Process for electroslag refining of uranium and uranium alloys

DOEpatents

Lewis, P.S. Jr.; Agee, W.A.; Bullock, J.S. IV; Condon, J.B.

1975-07-22

A process is described for electroslag refining of uranium and uranium alloys wherein molten uranium and uranium alloys are melted in a molten layer of a fluoride slag containing up to about 8 weight percent calcium metal. The calcium metal reduces oxides in the uranium and uranium alloys to provide them with an oxygen content of less than 100 parts per million. (auth)

Evaluation of the mechanical properties of electroslag refined iron alloys

NASA Technical Reports Server (NTRS)

Bhat, G. K.

1976-01-01

Nitronic 40 (21Cr-6N-9Mn), HY-130, 9Ni-4Co, and D-6 alloys were prepared and evaluated in the form of 15.2 mm thick plates. Smooth bar tensile tests, double-edge sharp notch fracture toughness tests Charpy V-notch impact tests were conducted on appropriate heat treated specimens of the four steel plates at 22 C, -50 C, -100 C, -150 C, and -196 C. Similar material characterization, including metallographic evaluation studies on air melt and vacuum arc melt grades of same four alloy steels were conducted for comparative purposes. A cost analysis of manufacturing plates of air melt, electroslag remelt and vacuum arc remelt grades was performed. The results of both material characterization and cost analyses pointed out certain special benefits of electroslag processing iron base alloys.

Constant voltage electro-slag remelting control

DOEpatents

Schlienger, Max E.

1996-01-01

A system for controlling electrode gap in an electro-slag remelt furnace has a constant regulated voltage and an eletrode which is fed into the slag pool at a constant rate. The impedance of the circuit through the slag pool is directly proportional to the gap distance. Because of the constant voltage, the system current changes are inversely proportional to changes in gap. This negative feedback causes the gap to remain stable.

Constant voltage electro-slag remelting control

DOEpatents

Schlienger, M.E.

1996-10-22

A system for controlling electrode gap in an electro-slag remelt furnace has a constant regulated voltage and an electrode which is fed into the slag pool at a constant rate. The impedance of the circuit through the slag pool is directly proportional to the gap distance. Because of the constant voltage, the system current changes are inversely proportional to changes in gap. This negative feedback causes the gap to remain stable. 1 fig.

Multipurpose electroslag remelting furnace for modern energy and heavy engineering industry

NASA Astrophysics Data System (ADS)

Dub, A. V.; Dub, V. S.; Kriger, Yu. N.; Levkov, L. Ya.; Shurygin, D. A.; Kissel'man, M. A.; Nekhamin, C. M.; Chernyak, A. I.; Bessonov, A. V.; Kamantsev, S. V.; Sokolov, S. O.

2012-12-01

In 2011, a unique complex based on a multipurpose unit-type electroslag remelting (ESR) furnace is created to meet the demand for large high-quality solid and hollow billets for the products of power, atomic, petrochemical, and heavy machine engineering. This complex has modern low-frequency power supplies with a new control level that ensure a high homogeneity and quality of the billets and an increase in the engineering-and-economical performance of the production. A unique pilot ESR furnace is erected to adjust technological conditions and the main control system elements.

A Parametric Study of Slag Skin Formation in Electroslag Remelting

NASA Astrophysics Data System (ADS)

Yanke, Jeff; Krane, Matthew John M.

In electroslag remelting (ESR), the slag generates heat, chemically refines the melting electrode material, and forms frozen skin on the mold. An axisymmetric model is used to simulate fluid flow, heat transfer, solidification, and electromagnetics and their interaction with slag skin formation in ESR. A volume of fluid (VOF) method is used to track the slag/metal interface, allowing simulation of slag freezing to the mold. Mold diameter and applied current are varied to determine how these parameters affect melt rate and formation of slag skin during ESR. Variations in the slag skin thickness within the slag cap are found to have a significant impact on melt rate and depth of metal sump. Changes in slag cap volume resulted in small changes in melt rate.

Effect of electroslag remelting on carbides in 8Cr13MoV martensitic stainless steel

NASA Astrophysics Data System (ADS)

Zhu, Qin-tian; Li, Jing; Shi, Cheng-bin; Yu, Wen-tao

2015-11-01

The effect of electroslag remelting (ESR) on carbides in 8Cr13MoV martensitic stainless steel was experimentally studied. Phases precipitated from liquid steel during solidification were calculated using the Thermo-Calc software. The carbon segregation was analyzed by original position analysis (OPA), and the carbides were analyzed by optical microscopy (OM), scanning electron microscopy (SEM), energy- dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD). The results indicated that more uniform carbon distribution and less segregation were obtained in the case of samples subjected to the ESR process. After ESR, the amount of netty carbides decreased significantly, and the chromium and vanadium contents in the grain-boundary carbides was reduced. The total area and average size of carbides were obviously smaller after the ESR process. In the sample subjected to ESR, the morphology of carbides changed from lamellar and angular to globular or lump, whereas the types of carbides did not change; both M23C6 and M7C3 were present before and after the ESR process.

Pressurized metallurgy for high performance special steels and alloys

NASA Astrophysics Data System (ADS)

Jiang, Z. H.; Zhu, H. C.; Li, H. B.; Li, Y.; Liu, F. B.

2016-07-01

The pressure is one of the basic parameters which greatly influences the metallurgical reaction process and solidification of steels and alloys. In this paper the history and present situation of research and application of pressurized metallurgy, especially pressurized metallurgy for special steels and alloys have been briefly reviewed. In the following part the physical chemistry of pressurized metallurgy is summarized. It is shown that pressurizing may change the conditions of chemical reaction in thermodynamics and kinetics due to the pressure effect on gas volume, solubility of gas and volatile element in metal melt, activity or activity coefficient of components, and change the physical and chemical properties of metal melt, heat transfer coefficient between mould and ingot, thus greatly influencing phase transformation during the solidification process and the solidification structure, such as increasing the solidification nucleation rate, reducing the critical nucleation radius, accelerating the solidification speed and significant macro/micro-structure refinement, and eliminating shrinkage, porosity and segregation and other casting defects. In the third part the research works of pressured metallurgy performed by the Northeastern University including establishment of pressurized induction melting (PIM) and pressurized electroslag remelting (PESR) equipments and development of high nitrogen steels under pressure are described in detail. Finally, it is considered in the paper that application of pressurized metallurgy in manufacture of high performance special steels and alloys is a relatively new research area, and its application prospects will be very broad and bright.

Determination of the moisture content in the fluoride oxide fluxes of electroslag remelting

NASA Astrophysics Data System (ADS)

Vdovin, K. N.; Feoktistov, N. A.; Pivovarova, K. G.; Deryabin, D. A.

2016-12-01

ANF-32 flux has been studied with regard to the moisture content both after storage and upon operation. A simple and reliable procedure for the determination of the moisture content in ESR fluxes is proposed, and recommendations are given on monitoring the moisture content in calcined fluxes. The main sources of crystallization water of hydration are hydrogen sources.

Numerical Study on the Effect of Electrode Polarity on Desulfurization in Direct Current Electroslag Remelting Process

NASA Astrophysics Data System (ADS)

Wang, Qiang; Liu, Yu; Wang, Fang; Li, Guangqiang; Li, Baokuan; Qiao, Wenwei

2017-10-01

In order to clarify the influence of electrode polarity on desulfurization in direct current (DC) electroslag remelting process, a transient three-dimensional coupled mathematical model has been established. The finite volume method was invoked to simultaneously solve the mass, momentum, energy, and species conservation equations. The Joule heating and Lorentz force were fully coupled through calculating Maxwell's equations with the assistance of the magnetic potential vector. The motion of the metal-slag interface was described by using the volume of fluid approach. An auxiliary metallurgical kinetics module was introduced to determine the thermochemical and the electrochemical reaction rates. A reasonable agreement between the measured data and the simulated results are observed. A longer time and a larger area for the desulfurization can be provided by the metal pool-slag interface when compared with the metal droplet-slag interface. The electrochemical transfer rate at the metal pool-slag interface is positive in the DC reverse polarity (DCRP) remelting, while in the DC straight polarity (DCSP) remelting, the electrochemical transfer rate is negative at this interface. The desulfurization progress in the DCSP remelting thus is fall behind that in the DCRP remelting. The desulfurization rate of the DCRP remelting is around 70 pct and the rate of the DCSP remelting is about 40 pct.

Cold-Worked Inconel(R) 718 Bars

NASA Technical Reports Server (NTRS)

Montano, J. W.

1988-01-01

Cold working and double aging yield high strength without sacrifice of resistance to corrosion. Report presents data on mechanical properties and stress-corrosion resistance of triple-melted, solution-treated, work-strengthened, direct-double-aged Inconel(R) 718 alloy. Triple melting consists of vacuum induction melting, electro-slag remelting, and vacuum arm remelting. Data indicate advance in processing of large-diameter bars. New process increases yield strength without reducing the elongation, reduction of area, and grain size.

Advanced Metalworking Solutions for Naval Systems That Go in Harm’s Way

DTIC Science & Technology

2012-01-01

the LCS Program Office; Lockheed Martin Corporation; Gibbs & Cox, Inc.; Titanium Fabrication Corporation; Marinette Marine Corporation; Naval Surface...currently clad with Alloy 625 using an electro-slag strip process, but noticeable wear has been observed in the areas of the propulsor bearing. This...shafts from the machine shop to another location in the repair yards, adding construction time and cost. The IPT optimized laser ablation and mechanical

Electroslag and electrogas welding

NASA Technical Reports Server (NTRS)

Campbell, H. C.

1972-01-01

These two new joining methods perform welding in the vertical position, and therein lies the secret of their impressive advantages in material handling, in weld preparation, in welding speed, in freedom from distortion, and in weld soundness. Once the work has been set in the proper vertical position for welding, no further plate handling is required. The molten filler metal is held in place by copper shoes or dams, and the weld is completed in one pass.

Materials Trends in Marine Construction

DTIC Science & Technology

1990-01-01

purposes. Nickel and 5 chromium are added to increase toughness and both nickel and molybdenum are used to control the response of the alloy to the Q&T...submerged metal arc welding (SAW): 15%; CO shielded gas metal arc welding (GMAW): 30%; with gas tungsten arc welding ( GTAW ) and electroslag welding...ESW) providing the remainder. GMAW is used more for the high strength quenched and tempered steels, while GTAW is used on a limited basis to remelt the

Numerical Investigation of Influence of Electrode Immersion Depth on Heat Transfer and Fluid Flow in Electroslag Remelting Process

NASA Astrophysics Data System (ADS)

Wang, Qiang; Cai, Hui; Pan, Liping; He, Zhu; Liu, Shuang; Li, Baokuan

2016-12-01

The influence of the electrode immersion depth on the electromagnetic, flow and temperature fields, as well as the solidification progress in an electroslag remelting furnace have been studied by a transient three-dimensional coupled mathematical model. Maxwell's equations were solved by the electrical potential approach. The Lorentz force and Joule heating were added into the momentum and energy conservation equations as a source term, respectively, and were updated at each time step. The volume of fluid method was invoked to track the motion of the metal droplet and slag-metal interface. The solidification was modeled by an enthalpy-porosity formulation. An experiment was carried out to validate the model. The total amount of Joule heating decreases from 2.13 × 105 W to 1.86 × 105 W when the electrode immersion depth increases from 0.01 m to 0.03 m. The variation law of the slag temperature is different from that of the Joule heating. The volume average temperature rises from 1856 K to 1880 K when the immersion depth increases from 0.01 m to 0.02 m, and then drops to 1869 K if the immersion depth continuously increases to 0.03 m. As a result, the deepest metal pool, which is around 0.03 m, is formed when the immersion depth is 0.02 m.

Simulation in Metallurgical Processing: Recent Developments and Future Perspectives

NASA Astrophysics Data System (ADS)

Ludwig, Andreas; Wu, Menghuai; Kharicha, Abdellah

2016-08-01

This article briefly addresses the most important topics concerning numerical simulation of metallurgical processes, namely, multiphase issues (particle and bubble motion and flotation/sedimentation of equiaxed crystals during solidification), multiphysics issues (electromagnetic stirring, electro-slag remelting, Cu-electro-refining, fluid-structure interaction, and mushy zone deformation), process simulations on graphical processing units, integrated computational materials engineering, and automatic optimization via simulation. The present state-of-the-art as well as requirements for future developments are presented and briefly discussed.

Three-Dimensional Mathematical Model of Oxygen Transport Behavior in Electroslag Remelting Process

NASA Astrophysics Data System (ADS)

Huang, Xuechi; Li, Baokuan; Liu, Zhongqiu

2018-04-01

A transient three-dimensional model has been proposed to investigate the oxygen transport behavior in electroslag remelting process. The electromagnetism, heat transfer, multiphase flow, and species transport were calculated simultaneously by finite volume method. The volume of fluid approach was adopted to trace the metal-slag-air three-phase flow. Based on the necessary thermodynamics of oxygen transport behavior, a kinetic model was established to predict the mass source terms in species transport equation. The kinetic correction factor was proposed to account for the effect of the oxide scale formed on the electrode on the FeO content in slag. Finally, the effect of applied current on the oxygen transfer was studied. The predicted result agrees well with the measured data when the kinetic correction factor is set to be 0.5. The temperature distribution that affects the thermodynamics differs at the interfaces. The oxygen in air is absorbed into slag due to the oxidation at the slag/air interface. The Fe2O3 in slag and the oxide scale contribute to the increase of FeO content in slag, and the latter one plays the leading role. The oxygen transfer from slag to metal mainly occurs during the formation of the droplet at the slag/metal droplet interface. With the current increasing from 1200 to 1800 A, the oxygen content increases from 76.4 to 89.8 ppm, and then slightly declines to 89.2 ppm when the current increases to 2100 A.

Deoxidation Limits of Titanium Alloys during Pressure Electro Slag Remelting

NASA Astrophysics Data System (ADS)

Bartosinski, M.; Hassan-Pour, S.; Friedrich, B.; Ratiev, S.; Ryabtsev, A.

2016-07-01

This paper focuses on deoxidation of titanium alloys produced by aluminothermic reduction (ATR) and subsequent homogenizing and alloying by vacuum induction melting (VIM). The main goal of the performed research work is to outline the deoxidation limit during pressure electro slag remelting (PESR) of the described material. To obtain electrodes for deoxidation, a Ti-24Al-16V masteralloy was produced by ATR and afterwards melted in a 0.5 litre calcium- zirconate (lab scale) or 14 litres high purity calcia (pilot scale) crucibles with continuous addition of Ti-sponge after reaching liquid state in order to obtain a final Ti-6Al-4V alloy. During melting, in both cases evaporation of calcium was noticed. The cast ingots were analysed for oxygen using inert gas fusion method, matrix and alloying elements were analysed by XRF. Results show oxygen levels between 0.5 and 0.95 wt.-% for the ingots which were melted in calcium-zirconate crucibles and approx. 1 - 1.2 wt.-% for the material produced by utilization of calcia crucibles. The subsequent deoxidation was carried out in lab and pilot scale electroslag remelting furnaces using a commercially pure calcium fluoride slag and metallic calcium as deoxidation agent. It could be shown, that deoxidation of the highly contaminated material is possible applying this method to a certain limit. Pilot scale trials showed a reduction of oxygen contents by 1500 - 3500 ppm. Oxygen levels in lab scale trials showed weaker deoxidation effects. In order to describe the achieved deoxidation effects in a quantitative way, the analyzed oxygen contents of the obtained ingots are compared with calculated data resulting from a mathematical kinetic model. The modelled datasets are in good agreement with experimental oxygen values.

Modern trends in increasing the quality of the steels intended for cutting and metal-working tools: I. Improvement of granule metallurgy processes

NASA Astrophysics Data System (ADS)

Belyanchikov, L. N.

2008-12-01

The following new technological processes for producing fine gas-atomized powders of tool and high-speed steels with a low content of nonmetallic inclusions are considered: the process designed by Böhler Uddeholm Powder Technology (Austria) and processes involving a heated gas. In the former process, a metal is poured from a ladle with electroslag heating, and the atomizing unit consists of three injectors. A new process of producing tools from fine powders by three-dimensional printing, i.e., so-called 3D-printing, is described.

Investigation of Slag Compositions and Pressure Ranges Suitable for Electroslag Remelting under Vacuum Conditions

NASA Astrophysics Data System (ADS)

Radwitz, S.; Scholz, H.; Friedrich, B.

It is well known that high contents of oxygen and hydrogen in creep resistant structural steels like 21CrMoV5-7 have negative influence on a variety of material properties. To investigate the refining ability of various slag compositions under reduced pressure multiple experiments were performed in a 40 kW vacuum-induction furnace with the aim to ensure minimal oxygen and hydrogen contents. With regard to slag evaporation, different mixtures of fluorides and oxides as well as pure oxide systems were utilized. The pressure was varied in the range of 5 and 700 mbar.

Investigation of Heat Transfer and Magnetohydrodynamic Flow in Electroslag Remelting Furnace Using Vibrating Electrode

NASA Astrophysics Data System (ADS)

Wang, Fang; Wang, Qiang; Lou, Yanchun; Chen, Rui; Song, Zhaowei; Li, Baokuan

2016-01-01

A transient three-dimensional (3D) coupled mathematical model has been developed to understand the effect of a vibrating electrode on the electromagnetic, two-phase flow and temperature fields as well as the solidification in the electroslag remelting (ESR) process. With the magnetohydrodynamic model, the Joule heating and Lorentz force, which are the source terms in the energy and momentum equations, are recalculated at each iteration as a function of the phase distribution. The influence of the vibrating electrode on the formation of the metal droplet is demonstrated by the volume of fluid approach. Additionally, the solidification of the metal is modeled by an enthalpy-based technique, in which the mushy zone is treated as a porous medium with porosity equal to the liquid fraction. The present work is the first attempt to investigate the innovative technology of the ESR process with a vibrating electrode by a transient 3D comprehensive model. A reasonable agreement between the experiment and simulation is obtained. The results indicate that the whole process is presented as a periodic activity. When the metal droplets fall from the tip of the electrode, the horizontal component of velocity will generate electrode vibration. This will lead to the distribution variation of the flow field in the slag layer. The variation of temperature distribution occurs regularly and is periodically accompanied by the behavior of the falling metal droplets. With the decreasing vibrating frequency and amplitude, the relative velocity of the electrode and molten slag increase accordingly. The diameter of the molten droplets, the maximum temperature and the depth of the molten pool gradually become smaller, lower and shallower.

Effects of Reoxidation of Liquid Steel and Slag Composition on the Chemistry Evolution of Inclusions During Electroslag Remelting

NASA Astrophysics Data System (ADS)

Shi, Chengbin; Wang, Hui; Li, Jing

2018-06-01

Electroslag remelting (ESR) is increasingly used to produce some varieties of special steels and alloys, mainly because of its ability to provide extreme cleanliness and an excellent solidification structure simultaneously. In the present study, the combined effects of varying SiO2 contents in slag and reoxidation of liquid steel on the chemistry evolution of inclusions and the alloying element content in steel during ESR were investigated. The inclusions in the steel before ESR refining were found to be oxysulfides of patch-type (Ca,Mn)S adhering to a CaO-Al2O3-SiO2-MgO inclusion. The oxide inclusions in both the liquid metal pool and remelted ingots are CaO-Al2O3-MgO and MgAl2O4 together with CaO-Al2O3-SiO2-MgO inclusions (slightly less than 30 pct of the total inclusions), which were confirmed to originate from the reduction of SiO2 from the original oxide inclusions by dissolved Al in liquid steel during ESR. CaO-Al2O3-MgO and MgAl2O4 are newly formed inclusions resulting from the reactions taking place inside liquid steel in the liquid metal pool caused by reoxidation of liquid steel during ESR. Increasing the SiO2 content in slag not only considerably reduced aluminum pickup in parallel with silicon loss during ESR, but also suppressed the decrease in SiO2 content in oxide inclusions. (Ca,Mn)S inclusions were fully removed before liquid metal droplets collected in the liquid metal pool.

Method for treating rare earth-transition metal scrap

DOEpatents

Schmidt, Frederick A.; Peterson, David T.; Wheelock, John T.; Jones, Lawrence L.

1992-12-29

Rare earth-transition metal (e.g., iron) scrap (e.g., Nd-Fe-B scrap) is flux (slag) remelted to reduce tramp non-metallic impurities, such as oxygen and nitrogen, and metallic impurities, such as Li, Na, Al, etc., picked up by the scrap from previous fabrication operations. The tramp impurities are reduced to concentrations acceptable for reuse of the treated alloy in the manufacture of end-use articles, such as permanent magnets. The scrap is electroslag or inductoslag melted using a prefused, rare earth fluoride-bearing flux of CaF.sub.2, CaCl.sub.2 or mixtures thereof or the slag resulting from practice of the thermite reduction process to make a rare earth-iron alloy.

Method for treating rare earth-transition metal scrap

DOEpatents

Schmidt, F.A.; Peterson, D.T.; Wheelock, J.T.; Jones, L.L.

1992-12-29

Rare earth-transition metal (e.g., iron) scrap (e.g., Nd-Fe-B scrap) is flux (slag) remelted to reduce tramp non-metallic impurities, such as oxygen and nitrogen, and metallic impurities, such as Li, Na, Al, etc., picked up by the scrap from previous fabrication operations. The tramp impurities are reduced to concentrations acceptable for reuse of the treated alloy in the manufacture of end-use articles, such as permanent magnets. The scrap is electroslag or inductoslag melted using a rare earth fluoride-bearing flux of CaF[sub 2], CaCl[sub 2] or mixtures thereof or the slag resulting from practice of the thermite reduction process to make a rare earth-iron alloy. 3 figs.

Dynamic control of remelting processes

DOEpatents

Bertram, Lee A.; Williamson, Rodney L.; Melgaard, David K.; Beaman, Joseph J.; Evans, David G.

2000-01-01

An apparatus and method of controlling a remelting process by providing measured process variable values to a process controller; estimating process variable values using a process model of a remelting process; and outputting estimated process variable values from the process controller. Feedback and feedforward control devices receive the estimated process variable values and adjust inputs to the remelting process. Electrode weight, electrode mass, electrode gap, process current, process voltage, electrode position, electrode temperature, electrode thermal boundary layer thickness, electrode velocity, electrode acceleration, slag temperature, melting efficiency, cooling water temperature, cooling water flow rate, crucible temperature profile, slag skin temperature, and/or drip short events are employed, as are parameters representing physical constraints of electroslag remelting or vacuum arc remelting, as applicable.

Application experience of grade 10Kh9MFB chromium steel for steam shutoff and control valve bodies

NASA Astrophysics Data System (ADS)

Skorobogatykh, V. N.; Schenkova, I. A.; Danyushevskiy, I. A.; Grin', E. A.; Levkov, L. Ya.; Prudnikov, D. A.; Zhuravlev, D. N.; Bazhenov, A. M.

2017-04-01

In 2014-2015, the engineers of JSC "NPO "TsNIITMash", in cooperation with JSC "Energomash (Chekhov)—ChZEM", developed a technology for manufacturing D u = 250 mm valve bodies from 10Kh9MFB chromium steel by electroslag melting (ESM) and produced their pilot copies within the frame of import substitution program. This article provides results of research into determining the design values of metal characteristics, including short-term mechanical properties at working temperatures and impact and long-term strength. The test specimens have been sampled from the following four zones: bottom, central, branch-pipe, and head. Tensile short-term rupture testing has been performed at temperatures of 350, 450, 500, 550, 600, and 650°C. Testing for long-term strength has been carried out at temperatures of 550, 575, 600, and 625°C and stresses of 156.8, 137.2, 117.6, and 98 MPa. To estimate brittle fracture resistance, impact-strength tests have been run at temperatures of-20 and-10°C; 20 and 50°C. The specimens have been sampled from the middle of the blank section. All short-term mechanical properties and impact strength are in agreement with the requirements imposed on the metal of hot-deformed steam piping made of 10Kh9MFB steel as per TU (Technical Conditions) 14-3R-55-2001. The absence of microliquation of alloying elements and the high homogeneity of chemical composition (as demonstrated with nine specimens) have also been experimentally confirmed. Metallographic analysis has shown that the structure of the tested metal is that of tempered martensite with local areas of tempered bainite. Overall, the microscopic structure of metal is practically the same in all the studied zones. Service-life calculation of pilot valve bodies has proved conformity with the safety-margin regulations. Such properties of electroslag melting blank as long-term strength and allowable stress correspond to the level of deformed metal and to regulations.

Investigation into the Cyclic Strength of the Bodies of Steam Shutoff Valves from 10Kh9MFB-Sh Steel

NASA Astrophysics Data System (ADS)

Skorobogatykh, V. N.; Kunavin, S. A.; Prudnikov, D. A.; Shchenkova, I. A.; Bazhenov, A. M.; Zadoinyi, V. A.; Starkovskii, G. L.

2018-02-01

Steam shutoff valves are operated under complex loading conditions at thermal and nuclear power stations. In addition to exposure to high temperature and stresses resulting in fatigue, these valves are subjected to cyclic loads in heating-up-cooling down, opening-closing, etc. cycles. The number of these cycles to be specified in designing the valves should not exceed the maximum allowable value. Hence, the problem of cyclic failure rate of steam shutoff valve bodies is critical. This paper continues the previous publications about properties of the construction material for steam shutoff valve bodies (grade 10Kh9MFB-Sh steel) produced by electroslag melting and gives the results of investigation into the cyclic strength of this material. Fatigue curves for the steal used for manufacturing steam shutoff valve bodies are presented. The experimental data are compared with the calculated fatigue curves plotted using the procedures outlined in PNAE G-002-986 and RD 10-249-98. It is confirmed that these procedures may be used in designing valve bodies from 10Kh9MFB-Sh steel. The effect of the cyclic damage after preliminary cyclic loading of the specimens according to the prescribed load conditions on the high-temperature strength of the steel is examined. The influence of cyclic failure rate on the long-term strength was investigated using cylindrical specimens with a smooth working section in the as-made conditions and after two regimes of preliminary cyclic loading (training) at a working temperature of 570°C and the number of load cycles exceeding the design value, which was 2 × 103 cycles. The experiments corroborated that the material (10Kh9MFB-Sh steel) of the body manufactured by the method of electroslag melting had high resistance to cyclic failure rate. No effect of cyclic damages in the metal of the investigated specimens on the high-temperature strength has been found.

Further development and characterization of VM-103, a NASA wrought cobalt base alloy

NASA Technical Reports Server (NTRS)

Harlow, R. A.; Ritchie, E. E.

1972-01-01

The data obtained during this and previous programs indicate that the VM-103 has useful strength at temperatures as high 2200 F (1204 C), and can be considered as an alternate for other wrought superalloys such as L-605. The addition of 10 percent nickel to the standard composition improves both the hot and cold fabricability, ductility, impact strength, and metallurgical stability, while it only slightly reduces strength properties. Electroslag re-melting was effective in significantly increasing the fabricability of vacuum induction method VM-103, both with and without the 10 percent nickel addition. A specification for wrought VM-103 was developed and is included. Although thermomechanical processing improves lower temperature properties, no improvement occurs at temperatures at or above 2000 F (1093 C).

Generalized Constitutive-Based Theoretical and Empirical Models for Hot Working Behavior of Functionally Graded Steels

NASA Astrophysics Data System (ADS)

Vanini, Seyed Ali Sadough; Abolghasemzadeh, Mohammad; Assadi, Abbas

2013-07-01

Functionally graded steels with graded ferritic and austenitic regions including bainite and martensite intermediate layers produced by electroslag remelting have attracted much attention in recent years. In this article, an empirical model based on the Zener-Hollomon (Z-H) constitutive equation with generalized material constants is presented to investigate the effects of temperature and strain rate on the hot working behavior of functionally graded steels. Next, a theoretical model, generalized by strain compensation, is developed for the flow stress estimation of functionally graded steels under hot compression based on the phase mixture rule and boundary layer characteristics. The model is used for different strains and grading configurations. Specifically, the results for αβγMγ steels from empirical and theoretical models showed excellent agreement with those of experiments of other references within acceptable error.

Effect of deoxidation practice and heat treatment on the hydrogen attack of carbon steels

NASA Astrophysics Data System (ADS)

López, Hugo F.

1987-11-01

The hydrogen attack (HA) kinetics of an electroslag refined (ESR) and a rare earth metal (REM)-treated steel in the Q. and T. condition were investigated by a highly sensitive dilatometer. Measured activation energies for bubble growth of 108 to 203 kJ/mol and pressure exponents of 0.9 to 1.6 are rationalized in terms of surface or grain boundary self-diffusion of iron as the rate controlling mechanisms depending on the external hydrogen pressure and temperature. Comparisons of the HA susceptibility of these steels with published work show that although the HA resistance of the ESR steel is not influenced by the heat treatment, the REM steel shows a significant decrease in the rate of sample expansion. SEM observations indicate that the improvement in the HA resistance of the REM steel is related to the presence of a very low density of methane bubbles.

Microstructure Characterization and Corrosion Resistance Behavior of New Cobalt-Free Maraging Steel Produced Through ESR Techniques

NASA Astrophysics Data System (ADS)

Seikh, Asiful H.; Halfa, Hossam; Baig, Muneer; Khan, Sohail M. A.

2017-04-01

In this study, two different grades (M23 and M29) of cobalt-free low nickel maraging steel have been produced through electroslag remelting (ESR) process. The corrosion resistance of these ESR steels was investigated in 1 M H2SO4 solution using linear potentiodynamic polarization (LPP) and electrochemical impedance spectroscopy (EIS) techniques. The experiments were performed for different immersion time and solution temperature. To evaluate the corrosion resistance of the ESR steels, some significant characterization parameters from LPP and EIS curves were analyzed and compared with that of conventional C250 maraging steel. Irrespective of measurement techniques used, the results show that the corrosion resistance of the ESR steels was higher than the C250 steel. The microstructure of ESR steels was composed of uniform and well-distributed martensite accompanied with little amount of retained austenite in comparison with C250 steel.

Effect of Casting Material on the Cast Pressure After Sequential Cast Splitting.

PubMed

Roberts, Aaron; Shaw, K Aaron; Boomsma, Shawn E; Cameron, Craig D

2017-01-01

Circumferential casting is a vital component of nonoperative fracture management. These casts are commonly valved to release pressure and decrease the risk of complications from swelling. However, little information exists regarding the effect of different casting supplies on the pressure within the cast. Seventy-five long-arm casts were performed on human volunteers, divided between 5 experimental groups with 15 casts in each groups. Testing groups consisted of 2 groups with a plaster short-arm cast overwrapped with fiberglass to a long arm with either cotton or synthetic cast padding. The 3 remaining groups included fiberglass long-arm casts with cotton, synthetic, or waterproof cast padding. A pediatric blood pressure cuff bladder was placed within the cast and inflated to 100 mm Hg. After inflation, the cast was sequentially released with pressure reading preformed after each stage. Order of release consisted of cast bivalve, cast padding release, and cotton stockinet release. After release, the cast was overwrapped with a loose elastic bandage. Difference in pressure readings were compared based upon the cast material. Pressures within the cast were found to decrease with sequential release of cast. The cast type had no effect of change in pressure. Post hoc testing demonstrated that the type of cast padding significantly affected the cast pressures with waterproof padding demonstrating the highest pressure readings at all time-points in the study, followed by synthetic padding. Cotton padding had the lowest pressure readings at all time-points. Type of cast padding significantly influences the amount of pressure within a long-arm cast, even after bivalving the cast and cutting the cast padding. Cotton cast padding allows for the greatest change in pressure. Cotton padding demonstrates the greatest change in pressure within a long-arm cast after undergoing bivalve. Synthetic and waterproof cast padding should not be used in the setting of an acute fracture to accommodate swelling.

Comparison of marginal accuracy of castings fabricated by conventional casting technique and accelerated casting technique: an in vitro study.

PubMed

Reddy, S Srikanth; Revathi, Kakkirala; Reddy, S Kranthikumar

2013-01-01

Conventional casting technique is time consuming when compared to accelerated casting technique. In this study, marginal accuracy of castings fabricated using accelerated and conventional casting technique was compared. 20 wax patterns were fabricated and the marginal discrepancy between the die and patterns were measured using Optical stereomicroscope. Ten wax patterns were used for Conventional casting and the rest for Accelerated casting. A Nickel-Chromium alloy was used for the casting. The castings were measured for marginal discrepancies and compared. Castings fabricated using Conventional casting technique showed less vertical marginal discrepancy than the castings fabricated by Accelerated casting technique. The values were statistically highly significant. Conventional casting technique produced better marginal accuracy when compared to Accelerated casting. The vertical marginal discrepancy produced by the Accelerated casting technique was well within the maximum clinical tolerance limits. Accelerated casting technique can be used to save lab time to fabricate clinical crowns with acceptable vertical marginal discrepancy.

A numerical study on electrochemical transport of ions in calcium fluoride slag

NASA Astrophysics Data System (ADS)

Karimi-Sibaki, E.; Kharicha, A.; Wu, M.; Ludwig, A.

2016-07-01

Electrically resistive CaF 2-based slags are widely used in electroslag remelting (ESR) process to generate Joule heat for the melting of electrode. The electric current is conducted by ions (electrolyte) such as Ca +2 or F -, thus it is necessary to establish electrochemical models to study electrical behavior of slag. This paper presents a numerical model on electrochemical transport of ions in an arbitrary symmetrical (ZZ) and non-symmetrical (CaF2) stagnant electrolytes blocked by two parallel, planar electrodes. The dimensionless Poisson-Nernst-Planck (PNP) equations are solved to model electro-migration and diffusion of ions. The ions are considered to be inert that no Faradic reactions occur. Spatial variations of concentrations of ions, charge density and electric potential across the electrolyte are analyzed. It is shown that the applied potential has significant influence on the system response. At high applied voltage, the anodic potential drop near the electrode is significantly larger than cathodic potential drop in fully dissociated CaF2 electrolyte.

Radioactive scrap metal decontamination technology assessment report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Buckentin, J.M.; Damkroger, B.K.; Schlienger, M.E.

1996-04-01

Within the DOE complex there exists a tremendous quantity of radioactive scrap metal. As an example, it is estimated that within the gaseous diffusion plants there exists in excess of 700,000 tons of contaminated stainless steel. At present, valuable material is being disposed of when it could be converted into a high quality product. Liquid metal processing represents a true recycling opportunity for this material. By applying the primary production processes towards the material`s decontamination and re-use, the value of the strategic resource is maintained while drastically reducing the volume of material in need of burial. Potential processes for themore » liquid metal decontamination of radioactively contaminated metal are discussed and contrasted. Opportunities and technology development issues are identified and discussed. The processes compared are: surface decontamination; size reduction, packaging and burial; melting technologies; electric arc melting; plasma arc centrifugal treatment; air induction melting; vacuum induction melting; and vacuum induction melting and electroslag remelting.« less

Effects of heat input on the pitting resistance of Inconel 625 welds by overlay welding

NASA Astrophysics Data System (ADS)

Kim, Jun Seok; Park, Young IL; Lee, Hae Woo

2015-03-01

The objective of this study was to establish the relationship between the dilution ratio of the weld zone and pitting resistance depending on the heat input to welding of the Inconel alloy. Each specimen was produced by electroslag welding using Inconel 625 as the filler metal. In the weld zone of each specimen, dendrite grains were observed near the fusion line and equiaxed grains were observed on the surface. It was also observed that a melted zone with a high Fe content was formed around the fusion line, which became wider as the welding heat input increased. In order to evaluate the pitting resistance, potentiodynamic polarization tests and CPT tests were conducted. The results of these tests confirmed that there is no difference between the pitting resistances of each specimen, as the structures of the surfaces were identical despite the effect of the differences in the welding heat input for each specimen and the minor dilution effect on the surface.

Microstructural changes of a thermally aged stainless steel submerged arc weld overlay cladding of nuclear reactor pressure vessels

NASA Astrophysics Data System (ADS)

Takeuchi, T.; Kameda, J.; Nagai, Y.; Toyama, T.; Matsukawa, Y.; Nishiyama, Y.; Onizawa, K.

2012-06-01

The effect of thermal aging on microstructural changes in stainless steel submerged arc weld-overlay cladding of reactor pressure vessels was investigated using atom probe tomography (APT). In as-received materials subjected to post-welding heat treatments (PWHTs), with a subsequent furnace cooling, a slight fluctuation of the Cr concentration was observed due to spinodal decomposition in the δ-ferrite phase but not in the austenitic phase. Thermal aging at 400 °C for 10,000 h caused not only an increase in the amplitude of spinodal decomposition but also the precipitation of G phases with composition ratios of Ni:Si:Mn = 16:7:6 in the δ-ferrite phase. The degree of the spinodal decomposition in the submerged arc weld sample was similar to that in the electroslag weld one reported previously. We also observed a carbide on the γ-austenite and δ-ferrite interface. There were no Cr depleted zones around the carbide.

Fibreglass Total Contact Casting, Removable Cast Walkers, and Irremovable Cast Walkers to Treat Diabetic Neuropathic Foot Ulcers: A Health Technology Assessment

PubMed Central

Costa, Vania; Tu, Hong Anh; Wells, David; Weir, Mark; Holubowich, Corinne; Walter, Melissa

2017-01-01

Background Diabetic neuropathic foot ulcers are a risk factor for lower leg amputation. Many experts recommend offloading with fibreglass total contact casting, removable cast walkers, and irremovable cast walkers as a way to treat these ulcers. Methods We completed a health technology assessment, which included an evaluation of clinical benefits and harms, value for money, and patient preferences for offloading devices. We performed a systematic literature search on August 17, 2016, to identify randomized controlled trials that compared fibreglass total contact casting, removable cast walkers, and irremovable cast walkers with other treatments (offloading or non-offloading) in patients with diabetic neuropathic foot ulcers. We developed a decision-analytic model to assess the cost-effectiveness of fibreglass total contact casting, removable cast walkers, and irremovable cast walkers, and we conducted a 5-year budget impact analysis. Finally, we interviewed people with diabetes who had lived experience with foot ulcers, asking them about the different offloading devices and the factors that influenced their treatment choices. Results We identified 13 randomized controlled trials. The evidence suggests that total contact casting, removable cast walkers, and irremovable cast walkers are beneficial in the treatment of neuropathic, noninfected foot ulcers in patients with diabetes but without severe peripheral arterial disease. Compared to removable cast walkers, ulcer healing was improved with total contact casting (moderate quality evidence; risk difference 0.17 [95% confidence interval 0.00–0.33]) and irremovable cast walkers (low quality evidence; risk difference 0.21 [95% confidence interval 0.01–0.40]). We found no difference in ulcer healing between total contact casting and irremovable cast walkers (low quality evidence; risk difference 0.02 [95% confidence interval −0.11–0.14]). The economic analysis showed that total contact casting and irremovable cast walkers were less expensive and led to more health outcome gains (e.g., ulcers healed and quality-adjusted life-years) than removable cast walkers. Irremovable cast walkers were as effective as total contact casting and were associated with lower costs. The 5-year budget impact of funding total contact casting, removable cast walkers, and irremovable cast walkers (device costs only at 100% access) would be $17 to $20 million per year. The patients we interviewed felt that wound healing was improved with total contact casting than with removable cast walkers, but that removable cast walkers were more convenient and came with a lower cost burden. They reported no experience or familiarity with irremovable cast walkers. Conclusions Ulcer healing improved with total contact casting, irremovable cast walkers, and removable cast walkers, but total contact casting and irremovable cast walkers had higher rates of ulcer healing than removable cast walkers. Increased access to offloading devices could result in cost savings for the health system because of fewer amputations. Patients with diabetic foot ulcers reported a preference for total contact casting over removable cast walkers, largely because they perceived wound healing to be improved with total contact casting. However, cost, comfort, and convenience are concerns for patients. PMID:28989556

Fibreglass Total Contact Casting, Removable Cast Walkers, and Irremovable Cast Walkers to Treat Diabetic Neuropathic Foot Ulcers: A Health Technology Assessment.

PubMed

2017-01-01

Diabetic neuropathic foot ulcers are a risk factor for lower leg amputation. Many experts recommend offloading with fibreglass total contact casting, removable cast walkers, and irremovable cast walkers as a way to treat these ulcers. We completed a health technology assessment, which included an evaluation of clinical benefits and harms, value for money, and patient preferences for offloading devices. We performed a systematic literature search on August 17, 2016, to identify randomized controlled trials that compared fibreglass total contact casting, removable cast walkers, and irremovable cast walkers with other treatments (offloading or non-offloading) in patients with diabetic neuropathic foot ulcers. We developed a decision-analytic model to assess the cost-effectiveness of fibreglass total contact casting, removable cast walkers, and irremovable cast walkers, and we conducted a 5-year budget impact analysis. Finally, we interviewed people with diabetes who had lived experience with foot ulcers, asking them about the different offloading devices and the factors that influenced their treatment choices. We identified 13 randomized controlled trials. The evidence suggests that total contact casting, removable cast walkers, and irremovable cast walkers are beneficial in the treatment of neuropathic, noninfected foot ulcers in patients with diabetes but without severe peripheral arterial disease. Compared to removable cast walkers, ulcer healing was improved with total contact casting (moderate quality evidence; risk difference 0.17 [95% confidence interval 0.00-0.33]) and irremovable cast walkers (low quality evidence; risk difference 0.21 [95% confidence interval 0.01-0.40]). We found no difference in ulcer healing between total contact casting and irremovable cast walkers (low quality evidence; risk difference 0.02 [95% confidence interval -0.11-0.14]). The economic analysis showed that total contact casting and irremovable cast walkers were less expensive and led to more health outcome gains (e.g., ulcers healed and quality-adjusted life-years) than removable cast walkers. Irremovable cast walkers were as effective as total contact casting and were associated with lower costs. The 5-year budget impact of funding total contact casting, removable cast walkers, and irremovable cast walkers (device costs only at 100% access) would be $17 to $20 million per year. The patients we interviewed felt that wound healing was improved with total contact casting than with removable cast walkers, but that removable cast walkers were more convenient and came with a lower cost burden. They reported no experience or familiarity with irremovable cast walkers. Ulcer healing improved with total contact casting, irremovable cast walkers, and removable cast walkers, but total contact casting and irremovable cast walkers had higher rates of ulcer healing than removable cast walkers. Increased access to offloading devices could result in cost savings for the health system because of fewer amputations. Patients with diabetic foot ulcers reported a preference for total contact casting over removable cast walkers, largely because they perceived wound healing to be improved with total contact casting. However, cost, comfort, and convenience are concerns for patients.

Soft cast versus rigid cast for treatment of distal radius buckle fractures in children.

PubMed

Witney-Lagen, Caroline; Smith, Christine; Walsh, Graham

2013-04-01

Buckle fractures are extremely common and their optimum management is still under debate. This study aimed to ascertain whether buckle fractures of the distal radius can be safely and effectively treated in soft cast with only a single orthopaedic outpatient clinic appointment. A total of 232 children with buckle fractures of the distal radius were included in the study. 111 children with 112 distal radius fractures were treated in full rigid cast and 121 children with 123 fractures were treated with soft cast. The rigid cast children attended outpatient clinic for removal of cast at 3 weeks. Soft casts were removed by parents unwinding the cast at home after 3 weeks. Follow-up was conducted prospectively by telephone questionnaire at an average of 6 weeks post-injury. Outcome data were available for 117 children treated in soft cast and for 102 children treated in rigid cast. The most common mechanism of injury was a fall sustained from standing or running, followed by falls from bikes and then trampoline accidents. Overall, both groups recovered well. Overall satisfaction with the outcome of treatment was 97.4% in soft cast and 95.2% in rigid cast. Casts were reported as comfortable by 95.7% in soft cast and 93.3% in rigid cast. Cast changes were required for 6.8% of soft casts and 11.5% of rigid casts. The most frequent cause for changing rigid casts was getting the cast wet. None of the improved scores seen in the soft cast group were statistically significant. No re-fractures were seen in either group. Nearly all (94.9%) children in soft cast did bathe, shower or swim in their cast. Parents of both groups preferred treatment with soft cast (p < 0.001). Reasons given for preferring the soft cast included the ability to get the cast wet, avoidance of the plaster saw and not having to take time off work to attend a follow-up visit for cast removal. Buckle fractures of the distal radius can be safely and effectively treated in soft cast with only a single orthopaedic outpatient clinic appointment. Copyright © 2012 Elsevier Ltd. All rights reserved.

Incidence and etiology of unplanned cast changes for fractures in the pediatric population.

PubMed

DiPaola, Matthew J; Abzug, Joshua M; Pizzutillo, Peter D; Herman, Martin J

2014-09-01

The majority of pediatric fractures are treated in casts due to the child's ability to heal rapidly and remodel. Unplanned cast changes are a time and economic burden with potentially adverse effects on fracture management. The purpose of this study is to document the incidence, etiology, and complications related to unplanned cast changes. A prospective study was conducted over a 6-month period to determine the incidence of unplanned cast changes. All casts applied were nonwaterproof. Data collected include the reason for cast placement, type of cast placed, duration of wear before the unplanned change, reason for the unplanned change, experience level of the original cast applicator, and cast-related complications. A total of 1135 casts were placed with 58% placed by a resident, 38% by a cast technician, 2% by a physician's assistant, and 2% by an attending physician. Sixty casts (5.3%) required an unplanned change including 19 short-arm casts, 18 short-leg casts, 17 long-arm casts, 4 thumb spica casts, and 2 long-leg casts. The average duration from cast application until the unplanned change was 13 days. Twenty-eight (47%) were changed for wetness, 20 (33%) for wear/breakage, 2 (3%) for skin irritation, and 10 (17%) for other reasons including objects in the cast and patient self-removal. Two patients had superficial skin infections requiring oral antibiotics. No fracture reductions were lost secondary to an unplanned cast change. The need for an unplanned cast change did not correlate with the level of experience of the applicator. Most unplanned cast changes were the result of patient nonadherence to instructions and not related to cast application technique. Improved patient and family education regarding cast care may reduce the frequency of unplanned cast changes, thus reducing an economic and time burden on the health care system. Level II--prognostic study.

Reducing the Incidence of Cast-related Skin Complications in Children Treated With Cast Immobilization.

PubMed

Difazio, Rachel L; Harris, Marie; Feldman, Lanna; Mahan, Susan T

2017-12-01

Cast immobilization remains the mainstay of pediatric orthopaedic care, yet little is known about the incidence of cast-related skin complications in children treated with cast immobilization. The purposes of this quality improvement project were to: (1) establish a baseline rate of cast-related skin complications in children treated with cast immobilization, (2) identify trends in children who experienced cast-related skin complications, (3) design an intervention aimed at decreasing the rate of cast-related skin complications, and (4) determine the effectiveness of the intervention. A prospective interrupted time-series design was used to determine the incidence of cast-related skin complications overtime and compare the rates of skin complications before and after an intervention designed to decrease the incidence of cast-related heel complications. All consecutive patients who were treated with cast immobilization from September 2012 to September 2014 were included. A cast-related skin complications data collection tool was used to capture all cast-related skin complications. A high rate of heel events was noted in our preliminary analysis and an intervention was designed to decrease the rate of cast-related skin complications, including the addition of padding during casting and respective provider education. The estimated cast-related skin events rate for all patients was 8.9 per 1000 casts applied. The rate for the total preintervention sample was 13.6 per 1000 casts which decreased to 6.6 in the postintervention sample. When examining the heel-only group, the rate was 17.1 per 1000 lower extremity casts applied in the preintervention group and 6.8 in the postintervention group. Incorporating padding to the heel of lower extremity cast was an effective intervention in decreasing the incidence of cast-related skin complications in patients treated with cast immobilization. Level II.

Evaluation of the AISI 904L Alloy Weld Overlays Obtained by GMAW and Electro-Slag Welding Processes

NASA Astrophysics Data System (ADS)

Jorge, Jorge C. F.; Meira, O. G.; Madalena, F. C. A.; de Souza, L. F. G.; Araujo, L. S.; Mendes, M. C.

2017-05-01

The use of superaustenitic stainless steels (SASS) as an overlay replacement for nickel-based alloys can be an interesting alternative for the oil and gas industries, due to its lower cost, when compared to superalloys. Usually, the deposition is made with several welding passes by using conventional arc welding processes, such as gas tungsten arc welding (GTAW) or gas metal arc welding (GMAW) processes. In this respect, electro-slag welding (ESW), which promotes high heat inputs and low dilution of the welds, can also be attractive for this application, as it provides a higher productivity, once only one layer is needed for the deposition of the minimum thickness required. The present work evaluates the behavior of an AISI 904L SASS weld overlay deposited on a carbon steel ASTM A516 Grade 70 by ESW and GMAW processes. Both as-welded and heat-treated conditions were evaluated and compared. A multipass welding by GMAW process with three layers and 48 passes was performed on 12.5 × 200 × 250 mm steel plates with average welding energy of 1.0 kJ/mm. For ESW process, only one layer was deposited on 50 × 400 × 400 mm steel plates with average welding energy of 11.7 kJ/mm. After welding, a post-weld heat treatment (PWHT) at 620 °C for 10 h was performed in half of the steel plate, in order to allow the comparison between this condition and the as-welded one. For both processes, the austenitic microstructure of the weld deposits was characterized by optical microscopy and scanning electron microscopy with electron backscatter diffraction. A low proportion of secondary phases were observed in all conditions, and the PWHT did not promote significant changes on the hardness profile. Martensite for GMAW process and bainite for ESW process were the microstructural constituents observed at the coarse grain heat-affected zone, due to the different cooling rates. For ESW process, no evidences of partially diluted zones were found. As a consequence of the microstructural findings, the hardness results for ESW were lower than those usually observed for other electric arc welding processes. In addition, specimens subject to bending tests performed in accordance with the current standards used for qualification of welding procedures were approved. These evidences allow the conclusion that the ESW process can provide deposits with high quality despite the high welding energy levels, in order to achieve the desired productivity, being an interesting alternative for AISI 904L weld overlays.

Determining casting defects in near-net shape casting aluminum parts by computed tomography

NASA Astrophysics Data System (ADS)

Li, Jiehua; Oberdorfer, Bernd; Habe, Daniel; Schumacher, Peter

2018-03-01

Three types of near-net shape casting aluminum parts were investigated by computed tomography to determine casting defects and evaluate quality. The first, second, and third parts were produced by low-pressure die casting (Al-12Si-0.8Cu-0.5Fe-0.9Mg-0.7Ni-0.2Zn alloy), die casting (A356, Al-7Si-0.3Mg), and semi-solid casting (A356, Al-7Si-0.3Mg), respectively. Unlike die casting (second part), low-pressure die casting (first part) significantly reduced the formation of casting defects (i.e., porosity) due to its smooth filling and solidification under pressure. No significant casting defect was observed in the third part, and this absence of defects indicates that semi-solid casting could produce high-quality near-net shape casting aluminum parts. Moreover, casting defects were mostly distributed along the eutectic grain boundaries. This finding reveals that refinement of eutectic grains is necessary to optimize the distribution of casting defects and reduce their size. This investigation demonstrated that computed tomography is an efficient method to determine casting defects in near-net shape casting aluminum parts.

Urinary casts

MedlinePlus

... tubular epithelial casts; Waxy casts; Casts in the urine; Fatty casts; Red blood cell casts; White blood ... The urine sample you provide may need to be from your first morning urine. The sample needs to be ...

Casting Technology.

ERIC Educational Resources Information Center

Wright, Michael D.; And Others

1992-01-01

Three articles discuss (1) casting technology as it relates to industry, with comparisons of shell casting, shell molding, and die casting; (2) evaporative pattern casting for metals; and (3) high technological casting with silicone rubber. (JOW)

Electronic gap sensor and method

DOEpatents

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

1991-08-06

Disclosed are an apparatus and method for regulating the gap between a casting nozzle and a casting wheel in which the gap between the casting nozzle and the casting wheel is monitored by means of at least one sensing element protruding from the face of the casting nozzle. The sensing element is preferably connected to a voltage source and the casting wheel grounded. When the sensing element contacts the casting wheel, an electric circuit is completed. The completion of the circuit can be registered by an indicator, and the presence or absence of a completed circuit indicates the relative position of the casting nozzle to the casting wheel. The relative positions of the casting nozzle and casting wheel can thereby be selectively adjusted to continually maintain a predetermined distance between their adjacent surfaces. 5 figures.

Electronic gap sensor and method

DOEpatents

Williams, Robert S.; King, Edward L.; Campbell, Steven L.

1991-01-01

An apparatus and method for regulating the gap between a casting nozzle and a casting wheel in which the gap between the casting nozzle and the casting wheel is monitored by means of at least one sensing element protruding from the face of the casting nozzle. The sensing element is preferably connected to a voltage source and the casting wheel grounded. When the sensing element contacts the casting wheel, an electric circuit is completed. The completion of the circuit can be registered by an indicator, and the presence or absence of a completed circuit indicates the relative position of the casting nozzle to the casting wheel. The relative positions of the casting nozzle and casting wheel can thereby be selectively adjusted to continually maintain a predetermined distance between their adjacent surfaces.

Method of casting articles of a bulk-solidifying amorphous alloy

DOEpatents

Lin, X.; Johnson, W.L.; Peker, A.

1998-08-25

A casting charge of a bulk-solidifying amorphous alloy is cast into a mold from a temperature greater than its crystallized melting temperature, and permitted to solidify to form an article. The oxygen content of the casting charge is limited to an operable level, as excessively high oxygen contents produce premature crystallization during the casting operation. During melting, the casting charge is preferably heated to a temperature above a threshold temperature to eliminate heterogeneous crystallization nucleation sites within the casting charge. The casting charge may be cast from above the threshold temperature, or it may be cooled to the casting temperature of more than the crystallized melting point but not more than the threshold temperature, optionally held at this temperature for a period of time, and thereafter cast. 8 figs.

Method of casting articles of a bulk-solidifying amorphous alloy

DOEpatents

Lin, Xianghong; Johnson, William L.; Peker, Atakan

1998-01-01

A casting charge of a bulk-solidifying amorphous alloy is cast into a mold from a temperature greater than its crystallized melting temperature, and permitted to solidify to form an article. The oxygen content of the casting charge is limited to an operable level, as excessively high oxygen contents produce premature crystallization during the casting operation. During melting, the casting charge is preferably heated to a temperature above a threshold temperature to eliminate heterogeneous crystallization nucleation sites within the casting charge. The casting charge may be cast from above the threshold temperature, or it may be cooled to the casting temperature of more than the crystallized melting point but not more than the threshold temperature, optionally held at this temperature for a period of time, and thereafter cast.

How to Avoid Cast Saw Complications.

PubMed

Halanski, Matthew A

2016-06-01

As casts are routinely used in pediatric orthopaedics, casts saws are commonly used to remove such casts. Despite being a viewed as the "conservative" and therefore often assumed safest treatment modality, complications associated with the use of casts and cast saws occur. In this manuscript, we review the risk factors associated with cast saw injuries. Cast saw injuries are thermal or abrasive (or both) in nature. Thermal risk factors include: cast saw specifications (including a lack of attached vacuum), use of a dull blade, cutting in a concavity, too thin padding, and overly thick casting materials. Risk factors associated with abrasive injuries include: sharp blades, thin padding, and cutting over boney prominences. Because nearly all clinicians contact the skin with the blade during cast removal, appropriate "in-out technique" is critical. Such technique prevents a hot blade from remaining in contact with the skin for any significant time, diminishing the risk of burn. Similarly, using such technique prevents "dragging the blade" that may pull the skin taught, cutting it. It may be useful to teach proper technique as perforating a cast rather than cutting a cast.

[Manufacture and clinical application of 215 IPS-Empress casting ceramic restorations].

PubMed

Zhao, Na; Zhou, Jian

2008-08-01

To explore the manufacture and clinical application of IPS-Empress casting ceramic restorations. The problems in manufacture and clinical operation of 215 casting ceramic restorations were analyzed. In 215 casting ceramic restorations, 12 (5.58%) casting ceramic restorations were affected by clinical design or application, 15 (6.98%) casting ceramic restorations were affected by some manufacture problems, and 14 (6.51%) casting ceramic restorations were affected by clinical try-in. Through 2-3 years' follow-up, the achievement ratio of 215 IPS-Empress casting ceramic restorations was 94.88%, and 11 casting ceramic restorations were affected by some problems. Beauty and simultaneous enamel wear are the characteristics of casting ceramic restorations. But because of its brittle, the indications should be strictly selected.

Analysis of four dental alloys following torch/centrifugal and induction/ vacuum-pressure casting procedures.

PubMed

Thompson, Geoffrey A; Luo, Qing; Hefti, Arthur

2013-12-01

Previous studies have shown casting methodology to influence the as-cast properties of dental casting alloys. It is important to consider clinically important mechanical properties so that the influence of casting can be clarified. The purpose of this study was to evaluate how torch/centrifugal and inductively cast and vacuum-pressure casting machines may affect the castability, microhardness, chemical composition, and microstructure of 2 high noble, 1 noble, and 1 base metal dental casting alloys. Two commonly used methods for casting were selected for comparison: torch/centrifugal casting and inductively heated/ vacuum-pressure casting. One hundred and twenty castability patterns were fabricated and divided into 8 groups. Four groups were torch/centrifugally cast in Olympia (O), Jelenko O (JO), Genesis II (G), and Liberty (L) alloys. Similarly, 4 groups were cast in O, JO, G, and L by an inductively induction/vacuum-pressure casting machine. Each specimen was evaluated for casting completeness to determine a castability value, while porosity was determined by standard x-ray techniques. Each group was metallographically prepared for further evaluation that included chemical composition, Vickers microhardness, and grain analysis of microstructure. Two-way ANOVA was used to determine significant differences among the main effects. Statistically significant effects were examined further with the Tukey HSD procedure for multiple comparisons. Data obtained from the castability experiments were non-normal and the variances were unequal. They were analyzed statistically with the Kruskal-Wallis rank sum test. Significant results were further investigated statistically with the Steel-Dwass method for multiple comparisons (α=.05). The alloy type had a significant effect on surface microhardness (P<.001). In contrast, the technique used for casting did not affect the microhardness of the test specimen (P=.465). Similarly, the interaction between the alloy and casting technique was not significant (P=.119). A high level of castability (98.5% on average) was achieved overall. The frequency of casting failures as a function of alloy type and casting method was determined. Failure was defined as a castability index score of <100%. Three of 28 possible comparisons between alloy and casting combinations were statistically significant. The results suggested that casting technique affects the castability index of alloys. Radiographic analysis detected large porosities in regions near the edge of the castability pattern and infrequently adjacent to noncast segments. All castings acquired traces of elements found in the casting crucibles. The grain size for each dental casting alloy was generally finer for specimens produced by the induction/vacuum-pressure method. The difference was substantial for JO and L. This study demonstrated a relation between casting techniques and some physical properties of metal ceramic casting alloys. Copyright © 2013 Editorial Council for the Journal of Prosthetic Dentistry. Published by Mosby, Inc. All rights reserved.

Salvaged castings and methods of salvaging castings with defective cast cooling bumps

DOEpatents

Johnson, Robert Alan; Schaeffer, Jon Conrad; Lee, Ching-Pang; Abuaf, Nesim; Hasz, Wayne Charles

2002-01-01

Castings for gas turbine parts exposed on one side to a high-temperature fluid medium have cast-in bumps on an opposite cooling surface side to enhance heat transfer. Areas on the cooling surface having defectively cast bumps, i.e., missing or partially formed bumps during casting, are coated with a braze alloy and cooling enhancement material to salvage the part.

Applying network analysis and Nebula (neighbor-edges based and unbiased leverage algorithm) to ToxCast data.

PubMed

Ye, Hao; Luo, Heng; Ng, Hui Wen; Meehan, Joe; Ge, Weigong; Tong, Weida; Hong, Huixiao

2016-01-01

ToxCast data have been used to develop models for predicting in vivo toxicity. To predict the in vivo toxicity of a new chemical using a ToxCast data based model, its ToxCast bioactivity data are needed but not normally available. The capability of predicting ToxCast bioactivity data is necessary to fully utilize ToxCast data in the risk assessment of chemicals. We aimed to understand and elucidate the relationships between the chemicals and bioactivity data of the assays in ToxCast and to develop a network analysis based method for predicting ToxCast bioactivity data. We conducted modularity analysis on a quantitative network constructed from ToxCast data to explore the relationships between the assays and chemicals. We further developed Nebula (neighbor-edges based and unbiased leverage algorithm) for predicting ToxCast bioactivity data. Modularity analysis on the network constructed from ToxCast data yielded seven modules. Assays and chemicals in the seven modules were distinct. Leave-one-out cross-validation yielded a Q(2) of 0.5416, indicating ToxCast bioactivity data can be predicted by Nebula. Prediction domain analysis showed some types of ToxCast assay data could be more reliably predicted by Nebula than others. Network analysis is a promising approach to understand ToxCast data. Nebula is an effective algorithm for predicting ToxCast bioactivity data, helping fully utilize ToxCast data in the risk assessment of chemicals. Published by Elsevier Ltd.

Dimensional control of die castings

NASA Astrophysics Data System (ADS)

Karve, Aniruddha Ajit

The demand for net shape die castings, which require little or no machining, is steadily increasing. Stringent customer requirements are forcing die casters to deliver high quality castings in increasingly short lead times. Dimensional conformance to customer specifications is an inherent part of die casting quality. The dimensional attributes of a die casting are essentially dependent upon many factors--the quality of the die and the degree of control over the process variables being the two major sources of dimensional error in die castings. This study focused on investigating the nature and the causes of dimensional error in die castings. The two major components of dimensional error i.e., dimensional variability and die allowance were studied. The major effort of this study was to qualitatively and quantitatively study the effects of casting geometry and process variables on die casting dimensional variability and die allowance. This was accomplished by detailed dimensional data collection at production die casting sites. Robust feature characterization schemes were developed to describe complex casting geometry in quantitative terms. Empirical modeling was utilized to quantify the effects of the casting variables on dimensional variability and die allowance for die casting features. A number of casting geometry and process variables were found to affect dimensional variability in die castings. The dimensional variability was evaluated by comparisons with current published dimensional tolerance standards. The casting geometry was found to play a significant role in influencing the die allowance of the features measured. The predictive models developed for dimensional variability and die allowance were evaluated to test their effectiveness. Finally, the relative impact of all the components of dimensional error in die castings was put into perspective, and general guidelines for effective dimensional control in the die casting plant were laid out. The results of this study will contribute to enhancement of dimensional quality and lead time compression in the die casting industry, thus making it competitive with other net shape manufacturing processes.

Lower limb intracast pressures generated by different types of immobilisation casts.

PubMed

Chaudhury, Salma; Hazlerigg, Alexandra; Vusirikala, Anuhya; Nguyen, Joseph; Matthews, Stuart

2017-02-18

To determine if complete, split casts and backslabs [plaster of Paris (POP) and fiberglass] generate different intracast pressures and pain. Increased swelling within casts was modeled by a closed water system attached to an expandable bag placed directly under different types of casts applied to a healthy lower limb. Complete fiberglass and POP casts, split casts and backslabs were applied. Twenty-five milliliter aliquots of saline were injected into the system and the generated intracast pressures were measured using a sphygmomanometer. The subject was blinded to the pressure scores to avoid bias. All casts were applied to the same right limb on the same subject to avoid the effects of variations in anatomy or physiology on intracast pressures. Pain levels were evaluated using the Visual Analogue Score after each sequential saline injection. Each type of cast was reapplied four times and the measurements were repeated on four separate occasions. Sample sizes were determined by a pre-study 90% power calculation to detect a 20% difference in intracast pressures between cast groups. A significant difference between the various types of casts was noted when the saline volume was greater than 100 mL ( P = 0.009). The greatest intracast pressure was generated by complete fiberglass casts, which were significantly higher than complete POP casts or backslabs ( P = 0.018 and P = 0.008 respectively) at intracast saline volumes of 100 mL and higher. Backslabs produced a significantly lower intracast pressure compared to complete POP only once the saline volume within casts exceeded 225 mL ( P = 0.009). Intracast pressures were significantly lower in split casts ( P = 0.003). Split POP and fiberglass casts produced the lowest intracast pressures, even compared to backslabs ( P = 0.009). Complete fiberglass casts generated the highest pain levels at manometer pressures of 75 mmHg and greater ( P = 0.001). Split fiberglass casts had significantly reduced pain levels ( P = 0.001). In contrast, a split complete POP cast did not produce significantly reduced pain levels at pressures between 25-150 mmHg. There was no difference in pain generated by complete POP and backslabs at manometer pressures of 200 mmHg and lower. Fibreglass casts generate significantly higher intracast pressures and pain than POP casts. Split casts cause lower intracast pressures regardless of material, than complete casts and backslabs.

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 understanding of the feeding behavior in aluminum-silicon alloys and the effective feeding by considering the pressure gradient distribution of the molten metal at casting dendrite coherency point. For this study, we will identify the relationship between feeding efficiency, shrinkage behavior and how the change in riser size affects the pressure gradient in the casting. This understanding will be used to help in the design of effective risers.

The Role of Indian Caste Identity and Caste Inconsistent Norms on Status Representation

PubMed Central

Sankaran, Sindhuja; Sekerdej, Maciek; von Hecker, Ulrich

2017-01-01

The Indian caste system is a complex social structure wherein social roles like one’s profession became ‘hereditary,’ resulting in restricted social mobility and fixed status hierarchies. Furthermore, we argue that the inherent property of caste heightens group identification with one’s caste. Highly identified group members would protect the identity of the group in situations when group norms are violated. In this paper, we were interested in examining the consequence of caste norm violation and how an individual’s status is mentally represented. High caste norms are associated with moral values while the lower caste norms are associated with immorality. We predicted a ‘black sheep effect,’ that is, when high caste individuals’ group identity (caste norm violation condition) is threatened their salient high caste identity would increase, thereby resulting in devaluing the status of their fellow in-group member if the latter is perceived as perpetrator. We presented participants with a social conflict situation of a victim and a perpetrator that is ‘Caste norm consistent’ (Lower caste individual as a perpetrator and higher caste individual as a victim) and vice versa ‘Caste norm inconsistent’ condition (higher caste individual as perpetrator and lower caste individual as a victim). Then, participants had to choose from nine pictorial depictions representing the protagonists in the story on a vertical line, with varying degrees of status distance. Results showed evidence for the black sheep effect and, furthermore, revealed that no other identity (religious, national, and regional) resulted in devaluing the status of fellow in-group member. These results help us understand the ‘black sheep’ effect in the context of moral norms and status representation and are discussed in the framework of the Indian society. PMID:28408896

The Role of Indian Caste Identity and Caste Inconsistent Norms on Status Representation.

PubMed

Sankaran, Sindhuja; Sekerdej, Maciek; von Hecker, Ulrich

2017-01-01

The Indian caste system is a complex social structure wherein social roles like one's profession became 'hereditary,' resulting in restricted social mobility and fixed status hierarchies. Furthermore, we argue that the inherent property of caste heightens group identification with one's caste. Highly identified group members would protect the identity of the group in situations when group norms are violated. In this paper, we were interested in examining the consequence of caste norm violation and how an individual's status is mentally represented. High caste norms are associated with moral values while the lower caste norms are associated with immorality. We predicted a 'black sheep effect,' that is, when high caste individuals' group identity (caste norm violation condition) is threatened their salient high caste identity would increase, thereby resulting in devaluing the status of their fellow in-group member if the latter is perceived as perpetrator. We presented participants with a social conflict situation of a victim and a perpetrator that is ' Caste norm consistent' (Lower caste individual as a perpetrator and higher caste individual as a victim) and vice versa 'Caste norm inconsistent' condition (higher caste individual as perpetrator and lower caste individual as a victim). Then, participants had to choose from nine pictorial depictions representing the protagonists in the story on a vertical line, with varying degrees of status distance. Results showed evidence for the black sheep effect and, furthermore, revealed that no other identity (religious, national, and regional) resulted in devaluing the status of fellow in-group member. These results help us understand the 'black sheep' effect in the context of moral norms and status representation and are discussed in the framework of the Indian society.

Casting fine grained, fully dense, strong inorganic materials

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brown, Sam W.; Spencer, Larry S.; Phillips, Michael R.

2015-11-24

Methods and apparatuses for casting inorganic materials are provided. The inorganic materials include metals, metal alloys, metal hydrides and other materials. Thermal control zones may be established to control the propagation of a freeze front through the casting. Agitation from a mechanical blade or ultrasonic energy may be used to reduce porosity and shrinkage in the casting. After solidification of the casting, the casting apparatus may be used to anneal the cast part.

[The surface roughness analysis of the titanium casting founding by a new titanium casting investment material].

PubMed

Liang, Qin-ye; Wu, Xia-yi; Lin, Xue-feng

2012-04-01

To investigate the surface roughness property of the titanium castings cast in a new investment for titanium casting. Six wax patterns (20 mm × 20 mm × 0.5 mm) were invested using two investments: three in a new titanium investment material and three in the control material (Rematitan Plus). Six titanium specimens were obtained by conventional casting. After casting, surface roughness of the specimens were evaluated with a surface profilometer. The surface roughness of the specimens cast in new titanium investment material was (1.72 ± 0.08) µm, which was much smaller than that from Rematitan Plus [(1.91 ± 0.15) µm, P < 0.05]. The surfaces of titanium cast using these two investment materials are both smooth enough to fulfill the demand of the titanium precision-casting for prosthodontic clinical use.

Marginal accuracy of nickel chromium copings fabricated by conventional and accelerated casting procedures, produced with ringless and metal ring investment procedures: A comparative in vitro study.

PubMed

Alex, Deepa; Shetty, Y Bharath; Miranda, Glynis Anita; Prabhu, M Bharath; Karkera, Reshma

2015-01-01

Conventional investing and casting techniques are time-consuming and usually requires 2-4 h for completion. Accelerated nonstandard, casting techniques have been reported to achieve similar quality results in significantly less time, namely, in 30-40 min. During casting, it is essential to achieve compensation for the shrinkage of solidifying alloy by investment expansion. The metal casting ring restricts the thermal expansion of investment because the thermal expansion of the ring is lesser than that of the investment. The use of casting ring was challenged with the introduction of the ringless technique. A total of 40 test samples of nickel chromium (Ni-Cr) cast copings were obtained from the patterns fabricated using inlay casting wax. The 20 wax patterns were invested using metal ring and 20 wax patterns were invested using the ringless investment system. Of both the groups, 10 samples underwent conventional casting, and the other 10 underwent accelerated casting. The patterns were casted using the induction casting technique. All the test samples of cast copings were evaluated for vertical marginal gaps at four points on the die employing a stereo optical microscope. The vertical marginal discrepancy data obtained were tabulated. Mean and standard deviations were obtained. Vertical discrepancies were analyzed using analysis of variance and Tukey honestly significantly different. The data obtained were found to be very highly significant (P < 0.001). Mean vertical gap was the maximum for Group II (53.64 μm) followed by Group IV (47.62 μm), Group I (44.83 μm) and Group III (35.35 μm). The Ni-Cr cast copings fabricated with the conventional casting using ringless investment system showed significantly better marginal fit than that of cast copings fabricated from conventional and accelerated casting with metal ring investment and accelerated casting using ringless investment since those copings had shown the least vertical marginal discrepancies among the four methods evaluated in this study.

Venous haemodynamics of Jet Impulse Technology within a lower limb fibreglass cast: a randomized controlled trial.

PubMed

Braithwaite, Irene; Mackintosh, Stephen; Buchanan, Samantha; Schwarzenlander, Kerstin; De Ruyter, Bernadette

2017-02-01

We investigated popliteal venous haemodynamics of the VenaJet Jet Impulse Technology system within a below-knee fibreglass cast. Randomized controlled trial. Twenty-four healthy participants aged 18-54 had both feet placed within the Jet Impulse Technology system and were randomised for one or other leg to be within a below-knee fibreglass cast. Pacific Radiology, Lower Hutt, Wellington. The primary outcome variable was peak systolic velocity (cm/s) compared between legs with and without the cast at 60 min (after 10 min Jet Impulse Technology activation), using a mixed linear model and a non-inferiority bound of 4.8 cm/s. Secondary outcome variables were the difference in peak systolic velocity between the casted limb and the non-casted limb at baseline and 40 min after casting, and the difference in mean flow velocity (cm/s), vein diameter (mm), and total volume flow (L/min) between the casted limb and the non-casted limb at baseline, 40 and 60 min. The mean (standard deviation) peak systolic velocity was 4.6(1.5), 4.8(1.1), 28.8(16.1), and 4.3(1.2), 4.8(1.4) and 29.3(19.0) cm/s at baseline, 40 and 60 min in the casted and non-casted leg, respectively. The difference (95% confidence interval) between cast and no-cast at 60 min was -0.8 (-6.5 to 4.9) cm/s, P  = 0.78. The peak systolic velocity, flow velocity and total volume flow at 40 min were not statistically significantly different from baseline for both casted and non-casted limb. In healthy volunteers, the popliteal venous haemodynamics of the Jet Impulse Technology system was similar between the legs with and without a below-knee fibreglass cast. In-cast Jet Impulse Technology may provide a non-pharmacological option for venous thromboembolism prophylaxis for lower-limb cast-immobility.

Improved Foundry Castings Utilizing CAD/CAM (Computer Aided Design/ Computer Aided Manufacture). Volume 1. Overview

DTIC Science & Technology

1988-06-30

casting. 68 Figure 1-9: Line printer representation of roll solidification. 69 Figure I1-1: Test casting model. 76 Figure 11-2: Division of test casting...writing new casting analysis and design routines. The new routines would take advantage of advanced criteria for predicting casting soundness and cast...properties and technical advances in computer hardware and software. 11 2. CONCLUSIONS UPCAST, a comprehensive software package, has been developed for

Fretting fatigue behaviour of Ni-free high-nitrogen stainless steel in a simulated body fluid.

PubMed

Maruyama, Norio; Hiromoto, Sachiko; Akiyama, Eiji; Nakamura, Morihiko

2013-04-01

Fretting fatigue behaviour of Ni-free high-nitrogen steel (HNS) with a yield strength of about 800 MPa, which was prepared by nitrogen gas pressurized electroslag remelting, was studied in air and in phosphate-buffered saline (PBS(-)). For comparison, fretting fatigue behaviour of cold-rolled SUS316L steel (SUS316L(CR)) with similar yield strength was examined. The plain fatigue limit of HNS was slightly lower than that of SUS316L(CR) although the former had a higher tensile strength than the latter. The fretting fatigue limit of HNS was higher than that of SUS316L(CR) both in air and in PBS(-). A decrease in fatigue limit of HNS by fretting was significantly smaller than that of SUS316L(CR) in both environments, indicating that HNS has better fretting fatigue resistance than SUS316L(CR). The decrease in fatigue limit by fretting is discussed taking into account the effect of friction stress due to fretting and the additional influences of wear, tribocorrosion and plastic deformation in the fretted area.

Fretting fatigue behaviour of Ni-free high-nitrogen stainless steel in a simulated body fluid

NASA Astrophysics Data System (ADS)

Maruyama, Norio; Hiromoto, Sachiko; Akiyama, Eiji; Nakamura, Morihiko

2013-04-01

Fretting fatigue behaviour of Ni-free high-nitrogen steel (HNS) with a yield strength of about 800 MPa, which was prepared by nitrogen gas pressurized electroslag remelting, was studied in air and in phosphate-buffered saline (PBS(-)). For comparison, fretting fatigue behaviour of cold-rolled SUS316L steel (SUS316L(CR)) with similar yield strength was examined. The plain fatigue limit of HNS was slightly lower than that of SUS316L(CR) although the former had a higher tensile strength than the latter. The fretting fatigue limit of HNS was higher than that of SUS316L(CR) both in air and in PBS(-). A decrease in fatigue limit of HNS by fretting was significantly smaller than that of SUS316L(CR) in both environments, indicating that HNS has better fretting fatigue resistance than SUS316L(CR). The decrease in fatigue limit by fretting is discussed taking into account the effect of friction stress due to fretting and the additional influences of wear, tribocorrosion and plastic deformation in the fretted area.

Characteristics of Al2O3, MnS, and TiN inclusions in the remelting process of bearing steel

NASA Astrophysics Data System (ADS)

Yang, Liang; Cheng, Guo-guang

2017-08-01

The Al2O3, MnS, and TiN inclusions in bearing steel will deteriorate the steel's mechanical properties. Therefore, elucidating detailed characteristics of these inclusions in consumable electrode during the electroslag remelting process is important for achieving a subsequently clean ingot. In this study, a confocal scanning violet laser microscope was used to simulate the remelting process and observe, in real time, the behaviors of inclusions. The obtained images show that, after the temperature exceeded the steel solidus temperature, MnS and TiN inclusions in the specimen began to dissolve. Higher temperatures led to faster dissolution, and the inclusions disappeared before the steel was fully liquid. In the case of an observed Al2O3 inclusion, its shape changed from angular to a smooth ellipsoid in the region where the solid and liquid coexisted and it began to dissolve as the temperature continued to increase. This dissolution was driven by the difference in oxygen potential between the inclusion and the liquid steel.

Method and apparatus for in-situ drying investigation and optimization of slurry drying methodology

DOEpatents

Armstrong, Beth L.; Daniel, Claus; Howe, Jane Y.; Kiggans, Jr, James O.; Sabau, Adrian S.; Wood, III, David L.; Kalnaus, Sergiy

2016-05-10

A method of drying casted slurries that includes calculating drying conditions from an experimental model for a cast slurry and forming a cast film. An infrared heating probe is positioned on one side of the casted slurry and a thermal probe is positioned on an opposing side of the casted slurry. The infrared heating probe may control the temperature of the casted slurry during drying. The casted slurry may be observed with an optical microscope, while applying the drying conditions from the experimental model. Observing the casted slurry includes detecting the incidence of micro-structural changes in the casted slurry during drying to determine if the drying conditions from the experimental model are optimal.

Genetic variation in South Indian castes: evidence from Y-chromosome, mitochondrial, and autosomal polymorphisms

PubMed Central

Watkins, WS; Thara, R; Mowry, BJ; Zhang, Y; Witherspoon, DJ; Tolpinrud, W; Bamshad, MJ; Tirupati, S; Padmavati, R; Smith, H; Nancarrow, D; Filippich, C; Jorde, LB

2008-01-01

Background Major population movements, social structure, and caste endogamy have influenced the genetic structure of Indian populations. An understanding of these influences is increasingly important as gene mapping and case-control studies are initiated in South Indian populations. Results We report new data on 155 individuals from four Tamil caste populations of South India and perform comparative analyses with caste populations from the neighboring state of Andhra Pradesh. Genetic differentiation among Tamil castes is low (RST = 0.96% for 45 autosomal short tandem repeat (STR) markers), reflecting a largely common origin. Nonetheless, caste- and continent-specific patterns are evident. For 32 lineage-defining Y-chromosome SNPs, Tamil castes show higher affinity to Europeans than to eastern Asians, and genetic distance estimates to the Europeans are ordered by caste rank. For 32 lineage-defining mitochondrial SNPs and hypervariable sequence (HVS) 1, Tamil castes have higher affinity to eastern Asians than to Europeans. For 45 autosomal STRs, upper and middle rank castes show higher affinity to Europeans than do lower rank castes from either Tamil Nadu or Andhra Pradesh. Local between-caste variation (Tamil Nadu RST = 0.96%, Andhra Pradesh RST = 0.77%) exceeds the estimate of variation between these geographically separated groups (RST = 0.12%). Low, but statistically significant, correlations between caste rank distance and genetic distance are demonstrated for Tamil castes using Y-chromosome, mtDNA, and autosomal data. Conclusion Genetic data from Y-chromosome, mtDNA, and autosomal STRs are in accord with historical accounts of northwest to southeast population movements in India. The influence of ancient and historical population movements and caste social structure can be detected and replicated in South Indian caste populations from two different geographic regions. PMID:19077280

Twin-belt continuous caster with containment and cooling of the exiting cast product for enabling high-speed casting of molten-center product

DOEpatents

Dykes, Charles D.; Daniel, Sabah S.; Wood, J. F. Barry

1990-02-20

In continuously casting molten metal into cast product by a twin-belt machine, it is desirable to achieve dramatic increases in speed (linear feet per minute) at which cast product exits the machine, particularly in installations where steel cast product is intended to feed a downstream regular rolling mill (as distinct from a planetary mill) operating in tandem with the twin-belt caster. Such high-speed casting produces product with a relatively thin shell and molten interior, and the shell tends to bulge outwardly due to metallostatic head pressure of the molten center. A number of cooperative features enable high-speed, twin-belt casting: (1) Each casting belt is slidably supported adjacent to the caster exit pulley for bulge control and enhanced cooling of cast product. (2) Lateral skew steering of each belt provides an effective increase in moving mold length plus a continuity of heat transfer not obtained with prior art belt steering apparatus. (3) The exiting slab is contained and supported downstream from the casting machine to prevent bulging of the shell of the cast product, and (4) spray cooling is incorporated in the exit containment apparatus for secondary cooling of cast product.

Marginal Accuracy of Castings Fabricated with Ringless Casting Investment System and Metal Ring Casting Investment System: A Comparative Study.

PubMed

Kalavathi, M; Sachin, Bhuvana; Prasanna, B G; Shreeharsha, T V; Praveen, B; Ragher, Mallikarjuna

2016-02-01

The thermal expansion of the investment can be restricted by the metal casting ring because the thermal expansion of the ring is less than that of the investment. The ringless casting procedure is in use in clinical dentistry, though there is little scientific data to support its use in fixed partial dentures. In this study, marginal discrepancy of castings produced with the ringless casting technique and the conventional technique using the metal rings were compared. A total of 30 wax patterns were fabricated directly on a metal die. Optical stereomicroscope was used to measure the marginal discrepancy between the metal die and wax patterns. A total of 15 castings were invested using Bellavest T phosphate-bonded investment with the ringless technique and 15 were invested with the same investment with a metal ring; 30 castings were produced using a nickel-chromium ceramo-metal alloy. The internal surface of the castings was not modified and seated with finger pressure. The vertical marginal discrepancy was measured using an optical stereomicroscope at a magnification of 100x. The data obtained were statistically analyzed using students t-test (paired t-test and unpaired t-test). The castings of the ringless technique provided less vertical marginal discrepancy (240.56 ± 45.81 μ) than the castings produced with the conventional metal ring technique (281.98± 53.05 μ). The difference was statistically significant. The ringless casting technique had produced better marginal accuracy compared with conventional casting technique. Ringless casting system can be used routinely for clinical purpose.

46 CFR 56.60-10 - Cast iron and malleable iron.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 2 2010-10-01 2010-10-01 false Cast iron and malleable iron. 56.60-10 Section 56.60-10... APPURTENANCES Materials § 56.60-10 Cast iron and malleable iron. (a) The low ductility of cast iron and... avoided. Cast iron and malleable iron components shall not be used at temperatures above 450 °F. Cast iron...

Noise Reduction to Reduce Patient Anxiety During Cast Removal: Can We Decrease Patient Anxiety With Cast Removal by Wearing Noise Reduction Headphones During Cast Saw Use?

PubMed

Mahan, Susan T; Harris, Marie S; Lierhaus, Anneliese M; Miller, Patricia E; DiFazio, Rachel L

Noise reduction headphones decrease the sound during cast removal. Their effectiveness in decreasing anxiety has not been studied. Compare pediatric patients' anxiety levels during cast removal with and without utilization of noise reduction headphones combined with use of a personal electronic device. Quality improvement project. Patients randomly assigned to noise reduction headphone group or standard care group during cast removal. Faces, Legs, Activity, Cry, and Consolability Scale and heart rate were evaluated prior to, during, and after cast removal. Data were compared across groups. Fifty patients were included; 25 per group. No difference detected between the 2 groups in Faces, Legs, Activity, Cry, and Consolability Scale score prior to (p = .05) or after cast removal (p = .30). During cast removal, the headphone group had lower FLACC Scale scores (p = .03). Baseline heart rate was lower in the headphone group prior to (p = .02) and after (p = .005) cast removal with no difference during cast removal (p = .24). Utilizing noise reduction headphones and a personal electronic device during the cast removal process decreases patient anxiety.

[Variables effecting casting accuracy of quick heating casting investments].

PubMed

Takahashi, H; Nakamura, H; Iwasaki, N; Morita, N; Habu, N; Nishimura, F

1994-06-01

Recently, several new products of investments for "quick heating" have been put on the Japanese market. The total casting procedure time for this quick heating method involves only one hour; 30-minutes waiting after the start of mixing before placing the mold directly into the 700 degrees C furnace and 30-minutes heating in the furnace. The purpose of this study was to evaluate two variables effecting casting accuracy using these new investments. The effect of thickness of the casting liner inside the casting ring and the effect of waiting time before placing the mold into the 700 degrees C furnace were evaluated. A stainless-steel die with a convergence angle of 8 degrees was employed. Marginal discrepancies of the crown between the wax patterns and castings were measured. The size of the cast crown became larger when the thickness of the ring liner was thick and when the waiting time before placing the mold into the furnace was long. These results suggest that these new investments have the advantage of providing sound castings using short-time casting procedures. However, it is necessary to pay careful attention to the casting conditions for obtaining reproducible castings.

Distal limb cast sores in horses: risk factors and early detection using thermography.

PubMed

Levet, T; Martens, A; Devisscher, L; Duchateau, L; Bogaert, L; Vlaminck, L

2009-01-01

There is a lack of evidence-based data on the prevalence, outcome and risk factors of distal limb cast sores, and no objective tool has been described for the early detection of cast sores. To investigate the prevalence, location, outcome and risk factors of cast sores after application of a distal limb cast and to determine whether static thermography of the cast is a valuable tool for the assessment of sores. A prospective study was conducted on horses treated with a distal limb cast. At each cast removal, cast sores were graded as superficial sores (SS), deep dermal sores (DS) or full thickness skin ulcerations (FS). In several cases, a thermographic evaluation of the cast was performed immediately prior to removal and differences in temperature (AT) between the coolest point of the cast and 2 cast regions predisposed for sore development (dorsoproximal mc/mtIII and palmar/plantar fetlock) were calculated. Mean +/- s.d. total casting time of 70 horses was 31 +/- 18 days. Overall, 57 legs (81%) developed at least SS. Twenty-four legs (34%) ultimately developed DS and one horse had an FS. Multivariable analysis showed that the severity of sores was positively associated with increasing age (OR: 1.111, P = 0.028), a normal (vs. swollen) limb (OR: 3387, P = 0.023) and an increase in total casting time (OR per week: 1.363, P = 0.002). The thermographic evaluation (35 casts) revealed that the severity of sores was positively associated with increasing deltaT (OR: 2.100, P = 0.0005). The optimal cut-off values for the presence of SS and DS were set at, respectively, deltaT = 23 and 43 degrees C. Distal limb cast is a safe coaptation technique with increasing risk of developing sores with time. Thermography is a valuable and rapid clinical tool to monitor the development of cast sores.

Development and Implementation of the Casting of Rods Made of Refractory Cast Alloys

NASA Astrophysics Data System (ADS)

Kabanov, I. V.; Urin, S. L.; Ivanyuk, A. S.; Nesterov, A. N.; Bogdanov, S. V.

2017-12-01

The problems of the production of a so-called casting rod blank made of a refractory casting alloy in the vacuum induction furnaces of AO Metallurgical Plant Electrostal are considered. A unique technology of casting and subsequent treatment of as-cast rod blanks made of refractory alloys is developed, tested, and optimized. As a result of the developed and performed measures for the production of metal products in the Consarc furnace, the ingot-to-product yield increases by 15% as compared to metal casting in an ISV-1.0 furnace. As a result, we have widened the range of cast alloy grades and are going to cast metals for the manufacture of blanks of other sizes and ranges of alloy an steel grades.

Energy Consumption of Die Casting Operations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jerald Brevick; clark Mount-Campbell; Carroll Mobley

2004-03-15

Molten metal processing is inherently energy intensive and roughly 25% of the cost of die-cast products can be traced to some form of energy consumption [1]. The obvious major energy requirements are for melting and holding molten alloy in preparation for casting. The proper selection and maintenance of melting and holding equipment are clearly important factors in minimizing energy consumption in die-casting operations [2]. In addition to energy consumption, furnace selection also influences metal loss due to oxidation, metal quality, and maintenance requirements. Other important factors influencing energy consumption in a die-casting facility include geographic location, alloy(s) cast, starting formmore » of alloy (solid or liquid), overall process flow, casting yield, scrap rate, cycle times, number of shifts per day, days of operation per month, type and size of die-casting form of alloy (solid or liquid), overall process flow, casting yield, scrap rate, cycle times, number of shifts per day, days of operation per month, type and size of die-casting machine, related equipment (robots, trim presses), and downstream processing (machining, plating, assembly, etc.). Each of these factors also may influence the casting quality and productivity of a die-casting enterprise. In a die-casting enterprise, decisions regarding these issues are made frequently and are based on a large number of factors. Therefore, it is not surprising that energy consumption can vary significantly from one die-casting enterprise to the next, and within a single enterprise as function of time.« less

Venous haemodynamics of Jet Impulse Technology within a lower limb fibreglass cast: a randomized controlled trial

PubMed Central

Mackintosh, Stephen; Buchanan, Samantha; Schwarzenlander, Kerstin; De Ruyter, Bernadette

2017-01-01

Objectives We investigated popliteal venous haemodynamics of the VenaJet Jet Impulse Technology system within a below-knee fibreglass cast. Design Randomized controlled trial. Participants Twenty-four healthy participants aged 18–54 had both feet placed within the Jet Impulse Technology system and were randomised for one or other leg to be within a below-knee fibreglass cast. Setting Pacific Radiology, Lower Hutt, Wellington Main outcome measures The primary outcome variable was peak systolic velocity (cm/s) compared between legs with and without the cast at 60 min (after 10 min Jet Impulse Technology activation), using a mixed linear model and a non-inferiority bound of 4.8 cm/s. Secondary outcome variables were the difference in peak systolic velocity between the casted limb and the non-casted limb at baseline and 40 min after casting, and the difference in mean flow velocity (cm/s), vein diameter (mm), and total volume flow (L/min) between the casted limb and the non-casted limb at baseline, 40 and 60 min. Results The mean (standard deviation) peak systolic velocity was 4.6(1.5), 4.8(1.1), 28.8(16.1), and 4.3(1.2), 4.8(1.4) and 29.3(19.0) cm/s at baseline, 40 and 60 min in the casted and non-casted leg, respectively. The difference (95% confidence interval) between cast and no-cast at 60 min was −0.8 (−6.5 to 4.9) cm/s, P = 0.78. The peak systolic velocity, flow velocity and total volume flow at 40 min were not statistically significantly different from baseline for both casted and non-casted limb. Conclusion In healthy volunteers, the popliteal venous haemodynamics of the Jet Impulse Technology system was similar between the legs with and without a below-knee fibreglass cast. In-cast Jet Impulse Technology may provide a non-pharmacological option for venous thromboembolism prophylaxis for lower-limb cast-immobility. PMID:28203384

Marginal accuracy of nickel chromium copings fabricated by conventional and accelerated casting procedures, produced with ringless and metal ring investment procedures: A comparative in vitro study

PubMed Central

Alex, Deepa; Shetty, Y. Bharath; Miranda, Glynis Anita; Prabhu, M. Bharath; Karkera, Reshma

2015-01-01

Background: Conventional investing and casting techniques are time-consuming and usually requires 2–4 h for completion. Accelerated nonstandard, casting techniques have been reported to achieve similar quality results in significantly less time, namely, in 30–40 min. During casting, it is essential to achieve compensation for the shrinkage of solidifying alloy by investment expansion. The metal casting ring restricts the thermal expansion of investment because the thermal expansion of the ring is lesser than that of the investment. The use of casting ring was challenged with the introduction of the ringless technique. Materials and Methods: A total of 40 test samples of nickel chromium (Ni-Cr) cast copings were obtained from the patterns fabricated using inlay casting wax. The 20 wax patterns were invested using metal ring and 20 wax patterns were invested using the ringless investment system. Of both the groups, 10 samples underwent conventional casting, and the other 10 underwent accelerated casting. The patterns were casted using the induction casting technique. All the test samples of cast copings were evaluated for vertical marginal gaps at four points on the die employing a stereo optical microscope. Results: The vertical marginal discrepancy data obtained were tabulated. Mean and standard deviations were obtained. Vertical discrepancies were analyzed using analysis of variance and Tukey honestly significantly different. The data obtained were found to be very highly significant (P < 0.001). Mean vertical gap was the maximum for Group II (53.64 μm) followed by Group IV (47.62 μm), Group I (44.83 μm) and Group III (35.35 μm). Conclusion: The Ni-Cr cast copings fabricated with the conventional casting using ringless investment system showed significantly better marginal fit than that of cast copings fabricated from conventional and accelerated casting with metal ring investment and accelerated casting using ringless investment since those copings had shown the least vertical marginal discrepancies among the four methods evaluated in this study. PMID:26929488

Factors contributing to the temperature beneath plaster or fiberglass cast material

PubMed Central

Hutchinson, Michael J; Hutchinson, Mark R

2008-01-01

Background Most cast materials mature and harden via an exothermic reaction. Although rare, thermal injuries secondary to casting can occur. The purpose of this study was to evaluate factors that contribute to the elevated temperature beneath a cast and, more specifically, evaluate the differences of modern casting materials including fiberglass and prefabricated splints. Methods The temperature beneath various types (plaster, fiberglass, and fiberglass splints), brands, and thickness of cast material were measured after they were applied over thermometer which was on the surface of a single diameter and thickness PVC tube. A single layer of cotton stockinette with variable layers and types of cast padding were placed prior to application of the cast. Serial temperature measurements were made as the cast matured and reached peak temperature. Time to peak, duration of peak, and peak temperature were noted. Additional tests included varying the dip water temperature and assessing external insulating factors. Ambient temperature, ambient humidity and dip water freshness were controlled. Results Outcomes revealed that material type, cast thickness, and dip water temperature played key roles regarding the temperature beneath the cast. Faster setting plasters achieved peak temperature quicker and at a higher level than slower setting plasters. Thicker fiberglass and plaster casts led to greater peak temperature levels. Likewise increasing dip-water temperature led to elevated temperatures. The thickness and type of cast padding had less of an effect for all materials. With a definition of thermal injury risk of skin injury being greater than 49 degrees Celsius, we found that thick casts of extra fast setting plaster consistently approached dangerous levels (greater than 49 degrees for an extended period). Indeed a cast of extra-fast setting plaster, 20 layers thick, placed on a pillow during maturation maintained temperatures over 50 degrees of Celsius for over 20 minutes. Conclusion Clinicians should be cautious when applying thick casts with warm dip water. Fast setting plasters have increased risk of thermal injury while brand does not appear to play a significant role. Prefabricated fiberglass splints appear to be safer than circumferential casts. The greatest risk of thermal injury occurs when thick casts are allowed to mature while resting on pillow. PMID:18298851

Non-rigid Reconstruction of Casting Process with Temperature Feature

NASA Astrophysics Data System (ADS)

Lin, Jinhua; Wang, Yanjie; Li, Xin; Wang, Ying; Wang, Lu

2017-09-01

Off-line reconstruction of rigid scene has made a great progress in the past decade. However, the on-line reconstruction of non-rigid scene is still a very challenging task. The casting process is a non-rigid reconstruction problem, it is a high-dynamic molding process lacking of geometric features. In order to reconstruct the casting process robustly, an on-line fusion strategy is proposed for dynamic reconstruction of casting process. Firstly, the geometric and flowing feature of casting are parameterized in manner of TSDF (truncated signed distance field) which is a volumetric block, parameterized casting guarantees real-time tracking and optimal deformation of casting process. Secondly, data structure of the volume grid is extended to have temperature value, the temperature interpolation function is build to generate the temperature of each voxel. This data structure allows for dynamic tracking of temperature of casting during deformation stages. Then, the sparse RGB features is extracted from casting scene to search correspondence between geometric representation and depth constraint. The extracted color data guarantees robust tracking of flowing motion of casting. Finally, the optimal deformation of the target space is transformed into a nonlinear regular variational optimization problem. This optimization step achieves smooth and optimal deformation of casting process. The experimental results show that the proposed method can reconstruct the casting process robustly and reduce drift in the process of non-rigid reconstruction of casting.

Characterization of Ni-Cr alloys using different casting techniques and molds.

PubMed

Chen, Wen-Cheng; Teng, Fu-Yuan; Hung, Chun-Cheng

2014-02-01

This study differentiated the mechanical properties of nickel-chromium (Ni-Cr) alloys under various casting techniques (different casting molds and casting atmospheres). These techniques were sampled by a sand mold using a centrifugal machine in ambient air (group I) and electromagnetic induction in an automatic argon castimatic casting machine (group II). The specimen casting used a graphite mold by a castimatic casting machine (group III). The characteristics of the Ni-Cr alloys, yield and ultimate tensile strength, bending modulus, microhardness, diffraction phase, grindability, ability to spring back, as well as ground microstructure and pattern under different casting conditions were evaluated. The group III specimens exhibited the highest values in terms of strength, modulus, hardness, and grindability at a grind rate of 500 rpm. Moreover, group III alloys exhibited smaller grain sizes, higher ability to spring back, and greater ductility than those casted by sand investment (groups I and II). The main factor, "casting mold," significantly influenced all mechanical properties. The graphite mold casting of the Ni-Cr dental alloys in a controlled atmosphere argon casting system provided an excellent combination of high mechanical properties and good ability to spring back, and preserved the ductile properties for application in Ni-Cr porcelain-fused system. The results can offer recommendations to assist a prosthetic technician in selecting the appropriate casting techniques to obtain the desired alloy properties. Copyright © 2013 Elsevier B.V. All rights reserved.

40 CFR 464.30 - Applicability; description of the ferrous casting subcategory.

Code of Federal Regulations, 2010 CFR

2010-07-01

... ferrous casting subcategory. 464.30 Section 464.30 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS METAL MOLDING AND CASTING POINT SOURCE CATEGORY Ferrous Casting Subcategory § 464.30 Applicability; description of the ferrous casting subcategory. The...

Microstructural Evolution in Intensively Melt Sheared Direct Chill Cast Al-Alloys

NASA Astrophysics Data System (ADS)

Jones, S.; Rao, A. K. Prasada; Patel, J. B.; Scamans, G. M.; Fan, Z.

The work presented here introduces the novel melt conditioned direct chill casting (MC-DC) technology, where intensive melt shearing is applied to the conventional direct-chill casting process. MC-DC casting can successfully produce high quality Al-alloy billets. The results obtained from 80 mm diameter billets cast at speed of 200 mm/min show that MC-DC casting of Al-alloys, substantially refines the microstructure and reduces macro-segregation. In this paper, we present the preliminary results and discuss microstructural evolution during MC-DC casting of Al-alloys.

Driving with a short arm cast in a simulator.

PubMed

Mansour, Damian; Mansour, Kristin Gotaas; Kenny, Benjamin William; Attia, John; Meads, Bryce

2015-12-01

To test the ability to steer in a driving simulator in subjects with a short arm cast. 17 men and 13 women aged 23 to 67 (mean, 37) years who had a valid driver's licence were randomised to the cast-first group (n=16; 7 had the cast on the dominant arm) or the cast-second group (n=14; 8 had the cast on the dominant arm) and drove in a simulator. A short arm plaster-of-Paris cast was applied in a neutral position, allowing free movement of the metacarpophalangeal joints, thumb, and elbow joint. Outcome measures included the number of driving off track instances, the number of crashes, the lap time, and the effect of hand dominance on these parameters. Subjects were asked whether the cast had impeded their steering ability. Subjects with or without a cast were comparable in terms of the number of driving off track instances, number of crashes, and lap time. Compared with no cast, the odds ratio (OR) of a subject in a cast driving off the track was 1.02 (p=0.921) and having a crash was 0.79 (p=0.047). All subjects were 1.23 times more likely to drive off the track in their first lap (OR=2.66, p=0.019). The mean lap time decreased for each consecutive lap from the 2nd to 5th laps. Subjects driving with a cast on the dominant or non-dominant arm were comparable. 26 out of the 30 participants considered that the plaster cast impeded their steering ability. Compared with no cast, driving with a short arm cast did not significantly decrease steering ability in a driving simulator.

Quiet breathing in hindlimb casted mice.

PubMed

Receno, Candace N; Roffo, Katelynn E; Mickey, Marisa C; DeRuisseau, Keith C; DeRuisseau, Lara R

2018-06-07

The hindlimb casting model was developed to study skeletal muscle reloading following a period of unloading. It is unknown if ventilation parameters of mice are affected by the casting model. We tested the hypothesis that hindlimb casted mice have similar ventilatory patterns compared to mice with the casts removed. Male CD-1 mice underwent 14 days of hindlimb immobilization via plaster casting. Breathing parameters were obtained utilizing unrestrained barometric plethysmography (UBP). Breathing traces were analyzed with Ponemah software for breathing frequency, tidal volume (TV), and minute ventilation (MV). Frequency, TV and MV did not show any differences in quiet breathing patterns during or post-casting in mice. Thus, the hindlimb casting model does not complicate breathing during and after casting and should not interfere with the unloading and reloading of skeletal muscle. Copyright © 2018 Elsevier B.V. All rights reserved.

40 CFR 464.10 - Applicability; description of the aluminum casting subcategory.

Code of Federal Regulations, 2010 CFR

2010-07-01

... aluminum casting subcategory. 464.10 Section 464.10 Protection of Environment ENVIRONMENTAL PROTECTION... Aluminum Casting Subcategory § 464.10 Applicability; description of the aluminum casting subcategory. The... introduction of pollutants into publicly owned treatment works resulting from aluminum casting operations as...

40 CFR 464.20 - Applicability; description of the copper casting subcategory.

Code of Federal Regulations, 2011 CFR

2011-07-01

... copper casting subcategory. 464.20 Section 464.20 Protection of Environment ENVIRONMENTAL PROTECTION... Copper Casting Subcategory § 464.20 Applicability; description of the copper casting subcategory. The... introduction of pollutants into publicly owned treatment works resulting from copper casting operations as...

40 CFR 464.20 - Applicability; description of the copper casting subcategory.

Code of Federal Regulations, 2010 CFR

2010-07-01

... copper casting subcategory. 464.20 Section 464.20 Protection of Environment ENVIRONMENTAL PROTECTION... Copper Casting Subcategory § 464.20 Applicability; description of the copper casting subcategory. The... introduction of pollutants into publicly owned treatment works resulting from copper casting operations as...

Method of reducing the green density of a slip cast article

DOEpatents

Mangels, John A.; Dickie, Ray A.

1985-01-01

The method disclosed in this specification is one of reducing the green density of an article cast in a slip casting operation. The article is cast from a casting slip containing silicon metal particles, yttrium containing particles, and a small amount of a fluoride salt which is effective to suppress flocculation of the silicon metal particles by y.sup.+3 ions derived from the yttrium containing particles. The method is characterized by the following step. A small amount of compound which produces a cation which will partly flocculate the particles of silicon metal is added to the casting slip. The small amount of this compound is added so that when the casting slip is slip cast into a casting mold, the partly flocculated particles of silicon will interrupt an otherwise orderly packing of the particles of silicon and particles of yttrium. In this manner, the green density of the slip cast article is reduced and the article may be more easily nitrided.

Management of Intolerance to Casting the Upper Extremities in Claustrophobic Patients

PubMed Central

Nagura, Issei; Kanatani, Takako; Sumi, Masatoshi; Inui, Atsuyuki; Mifune, Yutaka; Kokubu, Takeshi; Kurosaka, Masahiro

2014-01-01

Introduction. Some patients showed unusual responses to the immobilization without any objective findings with casts in upper extremities. We hypothesized their that intolerance with excessive anxiety to casts is due to claustrophobia triggered by cast immobilization. The aim of this study is to analyze the relevance of cast immobilization to the feeling of claustrophobia and discover how to handle them. Methods. There were nine patients who showed the caustrophobic symptoms with their casts. They were assesed whether they were aware of their claustrophobis themselves. Further we investigated the alternative immobilization to casts. Results. Seven out of nine cases that were aware of their claustrophobic tendencies either were given removable splints initially or had the casts converted to removable splints when they exhibited symptoms. The two patients who were unaware of their latent claustrophobic tendencies were identified when they showed similar claustrophobic symptoms to the previous patients soon after short arm cast application. We replaced the casts with removable splints. This resolved the issue in all cases. Conclusions. We should be aware of the claustrophobia if patients showed unusual responses to the immobilization without any objective findings with casts in upper extremities, where removal splint is practical alternative to cast to continue the treatment successfully. PMID:25379544

AMCC casting development, volume 2

NASA Technical Reports Server (NTRS)

1995-01-01

PCC successfully cast and performed nondestructive testing, FPI and x-ray, on seventeen AMCC castings. Destructive testing, lab analysis and chemical milling, was performed on eleven of the castings and the remaining six castings were shipped to NASA or Aerojet. Two of the six castings shipped, lots 015 and 016, were fully processed per blueprint requirements. PCC has fully developed the gating and processing parameters of this part and feels the part could be implemented into production, after four more castings have been completed to ensure the repeatability of the process. The AMCC casting has been a technically challenging part due to its size, configuration, and alloy type. The height and weight of the wax pattern assembly necessitated the development of a hollow gating system to ensure structural integrity of the shell throughout the investment process. The complexity in the jacket area of the casting required the development of an innovative casting technology that PCC has termed 'TGC' or thermal gradient control. This method of setting up thermal gradients in the casting during solidification represents a significant process improvement for PCC and has been successfully implemented on other programs. The alloy, JBK75, is a relatively new alloy in the investment casting arena and required our engineering staff to learn the gating, processing, and dimensional characteristics of the material.

Optimization to Develop Multiple Response Microstructure and Hardness of Ductile Iron Casting by using GRA

NASA Astrophysics Data System (ADS)

Kabnure, Bahubali Bhupal; Shinde, Vasudev Dhondiram; Kolhapure, Rakesh Ramchandra

2018-05-01

Ductile irons are important engineering materials because of its high strength to weight ratio and castability. The ductile iron castings are used widely for automobile applications due to their wide spectrum of property range. Weight reduction is important in automobile to improve its fuel efficiency which can be achieved by thinning down the casting sections without altering its functionality. Generally, automobile castings are having varying section thickness. Varying thickness castings offers different cooling rates while solidification of the casting. The solidification cooling rate decides the final microstructure of the cast components. Cooling rate was found to affect directly the amount of pearlite and ultimately the as cast properties in varying thickness ductile iron castings. In view of this, the automobile impeller casting is selected for study in the present work as it consists of varying section thickness in which small sections are connected to central hub. The casting solidification simulations were performed and analyzed. The solidification cooling rates were analyzed further to correlate the experimental processing parameters. The samples from poured castings were analyzed for microstructure and hardness at different section thickness. Multiple response optimization of microstructure and hardness was carried out by combined Taguchi and Grey Relational Analysis (GRA). Contribution of input variables on the output variables is attained using ANOVA.

Modelling the Cast Component Weight in Hot Chamber Die Casting using Combined Taguchi and Buckingham's π Approach

NASA Astrophysics Data System (ADS)

Singh, Rupinder

2018-02-01

Hot chamber (HC) die casting process is one of the most widely used commercial processes for the casting of low temperature metals and alloys. This process gives near-net shape product with high dimensional accuracy. However in actual field environment the best settings of input parameters is often conflicting as the shape and size of the casting changes and one have to trade off among various output parameters like hardness, dimensional accuracy, casting defects, microstructure etc. So for online inspection of the cast components properties (without affecting the production line) the weight measurement has been established as one of the cost effective method (as the difference in weight of sound and unsound casting reflects the possible casting defects) in field environment. In the present work at first stage the effect of three input process parameters (namely: pressure at 2nd phase in HC die casting; metal pouring temperature and die opening time) has been studied for optimizing the cast component weight `W' as output parameter in form of macro model based upon Taguchi L9 OA. After this Buckingham's π approach has been applied on Taguchi based macro model for the development of micro model. This study highlights the Taguchi-Buckingham based combined approach as a case study (for conversion of macro model into micro model) by identification of optimum levels of input parameters (based on Taguchi approach) and development of mathematical model (based on Buckingham's π approach). Finally developed mathematical model can be used for predicting W in HC die casting process with more flexibility. The results of study highlights second degree polynomial equation for predicting cast component weight in HC die casting and suggest that pressure at 2nd stage is one of the most contributing factors for controlling the casting defect/weight of casting.

41. PHOTOGRAPHY OF BLUE PRINT (MINNEAPOLIS CITY ENGINEER) END AND ...

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

41. PHOTOGRAPHY OF BLUE PRINT (MINNEAPOLIS CITY ENGINEER) END AND CENTRE CASTING OF CAST STEEL, MASONRY CASTING OF CAST IRON CASTING, FOR MINNEAPOLIS STEEL ARCH (4 x 5 negative) - Steel Arch Bridge, Hennepin Avenue spanning west channel of Mississippi River, Minneapolis, Hennepin County, MN

Basic Casting from A to Z. Student's Instruction Booklet.

ERIC Educational Resources Information Center

Zebco, Tulsa, OK.

A profusely illustrated student instruction booklet contains step-by-step directions and diagrams for learning four basic casting techniques. Separate sections cover basic spin-casting, spinning, bait-casting, and fly-casting. Each section details recommended equipment (reel, rod, line, plug, tackle, lures, leaders, flies), describes specific…

Genetic evidence on the origins of Indian caste populations.

PubMed

Bamshad, M; Kivisild, T; Watkins, W S; Dixon, M E; Ricker, C E; Rao, B B; Naidu, J M; Prasad, B V; Reddy, P G; Rasanayagam, A; Papiha, S S; Villems, R; Redd, A J; Hammer, M F; Nguyen, S V; Carroll, M L; Batzer, M A; Jorde, L B

2001-06-01

The origins and affinities of the approximately 1 billion people living on the subcontinent of India have long been contested. This is owing, in part, to the many different waves of immigrants that have influenced the genetic structure of India. In the most recent of these waves, Indo-European-speaking people from West Eurasia entered India from the Northwest and diffused throughout the subcontinent. They purportedly admixed with or displaced indigenous Dravidic-speaking populations. Subsequently they may have established the Hindu caste system and placed themselves primarily in castes of higher rank. To explore the impact of West Eurasians on contemporary Indian caste populations, we compared mtDNA (400 bp of hypervariable region 1 and 14 restriction site polymorphisms) and Y-chromosome (20 biallelic polymorphisms and 5 short tandem repeats) variation in approximately 265 males from eight castes of different rank to approximately 750 Africans, Asians, Europeans, and other Indians. For maternally inherited mtDNA, each caste is most similar to Asians. However, 20%-30% of Indian mtDNA haplotypes belong to West Eurasian haplogroups, and the frequency of these haplotypes is proportional to caste rank, the highest frequency of West Eurasian haplotypes being found in the upper castes. In contrast, for paternally inherited Y-chromosome variation each caste is more similar to Europeans than to Asians. Moreover, the affinity to Europeans is proportionate to caste rank, the upper castes being most similar to Europeans, particularly East Europeans. These findings are consistent with greater West Eurasian male admixture with castes of higher rank. Nevertheless, the mitochondrial genome and the Y chromosome each represents only a single haploid locus and is more susceptible to large stochastic variation, bottlenecks, and selective sweeps. Thus, to increase the power of our analysis, we assayed 40 independent, biparentally inherited autosomal loci (1 LINE-1 and 39 Alu elements) in all of the caste and continental populations (approximately 600 individuals). Analysis of these data demonstrated that the upper castes have a higher affinity to Europeans than to Asians, and the upper castes are significantly more similar to Europeans than are the lower castes. Collectively, all five datasets show a trend toward upper castes being more similar to Europeans, whereas lower castes are more similar to Asians. We conclude that Indian castes are most likely to be of proto-Asian origin with West Eurasian admixture resulting in rank-related and sex-specific differences in the genetic affinities of castes to Asians and Europeans.

Genetic Evidence on the Origins of Indian Caste Populations

PubMed Central

Bamshad, Michael; Kivisild, Toomas; Watkins, W. Scott; Dixon, Mary E.; Ricker, Chris E.; Rao, Baskara B.; Naidu, J. Mastan; Prasad, B.V. Ravi; Reddy, P. Govinda; Rasanayagam, Arani; Papiha, Surinder S.; Villems, Richard; Redd, Alan J.; Hammer, Michael F.; Nguyen, Son V.; Carroll, Marion L.; Batzer, Mark A.; Jorde, Lynn B.

2001-01-01

The origins and affinities of the ∼1 billion people living on the subcontinent of India have long been contested. This is owing, in part, to the many different waves of immigrants that have influenced the genetic structure of India. In the most recent of these waves, Indo-European-speaking people from West Eurasia entered India from the Northwest and diffused throughout the subcontinent. They purportedly admixed with or displaced indigenous Dravidic-speaking populations. Subsequently they may have established the Hindu caste system and placed themselves primarily in castes of higher rank. To explore the impact of West Eurasians on contemporary Indian caste populations, we compared mtDNA (400 bp of hypervariable region 1 and 14 restriction site polymorphisms) and Y-chromosome (20 biallelic polymorphisms and 5 short tandem repeats) variation in ∼265 males from eight castes of different rank to ∼750 Africans, Asians, Europeans, and other Indians. For maternally inherited mtDNA, each caste is most similar to Asians. However, 20%–30% of Indian mtDNA haplotypes belong to West Eurasian haplogroups, and the frequency of these haplotypes is proportional to caste rank, the highest frequency of West Eurasian haplotypes being found in the upper castes. In contrast, for paternally inherited Y-chromosome variation each caste is more similar to Europeans than to Asians. Moreover, the affinity to Europeans is proportionate to caste rank, the upper castes being most similar to Europeans, particularly East Europeans. These findings are consistent with greater West Eurasian male admixture with castes of higher rank. Nevertheless, the mitochondrial genome and the Y chromosome each represents only a single haploid locus and is more susceptible to large stochastic variation, bottlenecks, and selective sweeps. Thus, to increase the power of our analysis, we assayed 40 independent, biparentally inherited autosomal loci (1 LINE-1 and 39 Alu elements) in all of the caste and continental populations (∼600 individuals). Analysis of these data demonstrated that the upper castes have a higher affinity to Europeans than to Asians, and the upper castes are significantly more similar to Europeans than are the lower castes. Collectively, all five datasets show a trend toward upper castes being more similar to Europeans, whereas lower castes are more similar to Asians. We conclude that Indian castes are most likely to be of proto-Asian origin with West Eurasian admixture resulting in rank-related and sex-specific differences in the genetic affinities of castes to Asians and Europeans. PMID:11381027

Caste, Class and the Love-Marriage: Social Change in India

ERIC Educational Resources Information Center

Corwin, Lauren A.

1977-01-01

The present study of a small town in rural West Bengal, India, reveals a number of "love-marriages" involving individuals from castes of distinctly different ranks in the local caste hierarchy. Despite the prevailing rule of caste endogamy, inter-caste couples appear to face little difficulty. (Author)

Release of ToxCastDB and ExpoCastDB databases

EPA Science Inventory

EPA has released two databases - the Toxicity Forecaster database (ToxCastDB) and a database of chemical exposure studies (ExpoCastDB) - that scientists and the public can use to access chemical toxicity and exposure data. ToxCastDB users can search and download data from over 50...

Adhesion Casting In Low Gravity

NASA Technical Reports Server (NTRS)

Noever, David A.; Cronise, Raymond J.

1996-01-01

Adhesion casting in low gravity proposed as technique for making new and improved materials. Advantages of low-gravity adhesion casting, in comparison with adhesion casting in normal Earth gravity, comes from better control over, and greater uniformity of, thicknesses of liquid films that form on and adhere to solid surfaces during casting.

21 CFR 888.5960 - Cast removal instrument.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cast removal instrument. 888.5960 Section 888.5960...) MEDICAL DEVICES ORTHOPEDIC DEVICES Surgical Devices § 888.5960 Cast removal instrument. (a) Identification. A cast removal instrument is an AC-powered, hand-held device intended to remove a cast from a...

40 CFR 466.20 - Applicability; description of the cast iron basis material subcategory.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 29 2010-07-01 2010-07-01 false Applicability; description of the cast... Cast Iron Basis Material Subcategory § 466.20 Applicability; description of the cast iron basis... of pollutants into publicly owned treatment works from porcelain enameling of cast iron basis...

CAST FLOOR WITH VIEW OF TORPEDO LADLE (BENEATH CAST FLOOR) ...

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

CAST FLOOR WITH VIEW OF TORPEDO LADLE (BENEATH CAST FLOOR) AND KEEPERS OF THE CAST HOUSE FLOOR, S.L. KIMBROUGH AND DAVID HOLMES. - U.S. Steel, Fairfield Works, Blast Furnace No. 8, North of Valley Road, West of Ensley-Pleasant Grove Road, Fairfield, Jefferson County, AL

Adaptive significance of the Indian caste system: an ecological perspective.

PubMed

Gadgil, M; Malhotra, K C

1983-01-01

Indian society is an agglomeration of several thousand endogamous groups or castes each with a restricted geographical range and a hereditarily determined mode of subsistence. These reproductively isolated castes may be compared to biological species, and the society thought of as a biological community with each caste having its specific ecological niche. In this paper we examine the ecological-niche relationships of castes which are directly dependent on natural resources. Evidence is presented to show that castes living together in the same region had so organized their pattern of resource use as to avoid excessive intercaste competition for limiting resources. Furthermore, territorial division of the total range of the caste regulated intra-caste competition. Hence, a particular plant or animal resource in a given locality was used almost exclusively by a given lineage within a caste generation after generation. This favoured the cultural evolution of traditions ensuring sustainable use of natural resources. This must have contributed significantly to the stability of Indian caste society over several thousand years. The collapse of the base of natural resources and increasing monetarization of the economy has, however, destroyed the earlier complementarity between the different castes and led to increasing conflicts between them in recent years.

Microstructure and mechanical properties of zirconium doped NiAl/Cr(Mo) hypoeutectic alloy prepared by injection casting

NASA Astrophysics Data System (ADS)

Sheng, L. Y.; Du, B. N.; Guo, J. T.

2017-01-01

NiAl based materials has been considered as most potential candidate of turbine blade, due to its excellent high-temperature properties. However the bad room-temperature properties handicap its application. In the present paper, the zirconium doped NiAl/Cr(Mo) hypoeutectic alloy is fabricated by conventional casting and injection casting technology to improve its room-temperature properties. The microstructure and compressive properties at different temperatures of the conventionally-cast and injection-cast were investigated. The results exhibit that the conventionally-cast alloy comprises coarse primary NiAl phase and eutectic cell, which is dotted with irregular Ni2AlZr Heusler phase. Compared with the conventionally-cast alloy, the injection-cast alloy possesses refined the primary NiAl, eutectic cell and eutectic lamella. In addition, the Ni2AlZr Heusler phase become smaller and distribute uniformly. Moreover, the injection casting decrease the area fraction of primary NiAl phase at the cell interior or cell boundaries. The compressive ductility and yield strength of the injection-cast alloy at room temperature increase by about 100% and 35% over those of conventionally-cast alloy, which should be ascribed to the microstructure optimization.

The Soldiers in Societies: Defense, Regulation, and Evolution

PubMed Central

Tian, Li; Zhou, Xuguo

2014-01-01

The presence of reproductively altruistic castes is one of the primary traits of the eusocial societies. Adaptation and regulation of the sterile caste, to a certain extent, drives the evolution of eusociality. Depending on adaptive functions of the first evolved sterile caste, eusocial societies can be categorized into the worker-first and soldier-first lineages, respectively. The former is marked by a worker caste as the first evolved altruistic caste, whose primary function is housekeeping, and the latter is highlighted by a sterile soldier caste as the first evolved altruistic caste, whose task is predominantly colony defense. The apparent functional differences between these two fundamentally important castes suggest worker-first and soldier-first eusociality are potentially driven by a suite of distinctively different factors. Current studies of eusocial evolution have been focused largely on the worker-first Hymenoptera, whereas understanding of soldier-first lineages including termites, eusocial aphids, gall-dwelling thrips, and snapping shrimp, is greatly lacking. In this review, we summarize the current state of knowledge on biology, morphology, adaptive functions, and caste regulation of the soldier caste. In addition, we discuss the biological, ecological and genetic factors that might contribute to the evolution of distinct caste systems within eusocial lineages. PMID:24644427

Analysis of Mold Friction in a Continuous Casting Using Wavelet Transform

NASA Astrophysics Data System (ADS)

Ma, Yong; Fang, Bohan; Ding, Qiqi; Wang, Fangyin

2018-04-01

Mold friction (MDF) is an important parameter reflecting the lubrication condition between the initial shell and the mold during continuous casting. In this article, based on practical MDF from the slab continuous casting driven by a mechanical vibration device, the characteristics of friction were analyzed by continuous wavelet transform (CWT) and discrete wavelet transform (DWT) in different casting conditions, such as normal casting, level fluctuation, and alarming of the temperature measurement system. The results show that the CWT of friction accurately captures the subtle changes in friction force, such as the periodic characteristic of MDF during normal casting and the disordered feature of MDF during level fluctuation. Most important, the results capture the occurrence of abnormal casting and display the friction frequency characteristics at this abnormal time. In addition, in this article, there are some abnormal casting conditions, and the friction signal is stable until there is a sudden large change when abnormal casting, such as split breakout and submerged entry nozzle breakage, occurs. The DWT has a good ability to capture the friction characteristics for such abnormal situations. In particular, the potential abnormal features of MDF were presented in advance, which provides strong support for identifying abnormal casting and even preventing abnormal casting.

Very High Cycle Fatigue Behavior of a Directionally Solidified Ni-Base Superalloy DZ4

PubMed Central

Nie, Baohua; Zhao, Zihua; Liu, Shu; Chen, Dongchu; Ouyang, Yongzhong; Hu, Zhudong; Fan, Touwen; Sun, Haibo

2018-01-01

The effect of casting pores on the very high cycle fatigue (VHCF) behavior of a directionally solidified (DS) Ni-base superalloy DZ4 is investigated. Casting and hot isostatic pressing (HIP) specimens were subjected to very high cycle fatigue loading in an ambient atmosphere. The results demonstrated that the continuously descending S-N curves were exhibited for both the casting and HIP specimens. Due to the elimination of the casting pores, the HIP samples had better fatigue properties than the casting samples. The subsurface crack initiated from the casting pore in the casting specimens at low stress amplitudes, whereas fatigue crack initiated from crystallographic facet decohesion for the HIP specimens. When considering the casting pores as initial cracks, there exists a critical stress intensity threshold ranged from 1.1 to 1.3 MPam, below which fatigue cracks may not initiate from the casting pores. Furthermore, the effect of the casting pores on the fatigue limit is estimated based on a modified El Haddad model, which is in good agreement with the experimental results. Fatigue life for both the casting and HIP specimens is well predicted using the Fatigue Indicator Parameter (FIP) model. PMID:29320429

AIS/DOE Technology Roadmap Program: Strip Casting: Anticipating New Routes To Steel Sheet

DOE Office of Scientific and Technical Information (OSTI.GOV)

Prof. Alan W. Camb; Prof. Anthony Rollett

2001-08-31

To determine the potential for strip casting in the steel industry and to develop the fundamental knowledge necessary to allow the role of strip casting in the modern steel industry to be understood. Based upon a study of carbon steel strip castings that were either produced for the program at British Steel or were received from a pre-commercial production machine, the following conclusions were made. Strip casting of carbon steels is technically feasible for sheet material from slightly less than 1 mm thick to 3 mm thick, and, assuming that it is economically viable, it will be first applied inmore » carbon steel markets that do not require stringent surface quality or extensive forming. The potential of strip casting as a casting process to be developed for steel castings is very high as the cast strip has some very novel characteristics. Direct cast carbon strip has better surface quality, shape and profile than any other casting process currently available. The more rapidly solidified structure of direct cast strip tends to be strong with low ductility; however, with adequate thermal treatment, it is possible to develop a variety of properties from the same grade. The process is more amenable at this time to production tonnages per year of the order of 500,000 tons and as such will first find niche type applications. This technology is an additional technology for steel production and will be in addition to, rather than a replacement for, current casting machines.« less

Evaluation of the microstructure, secondary dendrite arm spacing, and mechanical properties of Al-Si alloy castings made in sand and Fe-Cr slag molds

NASA Astrophysics Data System (ADS)

Narasimha Murthy, I.; Babu Rao, J.

2017-07-01

The microstructure and mechanical properties of as-cast A356 (Al-Si) alloy castings were investigated. A356 alloy was cast into three different molds composed of sand, ferrochrome (Fe-Cr) slag, and a mixture of sand and Fe-Cr. A sodium silicate-CO2 process was used to make the necessary molds. Cylindrical-shaped castings were prepared. Cast products with no porosity and a good surface finish were achieved in all of the molds. These castings were evaluated for their metallography, secondary dendrite arm spacing (SDAS), and mechanical properties, including hardness, compression, tensile, and impact properties. Furthermore, the tensile and impact samples were analyzed by fractography. The results show that faster heat transfer in the Fe-Cr slag molds than in either the silica sand or mixed molds led to lower SDAS values with a refined microstructure in the products cast in Fe-Cr slag molds. Consistent and enhanced mechanical properties were observed in the slag mold products than in the castings obtained from either sand or mixed molds. The fracture surface of the slag mold castings shows a dimple fracture morphology with a transgranular fracture nature. However, the fracture surfaces of the sand mold castings display brittle fracture. In conclusion, products cast in Fe-Cr slag molds exhibit an improved surface finish and enhanced mechanical properties compared to those of products cast in sand and mixed molds.

Effects of Casting Size on Microstructure and Mechanical Properties of Spheroidal and Compacted Graphite Cast Irons: Experimental Results and Comparison with International Standards

NASA Astrophysics Data System (ADS)

Ceschini, L.; Morri, Alessandro; Morri, Andrea

2017-05-01

The aim of this research was to investigate the effects of casting size (10-210 mm) on the microstructure and mechanical properties of spheroidal (SGI) and compacted (CGI) graphite cast irons. A comparison of the experimental mechanical data with those specified by ISO standards is presented and discussed. The study highlighted that the microstructure and mechanical properties of SGI (also known as ductile or nodular cast iron) are more sensitive to casting size than CGI (also known as vermicular graphite cast irons). In particular, in both types of cast iron, hardness, yield strength and ultimate tensile strength decreased, with increasing casting size, by 27% in SGI and 17% in CGI. Elongation to failure showed, instead, an opposite trend, decreasing from 5 to 3% in CGI, while increasing from 5 to 11% in SGI. These results were related to different microstructures, the ferritic fraction being more sensitive to the casting size in SGI than CGI. Degeneration of spheroidal graphite was observed at casting size above 120 mm. The microstructural similarities between degenerated SGI and CGI suggested the proposal of a unified empirical constitutional law relating the most important microstructural parameters to the ultimate tensile strength. An outstanding result was also the finding that standard specifications underestimated the mechanical properties of both cast irons (in particular SGI) and, moreover, did not take into account their variation with casting size, at thicknesses over 60 mm.

Analysis and comparison of the biomechanical properties of univalved and bivalved cast models.

PubMed

Crickard, Colin V; Riccio, Anthony I; Carney, Joseph R; Anderson, Terrence D

2011-01-01

Fiberglass casts are frequently valved to relieve the pressure associated with upper extremity swelling after a surgical procedure or when applied after reduction of a displaced fracture in a child. Although different opinions exist regarding the valving of casts, no research to date has explored the biomechanical effects of this commonly used technique. As cast integrity is essential for the maintenance of fracture reduction, it is important to understand whether casts are structurally compromised after valving. Understanding the effects of valving on cast integrity may help guide clinicians in the technique of valving while minimizing the potential for a loss of fracture reduction. Thirty standardized cylindrical fiberglass cast models were created. Ten models were left intact, 10 were univalved, and 10 were bivalved. All the models were mechanically tested by a 3-point bending apparatus secured to a biaxial materials testing system. Load to failure and bending stiffness were recorded for each sample. Differences in load of failure and bending stiffness were compared among the groups. Unvalved cast models had the highest failure load and bending stiffness, whereas bivalved casts showed the lowest value for both failure load and bending stiffness. Univalved casts had a failure load measured to be between those of unvalved and bivalved cast models. Analysis of variance showed significance when failure load and bending stiffness data among all the groups were compared. A post hoc Bonferroni statistical analysis showed significance in bending stiffness between intact and bivalved models (P < 0.01), intact and univalved models (P < 0.01), but no significant difference in bending stiffness between univalved and bivalved models (P > 0.01). Differences in measured failure load values were found to be statistically significant among all cast models (P < 0.01). Valving significantly decreases the bending stiffness and load to failure of fiberglass casts. Univalved casts have a higher load to failure than bivalved casts. Valving adversely alters the structural integrity of fiberglass casts. This may impair a cast's ability to effectively immobilize an extremity or maintain a fracture reduction.

MicroRNAs Associated with Caste Determination and Differentiation in a Primitively Eusocial Insect

PubMed Central

Collins, David H.; Mohorianu, Irina; Beckers, Matthew; Moulton, Vincent; Dalmay, Tamas; Bourke, Andrew F. G.

2017-01-01

In eusocial Hymenoptera (ants, bees and wasps), queen and worker adult castes typically arise via environmental influences. A fundamental challenge is to understand how a single genome can thereby produce alternative phenotypes. A powerful approach is to compare the molecular basis of caste determination and differentiation along the evolutionary trajectory between primitively and advanced eusocial species, which have, respectively, relatively undifferentiated and strongly differentiated adult castes. In the advanced eusocial honeybee, Apis mellifera, studies suggest that microRNAs (miRNAs) play an important role in the molecular basis of caste determination and differentiation. To investigate how miRNAs affect caste in eusocial evolution, we used deep sequencing and Northern blots to isolate caste-associated miRNAs in the primitively eusocial bumblebee Bombus terrestris. We found that the miRNAs Bte-miR-6001-5p and -3p are more highly expressed in queen- than in worker-destined late-instar larvae. These are the first caste-associated miRNAs from outside advanced eusocial Hymenoptera, so providing evidence for caste-associated miRNAs occurring relatively early in eusocial evolution. Moreover, we found little evidence that miRNAs previously shown to be associated with caste in A. mellifera were differentially expressed across caste pathways in B. terrestris, suggesting that, in eusocial evolution, the caste-associated role of individual miRNAs is not conserved. PMID:28361900

Novel technologies for the lost foam casting process

NASA Astrophysics Data System (ADS)

Jiang, Wenming; Fan, Zitian

2018-03-01

Lost foam casting (LFC) is a green precision casting process categorized as a near net forming technology. Yet, despite its popularity, it still suffers from some technological problems, such as poor filling ability of the castings, coarse and non-dense microstructure, low mechanical properties for the Al and Mg LFC processes, and defective carburization for the low carbon steel LFC process. These drawbacks restrict the development and widespread application of the LFC process. To solve these problems, the present study developed several novel LFC technologies, namely, LFC technologies under vacuum and low pressure, vibration solidification, and pressure solidification conditions; expendable shell casting technology; and preparation technology of bimetallic castings based on the LFC process. The results showed that the LFC under vacuum and low pressure evidently improved the filling ability and solved the oxidization problem of the alloys, which is suitable for producing complex and thinwall castings. The vibration and pressure solidifications increased the compactness of the castings and refined the microstructure, significantly improving the mechanical properties of the castings. The expendable shell casting technology could solve the pore, carburization, and inclusion defects of the traditional LFC method, obtaining castings with acceptable surface quality. Moreover, the Al/Mg and Al/Al bimetallic castings with acceptable metallurgical bonding were successfully fabricated using the LFC process. These proposed novel LFC technologies can solve the current technological issues and promote the technological progress of the LFC process.

Development of a New Membrane Casting Apparatus for Studying Macrovoid Defects in Low-G

NASA Technical Reports Server (NTRS)

Lee, Hanyong; Hwang, Sun-Tak; Krantz, William B.; Greenberg, Alan R.; Khare, Vivek; Zartman, Jeremiah; Todd, Paul W.

2002-01-01

A new membrane-casting apparatus is developed for studying macrovoid defects in polymeric membranes made by the wet- and dry-casting process in low-gravity. Macrovoids are large (10-50 micron), open cavities interspersed among the smaller pores in the substructure under the gelled skin surface layer of the cast membrane. Although their occurrence is considered endemic to the wet- and dry-casting process since they can lead to compaction or skin rupture in the membrane process, recent studies suggest several useful applications such as transdermal and osmotic drug delivery systems, miniature bioreactors, etc. However, lack of knowledge about the macrovoid formation mechanism is an obstacle to further development of applications using them. An on-going debate is the role of the surface-tension-driven solutocapillary convection during macrovoid formation. The rapid growth of macrovoids within 1-5 seconds and the high polymer concentration in and near macrovoids make it difficult to explain the mechanism of macrovoid growth by diffusion alone, which is the widely accepted hypothesis proposed by Reuvers et al. The hypothesis advanced by our research group can explain this rapid growth via a mechanism that involves diffusion from the casting solution in the meta-stable region to the macrovoid enhanced by solutocapillary convection induced by the steep nonsolvent concentration gradient in the vicinity of the macrovoid. Since macrovoid growth is hypothesized to be the interplay of a solutocapillary-induced driving force counteracted by viscous drag and buoyancy, eliminate the latter provides a means for testing this hypothesis. Moreover, free convection mass transfer in the nonsolvent immersion bath used to cause phase-separation in membrane casting complicates developing a model for both the wet-casting process and macrovoid growth. The low-g environment minimizes gravitationally induced free convection thereby permitting a tractable solution to the ternary diffusion equations that characterize membrane formation. NASA's Parabolic Flight Research Aircraft provides a small window of low-g (approximately 25 s) that can be used to study macrovoid development in both wet- and dry-cast membranes if an appropriate casting apparatus is used. This casting apparatus should be able to cast the membrane in both low- and high-g in a manner so that essential one-dimensional mass transfer conditions are achieved to insure lateral uniformity in the membrane. The apparatus used in previous research on membrane casting in low-gravity was operated with the plunger driven mechanism. The spring-loaded plunger pushes the bottom block containing the polymer casting solution well directly under the absorbent chamber located in the upper stationary block. However, membranes made via this casting apparatus often displayed lateral nonuniformities that precluded obtaining quantitative information on the macrovoid growth process. Thus, it was necessary to determine the reason for these structural irregularities observed in the low-g casting apparatus. Both experimental as well as computer simulation studies of the low-g casting apparatus established that the impulsive action of the plunger caused the undesired structural nonuniformities. The simulation results showed that the width-to-depth aspect ratio of the shallow well that contains the casting solution in this apparatus was not an important factor in minimizing this problem. Even for a 40:1 (width : depth) aspect ratio, any convection induced by the horizontal motion of the interface of the casting solution will be damped out within 6.25x10(exp 4) seconds. However, the experimental studies revealed that the impulsive motion of the plunger caused a 'sloshing' of the casting solution that had to be eliminated. Therefore, the plungerdriven mechanism was changed to a cam-driven mechanism that did not cause any impulsive motion of the casting solution. Other refinements to this new membrane-casting apparatus include provision for removing the membranes from the casting wells in a less destructive manner. This was accomplished by using a slit geometry for the casting well that permitted disassembly for removal of the cast membrane. The materials used in the construction of this casting apparatus were chosen to insure wetting at the side walls and to maintain precise control of the thickness of the polymer solution in the casting well. An additional provision in this new casting apparatus is the ability to carry out both wet- as well as dry-casting. As such, this apparatus permitted the first studies of the wet-casting of polymeric membranes in low-g. Both wet- and dry-casting experiments on NASA's KC-135 research aircraft employing this new membrane-casting apparatus are scheduled in July 2002. The morphology of the resulting membranes will be characterized using an environmental scanning electron microscope (ESEM). The results of these low-g studies will be reported later.

Cross-Validation of the Computerized Adaptive Screening Test (CAST).

ERIC Educational Resources Information Center

Pliske, Rebecca M.; And Others

The Computerized Adaptive Screening Test (CAST) was developed to provide an estimate at recruiting stations of prospects' Armed Forces Qualification Test (AFQT) scores. The CAST was designed to replace the paper-and-pencil Enlistment Screening Test (EST). The initial validation study of CAST indicated that CAST predicts AFQT at least as accurately…

Materials for Advanced Ultrasupercritical Steam Turbines Task 4: Cast Superalloy Development

DOE Office of Scientific and Technical Information (OSTI.GOV)

Thangirala, Mani

The Steam Turbine critical stationary structural components are high integrity Large Shell and Valve Casing heavy section Castings, containing high temperature steam under high pressures. Hence to support the development of advanced materials technology for use in an AUSC steam turbine capable of operating with steam conditions of 760°C (1400°F) and 35 Mpa (5000 psia), Casting alloy selection and evaluation of mechanical, metallurgical properties and castability with robust manufacturing methods are mandated. Alloy down select from Phase 1 based on producability criteria and creep rupture properties tested by NETL-Albany and ORNL directed the consortium to investigate cast properties of Haynesmore » 282 and Haynes 263. The goals of Task 4 in Phase 2 are to understand a broader range of mechanical properties, the impact of manufacturing variables on those properties. Scale up the size of heats to production levels to facilitate the understanding of the impact of heat and component weight, on metallurgical and mechanical behavior. GE Power & Water Materials and Processes Engineering for the Phase 2, Task 4.0 Castings work, systematically designed and executed casting material property evaluation, multiple test programs. Starting from 15 lbs. cylinder castings to world’s first 17,000 lbs. poured weight, heavy section large steam turbine partial valve Haynes 282 super alloy casting. This has demonstrated scalability of the material for steam Turbine applications. Activities under Task 4.0, Investigated and characterized various mechanical properties of Cast Haynes 282 and Cast Nimonic 263. The development stages involved were: 1) Small Cast Evaluation: 4 inch diam. Haynes 282 and Nimonic 263 Cylinders. This provided effects of liquidus super heat range and first baseline mechanical data on cast versions of conventional vacuum re-melted and forged Ni based super alloys. 2) Step block castings of 300 lbs. and 600 lbs. Haynes 282 from 2 foundry heats were evaluated which demonstrated the importance of proper heat treat cycles for Homogenization, and Solutionizing parameters selection and implementation. 3) Step blocks casting of Nimonic 263: Carried out casting solidification simulation analysis, NDT inspection methods evaluation, detailed test matrix for Chemical, Tensile, LCF, stress rupture, CVN impact, hardness and J1C Fracture toughness section sensitivity data and were reported. 4) Centrifugal Casting of Haynes 282, weighing 1400 lbs. with hybrid mold (half Graphite and half Chromite sand) mold assembly was cast using compressor casing production tooling. This test provided Mold cooling rates influence on centrifugally cast microstructure and mechanical properties. Graphite mold section out performs sand mold across all temperatures for 0.2% YS; %Elongation, %RA, UTS at 1400°F. Both Stress-LMP and conditional Fracture toughness plots data were in the scatter band of the wrought alloy. 5) Fundamental Studies on Cooling rates and SDAS test program. Evaluated the influence of 6 mold materials Silica, Chromite, Alumina, Silica with Indirect Chills, Zircon and Graphite on casting solidification cooling rates. Actual Casting cooling rates through Liquidus to Solidus phase transition were measured with 3 different locations based thermocouples placed in each mold. Compared with solidification simulation cooling rates and measurement of SDAS, microstructure features were reported. The test results provided engineered casting potential methods, applicable for heavy section Haynes 282 castings for optimal properties, with foundry process methods and tools. 6) Large casting of Haynes 282 Drawings and Engineering FEM models and supplemental requirements with applicable specifications were provided to suppliers for the steam turbine proto type feature valve casing casting. Molding, melting and casting pouring completed per approved Manufacturing Process Plan during 2014 Q4. The partial valve casing was successfully cast after casting methods were validated with solidification simulation analysis and the casting met NDT inspection and acceptance criteria. Heat treated and sectioned to extract trepan samples at different locations comparing with cast on coupons test data. Material properties requisite for design, such as tensile, creep/rupture, LCF, Fracture Toughness, Charpy V-notch chemical analysis testing were carried out. The test results will be presented in the final report. The typical Haynes 282 large size Steam Turbine production casting from Order to Delivery foundry schedule with the activity break up is shown in Figures 107 and 108. • From Purchase Order placement to Casting pouring ~ 26 weeks. 1. Sales and commercial review 3 2. Engineering Drawings/models review 4 3. Pattern and core box manufacturing 6 4. Casting process engineering review 4 5. FEM and solidification simulation analysis 4 6. Gating & Feeder Attachments, Ceramic tiling 2 7. Molding and coremaking production scheduling 6 8. Melting planning and schedule 3 9. Pouring, cooling and shake out 2 • From Pouring to casting Delivery ~ 29 weeks 10. Shot blast and riser cutting, gates removal 3 11. Homogenizing , solutionizing HT furnace prep 4 12. Grinding, Fettling 2 13. Aging HT Cycle, cooling 2 14. VT and LPT NDT inspections 2 15. Radiographic inspection 4 16. Mechanical testing, Chemical analysis test certs 4 17. Casting weld repair upgrades and Aging PWHT 4 18. NDT after weld repairs and casting upgrades 3 19. Casting Final Inspection and test certifications 3 20. Package and delivery 2 Hence the Total Lead time from P.O to Casting delivery is approximately 55 weeks. The Task 4.2 and Task 4.3 activities and reporting completed.« less

Triple Plate Mold Final Report: Optimization of the Mold Design and Casting Parameters for a Thin U-10mo Fuel Casting

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aikin, Jr., Robert M.

This work describes the experiments and modeling that have been performed to improve and try to optimize the simultaneous casting of three plates of U-10wt%Mo in a single coil vacuum induction melting (VIM) furnace. The plates of interest are 280 mm wide by 203 mm tall by 5 mm thick (11" x 8" x 0.2"). The initial mold design and processing parameters were supplied by Y-12. The mold and casting cavity were instrumented with a number of thermocouples, and the casting performed to determine the thermal history of the mold and casting. The resulting cast plates were radiographed and numerousmore » defects identified. Metallography was performed to help identify the nature of the radiographically observed defects. This information was then used to validate a mold filling and solidification model of that casting. Based on the initial casting, good casting design practice, and process simulation of several design alternatives, a revised design was developed with the goal of minimizing casting defects such as porosity. The redesigned mold had a larger hot-top and had its long axis along the horizontal direction. These changes were to try to develop a strong thermal gradient conducive to good feeding and minimization of micro- and macroporosity in the cast plates. An instrumented casting was then performed with the revised mold design and a linear distributor. This design yielded cast plates with significantly less radiographically identified defects. Unfortunately, there was significant variation in plate weight and metal content in their hot-tops. Fluid flow simulations were then performed on this mold/distributor design. This helped identify the issue with this linear distributor design. Additional simulations were then performed on candidate distributor redesigns and a preferred distributor annular design was identified. This improved annular design was used to produce a third instrumented casting with favorable results. These refined designs and their radiographic characterization are compared to the initial design.« less

Materials processing threshold report: 2. Use of low gravity for cast iron process development

NASA Technical Reports Server (NTRS)

Frankhouser, W. L.

1980-01-01

Potential applications of a low gravity environment of interest to the commercial producers of cast iron were assessed to determine whether low gravity conditions offer potential opportunities to producers for improving cast iron properties and expanding the use of cast irons. The assessment is limited to the gray and nodular types of iron, however, the findings are applicable to all cast irons. The potential advantages accrued through low gravity experiments with cast irons are described.

Characterization of calpastatin gene in fish: its potential role in muscle growth and fillet quality.

PubMed

Salem, Mohamed; Yao, Jianbo; Rexroad, Caird E; Kenney, P Brett; Semmens, Kenneth; Killefer, John; Nath, Joginder

2005-08-01

Calpastatin (CAST), the specific inhibitor of the calpain proteases, plays a role in muscle growth and meat quality. In rainbow trout (RBT), we identified cDNAs coding for two CAST isoforms, a long (CAST-L) and a short isoform (CAST-S), apparently derived from two different genes. Zebrafish and pufferfish CAST cDNA and genomic sequences were retrieved from GenBank and their exon/intron structures were characterized. Fish CASTs are novel in that they have fewer repetitive inhibitory domains as compared to their mammalian counterparts (one or two vs. four). The expressions of CAST mRNAs were measured in three RBT strains with different growth rates and fillet firmness that were fed either high energy or control diets. CAST-L and S expressions were significantly lower (p<0.01) in the strain that has the slowest growth rate and yielded the softest fillet. Strain or diet did not affect level of calpain mRNAs. However, the decrease in the CAST/calpain ratio at the mRNA level did not lead to a corresponding change in the calpain catalytic activity. Further investigation should reveal a potential use of the CAST gene as a tool to monitor fish muscle growth and fillet firmness.

Chemical-Gene Interactions from ToxCast Bioactivity Data ...

EPA Pesticide Factsheets

Characterizing the effects of chemicals in biological systems is often summarized by chemical-gene interactions, which have sparse coverage in the literature. The ToxCast chemical screening program has produced bioactivity data for nearly 2000 chemicals and over 450 gene targets. To evaluate the information gained from the ToxCast project, a ToxCast bioactivity network was created comprising ToxCast chemical-gene interactions based on assay data and compared to a chemical-gene association network from literature. The literature network was compiled from PubMed articles, excluding ToxCast publications, mapped to genes and chemicals. Genes were identified by curated associations available from NCBI while chemicals were identified by PubChem submissions. The frequencies of chemical-gene associations from the literature network were log-scaled and then compared to the ToxCast bioactivity network. In total, 140 times more chemical-gene associations were present in the ToxCast network in comparison to the literature-derived network highlighting the vast increase in chemical-gene interactions putatively elucidated by the ToxCast research program. There were 165 associations found in the literature network that were reproduced by ToxCast bioactivity data, and 336 associations in the literature network were not reproduced by the ToxCast bioactivity network. The literature network relies on the assumption that chemical-gene associations represent a true chemical-gene inte

Cool Cast Facts

MedlinePlus

... Kinds of Casts? Most casts are made of fiberglass. Fiberglass is a kind of plastic that can be ... to the body part. It dries hard. Some fiberglass casts are waterproof. Doctors only use this type ...

Casting for infantile scoliosis: the pitfall of increased peak inspiratory pressure.

PubMed

Dhawale, Arjun A; Shah, Suken A; Reichard, Samantha; Holmes, Laurens; Brislin, Robert; Rogers, Kenneth; Mackenzie, William G

2013-01-01

Serial cast correction is a popular treatment option for progressive infantile scoliosis. Body casting can lead to chest and abdominal expansion restriction and result in decreased chest wall compliance. There are no studies evaluating the effects of casting on ventilation in infantile scoliosis. This study examines changes in peak inspiratory pressure (PIP) during serial casting for infantile scoliosis. We retrospectively reviewed data obtained from 37 serial Cotrel elongation, derotation, and flexion cast corrections in patients with infantile scoliosis. Patient demographics, radiographic measurements, and anesthesia data were recorded. Anesthesia technique was standardized: children were intubated with rigid endotracheal tubes (ETTs); tidal volume was held constant at 8 to 10 cm(3)/kg using volume control ventilation; and PIP was recorded at baseline, after cast application before window cutout, and after window cutout before extubation. Any complications were documented. We assessed the PIP changes with a repeated measures analysis of variance (ANOVA). The mean age at first casting was 21.8 months (range, 12 to 42 mo) and mean follow-up since first casting was 22.4 months (range, 13 to 40 mo) with mean major Cobb angle of 53±15 degrees. The mean PIP was 15.5±4.9 cm H(2)O before casting, 31.9±7.9 cm H(2)O after cast application, and 20.4±5.6 cm H2O after making windows. There was a 106% increase after casting and 32% increase after window cutout from the baseline PIP levels. There was a significant difference in PIP on repeated measures ANOVA (P<0.0001). Intraoperatively, there was difficulty in maintaining ventilation during 2 procedures and 1 hypotensive episode. One patient developed hypoxemia after casting and another had delayed difficulty in breathing. Casting resulted in an increased PIP due to transient restrictive pulmonary process; after windows were cut out, the PIP reduced but not to baseline. In patients with underlying pulmonary disease, the casting process may induce respiratory complications, and a proper period of observation after casting is necessary. Case series, level 4.

GRINDING ROOM AT SOUTHERN DUCTILE CASTING COMPANY, BESSEMER FOUNDRY SHOWING ...

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

GRINDING ROOM AT SOUTHERN DUCTILE CASTING COMPANY, BESSEMER FOUNDRY SHOWING WHEELABORATOR THAT IMPALE SHOT AT TUMBLING CASTINGS TO REMOVE EXCESS SURFACE METALS AND SAND; ANNEALING OVENS TO HEAT CERTAIN CASTINGS TO ACHIEVE A DESIRED CHARACTERISTIC; AND GRINDING WHEELS USED TO REMOVE GATES. - Southern Ductile Casting Company, Grinding & Shipping, 2217 Carolina Avenue, Bessemer, Jefferson County, AL

21 CFR 880.6185 - Cast cover.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cast cover. 880.6185 Section 880.6185 Food and....6185 Cast cover. (a) Identification. A cast cover is a device intended for medical purposes that is made of waterproof material and placed over a cast to protect it from getting wet during a shower or a...

Processing of IN-718 Lattice Block Castings

NASA Technical Reports Server (NTRS)

Hebsur, Mohan G.

2002-01-01

Recently a low cost casting method known as lattice block casting has been developed by JAM Corporation, Wilmington, Massachusetts for engineering materials such as aluminum and stainless steels that has shown to provide very high stiffness and strength with only a fraction of density of the alloy. NASA Glenn Research Center has initiated research to investigate lattice block castings of high temperature Ni-base superalloys such as the model system Inconel-718 (IN-718) for lightweight nozzle applications. Although difficulties were encountered throughout the manufacturing process , a successful investment casting procedure was eventually developed. Wax formulation and pattern assembly, shell mold processing, and counter gravity casting techniques were developed. Ten IN-718 lattice block castings (each measuring 15-cm wide by 30-cm long by 1.2-cm thick) have been successfully produced by Hitchiner Gas Turbine Division, Milford, New Hampshire, using their patented counter gravity casting techniques. Details of the processing and resulting microstructures are discussed in this paper. Post casting processing and evaluation of system specific mechanical properties of these specimens are in progress.

Research on the influence of moulding-casting technology on the quality of castings

NASA Astrophysics Data System (ADS)

Josan, A.; Pinca Bretotean, C.; Raţiu, S.; Ardelean, E.; Ardelean, M.

2017-05-01

The quality of castings has a particularly role in the Romanian foundries. In this context, quality assurance is the overall objective of the foundries. The paper presents the critical analysis performed on moulding-casting technology of the type Lifting mechanism. This casting is a subset of the lifting and rotating mechanism of the furnace vault. The casting analysed is a medium size, with weight of 114 kg. The current moulding-casting technology involves moulding into three mould-parts leading to the occurrence of defects (decentering of the core, displacement of the lower mould and the middle mould and occurrence of burrs in area separated. Thus, to reduce the percentage of defects registered in industrial practice is necessary to change the moulding-casting technology. This requires the use of two mould-parts, re-dimensioning of the core and the core box and dimensioning of the runner network. The adoption of these changes in industrial practice has direct implications on the cost of casting and foundry costs default.

Effect of flask vibration time on casting integrity, Surface Penetration and Coating Inclusion in lost foam casting of Al-Si Alloy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Karimian, Majid; Idris, M. H.; Ourdjini, A.

2011-01-17

The paper presents the result of an experimental investigation conducted on medium aluminum silicon alloy casting- LM6, using no-vacuum assisted lost foam casting process. The study is directed for establishing the relationship between the flask vibrations times developed for molded sample on the casting integrity, surface penetration and coating inclusion defects of the casting. Four different flask vibration times namely 180, 120, 90 and 60 sec. were investigated. The casting integrity was investigated in terms of fulfilling in all portions and edges. The surface penetration was measured using optical microscope whilst image analyzer was used to quantify the percentage ofmore » coating inclusion in the casting. The results show that vibration time has significant influence on the fulfilling as well as the internal integrity of the lost foam casting. It was found that the lower vibration time produced comparatively sound casing.« less

Pneumatic gap sensor and method

DOEpatents

Bagdal, Karl T.; King, Edward L.; Follstaedt, Donald W.

1992-01-01

An apparatus and method for monitoring and maintaining a predetermined width in the gap between a casting nozzle and a casting wheel, wherein the gap is monitored by means of at least one pneumatic gap sensor. The pneumatic gap sensor is mounted on the casting nozzle in proximity to the casting surface and is connected by means of a tube to a regulator and a transducer. The regulator provides a flow of gas through a restictor to the pneumatic gap sensor, and the transducer translates the changes in the gas pressure caused by the proximity of the casting wheel to the pneumatic gap sensor outlet into a signal intelligible to a control device. The relative positions of the casting nozzle and casting wheel can thereby be selectively adjusted to continually maintain a predetermined distance between their adjacent surfaces. The apparatus and method enables accurate monitoring of the actual casting gap in a simple and reliable manner resistant to the extreme temperatures and otherwise hostile casting environment.

Pneumatic gap sensor and method

DOEpatents

Bagdal, K.T.; King, E.L.; Follstaedt, D.W.

1992-03-03

An apparatus and method for monitoring and maintaining a predetermined width in the gap between a casting nozzle and a casting wheel, wherein the gap is monitored by means of at least one pneumatic gap sensor. The pneumatic gap sensor is mounted on the casting nozzle in proximity to the casting surface and is connected by means of a tube to a regulator and a transducer. The regulator provides a flow of gas through a restictor to the pneumatic gap sensor, and the transducer translates the changes in the gas pressure caused by the proximity of the casting wheel to the pneumatic gap sensor outlet into a signal intelligible to a control device. The relative positions of the casting nozzle and casting wheel can thereby be selectively adjusted to continually maintain a predetermined distance between their adjacent surfaces. The apparatus and method enables accurate monitoring of the actual casting gap in a simple and reliable manner resistant to the extreme temperatures and otherwise hostile casting environment. 6 figs.

Energy Saving Melting and Revert Reduction (E-SMARRT): Precision Casting of Steel

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dr. Von L. Richards

2011-09-30

This project addresses improvements in metal casting processes by reducing scrap and reducing the cost of production, due to scrap reduction from investment casting and yield improvement offered by lost foam casting as compared to no-bake or green sand molding. The objectives for the investment casting portion of the subtask are to improve knowledge of fracture toughness of mold shells and the sources of strength limiting flaws and to understand the effects of wax reclamation procedures on wax properties. Applying 'clean steel' approaches to pouring technology and cleanliness in investment casting of steel are anticipated to improve incoming materials inspectionmore » procedures as they affect the microstructure and toughness of the shell. This project focused on two areas of study in the production of steel castings to reduce scrap and save energy: (1) Reducing the amount of shell cracking in investment cast steel production; (2) Investigate the potential of lost foam steel casting The basic findings regarding investment casting shell cracking were: (1) In the case of post pouring cracking, this could be related to phase changes in silica upon cooling and could be delayed by pouring arrangement strategies that maintained the shell surface at temperature for longer time. Employing this delay resulted in less adherent oxidation of castings since the casting was cooler at the time o fair exposure. (2) A model for heat transfer through water saturated shell materials under steam pressure was developed. (3) Initial modeling result of autoclave de-waxing indicated the higher pressure and temperature in the autoclave would impose a steeper temperature gradient on the wax pattern, causing some melt flow prior to bulk expansion and decreasing the stress on the green shell. Basic findings regarding lost foam casting of steel at atmospheric pressure: (1) EPS foam generally decomposes by the collapse mode in steel casting. (2) There is an accumulation of carbon pick-up at the end of the casting opposite the gate. (3) It is recommended that lost foam castings in steel be gated for a quiescent fill in an empty cavity mold to prevent foam occlusion defects from the collapse mode. The energy benefit is primarily in yield savings and lower casting weight per function due to elimination of draft and parting lines for the larger lost foam castings. For the smaller investment casting, scrap losses due to shell cracking will be reduced. Both of these effects will reduce the metal melted per good ton of castings. There will also be less machine stock required per casting which is a yield savings and a small additional energy savings in machining. Downstream savings will come from heavy truck and railroad applications. Application of these processes to heavy truck castings will lighten the heavy truck fleet by about ten pounds per truck. Using ten years to achieve full penetration of the truck fleet at linear rate this will result in a fuel savings of 131 trillion BTU over ten years.« less

Generation and evaluation of 3D digital casts of maxillary defects based on multisource data registration: A pilot clinical study.

PubMed

Ye, Hongqiang; Ma, Qijun; Hou, Yuezhong; Li, Man; Zhou, Yongsheng

2017-12-01

Digital techniques are not clinically applied for 1-piece maxillary prostheses containing an obturator and removable partial denture retained by the remaining teeth because of the difficulty in obtaining sufficiently accurate 3-dimensional (3D) images. The purpose of this pilot clinical study was to generate 3D digital casts of maxillary defects, including the defective region and the maxillary dentition, based on multisource data registration and to evaluate their effectiveness. Twelve participants with maxillary defects were selected. The maxillofacial region was scanned with spiral computer tomography (CT), and the maxillary arch and palate were scanned using an intraoral optical scanner. The 3D images from the CT and intraoral scanner were registered and merged to form a 3D digital cast of the maxillary defect containing the anatomic structures needed for the maxillary prosthesis. This included the defect cavity, maxillary dentition, and palate. Traditional silicone impressions were also made, and stone casts were poured. The accuracy of the digital cast in comparison with that of the stone cast was evaluated by measuring the distance between 4 anatomic landmarks. Differences and consistencies were assessed using paired Student t tests and the intraclass correlation coefficient (ICC). In 3 participants, physical resin casts were produced by rapid prototyping from digital casts. Based on the resin casts, maxillary prostheses were fabricated by using conventional methods and then evaluated in the participants to assess the clinical applicability of the digital casts. Digital casts of the maxillary defects were generated and contained all the anatomic details needed for the maxillary prosthesis. Comparing the digital and stone casts, a paired Student t test indicated that differences in the linear distances between landmarks were not statistically significant (P>.05). High ICC values (0.977 to 0.998) for the interlandmark distances further indicated the high degree of consistency between the digital and stone casts. The maxillary prostheses showed good clinical effectiveness, indicating that the corresponding digital casts met the requirements for clinical application. Based on multisource data from spiral CT and the intraoral scanner, 3D digital casts of maxillary defects were generated using the registration technique. These casts were consistent with conventional stone casts in terms of accuracy and were suitable for clinical use. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Dimensional accuracy and surface property of titanium casting using gypsum-bonded alumina investment.

PubMed

Yan, Min; Takahashi, Hidekazu; Nishimura, Fumio

2004-12-01

The aim of the present study was to evaluate the dimensional accuracy and surface property of titanium casting obtained using a gypsum-bonded alumina investment. The experimental gypsum-bonded alumina investment with 20 mass% gypsum content mixed with 2 mass% potassium sulfate was used for five cp titanium castings and three Cu-Zn alloy castings. The accuracy, surface roughness (Ra), and reaction layer thickness of these castings were investigated. The accuracy of the castings obtained from the experimental investment ranged from -0.04 to 0.23%, while surface roughness (Ra) ranged from 7.6 to 10.3microm. A reaction layer of about 150 microm thickness under the titanium casting surface was observed. These results suggested that the titanium casting obtained using the experimental investment was acceptable. Although the reaction layer was thin, surface roughness should be improved.

An investigation of squeeze-cast alloy 718

NASA Technical Reports Server (NTRS)

Gamwell, W. R.

1993-01-01

Alloy 718 billets produced by the squeeze-cast process have been evaluated for use as potential replacements for propulsion engine components which are normally produced from forgings. Alloy 718 billets were produced using various processing conditions. Structural characterizations were performed on 'as-cast' billets. As-cast billets were then homogenized and solution treated and aged according to conventional heat-treatment practices for this alloy. Mechanical property evaluations were performed on heat-treated billets. As-cast macrostructures and microstructures varied with squeeze-cast processing parameters. Mechanical properties varied with squeeze-cast processing parameters and heat treatments. One billet exhibited a defect free, refined microstructure, with mechanical properties approaching those of wrought alloy 718 bar, confirming the feasibility of squeeze-casting alloy 718. However, further process optimization is required, and further structural and mechanical property improvements are expected with process optimization.

The efficiencies of cast blasting in wide pits

DOE Office of Scientific and Technical Information (OSTI.GOV)

Martin, R.L.; King, M.G.

Blasting activities in all four pits at Thunder Basin Coal`s Black Thunder Mine are focused on cast blasting. With widths varying from 190 feet to 265 feet and bench heights varying from 90 feet to 175 feet, casting efficiencies vary with different geometry`s. For example, the percent cast to final in the 200 foot pit is on the average higher than the 270 foot pit. The powder factors are somewhat higher in the narrower pits, thus increasing the cost of blasting. This leads to a very detailed look at the actual benefit of cast blasting and the associated cost ofmore » these benefits. The simple solution would be to reduce the width of the pits, thereby increasing the percent cast to final. However, the lower rehandle and low coal loss associated with wide pits would be fortified. Upon further review it becomes obvious that the wider pits could not be compared to the narrow pits with the cast to final percent indices. The focus should be shifted to cubic yards cast to final per lineal foot of pit. This will allow for more accurate measures of the casting efficiency of the shot. When comparing the pits with these indices their performances were much closer than the percent cast to final indices. The powder factors being higher in the narrow pits drove up the cost per cubic yard cast to final. Therefore, even though the percent cast to final was higher, the cost per cubic yard was also higher.« less

A Comparative Evaluation of the Effect of Double Casting Technique Using Functionally Generated Path and Conventional Single Casting with Respect to Functional Articulation, Patient Satisfaction and Chair Side Time, in Single Unit Molar Teeth: An In Vivo Study.

PubMed

Memon, Sarfaraz

2014-12-01

A stable centric occlusal position that shows no evidence of occlusal disease should not be altered. Confirmative restorative dentistry deals with making restorations that are in harmony with existing jaw relations. Conventional techniques for construction have been unsuccessful in producing a prosthesis that can be inserted without minor intraoral occlusal adjustment. This study was conducted to evaluate the benefits of the double casting technique with FGP over the conventional casting technique. Ten patients with root canal treated maxillary molar were selected for the fabrication of metal crown. Two techniques, one involving the conventional fabrication and other using functionally generated path with double casting were used to fabricate the prosthesis. A comparison based on various parameters which was done between the two techniques. The change in the height of castings for the double casting group was less compared to the conventional group and was highly statistically significant (P < 0.001). The time taken for occlusal correction was significantly lower in double casting group than the conventional group (P < 0.001). The patient satisfaction (before occlusal correction) indicated better satisfaction for double casting group compared to conventional (P < 0.01). The functionally generated path with double casting technique resulted in castings which had better dimensional accuracy, less occlusal correction and better patient satisfaction compared to the conventional castings.

Vascular Corrosion Casting: Review of Advantages and Limitations in the Application of Some Simple Quantitative Methods.

PubMed

Hossler, Fred E.; Douglas, John E.

2001-05-01

Vascular corrosion casting has been used for about 40 years to produce replicas of normal and abnormal vasculature and microvasculature of various tissues and organs that could be viewed at the ultrastructural level. In combination with scanning electron microscopy (SEM), the primary application of corrosion casting has been to describe the morphology and anatomical distribution of blood vessels in these tissues. However, such replicas should also contain quantitative information about that vasculature. This report summarizes some simple quantitative applications of vascular corrosion casting. Casts were prepared by infusing Mercox resin or diluted Mercox resin into the vasculature. Surrounding tissues were removed with KOH, hot water, and formic acid, and the resulting dried casts were observed with routine SEM. The orientation, size, and frequency of vascular endothelial cells were determined from endothelial nuclear imprints on various cast surfaces. Vascular volumes of heart, lung, and avian salt gland were calculated using tissue and resin densities, and weights. Changes in vascular volume and functional capillary density in an experimentally induced emphysema model were estimated from confocal images of casts. Clearly, corrosion casts lend themselves to quantitative analysis. However, because blood vessels differ in their compliances, in their responses to the toxicity of casting resins, and in their response to varying conditions of corrosion casting procedures, it is prudent to use care in interpreting this quantitative data. Some of the applications and limitations of quantitative methodology with corrosion casts are reviewed here.

Investigation of Materials Processing Technology

DTIC Science & Technology

1993-07-01

Figure 6: Time-temperature curves of A357 casting in Cu mold ................. 12 Figure 7: Time-temperature curves of 17 -4 casting in ceramic mold...simulation of 17 -4 ................ 17 Figure 12: IHTC from IHEAT simulation of 17 -4 casting ..................... 18 Figure 13: Temperature profiles...mold used for Ti castings .......................... 23 Figure 16: Cooling curves for a Ti casting in ceramic mold .................. 24 Figure 17

49 CFR 192.373 - Service lines: Cast iron and ductile iron.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 3 2010-10-01 2010-10-01 false Service lines: Cast iron and ductile iron. 192.373... Regulators, and Service Lines § 192.373 Service lines: Cast iron and ductile iron. (a) Cast or ductile iron... cast iron pipe or ductile iron pipe is installed for use as a service line, the part of the service...

Hot forging of roll-cast high aluminum content magnesium alloys

NASA Astrophysics Data System (ADS)

Kishi, Tomohiro; Watari, Hisaki; Suzuki, Mayumi; Haga, Toshio

2017-10-01

This paper reports on hot forging of high aluminum content magnesium alloy sheets manufactured using horizontal twin-roll casting. AZ111 and AZ131 were applied for twin-roll casting, and a hot-forging test was performed to manufacture high-strength magnesium alloy components economically. For twin-roll casting, the casting conditions of a thick sheet for hot forging were investigated. It was found that twin-roll casting of a 10mm-thick magnesium alloy sheet was possible at a roll speed of 2.5m/min. The grain size of the cast strip was 50 to 70µm. In the hot-forging test, blank material was obtained from as-cast strip. A servo press machine with a servo die cushion was used to investigate appropriate forging conditions (e.g., temperature, forging load, and back pressure) for twin-roll casts (TRCs) AZ111 and AZ131. It was determined that high aluminum content magnesium alloy sheets manufactured using twin-roll casting could be forged with a forging load of 150t and a back pressure of 3t at 420 to 430°C. Applying back pressure during hot forging effectively forged a pin-shaped product.

Casting materials and their application in research and teaching.

PubMed

Haenssgen, Kati; Makanya, Andrew N; Djonov, Valentin

2014-04-01

From a biological point of view, casting refers to filling of anatomical and/or pathological spaces with extraneous material that reproduces a three-dimensional replica of the space. Casting may be accompanied by additional procedures such as corrosion, in which the soft tissue is digested out, leaving a clean cast, or the material may be mixed with radiopaque substances to allow x-ray photography or micro computed topography (µCT) scanning. Alternatively, clearing of the surrounding soft tissue increases transparency and allows visualization of the casted cavities. Combination of casting with tissue fixation allows anatomical dissection and didactic surgical procedures on the tissue. Casting materials fall into three categories namely, aqueous substances (India ink, Prussian blue ink), pliable materials (gelatins, latex, and silicone rubber), or hard materials (methyl methacrylates, polyurethanes, polyesters, and epoxy resins). Casting has proved invaluable in both teaching and research and many phenomenal biological processes have been discovered through casting. The choice of a particular material depends inter alia on the targeted use and the intended subsequent investigative procedures, such as dissection, microscopy, or µCT. The casting material needs to be pliable where anatomical and surgical manipulations are intended, and capillary-passable for ultrastructural investigations.

Development and evaluation of a digital dental modeling method based on grating projection and reverse engineering software.

PubMed

Zhou, Qin; Wang, Zhenzhen; Chen, Jun; Song, Jun; Chen, Lu; Lu, Yi

2016-01-01

For reasons of convenience and economy, attempts have been made to transform traditional dental gypsum casts into 3-dimensional (3D) digital casts. Different scanning devices have been developed to generate digital casts; however, each has its own limitations and disadvantages. The purpose of this study was to develop an advanced method for the 3D reproduction of dental casts by using a high-speed grating projection system and noncontact reverse engineering (RE) software and to evaluate the accuracy of the method. The methods consisted of 3 main steps: the scanning and acquisition of 3D dental cast data with a high-resolution grating projection system, the reconstruction and measurement of digital casts with RE software, and the evaluation of the accuracy of this method using 20 dental gypsum casts. The common anatomic landmarks were measured directly on the gypsum casts with a Vernier caliper and on the 3D digital casts with the Geomagic software measurement tool. Data were statistically assessed with the t test. The grating projection system had a rapid scanning speed, and smooth 3D dental casts were obtained. The mean differences between the gypsum and 3D measurements were approximately 0.05 mm, and no statistically significant differences were found between the 2 methods (P>.05), except for the measurements of the incisor tooth width and maxillary arch length. A method for the 3D reconstruction of dental casts was developed by using a grating projection system and RE software. The accuracy of the casts generated using the grating projection system was comparable with that of the gypsum casts. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Focused Molding Using Adhesive Pads in Mehta Casting for Early-Onset Scoliosis.

PubMed

Abraham, Roby; Sponseller, Paul D

2014-11-01

Prospective clinical series. To determine the effect of adhesive pads placed over the apex of scoliosis curves on curve correction 1) after the first cast and 2) after the final cast. Early-onset scoliosis is often effectively managed by serial casting. Properly localizing the apex of the molds with the cast in place is challenging. The authors explored the effectiveness of a novel technique: incorporation of adhesive pads placed over the major curve apex before Mehta casting. The 27 patients who received body casts (2000-2013) were divided into 2 groups: those without and with apical adhesive pads (5-6 layers of pads placed on the major curve's apex during casting): non-pad (NP) group (n = 12) and pad (P) group (n = 15), respectively. Groups were compared regarding the percentage of Cobb angle change from the first cast and curve correction to a Cobb angle of <25° with Student t and chi-square tests (significance was p < .05). The mean percentage of major first-cast curve correction was 39% ± 18% and 56% ± 17% in the NP and P groups, respectively. Of the 26 patients out of a cast, 11 (42%) had a Cobb angle of <25°: 3 (25%) and 8 (57%) in the NP and P groups, respectively. The mean differences between the 2 groups in percentage of major curve correction and this Cobb angle correction were significant: p = .023 and .005, respectively. Adhesive pads placed over major curve(s) during Mehta casting were effective in increasing the amount of major curve correction from the first cast for idiopathic early-onset scoliosis and in decreasing curves to <25° at final follow-up. Copyright © 2014 Scoliosis Research Society. Published by Elsevier Inc. All rights reserved.

A comparison between the dimensions of positive transtibial residual limb molds prepared by air pressure casting and weight-bearing casting methods.

PubMed

Hajiaghaei, Behnam; Ebrahimi, Ismail; Kamyab, Mojtaba; Saeedi, Hassan; Jalali, Maryam

2016-01-01

Creating a socket with proper fit is an important factor to ensure the comfort and control of prosthetic devices. Several techniques are commonly used to cast transtibial stumps but their effect on stump shape deformation is not well understood. This study compares the dimensions, circumferences and volumes of the positive casts and also the socket comfort between two casting methods. Our hypothesis was that the casts prepared by air pressure method have less volume and are more comfortable than those prepared by weight bearing method. Fifteen transtibial unilateral amputees participated in the study. Two weight bearing and air pressure casting methods were utilized for their residual limbs. The diameters and circumferences of various areas of the residual limbs and positive casts were compared. The volumes of two types of casts were measured by a volumeter and compared. Visual Analogue Scale (VAS) was used to measure the sockets fit comfort. Circumferences at 10 and 15 cm below the patella on the casts were significantly smaller in air pressure casting method compared to the weight bearing method (p=0.00 and 0.01 respectively). The volume of the cast in air pressure method was lower than that of the weight bearing method (p=0.006). The amputees found the fit of the sockets prepared by air pressure method more comfortable than the weight bearing sockets (p=0.015). The air pressure casting reduced the circumferences of the distal portion of residual limbs which has more soft tissue and because of its snug fit it provided more comfort for amputees, according to the VAS measurements.

Strain Rate Dependency of Bronze Metal Matrix Composite Mechanical Properties as a Function of Casting Technique

NASA Astrophysics Data System (ADS)

Brown, Lloyd; Joyce, Peter; Radice, Joshua; Gregorian, Dro; Gobble, Michael

2012-07-01

Strain rate dependency of mechanical properties of tungsten carbide (WC)-filled bronze castings fabricated by centrifugal and sedimentation-casting techniques are examined, in this study. Both casting techniques are an attempt to produce a functionally graded material with high wear resistance at a chosen surface. Potential applications of such materials include shaft bushings, electrical contact surfaces, and brake rotors. Knowledge of strain rate-dependent mechanical properties is recommended for predicting component response due to dynamic loading or impact events. A brief overview of the casting techniques for the materials considered in this study is followed by an explanation of the test matrix and testing techniques. Hardness testing, density measurement, and determination of the volume fraction of WC particles are performed throughout the castings using both image analysis and optical microscopy. The effects of particle filling on mechanical properties are first evaluated through a microhardness survey of the castings. The volume fraction of WC particles is validated using a thorough density survey and a rule-of-mixtures model. Split Hopkinson Pressure Bar (SHPB) testing of various volume fraction specimens is conducted to determine strain dependence of mechanical properties and to compare the process-property relationships between the two casting techniques. The baseline performances of C95400 bronze are provided for comparison. The results show that the addition of WC particles improves microhardness significantly for the centrifugally cast specimens, and, to a lesser extent, in the sedimentation-cast specimens, largely because the WC particles are more concentrated as a result of the centrifugal-casting process. Both metal matrix composites (MMCs) demonstrate strain rate dependency, with sedimentation casting having a greater, but variable, effects on material response. This difference is attributed to legacy effects from the casting process, namely, porosity and localized WC particle grouping.

Precision cast vs. wrought superalloys

NASA Technical Reports Server (NTRS)

Tien, J. K.; Borofka, J. C.; Casey, M. E.

1986-01-01

While cast polycrystalline superalloys recommend themselves in virtue of better 'buy-to-fly' ratios and higher strengthening gamma-prime volume fractions than those of wrought superalloys, the expansion of their use into such critical superalloy applications as gas turbine hot section components has been slowed by insufficient casting process opportunities for microstructural control. Attention is presently drawn, however, to casting process developments facilitating the production of defect-tolerant superalloy castings having improved fracture reliability. Integrally bladed turbine wheel and thin-walled turbine exhaust case near-net-shape castings have been produced by these means.

Improved Safety and Cost Savings from Reductions in Cast-Saw Burns After Simulation-Based Education for Orthopaedic Surgery Residents.

PubMed

Bae, Donald S; Lynch, Hayley; Jamieson, Katherine; Yu-Moe, C Winnie; Roussin, Christopher

2017-09-06

The purpose of this investigation was to characterize the clinical efficacy and cost-effectiveness of simulation training aimed at reducing cast-saw injuries. Third-year orthopaedic residents underwent simulation-based instruction on distal radial fracture reduction, casting, and cast removal using an oscillating saw. The analysis compared incidences of cast-saw injuries and associated costs before and after the implementation of the simulation curriculum. Actual and potential costs associated with cast-saw injuries included wound care, extra clinical visits, and potential total payment (indemnity and expense payments). Curriculum costs were calculated through time-derived, activity-based accounting methods. The researchers compared the costs of cast-saw injuries and the simulation curriculum to determine overall savings and return on investment. In the 2.5 years prior to simulation, cast-saw injuries occurred in approximately 4.3 per 100 casts cut by orthopaedic residents. For the 2.5-year period post-simulation, the injury rate decreased significantly to approximately 0.7 per 100 casts cut (p = 0.002). The total cost to implement the casting simulation was $2,465.31 per 6-month resident rotation. On the basis of historical data related to cast-saw burns (n = 6), total payments ranged from $2,995 to $25,000 per claim. The anticipated savings from averted cast-saw injuries and associated medicolegal payments in the 2.5 years post-simulation was $27,131, representing an 11-to-1 return on investment. Simulation-based training for orthopaedic surgical residents was effective in reducing cast-saw injuries and had a high theoretical return on investment. These results support further investment in simulation-based training as cost-effective means of improving patient safety and clinical outcomes. Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Casting of Ti-6Al-4V alloy compared with pure Ti in an Ar-arc casting machine.

PubMed

Syverud, M; Okabe, T; Herø, H

1995-10-01

Dental prostheses of Ti are normally cast in pure Ti. Some appliances, however, require higher yield strength. Casting of Ti alloys is of interest in such cases. The objective of the present work was to study the quality of castings made of Ti-6Al-4V compared with those made of pure Ti. Casting was made into a mold kept at room temperature using a MgO-Al2O3 investment. A standardized five-unit bridge was cast, consisting of two cylindrical crowns with sharp margins and three pontics. The overall mold filling was satisfactory. The margins of the casting alloys were, however, more rugged and incomplete than those of pure Ti. The most likely reason for this difference is the increased formation of dendrites in the alloy and thus more resistance to fluid flow. Furthermore, the sprue of the alloy was also found to contain some spherical, internal pores. Such pores were rare in the pure Ti castings. The surface reactions were found to be minimal for both of the materials. Increased casting deficiencies observed in the cast bridges of the Ti-6Al-4V alloy, compared with pure Ti, were: 1) the margins of the crowns in the bridge were less complete and 2) there was a tendency to an increased internal porosity, particularly in the sprues.

An audit of complications of fiberglass cast and hybrid cast for fractures of the foot, ankle and forearm in a Swedish emergency department.

PubMed

Ekwall, Anna; Carlberg, Eva; Palmberg, Gunilla; Sloberg, Rut

2018-06-01

Patients of all ages present to the Emergency Department (ED) with fractures that require immobilization using a cast. Various casting materials are used, all with advantages and disadvantages and there are considerable risks associated with fracture management using cast immobilization. The frequency and severity of complications from fiberglass or hybrid casts applied in the emergency setting has not previously been studied. The aim of this audit was to describe all the complications that occurred within 30 days in patients who had a fiberglass cast applied for immobilization of uncomplicated, non-angulated fractures of the foot, ankle or forearm. A retrospective care record audit was conducted that included 430 patients. The most common complications found were skin complications and cast related problems. No severe complications (e.g. compartment syndrome, venous thromboembolism or infection) were found. Fiberglass casts did not cause severe complications in this group of patients with uncomplicated fractures of the extremities. However, 25% of the patients experienced some form of complication. Interventions are needed that minimize the frequency of complications. As with all healthcare interventions, it is crucial that staff applying casts and providing follow-up care are competent. If casts are applied correctly and the patient is well informed and concordant, complications can be avoided. Copyright © 2018 Elsevier Ltd. All rights reserved.

The transcriptomic and evolutionary signature of social interactions regulating honey bee caste development.

PubMed

Vojvodic, Svjetlana; Johnson, Brian R; Harpur, Brock A; Kent, Clement F; Zayed, Amro; Anderson, Kirk E; Linksvayer, Timothy A

2015-11-01

The caste fate of developing female honey bee larvae is strictly socially regulated by adult nurse workers. As a result of this social regulation, nurse-expressed genes as well as larval-expressed genes may affect caste expression and evolution. We used a novel transcriptomic approach to identify genes with putative direct and indirect effects on honey bee caste development, and we subsequently studied the relative rates of molecular evolution at these caste-associated genes. We experimentally induced the production of new queens by removing the current colony queen, and we used RNA sequencing to study the gene expression profiles of both developing larvae and their caregiving nurses before and after queen removal. By comparing the gene expression profiles of queen-destined versus worker-destined larvae as well as nurses observed feeding these two types of larvae, we identified larval and nurse genes associated with caste development. Of 950 differentially expressed genes associated with caste, 82% were expressed in larvae with putative direct effects on larval caste, and 18% were expressed in nurses with putative indirect effects on caste. Estimated selection coefficients suggest that both nurse and larval genes putatively associated with caste are rapidly evolving, especially those genes associated with worker development. Altogether, our results suggest that indirect effect genes play important roles in both the expression and evolution of socially influenced traits such as caste.

Modeling the surface contamination of dental titanium investment castings.

PubMed

Atwood, R C; Lee, P D; Curtis, R V

2005-02-01

The objective of this study was to develop a computational tool for assisting the design of titanium dental castings with minimal defects and to compare computational simulations with casting experiments. Modeling. An in-house cellular-automata solidification and finite-difference diffusion program was coupled with a commercial casting program and applied to (a) simple geometric wedge models and (b) a 3D-laser scan of a molar crown casting. Experimental. Wedges and molar crowns were hand-waxed and investment cast in commercial purity grade 1 (CP-1) titanium by a commercial dental laboratory. The castings were sectioned and analyzed using light and scanning electron microscopy, X-ray microanalysis, and microhardness testing. In the wedge sample, contamination with impurities (Al, Si), including intermetallic precipitates, was found to extend to a depth ranging from 30 to 120 microm depending on the section thickness and hence the local cooling rate. Microstructural and mechanical (hardness) effects were found to a depth ranging from 80 to 250 microm. The coupled micro/macro model predictions showed reasonable agreement for the pattern of contamination. Dental and medical applications demand close dimensional tolerance and freedom from surface impurities and structural flaws in castings having unique shapes. The ability to predict the structural, mechanical, and chemical changes resulting from the casting process will help to design the casting and post-casting processes to minimize these problems.

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

Code of Federal Regulations, 2010 CFR

2010-10-01

... 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 repairs...

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

Code of Federal Regulations, 2011 CFR

2011-10-01

... 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 repairs...

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

Code of Federal Regulations, 2013 CFR

2013-10-01

... 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 repairs...

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

Code of Federal Regulations, 2012 CFR

2012-10-01

... 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 repairs...

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

Code of Federal Regulations, 2014 CFR

2014-10-01

... 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 repairs...

Y-chromosomal insights into the genetic impact of the caste system in India.

PubMed

Zerjal, Tatiana; Pandya, Arpita; Thangaraj, Kumarasamy; Ling, Edmund Y S; Kearley, Jennifer; Bertoneri, Stefania; Paracchini, Silvia; Singh, Lalji; Tyler-Smith, Chris

2007-03-01

The caste system has persisted in Indian Hindu society for around 3,500 years. Like the Y chromosome, caste is defined at birth, and males cannot change their caste. In order to investigate the genetic consequences of this system, we have analysed male-lineage variation in a sample of 227 Indian men of known caste, 141 from the Jaunpur district of Uttar Pradesh and 86 from the rest of India. We typed 131 Y-chromosomal binary markers and 16 microsatellites. We find striking evidence for male substructure: in particular, Brahmins and Kshatriyas (but not other castes) from Jaunpur each show low diversity and the predominance of a single distinct cluster of haplotypes. These findings confirm the genetic isolation and drift within the Jaunpur upper castes, which are likely to result from founder effects and social factors. In the other castes, there may be either larger effective population sizes, or less strict isolation, or both.

Metallic Fuel Casting Development and Parameter Optimization Simulations

DOE Office of Scientific and Technical Information (OSTI.GOV)

R.S. Fielding; J. Crapps; C. Unal

One of the advantages of metallic fuel is the abilility to cast the fuel slugs to near net shape with little additional processing. However, the high aspect ratio of the fuel is not ideal for casting. EBR-II fuel was cast using counter gravity injection casting (CGIC) but, concerns have been raised concerning the feasibility of this process for americium bearing alloys. The Fuel Cycle Research and Development program has begun developing gravity casting techniques suitable for fuel production. Compared to CGIC gravity casting does not require a large heel that then is recycled, does not require application of a vacuummore » during melting, and is conducive to re-usable molds. Development has included fabrication of two separate benchscale, approximately 300 grams, systems. To shorten development time computer simulations have been used to ensure mold and crucible designs are feasible and to identify which fluid properties most affect casting behavior and therefore require more characterization.« less

Computational Multi-Scale Modeling of the Microstructure and Segregation of Cast Mg Alloys at Low Superheat

NASA Astrophysics Data System (ADS)

Nastac, Laurentiu; El-Kaddah, Nagy

It is well known that casting at low superheat has a strong influence on the solidification structures of the cast alloy. Recent studies on casting magnesium AZ alloys at low superheat using the Magnetic Suspension Melting (MSM) process have shown that the cast alloy exhibit a fine globular grain structure, and the grain size depend on the cooling rate. This paper describes a stochastic mesoscopic model for predicting the grain structure and segregation in cast alloys at low superheat. This model was applied to predict the globular solidification morphology and solute redistribution of Al in cast Mg AZ31B alloy at different cooling rates. The predictions were found to be in good agreement with the observed grain structure and Al segregation. This makes the model a very useful tool for optimizing the solidification structure of cast magnesium alloys.

Casting Of Multilayer Ceramic Tapes

NASA Technical Reports Server (NTRS)

Collins, Earl R., Jr.

1991-01-01

Procedure for casting thin, multilayer ceramic membranes, commonly called tapes, involves centrifugal casting at accelerations of 1,800 to 2,000 times normal gravitational acceleration. Layers of tape cast one at a time on top of any previous layer or layers. Each layer cast from slurry of ground ceramic suspended in mixture of solvents, binders, and other components. Used in capacitors, fuel cells, and electrolytic separation of oxygen from air.

'Fast cast' and 'needle Tenotomy' protocols with the Ponseti method to improve clubfoot management in Bangladesh.

PubMed

Evans, Angela; Chowdhury, Mamun; Rana, Sohel; Rahman, Shariar; Mahboob, Abu Hena

2017-01-01

The management of congenital talipes equino varus ( clubfoot deformity ) has been transformed in the last 20 years as surgical correction has been replaced by the non-surgical Ponseti method. The Ponseti method, consists of corrective serial casting followed by maintenance bracing, and has been repeatedly demonstrated to give best results - regarded as the 'gold standard' treatment for paediatric clubfoot. To develop the study protocol Level 2 evidence was used to modify the corrective casting phase of the Ponseti method in children aged up to 12 months. Using Level 4 evidence, the percutaneous Achilles tenotomy (PAT) was performed using a 19-gauge needle instead of a scalpel blade, a technique found to reduce bleeding and scarring. A total of 123 children participated in this study; 88 male, 35 female. Both feet were affected in 67 cases, left only in 22 cases, right only in 34 cases. Typical clubfeet were found in 112/123 cases, six atypical, five syndromic. The average age at first cast was 51 days (13-240 days).The average number of casts applied was five (2-10 casts). The average number of days between the first cast and brace was 37.8 days (10-122 days), including 21 days in a post-PAT cast. Hence, average time of corrective casts was 17 days.Parents preferred the reduced casting time, and were less concerned about unseen skin wounds.PAT was performed in 103/123 cases, using the needle technique. All post tenotomy casts were in situ for three weeks. Minor complications occurred in seven cases - four cases had skin lesions, three cases disrupted casting phase. At another site, 452 PAT were performed using the needle technique. The 'fast cast' protocol Ponseti casting was successfully used in infants aged less than 8 months. Extended manual manipulation of two minutes was the essential modification. Parents preferred the faster treatment phase, and ability to closer observe the foot and skin. The treating physiotherapists preferred the 'fast cast' protocol, achieving better correction with less complication. The needle technique for PAT is a further improvement for the Ponseti method.

Genetic affinities among the lower castes and tribal groups of India: inference from Y chromosome and mitochondrial DNA.

PubMed

Thanseem, Ismail; Thangaraj, Kumarasamy; Chaubey, Gyaneshwer; Singh, Vijay Kumar; Bhaskar, Lakkakula V K S; Reddy, B Mohan; Reddy, Alla G; Singh, Lalji

2006-08-07

India is a country with enormous social and cultural diversity due to its positioning on the crossroads of many historic and pre-historic human migrations. The hierarchical caste system in the Hindu society dominates the social structure of the Indian populations. The origin of the caste system in India is a matter of debate with many linguists and anthropologists suggesting that it began with the arrival of Indo-European speakers from Central Asia about 3500 years ago. Previous genetic studies based on Indian populations failed to achieve a consensus in this regard. We analysed the Y-chromosome and mitochondrial DNA of three tribal populations of southern India, compared the results with available data from the Indian subcontinent and tried to reconstruct the evolutionary history of Indian caste and tribal populations. No significant difference was observed in the mitochondrial DNA between Indian tribal and caste populations, except for the presence of a higher frequency of west Eurasian-specific haplogroups in the higher castes, mostly in the north western part of India. On the other hand, the study of the Indian Y lineages revealed distinct distribution patterns among caste and tribal populations. The paternal lineages of Indian lower castes showed significantly closer affinity to the tribal populations than to the upper castes. The frequencies of deep-rooted Y haplogroups such as M89, M52, and M95 were higher in the lower castes and tribes, compared to the upper castes. The present study suggests that the vast majority (> 98%) of the Indian maternal gene pool, consisting of Indio-European and Dravidian speakers, is genetically more or less uniform. Invasions after the late Pleistocene settlement might have been mostly male-mediated. However, Y-SNP data provides compelling genetic evidence for a tribal origin of the lower caste populations in the subcontinent. Lower caste groups might have originated with the hierarchical divisions that arose within the tribal groups with the spread of Neolithic agriculturalists, much earlier than the arrival of Aryan speakers. The Indo-Europeans established themselves as upper castes among this already developed caste-like class structure within the tribes.

Genetic affinities among the lower castes and tribal groups of India: inference from Y chromosome and mitochondrial DNA

PubMed Central

Thanseem, Ismail; Thangaraj, Kumarasamy; Chaubey, Gyaneshwer; Singh, Vijay Kumar; Bhaskar, Lakkakula VKS; Reddy, B Mohan; Reddy, Alla G; Singh, Lalji

2006-01-01

Background India is a country with enormous social and cultural diversity due to its positioning on the crossroads of many historic and pre-historic human migrations. The hierarchical caste system in the Hindu society dominates the social structure of the Indian populations. The origin of the caste system in India is a matter of debate with many linguists and anthropologists suggesting that it began with the arrival of Indo-European speakers from Central Asia about 3500 years ago. Previous genetic studies based on Indian populations failed to achieve a consensus in this regard. We analysed the Y-chromosome and mitochondrial DNA of three tribal populations of southern India, compared the results with available data from the Indian subcontinent and tried to reconstruct the evolutionary history of Indian caste and tribal populations. Results No significant difference was observed in the mitochondrial DNA between Indian tribal and caste populations, except for the presence of a higher frequency of west Eurasian-specific haplogroups in the higher castes, mostly in the north western part of India. On the other hand, the study of the Indian Y lineages revealed distinct distribution patterns among caste and tribal populations. The paternal lineages of Indian lower castes showed significantly closer affinity to the tribal populations than to the upper castes. The frequencies of deep-rooted Y haplogroups such as M89, M52, and M95 were higher in the lower castes and tribes, compared to the upper castes. Conclusion The present study suggests that the vast majority (>98%) of the Indian maternal gene pool, consisting of Indio-European and Dravidian speakers, is genetically more or less uniform. Invasions after the late Pleistocene settlement might have been mostly male-mediated. However, Y-SNP data provides compelling genetic evidence for a tribal origin of the lower caste populations in the subcontinent. Lower caste groups might have originated with the hierarchical divisions that arose within the tribal groups with the spread of Neolithic agriculturalists, much earlier than the arrival of Aryan speakers. The Indo-Europeans established themselves as upper castes among this already developed caste-like class structure within the tribes. PMID:16893451

It is not just comfort: waterproof casting increases physical functioning in children with minimally angulated distal radius fractures.

PubMed

Silva, Mauricio; Avoian, Tigran; Warnock, Robert Sean; Sadlik, Gal; Ebramzadeh, Edward

2017-09-01

Waterproof casting has been reported to increase patient comfort and satisfaction, and decrease skin irritation. There are no available data on the influence of waterproof casting materials on physical function in pediatric patients. Our aim was to determine whether the use of waterproof casting would result in faster recovery of physical function while maintaining similar clinical outcomes as those obtained with nonwaterproof materials. Twenty-six children with nonangulated or minimally angulated distal radius fractures were assigned randomly to initially receive a short-arm cast made of one of two optional materials: a hybrid mesh material with a waterproof lining or fiberglass with a nonwaterproof skin protector. Two weeks later, the initial cast was removed and replaced with a short-arm cast made of the alternative option. We compared the rate of fracture displacement, physical function, pain, skin changes, itchiness, and patient satisfaction. No evidence of displacement was found in either group. The mean Activities Scale for Kids - Performance (ASK-P) (physical function) score was 10% higher during the period of time when a waterproof cast was used (P=0.04). When a waterproof cast was used during the first 2 weeks of treatment, the mean total ASK-P scores were 23% higher than that when a nonwaterproof one was used during the same period of time (P=0.003). Patients who received a waterproof cast as the initial treatment reported lower functional scores overall and in almost every domain of the ASK-P once they were in a nonwaterproof one; similarly, those who received a nonwaterproof cast as the initial treatment reported higher functional scores overall and in every domain of the ASK-P once they were in a waterproof cast. Compared with a nonwaterproof cast, the use of waterproof casting resulted in comparable levels of pain, itchiness, skin irritability, and overall patient satisfaction. The results of this randomized, cross-over trial suggest that the use of waterproof casting material for the treatment of nondisplaced or minimally displaced distal radius fractures in children can result in a faster recovery of physical function, while providing comparable stability, pain, itchiness, skin irritability, and overall patient satisfaction. II.

Concise Associated Symptoms Tracking scale: a brief self-report and clinician rating of symptoms associated with suicidality.

PubMed

Trivedi, Madhukar H; Wisniewski, Stephen R; Morris, David W; Fava, Maurizio; Kurian, Benji T; Gollan, Jackie K; Nierenberg, Andrew A; Warden, Diane; Gaynes, Bradley N; Luther, James F; Rush, A John

2011-06-01

US Food and Drug Administration (FDA) warnings recommend monitoring negative symptoms associated with the initiation of antidepressant medications as these symptoms may interfere with full recovery and pose safety concerns. There is currently no brief, reliable rating instrument for assessing treatment-emergent, negative symptoms. We evaluated the psychometric properties of 2 versions of the newly developed 17-item Concise Associated Symptom Tracking (CAST) scale, the CAST Clinician Rating (CAST-C) and CAST Self-Rated (CAST-SR), which are brief instruments designed to measure the 5 relevant associated symptom domains (irritability, anxiety, mania, insomnia, and panic). The study enrolled 265 outpatients with major depressive disorder (MDD), from July 2007 through February 2008, into an 8-week, open-label trial with a selective serotonin reuptake inhibitor. Diagnosis of MDD was determined by the Psychiatric Diagnostic Screening questionnaire and an MDD checklist based on DSM-IV-TR criteria. Suicidality (suicidal ideation with associated behaviors) is 1 of 9 symptoms of MDD (depressed mood, loss of interest, appetite or weight change, sleep disturbance, reduced concentration or indecisiveness, fatigue or decreased energy, psychomotor agitation or retardation, feelings of worthlessness or excessive guilt). Psychometric evaluations were conducted on both versions of the CAST. Cronbach α was .80 (CAST-C) and .81 (CAST-SR). Factor analysis identified 5 factors for each scale: (1) irritability, (2) anxiety, (3) mania, (4) insomnia, and (5) panic. When the item that cross-loaded on 2 factors was eliminated, the 16-item solution had a better goodness of fit (CAST-C: 0.90 vs 0.87; CAST-SR: 0.88 vs 0.84). Cronbach α for the 16-item versions was .77 (CAST-C) and .78 (CAST-SR). The 5 associated CAST symptom domains correlated well with other standard measures of these domains. The 16-item CAST-C and CAST-SR demonstrated excellent psychometric properties. These are potentially useful measures for monitoring treatment-emergent negative symptoms associated with antidepressants, as recommended by the FDA. Clinicaltrials.gov Identifier: NCT00532103. © Copyright 2011 Physicians Postgraduate Press, Inc.

Women's health in a rural community in Kerala, India: do caste and socioeconomic position matter?

PubMed Central

Mohindra, K S; Haddad, Slim; Narayana, D

2006-01-01

Objectives To examine the social patterning of women's self‐reported health status in India and the validity of the two hypotheses: (1) low caste and lower socioeconomic position is associated with worse reported health status, and (2) associations between socioeconomic position and reported health status vary across castes. Design Cross‐sectional household survey, age‐adjusted percentages and odds ratios, and multilevel multinomial logistic regression models were used for analysis. Setting A panchayat (territorial decentralised unit) in Kerala, India, in 2003. Participants 4196 non‐elderly women. Outcome measures Self‐perceived health status and reported limitations in activities in daily living. Results Women from lower castes (scheduled castes/scheduled tribes (SC/ST) and other backward castes (OBC) reported a higher prevalence of poor health than women from forward castes. Socioeconomic inequalities were observed in health regardless of the indicators, education, women's employment status or household landholdings. The multilevel multinomial models indicate that the associations between socioeconomic indicators and health vary across caste. Among SC/ST and OBC women, the influence of socioeconomic variables led to a “magnifying” effect, whereas among forward caste women, a “buffering” effect was found. Among lower caste women, the associations between socioeconomic factors and self‐assessed health are graded; the associations are strongest when comparing the lowest and highest ratings of health. Conclusions Even in a relatively egalitarian state in India, there are caste and socioeconomic inequalities in women's health. Implementing interventions that concomitantly deal with caste and socioeconomic disparities will likely produce more equitable results than targeting either type of inequality in isolation. PMID:17108296

Improving Metal Casting Process

NASA Technical Reports Server (NTRS)

1998-01-01

Don Sirois, an Auburn University research associate, and Bruce Strom, a mechanical engineering Co-Op Student, are evaluating the dimensional characteristics of an aluminum automobile engine casting. More accurate metal casting processes may reduce the weight of some cast metal products used in automobiles, such as engines. Research in low gravity has taken an important first step toward making metal products used in homes, automobiles, and aircraft less expensive, safer, and more durable. Auburn University and industry are partnering with NASA to develop one of the first accurate computer model predictions of molten metals and molding materials used in a manufacturing process called casting. Ford Motor Company's casting plant in Cleveland, Ohio is using NASA-sponsored computer modeling information to improve the casting process of automobile and light-truck engine blocks.

Numerical simulation of the casting process of titanium tooth crowns and bridges.

PubMed

Wu, M; Augthun, M; Wagner, I; Sahm, P R; Spiekermann, H

2001-06-01

The objectives of this paper were to simulate the casting process of titanium tooth crowns and bridges; to predict and control porosity defect. A casting simulation software, MAGMASOFT, was used. The geometry of the crowns with fine details of the occlusal surface were digitized by means of laser measuring technique, then converted and read in the simulation software. Both mold filling and solidification were simulated, the shrinkage porosity was predicted by a "feeding criterion", and the gas pore sensitivity was studied based on the mold filling and solidification simulations. Two types of dental prostheses (a single-crown casting and a three-unit-bridge) with various sprue designs were numerically "poured", and only one optimal design for each prosthesis was recommended for real casting trial. With the numerically optimized design, real titanium dental prostheses (five replicas for each) were made on a centrifugal casting machine. All the castings endured radiographic examination, and no porosity was detected in the cast prostheses. It indicates that the numerical simulation is an efficient tool for dental casting design and porosity control. Copyright 2001 Kluwer Academic Publishers

A Comparative Study of Hot Deformation Behaviors for Sand Casting and Centrifugal Casting Q235B Flange Blanks

NASA Astrophysics Data System (ADS)

Qin, Fangcheng; Li, Yongtang; Ju, Li

2017-03-01

Hot compression tests of sand casting and centrifugal casting Q235B flange blanks were performed at strain rate range of 0.01-5 s-1 and temperature range of 850-1,150 °C. The evolutions of microstructure and texture were revealed. The constitutive models based on Arrhenius constitutive modeling were proposed by considering the effects of strain on material constants. The results show that recrystallization in centrifugal casting Q235B is more apparent than that in sand casting, resulting in the finer grains and lower flow stress for centrifugal casting Q235B. The intensities of textures slightly weaken with the increase of temperature. At 1,050 °C and 5 s-1, the textures of sand casting are characterized by strong {001}<100> and {001}<110>, which are related with severe deformation, while the textures of centrifugal casting are composed of {110}<110> and {111}<112>, which are related with dynamic recovery and shear deformation. A good agreement between the predicted and experimental flow stress is achieved and demonstrates that the proposed constitutive models are reliable.

Development of a new casting method to fabricate U–Zr alloy containing minor actinides

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jong Hwan Kim; Hoon Song; Hyung Tae Kim

2014-01-01

Metal fuel slugs of U–Zr alloys for a sodium-cooled fast reactor (SFR) have conventionally been fabricated using an injection casting method. However, casting alloys containing volatile radioactive constituents, such as Am, are problematic in a conventional injection casting method. As an alternative fabrication method, low pressure gravity casting has been developed. Casting soundness, microstructural characteristics, alloying composition, density, and fuel losses were evaluated for the following as-cast fuel slugs: U–10 wt% Zr, U–10 wt% Zr–5 wt% RE, and U–10 wt% Zr–5 wt% RE–5 wt% Mn. The U and Zr contents were uniform throughout the matrix, and impurities such as oxyen,more » carbon, and nitrogen satisfied the specification of total impurities less than 2,000 ppm. The appearance of the fuel slugs was generally sound, and the internal integrity was shown to be satisfactory based on gamma-ray radiography. In a volatile surrogate casting test, the U–Zr–RE–Mn fuel slug showed that nearly all of the manganese was retained when casting was done under an inert atmosphere.« less

The perception of 3-D shape from shadows cast onto curved surfaces.

PubMed

Norman, J Farley; Lee, Young-lim; Phillips, Flip; Norman, Hideko F; Jennings, L RaShae; McBride, T Ryan

2009-05-01

In a natural environment, cast shadows abound. Objects cast shadows both upon themselves and upon background surfaces. Previous research on the perception of 3-D shape from cast shadows has only examined the informativeness of shadows cast upon flat background surfaces. In outdoor environments, however, background surfaces often possess significant curvature (large rocks, trees, hills, etc.), and this background curvature distorts the shape of cast shadows. The purpose of this study was to determine the extent to which observers can "discount" the distorting effects of curved background surfaces. In our experiments, observers viewed deforming or static shadows of naturally shaped objects, which were cast upon flat and curved background surfaces. The results showed that the discrimination of 3-D object shape from cast shadows was generally invariant over the distortions produced by hemispherical background surfaces. The observers often had difficulty, however, in identifying the shadows cast onto saddle-shaped background surfaces. The variations in curvature which occur in different directions on saddle-shaped background surfaces cause shadow distortions that lead to difficulties in object recognition and discrimination.

Numerical simulation of the solidification microstructure of a 17-4PH stainless steel investment casting and its experimental verification

NASA Astrophysics Data System (ADS)

Li, You Yun; Tsai, DeChang; Hwang, Weng Sing

2008-06-01

The purpose of this study is to develop a technique of numerically simulating the microstructure of 17-4PH (precipitation hardening) stainless steel during investment casting. A cellular automation (CA) algorithm was adopted to simulate the nucleation and grain growth. First a calibration casting was made, and then by comparing the microstructures of the calibration casting with those simulated using different kinetic growth coefficients (a2, a3) in CA, the most appropriate set of values for a2 and a3 would be obtained. Then, this set of values was applied to the microstructure simulation of a separate casting, where the casting was actually made. Through this approach, this study has arrived at a set of growth kinetic coefficients from the calibration casting: a2 is 2.9 × 10-5, a3 is 1.49 × 10-7, which is then used to predict the microstructure of the other test casting. Consequently, a good correlation has been found between the microstructure of actual 17-4PH casting and the simulation result.

Consanguineous marriages and matrimonial distance: a study among three South Indian caste groups.

PubMed

Reddy, P G

1988-12-01

Reddy studies consanguineous marriages and matrimonial distance in 3 castes of Nellore district, Andhra Pradesh, South India. The castes include the well-to-do agricultural caste, the Desuri Kapu; the 2nd, artisan caste in the middle of the hierarchy, the Devanga; and the third caste at the bottom of the social ladder, the Mala. During field work conducted in 1978-1979, prominent elders of the villages were approached; information on the consanguinity of marriage and matrimonial distance was gathered through intensive interviews of both men and women from all the households of the 3 castes. Among the total of 979 marriages, 28.9% occurred within the village, the proportion of intra-village marriages being significantly higher in Nellore taluk than in Sullurpet. The 3 castes overall show little difference in the incidence of intra-village marriages, but there is some within caste regional variation in the incidence of intra-village marriages, the Devanga showing a significantly higher incidence in Nellore than in Sullurpet. Intra-village marriages are more common among consanguineous couples (41.5%) than among non-consanguineous (18.3%), a highly significant excess in each of the caste groups. In short, Reddy concludes that intra-village marriages are more common among consanguineous couples than non-consanguineous, and mean matrimonial distance is also lower.

Caste development and evolution in ants: it's all about size.

PubMed

Trible, Waring; Kronauer, Daniel J C

2017-01-01

Female ants display a wide variety of morphological castes, including workers, soldiers, ergatoid (worker-like) queens and queens. Alternative caste development within a species arises from a variable array of genetic and environmental factors. Castes themselves are also variable across species and have been repeatedly gained and lost throughout the evolutionary history of ants. Here, we propose a simple theory of caste development and evolution. We propose that female morphology varies as a function of size, such that larger individuals possess more queen-like traits. Thus, the diverse mechanisms that influence caste development are simply mechanisms that affect size in ants. Each caste-associated trait has a unique relationship with size, producing a phenotypic space that permits some combinations of worker- and queen-like traits, but not others. We propose that castes are gained and lost by modifying the regions of this phenotypic space that are realized within a species. These modifications can result from changing the size-frequency distribution of individuals within a species, or by changing the association of tissue growth and size. We hope this synthesis will help unify the literature on caste in ants, and facilitate the discovery of molecular mechanisms underlying caste development and evolution. © 2017. Published by The Company of Biologists Ltd.

A new method to acquire 3-D images of a dental cast

NASA Astrophysics Data System (ADS)

Li, Zhongke; Yi, Yaxing; Zhu, Zhen; Li, Hua; Qin, Yongyuan

2006-01-01

This paper introduced our newly developed method to acquire three-dimensional images of a dental cast. A rotatable table, a laser-knife, a mirror, a CCD camera and a personal computer made up of a three-dimensional data acquiring system. A dental cast is placed on the table; the mirror is installed beside the table; a linear laser is projected to the dental cast; the CCD camera is put up above the dental cast, it can take picture of the dental cast and the shadow in the mirror; while the table rotating, the camera records the shape of the laser streak projected on the dental cast, and transmit the data to the computer. After the table rotated one circuit, the computer processes the data, calculates the three-dimensional coordinates of the dental cast's surface. In data processing procedure, artificial neural networks are enrolled to calibrate the lens distortion, map coordinates form screen coordinate system to world coordinate system. According to the three-dimensional coordinates, the computer reconstructs the stereo image of the dental cast. It is essential for computer-aided diagnosis and treatment planning in orthodontics. In comparison with other systems in service, for example, laser beam three-dimensional scanning system, the characteristic of this three-dimensional data acquiring system: a. celerity, it casts only 1 minute to scan a dental cast; b. compact, the machinery is simple and compact; c. no blind zone, a mirror is introduced ably to reduce blind zone.

Obtaining of High Cr Content Cast Iron Materials

NASA Astrophysics Data System (ADS)

Florea, C.; Bejinariu, C.; Carcea, I.; Cimpoesu, N.; Chicet, D. L.; Savin, C.

2017-06-01

We have obtained, through the classic casting process, 3 highly chromium-based experimental alloys proposed for replacing the FC 250 classical cast iron in braking applications. Casting was carried out in an induction furnace and cast into moulds made of KALHARTZ 8500 resin casting mixture and HARTER hardener at SC RanCon SRL Iasi. It is known that the microstructure of the cast iron is a combination of martensite with a small amount of residual austenite after the heat treatment of the ingot. In the case of high-alloy chromium alloys, the performance of the material is due to the presence of M7C3 carbides distributed in the iron matrix Resistance to machining and deformation is based on alloy composition and microstructure, while abrasion resistance will depend on properties and wear conditions.

Possibility of reconstruction of dental plaster cast from 3D digital study models

PubMed Central

2013-01-01

Objectives To compare traditional plaster casts, digital models and 3D printed copies of dental plaster casts based on various criteria. To determine whether 3D printed copies obtained using open source system RepRap can replace traditional plaster casts in dental practice. To compare and contrast the qualities of two possible 3D printing options – open source system RepRap and commercially available 3D printing. Design and settings A method comparison study on 10 dental plaster casts from the Orthodontic department, Department of Stomatology, 2nd medical Faulty, Charles University Prague, Czech Republic. Material and methods Each of 10 plaster casts were scanned by inEos Blue scanner and the printed on 3D printer RepRap [10 models] and ProJet HD3000 3D printer [1 model]. Linear measurements between selected points on the dental arches of upper and lower jaws on plaster casts and its 3D copy were recorded and statistically analyzed. Results 3D printed copies have many advantages over traditional plaster casts. The precision and accuracy of the RepRap 3D printed copies of plaster casts were confirmed based on the statistical analysis. Although the commercially available 3D printing enables to print more details than the RepRap system, it is expensive and for the purpose of clinical use can be replaced by the cheaper prints obtained from RepRap printed copies. Conclusions Scanning of the traditional plaster casts to obtain a digital model offers a pragmatic approach. The scans can subsequently be used as a template to print the plaster casts as required. Using 3D printers can replace traditional plaster casts primarily due to their accuracy and price. PMID:23721330

Directional migration in the Hindu castes: inferences from mitochondrial, autosomal and Y-chromosomal data.

PubMed

Wooding, Stephen; Ostler, Christopher; Prasad, B V Ravi; Watkins, W Scott; Sung, Sandy; Bamshad, Mike; Jorde, Lynn B

2004-08-01

Genetic, ethnographic, and historical evidence suggests that the Hindu castes have been highly endogamous for several thousand years and that, when movement between castes does occur, it typically consists of females joining castes of higher social status. However, little is known about migration rates in these populations or the extent to which migration occurs between caste groups of low, middle, and high social status. To investigate these aspects of migration, we analyzed the largest collection of genetic markers collected to date in Hindu caste populations. These data included 45 newly typed autosomal short tandem repeat polymorphisms (STRPs), 411 bp of mitochondrial DNA sequence, and 43 Y-chromosomal single-nucleotide polymorphisms that were assayed in more than 200 individuals of known caste status sampled in Andrah Pradesh, in South India. Application of recently developed likelihood-based analyses to this dataset enabled us to obtain genetically derived estimates of intercaste migration rates. STRPs indicated migration rates of 1-2% per generation between high-, middle-, and low-status caste groups. We also found support for the hypothesis that rates of gene flow differ between maternally and paternally inherited genes. Migration rates were substantially higher in maternally than in paternally inherited markers. In addition, while prevailing patterns of migration involved movement between castes of similar rank, paternally inherited markers in the low-status castes were most likely to move into high-status castes. Our findings support earlier evidence that the caste system has been a significant, long-term source of population structuring in South Indian Hindu populations, and that patterns of migration differ between males and females. Copyright 2004 Springer-Verlag

Cyp15F1: a novel cytochrome P450 gene linked to juvenile hormone-dependent caste differention in the termite Reticulitermes flavipes.

PubMed

Tarver, Matthew R; Coy, Monique R; Scharf, Michael E

2012-07-01

Termites are eusocial insects that jointly utilize juvenile hormone (JH), pheromones, and other semiochemicals to regulate caste differentiation and achieve caste homeostasis. Prior EST sequencing from the symbiont-free gut transcriptome of Reticulitermes flavipes unexpectedly revealed a number of unique cytochrome P450 (Cyp) transcripts, including fragments of a Cyp15 family gene (Cyp15F1) with homology to other insect Cyp15s that participate in JH biosynthesis. The present study investigated the role of Cyp15F1 in termite caste polyphenism and specifically tested the hypothesis that it plays a role in JH-dependent caste differentiation. After assembling the full-length Cyp15F1 cDNA sequence, we (i) determined its mRNA tissue expression profile, (ii) investigated mRNA expression changes in response to JH and the caste-regulatory primer pheromones γ-cadinene (CAD) and γ-cadinenal (ALD), and (iii) used RNA interference (RNAi) in combination with caste differentiation bioassays to investigate gene function at the phenotype level. Cyp15F1 has ubiquitous whole-body expression (including gut tissue); is rapidly and sustainably induced from 3 h to 48 h by JH, CAD, and ALD; and functions at least in part by facilitating JH-dependent soldier caste differentiation. These findings provide the second example of a termite caste regulatory gene identified through the use of RNAi, and significantly build upon our understanding of termite caste homeostatic mechanisms. These results also reinforce the concept of environmental caste determination in termites by revealing how primer pheromones, as socioenvironmental factors, can directly influence Cyp15 expression and caste differentiation. © 2012 Wiley Periodicals, Inc.

Energy Saving Melting and Revert Reduction Technology (Energy-SMARRT): Light Metals Permanent Mold Casting

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fasoyinu, Yemi

2014-03-31

Current vehicles use mostly ferrous components for structural applications. It is possible to reduce the weight of the vehicle by substituting these parts with those made from light metals such as aluminum and magnesium. Many alloys and manufacturing processes can be used to produce these light metal components and casting is known to be most economical. One of the high integrity casting processes is permanent mold casting which is the focus of this research report. Many aluminum alloy castings used in automotive applications are produced by the sand casting process. Also, aluminum-silicon (Al-Si) alloys are the most widely used alloymore » systems for automotive applications. It is possible that by using high strength aluminum alloys based on an aluminum-copper (Al-Cu) system and permanent mold casting, the performance of these components can be enhanced significantly. This will also help to further reduce the weight. However, many technological obstacles need to be overcome before using these alloys in automotive applications in an economical way. There is very limited information in the open literature on gravity and low-pressure permanent mold casting of high strength aluminum alloys. This report summarizes the results and issues encountered during the casting trials of high strength aluminum alloy 206.0 (Al-Cu alloy) and moderate strength alloy 535.0 (Al-Mg alloy). Five engineering components were cast by gravity tilt-pour or low pressure permanent mold casting processes at CanmetMATERIALS (CMAT) and two production foundries. The results of the casting trials show that high integrity engineering components can be produced successfully from both alloys if specific processing parameters are used. It was shown that a combination of melt processing and mold temperature is necessary for the elimination of hot tears in both alloys.« less

Multidisciplinary approach to improve the quality of below-knee plaster casting.

PubMed

Williams, John Teudar; Kedrzycki, Marta; Shenava, Yathish

2018-01-01

In our trauma unit, we noted a high rate of incorrectly applied below-knee casts for ankle fractures, in some cases requiring reapplication. This caused significant discomfort and inconvenience for patients and additional burden on plaster-room services. Our aim was to improve the quality of plaster casts and reduce the proportion that needed to be reapplied. Our criteria for plaster cast quality were based on the British Orthopaedic Association Casting Standards (2015) and included neutral (plantargrade) ankle position, adequacy of fracture reduction and rate of cast reapplication. Baseline data collection was performed over a 2-month period by two independent reviewers. After distributing findings and presenting to relevant departments, practical casting sessions with orthopaedic technicians were arranged for the multidisciplinary team responsible for casting. This was later supplemented by new casting guidelines in clinical areas and available online. Postintervention data collection was performed over two separate cycles to assess the effect and permanence of intervention. Data from the preintervention period (n=29) showed median ankle position was 32° plantarflexion (PF), with nine (31%) inadequate reductions and six (20%) backslabs reapplied. Following Plan-Do-Study-Act (PDSA) 1, ankle position was significantly improved (median 25° PF), there were fewer inadequate reductions (12%; 2/17) and a lower rate of reapplication (0%; 0/17). After PDSA 2 (n=16), median ankle position was 21° PF, there was one (6%) inadequate reduction and two (12%) reapplications of casts. Following implementation of plaster training sessions for accident and emergency and junior orthopaedic staff, in addition to publishing guidance and new protocol, there has been a sustained improvement in the quality of below-knee backslabs and fewer cast reapplications. These findings justify continuation and expansion of the current programme to include other commonly applied plaster casts.

Accuracy of ringless casting and accelerated wax-elimination technique: a comparative in vitro study.

PubMed

Prasad, Rahul; Al-Keraif, Abdulaziz Abdullah; Kathuria, Nidhi; Gandhi, P V; Bhide, S V

2014-02-01

The purpose of this study was to determine whether the ringless casting and accelerated wax-elimination techniques can be combined to offer a cost-effective, clinically acceptable, and time-saving alternative for fabricating single unit castings in fixed prosthodontics. Sixty standardized wax copings were fabricated on a type IV stone replica of a stainless steel die. The wax patterns were divided into four groups. The first group was cast using the ringless investment technique and conventional wax-elimination method; the second group was cast using the ringless investment technique and accelerated wax-elimination method; the third group was cast using the conventional metal ring investment technique and conventional wax-elimination method; the fourth group was cast using the metal ring investment technique and accelerated wax-elimination method. The vertical marginal gap was measured at four sites per specimen, using a digital optical microscope at 100× magnification. The results were analyzed using two-way ANOVA to determine statistical significance. The vertical marginal gaps of castings fabricated using the ringless technique (76.98 ± 7.59 μm) were significantly less (p < 0.05) than those castings fabricated using the conventional metal ring technique (138.44 ± 28.59 μm); however, the vertical marginal gaps of the conventional (102.63 ± 36.12 μm) and accelerated wax-elimination (112.79 ± 38.34 μm) castings were not statistically significant (p > 0.05). The ringless investment technique can produce castings with higher accuracy and can be favorably combined with the accelerated wax-elimination method as a vital alternative to the time-consuming conventional technique of casting restorations in fixed prosthodontics. © 2013 by the American College of Prosthodontists.

Improved Net-Level Filling And Finishing Of Large Castings

NASA Technical Reports Server (NTRS)

Johnson, Erik P.; Brown, Richard F.

1995-01-01

Improved method of vacuum casting of large, generally cylindrical objects to net sizes and shapes reduces amount of direct manual labor by workers in proximity to cast material. Original application for which method devised is fabrication of solid rocket-motor segments containing solid propellant, wherein need to minimize exposure of workers to propellant material being cast. Improved method adaptable to other applications involving large castings of toxic, flammable, or otherwise hazardous materials.

Efficiency and Safety: The Best Time to Valve a Plaster Cast.

PubMed

Steiner, Samuel R H; Gendi, Kirollos; Halanski, Matthew A; Noonan, Kenneth J

2018-04-18

The act of applying, univalving, and spreading a plaster cast to accommodate swelling is commonly performed; however, cast saws can cause thermal and/or abrasive injury to the patient. This study aims to identify the optimal time to valve a plaster cast so as to reduce the risk of cast-saw injury and increase spreading efficiency. Plaster casts were applied to life-sized pediatric models and were univalved at set-times of 5, 8, 12, or 25 minutes. Outcome measures included average and maximum force applied during univalving, blade-to-skin touches, cut time, force needed to spread, number of spread attempts, spread completeness, spread distance, saw blade temperature, and skin surface temperature. Casts allowed to set for ≥12 minutes had significantly fewer blade-to-skin touches compared with casts that set for <12 minutes (p < 0.001). For average and maximum saw blade force, no significant difference was observed between individual set-times. However, in a comparison of the shorter group (<12 minutes) and the longer group (≥12 minutes), the longer group had a higher average force (p = 0.009) but a lower maximum force (p = 0.036). The average temperature of the saw blade did not vary between groups. The maximum force needed to "pop," or spread, the cast was greater for the 5-minute and 8-minute set-times. Despite requiring more force to spread the cast, 0% of attempts at 5 minutes and 54% of attempts at 8 minutes were successful in completely spreading the cast, whereas 100% of attempts at 12 and 25 minutes were successful. The spread distance was greatest for the 12-minute set-time at 5.7 mm. Allowing casts to set for 12 minutes is associated with decreased blade-to-skin contact, less maximum force used with the saw blade, and a more effective spread. Adherence to the 12-minute interval could allow for fewer cast-saw injuries and more effective spreading.

Effect of dental technician disparities on the 3-dimensional accuracy of definitive casts.

PubMed

Emir, Faruk; Piskin, Bulent; Sipahi, Cumhur

2017-03-01

Studies that evaluated the effect of dental technician disparities on the accuracy of presectioned and postsectioned definitive casts are lacking. The purpose of this in vitro study was to evaluate the accuracy of presectioned and postsectioned definitive casts fabricated by different dental technicians by using a 3-dimensional computer-aided measurement method. An arch-shaped metal master model consisting of 5 abutments resembling prepared mandibular incisors, canines, and first molars and with a 6-degree total angle of convergence was designed and fabricated by computer-aided design and computer-aided manufacturing (CAD-CAM) technology. Complete arch impressions were made (N=110) from the master model, using polyvinyl siloxane (PVS) and delivered to 11 dental technicians. Each technician fabricated 10 definitive casts with dental stone, and the obtained casts were numbered. All casts were sectioned, and removable dies were obtained. The master model and the presectioned and postsectioned definitive casts were digitized with an extraoral scanner, and the virtual master model and virtual presectioned and postsectioned definitive casts were obtained. All definitive casts were compared with the master model by using computer-aided measurements, and the 3-dimensional accuracy of the definitive casts was determined with best fit alignment and represented in color-coded maps. Differences were analyzed using univariate analyses of variance, and the Tukey honest significant differences post hoc tests were used for multiple comparisons (α=.05). The accuracy of presectioned and postsectioned definitive casts was significantly affected by dental technician disparities (P<.001). The largest dimensional changes were detected in the anterior abutments of both of the definitive casts. The changes mostly occurred in the mesiodistal dimension (P<.001). Within the limitations of this in vitro study, the accuracy of presectioned and postsectioned definitive casts is susceptible to dental technician differences. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

7 CFR 1160.607 - Tabulation of ballots.

Code of Federal Regulations, 2010 CFR

2010-01-01

... referendum agent shall verify the validity of all ballots cast in accordance with the instructions and... ballots cast, including the disqualified ballots, shall be ascertained. The number of ballots cast approving, the number of ballots cast disapproving, and the pounds of fluid milk products distributed during...

75 FR 23295 - Iron Construction Castings From Brazil, Canada, and China

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-03

... ``heavy'' iron construction castings from Brazil, the antidumping duty order on ``heavy'' iron... the countervailing duty order on ``heavy'' iron construction castings from Brazil, the antidumping duty order on ``heavy'' iron construction castings from Canada, and the antidumping duty orders on iron...

Vertical marginal gap evaluation of conventional cast and computer numeric controlled-milled titanium full-arch implant-supported frameworks.

PubMed

Alfadda, Sara A

2014-01-01

To use a novel approach to measure the amount of vertical marginal gap in computer numeric controlled (CNC)-milled titanium frameworks and conventional cast frameworks. Ten cast frameworks were fabricated on the mandibular master casts of 10 patients. Then, 10 CNC-milled titanium frameworks were fabricated by laser scanning the cast frameworks. The vertical marginal gap was measured and analyzed using the Contura-G2 coordinate measuring machine and special computer software. The CNC-milled titanium frameworks showed an overall reduced mean vertical gap compared with the cast frameworks in all five analogs. This difference was highly statistically significant in the distal analogs. The largest mean gap in the cast framework was recorded in the most distal analogs, and the least amount was in the middle analog. Neither of the two types of frameworks provided a completely gap-free superstructure. The CNCmilled titanium frameworks showed a significantly smaller vertical marginal gap than the cast frameworks.

Emulsion based cast booster - a priming system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gupta, R.N.; Mishra, A.K.

2005-07-01

This paper explores the potential of emulsion based cast booster to be used as primer to initiate bulk delivered emulsion explosives used in mines. An attempt has been made for comparative study between conventional cast booster and emulsion based cast booster in terms of the initiation process developed and their capability to develop and maintain the stable detonation process in the column explosives. The study has been conducted using a continuous velocity of detonation (VOD) measuring instrument. During this study three blasts have been monitored. In each blast two holes have been selected for study, the first hole being initiatedmore » with conventional cast booster while the other one with emulsion based cast booster. The findings of the study advocates that emulsion based cast booster is capable of efficient priming of bulk delivered column explosive with stable detonation process in the column. Further, the booster had advantages over the conventional PETN/TNT based cast booster. 5 refs., 2 figs., 1 tab., 1 photo.« less

Y-chromosomal insights into the genetic impact of the caste system in India

PubMed Central

Zerjal, Tatiana; Pandya, Arpita; Thangaraj, Kumarasamy; Ling, Edmund Y. S.; Kearley, Jennifer; Bertoneri, Stefania; Paracchini, Silvia; Singh, Lalji; Tyler-Smith, Chris

2008-01-01

The caste system has persisted in Indian Hindu society for around 3,500 years. Like the Y chromosome, caste is defined at birth, and males cannot change their caste. In order to investigate the genetic consequences of this system, we have analysed male-lineage variation in a sample of 227 Indian men of known caste, 141 from the Jaunpur district of Uttar Pradesh and 86 from the rest of India. We typed 131 Y-chromosomal binary markers and 16 microsatellites. We find striking evidence for male substructure: in particular, Brahmins and Kshatriyas (but not other castes) from Jaunpur each show low diversity and the predominance of a single distinct cluster of haplotypes. These findings confirm the genetic isolation and drift within the Jaunpur upper castes, which are likely to result from founder effects and social factors. In the other castes, there may be either larger effective population sizes, or less strict isolation, or both. PMID:17075717

Caste-, work-, and descent-based discrimination as a determinant of health in social epidemiology.

PubMed

Patil, Rajan R

2014-01-01

Social epidemiology explores health in the context of broad social determinants of health, where the boundary lines between health and politics appear increasingly blurred. Social determinants of health such as caste, discrimination, and social exclusion are inherently political in nature, hence it becomes imperative to look at health through a broader perspective of political philosophy, ideology, and caste that imposes enormous obstacles to a person's full attainment of civil, political, economic, social, and cultural rights. Caste is descent based and hereditary in nature. It is a characteristic determined by one's birth into a particular caste, irrespective of the faith practiced by the individual. Caste denotes a system of rigid social stratification into ranked groups defined by descent and occupation. Under various caste systems throughout the world, caste divisions also dominate in housing, marriage, and general social interaction divisions that are reinforced through the practice and threat of social ostracism, economic boycotts, and even physical violence-all of which undermine health equality.

Direct Cast U-6Nb – 2017 Progress on Cylindrical Castings

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aikin, Jr., Robert M.

2017-10-04

This report describes work to further develop a sound technical basis and best practices for mold design and process parameters for the Direct Casting of U-6wt%Nb components. One major challenge to the production of U-6Nb components is the propensity for niobium segregation during casting and solidification. This is especially true for cylindrical castings where the vertical side walls allow flotation of Nb resulting in severe inverse macrosegregation. In this work, a small (120 mm diameter by 180 mm tall) and large cylinder (250 mm diameter by 310 mm tall) are examined with a focus on reducing, or eliminating, niobium segregation.more » It is demonstrated that counter gravity casting (top-to-bottom solidification) can be used to minimize segregation in the small cylinder. Attempts to counter gravity cast the large cylinder were unsuccessful, in large part due to size limitations of the current furnace. A path forward for casting of the large cylinders is discussed.« less

Three solutions to a single problem: alternative casting frames for treating infantile idiopathic scoliosis.

PubMed

Halanski, Matthew A; Harper, Benjamin L; Cassidy, Jeffry A; Crawford, Haemish A

2013-07-01

This is a technique article discussing 3 alternative frames for casting children with infantile scoliosis. To provide surgeons with alternatives to expensive specialized casting tables to allow local treatment of these children utilizing readily available materials present at most institutions. Casting for infantile scoliosis has become more popular as reports have shown promising results with this technique without the morbidity and complications associated with more invasive procedures. However, without a specialized casting table, treating these patients has been limited to a few centers throughout the country often causing patients to travel large distances to receive care. Three different alternatives to commercially available casting frames are presented. Requirements, setup, and techniques are discussed. Each surgeon has had success with each of these frames. These provide adequate support and traction while allowing enough access to the trunk to apply a well-molded cast. Cotrel/Metha casting for infantile scoliosis can be accomplished without a specialized table using commonly available equipment.

Development of the Electromagnetic Continuous Casting Technology for of Magnesium Alloys

NASA Astrophysics Data System (ADS)

Park, Joon-Pyo; Kim, Myoung-Gyun; Kim, Jong-Ho; Lee, Gyu-Chang

Currently, magnesium billets produced by ingot casting or direct chill casting process, result in low-quality surfaces and low productivity, Continuous casting technology to solve these problem has not only high-quality surface billets with fine-grained and homogeneous microstructure but also cost down. The latent heat of fusion per weight (J/g) of magnesium is similar to other metals, however, considering the heat emitted to the mold surface during continuous casting in meniscus region and converting it to the latent heat of fusion per volume, magnesium will be rapidly solidified in the mold during continuous casting, which induces subsequent surface defect formation. In this study, electromagnetic casting and stirring (EMC and EMS) techniques are proposed to control solidification process conveniently by compensating the low latent heat of solidification by volume and to fabricate magnesium billet with high-quality surface. This technique was extended to large scale billets up to 300 mm diameter and continuous casting was successfully conducted. Then magnesium billet was used for the fabrication of prototype automobile pulley.

Caste-based social inequalities and childhood anemia in India: results from the National Family Health Survey (NFHS) 2005-2006.

PubMed

Vart, Priya; Jaglan, Ajay; Shafique, Kashif

2015-06-05

Caste is one of the traditional measures of social segregation in India and differs from other indicators as it is both, endogamous and hereditary. Evidence suggests that belonging to lower castes exposes one to social inequalities and affects health adversely. We examined the association of caste with childhood anemia in India and explored the effect modifying role of adult education and household wealth. A cross-sectional analysis of National Family Health Survey (NFHS) data of 43,484 children aged 6-59 months was performed. Poisson regression analysis was conducted to study the association between caste and childhood anemia accounting for various maternal, child, and household related variables. Caste was categorized as "other caste" (least disadvantageous), "other backward caste", "scheduled tribe" and "scheduled caste" (most disadvantageous). Anemia was defined as mild (hemoglobin level 7-11 g/dL), moderate (hemoglobin level 5-7 g/dL) and severe (hemoglobin level <5 g/dL). We found that children in scheduled caste had higher risk of having anemia [mild anemia: RR = 1.10, 95% CI = 1.05-1.15; moderate anemia: RR = 1.19, 95% CI = 1.14-1.24; severe anemia: RR = 1.87, 95% CI = 1.51-2.31] after accounting for child, maternal and household covariates including adult education and household wealth. The interaction of caste with adult education and household wealth was not statistically significant for any level of anemia. Sensitivity analyses for children born to mothers of age ≥ 18 years at first child birth and body mass index (BMI) ≥ 18.5 kg/m(2), resulted in similar findings. Caste is an independent determinant of childhood anemia in India. The level of adult education and household wealth did not modify the association between caste and childhood anemia. The findings may be used for countering childhood anemia and it may be beneficial to target future public health actions towards disadvantageous castes in India.

Oral Sucrose for Pain Relief During Clubfoot Casting: A Double-Blinded Randomized Controlled Trial.

PubMed

Milbrandt, Todd; Kryscio, Richard; Muchow, Ryan; Walker, Janet; Talwalkar, Vishwas; Iwinski, Henry

2016-09-15

Idiopathic clubfoot treatment is treated by manipulation and casting utilizing the Ponseti technique which can make the infant fussy and irritable. The goal of this study was to determine which intervention could decrease this pain response in infants undergoing Ponseti casting for idiopathic clubfeet. Our hypothesis was that the administration of oral sucrose solution or milk would be the most effective in accomplishing that goal. We conducted a double-blinded randomized controlled trial at a tertiary pediatric orthopaedic center on 33 children (average age=17.94 d; SD=20.51 d) undergoing clubfoot manipulation and casting and their guardians. Each cast was considered a new event and was randomized to an oral 20% sucrose solution (S), water (W), or milk (M) in a bottle (breast or nonbreast). We assessed the Neonatal Infant Pain Scale (NIPS), heart rate, and oxygen saturation before, during, and after the casting. A total of 131 casts were randomized and 118 analyzed (37 M, 42 S, 39 W). Each child underwent an average of 3.97 casts (SD=1.74). There were no significant differences seen between the groups before casting in their mean NIPS score (M=2.2; SD=2.38, S=1.84, SD=2.18, W=1.61, SD=2.12). However during casting, mean NIPS score for both milk, 0.91 (SD=1.26, P=0.0005) and sucrose, 0.64 (SD=1.27, P<0.0001) were significantly less than water, 2.27 (SD=2.03) but not different from each other (P=0.33). Postcasting, the sucrose NIPS score, 0.69 (SD=1.53) continued to be significantly less than milk, 2.11 (SD=2.37, P=0.0065. There was no correlation between heart rate or oxygen saturation and NIPS. Sucrose solution and milk during Ponseti casting and manipulation were effective in decreasing the pain response in children undergoing manipulation and casting for clubfeet. The sucrose solution administration continued the pain relief into the postcasting period. In addition to the benefits of improving the patient experience during casting, a less irritable child may result in better casting. Level 1 evidence.

The role of serial casting in early-onset scoliosis (EOS).

PubMed

Baulesh, David M; Huh, Jeannie; Judkins, Timothy; Garg, Sumeet; Miller, Nancy H; Erickson, Mark A

2012-01-01

Serial casting has demonstrated efficacy for idiopathic early-onset scoliosis (EOS). Results of casting in nonidiopathic (syndromic and congenital) EOS patients have not previously been well described. A total of 53 patients underwent serial casting for EOS from 2005 to 2010 at a single institution. Deformity was classified as idiopathic or nonidiopathic. Diagnosis, time in cast, number of casts, use of bracing, complications, and outcomes were recorded. Radiographic measures included Cobb angle and thoracic height (T1-T12). Thoracic height velocity was calculated and compared with established norms. A total of 36 patients, 19 idiopathic and 17 nonidiopathic (14 syndromic, 3 congenital), completed cast treatment and had >6-month follow-up and were therefore included. Of those, 17% (6/36) experienced resolution of their deformity, 53% (19/26) are currently in braces, and 31% (11/36) had undergone surgery. Surgery occurred on average at age 5.6 years and was delayed by an average of 2.1 years from time of first cast. A 19% complication was observed. There was no statistical difference in the rate of resolution of deformity between idiopathic (5/19) and nonidiopathic (1/17) patients (P=0.182), although there exists a trend toward greater curve correction in idiopathic patients. Surgery occurred in fewer patients (2/19) in the idiopathic group compared with the nonidiopathic group (9/17) (P=0.006). Significant improvements in Cobb angle was observed in the idiopathic group (12.2 degrees) during casting (P=0.003). Nonidiopathic patients did not maintain the correction gained during casting at the time of final follow-up. T1-T12 height increased across all study patients regardless of etiology during the period of casting at similar velocity to established norms of 1.4 cm/y for this age group. Serial casting offers modest deformity correction in idiopathic deformities compared with nonidiopathic deformities. Thoracic height growth continued throughout the casting period at normal velocity. Serial casting maintained normal longitudinal thoracic growth in all patients with EOS in this cohort. Although many required surgery, the increased thoracic height may have positive implications on ultimate pulmonary function. Therapeutic level III.

Caste in 21st Century India: Competing Narratives

PubMed Central

Desai, Sonalde; Dubey, Amaresh

2012-01-01

Recent debates regarding inclusion of caste in 2011 Census have raised questions about whether caste still matters in modern India. Ethnographic studies of the mid-20th century identified a variety of dimensions along which caste differentiation occurs. At the same time, whether this differentiation translates into hierarchy remains a contentious issue as does the persistence of caste, given the economic changes of the past two decades. Using data from a nationally representative survey of 41,554 households conducted in 2005, this paper examines the relationship between social background and different dimensions of well-being. The results suggest continued persistence of caste disparities in education, income and social networks. PMID:22736803

Genetic structure of Rajaka caste and affinities with other caste populations of Andhra Pradesh, India.

PubMed

Parvatheesam, C; Babu, B V; Babu, M C

1997-01-01

The present study gives an account of the genetic structure in terms of distribution of a few genetic markers, viz., A1A2B0, Rh(D), G6PD deficiency and haemoglobin among the Rajaka caste population of Andhra Pradesh, India. The genetic relationships of the Rajaka caste with other Andhra caste populations were investigated in terms of genetic distance, i.e., Sq B (mn) of Balakrishnan and Sanghvi. Relatively lesser distance was established between the Rajaka and two Panchama castes. Also, the pattern of genetic distance corroborates the hierarchical order of the Hindu varna system.

Transmutation Fuel Fabrication-Fiscal Year 2016

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fielding, Randall Sidney; Grover, Blair Kenneth

ABSTRACT Nearly all of the metallic fuel that has been irradiated and characterized by the Advanced Fuel Campaign, and its earlier predecessors, has been arc cast. Arc casting is a very flexible method of casting lab scale quantities of materials. Although the method offers flexibility, it is an operator dependent process. Small changes in parameter space or alloy composition may affect how the material is cast. This report provides a historical insight in how the casting process has been modified over the history of the advanced fuels campaign as well as the physical parameters of the fuels cast in fiscalmore » year 2016.« less

A Recipe for Soft Fluidic Elastomer Robots

PubMed Central

Marchese, Andrew D.; Katzschmann, Robert K.

2015-01-01

Abstract This work provides approaches to designing and fabricating soft fluidic elastomer robots. That is, three viable actuator morphologies composed entirely from soft silicone rubber are explored, and these morphologies are differentiated by their internal channel structure, namely, ribbed, cylindrical, and pleated. Additionally, three distinct casting-based fabrication processes are explored: lamination-based casting, retractable-pin-based casting, and lost-wax-based casting. Furthermore, two ways of fabricating a multiple DOF robot are explored: casting the complete robot as a whole and casting single degree of freedom (DOF) segments with subsequent concatenation. We experimentally validate each soft actuator morphology and fabrication process by creating multiple physical soft robot prototypes. PMID:27625913

A Recipe for Soft Fluidic Elastomer Robots.

PubMed

Marchese, Andrew D; Katzschmann, Robert K; Rus, Daniela

2015-03-01

This work provides approaches to designing and fabricating soft fluidic elastomer robots. That is, three viable actuator morphologies composed entirely from soft silicone rubber are explored, and these morphologies are differentiated by their internal channel structure, namely, ribbed, cylindrical, and pleated. Additionally, three distinct casting-based fabrication processes are explored: lamination-based casting, retractable-pin-based casting, and lost-wax-based casting. Furthermore, two ways of fabricating a multiple DOF robot are explored: casting the complete robot as a whole and casting single degree of freedom (DOF) segments with subsequent concatenation. We experimentally validate each soft actuator morphology and fabrication process by creating multiple physical soft robot prototypes.

Microstructure and Corrosion Characterization of Squeeze Cast AM50 Magnesium Alloys

NASA Astrophysics Data System (ADS)

Sachdeva, Deepika; Tiwari, Shashank; Sundarraj, Suresh; Luo, Alan A.

2010-12-01

Squeeze casting of magnesium alloys potentially can be used in lightweight chassis components such as control arms and knuckles. This study documents the microstructural analysis and corrosion behavior of AM50 alloys squeeze cast at different pressures between 40 and 120 MPa and compares them with high-pressure die cast (HPDC) AM50 alloy castings and an AM50 squeeze cast prototype control arm. Although the corrosion rates of the squeeze cast samples are slightly higher than those observed for the HPDC AM50 alloy, the former does produce virtually porosity-free castings that are required for structural applications like control arms and wheels. This outcome is extremely encouraging as it provides an opportunity for additional alloy and process development by squeeze casting that has remained relatively unexplored for magnesium alloys compared with aluminum. Among the microstructural parameters analyzed, it seems that the β-phase interfacial area, indicating a greater degree of β network, leads to a lower corrosion rate. Weight loss was the better method for determining corrosion behavior in these alloys that contain a large fraction of second phase, which can cause perturbations to an overall uniform surface corrosion behavior.

Independent origins of Indian caste and tribal paternal lineages.

PubMed

Cordaux, Richard; Aunger, Robert; Bentley, Gillian; Nasidze, Ivane; Sirajuddin, S M; Stoneking, Mark

2004-02-03

The origins of the nearly one billion people inhabiting the Indian subcontinent and following the customs of the Hindu caste system are controversial: are they largely derived from Indian local populations (i.e. tribal groups) or from recent immigrants to India? Archaeological and linguistic evidence support the latter hypothesis, whereas recent genetic data seem to favor the former hypothesis. Here, we analyze the most extensive dataset of Indian caste and tribal Y chromosomes to date. We find that caste and tribal groups differ significantly in their haplogroup frequency distributions; caste groups are homogeneous for Y chromosome variation and more closely related to each other and to central Asian groups than to Indian tribal or any other Eurasian groups. We conclude that paternal lineages of Indian caste groups are primarily descended from Indo-European speakers who migrated from central Asia approximately 3,500 years ago. Conversely, paternal lineages of tribal groups are predominantly derived from the original Indian gene pool. We also provide evidence for bidirectional male gene flow between caste and tribal groups. In comparison, caste and tribal groups are homogeneous with respect to mitochondrial DNA variation, which may reflect the sociocultural characteristics of the Indian caste society.

Properties of a hybrid plaster-fibreglass cast

PubMed Central

Charles, Mark N.; Yen, David

2000-01-01

Objective To examine the suitability of a plaster-fibreglass hybrid cast for orthopedic applications, comparing them to plaster of Paris (POP) and fibreglass constructs. Method Groups of 10 standardized hybrid, POP and fibreglass casts were studied. An Instron servo-hydraulic system was used to test the casts in 3-point bending and shear. Outcome measures Strength, stiffness, weight, thickness and cost of the 3 types of cast, and shear strength at the interface between the POP and fibreglass in the hybrid casts. Results The hybrid casts were twice as strong as the POP constructs, were stiffer and weighed 14% less but were thicker and cost 2.5 times more. They were almost as strong as and less than half the cost of the fibreglass constructs but were thicker, not as stiff, and weighed 42% more. The shear strength of the POP–fibreglass interface in the hybrid casts was higher than the 3-point bending strength of this construct by a factor of 3. Conclusions Plaster-fibreglass hybrid casts should be considered for orthopedic use on the basis of their strength, stiffness, weight and cost, combined with their acknowledged advantages of good moulding ability and water resistance. PMID:11045095

Short-term after-effect of forearm cast removal in children.

PubMed

Katz, Kalman; Weigl, Daniel; Becker, Tal; Attias, Joseph; Bar-On, Elhanan

2011-05-01

To investigate the sensation in the hand after forearm cast removal in children. The study group included 33 consecutive children who were treated nonoperatively for a forearm fracture at our center over a 1-year period. The children were asked to report any sensation in the ipsilateral hand after cast removal, and the findings were analyzed against background and fracture-related data. The patients ranged in age from 6 to 14 years (median 10.00 years). Seventeen had been immobilized in an above-elbow cast and the remainder in a below-elbow cast. All children treated with an above-elbow cast complained that after cast removal, the hand on that side felt limp, and they had to hold it with the contralateral hand. By contrast, only one child treated with a below-elbow cast reported this sensation (p = 0.0001, Fisher exact test). Orthopedic surgeons and rehabilitation unit staff should be aware of the possibility of a very short-term sensation of drooping and weakness of the hand after removal of an above-elbow cast in children and prepare the child and parents accordingly in order to lessen unnecessary anxiety.

Comparative study on stiffness properties of WOODCAST and conventional casting materials.

PubMed

Pirhonen, Eija; Pärssinen, Antti; Pelto, Mika

2013-08-01

Plaster-of-Paris and synthetic materials (e.g. fibreglass) have been in clinical use as casting materials for decades. An innovative casting material, WOODCAST, brings interesting alternatives to the traditional materials. The aim of this study was to compare the stiffness properties of the WOODCAST material to traditional casting materials. In immobilization by casting, materials with variable stiffness properties are required. Ring stiffness of cylindrical samples correlates well with cast rigidity. For load-bearing structures, the use of the WOODCAST Splint is recommended as equally high stiffness was obtained with the WOODCAST Splint as was with fibreglass. The WOODCAST 2 mm product is optimal for structures where some elasticity is required, and WOODCAST Ribbon can be used in any WOODCAST structure where further reinforcement is needed. The results show that WOODCAST material can be used in replacing traditional casting materials used in extremity immobilization. The mechanical properties of casting material play an important role in safe and effective fracture immobilization. Stiffness properties of the WOODCAST casting material and conventional materials - fibreglass and plaster-of-Paris - were analysed in this study. The WOODCAST Splint appears to compare favorably with traditional materials such as Scotchcast.

Evaluation of marginal gap of Ni-Cr copings made with conventional and accelerated casting techniques.

PubMed

Tannamala, Pavan Kumar; Azhagarasan, Nagarasampatti Sivaprakasam; Shankar, K Chitra

2013-01-01

Conventional casting techniques following the manufacturers' recommendations are time consuming. Accelerated casting techniques have been reported, but their accuracy with base metal alloys has not been adequately studied. We measured the vertical marginal gap of nickel-chromium copings made by conventional and accelerated casting techniques and determined the clinical acceptability of the cast copings in this study. Experimental design, in vitro study, lab settings. Ten copings each were cast by conventional and accelerated casting techniques. All copings were identical, only their mold preparation schedules differed. Microscopic measurements were recorded at ×80 magnification on the perpendicular to the axial wall at four predetermined sites. The marginal gap values were evaluated by paired t test. The mean marginal gap by conventional technique (34.02 μm) is approximately 10 μm lesser than that of accelerated casting technique (44.62 μm). As the P value is less than 0.0001, there is highly significant difference between the two techniques with regard to vertical marginal gap. The accelerated casting technique is time saving and the marginal gap measured was within the clinically acceptable limits and could be an alternative to time-consuming conventional techniques.

Rough case-based reasoning system for continues casting

NASA Astrophysics Data System (ADS)

Su, Wenbin; Lei, Zhufeng

2018-04-01

The continuous casting occupies a pivotal position in the iron and steel industry. The rough set theory and the CBR (case based reasoning, CBR) were combined in the research and implementation for the quality assurance of continuous casting billet to improve the efficiency and accuracy in determining the processing parameters. According to the continuous casting case, the object-oriented method was applied to express the continuous casting cases. The weights of the attributes were calculated by the algorithm which was based on the rough set theory and the retrieval mechanism for the continuous casting cases was designed. Some cases were adopted to test the retrieval mechanism, by analyzing the results, the law of the influence of the retrieval attributes on determining the processing parameters was revealed. A comprehensive evaluation model was established by using the attribute recognition theory. According to the features of the defects, different methods were adopted to describe the quality condition of the continuous casting billet. By using the system, the knowledge was not only inherited but also applied to adjust the processing parameters through the case based reasoning method as to assure the quality of the continuous casting and improve the intelligent level of the continuous casting.

Detecting novel SNPs and breed-specific haplotypes at calpastatin gene in Iranian fat- and thin-tailed sheep breeds and their effects on protein structure.

PubMed

Aali, Mohsen; Moradi-Shahrbabak, Mohammad; Moradi-Shahrbabak, Hosein; Sadeghi, Mostafa

2014-03-01

Calpastatin has been introduced as a potential candidate gene for growth and meat quality traits. In this study, genetic variability was investigated in the exon 6 and its intron boundaries of ovine CAST gene by PCR-SSCP analysis and DNA sequencing. Also a protein sequence and structural analysis were performed to predict the possible impact of amino acid substitutions on physicochemical properties and structure of the CAST protein. A total of 487 animals belonging to four ancient Iranian sheep breeds with different fat metabolisms, Lori-Bakhtiari and Chall (fat-tailed), Zel-Atabay cross-bred (medium fat-tailed) and Zel (thin-tailed), were analyzed. Eight unique SSCP patterns, representing eight different sequences or haplotypes, CAST-1, CAST-2 and CAST-6 to CAST-11, were identified. Haplotypes CAST-1 and CAST-2 were most common with frequency of 0.365 and 0.295. The novel haplotype CAST-8 had considerable frequency in Iranian sheep breeds (0.129). All the consensus sequences showed 98-99%, 94-98%, 92-93% and 82-83% similarity to the published ovine, caprine, bovine and porcine CAST locus sequences, respectively. Sequence analysis revealed four SNPs in intron 5 (C24T, G62A, G65T and T69-) and three SNPs in exon 6 (c.197A>T, c.282G>T and c.296C>G). All three SNPs in exon 6 were missense mutations which would result in p.Gln 66 Leu, p.Glu 94 Asp and p.Pro 99 Arg substitutions, respectively, in CAST protein. All three amino acid substitutions affected the physicochemical properties of ovine CAST protein including hydrophobicity, amphiphilicity and net charge and subsequently might influence its structure and effect on the activity of Ca2+ channels; hence, they might regulate calpain activity and afterwards meat tenderness and growth rate. The Lori-Bakhtiari population showed the highest heterozygosity in the ovine CAST locus (0.802). Frequency difference of haplotypes CAST-10 and CAST-8 between Lori-Bakhtiari (fat-tailed) and Zel (thin-tailed) breeds was highly significant (P<0.001), indicating that these two haplotypes might be breed-specific haplotypes that distinguish between fat-tailed and thin-tailed sheep breeds. Copyright © 2013 Elsevier B.V. All rights reserved.

[A surface reacted layer study of titanium-zirconium alloy after dental casting].

PubMed

Zhang, Y; Guo, T; Li, Z; Li, C

2000-10-01

To investigate the influence of the mold temperature on the surface reacted layer of Ti-Zr alloy castings. Ti-Zr alloy was casted into a mold which was made of a zircon (ZrO2.SiO2) for inner coating and a phosphate-bonded material for outer investing with a casting machine (China) designed as vacuum, pressure and centrifuge. At three mold temperatures (room temperature, 300 degrees C, 600 degrees C) the Ti-Zr alloy was casted separately. The surface roughness of the castings was calculated by instrument of smooth finish (China). From the surface to the inner part the Knoop hardness and thickness in reacted layer of Ti-Zr alloy casting was measured. The structure of the surface reacted layer was analysed by SEM. Elemental analyses of the interfacial zone of the casting was made by element line scanning observation. The surface roughness of the castings was increased significantly with the mold temperature increasing. At a higher mold temperature the Knoop hardness of the reactive layer was increased. At the three mold temperature the outmost surface was very hard, and microhardness data decreased rapidly where they reached constant values. The thickness was about 85 microns for castings at room temperature and 300 degrees C, 105 microns for castings at 600 degrees C. From the SEM micrograph of the Ti-Zr alloy casting, the surface reacted layer could be divided into three different layers. The first layer was called non-structure layer, which thickness was about 10 microns for room temperature group, 20 microns for 300 degrees C and 25 microns for 600 degrees C. The second layer was characterized by coarse-grained acicular crystal, which thickness was about 50 microns for three mold temperatures. The third layer was Ti-Zr alloy. The element line scanning showed non-structure layer with higher level of element of O, Al, Si and Zr, The higher the mold temperature during casting, the deeper the Si permeating and in the second layer the element Si could also be found. The mold temperature is one of the major factors influencing to casting quality. In order to reduce the surface reacted layer of Ti-Zr alloy castings, the lower mold temperature and the investment without Si should be chosen.

Quengel Casting for the Management of Pediatric Knee Flexion Contractures: A 26-Year Single Institution Experience.

PubMed

Wiley, Marcel R; Riccio, Anthony I; Felton, Kevin; Rodgers, Jennifer A; Wimberly, Robert L; Johnston, Charles E

Quengel casting was introduced in 1922 for nonsurgical treatment of knee flexion contractures (KFC) associated with hemophilic arthropathy. It consists of an extension-desubluxation hinge fixed to a cast allowing for gradual correction of a flexion deformity while preventing posterior tibial subluxation. The purpose of this study is to report 1 center's experience with this technique for the treatment of pediatric KFC. A retrospective review was conducted over a 26-year period. All patients with KFC treated with Quengel casting were included. Demographic data, associated medical conditions, adjunctive soft tissue releases, complications, and the need for late surgical intervention were recorded. Tibiofemoral angle measurements in maximal extension were recorded at initiation and termination of casting, 1-year follow-up, and final follow-up. Success was defined as no symptomatic recurrence of KFC or need for subsequent surgery. Eighteen patients (26 knees) were treated for KFC with Quengel casting. Average age at initiation of casting was 8.1 years with average follow-up of 59.9 months. Fifteen knees (58%) underwent soft tissue releases before casting. An average of 1.5 casts per knee were applied over an average of 23.9 days. Average KFC before casting was 50.6 degrees (range, 15 to 100 degrees) which improved to 5.96 degrees (0 to 40 degrees) at cast removal (P<0.00001). Sixteen patients (22 knees) had 1-year follow-up or failed casting before 1 year. Of these, 11 knees (50%) had a successful outcome. Residual KFC of those treated successfully was 6.8 degrees (range, 0 to 30 degrees) at 1 year and 8.2 degrees (range, 0 to 30 degrees) at final follow-up, averaging 71.4 months (P=0.81). Of the 11 knees deemed failures, all had recurrence of deformity within an average of 1 year from cast removal. Surgical release before Quengel casting did not improve the chances for success (P=0.09). Quengel casting can improve pediatric KFC an average of 44.2 degrees with minimal complications. Although 50% of treated patients will demonstrate significant recurrence or need later surgery, the majority of those treated successfully have durable results at intermediate term follow-up. Level IV-therapeutic study.

Structure, Microsegregation, and Precipitates of an Alloy 690 ESR Ingot in Industrial Scale

NASA Astrophysics Data System (ADS)

Wang, Min; Zha, Xiangdong; Gao, Ming; Ma, Yingche; Liu, Kui; Li, Yiyi

2015-11-01

The structure, interdendritic, and intergranular segregation, and precipitates of an Alloy 690 electro-slag remelting (ESR) ingot in commercial scale (3t) were investigated by the optical microscopy, electroprobe microanalysis, scanning electron microscopy, and transmission electron microscopy (TEM) techniques. The results indicate that the central longitudinal section of the ESR ingot comprised the ramp-up, steady-state, and hot-top regions, which could be easily distinguished from each other through the macrostructures of them. In the interdendritic area, Cr and Ti were enriched, while Ni and Fe were depleted, and the nominal segregation indexes ( ζ i = C 0 i / C interdendritic i ) of Ti, Cr, and Ni were 0.40, 0.91, and 1.04, respectively, in the hot-top region where suffered the severest segregation. Nitrides, principally precipitated between dendrites, were identified as TiN by TEM and EDS. The morphology, size distribution, and volume fraction of them were determined as well. In terms of the intergranular area, Cr and C coexisted, while Ni and Fe were depleted. And the dendrite-like carbides continuously distributed on the interface between grains, which were identified as M23C6 by the selected area diffraction pattern.

A thermodynamic description for water, hydrogen fluoride and hydrogen dissolutions in cryolite-base molten salts.

PubMed

Wang, Kun; Chartrand, Patrice

2018-06-15

This paper presents a quantitative thermodynamic description for water, hydrogen fluoride and hydrogen dissolutions in cryolite-base molten salts, which is of technological importance to the Hall-Héroult electrolytic aluminum extraction cell. The Modified Quasichemical Model in the Quadruplet Approximation (MQMQA), as used to treat a large variety of molten salt systems, was adopted to thermodynamically describe the present liquid phase; all solid solutions were modeled using the Compound Energy Formalism (CEF); the gas phase was thermodynamically treated as an ideal mixture of all possible species. The model parameters were mainly obtained by critical evaluations and optimizations of thermodynamic and phase equilibrium data available from relative experimental measurements and theoretical predictions (first-principles calculations and empirical estimations) for the lower-order subsystems. These optimized model parameters were thereafter merged within the Kohler/Toop interpolation scheme, facilitating the prediction of gas solubility (H2O, HF and H2) in multicomponent cryolite-base molten salts using the FactSage thermochemical software. Several interesting diagrams were finally obtained in order to provide useful information for the industrial partners dedicated to the Hall-Héroult electrolytic aluminum production or other molten-salt technologies (the purification process and electroslag refining).

75 FR 49945 - Iron Construction Castings From Brazil, Canada, and China

Federal Register 2010, 2011, 2012, 2013, 2014

2010-08-16

... Review)] Iron Construction Castings From Brazil, Canada, and China AGENCY: United States International... and antidumping duty orders on iron construction castings from Brazil, Canada, and China. SUMMARY: The... duty and or antidumping duty orders on iron construction castings from Brazil, Canada, and China would...

76 FR 63936 - Agency Information Collection Activities: Proposed Collection; Comment Request; PrepCAST

Federal Register 2010, 2011, 2012, 2013, 2014

2011-10-14

...CAST AGENCY: Federal Emergency Management Agency, DHS. ACTION: Notice. SUMMARY: The Federal Emergency...CAST) (formerly known as the National Incident Management System Compliance Assistance Support Tool (NIMSCAST)). PrepCAST is a self-assessment tool for State, territorial, Tribal, and local governments to...

40 CFR 464.25 - Pretreatment standards for existing sources.

Code of Federal Regulations, 2010 CFR

2010-07-01

...) EFFLUENT GUIDELINES AND STANDARDS METAL MOLDING AND CASTING POINT SOURCE CATEGORY Copper Casting... existing sources. (a) Casting Quench Operations. PSES Pollutant or pollutant property Maximum for any 1 day... monitoring) 1.2 0.399 (b) Direct Chill Casting Operations. PSES Pollutant or pollutant property Maximum for...

Application of TRIZ Theory in Patternless Casting Manufacturing Technique

NASA Astrophysics Data System (ADS)

Yang, Weidong; Gan, Dequan; Jiang, Ping; Tian, Yumei

The ultimate goal of Patternless Casting Manufacturing (referred to as PCM) is how to obtain the casts by casting the sand mold directly. In the previous PCM, the resin content of sand mold is much higher than that required by traditional resin sand, so the casts obtained are difficult to be sound and qualified products, which limits the application of this technique greatly. In this paper, the TRIZ algorithm is introduced to the innovation process in PCM systematically.

Report on results of current and future metal casting

DOE Office of Scientific and Technical Information (OSTI.GOV)

Unal, Cetin; Carlson, Neil N.

2015-09-28

New modeling capabilities needed to simulate the casting of metallic fuels are added to Truchas code. In this report we summarize improvements we made in FY2015 in three areas; (1) Analysis of new casting experiments conducted with BCS and EFL designs, (2) the simulation of INL’s U-Zr casting experiments with Flow3D computer program, (3) the implementation of surface tension model into Truchas for unstructured mesh required to run U-Zr casting.

The ToxCast Chemical Landscape - Paving the Road to 21st ...

EPA Pesticide Factsheets

The ToxCast high-throughput screening (HTS) program within the U.S. Environmental Protection Agency (EPA) was launched in 2007. Phase I of the program screened 310 chemicals, mostly pesticides, across hundreds of ToxCast assay endpoints. In Phase II, the ToxCast library was expanded to 1878 chemicals, culminating in public release of screening data at the end of 2013. Concurrently, a larger EPA library of 3726 chemicals (including the Phase II chemicals) was undergoing screening in the cross-federal agency Tox21 HTS project. Four years later, Phase III of EPA’s ToxCast program is actively screening a diverse library consisting of more than 3800 chemicals, 96% of which are also undergoing Tox21 screening. The majority of ToxCast studies, to date, have focused on using HTS results to build biologically based models for predicting in vivo toxicity endpoints. The focus of the present article, in contrast, is on the EPA chemical library underpinning these efforts. A history of the phased construction of EPA’s ToxCast library is presented, considering factors influencing chemical selection as well as the various quality measures implemented. Next, Chemical Abstracts Service Registry Numbers (CASRN), which were used to compile initial chemical nominations for ToxCast testing, are used to assess overlaps of the current ToxCast library with important toxicity, regulatory, and exposure inventories. Lastly, ToxCast chemicals are described in terms of generaliz

Comparative Evaluation of Conventional and Accelerated Castings on Marginal Fit and Surface Roughness.

PubMed

Jadhav, Vivek Dattatray; Motwani, Bhagwan K; Shinde, Jitendra; Adhapure, Prasad

2017-01-01

The aim of this study was to evaluate the marginal fit and surface roughness of complete cast crowns made by a conventional and an accelerated casting technique. This study was divided into three parts. In Part I, the marginal fit of full metal crowns made by both casting techniques in the vertical direction was checked, in Part II, the fit of sectional metal crowns in the horizontal direction made by both casting techniques was checked, and in Part III, the surface roughness of disc-shaped metal plate specimens made by both casting techniques was checked. A conventional technique was compared with an accelerated technique. In Part I of the study, the marginal fit of the full metal crowns as well as in Part II, the horizontal fit of sectional metal crowns made by both casting techniques was determined, and in Part III, the surface roughness of castings made with the same techniques was compared. The results of the t -test and independent sample test do not indicate statistically significant differences in the marginal discrepancy detected between the two casting techniques. For the marginal discrepancy and surface roughness, crowns fabricated with the accelerated technique were significantly different from those fabricated with the conventional technique. Accelerated casting technique showed quite satisfactory results, but the conventional technique was superior in terms of marginal fit and surface roughness.

The effects of weld-repair and hot isostatic pressing on the fracture properties of Ti-5Al-2.5Sn ELI castings

NASA Technical Reports Server (NTRS)

Misra, M. S.; Lemeshewsky, S.; Bolstad, D.

1982-01-01

The Ti-5Al-2.5Sn extremely low interstitial alloy employed in the large castings which form the critical attachment fittings of the Space Shuttle External Tank was selected because of its high fracture resistance at cryogenic temperatures. Casting was selected over alternative fabrication methods because of its lower cost and adaptability to design changes, although it was found necessary to weld-repair surface and subsurface casting defects in order to reduce the scrap rate and maintain the inherent cost advantage of the castings. Hot Isostatic Pressing was experimentally found to heal the surface and internal defects of the castings, but did not improve tensile or fracture properties and was therefore rejected as a production technique. Production castings are instead weld-repaired, without any mechanical property degradation.

Method and mold for casting thin metal objects

DOEpatents

Pehrson, Brandon P; Moore, Alan F

2014-04-29

Provided herein are various embodiments of systems for casting thin metal plates and sheets. Typical embodiments include layers of mold cavities that are oriented vertically for casting the metal plates. In some embodiments, the mold cavities include a beveled edge such that the plates that are cast have a beveled edge. In some embodiments, the mold cavities are filled with a molten metal through an open horizontal edge of the cavity. In some embodiments, the mold cavities are filled through one or more vertical feed orifices. Further disclosed are methods for forming a thin cast metal plate or sheet where the thickness of the cast part is in a range from 0.005 inches to 0.2 inches, and the surface area of the cast part is in a range from 16 square inches to 144 square inches.

Method for casting thin metal objects

DOEpatents

Pehrson, Brandon P; Moore, Alan F

2015-04-14

Provided herein are various embodiments of systems for casting thin metal plates and sheets. Typical embodiments include layers of mold cavities that are oriented vertically for casting the metal plates. In some embodiments, the mold cavities include a beveled edge such that the plates that are cast have a beveled edge. In some embodiments, the mold cavities are filled with a molten metal through an open horizontal edge of the cavity. In some embodiments, the mold cavities are filled through one or more vertical feed orifices. Further disclosed are methods for forming a thin cast metal plate or sheet where the thickness of the cast part is in a range from 0.005 inches to 0.2 inches, and the surface area of the cast part is in a range from 16 square inches to 144 square inches.

Cause and Prevention of Explosions Involving DC Casting of Aluminum Sheet Ingot

NASA Astrophysics Data System (ADS)

Richter, Ray T.; Ekenes, J. Martin

The casting of aluminum alloy sheet ingot and T-bar presents the potential for some of the most volatile situations that can occur in DC (direct chill) and EMC (Electromagnetic) casting processes. Aluminum Association explosion incident data from over 300 explosions spanning a twenty-year period were reviewed and analyzed looking for common factors and repetitive reasons for explosions. Analysis of explosions occurring during the three stages of sheet ingot casting, `start of cast', `steady state' and `end of cast', were examined and prioritized. Case studies illustrate the need for understanding both technical and non-technical factors contributing to explosions involving molten metal. This paper identifies the major causes of explosions involving DC casting of aluminum alloy sheet ingot and makes recommendations for how to prevent the recurrence of such events and minimize the risk of injury.

Optimization of Squeeze Casting for Aluminum Alloy Parts

DOE Office of Scientific and Technical Information (OSTI.GOV)

David Schwam; John F. Wallace; Qingming Chang

2002-07-30

This study was initiated with the installation of a new production size UBE 350 Ton VSC Squeeze Casting system in the Metal Casting Laboratory at Case Western University. A Lindberg 75k W electrical melting furnace was installed alongside. The challenge of installation and operation of such industrial-size equipment in an academic environment was met successfully. Subsequently, a Sterling oil die heater and a Visi-Track shot monitoring system were added. A significant number of inserts were designed and fabricated over the span of the project, primarily for squeeze casting different configurations of test bars and plates. A spiral ''ribbon insert'' formore » evaluation of molten metal fluidity was also fabricated. These inserts were used to generate a broad range of processing conditions and determine their effect on the quality of the squeeze cast parts. This investigation has studied the influence of the various casting variables on the quality of indirect squeeze castings primarily of aluminum alloys. The variables studied include gating design, fill time and fill patter, metal pressure and die temperature variations. The quality of the die casting was assessed by an analysis of both their surface condition and internal soundness. The primary metal tested was an aluminum 356 alloy. In addition to determining the effect of these casting variables on casting quality as measured by a flat plate die of various thickness, a number of test bar inserts with different gating designs have been inserted in the squeeze casting machine. The mechanical properties of these test bars produced under different squeeze casting conditions were measured and reported. The investigation of the resulting properties also included an analysis of the microstructure of the squeeze castings and the effect of the various structural constituents on the resulting properties. The main conclusions from this investigation are as follows: The ingate size and shape are very important since it must remain open until the casting is solidified and pressure is maintained on the solidifying casting. Fanned gates, particularly on the smaller section castings avoid jetting effects at the ingate end. The fan type ingate helps accomplish a rapid fill without high velocities. The molten metal has to fill the cavity before localized solidification occurs. This is best accomplished with a larger ingate to attain rapid filling without excessive velocity or jetting that occurs at high metal velocities. Straight gates are prone to case jetting of the metal stream even a low velocities. Fanned gates allow use of higher fill velocity without excessive jetting. A higher metal pressure provides a more complete fill of the die including improved compensation for solidification shrinkage. With the proper filling pattern, ingates, overflows and die temperature for a given die, very good tensile properties can be attained in squeeze casting. In general, the smaller squeeze castings require higher die temperatures. Computer models using the UES Procast and MagmaSoft finite element software can, after suitable adjustments, predict the flow pattern in the die cavity.« less

Data Package for Secondary Waste Form Down-Selection—Cast Stone

DOE Office of Scientific and Technical Information (OSTI.GOV)

Serne, R. Jeffrey; Westsik, Joseph H.

2011-09-05

Available literature on Cast Stone and Saltstone was reviewed with an emphasis on determining how Cast Stone and related grout waste forms performed in relationship to various criteria that will be used to decide whether a specific type of waste form meets acceptance criteria for disposal in the Integrated Disposal Facility (IDF) at Hanford. After the critical review of the Cast Stone/Saltstone literature, we conclude that Cast Stone is a good candidate waste form for further consideration. Cast stone meets the target IDF acceptance criteria for compressive strength, no free liquids, TCLP leachate are below the UTS permissible concentrations andmore » leach rates for Na and Tc-99 are suiteably low. The cost of starting ingredients and equipment necessary to generate Cast Stone waste forms with secondary waste streams are low and the Cast Stone dry blend formulation can be tailored to accommodate variations in liquid waste stream compositions. The database for Cast Stone short-term performance is quite extensive compared to the other three candidate waste solidification processes. The solidification of liquid wastes in Cast Stone is a mature process in comparison to the other three candidates. Successful production of Cast Stone or Saltstone has been demonstrated from lab-scale monoliths with volumes of cm3 through m3 sized blocks to 210-liter sized drums all the way to the large pours into vaults at Savannah River. To date over 9 million gallons of low activity liquid waste has been solidified and disposed in concrete vaults at Savannah River.« less

21 CFR 888.5940 - Cast component.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Cast component. 888.5940 Section 888.5940 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Surgical Devices § 888.5940 Cast component. (a) Identification. A cast component is a...

21 CFR 888.5940 - Cast component.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Cast component. 888.5940 Section 888.5940 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Surgical Devices § 888.5940 Cast component. (a) Identification. A cast component is a...

21 CFR 888.5940 - Cast component.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Cast component. 888.5940 Section 888.5940 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Surgical Devices § 888.5940 Cast component. (a) Identification. A cast component is a...

Updates on EPA’s High-Throughput Exposure Forecast (ExpoCast) Research Project (CPCP)

EPA Science Inventory

Recent research advances by the ORD ExpoCast project (CSS Rapid Exposure and Dosimetry) are presented to the computational toxicology community in the context of prioritizing chemicals on a risk-basis using joint ExpoCast and ToxCast predictions. Recent publications by Wambaugh e...

Casting copper to tungsten for high-power arc lamp cathodes

NASA Technical Reports Server (NTRS)

Will, H. A.

1974-01-01

Voids forming at interface when copper is cast onto tungsten can be eliminated by adding wetting agent during casting process. Small amount of copper and nickel are cast onto thoriated tungsten insert, insert is recast with more copper to form electrode. Good thermal conductance results in long-lived cathode.

75 FR 67395 - Iron Construction Castings From Brazil, Canada, and China; Determinations

Federal Register 2010, 2011, 2012, 2013, 2014

2010-11-02

... Review)] Iron Construction Castings From Brazil, Canada, and China; Determinations On the basis of the...), that revocation of the countervailing duty order on heavy iron construction castings from Brazil, the... iron construction castings (both heavy and light) from Brazil and China would be likely to lead to...

40 CFR 464.40 - Applicability; description of the zinc casting subcategory.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 30 2011-07-01 2011-07-01 false Applicability; description of the zinc... (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS METAL MOLDING AND CASTING POINT SOURCE CATEGORY Zinc Casting Subcategory § 464.40 Applicability; description of the zinc casting subcategory. The provisions of this...

40 CFR 464.40 - Applicability; description of the zinc casting subcategory.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 29 2010-07-01 2010-07-01 false Applicability; description of the zinc... (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS METAL MOLDING AND CASTING POINT SOURCE CATEGORY Zinc Casting Subcategory § 464.40 Applicability; description of the zinc casting subcategory. The provisions of this...

76 FR 27668 - Algonac Cast Products, Inc., Algonac, MI; Notice of Revised Determination on Reconsideration

Federal Register 2010, 2011, 2012, 2013, 2014

2011-05-12

... DEPARTMENT OF LABOR Employment and Training Administration [TA-W-74,549] Algonac Cast Products... workers and former workers of Algonac Cast Products, Inc., Algonac, Michigan (subject firm) to apply for... Algonac Cast Products, Inc., Algonac, Michigan. Conclusion After careful review of the additional facts...

40 CFR 464.16 - Pretreatment standards for new sources.

Code of Federal Regulations, 2010 CFR

2010-07-01

... GUIDELINES AND STANDARDS METAL MOLDING AND CASTING POINT SOURCE CATEGORY Aluminum Casting Subcategory § 464... CFR part 403 and achieve the following pretreatment standards for new sources. (a) Casting Cleaning...) 0.114 0.0431 (b) Casting Quench Operations. PSNS Pollutant or pollutant property Maximum for any 1...

40 CFR 464.26 - Pretreatment standards for new sources.

Code of Federal Regulations, 2010 CFR

2010-07-01

... GUIDELINES AND STANDARDS METAL MOLDING AND CASTING POINT SOURCE CATEGORY Copper Casting Subcategory § 464.26... and achieve the following pretreatment standards for new sources. (a) Casting Quench Operations. PSNS... 0.0335 0.0109 Oil and grease (for alternate monitoring) 1.2 0.399 (b) Direct Chill Casting...

21 CFR 888.5980 - Manual cast application and removal instrument.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Manual cast application and removal instrument... SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Surgical Devices § 888.5980 Manual cast application and removal instrument. (a) Identification. A manual cast application and removal instrument is a...

The Ins and Outs of Relief Casting.

ERIC Educational Resources Information Center

Greene, Yvonne

2000-01-01

Describes a unit on clay casting that introduces students to relief sculpture. The unit takes three 45 to 50 minute class periods three weeks apart. Discusses each class session in detail: (1) creating the casting; (2) turning out and rinsing the casting; and (3) enriching the surface with color. (CMK)

40 CFR 464.15 - Pretreatment standards for existing sources.

Code of Federal Regulations, 2010 CFR

2010-07-01

...) EFFLUENT GUIDELINES AND STANDARDS METAL MOLDING AND CASTING POINT SOURCE CATEGORY Aluminum Casting... existing sources. (a) Casting Cleaning Operations. PSES Pollutant or pollutant property Maximum for any 1....0771 0.0421 Lead (T) 0.0791 0.039 Zinc (T) 0.114 0.0431 (b) Casting Quench Operation. PSES Pollutant or...

49 CFR 192.755 - Protecting cast-iron pipelines.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 3 2010-10-01 2010-10-01 false Protecting cast-iron pipelines. 192.755 Section... NATURAL AND OTHER GAS BY PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS Maintenance § 192.755 Protecting cast-iron pipelines. When an operator has knowledge that the support for a segment of a buried cast-iron...

77 FR 8272 - Agency Information Collection Activities: Submission for OMB Review; Comment Request, PrepCAST.

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-14

..., PrepCAST. AGENCY: Federal Emergency Management Agency, DHS. ACTION: Notice. SUMMARY: The Federal... . SUPPLEMENTARY INFORMATION: Collection of Information Title: PrepCAST. Type of information collection: Revision.... Abstract: PrepCAST is a collection instrument that will collect preparedness information at the State...

40 CFR 721.10667 - Slimes and sludges, aluminum and iron casting, wastewater treatment, solid waste.

Code of Federal Regulations, 2014 CFR

2014-07-01

... casting, wastewater treatment, solid waste. 721.10667 Section 721.10667 Protection of Environment... iron casting, wastewater treatment, solid waste. (a) Chemical substance and significant new uses... and iron casting, wastewater treatment, solid waste (PMN P-12-560; CAS No. 1391739-82-4; chemical...

40 CFR 721.10667 - Slimes and sludges, aluminum and iron casting, wastewater treatment, solid waste.

Code of Federal Regulations, 2013 CFR

2013-07-01

... casting, wastewater treatment, solid waste. 721.10667 Section 721.10667 Protection of Environment... iron casting, wastewater treatment, solid waste. (a) Chemical substance and significant new uses... and iron casting, wastewater treatment, solid waste (PMN P-12-560; CAS No. 1391739-82-4; chemical...

The ToxCast Chemical Landscape - Paving the Road to 21st Century Toxicology

EPA Science Inventory

The ToxCast high-throughput screening (HTS) program within the U.S. Environmental Protection Agency (EPA) was launched in 2007. Phase I of the program screened 310 chemicals, mostly pesticides, across hundreds of ToxCast assay endpoints. In Phase II, the ToxCast library was exp...

When Your Child Needs a Cast

MedlinePlus

... a waterproof plastic cast protector instead of plastic bags. You can buy this at a drugstore. Keep the cast completely out of the water by propping it up on the side of the tub. If the cast or liner gets splashed, gently blow air into it from a hair dryer on the ...

21 CFR 888.5940 - Cast component.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Cast component. 888.5940 Section 888.5940 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES... the cast heel, toe cap, cast support, and walking iron. (b) Classification. Class I (general controls...

21 CFR 888.5940 - Cast component.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cast component. 888.5940 Section 888.5940 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES... the cast heel, toe cap, cast support, and walking iron. (b) Classification. Class I (general controls...

Netcast™ Shape Casting Technology: A Technological Breakthrough that Enhances the Cost Effectiveness of Aluminum Forgings

NASA Astrophysics Data System (ADS)

Anderson, Mark; Bruski, Richard; Groszkiewicz, Daniel; Wagstaff, Bob

A new Direct Chill (DC) casting process is introduced to semi-continuous casting where near net shaped ingots are solidified. This process is currently being used at Alcan Engineered Cast Products (ECP) facility in Jonquiere, Canada, sectioned, then forged at Alcoa Automotive, Kentucky Casting Center (KCC). Finished forgings are machined and assembled into the Ford D/EW98 platform as suspension components. A brief description of the process and the implications on the forging process are presented.

Rapid Cycle Casting of Steel

DTIC Science & Technology

1981-07-01

C’, and at temperature T, are Infiltrated by !L amougt of liquid of composition C’., such that ,C, 4 f+.C’L - X. V. 7 average carbon content of the...maximum liquid penetration was 100 mm at an infiltration pressure of 755 kPa. The average casting composition was 0.94 w/o carbon . The segregation at...content* at four casting locations. 2. Results The casting composition ( carbon content) as a function of casting location is given in Table D-IV. The

The role of water in slip casting

NASA Technical Reports Server (NTRS)

Mccauley, R. A.; Phelps, G. W.

1984-01-01

Slips and casting are considered in terms of physical and colloidal chemistry. Casting slips are polydisperse suspensions of lyophobic particles in water, whose degree of coagulation is controlled by interaction of flocculating and deflocculating agents. Slip casting rate and viscosity are functions of temperature. Slip rheology and response to deflocculating agents varies significantly as the kinds and amounts of colloid modifiers change. Water is considered as a raw material. Various concepts of water/clay interactions and structures are discussed. Casting is a de-watering operation in which water moves from slip to cast to mold in response to a potential energy termed moisture stress. Drying is an evaporative process from a free water surface.

Research of Mechanical Property Gradient Distribution of Al-Cu Alloy in Centrifugal Casting

NASA Astrophysics Data System (ADS)

Sun, Zhi; Sui, Yanwei; Liu, Aihui; Li, Bangsheng; Guo, Jingjie

Al-Cu alloy castings are obtained using centrifugal casting. The regularity of mechanical property gradient distribution of Al-Cu alloy castings with the same centrifugal radius at different positions is investigated. The result shows that the tensile strength, yield strength, elongation and microscope hardness exhibit the following gradient distribution characteristic — high on both sides and low on the center. The trend of mechanical property gradient distribution of Al-Cu alloy increases with the increase in the rotation speed. Moreover, the mechanical properties of casting centerline two sides have asymmetry. The reason is that the grain size of casting centerline two sides and Al2Cu phase and Cu content change correspondingly.

ICAM Manufacturing Cost/Design Guide. Volume 3. Airframes. User’s Manual.

DTIC Science & Technology

1983-01-01

COST-DRIVER EFFECT 17 -413H Investment Cast 17 - 4PH Investment Cast 2 2 - U) *oo 0±0.01 ±0.02 ±0.03 0±0.01 ±0.02 ±0.03 356iA356 Aluminum 356/A356...B +20% CAST B +50% 17 - 4PH CRES DORC BASE INVESTMENT D OR C WITH 10% B +20% CAST D OR C WITH 50% B +30% B +60% NOTE: X-Ray Grade A Is an Impractical...per QQ-A-601 (sand castings) - 357 per MIL-A-21180 (sand castings) a Steel - 17 - 4PH CRES per AMS-5342, 5343, and 5344 or * company equivalent

Effect of carbon content on friction and wear of cast irons

NASA Technical Reports Server (NTRS)

Buckley, D. H.

1977-01-01

Friction and wear experiments were conducted with cast irons and wrought steels containing various amounts of carbon in the alloy structure in contact with 52100 steel. Gray cast irons were found to exhibit lower friction and wear characteristics than white cast irons. Further, gray cast iron wear was more sensitive to carbon content than was white. Wear with gray cast iron was linearly related to load, and friction was found to be sensitive to relative humidity and carbon content. The form, in which the carbon is present in the alloy, is more important, as the carbon content and no strong relationship seems to exist between hardness of these ferrous alloys and wear.

An objective assessment of safety to drive in an upper limb cast.

PubMed

Stevenson, H L; Peterson, N; Talbot, C; Dalal, S; Watts, A C; Trail, I A

2013-03-01

Patients managed with upper limb cast immobilization often seek advice about driving. There is very little published data to assist in decision making, and advice given varies between healthcare professionals. There are no specific guidelines available from the UK Drivers and Vehicles Licensing Agency, police, or insurance companies. Evidence-based guidelines would enable clinicians to standardize the advice given to patients. Six individuals (three male, three female; mean age 36 years, range 27-43 years) were assessed by a mobility occupational therapist and driving standards agency examiner while completing a formal driving test in six different types of upper limb casts (above-elbow, below-elbow neutral, and below-elbow cast incorporating the thumb [Bennett's cast]) on both left and right sides. Of the 36 tests, participants passed 31 tests, suggesting that most people were able to safely drive with upper limb cast immobilization. However, driving in a left above-elbow cast was considered unsafe.

A Winning Cast

NASA Technical Reports Server (NTRS)

2001-01-01

Howmet Research Corporation was the first to commercialize an innovative cast metal technology developed at Auburn University, Auburn, Alabama. With funding assistance from NASA's Marshall Space Flight Center, Auburn University's Solidification Design Center (a NASA Commercial Space Center), developed accurate nickel-based superalloy data for casting molten metals. Through a contract agreement, Howmet used the data to develop computer model predictions of molten metals and molding materials in cast metal manufacturing. Howmet Metal Mold (HMM), part of Howmet Corporation Specialty Products, of Whitehall, Michigan, utilizes metal molds to manufacture net shape castings in various alloys and amorphous metal (metallic glass). By implementing the thermophysical property data from by Auburn researchers, Howmet employs its newly developed computer model predictions to offer customers high-quality, low-cost, products with significantly improved mechanical properties. Components fabricated with this new process replace components originally made from forgings or billet. Compared with products manufactured through traditional casting methods, Howmet's computer-modeled castings come out on top.

In Situ Casting and Imaging of the Rat Airway Tree for Accurate 3D Reconstruction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jacob, Rick E.; Colby, Sean M.; Kabilan, Senthil

The use of anatomically accurate, animal-specific airway geometries is important for understanding and modeling the physiology of the respiratory system. One approach for acquiring detailed airway architecture is to create a bronchial cast of the conducting airways. However, typical casting procedures either do not faithfully preserve the in vivo branching angles, or produce rigid casts that when removed for imaging are fragile and thus easily damaged. We address these problems by creating an in situ bronchial cast of the conducting airways in rats that can be subsequently imaged in situ using 3D micro-CT imaging. We also demonstrate that deformations inmore » airway branch angles resulting from the casting procedure are small, and that these angle deformations can be reversed through an interactive adjustment of the segmented cast geometry. Animal work was approved by the Institutional Animal Care and Use Committee of Pacific Northwest National Laboratory.« less

Casting And Solidification Technology (CAST): Directional solidification phenomena in a metal model at reduced gravity

NASA Technical Reports Server (NTRS)

Mccay, M. H.

1988-01-01

The Casting and Solidification Technology (CAST) experiment will study the phenomena that occur during directional solidification of an alloy, e.g., constitutional supercooling, freckling, and dendrite coarsening. The reduced gravity environment of space will permit the individual phenomena to be examined with minimum complication from buoyancy driven flows.

49 CFR 192.489 - Remedial measures: Cast iron and ductile iron pipelines.

Code of Federal Regulations, 2011 CFR

2011-10-01

... for Corrosion Control § 192.489 Remedial measures: Cast iron and ductile iron pipelines. (a) General graphitization. Each segment of cast iron or ductile iron pipe on which general graphitization is found to a... 49 Transportation 3 2011-10-01 2011-10-01 false Remedial measures: Cast iron and ductile iron...

49 CFR 192.489 - Remedial measures: Cast iron and ductile iron pipelines.

Code of Federal Regulations, 2010 CFR

2010-10-01

... for Corrosion Control § 192.489 Remedial measures: Cast iron and ductile iron pipelines. (a) General graphitization. Each segment of cast iron or ductile iron pipe on which general graphitization is found to a... 49 Transportation 3 2010-10-01 2010-10-01 false Remedial measures: Cast iron and ductile iron...

40 CFR 464.40 - Applicability; description of the zinc casting subcategory.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 31 2012-07-01 2012-07-01 false Applicability; description of the zinc casting subcategory. 464.40 Section 464.40 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) METAL MOLDING AND CASTING POINT SOURCE CATEGORY Zinc Casting Subcategory § 464.40...

40 CFR 464.40 - Applicability; description of the zinc casting subcategory.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 31 2013-07-01 2013-07-01 false Applicability; description of the zinc casting subcategory. 464.40 Section 464.40 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) METAL MOLDING AND CASTING POINT SOURCE CATEGORY Zinc Casting Subcategory § 464.40...

40 CFR 464.40 - Applicability; description of the zinc casting subcategory.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 30 2014-07-01 2014-07-01 false Applicability; description of the zinc casting subcategory. 464.40 Section 464.40 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) METAL MOLDING AND CASTING POINT SOURCE CATEGORY Zinc Casting Subcategory § 464.40...

75 FR 10216 - Malleable Cast Iron Pipe Fittings from the People's Republic of China: Notice of Rescission of...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-05

... DEPARTMENT OF COMMERCE International Trade Administration [A-570-881] Malleable Cast Iron Pipe... antidumping duty order on malleable cast iron pipe fittings from the People's Republic of China (``PRC''). See... malleable cast iron pipe fittings from the PRC. See Initiation of Antidumping and Countervailing Duty...

46 CFR 153.239 - Use of cast iron.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 5 2010-10-01 2010-10-01 false Use of cast iron. 153.239 Section 153.239 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SHIPS CARRYING BULK... Systems § 153.239 Use of cast iron. (a) Cast iron used in a cargo containment system must meet the...

78 FR 74163 - Johnstown Specialty Castings Inc., a Subsidiary of WHEMCO, Including On-Site Leased Workers From...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-12-10

... Castings Inc., a Subsidiary of WHEMCO, Including On-Site Leased Workers From Berkebile Excavating Company... Assistance on June 25, 2013, applicable to workers of Johnstown Specialty Castings, Inc., a subsidiary of... Castings, Inc., a subsidiary of WHEMCO. The Department has determined that these workers were sufficiently...

78 FR 68474 - Non-Malleable Cast Iron Pipe Fittings From China; Scheduling of an Expedited Five-Year Review...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-11-14

... INTERNATIONAL TRADE COMMISSION [Investigation No. 731-TA-990 (Second Review)] Non-Malleable Cast... Duty Order on Non-Malleable Cast Iron Pipe Fittings From China AGENCY: United States International... determine whether revocation of the antidumping duty order on non-malleable cast iron pipe fittings from...

The use of porcine corrosion casts for teaching human anatomy.

PubMed

Eberlova, Lada; Liska, Vaclav; Mirka, Hynek; Tonar, Zbynek; Haviar, Stanislav; Svoboda, Milos; Benes, Jan; Palek, Richard; Emingr, Michal; Rosendorf, Jachym; Mik, Patrik; Leupen, Sarah; Lametschwandtner, Alois

2017-09-01

In teaching and learning human anatomy, anatomical autopsy and prosected specimens have always been indispensable. However, alternative methods must often be used to demonstrate particularly delicate structures. Corrosion casting of porcine organs with Biodur E20 ® Plus is valuable for teaching and learning both gross anatomy and, uniquely, the micromorphology of cardiovascular, respiratory, digestive, and urogenital systems. Assessments of casts with a stereomicroscope and/or scanning electron microscope as well as highlighting cast structures using color coding help students to better understand how the structures that they have observed as two-dimensional images actually exist in three dimensions, and students found using the casts to be highly effective in their learning. Reconstructions of cast hollow structures from (micro-)computed tomography scans and videos facilitate detailed analyses of branching patterns and spatial arrangements in cast structures, aid in the understanding of clinically relevant structures and provide innovative visual aids. The casting protocol and teaching manual we offer can be adjusted to different technical capabilities and might also be found useful for veterinary or other biological science classes. Copyright © 2017 Elsevier GmbH. All rights reserved.

Prediction model of austenite growth and the role of MnS inclusions in non-quenched and tempered steel

NASA Astrophysics Data System (ADS)

Jiang, Bo; Wu, Meng; Sun, He; Wang, Zhilin; Zhao, Zhigang; Liu, Yazheng

2018-01-01

The austenite growth behavior of non-quenched and tempered steels (casted by continuous casting and molding casting processes) was studied. The austenite grain size of steel B casted by continuous casting process is smaller than that of steel A casted by molding casting process at the same heating parameters. The abnormal austenite growth temperature of the steels A and B are 950 °C and 1000 °C, respectively. Based on the results, the models for the austenite grain growth below and above the abnormal austenite growth temperature of the investigated steels were established. The dispersedly distributed fine particles MnS in steel B is the key factor refining the austenite grain by pinning the migration of austenite grain boundary. The elongated inclusions MnS are ineffective in preventing the austenite grain growth at high heating temperature. For the non-quenched and tempered steel, the continuous casting process should be adopted and the inclusion MnS should be elliptical, smaller in size and distributed uniformly in order to refine the final microstructure and also improve the mechanical properties.

The Effect of Sr Modifier Additions on Double Oxide Film Defects in 2L99 Alloy Castings

NASA Astrophysics Data System (ADS)

Chen, Qi; Griffiths, W. D.

2017-11-01

In this paper, Sr modifier (300 ppm) was added to 2L99 alloy sand castings to investigate its effect on bifilm defects in the castings. Two different sand molds were used in this study, with good and bad running system designs, to introduce different amounts of bifilm defects into the castings. The mechanical properties of the modified 2L99 castings were compared to the properties of unmodified castings and showed that with high bifilm defect contents (H) the Sr addition reduced the Weibull modulus of the UTS by 67 pct and the Position Parameter by 5 pct, and introduced a bimodal distribution into the Weibull plot of the pct Elongation. However, for castings with low bifilm defect content (L), the Weibull moduli of both the UTS and pct Elongation were significantly improved (by 78 and 73 pct, respectively) with the addition of Sr. The Position Parameter of the pct Elongation was improved by 135 pct. The results suggested that a desirable modification effect can only be achieved while the bifilm defect content in a casting was low.

Glovebox Advanced Casting System Casting Optimization

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fielding, Randall Sidney

2016-03-01

Casting optimization in the GACS included three broad areas; casting of U-10Zr pins, incorporation of an integral FCCI barrier, and development of a permanent crucible coating. U-10Zr casting was improved over last year’s results by modifying the crucible design to minimize contact with the colder mold. Through these modifications casting of a three pin batch was successful. Incorporation of an integral FCCI barrier also was optimized through furnace chamber pressure changes during the casting cycle to reduce gas pressures in the mold cavities which led to three full length pins being cast which incorporated FCCI barriers of three different thicknesses.more » Permanent crucible coatings were tested against a base case; 1500°C for 10 minutes in a U-20Pu-10Zr molten alloy. None of the candidate coating materials showed evidence of failure upon initial visual examination. In all areas of work a large amount of characterization will be needed to fully determine the effects of the optimization activities. The characterization activities and future work will occur next year.« less

Characterization and expression of the calpastatin gene in Cyprinus carpio.

PubMed

Chen, W X; Ma, Y

2015-07-03

Calpastatin, an important protein used to regulate meat quality traits in animals, is encoded by the CAST gene. The aim of the present study was to clone the cDNA sequence of the CAST gene and detect the expression of CAST in the tissues of Cyprinus carpio. The cDNA of the C. carpio CAST gene, amplified using rapid amplification of cDNA ends PCR, is 2834 bp in length (accession No. JX275386), contains a 2634-bp open reading frame, and encodes a protein with 877 amino acid residues. The amino acid sequence of the C. carpio CAST gene was 88, 80, and 59% identical to the sequences observed in grass carp, zebrafish, and other fish, respectively. The C. carpio CAST was observed to contain four conserved domains with 54 serine phosphorylation loci, 28 threonine phosphorylation loci, 1 tyrosine phosphorylation loci, and 6 specific protein kinase C phosphorylation loci. The CAST gene showed widespread expression in different tissues of C. carpio. Surprisingly, the relative expression of the CAST transcript in the muscle and heart tissues of C. carpio was significantly higher than in other tissues (P < 0.01).

Physical and Clinical Evaluation of Hip Spica Cast applied with Three-slab Technique using Fibreglass Material

PubMed Central

Bitar, KM; Ferdhany, ME; Saw, A

2016-01-01

Introduction: Hip spica casting is an important component of treatment for developmental dysplasia of the hip (DDH) and popular treatment method for femur fractures in children. Breakage at the hip region is a relatively common problem of this cast. We have developed a three-slab technique of hip spica application using fibreglass as the cast material. The purpose of this review was to evaluate the physical durability of the spica cast and skin complications with its use. Methodology: A retrospective review of children with various conditions requiring hip spica immobilisation which was applied using our method. Study duration was from 1st of January 2014 until 31st December 2015. Our main outcomes were cast breakage and skin complications. For children with hip instability, the first cast would be changed after one month, and the second cast about two months later. Results: Twenty-one children were included, with an average age of 2.2 years. The most common indication for spica immobilisation was developmental dysplasia of the hip. One child had skin irritation after spica application. No spica breakage was noted. Conclusion: This study showed that the three-slab method of hip spica cast application using fibreglass material was durable and safe with low risk of skin complications. PMID:28553442

Hands-Off and Hands-On Casting Consistency of Amputee below Knee Sockets Using Magnetic Resonance Imaging

PubMed Central

Rowe, Philip

2013-01-01

Residual limb shape capturing (Casting) consistency has a great influence on the quality of socket fit. Magnetic Resonance Imaging was used to establish a reliable reference grid for intercast and intracast shape and volume consistency of two common casting methods, Hands-off and Hands-on. Residual limbs were cast for twelve people with a unilateral below knee amputation and scanned twice for each casting concept. Subsequently, all four volume images of each amputee were semiautomatically segmented and registered to a common coordinate system using the tibia and then the shape and volume differences were calculated. The results show that both casting methods have intra cast volume consistency and there is no significant volume difference between the two methods. Inter- and intracast mean volume differences were not clinically significant based on the volume of one sock criteria. Neither the Hands-off nor the Hands-on method resulted in a consistent residual limb shape as the coefficient of variation of shape differences was high. The resultant shape of the residual limb in the Hands-off casting was variable but the differences were not clinically significant. For the Hands-on casting, shape differences were equal to the maximum acceptable limit for a poor socket fit. PMID:24348164

Caste- and ethnicity-based inequalities in HIV/AIDS-related knowledge gap: a case of Nepal.

PubMed

Atteraya, Madhu; Kimm, HeeJin; Song, In Han

2015-05-01

Caste- and ethnicity-based inequalities are major obstacles to achieving health equity. The authors investigated whether there is any association between caste- and ethnicity-based inequalities and HIV-related knowledge within caste and ethnic populations. They used the 2011 Nepal Demographic and Health Survey, a nationally represented cross-sectional study data set. The study sample consisted of 11,273 women between 15 and 49 years of age. Univariate and logistic regression models were used to examine the relationship between caste- and ethnicity-based inequalities and HIV-related knowledge. The study sample was divided into high Hindu caste (47.9 percent), "untouchable" caste (18.4 percent), and indigenous populations (33.7 percent). Within the study sample, the high-caste population was found to have the greatest knowledge of the means by which HIV is prevented and transmitted. After controlling for socioeconomic and demographic characteristics, untouchables were the least knowledgeable. The odds ratio for incomplete knowledge about transmission among indigenous populations was 1.27 times higher than that for high Hindu castes, but there was no significant difference in knowledge of preventive measures. The findings suggest the existence of a prevailing HIV knowledge gap. This in turn suggests that appropriate steps need to be implemented to convey complete knowledge to underprivileged populations.

Hands-off and hands-on casting consistency of amputee below knee sockets using magnetic resonance imaging.

PubMed

Safari, Mohammad Reza; Rowe, Philip; McFadyen, Angus; Buis, Arjan

2013-01-01

Residual limb shape capturing (Casting) consistency has a great influence on the quality of socket fit. Magnetic Resonance Imaging was used to establish a reliable reference grid for intercast and intracast shape and volume consistency of two common casting methods, Hands-off and Hands-on. Residual limbs were cast for twelve people with a unilateral below knee amputation and scanned twice for each casting concept. Subsequently, all four volume images of each amputee were semiautomatically segmented and registered to a common coordinate system using the tibia and then the shape and volume differences were calculated. The results show that both casting methods have intra cast volume consistency and there is no significant volume difference between the two methods. Inter- and intracast mean volume differences were not clinically significant based on the volume of one sock criteria. Neither the Hands-off nor the Hands-on method resulted in a consistent residual limb shape as the coefficient of variation of shape differences was high. The resultant shape of the residual limb in the Hands-off casting was variable but the differences were not clinically significant. For the Hands-on casting, shape differences were equal to the maximum acceptable limit for a poor socket fit.

Does the casting mode influence microstructure, fracture and properties of different metal ceramic alloys?

PubMed

Bauer, José Roberto de Oliveira; Grande, Rosa Helena Miranda; Rodrigues-Filho, Leonardo Eloy; Pinto, Marcelo Mendes; Loguercio, Alessandro Dourado

2012-01-01

The aim of the present study was to evaluate the tensile strength, elongation, microhardness, microstructure and fracture pattern of various metal ceramic alloys cast under different casting conditions. Two Ni-Cr alloys, Co-Cr and Pd-Ag were used. The casting conditions were as follows: electromagnetic induction under argon atmosphere, vacuum, using blowtorch without atmosphere control. For each condition, 16 specimens, each measuring 25 mm long and 2.5 mm in diameter, were obtained. Ultimate tensile strength (UTS) and elongation (EL) tests were performed using a Kratos machine. Vickers Microhardness (VM), fracture mode and microstructure were analyzed by SEM. UTS, EL and VM data were statistically analyzed using ANOVA. For UTS, alloy composition had a direct influence on casting condition of alloys (Wiron 99 and Remanium CD), with higher values shown when cast with Flame/Air (p < 0.05). The factors 'alloy" and 'casting condition" influenced the EL and VM results, generally presenting opposite results, i.e., alloy with high elongation value had lower hardness (Wiron 99), and casting condition with the lowest EL values had the highest VM values (blowtorch). Both factors had significant influence on the properties evaluated, and prosthetic laboratories should select the appropriate casting method for each alloy composition to obtain the desired property.

Objective assessment of plaster cast quality in pediatric distal forearm fractures: Is there an optimal index?

PubMed

Labronici, Pedro José; Ferreira, Leonardo Termis; Dos Santos Filho, Fernando Claudino; Pires, Robinson Esteves Santos; Gomes, Davi Coutinho Fonseca Fernandes; da Silva, Luiz Henrique Penteado; Gameiro, Vinicius Schott

2017-02-01

Several so-called casting indices are available for objective evaluation of plaster cast quality. The present study sought to investigate four of these indices (gap index, padding index, Canterbury index, and three-point index) as compared to a reference standard (cast index) for evaluation of plaster cast quality after closed reduction of pediatric displaced distal forearm fractures. Forty-three radiographs from patients with displaced distal forearm fractures requiring manipulation were reviewed. Accuracy, sensitivity, specificity, false-positive probability, false-negative probability, positive predictive value, negative predictive value, positive likelihood ratio, and negative likelihood ratio were calculated for each of the tested indices. Comparison among indices revealed diagnostic agreement in only 4.7% of cases. The strongest correlation with the cast index was found for the gap index, with a Spearman correlation coefficient of 0.94. The gap index also displayed the best agreement with the cast index, with both indices yielding the same result in 79.1% of assessments. When seeking to assess plaster cast quality, the cast index and gap index should be calculated; if both indices agree, a decision on quality can be made. If the cast and gap indices disagree, the padding index can be calculated as a tiebreaker, and the decision based on the most frequent of the three results. Calculation of the three-point index and Canterbury index appears unnecessary. Copyright © 2016 Elsevier Ltd. All rights reserved.

Evaluation of cast creep occurring during simulated clubfoot correction

PubMed Central

Cohen, Tamara L; Altiok, Haluk; Wang, Mei; McGrady, Linda M; Krzak, Joseph; Graf, Adam; Tarima, Sergey; Smith, Peter A; Harris, Gerald, F

2016-01-01

The Ponseti method is a widely accepted and highly successful conservative treatment of pediatric clubfoot involving weekly manipulations and cast applications. Qualitative assessments have indicated the potential success of the technique with cast materials other than standard plaster of Paris. However, guidelines for clubfoot correction based on the mechanical response of these materials have yet to be investigated. The current study sought to characterize and compare the ability of three standard cast materials to maintain the Ponseti corrected foot position by evaluating cast creep response. A dynamic cast testing device, built to model clubfoot correction, was wrapped in plaster-of-Paris, semi-rigid fiberglass, and rigid fiberglass. Three-dimensional motion responses to two joint stiffnesses were recorded. Rotational creep displacement and linearity of the limb-cast composite were analyzed. Minimal change in position over time was found for all materials. Among cast materials, the rotational creep displacement was significantly different (p < 0.0001). The most creep displacement occurred in the plaster-of-Paris (2.0 degrees), then the semi-rigid fiberglass (1.0 degrees), and then the rigid fiberglass (0.4 degrees). Torque magnitude did not affect creep displacement response. Analysis of normalized rotation showed quasi—linear viscoelastic behavior. This study provided a mechanical evaluation of cast material performance as used for clubfoot correction. Creep displacement dependence on cast material and insensitivity to torque were discovered. This information may provide a quantitative and mechanical basis for future innovations for clubfoot care. PMID:23636764

Evaluation of the marginal fit of metal copings fabricated on three different marginal designs using conventional and accelerated casting techniques: an in vitro study.

PubMed

Vaidya, Sharad; Parkash, Hari; Bhargava, Akshay; Gupta, Sharad

2014-01-01

Abundant resources and techniques have been used for complete coverage crown fabrication. Conventional investing and casting procedures for phosphate-bonded investments require a 2- to 4-h procedure before completion. Accelerated casting techniques have been used, but may not result in castings with matching marginal accuracy. The study measured the marginal gap and determined the clinical acceptability of single cast copings invested in a phosphate-bonded investment with the use of conventional and accelerated methods. One hundred and twenty cast coping samples were fabricated using conventional and accelerated methods, with three finish lines: Chamfer, shoulder and shoulder with bevel. Sixty copings were prepared with each technique. Each coping was examined with a stereomicroscope at four predetermined sites and measurements of marginal gaps were documented for each. A master chart was prepared for all the data and was analyzed using Statistical Package for the Social Sciences version. Evidence of marginal gap was then evaluated by t-test. Analysis of variance and Post-hoc analysis were used to compare two groups as well as to make comparisons between three subgroups . Measurements recorded showed no statistically significant difference between conventional and accelerated groups. Among the three marginal designs studied, shoulder with bevel showed the best marginal fit with conventional as well as accelerated casting techniques. Accelerated casting technique could be a vital alternative to the time-consuming conventional casting technique. The marginal fit between the two casting techniques showed no statistical difference.

Comparative Evaluation of Conventional and Accelerated Castings on Marginal Fit and Surface Roughness

PubMed Central

Jadhav, Vivek Dattatray; Motwani, Bhagwan K.; Shinde, Jitendra; Adhapure, Prasad

2017-01-01

Aims: The aim of this study was to evaluate the marginal fit and surface roughness of complete cast crowns made by a conventional and an accelerated casting technique. Settings and Design: This study was divided into three parts. In Part I, the marginal fit of full metal crowns made by both casting techniques in the vertical direction was checked, in Part II, the fit of sectional metal crowns in the horizontal direction made by both casting techniques was checked, and in Part III, the surface roughness of disc-shaped metal plate specimens made by both casting techniques was checked. Materials and Methods: A conventional technique was compared with an accelerated technique. In Part I of the study, the marginal fit of the full metal crowns as well as in Part II, the horizontal fit of sectional metal crowns made by both casting techniques was determined, and in Part III, the surface roughness of castings made with the same techniques was compared. Statistical Analysis Used: The results of the t-test and independent sample test do not indicate statistically significant differences in the marginal discrepancy detected between the two casting techniques. Results: For the marginal discrepancy and surface roughness, crowns fabricated with the accelerated technique were significantly different from those fabricated with the conventional technique. Conclusions: Accelerated casting technique showed quite satisfactory results, but the conventional technique was superior in terms of marginal fit and surface roughness. PMID:29042726

The Design of 3D-Printed Lattice-Reinforced Thickness-Varying Shell Molds for Castings.

PubMed

Shangguan, Haolong; Kang, Jinwu; Yi, Jihao; Zhang, Xiaochuan; Wang, Xiang; Wang, Haibin; Huang, Tao

2018-03-30

3D printing technologies have been used gradually for the fabrication of sand molds and cores for castings, even though these molds and cores are dense structures. In this paper, a generation method for lattice-reinforced thickness-varying shell molds is proposed and presented. The first step is the discretization of the STL (Stereo Lithography) model of a casting into finite difference meshes. After this, a shell is formed by surrounding the casting with varying thickness, which is roughly proportional to the surface temperature distribution of the casting that is acquired by virtually cooling it in the environment. A regular lattice is subsequently constructed to support the shell. The outside surface of the shell and lattice in the cubic mesh format is then converted to STL format to serve as the external surface of the new shell mold. The internal surface of the new mold is the casting's surface with the normals of all of the triangles in STL format reversed. Experimental verification was performed on an Al alloy wheel hub casting. Its lattice-reinforced thickness-varying shell mold was generated by the proposed method and fabricated by the binder jetting 3D printing. The poured wheel hub casting was sound and of good surface smoothness. The cooling rate of the wheel hub casting was greatly increased due to the shell mold structure. This lattice-reinforced thickness-varying shell mold generation method is of great significance for mold design for castings to achieve cooling control.

A novel use of QR code stickers after orthopaedic cast application.

PubMed

Gough, A T; Fieraru, G; Gaffney, Pav; Butler, M; Kincaid, R J; Middleton, R G

2017-07-01

INTRODUCTION We present a novel solution to ensure that information and contact details are always available to patients while in cast. An information sticker containing both telephone numbers and a Quick Response (QR) code is applied to the cast. When scanned with a smartphone, the QR code loads the plaster team's webpage. This contains information and videos about cast care, complications and enhancing recovery. METHODS A sticker was designed and applied to all synthetic casts fitted in our fracture clinic. On cast removal, patients completed a questionnaire about the sticker. A total of 101 patients were surveyed between November 2015 and February 2016. The questionnaire comprised ten binary choice questions. RESULTS The vast majority (97%) of patients had the sticker still on their cast when they returned to clinic for cast removal. Eighty-four per cent of all patients felt reassured by the presence of the QR code sticker. Nine per cent used the contact details on the cast to seek advice. Over half (56%) had a smartphone and a third (33%) of these scanned the QR code. Of those who scanned the code, 95% found the information useful. CONCLUSIONS This study indicates that use of a QR code reassures patients and is an effective tool in the proactive management of potential cast problems. The QR code sticker is now applied to all casts across our trust. In line with NHS England's Five Year Forward View calling for enhanced use of smartphone technology, our trust is continuing to expand its portfolio of patient information accessible via QR codes. Other branches of medicine may benefit from incorporating QR codes as portals to access such information.

Cardiovascular cast model fabrication and casting effectiveness evaluation in fetus with severe congenital heart disease or normal heart.

PubMed

Wang, Yu; Cao, Hai-yan; Xie, Ming-xing; He, Lin; Han, Wei; Hong, Liu; Peng, Yuan; Hu, Yun-fei; Song, Ben-cai; Wang, Jing; Wang, Bin; Deng, Cheng

2016-04-01

To investigate the application and effectiveness of vascular corrosion technique in preparing fetal cardiovascular cast models, 10 normal fetal heart specimens with other congenital disease (control group) and 18 specimens with severe congenital heart disease (case group) from induced abortions were enrolled in this study from March 2013 to June 2015 in our hospital. Cast models were prepared by injecting casting material into vascular lumen to demonstrate real geometries of fetal cardiovascular system. Casting effectiveness was analyzed in terms of local anatomic structures and different anatomical levels (including overall level, atrioventricular and great vascular system, left-sided and right-sided heart), as well as different trimesters of pregnancy. In our study, all specimens were successfully casted. Casting effectiveness analysis of local anatomic structures showed a mean score from 1.90±1.45 to 3.60±0.52, without significant differences between case and control groups in most local anatomic structures except left ventricle, which had a higher score in control group (P=0.027). Inter-group comparison of casting effectiveness in different anatomical levels showed no significant differences between the two groups. Intra-group comparison also revealed undifferentiated casting effectiveness between atrioventricular and great vascular system, or left-sided and right-sided heart in corresponding group. Third-trimester group had a significantly higher perfusion score in great vascular system than second-trimester group (P=0.046), while the other anatomical levels displayed no such difference. Vascular corrosion technique can be successfully used in fabrication of fetal cardiovascular cast model. It is also a reliable method to demonstrate three-dimensional anatomy of severe congenital heart disease and normal heart in fetus.

Effect of pressure difference on the quality of titanium casting.

PubMed

Watanabe, I; Watkins, J H; Nakajima, H; Atsuta, M; Okabe, T

1997-03-01

In casting titanium using a two-compartment casting machine, Herø et al. (1993) reported that the pressure difference between the melting chamber and the mold chamber affected the soundness of the castings. This study tested the hypothesis that differences in pressure produce castings with various amounts of porosity and different mechanical properties values. Plastic dumbbell-shaped patterns were invested with an alumina-based, phosphate-bonded investment material. Both chambers of the casting machine were evacuated to 6 x 10(-2) torr; the argon pressure difference was then adjusted to either 50, 150, 300, or 450 torr. The porosity of the cast specimens was determined by x-ray radiography and quantitative image analysis. Tensile strength and elongation were measured by means of a universal testing machine at a strain rate of 1.7 x 10(-4)/s. The fractured surfaces were examined by SEM. Changes in Vickers hardness with depth from the cast surface were measured on polished cross-sections of the specimens. Raising the argon pressure difference to 300 and 450 torr caused a significant increase in internal porosity and a resultant decrease in the engineering tensile strength and elongation. The highest tensile strength (approximately 540 MPa), elongation (approximately 10%), bulk hardness (HV50g 209), and lowest porosity level (approximately 0.8%) occurred in the specimens cast at 150 torr. Turbulence of the metal during casting was thought to be responsible for the increase in porosity levels with the increase in argon pressure difference. By choosing an argon pressure difference (around 150 torr) suitable for this geometry, we could produce castings which have adequate mechanical properties and low porosity levels.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nick Cannell; Dr. Mark Samonds; Adi Sholapurwalla

The investment casting process is an expendable mold process where wax patterns of the part and rigging are molded, assembled, shelled and melted to produce a ceramic mold matching the shape of the component to be cast. Investment casting is an important manufacturing method for critical parts because of the ability to maintain dimensional shape and tolerances. However, these tolerances can be easily exceeded if the molding components do not maintain their individual shapes well. In the investment casting process there are several opportunities for the final casting shape to not maintain the intended size and shape, such as shrinkagemore » of the wax in the injection tool, the modification of the shape during shell heating, and with the thermal shrink and distortion in the casting process. Studies have been completed to look at the casting and shell distortions through the process in earlier phases of this project. Dr. Adrian Sabau at Oak Ridge National Labs performed characterizations and validations of 17-4 PH stainless steel in primarily fused silica shell systems with good agreement between analysis results and experimental data. Further tasks provided material property measurements of wax and methodology for employing a viscoelastic definition of wax materials into software. The final set of tasks involved the implementation of the findings into the commercial casting analysis software ProCAST, owned and maintained by ESI Group. This included: o the transfer of the wax material property data from its raw form into separate temperature-dependent thermophysical and mechanical property datasets o adding this wax material property data into an easily viewable and modifiable user interface within the pre-processing application of the ProCAST suite, namely PreCAST o and validating the data and viscoelastic wax model with respect to experimental results« less

Spall behavior of cast iron with varying microstructures

NASA Astrophysics Data System (ADS)

Plume, Gifford; Rousseau, Carl-Ernst

2014-07-01

The spall strength of cast iron with varying microstructures has been investigated using plate impact at moderate speed. Stress history measurements were made with manganin stress gauges embedded between the back face of the specimen and a low impedance polycarbonate backing. Five separate cast irons were tested. Four of these consisted of gray cast iron with graphite in flake form, with three classified as Type VII A2 and the fourth containing a bimodal distribution of Types VII A4 and VII D8. The fifth casting consisted of ductile cast iron with graphite in nodular form, classified as Type I, size class 5. The spall strength for the Type VII A2 gray cast irons varied between 40 and 370 MPa, and that of the additional gray cast iron, between 410 and 490 MPa. The spall strength of the ductile cast iron fell within the range of 0.94-1.2 GPa. It is shown that the spall strength is linked to the damage level at the spall plane, where an increased level of tensile stress is required to generate higher levels of damage. Post mortem analysis was performed on the recovered samples, revealing the graphite phase to be the primary factor governing the spall fracture of cast irons, where crack nucleation is directly correlated to the debonding of graphite from the metal matrix. The average length of graphite found within a casting is linked to the material's strength, where strength increases as a function of decreasing length. The morphology and mean free path of graphite precipitates further govern the subsequent coalescence of initiated cracks to form a complete fracture plane. In cases where graphite spacing is large, increased energy level is required to complete the fracture process. A secondary factor governing the spall fracture of cast irons has also been linked to the microstructure of the metal matrix, with pearlite yielding higher spall strengths than free ferrite.

Comparative study of two commercially pure titanium casting methods

PubMed Central

RODRIGUES, Renata Cristina Silveira; FARIA, Adriana Claudia Lapria; ORSI, Iara Augusta; de MATTOS, Maria da Gloria Chiarello; MACEDO, Ana Paula; RIBEIRO, Ricardo Faria

2010-01-01

The interest in using titanium to fabricate removable partial denture (RPD) frameworks has increased, but there are few studies evaluating the effects of casting methods on clasp behavior. Objective This study compared the occurrence of porosities and the retentive force of commercially pure titanium (CP Ti) and cobalt-chromium (Co-Cr) removable partial denture circumferential clasps cast by induction/centrifugation and plasma/vacuum-pressure. Material and Methods 72 frameworks were cast from CP Ti (n=36) and Co-Cr alloy (n=36; control group). For each material, 18 frameworks were casted by electromagnetic induction and injected by centrifugation, whereas the other 18 were casted by plasma and injected by vacuum-pressure. For each casting method, three subgroups (n=6) were formed: 0.25 mm, 0.50 mm, and 0.75 mm undercuts. The specimens were radiographed and subjected to an insertion/removal test simulating 5 years of framework use. Data were analyzed by ANOVA and Tukey's to compare materials and cast methods (α=0.05). Results Three of 18 specimens of the induction/centrifugation group and 9 of 18 specimens of plasma/vacuum-pressure cast presented porosities, but only 1 and 7 specimens, respectively, were rejected for simulation test. For Co-Cr alloy, no defects were found. Comparing the casting methods, statistically significant differences (p<0.05) were observed only for the Co-Cr alloy with 0.25 mm and 0.50 mm undercuts. Significant differences were found for the 0.25 mm and 0.75 mm undercuts dependent on the material used. For the 0.50 mm undercut, significant differences were found when the materials were induction casted. Conclusion Although both casting methods produced satisfactory CP Ti RPD frameworks, the occurrence of porosities was greater in the plasma/vacuum-pressure than in the induction/centrifugation method, the latter resulting in higher clasp rigidity, generating higher retention force values. PMID:21085805

Effect of surface contamination on adhesive bonding of cast pure titanium and Ti-6Al-4V alloy.

PubMed

Watanabe, I; Watanabe, E; Yoshida, K; Okabe, T

1999-03-01

There is little information regarding bond strengths of resin cements to cast titanium surfaces contaminated by investment material. This study examined the effect of surface contamination on the shear bond strength of resin cements to cast titanium and Ti-6Al-4V alloy. Two types of disks were cast from commercially pure titanium (CP-Ti) and Ti-6Al-4V alloy ingots using an argon-arc pressure casting unit and a phosphate-bonded Al2 O3 /LiAlSiO6 investment. After casting, disks were subjected to 3 surface treatments: (1) cast surface sandblasted (50 microm-sized Al2 O3 ) for 30 seconds; (2) metal surface sanded with silicon-carbide paper (600 grit) after grinding the contaminated cast surface (approximately 200 microm in thickness); and (3) metal surface sandblasted for 30 seconds after treatment 2. Surface structures were examined after each treatment with SEM and optical microscopy. Each type of disk was then bonded with 2 types of luting materials. Bonded specimens were subjected to thermocycling for up to 50,000 cycles, and shear bond strengths were determined after 0 (baseline) and 50,000 thermocycles. Results were statistically analyzed with 3-way ANOVA (P <.05). Microscopic observation of cast CP-Ti and Ti-6Al-4V exhibited noticeable structures on the cast surfaces apparently contaminated with investment material. However, there were no statistical differences (P >.05) in the bond strengths of both cements between contaminated (treatment 1) and uncontaminated surfaces (treatment 3) for both metals at baseline and after 50,000 thermocycles. The bond strength of specimens sanded with silicon-carbide paper (treatment 2) deteriorated dramatically after 50,000 thermocycles. Contamination of the cast metal surfaces by elements of the investment during casting did not affect bond strengths of the luting materials to CP-Ti and Ti-6Al-4V.

Development of an expert system for the simulation model for casting metal substructure of a metal-ceramic crown design.

PubMed

Matin, Ivan; Hadzistevic, Miodrag; Vukelic, Djordje; Potran, Michal; Brajlih, Tomaz

2017-07-01

Nowadays, the integrated CAD/CAE systems are favored solutions for the design of simulation models for casting metal substructures of metal-ceramic crowns. The worldwide authors have used different approaches to solve the problems using an expert system. Despite substantial research progress in the design of experts systems for the simulation model design and manufacturing have insufficiently considered the specifics of casting in dentistry, especially the need for further CAD, RE, CAE for the estimation of casting parameters and the control of the casting machine. The novel expert system performs the following: CAD modeling of the simulation model for casting, fast modeling of gate design, CAD eligibility and cast ability check of the model, estimation and running of the program code for the casting machine, as well as manufacturing time reduction of the metal substructure. The authors propose an integration method using common data model approach, blackboard architecture, rule-based reasoning and iterative redesign method. Arithmetic mean roughness values was determinated with constant Gauss low-pass filter (cut-off length of 2.5mm) according to ISO 4287 using Mahr MARSURF PS1. Dimensional deviation between the designed model and manufactured cast was determined using the coordinate measuring machine Zeiss Contura G2 and GOM Inspect software. The ES allows for obtaining the castings derived roughness grade number N7. The dimensional deviation between the simulation model of the metal substructure and the manufactured cast is 0.018mm. The arithmetic mean roughness values measured on the casting substructure are from 1.935µm to 2.778µm. The realized developed expert system with the integrated database is fully applicable for the observed hardware and software. Values of the arithmetic mean roughness and dimensional deviation indicate that casting substructures are surface quality, which is more than enough and useful for direct porcelain veneering. The manufacture of the substructure shows that the proposed ES allows the improvement of the design process while reducing the manufacturing time. Copyright © 2017 Elsevier B.V. All rights reserved.

The therapeutic characteristics of serial casting on congenital scoliosis: a comparison with non-congenital cases from a single-center experience.

PubMed

Cao, Jun; Zhang, Xue-Jun; Sun, Ning; Sun, Lin; Guo, Dong; Qi, Xin-Yu; Bai, Yun-Song; Sun, Bao-Sheng

2017-04-04

The therapeutic efficacy of serial casting on idiopathic scoliosis has been gradually documented. However, literatures on serial casting for congenital scoliosis (CS) remain extremely rare. This paper aimed to compare the treatment outcomes of serial casting between CS and non-CS patients to comprehensively evaluate the therapeutic characteristics of serial casting on CS patients. A total of 23 early-onset scoliosis cases were included and divided into congenital scoliosis (CS, n = 8) and non-congenital group (non-CS, n = 15). Therapeutic outcomes including the major curve Cobb angle, thoracic kyphosis angle, lumbar lodosis angle, and thoracic spine growing rate were compared between groups at precast, after the first cast, and at the latest follow-up, respectively. All patients received the first cast at the age of 3.25 ± 1.20 years and 5.70 ± 1.18 times of cast corrections. The average casting time was 17.17 ± 3.38 months, and the mean follow-up time was 23.91 ± 12.28 months. Both CS and non-CS groups had significant decrease in Cobb angle after the first cast and at the latest follow-up (all P < 0.05). Cobb angle was significantly lower in non-CS group than in CS group at both time points (all P < 0.01). The correction rate of Cobb angle was significantly higher in non-CS group than in CS group (around 50 vs. 20%, both P < 0.01). The mean thoracic growth rate was significantly lower in CS group than in non-CS group (0.72 ± 0.20 vs. 1.42 ± 0.22 cm/year, P < 0.001). At the latest follow-up, there are 2 cases receiving growing rod surgery, 8 cases wearing a brace, and 13 cases continuing serial casting. Although the therapeutic efficacy of casting on CS patients is not as good as that on non-CS patients, casting is still an efficient treatment option for CS patients to delay the need for initial surgery.

Accuracy and precision of occlusal contacts of stereolithographic casts mounted by digital interocclusal registrations.

PubMed

Krahenbuhl, Jason T; Cho, Seok-Hwan; Irelan, Jon; Bansal, Naveen K

2016-08-01

Little peer-reviewed information is available regarding the accuracy and precision of the occlusal contact reproduction of digitally mounted stereolithographic casts. The purpose of this in vitro study was to evaluate the accuracy and precision of occlusal contacts among stereolithographic casts mounted by digital occlusal registrations. Four complete anatomic dentoforms were arbitrarily mounted on a semi-adjustable articulator in maximal intercuspal position and served as the 4 different simulated patients (SP). A total of 60 digital impressions and digital interocclusal registrations were made with a digital intraoral scanner to fabricate 15 sets of mounted stereolithographic (SLA) definitive casts for each dentoform. After receiving a total of 60 SLA casts, polyvinyl siloxane (PVS) interocclusal records were made for each set. The occlusal contacts for each set of SLA casts were measured by recording the amount of light transmitted through the interocclusal records. To evaluate the accuracy between the SP and their respective SLA casts, the areas of actual contact (AC) and near contact (NC) were calculated. For precision analysis, the coefficient of variation (CoV) was used. The data was analyzed with t tests for accuracy and the McKay and Vangel test for precision (α=.05). The accuracy analysis showed a statistically significant difference between the SP and the SLA cast of each dentoform (P<.05). For the AC in all dentoforms, a significant increase was found in the areas of actual contact of SLA casts compared with the contacts present in the SP (P<.05). Conversely, for the NC in all dentoforms, a significant decrease was found in the occlusal contact areas of the SLA casts compared with the contacts in the SP (P<.05). The precision analysis demonstrated the different CoV values between AC (5.8 to 8.8%) and NC (21.4 to 44.6%) of digitally mounted SLA casts, indicating that the overall precision of the SLA cast was low. For the accuracy evaluation, statistically significant differences were found between the occlusal contacts of all digitally mounted SLA casts groups, with an increase in AC values and a decrease in NC values. For the precision assessment, the CoV values of the AC and NC showed the digitally articulated cast's inability to reproduce the uniform occlusal contacts. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

A simple technique to prolong molding time during application of a fiberglass cast: An in vitro study

PubMed Central

Ayzenberg, Mark; Narvaez, Michael; Raphael, James

2018-01-01

Casting is routinely used for acute and post-operative immobilization and remains a cornerstone in the non-operative management of fractures and deformities. The application of a properly fitted and wellmolded cast, especially for a trainee, can be challenging. We present a simple method of prolonging cure time of fiberglass cast — placing ice in the dip water. Eight-ply, fiveinch fiberglass cast was circumferentially applied to an aluminum-wrapped cardboard cylinder. An electronic, 2-channel temperature sensor (TR-71wf Temp Logger, T&D Corporation, Matsumoto, Japan), accurate to 0.1ºC and accurate to ±0.3ºC, was placed between the fourth and fifth layers of fiberglass. Thirty total casts were tested using 9±1ºC (cold), 22±1ºC (ambient), and 36±1ºC (warm) dip water. Room temperature was maintained at 24±1ºC. Cast temperatures were measured during the exothermic reaction generated by the cast curing. Peak temperatures and cure times were recorded. Cure time was defined as the point of downward deflection on the timetemperature curve immediately after peak. Cure and peak temperatures were compared among groups using analysis of variance. Mean cure time was 3.5±0.1 minutes for warm water, 5.0±0.4 minutes for ambient water and 7.0±0.5 minutes for cold water. Peak temperature, measured between layers 4 and 5 of the cast material, was 36.6±0.8ºC for warm water, 31.1±1.4ºC for ambient water and 25.2±0.5ºC for cold water. Cold afforded, on average, an additional 2 minutes (40% increase) in cure time compared to ambient water and an additional 3.5 minutes (100% increase) compared to warm water. Cure time differences were significant (P<0.001) for all groups, as were peak temperature differences (P<0.001). Temperatures concerning for development of burns were never reached. Utilizing iced dip water when casting is a simple and effective method to prolong the time available for cast application. Orthopedic residents and trainees may find this useful in learning to fabricate a high quality cast. For the experienced orthopedic surgeon, this method eliminates the need to bridge longlimb casts and facilitates the application of complex casts. PMID:29770174

Quality criteria for pure titanium casting, laboratory soldering, intraoral welding, and a device to aid in making uncontaminated castings.

PubMed

Hruska, A R; Borelli, P

1991-10-01

Procedures for casting, laboratory soldering, and intraoral welding of titanium for dental restorations are described and illustrated. Pure titanium and titanium 6A1-4Va alloy castings may be used for virtually any prosthodontic rehabilitation as well as for implants, with the proper equipment and technique.

75 FR 75964 - Non-Malleable Cast Iron Pipe Fittings From the People's Republic of China: Extension of Time...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-12-07

... DEPARTMENT OF COMMERCE International Trade Administration [A-570-875] Non-Malleable Cast Iron Pipe...-malleable cast iron pipe fittings from the People's Republic of China (``PRC''). See Initiation of...-malleable cast iron pipe fittings from the PRC within the time limits mandated by section 751(a)(3)(A) of...

75 FR 54595 - Certain Iron Construction Castings From Brazil, Canada, and the People's Republic of China: Final...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-09-08

...] Certain Iron Construction Castings From Brazil, Canada, and the People's Republic of China: Final Results... construction castings from Brazil, Canada, and the People's Republic of China (PRC), pursuant to section 751(c... antidumping duty orders\\1\\ on certain iron construction castings from Brazil, Canada, and the PRC pursuant to...

Estimation of Heat Transfer Coefficient in Squeeze Casting of Magnesium Alloy AM60 by Experimental Polynomial Extrapolation Method

NASA Astrophysics Data System (ADS)

Sun, Zhizhong; Niu, Xiaoping; Hu, Henry

In this work, a different wall-thickness 5-step (with thicknesses as 3, 5, 8, 12, 20 mm) casting mold was designed, and squeeze casting of magnesium alloy AM60 was performed in a hydraulic press. The casting-die interfacial heat transfer coefficients (IHTC) in 5-step casting were determined based on experimental thermal histories data throughout the die and inside the casting which were recorded by fine type-K thermocouples. With measured temperatures, heat flux and IHTC were evaluated using the polynomial curve fitting method. The results show that the wall thickness affects IHTC peak values significantly. The IHTC value for the thick step is higher than that for the thin steps.

Method and apparatus for planar drag strip casting

DOEpatents

Powell, John C.; Campbell, Steven L.

1991-01-01

The present invention is directed to an improved process and apparatus for strip casting. The combination of a planar flow casting nozzle positioned back from the top dead center position with an attached nozzle extension, provides an increased level of casting control and quality. The nozzle extension provides a means of containing the molten pool above the rotating substrate to increase the control of molten metal at the edges of the strip and increase the range of coating thicknesses which may be produced. The level of molten metal in the containment means is regulated to be above the level of melt supplying the casting nozzle which produces a condition of planar drag flow with the casting substrate prior to solidification.

Method and apparatus for planar drag strip casting

DOEpatents

Powell, J.C.; Campbell, S.L.

1991-11-12

The present invention is directed to an improved process and apparatus for strip casting. The combination of a planar flow casting nozzle positioned back from the top dead center position with an attached nozzle extension, provides an increased level of casting control and quality. The nozzle extension provides a means of containing the molten pool above the rotating substrate to increase the control of molten metal at the edges of the strip and increase the range of coating thicknesses which may be produced. The level of molten metal in the containment means is regulated to be above the level of melt supplying the casting nozzle which produces a condition of planar drag flow with the casting substrate prior to solidification. 5 figures.

Benefit from NASA

NASA Image and Video Library

1998-01-01

Don Sirois, an Auburn University research associate, and Bruce Strom, a mechanical engineering Co-Op Student, are evaluating the dimensional characteristics of an aluminum automobile engine casting. More accurate metal casting processes may reduce the weight of some cast metal products used in automobiles, such as engines. Research in low gravity has taken an important first step toward making metal products used in homes, automobiles, and aircraft less expensive, safer, and more durable. Auburn University and industry are partnering with NASA to develop one of the first accurate computer model predictions of molten metals and molding materials used in a manufacturing process called casting. Ford Motor Company's casting plant in Cleveland, Ohio is using NASA-sponsored computer modeling information to improve the casting process of automobile and light-truck engine blocks.

Comparison of cast materials for the treatment of congenital idiopathic clubfoot using the Ponseti method: a prospective randomized controlled trial

PubMed Central

Hui, Catherine; Joughin, Elaine; Nettel-Aguirre, Alberto; Goldstein, Simon; Harder, James; Kiefer, Gerhard; Parsons, David; Brauer, Carmen; Howard, Jason

2014-01-01

Background The Ponseti method of congenital idiopathic clubfoot correction has traditionally specified plaster of Paris (POP) as the cast material of choice; however, there are negative aspects to using POP. We sought to determine the influence of cast material (POP v. semirigid fibreglass [SRF]) on clubfoot correction using the Ponseti method. Methods Patients were randomized to POP or SRF before undergoing the Ponseti method. The primary outcome measure was the number of casts required for clubfoot correction. Secondary outcome measures included the number of casts by severity, ease of cast removal, need for Achilles tenotomy, brace compliance, deformity relapse, need for repeat casting and need for ancillary surgical procedures. Results We enrolled 30 patients: 12 randomized to POP and 18 to SRF. There was no difference in the number of casts required for clubfoot correction between the groups (p = 0.13). According to parents, removal of POP was more difficult (p < 0.001), more time consuming (p < 0.001) and required more than 1 method (p < 0.001). At a final follow-up of 30.8 months, the mean times to deformity relapse requiring repeat casting, surgery or both were 18.7 and 16.4 months for the SRF and POP groups, respectively. Conclusion There was no significant difference in the number of casts required for correction of clubfoot between the 2 materials, but SRF resulted in a more favourable parental experience, which cannot be ignored as it may have a positive impact on psychological well-being despite the increased cost associated. PMID:25078929

Pacman in the sky with shadows: the effect of cast shadows on the perceptual completion of occluded figures by chimpanzees and humans.

PubMed

Tomonaga, Masaki; Imura, Tomoko

2010-07-08

Humans readily perceive whole shapes as intact when some portions of these shapes are occluded by another object. This type of amodal completion has also been widely reported among nonhuman animals and is related to pictorial depth perception. However, the effect of a cast shadow, a critical pictorial-depth cue for amodal completion has been investigated only rarely from the comparative-cognitive perspective. In the present study, we examined this effect in chimpanzees and humans. Chimpanzees were slower in responding to a Pacman target with an occluding square than to the control condition, suggesting that participants perceptually completed the whole circle. When a cast shadow was added to the square, amodal completion occurred in both species. On the other hand, however, critical differences between the species emerged when the cast shadow was added to the Pacman figure, implying that Pacman was in the sky casting a shadow on the square. The cast shadow prevented, to a significant extent, compulsory amodal completion in humans, but had no effect on chimpanzees. These results suggest that cast shadows played a critical role in enabling humans to infer the spatial relationship between Pacman and the square. For chimpanzees, however, a cast shadow may be perceived as another "object". A limited role for cast shadows in the perception of pictorial depth has also been reported with respect to human cognitive development. Further studies on nonhuman primates using a comparative-developmental perspective will clarify the evolutionary origin of the role of cast shadows in visual perception.

Reproducibility of the index of orthognathic functional treatment need scores derived from plaster study casts and their three-dimensional digital equivalents: a pilot study.

PubMed

McCrory, Emma; McGuinness, Niall Jp; Ulhaq, Aman

2018-06-01

To determine the reproducibility of Index of Orthognathic Functional Treatment Need (IOFTN) scores derived from plaster casts and their three-dimensional (3D) digital equivalents. Pilot study, prospective analytical. UK hospital orthodontic department. Thirty casts and their digital equivalents, representing the pre-treatment malocclusions of patients requiring orthodontic-orthognathic surgical treatment, were scored by four clinicians using IOFTN. Casts were scanned using a 3Shape digital scanner and 3D models produced using OrthoAnalyzer TM (3Shape Ltd, Copenhagen, Denmark). Examiners independently determined the IOFTN scores for the casts and digital models, to test their inter- and intra-operator reliability using weighted Kappa scores. Intra-operator agreement with IOFTN major categories (1-5: treatment need) was very good for plaster casts (0.83-0.98) and good-very good for digital models (0.78-0.83). Inter-operator agreement was moderate-very good for casts (0.58-0.82) and good-very good for digital models (0.65-0.92). Intra-operator agreement with IOFTN sub-categories (1-14: feature of malocclusion) was good-very good for casts (0.70-0.97) and digital models (0.80-0.94). Inter-operator agreement was moderate-good for casts (0.53-0.77); and moderate-very good for the digital models (0.58-0.90). Digital models are an acceptable alternative to plaster casts for examining the malocclusion of patients requiring combined orthodontic-orthognathic surgical treatment and determining treatment need.

Genetic profile based upon 15 microsatellites of four caste groups of the eastern Indian state, Bihar.

PubMed

Ashma, R; Kashyap, V K

2003-01-01

The formation of caste groups among the Hindu community and the practice of endogamy exert a great impact on the genetic structure and diversity of the Indian population. Allele frequency data of 15 microsatellite loci clearly portray the genetic diversity and relatedness among four socio-culturally advanced caste groups: Brahmin, Bhumihar, Rajput and Kayasth of Caucasoid ethnicity of Bihar. The study seeks to understand the impact of the man-made caste system on the genetic profile of the four major caste groups of Bihar. Computation of average heterozygosity, most frequent allele, allele diversity and coefficient of gene differentiation (Gst), along with genetic distance (DA)and principal coordinate analysis were performed to assess intra-population and inter-population diversity. The average Gst value for all the loci was 0.012 +/- 0.0033, and the level of average heterozygosity was approximately 75.5%, indicating genetic similarity and intra-population diversity. Genetic distance (DA) values and the phylogenetic tree along with other higher caste groups of India indicate the relative distance between them. The present study clearly depicts the genetic profile of these caste groups, their inherent closeness in the past, and the impact of the imposed caste system that later restricted the gene flow. The study highlights the status of Bhumihar and Kayasth in the Hindu caste system. The former was found clustering with the Brahmin group (as expected, since Bhumihar is known to be a subclass of Brahmin), whereas the distance between the Brahmin and Kayasth caste groups was found to be large. North-eastern Indian Mongoloids form a separate cluster.

The influence of flushing time on the bonding quality of liquid white cast iron on the solid surface of similar material

NASA Astrophysics Data System (ADS)

Bandanadjaja, Beny; Purwadi, Wiwik; Idamayanti, Dewi; Lilansa, Noval; Hanaldi, Kus; Nurzaenal, Friya Kurnia

2018-05-01

Hard metal castings are widely used in the coal mill pulverizer as construction material for coal crushers. During its operation crushers and mills experience degradation caused by abrasion load. This research dealed with the surface overlaying of similiar material on the surface of white cast iron by mean of gravity casting. The die blank casting was preheated prior to the casting process of outer layer made of Ni-Hard white cast iron to guarantee bonding processes and avoid any crack. The preheating temperature of die blankin ther range of 500C up to 850C was set up to reach the interface temperature in the range of 887°C -1198°C and the flushing time was varied between 10-20 seconds. Studies carried on the microstructure of sample material revealed a formation of metallurgical bonding at the preheating temperature above 625 °C by pouring temperature ranging from 1438 °C to 1468 °C. Metallographical and chemical composition by mean of EDS examination were performed to observed the resut. This research concludes that the casting of Ni-Hard 1 overlay by applying gravity casting method can be done by preheating the surface of casting to 625 °C, interface temperature of 1150 °C, flushing time of 7 seconds and pouring temperature of 1430 °C. Excellent metallurgical bonding at the contact area between dieblank and overlay material has been achieved in which there is no parting line at the interface area to be observed.

Casting made simple using modified sprue design: an in vitro study.

PubMed

Baskaran, B Eswaran; Geetha Prabhu, K R; Prabhu, R; Krishna, G Phani; Eswaran, M A; Gajapathi, B

2014-01-01

Success in dental casting restorations for fixed partial dentures (FPDs) depends on the castability. Castability is described as the ability of an alloy to faithfully reproduce sharp detail and fine margins of a wax pattern. The goal of a prosthodontist is to provide the patient with restorations that fit precisely. Regardless of the alloy used for casting, the casting technique should yield a casted alloy, which should possess sufficient mass, surface hardness and minimal porosity after casting. Twenty patterns for casting were made from three-dimensional printed resin pattern simulating a 3 unit FPD and casted using modified sprue technique. Later test samples were cemented sequentially on stainless steel model using pressure indicating paste and evaluated for vertical marginal gap in eight predetermined reference areas. Marginal gap were measured in microns using Video Measuring System (VMS2010F-CIP Corporation, Korea). A portion of the axial wall of the cast abutments depicting premolar and molar were sectioned and embedded in acrylic resin and tested for micro hardness using Reichert Polyvar 2 Met Microhardness tester (Reichert, Austria) and porosity using Quantimet Image Analyzer (Quantimet Corporation London, England). The results obtained for marginal gap, micro hardness, and porosity of all test samples were tabulated, descriptive statistics were calculated and the values were found to be within the clinically acceptable range. The new sprue technique can be an alternative and convenient method for casting which would minimize metal wasting and less time consuming. However, further studies with same technique on various parameters are to be conducted for its broad acceptance.

Aluminum-fly ash metal matrix composites for automotive parts. [Reports for October 1 to December 1998, and January 31 to March 31, 1999

DOE Office of Scientific and Technical Information (OSTI.GOV)

Weiss, David; Purgert, Robert; Rhudy, Richard

1999-04-21

Some highlights are: (1) Material development, process development, and part validation are occurring simultaneously on a fast track schedule. (2) Prior project activity has resulted in a program emphasis on three components--manifolds, mounting brackets, and motor mounts; and three casting techniques--squeeze casting, pressure die casting, and sand casting. (3) With the project focus, it appears possible to offer manifolds and mounting brackets for automotive qualification testing on a schedule in line with the PNGV Year 2004 goal. (4) Through an iterative process of fly ash treatment, MMC ingot preparation, foundry process refinement, and parts production, both foundries (Eck Industries andmore » Thompson Aluminum Casting Company) are addressing the pre-competitive issues of: (a) Optimum castability with fly ash shapes and sizes; (b) Best mechanical properties derived from fly ash shapes and sizes; (c) Effective fly ash classification processes; (d) Mechanical properties resulting from various casting processes and fly ash formulations. Eck and TAC continued experiments with batch ingot provided by both Eck and the University of Wisconsin at Milwaukee. Castings were run that contained varying amounts of fly ash and different size fractions. Components were cast using cenosphere material to ascertain the effects of squeeze casting and to determine whether the pressure would break the cenospheres. Test parts are currently being machined into substandard test bars for mechanical testing. Also, the affect of heat treatments on ashalloy are being studied through comparison to two lots, one heat treated and one in the ''as cast'' condition.« less

Aluminum-fly ash metal matrix composites for automotive parts. [Reports for October 1 to December 31, 1999, and January 1 - to March 31, 2000

DOE Office of Scientific and Technical Information (OSTI.GOV)

Weiss, David; Purgert, Robert; Rhudy, Richard

2000-04-21

The highlights of this report are: (1) fly ash classified by less than 100 microns in size was mixed into a 300 lb melt of alloy 535 without the need of a magnesium additive; (2) a vibratory feeder fitted with a sieve was used as the means to minimize particle clustering while introducing fly ash into the aluminum alloy 535 melt; and (3) the industrial-size field test was successful in that sand mold castings and permanent mold castings of tensile bars, K mold bars, and ingots were made from aluminum alloy 535-fly ash mix. Use of aluminum alloy 535 containingmore » 7% magnesium precluded the need to introduce additional magnesium into the melt. The third round of sand mold castings as well as permanent mold castings produced components and ingots of alloy 535 instead of alloy 356. The ingots will be remelted and cast into parts to assess the improvement of flyash distribution which occurs through reheating and the solidification wetting process. Microstructure analysis continues on sand and permanent mold castings to study particle distribution in the components. A prototype sand cast intake manifold casting was found to be pressure tight which is a major performance requirement for this part. Another heat of pressure die cast brackets of A380-classified fly ash will be made to examine their strength and fly ash distribution. Ingots of A356-fly ash have been made at Eck for remelting at Thompson Aluminum for squeeze casting into motor mounts.« less

Serious infectious complications related to extremity cast/splint placement in children.

PubMed

Delasobera, B Elizabeth; Place, Rick; Howell, John; Davis, Jonathan E

2011-07-01

Extremity injuries necessitating splinting or casting are commonly seen in the emergency department (ED) setting. Subsequently, it is not uncommon for patients to present to the ED with complaints related to an extremity cast or splint. To present a literature-based approach to the identification and initial management of patients with possible infectious cast/splint complications in the ED setting. We present two cases of serious infectious complications arising from extremity cast/splint placement seen in a single pediatric ED: a case of toxic shock syndrome in an 8-year-old child, and a case of necrotizing fasciitis resulting in upper extremity amputation in a 3-year-old child. A wide spectrum of potential extremity cast/splint infectious complications may be seen, which include limb- or life-threatening infections such as toxic shock syndrome and necrotizing fasciitis. Simply considering these diagnoses, and removing the cast or splint to carefully inspect the affected extremity, are potential keys to early identification and optimal outcome of cast/splint complications. It is also prudent to maintain particular vigilance when treating a patient with a water-exposed cast, which may lead to moist padding, skin breakdown, and potential infection. In patients with suspected serious infections, aggressive fluid management and antibiotic therapy should be initiated and appropriate surgical consultation obtained without delay. Copyright © 2011 Elsevier Inc. All rights reserved.

[Cohort study of the incidence of heel pressure sores in patients with leg casts at the Rizzoli Orthopedic Hospital and of the associated risk factors].

PubMed

Forni, Cristiana; Zoli, Marina; Loro, Loretta; Tremosini, Morena; Mini, Sandra; Pirini, Valter; Turrini, Roberta; Durante, Stefano; Nicolini, Annamaria; Riccioni, Francesca; Girolami, Roberto

2009-01-01

Pressure sores, especially at the heel, are a side effect of the cast. To assess the incidence of late skin complications (heel pressure sores) of a cast and determine risk factors. All consecutive patients treated with a leg cast over a 16 months observation time were recruited. Risk factors were identified by the nurse that placed the cast and skin lesions classified with the NPUAP scale when the cast was removed. In the 216 enrolled patients 17.6% (38) developed a pressure sore: 16/124 in orthopedic wards; 22/92 in oncology wards. The multivariate analysis identified the following risk factors: administration of cytotoxic drugs (p = 0.033; OR = 2.61; having a cancer did not increase the risk); skin redness before cast application (p = 0.001; OR = 4.44) and having reported symptoms after the application (p = 0.000; OR = 7.86). Pressure sores were mainly stage 1 and only 6/216 (2.4%) > or = stage II. The type of plaster cast, the material, the number of days it was worn and having had a surgery are not significant risk factors. Pressure sores related to leg plaster casts are a frequent complication in at risk sub-groups. The acknowledgement and identification of specific risk factors may allow to identify and evaluate preventive interventions to improve the care of these patients.

Accuracy of impressions with different impression materials in angulated implants.

PubMed

Reddy, S; Prasad, K; Vakil, H; Jain, A; Chowdhary, R

2013-01-01

To evaluate the dimensional accuracy of the resultant (duplicative) casts made from two different impression materials (polyvinyl siloxane and polyether) in parallel and angulated implants. Three definitive master casts (control groups) were fabricated in dental stone with three implants, placed at equi-distance. In first group (control), all three implants were placed parallel to each other and perpendicular to the plane of the cast. In the second and third group (control), all three implants were placed at 10° and 15 o angulation respectively to the long axis of the cast, tilting towards the centre. Impressions were made with polyvinyl siloxane and polyether impression materials in a special tray, using a open tray impression technique from the master casts. These impressions were poured to obtain test casts. Three reference distances were evaluated on each test cast by using a profile projector and compared with control groups to determine the effect of combined interaction of implant angulation and impression materials on the accuracy of implant resultant cast. Statistical analysis revealed no significant difference in dimensional accuracy of the resultant casts made from two different impression materials (polyvinyl siloxane and polyether) by closed tray impression technique in parallel and angulated implants. On the basis of the results of this study, the use of both the impression materials i.e., polyether and polyvinyl siloxane impression is recommended for impression making in parallel as well as angulated implants.

Compound cast product and method for producing a compound cast product

DOEpatents

Meyer, Thomas N.; Viswanathan, Srinath

2002-09-17

A compound cast product is formed in a casting mold (14) having a mold cavity (16) sized and shaped to form the cast product. A plurality of injectors (24) is supported from a bottom side (26) of the casting mold (14). The injectors (24) are in fluid communication with the mold cavity (16) through the bottom side (26) of the casting mold (14). A molten material holder furnace (12) is located beneath the casting mold (14). The holder furnace (12) defines molten material receiving chambers (36) configured to separately contain supplies of two different molten materials (37, 38). The holder furnace (12) is positioned such that the injectors (24) extend downward into the receiving chamber (36). The receiving chamber (36) is separated into at least two different flow circuits (51, 52). A first molten material (37) is received in a first flow circuit (51), and a second molten material (38) is received into a second flow circuit (52). The first and second molten materials (37, 38) are injected into the mold cavity (16) by the injectors (24) acting against the force of gravity. The injectors (24) are positioned such that the first and second molten materials (37, 38) are injected into different areas of the mold cavity (16). The molten materials (37, 38) are allowed to solidify and the resulting compound cast product is removed from the mold cavity (16).

40 CFR 63.5810 - What are my options for meeting the standards for open molding and centrifugal casting operations...

Code of Federal Regulations, 2011 CFR

2011-07-01

... standards for open molding and centrifugal casting operations at new and existing sources? 63.5810 Section... § 63.5810 What are my options for meeting the standards for open molding and centrifugal casting... (d) of this section to meet the standards for open molding or centrifugal casting operations in Table...

40 CFR 63.5810 - What are my options for meeting the standards for open molding and centrifugal casting operations...

Code of Federal Regulations, 2010 CFR

2010-07-01

... standards for open molding and centrifugal casting operations at new and existing sources? 63.5810 Section... § 63.5810 What are my options for meeting the standards for open molding and centrifugal casting... (d) of this section to meet the standards for open molding or centrifugal casting operations in Table...

Gendered-Caste Discrimination, Human Rights Education, and the Enforcement of the Prevention of Atrocities Act in India

ERIC Educational Resources Information Center

Kapoor, Dip

2007-01-01

Despite the constitutional ban on the practice of untouchability and caste-based discrimination, this article elaborates on a gendered-caste-based discriminatory reality in rural India, the difficulties of enforcing legal remedies, and on related human rights praxis to address gendered-caste atrocities by drawing on the experiences of a Canadian…

Designing High Performance Steel Castings Today: Proceedings of the Steel Founders Society of America, Technical and Operating Conference December 7-10, 2016Chicago, IL

DTIC Science & Technology

2016-12-10

will be 2 x failure (critical) depth. G. INSPECTION REQUIREMENTS Either the No- Bake sand or Investment process is selected based on which... Bake sand and the Investment Casting Handbook by the Investment Casting Institute has the tolerance values for investment castings. Typically there

An Analysis of Industrial Technology Curriculum and Its Significance to the Casting Industry.

ERIC Educational Resources Information Center

Hauser, Roger Emmett

The purpose of this study was to determine to what extent industrial technology programs are training technologists in light of the needs of the casting industry. To determine the type of curriculum needed to prepare individuals for entry into the casting industry, and to study industrial technology programs as they relate to metal casting,…

25 CFR 217.6 - Method of casting votes.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 25 Indians 1 2010-04-01 2010-04-01 false Method of casting votes. 217.6 Section 217.6 Indians.... § 217.6 Method of casting votes. Within 30 days after an issue and any analysis provided for in §§ 217.4... superintendent in writing of the number of votes cast for and against the proposed or alternative solutions. If...

40 CFR Table 12 to Subpart Wwww of... - Data Requirements for New and Existing Continuous Lamination Lines and Continuous Casting Lines...

Code of Federal Regulations, 2010 CFR

2010-07-01

... Continuous Lamination Lines and Continuous Casting Lines Complying With a Lbs/Ton Organic HAP Emissions Limit... Requirements for New and Existing Continuous Lamination Lines and Continuous Casting Lines Complying With a Lbs... with a lbs/ton organic HAP emissions limit for continuous lamination lines and continuous casting lines...

Advanced Casting Technology

DTIC Science & Technology

1982-08-01

components with consequent cost and weight benefits but there is traditionally a reluctance by designers to trust castings. The object of the...Specialist Meeting was to present the current state of developments of advanced casting technology, and to bring together designers and materials and...significantly in the near future. The discussion highlighted areas needing further attention, which included: — Designers need to design for casting, not

New methods and materials for molding and casting ice formations

NASA Technical Reports Server (NTRS)

Reehorst, Andrew L.; Richter, G. Paul

1987-01-01

This study was designed to find improved materials and techniques for molding and casting natural or simulated ice shapes that could replace the wax and plaster method. By utilizing modern molding and casting materials and techniques, a new methodology was developed that provides excellent reproduction, low-temperature capability, and reasonable turnaround time. The resulting casts are accurate and tough.

Quality Management and Control of Low Pressure Cast Aluminum Alloy

NASA Astrophysics Data System (ADS)

Zhang, Dianxi; Zhang, Yanbo; Yang, Xiufan; Chen, Zhaosong; Jiang, Zelan

2018-01-01

This paper briefly reviews the history of low pressure casting and summarizes the major production processes of low pressure casting. It briefly introduces the quality management and control of low pressure cast aluminum alloy. The main processes include are: preparation of raw materials, Melting, refining, physical and chemical analysis, K-mode inspection, sand core, mold, heat treatment and so on.

Ageless Aluminum-Cerium-Based Alloys in High-Volume Die Casting for Improved Energy Efficiency

DOE PAGES

Stromme, Eric T.; Henderson, Hunter B.; Sims, Zachary C.; ...

2018-04-25

Strong chemical reactions between Al and Ce lead to the formation of intermetallics with exceptional thermal stability. The rapid formation of intermetallics directly from the liquid phase during solidification of Al-Ce alloys leads to an ultrafine microconstituent structure that effectively strengthens as-cast alloys without further microstructural optimization via thermal processing. Die casting is a high-volume manufacturing technology that accounts for greater than 40% of all cast Al products, whereas Ce is highly overproduced as a waste product of other rare earth element (REE) mining. Reducing heat treatments would stimulate significant improvements in manufacturing energy efficiency, exceeding (megatonnes/year) per large-scale heat-treatmentmore » line. In this study, multiple compositions were evaluated with wedge mold castings to test the sensitivity of alloys to the variable solidification rate inherent in high-pressure die casting. Once a suitable composition was determined, it was successfully demonstrated at 800 lbs/h in a 600-ton die caster, after which the as-die cast parts performed similarly to ubiquitous A380 in the same geometry without requiring heat treatment. Furthermore, this work demonstrates the compatibility of Al REE alloys with high-volume die-casting applications with minimal heat treatments.« less

Prediction of Shrinkage Porosity Defect in Sand Casting Process of LM25

NASA Astrophysics Data System (ADS)

Rathod, Hardik; Dhulia, Jay K.; Maniar, Nirav P.

2017-08-01

In the present worldwide and aggressive environment, foundry commercial enterprises need to perform productively with least number of rejections and create casting parts in shortest lead time. It has become extremely difficult for foundry industries to meet demands of defects free casting and meet strict delivery schedules. The process of casting solidification is complex in nature. Prediction of shrinkage defect in metal casting is one of the critical concern in foundries and is one of the potential research areas in casting. Due to increasing pressure to improve quality and to reduce cost, it is very essential to upgrade the level of current methodology used in foundries. In the present research work, prediction methodology of shrinkage porosity defect in sand casting process of LM25 using experimentation and ANSYS is proposed. The objectives successfully achieved are prediction of shrinkage porosity distribution in Al-Si casting and determining effectiveness of investigated function for predicting shrinkage porosity by correlating results of simulating studies to those obtained experimentally. The real-time application of the research reflects from the fact that experimentation is performed on 9 different Y junctions at foundry industry and practical data obtained from experimentation are used for simulation.

Ageless Aluminum-Cerium-Based Alloys in High-Volume Die Casting for Improved Energy Efficiency

NASA Astrophysics Data System (ADS)

Stromme, Eric T.; Henderson, Hunter B.; Sims, Zachary C.; Kesler, Michael S.; Weiss, David; Ott, Ryan T.; Meng, Fanqiang; Kassoumeh, Sam; Evangelista, James; Begley, Gerald; Rios, Orlando

2018-06-01

Strong chemical reactions between Al and Ce lead to the formation of intermetallics with exceptional thermal stability. The rapid formation of intermetallics directly from the liquid phase during solidification of Al-Ce alloys leads to an ultrafine microconstituent structure that effectively strengthens as-cast alloys without further microstructural optimization via thermal processing. Die casting is a high-volume manufacturing technology that accounts for greater than 40% of all cast Al products, whereas Ce is highly overproduced as a waste product of other rare earth element (REE) mining. Reducing heat treatments would stimulate significant improvements in manufacturing energy efficiency, exceeding (megatonnes/year) per large-scale heat-treatment line. In this study, multiple compositions were evaluated with wedge mold castings to test the sensitivity of alloys to the variable solidification rate inherent in high-pressure die casting. Once a suitable composition was determined, it was successfully demonstrated at 800 lbs/h in a 600-ton die caster, after which the as-die cast parts performed similarly to ubiquitous A380 in the same geometry without requiring heat treatment. This work demonstrates the compatibility of Al REE alloys with high-volume die-casting applications with minimal heat treatments.

Ageless Aluminum-Cerium-Based Alloys in High-Volume Die Casting for Improved Energy Efficiency

NASA Astrophysics Data System (ADS)

Stromme, Eric T.; Henderson, Hunter B.; Sims, Zachary C.; Kesler, Michael S.; Weiss, David; Ott, Ryan T.; Meng, Fanqiang; Kassoumeh, Sam; Evangelista, James; Begley, Gerald; Rios, Orlando

2018-04-01

Strong chemical reactions between Al and Ce lead to the formation of intermetallics with exceptional thermal stability. The rapid formation of intermetallics directly from the liquid phase during solidification of Al-Ce alloys leads to an ultrafine microconstituent structure that effectively strengthens as-cast alloys without further microstructural optimization via thermal processing. Die casting is a high-volume manufacturing technology that accounts for greater than 40% of all cast Al products, whereas Ce is highly overproduced as a waste product of other rare earth element (REE) mining. Reducing heat treatments would stimulate significant improvements in manufacturing energy efficiency, exceeding (megatonnes/year) per large-scale heat-treatment line. In this study, multiple compositions were evaluated with wedge mold castings to test the sensitivity of alloys to the variable solidification rate inherent in high-pressure die casting. Once a suitable composition was determined, it was successfully demonstrated at 800 lbs/h in a 600-ton die caster, after which the as-die cast parts performed similarly to ubiquitous A380 in the same geometry without requiring heat treatment. This work demonstrates the compatibility of Al REE alloys with high-volume die-casting applications with minimal heat treatments.

Ageless Aluminum-Cerium-Based Alloys in High-Volume Die Casting for Improved Energy Efficiency

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stromme, Eric T.; Henderson, Hunter B.; Sims, Zachary C.

Strong chemical reactions between Al and Ce lead to the formation of intermetallics with exceptional thermal stability. The rapid formation of intermetallics directly from the liquid phase during solidification of Al-Ce alloys leads to an ultrafine microconstituent structure that effectively strengthens as-cast alloys without further microstructural optimization via thermal processing. Die casting is a high-volume manufacturing technology that accounts for greater than 40% of all cast Al products, whereas Ce is highly overproduced as a waste product of other rare earth element (REE) mining. Reducing heat treatments would stimulate significant improvements in manufacturing energy efficiency, exceeding (megatonnes/year) per large-scale heat-treatmentmore » line. In this study, multiple compositions were evaluated with wedge mold castings to test the sensitivity of alloys to the variable solidification rate inherent in high-pressure die casting. Once a suitable composition was determined, it was successfully demonstrated at 800 lbs/h in a 600-ton die caster, after which the as-die cast parts performed similarly to ubiquitous A380 in the same geometry without requiring heat treatment. Furthermore, this work demonstrates the compatibility of Al REE alloys with high-volume die-casting applications with minimal heat treatments.« less

Geometrical effects of conventional and digital prosthodontic planning wax-ups on lateral occlusal contact number, contact area, and steepness.

PubMed

Abduo, Jaafar

2017-01-01

This study evaluated and compared the effect of conventional and digital wax-ups on three lateral occlusion variables: contact number, contact area, and steepness. Dental casts of 10 patients with Angle Class I relationship were included in the study. All patients required fixed prosthodontic treatment that would affect lateral occlusion. The casts of all patients received conventional and digital wax-ups. For pretreatment, conventional wax-up, and digital wax-up casts, contact number, contact area, and occlusion steepness were measured at four lateral positions, that is, at excursions of 0.5, 1.0, 2.0, and 3.0 mm from maximal intercuspation. Lateral occlusion scheme variables were affected by use of diagnostic wax-ups. For all types of casts, contact number decreased as excursion increased. The two types of wax-ups had similar contact number patterns, and contact number was significantly greater for these casts than for pretreatment casts in the earlier stages of excursion. Similarly, contact area gradually decreased with increasing excursion in the pretreatment and conventional and digital wax-up casts. There was only a minimal decrease in occlusion steepness as excursion increased. However, lateral occlusion was generally steeper for digital wax-up casts.

Micro-structure and Air-tightness of Squeeze Casting Motor housing for New Energy Vehicle

NASA Astrophysics Data System (ADS)

Jiang, Y. F.; Kang, Z. Q.; Jiang, W. F.; Wang, K. W.; Sha, D. L.; Li, M. L.; Sun, J.

2018-05-01

In order to improve the performance of automobile parts, the influence of squeeze casting process parameters on casting defects, material structure and air-tightness of aluminum alloy motor housing for new energy vehicle was studied. The results show that the density of the castings increases with the increase in pressure and mold temperature. With increase in pouring temperature, it increases first and then decreases. Pressure has the greatest influence on the density of the castings. Under a certain pressure, with moderate increase in casting temperature and mold temperature, the grain growth begins to increase; the dendrites become less, the new α - Al grains are spherical and granular, the micro-structure is uniform. Also, with increase in pressure, this effect is more pronounced, the air-tightness of castings improve. In conclusion, when the pressure is 110MPa, pouring temperature is 680° C, mold temperature is 280° C, pressure holding for 30s, and punch speed of 0.1m/s, there is no clear shrinkage in the casting, the structure is uniform, the qualified rate of air-tightness of production reaches 86%, and the performance is excellent.

Fabrication of silk fibroin film using centrifugal casting technique for corneal tissue engineering.

PubMed

Lee, Min Chae; Kim, Dong-Kyu; Lee, Ok Joo; Kim, Jung-Ho; Ju, Hyung Woo; Lee, Jung Min; Moon, Bo Mi; Park, Hyun Jung; Kim, Dong Wook; Kim, Su Hyeon; Park, Chan Hum

2016-04-01

Films prepared from silk fibroin have shown potential as biomaterials in tissue engineering applications for the eye. Here, we present a novel process for fabrication of silk fibroin films for corneal application. In this work, fabrication of silk fibroin films was simply achieved by centrifugal force. In contrast to the conventional dry casting method, we carried out the new process in a centrifuge with a rotating speed of 4000 rpm, where centrifugal force was imposed on an aluminum tube containing silk fibroin solution. In the present study, we also compared the surface roughness, mechanical properties, transparency, and cell proliferation between centrifugal and dry casting method. In terms of surface morphology, films fabricated by the centrifugal casting have less surface roughness than those by the dry casting. For elasticity and transparency, silk fibroin films obtained from the centrifugal casting had favorable results compared with those prepared by dry casting. Furthermore, primary human corneal keratocytes grew better in films prepared by the centrifugal casting. Therefore, our results suggest that this new fabrication process for silk fibroin films offers important potential benefits for corneal tissue regeneration. © 2015 Wiley Periodicals, Inc.

AMCC casting development. Volume 1: Executive Summary

NASA Technical Reports Server (NTRS)

1995-01-01

The Advanced Combustion Chamber Casting (AMCC) has been a technically challenging part due to its size, configuration, and alloy type. The height and weight of the wax pattern assembly necessitated the development of a hollow gating system to ensure structural integrity of the shell throughout the investment process. The complexity in the jacket area of the casting required the development of an innovative casting technology that PCC has termed 'TGC' or Thermal Gradient Control. This method, of setting up thermal gradients in the casting during solidification, represents a significant process improvement for PCC and has been successfully implemented on other programs. Metallurgical integrity of the final four castings was very good. Only the areas of the parts that utilized 'TGC Shape & Location System #2' showed any significant areas of microshrinkage when evaluated by non-destructive tests. Alumina oxides detected by FPI on the 'float' surfaces (top sid surfaces of the casting during solidification) of the part were almost entirely less than the acceptance criteria of .032 inches in diameter. Destructive chem mill of the castings was required to determine the effect of the process variables used during the processing of these last four parts (with the exception of the 'Shape & Location of TGC' variable).

Development of cast alumina-forming austenitic stainless steels

DOE PAGES

Muralidharan, G.; Yamamoto, Y.; Brady, M. P.; ...

2016-09-06

Cast Fe-Ni-Cr chromia-forming austenitic stainless steels with Ni levels up to 45 wt. % are used at high temperatures in a wide range of industrial applications that demand microstructural stability, corrosion resistance, and creep strength. Although alumina scales offer better corrosion protection at these temperatures, designing cast austenitic alloys that form a stable alumina scale and achieve creep strength comparable to existing cast chromia-forming alloys is challenging. This work outlines the development of cast Fe-Ni-Cr-Al austenitic stainless steels containing about 25 wt. % Ni with good creep strength and the ability to form a protective alumina scale for use atmore » temperatures up to 800 C - 850 C in H 2O-, S-, and C- containing environments. Creep properties of the best alloy were comparable to that of HK-type cast chromia-forming alloy along with improved oxidation resistance typical of alumina-forming alloys. Lastly, challenges in the design of cast alloys and a potential path to increasing the temperature capability are discussed.« less

The Effect of Alloying Elements on Thermal Conductivity and Casting Characteristic in High Pressure Die Casting of Aluminum Alloy

NASA Astrophysics Data System (ADS)

Kim, Cheol-Woo; Cho, Jae-Ik; Choi, Se-Weon; Kim, Young-Chan; Kang, Chang-Seog

Recently, demand of aluminum alloys for use in high thermal conductivity application is increases but the most aluminum die casting alloys exhibit very lower thermal properties because of their high concentrations of alloying elements. However, those alloying elements are essential to obtain sufficient fluidity and mechanical strength. Therefore, the purpose of this study is to analyze the effect of alloying elements in die casting alloys, Si, Cu, Mg, Fe and Mn, in thermal conductivity, die casting characteristics and mechanical properties and find out the appropriate amount of each alloying element for development of heat sink component. The results showed that Mn had the most deleterious effect in thermal conductivity and Si and Fe contents were important to improve strength and limit casting defects, such as hot tearing and die soldering. The alloy with 0.2 1.0wt%Cu, 0.3 0.6wt%Fe and 1.0 2.0wt%Si showed very good combination of high thermal conductivity and good casting characteristics.

Development, fabrication and test of a high purity silica heat shield

NASA Technical Reports Server (NTRS)

Rusert, E. L.; Drennan, D. N.; Biggs, M. S.

1978-01-01

A highly reflective hyperpure ( 25 ppm ion impurities) slip cast fused silica heat shield material developed for planetary entry probes was successfully scaled up. Process development activities for slip casting large parts included green strength improvements, casting slip preparation, aggregate casting, strength, reflectance, and subscale fabrication. Successful fabrication of a one-half scale Saturn probe (shape and size) heat shield was accomplished while maintaining the silica high purity and reflectance through the scale-up process. However, stress analysis of this original aggregate slip cast material indicated a small margin of safety (MS. = +4%) using a factor of safety of 1.25. An alternate hyperpure material formulation to increase the strength and toughness for a greater safety margin was evaluated. The alternate material incorporates short hyperpure silica fibers into the casting slip. The best formulation evaluated has a 50% by weight fiber addition resulting in an 80% increase in flexural strength and a 170% increase in toughness over the original aggregate slip cast materials with comparable reflectance.

Development of Cast Alumina-Forming Austenitic Stainless Steels

NASA Astrophysics Data System (ADS)

Muralidharan, G.; Yamamoto, Y.; Brady, M. P.; Walker, L. R.; Meyer, H. M., III; Leonard, D. N.

2016-11-01

Cast Fe-Ni-Cr chromia-forming austenitic stainless steels with Ni levels up to 45 wt.% are used at high temperatures in a wide range of industrial applications that demand microstructural stability, corrosion resistance, and creep strength. Although alumina scales offer better corrosion protection at these temperatures, designing cast austenitic alloys that form a stable alumina scale and achieve creep strength comparable to existing cast chromia-forming alloys is challenging. This work outlines the development of cast Fe-Ni-Cr-Al austenitic stainless steels containing about 25 wt.% Ni with good creep strength and the ability to form a protective alumina scale for use at temperatures up to 800-850°C in H2O-, S-, and C-containing environments. Creep properties of the best alloy were comparable to that of HK-type cast chromia-forming alloys along with improved oxidation resistance typical of alumina-forming alloys. Challenges in the design of cast alloys and a potential path to increasing the temperature capability are discussed.

Thin Gauge Twin-Roll Casting, Process Capabilities and Product Quality

NASA Astrophysics Data System (ADS)

Daaland, O.; Espedal, A. B.; Nedreberg, M. L.; Alvestad, I.

Traditionally industrial twin roll casters have been operated at gauges 6-10 mm, depending on the type of caster and the final product requirements. Over the past few years it has become apparent that a significant increase in productivity can be achieved when the casting gauge is reduced. Hydro Aluminium embarked on an extensive research and development, thin gauge casting programme, in the beginning of the 1990's and this paper presents some results from a five year lasting project (joint programme between Hydro Aluminium a.s. and Lauener Engineering). Based on more than 400 casting trials the major benefits and limitations of casting at reduced gauge and increased speed are outlined. Important aspects related to process development and product quality are discussed including: productivity and limitations, surface defects, microstructural characteristics, cooling rates and dendrite structure, segregation behaviour and mechanical properties after thermo-mechanical processing. Results for casting of several alloys are given. Additionally, numerical modelling results of the strip casting process are included.

Simulation of cracking cores when molding piston components

NASA Astrophysics Data System (ADS)

Petrenko, Alena; Soukup, Josef

2014-08-01

The article deals with pistons casting made from aluminum alloy. Pistons are casting at steel mold with steel core. The casting is provided by gravity casting machine. The each machine is equipped by two metal molds, which are preheated above temperature 160 °C before use. The steel core is also preheated by flame. The metal molds and cores are heated up within the casting process. The temperature of the metal mold raise up to 200 °C and temperature of core is higher. The surface of the core is treated by nitration. The mold and core are cooled down by water during casting process. The core is overheated and its top part is finally cracked despite its intensive water-cooling. The life time cycle of the core is decreased to approximately 5 to 15 thousands casting, which is only 15 % of life time cycle of core for production of other pistons. The article presents the temperature analysis of the core.

Influence of rotational speed of centrifugal casting process on appearance, microstructure, and sliding wear behaviour of Al-2Si cast alloy

NASA Astrophysics Data System (ADS)

Mukunda, P. G.; Shailesh, Rao A.; Rao, Shrikantha S.

2010-02-01

Although the manner in which the molten metal flows plays a major role in the formation of the uniform cylinder in centrifugal casting, not much information is available on this topic. The flow in the molten metal differs at various rotational speeds, which in turn affects the final casting. In this paper, the influence of the flow of molten metal of hyper eutectic Al-2Si alloys at various rotational speeds is discussed. At an optimum speed of 800 rpm, a uniform cylinder was formed. For the rotational speeds below and above these speeds, an irregular shaped casting was formed, which is mainly due to the influence of melt. Primary á-Al particles were formed in the tube periphery at low rotational speed, and their sizes and shapes were altered with changes in rotational speeds. The wear test for the inner surface of the casting showed better wear properties for the casting prepared at the optimum speed of rotation.

Effect of Heating Time on Hardness Properties of Laser Clad Gray Cast Iron Surface

NASA Astrophysics Data System (ADS)

Norhafzan, B.; Aqida, S. N.; Mifthal, F.; Zulhishamuddin, A. R.; Ismail, I.

2018-03-01

This paper presents effect of heating time on cladded gray cast iron. In this study, the effect of heating time on cladded gray cast iron and melted gray cast iron were analysed. The gray cast iron sample were added with mixed Mo-Cr powder using laser cladding technique. The mixed Mo and Cr powder was pre-placed on gray cast iron surface. Modified layer were sectioned using diamond blade cutter and polish using SiC abrasive paper before heated. Sample was heated in furnace for 15, 30 and 45 minutes at 650 °C and cool down in room temperature. Metallographic study was conduct using inverted microscope while surface hardness properties were tested using Wilson hardness test with Vickers scale. Results for metallographic study showed graphite flakes within matrix of pearlite. The surface hardness for modified layer decreased when increased heating time process. These findings are significant to structure stability of laser cladded gray cast iron with different heating times.

The development of ultrahigh strength low alloy cast steels with increased toughness

NASA Astrophysics Data System (ADS)

Lynch, Paul C.

This work describes the initial work on the development of the next generation of ultrahigh strength low alloy (UHSLA) cast steels. These UHSLA cast steels have both ultrahigh strength levels and good impact toughness. The influence of heat treatment, secondary processing using hot isostatic processing (HIP), and chemical composition on the microstructure and properties of UHSLA cast steels have been evaluated. The extent of microsegregation reduction expected during the heat treatment of UHSLA cast steels has also been estimated by diffusion modeling. This new family of UHSLA cast steels is similar in composition and properties to UHSLA wrought steels. However, the heat treatment and secondary processing of the UHSLA cast steels is used to develop microstructures and properties typically developed through thermomechanical processing and heat treatment for wrought UHSLA steels. Two martensitic UHSLA steels, 4340+ (silicon modified 4340) and ES-1 were investigated for this study. For the 4340+ alloy, heat treatment variables evaluated include homogenization temperature and time, tempering temperature, and austempering temperature and time. For the ES-1 alloy, heat treatment variables evaluated include homogenization temperature and time, austenization temperature, cryogenic treatment, and tempering temperature. The effect of high temperature hot isostatic processing (HIP) on the 4340+ and ES- 1 alloys was also investigated. Tensile properties, charpy v-notch impact toughness (CVN), microstructures, and fractographs have all been characterized after heat treatment. The effects of HIP on microporosity reduction in the ES-1 alloy were also investigated. The experiments carried out on the investment cast 4340+ alloy have shown that increasing the homogenization temperature can increase CVN without changing the ultimate tensile strength (UTS) or yield strength (YS) of the cast material. By replacing the homogenization step in the conventional heat treatment process with a high temperature HIP treatment, both the CVN and ductility of the alloy was found to increase while maintaining comparable ultimate tensile strength (UTS) and yield strength (YS) levels as compared to the original homogenization treatment. Austempering the (IC) 4340+ material led to a significant increase in CVN and ductility at the expense of UTS and yield strength as the primarily martensitic microstructure was converted to a mixed martensitic-bainitic structure. An initial heat of induction melted, aluminum deoxidized investment cast ES-1 with 0.06 wt % of aluminum showed that the average -40°F and +72°F impact toughness, % elongation, and UTS and YS of the fully heat treated investment cast + HIP ES-1 material lagged significantly behind that of the vacuum degassed cast + HIP ES-1 ingot material. Even though the % elongation and impact toughness of the investment cast ES-1 material changed between heat treatment conditions, the average UTS and YS values remained relatively unchanged throughout the heat treatments for the investment cast study. Etched micrographs of the investment cast ES-1 material showed evidence of significant differences in microsegregation reduction between the samples homogenized at 2125°F for 4 hours and those not homogenized at 2125°F for 4 hours. SEM fracture surface work performed on the investment cast material clearly showed that the induction melted investment and aluminum killed cast material contained significant amounts of MnS and Al2O3 inclusions that were not discovered in the vacuum degassed cast ingot material. Lastly, the results of a third heat of induction melted, aluminum deoxidized investment cast ES-1 material possessing just 0.01wt% of aluminum showed that the decrease in aluminum content from the first experimental heat did not improve the mechanical properties of the investment cast material. (Abstract shortened by UMI.)

Numerical simulation and optimization of casting process for complex pump

NASA Astrophysics Data System (ADS)

Liu, Xueqin; Dong, Anping; Wang, Donghong; Lu, Yanling; Zhu, Guoliang

2017-09-01

The complex shape of the casting pump body has large complicated structure and uniform wall thickness, which easy give rise to casting defects. The numerical simulation software ProCAST is used to simulate the initial top gating process, after analysis of the material and structure characteristics of the high-pressure pump. The filling process was overall smooth, not there the water shortage phenomenon. But the circular shrinkage defects appear at the bottom of casting during solidification process. Then, the casting parameters were optimized and adding cold iron in the bottom. The shrinkage weight was reduced from 0.00167g to 0.0005g. The porosity volume was reduced from 1.39cm3 to 0.41cm3. The optimization scheme is simulated and actual experimented. The defect has been significantly improved.

Tuning the properties of polyhydroxybutyrate films using acetic acid via solvent casting

PubMed Central

Anbukarasu, Preetam; Sauvageau, Dominic; Elias, Anastasia

2015-01-01

Biodegradable polyhydroxybutyrate (PHB) films were fabricated using acetic acid as an alternative to common solvents such as chloroform. The PHB films were prepared using a solvent casting process at temperatures ranging from 80 °C to 160 °C. The crystallinity, mechanical properties and surface morphology of the films cast at different temperatures were characterized and compared to PHB films cast using chloroform as a solvent. Results revealed that the properties of the PHB film varied considerably with solvent casting temperature. In general, samples processed with acetic acid at low temperatures had comparable mechanical properties to PHB cast using chloroform. This acetic acid based method is environmentally friendly, cost efficient and allows more flexible processing conditions and broader ranges of polymer properties than traditional methods. PMID:26640089

Tuning the properties of polyhydroxybutyrate films using acetic acid via solvent casting

NASA Astrophysics Data System (ADS)

Anbukarasu, Preetam; Sauvageau, Dominic; Elias, Anastasia

2015-12-01

Biodegradable polyhydroxybutyrate (PHB) films were fabricated using acetic acid as an alternative to common solvents such as chloroform. The PHB films were prepared using a solvent casting process at temperatures ranging from 80 °C to 160 °C. The crystallinity, mechanical properties and surface morphology of the films cast at different temperatures were characterized and compared to PHB films cast using chloroform as a solvent. Results revealed that the properties of the PHB film varied considerably with solvent casting temperature. In general, samples processed with acetic acid at low temperatures had comparable mechanical properties to PHB cast using chloroform. This acetic acid based method is environmentally friendly, cost efficient and allows more flexible processing conditions and broader ranges of polymer properties than traditional methods.

Cast abscess: a case report.

PubMed

Carmichael, Kelly D; Goucher, Nicholas R

2006-01-01

This report describes a case in which a pediatric patient wounded his ankle when he stuck an object inside the cast while trying to scratch himself. The wound became infected and resulted in a limb-threatening abscess. Although most patients treated with casts do not have any significant problems, it is important to emphasize cast care instructions to young patients and their parents. In addition, it may be equally important to advise patients about safe methods to alleviate itching, such as blowing cool air under the cast. In this way, the risk of serious infectious complications can be minimized.

Influence of time of placement of investments for burnout and the type of rings being used on the casting accuracy.

PubMed

Shah, Shabir A; Naqash, Talib Amin; Padmanabhan, T V; Subramanium; Lambodaran; Nazir, Shazana

2014-03-01

The sole objective of casting procedure is to provide a metallic duplication of missing tooth structure, with as great accuracy as possible. The ability to produce well fitting castings require strict adherence to certain fundamentals. A study was undertaken to comparatively evaluate the effect on casting accuracy by subjecting the invested wax patterns to burnout after different time intervals. The effect on casting accuracy using metal ring into a pre heated burnout furnace and using split ring was also carried. The readings obtained were tabulated and subjected to statistical analysis.

[Exploring a new method for superimposition of pre-treatment and post-treatment mandibular digital dental casts in adults].

PubMed

Dai, F F; Liu, Y; Xu, T M; Chen, G

2018-04-18

To explore a cone beam computed tomography (CBCT)-independent method for mandibular digital dental cast superimposition to evaluate three-dimensional (3D) mandibular tooth movement after orthodontic treatment in adults, and to evaluate the accuracy of this method. Fifteen post-extraction orthodontic treatment adults from the Department of Orthodontics, Peking University School and Hospital of Stomatology were included. All the patients had four first premolars extracted, and were treated with straight wire appliance. The pre- and post-treatment plaster dental casts and craniofacial CBCT scans were obtained. The plaster dental casts were transferred to digital dental casts by 3D laser scanning, and lateral cephalograms were created from the craniofacial CBCT scans by orthogonal projection. The lateral cephalogram-based mandibular digital dental cast superimposition was achieved by sequential maxillary dental cast superimposition registered on the palatal stable region, occlusal transfer, and adjustment of mandibular rotation and translation obtained from lateral cephalogram superimposition. The accuracy of the lateral cephalogram-based mandibular digital dental cast superimposition method was evaluated with the CBCT-based mandibular digital dental cast superimposition method as the standard reference. After mandibular digital dental cast superimposition using both methods, 3D coordinate system was established, and 3D displacements of the lower bilateral first molars, canines and central incisors were measured. Differences between the two superimposition methods in tooth displacement measurements were assessed using the paired t-test with the level of statistical significance set at P<0.05. No significant differences were found between the lateral cephalogram-based and CBCT-based mandibular digital dental cast superimposition methods in 3D displacements of the lower first molars, and sagittal and vertical displacements of the canines and central incisors; transverse displacements of the canines and central incisors differed by (0.3±0.5) mm with statistical significance. The lateral cephalogram-based mandibular digital dental cast superimposition method has the similar accuracy as the CBCT-based mandibular digital dental cast superimposition method in 3D evaluation of mandibular orthodontic tooth displacement, except for minor differences for the transverse displacements of anterior teeth. This method is applicable to adult patients with conventional orthodontic treatment records, especially the previous precious orthodontic data in the absence of CBCT scans.

Accuracy of single-abutment digital cast obtained using intraoral and cast scanners.

PubMed

Lee, Jae-Jun; Jeong, Ii-Do; Park, Jin-Young; Jeon, Jin-Hun; Kim, Ji-Hwan; Kim, Woong-Chul

2017-02-01

Scanners are frequently used in the fabrication of dental prostheses. However, the accuracy of these scanners is variable, and little information is available. The purpose of this in vitro study was to compare the accuracy of cast scanners with that of intraoral scanners by using different image impression techniques. A poly(methyl methacrylate) master model was fabricated to replicate a maxillary first molar single-abutment tooth model. The master model was scanned with an accurate engineering scanner to obtain a true value (n=1) and with 2 intraoral scanners (CEREC Bluecam and CEREC Omnicam; n=6 each). The cast scanner scanned the master model and duplicated the dental stone cast from the master model (n=6). The trueness and precision of the data were measured using a 3-dimensional analysis program. The Kruskal-Wallis test was used to compare the different sets of scanning data, followed by a post hoc Mann-Whitney U test with a significance level modified by Bonferroni correction (α/6=.0083). The type 1 error level (α) was set at .05. The trueness value (root mean square: mean ±standard deviation) was 17.5 ±1.8 μm for the Bluecam, 13.8 ±1.4 μm for the Omnicam, 17.4 ±1.7 μm for cast scanner 1, and 12.3 ±0.1 μm for cast scanner 2. The differences between the Bluecam and the cast scanner 1 and between the Omnicam and the cast scanner 2 were not statistically significant (P>.0083), but a statistically significant difference was found between all the other pairs (P<.0083). The precision of the scanners was 12.7 ±2.6 μm for the Bluecam, 12.5 ±3.7 μm for the Omnicam, 9.2 ±1.2 μm for cast scanner 1, and 6.9 ±2.6 μm for cast scanner 2. The differences between Bluecam and Omnicam and between Omnicam and cast scanner 1 were not statistically significant (P>.0083), but there was a statistically significant difference between all the other pairs (P<.0083). An Omnicam in video image impression had better trueness than a cast scanner but with a similar level of precision. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

40 CFR 421.1 - Applicability.

Code of Federal Regulations, 2010 CFR

2010-07-01

... to alloying or casting of nonferrous metals is limited to alloying or casting of hot metal directly... cooling is included in the aluminum forming, nonferrous metals forming, or metal molding and casting point...

Methods and apparatuses for manufacturing monocrystalline cast silicon and monocrystalline cast silicon bodies for photovoltaics

DOEpatents

Stoddard, Nathan G [Gettysburg, PA

2011-11-01

Methods and apparatuses are provided for casting silicon for photovoltaic cells and other applications. With such methods and apparatuses, a cast body of monocrystalline silicon may be formed that is free of, or substantially free of, radially-distributed impurities and defects and having at least two dimensions that are each at least about 35 cm is provided.

Evaluation of three variables affecting the casting of base metal alloys.

PubMed

Wight, T A; Grisius, R J; Gaugler, R W

1980-04-01

All the vented samples with sprue widths of 2 mm or more were defect free, whereas the corresponding unvented samples had extensive voids and porosity in all but one casting. All castings with a sprue width of 1 mm were defective regardless of whether or not vents were used. The thickness of the investment above the pattern had no effect on casting results.

Study of the pore structure of ceramics prepared by the slip casting method

NASA Technical Reports Server (NTRS)

Guzman, I. Y.; Dobysh, A. V.

1984-01-01

The porosity of the slip cast Si3N4 is similar to that of pressed Si3N4 formed at 2500 kg/sq cm. The porosity of cast Si oxynitride is equivalent to that of samples stressed at 10,000 kg/sq cm. Crucibles formed from these materials by slip casting have high thermal shock and corrosion resistance.

Cast dielectric composite linear accelerator

DOEpatents

Sanders, David M [Livermore, CA; Sampayan, Stephen [Manteca, CA; Slenes, Kirk [Albuquerque, NM; Stoller, H M [Albuquerque, NM

2009-11-10

A linear accelerator having cast dielectric composite layers integrally formed with conductor electrodes in a solventless fabrication process, with the cast dielectric composite preferably having a nanoparticle filler in an organic polymer such as a thermosetting resin. By incorporating this cast dielectric composite the dielectric constant of critical insulating layers of the transmission lines of the accelerator are increased while simultaneously maintaining high dielectric strengths for the accelerator.

Energy Saving Melting and Revert Reduction Technology (Energy-SMARRT): Clean Steel Casting Production

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kuyucak, Selcuk; Li, Delin

2013-12-31

Inclusions in steel castings can cause rework, scrap, poor machining, and reduced casting performance, which can obviously result in excess energy consumption. Significant progress in understanding inclusion source, formation and control has been made. Inclusions can be defined as non-metallic materials such as refractory, sand, slag, or coatings, embedded in a metallic matrix. This research project has focused on the mold filling aspects to examine the effects of pouring methods and gating designs on the steel casting cleanliness through water modeling, computer modeling, and melting/casting experiments. Early in the research project, comprehensive studies of bottom-pouring water modeling and low-alloy steelmore » casting experiments were completed. The extent of air entrainment in bottom-poured large castings was demonstrated by water modeling. Current gating systems are designed to prevent air aspiration. However, air entrainment is equally harmful and no prevention measures are in current practice. In this study, new basin designs included a basin dam, submerged nozzle, and nozzle extension. The entrained air and inclusions from the gating system were significantly reduced using the new basin method. Near the end of the project, there has been close collaboration with Wescast Industries Inc., a company manufacturing automotive exhaust components. Both computer modeling using Magma software and melting/casting experiments on thin wall turbo-housing stainless steel castings were completed in this short period of time. Six gating designs were created, including the current gating on the pattern, non-pressurized, partially pressurized, naturally pressurized, naturally pressurized without filter, and radial choke gating without filter, for Magma modeling. The melt filling velocity and temperature were determined from the modeling. Based on the simulation results, three gating designs were chosen for further melting and casting experiments on the same casting pattern using the lip pouring method. It was observed again that gating designs greatly influenced the melt filling velocity and the number of inclusion defects. The radial choked gating showed improvements in casting cleanliness and yield over the other gatings, even though no mold filters were used in the gating system.« less

The effects of different types of investments on the alpha-case layer of titanium castings.

PubMed

Guilin, Yu; Nan, Li; Yousheng, Li; Yining, Wang

2007-03-01

Different types of investments affect the formation of the alpha-case (alpha-case) layer on titanium castings. This alpha-case layer may possibly alter the mechanical properties of cast titanium, which may influence the fabrication of removable and fixed prostheses. The formation mechanism for the alpha-case layer is not clear. The aim of this study was to evaluate the effect of 3 types of investments on the microstructure, composition, and microhardness of the alpha-case layer on titanium castings. Fifteen wax columns with a diameter of 5 mm and a length of 40 mm were divided into 3 groups of 5 patterns each. Patterns were invested using 3 types of investment materials, respectively, and were cast in pure titanium. The 3 types of materials tested were SiO(2)-, Al(2)O(3)-, and MgO-based investments. All specimens were sectioned and prepared for metallographic observation. The microstructure and composition of the surface reaction layer of titanium castings were investigated by scanning electron microscopy (SEM) and electron probe microanalysis (EPMA). The surface microhardness (VHN) for all specimens was measured using a hardness testing machine, and a mean value for each group was calculated. The alpha-case layer on titanium castings invested with SiO(2)-, Al(2)O(3)-, and MgO-based investments consisted of 3 layers-namely, the oxide layer, alloy layer, and hardening layer. In this study, the oxide layer and alloy layer were called the reaction layer. The thickness of the reaction layer for titanium castings using SiO(2)-, Al(2)O(3)-, and MgO-based investments was approximately 80 microm, 50 microm, and 14 microm, respectively. The surface microhardness of titanium castings made with SiO(2)-based investments was the highest, and that with MgO-based investments was the lowest. The type of investment affects the microstructure and microhardness of the alpha-case layer of titanium castings. Based on the thickness of the surface reaction layer and the surface microhardness of titanium castings, MgO-based investment materials may be the best choice for casting these materials.

Fabrication of titanium removable dental prosthesis frameworks with a 2-step investment coating method.

PubMed

Koike, Mari; Hummel, Susan K; Ball, John D; Okabe, Toru

2012-06-01

Although pure titanium is known to have good biocompatibility, a titanium alloy with better strength is needed for fabricating clinically acceptable, partial removable dental prosthesis (RDP) frameworks. The mechanical properties of an experimental Ti-5Al-5Cu alloy cast with a 2-step investment technique were examined for RDP framework applications. Patterns for tests for various properties and denture frameworks for a preliminary trial casting were invested with a 2-step coating method using 2 types of mold materials: a less reactive spinel compound (Al(2)O(3)·MgO) and a less expensive SiO(2)-based material. The yield and tensile strength (n=5), modulus of elasticity (n=5), elongation (n=5), and hardness (n=8) of the cast Ti-5Al-5Cu alloy were determined. The external appearance and internal porosities of the preliminary trial castings of denture frameworks (n=2) were examined with a conventional dental radiographic unit. Cast Ti-6Al-4V alloy and commercially pure titanium (CP Ti) were used as controls. The data for the mechanical properties were statistically analyzed with 1-way ANOVA (α=.05). The yield strength of the cast Ti-5Al-5Cu alloy was 851 MPa and the hardness was 356 HV. These properties were comparable to those of the cast Ti-6Al-4V and were higher than those of CP Ti (P<.05). One of the acrylic resin-retention areas of the Ti-5Al-5Cu frameworks was found to have been incompletely cast. The cast biocompatible experimental Ti-5Al-5Cu alloy exhibited high strength when cast with a 2-step coating method. With a dedicated study to determine the effect of sprue design on the quality of castings, biocompatible Ti-5Al-5Cu RDP frameworks for a clinical trial can be produced. Copyright © 2012 The Editorial Council of the Journal of Prosthetic Dentistry. Published by Mosby, Inc. All rights reserved.

Effect of microstructure and surface features on wetting angle of a Fe-3.2 wt%C.E. cast iron with water

NASA Astrophysics Data System (ADS)

Riahi, Samira; Niroumand, Behzad; Dorri Moghadam, Afsaneh; Rohatgi, Pradeep K.

2018-05-01

In the present study, variation in surface wetting behavior of a hypoeutectic cast iron with its microstructural features and surface roughness was investigated. Samples with an identical composition, i.e. Fe-3.2 wt%C.E., and different microstructures (a gray cast iron with A-type flake graphite and a white cast iron) were fabricated by gravity casting of molten cast iron in a chill mold at different cooling rates. A variation of surface roughness was also developed by polishing, a four-stage electroetching and a four-stage mechanical abrading on the samples. Roughness and water contact angles of all surfaces were then measured. The surface roughness factor and the solid fraction in contact with water by the Wenzel and Cassie-Baxter contact models were also calculated and compared with the corresponding measured contact angles to find out which regime was active. Results indicated that the surface microstructure and the type of constituents present at the surface influenced the cast iron surface wettability and that it was possible to change the surface contact angle by modification of the surface microstructure. The mechanically abraded gray cast iron followed the Wenzel-type regime while the electroetched surfaces of gray cast iron exhibited a transition from Wenzel to Cassie-Baxter type regime. In white cast iron, the results indicated Wenzel type behavior in the electroetched samples while for the mechanically abraded samples, none of these two models could predict the wetting behavior. Furthermore, the wetting angles of both gray and white cast irons were measured after 1, 2, 3 and 4 weeks of air exposure. The results showed that the wetting angles of both samples increased to above 90° after one week of air exposure which was likely due to adsorption of low surface energy hydrocarbons on the surfaces.

ToxCast Chemical Landscape: Paving the Road to 21st Century Toxicology.

PubMed

Richard, Ann M; Judson, Richard S; Houck, Keith A; Grulke, Christopher M; Volarath, Patra; Thillainadarajah, Inthirany; Yang, Chihae; Rathman, James; Martin, Matthew T; Wambaugh, John F; Knudsen, Thomas B; Kancherla, Jayaram; Mansouri, Kamel; Patlewicz, Grace; Williams, Antony J; Little, Stephen B; Crofton, Kevin M; Thomas, Russell S

2016-08-15

The U.S. Environmental Protection Agency's (EPA) ToxCast program is testing a large library of Agency-relevant chemicals using in vitro high-throughput screening (HTS) approaches to support the development of improved toxicity prediction models. Launched in 2007, Phase I of the program screened 310 chemicals, mostly pesticides, across hundreds of ToxCast assay end points. In Phase II, the ToxCast library was expanded to 1878 chemicals, culminating in the public release of screening data at the end of 2013. Subsequent expansion in Phase III has resulted in more than 3800 chemicals actively undergoing ToxCast screening, 96% of which are also being screened in the multi-Agency Tox21 project. The chemical library unpinning these efforts plays a central role in defining the scope and potential application of ToxCast HTS results. The history of the phased construction of EPA's ToxCast library is reviewed, followed by a survey of the library contents from several different vantage points. CAS Registry Numbers are used to assess ToxCast library coverage of important toxicity, regulatory, and exposure inventories. Structure-based representations of ToxCast chemicals are then used to compute physicochemical properties, substructural features, and structural alerts for toxicity and biotransformation. Cheminformatics approaches using these varied representations are applied to defining the boundaries of HTS testability, evaluating chemical diversity, and comparing the ToxCast library to potential target application inventories, such as used in EPA's Endocrine Disruption Screening Program (EDSP). Through several examples, the ToxCast chemical library is demonstrated to provide comprehensive coverage of the knowledge domains and target inventories of potential interest to EPA. Furthermore, the varied representations and approaches presented here define local chemistry domains potentially worthy of further investigation (e.g., not currently covered in the testing library or defined by toxicity "alerts") to strategically support data mining and predictive toxicology modeling moving forward.

14 CFR 29.621 - Casting factors.

Code of Federal Regulations, 2011 CFR

2011-01-01

... established. (3) For castings procured to a specification that guarantees the mechanical properties of the material in the casting and provides for demonstration of these properties by test of coupons cut from the...

14 CFR 27.621 - Casting factors.

Code of Federal Regulations, 2010 CFR

2010-01-01

... established. (3) For castings procured to a specification that guarantees the mechanical properties of the material in the casting and provides for demonstration of these properties by test of coupons cut from the...

14 CFR 29.621 - Casting factors.

Code of Federal Regulations, 2010 CFR

2010-01-01

... established. (3) For castings procured to a specification that guarantees the mechanical properties of the material in the casting and provides for demonstration of these properties by test of coupons cut from the...

14 CFR 27.621 - Casting factors.

Code of Federal Regulations, 2011 CFR

2011-01-01

... established. (3) For castings procured to a specification that guarantees the mechanical properties of the material in the casting and provides for demonstration of these properties by test of coupons cut from the...

Adaptive changes in the motor cortex during and after longterm forelimb immobilization in adult rats.

PubMed

Viaro, Riccardo; Budri, Mirco; Parmiani, Pierantonio; Franchi, Gianfranco

2014-05-15

Experimental and clinical studies have attempted to evaluate the changes in cortical activity seen after immobilization-induced longterm sensorimotor restriction, although results remain controversial. We used intracortical microstimulation (ICMS), which provides topographic movement representations of the motor areas in both hemispheres with optimal spatial characterization, combined with behavioural testing to unravel the effects of limb immobilization on movement representations in the rat primary motor cortex (M1). Unilateral forelimb immobilization in rats was achieved by casting the entire limb and leaving the cast in place for 15 or 30 days. Changes in M1 were bilateral and specific for the forelimb area, but were stronger in the contralateral-to-cast hemisphere. The threshold current required to evoke forelimb movement increased progressively over the period in cast, whereas the forelimb area size decreased and the non-excitable area size increased. Casting resulted in a redistribution of proximal/distal movement representations: proximal forelimb representation increased, whereas distal representation decreased in size. ICMS after cast removal showed a reversal of changes, which remained partial at 15 days. Local application of the GABAA-antagonist bicuculline revealed the impairment of cortical synaptic connectivity in the forelimb area during the period of cast and for up to 15 days after cast removal. Six days of rehabilitation using a rotarod performance protocol after cast removal did not advance map size normalization in the contralateral-to-cast M1 and enabled the cortical output towards the distal forelimb only in sites that had maintained their excitability. These results are relevant to our understanding of adult M1 plasticity during and after sensorimotor deprivation, and to new approaches to conditions that require longterm limb immobilization. © 2014 The Authors. The Journal of Physiology © 2014 The Physiological Society.

An alternative section method for casting and posterior laser welding of metallic frameworks for an implant-supported prosthesis.

PubMed

de Aguiar, Fábio Afrânio; Tiossi, Rodrigo; Rodrigues, Renata Cristina Silveira; Mattos, Maria de Gloria Chiarello; Ribeiro, Ricardo Faria

2009-04-01

The aim of this study was to compare the accuracy of fit of three types of implant-supported frameworks cast in Ni-Cr alloy: specifically, a framework cast as one piece compared to frameworks cast separately in sections to the transverse or the diagonal axis, and later laser welded. Three sets of similar implant-supported frameworks were constructed. The first group of six 3-unit implant-supported frameworks were cast as one piece, the second group of six were sectioned in the transverse axis of the pontic region prior to casting, and the last group of six were sectioned in the diagonal axis of the pontic region prior to casting. The sectioned frameworks were positioned in the matrix (10 N.cm torque) and laser welded. To evaluate passive fit, readings were made with an optical microscope with both screws tightened and with only one-screw tightened. Data were submitted to ANOVA and Tukey-Kramer's test (p < 0.05). When both screws were tightened, no differences were found between the three groups (p > 0.05). In the single-screw-tightened test, with readings made opposite to the tightened side, the group cast as one piece (57.02 +/- 33.48 mum) was significantly different (p < 0.05) from the group sectioned diagonally (18.92 +/- 4.75 microm) but no different (p > 0.05) from the group transversally sectioned (31.42 +/- 20.68 microm). On the tightened side, no significant differences were found between the groups (p > 0.05). Results of this study showed that casting diagonally sectioned frameworks lowers misfit levels of prosthetic implant-supported frameworks and also improves the levels of passivity to the same frameworks when compared to structures cast as one piece.

Results of Casting in Severe Curves in Infantile Scoliosis.

PubMed

Stasikelis, Peter J; Carpenter, Ashley M

2018-04-01

Previous work has demonstrated best results for casting in infantile scoliosis when the curves are small and the child begins casting under 2 years of age. This study examines if casting can delay the need for growth friendly instrumentation in severe curves (50 to 106 degrees) and how the comorbidities of syrinx or genetic syndromes affected outcomes. All children undergoing casting for scoliosis at a single institution over an 8-year period were examined. Inclusion criteria included initial curve at first casting of ≥50 degrees, age ≤3 years at the start of casting, and a minimum follow-up of 3 years. Of 148 children undergoing casting during this period, 44 met our inclusion criteria. All children underwent magnetic resonance imaging. Ten children with a syrinx were identified. Ten children had known genetic syndromes (2 who also had a syrinx). The 26 children without these comorbidities were considered idiopathic. Curve magnitude ranged from 50 to 106 degrees. Nine of the 26 (35%) children in the children with idiopathic curves demonstrated resolution of their curves, while only 3 of the remaining 18 (17%) did. Of the children that did not have resolution of their curves, 14 were maintained over the entire follow-up period to within 15 degrees of their initial curve and 13 were improved 15 degrees or more. Only 5 children had an increase of 15 degrees or more over the follow-up period and 4 of these have undergone growth friendly instrumentation after a mean delay from initial cast of 71 months (range, 18 to 100 mo). This study demonstrates that even in severe curves, casting was effective in delaying instrumentation in all cases, and led to curve resolution of the curves in 12 of 44 children. Level III-case control study.

MACHINING ELIMINATION THROUGH APPLICATION OF THREAD FORMING FASTENERS IN NET SHAPED CAST HOLES

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cleaver, Ryan J; Cleaver, Todd H; Talbott, Richard

The ultimate objective of this work was to eliminate approximately 30% of the machining performed in typical automotive engine and transmission plants by using thread forming fasteners in as-cast holes of aluminum and magnesium cast components. The primary issues at the source of engineers reluctance to implementing thread forming fasteners in lightweight castings are: * Little proof of consistency of clamp load vs. input torque in either aluminum or magnesium castings. * No known data to understand the effect on consistency of clamp load as casting dies wear. The clamp load consistency concern is founded in the fact that amore » portion of the input torque used to create clamp load is also used to create threads. The torque used for thread forming may not be consistent due to variations in casting material, hole size and shape due to tooling wear and process variation (thermal and mechanical). There is little data available to understand the magnitude of this concern or to form the basis of potential solutions if the range of clamp load variation is very high (> +/- 30%). The range of variation that can be expected in as-cast hole size and shape over the full life cycle of a high pressure die casting die was established in previous work completed by Pacific Northwest National Laboratory, (PNNL). This established range of variation was captured in a set of 12 cast bosses by designing core pins at the size and draft angles identified in the sited previous work. The cast bosses were cut into nuts that could be used in the Ford Fastener Laboratory test-cell to measure clamp load when a thread forming fastener was driven into a cast nut. There were two sets of experiments run. First, a series of cast aluminum nuts were made reflecting the range of shape and size variations to be expected over the life cycle of a die casting die. Taptite thread forming fasteners, (a widely used thread forming fastener suitable for aluminum applications), were driven into the various cored, as-cast nuts at a constant input torque and resulting clamp loads were recorded continuously. The clamp load data was used to determine the range of clamp loads to be expected. The bolts were driven to failure. The clamp load corresponding to the target input of 18.5 Nm was recorded for each fastener. In a like fashion, a second set of experiments were run with cast magnesium nuts and ALtracs thread forming fasteners, (a widely used thread forming fastener suitable for magnesium applications). Again all clamp loads were recorded and analyzed similarly to the Taptites in aluminum cast nuts. Results from previous work performed on the same test cell for a Battelle project using standard M8 bolts into standard M8 nuts were included as a comparator for a standard bolt and nut application. The results for the thread forming fasteners in aluminum cast holes were well within industry expectations of +/- 30% for out of the box and robustness range testing. The results for the dry and lubed extreme conditions were only slightly higher than industry expectations at +/- 35.6%. However, when compared to the actual Battelle results (+/- 40%) for a standard bolt and nut the tread forming fasteners performed slightly better. The results for the thread forming fasteners in magnesium cast holes were all well within industry expectations of +/- 30% for all three conditions. The robustness range (.05mm larger and smaller holes than the expected wear pattern of a die casting die at full life cycle) results also fell within the industry expectations for standard threaded fasteners. These results were very encouraging. It was concluded that this work showed that clamp load variation with thread forming fasteners is consistent with industry expectations for standard steel bolts and nuts at +/- 30%. There does not appear to be any significant increase in clamp load variation due to the application of thread forming fasteners in as-cast holes of aluminum or magnesium over the effective life of a die casting mold. The fully implemented potential benefit of thread forming fasteners in as-cast holes of aluminum and magnesium is estimated to be 6 trillion Btu per year for North America. Economic benefit is estimated to be nearly $800 million per year. Environmental benefits and quality improvements will also result from full implementation of this technology.« less

22 CFR 121.10 - Forgings, castings, and machined bodies.

Code of Federal Regulations, 2014 CFR

2014-04-01

... STATES MUNITIONS LIST Enumeration of Articles § 121.10 Forgings, castings, and machined bodies. The U.S. Munitions List controls as defense articles those forgings, castings, and other unfinished products, such as...

Modeling and simulation of clutch pressure plate casting using alternate materials

NASA Astrophysics Data System (ADS)

Madhuraj, H. N.; Bharath, M. R.

2018-04-01

Clutch Pressure Plate is a stress bearing component in the clutch assembly. Cast iron alloys like FG300, G2500 are commonly used for clutch pressure plate castings. These materials have high compressive strength, low tensile strength & no ductility but these cost high for the manufacturers. There is a need for alternate material so as to reduce cost, defects in castings without losing the life and effectiveness of the clutch plate. The work carried out here is modeling the clutch pressure plate using CAD tool. And then the casting process is simulated by casting simulation for fluid flow and solidification analysis by trying alternate material. Here the castability of the alternate material En-Gjs-400-15 and the commonly used material FG300 for the clutch pressure plate component is analyzed by designing and optimizing a proper gating system.

Strip casting with fluxing agent applied to casting roll

DOEpatents

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

1997-07-29

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

Serial casting for neuromuscular flatfoot and vertical talus in an adolescent with hereditary spastic paraplegia.

PubMed

Sweet, Laurene A; OʼNeill, Lindsey M; Dobbs, Matthew B

2014-01-01

The purpose of this report is to explore assessment and serial casting intervention for painful rigid flatfoot deformities with vertical talus in an adolescent girl with hereditary spastic paraplegia who was nonambulatory. The participant's right foot underwent 2 phases of casting with correction first toward hindfoot inversion and then dorsiflexion. Because of a vertical talus, her left foot required an intermediate casting toward plantar flexion, inversion, and forefoot adduction prior to casting toward dorsiflexion. The patient improved despite the underlying progressive neuromuscular disorder. Pain ameliorated and she returned to supported standing and transfers. Spasticity decreased bilaterally and the flexibility of her foot deformities improved to allow orthotic fabrication in subtalar neutral. Results were maintained at 12 and 16 months. Individualized multiphase serial casting requires further investigation with patients such as those with hereditary spastic paraplegia.

Vacuum investment cast PH13-8Mo corrosion resistant steel. (SAE standard)

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

1991-07-01

An industry-wide interest has arisen with regards to the properties and capabilities of investment cast PH 13-8Mo corrosion resistant steel. Specifically of interest are the structural applications in the aerospace industry for this product heat treated to the H1000 condition. The objective of this AMEC cooperative test program was to generate and compile useful data for aerospace structural evaluation of investment cast PH 13-8Mo heat treated to H1000. The determination was made of overall mechanical properties, fatigue, fracture toughness, and crack growth data along with basic microstructural evaluation of the investment cast material. The evaluation of mechanical property variations betweenmore » cast and machined tensile specimens and evaluation of microstructural constituents. PH 13-8Mo, H1000 investment castings for use in the aerospace industry is included.« less

A comparative study of the microstructures observed in statically cast and continuously cast Bi-In-Sn ternary eutectic alloy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sengupta, S.; Soda, H.; McLean, A.

2000-01-01

A ternary eutectic alloy with a composition of 57.2 pct Bi, 24.8 pct In, and 18 pct Sn was continuously cast into wire of 2 mm diameter with casting speeds of 14 and 79 mm/min using the Ohno Continuous Casting (OCC) process. The microstructures obtained were compared with those of statically cast specimens. Extensive segregation of massive Bi blocks, Bi complex structures, and tin-rich dendrites was found in specimens that were statically cast. Decomposition of {radical}Sn by a eutectoid reaction was confirmed based on microstructural evidence. Ternary eutectic alloy with a cooling rate of approximately 1 C/min formed a doublemore » binary eutectic. The double binary eutectic consisted of regions of BiIn and decomposed {radical}Sn in the form of a dendrite cell structure and regions of Bi and decomposed {radical}Sn in the form of a complex-regular cell. The Bi complex-regular cells, which are a ternary eutectic constituent, existed either along the boundaries of the BiIn-decomposed {radical}Sn dendrite cells or at the front of elongated dendrite cell structures. In the continuously cast wires, primary Sn dendrites coupled with a small Bi phase were uniformly distributed within the Bi-In alloy matrix. Neither massive Bi phase, Bi complex-regular cells, no BiIn eutectic dendrite cells were observed, resulting in a more uniform microstructure in contrast to the heavily segregated structures of the statically cast specimens.« less

Role of chicken astrovirus as a causative agent of gout in commercial broilers in India.

PubMed

Bulbule, N R; Mandakhalikar, K D; Kapgate, S S; Deshmukh, V V; Schat, K A; Chawak, M M

2013-01-01

Several outbreaks of gout were reported in commercial broilers in India during 2011 and 2012, causing up to 40% mortality in the birds. Gross and histopathological observations confirmed gout. Quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) analysis from kidney samples of gout-affected birds indicated the presence of chicken astrovirus (CAstV) in 41.7% of cases and a mixed infection of CAstV and avian nephritis virus (ANV) in 36.4% of cases. CAstV isolated from gout-affected kidneys by inoculating embryonated specific pathogen free (SPF) eggs showed dwarfing in embryos and a cytopathic effect in chicken embryo kidney cells. Inoculation of 1-day-old SPF and broiler chicks with CAstVs caused gout and mortality between 4 and 10 days post inoculation. Virus isolation and qRT-PCR analysis showed the presence of only CAstV in inoculated chicks. Sequence analysis of capsid genes indicated a major group of Indian CAstVs that displayed 92.0 to 99.2% intergroup amino acid identity and 83.9 to 90.4% identity with subgroup Bi CAstVs of UK origin. We designated this group Indian Bi. Analysis of the partial polymerase amino acid sequences of our isolates indicated two groups of CAstVs (Indian 1 and 2) that displayed 90.2 to 95.5% amino acid identity between them. We thus report for the first time that, in addition to infectious bronchitis virus and ANV, CAstVs are a causative agent of gout.

Freeze Tape Cast Thick Mo Doped Li 4Ti 5O 12 Electrodes for Lithium-Ion Batteries

DOE PAGES

Ghadkolai, Milad Azami; Creager, Stephen; Nanda, Jagjit; ...

2017-08-30

Lithium titanate (Li 4Ti 5O 12) powders with and without molybdenum doping (LTO and MoLTO respectively) were synthesized by a solid-state method and used to fabricate electrodes on Cu foil using a normal tape-cast method and a novel freeze-tape-cast method. Modest molybdenum doping produces a significant electronic conductivity increase (e.g. 1 mS cm -1 for MoLTO vs 10 -7 mS cm -1 for LTO) that is thought to reflect a partial Ti 4+ reduction to Ti 3+ with charge compensation by the Mo 6+ dopant, producing a stable mixed-valent Ti 4+/3+ state. Freeze-tape-cast electrodes were fabricated by a variant ofmore » the normal tape-cast method that includes a rapid freezing step in which the solvent in the Cu-foil-supported slurry is rapidly frozen on a cold finger then subsequently sublimed to create unidirectional columnar macropores in the electrode. The resulting electrodes exhibit high porosity and low tortuosity which enhances electrolyte accessibility throughout the full electrode thickness. Freeze-tape-cast electrodes subjected to galvanostatic charge-discharge testing as cathodes in cells vs. a lithium metal anode exhibit higher specific capacity and lower capacity loss at high discharge rates compared with normal-tape-cast electrodes of the same mass loading, despite the fact that the freeze-tape-cast electrodes are nearly twice as thick as the normal tape cast electrodes.« less

The application of multi-baseline digital close-range photogrammetry in three-dimensional imaging and measurement of dental casts.

PubMed

Fu, Xiaoming; Peng, Chun; Li, Zan; Liu, Shan; Tan, Minmin; Song, Jinlin

2017-01-01

To explore a new technique for reconstructing and measuring three-dimensional (3D) models of orthodontic plaster casts using multi-baseline digital close-range photogrammetry (MBDCRP) with a single-lens reflex camera. Thirty sets of orthodontic plaster casts that do not exhibit severe horizontal overlap (>2 mm) between any two teeth were recorded by a single-lens reflex camera with 72 pictures taken in different directions. The 3D models of these casts were reconstructed and measured using the open source software MeshLab. These parameters, including mesio-distal crown diameter, arch width, and arch perimeter, were recorded six times on both the 3D digital models and on plaster casts by two examiners. Statistical analysis was carried out using the Bland-Altman method to measure agreement between the novel method and the traditional calliper method by calculating the differences between mean values. The average differences between the measurements of the photogrammetric 3D models and the plaster casts were 0.011-0.402mm. The mean differences between measurements obtained by the photogrammetric 3D models and the dental casts were not significant except for the lower arch perimeter (P>0.05), and all the differences were regarded as clinically acceptable (<0.5 mm). Measurements obtained by MBDCRP are compared well with those obtained from plaster casts, indicating that MBDCRP is an alternate way to store and measure dental plaster casts without severe horizontal overlap between any two teeth.

Structural and compositional analysis of a casting mold sherd from ancient China.

PubMed

Zong, Yunbing; Yao, Shengkun; Lang, Jianfeng; Chen, Xuexiang; Fan, Jiadong; Sun, Zhibin; Duan, Xiulan; Li, Nannan; Fang, Hui; Zhou, Guangzhao; Xiao, Tiqiao; Li, Aiguo; Jiang, Huaidong

2017-01-01

Casting had symbolic significance and was strictly controlled in the Shang dynasty of ancient China. Vessel casting was mainly distributed around the Shang capital, Yin Ruins, which indicates a rigorous centralization of authority. Thus, for a casting mold to be excavated far from the capital region is rare. In addition to some bronze vessel molds excavated at the Buyao Village site, another key discovery of a bronze vessel mold occurred at Daxinzhuang. The Daxinzhuang site was a core area in the east of Shang state and is an important site to study the eastward expansion of the Shang. Here, combining synchrotron X-rays and other physicochemical analysis methods, nondestructive three-dimensional structure imaging and different elemental analyses were conducted on this mold sherd. Through high penetration X-ray tomography, we obtained insights on the internal structure and discovered some pores. We infer that the generation of pores inside the casting mold sherd was used to enhance air permeability during casting. Furthermore, we suppose that the decorative patterns on the surface were carved and not pasted onto it. Considering the previous compositional studies of bronze vessels, the copper and iron elements were analyzed by different methods. Unexpectedly, a larger amount of iron than of copper was detected on the surface. According to the data analysis and archaeological context, the source of iron on the casting mold sherd could be attributed to local soil contamination. A refined compositional analysis confirms that this casting mold was fabricated locally and used for bronze casting.

Biceps Tendon Lengthening Surgery for Failed Serial Casting Patients With Elbow Flexion Contractures Following Brachial Plexus Birth Injury.

PubMed

Nath, Rahul K; Somasundaram, Chandra

2016-01-01

Assessment of surgical outcomes of biceps tendon lengthening (BTL) surgery in obstetric brachial plexus injury (OBPI) patients with elbow flexion contractures, who had unsuccessful serial casting. Serial casting and splinting have been shown to be effective in correcting elbow flexion contractures in OBPI. However, the possibilities of radial head dislocations and other complications have been reported in serial casting and splinting. Literature indicates surgical intervention when such nonoperative techniques and range-of-motion exercises fail. Here, we demonstrated a significant reduction of the contractures of the affected elbow and improvement in arm length to more normal after BTL in these patients, who had unsuccessful serial casting. Ten OBPI patients (6 girls and 4 boys) with an average age of 11.2 years (4-17.7 years) had BTL surgery after unsuccessful serial casting. Mean elbow flexion contracture was 40° before and 37° (average) after serial casting. Mean elbow flexion contracture was reduced to 8° (0°-20°) post-BTL surgical procedure with an average follow-up of 11 months. This was 75% improvement and statistically significant (P < .001) when compared to 7% insignificant (P = .08) improvement after serial casting. These OBPI patients in our study had 75% significant reduction in elbow flexion contractures and achieved an improved and more normal length of the affected arm after the BTL surgery when compared to only 7% insignificant reduction and no improvement in arm length after serial casting.

Distortion of three-unit implant frameworks during casting, soldering, and simulated porcelain firings.

PubMed

Zervas, P J; Papazoglou, E; Beck, F M; Carr, A B

1999-09-01

The aim of this study was to assess distortion inherent in casting, soldering, and simulated porcelain firings of screw-retained, implant-supported three-unit fixed partial dentures (FPDs). Ten wax patterns were fabricated on a die-stone cast containing two implants, 20 mm apart from center to center. Five specimens were cast in a high-palladium alloy, exposed to simulated porcelain firings, sectioned, and then soldered with low-fusing solder. Five specimens were cast, sectioned, soldered with high-fusing solder, and then exposed to simulated porcelain firings. For each specimen, two horizontal and six vertical distances between appropriately scribed reference points were measured with a traveling microscope. Comparisons were made among the various measurements taken after wax-pattern fabrication, casting, high- and low-fusing soldering, and each porcelain firing. Data were analyzed using a repeated-measures factorial ANOVA (alpha = 0.05). Significant difference was detected in the amount of horizontal distortion during casting (53 +/- 24 microns) and high-fusing soldering (-49 +/- 50 microns), as well as in the amount of horizontal distortion during high-fusing soldering (-49 +/- 50 microns) and low-fusing soldering (17 +/- 26 microns). However, no clinically significant difference was found in the amount of horizontal distortion during casting, low-fusing, and high-fusing soldering. The greatest amount of distortion during the simulated porcelain firings took place during the oxidizing cycle. Soldering did not improve the casting misfit of a three-unit implant-retained FPD model. Metal-ceramic implant frameworks should be oxidized before intraoral fit evaluation.

The Design of 3D-Printed Lattice-Reinforced Thickness-Varying Shell Molds for Castings

PubMed Central

Shangguan, Haolong; Kang, Jinwu; Yi, Jihao; Zhang, Xiaochuan; Wang, Xiang; Wang, Haibin; Huang, Tao

2018-01-01

3D printing technologies have been used gradually for the fabrication of sand molds and cores for castings, even though these molds and cores are dense structures. In this paper, a generation method for lattice-reinforced thickness-varying shell molds is proposed and presented. The first step is the discretization of the STL (Stereo Lithography) model of a casting into finite difference meshes. After this, a shell is formed by surrounding the casting with varying thickness, which is roughly proportional to the surface temperature distribution of the casting that is acquired by virtually cooling it in the environment. A regular lattice is subsequently constructed to support the shell. The outside surface of the shell and lattice in the cubic mesh format is then converted to STL format to serve as the external surface of the new shell mold. The internal surface of the new mold is the casting’s surface with the normals of all of the triangles in STL format reversed. Experimental verification was performed on an Al alloy wheel hub casting. Its lattice-reinforced thickness-varying shell mold was generated by the proposed method and fabricated by the binder jetting 3D printing. The poured wheel hub casting was sound and of good surface smoothness. The cooling rate of the wheel hub casting was greatly increased due to the shell mold structure. This lattice-reinforced thickness-varying shell mold generation method is of great significance for mold design for castings to achieve cooling control. PMID:29601543

SLIP CASTING METHOD

DOEpatents

Allison, A.G.

1959-09-01

S>A process is described for preparing a magnesium oxide slip casting slurry which when used in conjunction with standard casting techniques results in a very strong "green" slip casting and a fired piece of very close dimensional tolerance. The process involves aging an aqueous magnestum oxide slurry, having a basic pH value, until it attains a specified critical viscosity at which time a deflocculating agent is added without upsetting the basic pH value.

Fracture Analysis of Cast Steel Sling

NASA Astrophysics Data System (ADS)

Li, Xinghui

2018-02-01

The fracture reasons of ZG270-500 cast steel sling are analyzed through such means as macroscopic morphology analysis, chemical composition analysis, and microscopic metallography analysis. Results: coarse Widmanstatten structure and casting defects occurring in casting and subsequent heat treatment process reduce the strength, plasticity and toughness of the steel, which is the main reason of brittle fracture of the sling during work, and corresponding improvement suggestions are proposed herein.

Methods and apparatuses for manufacturing geometric multicrystalline cast silicon and geometric multicrystalline cast silicon bodies for photovoltaics

DOEpatents

Stoddard, Nathan G

2015-02-10

Methods and apparatuses are provided for casting silicon for photovoltaic cells and other applications. With such methods and apparatuses, a cast body of geometrically ordered multi-crystalline silicon may be formed that is free or substantially free of radially-distributed impurities and defects and having at least two dimensions that are each at least about 10 cm is provided.

Preliminary Study into Shell Mold Casting of Nominal 60-Nitinol Alloy

DTIC Science & Technology

The present study was initiated to determine the feasibility of shell mold casting nominal 60- Nitinol into suitable EOD (Explosive Ordnance Disposal...surface finish and definition and property response of cast alloy. Based upon the results, 60- Nitinol appears quite suited to shell molding and a...concern lies in the casting porosity associated with the relatively large liquid-to-solid shrinkage of nominal 60- Nitinol .

W.E.B. Du Bois and Caste Education: Racial Capitalist Schooling from Reconstruction to Jim Crow

ERIC Educational Resources Information Center

Pierce, Clayton

2017-01-01

This essay provides the first account and examination of caste education in the work of W.E.B. Du Bois. In so doing, I argue that caste education plays a central role in realizing the political and social goals of racial capitalist society for Du Bois. Using Du Bois's caste analytic, I take up and articulate three biopolitical governing strategies…

Local ventilation solution for large, warm emission sources.

PubMed

Kulmala, Ilpo; Hynynen, Pasi; Welling, Irma; Säämänen, Arto

2007-01-01

In a foundry casting line, contaminants are released from a large area. Casting fumes include both volatile and particulate compounds. The volatile fraction contains hydrocarbons, whereas the particulate fraction mostly comprises a mixture of vaporized metal fumes. Casting fumes lower the air quality in foundries. The design of local ventilation for the casting area is a challenging task, because of the large casting area and convection plumes from warm moulds. A local ventilation solution for the mould casting area was designed and dimensioned with the aid of computational fluid dynamic (CFD) calculations. According to the calculations, the most efficient solution was a push-pull ventilation system. The prototype of the push-pull system was built and tested in actual operation at the foundry. The push flow was generated by a free plane jet that blew across the 10 m wide casting area towards an exhaust hood on the opposite side of the casting lines. The capture efficiency of the prototype was determined by the tracer gas method. The measured capture efficiencies with push jet varied between 40 and 80%, depending on the distance between the source and the exhaust. With the aid of the push flow, the average capture efficiency was increased from 40 (without jet) to 60%.

Experimental Studies of Heat-Transfer Behavior at a Casting/Water-Cooled-Mold Interface and Solution of the Heat-Transfer Coefficient

NASA Astrophysics Data System (ADS)

Zeng, Y. D.; Wang, F.

2018-02-01

In this paper, we propose an experimental model for forming an air gap at the casting/mold interface during the solidification process of the casting, with the size and formation time of the air gap able to be precisely and manually controlled. Based on this model, experiments of gravity casting were performed, and on the basis of the measured temperatures at different locations inside the casting and the mold, the inverse analysis method of heat transfer was applied to solve for the heat-transfer coefficient at the casting/mold interface during the solidification process. Furthermore, the impacts of the width and formation time of the air gap on the interface heat-transfer coefficient (IHTC) were analyzed. The results indicate that the experimental model succeeds in forming an air gap having a certain width at any moment during solidification of the casting, thus allowing us to conveniently and accurately study the impact of the air gap on IHTC using the model. In addition, the casting/mold IHTC is found to first rapidly decrease as the air gap forms and then slowly decrease as the solidification process continues. Moreover, as the width of the air gap and the formation time of the air gap increase, the IHTC decreases.

Setting and stiffening of cementitious components in Cast Stone waste form for disposal of secondary wastes from the Hanford waste treatment and immobilization plant

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chung, Chul-Woo; Chun, Jaehun, E-mail: jaehun.chun@pnnl.gov; Um, Wooyong

2013-04-01

Cast Stone is a cementitious waste form, a viable option to immobilize secondary nuclear liquid wastes generated from the Hanford Waste Treatment and Immobilization Plant. However, no study has been performed to understand the flow and stiffening behavior, which is essential to ensure proper workability and is important to safety in a nuclear waste field-scale application. X-ray diffraction, rheology, and ultrasonic wave reflection methods were used to understand the specific phase formation and stiffening of Cast Stone. Our results showed a good correlation between rheological properties of the fresh mixture and phase formation in Cast Stone. Secondary gypsum formation wasmore » observed with low concentration simulants, and the formation of gypsum was suppressed in high concentration simulants. A threshold concentration for the drastic change in stiffening was found at 1.56 M Na concentration. It was found that the stiffening of Cast Stone was strongly dependent on the concentration of simulant. Highlights: • A combination of XRD, UWR, and rheology gives a better understanding of Cast Stone. • Stiffening of Cast Stone was strongly dependent on the concentration of simulant. • A drastic change in stiffening of Cast Stone was found at 1.56 M Na concentration.« less

Setting and Stiffening of Cementitious Components in Cast Stone Waste Form for Disposal of Secondary Wastes from the Hanford waste treatment and immobilization plant

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chung, Chul-Woo; Chun, Jaehun; Um, Wooyong

2013-04-01

Cast stone is a cementitious waste form, a viable option to immobilize secondary nuclear liquid wastes generated from Hanford vitrification plant. While the strength and radioactive technetium leaching of different waste form candidates have been reported, no study has been performed to understand the flow and stiffening behavior of Cast Stone, which is essential to ensure the proper workability, especially considering necessary safety as a nuclear waste form in a field scale application. The rheological and ultrasonic wave reflection (UWR) measurements were used to understand the setting and stiffening Cast Stone batches. X-ray diffraction (XRD) was used to find themore » correlation between specific phase formation and the stiffening of the paste. Our results showed good correlation between rheological properties of the fresh Cast Stone mixture and phase formation during hydration of Cast Stone. Secondary gypsum formation originating from blast furnace slag was observed in Cast Stone made with low concentration simulants. The formation of gypsum was suppressed in high concentration simulants. It was found that the stiffening of Cast Stone was strongly dependent on the concentration of simulant. A threshold concentration for the drastic change in stiffening was found at 1.56 M Na concentration.« less

Characterization of Technetium Speciation in Cast Stone

DOE Office of Scientific and Technical Information (OSTI.GOV)

Um, Wooyong; Jung, Hun Bok; Wang, Guohui

2013-11-11

This report describes the results from laboratory tests performed at Pacific Northwest National Laboratory (PNNL) for the U.S. Department of Energy (DOE) EM-31 Support Program (EMSP) subtask, “Production and Long-Term Performance of Low Temperature Waste Forms” to provide additional information on technetium (Tc) speciation characterization in the Cast Stone waste form. To support the use of Cast Stone as an alternative to vitrification for solidifying low-activity waste (LAW) and as the current baseline waste form for secondary waste streams at the Hanford Site, additional understanding of Tc speciation in Cast Stone is needed to predict the long-term Tc leachability frommore » Cast Stone and to meet the regulatory disposal-facility performance requirements for the Integrated Disposal Facility (IDF). Characterizations of the Tc speciation within the Cast Stone after leaching under various conditions provide insights into how the Tc is retained and released. The data generated by the laboratory tests described in this report provide both empirical and more scientific information to increase our understanding of Tc speciation in Cast Stone and its release mechanism under relevant leaching processes for the purpose of filling data gaps and to support the long-term risk and performance assessments of Cast Stone in the IDF at the Hanford Site.« less

Casting evaluation of U-Zr alloy system fuel slug for SFR prepared by injection casting method

DOE Office of Scientific and Technical Information (OSTI.GOV)

Song, Hoon; Kim, Jong-Hwan; Kim, Ki-Hwan

2013-07-01

Metal fuel slugs of U-Pu-Zr alloys for Sodium-cooled Fast Reactor (SFR) have conventionally been fabricated by a vacuum injection casting method. Recently, management of minor actinides (MA) became an important issue because direct disposal of the long-lived MA can be a long-term burden for a tentative repository up to several hundreds of thousand years. In order to recycle transuranic elements (TRU) retained in spent nuclear fuel, remote fabrication capability in a shielded hot cell should be prepared. Moreover, generation of long-lived radioactive wastes and loss of volatile species should be minimized during the recycled fuel fabrication step. In order tomore » prevent the evaporation of volatile elements such as Am, alternative fabrication methods of metal fuel slugs have been studied applying gravity casting, and improved injection casting in KAERI, including melting under inert atmosphere. And then, metal fuel slugs were examined with casting soundness, density, chemical analysis, particle size distribution and microstructural characteristics. Based on these results there is a high level of confidence that Am losses will also be effectively controlled by application of a modest amount of overpressure. A surrogate fuel slug was generally soundly cast by improved injection casting method, melted fuel material under inert atmosphere.« less

Experimental investigation on in-situ microwave casting of copper

NASA Astrophysics Data System (ADS)

Raman Mishra, Radha; Sharma, Apurbba Kumar

2018-04-01

The in-situ microwave casting of metallic materials is a recently developed casting process. The process works on the principles of hybrid microwave heating and is accomplished inside the applicator cavity. The process involves – melting of the charge, in-situ pouring and solidification of the melt. The electromagnetic and thermal properties of the charge affects microwave-material interaction and hence melting of the charge. On the other hand, cooling conditions inside the applicator controls solidification process. The present work reports on in-situ casting of copper developed inside a multimode cavity at 2.45 GHz using 1400 W. The molten metal was allowed to get poured in-situ inside a graphite mold and solidification was carried out in the same mold inside the applicator cavity. The interaction of microwave with the charge during exposure was studied and the role of oxide layer during meltingthe copper blocks has been presented. The developed in-situ cast was characterized to access the cast quality. Microstructural study revealed the homogeneous and dense structure of the cast. The X-ray diffraction pattern indicated presence of copper in different orientations with (1 1 1) as the dominant orientation. The average micro indentation hardness of the casts was found 93±20 HV.

Photoresponsive molecularly imprinted hydrogel casting membrane for the determination of trace tetracycline in milk.

PubMed

Wang, Qiang; Lv, Zhen; Tang, Qian; Gong, Cheng-Bin; Lam, Michael Hon Wah; Ma, Xue-Bing; Chow, Cheuk-Fai

2016-03-01

This study aimed to develop a photoresponsive molecularly imprinted hydrogel (MIH) casting membrane for the determination of trace tetracycline (TC) in milk. This MIH casting membrane combined the specificity of MIHs, the photoresponsive properties of azobenzene, and the portable properties of a membrane. Photoresponsive TC-imprinted MIHs were initially fabricated and then cast on sodium dodecyl sulfonate polyacrylamide gel. After TC removal, a photoresponsive MIH casting membrane was obtained. The photoresponsive properties of the MIH casting membrane were robust, and no obvious photodegradation was observed after 20 cycles. The MIH casting membrane displayed specific affinity to TC upon alternate irradiation at 365 and 440 nm; it could quantitatively uptake and release TC. The TC concentration (0.0-2.0 × 10(-4) mol l(-1)) in aqueous solution displayed a linear relationship with the photoisomerization rate constant of azobenzene within the MIH casting membrane. As such, a quick detection method for trace TC in aqueous foodstuff samples was established. The recovery of this method for TC in milk was investigated with a simple pretreatment of milk, and a high recovery of 100.54-106.35% was obtained. Therefore, the fabricated membrane can be used as a portable molecular sensor that can be easily recycled. Copyright © 2015 John Wiley & Sons, Ltd.

Long-Term Resolution of Severe Ankle Contractures Using Botulinum Toxin, Serial Casting, Splinting, and Motor Retraining.

PubMed

Leung, Joan; Stroud, Katarina

2018-01-01

Purpose: Serial casting for ankle contractures is traditionally performed in prone, a position that patients may not easily tolerate. Also, although serial casting is effective in correcting contracture, its effect dissipates quickly. This case report describes a procedure for performing casting for ankle contractures in a supine or sitting position. It also describes a process that enables the effect of serial casting to be maintained long term. Client Description: The client was an adult who had suffered traumatic brain injury and severe bilateral ankle contractures. Intervention: He received botulinum toxin and serial casting for his bilateral ankle contractures, one ankle at 8 months and the other at 13 months after the injury. He then underwent a programme of splinting and motor training. Measures and Outcome: The client gained more than 40° dorsiflexion for both ankles after receiving botulinum toxin injections and serial casting. The improvement in ankle range enabled him to progress to walking practice. Ankle splinting was gradually reduced. On discharge at 25 months post-injury, the ankle joint range was maintained. Implications: The use of botulinum toxin and serial casting, followed by an intensive programme of splinting and motor training, may be an option to consider for effective long-term resolution of severe contractures after acquired brain injury.

Caste and maternal health care service use among rural Hindu women in Maitha, Uttar Pradesh, India.

PubMed

Saroha, Ekta; Altarac, Maja; Sibley, Lynn M

2008-01-01

The objective of this study was to examine the association between caste and maternal health care service use among rural Hindu women in India. We analyzed data from the Morbidity and Performance Assessment, a population-based cross-sectional study, for 482 Hindu women who were pregnant during January 1998 to January 1999 in Maitha, Uttar Pradesh, India. Maternal health care service use among both upper and lower caste women was very low. Upper caste women were almost three times more likely to use antenatal care (odds ratio [OR] = 2.72; 95% confidence interval [CI], 1.40-5.30), tetanus toxoid (OR = 2.50; 95% CI, 1.48-4.21), and contraceptives (OR = 2.66; 95% CI, 1.28-5.54) and almost five times (OR = 4.77; 95% CI, 1.81-12.54) more likely to have a trained birth attendant compared to the lower caste women. Caste was a significant determinant of tetanus toxoid use and trained birth attendant even after adjusting for sociodemographic factors. Besides caste, maternal literacy was the one sociodemographic factor that was significantly associated with the use of all maternal health care services. Information dissemination and awareness generation can improve the use of subsidized maternal health care services among women of all caste groups.

Integrated System of Thermal/Dimensional Analysis for Quality Control of Metallic Melt and Ductile Iron Casting Solidification

NASA Astrophysics Data System (ADS)

Stan, Stelian; Chisamera, Mihai; Riposan, Iulian; Neacsu, Loredana; Cojocaru, Ana Maria; Stan, Iuliana

2018-03-01

The main objective of the present work is to introduce a specific experimental instrument and technique for simultaneously evaluating cooling curves and expansion or contraction of cast metals during solidification. Contraction/expansion analysis illustrates the solidification parameters progression, according to the molten cast iron characteristics, which are dependent on the melting procedure and applied metallurgical treatments, mold media rigidity and thermal behavior [heat transfer parameters]. The first part of the paper summarizes the performance of this two-mold device. Its function is illustrated by representative shrinkage tendency results in ductile cast iron as affected by mold rigidity (green sand and furan resin sand molds) and inoculant type (FeSi-based alloys), published in part previously. The second part of the paper illustrates an application of this equipment adapted for commercial foundry use. It conducts thermal analysis and volume change measurements in a single ceramic cup so that mold media as well as solidification conditions are constants, with cast iron quality as the variable. Experiments compared gray and ductile cast iron solidification patterns. Gray iron castings are characterized by higher undercooling at the beginning and at the end of solidification and lower graphitic expansion. Typically, ductile cast iron exhibits higher graphitic, initial expansion, conducive for shrinkage formation in soft molds.

Metal casts showing the three-dimensional structure of the human inner ear were converted into jewelry.

PubMed

Heywood, Peter

2015-06-01

This article describes a straightforward method for making metal casts of the human inner ear developed in 1937 by M. Wharton Young of Howard University College of Medicine. These casts were used to study anatomy, but there do not appear to be any published photographs of the casts. Inner ear casts converted into jewelry provide the only known images of this work. Later, Young studied the inner ear in living rhesus monkeys by injecting mercury into their membranous labyrinths. Young's investigations indicated a blind-ending perilymphatic sac that was not in continuity with the subarachnoid space.

Increasing the reliability and quality of important cast products made of chemically active metals and alloys

NASA Astrophysics Data System (ADS)

Varfolomeev, M. S.; Moiseev, V. S.; Shcherbakova, G. I.

2017-01-01

A technology is developed to produce highly thermoresistant ceramic monoxide corundum molds using investment casting and an aluminum-organic binder. This technology is a promising trend in creating ceramic molds for precision complex-shape casting of important ingots made of high-alloy steels, high-temperature and titanium alloys, and refractory metals. The use of the casting molds that have a high thermal and chemical resistance to chemically active metals and alloys under high-temperature casting minimizes the physicochemical interaction and substantially decreases the depth of the hard-to-remove metal oxide layer on important products, which increases their service properties.

Evaluation of Serial Casting for Boys with Duchenne Muscular Dystrophy: A Case Report.

PubMed

Carroll, Kate; de Valle, Katy; Kornberg, Andrew; Ryan, Monique; Kennedy, Rachel

2018-02-01

To report the effects of below-knee serial casting in two boys with Duchenne muscular dystrophy who presented with well-preserved strength and calf shortening. Bilateral below-knee serial casts were applied over two weeks with follow-up of daily stretching and wearing of customized night splints. Outcome measures were performed at baseline, 1, 3, 6, and 12 months post-casting. These included measures of calf length, leg strength, motor function, endurance, and spatio-temporal gait parameters. Both boys completed serial casting with gains in muscle length. No adverse effects on strength or motor function were observed over a 12-month follow-up period.

Clubfoot repair - series (image)

MedlinePlus

... and maintained with a new cast. This serial casting is continued for 3 or more months and is successful in at least 50% of cases. If the casts do not provide enough correction of the clubfoot, surgery is considered.

FINISHED CASTINGS ARE ONLY GROUND BEFORE THEY ARE SHIPPED TO ...

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

FINISHED CASTINGS ARE ONLY GROUND BEFORE THEY ARE SHIPPED TO CUSTOMERS WHO COMPLETE THE FINISHING IN THEIR OWN MACHINE SHOPS. - Southern Ductile Casting Company, Grinding & Shipping, 2217 Carolina Avenue, Bessemer, Jefferson County, AL

Effect of mold designs on molten metal behaviour in high-pressure die casting

NASA Astrophysics Data System (ADS)

Ibrahim, M. D.; Rahman, M. R. A.; Khan, A. A.; Mohamad, M. R.; Suffian, M. S. Z. M.; Yunos, Y. S.; Wong, L. K.; Mohtar, M. Z.

2017-04-01

This paper presents a research study conducted in a local automotive component manufacturer that produces aluminium alloy steering housing local and global markets. This study is to investigate the effect of design modification of mold in die casting as to improve the production rate. Design modification is carried out on the casting shot of the mold. Computer flow simulation was carried out to study the flow of molten metal in the mold with respect to the mold design modification. The design parameters of injection speed, die temperature and clamping force has been included in the study. The result of the simulation showed that modifications of casting shot give significant impact towards the molten flow behaviour in casting process. The capabilities and limitations of die casting process simulation to conduct defect analysis had been optimized. This research will enhance the efficiency of the mass production of the industry of die casting with the understanding of defect analysis, which lies on the modification of the mold design, a way early in its stages of production.

Development of a New Ferrous Aluminosilicate Refractory Material for Investment Casting of Aluminum Alloys

NASA Astrophysics Data System (ADS)

Yuan, Chen; Jones, Sam; Blackburn, Stuart

2012-12-01

Investment casting is a time-consuming, labour intensive process, which produces complex, high value-added components for a variety of specialised industries. Current environmental and economic pressures have resulted in a need for the industry to improve current casting quality, reduce manufacturing costs and explore new markets for the process. Alumino-silicate based refractories are commonly used as both filler and stucco materials for ceramic shell production. A new ceramic material, norite, is now being produced based on ferrous aluminosilicate chemistry, having many potential advantages when used for the production of shell molds for casting aluminum alloy. This paper details the results of a direct comparison made between the properties of a ceramic shell system produced with norite refractories and a typical standard refractory shell system commonly used in casting industry. A range of mechanical and physical properties of the systems was measured, and a full-scale industrial casting trial was also carried out. The unique properties of the norite shell system make it a promising alternative for casting aluminum based alloys in the investment foundry.

Permanent Mold Casting of JIS-AC4C Aluminum Alloy Using a Low-Temperature Mold

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yamagata, Hiroshi; Nikawa, Makoto

2011-01-17

Permanent mold casting using mold temperatures below 200 deg. C was conducted to obtain a high-strength, thin-walled casting. Al-7.36 mass% Si -0.18 Cu- 0.27Mg-0.34Fe alloy JIS-AC4C was cast using a bottom pouring cast plan. The product had a rectangular tube shape (70 mm W x 68 mm D x 180 mm H) with wall thicknesses of 1, 3 and 5 mm. The effect of heat insulation at the melt path was compared when using a sand runner insert and when using a steel runner insert as well as a powder mold release agent. Fine microstructures were observed in the casting.more » The smaller the thickness, the higher the hardness with smaller secondary dendrite arm spacing (SDAS). However, the hardness and the SDAS were unaffected by the mold temperature. It was proposed that the avoidance of the formation of primary {alpha} dendrite at the melt path generates a higher strength casting with adequate mold filling.« less

On Macrosegregation

NASA Astrophysics Data System (ADS)

Ludwig, Andreas; Wu, Menghuai; Kharicha, Abdellah

2015-11-01

Macrosegregations, namely compositional inhomogeneities at a scale much larger than the microstructure, are typically classified according to their metallurgical appearance. In ingot castings, they are known as `A' and `V' segregation, negative cone segregation, and positive secondary pipe segregation. There exists `inverse' segregation at casting surfaces and `centerline' segregation in continuously cast slabs and blooms. Macrosegregation forms if a relative motion between the solute-enriched or -depleted melt and dendritic solid structures occurs. It is known that there are four basic mechanisms for the occurrence of macrosegregation. In the recent years, the numerical description of the combination of these mechanisms has become possible and so a tool has emerged which can be effectively used to get a deeper understanding into the process details which are responsible for the formation of the above-mentioned different macrosegregation appearances. Based on the most sophisticated numerical models, we consequently associate the four basic formation mechanisms with the physical phenomena happening during (i) DC-casting of copper-based alloys, (ii) DC-casting of aluminum-based alloys, (iii) continuous casting of steel, and (iv) ingot casting of steel.

Serial elongation derotation flexion (EDF) casting for patients with infantile and juvenile scoliosis.

PubMed

Canavese, Federico; Rousset, Marie; Mansour, Mounira; Samba, Antoine; Dimeglio, Alain

2016-02-01

Infantile and juvenile scoliosis, among different types of spinal deformity, is still a challenge for pediatric orthopedic surgeons. The ideal treatment of infantile and juvenile scoliosis has not yet been identified as both clinicians and surgeons still face multiple challenges, including preservation of the thoracic spine, thoracic cage, lung growth and cardiac function without reducing spinal motion. Elongation, derotation, flexion (EDF) casting technique is a custom-made thoracolumbar cast based on a three dimensional correction concept. This cast offers three-dimensional correction and can control the evolution of the deformity in some cases. Spinal growth can be guided by EDF casting as it can influence the initially curved spine to grow straighter. This article aimed to provide a comprehensive review of how infantile and juvenile scoliosis can affect normal spine and thorax and how these deformities can be treated with serial EDF casting technique. A current literature review is mandatory in order to understand the principles of the serial EDF casting technique and the effectiveness of conservative treatment in young and very young patients.

Development of casting investment preventing blackening of noble metal alloys part 1. Application of developed investment for Ag-Pd-Cu-Au alloy.

PubMed

Kakuta, Kiyoshi; Nakai, Akira; Goto, Shin-ichi; Wakamatsu, Yasushi; Yara, Atushi; Miyagawa, Yukio; Ogura, Hideo

2003-03-01

The objective of this study is to develop a casting investment that prevents the blackening of the cast surface of noble metal alloys. The experimental investments were prepared using a gypsum-bonded investment in which the metallic powders such as boron (B), silicon (Si), aluminum (Al) and titanium (Ti) were added as oxidizing agents. An Ag-Pd-Cu-Au alloy was cast into the mold made of the prepared investment. The effect of the addition of each metal powder was evaluated from the color difference between the as-cast surface and the polished surface of the cast specimen. The color of the as-cast surface approached that of the polished surface with increasing B and Al content. A lower mean value in the color difference was obtained at 0.25-1.00 mass% B content. B and Al are useful as an additive in a gypsum-bonded investment to prevent the blackening of an Ag-Pd-Cu-Au alloy. The effects of Si and Ti powder addition could not be found.

Laser welding of removable partial denture frameworks.

PubMed

Brudvik, James S; Lee, Seungbum; Croshaw, Steve N; Reimers, Donald L; Reimers, Dave L

2008-01-01

To identify and measure distortions inherent in the casting process of a Class III mandibular cobalt-chromium (Co-Cr) framework to illustrate the problems faced by the laboratory technician and the clinician and to measure the changes that occur during the correction of the fit discrepancy using laser welding. Five identical castings of a Co-Cr alloy partial denture casting were made and measured between 3 widely separated points using the x, y, and z adjustments of a Nikon Measurescope. The same measurements were made after each of the following clinical and laboratory procedures: sprue removal, sectioning of the casting into 3 parts through the posterior meshwork, fitting the segments to the master cast, picking up the segments using resin, and laser welding of the 3 segments. Measurements of all 5 castings showed a cross-arch decrease after sprue removal, an increase after fitting the segments to the master cast, and a slight decrease after resin pickup and laser welding. Within the limitations of this study, the findings suggest that precise tooth-frame relations can be established by resin pickup and laser welding of segments of Co-Cr removable partial denture frameworks.

Mechanical strength and microstructure of laser-welded Ti-6Al-7Nb alloy castings.

PubMed

Srimaneepong, Viritpon; Yoneyama, Takayuki; Kobayashi, Equo; Doi, Hisashi; Hanawa, Takao

2005-12-01

Mechanical properties of laser-welded castings of Ti-6Al-7Nb alloy, CP Ti, and Co-Cr alloy were investigated and compared to the unwelded castings using a tensile test. Dumbbell-shaped specimens were cut at the center, and two halves of the specimens were welded with an Nd:YAG laser welding machine at 220 or 260 V of laser voltage. The mechanical strength of 260 V groups was higher than that of 220 V groups for Ti-6Al-7Nb and Co-Cr alloys except for CP Ti. All 260 V laser-welded castings of Ti-6Al-7Nb alloy and CP Ti, which fractured outside the welded joints, exhibited ductile characteristics, while all laser-welded Co-Cr alloy castings, which fractured within the welded joints, showed brittle characteristics. This study proved that the mechanical strength of laser-welded Ti-6Al-7Nb alloy and CP Ti castings was as high as that of unwelded castings, while the mechanical properties of laser-welded alloy joints were influenced by microstructural changes.

Effect of Heat Treatment on the Impact Toughness of `High-Chromium Cast Iron - Low Alloy Steel' Bimetal Components

NASA Astrophysics Data System (ADS)

Özdemir, Z.

2017-03-01

A bimetallic `low-alloy steel - high-chromium cast iron' composite obtained by successive sand casting is studied and shown to have good cohesion on the interface and no casting defects. The hardness and the impact toughness of the bimetal increase simultaneously. The microstructure is more homogeneous after diffusion annealing at 1040°C, rapid cooling, and 3-h tempering at 270°C.

Effect of Grain Refining on Defect Formation in DC Cast Al-Zn-Mg-Cu Alloy Billet

NASA Astrophysics Data System (ADS)

Nadella, Ravi; Eskin, Dmitry; Katgerman, Laurens

In direct chill (DC) casting, the effect of grain refining on the prominent defects such as hot cracking and macrosegregation remains poorly understood, especially for multi-component commercial aluminum alloys. In this work, DC casting experiments were conducted on a 7075 alloy with and without grain refining at two casting speeds. The grain refiner was introduced either in the launder or in the furnace. The concentration profiles of Zn, Cu and Mg, measured along the billet diameter, showed that the increasing casting speed raises the segregation levels but grain refining does not seem to have a noticeable effect. However, hot cracking tendency is significantly reduced with grain refining and it is observed that crack is terminated with the introduction of grain refiner at a lower casting speed. These experimental results are correlated with microstructural observations such as grain size and morphology, and the occurrence of floating grains.

Modeling of interdendritic porosity defects in an integrated computational materials engineering approach for metal casting

DOE PAGES

Sabau, Adrian S.

2016-04-22

Modeling and simulation of multiphysical phenomena needs to be considered in the design and optimization of mechanical properties of cast components in order to accelerate the introduction of new cast alloys. The data on casting defects, including microstructure features, is crucial for evaluating the final performance-related properties of the component. Here in this paper, the required models for the prediction of interdendritic casting defects, such as microporosity and hot tears, are reviewed. The data on calculated solidification shrinkage is presented and its effects on microporosity levels discussed. Numerical simulation results for microporosity are presented for A356, 356 and 319 aluminummore » alloys using ProCAST TM software. The calculated pressure drop of the interdendritic liquid was observed to be quite significant and the regions of high-pressure drop can be used as an indicator of the severity of interdendritic microporosity defects.« less

Bile Cast Nephropathy Caused by Obstructive Cholestasis.

PubMed

Aniort, Julien; Poyet, Anaïs; Kemeny, Jean-Louis; Philipponnet, Carole; Heng, Anne-Elisabeth

2017-01-01

Acute kidney injury (AKI) is a major complication in patients with liver disease. Although hepatorenal syndrome is frequently involved, bile cast nephropathy, characterized by tubular bile cast formation, has been scarcely described in the setting of severe liver failure. Few renal histology studies are available in these patients. We describe a case of bile cast nephropathy in a patient with obstructive cholestasis caused by stones in the common bile duct. The kidney biopsy confirmed this diagnosis, with several green casts in tubular lumens, tubular injury, and bilirubin composition of the tubular casts with Hall stain. The patient had no confounding cause of kidney failure, and complete kidney recovery followed removal of the bile duct obstruction. This case shows that severe cholestasis is sufficient to cause AKI, and that AKI can be reversible after treatment of the biliary obstruction. Copyright © 2016 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.

Religion insulates ingroup evaluations: the development of intergroup attitudes in India.

PubMed

Dunham, Yarrow; Srinivasan, Mahesh; Dotsch, Ron; Barner, David

2014-03-01

Research on the development of implicit intergroup attitudes has placed heavy emphasis on race, leaving open how social categories that are prominent in other cultures might operate. We investigate two of India's primary means of social distinction, caste and religion, and explore the development of implicit and explicit attitudes towards these groups in minority-status Muslim children and majority-status Hindu children, the latter drawn from various positions in the Hindu caste system. Results from two tests of implicit attitudes find that caste attitudes parallel previous findings for race: higher-caste children as well as lower-caste children have robust high-caste preferences. However, results for religion were strikingly different: both lower-status Muslim children and higher-status Hindu children show strong implicit ingroup preferences. We suggest that religion may play a protective role in insulating children from the internalization of stigma. © 2013 John Wiley & Sons Ltd.

A survey of DNA methylation across social insect species, life stages, and castes reveals abundant and caste-associated methylation in a primitively social wasp

NASA Astrophysics Data System (ADS)

Weiner, Susan A.; Galbraith, David A.; Adams, Dean C.; Valenzuela, Nicole; Noll, Fernando B.; Grozinger, Christina M.; Toth, Amy L.

2013-08-01

DNA methylation plays an important role in the epigenetic control of developmental and behavioral plasticity, with connections to the generation of striking phenotypic differences between castes (larger, reproductive queens and smaller, non-reproductive workers) in honeybees and ants. Here, we provide the first comparative investigation of caste- and life stage-associated DNA methylation in several species of bees and vespid wasps displaying different levels of social organization. Our results reveal moderate levels of DNA methylation in most bees and wasps, with no clear relationship to the level of sociality. Strikingly, primitively social Polistes dominula paper wasps show unusually high overall DNA methylation and caste-related differences in site-specific methylation. These results suggest DNA methylation may play a role in the regulation of behavioral and physiological differences in primitively social species with more flexible caste differences.

Strip casting with fluxing agent applied to casting roll

DOEpatents

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

1997-01-01

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

Modeling of Casting Defects in an Integrated Computational Materials Engineering Approach

NASA Astrophysics Data System (ADS)

Sabau, Adrian S.

To accelerate the introduction of new cast alloys the modeling and simulation of multiphysical phenomena needs to be considered in the design and optimization of mechanical properties of cast components. The required models related to casting defects, such as microporosity and hot tears are reviewed. Three aluminum alloys are considered A356, 356 and 319. The data on calculated solidification shrinkage is presented and its effects on microporosity levels discussed. Examples are given for predicting microporosity defects and microstructure distribution for a plate casting. Models to predict fatigue life and yield stress are briefly highlighted here for the sake of completion and to illustrate how the length scales of the microstructure features as well as porosity defects are taken into account for modeling the mechanical properties. The data on casting defects including microstructure features, is crucial for evaluating the final performance-related properties of the component.

Effect of inlet geometry on macrosegregation during the direct chill casting of 7050 alloy billets: experiments and computer modelling

NASA Astrophysics Data System (ADS)

Zhang, L.; Eskin, D. G.; Miroux, A.; Subroto, T.; Katgerman, L.

2012-07-01

Controlling macrosegregation is one of the major challenges in direct-chill (DC) casting of aluminium alloys. In this paper, the effect of the inlet geometry (which influences the melt distribution) on macrosegregation during the DC casting of 7050 alloy billets was studied experimentally and by using 2D computer modelling. The ALSIM model was used to determine the temperature and flow patterns during DC casting. The results from the computer simulations show that the sump profiles and flow patterns in the billet are strongly influenced by the melt flow distribution determined by the inlet geometry. These observations were correlated to the actual macrosegregation patterns found in the as-cast billets produced by having two different inlet geometries. The macrosegregation analysis presented here may assist in determining the critical parameters to consider for improving the casting of 7XXX aluminium alloys.

Development of an Innovative Laser-Assisted Coating Process for Extending Lifetime of Metal Casting Dies. Final Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Madhav Rao Gonvindaraju

1999-10-18

Die casting dies used in the metal casting industry fail due to thermal fatigue cracking accompanied by the presence of residual tensile stresses, corrosion, erosion and wear of die surfaces. This phase 1 SBIR Final Report summarize Karta Technologies research involving the development of an innovative laser coating technology for metal casting dies. The process involves depositing complex protective coatings of nanocrystalline powders of TiC followed by a laser shot peening. The results indicate a significant improvement in corrosion and erosion resistance in molten aluminum for H13 die casting die steels. The laser-coated samples also showed improved surface finish, amore » homogeneous and uniform coating mircrostructure. The technology developed in this research can have a significant impact on the casting industry by saving the material costs involved in replacing dies, reducing downtime and improving the quality.« less

Structure and properties of stir-cast zinc alloys

DOE Office of Scientific and Technical Information (OSTI.GOV)

LeHuy, H.; Blain J.; Masounave, J.

Stir casting (or rheocasting) of ZA-27 zinc alloys was investigated experimentally. By vigorously agitating the alloys during cooling, the dendrites that were forming were fragmented giving a unique structure composed of spherical and rosette shaped particles suspended in the remaining liquid. Under high shear rates ({center dot}{gamma} = 300s{sup {minus}1} or more) the slurries with primary particle concentrations as high as 60% displayed viscosities as low as 20 poises and could easily be casted. The effects of processing variables such as shearing and cooling rates and casting temperatures were studied. Their relative importance on the rheological and microstructural behavior ofmore » the stir cast alloys are discussed. Results from viscosity measurements on slurries show that non-dendritical ZA-27 alloys obey a power law fluid model. Finally, results from mechanical and compressive studies carried out on solidified slurries are discussed and compared to conventional casted and wrought alloy properties.« less

Caste development and reproduction: a genome-wide analysis of hallmarks of insect eusociality

PubMed Central

Cristino, A S; Nunes, F M F; Lobo, C H; Bitondi, M M G; Simões, Z L P; Da Fontoura Costa, L; Lattorff, H M G; Moritz, R F A; Evans, J D; Hartfelder, K

2006-01-01

The honey bee queen and worker castes are a model system for developmental plasticity. We used established expressed sequence tag information for a Gene Ontology based annotation of genes that are differentially expressed during caste development. Metabolic regulation emerged as a major theme, with a caste-specific difference in the expression of oxidoreductases vs. hydrolases. Motif searches in upstream regions revealed group-specific motifs, providing an entry point to cis-regulatory network studies on caste genes. For genes putatively involved in reproduction, meiosis-associated factors came out as highly conserved, whereas some determinants of embryonic axes either do not have clear orthologs (bag of marbles, gurken, torso), or appear to be lacking (trunk) in the bee genome. Our results are the outcome of a first genome-based initiative to provide an annotated framework for trends in gene regulation during female caste differentiation (representing developmental plasticity) and reproduction. PMID:17069641

Fabrication of Ti-0.48Al Alloy by Centrifugal Casting.

PubMed

Park, Jong Bum; Lee, Jung-Il; Ryu, Jeong Ho

2018-09-01

Many of the unique properties of TiAl alloys that make are attractive for use in high-temperature structural applications also make it challenging to process them into useful products. Cast TiAl is rapidly nearing commercialization, particularly in the vehicle industry, owing to its low production cost. In this study, the centrifugal casting of a TiAl (Ti-48%Al, mole fraction) turbocharger was simulated and an experimental casting was created in vacuum using an induction melting furnace coupled to a ceramic composite mold. Numerical simulation results agreed with the experiment. The crystal structure, microstructure, and chemical composition of the TiAl prepared by centrifugal casting were studied by X-ray diffractometry, optical microscopy, field emission scanning electron microscopy (FE-SEM) and energy dispersive spectroscopy (EDS). FE-SEM and EDS examinations of the TiAl casting revealed that the thickness of the oxide layer (α-case) was typically less than 35 μm.

Effect of bionic coupling units' forms on wear resistance of gray cast iron under dry linear reciprocating sliding condition

NASA Astrophysics Data System (ADS)

Pang, Zuobo; Zhou, Hong; Xie, Guofeng; Cong, Dalong; Meng, Chao; Ren, Luquan

2015-07-01

In order to get close to the wear form of guide rails, the homemade linear reciprocating wear testing machine was used for the wear test. In order to improve the wear-resistance of gray cast iron guide rail, bionic coupling units of different forms were manufactured by a laser. Wear behavior of gray-cast-iron with bionic-coupling units has been studied under dry sliding condition at room temperature using the wear testing machine. The wear resistance was evaluated by means of weight loss measurement and wear morphology. The results indicated that bionic coupling unit could improve the wear resistance of gray cast iron. The wear resistance of gray cast iron with reticulation bionic coupling unit is the best. When the load and speed changed, reticulation bionic coupling unit still has excellent performance in improving the wear resistance of gray cast iron.

Cast erosion from the cleaning of debris after the use of a cast trimmer.

PubMed

Hansen, Paul A; Beatty, Mark W

2017-02-01

Whether using tap water to rinse off debris will make a clinical difference to the surface detail of a gypsum cast is unknown. In addition, how best to remove debris from the cast is unknown. The purpose of this in vitro study was to evaluate the efficiency of different methods of cleaning a gypsum cast after trimming and the effect of short-term exposure to tap water on the surface quality of the cast. A die fitting American National Standards Institute/American Dental Association specification 25 (International Standards Organization specification 6873) for dental gypsum products was embedded in a Dentoform with the machined lines positioned at the same level as the occlusal surface of the posterior teeth. A flat plate was used to ensure that the plane of occlusion for the die was at the same position as the posterior teeth. Forty polyvinyl siloxane impressions of the Dentoform were made and poured with vacuum-mixed improved Type IV dental stone. Each cast was inspected for the accurate reproduction of the lines. The base of the 2-stage pour was trimmed with a cast trimmer with water, and surface debris was removed by rinsing by hand under tap water for 10 seconds, by brushing the cast with a soft toothbrush for 10 seconds, or by resoaking the cast and using a soft camel hair brush in slurry water for 10 seconds. The amount of debris was evaluated on a scale of 1 to 4, and the quality of the 20-μm line was evaluated on a scale of 1 to 4 under ×15 magnification. The nonparametric Kruskal-Wallis ranks test was used to identify significant differences among the different cleaning methods (α=.05). Results of the Kruskal-Wallis and Kruskal-Wallis Z-value tests demonstrated that all cleaning methods produced cleaner casts than were observed for uncleansed controls (P<.001), but no differences in debris removal were found among the different cleaning methods (.065≤P≤.901). The ability to see the quality of a 20-μm line (P=.974) was not statistically different among the groups. Rinsing the cast under flowing tap water and brushing, or hand washing under flowing tap water, or using a soft camel hair brush in slurry water for 10 seconds had no noticeable effects on the quality of a 20-μm line, and all 3 methods resulted in a clean cast. Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Biceps Tendon Lengthening Surgery for Failed Serial Casting Patients With Elbow Flexion Contractures Following Brachial Plexus Birth Injury

PubMed Central

Somasundaram, Chandra

2016-01-01

Objective: Assessment of surgical outcomes of biceps tendon lengthening (BTL) surgery in obstetric brachial plexus injury (OBPI) patients with elbow flexion contractures, who had unsuccessful serial casting. Background: Serial casting and splinting have been shown to be effective in correcting elbow flexion contractures in OBPI. However, the possibilities of radial head dislocations and other complications have been reported in serial casting and splinting. Literature indicates surgical intervention when such nonoperative techniques and range-of-motion exercises fail. Here, we demonstrated a significant reduction of the contractures of the affected elbow and improvement in arm length to more normal after BTL in these patients, who had unsuccessful serial casting. Methods and Patients: Ten OBPI patients (6 girls and 4 boys) with an average age of 11.2 years (4-17.7 years) had BTL surgery after unsuccessful serial casting. Results: Mean elbow flexion contracture was 40° before and 37° (average) after serial casting. Mean elbow flexion contracture was reduced to 8° (0°-20°) post-BTL surgical procedure with an average follow-up of 11 months. This was 75% improvement and statistically significant (P < .001) when compared to 7% insignificant (P = .08) improvement after serial casting. Conclusion: These OBPI patients in our study had 75% significant reduction in elbow flexion contractures and achieved an improved and more normal length of the affected arm after the BTL surgery when compared to only 7% insignificant reduction and no improvement in arm length after serial casting. PMID:27648115

The application of multi-baseline digital close-range photogrammetry in three-dimensional imaging and measurement of dental casts

PubMed Central

Li, Zan; Liu, Shan; Tan, Minmin; Song, Jinlin

2017-01-01

Objective To explore a new technique for reconstructing and measuring three-dimensional (3D) models of orthodontic plaster casts using multi-baseline digital close-range photogrammetry (MBDCRP) with a single-lens reflex camera. Study design Thirty sets of orthodontic plaster casts that do not exhibit severe horizontal overlap (>2 mm) between any two teeth were recorded by a single-lens reflex camera with 72 pictures taken in different directions. The 3D models of these casts were reconstructed and measured using the open source software MeshLab. These parameters, including mesio-distal crown diameter, arch width, and arch perimeter, were recorded six times on both the 3D digital models and on plaster casts by two examiners. Statistical analysis was carried out using the Bland–Altman method to measure agreement between the novel method and the traditional calliper method by calculating the differences between mean values. Results The average differences between the measurements of the photogrammetric 3D models and the plaster casts were 0.011–0.402mm. The mean differences between measurements obtained by the photogrammetric 3D models and the dental casts were not significant except for the lower arch perimeter (P>0.05), and all the differences were regarded as clinically acceptable (<0.5 mm). Conclusions Measurements obtained by MBDCRP are compared well with those obtained from plaster casts, indicating that MBDCRP is an alternate way to store and measure dental plaster casts without severe horizontal overlap between any two teeth. PMID:28640827

Influence of S. mutans on base-metal dental casting alloy toxicity.

PubMed

McGinley, E L; Dowling, A H; Moran, G P; Fleming, G J P

2013-01-01

We have highlighted that exposure of base-metal dental casting alloys to the acidogenic bacterium Streptococcus mutans significantly increases cellular toxicity following exposure to immortalized human TR146 oral keratinocytes. With Inductively Coupled Plasma-Mass Spectrometry (ICP-MS), S. mutans-treated nickel-based (Ni-based) and cobalt-chromium-based (Co-Cr-based) dental casting alloys were shown to leach elevated levels of metal ions compared with untreated dental casting alloys. We targeted several biological parameters: cell morphology, viable cell counts, cell metabolic activity, cell toxicity, and inflammatory cytokine expression. S. mutans-treated dental casting alloys disrupted cell morphology, elicited significantly decreased viable cell counts (p < 0.0001) and cell metabolic activity (p < 0.0001), and significantly increased cell toxicity (p < 0.0001) and inflammatory cytokine expression (p < 0.0001). S. mutans-treated Ni-based dental casting alloys induced elevated levels of cellular toxicity compared with S. mutans-treated Co-Cr-based dental casting alloys. While our findings indicated that the exacerbated release of metal ions from S. mutans-treated base-metal dental casting alloys was the likely result of the pH reduction during S. mutans growth, the exact nature of mechanisms leading to accelerated dissolution of alloy-discs is not yet fully understood. Given the predominance of S. mutans oral carriage and the exacerbated cytotoxicity observed in TR146 cells following exposure to S. mutans-treated base-metal dental casting alloys, the implications for the long-term stability of base-metal dental restorations in the oral cavity are a cause for concern.

Structural and compositional analysis of a casting mold sherd from ancient China

PubMed Central

Zong, Yunbing; Yao, Shengkun; Lang, Jianfeng; Chen, Xuexiang; Fan, Jiadong; Sun, Zhibin; Duan, Xiulan; Li, Nannan; Fang, Hui; Zhou, Guangzhao; Xiao, Tiqiao; Li, Aiguo; Jiang, Huaidong

2017-01-01

Casting had symbolic significance and was strictly controlled in the Shang dynasty of ancient China. Vessel casting was mainly distributed around the Shang capital, Yin Ruins, which indicates a rigorous centralization of authority. Thus, for a casting mold to be excavated far from the capital region is rare. In addition to some bronze vessel molds excavated at the Buyao Village site, another key discovery of a bronze vessel mold occurred at Daxinzhuang. The Daxinzhuang site was a core area in the east of Shang state and is an important site to study the eastward expansion of the Shang. Here, combining synchrotron X-rays and other physicochemical analysis methods, nondestructive three-dimensional structure imaging and different elemental analyses were conducted on this mold sherd. Through high penetration X-ray tomography, we obtained insights on the internal structure and discovered some pores. We infer that the generation of pores inside the casting mold sherd was used to enhance air permeability during casting. Furthermore, we suppose that the decorative patterns on the surface were carved and not pasted onto it. Considering the previous compositional studies of bronze vessels, the copper and iron elements were analyzed by different methods. Unexpectedly, a larger amount of iron than of copper was detected on the surface. According to the data analysis and archaeological context, the source of iron on the casting mold sherd could be attributed to local soil contamination. A refined compositional analysis confirms that this casting mold was fabricated locally and used for bronze casting. PMID:28296963

The effect and complication of botulinum toxin type a injection with serial casting for the treatment of spastic equinus foot.

PubMed

Lee, Sook Joung; Sung, In Young; Jang, Dae Hyun; Yi, Jin Hwa; Lee, Jin Ho; Ryu, Ju Seok

2011-06-01

To identify the effect of serial casting combined with Botulinum toxin type A (BTX-A) injection on spastic equinus foot. Twenty-nine children with cerebral palsy who had equinus foot were recruited from the outpatient clinic of Rehabilitation Medicine. The children were divided into 2 groups, one of which received serial casting after BTX-A injection, and the other which only received BTX-A injection. Serial casting started 3 weeks after the BTX-A injection, and was changed weekly for 3 times. Spasticity of the ankle joint was evaluated using the modified Ashworth scale (MAS), and the modified Tardieu scale (MTS). Gait pattern was measured using the physician's rating scale (PRS). The degree of ankle dorsiflexion and the MAS improved significantly until 12 weeks following the BTX-A injection in the serial casting group (p<0.001), while the BTX-A injection-only group improved until 6 weeks following injection (p<0.05). The combined group showed a significantly greater increase in the degree of dorsiflexion compared to the BTX-A injection-only group at post-injection weeks 6 and 12 (p<0.05). Three children (11.5%) suffered from foot ulcers as a complication caused by the serial casting. Our study demonstrated that the effect of BTX-A injection with serial casting was superior and lasted longer than the effect of BTX-A injection only in patients with spastic equinus foot. We therefore recommend BTX-A injection with serial casting for the treatment of equinus foot. However, physicians must also consider the possible complications associated with serial casting.

Comparative Evaluation of Marginal Accuracy of a Cast Fixed Partial Denture Compared to Soldered Fixed Partial Denture Made of Two Different Base Metal Alloys and Casting Techniques: An In vitro Study.

PubMed

Jei, J Brintha; Mohan, Jayashree

2014-03-01

The periodontal health of abutment teeth and the durability of fixed partial denture depends on the marginal adaptation of the prosthesis. Any discrepancy in the marginal area leads to dissolution of luting agent and plaque accumulation. This study was done with the aim of evaluating the accuracy of marginal fit of four unit crown and bridge made up of Ni-Cr and Cr-Co alloys under induction and centrifugal casting. They were compared to cast fixed partial denture (FPD) and soldered FPD. For the purpose of this study a metal model was fabricated. A total of 40 samples (4-unit crown and bridge) were prepared in which 20 Cr-Co samples and 20 Ni-Cr samples were fabricated. Within these 20 samples of each group 10 samples were prepared by induction casting technique and other 10 samples with centrifugal casting technique. The cast FPD samples obtained were seated on the model and the samples were then measured with travelling microscope having precision of 0.001 cm. Sectioning of samples was done between the two pontics and measurements were made, then the soldering was made with torch soldering unit. The marginal discrepancy of soldered samples was measured and all findings were statistically analysed. The results revealed minimal marginal discrepancy with Cr-Co samples when compared to Ni-Cr samples done under induction casting technique. When compared to cast FPD samples, the soldered group showed reduced marginal discrepancy.

25 CFR 81.21 - Counting of ballots.

Code of Federal Regulations, 2010 CFR

2010-04-01

... STATUTE § 81.21 Counting of ballots. All duly cast ballots are to be counted. Even though it will not be... counted for purposes of determining whether the required percentage of voters have cast their ballots in... of votes cast. ...

Semi-simultaneous application of neutron and X-ray radiography in revealing the defects in an Al casting.

PubMed

Balaskó, M; Korösi, F; Szalay, Zs

2004-10-01

A semi-simultaneous application of neutron and X-ray radiography (NR, XR) respectively, was applied to an Al casting. The experiments were performed at the 10MW VVR-SM research reactor in Budapest (Hungary). The aim was to reveal, identify and parameterize the hidden defects in the Al casting. The joint application of NR and XR revealed hidden defects located in the Al casting. Image analysis of the NR and XR images unveiled a cone-like dimensionality of the defects. The spectral density analysis of the images showed a distinctly different character for the hidden defect region of Al casting in comparison with that of the defect-free one.

Evaluation of Uranium-235 Measurement Techniques

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kaspar, Tiffany C.; Lavender, Curt A.; Dibert, Mark W.

2017-05-23

Monolithic U-Mo fuel plates are rolled to final fuel element form from the original cast ingot, and thus any inhomogeneities in 235U distribution present in the cast ingot are maintained, and potentially exaggerated, in the final fuel foil. The tolerance for inhomogeneities in the 235U concentration in the final fuel element foil is very low. A near-real-time, nondestructive technique to evaluate the 235U distribution in the cast ingot is required in order to provide feedback to the casting process. Based on the technical analysis herein, gamma spectroscopy has been recommended to provide a near-real-time measure of the 235U distribution inmore » U-Mo cast plates.« less

Process for manufacturing a lithium alloy electrochemical cell

DOEpatents

Bennett, William R.

1992-10-13

A process for manufacturing a lithium alloy, metal sulfide cell tape casts slurried alloy powders in an organic solvent containing a dissolved thermoplastic organic binder onto casting surfaces. The organic solvent is then evaporated to produce a flexible tape removable adhering to the casting surface. The tape is densified to increase its green strength and then peeled from the casting surface. The tape is laminated with a separator containing a lithium salt electrolyte and a metal sulfide electrode to form a green cell. The binder is evaporated from the green cell at a temperature lower than the melting temperature of the lithium salt electrolyte. Lithium alloy, metal sulfide and separator powders may be tape cast.

Detection of canine astrovirus in dogs with diarrhea in Japan.

PubMed

Takano, Tomomi; Takashina, Midori; Doki, Tomoyoshi; Hohdatsu, Tsutomu

2015-06-01

Canine astrovirus (CAstV) is the causative agent of gastroenteritis in dogs. We collected rectal swabs from dogs with or without diarrhea symptoms in Japan and examined the feces for the presence of CAstV by RT-PCR with primers based on a conserved region of the ORF1b gene. The ORF1b gene of CAstV was not detected in the 42 dogs without clinical illness but was present in three pups out of the 31 dogs with diarrhea symptoms. Based on the full-length capsid protein, the CAstV KU-D4-12 strain that we detected in this study shared high homology with the novel virulent CAstV VM-2011 strain.

Development of Metal Casting Molds By Sol-Gel Technology Using Planetary Resources

NASA Technical Reports Server (NTRS)

Sibille, L.; Sen, S.; Curreri, P.; Stefanescu, D.

2000-01-01

Metals extracted from planetary soils will eventually need to be casted and shaped in-situ to produce useful products. In response to this challenge, we propose to develop and demonstrate the manufacturing of a specific product using Lunar and Martian soil simulants, i.e. a mold for the casting of metal and alloy parts, which will be an indispensable tool for the survival of outposts on the Moon and Mars. Drawing from our combined knowledge of sol-gel and metal casting technologies, we set out to demonstrate the extraordinary potential of mesoporous materials such as aerogels to serve as efficient casting molds as well as fulfilling numerous other needs of an autonomous planetary outpost.

Three-dimensional microstructure simulation of Ni-based superalloy investment castings

NASA Astrophysics Data System (ADS)

Pan, Dong; Xu, Qingyan; Liu, Baicheng

2011-05-01

An integrated macro and micro multi-scale model for the three-dimensional microstructure simulation of Ni-based superalloy investment castings was developed, and applied to industrial castings to investigate grain evolution during solidification. A ray tracing method was used to deal with the complex heat radiation transfer. The microstructure evolution was simulated based on the Modified Cellular Automaton method, which was coupled with three-dimensional nested macro and micro grids. Experiments for Ni-based superalloy turbine wheel investment casting were carried out, which showed a good correspondence with the simulated results. It is indicated that the proposed model is able to predict the microstructure of the casting precisely, which provides a tool for the optimizing process.

Software Analytical Instrument for Assessment of the Process of Casting Slabs

NASA Astrophysics Data System (ADS)

Franěk, Zdeněk; Kavička, František; Štětina, Josef; Masarik, Miloš

2010-06-01

The paper describes the original proposal of ways of solution and function of the program equipment for assessment of the process of casting slabs. The program system LITIOS was developed and implemented in EVRAZ Vitkovice Steel Ostrava on the equipment of continuous casting of steel (further only ECC). This program system works on the data warehouse of technological parameters of casting and quality parameters of slabs. It enables an ECC technologist to analyze the course of casting melt and with using statistics methods to set the influence of single technological parameters on the duality of final slabs. The system also enables long term monitoring and optimization of the production.

Modern Cast Irons in Chemical Engineering

DTIC Science & Technology

1934-11-09

fl’ceew. T I SOCIETY OF CHEMICAL INDUSTRY CHEMICAL ENGINEERING GROUP MODERN CAST IRONS IN CHEMICAL ENGINEERING By J. G. PEARCE, M.Sc., F.Inst.P...CAST IRONS IN CHEMICAL ENGINEERING By J. G. PEARCE, M.Sc., F.Inst.P., M.I.E.E.* INTRODUCTION to chemical or thermal resistance. Small blow-holes Any...consideration of modern cast irons in chemical seldom appear to reduce the mechanical strength of engineering should strictly be prefaced by a definition

Metal Matrix Composite LOX Turbopump Housing Via Novel Tool-Less Net-Shape Pressure Infiltration Casting Technology

NASA Technical Reports Server (NTRS)

Shah, Sandeep; Lee, Jonathan; Bhat, Biliyar; Wells, Doug; Gregg, Wayne; Marsh, Matthew; Genge, Gary; Forbes, John; Salvi, Alex; Cornie, James A.;

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

Once installed, the 'HindCast Player' HyperCard stack displays the spill trajectory of the EXXON Valdez oil spill in the Prince William Sound in March of 1989. The product, 'Exxon Valdez Hind Cast' contains one compressed file and one documentation file. The file containing the documentation is named 'Read.me', and the compressed file is named Exxon HindCasts'. The compressed folder contains a moov file called 'EXXON Valdez', a HyperCard Stack called, 'HindCast Player v/2', and Apples QuickTime(TM) extension file.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ghadkolai, Milad Azami; Creager, Stephen; Nanda, Jagjit

Lithium titanate (Li 4Ti 5O 12) powders with and without molybdenum doping (LTO and MoLTO respectively) were synthesized by a solid-state method and used to fabricate electrodes on Cu foil using a normal tape-cast method and a novel freeze-tape-cast method. Modest molybdenum doping produces a significant electronic conductivity increase (e.g. 1 mS cm -1 for MoLTO vs 10 -7 mS cm -1 for LTO) that is thought to reflect a partial Ti 4+ reduction to Ti 3+ with charge compensation by the Mo 6+ dopant, producing a stable mixed-valent Ti 4+/3+ state. Freeze-tape-cast electrodes were fabricated by a variant ofmore » the normal tape-cast method that includes a rapid freezing step in which the solvent in the Cu-foil-supported slurry is rapidly frozen on a cold finger then subsequently sublimed to create unidirectional columnar macropores in the electrode. The resulting electrodes exhibit high porosity and low tortuosity which enhances electrolyte accessibility throughout the full electrode thickness. Freeze-tape-cast electrodes subjected to galvanostatic charge-discharge testing as cathodes in cells vs. a lithium metal anode exhibit higher specific capacity and lower capacity loss at high discharge rates compared with normal-tape-cast electrodes of the same mass loading, despite the fact that the freeze-tape-cast electrodes are nearly twice as thick as the normal tape cast electrodes.« less

Energy-Saving Melting and Revert Reduction Technology (E-SMARRT): Lost Foam Thin Wall - Feasibility of Producing Lost Foam Castings in Aluminum and Magnesium Based Alloys

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fasoyinu, Yemi; Griffin, John A.

2014-03-31

With the increased emphasis on vehicle weight reduction, production of near-net shape components by lost foam casting will make significant inroad into the next-generation of engineering component designs. The lost foam casting process is a cost effective method for producing complex castings using an expandable polystyrene pattern and un-bonded sand. The use of un-bonded molding media in the lost foam process will impose less constraint on the solidifying casting, making hot tearing less prevalent. This is especially true in Al-Mg and Al-Cu alloy systems that are prone to hot tearing when poured in rigid molds partially due to their longmore » freezing range. Some of the unique advantages of using the lost foam casting process are closer dimensional tolerance, higher casting yield, and the elimination of sand cores and binders. Most of the aluminum alloys poured using the lost foam process are based on the Al-Si system. Very limited research work has been performed with Al-Mg and Al-Cu type alloys. With the increased emphasis on vehicle weight reduction, and given the high-strength-to-weight-ratio of magnesium, significant weight savings can be achieved by casting thin-wall (≤ 3 mm) engineering components from both aluminum- and magnesium-base alloys.« less

Culture in Psychiatric Epidemiology: Using Ethnography and Multiple Mediator Models to Assess the Relationship of Caste with Depression and Anxiety in Nepal

PubMed Central

Kohrt, Brandon A.; Speckman, Rebecca A.; Kunz, Richard D.; Baldwin, Jennifer L.; Upadhaya, Nawaraj; Acharya, Nanda Raj; Sharma, Vidya Dev; Nepal, Mahendra K.; Worthman, Carol M.

2013-01-01

Background The causes of ethnic and caste-based disparities in mental health are poorly understood. Aim To identify mediators underlying caste-based disparities in mental health in Nepal. Subjects and methods A mixed methods ethnographic and epidemiological study of 307 adults (Dalit/Nepali, n=75; high caste Brahman and Chhetri, n=232) assessed with Nepali versions of Beck Depression (BDI) and Anxiety (BAI) Inventories. Results One third (33.7%) of participants were classified as depressed: Dalit/Nepali 50.0%, high caste 28.4%. One quarter (27.7%) of participants were classified as anxious: Dalit/Nepali 50.7%, high caste 20.3%. Ethnographic research identified four potential mediators: stressful life events, owning few livestock, no household income, and lack of social support. The direct effect of caste was 1.08 (95% CI -1.10—3.27) on depression score and 4.76 (95% CI 2.33—7.19) on anxiety score. All four variables had significant indirect (mediation) effects on anxiety, and all but social support had significant indirect effects on depression. Conclusion Caste-based disparities in mental health in rural Nepal are statistically mediated by poverty, lack of social support, and stressful life events. Interventions should target these areas to alleviate the excess mental health burden born by Dalit/Nepali women and men. PMID:19381985

Culture in psychiatric epidemiology: using ethnography and multiple mediator models to assess the relationship of caste with depression and anxiety in Nepal.

PubMed

Kohrt, Brandon A; Speckman, Rebecca A; Kunz, Richard D; Baldwin, Jennifer L; Upadhaya, Nawaraj; Acharya, Nanda Raj; Sharma, Vidya Dev; Nepal, Mahendra K; Worthman, Carol M

2009-01-01

The causes of ethnic and caste-based disparities in mental health are poorly understood. The study aimed to identify mediators underlying caste-based disparities in mental health in Nepal. A mixed methods ethnographic and epidemiological study of 307 adults (Dalit/Nepali, n=75; high caste Brahman and Chhetri, n=232) was assessed with Nepali versions of Beck Depression (BDI) and Anxiety (BAI) Inventories. One-third (33.7%) of participants were classified as depressed: Dalit/Nepali 50.0%, high caste 28.4%. One quarter (27.7%) of participants were classified as anxious: Dalit/Nepali 50.7%, high caste 20.3%. Ethnographic research identified four potential mediators: Stressful life events, owning few livestock, no household income, and lack of social support. The direct effect of caste was 1.08 (95% CI -1.10-3.27) on depression score and 4.76 (95% CI 2.33-7.19) on anxiety score. All four variables had significant indirect (mediation) effects on anxiety, and all but social support had significant indirect effects on depression. Caste-based disparities in mental health in rural Nepal are statistically mediated by poverty, lack of social support, and stressful life events. Interventions should target these areas to alleviate the excess mental health burden born by Dalit/Nepali women and men.

Competitive allele-specific TaqMan PCR (Cast-PCR) is a sensitive, specific and fast method for BRAF V600 mutation detection in Melanoma patients

PubMed Central

Barbano, Raffaela; Pasculli, Barbara; Coco, Michelina; Fontana, Andrea; Copetti, Massimiliano; Rendina, Michelina; Valori, Vanna Maria; Graziano, Paolo; Maiello, Evaristo; Fazio, Vito Michele; Parrella, Paola

2015-01-01

BRAF codon 600 mutation testing of melanoma patients is mandatory for the choice of the most appropriate therapy in the clinical setting. Competitive allele specific TaqMan PCR (Cast-PCR) technology allows not only the selective amplification of minor alleles, but it also blocks the amplification of non-mutant allele. We genotyped codon 600 of the BRAF gene in 54 patients’ samples by Cast-PCR and bidirectional direct sequence analysis. All the mutations detected by sequencing were also identified by Cast-PCR. In addition, Cast-PCR assay detected four samples carrying mutations and was able to clearly identify two mutations of uncertain interpretation by Sanger sequencing. The limit of detection of Cast-PCR was evaluated by constructing dilution curves of BRAFV600E and BRAFV600K mutated clinical samples mixed with a not-mutated specimens. Both mutations could be detected until a 1:100 mutated/not mutated ratio. Cloning and sequencing of the clones was used to confirm mutations on representative discrepant cases. Cast PCR performances were not affected by intratumour heterogeneity, and less affected by melanin content. Our results indicate that Cast-PCR is a reliable diagnostic tool for the identification of melanoma patients as eligible to be treated with TKIs and might be implemented in the clinical setting as elective screening method. PMID:26690267

Comparative Analysis of the Microstructural Features of 28 wt.% Cr Cast Iron Fabricated by Pulsed Plasma Deposition and Conventional Casting

NASA Astrophysics Data System (ADS)

Chabak, Yu. G.; Efremenko, V. G.; Shimizu, K.; Lekatou, A.; Pastukhova, T. V.; Azarkhov, A. Yu.; Zurnadzhy, V. I.

2018-02-01

The effect of pulsed plasma deposition (by an electrothermal axial plasma accelerator) followed by post-heat treatment on the structure and microhardness of a 28 wt.% Cr white cast iron is analyzed and discussed with respect to the microstructure of the conventionally cast monolithic counterpart. The cast iron (as deposited on a 14 wt.% Cr cast iron substrate) had a microhardness of 630-750 HV0.05; it had layered light contrast/dark contrast structure where dark contrast layers contain fine carbide network. Pulsed plasma deposition followed by heat treatment resulted in a substantial refinement of the microstructure: eutectic M7C3 coarse acicular plates in the conventional cast iron were replaced by fine M7C3, M3C2, M3C particles (Cr depleted in favor of Fe), while the initial carbide particle of 2-3 μm was reduced to 0.6 μm. Secondary dendrite arm spacing decreased from 15 to 1.3 μm, accordingly. The carbide volume fraction in the post-heat-treated coating remarkably increased with respect to the conventional counterpart resulting in a substantial increase in the coating hardness (1300-1750 HV0.05). The heat-treated coating displayed higher resistance to three-body abrasion than the as-deposited coating and similar resistance with that of the conventionally cast iron.

Soldier caste influences on candidate primer pheromone levels and juvenile hormone-dependent caste differentiation in workers of the termite Reticulitermes flavipes.

PubMed

Tarver, Matthew R; Schmelz, Eric A; Scharf, Michael E

2011-06-01

Caste systems and the division of labor they make possible are common underlying features of all social insects. Multiple extrinsic factors have been shown to impact caste composition in social insect colonies. Primer pheromones are one type of extrinsic caste-regulatory factor; they are chemical signaling molecules produced by certain colony members to impact developmental physiology of recipient nestmates. However, only limited evidence exists regarding primer pheromones and their actions in eusocial termites. In previous research we identified two soldier-produced terpenes, γ-cadinene (CAD) and γ-cadinenal (ALD), as candidate primer pheromones of the lower termite Reticulitermes flavipes. In the present study we tested hypotheses related to CAD and ALD action in recipient individuals. We examined the influences of terminally developed soldier termites on (1) CAD and ALD levels and (2) caste differentiation in developmentally totipotent workers. Our findings show CAD and ALD (respectively) are caste stimulatory and inhibitory components of chemical blends present in soldier heads, ALD levels increase significantly (10.9×) in workers only in the presence of soldiers, and soldiers can reduce developmental-hormone response thresholds of workers, presumably via ALD action. These findings provide novel evidence supporting that CAD and ALD are authentic caste-regulatory primer pheromones in Reticulitermes. Copyright © 2011 Elsevier Ltd. All rights reserved.

Caste- and development-associated gene expression in a lower termite

PubMed Central

Scharf, Michael E; Wu-Scharf, Dancia; Pittendrigh, Barry R; Bennett, Gary W

2003-01-01

Background Social insects such as termites express dramatic polyphenism (the occurrence of multiple forms in a species on the basis of differential gene expression) both in association with caste differentiation and between castes after differentiation. We have used cDNA macroarrays to compare gene expression between polyphenic castes and intermediary developmental stages of the termite Reticulitermes flavipes. Results We identified differentially expressed genes from nine ontogenic categories. Quantitative PCR was used to quantify precise differences in gene expression between castes and between intermediary developmental stages. We found worker and nymph-biased expression of transcripts encoding termite and endosymbiont cellulases; presoldier-biased expression of transcripts encoding the storage/hormone-binding protein vitellogenin; and soldier-biased expression of gene transcripts encoding two transcription/translation factors, two signal transduction factors and four cytoskeletal/muscle proteins. The two transcription/translation factors showed significant homology to the bicaudal and bric-a-brac developmental genes of Drosophila. Conclusions Our results show differential expression of regulatory, structural and enzyme-coding genes in association with termite castes and their developmental precursor stages. They also provide the first glimpse into how insect endosymbiont cellulase gene expression can vary in association with the caste of a host. These findings shed light on molecular processes associated with termite biology, polyphenism, caste differentiation and development and highlight potentially interesting variations in developmental themes between termites, other insects, and higher animals. PMID:14519197

Precision of Fit of Titanium and Cast Implant Frameworks Using a New Matching Formula

PubMed Central

Sierraalta, Marianella; Vivas, Jose L.; Razzoog, Michael E.; Wang, Rui-Feng

2012-01-01

Statement of the Problem. Fit of prosthodontic frameworks is linked to the lifetime survival of dental implants and maintenance of surrounding bone. Purpose. The purpose of this study was to evaluate and compare the precision of fit of milled one-piece Titanium fixed complete denture frameworks to that of conventional cast frameworks. Material and Methods. Fifteen casts fabricated from a single edentulous CAD/CAM surgical guide were separated in two groups and resin patterns simulating the framework for a fixed complete denture developed. Five casts were sent to dental laboratories to invest, cast in a Palladium-Gold alloy and fit the framework. Ten casts had the resin pattern scanned for fabrication of milled bars in Titanium. Using measuring software, positions of implant replicas in the definitive model were recorded. The three dimensional spatial orientation of each implant replica was matched to the implant replica. Results. Results demonstrated the mean vertical gap of the Cast framework was 0.021 (+0.004) mm and 0.012 (0.002) mm determined by fixed and unfixed best-fit matching coordinate system. For Titanium frameworks they were 0.0037 (+0.0028) mm and 0.0024 (+0.0005) mm, respectively. Conclusions. Milled one-piece Titanium fixed complete denture frameworks provided a more accurate precision of fit then traditional cast frameworks. PMID:22550486

Development of a CFD code for casting simulation

NASA Technical Reports Server (NTRS)

Murph, Jesse E.

1993-01-01

Because of high rejection rates for large structural castings (e.g., the Space Shuttle Main Engine Alternate Turbopump Design Program), a reliable casting simulation computer code is very desirable. This code would reduce both the development time and life cycle costs by allowing accurate modeling of the entire casting process. While this code could be used for other types of castings, the most significant reductions of time and cost would probably be realized in complex investment castings, where any reduction in the number of development castings would be of significant benefit. The casting process is conveniently divided into three distinct phases: (1) mold filling, where the melt is poured or forced into the mold cavity; (2) solidification, where the melt undergoes a phase change to the solid state; and (3) cool down, where the solidified part continues to cool to ambient conditions. While these phases may appear to be separate and distinct, temporal overlaps do exist between phases (e.g., local solidification occurring during mold filling), and some phenomenological events are affected by others (e.g., residual stresses depend on solidification and cooling rates). Therefore, a reliable code must accurately model all three phases and the interactions between each. While many codes have been developed (to various stages of complexity) to model the solidification and cool down phases, only a few codes have been developed to model mold filling.

Grain Refinement and Improvement of Solidification Defects in Direct-Chill Cast Billets of A4032 Alloy by Melt Conditioning

NASA Astrophysics Data System (ADS)

Li, Hu-Tian; Zhao, Pizhi; Yang, Rongdong; Patel, Jayesh B.; Chen, Xiangfu; Fan, Zhongyun

2017-10-01

Melt-conditioned, direct-chill (MC-DC) casting is an emerging technology to manipulate the solidification process by melt conditioning via intensive shearing in the sump during DC casting to tailor the solidification microstructure and defect formation. When using MC-DC casting technology in an industrial scale DC cast billet of an A4032 aluminum alloy, significant grain refinement and uniform microstructure can be achieved in the primary α-Al phase with fine secondary dendritic arm spacing (SDAS). Improved macrosegregation is quantitatively characterized and correlated with the suppression of channel segregation. The mechanisms for the prevention of channel segregation are attributed to the increased local cooling rate in the liquid-solid phase region in the sump and the formation of fine equiaxed dendritic grains under intensive melt shearing during MC-DC casting. A critical cooling rate has been identified to be around 0.5 to 1 K/s (°C/s) for the channel segregation to happen in the investigated alloy based on quantitative metallographic results of SDAS. Reduction and refinement of microporosity is attributed to the improved permeability in the liquid-solid phase region estimated by the Kozeny-Carman relationship. The potential improvement in the mechanical properties achievable in MC-DC cast billets is indicated by the finer and more uniform forging streamline in the forgings of MC-DC cast billet.

Social class related inequalities in household health expenditure and economic burden: evidence from Kerala, south India

PubMed Central

2011-01-01

Background In the Indian context, a household's caste characteristics are most relevant for identifying its poverty and vulnerability status. Inadequate provision of public health care, the near-absence of health insurance and increasing dependence on the private health sector have impoverished the poor and the marginalised, especially the scheduled tribe population. This study examines caste-based inequalities in households' out-of-pocket health expenditure in the south Indian state of Kerala and provides evidence on the consequent financial burden inflicted upon households in different caste groups. Methods Using data from a 2003-2004 panel survey in Kottathara Panchayat that collected detailed information on health care consumption from 543 households, we analysed inequality in per capita out-of-pocket health expenditure across castes by considering households' health care needs and types of care utilised. We used multivariate regression to measure the caste-based inequality in health expenditure. To assess health expenditure burden, we analysed households incurring high health expenses and their sources of finance for meeting health expenses. Results The per capita health expenditures reported by four caste groups accord with their status in the caste hierarchy. This was confirmed by multivariate analysis after controlling for health care needs and influential confounders. Households with high health care needs are more disadvantaged in terms of spending on health care. Households with high health care needs are generally at higher risk of spending heavily on health care. Hospitalisation expenditure was found to have the most impoverishing impacts, especially on backward caste households. Conclusion Caste-based inequality in household health expenditure reflects unequal access to quality health care by different caste groups. Households with high health care needs and chronic health care needs are most affected by this inequality. Households in the most marginalised castes and with high health care need require protection against impoverishing health expenditures. Special emphasis must be given to funding hospitalisation, as this expenditure puts households most at risk in terms of mobilising monetary resources. However, designing protection instruments requires deeper understanding of how the uncovered financial burden of out-patient and hospitalisation expenditure creates negative consequences and of the relative magnitude of this burden on households. PMID:21214941

Serial elongation, derotation and flexion (EDF) casting under general anesthesia and neuromuscular blocking drugs improve outcome in patients with juvenile scoliosis: preliminary results.

PubMed

Canavese, Federico; Botnari, Alexei; Dimeglio, Alain; Samba, Antoine; Pereira, Bruno; Gerst, Adeline; Granier, Marie; Rousset, Marie; Dubousset, Jean

2016-02-01

Juvenile scoliosis (JS), among different types of spinal deformity, remains still a challenge for orthopedic surgeons. Elongation, derotation and flexion (EDF) casting technique is a custom-made thoracolumbar cast based on a three-dimensional correction concept. The primary objective of the present study was to measure changes on plain radiographs of patients with JS treated with EDF plaster technique. The second aim was to evaluate the effectiveness of the EDF plaster technique realized under general anesthesia (GA) and neuromuscular blocking drugs, i.e. curare, on the radiological curve correction. A retrospective comparative case series study was performed in which were included forty-four skeletally immature patients. Three patient groups were selected. Group 1: EDF cast applied with patients awaken and no anesthesia; Group 2: EDF cast applied under GA without neuromuscular blocking drugs; Group 3: EDF cast applied under GA with neuromuscular blocking drugs. All the patients were treated with two serial EDF casts by 2 months and a half each. All measurements were taken from the radiographic exams. Cobb's angle; RVAD and Nash and Moe grade of rotation were assessed before and after applying the cast. Thirty-four (77.3 %) patients were followed up at least 24 months after removal of last EDF cast. Eighteen patients (3 males, 15 females) were included in Group 1, 12 (2 males, 10 females) in Group 2 and 14 (5 males, 9 females) in Group 3. Serial EDF casting was more effective at initial curve reduction and in preventing curve progression when applied under GA with neuromuscular blocking drugs, i.e. curare. RVAD and Nash and Moe score improved significantly in all groups of patients treated according to principles of EDF technique. During follow-up period, six patients required surgery in Group 1 (6/18; 33.3 %), 3 patients required surgery in Group 2 (3/12; 25 %) and 2 patients underwent surgery in Group 3 (2/14; 15 %). Preliminary results show EDF casting is effective in controlling the curve in both frontal (Cobb's angle) and transverse plane (rib vertebral angle and apical vertebral rotation degree).

Effects of alloying elements on the microstructure and fatigue properties of cast iron for internal combustion engine exhaust manifolds

NASA Astrophysics Data System (ADS)

Eisenmann, David J.

In the design of exhaust manifolds for internal combustion engines the materials used must exhibit resistance to corrosion at high temperatures while maintaining a stable microstructure. Cast iron has been used for manifolds for many years by auto manufacturers due to a combination of suitable mechanical properties, low cost, and ease of casting. Over time cast iron is susceptible to microstructural changes, corrosion, and oxidation which can result in failure due to fatigue. This thesis seeks to answer the question: "Can observed microstructural changes and measured high temperature fatigue life in cast iron alloys be used to develop a predictive model for fatigue life?" the importance of this question lies in the fact that there is little data for the behavior of cast iron alloys at high temperature. For this study two different types of cast iron, 50HS and HSM will be examined. Of particular concern for the high Si+C cast irons (and Mo in the case of the HSM cast iron) are subsurface microstructural changes that result due to heat treatment including (1) decarburization, (2) ferrite formation, (3) graphitization, (4) internal oxidation of the Si, (5) high temperature fatigue resistance, and (6) creep potential. Initial results obtained include microstructure examination after being exposed to high temperatures, grain size, nodule size, and hardness measurements. The initial examinations concluded that both cast irons performed fairly similarly, although the microstructure of the HSM samples did show slightly better resistance to high temperature as compared to that of the 50HS. Follow on work involved high temperature fatigue testing of these two materials in order to better determine if the newer alloy, HSM is a better choice for exhaust manifolds. Correlations between fatigue performance and microstructure were made and discussed, with the results examined in light of current and proposed models for predicting fatigue performance based on computational methods, to see if any suitable models exist that might be used to assist in designing with these cast alloys.

Cheminformatic Analysis of the US EPA ToxCast Chemical Library

EPA Science Inventory

The ToxCast project is employing high throughput screening (HTS) technologies, along with chemical descriptors and computational models, to develop approaches for screening and prioritizing environmental chemicals for further toxicity testing. ToxCast Phase I generated HTS data f...

75 FR 20387 - Contech Castings, LLC, Including Workers Whose Unemployment Insurance (UI) Wages Are Reported...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-04-19

... aluminum and magnesium die casted component parts for automobiles. New information shows that the assets of... casted component parts for automobiles. The amended notice applicable to TA-W-72,649 is hereby issued as...

A mechanical property and stress corrosion evaluation of VIM-ESR-VAR work strengthened and direct double aged Inconel 718 bar material

NASA Technical Reports Server (NTRS)

Montano, J. W.

1986-01-01

Presented are the mechanical properties and the stress corrosion resistance of triple melted vacuum induction melted (VIM), electro-slag remelted (ESR), and vacuum arc remelted (VAR), solution treated, work strengthened and direct double aged Inconel 718 alloy bars 4.00 in. (10.16) and 5.75 in. (14.60 cm) diameter. Tensile, charpy v-notched impact, and compact tension specimens were tested at ambient temperature in both the longitudinal and transverse directions. Longitudinal tensile and yield strengths in excess of 220 ksi (1516.85 MPa) and 200 ksi (1378.00 MPa) respectively, were realized at ambient temperature. Additional charpy impact and compact tension tests were performed at -100 F (-73 C). Longitudinal charpy impact strength equalled or exceeded 12.0 ft-lbs (16.3 Joules) at ambient and at -100 F(-73 C) while longitudinal compact (LC) tension fracture toughness strength remained above 79 ksi (86.80 MPa) at ambient and at -100 F(-73 C) temperatures. No failures occurred in the longitudinal or transverse tensile specimens stressed to 75 and 100 percent of their respective yield strengths and exposed to a salt fog environment for 180 days. Tensile tests performed after the stress corrosion test indicated no mechanical property degradation.

Comparison of Growing Rod Instrumentation Versus Serial Cast Treatment for Early-Onset Scoliosis.

PubMed

Johnston, Charles E; McClung, Anna M; Thompson, George H; Poe-Kochert, Connie; Sanders, James O

2013-09-01

A comparison of 2 methods of early-onset scoliosis treatment using radiographic measures and complication rates. To determine whether a delaying tactic (serial casting) has comparable efficacy to a surgical method (insertion of growing rod instrumentation [GRI]) in the initial phase of early-onset deformity management. Serial casts are used in experienced centers to delay operative management of curves of surgical magnitude (greater than 50°) in children up to age 6 years. A total of 27 casted patients from 3 institutions were matched with 27 patients from a multicenter database according to age (within 6 months of each other), curve magnitude (within 10° of each other), and diagnosis. Outcomes were compared according to major curve magnitude, spine length (T1-S1), duration and number of treatment encounters, and complications. There was no difference in age (5.5 years) or initial curve magnitude (65°) between groups, which reflects the accuracy of the matching process. Six pairs of patients had neuromuscular diagnoses, 11 had idiopathic deformities, and 10 had syndromic scoliosis. Growing rod instrumentation patients had smaller curves (45.9° vs. 64.9°; p = .002) at follow-up, but there was no difference in absolute spine length (GRI = 32.0 cm; cast = 30.6 cm; p = .26), even though GRI patients had been under treatment for a longer duration (4.5 vs. 2.4 years; p < .0001) and had undergone a mean of 5.5 lengthenings compared with 4.0 casts. Growing rod instrumentation patients had a 44% complication rate, compared with 1 cast complication. Of 27 casted patients, 15 eventually had operative treatment after a mean delay of 1.7 years after casting. Cast treatment is a valuable delaying tactic for younger children with early-onset scoliosis. Spine deformity is adequately controlled, spine length is not compromised, and surgical complications associated with early GRI treatment are avoided. Copyright © 2013 Scoliosis Research Society. Published by Elsevier Inc. All rights reserved.

Modeling on Fluid Flow and Inclusion Motion in Centrifugal Continuous Casting Strands

NASA Astrophysics Data System (ADS)

Wang, Qiangqiang; Zhang, Lifeng; Sridhar, Seetharaman

2016-08-01

During the centrifugal continuous casting process, unreasonable casting parameters can cause violent level fluctuation, serious gas entrainment, and formation of frozen shell pieces at the meniscus. Thus, in the current study, a three-dimensional multiphase turbulent model was established to study the transport phenomena during centrifugal continuous casting process. The effects of nozzle position, casting and rotational speed on the flow pattern, centrifugal force acting on the molten steel, level fluctuation, gas entrainment, shear stress on mold wall, and motion of inclusions during centrifugal continuous casting process were investigated. Volume of Fluid model was used to simulate the molten steel-air two-phase. The level fluctuation and the gas entrainment during casting were calculated by user-developed subroutines. The trajectory of inclusions in the rotating system was calculated using the Lagrangian approach. The results show that during centrifugal continuous casting, a large amount of gas was entrained into the molten steel, and broken into bubbles of various sizes. The greater the distance to the mold wall, the smaller the centrifugal force. Rotation speed had the most important influence on the centrifugal force distribution at the side region. Angular moving angle of the nozzle with 8° and keeping the rotation speed with 60 revolutions per minute can somehow stabilize the level fluctuation. The increase of angular angle of nozzle from 8 to 18 deg and rotation speed from 40 to 80 revolutions per minute favored to decrease the total volume of entrained bubbles, while the increase of distance of nozzle moving left and casting speed had reverse effects. The trajectories of inclusions in the mold were irregular, and then rotated along the strand length. After penetrating a certain distance, the inclusions gradually moved to the center of billet and gathered there. More work, such as the heat transfer, the solidification, and the inclusions entrapment during centrifugal continuous casting, will be performed.

Caste-, sex-, and age-dependent expression of immune-related genes in a Japanese subterranean termite, Reticulitermes speratus

PubMed Central

Kobayashi, Kazuya; Matsuura, Kenji

2017-01-01

Insects protect themselves from microbial infections through innate immune responses, including pathogen recognition, phagocytosis, the activation of proteolytic cascades, and the synthesis of antimicrobial peptides. Termites, eusocial insects inhabiting microbe-rich wood, live in closely-related family groups that are susceptible to shared pathogen infections. To resist pathogenic infection, termite families have evolved diverse immune adaptations at both individual and societal levels, and a strategy of trade-offs between reproduction and immunity has been suggested. Although termite immune-inducible genes have been identified, few studies have investigated the differential expression of these genes between reproductive and neuter castes, and between sexes in each caste. In this study, we compared the expression levels of immune-related genes among castes, sexes, and ages in a Japanese subterranean termite, Reticulitermes speratus. Using RNA-seq, we found 197 immune-related genes, including 40 pattern recognition proteins, 97 signalling proteins, 60 effectors. Among these genes, 174 showed differential expression among castes. Comparing expression levels between males and females in each caste, we found sexually dimorphic expression of immune-related genes not only in reproductive castes, but also in neuter castes. Moreover, we identified age-related differential expression of 162 genes in male and/or female reproductives. In addition, although R. speratus is known to use the antibacterial peptide C-type lysozyme as an egg recognition pheromone, we determined that R. speratus has not only C-type, but also P-type and I-type lysozymes, as well as other termite species. Our transcriptomic analyses revealed immune response plasticity among all castes, and sex-biased expression of immune genes even in neuter castes, suggesting a sexual division of labor in the immune system of R. speratus. This study heightens the understanding of the evolution of antimicrobial strategies in eusocial insects, and of sexual roles in insect societies as a whole. PMID:28410430

Caste-, sex-, and age-dependent expression of immune-related genes in a Japanese subterranean termite, Reticulitermes speratus.

PubMed

Mitaka, Yuki; Kobayashi, Kazuya; Matsuura, Kenji

2017-01-01

Insects protect themselves from microbial infections through innate immune responses, including pathogen recognition, phagocytosis, the activation of proteolytic cascades, and the synthesis of antimicrobial peptides. Termites, eusocial insects inhabiting microbe-rich wood, live in closely-related family groups that are susceptible to shared pathogen infections. To resist pathogenic infection, termite families have evolved diverse immune adaptations at both individual and societal levels, and a strategy of trade-offs between reproduction and immunity has been suggested. Although termite immune-inducible genes have been identified, few studies have investigated the differential expression of these genes between reproductive and neuter castes, and between sexes in each caste. In this study, we compared the expression levels of immune-related genes among castes, sexes, and ages in a Japanese subterranean termite, Reticulitermes speratus. Using RNA-seq, we found 197 immune-related genes, including 40 pattern recognition proteins, 97 signalling proteins, 60 effectors. Among these genes, 174 showed differential expression among castes. Comparing expression levels between males and females in each caste, we found sexually dimorphic expression of immune-related genes not only in reproductive castes, but also in neuter castes. Moreover, we identified age-related differential expression of 162 genes in male and/or female reproductives. In addition, although R. speratus is known to use the antibacterial peptide C-type lysozyme as an egg recognition pheromone, we determined that R. speratus has not only C-type, but also P-type and I-type lysozymes, as well as other termite species. Our transcriptomic analyses revealed immune response plasticity among all castes, and sex-biased expression of immune genes even in neuter castes, suggesting a sexual division of labor in the immune system of R. speratus. This study heightens the understanding of the evolution of antimicrobial strategies in eusocial insects, and of sexual roles in insect societies as a whole.

A Critical Evaluation of the Updated Evidence for Casting for Equinus Deformity in Children with Cerebral Palsy.

PubMed

Tustin, Kylee; Patel, Anita

2017-01-01

Equinus deformity is common in ambulant children with cerebral palsy (CP). Although lower leg casting is frequently used, the physiological basis for casting and effects beyond range of motion (ROM) gains are unclear. This review critically evaluates the updated evidence for casting in the management of ankle equinus in children with CP. Comprehensive searches were conducted using electronic databases AMED, MEDLINE, CINAHL, Scopus, PEDro and the Cochrane Database of Systematic Reviews, publication years 2005-2014, in order to identify literature published since an earlier comprehensive systematic review. Only studies evaluating lower leg casting for conservative management of equinus deformity in children with CP were considered. Two independent raters critically appraised studies against the hierarchy of levels of evidence and rigour of study conduct questions proposed by the American Academy of Cerebral Palsy and Developmental Medicine's methodology for systematic review. Four relevant systematic reviews were identified, although these largely concerned earlier literature. Five original studies were included, all demonstrating improvement in dorsiflexion ROM. Combined treatment with botulinum toxin and casting offered greater and/or more sustained ROM gains than botulinum toxin alone in three studies. Effects on gait parameters and motor function were inconsistent. Participation outcomes were not evaluated. Methodological limitations make firm conclusions difficult. Recent years have offered little progress in the state of evidence for casting in the management of equinus deformity. Casting appears to offer at least short-term improvement in ankle dorsiflexion, although the proposition that this improves function or avoids surgery is not well substantiated. Future research needs to ensure more robust study design and broader evaluation across domains of the International Classification of Functioning, Disability and Health to determine the functional and long-term effect of casting for equinus deformity. Greater knowledge is required of the effect of casting on muscle structure and function in spastic CP. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

Effect of molybdenum, vanadium, boron on mechanical properties of high chromium white cast iron in as-cast condition

NASA Astrophysics Data System (ADS)

Nurjaman, F.; Sumardi, S.; Shofi, A.; Aryati, M.; Suharno, B.

2016-02-01

In this experiment, the effect of the addition carbide forming elements on high chromium white cast iron, such as molybdenum, vanadium and boron on its mechanical properties and microstructure was investigated. The high chromium white cast iron was produced by casting process and formed in 50 mm size of grinding balls with several compositions. Characterization of these grinding balls was conducted by using some testing methods, such as: chemical and microstructure analysis, hardness, and impact test. From the results, the addition of molybdenum, vanadium, and boron on high chromium white cast iron provided a significant improvement on its hardness, but reduced its toughness. Molybdenum induced fully austenitic matrix and Mo2C formation among eutectic M7C3 carbide. Vanadium was dissolved in the matrix and carbide. While boron was played a role to form fine eutectic carbide. Grinding balls with 1.89 C-13.1 Cr-1.32 Mo-1.36 V-0.00051 B in as-cast condition had the highest hardness, which was caused by finer structure of eutectic carbide, needle like structure (upper bainite) matrix, and martensite on its carbide boundary.

Numerical simulation of the casting process of titanium removable partial denture frameworks.

PubMed

Wu, Menghuai; Wagner, Ingo; Sahm, Peter R; Augthun, Michael

2002-03-01

The objective of this work was to study the filling incompleteness and porosity defects in titanium removal partial denture frameworks by means of numerical simulation. Two frameworks, one for lower jaw and one for upper jaw, were chosen according to dentists' recommendation to be simulated. Geometry of the frameworks were laser-digitized and converted into a simulation software (MAGMASOFT). Both mold filling and solidification of the castings with different sprue designs (e.g. tree, ball, and runner-bar) were numerically calculated. The shrinkage porosity was quantitatively predicted by a feeding criterion, the potential filling defect and gas pore sensitivity were estimated based on the filling and solidification results. A satisfactory sprue design with process parameters was finally recommended for real casting trials (four replica for each frameworks). All the frameworks were successfully cast. Through X-ray radiographic inspections it was found that all the castings were acceptably sound except for only one case in which gas bubbles were detected in the grasp region of the frame. It is concluded that numerical simulation aids to achieve understanding of the casting process and defect formation in titanium frameworks, hence to minimize the risk of producing defect casting by improving the sprue design and process parameters.

Stress-strain relationship and seismic performance of cast-in-situ phosphogypsum.

PubMed

Zhang, Yichao; Dai, Shaobin; Weng, Wanlin; Huang, Jun; Su, Ying; Cai, Yue

2017-06-16

Phosphogypsum is a waste by-product during the production of phosphoric acid. It not only occupies landfill, but also pollutes the environment, which becomes an important factor restricting the sustainable development of the phosphate fertilizer industry. Research into cast-in-situ phosphogypsum will greatly promote the comprehensive utilization of stored phosphogypsum. The aim of this study was to clarify the mechanical properties of phosphogypsum. Stress-strain relationships of cast-in-situ phosphogypsum were investigated through axial compressive experiments, and seismic performance of cast-in-situ phosphogypsum walls and aerated-concrete masonry walls were simulated based on the experimental results and using finite element analysis. The results showed that the stress-strain relationship fitted into a polynomial equation. Moreover, the displacement ductility index and the energy dissipation index of cast-in-situ phosphogypsum wall were 6.587 and 3.425, respectively. The stress-strain relationship for earthquake-resistant performance of cast-in-situ phosphogypsum walls is better than that of aerated-concrete masonry walls. The curve of stress-strain relationship and the evaluation of earthquake-resistant performance provide theoretical support for the application of cast-in-situ phosphogypsum in building walls.

PRKAG3 and CAST genetic polymorphisms and quality traits of dry-cured hams--I. Associations in Spanish dry-cured ham Jamón Serrano.

PubMed

Gou, P; Zhen, Z Y; Hortós, M; Arnau, J; Diestre, A; Robert, N; Claret, A; Čandek-Potokar, M; Santé-Lhoutellier, V

2012-12-01

The functional single polymorphisms identified in the calpastatin (CAST) gene have been related to the rate of meat tenderization and the protein turnover after slaughter, and the Ile199Val polymorphism identified in the coding region of the protein kinase AMP-activated (PRKAG3) gene has been proven to affect ultimate pH in muscle. The aim of the present study was to show the effects of these genetic polymorphisms on the quality traits of Spanish dry-cured ham Jamón Serrano. A tissue sample from 665 crossbreed pigs were genotyped for PRKAG3 Ile199Val, CAST Arg249Lys and CAST Ser638Arg polymorphisms, and a subsample of 120 dry cured hams was selected to perform physico-chemical, rheological, instrumental colour and sensory analyses. Associations between the polymorphisms and several quality traits of dry-cured ham, mainly related to flavour and texture, were found. The genotypes PRKAG3 Ile/Ile, CAST249 Arg/Arg and CAST638 Arg/Arg, and the haplotype CAST 249Arg-638Arg were the most favourable for Jamón Serrano production. Copyright © 2012 Elsevier Ltd. All rights reserved.

A chromatin link to caste identity in the carpenter ant Camponotus floridanus

PubMed Central

Simola, Daniel F.; Ye, Chaoyang; Mutti, Navdeep S.; Dolezal, Kelly; Bonasio, Roberto; Liebig, Jürgen; Reinberg, Danny; Berger, Shelley L.

2013-01-01

In many ant species, sibling larvae follow alternative ontogenetic trajectories that generate striking variation in morphology and behavior among adults. These organism-level outcomes are often determined by environmental rather than genetic factors. Therefore, epigenetic mechanisms may mediate the expression of adult polyphenisms. We produced the first genome-wide maps of chromatin structure in a eusocial insect and found that gene-proximal changes in histone modifications, notably H3K27 acetylation, discriminate two female worker and male castes in Camponotus floridanus ants and partially explain differential gene expression between castes. Genes showing coordinated changes in H3K27ac and RNA implicate muscle development, neuronal regulation, and sensory responses in modulating caste identity. Binding sites of the acetyltransferase CBP harbor the greatest caste variation in H3K27ac, are enriched with motifs for conserved transcription factors, and show evolutionary expansion near developmental and neuronal genes. These results suggest that environmental effects on caste identity may be mediated by differential recruitment of CBP to chromatin. We propose that epigenetic mechanisms that modify chromatin structure may help orchestrate the generation and maintenance of polyphenic caste morphology and social behavior in ants. PMID:23212948

[Comparative adaptation of crowns of selective laser melting and wax-lost-casting method].

PubMed

Li, Guo-qiang; Shen, Qing-yi; Gao, Jian-hua; Wu, Xue-ying; Chen, Li; Dai, Wen-an

2012-07-01

To investigate the marginal adaptation of crowns fabricated by selective laser melting (SLM) and wax-lost-casting method, so as to provide an experimental basis for clinic. Co-Cr alloy full crown were fabricated by SLM and wax-lost-casting for 24 samples in each group. All crowns were cemented with zinc phosphate cement and cut along longitudinal axis by line cutting machine. The gap between crown tissue surface and die was measured by 6-point measuring method with scanning electron microscope (SEM). The marginal adaptation of crowns fabricated by SLM and wax-lost-casting were compared statistically. The gap between SLM crowns were (36.51 ± 2.94), (49.36 ± 3.31), (56.48 ± 3.35), (42.20 ± 3.60) µm, and wax-lost-casting crowns were (68.86 ± 5.41), (58.86 ± 6.10), (70.62 ± 5.79), (69.90 ± 6.00) µm. There were significant difference between two groups (P < 0.05). Co-Cr alloy full crown fabricated by wax-lost-casting method and SLM method provide acceptable marginal adaptation in clinic, and the marginal adaptation of SLM is better than that of wax-lost-casting method.

The Effects of Fracture Origin Size on Fatigue Properties of Ductile Cast Iron with Small Chill Structures

NASA Astrophysics Data System (ADS)

Sameshima, Daigo; Nakamura, Takashi; Horikawa, Noritaka; Oguma, Hiroyuki; Endo, Takeshi

Reducing the weight of a machine structure is an increasingly important consideration both for the conservation of resources during production and for the energy saving during operation. With these objectives in mind, thin-walled ductile cast iron has recently been developed. Because rapid cooling could result in brittle microstructure of cementite (chill) in this cast iron, it is necessary to investigate the effect of cementite on the fatigue properties. Therefore, fatigue tests were carried out on a ductile cast iron of block castings which contained a relatively small amount of cementite. Fracture surface observation indicated that the fracture origins were located at graphite clusters and cast shrinkage porosity, not at cementite. It appears that when the size of the cementite is smaller than that of the graphite, the cementite does not affect the fatigue properties of ductile cast iron. Not surprisingly, the fatigue lives were found to increase with decrease in the size of the fatigue fracture origin. The threshold initial stress intensity factor range ΔKini,th for fatigue failure was found to be about 3-4MPa√m, independent of microstructure.

An innovative method for nondestructive analysis of cast iron artifacts at Hopewell Furnace National Historic Site, Pennsylvania

USGS Publications Warehouse

Sloto, R.A.; Helmke, M.F.

2011-01-01

Iron ore containing elevated concentrations of trace metals was smelted at Hopewell Furnace during its 113 years of operation (1771-1883). For this study, we sampled iron ore, cast iron furnace products, slag, soil, groundwater, streamflow, and streambed sediment to determine the fate of trace metals released into the environment during the iron-smelting process. Standard techniques were used to sample and analyze all media except cast iron. We analyzed the trace-metal content of the cast iron using a portable X-ray fluorescence spectrometer, which provided rapid, on-site, nondestructive analyses for 23 elements. The artifacts analyzed included eight cast iron stoves, a footed pot, and a kettle in the Hopewell Furnace museum. We measured elevated concentrations of arsenic, copper, lead, and zinc in the cast iron. Lead concentrations as great as 3,150 parts per million were measured in the stoves. Cobalt was detectable but not quantifiable because of interference with iron. Our study found that arsenic, cobalt, and lead were not released to soil or slag, which could pose a significant health risk to visitors and employees. Instead, our study demonstrates these heavy metals remained with the cast iron and were removed from the site.

Performance of prestressed girders cast with LWSCC.

DOT National Transportation Integrated Search

2012-08-01

Bond of prestressing steel has been a much debated topic since the 1950s. Limited data are available on the transfer and development length of strands cast in self : consolidating concrete (SCC) and even less for strands cast in light weight, self-co...

Umbra/penumbra detector

DOEpatents

Carner, Jr., Don C.

1988-01-01

A device which monitors the characteristics of an image cast upon a radiation sensitive substrate. This includes a shadow casting object or mask and at least one source of radiation disposed above the object or mask so that the image cast on the substrate can be analyzed.

An Investigation into the Effects of Sprue Attachment Design on Porosity and Castability

DTIC Science & Technology

1990-12-01

of a dental alloy: sprue design, mold temperature, fusing and casting temperature of the alloy, type of casting machine, casting force, burnout time... Student at: University of Texas, San Antonio AFIT/CI/CIA-90-119 AFIT/CI Wright-Patterson AFB OH 45433-6583 Approved for Public Release IAW AFR 190-1...Supervising Professor: E. Steven Duke, D.D.S., M.S.D. Many variables are involved in the process of fabricating a dense dental casting which accurately

Improved Casting Furnace Conceptual Design

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fielding, Randall Sidney; Tolman, David Donald

In an attempt to ensure more consistent casting results and remove some schedule variance associated with casting, an improved casting furnace concept has been developed. The improved furnace uses the existing arc melter hardware and glovebox utilities. The furnace concept was designed around physical and operational requirements such as; a charge sized of less than 30 grams, high heating rates and minimal additional footprint. The conceptual model is shown in the report as well as a summary of how the requirements were met.

Rapid solution casting under vacuum of very thick sheets of a segmented polyurethane elastomer

NASA Technical Reports Server (NTRS)

Cuddihy, E. F.; Moacanin, J.

1981-01-01

A technique has been developed for rapidly casting from solution under vacuum smooth, bubble-free, clear-white and uniformly thick (about 0.20 cm) sheets of a segmented polyurethane elastomer. The casting is carried out from dimethylformamide solutions inside temperature-controlled air-circulated ovens in order to minimize the establishment of thermal gradients throughout the casting solution. The technique produces quality sheets in 9 days, compared with 40-45 days for an inferior film produced in open pans.

Advanced rotary engine components utilizing fiber reinforced Mg castings

NASA Technical Reports Server (NTRS)

Goddard, D.; Whitman, W.; Pumphrey, R.; Lee, C.-M.

1986-01-01

Under a two-phase program sponsored by NASA, the technology for producing advanced rotary engine components utilizing graphite fiber-reinforced magnesium alloy casting is being developed. In Phase I, the successful casting of a simulated intermediate housing was demonstrated. In Phase II, the goal is to produce an operating rotor housing. The effort involves generation of a material property data base, optimization of parameters, and development of wear- and corrosion-resistant cast surfaces and surface coatings. Results to date are described.

Prosthetic management of malpositioned implant using custom cast abutment

PubMed Central

Chatterjee, Aishwarya; Ragher, Mallikarjuna; Patil, Sanket; Chatterjee, Debopriya; Dandekeri, Savita; Prabhu, Vishnu

2015-01-01

Two cases are reported with malpositioned implants. Both the implants were placed 6–7 months back. They had osseointegrated well with the surrounding bone. However, they presented severe facial inclination. Case I was restored with custom cast abutment with an auto polymerizing acrylic gingival veneer. Case II was restored with custom cast UCLA type plastic implant abutment. Ceramic was directly fired on the custom cast abutments. The dual treatment strategy resulted in functional and esthetic restorations despite facial malposition of the implants. PMID:26538957

Rapidly solidified titanium alloys by melt overflow

NASA Technical Reports Server (NTRS)

Gaspar, Thomas A.; Bruce, Thomas J., Jr.; Hackman, Lloyd E.; Brasmer, Susan E.; Dantzig, Jonathan A.; Baeslack, William A., III

1989-01-01

A pilot plant scale furnace was designed and constructed for casting titanium alloy strips. The furnace combines plasma arc skull melting techniques with melt overflow rapid solidification technology. A mathematical model of the melting and casting process was developed. The furnace cast strip of a suitable length and width for use with honeycomb structures. Titanium alloys Ti-6Al-4V and Ti-14Al-21 Nb were successfully cast into strips. The strips were evaluated by optical metallography, microhardness measurements, chemical analysis, and cold rolling.