow the southeastern border of a deep flexural basin and may be related to the subsidence of the Tarim platform loaded by the western Kunlun northward overthrust. The Hotan-Qira normal fault system vertically offsets the piedmont slope by 70 m. Highest fault scarps reach 20 m and often display evidence for recent reactivations about 2 m high. Successive stream entrenchments in uplifted footwallls have formed inset terraces. We have leveled topographic profiles across fault scarps and transverse abandoned terrace risers. The state of degradation of each terrace edge has been characterized by a degradation coefficient tau, derived by comparison with analytical erosion models. Edges of highest abandoned terraces yield a degradation coefficient of 33 +/- 4 sq.m. Profiles of cumulative fault scarps have been analyzed in a similar way using synthetic profiles generated with a simple incremental fault scarp model.

  3. Full time-domain nonlinear coupled dynamic analysis of a truss spar and its mooring/riser system in irregular wave

    NASA Astrophysics Data System (ADS)

    Yang, MinDong; Teng, Bin; Xiao, LongFei; Ning, DeZhi; Shi, ZhongMin; Qu, Yan

    2014-01-01

    A new full time-domain nonlinear coupled method has been established and then applied to predict the responses of a Truss Spar in irregular wave. For the coupled analysis, a second-order time-domain approach is developed to calculate the wave forces, and a finite element model based on rod theory is established in three dimensions in a global coordinate system. In numerical implementation, the higher-order boundary element method (HOBEM) is employed to solve the velocity potential, and the 4th-order Adams-Bashforth-Moultn scheme is used to update the second-order wave surface. In deriving convergent solutions, the hull displacements and mooring tensions are kept consistent at the fairlead and the motion equations of platform and mooring-lines/risers are solved simultaneously using Newmark- β integration scheme including Newton-Raphson iteration. Both the coupled quasi-static analysis and the coupled dynamic analysis are performed. The numerical simulation results are also compared with the model test results, and they coincide very well as a whole. The slow-drift responses can be clearly observed in the time histories of displacements and mooring tensions. Some important characteristics of the coupled responses are concluded.

  4. Active tectonics in southern Xinjiang, China: Analysis of terrace riser and normal fault scarp degradation along the Hotan-Qira fault system

    SciTech Connect

    Avouac, J.P.; Peltzer, G. |

    1993-12-01

    The northern piedmont of the western Kunlun mountains (Xinjiang, China) is marked at its easternmost extremity, south of the Hotan-Qira oases, by a set of normal faults trending N50E for nearly 70 km. Conspicuous on Landsat and SPOT images, these faults follow the southeastern border of a deep flexural basin and may be related to the subsidence of the Tarim platform loaded by the western Kunlun northward overthrust. The Hotan-Qira normal fault system vertically offsets the piedmont slope by 70 m. Highest fault scarps reach 20 m and often display evidence for recent reactivations about 2 m high. Successive stream entrenchments in uplifted footwallls have formed inset terraces. We have leveled topographic profiles across fault scarps and transverse abandoned terrace risers. The state of degradation of each terrace edge has been characterized by a degradation coefficient tau, derived by comparison with analytical erosion models. Edges of highest abandoned terraces yield a degradation coefficient of 33 +/- 4 sq.m. Profiles of cumulative fault scarps have been analyzed in a similar way using synthetic profiles generated with a simple incremental fault scarp model.

  5. Voidage and pressure profile characteristics of sand-iron ore-coal-FCC single-particle systems in the riser of a pilot plant circulating fluidized bed

    SciTech Connect

    Das, M.; Meikap, B.C.; Saha, R.K.

    2008-06-15

    Hydrodynamic behaviors of single system of particles were investigated in a circulating fluidized bed (CFB) unit. Particles belonging to Geldart groups A and B like sand of various sizes (90, 300, 417, 522, 599, and 622 mu m), FCC catalyst (120 mu m), iron ore (166 and 140 {mu} m), and coal (335 and 168 {mu} m) were used to study the hydrodynamic characteristics. Superficial air velocity used in the present study ranged between 2.01 and 4.681 m/s and corresponding mass fluxes were 12.5-50 kg/(m{sup 2} s). A CFB needs the creation of some special hydrodynamic conditions, namely a certain combination of superficial gas velocity, solids circulation rate, particle diameter, density of particle, etc. which can give rise to a state wherein the solid particles are subjected to an upward velocity greater than the terminal or free fall velocity of the majority of the individual particles. The hydrodynamics of the bed was investigated in depth and theoretical analysis is presented to support the findings. Based on gas-solid momentum balance in the riser, a distinction between apparent and real voidage has been made. The effects of acceleration and friction on the real voidage have been estimated. Results indicated a 0.995 voidage for higher superficial gas velocity of 4.681. m/s.

  6. 77 FR 30589 - SteelRiver Infrastructure Partners LP, SteelRiver Infrastructure Associates LLC, SteelRiver...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-23

    ... Surface Transportation Board SteelRiver Infrastructure Partners LP, SteelRiver Infrastructure Associates LLC, SteelRiver Infrastructure Fund North America LP, and Patriot Funding LLC--Control Exemption--Patriot Rail Corp., et al. SteelRiver Infrastructure Partners LP (SRIP LP), SteelRiver...

  7. Ferritic steel melt and FLiBe/steel experiment : melting ferritic steel.

    SciTech Connect

    Troncosa, Kenneth P.; Smith, Brandon M.; Tanaka, Tina Joan

    2004-11-01

    In preparation for developing a Z-pinch IFE power plant, the interaction of ferritic steel with the coolant, FLiBe, must be explored. Sandia National Laboratories Fusion Technology Department was asked to drop molten ferritic steel and FLiBe in a vacuum system and determine the gas byproducts and ability to recycle the steel. We tried various methods of resistive heating of ferritic steel using available power supplies and easily obtained heaters. Although we could melt the steel, we could not cause a drop to fall. This report describes the various experiments that were performed and includes some suggestions and materials needed to be successful. Although the steel was easily melted, it was not possible to drip the molten steel into a FLiBe pool Levitation melting of the drop is likely to be more successful.

  8. History of ultrahigh carbon steels

    SciTech Connect

    Wadsworth, J.; Sherby, O.D.

    1997-06-20

    The history and development of ultrahigh carbon steels (i.e., steels containing between 1 and 2.l percent C and now known as UHCS) are described. The early use of steel compositions containing carbon contents above the eutectoid level is found in ancient weapons from around the world. For example, both Damascus and Japanese sword steels are hypereutectoid steels. Their manufacture and processing is of interest in understanding the role of carbon content in the development of modern steels. Although sporadic examples of UHCS compositions are found in steels examined in the early part of this century, it was not until the mid-1970s that the modern study began. This study had its origin in the development of superplastic behavior in steels and the recognition that increasing the carbon content was of importance in developing that property. The compositions that were optimal for superplasticity involved the development of steels that contained higher carbon contents than conventional modern steels. It was discovered, however, that the room temperature properties of these compositions were of interest in their own right. Following this discovery, a period of intense work began on understanding their manufacture, processing, and properties for both superplastic forming and room temperature applications. The development of superplastic cast irons and iron carbides, as well as those of laminated composites containing UHCS, was an important part of this history.

  9. 46 CFR 59.20-1 - Carbon-steel or alloy-steel castings.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 2 2011-10-01 2011-10-01 false Carbon-steel or alloy-steel castings. 59.20-1 Section 59... BOILERS, PRESSURE VESSELS AND APPURTENANCES Welding Repairs to Castings § 59.20-1 Carbon-steel or alloy-steel castings. Defects in carbon-steel or alloy-steel castings may be repaired by welding. The...

  10. 46 CFR 59.20-1 - Carbon-steel or alloy-steel castings.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 2 2013-10-01 2013-10-01 false Carbon-steel or alloy-steel castings. 59.20-1 Section 59... BOILERS, PRESSURE VESSELS AND APPURTENANCES Welding Repairs to Castings § 59.20-1 Carbon-steel or alloy-steel castings. Defects in carbon-steel or alloy-steel castings may be repaired by welding. The...

  11. 46 CFR 59.20-1 - Carbon-steel or alloy-steel castings.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 2 2012-10-01 2012-10-01 false Carbon-steel or alloy-steel castings. 59.20-1 Section 59... BOILERS, PRESSURE VESSELS AND APPURTENANCES Welding Repairs to Castings § 59.20-1 Carbon-steel or alloy-steel castings. Defects in carbon-steel or alloy-steel castings may be repaired by welding. The...

  12. 46 CFR 59.20-1 - Carbon-steel or alloy-steel castings.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 2 2014-10-01 2014-10-01 false Carbon-steel or alloy-steel castings. 59.20-1 Section 59... BOILERS, PRESSURE VESSELS AND APPURTENANCES Welding Repairs to Castings § 59.20-1 Carbon-steel or alloy-steel castings. Defects in carbon-steel or alloy-steel castings may be repaired by welding. The...

  13. 46 CFR 59.20-1 - Carbon-steel or alloy-steel castings.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Carbon-steel or alloy-steel castings. 59.20-1 Section 59... BOILERS, PRESSURE VESSELS AND APPURTENANCES Welding Repairs to Castings § 59.20-1 Carbon-steel or alloy-steel castings. Defects in carbon-steel or alloy-steel castings may be repaired by welding. The...

  14. Coated 4340 Steel

    DTIC Science & Technology

    2013-08-26

    plasma vapor NAWCADPAX/TR-2013/252 2 deposition (reference 9), chemical vapor deposition, hot dip galvanizing, anodizing, composite coatings ...electroplating on 4340 steel. Assess the impact of substitute primer and sacrificial coating on corrosion fatigue and SCC, in particular leading ...alternative coatings qualified to MIL-PRE-23377 Class N and an electroplated zinc -nickel alloy passivated with a trivalent chromium solution which is

  15. Ultrahigh Carbon Steel.

    DTIC Science & Technology

    1984-10-01

    ferrite grains, 0.5-2 pm, containing fine spheroidized cementite particles, they have been shown not only to be super - plastic at intermediate...utilized to prepare ferrous laminated composites with super - plastic properties at intermediate temperatures’ 19 Ŗ 1 and with very high impact resistance...as an alloying addition that could alter the super - plastic properties of UHC steels because of its influence on the thermodynam- ics of the Fe-C

  16. Nanoprecipitates in Steels

    SciTech Connect

    Schneibel, Joachim H; Lu, Zhao Ping; Shim, Sang Hoon

    2007-01-01

    The creep strength of ferritic steels can be substantially improved by the incorporation of a high number density of nano-scale dispersoids. Examples for such alloys are the oxide dispersion strengthened steels MA956, MA957, and PM2000. The dispersoids in these steels contain Y and Ti, or Y and Al. They can be as small as a few nanometers in size. Processing is traditionally carried out by mechanical alloying of elemental or pre-alloyed powders mixed with Y{sub 2}O{sub 3} powder. The goal of the present research is to identify alternative ways of producing ultrafine dispersoids. One possible way is internal oxidation, in which reactive elements dissolved in a metallic matrix are selectively oxidized. Internal oxidation experiments were carried out with Fe-Y, Fe-Ti-Y, and Fe-Al-Y precursors. Microstructural analysis showed that dispersoid dimensions as small as 10 nm could be achieved. Atomized Fe-0.25 at% Y powder was internally oxidized and consolidated by hot forging. An increase in the high-temperature creep strength by {approx} 20% was observed. Since it is likely that the composition of the precursor alloys is crucial for maximizing the number density and thermal stability of the oxides, experiments allowing the rapid screening of different compositions have been initiated.

  17. Nanoprecipitates in Steels

    SciTech Connect

    Schneibel, Joachim H; Kad, Bimal

    2008-01-01

    The creep strength of ferritic steels can be substantially improved by the incorporation of a high number density of nano-scale dispersoids. Examples for such alloys are the oxide dispersion strengthened steels MA956, MA957, and PM2000. The dispersoids in these steels contain Y and Ti, or Y and Al. They can be as small as a few nanometers in size. Processing is traditionally carried out by mechanical alloying of elemental or pre-alloyed powders mixed with Y{sub 2}O{sub 3} powder. The goal of the present research is to identify alternative ways of producing ultrafine dispersoids. One possible way is internal oxidation, in which reactive elements dissolved in a metallic matrix are selectively oxidized. Internal oxidation experiments were carried out with Fe-Y, Fe-Ti-Y, and Fe-Al-Y precursors. Microstructural analysis showed that dispersoid dimensions as small as 10 nm could be achieved. Atomized Fe-0.25 at% Y powder was internally oxidized and consolidated by hot forging. An increase in the high-temperature creep strength by {approx} 20% was observed. Since it is likely that the composition of the precursor alloys is crucial for maximizing the number density and thermal stability of the oxides, experiments allowing the rapid screening of different compositions have been initiated.

  18. Stainless Steel Permeability

    SciTech Connect

    Buchenauer, Dean A.; Karnesky, Richard A.

    2015-09-01

    An understanding of the behavior of hydrogen isotopes in materials is critical to predicting tritium transport in structural metals (at high pressure), estimating tritium losses during production (fission environment), and predicting in-vessel inventory for future fusion devices (plasma driven permeation). Current models often assume equilibrium diffusivity and solubility for a class of materials (e.g. stainless steels or aluminum alloys), neglecting trapping effects or, at best, considering a single population of trapping sites. Permeation and trapping studies of the particular castings and forgings enable greater confidence and reduced margins in the models. For FY15, we have continued our investigation of the role of ferrite in permeation for steels of interest to GTS, through measurements of the duplex steel 2507. We also initiated an investigation of the permeability in work hardened materials, to follow up on earlier observations of unusual permeability in a particular region of 304L forgings. Samples were prepared and characterized for ferrite content and coated with palladium to prevent oxidation. Issues with the poor reproducibility of measurements at low permeability were overcome, although the techniques in use are tedious. Funding through TPBAR and GTS were secured for a research grade quadrupole mass spectrometer (QMS) and replacement turbo pumps, which should improve the fidelity and throughput of measurements in FY16.

  19. Process for dezincing galvanized steel

    DOEpatents

    Morgan, W.A.; Dudek, F.J.; Daniels, E.J.

    1998-07-14

    A process is described for removing zinc from galvanized steel. The galvanized steel is immersed in an electrolyte containing at least about 15% by weight of sodium or potassium hydroxide and having a temperature of at least about 75 C and the zinc is galvanically corroded from the surface of the galvanized steel. The material serving as the cathode is principally a material having a standard electrode potential which is intermediate of the standard electrode potentials of zinc and cadmium in the electrochemical series. The corrosion rate may be accelerated by (1) increasing the number density of corrosion sites in the galvanized steel by mechanically abrading or deforming the galvanized steel, (2) heating the galvanized steel to form an alloy of zinc on the surface of the galvanized steel, (3) mixing the galvanized steel with a material having a standard electrode potential which is intermediate of the standard electrode potentials of zinc and cadmium in the electrochemical series, or (4) moving the galvanized steel relative to itself and to the electrolyte while immersed in the electrolyte. 1 fig.

  20. Process for dezincing galvanized steel

    DOEpatents

    Morgan, William A.; Dudek, Frederick J.; Daniels, Edward J.

    1998-01-01

    A process for removing zinc from galvanized steel. The galvanized steel is immersed in an electrolyte containing at least about 15% by weight of sodium or potassium hydroxide and having a temperature of at least about 75.degree. C. and the zinc is galvanically corroded from the surface of the galvanized steel. The material serving as the cathode is principally a material having a standard electrode potential which is intermediate of the standard electrode potentials of zinc and cadmium in the electrochemical series. The corrosion rate may be accelerated by (i) increasing the number density of corrosion sites in the galvanized steel by mechanically abrading or deforming the galvanized steel, (ii) heating the galvanized steel to form an alloy of zinc on the surface of the galvanized steel, (iii) mixing the galvanized steel with a material having a standard electrode potential which is intermediate of the standard electrode potentials of zinc and cadmium in the electrochemical series, or (iv) moving the galvanized steel relative to itself and to the electrolyte while immersed in the electrolyte.

  1. Hydrogen Embrittlement of Gun Steel

    DTIC Science & Technology

    1987-11-01

    8217s HY80 and HY130 steels were checked for the critical hydrogen concentrations which were determined to be 6 ppm for HY8O steel 8 and 3 ppm for HY130...JOTC FILE COPY AD-A188 972 AD 1 TECHNICAL REPORT ARCCB-TR-87030 HYDROGEN EMBRITTLEMENT OF GUN STEEL F’ GERALD L. SPFNCER DTIC DEC 1 5 1987 NOVEMBER...PtEtIOC COVERED HYDROGEN EMBRITTLEHENT OF GUN STEEL Final OG EOTNME 6. PERFORMINGORO EOTNME 7. A*JTNOR(s) S. CONTRACT OR GRANT NUMBER(&) Gerald L

  2. High strength, tough alloy steel

    DOEpatents

    Thomas, Gareth; Rao, Bangaru V. N.

    1979-01-01

    A high strength, tough alloy steel is formed by heating the steel to a temperature in the austenite range (1000.degree.-1100.degree. C.) to form a homogeneous austenite phase and then cooling the steel to form a microstructure of uniformly dispersed dislocated martensite separated by continuous thin boundary films of stabilized retained austenite. The steel includes 0.2-0.35 weight % carbon, at least 1% and preferably 3-4.5% chromium, and at least one other substitutional alloying element, preferably manganese or nickel. The austenite film is stable to subsequent heat treatment as by tempering (below 300.degree. C.) and reforms to a stable film after austenite grain refinement.

  3. Induction heat treatment of steel

    SciTech Connect

    Semiatin, S.L.; Stutz, D.E.

    1985-01-01

    This book discusses the induction heating. After reviewing heat treating operations for steel and the principles of the heat treatment of steel, an overview of induction heat treating is provided. Next, consideration is given to equipment and equipment selection, coil design, power requirements and temperature control. A discussion of surface and through hardening of steel is provided, including information on frequency and power selection and quenching apparatus. Tempering is considered, followed by information on control of residual stresses, cracking, temper brittleness and the important metallurgical and hardness differences between induction and furnace treated steel.

  4. Research and development of rapid hydrogenation for coal conversion to synthetic motor fuels (riser cracking of coal). Final report, April 1, 1976-September 30, 1980

    SciTech Connect

    Duncan, D. A.; Beeson, J. L.; Oberle, R. D.

    1981-02-01

    The objective of the program described was to develop a noncatalytic process for the hydropyrolysis of lignite and coal to produce high-octane blending gasoline constituents, methane, ethane, and carbon oxides. The process would operate in a balanced plant mode, using spent char to generate process hydrogen by steam-oxygen gasification. The technical program included the construction and operating of a bench-scale unit (5-10 lb/hr), the design, construction, and operation of a process development unit (PDU) (100 lb/hr), and a final technical and economic assessment of the process, called Riser Cracking of Coal. In the bench-scale unit program, 143 runs were made investigating the effects of pressure, temperature, heating rate, residence time, and particle size, processing North Dakota lignite in hydrogen. Some runs were made in which the hydrogen was preheated to pyrolysis temperatures prior to contact with the coal, and, also, in which steam was substituted for half of the hydrogen. Attempts to operate the bench-scale unit at 1200 psig and 1475/sup 0/F were not successful. Depth of carbon conversion was found to be influenced by hydrogen pressure, hydrogen-to-coal ratio, and the severity of the thermal treatment. The composition of hydrocarbon liquids produced was found to change with severity. At low severity, the liquids contained sizable fractions of phenols and cresols. At high severity, the fraction of phenols and cresols was much reduced, with an attendant increase in BTX. In operating the PDU, it was necessary to use more oxygen than was planned to achieve pyrolysis temperatures because of heat losses, and portions of hydrocarbon products were lost through combustion with a large increase in carbon oxide yields. Economic studies, however, showed that selling prices for gasoline blending stock, fuel oil, and fuel gas are competitive in current markets, so that the process is held to warrant further development.

  5. Biodegradation of 2,4,6-trichlorophenol in a packed-bed biofilm reactor equipped with an internal net draft tube riser for aeration and liquid circulation.

    PubMed

    Jesús, A Gómez-De; Romano-Baez, F J; Leyva-Amezcua, L; Juárez-Ramírez, C; Ruiz-Ordaz, N; Galíndez-Mayer, J

    2009-01-30

    For the aerobic biodegradation of the fungicide and defoliant 2,4,6-trichlorophenol (2,4,6-TCP), a bench-scale packed-bed bioreactor equipped with a net draft tube riser for liquid circulation and oxygenation (PB-ALR) was constructed. To obtain a high packed-bed volume relative to the whole bioreactor volume, a high A(D)/A(R) ratio was used. Reactor's downcomer was packed with a porous support of volcanic stone fragments. PB-ALR hydrodynamics and oxygen mass transfer behavior was evaluated and compared to the observed behavior of the unpacked reactor operating as an internal airlift reactor (ALR). Overall gas holdup values epsilon(G), and zonal oxygen mass transfer coefficients determined at various airflow rates in the PB-ALR, were higher than those obtained with the ALR. When comparing mixing time values obtained in both cases, a slight increment in mixing time was observed when reactor was operated as a PB-ALR. By using a mixed microbial community, the biofilm reactor was used to evaluate the aerobic biodegradation of 2,4,6-TCP. Three bacterial strains identified as Burkholderia sp., Burkholderia kururiensis and Stenotrophomonas sp. constituted the microbial consortium able to cometabolically degrade the 2,4,6-TCP, using phenol as primary substrate. This consortium removed 100% of phenol and near 99% of 2,4,6-TCP. Mineralization and dehalogenation of 2,4,6-TCP was evidenced by high COD removal efficiencies ( approximately 95%), and by the stoichiometric release of chloride ions from the halogenated compound ( approximately 80%). Finally, it was observed that the microbial consortium was also capable to metabolize 2,4,6-TCP without phenol as primary substrate, with high removal efficiencies (near 100% for 2,4,6-TCP, 92% for COD and 88% for chloride ions).

  6. Reduction in Energy Consumption & Variability in Steel Foundry Operations

    SciTech Connect

    Frank Peters

    2005-05-04

    This project worked to improve the efficiency of the steel casting industry by reducing the variability that occurs because of process and product variation. The project focused on the post shakeout operations since roughly half of the production costs are in this area. These improvements will reduce the amount of variability, making it easier to manage the operation and improve the competitiveness. The reduction in variability will also reduce the need for many rework operations, which will result in a direct reduction of energy usage, particularly by the reduction of repeated heat treatment operations. Further energy savings will be realized from the reduction of scrap and reduced handling. Field studies were conducted at ten steel foundries that represented the U.S. steel casting industry, for a total of over 100 weeks of production observation. These studies quantified the amount of variability, and looked toward determining the source. A focus of the data collected was the grinding operations since this is a major effort in the cleaning room, and it represents the overall casting quality. The grinding was divided into two categories, expected and unexpected. Expected grinding is that in which the location of the effort is known prior to making the casting, such as smoothing parting lines, gates, and riser contacts. Unexpected grinding, which was approximately 80% of the effort, was done to improve the surfaces at weld repair locations, to rectify burnt on sand, and other surface anomalies at random locations. Unexpected grinding represents about 80% of the grinding effort. By quantifying this effort, the project raised awareness within the industry and the industry is continuing to make improvements. The field studies showed that the amount of variation of grinding operations (normalized because of the diverse set of parts studied) was very consistent across the industry. The field studies identified several specific sources that individually contributed to

  7. The industrial ecology of steel

    SciTech Connect

    Considine, Timothy J.; Jablonowski, Christopher; Considine, Donita M.M.; Rao, Prasad G.

    2001-03-26

    This study performs an integrated assessment of new technology adoption in the steel industry. New coke, iron, and steel production technologies are discussed, and their economic and environmental characteristics are compared. Based upon detailed plant level data on cost and physical input-output relations by process, this study develops a simple mathematical optimization model of steel process choice. This model is then expanded to a life cycle context, accounting for environmental emissions generated during the production and transportation of energy and material inputs into steelmaking. This life-cycle optimization model provides a basis for evaluating the environmental impacts of existing and new iron and steel technologies. Five different plant configurations are examined, from conventional integrated steel production to completely scrap-based operations. Two cost criteria are used to evaluate technology choice: private and social cost, with the latter including the environmental damages associated with emissions. While scrap-based technologies clearly generate lower emissions in mass terms, their emissions of sulfur dioxide and nitrogen oxides are significantly higher. Using conventional damage cost estimates reported in the literature suggests that the social costs associated with scrap-based steel production are slightly higher than with integrated steel production. This suggests that adopting a life-cycle viewpoint can substantially affect environmental assessment of new technologies. Finally, this study also examines the impacts of carbon taxes on steel production costs and technology choice.

  8. MINOS Detector Steel Magnetic Measurements

    SciTech Connect

    Robert C. Trendler and Walter F. Jaskierny

    1999-03-03

    Magnetic measurements were made on one steel plate of the MINOS far detector. The conventionally used technique of measuring sense coil voltage induced by step changes in excitation current voltage was successful in providing stable, repeatable measurements. Measurements were made at several locations on the steel and the results are presented.

  9. Hydrogen Embrittlement of Structural Steels

    SciTech Connect

    Somerday, Brian P.; San Marchi, Christopher W

    2014-08-01

    Carbon-manganese steels are candidates for the structural materials in hydrogen gas pipelines; however, it is well known that these steels are susceptible to hydrogen embrittlement. Decades of research and industrial experience have established that hydrogen embrittlement compromises the structural integrity of steel components. This experience has also helped identify the failure modes that can operate in hydrogen containment structures. As a result, there are tangible ideas for managing hydrogen embrittlement in steels and quantifying safety margins for steel hydrogen containment structures. For example, fatigue crack growth aided by hydrogen embrittlement is a well-established failure mode for steel hydrogen containment structures subjected to pressure cycling. This pressure cycling represents one of the key differences in operating conditions between current hydrogen pipelines and those anticipated in a hydrogen delivery infrastructure. Applying structural integrity models in design codes coupled with measurement of relevant material properties allows quantification of the reliability/integrity of steel hydrogen pipelines subjected to pressure cycling. Furthermore, application of these structural integrity models is aided by the development of physics-based predictive models, which provide important insights such as the effects of microstructure on hydrogen-assisted fatigue crack growth. Successful implementation of these structural integrity and physics-based models enhances confidence in the design codes and enables decisions about materials selection and operating conditions for reliable and efficient steel hydrogen pipelines.

  10. Magnetoacoustic stress measurements in steel

    NASA Technical Reports Server (NTRS)

    Namkung, M.; Utrata, D.; Allison, S. G.; Heyman, J. S.

    1985-01-01

    Uniaxial stress effects on the low-field magnetoacoustic interaction have been studied using bulk compressional waves and Rayleigh surface waves in numerous steel samples having various impurity concentrations (Namkung et al., 1984). The results invariably showed that the initial slope of acoustic natural velocity variations, with respect to net induced magnetization parallel to the stress axis, is positive under tension and negative under compression. The results of current measurements in railroad rail steel having about 0.68 wt percent carbon content are typical for medium range carbon steels. The low-field natural velocity slope in this particular type of steel, which is almost zero when unstressed, becomes steeper with increased magnitude of stress in both directions. Hence, the nondestructive determination of the sign of residual stress in railroad wheels and rails is possible using this technique. This paper discusses the basic physical mechanism underlying the experimental observations and presents the results obtained in railroad rail steel.

  11. 2169 Steel Waveform Experiments

    NASA Astrophysics Data System (ADS)

    Furnish, M.; Alexander, C.; Reinhart, W.; Brown, J.

    2013-06-01

    In support of efforts to develop multiscale models of materials, we performed eight gas gun impact experiments on 2169 steel (21% Cr, 6% Ni, 9% Mn). These experiments provided shock, reshock and release velocimetry data, with initial shock stresses ranging from 10 to 50 GPa (particle velocities from 0.25 to 1.05 km/s). Both windowed and free-surface measurements were used, with samples 1 to 5 mm thick. The study focused on dynamic strength determination via the release/reshock paths. Reshock tests with explosively welded impactors produced clean results. The free-surface samples, which were steps on a single piece of steel, showed lower wavespeeds for thin (1 mm) samples than for thicker (2 or 4 mm) samples. A configuration used for the last three shots allowed release information to be determined from these free surface samples as well. The sample strength appears to increase with stress from ~1 GPa to ~3 GPa over this range, consistent with other recent work but about 40% above the Steinberg model. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  12. Steel forgings: Second volume

    SciTech Connect

    Nisbett, E.G.; Melilli, A.S.

    1997-12-31

    Steel is supplied in many product forms, most of which are produced in terms of basic dimensions such as width and thickness, or diameter and with length describing quantity. Forgings and castings by contrast are diverse in shape and form and are individually made for a specific purpose, either as self contained units such as crankshafts, valve bodies or turbine rotors, or as discrete components to be fabricated into a larger assembly, as for example a nozzle for a pressure vessel. The specification and testing of forgings is therefore more varied, complex, and demanding than is the case for other product forms. This is augmented by the fact that forgings are often expected to give better reliability and service performance than can be expected when the same part is fabricated from sections of other steel product forms, if this were in fact practical. Given these unique circumstances the exchange of ideas on forging manufacturing techniques and experience, materials data and service experience has been an essential driving force in developing forging techniques and applications in every industrial field. The format of the symposium was similar to that of Williamsburg, focusing on the scope of the subcommittee in the areas of pressure vessel and nuclear forgings, turbine and generator forgings, general industrial forgings, and test methods for forgings. Separate abstracts were prepared for 17 papers.

  13. Connections: Superplasticity, Damascus Steels, Laminated Steels, and Carbon Dating

    NASA Astrophysics Data System (ADS)

    Wadsworth, Jeffrey

    2016-12-01

    In this paper, a description is given of the connections that evolved from the initial development of a family of superplastic plain carbon steels that came to be known as Ultra-High Carbon Steels (UHCS). It was observed that their very high carbon contents were similar, if not identical, to those of Damascus steels. There followed a series of attempts to rediscover how the famous patterns found on Damascus steels blades were formed. At the same time, in order to improve the toughness at room temperature of the newly-developed UHCS, laminated composites were made of alternating layers of UHCS and mild steel (and subsequently other steels and other metals). This led to a study of ancient laminated composites, the motives for their manufacture, and the plausibility of some of the claims relating to the number of layers in the final blades. One apparently ancient laminated composite, recovered in 1837 from the great pyramid of Giza which was constructed in about 2750 B.C., stimulated a carbon dating study of ancient steels. The modern interest in "Bladesmithing" has connections back to many of these ancient weapons.

  14. 49 CFR 192.55 - Steel pipe.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Steel pipe. 192.55 Section 192.55 Transportation... BY PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS Materials § 192.55 Steel pipe. (a) New steel pipe is... in accordance with paragraph (c) or (d) of this section. (b) Used steel pipe is qualified for...

  15. 49 CFR 192.55 - Steel pipe.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 3 2011-10-01 2011-10-01 false Steel pipe. 192.55 Section 192.55 Transportation... BY PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS Materials § 192.55 Steel pipe. (a) New steel pipe is... in accordance with paragraph (c) or (d) of this section. (b) Used steel pipe is qualified for...

  16. 49 CFR 192.55 - Steel pipe.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 3 2013-10-01 2013-10-01 false Steel pipe. 192.55 Section 192.55 Transportation... BY PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS Materials § 192.55 Steel pipe. (a) New steel pipe is... in accordance with paragraph (c) or (d) of this section. (b) Used steel pipe is qualified for...

  17. 49 CFR 192.55 - Steel pipe.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 3 2012-10-01 2012-10-01 false Steel pipe. 192.55 Section 192.55 Transportation... BY PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS Materials § 192.55 Steel pipe. (a) New steel pipe is... in accordance with paragraph (c) or (d) of this section. (b) Used steel pipe is qualified for...

  18. 49 CFR 192.55 - Steel pipe.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 3 2014-10-01 2014-10-01 false Steel pipe. 192.55 Section 192.55 Transportation... BY PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS Materials § 192.55 Steel pipe. (a) New steel pipe is... in accordance with paragraph (c) or (d) of this section. (b) Used steel pipe is qualified for...

  19. Occupational Profiles in the European Steel Industry.

    ERIC Educational Resources Information Center

    Franz, Hans-Werner; And Others

    The steel industry in Europe has faced great changes, with resulting layoffs and restructuring. Now that the most basic changes seem to be over, it has become evident that the remaining steel industry requires more highly trained workers than was the case previously. Although steel maintenance employees were always highly skilled, steel production…

  20. Improving the toughness of ultrahigh strength steel

    SciTech Connect

    Soto, Koji

    2002-01-01

    The ideal structural steel combines high strength with high fracture toughness. This dissertation discusses the toughening mechanism of the Fe/Co/Ni/Cr/Mo/C steel, AerMet 100, which has the highest toughness/strength combination among all commercial ultrahigh strength steels. The possibility of improving the toughness of this steel was examined by considering several relevant factors.

  1. Hypereutectoid high-speed steels

    SciTech Connect

    Kremnev, L.S.

    1986-01-01

    Half of the tungsten and molybdenum contained in R6M5 and R18 steels is concentrated in the undissolved eutectic carbides hindering austenitic grain gowth in hardening and providing the necessary strength and impact strength. This article describes the tungsten-free low-alloy high-speed steel 11M5F with a chemical composition of 1.03-1.10% C, 5.2-5.7% Mo, 3.8-4.2% Cr, 1.3-1.7% V, 0.3-0.6% Si, and 0.3% Ce. The properties of 11M5F and R6M5 steels are examined and compared. The results of production and laboratory tests of the cutting properties of tools of the steels developed showed their high effectiveness, especially of 11M5F steel with 1% A1. The life of tools of the tungsten-free steels is two or three times greater than the life of tools of R6M5 steel.

  2. Welding tritium exposed stainless steel

    SciTech Connect

    Kanne, W.R. Jr.

    1994-11-01

    Stainless steels that are exposed to tritium become unweldable by conventional methods due to buildup of decay helium within the metal matrix. With longer service lives expected for tritium containment systems, methods for welding on tritium exposed material will become important for repair or modification of the systems. Solid-state resistance welding and low-penetration overlay welding have been shown to mitigate helium embrittlement cracking in tritium exposed 304 stainless steel. These processes can also be used on stainless steel containing helium from neutron irradiation, such as occurs in nuclear reactors.

  3. Stainless steel decontamination manipulators

    SciTech Connect

    Sullivan, R.J.

    1986-01-01

    Three, large-volume coverage manipulator systems were designed and built for the Defense Water Processing Facility at the Savannah River Laboratory. These stainless steel systems will be used for high-pressure spray decontamination of waste containers and large process equipment modules. Each system has a manipulator arm, folding boom, and vertical drive and guide structure. Handling capacity is 45 kg, horizontal reach is 4.6 m with a 180-deg swing motion, and the vertical travel is 6 m. The system is remotely removable and replaceable in modules using an overhead crane and an impact wrench. The manipulator arm has seven motions: Shoulder rotation and pivot, elbow pivot, wrist pivot and rotation, and grip open-close. All motions are variable speed and are slip-clutch protected to prevent overloading from external forces (collisions).

  4. Advanced steel reheat furnace

    SciTech Connect

    Moyeda, D.; Sheldon, M.; Koppang, R.; Lanyi, M.; Li, X.; Eleazer, B.

    1997-10-01

    Energy and Environmental Research Corp. (EER) under a contract from the Department of Energy is pursuing the development and demonstration of an Advanced Steel Reheating Furnace. This paper reports the results of Phase 1, Research, which has evaluated an advanced furnace concept incorporating two proven and commercialized technologies previously applied to other high temperature combustion applications: EER`s gas reburn technology (GR) for post combustion NOx control; and Air Product`s oxy-fuel enrichment air (OEA) for improved flame heat transfer in the heating zones of the furnace. The combined technologies feature greater production throughput with associated furnace efficiency improvements; lowered NOx emissions; and better control over the furnace atmosphere, whether oxidizing or reducing, leading to better control over surface finish.

  5. Method for welding chromium molybdenum steels

    SciTech Connect

    Sikka, V.K.

    1986-09-16

    A process is described for welding chromium-molybdenum steels which consist of: subjecting the steel to normalization by heating to above the transformation temperature and cooling in air; subjecting the steel to a partial temper by heating to a temperature less than a full temper; welding the steel using an appropriate filler metal; subjecting the steel to a full temper by heating to a temperature sufficient to optimize strength, reduce stress, increase ductility and reduce hardness.

  6. 2169 steel waveform experiments.

    SciTech Connect

    Furnish, Michael David; Alexander, C. Scott; Reinhart, William Dodd; Brown, Justin L.

    2012-11-01

    In support of LLNL efforts to develop multiscale models of a variety of materials, we have performed a set of eight gas gun impact experiments on 2169 steel (21% Cr, 6% Ni, 9% Mn, balance predominantly Fe). These experiments provided carefully controlled shock, reshock and release velocimetry data, with initial shock stresses ranging from 10 to 50 GPa (particle velocities from 0.25 to 1.05 km/s). Both windowed and free-surface measurements were included in this experiment set to increase the utility of the data set, as were samples ranging in thickness from 1 to 5 mm. Target physical phenomena included the elastic/plastic transition (Hugoniot elastic limit), the Hugoniot, any phase transition phenomena, and the release path (windowed and free-surface). The Hugoniot was found to be nearly linear, with no indications of the Fe phase transition. Releases were non-hysteretic, and relatively consistent between 3- and 5-mmthick samples (the 3 mm samples giving slightly lower wavespeeds on release). Reshock tests with explosively welded impactors produced clean results; those with glue bonds showed transient releases prior to the arrival of the reshock, reducing their usefulness for deriving strength information. The free-surface samples, which were steps on a single piece of steel, showed lower wavespeeds for thin (1 mm) samples than for thicker (2 or 4 mm) samples. A configuration used for the last three shots allows release information to be determined from these free surface samples. The sample strength appears to increase with stress from ~1 GPa to ~ 3 GPa over this range, consistent with other recent work but about 40% above the Steinberg model.

  7. JPDR vessel steel examination

    SciTech Connect

    Corwin, W.R.; Broadhead, B.L.; Sokolov, M.A.

    1995-10-01

    There is a need to validate the results of irradiation effects research by the examination of material taken directly from the wall of a pressure vessel which has been irradiated during normal service. This task has been included with the HSSI Program to provide just such an evaluation of material from the wall of the pressure vessel from the JPDR. The JPDR was a small BWR that began operation in 1963. It operated until 1976, accumulating {approximately}17,000 h of operation, of which a little over 14,000 h were with the original 45-MWTh core, and the remaining fraction, late in life, with an upgraded 90-MWTh core. The pressure vessel of the JPDR, fabricated from A 302, grade B, modified steel with an internal weld overlay cladding of 304 stainless steel, is approximately 2 m ID and 73 mm thick. It was fabricated from two shell halves joined by longitudinal seam welds located 180{degrees} from each other. The rolling direction of the shell plates is parallel to the axis of the vessel. It operated at 273{degrees}C and reached a maximum fluence of about 2.3 x 10{sup 18} n/cm{sup 2} (> 1 MeV). The impurity contents in the base metal are 0.10 to 0.11% Cu and 0.010 to 0.017% P with a nickel content of 0.63 to 0.65%. Impurity contents of the weld metal are 0.11 to 0.14% Cu and 0.025 to 0.039% P with a nickel content of 0.59%.

  8. Fabrication of stainless steel foil utilizing chromized steel strip

    NASA Astrophysics Data System (ADS)

    Loria, Edward A.

    1980-10-01

    Stainless steel foil has properties which are, in many respects, unmatched by alternative thin films. The high strength to weight ratio and resistance to corrosion and oxidation at elevated temperatures are generally advantageous. The aerospace and automotive industries have used Type 430 and 304 foil in turbine engine applications. Foil around 2 mils (5.1 × 10-3 cm) thick has been appropriate for the recuperator or heat exchanger and this product has also been used in honeycomb and truss-core structures. Further, such foil has been employed as a wrap to protect tool steel parts from contamination during heat treating. A large part of the high cost of producing stainless steel foil by rolling is due to the complicated and expensive rolling mill and annealing equipment involved. A method will be described which produces (solid) stainless steel foil from chromized (coated) steel which can be cheaper than the conventional processing stainless steel, such as Type 430, from ingot to foil. Also, the material is more ductile and less work hardenable during processing to foil and consequently intermediate annealing treatments are eliminated and scrap losses minimized.

  9. Rebuilding Steam Turbine Generator Reduces Costs at a Steel Mill (Bethlehem Steel Corporation (BSC))

    SciTech Connect

    1999-04-01

    Rebuilding steam turbine generator reduces costs at a steel mill. To remain competitive in the rapidly changing global marketplace, Bethlehem Steel Corporation (BSC), the second largest producer of steel in the United States, was looking for...

  10. Hydrogen embrittlement of structural steels.

    SciTech Connect

    Somerday, Brian P.

    2010-06-01

    Carbon-manganese steels are candidates for the structural materials in hydrogen gas pipelines, however it is well known that these steels are susceptible to hydrogen embrittlement. Decades of research and industrial experience have established that hydrogen embrittlement compromises the structural integrity of steel components. This experience has also helped identify the failure modes that can operate in hydrogen containment structures. As a result, there are tangible ideas for managing hydrogen embrittement in steels and quantifying safety margins for steel hydrogen containment structures. For example, fatigue crack growth aided by hydrogen embrittlement is a key failure mode for steel hydrogen containment structures subjected to pressure cycling. Applying appropriate structural integrity models coupled with measurement of relevant material properties allows quantification of safety margins against fatigue crack growth in hydrogen containment structures. Furthermore, application of these structural integrity models is aided by the development of micromechanics models, which provide important insights such as the hydrogen distribution near defects in steel structures. The principal objective of this project is to enable application of structural integrity models to steel hydrogen pipelines. The new American Society of Mechanical Engineers (ASME) B31.12 design code for hydrogen pipelines includes a fracture mechanics-based design option, which requires material property inputs such as the threshold for rapid cracking and fatigue crack growth rate under cyclic loading. Thus, one focus of this project is to measure the rapid-cracking thresholds and fatigue crack growth rates of line pipe steels in high-pressure hydrogen gas. These properties must be measured for the base materials but more importantly for the welds, which are likely to be most vulnerable to hydrogen embrittlement. The measured properties can be evaluated by predicting the performance of the pipeline

  11. Fatigue handbook: Offshore steel structures

    SciTech Connect

    Almarnaess, A.

    1985-01-01

    The contents of this book are: Overview of Offshore Steel Structures; Loads on Ocean Structures; Fracture Mechanics As a Tool in Fatigue Analysis; Basic Fatigue Properties of Welded Joints; Significance of Defects; Improving the Fatigue Strength of Welded Joints; Effects of Marine Environment and Cathodic Protection on Fatigue of Structural Steels Fatigue of Tubular Joints; Unstable Fracture; Fatigue Life Calculations; and Fatigue in Building Codes Background and Applications.

  12. Process Hood Stand Support Steel

    SciTech Connect

    VAN KATWIJK, C.

    2000-04-03

    This package is written to comply with EN-6-035-00 for upgrade dedication of commercial grade items (CGI). The SNF-5953 CGI package provides the Technical evaluation to identify the critical characteristics and the acceptance criteria associated with the safety function of the Hood Stand Support Steel. Completion of the technical and quality requirements identified in the dedication package will provide enough data to be reasonably assured that CGI Hood Stand Support Steel will perform its SC function.

  13. Analysis of plasma nitrided steels

    NASA Technical Reports Server (NTRS)

    Salik, J.; Ferrante, J.; Honecy, F.; Hoffman, R., Jr.

    1987-01-01

    The analysis of plasma nitrided steels can be divided to two main categories - structural and chemical. Structural analysis can provide information not only on the hardening mechanisms but also on the fundamental processes involved. Chemical analysis can be used to study the kinetics for the nitriding process and its mechanisms. In this paper preliminary results obtained by several techniques of both categories are presented and the applicability of those techniques to the analysis of plasma-nitrided steels is discussed.

  14. Wear of steel by rubber

    NASA Technical Reports Server (NTRS)

    Gent, A. N.; Pulford, C. T. R.

    1978-01-01

    Wear of a steel blade used as a scraper to abrade rubber surfaces has been found to take place much more rapidly on a cis-polyisoprene (natural rubber) surface than on a cis-polybutadiene surface, and much more rapidly in an inert atmosphere than in air. These observations are attributed to the direct attack upon steel of free-radical species generated by mechanical rupture of elastomer molecules during abrasion.

  15. Wear of steel by rubber

    NASA Technical Reports Server (NTRS)

    Gent, A. N.; Pulford, C. T. R.

    1978-01-01

    Wear of a steel blade used as a scraper to abrade rubber surfaces has been found to take place much more rapidly on a cis-polyisoprene (natural rubber) surface than on a cis-polybutadiene surface, and much more rapidly in an inert atmosphere than in air. These observations are attributed to the direct attack upon steel of free-radical species generated by mechanical rupture of elastomer molecules during abrasion.

  16. Development of New Stainless Steel

    SciTech Connect

    Robert F. Buck

    2005-08-30

    A new family of innovative martensitic stainless steels, 521-A, 521-B, and 521-C has been developed by Advanced Steel Technology, LLC (Trafford, PA) as high strength fastener (bolt) materials for use at moderate temperatures in turbine engines, including steam turbines, gas turbines, and aircraft engines. The primary objective of the development program was to create a martensitic stainless steel with high strength at moderate temperatures, and which could replace the expensive nickel-based superalloy IN 718 in some fasteners applications. A secondary objective was to replace conventional 12Cr steels such as AISI 422 used as blades, buckets and shafts that operate at intermediate temperatures in turbine engines with stronger steel. The composition of the new alloys was specifically designed to produce excellent mechanical properties while integrating heat treatment steps into production to reduce energy consumption during manufacturing. As a result, production costs and energy consumption during production of rolled bar products is significantly lower than conventional materials. Successful commercialization of the new alloys would permit the installed cost of certain turbine engines to be reduced without sacrificing high availability or operational flexibility, thereby enhancing the global competitiveness of U.S. turbine engine manufacturers. Moreover, the domestic specialty steel industry would also benefit through increased productivity and reduced operating costs, while increasing their share of the international market for turbine engine fasteners, blades, buckets and shafts.

  17. Review on Cold-Formed Steel Connections

    PubMed Central

    Tan, Cher Siang; Mohammad, Shahrin; Md Tahir, Mahmood; Shek, Poi Ngian

    2014-01-01

    The concept of cold-formed light steel framing construction has been widespread after understanding its structural characteristics with massive research works over the years. Connection serves as one of the important elements for light steel framing in order to achieve its structural stability. Compared to hot-rolled steel sections, cold-formed steel connections perform dissimilarity due to the thin-walled behaviour. This paper aims to review current researches on cold-formed steel connections, particularly for screw connections, storage rack connections, welded connections, and bolted connections. The performance of these connections in the design of cold-formed steel structures is discussed. PMID:24688448

  18. Review on cold-formed steel connections.

    PubMed

    Lee, Yeong Huei; Tan, Cher Siang; Mohammad, Shahrin; Tahir, Mahmood Md; Shek, Poi Ngian

    2014-01-01

    The concept of cold-formed light steel framing construction has been widespread after understanding its structural characteristics with massive research works over the years. Connection serves as one of the important elements for light steel framing in order to achieve its structural stability. Compared to hot-rolled steel sections, cold-formed steel connections perform dissimilarity due to the thin-walled behaviour. This paper aims to review current researches on cold-formed steel connections, particularly for screw connections, storage rack connections, welded connections, and bolted connections. The performance of these connections in the design of cold-formed steel structures is discussed.

  19. 38. Photocopy of photograph. STEEL PLANT, BOILERS UNDER CONSTRUCTION IN ...

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

    38. Photocopy of photograph. STEEL PLANT, BOILERS UNDER CONSTRUCTION IN BOILER PLANT LOCATED EAST OF MAIN STEEL PLANT, 1909. (From the Bethlehem Steel Corporation collection, Seattle, WA) - Irondale Iron & Steel Plant, Port Townsend, Jefferson County, WA

  20. A microstructure sensitive study of rolling contact fatigue in bearing steels: A numerical and experimental approach

    NASA Astrophysics Data System (ADS)

    Pandkar, Anup Surendra

    Bearings are an integral part of machine components that transmit rotary power such as cars, motors, engines etc. Safe bearing operation is essential to avoid serious failures and accidents, which necessitates their timely replacement. This calls for an accurate bearing life prediction methods. Based on the Lundberg-Palmgen (LP) model, current life models consistently under predict bearings lives. Improvement in life prediction requires understanding of the bearing failure mechanism i.e. Rolling Contact Fatigue (RCF). The goal of this research is to develop a mechanistic framework required for an improved bearing life prediction model. Such model should account for metal plasticity, influence of microstructural features and cyclically evolving stressstrain fields induced during RCF. To achieve this, elastic-plastic finite element (FE) study is undertaken to investigate the response of M50-NiL bearing steel during RCF. Specifically, a microstructure sensitive study of the influence of non-metallic inclusions on RCF response of bearings is presented. M50-NiL microstructure consists of carbides which are orders of magnitude smaller than bearing dimensions. To account for this size difference, a multi-scale FE modeling approach is employed. The FE results reveal that hard carbide particles act as local stress risers, alter surrounding stressstrain fields and cause micro-scale yielding of steel matrix. Moreover, they introduce a shear stress cycle with non-zero mean stress, which promotes micro-plastic strain accumulation via ratcheting mechanism. Localized ratcheting is primarily responsible for cyclic hardening within the RCF affected region. Such evolution of subsurface hardness can be used to quantify RCF induced damage. To investigate this further, cyclic hardening response of the RCF affected region is simulated. The results show good agreement with the experimental observations. The cyclic stress-strain fields obtained from these simulations and the knowledge of

  1. Method of Making Steel Strapping and Strip

    SciTech Connect

    1999-12-10

    Fact sheet written for the Inventions and Innovation Program about a new method for making steel strapping and strip from rod stock produced from scrap steel. There is a large movement in the American steel industry to utilize more recycled steel. Recycled steel melted in the electric arc furnaces of mini-mills is being used as the source of raw materials for an increasing number of products, largely due to its lower price. However, conventional processes for producing steel strapping and cold-rolled strip steel restrict manufacturers from using more than 50% recycled steel. In addition, steel strapping and cold-rolled strip steel traditionally require many production steps. They are produced from primary steel that has been cast into slab, heated, rolled to achieve the desired thickness, and slit to the desired width. The slitting process produces microcracks along the edge of the strapping or strip, which reduce tensile strength. A new continuous process produces steel strapping and 1/2 inch to 6 inch strip steel from the rod and strip stock made from scrap steel in mini-mills. The new process creates steel strapping and strip with improved strength and quality due to the absence of microcracks caused by the conventional slitting process. The finished product is cheaper because of the lower cost associated with using rod ad lower conversion costs. In addition, the higher tensile strength of the product allows for thinner strapping. The process represents a new approach to producing any steel strapping used for bundling and packaging items for storage or transport. In addition, this innovative new process can be used to produce cold-rolled strip steel, a basic raw material for automobile parts, hardware, office equipment, and many other products.

  2. The microstructure of chromium-tungsten steels

    NASA Astrophysics Data System (ADS)

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

    1989-03-01

    Chromium-tungsten steels are being developed to replace the Cr-Mo steels for fusion-reactor applications. Eight experimental steels were produced and examined by optical and electron microscopy. Chromium concentrations of 2.25, 5, 9 and 12 pct were used. Steels with these chromium compositions and with 2 pct W and 0.25 pct V were produced. To determine the effect of tungsten and vanadium, three other 2.25Cr steels were produced as follows: an alloy with 2 pct W and 0 pct V and alloys with 0 and 1 pct W and 0.25 pct V. A 9Cr steel containing 2 pct W, 0.25 pct V, and 0.07 pct Ta also was studied. For all alloys, carbon was maintained at 0.1 pct. Two pct tungsten was required in the 2.25Cr steels to produce 100 pct bainite (no polygonal ferrite). The 5Cr and 9Cr steels were 100 pct martensite, but the 12Cr steel contained about 25 pct delta-ferrite. Precipitate morphology and precipitate types varied, depending on the chromium content. For the 2.25Cr steels, M3C and M7C3 were the primary precipitates; for the 9Cr and 12Cr steels, M23C6 was the primary precipitate. The 5Cr steel contained M7C3 and M23C6. All of the steels with vanadium also contained MC.

  3. Catenary nanostructures as compact Bessel beam generators

    PubMed Central

    Li, Xiong; Pu, Mingbo; Zhao, Zeyu; Ma, Xiaoliang; Jin, Jinjin; Wang, Yanqin; Gao, Ping; Luo, Xiangang

    2016-01-01

    Non-diffracting Bessel beams, including zero-order and high-order Bessel Beams which carry orbital angular momentum (OAM), enable a variety of important applications in optical micromanipulation, sub-diffraction imaging, high speed photonics/quantum communication, etc. The commonly used ways to create Bessel beams, including an axicon or a digital hologram written to a spatial light modulator (SLM), have great challenges to operate at the nanoscale. Here we theoretically design and experimentally demonstrate one kind of planar Bessel beam generators based on metasurfaces with analytical structures perforated in ultra-thin metallic screens. Continuous phase modulation between 0 to 2π is realized with a single element. In addition, due to the dispersionless phase shift stemming from spin-orbit interaction, the proposed device can work in a wide wavelength range. The results may find applications in future optical communication, nanofabrication and super-resolution imaging, etc. PMID:26843142

  4. Catenary nanostructures as compact Bessel beam generators.

    PubMed

    Li, Xiong; Pu, Mingbo; Zhao, Zeyu; Ma, Xiaoliang; Jin, Jinjin; Wang, Yanqin; Gao, Ping; Luo, Xiangang

    2016-02-04

    Non-diffracting Bessel beams, including zero-order and high-order Bessel Beams which carry orbital angular momentum (OAM), enable a variety of important applications in optical micromanipulation, sub-diffraction imaging, high speed photonics/quantum communication, etc. The commonly used ways to create Bessel beams, including an axicon or a digital hologram written to a spatial light modulator (SLM), have great challenges to operate at the nanoscale. Here we theoretically design and experimentally demonstrate one kind of planar Bessel beam generators based on metasurfaces with analytical structures perforated in ultra-thin metallic screens. Continuous phase modulation between 0 to 2π is realized with a single element. In addition, due to the dispersionless phase shift stemming from spin-orbit interaction, the proposed device can work in a wide wavelength range. The results may find applications in future optical communication, nanofabrication and super-resolution imaging, etc.

  5. Submerged arc fillet welds between mild steel and stainless steel

    SciTech Connect

    Kotecki, D.J.; Rajan, V.B.

    1997-02-01

    Submerged arc fillet welds between mild steel and Type 304 stainless steel, made with ER309L wire, may contain no ferrite and be at risk of hot cracking, or they may be sufficiently diluted that they transform to martensite with both hot cracking risk and low ductility. This situation is most prevalent when direct current electrode positive (DCEP) polarity is used and when the flange is the mild steel part of the T-joint. A flux that adds chromium to the weld can somewhat alleviate this tendency. Direct current electrode negative (DCEN) polarity greatly reduces this tendency by limiting dilution. Fillet weld compositions and dilutions are obtained for a number of welding conditions and fluxes.

  6. Nickel release from stainless steels.

    PubMed

    Haudrechy, P; Mantout, B; Frappaz, A; Rousseau, D; Chabeau, G; Faure, M; Claudy, A

    1997-09-01

    In 1994, a study of nickel release and allergic contact dermatitis from nickel-plated metals and stainless steels was published in this journal. It was shown that low-sulfur stainless steel grades like AISI 304, 316L or 430 (S < or = 0.007%) release less than 0.03 microgram/cm2/week of nickel in acid artificial sweat and elicit no reactions in patients already sensitized to nickel. In contrast, nickel-plated samples release around 100 micrograms/cm2/week of Ni and high-sulfur stainless steel (AISI 303-S approximately 0.3%) releases about 1.5 micrograms/cm2/week in this acid artificial sweat. Applied on patients sensitized to nickel, these metals elicit positive reactions in 96% and 14%, respectively, of the patients. The main conclusion was that low-sulfur stainless steels like AISI 304, 316L or 430, even when containing Ni, should not elicit nickel contact dermatitis, while metals having a mean corrosion resistance like a high-sulfur stainless steel (AISI 303) or nickel-plated steel should be avoided. The determining characteristic was in fact the corrosion resistance in chloride media, which, for stainless steels, is connected, among other factors, to the sulfur content. Thus, a question remained concerning the grades with an intermediate sulfur content, around 0.03%, which were not studied. They are the object of the study presented in this paper. 3 tests were performed: leaching experiments, dimethylglyoxime and HNO3 spot tests, and clinical patch tests; however, only stainless steels were tested: a low-sulfur AISI 304 and AISI 303 as references and 3 grades with a sulfur content around 0.03%: AISI 304L, AISI 304L added with Ca, AISI 304L+Cu. Leaching experiments showed that the 4 non-resulfurised grades released less than 0.5 microgram/cm2/week in acid sweat while the reulfurized AISI 303 released around or more than 0.5 microgram/cm2/week. This is explained by the poorer corrosion resistance of the resulfurized grade. Yet all these grades had the same

  7. 29 CFR 1926.754 - Structural steel assembly.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 29 Labor 8 2013-07-01 2013-07-01 false Structural steel assembly. 1926.754 Section 1926.754 Labor... (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Steel Erection § 1926.754 Structural steel...) Tripping hazards. Shear connectors (such as headed steel studs, steel bars or steel lugs), reinforcing...

  8. 29 CFR 1926.754 - Structural steel assembly.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 8 2010-07-01 2010-07-01 false Structural steel assembly. 1926.754 Section 1926.754 Labor... (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Steel Erection § 1926.754 Structural steel...) Tripping hazards. Shear connectors (such as headed steel studs, steel bars or steel lugs), reinforcing...

  9. 29 CFR 1926.754 - Structural steel assembly.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 8 2011-07-01 2011-07-01 false Structural steel assembly. 1926.754 Section 1926.754 Labor... (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Steel Erection § 1926.754 Structural steel...) Tripping hazards. Shear connectors (such as headed steel studs, steel bars or steel lugs), reinforcing...

  10. 29 CFR 1926.754 - Structural steel assembly.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 29 Labor 8 2012-07-01 2012-07-01 false Structural steel assembly. 1926.754 Section 1926.754 Labor... (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Steel Erection § 1926.754 Structural steel...) Tripping hazards. Shear connectors (such as headed steel studs, steel bars or steel lugs), reinforcing...

  11. 29 CFR 1926.754 - Structural steel assembly.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 Labor 8 2014-07-01 2014-07-01 false Structural steel assembly. 1926.754 Section 1926.754 Labor... (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Steel Erection § 1926.754 Structural steel...) Tripping hazards. Shear connectors (such as headed steel studs, steel bars or steel lugs), reinforcing...

  12. Steel erected at A-3 Test Stand

    NASA Technical Reports Server (NTRS)

    2008-01-01

    Workers erect the first fabricated steel girders to arrive at the A-3 Test Stand at Stennis Space Center. Steel work began at the construction site Oct. 29 and is scheduled to continue into next spring.

  13. Steel erected at A-3 Test Stand

    NASA Image and Video Library

    2008-10-29

    Workers erect the first fabricated steel girders to arrive at the A-3 Test Stand at Stennis Space Center. Steel work began at the construction site Oct. 29 and is scheduled to continue into next spring.

  14. Steel erected at A-3 Test Stand

    NASA Technical Reports Server (NTRS)

    2008-01-01

    Workers erect the first fabricated steel girders to arrive at the A-3 Test Stand at Stennis Space Center. Steel work began at the construction site Oct. 29 and is scheduled to continue into next spring.

  15. High-temperature brazing of stainless steel

    NASA Technical Reports Server (NTRS)

    Beuyukian, C. S.; Heisman, R. M.; Mitchell, M. J.

    1978-01-01

    Prevention of iron contamination of platens is eliminated by placing alumina/silica ceramic-fiber blankets between platens and carbon-steel plate. Carbon-steel plates provide rigidity and improve heat transfer.

  16. Electromechanical Surface Hardening of Tubing Steels

    NASA Astrophysics Data System (ADS)

    Fedorova, L. V.; Fedorov, S. K.; Serzhant, A. A.; Golovin, V. V.; Systerov, S. V.

    2017-07-01

    Results of metallographic studies of the structure of steels 38G2S and 37G2F and steels of group D after electromechanical surface hardening of tube specimens over the external diameter are presented.

  17. Corrosion control of steel-reinforced concrete

    NASA Astrophysics Data System (ADS)

    Chung, D. D. L.

    2000-10-01

    The methods and materials for corrosion control of steel-reinforced concrete are reviewed. The methods are steel surface treatment, the use of admixtures in concrete, surface coating on concrete, and cathodic protection.

  18. High-temperature brazing of stainless steel

    NASA Technical Reports Server (NTRS)

    Beuyukian, C. S.; Heisman, R. M.; Mitchell, M. J.

    1978-01-01

    Prevention of iron contamination of platens is eliminated by placing alumina/silica ceramic-fiber blankets between platens and carbon-steel plate. Carbon-steel plates provide rigidity and improve heat transfer.

  19. New Development of HSLA Steels in China

    NASA Astrophysics Data System (ADS)

    Zhang, Xiao-gang; Yang, Cai-fu; Shang, Cheng-jia

    During the last decade, the adjustment and upgrade of steel product structures always be very important tasks in China's iron and steel industry. Since there is a fast growth of steel production in China, a series of research achievements in the technology area of HSLA steels have been made and applied successfully in the actual production, and thereby promoted a rapid development and application of China's HSLA Steel products. However, The China's iron and steel industry is now facing the excess production capacity and under pressure from respects of resource, energy and environment, therefore, it would be an effective way to realize the sustainable development in China's iron and steel industry by strengthening the applications of HSLA steels continuously and positively.

  20. Developments in HSLA steel products

    NASA Astrophysics Data System (ADS)

    Paules, John R.

    1991-01-01

    The technology of microalloyed steels is expanding beyond its original emphasis on low-carbon, severely control-rolled strip and plate products. A variety of economical, high-strength, tough, as-rolled or as-forged microalloyed products are replacing more expensive heat-treated steels. Recrystallization-controlled rolling is being utilized to produce very fine ferrite grain sizes and good toughness in strip, plate and bar products processed with relatively high rolling temperatures. High-strength microalloyed long products such as railroad joint bars, truck frame rails and flat bars for truck trailer construction are replacing heat-treated parts. Microalloyed, medium-carbon forging steels are used extensively for automobile engine and suspension components. Fully pearlitic high-carbon rods are being microalloyed to enhance the properties of wire and springs.

  1. ESF GROUND SUPPORT - STRUCTURAL STEEL ANALYSIS

    SciTech Connect

    T. Misiak

    1996-06-26

    The purpose and objective of this analysis are to expand the level of detail and confirm member sizes for steel sets included in the Ground Support Design Analysis, Reference 5.20. This analysis also provides bounding values and details and defines critical design attributes for alternative configurations of the steel set. One possible configuration for the steel set is presented. This analysis covers the steel set design for the Exploratory Studies Facility (ESF) entire Main Loop 25-foot diameter tunnel.

  2. Corrosion Behavior of Steel Fibrous Concrete

    DTIC Science & Technology

    1977-05-01

    Crvtaiue wi ,rerse sido it necessaty m’d Identify by block number) steel fibrous concrete corrosion cracked fibrous concrete 20 ABST RACT (Continue...dissolved gas in liq- Although chloride ions affect the rate of steel corro- uids. sion in concrete , corrosion can occur without them. Verbeck has...repcrted that steel subjected to a concrete Corrosion of steel will not occur without water. Not environment normally develops a protective oxide film

  3. The coupling VIV analysis of SCRs with rigid swing

    NASA Astrophysics Data System (ADS)

    Liu, Juan; Huang, Weiping

    2015-08-01

    With the development of deepwater oil and gas exploration, Steel Catenary Risers (SCRs) become preferred risers for resource production, import and export. Vortex induced vibration (VIV) is the key problem encountered in the design of SCRs. In this study, a new model, the rigid swing model, is proposed based on the consideration of large curvature of SCRs. The sag bend of SCRs is assumed as a rigid swing system around the axis from the hanging point to the touch down point (TDP) in the model. The torque, produced by the lift force and the swing vector, provides the driving torque for the swing system, and the weight of SCRs provides the restoring torque. The simulated response of rigid swing is coupled with bending vibration, and then the coupling VIV model of SCRs is studied in consideration of bending vibration and rigid motion. The calculated results indicate that the rigid swing has a magnitude equal to that of bending vibration, and the rigid motion affects the dynamic response of SCRs and can not be neglected in the VIV analysis.

  4. Steel erected at A-3 Test Stand

    NASA Technical Reports Server (NTRS)

    2008-01-01

    Fabricated steel began arriving by truck Oct. 24 for construction of the A-3 Test Stand that will be used to test the engine for the nation's next generation of moon rockets. Within days workers from Lafayette Steel Erector Inc. began assembling the 16 steel stages needed on the foundation and footings poured in the previous year.

  5. Recycling steel automatically - through resource recovery

    SciTech Connect

    Foley, W.J.

    1997-12-01

    Last year, more than 55 percent of all steel cans were recycled. But no matter how effective the local recycling programs may be, some steel cans and other steel products are overlooked and appear in MSW. This missed steel fraction is automatically recycled by resource recovery facilities through magnetic separation. More than three-fourths of the operating resource recovery plants magnetically separate steel cans and other discarded steel items either pre- or post-combustion. Recovering ferrous scrap clearly reduces the post-combustion material that is landfilled and heightens the facilities` environmental performance. Both the resource recovery and steel industries must heighten public awareness of the benefits of automatic steel recycling. Magnetic separation at resource recovery facilities is a simple method of diverting what would otherwise be relegated as solid waste to the landfill. It should be recognized as an increasingly important and valued part of the resource recovery and steel industries` overall recycling efforts. This paper will discuss the status of steel can recycling in the United States, describe how recovered ferrous is beneficiated before recycling by the steel industry, and make recommendations for heightening awareness of the steel recycling contribution made by resource recovery facilities.

  6. Steel erected at A-3 Test Stand

    NASA Image and Video Library

    2008-10-24

    Fabricated steel began arriving by truck Oct. 24 for construction of the A-3 Test Stand that will be used to test the engine for the nation's next generation of moon rockets. Within days workers from Lafayette Steel Erector Inc. began assembling the 16 steel stages needed on the foundation and footings poured in the previous year.

  7. Steel erected at A-3 Test Stand

    NASA Technical Reports Server (NTRS)

    2008-01-01

    Fabricated steel began arriving by truck Oct. 24 for construction of the A-3 Test Stand that will be used to test the engine for the nation's next generation of moon rockets. Within days workers from Lafayette Steel Erector Inc. began assembling the 16 steel stages needed on the foundation and footings poured in the previous year.

  8. Steeling and Resilience in Art Education

    ERIC Educational Resources Information Center

    Heise, Donalyn

    2014-01-01

    Steel is an incredibly strong alloy of iron and carbon. Due to its incredible strength and durability, this resilient material is commonly used for constructing buildings. The transitive verb "steeling" is defined in Miriam-Webster dictionary as "to fill with resolution or determination, as in, she 'steeled herself to face the…

  9. Steeling and Resilience in Art Education

    ERIC Educational Resources Information Center

    Heise, Donalyn

    2014-01-01

    Steel is an incredibly strong alloy of iron and carbon. Due to its incredible strength and durability, this resilient material is commonly used for constructing buildings. The transitive verb "steeling" is defined in Miriam-Webster dictionary as "to fill with resolution or determination, as in, she 'steeled herself to face the…

  10. Steel: Price and Policy Issues

    DTIC Science & Technology

    2006-08-31

    semi-finished slab steel. It has no U.S. production assets, though it acquired the leading Canadian producer, Dofasco , in January 2006 and earlier was...Bloomberg.com, “Mittal Makes $22.7 Bln. Unsolicited Bid for Arcelor” (Jan. 27, 2006); Wall St. Journal, “Arcelor Transfers Dofasco Unit to Block...Stelco 56 Canada Y 4.54 4.91 Dofasco 60 Canada Y 4.19 4.99 Steel Dynamics 76 USA Y 3.28 3.15 Altos Hornos de Mexico 78 Mexico Y 3.24 3.01 Ipsco 82 USA

  11. Metallography of maraging 350 steel

    SciTech Connect

    Hutson, S.M.; Merten, C.W.

    1987-01-01

    A technique for etching maraging 350 steel with Glyceregia is described. Surface activation procedures are integral to this technique. Microstructural features revealed by this technique are compared with those obtained with Kalling's reagent, Fry's reagent, and 5% Nital, three etchants commonly used to reveal microstructures of maraging steels. Features which may be simultaneously revealed using Glyceregia include prior austenite grain boundaries, martensitic structure, precipitates, titanium carbo-nitrides, and reverted austenite. The other etchants examined in this investigation typically reveal only a few of the microstructural features detailed above at any one time. 11 refs., 10 figs., 2 tabs.

  12. Plating on stainless steel alloys

    SciTech Connect

    Dini, J.W.; Johnson, H.R.

    1981-09-11

    Quantitative adhesion data are presented for a variety of electroplated stainless steel type alloys. Results show that excellent adhesion can be obtained by using a Wood's nickel strike or a sulfamate nickel strike prior to final plating. Specimens plated after Wood's nickel striking failed in the deposit rather than at the interface between the substrate and the coating. Flyer plate quantitative tests showed that use of anodic treatment in sulfuric acid prior to Wood's nickel striking even further improved adhesion. In contrast activation of stainless steels by immersion or cathodic treatment in hydrochloric acid resulted in very reduced bond strengths with failure always occurring at the interface between the coating and substrate.

  13. Teaching Steel Connections Using an Interactive Virtual Steel Sculpture

    ERIC Educational Resources Information Center

    Moaveni, Saeed; Chou, Karen C.

    2015-01-01

    Steel connections play important roles in the integrity of a structure, and many structural failures are attributed to connection failures. Connections are the glue that holds a structure together. The failures of the Hartford Coliseum in 1977, the Hyatt Regency Hotel in Kansas City in 1980, and the I-35W Bridge in Minneapolis in 2007 are all…

  14. Teaching Steel Connections Using an Interactive Virtual Steel Sculpture

    ERIC Educational Resources Information Center

    Moaveni, Saeed; Chou, Karen C.

    2015-01-01

    Steel connections play important roles in the integrity of a structure, and many structural failures are attributed to connection failures. Connections are the glue that holds a structure together. The failures of the Hartford Coliseum in 1977, the Hyatt Regency Hotel in Kansas City in 1980, and the I-35W Bridge in Minneapolis in 2007 are all…

  15. Superhard Nanocrystalline Homometallic Stainless Steel on Steel for Seamless Coatings

    NASA Technical Reports Server (NTRS)

    Tobin, Eric J.; Hafley, R. (Technical Monitor)

    2002-01-01

    The objective of this work is to deposit nanocrystalline stainless steel onto steel substrates (homometallic) for enhanced wear and corrosion resistance. Homometallic coatings provide superior adhesion, and it has been shown that ultrafine-grained materials exhibit the increased hardness and decreased permeability desired for protective coatings. Nanocrystals will be produced by controlling nucleation and growth and use of an ion beam during deposition by e-beam evaporation or sputtering. Phase I is depositing 31 6L nanocrystalline stainless steel onto 31 6L stainless steel substrates. These coatings exhibit hardnesses comparable to those normally obtained for ceramic coatings such ZrO2, and possess the superior adhesion of seamless, homometallic coatings. Hardening the surface with a similar material also enhances adhesion, by avoiding problems associated with thermal and lattice mismatch. So far we have deposited nanocrystalline homometallic 316L stainless steel coatings by varying the ions and the current density of the ion beams. For all deposition conditions we have produced smooth, uniform, superhard coatings. All coatings exhibit hardness of at least 200% harder than that of bulk materials. Our measurements indicate that there is a direct relationship between nanohardness and the current density of the ion beam. Stress measurements indicate that stress in the films is increasingly proportional to current density of the ion beam. TEM, XPS, and XRD results indicate that the coated layers consist of FCC structure nanocrystallites with a dimension of about 10 to 20 nm. The Ni and Mo concentration of these coating are lower than those of bulk 316L but the concentration of Cr is higher.

  16. Bearing steels in the 21. century

    SciTech Connect

    Tsubota, Kazuichi; Sato, Toshio; Kato, Yoshiyuki; Hiraoka, Kazuhiko; Hayashi, Ryoji

    1998-12-31

    Oxygen content of bearing steel will be reduced to below 3 ppm in the year 2000 if the current trend for the reduction of oxygen in the steel continues. As a result, size of oxide inclusions will become smaller and the fatigue life will be doubled. From the viewpoint of life prediction, cleanliness evaluation methods currently used are not effective. Inclusion Rating Method by Statistics of Extreme is useful for both cleanliness evaluation and fatigue life prediction. Bearings made of suitably heat treated carbon steels or low alloy steels, which possess equivalent fatigue properties to bearing steels, will increase owing to the requirement for lower cost and better formability.

  17. Reduced-activation steels: Future development for improved creep strength

    NASA Astrophysics Data System (ADS)

    Klueh, R. L.

    2008-08-01

    Reduced-activation steels for fusion applications were developed in the 1980s to replace the elevated-temperature commercial steels first considered. The new steels were patterned after the commercial steels, with the objective that the new steels have yield stress and ultimate tensile strength and impact toughness in a Charpy test comparable to or better than the steels they replaced. That objective was achieved in reduced-activation steels developed in Japan, Europe, and the United States. Although tensile and impact toughness of the reduced-activation steels exceed those of the commercial steels they were patterned after, their creep-rupture properties are inferior to some commercial steels they replaced. They are even more inferior to commercial steels developed since the 1980s. In this paper, compositional differences between reduced-activation steels and new commercial steels are examined, and compositions are proposed for development of new-and-improved reduced-activation steels.

  18. Precision machining of steel decahedrons

    NASA Technical Reports Server (NTRS)

    Abernathy, W. J.; Sealy, J. R.

    1972-01-01

    Production of highly accurate decahedron prisms from hardened stainless steel is discussed. Prism is used to check angular alignment of mounting pads of strapdown inertial guidance system. Accuracies obtainable using recommended process and details of operation are described. Photographic illustration of production device is included.

  19. STEFINS: a steel freezing integral simulation program

    SciTech Connect

    Frank, M.V.

    1980-09-01

    STEFINS (STEel Freezing INtegral Simulation) is a computer program for the calculation of the rate of solidification of molten steel on solid steel. Such computations arize when investigating core melt accidents in fast reactors. In principle this problem involves a coupled two-dimensional thermal and hydraulic approach. However, by physically reasonable assumptions a decoupled approach has been developed. The transient solidification of molten steel on a cold wall is solved in the direction normal to the molten steel flow and independent from the solution for the molten steel temperature and Nusselt number along the direction of flow. The solutions to the applicable energy equations have been programmed in cylindrical and slab geometries. Internal gamma heating of steel is included.

  20. Dendritic inhomogeneity of stainless maraging steels

    SciTech Connect

    Krasnikova, S.I.; Drobot, A.V.; Shmelev, A.Y.; Vukelich, S.B.

    1986-03-01

    The authors investigated dendritic inhomogeneity in industrial ingots 630 mm (steel I) in diameter and 500 mm (steel II) in diameter. The variation in the degree of dendritic inhomogeneity was investigated over the height of the ingots and across the sections on an MS-46 microprobe. It was established that the elements can be placed in the following order in accordance with the degree of reduction in the liquation factor: titanium, molybdenum, nickel, chromium, and cobalt. Titanium and molybdenum exhibit forward liquation in both steels, and chromium in steel II. The distribution of nickel and chromium in the steel I ingots and cobalt in the steel II ingots is unconventional. Dendritic inhomogeneity, which must be considered in assigning the heat treatment for finished articles, develops during the crystallization of stainless maraging steels.

  1. Thermal Linear Expansion of Nine Selected AISI Stainless Steels

    DTIC Science & Technology

    1978-04-01

    stainless steels. The nine selected stainless steels are AISI 303, 304, 304L, 316, 317, 321, 347, 410 , and 430. The recoended values Include the...point of the stainless steels. The nine selected stainless steels are AISI 303, 304, 304L, 316, 317, 321, 347, 410 , and 430. The recommended values...Stainless Steel..................................26 8. AISI 410 Stainless Steel..................................29 9. AISI 430 Stainless Steel

  2. Comparative Structural Strength Research of Hardened Carbon Steel and Hot-Rolled Alloy Steel

    NASA Astrophysics Data System (ADS)

    Bogomolov, A. V.; Zhakupov, A. N.; Kanayev, A. T.; Sikach, I. A.; Tugumov, K. K.

    2016-08-01

    Experiments on quantitative evaluation of fatigue strength showed that St5ps and St5sp carbon steels with A400 strength class can be fully applied for erection of constructions and buildings having cyclical loads during operation. Study of corrosion resistance of hardened carbon steel in comparison with hot-rolled alloy steel consists in difference in structures and hence, difference in intensity of electric and chemical processes featuring presence of steel in concrete. Structure of St5sp steel with A400 strength class in surface area has significantly less corrosion rate than ferritic-perlitic structure of 35GS steel with A400 strength class.

  3. [Radioactivity monitoring of steel processing in Croatian steel mills and foundries].

    PubMed

    Sofilić, Tahir; Marjanović, Tihana; Rastovcan-Mioc, Alenka

    2006-03-01

    The last twenty years have seen a number of cases of radioactive pollution in metallurgical industry. Therefore many metal producers have implemented systematic monitoring of radioactivity in their production processes, especially in steel processing, steel being the most applied construction material with the annual world output of over billion tonnes. Learning from the experience of the best known steel producers in Europe and the world Croatian steel mills have introduced radioactivity surveillance and control systems for radioactive elements in steel scrap, semi-finished and finished products. This paper argues in favour of radioactivity surveillance and control systems in steel and steel castings production in Croatia, and describes current systems and solutions available. Since we lack our own standards and regulations to control both domestic and imported steel scrap, semi-finished products (crude steel, hot and cold rolled strip) and finished products, we need to start implementing radioactivity surveillance and control systems in our steel and steel castings production applying the current international recommendations and guidelines, until we build up our own monitoring system and adopt legislation on the national level. This paper gives an overview of the basic types of radioactivity surveillance and control systems, the most frequent requirements to be met, as well as of the measurement and information flow in their application in steel and steel castings production.

  4. Microstructure and Mechanical Properties of HSLA-100 Steel

    DTIC Science & Technology

    1990-12-01

    13 Figure 4. High Strength Bainite Strength Components .................... 20 Figure 5. Bainitic Steel Tempering and DBTT ...21 Figure 6. Tempered Bainite Steel Yield Stress and DBTT .................. 21 Figure 7. HSLA-100 Steel Yield Strength versus Aging...Energy at -84°C ............... 31 Figure 14. HSLA-100 Steel Lot GQH DBTT ............................ 31 Figure 15. HSLA-100 Steel Lot GQH Ductility

  5. Bond characteristics of steel fiber and deformed reinforcing steel bar embedded in steel fiber reinforced self-compacting concrete (SFRSCC)

    NASA Astrophysics Data System (ADS)

    Aslani, Farhad; Nejadi, Shami

    2012-09-01

    Steel fiber reinforced self-compacting concrete (SFRSCC) is a relatively new composite material which congregates the benefits of the self-compacting concrete (SCC) technology with the profits derived from the fiber addition to a brittle cementitious matrix. Steel fibers improve many of the properties of SCC elements including tensile strength, ductility, toughness, energy absorption capacity, fracture toughness and cracking. Although the available research regarding the influence of steel fibers on the properties of SFRSCC is limited, this paper investigates the bond characteristics between steel fiber and SCC firstly. Based on the available experimental results, the current analytical steel fiber pullout model (Dubey 1999) is modified by considering the different SCC properties and different fiber types (smooth, hooked) and inclination. In order to take into account the effect of fiber inclination in the pullout model, apparent shear strengths (τ (app)) and slip coefficient (β) are incorporated to express the variation of pullout peak load and the augmentation of peak slip as the inclined angle increases. These variables are expressed as functions of the inclined angle (ϕ). Furthurmore, steel-concrete composite floors, reinforced concrete floors supported by columns or walls and floors on an elastic foundations belong to the category of structural elements in which the conventional steel reinforcement can be partially replaced by the use of steel fibers. When discussing deformation capacity of structural elements or civil engineering structures manufactured using SFRSCC, one must be able to describe thoroughly both the behavior of the concrete matrix reinforced with steel fibers and the interaction between this composite matrix and discrete steel reinforcement of the conventional type. However, even though the knowledge on bond behavior is essential for evaluating the overall behavior of structural components containing reinforcement and steel fibers

  6. Bond characteristics of steel fiber and deformed reinforcing steel bar embedded in steel fiber reinforced self-compacting concrete (SFRSCC)

    NASA Astrophysics Data System (ADS)

    Aslani, Farhad; Nejadi, Shami

    2012-09-01

    Steel fiber reinforced self-compacting concrete (SFRSCC) is a relatively new composite material which congregates the benefits of the self-compacting concrete (SCC) technology with the profits derived from the fiber addition to a brittle cementitious matrix. Steel fibers improve many of the properties of SCC elements including tensile strength, ductility, toughness, energy absorption capacity, fracture toughness and cracking. Although the available research regarding the influence of steel fibers on the properties of SFRSCC is limited, this paper investigates the bond characteristics between steel fiber and SCC firstly. Based on the available experimental results, the current analytical steel fiber pullout model (Dubey 1999) is modified by considering the different SCC properties and different fiber types (smooth, hooked) and inclination. In order to take into account the effect of fiber inclination in the pullout model, apparent shear strengths ( τ ( app)) and slip coefficient ( β) are incorporated to express the variation of pullout peak load and the augmentation of peak slip as the inclined angle increases. These variables are expressed as functions of the inclined angle ( ϕ). Furthurmore, steel-concrete composite floors, reinforced concrete floors supported by columns or walls and floors on an elastic foundations belong to the category of structural elements in which the conventional steel reinforcement can be partially replaced by the use of steel fibers. When discussing deformation capacity of structural elements or civil engineering structures manufactured using SFRSCC, one must be able to describe thoroughly both the behavior of the concrete matrix reinforced with steel fibers and the interaction between this composite matrix and discrete steel reinforcement of the conventional type. However, even though the knowledge on bond behavior is essential for evaluating the overall behavior of structural components containing reinforcement and steel fibers

  7. A mortality study among mild steel and stainless steel welders.

    PubMed Central

    Moulin, J J; Wild, P; Haguenoer, J M; Faucon, D; De Gaudemaris, R; Mur, J M; Mereau, M; Gary, Y; Toamain, J P; Birembaut, Y

    1993-01-01

    A mortality study was carried out in conjunction with the European mortality study among welders coordinated by the International Agency for Research on Cancer (IARC). The study was aimed at assessing risks for lung cancer in relation to exposure to asbestos, welding fumes containing chromium and nickel, and tobacco smoke. The study included a cohort of 2721 welders and an internal comparison group of 6683 manual workers employed in 13 factories in France. The mortality of the two cohorts was studied from 1975 to 1988 by the historical prospective method. Job histories of welders were traced including welding processes used, metals welded, and proportion of worktime spent in welding. Data on smoking habits were collected from medical records. The observed number of deaths were compared with those expected (standardised mortality ratio (SMR)) based on national rates with adjustments for age, sex, and calendar time. The smoking habits of 87% of the whole study population were known. The distribution of welders and controls according to smoking was not statistically different. The overall mortality was slightly higher for welders (SMR = 1.02, 95% confidence interval (95% CI) 0.89-1.18) than for controls (SMR = 0.91, 95% CI 0.84-0.99). For lung cancer, the SMR was 1.24 (95% CI 0.75-1.94) for welders, whereas the corresponding value was lower for controls (SMR = 0.94, 95% CI 0.68-1.26). The SMR for lung cancer was 1.59 among non-shipyard mild steel welders (95% CI 0.73-3.02). This contrasted with the results for all stainless steel welders (SMR = 0.92, 95% CI 0.19-2.69), and for stainless steel welders predominantly exposed to chromium VI (SMR = 1.03, 95% CI 0.12-3.71). Moreover, SMRs for lung cancer for mild steel welders tended to increase with duration of exposure and time since first exposure, leading to significant excesses for duration > or = 20 years and latency > or = 20 years. Such a pattern was not found for stainless steel welders. PMID:8457490

  8. Niobium in Microalloyed Rail Steels

    NASA Astrophysics Data System (ADS)

    Ray, A.; Bhadeshia, H. K. D. H.

    Rails generally do not have a homogeneous austenite grain structure across their sections because the degree of plastic strain achieved during hot-rolling depends on location. Here we explore a philosophy in which niobium microalloying may be introduced in order to thermomechanically process the material so that pancaked and refined austenite grains may eventually be achieved in the critical regions of the rail. The essential principle in alloy design involves the avoidance of coarse niobium carbide precipitates in the regions of the steel that contain chemical segregation caused by non-equilibrium solidification. Both pearlitic and cementite-free bainitic rails have been studied. The work is of generic value to the design of high-carbon microalloyed steels.

  9. Longer Life for Steel Structures

    NASA Technical Reports Server (NTRS)

    1990-01-01

    IC 531 is a coating manufactured and marketed by Inorganic Coatings, Inc. The coating was developed by Goddard to protect structures at Kennedy Space Center. It is a high ratio potassium silicate formula. The coating is water based, nontoxic, and nonflammable. It generates no volatile organic compounds nor hazardous chemical waste, and bonds to steel in 30 minutes. At the present time, no one can say for sure how long IC 531's effective lifetime is. Some of the original Goddard test applications of 1976 are still going strong after lengthy exposure to the Sun, salt and moisture. Says IC in company literature: 'IC 531 offers virtually permanent protection for steel. We predict it will protect structures for well beyond 25 years. If necessary, it is infinitely maintainable; if damaged, it can easily be touched up with more IC 531.'

  10. Light microscopy of carbon steels

    SciTech Connect

    Samuels, L.E.

    1998-12-31

    Containing over 1,200 representative micrographs and the information and explanatory text that makes them really useful: composition, condition, etchant, and magnification, and more than 100 graphs and tables, this how to book not only gives everyday working examples, but also discusses the relationship between the constitution, metallurgy, and microstructure of various carbon steel products. Written by a renowned expert in metallography, this definitive work is a must for all those working in this area. Contents include: nomenclature of phases and constituents; phase transformations; low-carbon irons and steels; annealing and normalizing; spheroidization and graphitization; austenitization; transformation of austenite; tempering of martensite; welding; surface oxidation, decarburation; and oxidation scaling; glossary of terms; etching methods; conversion tables.

  11. Underwater wet welding of steel

    SciTech Connect

    Ibarra, S.; Liu, S.; Olson, D.L.

    1995-05-01

    Underwater wet welding is conducted directly in water with the shielded metal arc (SMA) and flux cored arc (FCA) welding processes. Underwater wet welding has been demonstrated as an acceptable repair technique down to 100 meters (325 ft.) in depth, but wet welds have been attempted on carbon steel structures down to 200 meters (650 ft.). The primary purpose of this interpretive report is to document and evaluate current understanding of metallurgical behavior of underwater wet welds so that new welding consumables can be designed and new welding practices can be developed for fabrication and repair of high strength steel structures at greater depths. First the pyrometallurgical and physical metallurgy behaviors of underwater weldments are discussed. Second, modifications of the welding consumables and processes are suggested to enhance the ability to apply wet welding techniques.

  12. Steel Industry Energy Bandwidth Study

    SciTech Connect

    none,

    2004-10-01

    ITP conducted a study on energy use and potential savings, or "bandwidth" study, in major steelmaking processes. Intended to provide a realistic estimate of the potential amount of energy that can be saved in an industrial process, the "bandwidth" refers to the difference between the amount of energy that would be consumed in a process using commercially available technology versus the minimum amount of energy needed to achieve those same results based on the 2nd law of thermodynamics. The Steel Industry Energy Bandwidth Study (PDF 133 KB) also estimates steel industry energy use in the year 2010, and uses that value as a basis for comparison against the minimum requirements. This energy savings opportunity for 2010 will aid focus on longer term R&D.

  13. Existing Steel Railway Bridges Evaluation

    NASA Astrophysics Data System (ADS)

    Vičan, Josef; Gocál, Jozef; Odrobiňák, Jaroslav; Koteš, Peter

    2016-12-01

    The article describes general principles and basis of evaluation of existing railway bridges based on the concept of load-carrying capacity determination. Compared to the design of a new bridge, the modified reliability level for existing bridges evaluation should be considered due to implementation of the additional data related to bridge condition and behaviour obtained from regular inspections. Based on those data respecting the bridge remaining lifetime, a modification of partial safety factors for actions and materials could be respected in the bridge evaluation process. A great attention is also paid to the specific problems of determination of load-caring capacity of steel railway bridges in service. Recommendation for global analysis and methodology for existing steel bridge superstructure load-carrying capacity determination are described too.

  14. Welding of high chromium steels

    NASA Technical Reports Server (NTRS)

    Miller, W B

    1928-01-01

    A brief description is given of different groups of high chromium steels (rustless iron and stainless steels) according to their composition and more generally accepted names. The welding procedure for a given group will be much the same regardless of the slight variations in chemical composition which may exist within a certain group. Information is given for the tensile properties (yield point and ultimate strength) of metal sheets and welds before and after annealing on coupons one and one-half inches wide. Since welds in rustless iron containing 16 to 18 percent chromium and 7 to 12 percent nickel show the best combination of strength and ductility in the 'as welded' or annealed condition, it is considered the best alloy to use for welded construction.

  15. Nano-composite stainless steel

    DOEpatents

    Dehoff, Ryan R.; Blue, Craig A.; Peter, William H.; Chen, Wei; Aprigliano, Louis F.

    2015-07-14

    A composite stainless steel composition is composed essentially of, in terms of wt. % ranges: 25 to 28 Cr; 11 to 13 Ni; 7 to 8 W; 3.5 to 4 Mo; 3 to 3.5 B; 2 to 2.5 Mn; 1 to 1.5 Si; 0.3 to 1.7 C; up to 2 O; balance Fe. The composition has an austenitic matrix phase and a particulate, crystalline dispersed phase.

  16. Steel Industry Marginal Opportunity Analysis

    SciTech Connect

    none,

    2005-09-01

    The Steel Industry Marginal Opportunity Analysis (PDF 347 KB) identifies opportunities for developing advanced technologies and estimates both the necessary funding and the potential payoff. This analysis determines what portion of the energy bandwidth can be captured through the adoption of state-of-the-art technology and practices. R&D opportunities for addressing the remainder of the bandwidth are characterized and plotted on a marginal opportunity curve.

  17. Powder Processing of Trip Steel

    DTIC Science & Technology

    1977-04-01

    60, 1967, p. 252-259. 2. AZRIN, M ., OLSON, G. B., and GAGNE, R. A. Inhomogeneous Deformation and Strain-Rate Effects in High-Strength TRIP Steels...Mat. Sci. Eng., v. 23, May 1976, p. 33^1. 3. ANTOLOVICH , S. D., and SINGH, B. On the Toughness Increment Associated with the Austenite to Martensite...1 ATTN: SCCR-2 Naval Research Laboratory, Washington, D. C. 20375 1 ATTN: Dr. J. M . Krafft - Code 8430 Chief of Naval Research, Arlington

  18. A study of Damascus steel

    SciTech Connect

    Berge, P.

    1995-02-16

    The Damascus sword has been an article of fascination for many years to blade collectors and metallurgists alike. The blades were given their name by Europeans who encountered these blades which originated from Damascus, Syria. They are best known for the appearance of the blade face. Genuine Damascus blades show swirling patterns of alternating light and dark regions which are due to the microstructure of the steel. The microstructure consists of arrays of well rounded cementite patterns in a matrix of either pearlite, bainite, or martensite. When this structure is etched the matrix will turn dark leaving the cementite particles light. Although many blades were produced over the centuries, while some of the process is known the making of a genuine Damascus blade today is generally considered a lost art. Many scientists have studied the subject in an attempt to understand the complex process by which the clustered arrays of cementite particles develop in the steel blades. The most prominent theories to date are presented in the General Introduction to this thesis. The thesis is divided into four main parts. In the first part, four proposed mechanisms of cementite cluster sheet formation as they relate to the banding theory are introduced. Experiments to investigate these mechanisms are presented. In Part II, collaborative research focused on the methodology of the reconstructed process for making Damascus steel is presented. In the third part, a study into the graphitization of the reconstructed blades is presented. In Part IV, experimental attempts at producing Damascus steel ingots in the laboratory are presented.

  19. Preparation and characterization of 304 stainless steel/Q235 carbon steel composite material

    NASA Astrophysics Data System (ADS)

    Shen, Wenning; Feng, Lajun; Feng, Hui; Cao, Ying; Liu, Lei; Cao, Mo; Ge, Yanfeng

    The composite material of 304 stainless steel reinforced Q235 carbon steel has been prepared by modified hot-rolling process. The resulted material was characterized by scanning electron microscope, three-electrode method, fault current impact method, electrochemical potentiodynamic polarization curve measurement and electrochemical impedance spectroscopy. The results showed that metallurgical bond between the stainless steel layer and carbon steel substrate has been formed. The composite material exhibited good electrical conductivity and thermal stability. The average grounding resistance of the composite material was about 13/20 of dip galvanized steel. There has no surface crack and bubbling formed after fault current impact. The composite material led to a significant decrease in the corrosion current density in soil solution, compared with that of hot dip galvanized steel and bare carbon steel. On the basis polarization curve and EIS analyses, it can be concluded that the composite material showed improved anti-corrosion property than hot-dip galvanized steel.

  20. 77 FR 67400 - RG Steel Wheeling, LLC, a Division of RG Steel, LLC, Doing Business as Wheeling Corrugating...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-09

    ... Employment and Training Administration RG Steel Wheeling, LLC, a Division of RG Steel, LLC, Doing Business as..., 2012, applicable to workers of RG Steel Wheeling, LLC, a division of RG Steel, LLC, doing business as... RG Steel, LLC, doing business as Wheeling Corrugating Company, Beech Bottom, West Virginia,...

  1. Nickel: makes stainless steel strong

    USGS Publications Warehouse

    Boland, Maeve A.

    2012-01-01

    Nickel is a silvery-white metal that is used mainly to make stainless steel and other alloys stronger and better able to withstand extreme temperatures and corrosive environments. Nickel was first identified as a unique element in 1751 by Baron Axel Fredrik Cronstedt, a Swedish mineralogist and chemist. He originally called the element kupfernickel because it was found in rock that looked like copper (kupfer) ore and because miners thought that "bad spirits" (nickel) in the rock were making it difficult for them to extract copper from it. Approximately 80 percent of the primary (not recycled) nickel consumed in the United States in 2011 was used in alloys, such as stainless steel and superalloys. Because nickel increases an alloy's resistance to corrosion and its ability to withstand extreme temperatures, equipment and parts made of nickel-bearing alloys are often used in harsh environments, such as those in chemical plants, petroleum refineries, jet engines, power generation facilities, and offshore installations. Medical equipment, cookware, and cutlery are often made of stainless steel because it is easy to clean and sterilize. All U.S. circulating coins except the penny are made of alloys that contain nickel. Nickel alloys are increasingly being used in making rechargeable batteries for portable computers, power tools, and hybrid and electric vehicles. Nickel is also plated onto such items as bathroom fixtures to reduce corrosion and provide an attractive finish.

  2. Utilization of structural steel in buildings.

    PubMed

    Moynihan, Muiris C; Allwood, Julian M

    2014-08-08

    Over one-quarter of steel produced annually is used in the construction of buildings. Making this steel causes carbon dioxide emissions, which climate change experts recommend be reduced by half in the next 37 years. One option to achieve this is to design and build more efficiently, still delivering the same service from buildings but using less steel to do so. To estimate how much steel could be saved from this option, 23 steel-framed building designs are studied, sourced from leading UK engineering firms. The utilization of each beam is found and buildings are analysed to find patterns. The results for over 10 000 beams show that average utilization is below 50% of their capacity. The primary reason for this low value is 'rationalization'-providing extra material to reduce labour costs. By designing for minimum material rather than minimum cost, steel use in buildings could be drastically reduced, leading to an equivalent reduction in 'embodied' carbon emissions.

  3. RESIDUAL STRESS IN HARDENED STEEL CYLINDERS

    DTIC Science & Technology

    ultimate strength of the steel and in some instances caused cracking, and (4) stress patterns of interrupted quench specimens were not consistent enough to warrant a conclusion. (Author)...A study was conducted to (1) measure residual stress in hardened steel solid cylinders, (2) correlate the stress values with heat treatments, and (3...develop a dissolution technique. Residual stress patterns for 12 solid cylinders of 4160 steel, heat treated by various methods, were determined

  4. Cadmium Alternatives for High-Strength Steel

    DTIC Science & Technology

    2011-09-22

    FINAL REPORT Cadmium Alternatives for High-Strength Steel WP-200022 Steven A. Brown Naval Air Warfare Center Aircraft Division Patuxent...ESTCP WP-0022 Final Report “Cadmium Alternatives for High-Strength Steel ” 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Steven...SUPPLEMENTARY NOTES 14. ABSTRACT Testing was conducted for cadmium alternative coating systems IAW the “High Strength Steel Joint Test Protocol for

  5. Evaluation of the Benefits of HSLA Steels

    DTIC Science & Technology

    1989-03-01

    quenched and tempered steels , such as HY80 and HY1OO, require preheat and interpass temperature controls during welding of plates thicker than 1/2 inch...interpass tempera- tures and heat input limitations. Strict adherence to these requirements is mandatory to avoid cracking in hydrogen- sensitive steels ...requirement and excellent weldability of this steel will probably lower produc- tion costs and cracking -related repairs enough to overcome the slight

  6. Solidification Based Grain Refinement in Steels

    DTIC Science & Technology

    2011-09-27

    Please complete the Award Information section below so that technical information can be related to a specific award. Please save the file using the...Technology, Vol. 21, No. 3, pp. 325-333, 2005. 4. Peter. J., Peaslee, K. D.. and Panda , D. "Thermomechanical processing of HSLA wide-flange steel beams...niobium precipitates in HSLA steel". Steel Research International, Vol. 75, No. 1 Lpp. 753-758. 2004. 20. Peter, Joerg; Peaslee, Kent D.; Panda Dhiren

  7. Recycling steel. Conducting a waste audit.

    PubMed

    Crawford, G

    1996-01-01

    This is the second in a series of three articles regarding steel can recycling from foodservice operations of healthcare facilities. This article highlights the basic methods of recycling steel cans, and includes information on conducting a waste audit and negotiating with a hauler regarding the benefits of recycling. The previous article discussed how steel is recycled across the country. The next article will convey a case history of actual foodservice recycling practice from a healthcare facility.

  8. Nonmetallic Inclusions in HSLA Steel Weldments

    DTIC Science & Technology

    1989-12-01

    lowering the DBTT . Nickel prevents the hot shortness phenomenon often observed in copper-bearing steels . Nickel is also an austenite stabilizer. By lowering... STEEL WELDMENTS by Brent A. Douglas December, 1989 Thesis Advisor Alan G. Fox Approved for public release; distribution is unlimited. 90 ,-. S...ACCESSION NO. II. TITLE (Incude Security Claw fication) Nonmetallic Inclusions In HSLA Steel Weldments IZ. PERSONAL AUTHOR(S) Douglas, Brent A. 138

  9. Bending Properties of Al-Steel and Steel-Steel Composite Metal Foams

    NASA Astrophysics Data System (ADS)

    Brown, Judith A.; Vendra, Lakshmi J.; Rabiei, Afsaneh

    2010-11-01

    The performance of new composite metal foams (CMFs) under bending was evaluated with simultaneous acoustic emission (AE) monitoring on samples processed by cast and powder metallurgy (PM) techniques. The results showed high maximum strength in all samples up to 86 MPa with more ductile failure in PM samples. Acoustic emission behavior confirmed that the dominating failure mechanism of cast CMF is the brittle fracture of intermetallic phases that mostly exist at the interface of the steel spheres with the aluminum matrix, whereas in PM samples (100 pct steel), the failure is governed by the propagation of preexisting microporosities in the matrix resulting in a complete ductile failure. SEM imaging of the fracture surfaces supported these findings.

  10. The Structure and Mechanical Properties of Bridge Steel Weldings With Glass-Steel Liners

    NASA Astrophysics Data System (ADS)

    Muzalev, V. N.; Semukhin, B. S.; Danilov, V. I.

    2016-04-01

    A new technology is developed for welding multi-span bridge constructions. The mechanical properties and structure of the low-carbon bridge steel welds have been studied. The welding parameters and application of steel-glass liners provide for long-term service of steel constructions in conformity with the welding industry specifications.

  11. Corrosion of stainless steel, 2. edition

    SciTech Connect

    Sedriks, A.J.

    1996-10-01

    The book describes corrosion characteristics in all the major and minor groups of stainless steels, namely, in austenitic, ferritic, martensitic, duplex, and precipitation hardenable steels. Several chapters are spent on those special forms of corrosion that are investigated in the great detail in stainless steels, namely, pitting corrosion, crevice corrosion, and stress corrosion cracking. The influences of thermal treatment (heat affected zone cases), composition, and microstructure on corrosion are given good coverage. Corrosive environments include high temperature oxidation, sulfidation as well as acids, alkalis, various different petroleum plant environments, and even human body fluids (stainless steels are commonly used prosthetic materials).

  12. Recycling steel automatically -- through resource recovery

    SciTech Connect

    Crawford, G.L.

    1996-12-31

    More than three-fourths of the operating resource recovery plants magnetically separate steel cans and other discarded steel items either pre- or post-combustion. This last year, 121 resource recovery facilities combusted about 14% of the solid waste for communities across the US. Automatic recycling of steel clearly reduces the post-combustion material that is landfilled and heightens the facilities environmental performance through tangible recycling achievement. Even though about one out of every six steel cans is recycled automatically through resource recovery, not many people are aware of automatic recycling of steel cans through resource recovery. How many people know that their local resource recovery plant is insuring that virtually all of their food, beverage and general purpose cans--including paint and aerosol--are being recycled so easily and efficiently? Magnetic separation at resource recovery facilities is a fundamentally simple and desirable method of diverting what would otherwise be relegated as solid waste to the landfill. It should be recognized as an increasingly important and valued part of the resource recovery and steel industries overall recycling efforts. This paper will provide the latest information on steel recycled automatically from resource recovery facilities within the total context of all recycling accomplished annually by the steel industry. Most important, recommendations are provided for building public awareness of the automatic steel recycling contribution made so solidly by resource recovery facilities.

  13. Modified 43XX Steels for High Toughness

    DTIC Science & Technology

    1980-04-01

    AL AMMRC TR 80-20 MODIFIED 43XX STEELS FOR HIGH TOUGHNESS T CS.,•, °x ,•, o o,,o,,,sD T I W4 AftELECTE APRIL 1980 J N.J. Kar, V.F. Zackay and E.R...carried out. Isohra tasomions in these steels resulted inn bbaainni 11-v DI FOR Z 47 RITIOW OF I NOV695 IS OBSOLETE UCASFE SECURITY UCLASSIFIEDINOFTI PAGE...this investigation for Si-modified AISI 4330 steel appear to be superior to those for unmodified AISI 4340 and 300-M steels , whilst the strength-tough

  14. 30. Photocopy of photograph. STEEL PLANT, OPEN HEARTH FURNACE CHARGING ...

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

    30. Photocopy of photograph. STEEL PLANT, OPEN HEARTH FURNACE CHARGING CREW, 1910. (From the Bethlehem Steel Corporation Colletion, Seattle, WA) - Irondale Iron & Steel Plant, Port Townsend, Jefferson County, WA

  15. 37. Photocopy of photograph. STEEL PLANT, OPEN HOUSE INSIDE PLANT ...

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

    37. Photocopy of photograph. STEEL PLANT, OPEN HOUSE INSIDE PLANT AT TIME OF ITS OPENING, 1910. (From the Bethlehem Steel Corporation Collection, Seattle, WA) - Irondale Iron & Steel Plant, Port Townsend, Jefferson County, WA

  16. North and west facades of crucible steel building; looking southeast ...

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

    North and west facades of crucible steel building; looking southeast - Bethlehem Steel Corporation, South Bethlehem Works, Crucible Steel Plant, Along Lehigh River, North of Fourth Street, West of Minsi Trail Bridge, Bethlehem, Northampton County, PA

  17. FINAL REPORT: Reduction in Energy Consumption and Variability in Steel Foundry Operations

    SciTech Connect

    F. Peters

    2005-05-24

    This project worked to improve the efficiency of the steel casting industry by reducing the variability that occurs because of process and product variation. The project focused on the post shakeout operations since roughly half of the production costs are in this area. These improvements will reduce the amount of variability, making it easier to manage the operation and improve the competitiveness. The reduction in variability will also reduce the need for many rework operations, which will result in a direct reduction of energy usage, particularly by the reduction of repeated heat treatment operations. Further energy savings will be realized from the reduction of scrap and reduced handling. Field studies were conducted at ten steel foundries that represented the U.S. steel casting industry, for a total of over 100 weeks of production observation. These studies quantified the amount of variability, and looked toward determining the source. A focus of the data collected was the grinding operations since this is a major effort in the cleaning room, and it represents the overall casting quality. The grinding was divided into two categories, expected and unexpected. Expected grinding is that in which the location of the effort is known prior to making the casting, such as smoothing parting lines, gates, and riser contacts. Unexpected grinding, which was approximately 80% of the effort, was done to improve the surfaces at weld repair locations, to rectify burnt on sand, and other surface anomalies at random locations. Unexpected grinding represents about 80% of the grinding effort. By quantifying this effort, the project raised awareness within the industry and the industry is continuing to make improvements. The field studies showed that the amount of variation of grinding operations (normalized because of the diverse set of parts studied) was very consistent across the industry. The field studies identified several specific sources that individually contributed to

  18. Steel shear walls, behavior, modeling and design

    SciTech Connect

    Astaneh-Asl, Abolhassan

    2008-07-08

    In recent years steel shear walls have become one of the more efficient lateral load resisting systems in tall buildings. The basic steel shear wall system consists of a steel plate welded to boundary steel columns and boundary steel beams. In some cases the boundary columns have been concrete-filled steel tubes. Seismic behavior of steel shear wall systems during actual earthquakes and based on laboratory cyclic tests indicates that the systems are quite ductile and can be designed in an economical way to have sufficient stiffness, strength, ductility and energy dissipation capacity to resist seismic effects of strong earthquakes. This paper, after summarizing the past research, presents the results of two tests of an innovative steel shear wall system where the boundary elements are concrete-filled tubes. Then, a review of currently available analytical models of steel shear walls is provided with a discussion of capabilities and limitations of each model. We have observed that the tension only 'strip model', forming the basis of the current AISC seismic design provisions for steel shear walls, is not capable of predicting the behavior of steel shear walls with length-to-thickness ratio less than about 600 which is the range most common in buildings. The main reasons for such shortcomings of the AISC seismic design provisions for steel shear walls is that it ignores the compression field in the shear walls, which can be significant in typical shear walls. The AISC method also is not capable of incorporating stresses in the shear wall due to overturning moments. A more rational seismic design procedure for design of shear walls proposed in 2000 by the author is summarized in the paper. The design method, based on procedures used for design of steel plate girders, takes into account both tension and compression stress fields and is applicable to all values of length-to-thickness ratios of steel shear walls. The method is also capable of including the effect of

  19. Controlling DC permeability in cast steels

    NASA Astrophysics Data System (ADS)

    Sumner, Aaran; Gerada, Chris; Brown, Neil; Clare, Adam

    2017-05-01

    Annealing (at multiple cooling rates) and quenching (with tempering) was performed on specimens of cast steel of varying composition. The aim was to devise a method for selecting the steel with the highest permeability, from any given range of steels, and then increasing the permeability by heat treatment. Metallographic samples were imaged using optical microscopy to show the effect of the applied heat treatments on the microstructure. Commonly cast steels can have DC permeability altered by the careful selection of a heat treatment. Increases of up to 381% were achieved by annealing using a cooling rate of 6.0 °C/min. Annealing was found to cause the carbon present in the steel to migrate from grain boundaries and from within ferrite crystals into adjacent pearlite crystals. The migration of the carbon resulted in less carbon at grain boundaries and within ferrite crystals reducing the number of pinning sites between magnetic domains. This gives rise to a higher permeability. Quenching then tempering was found to cause the formation of small ferrite crystals with the carbon content of the steel predominately held in the martensitic crystal structures. The results show that with any given range of steel compositions the highest baseline DC permeability will be found with the steel that has the highest iron content and the lowest carbon content. For the samples tested in this paper a cooling rate of 4.5 °C/min resulted in the relative permeability of the sample with the highest baseline permeability, AS4, increasing from 783 to 1479 at 0.5 T. This paper shows how heat treatments commonly applied to hypoeutectoid cast steels, to improve their mechanical performance, can be used to also enhance electromagnetic properties of these alloys. The use of cast steels allows the creation of DC components for electrical machines not possible by the widely used method of stacking of electrical grade sheet steels.

  20. Corrosion Behavior of IF Steel in Various Media and Its Comparison with Mild Steel

    NASA Astrophysics Data System (ADS)

    Singh, G. P.; Moon, A. P.; Sengupta, S.; Deo, G.; Sangal, S.; Mondal, K.

    2015-05-01

    The present work discusses corrosion behavior of an interstitial-free (IF) steel in 0.6 M NaCl, 1 M NaOH, and 1 M HCl solutions, and its comparison with mild steel (MS). Dynamics polarization and AC Impedance Spectroscopy explain different polarization behaviors of the steel samples. All the steels were exposed to open atmosphere for 100 days, and to 0.6 M NaCl salt fog for 30 days. Scanning electron microscopy, x-ray diffraction, and Raman and Fourier Transformed Infrared Spectroscopy were used to characterize microstructure of the steels, rust constituents, and morphologies. Corrosion behavior of the steels has close relation with the morphology and constituents of the rusts. It has been observed that the corrosion in the IF and MS steels is uniform in nature.

  1. Clean steel technology -- Fundamental to the development of high performance steels

    SciTech Connect

    Wilson, A.D.

    1999-07-01

    The use of clean steel technology (low sulfur with calcium treatment for inclusion shape control) is a fundamental building block in the development of high performance plate steels. A brief review will be presented of the benefits of calcium treatment and its effect on non-metallic inclusions (sulfides and oxides) and reducing sulfur levels. During the past thirty years the requirements for low sulfur levels have been reduced from 0.010% maximum to 0.001% maximum. The effects of clean steel practices on specific properties will be reviewed including tensile ductility, Charpy V-notch and fracture toughness, fatigue crack propagation and hydrogen-induced-cracking resistance. Traditional low sulfur plate steel applications have included pressure vessels. offshore platforms, plastic injection molds and line-pipe skelp. More recent applications will be discussed including bridge steels, high strength structural steels to 130 ksi (897 MPa) minimum yield strength, 9% nickel steels for cryogenic applications, and military armor.

  2. High Strength Steel Welding Research

    DTIC Science & Technology

    2007-11-02

    22000 C to 15000 C. - Kluken and Gr6ng [57] considered three major growth processes: collision, 0S diffusion, and Ostwald ripening. They excluded...0- zz * 22000 - * 21000 *20000 0 0 0 0 0 .51o.5225o . Figure 4.7 Temperature profiles at indicated heights for a UMAW process with 220-ppm hydrogen...steel weld metal. With increasing S100 -- 1 0.-Pt I -. , -s ll ie (XO oil - a - IS - 3S0 o 0.20 -- 30 t* \\+ 0~4xo- bg s0o 10 10 IV 60o I0D ISO 0o 0o OION

  3. [Initial stages of steel biocorrosion].

    PubMed

    Zhigletsova, S K; Rodin, V B; Kobelev, V S; Aleksandrova, N V; Rasulova, G E; Kholodenko, V P

    2000-01-01

    Initial stages of corrosion of mild steel induced by Klebsiela rhinoscleromatis BO2 were studied in various media. The effect of the microorganism was detected 8-10 h after inoculation. The number of viable cells were virtually unchanged within one month in all media, but the corrosive activity of the strain decreased. The corrosive activity of microorganisms can be determined by spectrophotometry even only after incubation for 24 h. At a low level of organic substrate, even strong colonization with microorganisms does not inevitably result in a significant damage to metals.

  4. Chromizing of 3Cr Steel

    SciTech Connect

    Ravi, Vilupanur; Harrison, Bradley; Koch, Jordan; Ly, Alexander; Schissler, Andrew; Pint, Bruce A; Haynes, James A

    2011-01-01

    Grade 315 steel (Fe-2.9 Cr-1.7 W-0.7 Mo-0.3 Mn-0.3 Si-0.2 V-0.1 Ni-0.13 C-0.01 N) was chromized by the halide-activated pack cementation (HAPC) process. Key process parameters, i.e., coating temperatures and pack compositions, were investigated. Ammonium chloride-activated packs in the 700-1000 C range produced coatings nominally in the 1-8 {micro}m range, as determined by optical and scanning electron microscopy (SEM). Coatings applied in the 900-1000 C temperature range resulted in Cr-rich coatings. The predominant phase in the coating was identified as Cr23C6 by X-ray diffraction. In addition, the presence of chromium nitride, Cr2N, was observed in the coating. The power generation industry is faced with an ever-increasing demand for energy while simultaneously having to reduce carbon emissions. These goals can be facilitated by increasing plant efficiency through the use of higher operating temperatures and pressures. Traditional construction materials, e.g., the ferritic Grade 22 high strength low alloy steel, are limited to operations below {approx} 550 C. Therefore, new materials are required for future plants designed to operate up to 650 C and possibly higher. These new materials need to have improved tensile strength, ductility, toughness, corrosion resistance, and creep properties at elevated temperatures. Oak Ridge National Laboratory (ORNL) is investigating the oxidation and creep behavior of various coatings on Grade 315 steel (Fe-2.9 Cr-1.7 W-0.7 Mo-0.3 Mn-0.3 Si-0.2 V-0.1 Ni-0.13 C-0.01 N), a super-bainitic steel developed for superior creep properties. Thin, chemical vapor-deposited (CVD) aluminide coatings were used to compensate for the reduced corrosion and oxidation resistance that resulted from the low chromium content of the alloy. However, the aluminized Grade 315 alloys performed less-than-favorably under conditions relevant to fossil boilers, leading to the conclusion that higher chromium contents are required for the formation of

  5. Help for the Steel Industry

    NASA Astrophysics Data System (ADS)

    1991-01-01

    A collaboration between NASA Lewis Research Center (LRC) and Gladwin Engineering resulted in the adaptation of aerospace high temperature metal technology to the continuous casting of steel. The continuous process is more efficient because it takes less time and labor. A high temperature material, once used on the X-15 research plane, was applied to metal rollers by a LRC developed spraying technique. Lewis Research Center also supplied mold prototype of metal composites, reducing erosion and promoting thermal conductivity. Rollers that previously cracked due to thermal fatigue, lasted longer. Gladwin's sales have increased, and additional NASA-developed innovations are anticipated.

  6. Multiple Impacts on Monolithic Steel

    DTIC Science & Technology

    1982-04-01

    Two-dimensional computer code , . Eulerian computer code Shaped-charge penetration Multiple impact .6, ABYRAC• ( - ms i N twSMW Mni/ffir b? Wok nuftd...material was copper with a yield stress in shear of 1.3 kbar. Before impact, the velocity of the penetrators was 5.0 km/s and the diameter, 3 mm. The steel...target was semi-infinite with a yield stress in shear of 6.8 kbar. Five impact situations were considered: (1) one impact by a 27.0- m-long penetrator

  7. Titanium "irons" and titanium "steels"

    NASA Astrophysics Data System (ADS)

    Firstov, S. A.; Tkachenko, S. V.; Kuz'menko, N. N.

    2009-01-01

    Special features of the structure and properties of promising structural alloys based on the Ti-Si system are described. The similarity of the diagrams of phase equilibria of the Fe-Si and Fe-C systems makes it possible to classify the alloys of the Ti-Si system into titanium "steels" and "irons" depending on the silicon content. Results of studies of the effects of alloying, heat treatment, and thermomechanical treatment on the phase and structural transformations and on some properties of alloys based on the Ti-Si system are presented.

  8. METHOD FOR JOINING ALUMINUM TO STAINLESS STEEL

    DOEpatents

    Lemon, L.C.

    1960-05-24

    Aluminum may be joined to stainless steel without the use of flux by tinning the aluminum with a tin solder containing 1% silver and 1% lead, tinning the stainless steel with a 50% lead 50% tin solder, and then sweating the tinned surfaces together.

  9. Chem I Supplement: Chemistry of Steel Making.

    ERIC Educational Resources Information Center

    Sellers, Neal

    1980-01-01

    Provides information about the chemistry of steel making applicable to teaching secondary school science. Generalized chemical reactions describe the manufacture of steel from iron ore. Also discussed are raw materials, processing choices, and how various furnaces (blast, direct reduction, open hearth, basic oxygen, electric) work. (CS)

  10. Mineral resource of the month: steel

    USGS Publications Warehouse

    Fenton, Michael D.

    2007-01-01

    About 96 million metric tons of steel was produced in the United States last year — more than any other metal. And the $3.46 billion of iron and steel scrap exported was also the highest of any metal scrap export, helping to reduce the U.S. trade deficit.

  11. African Drum and Steel Pan Ensembles.

    ERIC Educational Resources Information Center

    Sunkett, Mark E.

    2000-01-01

    Discusses how to develop both African drum and steel pan ensembles providing information on teacher preparation, instrument choice, beginning the ensemble, and lesson planning. Includes additional information for the drum ensembles. Lists references and instructional materials, sources of drums and pans, and common note layout/range for steel pan…

  12. Ellie Mannette: Master of the Steel Drum.

    ERIC Educational Resources Information Center

    Svaline, J. Marc

    2001-01-01

    Presents an interview with Elliot ("Ellie") Mannette who has played a major role in the development and application of steel drums. States that he has spent most of his life designing and teaching the steel drums. Covers interview topics and background information on Mannette. (CMK)

  13. A recycling process for dezincing steel scrap

    SciTech Connect

    Dudek, F.J.; Daniels, E.J. ); Morgan, W.A.; Kellner, A.W.; Harrison, J. )

    1992-01-01

    In response to the several-fold increase in consumption of galvanized steel in the last decade and the problems associated with refurnacing larger quantities of galvanized steel scrap, a process is being developed to separate and recover the steel and zinc from galvanized ferrous scrap. The zinc is dissolved from the scrap in hot caustic using anodic assistance and is electrowon as dendritic powder. The process is effective for zinc, lead, aluminum, and cadmium removal on loose and baled scrap and on all types of galvanized steel. The process has been pilot tested for batch treatment of 1,000 tons of mostly baled scrap. A pilot plant to continuously treat loose scrap is under construction. Use of degalvanized steel scrap decreases raw materials and environmental compliance costs to steel- and iron-makers, may enable integrated steel producers to recycle furnace dusts to the sinter plant, and may enable EAF production of flat products without use of DRI or pig iron. Recycling the components of galvanized steel scrap saves primary energy, decreases zinc imports, and adds value to the scrap.

  14. A recycling process for dezincing steel scrap

    SciTech Connect

    Dudek, F.J.; Daniels, E.J.; Morgan, W.A.; Kellner, A.W.; Harrison, J.

    1992-08-01

    In response to the several-fold increase in consumption of galvanized steel in the last decade and the problems associated with refurnacing larger quantities of galvanized steel scrap, a process is being developed to separate and recover the steel and zinc from galvanized ferrous scrap. The zinc is dissolved from the scrap in hot caustic using anodic assistance and is electrowon as dendritic powder. The process is effective for zinc, lead, aluminum, and cadmium removal on loose and baled scrap and on all types of galvanized steel. The process has been pilot tested for batch treatment of 1,000 tons of mostly baled scrap. A pilot plant to continuously treat loose scrap is under construction. Use of degalvanized steel scrap decreases raw materials and environmental compliance costs to steel- and iron-makers, may enable integrated steel producers to recycle furnace dusts to the sinter plant, and may enable EAF production of flat products without use of DRI or pig iron. Recycling the components of galvanized steel scrap saves primary energy, decreases zinc imports, and adds value to the scrap.

  15. Low Mn alloy steel for cryogenic service

    DOEpatents

    Morris, J.W. Jr.; Niikura, M.

    A ferritic cryogenic steel which has a relatively low (about 4 to 6%) manganese content and which has been made suitable for use at cryogenic temperatures by a thermal cycling treatment followed by a final tempering. The steel includes 4 to 6% manganese, 0.02 to 0.06% carbon, 0.1 to 0.4% molybdenum and 0 to 3% nickel.

  16. History dependence of magnetomechanical properties of steel

    NASA Astrophysics Data System (ADS)

    Melquiond, F.; Mouroux, A.; Jouglar, J.; Vuillermoz, P. L.; Weinstock, H.

    1996-05-01

    Magnetomechanical measurements using a superconducting SQUID magnetic gradiometer and a tensile-testing machine have been performed on a variety of steel specimens to determine the change in magnetization due to applied stress and the possible application of the observed behavior as a new form of nondestructive evaluation in steel. This study builds on earlier related measurements.

  17. Why Not Start a Steel Band?

    ERIC Educational Resources Information Center

    Svaline, J. Marc

    1995-01-01

    Suggests expanding the eclectic nature of a band program by creating a steel band, a Caribbean-based percussion ensemble. The steel band complements multicultural education and attracts students to the music program. Discusses maintenance, repertoire, and performance. Includes classification of pans and a list of schools with established programs.…

  18. Forming "dynamic" membranes on stainless steel

    NASA Technical Reports Server (NTRS)

    Brandon, C. A.; Gaddis, J. L.

    1979-01-01

    "Dynamic" zirconium polyacrylic membrane is formed directly on stainless steel substrate without excessive corrosion of steel. Membrane is potentially useful in removal of contaminated chemicals from solution through reversed osmosis. Application includes use in filtration and desalination equipment, and in textile industry for separation of dyes from aqueous solvents.

  19. Ellie Mannette: Master of the Steel Drum.

    ERIC Educational Resources Information Center

    Svaline, J. Marc

    2001-01-01

    Presents an interview with Elliot ("Ellie") Mannette who has played a major role in the development and application of steel drums. States that he has spent most of his life designing and teaching the steel drums. Covers interview topics and background information on Mannette. (CMK)

  20. Method for welding chromium molybdenum steels

    DOEpatents

    Sikka, Vinod K.

    1986-01-01

    Chromium-molybdenum steels exhibit a weakening after welding in an area adjacent to the weld. This invention is an improved method for welding to eliminate the weakness by subjecting normalized steel to a partial temper prior to welding and subsequently fully tempering the welded article for optimum strength and ductility.

  1. The Mechanical Metallurgy of Armour Steels

    DTIC Science & Technology

    2016-10-01

    battlefield threats and continue to be highly competitive armour materials . The relationship between armour steel mechanical properties, specifically...their mechanical metallurgy, and ballistic performance is explained, where such performance is primarily determined by material strength, hardness and...armour materials . However, the factors that are most important for the ballistic and structural performance of armour steels are not commonly well

  2. Diffusion brazing nickel-plated stainless steel

    NASA Technical Reports Server (NTRS)

    Beuyukian, C. S.; Mitchell, M. J.

    1976-01-01

    To bond parts, sandwich assembly is made up of aluminum core, aluminum face sheet with brazing alloy interface, and nickel plated stainless steel part. Sandwich is placed between bottom and top glide sheet that is placed in stainless steel retort where assembly is bonded at 580 C.

  3. Chem I Supplement: Chemistry of Steel Making.

    ERIC Educational Resources Information Center

    Sellers, Neal

    1980-01-01

    Provides information about the chemistry of steel making applicable to teaching secondary school science. Generalized chemical reactions describe the manufacture of steel from iron ore. Also discussed are raw materials, processing choices, and how various furnaces (blast, direct reduction, open hearth, basic oxygen, electric) work. (CS)

  4. Diffusion brazing nickel-plated stainless steel

    NASA Technical Reports Server (NTRS)

    Beuyukian, C. S.; Mitchell, M. J.

    1976-01-01

    To bond parts, sandwich assembly is made up of aluminum core, aluminum face sheet with brazing alloy interface, and nickel plated stainless steel part. Sandwich is placed between bottom and top glide sheet that is placed in stainless steel retort where assembly is bonded at 580 C.

  5. Tubercles and Localized Corrosion on Carbon Steel

    DTIC Science & Technology

    2010-12-01

    with symbiotic relationships and nutrient cycling. Miller and Tiller [14] indicated, "iron bacteria , which, together with the ferric hydroxide...conclude localized corrosion directly under the tubercles or a role for bacteria in their formation. 15. SUBJECT TERMS tubercle, carbon steel... bacteria in their formation. Introduction It is well established that tubercles formed on austenitic 300 series (304 or 316) stainless steel in

  6. The comparison of frictional resistance in titanium, self-ligating stainless steel, and stainless steel brackets using stainless steel and TMA archwires: An in vitro study

    PubMed Central

    Khalid, Syed Altaf; Kumar, Vadivel; Jayaram, Prithviraj

    2012-01-01

    Aim: The aim of the study was to compare the frictional resistance of titanium, self-ligating stainless steel, and conventional stainless steel brackets, using stainless steel and titanium molybdenum alloy (TMA) archwires. Materials and Methods: We compared the frictional resistance in 0.018 slot and 0.022 slot of the three brackets – titanium, self-ligating stainless steel, and conventional stainless steel – using stainless steel archwires and TMA archwires. An in vitro study of simulated canine retraction was undertaken to evaluate the difference in frictional resistance between titanium, self-ligating stainless steel, and stainless steel brackets, using stainless steel and TMA archwires. Results and Conclusion: We compared the frictional resistance of titanium, self-ligating stainless steel, and conventional stainless steel brackets, using stainless steel and TMA archwires, with the help of Instron Universal Testing Machine. One-way analysis of variance (ANOVA), Student's “t” test, and post hoc multiple range test at level of <0.05 showed statistically significant difference in the mean values of all groups. Results demonstrated that the titanium, self-ligating stainless steel, and stainless steel brackets of 0.018-inch and 0.022-inch slot had no significant variations in frictional résistance. The self-ligating bracket with TMA archwires showed relatively less frictional resistance compared with the other groups. The titanium bracket with TMA archwires showed relatively less frictional resistance compared with the stainless steel brackets. PMID:23066253

  7. The comparison of frictional resistance in titanium, self-ligating stainless steel, and stainless steel brackets using stainless steel and TMA archwires: An in vitro study.

    PubMed

    Khalid, Syed Altaf; Kumar, Vadivel; Jayaram, Prithviraj

    2012-08-01

    The aim of the study was to compare the frictional resistance of titanium, self-ligating stainless steel, and conventional stainless steel brackets, using stainless steel and titanium molybdenum alloy (TMA) archwires. We compared the frictional resistance in 0.018 slot and 0.022 slot of the three brackets - titanium, self-ligating stainless steel, and conventional stainless steel - using stainless steel archwires and TMA archwires. An in vitro study of simulated canine retraction was undertaken to evaluate the difference in frictional resistance between titanium, self-ligating stainless steel, and stainless steel brackets, using stainless steel and TMA archwires. We compared the frictional resistance of titanium, self-ligating stainless steel, and conventional stainless steel brackets, using stainless steel and TMA archwires, with the help of Instron Universal Testing Machine. One-way analysis of variance (ANOVA), Student's "t" test, and post hoc multiple range test at level of <0.05 showed statistically significant difference in the mean values of all groups. Results demonstrated that the titanium, self-ligating stainless steel, and stainless steel brackets of 0.018-inch and 0.022-inch slot had no significant variations in frictional résistance. The self-ligating bracket with TMA archwires showed relatively less frictional resistance compared with the other groups. The titanium bracket with TMA archwires showed relatively less frictional resistance compared with the stainless steel brackets.

  8. Stress corrosion cracking of stainless steels

    NASA Astrophysics Data System (ADS)

    Hehemann, R. F.

    1985-11-01

    The similarities and differences in the stress corrosion cracking response of ferritic and austenitic stainless steels in chloride solutions will be examined. Both classes of materials exhibit a cracking potential: similar transient response (to loading) of the potential in open circuit tests or the current in potentiostatic tests and similar enrichment of chromium and depletion of iron in the film associated with localized corrosion processes. The ferritic steels are more resistant to localized corrosion than are the austenitic steels, which is responsible for the difference in the influence of prior thermal and mechanical history on cracking susceptibility of the two types of steel. Similarities in the fractography of stress corrosion cracks and those produced by brittle delayed failure during cathodic charging of the ferritic steels indicate that hydrogen embrittlement is involved in the failure process.

  9. Hydrogen transport in iron and steel

    NASA Technical Reports Server (NTRS)

    Louthan, M. R., Jr.; Derrick, R. G.; Donovan, J. A.; Caskey, G. R., Jr.

    1976-01-01

    The permeabilities of protium, deuterium, and tritium in foil specimens of Marz grade iron, 4130 steel, Armco iron, HP-9-4-20, and T-1 steels were studied at hydrogen pressures between 0.02 and 0.5 MPa over the temperature range 260-700 K. The permeability was measured by a pressure-rise method, deuterium counting with a detector, and radioactivity counting. Good agreement is found between the measurement techniques used. It is shown that the permeabilities of protium, deuterium, and tritium in iron and T-1 steel at temperatures as low as 260 K are in good agreement with the equation proposed by Gonzalez (1967). However, the permeabilities of HP-9-4-20 and 4130 steel to hydrogen are typically lower than predicted. The isotope effect on hydrogen permeability of HP-9-4-20, 4130 and T-1 steels, and high-purity iron can be estimated by an inverse square root of mass correction.

  10. An understanding of HSLA-65 plate steels

    NASA Astrophysics Data System (ADS)

    Sampath, K.

    2006-02-01

    HSLA-65 plate steels can be produced using one of five plate manufacturing techniques: normalizing, controlled rolling (CR), controlled rolling followed by accelerated cooling (CR-AC), direct quenching and tempering (DQT), or conventional quenching and tempering (Q&T). The HSLA-65 steels are characterized by low carbon content and low alloy content, and they exhibit a low carbon equivalent that allows improved plate weldability. These characteristics in turn (a) provide the steel plate with a refined microstructure that ensures high strength and toughness; (b) eliminate or substantially reduce the need for preheating during welding; (c) resist susceptibility to hydrogen-assisted cracking (HAC) in the weld heat affected zone (HAZ) when fusion (arc) welded using low heat-input conditions; and (d) depending on section thickness, facilitate high heat-input welding (about 2 kJ/mm) without significant loss of strength or toughness in the HAZ. However, application of this plate manufacturing process and of these controls produces significant differences in the metallurgical structure and range of mechanical properties of the HSLA-65 plate steels both among themselves and versus conventional higher strength steel (HSS) plates. For example, among the HSLA-65 plate steels, those produced by Q&T exhibit minimal variability in mechanical properties, especially in thicker plates. Besides variability in mechanical properties depending on plate thickness, the CR and CR-AC plate steels exhibit a relatively higher yield strength to ultimate tensile strength (YS/UTS) ratio than do DQT and Q&T steels. Such differences in processing and properties of HSLA-65 plate steels could potentially affect the selection and control of various secondary fabrication practices, including arc welding. Consequently, fabricators must exercise extreme caution when transferring allowable limits of certified secondary fabrication practices from one type of HSLA-65 plate steel to another, even for the

  11. Automated Steel Cleanliness Analysis Tool (ASCAT)

    SciTech Connect

    Gary Casuccio; Michael Potter; Fred Schwerer; Dr. Richard J. Fruehan; Dr. Scott Story

    2005-12-30

    The objective of this study was to develop the Automated Steel Cleanliness Analysis Tool (ASCATTM) to permit steelmakers to evaluate the quality of the steel through the analysis of individual inclusions. By characterizing individual inclusions, determinations can be made as to the cleanliness of the steel. Understanding the complicating effects of inclusions in the steelmaking process and on the resulting properties of steel allows the steel producer to increase throughput, better control the process, reduce remelts, and improve the quality of the product. The ASCAT (Figure 1) is a steel-smart inclusion analysis tool developed around a customized next-generation computer controlled scanning electron microscopy (NG-CCSEM) hardware platform that permits acquisition of inclusion size and composition data at a rate never before possible in SEM-based instruments. With built-in customized ''intelligent'' software, the inclusion data is automatically sorted into clusters representing different inclusion types to define the characteristics of a particular heat (Figure 2). The ASCAT represents an innovative new tool for the collection of statistically meaningful data on inclusions, and provides a means of understanding the complicated effects of inclusions in the steel making process and on the resulting properties of steel. Research conducted by RJLG with AISI (American Iron and Steel Institute) and SMA (Steel Manufactures of America) members indicates that the ASCAT has application in high-grade bar, sheet, plate, tin products, pipes, SBQ, tire cord, welding rod, and specialty steels and alloys where control of inclusions, whether natural or engineered, are crucial to their specification for a given end-use. Example applications include castability of calcium treated steel; interstitial free (IF) degasser grade slag conditioning practice; tundish clogging and erosion minimization; degasser circulation and optimization; quality assessment/steel cleanliness; slab, billet

  12. Superstrength of nanograined steel with nanoscale intermetallic precipitates transformed from shock-compressed martensitic steel

    NASA Astrophysics Data System (ADS)

    Yu, Hailiang; Yan, Ming; Lu, Cheng; Tieu, Anh Kiet; Li, Huijun; Zhu, Qiang; Godbole, Ajit; Li, Jintao; Su, Lihong; Kong, Charlie

    2016-11-01

    An increasing number of industrial applications need superstrength steels. It is known that refined grains and nanoscale precipitates can increase strength. The hardest martensitic steel reported to date is C0.8 steel, whose nanohardness can reach 11.9 GPa through incremental interstitial solid solution strengthening. Here we report a nanograined (NG) steel dispersed with nanoscale precipitates which has an extraordinarily high hardness of 19.1 GPa. The NG steel (shock-compressed Armox 500T steel) was obtained under these conditions: high strain rate of 1.2 μs-1, high temperature rise rate of 600 Kμs-1 and high pressure of 17 GPa. The mean grain size achieved was 39 nm and reinforcing precipitates were indexed in the NG steel. The strength of the NG steel is expected to be ~3950 MPa. The discovery of the NG steel offers a general pathway for designing new advanced steel materials with exceptional hardness and excellent strength.

  13. Superstrength of nanograined steel with nanoscale intermetallic precipitates transformed from shock-compressed martensitic steel

    PubMed Central

    Yu, Hailiang; Yan, Ming; Lu, Cheng; Tieu, Anh Kiet; Li, Huijun; Zhu, Qiang; Godbole, Ajit; Li, Jintao; Su, Lihong; Kong, Charlie

    2016-01-01

    An increasing number of industrial applications need superstrength steels. It is known that refined grains and nanoscale precipitates can increase strength. The hardest martensitic steel reported to date is C0.8 steel, whose nanohardness can reach 11.9 GPa through incremental interstitial solid solution strengthening. Here we report a nanograined (NG) steel dispersed with nanoscale precipitates which has an extraordinarily high hardness of 19.1 GPa. The NG steel (shock-compressed Armox 500T steel) was obtained under these conditions: high strain rate of 1.2 μs−1, high temperature rise rate of 600 Kμs−1 and high pressure of 17 GPa. The mean grain size achieved was 39 nm and reinforcing precipitates were indexed in the NG steel. The strength of the NG steel is expected to be ~3950 MPa. The discovery of the NG steel offers a general pathway for designing new advanced steel materials with exceptional hardness and excellent strength. PMID:27892460

  14. 29 CFR 1926.757 - Open web steel joists.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 8 2011-07-01 2011-07-01 false Open web steel joists. 1926.757 Section 1926.757 Labor... (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Steel Erection § 1926.757 Open web steel joists... and columns are not framed in at least two directions with solid web structural steel members, a...

  15. 29 CFR 1926.757 - Open web steel joists.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 8 2010-07-01 2010-07-01 false Open web steel joists. 1926.757 Section 1926.757 Labor... (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Steel Erection § 1926.757 Open web steel joists... and columns are not framed in at least two directions with solid web structural steel members, a...

  16. 49 CFR 192.105 - Design formula for steel pipe.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 3 2014-10-01 2014-10-01 false Design formula for steel pipe. 192.105 Section 192... for steel pipe. (a) The design pressure for steel pipe is determined in accordance with the following... § 192.113. T=Temperature derating factor determined in accordance with § 192.115. (b) If steel pipe...

  17. 49 CFR 178.504 - Standards for steel drums.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Standards for steel drums. 178.504 Section 178.504...-bulk Performance-Oriented Packaging Standards § 178.504 Standards for steel drums. (a) The following are identification codes for steel drums: (1) 1A1 for a non-removable head steel drum; and (2) 1A2...

  18. 46 CFR 154.195 - Aluminum cargo tank: Steel enclosure.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 5 2014-10-01 2014-10-01 false Aluminum cargo tank: Steel enclosure. 154.195 Section... Equipment Hull Structure § 154.195 Aluminum cargo tank: Steel enclosure. (a) An aluminum cargo tank and its dome must be enclosed by the vessel's hull structure or a separate steel cover. (b) The steel cover...

  19. 46 CFR 154.195 - Aluminum cargo tank: Steel enclosure.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Aluminum cargo tank: Steel enclosure. 154.195 Section... Equipment Hull Structure § 154.195 Aluminum cargo tank: Steel enclosure. (a) An aluminum cargo tank and its dome must be enclosed by the vessel's hull structure or a separate steel cover. (b) The steel cover...

  20. 49 CFR 192.105 - Design formula for steel pipe.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 3 2011-10-01 2011-10-01 false Design formula for steel pipe. 192.105 Section 192... for steel pipe. (a) The design pressure for steel pipe is determined in accordance with the following... § 192.113. T=Temperature derating factor determined in accordance with § 192.115. (b) If steel pipe...

  1. 19 CFR 360.101 - Steel import licensing.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 19 Customs Duties 3 2012-04-01 2012-04-01 false Steel import licensing. 360.101 Section 360.101 Customs Duties INTERNATIONAL TRADE ADMINISTRATION, DEPARTMENT OF COMMERCE STEEL IMPORT MONITORING AND ANALYSIS SYSTEM § 360.101 Steel import licensing. (a) In general. (1) All imports of basic steel...

  2. 49 CFR 192.315 - Wrinkle bends in steel pipe.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Wrinkle bends in steel pipe. 192.315 Section 192... Transmission Lines and Mains § 192.315 Wrinkle bends in steel pipe. (a) A wrinkle bend may not be made on steel... wrinkle bend on steel pipe must comply with the following: (1) The bend must not have any sharp kinks....

  3. 49 CFR 178.504 - Standards for steel drums.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 3 2014-10-01 2014-10-01 false Standards for steel drums. 178.504 Section 178.504...-Oriented Packaging Standards § 178.504 Standards for steel drums. (a) The following are identification codes for steel drums: (1) 1A1 for a non-removable head steel drum; and (2) 1A2 for a removable...

  4. 19 CFR 360.101 - Steel import licensing.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 19 Customs Duties 3 2013-04-01 2013-04-01 false Steel import licensing. 360.101 Section 360.101 Customs Duties INTERNATIONAL TRADE ADMINISTRATION, DEPARTMENT OF COMMERCE STEEL IMPORT MONITORING AND ANALYSIS SYSTEM § 360.101 Steel import licensing. (a) In general. (1) All imports of basic steel...

  5. 46 CFR 154.195 - Aluminum cargo tank: Steel enclosure.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 5 2013-10-01 2013-10-01 false Aluminum cargo tank: Steel enclosure. 154.195 Section... Equipment Hull Structure § 154.195 Aluminum cargo tank: Steel enclosure. (a) An aluminum cargo tank and its dome must be enclosed by the vessel's hull structure or a separate steel cover. (b) The steel cover...

  6. 49 CFR 192.315 - Wrinkle bends in steel pipe.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 3 2013-10-01 2013-10-01 false Wrinkle bends in steel pipe. 192.315 Section 192... Transmission Lines and Mains § 192.315 Wrinkle bends in steel pipe. (a) A wrinkle bend may not be made on steel... wrinkle bend on steel pipe must comply with the following: (1) The bend must not have any sharp kinks....

  7. 49 CFR 192.105 - Design formula for steel pipe.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 3 2012-10-01 2012-10-01 false Design formula for steel pipe. 192.105 Section 192... for steel pipe. (a) The design pressure for steel pipe is determined in accordance with the following... § 192.113. T=Temperature derating factor determined in accordance with § 192.115. (b) If steel pipe...

  8. 49 CFR 178.504 - Standards for steel drums.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 3 2013-10-01 2013-10-01 false Standards for steel drums. 178.504 Section 178.504...-Oriented Packaging Standards § 178.504 Standards for steel drums. (a) The following are identification codes for steel drums: (1) 1A1 for a non-removable head steel drum; and (2) 1A2 for a removable...

  9. 19 CFR 360.101 - Steel import licensing.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 19 Customs Duties 3 2014-04-01 2014-04-01 false Steel import licensing. 360.101 Section 360.101 Customs Duties INTERNATIONAL TRADE ADMINISTRATION, DEPARTMENT OF COMMERCE STEEL IMPORT MONITORING AND ANALYSIS SYSTEM § 360.101 Steel import licensing. (a) In general. (1) All imports of basic steel...

  10. 19 CFR 360.101 - Steel import licensing.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 19 Customs Duties 3 2011-04-01 2011-04-01 false Steel import licensing. 360.101 Section 360.101 Customs Duties INTERNATIONAL TRADE ADMINISTRATION, DEPARTMENT OF COMMERCE STEEL IMPORT MONITORING AND ANALYSIS SYSTEM § 360.101 Steel import licensing. (a) In general. (1) All imports of basic steel...

  11. 49 CFR 178.504 - Standards for steel drums.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 3 2012-10-01 2012-10-01 false Standards for steel drums. 178.504 Section 178.504...-Oriented Packaging Standards § 178.504 Standards for steel drums. (a) The following are identification codes for steel drums: (1) 1A1 for a non-removable head steel drum; and (2) 1A2 for a removable...

  12. 49 CFR 178.504 - Standards for steel drums.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 3 2011-10-01 2011-10-01 false Standards for steel drums. 178.504 Section 178.504...-Oriented Packaging Standards § 178.504 Standards for steel drums. (a) The following are identification codes for steel drums: (1) 1A1 for a non-removable head steel drum; and (2) 1A2 for a removable...

  13. 49 CFR 192.315 - Wrinkle bends in steel pipe.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 3 2014-10-01 2014-10-01 false Wrinkle bends in steel pipe. 192.315 Section 192... Transmission Lines and Mains § 192.315 Wrinkle bends in steel pipe. (a) A wrinkle bend may not be made on steel... wrinkle bend on steel pipe must comply with the following: (1) The bend must not have any sharp kinks....

  14. 49 CFR 192.105 - Design formula for steel pipe.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 3 2013-10-01 2013-10-01 false Design formula for steel pipe. 192.105 Section 192... for steel pipe. (a) The design pressure for steel pipe is determined in accordance with the following... § 192.113. T=Temperature derating factor determined in accordance with § 192.115. (b) If steel pipe...

  15. 75 FR 8746 - Certain Steel Grating From China

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-25

    ... COMMISSION Certain Steel Grating From China AGENCY: United States International Trade Commission. ACTION... retarded, by reason of subsidized and less-than-fair-value imports from China of certain steel gratings... ``certain steel grating, consisting of two or more pieces of steel, including load- bearing pieces and...

  16. 49 CFR 192.315 - Wrinkle bends in steel pipe.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 3 2012-10-01 2012-10-01 false Wrinkle bends in steel pipe. 192.315 Section 192... Transmission Lines and Mains § 192.315 Wrinkle bends in steel pipe. (a) A wrinkle bend may not be made on steel... wrinkle bend on steel pipe must comply with the following: (1) The bend must not have any sharp kinks....

  17. 19 CFR 360.101 - Steel import licensing.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 19 Customs Duties 3 2010-04-01 2010-04-01 false Steel import licensing. 360.101 Section 360.101 Customs Duties INTERNATIONAL TRADE ADMINISTRATION, DEPARTMENT OF COMMERCE STEEL IMPORT MONITORING AND ANALYSIS SYSTEM § 360.101 Steel import licensing. (a) In general. (1) All imports of basic steel...

  18. 46 CFR 154.195 - Aluminum cargo tank: Steel enclosure.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 5 2012-10-01 2012-10-01 false Aluminum cargo tank: Steel enclosure. 154.195 Section... Equipment Hull Structure § 154.195 Aluminum cargo tank: Steel enclosure. (a) An aluminum cargo tank and its dome must be enclosed by the vessel's hull structure or a separate steel cover. (b) The steel cover...

  19. 46 CFR 154.195 - Aluminum cargo tank: Steel enclosure.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 5 2011-10-01 2011-10-01 false Aluminum cargo tank: Steel enclosure. 154.195 Section... Equipment Hull Structure § 154.195 Aluminum cargo tank: Steel enclosure. (a) An aluminum cargo tank and its dome must be enclosed by the vessel's hull structure or a separate steel cover. (b) The steel cover...

  20. 49 CFR 192.315 - Wrinkle bends in steel pipe.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 3 2011-10-01 2011-10-01 false Wrinkle bends in steel pipe. 192.315 Section 192... Transmission Lines and Mains § 192.315 Wrinkle bends in steel pipe. (a) A wrinkle bend may not be made on steel... wrinkle bend on steel pipe must comply with the following: (1) The bend must not have any sharp kinks....