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.

Coupled thermal-fluid-mechanics analysis of twin roll casting of A7075 aluminum alloy

NASA Astrophysics Data System (ADS)

Lee, Yun-Soo; Kim, Hyoung-Wook; Cho, Jae-Hyung; Chun, Se-Hwan

2017-09-01

Better understanding of temperature distribution and roll separation force during twin roll casting of aluminum alloys is critical to successfully fabricate good quality of aluminum strips. Therefore, the simulation techniques are widely applied to understand the twin roll casting process in a comprehensive way and to reduce the experimental time and cost of trial and error. However, most of the conventional approaches are considered thermally coupled flow, or thermally coupled mechanical behaviors. In this study, a fully coupled thermal-fluid-mechanical analysis of twin roll casting of A7075 aluminum strips was carried out using the finite element method. Temperature profile, liquid fraction and metal flow of aluminum strips with different thickness were predicted. Roll separation force and roll temperatures were experimentally obtained from a pilot-scale twin roll caster, and those results were compared with model predictions. Coupling the fluid of the liquid melt to the thermal and mechanical modeling reasonably predicted roll temperature distribution and roll separation force during twin roll casting.

Separation of overlapping dental arch objects using digital records of illuminated plaster casts.

PubMed

Yadollahi, Mohammadreza; Procházka, Aleš; Kašparová, Magdaléna; Vyšata, Oldřich; Mařík, Vladimír

2015-07-11

Plaster casts of individual patients are important for orthodontic specialists during the treatment process and their analysis is still a standard diagnostical tool. But the growing capabilities of information technology enable their replacement by digital models obtained by complex scanning systems. This paper presents the possibility of using a digital camera as a simple instrument to obtain the set of digital images for analysis and evaluation of the treatment using appropriate mathematical tools of image processing. The methods studied in this paper include the segmentation of overlapping dental bodies and the use of different illumination sources to increase the reliability of the separation process. The circular Hough transform, region growing with multiple seed points, and the convex hull detection method are applied to the segmentation of orthodontic plaster cast images to identify dental arch objects and their sizes. The proposed algorithm presents the methodology of improving the accuracy of segmentation of dental arch components using combined illumination sources. Dental arch parameters and distances between the canines and premolars for different segmentation methods were used as a measure to compare the results obtained. A new method of segmentation of overlapping dental arch components using digital records of illuminated plaster casts provides information with the precision required for orthodontic treatment. The distance between corresponding teeth was evaluated with a mean error of 1.38% and the Dice similarity coefficient of the evaluated dental bodies boundaries reached 0.9436 with a false positive rate [Formula: see text] and false negative rate [Formula: see text].

Anisotropic membranes for gas separation

DOEpatents

Gollan, Arye Z.

1987-01-01

A gas separation membrane has a dense separating layer about 10,000 Angstroms or less thick and a porous support layer 10 to 400 microns thick that is an integral unit with gradually and continuously decreasing pore size from the base of the support layer to the surface of the thin separating layer and is made from a casting solution comprising ethyl cellulose and ethyl cellulose-based blends, typically greater than 47.5 ethoxyl content ethyl cellulose blended with compatible second polymers, such as nitrocellulose. The polymer content of the casting solution is from about 10% to about 35% by weight of the total solution with up to about 50% of this polymer weight a compatible second polymer to the ethyl cellulose in a volatile solvent such as isopropanol, methylacetate, methanol, ethanol, and acetone. Typical nonsolvents for the casting solutions include water and formamide. The casting solution is cast in air from about zero to 10 seconds to allow the volatile solvent to evaporate and then quenched in a coagulation bath, typically water, at a temperature of 7.degree.-25.degree. C. and then air dried at ambient temperature, typically 10.degree.-30.degree. C.

DEGATING WORKERS REMOVING SPRUES AND RUNNERS MANUALLY WITH SLEDGEHAMMERS AND ...

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

DEGATING WORKERS REMOVING SPRUES AND RUNNERS MANUALLY WITH SLEDGEHAMMERS AND POWERED PNEUMATIC SEPARATORS FROM CASTINGS FROM ALL MOLDING MACHINES BEFORE SEPARATING PIECES INTO BINS AND TRANSPORTING THEM TO GRINDING AREAS. - Southern Ductile Casting Company, Shaking, Degating & Sand Systems, 2217 Carolina Avenue, Bessemer, Jefferson County, AL

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.

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

Optical Measurements with Related Chemical, Biological, and Physical Parameters from the Central Equatorial Pacific Ocean: NOAA Ship Discoverer Cruise RP-9-DI-84

DTIC Science & Technology

1986-09-01

stations one and two, separate casts were made for Freon sampling and deep geochemistry sampling with either Freon syringes or 30-liter bottles. On...subsequent stations, deep geochemistry and Freon sampling were done on one cast. A separate cast for chlorophyll using 10-liter bottles on the Rosette...vertical to horizontal. The deck sensor used was a Biospherical Instruments, Inc., Solar Reference Hemispherical Irradiance Sensor which monitors the

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.

The Role of Diesel Engines in Early Submarine Development

DTIC Science & Technology

2010-04-26

advantage of advances in metallurgical technology, could not match the superior technology in casting processes, alloy development, and heat treatments...metallurgical technology. NELSECO had the German plans and assistance from German engineers, but the foundries could not duplicate the casting to German...that the Germans and other European countries possessed. The U.S. commercial foundries did not want to undertake the risky development casting of low

Improvement of CO2/N2 separation performance by polymer matrix cellulose acetate butyrate

NASA Astrophysics Data System (ADS)

Lee, R. J.; Jawad, Z. A.; Ahmad, A. L.; Ngo, J. Q.; Chua, H. B.

2017-06-01

With the rapid development of modern civilization, carbon dioxide (CO2) is produced in large quantities and mainly generated from industrial sectors. The gas emission is the major contributor to global warming. To address this issue, the membrane technology is implemented for the CO2 removal, due to the energy efficiency and economic advantages presented. Cellulose acetate butyrate (CAB) is selected as the polymeric material, due to the excellent film-forming properties and capable of developing a defect-free layer of neat membrane. This study described the fabrication development of CAB using a wet phase inversion method with different casting conditions. Where the composition of the casting solutions (3-5 wt %) and solvent evaporation time (4-6 min) were determined. The outcomes of these dominant parameters were then used to determine the best CAB membrane for CO2/Nitrogen (N2) separation and supported by the characterization i.e. scanning electron micrograph. Gas permeation measurements showed satisfactory performance for CAB membrane fabricated with 5 min evaporation time and 4 wt% polymer composition (M2). Where, its permeance and selectivity are 120.19 GPU and 3.17, respectively. In summary, this study showed a brief outlined of the future direction and perspective of CAB membrane for CO2/N2 separation.

Energy Saving Melting and Revert Reduction Technology (E-SMARRT): Mechanical Performance of Dies

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

R. Allen Miller, Principal Investigator; Kabiri-Bamoradian, Contributors: Khalil; Delgado-Garza, Abelardo

2011-09-13

As a net shape process, die casting is intrinsically efficient and improvements in energy efficiency are strongly dependent on design and process improvements that reduce scrap rates so that more of the total consumed energy goes into acceptable, usable castings. A casting that is distorted and fails to meet specified dimensional requirements is typically remelted but this still results in a decrease in process yield, lost productivity, and increased energy consumption. This work focuses on developing, and expanding the use of, computer modeling methods that can be used to improve the dimensional accuracy of die castings and produce die designsmore » and machine/die setups that reduce rejection rates due to dimensional issues. A major factor contributing to the dimensional inaccuracy of the casting is the elastic deformations of the die cavity caused by the thermo mechanical loads the dies are subjected to during normal operation. Although thermal and die cavity filling simulation are widely used in the industry, structural modeling of the die, particularly for managing part distortion, is not yet widely practiced. This may be due in part to the need to have a thorough understanding of the physical phenomenon involved in die distortion and the mathematical theory employed in the numerical models to efficiently model the die distortion phenomenon. Therefore, two of the goals of this work are to assist in efforts to expand the use of structural modeling and related technologies in the die casting industry by 1) providing a detailed modeling guideline and tutorial for those interested in developing the necessary skills and capability and 2) by developing simple meta-models that capture the results and experience gained from several years of die distortion research and can be used to predict key distortion phenomena of relevance to a die caster with a minimum of background and without the need for simulations. These objectives were met. A detailed modeling tutorial was provided to NADCA for distribution to the industry. Power law based meta-models for predicting machine tie bar loading and for predicting maximum parting surface separation were successfully developed and tested against simulation results for a wide range of machines and experimental data. The models proved to be remarkably accurate, certainly well within the requirements for practical application. In addition to making die structural modeling more accessible, the work advanced the state-of-the-art by developing improved modeling of cavity pressure effects, which is typically modeled as a hydrostatic boundary condition, and performing a systematic analysis of the influence of ejector die design variables on die deflection and parting plane separation. This cavity pressure modeling objective met with less than complete success due to the limits of current finite element based fluid structure interaction analysis methods, but an improved representation of the casting/die interface was accomplished using a combination of solid and shell elements in the finite element model. This approximation enabled good prediction of final part distortion verified with a comprehensive evaluation of the dimensions of test castings produced with a design experiment. An extra deliverable of the experimental work was development of high temperature mechanical properties for the A380 die casting alloy. The ejector side design objective was met and the results were incorporated into the metamodels described above. This new technology was predicted to result in an average energy savings of 2.03 trillion BTU's/year over a 10 year period. Current (2011) annual energy saving estimates over a ten year period, based on commercial introduction in 2009, a market penetration of 70% by 2014 is 4.26 trillion BTU's/year by 2019. Along with these energy savings, reduction of scrap and improvement in casting yield will result in a reduction of the environmental emissions associated with the melting and pouring of the metal which will be saved as a result of this technology. The average annual estimate of CO2 reduction per year through 2020 is 0.085 Million Metric Tons of Carbon Equivalent (MM TCE).« less

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

Energy Saving Melting and Revert Reduction Technology (Energy SMARRT): Manufacturing Advanced Engineered Components Using Lost Foam Casting Technology

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

Littleton, Harry; Griffin, John

2011-07-31

This project was a subtask of Energy Saving Melting and Revert Reduction Technology (Energy SMARRT) Program. Through this project, technologies, such as computer modeling, pattern quality control, casting quality control and marketing tools, were developed to advance the Lost Foam Casting process application and provide greater energy savings. These technologies have improved (1) production efficiency, (2) mechanical properties, and (3) marketability of lost foam castings. All three reduce energy consumption in the metals casting industry. This report summarizes the work done on all tasks in the period of January 1, 2004 through June 30, 2011. Current (2011) annual energy savingmore » estimates based on commercial introduction in 2011 and a market penetration of 97% by 2020 is 5.02 trillion BTU's/year and 6.46 trillion BTU's/year with 100% market penetration by 2023. Along with these energy savings, reduction of scrap and improvement in casting yield will result in a reduction of the environmental emissions associated with the melting and pouring of the metal which will be saved as a result of this technology. The average annual estimate of CO2 reduction per year through 2020 is 0.03 Million Metric Tons of Carbon Equivalent (MM TCE).« less

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

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.;

Wide Strip Casting Technology of Magnesium Alloys

NASA Astrophysics Data System (ADS)

Park, W.-J.; Kim, J. J.; Kim, I. J.; Choo, D.

Extensive investigations relating to the production of high performance and low cost magnesium sheet by strip casting have been performed for the application to automotive parts and electronic devices. Research on magnesium sheet production technology started in 2004 by Research Institute of Industrial Science and Technology (RIST) with support of Pohang Iron and Steel Company (POSCO). POSCO has completed the world's first plant to manufacture magnesium coil. Another big project in order to develop wide strip casting technology for the automotive applications of magnesium sheets was started in succession.

Precision Casting via Advanced Simulation and Manufacturing

NASA Technical Reports Server (NTRS)

1997-01-01

A two-year program was conducted to develop and commercially implement selected casting manufacturing technologies to enable significant reductions in the costs of castings, increase the complexity and dimensional accuracy of castings, and reduce the development times for delivery of high quality castings. The industry-led R&D project was cost shared with NASA's Aerospace Industry Technology Program (AITP). The Rocketdyne Division of Boeing North American, Inc. served as the team lead with participation from Lockheed Martin, Ford Motor Company, Howmet Corporation, PCC Airfoils, General Electric, UES, Inc., University of Alabama, Auburn University, Robinson, Inc., Aracor, and NASA-LeRC. The technical effort was organized into four distinct tasks. The accomplishments reported herein. Task 1.0 developed advanced simulation technology for core molding. Ford headed up this task. On this program, a specialized core machine was designed and built. Task 2.0 focused on intelligent process control for precision core molding. Howmet led this effort. The primary focus of these experimental efforts was to characterize the process parameters that have a strong impact on dimensional control issues of injection molded cores during their fabrication. Task 3.0 developed and applied rapid prototyping to produce near net shape castings. Rocketdyne was responsible for this task. CAD files were generated using reverse engineering, rapid prototype patterns were fabricated using SLS and SLA, and castings produced and evaluated. Task 4.0 was aimed at developing technology transfer. Rocketdyne coordinated this task. Casting related technology, explored and evaluated in the first three tasks of this program, was implemented into manufacturing processes.

Direct metal laser sintering: a digitised metal casting technology.

PubMed

Venkatesh, K Vijay; Nandini, V Vidyashree

2013-12-01

Dental technology is undergoing advancements at a fast pace and technology is being imported from various other fields. One such imported technology is direct metal laser sintering technology for casting metal crowns. This article will discuss the process of laser sintering for making metal crowns and fixed partial dentures with a understanding of their pros and cons.

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).

Separation of polar gases from nonpolar gases

DOEpatents

Kulprathipanja, S.

1986-08-19

The separation of polar gases from nonpolar gases may be effected by passing a mixture of nonpolar gases over the face of a multicomponent membrane at separation conditions. The multicomponent membrane which is used to effect the separation will comprise a mixture of a glycol plasticizer having a molecular weight of from about 200 to about 600 and an organic polymer cast on a porous support. The porous support is pretreated prior to casting of the mixture thereon by contact with a polyhydric alcohol whereby the pores of the support are altered, thus adding to the increased permeability of the polar gas.

Development of Aerogel Molds for Metal Casting Using Lunar and Martian Regolith

NASA Technical Reports Server (NTRS)

2003-01-01

In the last few years NASA has set new priorities for research and development of technologies necessary to enable long-term presence on the Moon and Mars. Among these key technologies is what is known as in situ resource utilization, which defines all conceivable usage of mineral, liquid, gaseous, or biological resources on a visited planet. In response to this challenge, we have been focusing on developing and demonstrating 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. In addition, our purpose is to demonstrate the feasibility of using mesoporous materials such as aerogels to serve as efficient casting molds for high quality components in propulsion and other aerospace applications. The first part of the project consists of producing aerogels from the in situ resources available in Martian and Lunar soil. The approach we are investigating is to use chemical processes to solubilize silicates using organic reagents at low temperatures and then use these as precursors in the formation of aerogels for the fabrication of metal casting molds. One set of experiments consists of dissolving silica sources in basic ethylene glycol solution to form silicon glycolates. When ground silica aerogel was used as source material, a clear solution of silicon glycolate was obtained and reacted to form a gel thus proving the feasibility of this approach. The application of this process to Lunar and Martian simulants did not result in the formation of a gel; further study is in progress. In the second method acidified alcohol is reacted with the simulants to form silicate esters. Preliminary results indicate the presence of silicon alkoxide in the product distillation. However, no gel has been obtained so further characterization is ongoing. In the second part of the project, the focus has been on developing a series of aerogel plates suitable for thin plate metal casting and ingot metal castings. The influence of aerogels on thin wall metal castings was studied by placing aerogel plates into the cavities of thin sections of resin bonded sand molds. An 1 based commercial alloy ( 356) containing 7 percent Si was poured into these molds. Post-solidification studies provide evidence that aerogel inserts significantly reduce the cooling rate during solidification. The advantage of a lower rate using aerogel inserts was reflected in the reduction of casting defects such as shrinkage porosity. Quantitative results support the hypothesis that using aerogels as a mold material can offer definite advantages when used as casting thin sections. As a separate effort, silica aerogel with cylindrical cavities have been prepared and will be evaluated for casting commercial alloys.

Titanium Aluminide Casting Technology Development

NASA Astrophysics Data System (ADS)

Bünck, Matthias; Stoyanov, Todor; Schievenbusch, Jan; Michels, Heiner; Gußfeld, Alexander

2017-12-01

Titanium aluminide alloys have been successfully introduced into civil aircraft engine technology in recent years, and a significant order volume increase is expected in the near future. Due to its beneficial buy-to-fly ratio, investment casting bears the highest potential for cost reduction of all competing production technologies for TiAl-LPTB. However, highest mechanical properties can be achieved by TiAl forging. In view of this, Access e.V. has developed technologies for the production of TiAl investment cast parts and TiAl die cast billets for forging purposes. While these parts meet the highest requirements, establishing series production and further optimizing resource and economic efficiency are present challenges. In order to meet these goals, Access has recently been certified according to aircraft standards, aiming at qualifying parts for production on technology readiness level 6. The present work gives an overview of the phases of development and certification.

Removal of carbon, nitrogen and phosphorus from the separated liquid phase of hog manure by the multi-zone BioCAST technology.

PubMed

Yerushalmi, Laleh; Alimahmoodi, Mahmood; Afroze, Niema; Godbout, Stephane; Mulligan, Catherine N

2013-06-15

The removal of chemical oxygen demand (COD), total nitrogen (TN) and total phosphorus (TP) at concentrations of 960 ± 38 to 2400 ± 96 mg/L, 143 ± 9 to 235 ± 15 mg/L and 25 ± 2 to 57 ± 4 mg/L, respectively, from the separated liquid phase of hog manure by the multi-zone BioCAST technology is discussed. Despite the inhibitory effect of hog waste toward microbial activities, removal efficiencies up to 89.2% for COD, 69.2% for TN and 47.6% for TP were obtained during 185 d of continuous operation. The free ammonia inhibition was postulated to be responsible for the steady reduction of COD and TP removal with the increase of TN/TP ratio from 3.6 to 5.8. On the contrary, the increase of COD/TN ratio from 4.8 to 14.1 improved the removal of all contaminants. Nitrogen removal did not show any dependence on the COD/TP ratio, despite the steady increase of COD and TP removal with this ratio in the range of 19.3-50.6. The removal efficiencies of organic and inorganic contaminants increased progressively owing to the adaptation of microbial biomass, resulting from the presence of suspended biomass in the mixed liquor that circulated continuously between the three zones of aerobic, microaerophilic and anoxic, as well as the attached biomass immobilized inside the aerobic zone. Copyright © 2013 Elsevier B.V. All rights reserved.

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.

Remelt Ingot Production Technology

NASA Astrophysics Data System (ADS)

Grandfield, J. F.

The technology related to the production of remelt ingots (small ingots, sows and T-Bar) is reviewed. Open mold conveyors, sow casting, wheel and belt casting and VDC and HDC casting are described and compared. Process economics, capacity, product quality and process problems are listed. Trends in casting machine technology such as longer open mold conveyor lines are highlighted. Safety issues related to the operation of these processes are discussed. The advantages and disadvantages of the various machine configurations and options e.g. such as dry filling with the mold out of water and wet filling with the mold in water for open mould conveyors are discussed. The effect of mold design on machine productivity, mold cracking and mold life is also examined.

COPE AND DRAG PATTERNS, EACH IS USED AT SEPARATE TIMES ...

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

COPE AND DRAG PATTERNS, EACH IS USED AT SEPARATE TIMES TO CREATE INDIVIDUAL MOLD. HALVES FOR AN EXHAUST MANIFOLD CASTING SIT IN FRONT OF MATCHPLATE PATTERNS WITH BOTH COPE AND DRAG SIDES AFFIXED TO A SINGLE PLATE, USED TO CREATE BOTH MOLD HALVES AT THE SAME TIME, IN THE BACKGROUND. - Southern Ductile Casting Company, Mold Making, 2217 Carolina Avenue, Bessemer, Jefferson County, AL

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.

Cloud-Based Speech Technology for Assistive Technology Applications (CloudCAST).

PubMed

Cunningham, Stuart; Green, Phil; Christensen, Heidi; Atria, José Joaquín; Coy, André; Malavasi, Massimiliano; Desideri, Lorenzo; Rudzicz, Frank

2017-01-01

The CloudCAST platform provides a series of speech recognition services that can be integrated into assistive technology applications. The platform and the services provided by the public API are described. Several exemplar applications have been developed to demonstrate the platform to potential developers and users.

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.

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.

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

Space Technology for Palate Surgery

NASA Technical Reports Server (NTRS)

1980-01-01

University of Miami utilized NASA's spacecraft viewing technology to develop the optical profilometer provides more accurate measurements of cleft palate casts than has heretofore been possible, enabling better planning of corrective surgery. Lens like instrument electronically scans a palate cast precisely measuring its irregular contours by detecting minute differences in the intensity of a light beam reflected off the cast. Readings are computer processed and delivered to the surgeon by a teleprinter.

Next-generation casting technologies and their adaptation and development in Russia: I. at the beginning of a new technological paradigm

NASA Astrophysics Data System (ADS)

Semenov, A. B.; Gavrilenko, A. E.; Semenov, B. I.

2016-12-01

The up-to-date methods of powder metallurgy and casting technology are considered. They can be used to apply the design and technological solutions that are intended to form parts with the optimum space configuration, to deLcrease the number of assembly elements, and to decrease the number of mechanical and welded joints in units.

Rapid Prototyping Technology for Manufacturing GTE Turbine Blades

NASA Astrophysics Data System (ADS)

Balyakin, A. V.; Dobryshkina, E. M.; Vdovin, R. A.; Alekseev, V. P.

2018-03-01

The conventional approach to manufacturing turbine blades by investment casting is expensive and time-consuming, as it takes a lot of time to make geometrically precise and complex wax patterns. Turbine blade manufacturing in pilot production can be sped up by accelerating the casting process while keeping the geometric precision of the final product. This paper compares the rapid prototyping method (casting the wax pattern composition into elastic silicone molds) to the conventional technology. Analysis of the size precision of blade casts shows that silicon-mold casting features sufficient geometric precision. Thus, this method for making wax patterns can be a cost-efficient solution for small-batch or pilot production of turbine blades for gas-turbine units (GTU) and gas-turbine engines (GTE). The paper demonstrates how additive technology and thermographic analysis can speed up the cooling of wax patterns in silicone molds. This is possible at an optimal temperature and solidification time, which make the process more cost-efficient while keeping the geometric quality of the final product.

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.

Prosthetic misfit of implant-supported prosthesis obtained by an alternative section method

PubMed Central

Falcão-Filho, Hilmo Barreto Leite; de Aguiar, Fábio Afrânio; Rodrigues, Renata Cristina Silveira; de Mattos, Maria da Gloria Chiarello; Ribeiro, Ricardo Faria

2012-01-01

PURPOSE Adequate passive-fitting of one-piece cast 3-element implant-supported frameworks is hard to achieve. This short communication aims to present an alternative method for section of one-piece cast frameworks and for casting implant-supported frameworks. MATERIALS AND METHODS Three-unit implant-supported nickel-chromium (Ni-Cr) frameworks were tested for vertical misfit (n = 6). The frameworks were cast as one-piece (Group A) and later transversally sectioned through a diagonal axis (Group B) and compared to frameworks that were cast diagonally separated (Group C). All separated frameworks were laser welded. Only one side of the frameworks was screwed. RESULTS The results on the tightened side were significantly lower in Group C (6.43 ± 3.24 µm) when compared to Groups A (16.50 ± 7.55 µm) and B (16.27 ± 1.71 µm) (P<.05). On the opposite side, the diagonal section of the one-piece castings for laser welding showed significant improvement in the levels of misfit of the frameworks (Group A, 58.66±14.30 µm; Group B, 39.48±12.03 µm; Group C, 23.13±8.24 µm) (P<.05). CONCLUSION Casting diagonally sectioned frameworks lowers the misfit levels. Lower misfit levels for the frameworks can be achieved by diagonally sectioning one-piece frameworks. PMID:22737313

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

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...

First in vivo assessment of "Outwalk": a novel protocol for clinical gait analysis based on inertial and magnetic sensors.

PubMed

Ferrari, Alberto; Cutti, Andrea Giovanni; Garofalo, Pietro; Raggi, Michele; Heijboer, Monique; Cappello, Angelo; Davalli, Angelo

2010-01-01

A protocol named "Outwalk" was recently proposed to measure the thorax-pelvis and lower-limb kinematics during gait in free-living conditions, by means of an inertial and magnetic measurement system (IMMS). The aim of this study was to validate Outwalk on four healthy subjects when it is used in combination with a specific IMMS (Xsens Technologies, NL), against a reference protocol (CAST) and measurement system (optoelectronic system; Vicon, Oxford Metrics Group, UK). For this purpose, we developed an original approach based on three tests, which allowed to separately investigate: (1) the consequences on joint kinematics of the differences between protocols (Outwalk vs. CAST), (2) the accuracy of the hardware (Xsens vs. Vicon), and (3) the summation of protocols' differences and hardware accuracy (Outwalk + Xsens vs. CAST + Vicon). In order to assess joint-angles similarity, the coefficient of multiple correlation (CMC) was used. For test 3, the CMC showed that Outwalk + Xsens and CAST + Vicon kinematics can be interchanged, offset included, for hip, knee and ankle flexion-extension, and hip ab-adduction (CMC > 0.88). The other joint-angles can be interchanged offset excluded (CMC > 0.85). Tests 1 and 2 also showed that differences in offset between joint-angles were predominantly induced by differences in the protocols; differences in correlation by both hardware and protocols; differences in range of motion by the Xsens accuracy. Results thus support the commencement of a clinical trial of Outwalk on transtibial amputees.

High Strength and Wear Resistant Aluminum Alloy for High Temperature Applications

NASA Technical Reports Server (NTRS)

Lee, Jonathan A.; Munafo, Paul M. (Technical Monitor)

2002-01-01

In this paper, a new high strength and wear resistant aluminum cast alloy invented by NASA-MSFC for high temperature applications will be presented. Developed to meet U.S. automotive legislation requiring low-exhaust emission, the novel NASA 398 aluminum-silicon alloy offers dramatic improvement in tensile and fatigue strengths at elevated temperatures (500 F-800 F), enabling new pistons to utilize less material, which can lead to reducing part weight and cost as well as improving performance. NASA 398 alloy also offers greater wear resistance, surface hardness, dimensional stability, and lower thermal expansion compared to conventional aluminum alloys for several commercial and automotive applications. The new alloy can be produced economically using permanent steel molds from conventional gravity casting or sand casting. The technology was developed to stimulate the development of commercial aluminum casting products from NASA-developed technology by offering companies the opportunity to license this technology.

Characterization of dust from blast furnace cast house de-dusting.

PubMed

Lanzerstorfer, Christof

2017-10-01

During casting of liquid iron and slag, a considerable amount of dust is emitted into the cast house of a blast furnace (BF). Usually, this dust is extracted via exhaust hoods and subsequently separated from the ventilation air. In most BFs the cast house dust is recycled. In this study a sample of cast house dust was split by air classification into five size fractions, which were then analysed. Micrographs showed that the dominating particle type in all size fractions is that of single spherical-shaped particles. However, some irregular-shaped particles were also found and in the finest size fraction also some agglomerates were present. Almost spherical particles consisted of Fe and O, while highly irregular-shaped particles consisted of C. The most abundant element was Fe, followed by Ca and C. These elements were distributed relatively uniformly in the size fractions. As, Cd, Cu, K, Pb, S, Sb and Zn were enriched significantly in the fine size fractions. Thus, air classification would be an effective method for improved recycling. By separating a small fraction of fines (about 10-20%), a reduction of the mass of Zn in the coarse dust recycled in the range of 40-55% would be possible.

Rapid prototype fabrication processes for high-performance thrust cells

NASA Technical Reports Server (NTRS)

Hunt, K.; Chwiedor, T.; Diab, J.; Williams, R.

1994-01-01

The Thrust Cell Technologies Program (Air Force Phillips Laboratory Contract No. F04611-92-C-0050) is currently being performed by Rocketdyne to demonstrate advanced materials and fabrication technologies which can be utilized to produce low-cost, high-performance thrust cells for launch and space transportation rocket engines. Under Phase 2 of the Thrust Cell Technologies Program (TCTP), rapid prototyping and investment casting techniques are being employed to fabricate a 12,000-lbf thrust class combustion chamber for delivery and hot-fire testing at Phillips Lab. The integrated process of investment casting directly from rapid prototype patterns dramatically reduces design-to-delivery cycle time, and greatly enhances design flexibility over conventionally processed cast or machined parts.

Electroslag Processing for Marine Application. Summary Report on a Workshop Held in Annapolis, Maryland on 5-6 March 1985.

DTIC Science & Technology

1985-03-01

the ESC process technology to private industry. The task emphasizes four major areas: (1) advancement of ESC technology , (2) preparation of castings (by...to advance the technology . This can possibly be best accomplished by industry or by industry in cooperation with one or more Government agencies... Technology ( CANMET ) has been involved with electroslag casting for the past 4 years. Recently this equipment has been modified to produce thin-wall hollow

FIELD DEMONSTRATION OF EMERGING PIPE WALL INTEGRITY ASSESSMENT TECHNOLOGIES FOR LARGE CAST IRON WATER MAINS

EPA Science Inventory

The U.S. Environmental Protection Agency sponsored a large-scale field demonstration of innovative leak detection/location and condition assessment technologies on a 76-year old, 2,500-ft long, cement-lined, 24-in. cast iron water main in Louisville, KY from July through Septembe...

Field Demonstration of Emerging Pipe Wall Integrity Assessment Technologies for Large Cast Iron Water Mains - Paper

EPA Science Inventory

The U.S. Environmental Protection Agency (EPA) sponsored a large-scale field demonstration of innovative leak detection/location and condition assessment technologies on a 76-year old, 2,000-ft long, cement-lined, 24-in. cast-iron water main in Louisville, KY from July through Se...

DUMPING COOLED MOLDS FROM THE SHAKE OUT RAILS ONTO A ...

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

DUMPING COOLED MOLDS FROM THE SHAKE OUT RAILS ONTO A VIBRATING CONVEYOR WHICH TRANSPORTS CASTINGS AND SAND TO A SEPARATION SCREEN WHICH SIFTS SAND ONTO BELT CONVEYORS BELOW THAT CARRY IT PAST SWITCH-ACTIVATED WATER INJECTORS TO SIMILAR SWITCH-ACTIVATED FRESH SAND ADDERS BEFORE TRANSPORTING IT TO THE SAND STORAGE BIN WHILE CASTINGS ARE EITHER MANUALLY OR SMALL CRANE LIFTED TO DEGATING AREAS. - Southern Ductile Casting Company, Centerville Foundry, 101 Airport Road, Centreville, Bibb County, AL

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.

Designing a combined casting mold for manufacture of a gasoline centrifugal pump body using CAD/CAM-systems

NASA Astrophysics Data System (ADS)

Galin, N. E.; Ogol, I. I.; Chervach, Yu B.; Dammer, V. Kh; Ru, Jia Hong

2017-02-01

The present paper examines designing of a combined casting mold for manufacture of a gasoline centrifugal pump body. The paper offers technological solutions for obtaining high quality castings at the testing stage of the finished mold. The paper is intended for practical use and prepared by order of JSC ‘Tomsk Electrical Engineering Plant’ using software and equipment of the department ‘Technologies of Computer-Aided Machinery Manufacturing’ of the Tomsk Polytechnic University (TPU) under the economic contract within state import substitution program. In preparing the paper, CAD/CAM-systems KOMPAS-3D and PowerMILL were used. In 2015, the designed casting mold was introduced into the production process at JSC ‘Tomsk Electrical Engineering Plant’.

Compact CFB: The next generation CFB boiler

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

Utt, J.

1996-12-31

The next generation of compact circulating fluidized bed (CFB) boilers is described in outline form. The following topics are discussed: compact CFB = pyroflow + compact separator; compact CFB; compact separator is a breakthrough design; advantages of CFB; new design with substantial development history; KUHMO: successful demo unit; KUHMO: good performance over load range with low emissions; KOKKOLA: first commercial unit and emissions; KOKKOLA: first commercial unit and emissions; compact CFB installations; next generation CFB boiler; grid nozzle upgrades; cast segmented vortex finders; vortex finder installation; ceramic anchors; pre-cast vertical bullnose; refractory upgrades; and wet gunning.

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.

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

Investigation of optimal chemical composition of cast aluminum alloys for vibrational mechanical-chemical polishing and deposition of protective and decorative coatings

NASA Astrophysics Data System (ADS)

Ivanov, V. V.; Popov, S. I.; Kirichek, A. V.

2018-03-01

The article suggests the technology of vibration finishing processing of aluminum alloys with simultaneous coating. On the basis of experimental studies, cast alloys, working media, operating modes of equipment, activating solutions were chosen. The practical application of the developed technology on real parts is shown.

Tutorial Video Series: Using Stakeholder Outreach to Increase Usage of ToxCast Data (SETAC EU)

EPA Science Inventory

The limited amount of toxicity data on thousands of chemicals found in consumer products has led to the development of research endeavors such as the U.S. EPA’s Toxicity Forecaster (ToxCast). ToxCast uses high-throughput screening technology to evaluate thousands of chemicals for...

[Registration technology for mandibular angle osteotomy based on augmented reality].

PubMed

Zhu, Ming; Chai, Gang; Zhang, Yan; Ma, Xiao-Fei; Yu, Zhe-Yuan; Zhu, Yi-Jia

2010-12-01

To establish an effective path to register the operative plan to the real model of mandible made by rapid prototyping (RP) technology. Computerize tomography (CT) was performed on 20 patients to create 3D images, and computer aided operation planning information can be merged with the 3D images. Then dental cast was used to fix the signal which can be recognized by the software. The dental cast was transformed to 3D data with a laser scanner and a programmer that run on a personal computer named Rapidform matching the dental cast and the mandible image to generate the virtual image. Then the registration was achieved by video monitoring system. By using this technology, the virtual image of mandible and the cutting planes both can overlay the real model of mandible made by RP. This study found an effective way for registration by using dental cast, and this way might be a powerful option for the registration of augmented reality. Supported by Program for Innovation Research Team of Shanghai Municipal Education Commission.

Producing Foils From Direct Cast Titanium Alloy Strip

NASA Technical Reports Server (NTRS)

Stuart, T. A.; Gaspar, T. A.; Sukonnik, I. M.; Semiatan, S. L.; Batawi, E.; Peters, J. A.; Fraser, H. L.

1996-01-01

This research was undertaken to demonstrate the feasibility of producing high-quality, thin-gage, titanium foil from direct cast titanium strip. Melt Overflow Rapid Solidification Technology (MORST) was used to cast several different titanium alloys into 500 microns thick strip, 10 cm wide and up to 3 m long. The strip was then either ground, hot pack rolled or cold rolled, as appropriate, into foil. Gamma titanium aluminide (TiAl) was cast and ground to approximately 100 microns thick foil and alpha-2 titanium aluminide (Ti3AI) was cast and hot pack rolled to approximately 70 microns thick foil. CP Ti, Ti6Al2Sn4Zr2Mo, and Ti22AI23Nb (Orthorhombic), were successfully cast and cold-rolled into good quality foil (less than 125 microns thick). The foils were generally fully dense with smooth surfaces, had fine, uniform microstructures, and demonstrated mechanical properties equivalent to conventionally produced titanium. By eliminating many manufacturing steps, this technology has the potential to produce thin gage, titanium foil with good engineering properties at significantly reduced cost relative to conventional ingot metallurgy processing.

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.

Hydrophobic asymmetric ultrafiltration PVDF membranes: an alternative separator for VFB with excellent stability.

PubMed

Wei, Wenping; Zhang, Huamin; Li, Xianfeng; Zhang, Hongzhang; Li, Yun; Vankelecom, Ivo

2013-02-14

Polyvinylidene fluoride (PVDF) ultrafiltration membranes were investigated for the first time in vanadium redox flow battery (VFB) applications. Surprisingly, PVDF ultrafiltration membranes with hydrophobic pore walls and relatively large pore sizes of several tens of nanometers proved able to separate vanadium ions and protons efficiently, thus being suitable as a VFB separator. The ion selectivity of this new type of VFB membrane could be tuned readily by controlling the membrane morphology via changes in the composition of the membrane casting solution, and the casting thickness. The results showed that the PVDF membranes offered good performances and excellent stability in VFB applications, where it could, performance-wise, truly substitute Nafion in VFB applications, but at a much lower cost.

Casting technology for ODS steels - dispersion of nanoparticles in liquid metals

NASA Astrophysics Data System (ADS)

Sarma, M.; Grants, I.; Kaldre, I.; Bojarevics, A.; Gerbeth, G.

2017-07-01

Dispersion of particles to produce metal matrix nanocomposites (MMNC) can be achieved by means of ultrasonic vibration of the melt using ultrasound transducers. However, a direct transfer of this method to produce steel composites is not feasible because of the much higher working temperature. Therefore, an inductive technology for contactless treatment by acoustic cavitation was developed. This report describes the samples produced to assess the feasibility of the proposed method for nano-particle separation in steel. Stainless steel samples with inclusions of TiB2, TiO2, Y2O3, CeO2, Al2O3 and TiN have been created and analyzed. Additional experiments have been performed using light metals with an increased value of the steady magnetic field using a superconducting magnet with a field strength of up to 5 T.

Freeform fabrication of tissue-simulating phantoms by combining three-dimensional printing and casting

NASA Astrophysics Data System (ADS)

Shen, Shuwei; Zhao, Zuhua; Wang, Haili; Han, Yilin; Dong, Erbao; Liu, Bin; Liu, Wendong; Cromeens, Barrett; Adler, Brent; Besner, Gail; Ray, William; Hoehne, Brad; Xu, Ronald

2016-03-01

Appropriate surgical planning is important for improved clinical outcome and minimal complications in many surgical operations, such as a conjoined twin separation surgery. We combine 3D printing with casting and assembling to produce a solid phantom of high fidelity to help surgeons for better preparation of the conjoined twin separation surgery. 3D computer models of individual organs were reconstructed based on CT scanned data of the conjoined twins. The models were sliced, processed, and converted to an appropriate format for Fused Deposition Modeling (FDM). The skeletons of the phantom were printed directly by FDM using Acrylonitrile-Butadiene-Styrene (ABS) material, while internal soft organs were fabricated by casting silicon materials of different compositions in FDM printed molds. The skeleton and the internal organs were then assembled with appropriate fixtures to maintain their relative positional accuracies. The assembly was placed in a FMD printed shell mold of the patient body for further casting. For clear differentiation of different internal organs, CT contrast agents of different compositions were added in the silicon cast materials. The produced phantom was scanned by CT again and compared with that of the original computer models of the conjoined twins in order to verify the structural and positional fidelity. Our preliminary experiments showed that combining 3D printing with casting is an effective way to produce solid phantoms of high fidelity for the improved surgical planning in many clinical applications.

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.

[Effect of fluoride concentration on the corrosion behavior of cobalt-chromium alloy fabricated by two different technology processes].

PubMed

Qiuxia, Yang; Ying, Yang; Han, Xu; Di, Wu; Ke, Guo

2016-02-01

This study aims to determine the effect of fluoride concentration on the corrosion behavior of cobalt-chromium alloy fabricated by two different technology processes in a simulated oral environment. A total of 15 specimens were employed with selective laser melting (SLM) and another 15 for traditional casting (Cast) in cobalt-chromium alloy powders and blocks with the same material composition. The corrosion behavior of the specimens was studied by potentiodynamic polarization test under different oral environments with varying solubilities of fluorine (0, 0.05%, and 0.20% for each) in acid artificial saliva (pH = 5.0). The specimens were soaked in fluorine for 24 h, and the surface microstructure was observed under a field emission scanning electron microscope after immersing the specimens in the test solution at constant temperature. The corrosion potential (Ecorr) value of the cobalt-chromium alloy cast decreased with increasing fluoride concentration in acidic artificial saliva. The Ecorr, Icorr, and Rp values of the cobalt-chromium alloy fabricated by two different technology processes changed significantly when the fluoride concentration was 0.20% (P < 0.05). The Ecorr, Icorr, and Rp values of the cobalt-chromium alloy fabricated by two different technology processes exhibited a statistically significant difference. The Icorr value of the cobalt-chromium alloy cast was higher than that in the SLM group cobalt-chromium alloy when the fluoride concentration was 0.20% (P < 0.05). The Ecorr, tRp alues of the cobalt-chromium alloy cast were lower htan those of the SLM group cobalt-chromium alloy when the fluoride concentration was 0.20% (P< 0 .05). Fluoride ions adversely affected the corrosion resistance of the cobalt-chromium alloy fabricated by two different technology processes. The corrosion resistance of the cobalt-chromium alloy cast was worse than that of the SLM group cobalt-chromium alloy when the fluoride concentration was 0.20%.

Web Cast on Arsenic Demonstration Program: Lessons Learned

EPA Science Inventory

Web cast presentation covered 10 Lessons Learned items selected from the Arsenic Demonstration Program with supporting information. The major items discussed include system design and performance items and the cost of the technologies.

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.

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.

Development of a Thin-Wall Magnesium side door Inner Panel for Automobiles

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

Jekl, J.; Auld, J.; Sweet, C.

Cast magnesium side door inner panels can provide a good combination of weight, functional, manufacturing and economical requirements. However, several challenges exist including casting technology for thin-wall part design, multi-material incompatibility and relatively low strength vs steel. A project has been initiated, supported by the US Department of Energy, to design and develop a lightweight frame-under-glass door having a thin-wall, full die-cast, magnesium inner panel. This development project is the first of its kind within North America. Phase I of the project is now complete and the 2.0mm magnesium design, through casting process enablers, has met or exceeded all stiffnessmore » requirements, with significant mass reduction and part consolidation. In addition, a corrosion mitigation strategy has been established using industry-accepted galvanic isolation methods and coating technologies.« less

Water research program final report, March 15, 1970 to October 31, 1972. Separations processes

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

Minturn, R. E.

A summary article on separation by filtration is reprinted, and research is reported in the following areas: dynamic membranes, cast film membranes, concentration polarization, economic analysis; and enhanced heat transfer. (DHM)

Evaluating the Tensile Properties of Aluminum Foundry Alloys through Reference Castings-A Review.

PubMed

Anilchandra, A R; Arnberg, Lars; Bonollo, Franco; Fiorese, Elena; Timelli, Giulio

2017-08-30

The tensile properties of an alloy can be exploited if detrimental defects and imperfections of the casting are minimized and the microstructural characteristics are optimized through several strategies that involve die design, process management and metal treatments. This paper presents an analysis and comparison of the salient characteristics of the reference dies proposed in the literature, both in the field of pressure and gravity die-casting. The specimens produced with these reference dies, called separately poured specimens, are effective tools for the evaluation and comparison of the tensile and physical behaviors of Al-Si casting alloys. Some of the findings of the present paper have been recently developed in the frame of the European StaCast project whose results are complemented here with some more recent outcomes and a comprehensive analysis and discussion.

Ultra-smooth finishing of aspheric surfaces using CAST technology

NASA Astrophysics Data System (ADS)

Kong, John; Young, Kevin

2014-06-01

Growing applications for astronomical ground-based adaptive systems and air-born telescope systems demand complex optical surface designs combined with ultra-smooth finishing. The use of more sophisticated and accurate optics, especially aspheric ones, allows for shorter optical trains with smaller sizes and a reduced number of components. This in turn reduces fabrication and alignment time and costs. These aspheric components include the following: steep surfaces with large aspheric departures; more complex surface feature designs like stand-alone off-axis-parabola (OAP) and free form optics that combine surface complexity with a requirement for ultra-high smoothness, as well as special optic materials such as lightweight silicon carbide (SiC) for air-born systems. Various fabrication technologies for finishing ultra-smooth aspheric surfaces are progressing to meet these growing and demanding challenges, especially Magnetorheological Finishing (MRF) and ion-milling. These methods have demonstrated some good success as well as a certain level of limitations. Amongst them, computer-controlled asphere surface-finishing technology (CAST), developed by Precision Asphere Inc. (PAI), plays an important role in a cost effective manufacturing environment and has successfully delivered numerous products for the applications mentioned above. One of the most recent successes is the Gemini Planet Imager (GPI), the world's most powerful planet-hunting instrument, with critical aspheric components (seven OAPs and free form optics) made using CAST technology. GPI showed off its first images in a press release on January 7, 2014 . This paper reviews features of today's technologies in handling the ultra-smooth aspheric optics, especially the capabilities of CAST on these challenging products. As examples, three groups of aspheres deployed in astronomical optics systems, both polished and finished using CAST, will be discussed in detail.

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

Development of Thin Section Zinc Die Casting Technology

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

Goodwin, Frank

2013-10-31

A new high fluidity zinc high pressure die casting alloy, termed the HF alloy, was developed during laboratory trials and proven in industrial production. The HF alloy permits castings to be achieved with section thicknesses of 0.3 mm or less. Technology transfer activities were conducted to develop usage of the HF high fluidity alloy. These included production of a brochure and a one-hour webinar on the HF alloy. The brochure was then sent to 1,184 product designers in the Interzinc database. There was excellent reception to this mailing, and from this initial contact 5 technology transfer seminars were conducted formore » 81 participants from 30 companies across a wide range of business sectors. Many of the successful applications to date involve high quality surface finishes. Design and manufacturing assistance was given for development of selected applications.« less

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.

49 CFR 238.307 - Periodic mechanical inspection of passenger cars and unpowered vehicles used in passenger trains.

Code of Federal Regulations, 2014 CFR

2014-10-01

... body from separating in case of derailment. (9) All center castings on trucks are not cracked or broken... inspection of all center castings shall be conducted by jacking the equipment and rolling out the trucks at... component; (iii) A crack, break, excessive wear, structural defect, or weakness of a component; (iv) A leak...

Fatigue behavior in rheocast aluminum 357 suspension arms using the SEED process

NASA Astrophysics Data System (ADS)

Samuel, Ehab; Zheng, Chang-Qing; Bouaicha, Amine; Bouazara, Mohamed

Extensive studies have been devoted to the use of aluminum alloys in the automotive industry, by virtue of the favourable mechanical properties that can be attained. Moreover, the aluminum casting method employed has also been the subject of scrutiny, given the multitude of casting options available. The present work serves to illustrate the advancements made in the area of rheocasting, using the SEED method, as carried out at the National Research Council Canada — Aluminum Technology Centre. The SEED (Swirled Enthalpy Equilibration Device) process, which relies on heat extraction of the liquid aluminum alloy via mechanical agitation in a confined cylinder to form the semi-solid billet, has already proven successful in producing sound aluminum castings having an excellent combination of strength and ductility. Moreover, fatigue testing on the cast alloy parts has shown enormous potential for this emerging technology.

Liquid Metal Engineering by Application of Intensive Melt Shearing

NASA Astrophysics Data System (ADS)

Patel, Jayesh; Zuo, Yubo; Fan, Zhongyun

In all casting processes, liquid metal treatment is an essential step in order to produce high quality cast products. A new liquid metal treatment technology has been developed which comprises of a rotor/stator set-up that delivers high shear rate to the liquid melt. It generates macro-flow in a volume of melt for distributive mixing and intensive shearing for dispersive mixing. The high shear device exhibits significantly enhanced kinetics for phase transformations, uniform dispersion, distribution and size reduction of solid particles and gas bubbles, improved homogenisation of chemical composition and temperature fields and also forced wetting of usually difficult-to-wet solid particles in the liquid metal. Hence, it can benefit various casting processes to produce high quality cast products with refined microstructure and enhanced mechanical properties. Here, we report an overview on the application of the new high shear technology to the processing of light metal alloys.

Development of expert systems for modeling of technological process of pressure casting on the basis of artificial intelligence

NASA Astrophysics Data System (ADS)

Gavarieva, K. N.; Simonova, L. A.; Pankratov, D. L.; Gavariev, R. V.

2017-09-01

In article the main component of expert system of process of casting under pressure which consists of algorithms, united in logical models is considered. The characteristics of system showing data on a condition of an object of management are described. A number of logically interconnected steps allowing to increase quality of the received castings is developed

Microstructure and Dynamic Failure Properties of Freeze-Cast Materials for Thermobaric Warhead Cases

DTIC Science & Technology

2012-12-01

Function LLNL Lawrence Livermore National Laboratory PDF Probability Density Function PMMA Poly(Methyl Methacrylate) RM Reactive Materials SEM...FREEZE CAST MATERIALS Freeze casting technology combines compounds such as aluminum oxide and poly(methyl methacrylate) ( PMMA ) to develop a...Subsequently, the porous structure can be infiltrated with a variety of materials, such as a standard polymer like PMMA . This hybrid material is believed

Genetic affinity between diverse ethnoreligious communities of Tamil Nadu, India: a microsatellite study.

PubMed

Eaaswarkhanth, M; Vasulu, T S; Haque, Ikramul

2008-12-01

Historically, a number of local Hindu caste groups have converted to Islam and formed religious endogamous groups. Therefore the local caste groups and religious communities in a region are expected to show genetic relatedness. In this study we investigate the genetic relationship between Tamil-speaking (Dravidian language) Muslims (Sunni), six endogamous Hindu castes, and a tribal ethnic group (Irulars) using 13 CODIS (Combined DNA Index System) autosomal microsatellite markers. Muslims show the highest average heterozygosity (0.405) compared to the other groups. The neighbor-joining tree and the multidimensional-scaling plot show clustering of Tamil-speaking Muslims with three caste groups (Gounder, Paraiyar, and Vanniyar), whereas the Irular tribe is separated out of the cluster.

Lead/acid battery design and operation

NASA Astrophysics Data System (ADS)

Manders, J. E.; Bui, N.; Lambert, D. W. H.; Navarette, J.; Nelson, R. F.; Valeriote, E. M.

In keeping with the tradition of previous meetings, the Seventh Asian Battery Conference closed with the delegates putting questions to an expert panel of battery scientists and technologies. The proceedings were lively and the subjects were as follows. Grid alloys: gassing characteristics; influence of minor constituents on metallurgical and electrochemical characteristics; latest trends in composition; alloys for cast-on straps. Battery manufacture and operation: plate formation ( α-PbO 2: β-PbO 2 ratio); dendritic shorts. Separators: contribution to battery internal resistance; influence of negative-plate enveloping; reduced backweb. Valve-regulated lead/acid batteries: positive active-material: negative active-material ratio; hydrogen evolution and dry-out; negative-plate self-discharge; tank vs. box formation.

Casting technology for manufacturing metal rods from simulated metallic spent fuels

NASA Astrophysics Data System (ADS)

Leeand, Y. S.; Lee, D. B.; Kim, C. K.; Shin, Y. J.; Lee, J. H.

2000-09-01

A uranium metal rod 13.5 mm in diameter and 1,150 mm long was produced from simulated metallic spent fuels with advanced casting equipment using the directional-solidification method. A vacuum casting furnace equipped with a four-zone heater to prevent surface oxidation and the formation of surface shrinkage holes was designed. By controlling the axial temperature gradient of the casting furnace, deformation by the surface shrinkage phenomena was diminished, and a sound rod was manufactured. The cooling behavior of the molten uranium was analyzed using the computer software package MAGMAsoft.

Electroactive poly(vinylidene fluoride)-based structures for advanced applications.

PubMed

Ribeiro, Clarisse; Costa, Carlos M; Correia, Daniela M; Nunes-Pereira, João; Oliveira, Juliana; Martins, Pedro; Gonçalves, Renato; Cardoso, Vanessa F; Lanceros-Méndez, Senentxu

2018-04-01

Poly(vinylidene fluoride) (PVDF) and its copolymers are the polymers with the highest dielectric constants and electroactive responses, including piezoelectric, pyroelectric and ferroelectric effects. This semicrystalline polymer can crystallize in five different forms, each related to a different chain conformation. Of these different phases, the β phase is the one with the highest dipolar moment and the highest piezoelectric response; therefore, it is the most interesting for a diverse range of applications. Thus, a variety of processing methods have been developed to induce the formation of the polymer β phase. In addition, PVDF has the advantage of being easily processable, flexible and low-cost. In this protocol, we present a number of reproducible and effective methods to produce β-PVDF-based morphologies/structures in the form of dense films, porous films, 3D scaffolds, patterned structures, fibers and spheres. These structures can be fabricated by different processing techniques, including doctor blade, spin coating, printing technologies, non-solvent-induced phase separation (NIPS), temperature-induced phase separation (TIPS), solvent-casting particulate leaching, solvent-casting using a 3D nylon template, freeze extraction with a 3D poly(vinyl alcohol) (PVA) template, replica molding, and electrospinning or electrospray, with the fabrication method depending on the desired characteristics of the structure. The developed electroactive structures have shown potential to be used in a wide range of applications, including the formation of sensors and actuators, in biomedicine, for energy generation and storage, and as filtration membranes.

Position Accuracy of Implant Analogs on 3D Printed Polymer versus Conventional Dental Stone Casts Measured Using a Coordinate Measuring Machine.

PubMed

Revilla-León, Marta; Gonzalez-Martín, Óscar; Pérez López, Javier; Sánchez-Rubio, José Luis; Özcan, Mutlu

2017-11-17

To compare the accuracy of implant analog positions on complete edentulous maxillary casts made of either dental stone or additive manufactured polymers using a coordinate measuring machine (CMM). A completely edentulous maxillary model of a patient with 7 implant analogs was obtained. From this model, two types of casts were duplicated, namely conventional dental stone (CDS) using a custom tray impression technique after splinting (N = 5) and polymer cast using additive manufacturing based on the STL file generated. Polymer casts (N = 20; n = 5 per group) were fabricated using 4 different additive manufacturing technologies (multijet printing-MJP1, direct light processing-DLP, stereolithography-SLA, multijet printing-MJP2). CMM was used to measure the correct position of each implant, and distortion was calculated for each system at x-, y-, and z-axes. Measurements were repeated 3 times per specimen in each axis yielding a total of 546 measurements. Data were analyzed using ANOVA, Sheffé tests, and Bonferroni correction (α = 0.05). Compared to CMM, the mean distortion (μm) ranged from 22.7 to 74.9, 23.4 to 49.1, and 11.0 to 85.8 in the x-, y-, and z-axes, respectively. CDS method (x-axis: 37.1; z-axis: 27.62) showed a significant difference compared to DLP on the x-axis (22.7) (p = 0.037) and to MJP1 on the z-axis (11.0) (p = 0.003). Regardless of the cast system, x-axes showed more distortion (42.6) compared to y- (34.6) and z-axes (35.97). Among additive manufacturing technologies, MJP2 presented the highest (64.3 ± 83.6), and MJP1 (21.57 ± 16.3) and DLP (27.07 ± 20.23) the lowest distortion, which was not significantly different from CDS (32.3 ± 22.73) (p > 0.05). For the fabrication of the definitive casts for implant prostheses, one of the multijet printing systems and direct light processing additive manufacturing technologies showed similar results to conventional dental stone. Conventional dental stone casts could be accurately duplicated using some of the additive manufacturing technologies tested. © 2017 by the American College of Prosthodontists.

Cast Aluminum Structures Technology (CAST) Phase VI. Technology Transfer.

DTIC Science & Technology

1980-04-01

and other aspects of the program was provided as follows: o Phase I--Preliminary Design Richard C. Jones o Phase il--Manufacturing Methods Richard G...Christner o Phase Ill--Detailed Design Richard C. Jones o Phase IV--Fabrication of Demonstration Richard G. Christner Articles and Production... Richard C. Jones, assisted by Carlos J. Romero, Christian K. Gunther, Cecil E. Parsons, and Donald D. Goehler; and by Walter Hyler of Battelle Columbus

Multicomponent membranes

DOEpatents

Kulprathipanja, Santi; Kulkarni, Sudhir S.; Funk, Edward W.

1988-01-01

A multicomponent membrane which may be used for separating various components which are present in a fluid feed mixture comprises a mixture of a plasticizer such as a glycol and an organic polymer cast upon a porous organic polymer support. The membrane may be prepared by casting an emulsion or a solution of the plasticizer and polymer on the porous support, evaporating the solvent and recovering the membrane after curing.

49 CFR 238.307 - Periodic mechanical inspection of passenger cars and unpowered vehicles used in passenger trains.

Code of Federal Regulations, 2013 CFR

2013-10-01

... separating in case of derailment. (9) All center castings on trucks are not cracked or broken, to the extent... castings shall be conducted by jacking the equipment and rolling out the trucks at each COT&S cycle... crack, break, excessive wear, structural defect, or weakness of a component; (iv) A leak; (v) Use of a...

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.

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.

Building the Sun4Cast System: Improvements in Solar Power Forecasting

DOE PAGES

Haupt, Sue Ellen; Kosovic, Branko; Jensen, Tara; ...

2017-06-16

The Sun4Cast System results from a research-to-operations project built on a value chain approach, and benefiting electric utilities’ customers, society, and the environment by improving state-of-the-science solar power forecasting capabilities. As integration of solar power into the national electric grid rapidly increases, it becomes imperative to improve forecasting of this highly variable renewable resource. Thus, a team of researchers from public, private, and academic sectors partnered to develop and assess a new solar power forecasting system, Sun4Cast. The partnership focused on improving decision-making for utilities and independent system operators, ultimately resulting in improved grid stability and cost savings for consumers.more » The project followed a value chain approach to determine key research and technology needs to reach desired results. Sun4Cast integrates various forecasting technologies across a spectrum of temporal and spatial scales to predict surface solar irradiance. Anchoring the system is WRF-Solar, a version of the Weather Research and Forecasting (WRF) numerical weather prediction (NWP) model optimized for solar irradiance prediction. Forecasts from multiple NWP models are blended via the Dynamic Integrated Forecast (DICast) System, the basis of the system beyond about 6 h. For short-range (0-6 h) forecasts, Sun4Cast leverages several observation-based nowcasting technologies. These technologies are blended via the Nowcasting Expert System Integrator (NESI). The NESI and DICast systems are subsequently blended to produce short to mid-term irradiance forecasts for solar array locations. The irradiance forecasts are translated into power with uncertainties quantified using an analog ensemble approach, and are provided to the industry partners for real-time decision-making. The Sun4Cast system ran operationally throughout 2015 and results were assessed. As a result, this paper analyzes the collaborative design process, discusses the project results, and provides recommendations for best-practice solar forecasting.« less

Building the Sun4Cast System: Improvements in Solar Power Forecasting

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

Haupt, Sue Ellen; Kosovic, Branko; Jensen, Tara

The Sun4Cast System results from a research-to-operations project built on a value chain approach, and benefiting electric utilities’ customers, society, and the environment by improving state-of-the-science solar power forecasting capabilities. As integration of solar power into the national electric grid rapidly increases, it becomes imperative to improve forecasting of this highly variable renewable resource. Thus, a team of researchers from public, private, and academic sectors partnered to develop and assess a new solar power forecasting system, Sun4Cast. The partnership focused on improving decision-making for utilities and independent system operators, ultimately resulting in improved grid stability and cost savings for consumers.more » The project followed a value chain approach to determine key research and technology needs to reach desired results. Sun4Cast integrates various forecasting technologies across a spectrum of temporal and spatial scales to predict surface solar irradiance. Anchoring the system is WRF-Solar, a version of the Weather Research and Forecasting (WRF) numerical weather prediction (NWP) model optimized for solar irradiance prediction. Forecasts from multiple NWP models are blended via the Dynamic Integrated Forecast (DICast) System, the basis of the system beyond about 6 h. For short-range (0-6 h) forecasts, Sun4Cast leverages several observation-based nowcasting technologies. These technologies are blended via the Nowcasting Expert System Integrator (NESI). The NESI and DICast systems are subsequently blended to produce short to mid-term irradiance forecasts for solar array locations. The irradiance forecasts are translated into power with uncertainties quantified using an analog ensemble approach, and are provided to the industry partners for real-time decision-making. The Sun4Cast system ran operationally throughout 2015 and results were assessed. As a result, this paper analyzes the collaborative design process, discusses the project results, and provides recommendations for best-practice solar forecasting.« less

Bioinspired Diatomite Membrane with Selective Superwettability for Oil/Water Separation.

PubMed

Lo, Yu-Hsiang; Yang, Ching-Yu; Chang, Haw-Kai; Hung, Wei-Chen; Chen, Po-Yu

2017-05-03

Membranes with selective superwettability for oil/water separation have received significant attention during the past decades. Hierarchical structures and surface roughness are believed to improve the oil repellency and the stability of Cassie-Baxter state. Diatoms, unicellular photosynthetic algae, possess sophisticated skeletal shells (called frustules) which are made of hydrated silica. Motivated by the hierarchical micro- and nanoscale features of diatom, we fabricate a hierarchical diatomite membrane which consists of aligned micro-sized channels by the freeze casting process. The fine nano-porous structures of frustules are well preserved after the post sintering process. The bioinspired diatomite membrane performs both underwater superoleophobicity and superhydrophobicity under various oils. Additionally, we demonstrate the highly efficient oil/water separation capabililty of the membranes in various harsh environments. The water flux can be further adjusted by tuning the cooling rates. The eco-friendly and robust bioinspired membranes produced by the simple, cost-effective freeze casting method can be potentially applied for large scale and efficient oil/water separation.

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.

Arsenic Removal from Drinking Water - Web cast

EPA Science Inventory

Web cast presentation covered six topics: (1) Arsenic Chemistry, (2) Technology Selection/Arsenic Demonstration Program, (3) Case Study 1, (4) Caser Study 2, (5) Case Study 3, and (6) Media Regeneration Project. The presentation was considered a training session and consist of m...

Arsenic Removal from Drinking Water - Web Cast Presentation

EPA Science Inventory

Web cast presentation covered six topics: 1), Arsenic Chemistry, 2), Technology Selection/Arsenic Demonstration Program, 3), Case Study 1, 4), Caser Study 2, 5), Case Study 3, and 6), Media Regeneration Project. The presentation was considered a training session and consist of m...

ExpoCast: Exposure Science for Prioritization and Toxicity Testing (S)

EPA Science Inventory

The US EPA is completing the Phase I pilot for a chemical prioritization research program, called ToxCast. Here EPA is developing methods for using computational chemistry, high-throughput screening, and toxicogenomic technologies to predict potential toxicity and prioritize limi...

ExpoCast: Exposure Science for Prioritization and Toxicity Testing

EPA Science Inventory

The US EPA is completing the Phase I pilot for a chemical prioritization research program, called ToxCastTM. Here EPA is developing methods for using computational chemistry, high-throughput screening, and toxicogenomic technologies to predict potential toxicity and prioritize l...

Method of forming components for a high-temperature secondary electrochemical cell

DOEpatents

Mrazek, Franklin C.; Battles, James E.

1983-01-01

A method of forming a component for a high-temperature secondary electrochemical cell having a positive electrode including a sulfide selected from the group consisting of iron sulfides, nickel sulfides, copper sulfides and cobalt sulfides, a negative electrode including an alloy of aluminum and an electrically insulating porous separator between said electrodes. The improvement comprises forming a slurry of solid particles dispersed in a liquid electrolyte such as the lithium chloride-potassium chloride eutetic, casting the slurry into a form having the shape of one of the components and smoothing the exposed surface of the slurry, cooling the cast slurry to form the solid component, and removing same. Electrodes and separators can be thus formed.

COST AND PERFORMANCE REPORT: INNOVATIVE ACOUSTIC SENSOR TECHNOLOGIES FOR LEAK DETECTION IN CHALLENGING PIPE TYPES

DTIC Science & Technology

2016-12-30

Operational Variable LeakFinderRT Equipment Logistics Portable Case Pipe Material Pit Cast Iron, Spun Cast Iron, Steel , Ductile Iron, Asbestos Cement ...AND ACRONYMS AC asbestos cement AMI advanced metering infrastructure AWWA American Water Works Association CI cast iron DI ductile iron DoD...assessing their ability to detect and accurately locate leaks in challenging pipe types such as polyvinyl chloride (PVC), asbestos cement (AC), and

The Design and Construction Process of a Test Stand for Casting the Power Steering’S Housing with the Use of the Pdcpd Material

NASA Astrophysics Data System (ADS)

Sobek, M.; Baier, A.; Grabowski, Ł.

2018-01-01

The use of new technologies and materials in various industries is a natural process that is directly related to the very high rate of development of these technologies. Certain industries decide to much faster introduce new technologies and materials. One of such branches is the automotive industry, whose representatives are very energetically looking for both financial savings and savings resulting from the vehicles mass reduction. An economically justified approach to construction materials is leading the search for new solutions and materials. The use of a modern material such as the two-component PDCPD composite shows hitherto unknown possibilities of producing subassemblies of many different constructions. The possibility of using a modern composite material with parameters comparable to that of metals and significantly lighter, can be an excellent alternative in the selection of materials for many parts of motor vehicles. The potentiality of precise casting of tolerated surfaces will allow to reduce the operations related to machining process, which is an indispensable part of the production process of elements that are cast of metal. This article describes the process of designing and building a test stand for precise positioning of power steering gear components at the stage of casting their housing. The article presents the principle of operation of the test stand and the process of preparation for the casting and the cast itself will be rudely described. Due to the implementation of research as part of a research project with an industrial partner, the article will only describe some operations. This is related to the confidentiality of the project.

Understanding the Biology and Technology of ToxCast and Tox21 Assays

EPA Science Inventory

The ToxCast high-throughput toxicity (HTT) testing methods have been developed to evaluate the hazard potential of diverse environmental, industrial and consumer product chemicals. The main goal is prioritizing the compounds of greatest concern for more detailed toxicological stu...

Mississippi State University Center for Air Sea Technology FY95 Research Program

NASA Technical Reports Server (NTRS)

Yeske, Lanny; Corbin, James H.

1995-01-01

The Mississippi State University (MSU) Center for Air Sea Technology (CAST) evolved from the Institute for Naval Oceanography's (INO) Experimental Center for Mesoscale Ocean Prediction (ECMOP) which was started in 1989. MSU CAST subsequently began operation on 1 October 1992 under an Office of Naval Research (ONR) two-year grant which ended on 30 September 1994. In FY95 MSU CAST was successful in obtaining five additional research grants from ONR, as well as several other research contracts from the Naval Oceanographic Office via NASA, the Naval Research Laboratory, the Army Corps of Engineers, and private industry. In the past, MSU CAST technical research and development has produced tools, systems, techniques, and procedures that improve efficiency and overcome deficiency for both the operational and research communities residing with the Department of Defense, private industry, and university ocean modeling community. We continued this effort with the following thrust areas: to develop advanced methodologies and tools for model evaluation, validation and visualization, both oceanographic and atmospheric; to develop a system-level capability for conducting temporally and ; spatially scaled ocean simulations driven by or are responsive to ocean models, and take into consideration coupling to atmospheric models; to continue the existing oceanographic/atmospheric data management task with emphasis on distributed databases in a network environment, with database optimization and standardization, including use of Mosaic and World Wide Web (WWW) access; and to implement a high performance parallel computing technology for CAST ocean models

Freeform fabrication of tissue-simulating phantom for potential use of surgical planning in conjoined twins separation surgery.

PubMed

Shen, Shuwei; Wang, Haili; Xue, Yue; Yuan, Li; Zhou, Ximing; Zhao, Zuhua; Dong, Erbao; Liu, Bin; Liu, Wendong; Cromeens, Barrett; Adler, Brent; Besner, Gail; Xu, Ronald X

2017-09-08

Preoperative assessment of tissue anatomy and accurate surgical planning is crucial in conjoined twin separation surgery. We developed a new method that combines three-dimensional (3D) printing, assembling, and casting to produce anatomic models of high fidelity for surgical planning. The related anatomic features of the conjoined twins were captured by computed tomography (CT), classified as five organ groups, and reconstructed as five computer models. Among these organ groups, the skeleton was produced by fused deposition modeling (FDM) using acrylonitrile-butadiene-styrene. For the other four organ groups, shell molds were prepared by FDM and cast with silica gel to simulate soft tissues, with contrast enhancement pigments added to simulate different CT and visual contrasts. The produced models were assembled, positioned firmly within a 3D printed shell mold simulating the skin boundary, and cast with transparent silica gel. The produced phantom was subject to further CT scan in comparison with that of the patient data for fidelity evaluation. Further data analysis showed that the produced model reassembled the geometric features of the original CT data with an overall mean deviation of less than 2 mm, indicating the clinical potential to use this method for surgical planning in conjoined twin separation surgery.

Accuracy of three-dimensional dental resin models created by fused deposition modeling, stereolithography, and Polyjet prototype technologies: A comparative study.

PubMed

Rebong, Raymund E; Stewart, Kelton T; Utreja, Achint; Ghoneima, Ahmed A

2018-05-01

The aim of this study was to assess the dimensional accuracy of fused deposition modeling (FDM)-, Polyjet-, and stereolithography (SLA)-produced models by comparing them to traditional plaster casts. A total of 12 maxillary and mandibular posttreatment orthodontic plaster casts were selected from the archives of the Orthodontic Department at the Indiana University School of Dentistry. Plaster models were scanned, saved as stereolithography files, and printed as physical models using three different three-dimensional (3D) printers: Makerbot Replicator (FDM), 3D Systems SLA 6000 (SLA), and Objet Eden500V (Polyjet). A digital caliper was used to obtain measurements on the original plaster models as well as on the printed resin models. Comparison between the 3D printed models and the plaster casts showed no statistically significant differences in most of the parameters. However, FDM was significantly higher on average than were plaster casts in maxillary left mixed plane (MxL-MP) and mandibular intermolar width (Md-IMW). Polyjet was significantly higher on average than were plaster casts in maxillary intercanine width (Mx-ICW), mandibular intercanine width (Md-ICW), and mandibular left mixed plane (MdL-MP). Polyjet was significantly lower on average than were plaster casts in maxillary right vertical plane (MxR-vertical), maxillary left vertical plane (MxL-vertical), mandibular right anteroposterior plane (MdR-AP), mandibular right vertical plane (MdR-vertical), and mandibular left vertical plane (MdL-vertical). SLA was significantly higher on average than were plaster casts in MxL-MP, Md-ICW, and overbite. SLA was significantly lower on average than were plaster casts in MdR-vertical and MdL-vertical. Dental models reconstructed by FDM technology had the fewest dimensional measurement differences compared to plaster models.

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.

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.

2003-01-01

Metal matrix composites for propulsion components offer high performance and affordability, resulting in low weight and cost. The following sections in this viewgraph presentation describe the pressure infiltration casting of a metal matrix composite LOX turbopump housing: 1) Baseline Pump Design and Stress Analysis; 2) Tool-less Advanced Pressure Infiltration Casting Process; 3) Preform Splicing and Joining for Large Components such as Pump Housing; 4) Fullscale Pump Housing Redesign.

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.

An Application of CICCT Accident Categories to Aviation Accidents in 1988-2004

NASA Technical Reports Server (NTRS)

Evans, Joni K.

2007-01-01

Interventions or technologies developed to improve aviation safety often focus on specific causes or accident categories. Evaluation of the potential effectiveness of those interventions is dependent upon mapping the historical aviation accidents into those same accident categories. To that end, the United States civil aviation accidents occurring between 1988 and 2004 (n=26,117) were assigned accident categories based upon the taxonomy developed by the CAST/ICAO Common Taxonomy Team (CICTT). Results are presented separately for four main categories of flight rules: Part 121 (large commercial air carriers), Scheduled Part 135 (commuter airlines), Non-Scheduled Part 135 (on-demand air taxi) and Part 91 (general aviation). Injuries and aircraft damage are summarized by year and by accident category.

Pervaporation Separation of Water-Ethanol Mixtures Using Organic-Inorganic Nanocomposite Membranes

EPA Science Inventory

Preyssler type heteropolyacid viz., H14[NaP5W30O110] incorporated chitosan nanocomposite membranes (NCMs) were prepared by solution casting, characterized using a variety of techniques and employed in the pervaporation separation of water-ethanol mixtures as a function of feed wa...

SEPARATION OF VOLATILE ORGANIC COMPOUNDS FROM AQUEOUS SOLUTIONS BY PERVAPORATION USING S-B-S BLOCK COPOLYMER MEMBRANES.

EPA Science Inventory

Composite membranes of a block copolymer of styrene and butadiene (S-B-S) were cast on highly porous, hydrophobic thin films of PTFE, and used for the separation and recovery of volatile organic compounds (VOCs) from aqueous solutions by pervaporation. Trichloroethane, trichloroe...

Advanced separators based on aromatic polymer for high energy density lithium batteries

DOEpatents

Zhang, Zhengcheng; Woo, Jung-Je; Amine, Khalil

2017-03-21

A process includes casting a solution including poly(phenylene oxide), inorganic nanoparticles, a solvent, and a non-solvent on a substrate; and removing the solvent to form a porous film; wherein: the porous film is configured for use as a porous separator for a lithium ion battery.

SEPARATION OF VOLATILE ORGANIC COMPOUNDS FROM AQUEOUS SOLUTIONS BY PERVAPORATION USING S-B-S BLOCK COPOLYMER MEMBRANES

EPA Science Inventory

Composite membranes of a block copolymer of styrene and butadiene (S-B-S) were cast on highly porous, hydrophobic thin films of PTFE and used for the separation and recovery of volatile organic compounds (VOCs) from aqueous solutions by pervaporation. Trichloroethane, trichloroe...

Fixture for forming evaporative pattern (EPC) process patterns

DOEpatents

Turner, Paul C.; Jordan, Ronald R.; Hansen, Jeffrey S.

1993-01-01

A method of casting metal using evaporative pattern casting process patterns in combination with a fixture for creating and maintaining a desired configuration in flexible patterns. A pattern is constructed and gently bent to the curvature of a suitable fixture. String or thin wire, which burns off during casting, is used to tie the pattern to the fixture. The fixture with pattern is dipped in a commercially available refractory wash to prevent metal adherence and sticking to the fixture. When the refractory wash is dry, the fixture and pattern are placed in a flask, and sand is added and compacted by vibration. The pattern remains in position, restrained by the fixture. Metal that is poured directly into the pattern replaces the pattern exactly but does not contact or weld to the fixture due to the protective refractory layer. When solid, the casting is easily separated from the fixture. The fixture can be cleaned for reuse in conventional casting cleaning equipment.

Evaluating the Tensile Properties of Aluminum Foundry Alloys through Reference Castings—A Review

PubMed Central

Anilchandra, A.R.; Arnberg, Lars; Bonollo, Franco; Fiorese, Elena

2017-01-01

The tensile properties of an alloy can be exploited if detrimental defects and imperfections of the casting are minimized and the microstructural characteristics are optimized through several strategies that involve die design, process management and metal treatments. This paper presents an analysis and comparison of the salient characteristics of the reference dies proposed in the literature, both in the field of pressure and gravity die-casting. The specimens produced with these reference dies, called separately poured specimens, are effective tools for the evaluation and comparison of the tensile and physical behaviors of Al-Si casting alloys. Some of the findings of the present paper have been recently developed in the frame of the European StaCast project whose results are complemented here with some more recent outcomes and a comprehensive analysis and discussion. PMID:28867796

Energy-Saving Melting and Revert Reduction Technology (E-SMARRT): Final Summary Report

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

White, Thornton C

2014-03-31

Energy-Saving Melting and Revert Reduction Technology (E-SMARRT) is a balanced portfolio of R&D tasks that address energy-saving opportunities in the metalcasting industry. E-SMARRT was created to: • Improve important capabilities of castings • Reduce carbon footprint of the foundry industry • Develop new job opportunities in manufacturing • Significantly reduce metalcasting process energy consumption and includes R&D in the areas of: • Improvements in Melting Efficiency • Innovative Casting Processes for Yield Improvement/Revert Reduction • Instrumentation and Control Improvement • Material properties for Casting or Tooling Design Improvement The energy savings and process improvements developed under E-SMARRT have been mademore » possible through the unique collaborative structure of the E-SMARRT partnership. The E-SMARRT team consisted of DOE’s Office of Industrial Technology, the three leading metalcasting technical associations in the U.S: the American Foundry Society; the North American Die Casting Association; and the Steel Founders’ Society of America; and SCRA Applied R&D, doing business as the Advanced Technology Institute (ATI), a recognized leader in distributed technology management. This team provided collaborative leadership to a complex industry composed of approximately 2,000 companies, 80% of which employ less than 100 people, and only 4% of which employ more than 250 people. Without collaboration, these new processes and technologies that enable energy efficiencies and environment-friendly improvements would have been slow to develop and had trouble obtaining a broad application. The E-SMARRT R&D tasks featured low-threshold energy efficiency improvements that are attractive to the domestic industry because they do not require major capital investment. The results of this portfolio of projects are significantly reducing metalcasting process energy consumption while improving the important capabilities of metalcastings. Through June 2014, the E-SMARRT program predicts an average annual estimated savings of 59 Trillion BTUs per year over a 10 year period through Advanced Melting Efficiencies and Innovative Casting Processes. Along with these energy savings, an estimated average annual estimate of CO2 reduction per year over a ten year period is 3.56 Million Metric Tons of Carbon Equivalent (MM TCE).« less

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.;

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.;

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.;

20180416 - Understanding the Biology and Technology of ToxCast and Tox21 Assays (SETAC Durham NC)

EPA Science Inventory

The ToxCast high-throughput toxicity (HTT) testing methods have been developed to evaluate the hazard potential of diverse environmental, industrial and consumer product chemicals. The main goal is prioritizing the compounds of greatest concern for more detailed toxicological stu...

BLAST FURNACE CAST HOUSE EMISSION CONTROL TECHNOLOGY ASSESSMENT

EPA Science Inventory

The study describes the state-of-the-art of controlling fumes escaping from blast furnace cast houses. Background information is based on: a study of existing literature; visits to blast furnaces in the U.S., Japan, and Europe; meetings with an ad hoc group of experienced blast f...

Tox21 and ToxCast Chemical Landscapes: Laying the Foundation for 21st Century Toxicology

EPA Science Inventory

The U.S. Environmental Protection Agency’s ToxCast project and the related, multi-Agency Tox21 project are employing high-throughput technologies to screen hundreds to thousands of chemicals in hundreds of assays, probing a wide diversity of biological targets, pathways and mecha...

The US EPAs ToxCast Program for the Prioritization and Prediction of Environmental Chemical Toxicity

EPA Science Inventory

To meet the need for evaluating large numbers of chemicals for potential toxicity, the U.S. Environmental Protection Agency has initiated a research project call ToxCast that makes use of recent advances in molecular biology and high-throughput screening. These technologies have ...

Method of forming components for a high-temperature secondary electrochemical cell

DOEpatents

Mrazek, F.C.; Battles, J.E.

1981-05-22

A method of forming a component for a high-temperature secondary electrochemical cell having a positive electrode including a sulfide selected from the group consisting of iron sulfides, nickel sulfides, copper sulfides and cobalt sulfides, a negative electrode including an alloy of aluminum and an electrically insulating porous separator between said electrodes is described. The improvement comprises forming a slurry of solid particles dispersed in a liquid electrolyte such as the lithium chloride-potassium chloride eutectic, casting the slurry into a form having the shape of one of the components and smoothing the exposed surface of the slurry, cooling the cast slurry to form the solid component, and removing same. Electrodes and separators can be thus formed.

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.

Multiscale topo-morphologic opening of arteries and veins: a validation study on phantoms and CT imaging of pulmonary vessel casting of pigs

NASA Astrophysics Data System (ADS)

Gao, Zhiyun; Holtze, Colin; Sonka, Milan; Hoffman, Eric; Saha, Punam K.

2010-03-01

Distinguishing pulmonary arterial and venous (A/V) trees via in vivo imaging is a critical first step in the quantification of vascular geometry for purposes of determining, for instance, pulmonary hypertension, detection of pulmonary emboli and more. A multi-scale topo-morphologic opening algorithm has recently been introduced by us separating A/V trees in pulmonary multiple-detector X-ray computed tomography (MDCT) images without contrast. The method starts with two sets of seeds - one for each of A/V trees and combines fuzzy distance transform, fuzzy connectivity, and morphologic reconstruction leading to multi-scale opening of two mutually fused structures while preserving their continuity. The method locally determines the optimum morphological scale separating the two structures. Here, a validation study is reported examining accuracy of the method using mathematically generated phantoms with different levels of fuzziness, overlap, scale, resolution, noise, and geometric coupling and MDCT images of pulmonary vessel casting of pigs. After exsanguinating the animal, a vessel cast was generated using rapid-hardening methyl methacrylate compound with additional contrast by 10cc of Ethiodol in the arterial side which was scanned in a MDCT scanner at 0.5mm slice thickness and 0.47mm in plane resolution. True segmentations of A/V trees were computed from these images by thresholding. Subsequently, effects of distinguishing A/V contrasts were eliminated and resulting images were used for A/V separation by our method. Experimental results show that 92% - 98% accuracy is achieved using only one seed for each object in phantoms while 94.4% accuracy is achieved in MDCT cast images using ten seeds for each of A/V trees.

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.

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

Influence of Ni Interlayer on Microstructure and Mechanical Properties of Mg/Al Bimetallic Castings

NASA Astrophysics Data System (ADS)

Liu, Ning; Liu, Canchun; Liang, Chunyong; Zhang, Yongguang

2018-05-01

Dissimilar joining of magnesium and aluminum using a compound casting process was investigated in the present work. For the first time, a Ni interlayer prepared by plasma spraying was inserted between the two base metals to improve the interfacial characteristics. Examination of the interfacial regions using scanning electron microscopy, energy-dispersive X-ray spectroscopy, electron probe microanalysis, and X-ray diffraction revealed the formation of a three-layered interface between Mg and Al without the interlayer. The thickness of the interface was approximately 600 μm when the casting was performed at 700 °C and increased with increasing casting temperature. However, with the addition of the Ni interlayer, the Al-Mg reaction was successfully prevented, and metallurgical bonding between the Ni interlayer and two base metals was achieved at a casting temperature of 700 °C. Upon increasing this temperature, Mg-Ni and Al-Ni intermetallics were generated at the separate interfaces. The shear strength of the Mg/Al bimetallic castings with the Ni interlayer was substantially improved compared with that of the direct Mg/Al joint, with a maximum value of 25.4 MPa achieved at 700 °C. Fracture occurred mainly along the Mg/Ni interface for the Mg/Ni/Al multilayer structure castings.

Gene differentiation among ten endogamous groups of West Bengal, India.

PubMed

Chakraborty, R; Walter, H; Mukherjee, B N; Malhotra, K C; Sauber, P; Banerjee, S; Roy, M

1986-11-01

Ten endogamous populations of West Bengal, India have been surveyed for genetic variation in 12 systems. These populations encompass all social ranks in the caste hierarchy and cover almost the entire geographic area of the state. Gene diversity analysis suggests that these groups exhibit significant allele frequency variation at all but three loci. The overall genetic difference is not, however, in accord with the classification based on caste. Two low-ranking scheduled caste groups are, in fact, in close proximity with the high-caste ones, suggesting evidence of past generations of gene flow among them. Three different clusters of groups emerge from the present data, providing support for the anthropologic assertion that in Bengal Proto-Australoid, Caucasoid, and Mongoloid racial elements generally coexist. However, these three components are not uniformly present in all groups. Geographic separation of the groups is a strong determinant of the gene differentiation that exists among these populations.

Extrapolation of mammalian-based ToxCast assay results to non-mammalian species to evaluate endocrine disruption

EPA Science Inventory

In vitro high-throughput screening (HTS) and in silico technologies have emerged as 21st century tools for chemical hazard identification. In 2007 the U.S. Environmental Protection Agency (EPA) launched the ToxCast Program, which has screened thousands of chemicals in hundreds of...

Cross-species extrapolation of mammalian-based ToxCast Data using Sequence Alignment to Predict Across Species Susceptibility (SeqAPASS)

EPA Science Inventory

In vitro high-throughput screening (HTS) and in silico technologies have emerged as 21st century tools for chemical hazard identification. In 2007 the U.S. Environmental Protection Agency (EPA) launched the ToxCast Program, which has screened thousands of chemicals in hundreds of...

Hanford's Simulated Low Activity Waste Cast Stone Processing

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

Kim, Young

2013-08-20

Cast Stone is undergoing evaluation as the supplemental treatment technology for Hanford’s (Washington) high activity waste (HAW) and low activity waste (LAW). This report will only cover the LAW Cast Stone. The programs used for this simulated Cast Stone were gradient density change, compressive strength, and salt waste form phase identification. Gradient density changes show a favorable outcome by showing uniformity even though it was hypothesized differently. Compressive strength exceeded the minimum strength required by Hanford and greater compressive strength increase seen between the uses of different salt solution The salt waste form phase is still an ongoing process asmore » this time and could not be concluded.« less

Development of high purity large forgings for nuclear power plants

NASA Astrophysics Data System (ADS)

Tanaka, Yasuhiko; Sato, Ikuo

2011-10-01

The recent increase in the size of energy plants has been supported by the development of manufacturing technology for high purity large forgings for the key components of the plant. To assure the reliability and performance of the large forgings, refining technology to make high purity steels, casting technology for gigantic ingots, forging technology to homogenize the material and consolidate porosity are essential, together with the required heat treatment and machining technologies. To meet these needs, the double degassing method to reduce impurities, multi-pouring methods to cast the gigantic ingots, vacuum carbon deoxidization, the warm forging process and related technologies have been developed and further improved. Furthermore, melting facilities including vacuum induction melting and electro slag re-melting furnaces have been installed. By using these technologies and equipment, large forgings have been manufactured and shipped to customers. These technologies have also been applied to the manufacture of austenitic steel vessel components of the fast breeder reactors and components for fusion experiments.

CASTING DEFECT MODELING IN AN INTEGRATED COMPUTATIONAL MATERIALS ENGINEERING APPROACH

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

Sabau, Adrian S

2015-01-01

To accelerate the introduction of new cast alloys, the simultaneous 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 ofmore » 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. Thus, the data on casting defects, including microstructure features, is crucial for evaluating the final performance-related properties of the component. ACKNOWLEDGEMENTS This work was performed under a Cooperative Research and Development Agreement (CRADA) with the Nemak Inc., and Chrysler Co. for the project "High Performance Cast Aluminum Alloys for Next Generation Passenger Vehicle Engines. The author would also like to thank Amit Shyam for reviewing the paper and Andres Rodriguez of Nemak Inc. Research sponsored by the U. S. Department of Energy, Office of Energy Efficiency and Renewable Energy, Vehicle Technologies Office, as part of the Propulsion Materials Program under contract DE-AC05-00OR22725 with UT-Battelle, LLC. Part of this research was conducted through the Oak Ridge National Laboratory's High Temperature Materials Laboratory User Program, which is sponsored by the U. S. Department of Energy, Office of Energy Efficiency and Renewable Energy, Vehicle Technologies Program.« less

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

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

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).

Prospects for the domestic production of large-sized cast blades and vanes for industrial gas turbines

NASA Astrophysics Data System (ADS)

Kazanskiy, D. A.; Grin, E. A.; Klimov, A. N.; Berestevich, A. I.

2017-10-01

Russian experience in the production of large-sized cast blades and vanes for industrial gas turbines is analyzed for the past decades. It is noted that the production of small- and medium-sized blades and vanes made of Russian alloys using technologies for aviation, marine, and gas-pumping turbines cannot be scaled for industrial gas turbines. It is shown that, in order to provide manufacturability under large-scale casting from domestic nickel alloys, it is necessary to solve complex problems in changing their chemical composition, to develop new casting technologies and to optimize the heat treatment modes. An experience of PAO NPO Saturn in manufacturing the blades and vanes made of ChS88U-VI and IN738-LC foundry nickel alloys for the turbines of the GTE-110 gas turbine unit is considered in detail. Potentialities for achieving adopted target parameters for the mechanical properties of working blades cast from ChS88UM-VI modified alloy are established. For the blades made of IN738-LC alloy manufactured using the existing foundry technology, a complete compliance with the requirements of normative and technical documentation has been established. Currently, in Russia, the basis of the fleet of gas turbine plants is composed by foreign turbines, and, for the implementation of the import substitution program, one can use the positive experience of PAO NPO Saturn in casting blades from IN738-LC alloy based on a reverse engineering technique. A preliminary complex of studies of the original manufacturer's blades should be carried out, involving, first of all, the determination of geometric size using modern measurement methods as well as the studies on the chemical compositions of the used materials (base metal and protective coatings). Further, verifying the constructed calculation models based on the obtained data, one could choose available domestic materials that would meet the operating conditions of the blades according to their heat resistance and corrosion resistance.

Research Progresses and Suggestions of Manufacturing Technologies of Engine Bearing Bushes

NASA Astrophysics Data System (ADS)

Cao, J.; Yin, Z. W.; Li, H. L.; Y Gao, G.

2017-12-01

Bearing bush is a key part of diesel engine, and its performance directly influences the life of whole machine. Several manufacturing technologies of bearing bush such as centrifugal casting, sintering, electroplating and magnetron sputtering have been overviewed. Their bond strength, porosity, production efficient, layer thickness, frictional coefficient and corresponding materials analyzed and compared. Results show that the porosity and oxidation of sintering and centrifugal casting are higher than that of other two methods. However, the production efficiency and coating thickness are better than that of electroplating and magnetron sputtering. Based on above comparisons and discussions, the improvements of all manufacturing technologies are suggested and supersonic cold spraying is suggested. It is proved that cold spraying technology is the best choice in the future with the developing of low frictional materials.

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.

Battery components employing a silicate binder

DOEpatents

Delnick, Frank M [Albuquerque, NM; Reinhardt, Frederick W [Albuquerque, NM; Odinek, Judy G [Rio Rancho, NM

2011-05-24

A battery component structure employing inorganic-silicate binders. In some embodiments, casting or coating of components may be performed using aqueous slurries of silicates and electrode materials or separator materials.

Design and optimization of the micro-engine turbine rotor manufacturing using the rapid prototyping technology

NASA Astrophysics Data System (ADS)

Vdovin, R. A.; Smelov, V. G.

2017-02-01

This work describes the experience in manufacturing the turbine rotor for the micro-engine. It demonstrates the design principles for the complex investment casting process combining the use of the ProCast software and the rapid prototyping techniques. At the virtual modelling stage, in addition to optimized process parameters, the casting structure was improved to obtain the defect-free section. The real production stage allowed demonstrating the performance and fitness of rapid prototyping techniques for the manufacture of geometrically-complex engine-building parts.

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.

Chemical Degradation of the Cathodic Electrical Contact Between Carbon and Cast Iron in Aluminum Production Cells

NASA Astrophysics Data System (ADS)

Brassard, Martin; Désilets, Martin; Soucy, Gervais; Bilodeau, Jean-François; Forté, Martin

2017-06-01

The cathodic carbon to cast iron electrical contact degradation is one of the factors to consider in the cathode voltage drop (CVD) increase over the lifetime of aluminum production cells. Lab-scale experiments were carried out to study the cast iron to carbon interface chemical degradation and the impact of important cell parameters like temperature and bath chemistry. Laboratory degradation results were compared with industrial samples. A thermoelectric Ansys numerical model was then used to predict the effect of cast iron surface degradation over CVD. Results show that the aluminum formation on the cast iron surface and its subsequent diffusion creates an immiscible mixture of Fe-Al metal alloy and electrolytic bath. Disparities were also observed between industrial samples taken from two different technologies, suggesting that the degradation can be slowed down. Thermoelectric calculations finally revealed that the impact of the contact resistance augmentation is by far greater than the cast iron degradation.

Gas turbine bucket wall thickness control

DOEpatents

Stathopoulos, Dimitrios; Xu, Liming; Lewis, Doyle C.

2002-01-01

A core for use in casting a turbine bucket including serpentine cooling passages is divided into two pieces including a leading edge core section and a trailing edge core section. Wall thicknesses at the leading edge and the trailing edge of the turbine bucket can be controlled independent of each other by separately positioning the leading edge core section and the trailing edge core section in the casting die. The controlled leading and trailing edge thicknesses can thus be optimized for efficient cooling, resulting in more efficient turbine operation.

Implementation of trinary logic in a polarization encoded optical shadow-casting scheme.

PubMed

Rizvi, R A; Zaheer, K; Zubairy, M S

1991-03-10

The design of various multioutput trinary combinational logic units by a polarization encoded optical shadow-casting (POSC) technique is presented. The POSC modified algorithm is employed to design and implement these logic elements in a trinary number system with separate and simultaneous generation of outputs. A detailed solution of the POSC logic equations for a fixed source plane and a fixed decoding mask is given to obtain input pixel coding for a trinary half-adder, full adder, and subtractor.

[Studies on high temperature oxidation of noble metal alloys for dental use. (III) On high temperature oxidation resistance of noble metal alloys by adding small amounts of alloying elements. (author's transl)].

PubMed

Ohno, H

1976-11-01

The previous report pointed out the undesirable effects of high temperature oxidation on the casting. The influence of small separate additions of Zn, Mg, Si, Be and Al on the high temperature oxidation of the noble metal alloys was examined. These alloying elements were chosen because their oxide have a high electrical resistivity and they have much higher affinity for oxygen than Cu. The casting were oxidized at 700 degrees C for 1 hour in air. The results obtained were as follows: 1. The Cu oxides are not observed on the as-cast surface of noble metal alloys containing small amounts of Zn, Mg, Si, Be, and Al. The castings have gold- or silver-colored surface. 2. After heating of the unpolished and polished castings, the additions of Si, Be and Al are effective in preventing oxidation of Cu in the 18 carats gold alloys. Especially the golden surface is obtained by adding Be and Al. But there is no oxidation-resistance on the polished castings in the alloys containing Zn and Mg. 3. The zinc oxide film formed on the as-cast specimen is effective in preventing of oxidation Cu in 18 carats gold alloys. 4. It seems that the addition of Al is most available in dental application.

DSSTox ToxCast and Tox21 Chemical Inventories: Laying the Foundation for the U.S. EPA’s Computational Toxicology Research Programs

EPA Science Inventory

High quality chemical structure inventories provide the foundation of the U.S. EPA’s ToxCast and Tox21 projects, which are employing high-throughput technologies to screen thousands of chemicals in hundreds of biochemical and cell-based assays, probing a wide diversity of targets...

Workplace Basic Skills in the Metal Casting Industry for World Class Process and Technology.

ERIC Educational Resources Information Center

Rasmussen, Bonnie

A workplace basic skills project for the metal casting industry was established jointly by Central Alabama Community College and Robinson Foundry, Inc. Evaluation of the project was made through a commercial test of hourly workers' general literacy level gains, instructor-developed pre- and posttests of mastery of the industrial process and…

Tox21 and ToxCast Chemical Landscapes: Laying the Foundation for 21st Century Toxicology - Application of the Strategy to Chemical Testing

EPA Science Inventory

The U.S. Environmental Protection Agency’s ToxCast project and the related, multi-Agency Tox21 project are employing high-throughput technologies to screen hundreds to thousands of chemicals in hundreds of assays, probing a wide diversity of biological targets, pathways and mecha...

The casting and mechanism of formation of semi-permeable polymer membranes in a microgravity environment

NASA Astrophysics Data System (ADS)

Vera, I.

The National Electric Company of Venezuela, C.A.D.A.F.E., is sponsoring the development of this experiment which represents Venezuela's first scientific experiment in space. The apparatus for the automatic casting of polymer thin films will be contained in NASA's payload No. G-559 of the Get Away Special program for a future orbital space flight in the U.S. Space Shuttle. Semi-permeable polymer membranes have important applications in a variety of fields, such as medecine, energy, and pharmaceuticals, and in general fluid separation processes such as reverse osmosis, ultra-filtration, and electro-dialysis. The casting of semi-permeable membranes in space will help to identify the roles of convection in determining the strucutre of these membranes.

Wear Resistance of Aluminum Matrix Composites Reinforced with Al2O3 Particles After Multiple Remelting

NASA Astrophysics Data System (ADS)

Klasik, Adam; Pietrzak, Krystyna; Makowska, Katarzyna; Sobczak, Jerzy; Rudnik, Dariusz; Wojciechowski, Andrzej

2016-08-01

Based on previous results, the commercial composites of A359 (AlSi9Mg) alloy reinforced with 22 vol.% Al2O3 particles were submitted to multiple remelting by means of gravity casting and squeeze-casting procedures. The studies were focused on tribological tests, x-ray phase analyses, and microstructural examinations. More promising results were obtained for squeeze-casting method mainly because of the reduction of the negative microstructural effects such as shrinkage porosity or other microstructural defects and discontinuities. The results showed that direct remelting may be treated as economically well-founded and alternative way compared to other recycling processes. It was underlined that the multiple remelting method must be analyzed for any material separately.

Passivity of the bars manufactured using current technologies: laser-sintering, casting, and milling

NASA Astrophysics Data System (ADS)

Popescu, Diana; Popescu, Sabin; Pop, Daniel; Jivanescu, Anca; Todea, Carmen

2014-01-01

Implant overdentures are often selected as therapeutic options for the treatment of edentulous mandibles. "Passive-fit" between the mesostructures and the implants plays an important role in the longevity of the implant-prosthetic assembly in the oral cavity. "Mis-fit" can cause mechanical or biological complications. The purpose of this test was to investigate the passive adaptation of the bars manufactured through different technologies, and in this respect two bars (short and long) were fabricated by each process: laser-sintering, milling, casting. The tensions induced by tightening the connection screw between the bars and the underlying implants were recorded using strain gauges and used as measuring and comparing tool in testing the bars' "passivity". The results of the test showed that the milled bars had the best "passive-fit", followed by laser-sintered bars, while cast bars had the lowest adaptation level.

Synthetic Vision System Commercial Aircraft Flight Deck Display Technologies for Unusual Attitude Recovery

NASA Technical Reports Server (NTRS)

Prinzel, Lawrence J., III; Ellis, Kyle E.; Arthur, Jarvis J.; Nicholas, Stephanie N.; Kiggins, Daniel

2017-01-01

A Commercial Aviation Safety Team (CAST) study of 18 worldwide loss-of-control accidents and incidents determined that the lack of external visual references was associated with a flight crew's loss of attitude awareness or energy state awareness in 17 of these events. Therefore, CAST recommended development and implementation of virtual day-Visual Meteorological Condition (VMC) display systems, such as synthetic vision systems, which can promote flight crew attitude awareness similar to a day-VMC environment. This paper describes the results of a high-fidelity, large transport aircraft simulation experiment that evaluated virtual day-VMC displays and a "background attitude indicator" concept as an aid to pilots in recovery from unusual attitudes. Twelve commercial airline pilots performed multiple unusual attitude recoveries and both quantitative and qualitative dependent measures were collected. Experimental results and future research directions under this CAST initiative and the NASA "Technologies for Airplane State Awareness" research project are described.

Superalloy Lattice Block Structures

NASA Technical Reports Server (NTRS)

Nathal, M. V.; Whittenberger, J. D.; Hebsur, M. G.; Kantzos, P. T.; Krause, D. L.

2004-01-01

Initial investigations of investment cast superalloy lattice block suggest that this technology will yield a low cost approach to utilize the high temperature strength and environmental resistance of superalloys in lightweight, damage tolerant structural configurations. Work to date has demonstrated that relatively large superalloy lattice block panels can be successfully investment cast from both IN-718 and Mar-M247. These castings exhibited mechanical properties consistent with the strength of the same superalloys measured from more conventional castings. The lattice block structure also accommodates significant deformation without failure, and is defect tolerant in fatigue. The potential of lattice block structures opens new opportunities for the use of superalloys in future generations of aircraft applications that demand strength and environmental resistance at elevated temperatures along with low weight.

Cast and 3D printed ion exchange membranes for monolithic microbial fuel cell fabrication

NASA Astrophysics Data System (ADS)

Philamore, Hemma; Rossiter, Jonathan; Walters, Peter; Winfield, Jonathan; Ieropoulos, Ioannis

2015-09-01

We present novel solutions to a key challenge in microbial fuel cell (MFC) technology; greater power density through increased relative surface area of the ion exchange membrane that separates the anode and cathode electrodes. The first use of a 3D printed polymer and a cast latex membrane are compared to a conventionally used cation exchange membrane. These new techniques significantly expand the geometric versatility available to ion exchange membranes in MFCs, which may be instrumental in answering challenges in the design of MFCs including miniaturisation, cost and ease of fabrication. Under electrical load conditions selected for optimal power transfer, peak power production (mean 10 batch feeds) was 11.39 μW (CEM), 10.51 μW (latex) and 0.92 μW (Tangoplus). Change in conductivity and pH of anolyte were correlated with MFC power production. Digital and environmental scanning electron microscopy show structural changes to and biological precipitation on membrane materials following long term use in an MFC. The cost of the novel membranes was lower than the conventional CEM. The efficacy of two novel membranes for ion exchange indicates that further characterisation of these materials and their fabrication techniques, shows great potential to significantly increase the range and type of MFCs that can be produced.

Chitosan-Sodium Phytate Films with a Strong Water Barrier and Antimicrobial Properties Produced via One-Step-Consecutive-Stripping and Layer-by-Layer-Casting Technologies.

PubMed

Yang, Jie; Xiong, Liu; Li, Man; Sun, Qingjie

2018-06-20

The pursuit of sustainable functional materials requires the development of materials based on renewable resources and efficient fabrication methods. Here, we first fabricated chitosan-sodium phytate films via one-step-stripping and layer-by-layer-casting technologies. The proposed film-fabrication methods are general, facile, environmentally benign, cost-effective, and easy to scale up. The resultant one-step-stripped film was thin (9 ± 1 μm), soft, transparent, and strong, whereas the thickness of the layer-by-layer-cast film was 70 ± 3 μm. FTIR analysis of the films indicated the formation of interactions between the phosphoric groups in sodium phytate and the amino groups in chitosan. More importantly, the water-vapor-permeability values of the one-step-stripped and cast films were 4-5 orders of magnitude lower than chitosan films reported before. Layer-by-layer-cast films in particular exhibited high tensile strength (49.21 ± 1.12 MPa) and were more than three times stronger than other polyelectrolyte multilayer films. Both types of films remained stable in an acidic environment. Furthermore, the layer-by-layer-assembled films presented greater antimicrobial activity than the stripped films. The developed chitosan-sodium phytate films can enhance several biomedical and environmental applications, such as packaging, drug delivery, diagnostics, microfluidics, and biosensing.

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

Souza, Douglas F., E-mail: souzadf@outlook.com; Nunes, Eduardo H.M., E-mail: eduardohmn@gmail.com; Pimenta, Daiana S.

In this work we fabricated alumina samples by the freeze-casting technique using tert-butanol as the solvent. The prepared materials were examined by scanning electron microscopy and X-ray microtomography. Next, they were coated with sol–gel silica films by dip-coating. Permeability tests were carried out in order to assess the permeation behavior of the materials processed in this study. We observed that the sintering time and alumina loading showed a remarkable effect on both the structural properties and flexural strength of the freeze-cast samples. Nitrogen adsorption tests revealed that the silica prepared in this study exhibited a microporous structure. It was observedmore » that the presence of silica coatings on the alumina surface decreased the CO{sub 2} permeance by about one order of magnitude. Because of the similar kinetic diameters of nitrogen and carbon dioxide, the CO{sub 2}/N{sub 2} system showed a separation efficiency that was lower than that observed for the He/CO{sub 2} and He/N{sub 2} systems. We noticed that increasing the feed pressure improved the separation capacity of the obtained materials. - Highlights: • Porous alumina samples obtained by the freeze-casting technique • Microporous silica coating prepared by a simple sol–gel dip-coating methodology • Samples examined by SEM, μ-CT, and nitrogen sorption tests • Mechanical tests were carried out in the freeze-cast samples. • The presence of silica coatings on the alumina surface decreased the CO{sub 2} permeance.« less

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.

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

Eric S. Peterson; Jessica Trudeau; Bill Cleary

An active-surface membrane technology was used to separate a die lube manufacturing wastewater stream consisting of various oils, hydrocarbons, heavy metals, and silicones. The ultrafiltration membranes reduced organics from initial oil and grease contents by 20–25X, carbon oxygen demand (COD) by 1.5 to 2X, and total organic carbon (TOC) by 0.6, while the biological oxygen demand (BOD) remained constant. The active-surface membranes were not fouled as badly as non-active-surface systems and the active-surface membrane flux levels were consistently higher and more stable than those of the non-active-surface membranes tested. Field testing demonstrated that the rotary microfilter can concentrate the diemore » lube, i.e. remove the glycerin component, and produce a die lube suitable for recycling. The recycling system operated for six weeks with only seven cleaning cycles and no mechanical or electrical failures. Test data and quality records indicate that the die casting scrap was reduced from 8.4 to 7.8%. There is no doubt that this test yielded tremendous results. This separation process presents significant opportunities that can be evaluated further.« less

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

Peterson, E. S.; Trudeau, J.; Cleary, B.

An active-surface membrane technology was used to separate a die lube manufacturing wastewater stream consisting of various oils, hydrocarbons, heavy metals, and silicones. The ultrafiltration membranes reduced organics from initial oil and grease contents by 20-25X, carbon oxygen demand (COD) by 1.5 to 2X, and total organic carbon (TOC) by 0.6, while the biological oxygen demand (BOD) remained constant. The active-surface membranes were not fouled as badly as non-active-surface systems and the active-surface membrane flux levels were consistently higher and more stable than those of the non-active-surface membranes tested. Field testing demonstrated that the rotary microfilter can concentrate the diemore » lube, i.e. remove the glycerin component, and produce a die lube suitable for recycling. The recycling system operated for six weeks with only seven cleaning cycles and no mechanical or electrical failures. Test data and quality records indicate that the die casting scrap was reduced from 8.4 to 7.8%. There is no doubt that this test yielded tremendous results. This separation process presents significant opportunities that can be evaluated further.« less

Apollo 14 mission report. Supplement 7: Inflight demonstrations

NASA Technical Reports Server (NTRS)

1972-01-01

Experiments performed on board the Apollo 14 are reviewed. These include a liquid transfer demonstration during the transearth coast, electrophoresis separation, a composite casting demonstration, and a heat flow and convection demonstration.

In Vitro Screening of 1877 Industrial and Consumer Chemicals, Pesticides and Pharmaceuticals in up to 782 Assays: ToxCast Phase I and II (SOT)

EPA Science Inventory

In Phase II of the ToxCast program, the U.S. EPA and Tox21 partners screened 1,877 chemicals, including pesticides; food, cosmetics and personal care ingredients; pharmaceuticals; and industrial chemicals. Testing used a 782 in vitro assays across 7 technologies and multiple bi...

EPA's ToxCast Project: Lessons learned and future directions for use of HTS in predicting in vivo toxicology -- A Chemical Perspective

EPA Science Inventory

U.S. EPA’s ToxCast and the related Tox21 projects are employing high-throughput screening (HTS) technologies to profile thousands of chemicals, which in turn serve as probes of a wide diversity of targets, pathways and mechanisms related to toxicity. Initial models relating ToxCa...

Improved ceramic slip casting technique. [application to aircraft model fabrication

NASA Technical Reports Server (NTRS)

Buck, Gregory M. (Inventor); Vasquez, Peter (Inventor)

1993-01-01

A primary concern in modern fluid dynamics research is the experimental verification of computational aerothermodynamic codes. This research requires high precision and detail in the test model employed. Ceramic materials are used for these models because of their low heat conductivity and their survivability at high temperatures. To fabricate such models, slip casting techniques were developed to provide net-form, precision casting capability for high-purity ceramic materials in aqueous solutions. In previous slip casting techniques, block, or flask molds made of plaster-of-paris were used to draw liquid from the slip material. Upon setting, parts were removed from the flask mold and cured in a kiln at high temperatures. Casting detail was usually limited with this technique -- detailed parts were frequently damaged upon separation from the flask mold, as the molded parts are extremely delicate in the uncured state, and the flask mold is inflexible. Ceramic surfaces were also marred by 'parting lines' caused by mold separation. This adversely affected the aerodynamic surface quality of the model as well. (Parting lines are invariably necessary on or near the leading edges of wings, nosetips, and fins for mold separation. These areas are also critical for flow boundary layer control.) Parting agents used in the casting process also affected surface quality. These agents eventually soaked into the mold, the model, or flaked off when releasing the case model. Different materials were tried, such as oils, paraffin, and even an algae. The algae released best, but some of it remained on the model and imparted an uneven texture and discoloration on the model surface when cured. According to the present invention, a wax pattern for a shell mold is provided, and an aqueous mixture of a calcium sulfate-bonded investment material is applied as a coating to the wax pattern. The coated wax pattern is then dried, followed by curing to vaporize the wax pattern and leave a shell mold of the calcium sulfate-bonded investment material. The shell mold is cooled to room temperature, and a ceramic slip is poured therein. After a ceramic shell of desired thickness has set up in the shell mold, excess ceramic slip is poured out. While still wet, the shell mold is peeled from the ceramic shell to expose any delicate or detailed parts, after which the ceramic shell is cured to provide a complete, detailed, precision ceramic article without parting lines.

Cast CF8C-Plus Stainless Steel for Turbocharger Applications

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

Maziasz, P.J.; Shyam, A.; Evans, N.D.

2010-06-30

The purpose of this Cooperative Research and Development Agreement (CRADA) project is to provide the critical test data needed to qualify CF8C-Plus cast stainless steel for commercial production and use for turbocharger housings with upgraded performance and durability relative to standard commercial cast irons or stainless steels. The turbocharger technologies include, but are not limited to, heavy-duty highway diesel engines, and passenger vehicle diesel and gasoline engines. This CRADA provides additional critical high-temperature mechanical properties testing and data analysis needed to quality the new CF8C-Plus steels for turbocharger housing applications.

[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.

The casting of semi-permeable membranes in a microgravity environment

NASA Technical Reports Server (NTRS)

Vera, I.

1986-01-01

The experiment is to study polymeric membranes. Presently, semipermeable membranes are being manufactured from several different kinds of polymers all over the world and specific applications have been identified in fluid separation processes such as reverse osmosis, ultrafiltration and electrodialysis. Although, the ultrastructure of asymmetric and composite membranes have been under intensive study, still there are many questions about the factors affecting this structure and their degree of correlation. Nevertheless, there is indication that the entire morphological structure of polymeric membranes could be affected by the difference in specific gravity between the cast solution and the coagulation liquid normally used in the membranes preparation process. The casting of semipermeable membranes in space might help to identify the effect of gravity upon the structure of these membranes. It is important to recognize that the casting process involves changes of state and that in a microgravity environment, there will be a reduction on buoyancy-driven natural convection and density gradients.

An alternative impression technique for individuals with special care needs.

PubMed

Topouzelis, Nikolaos; Kotsiomiti, Eleni; Arhakis, Aristidis

2010-01-01

Impression making may be complicated in individuals with limited ability to cooperate with caregivers. An alternative technique for obtaining full-arch casts from sectional preliminary impressions is described. The technique is a modification of the procedure advocated for impression making in subjects with limited mouth opening. A pair of partial stock trays is selected to fit the right and left side of the arch. Two sectional irreversible hydrocolloid impressions are made separately. The first cast is placed into the second impression prior to pouring, to obtain a cast of the complete arch. The procedure was used during the treatment of an uncooperative young patient with Lesch-Nyhan Syndrome and provided a simple and reliable means to obtain the diagnostic cast of the mandibular teeth. It is recommended not only for uncooperative patients, but also for patients with special needs; such as those with anatomical restrictions, functional impairment, and movement disorders. ©2010 Special Care Dentistry Association and Wiley Periodicals, Inc.

Melt Conditioning of Light Metals by Application of High Shear for Improved Microstructure and Defect Control

NASA Astrophysics Data System (ADS)

Patel, Jayesh B.; Yang, Xinliang; Mendis, Chamini L.; Fan, Zhongyun

2017-04-01

Casting is the first step toward the production of majority of metal products whether the final processing step is casting or other thermomechanical processes such as extrusion or forging. The high shear melt conditioning provides an easily adopted pathway to producing castings with a more uniform fine-grained microstructure along with a more uniform distribution of the chemical composition leading to fewer defects as a result of reduced shrinkage porosities and the presence of large oxide films through the microstructure. The effectiveness of high shear melt conditioning in improving the microstructure of processes used in industry illustrates the versatility of the high shear melt conditioning technology. The application of high shear process to direct chill and twin roll casting process is demonstrated with examples from magnesium melts.

Multi-gel casting apparatus for vertical polyacrylamide gels with in-built solution flow system and liquid level detectors.

PubMed

Maurye, Praveen; Basu, Arpita; Bandyopadhyay, Tapas Kumar; Biswas, Jayanta Kumar; Mohanty, Bimal Prasana

2017-08-01

PAGE is the most widely used technique for the separation and biochemical analysis of biomolecules. The ever growing field of proteomics and genomics necessitates the analysis of many proteins and nucleic acid samples to understand further about the structure and function of cells. Simultaneous analysis of multiple protein samples often requires casting of many PAGE gels. Several variants of multi-gel casting/electrophoresis apparatuses are frequently used in research laboratories. Requirement of supplementary gels to match the growing demand for analyzing additional protein samples sometimes become a cause of concern. Available apparatuses are not amenable to and therefore, not recommended for any modification to accommodate additional gel casting units other than what is prescribed by the manufacturer. A novel apparatus is described here for casting multiple PAGE gels comprising four detachable components that provide enhanced practicability and performance of the apparatus. This newly modified apparatus promises to be a reliable source for making multiple gels in less time without hassle. Synchronized functioning of unique components broaden the possibilities of developing inexpensive, safe, and time-saving multi-gel casting apparatus. This apparatus can be easily fabricated and modified to accommodate desired number of gel casting units. The estimated cost (∼$300) for fabrication of the main apparatus is very competitive and effortless assembly procedure can be completed within ∼30 min. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Prediction of the As-Cast Structure of Al-4.0 Wt Pct Cu Ingots

NASA Astrophysics Data System (ADS)

Ahmadein, Mahmoud; Wu, M.; Li, J. H.; Schumacher, P.; Ludwig, A.

2013-06-01

A two-stage simulation strategy is proposed to predict the as-cast structure. During the first stage, a 3-phase model is used to simulate the mold-filling process by considering the nucleation, the initial growth of globular equiaxed crystals and the transport of the crystals. The three considered phases are the melt, air and globular equiaxed crystals. In the second stage, a 5-phase mixed columnar-equiaxed solidification model is used to simulate the formation of the as-cast structure including the distinct columnar and equiaxed zones, columnar-to-equiaxed transition, grain size distribution, macrosegregation, etc. The five considered phases are the extradendritic melt, the solid dendrite, the interdendritic melt inside the equiaxed grains, the solid dendrite, and the interdendritic melt inside the columnar grains. The extra- and interdendritic melts are treated as separate phases. In order to validate the above strategy, laboratory ingots (Al-4.0 wt pct Cu) are poured and analyzed, and a good agreement with the numerical predictions is achieved. The origin of the equiaxed crystals by the "big-bang" theory is verified to play a key role in the formation of the as-cast structure, especially for the castings poured at a low pouring temperature. A single-stage approach that only uses the 5-phase mixed columnar-equiaxed solidification model and ignores the mold filling can predict satisfactory results for a casting poured at high temperature, but it delivers false results for the casting poured at low temperature.

Effect of amine structure on CO2 capture by polymeric membranes.

PubMed

Taniguchi, Ikuo; Kinugasa, Kae; Toyoda, Mariko; Minezaki, Koki

2017-01-01

Poly(amidoamine)s (PAMAMs) incorporated into a cross-linked poly(ethylene glycol) exhibited excellent CO 2 separation properties over H 2 . However, the CO 2 permeability should be increased for practical applications. Monoethanolamine (MEA) used as a CO 2 determining agent in the current CO 2 capture technology at demonstration scale was readily immobilized in poly(vinyl alcohol) (PVA) matrix by solvent casting of aqueous mixture of PVA and the amine. The resulting polymeric membranes can be self-standing with the thickness above 3 μm and the amine fraction less than 80 wt%. The gas permeation properties were examined at 40 °C and under 80% relative humidity. The CO 2 separation performance increased with increase of the amine content in the polymeric membranes. When the amine fraction was 80 wt%, the CO 2 permeability coefficient of MEA containing membrane was 604 barrer with CO 2 selectivity of 58.5 over H 2 , which was much higher than the PAMAM membrane (83.7 barrer and 51.8, respectively) under the same operation conditions. On the other hand, ethylamine (EA) was also incorporated into PVA matrix to form a thin membrane. However, the resulting polymeric membranes exhibited slight CO 2 -selective gas permeation properties. The hydroxyl group of MEA was crucial for high CO 2 separation performance.

Effect of amine structure on CO2 capture by polymeric membranes

PubMed Central

Taniguchi, Ikuo; Kinugasa, Kae; Toyoda, Mariko; Minezaki, Koki

2017-01-01

Abstract Poly(amidoamine)s (PAMAMs) incorporated into a cross-linked poly(ethylene glycol) exhibited excellent CO2 separation properties over H2. However, the CO2 permeability should be increased for practical applications. Monoethanolamine (MEA) used as a CO2 determining agent in the current CO2 capture technology at demonstration scale was readily immobilized in poly(vinyl alcohol) (PVA) matrix by solvent casting of aqueous mixture of PVA and the amine. The resulting polymeric membranes can be self-standing with the thickness above 3 μm and the amine fraction less than 80 wt%. The gas permeation properties were examined at 40 °C and under 80% relative humidity. The CO2 separation performance increased with increase of the amine content in the polymeric membranes. When the amine fraction was 80 wt%, the CO2 permeability coefficient of MEA containing membrane was 604 barrer with CO2 selectivity of 58.5 over H2, which was much higher than the PAMAM membrane (83.7 barrer and 51.8, respectively) under the same operation conditions. On the other hand, ethylamine (EA) was also incorporated into PVA matrix to form a thin membrane. However, the resulting polymeric membranes exhibited slight CO2-selective gas permeation properties. The hydroxyl group of MEA was crucial for high CO2 separation performance. PMID:29383045

28. November 1969 CASTIRON DRAGON GROTESQUE BELOW BASE OF COLUMN ...

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

28. November 1969 CAST-IRON DRAGON GROTESQUE BELOW BASE OF COLUMN SEPARATING WINDOWS ON NORTH SIDE OF RIGGS LIBRARY - Georgetown University, Healy Building, Thirty-seventh & O Streets, Northwest, Washington, District of Columbia, DC

Application of heat pipe technology in permanent mold casting of nonferrous alloys

NASA Astrophysics Data System (ADS)

Elalem, Kaled

The issue of mold cooling is one, which presents a foundry with a dilemma. On the one hand; the use of air for cooling is safe and practical, however, it is not very effective and high cost. On the other hand, water-cooling can be very effective but it raises serious concerns about safety, especially with a metal such as magnesium. An alternative option that is being developed at McGill University uses heat pipe technology to carry out the cooling. The experimental program consisted of designing a permanent mold to produce AZ91E magnesium alloy and A356 aluminum alloy castings with shrinkage defects. Heat pipes were then used to reduce these defects. The heat pipes used in this work are novel and are patent pending. They are referred to as McGill Heat Pipes. Computer modeling was used extensively in designing the mold and the heat pipes. Final designs for the mold and the heat pipes were chosen based on the modeling results. Laboratory tests of the heat pipe were performed before conducting the actual experimental plan. The laboratory testing results verified the excellent performance of the heat pipes as anticipated by the model. An industrial mold made of H13 tool steel was constructed to cast nonferrous alloys. The heat pipes were installed and initial testing and actual industrial trials were conducted. This is the first time where a McGill heat pipe was used in an industrial permanent mold casting process for nonferrous alloys. The effects of cooling using heat pipes on AZ91E and A356 were evaluated using computer modeling and experimental trials. Microstructural analyses were conducted to measure the secondary dendrite arm spacing, SDAS, and the grain size to evaluate the cooling effects on the castings. The modeling and the experimental results agreed quite well. The metallurgical differences between AZ91E and A356 were investigated using modeling and experimental results. Selected results from modeling, laboratory and industrial trials are presented. The results show a promising future for heat pipe technology in cooling permanent molds for the casting of nonferrous alloys.

The Technological Enframing of Mathematics Education

ERIC Educational Resources Information Center

Thornton, Steve

2014-01-01

In this paper I seek to critique pervasive notions of what counts in mathematics education using Heidegger's notion of the technological enframing. I suggest that early childhood and schooling have become technologies in themselves, casting students and teachers as part of the standing reserve within the inexorable drive for economic advancement.…

Rapid manufacturing of metallic Molds for parts in Automobile

NASA Astrophysics Data System (ADS)

Zhang, Renji; Xu, Da; Liu, Yuan; Yan, Xudong; Yan, Yongnian

1998-03-01

The recent research of RPM (Rapid Prototyping Manufacturing) in our lab has been focused on the rapid creation of alloyed cast iron (ACI) molds. There are a lot of machinery parts in an automobile, so a lot of mettallic molds are needed in automobile industry. A new mold manufacturing technology has been proposed. A new large scale RP machine has been set up in our lab now. Then rapid prototypes could be manufactured by means of laminated object manufacturing (LOM) technology. The molds for parts in automobile have been produced by ceramic shell precision casting. An example is a drawing mold for cover parts in automobile. Sufficient precision and surface roughness have been obtained. Itis proved that this is a vew kind of technology. Work supported by the Mational Science Foundation of China.

This photographic copy of an engineering drawing shows floor plans, ...

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

This photographic copy of an engineering drawing shows floor plans, sections and elevations of Building E-86, with details typical of the steel frame and "Transite" building construction at JPL Edwards Facility. California Institute of Technology, Jet Propulsion Laboratory, Facilities Engineering and Construction Office: "Casting & Curing, Building E-86, Floor Plan, Elevations & Section," drawing no. E86/6, 25 February 1977. California Institute of Technology, Jet Propulsion Laboratory, Plant Engineering: engineering drawings of structures at JPL Edwards Facility. Drawings on file at JPL Plant Engineering, Pasadena, California - Jet Propulsion Laboratory Edwards Facility, Casting & Curing Building, Edwards Air Force Base, Boron, Kern County, CA

Three-Dimensional Analysis of Internal Adaptations of Crowns Cast from Resin Patterns Fabricated Using Computer-Aided Design/Computer-Assisted Manufacturing Technologies.

PubMed

Liu, Yushu; Ye, Hongqiang; Wang, Yong; Zhao, Yijao; Sun, Yuchun; Zhou, Yongsheng

2018-05-17

To evaluate the internal adaptations of cast crowns made from resin patterns produced using three different computer-aided design/computer-assisted manufacturing technologies. A full-crown abutment made of zirconia was digitized using an intraoral scanner, and the design of the crown was finished on the digital model. Resin patterns were fabricated using a fused deposition modeling (FDM) 3D printer (LT group), a digital light projection (DLP) 3D printer (EV group), or a five-axis milling machine (ZT group). All patterns were cast in cobalt-chromium alloy crowns. Crowns made from traditional handmade wax patterns (HM group) were used as controls. Each group contained 10 samples. The internal gaps of the patterns were analyzed using a 3D replica method and optical digitization. The results were compared using Kruskal-Wallis analysis of variance (ANOVA), a one-sample t test, and signed rank test (α = .05). For the LT group, the marginal and axial gaps were significantly larger than in the other three groups (P < .05), but the occlusal adaptation did not reveal a significant difference (P > .05). In the ZT group, the axial gap was slightly smaller than in the HM group (P < .0083). All the means of gaps in all areas in the four groups were less than 150 μm. Casting crowns using casting patterns made from all three CAD/CAM systems could not produce the prescribed parameters, but the crowns showed clinically acceptable internal adaptations.

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.

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

Separation of polar gases from nonpolar gases

DOEpatents

Kulprathipanja, Santi; Kulkarni, Sudhir S.

1986-01-01

Polar gases such as hydrogen sulfide, sulfur dioxide and ammonia may be separated from nonpolar gases such as methane, nitrogen, hydrogen or carbon dioxide by passing a mixture of polar and nonpolar gases over the face of a multicomponent membrane at separation conditions. The multicomponent membrane which is used to effect the separation will comprise a mixture of a glycol plasticizer having a molecular weight of from about 200 to about 600 and an organic polymer cast on a porous support. The use of such membranes as exemplified by polyethylene glycol and silicon rubber composited on polysulfone will permit greater selectivity accompanied by a high flux rate in the separation process.

Separation of polar gases from nonpolar gases

DOEpatents

Kulprathipanja, S.; Kulkarni, S.S.

1986-08-26

Polar gases such as hydrogen sulfide, sulfur dioxide and ammonia may be separated from nonpolar gases such as methane, nitrogen, hydrogen or carbon dioxide by passing a mixture of polar and nonpolar gases over the face of a multicomponent membrane at separation conditions. The multicomponent membrane which is used to effect the separation will comprise a mixture of a glycol plasticizer having a molecular weight of from about 200 to about 600 and an organic polymer cast on a porous support. The use of such membranes as exemplified by polyethylene glycol and silicon rubber composited on polysulfone will permit greater selectivity accompanied by a high flux rate in the separation process.

Carbon nanotube embedded PVDF membranes: Effect of solvent composition on the structural morphology for membrane distillation

NASA Astrophysics Data System (ADS)

Mapunda, Edgar C.; Mamba, Bhekie B.; Msagati, Titus A. M.

2017-08-01

Rapid population increase, growth in industrial and agricultural sectors and global climate change have added significant pressure on conventional freshwater resources. Tapping freshwater from non-conventional water sources such as desalination and wastewater recycling is considered as sustainable alternative to the fundamental challenges of water scarcity. However, affordable and sustainable technologies need to be applied for the communities to benefit from the treatment of non-conventional water source. Membrane distillation is a potential desalination technology which can be used sustainably for this purpose. In this work multi-walled carbon nanotube embedded polyvinylidene fluoride membranes for application in membrane distillation desalination were prepared via non-solvent induced phase separation method. The casting solution was prepared using mixed solvents (N, N-dimethylacetamide and triethyl phosphate) at varying ratios to study the effect of solvent composition on membrane morphological structures. Membrane morphological features were studied using a number of techniques including scanning electron microscope, atomic force microscope, SAXSpace tensile strength analysis, membrane thickness, porosity and contact angle measurements. It was revealed that membrane hydrophobicity, thickness, tensile strength and surface roughness were increasing as the composition of N, N-dimethylacetamide in the solvent was increasing with maximum values obtained between 40 and 60% N, N-dimethylacetamide. Internal morphological structures were changing from cellular structures to short finger-like and sponge-like pores and finally to large macro void type of pores when the amount of N, N-dimethylacetamide in the solvent was changed from low to high respectively. Multi-walled carbon nanotube embedded polyvinylidene fluoride membranes of desired morphological structures and physical properties can be synthesized by regulating the composition of solvents used to prepare the casting solution.

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

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

Development of polymer nano composite patterns using fused deposition modeling for rapid investment casting process

NASA Astrophysics Data System (ADS)

Vivek, Tiwary; Arunkumar, P.; Deshpande, A. S.; Vinayak, Malik; Kulkarni, R. M.; Asif, Angadi

2018-04-01

Conventional investment casting is one of the oldest and most economical manufacturing techniques to produce intricate and complex part geometries. However, investment casting is considered economical only if the volume of production is large. Design iterations and design optimisations in this technique proves to be very costly due to time and tooling cost for making dies for producing wax patterns. However, with the advent of Additive manufacturing technology, plastic patterns promise a very good potential to replace the wax patterns. This approach can be very useful for low volume production & lab requirements, since the cost and time required to incorporate the changes in the design is very low. This research paper discusses the steps involved for developing polymer nanocomposite filaments and checking its suitability for investment castings. The process parameters of the 3D printer machine are also optimized using the DOE technique to obtain mechanically stronger plastic patterns. The study is done to develop a framework for rapid investment casting for lab as well as industrial requirements.

Casting Simulation of an Austrian Bronze Age Sword Hilt

NASA Astrophysics Data System (ADS)

Pola, Annalisa; Mödlinger, Marianne; Piccardo, Paolo; Montesano, Lorenzo

2015-07-01

Bronze Age swords with a metal hilt can be considered the peak of Bronze Age casting technologies. To reconstruct the casting techniques used more than 3000 years ago, a metal hilted sword of the Schalenknauf type from Lower Austria was studied with the aid of macroscopic analyses and simulation of mold filling and casting solidification. A three-dimensional model of the hilt was created based on optical scanner measurements performed on a hilt recently discovered during archaeological excavations. Three different configurations of the gating system were considered, two on the pommel disk and one on the knob, and the effect of its location on the formation of casting defects was investigated. Three-dimensional computed tomography was used to detect internal defects, such as gas and shrinkage porosity, which were then compared with those calculated by simulation. The best match between actual and predicted hilt quality demonstrated the location of the gating system, which turned out to be on the pommel disk.

Turbine vane structure

DOEpatents

Irwin, John A.

1980-08-19

A liquid cooled stator blade assembly for a gas turbine engine includes an outer shroud having a pair of liquid inlets and a pair of liquid outlets supplied through a header and wherein means including tubes support the header radially outwardly of the shroud and also couple the header with the pair of liquid inlets and outlets. A pair of turbine vanes extend radially between the shroud and a vane platform to define a gas turbine motive fluid passage therebetween; and each of the vanes is cooled by an internal body casting of super alloy material with a grooved layer of highly heat conductive material that includes spaced apart flat surface trailing edges in alignment with a flat trailing edge of the casting joined to wall segments of the liner which are juxtaposed with respect to the internal casting to form an array of parallel liquid inlet passages on one side of the vane and a second plurality of parallel liquid return passages on the opposite side of the vane; and a superalloy heat and wear resistant imperforate skin covers the outer surface of the composite blade including the internal casting and the heat conductive layer; a separate trailing edge section includes an internal casting and an outer skin butt connected to the end surfaces of the internal casting and the heat conductive layer to form an easily assembled liquid cooled trailing edge section in the turbine vane.

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.

Secondary Waste Cast Stone Waste Form Qualification Testing Plan

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

Westsik, Joseph H.; Serne, R. Jeffrey

2012-09-26

The Hanford Tank Waste Treatment and Immobilization Plant (WTP) is being constructed to treat the 56 million gallons of radioactive waste stored in 177 underground tanks at the Hanford Site. The WTP includes a pretreatment facility to separate the wastes into high-level waste (HLW) and low-activity waste (LAW) fractions for vitrification and disposal. The LAW will be converted to glass for final disposal at the Integrated Disposal Facility (IDF). Cast Stone – a cementitious waste form, has been selected for solidification of this secondary waste stream after treatment in the ETF. The secondary-waste Cast Stone waste form must be acceptablemore » for disposal in the IDF. This secondary waste Cast Stone waste form qualification testing plan outlines the testing of the waste form and immobilization process to demonstrate that the Cast Stone waste form can comply with the disposal requirements. Specifications for the secondary-waste Cast Stone waste form have not been established. For this testing plan, Cast Stone specifications are derived from specifications for the immobilized LAW glass in the WTP contract, the waste acceptance criteria for the IDF, and the waste acceptance criteria in the IDF Permit issued by the State of Washington. This testing plan outlines the testing needed to demonstrate that the waste form can comply with these waste form specifications and acceptance criteria. The testing program must also demonstrate that the immobilization process can be controlled to consistently provide an acceptable waste form product. This testing plan also outlines the testing needed to provide the technical basis for understanding the long-term performance of the waste form in the disposal environment. These waste form performance data are needed to support performance assessment analyses of the long-term environmental impact of the secondary-waste Cast Stone waste form in the IDF« less

Fabrication of Microfluidic Valves Using a Hydrogel Molding Method

NASA Astrophysics Data System (ADS)

Sugiura, Yusuke; Hirama, Hirotada; Torii, Toru

2015-08-01

In this paper, a method for fabricating a microfluidic valve made of polydimethylsiloxane (PDMS) using a rapid prototyping method for microchannels through hydrogel cast molding is discussed. Currently, the valves in microchannels play an important role in various microfluidic devices. The technology to prototype microfluidic valves rapidly is actively being developed. For the rapid prototyping of PDMS microchannels, a method that uses a hydrogel as the casting mold has been recently developed. This technique can be used to prepare a three-dimensional structure through simple and uncomplicated methods. In this study, we were able to fabricate microfluidic valves easily using this rapid prototyping method that utilizes hydrogel cast molding. In addition, we confirmed that the valve displacement could be predicted within a range of constant pressures. Moreover, because microfluidic valves fabricated using this method can be directly observed from a cross-sectional direction, we anticipate that this technology will significantly contribute to clarifying fluid behavior and other phenomena in microchannels and microfluidic valves with complex structures.

Fabrication of Microfluidic Valves Using a Hydrogel Molding Method.

PubMed

Sugiura, Yusuke; Hirama, Hirotada; Torii, Toru

2015-08-24

In this paper, a method for fabricating a microfluidic valve made of polydimethylsiloxane (PDMS) using a rapid prototyping method for microchannels through hydrogel cast molding is discussed. Currently, the valves in microchannels play an important role in various microfluidic devices. The technology to prototype microfluidic valves rapidly is actively being developed. For the rapid prototyping of PDMS microchannels, a method that uses a hydrogel as the casting mold has been recently developed. This technique can be used to prepare a three-dimensional structure through simple and uncomplicated methods. In this study, we were able to fabricate microfluidic valves easily using this rapid prototyping method that utilizes hydrogel cast molding. In addition, we confirmed that the valve displacement could be predicted within a range of constant pressures. Moreover, because microfluidic valves fabricated using this method can be directly observed from a cross-sectional direction, we anticipate that this technology will significantly contribute to clarifying fluid behavior and other phenomena in microchannels and microfluidic valves with complex structures.

Energy efficient engine high-pressure turbine single crystal vane and blade fabrication technology report

NASA Technical Reports Server (NTRS)

Giamei, A. F.; Salkeld, R. W.; Hayes, C. W.

1981-01-01

The objective of the High-Pressure Turbine Fabrication Program was to demonstrate the application and feasibility of Pratt & Whitney Aircraft-developed two-piece, single crystal casting and bonding technology on the turbine blade and vane configurations required for the high-pressure turbine in the Energy Efficient Engine. During the first phase of the program, casting feasibility was demonstrated. Several blade and vane halves were made for the bonding trials, plus solid blades and vanes were successfully cast for materials evaluation tests. Specimens exhibited the required microstructure and chemical composition. Bonding feasibility was demonstrated in the second phase of the effort. Bonding yields of 75 percent for the vane and 30 percent for the blade were achieved, and methods for improving these yield percentages were identified. A bond process was established for PWA 1480 single crystal material which incorporated a transient liquid phase interlayer. Bond properties were substantiated and sensitivities determined. Tooling die materials were identified, and an advanced differential thermal expansion tooling concept was incorporated into the bond process.

Nucleated casting for the production of large superalloy ingots

NASA Astrophysics Data System (ADS)

Carter, William T.; Jones, Robin M. Forbes

2005-04-01

The gas turbine industry is continuously driven to achieve higher thermodynamic efficiency, higher electrical output, and higher reliability through turbine design improvements. The specific component of interest in this article is the turbine wheel, which is the rotating hub on which turbine blades are mounted. The wheel is mechanically loaded by both axial and centrifugal forces and thermally loaded by heat that is conducted from the turbine blades. Currently, the turbine wheel is forged from an ingot that is triple-melted, but nucleated casting is under development as a long-term option. This article describes the investigation into nucleated casting technology for future turbine wheel production.

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

Asmussen, R. Matthew; Pearce, Carolyn I.; Miller, Brian W.

A cementitious waste form, Cast Stone, is a possible candidate technology for the immobilization of low activity nuclear waste (LAW) at the Hanford site. This paper focuses on the addition of getter materials to Cast Stone that can sequester Tc from the LAW, and in turn, lower Tc release from the Cast Stone. Two getters which produce different products upon sequestering Tc from LAW were tested: Sn(II) apatite (Sn-A) that removes Tc as a Tc(IV)-oxide and potassium metal sulfide (KMS-2) that removes Tc as a Tc(IV)-sulfide species, allowing for a comparison of stability of the form of Tc upon enteringmore » the waste form. The Cast Stone with KMS-2 getter had the best performance with addition equivalent to ~0.08 wt% of the total waste form mass. The observed diffusion (D obs) of Tc decreased from 4.6 ± 0.2 × 10 -12 cm 2/s for Cast Stone that did not contain a getter to 5.4 ± 0.4 × 10 -13 cm 2/s for KMS-2 containing Cast Stone. Finally, it was found that Tc-sulfide species are more stable against re-oxidation within getter containing Cast Stone compared with Tc-oxide and is the origin of the decrease in Tc D obs when using the KMS-2.« less

Cast-in-place, ambiently-dried, silica-based, high-temperature insulation

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

Cheng, Eric Jianfeng; Thompson, Travis; Salvador, James R.

A novel sol-gel chemistry approach was developed to enable the simple integration of a cast-in-place, ambiently-dried insulation into high temperature applications. The insulation was silica based, synthesized using methyltrimethoxysilane (MTMS) as the precursor. MTMS created a unique silica microstructure that was mechanically robust, macroporous, and superhydrophobic. To allow for casting into and around small, orthogonal features, zirconia fibers were added to increase stiffness and minimize contraction that could otherwise cause cracking during drying. Radiative heat transport was reduced by adding titania powder as an opacifier. To assess relevance to high temperature thermoelectric generator technology, a comprehensive set of materials characterizationsmore » were conducted. The silica gel was thermally stable, retained superhydrophobicity with a water contact angle > 150° , and showed a high electrical resistance > 1 GΩ, regardless of heating temperature (up to 600 °C in Ar for 4 h). In addition, it exhibited a Young's modulus ~3.7 MPa in room temperature and a low thermal conductivity < 0.08 W/m.K before and after heat treatment. Thus, based on the simplicity of the manufacturing process and optimized material properties, we believe this technology can act as an effective cast-in-place thermal insulation (CTI) for thermoelectric generators and myriad other applications requiring improved thermal efficiency.« less

Cast-in-place, ambiently-dried, silica-based, high-temperature insulation

DOE PAGES

Cheng, Eric Jianfeng; Thompson, Travis; Salvador, James R.; ...

2017-02-03

A novel sol-gel chemistry approach was developed to enable the simple integration of a cast-in-place, ambiently-dried insulation into high temperature applications. The insulation was silica based, synthesized using methyltrimethoxysilane (MTMS) as the precursor. MTMS created a unique silica microstructure that was mechanically robust, macroporous, and superhydrophobic. To allow for casting into and around small, orthogonal features, zirconia fibers were added to increase stiffness and minimize contraction that could otherwise cause cracking during drying. Radiative heat transport was reduced by adding titania powder as an opacifier. To assess relevance to high temperature thermoelectric generator technology, a comprehensive set of materials characterizationsmore » were conducted. The silica gel was thermally stable, retained superhydrophobicity with a water contact angle > 150° , and showed a high electrical resistance > 1 GΩ, regardless of heating temperature (up to 600 °C in Ar for 4 h). In addition, it exhibited a Young's modulus ~3.7 MPa in room temperature and a low thermal conductivity < 0.08 W/m.K before and after heat treatment. Thus, based on the simplicity of the manufacturing process and optimized material properties, we believe this technology can act as an effective cast-in-place thermal insulation (CTI) for thermoelectric generators and myriad other applications requiring improved thermal efficiency.« less

Liquid-liquid phase separation and solidification behavior of Al55Bi36Cu9 monotectic alloy with different cooling rates

NASA Astrophysics Data System (ADS)

Bo, Lin; Li, Shanshan; Wang, Lin; Wu, Di; Zuo, Min; Zhao, Degang

2018-03-01

The cooling rate has a significant effect on the solidification behavior and microstructure of monotectic alloy. In this study, different cooling rate was designed through casting in the copper mold with different bore diameters. The effects of different cooling rate on the solidification behavior of Al55Bi36Cu9 (at.%) immiscible alloy have been investigated. The liquid-liquid phase separation of Al55Bi36Cu9 immiscible alloy melt was investigated by resistivity test. The solidification microstructure and phase analysis of Al55Bi36Cu9 immiscible alloy were performed by the SEM and XRD, respectively. The results showed that the liquid-liquid phase separation occurred in the solidification of Al55Bi36Cu9 monotectic melt from 917 °C to 653 °C. The monotectic temperature, liquid phase separation temperature and immiscibility zone of Al55Bi36Cu9 monotectic alloy was lower than those of Al-Bi binary monotectic alloy. The solidification morphology of Al55Bi36Cu9 monotectic alloy was very sensitive to the cooling rate. The Al/Bi core-shell structure formed when Al55Bi36Cu9 melt was cast in the copper mold with a 8 mm bore diameter.

The influence of cooling parameters on the speed of continuous steel casting

NASA Astrophysics Data System (ADS)

Tirian, G. O.; Gheorghiu, C. A.; Hepuţ, T.; Chioncel, C. P.

2018-01-01

This paper analyzes the cooling parameters of the continuous casting speed. In the researches carried out we aimed to establish some correlation equations between the parameters characterizing the continuous casting process, the temperature of the steel at the entrance to the crystallizer, the superheating of the steel and the flow of the cooling water in the crystallizer and different zones of the secondary cooling. Parallel to these parameters were also the values for the casting speed. The research was made for the casting of round ϕ270mm semi-finished steel products. The steel was developed in an electric EBT furnace with a capacity of 100t, treated in L.F. (Ladle - Furnace) and VD (Vacuum-Degassing) and poured in a 5-wire continuous casting plant. The obtained data was processed in MATLAB using three types of correlation equations. The obtained results are presented both in the analytical and graphical form, each correlation being analyzed from the technological point of view, indicating the optimal values for the independent parameters monitored. In the analysis we present a comparison between the results obtained after the three types of equations for each correlation.

Integral Fast Reactor fuel pin processor

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

Levinskas, D.

1993-01-01

This report discusses the pin processor which receives metal alloy pins cast from recycled Integral Fast Reactor (IFR) fuel and prepares them for assembly into new IFR fuel elements. Either full length as-cast or precut pins are fed to the machine from a magazine, cut if necessary, and measured for length, weight, diameter and deviation from straightness. Accepted pins are loaded into cladding jackets located in a magazine, while rejects and cutting scraps are separated into trays. The magazines, trays, and the individual modules that perform the different machine functions are assembled and removed using remote manipulators and master-slaves.

Integral Fast Reactor fuel pin processor

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

Levinskas, D.

1993-03-01

This report discusses the pin processor which receives metal alloy pins cast from recycled Integral Fast Reactor (IFR) fuel and prepares them for assembly into new IFR fuel elements. Either full length as-cast or precut pins are fed to the machine from a magazine, cut if necessary, and measured for length, weight, diameter and deviation from straightness. Accepted pins are loaded into cladding jackets located in a magazine, while rejects and cutting scraps are separated into trays. The magazines, trays, and the individual modules that perform the different machine functions are assembled and removed using remote manipulators and master-slaves.

Manufacturing polymer thin films in a micro-gravity environment

NASA Technical Reports Server (NTRS)

Vera, Ivan

1987-01-01

This project represents Venezuela's first scientific experiment in space. The apparatus for the automatic casting of two polymer thin films will be contained in NASA's Payload No. G-559 of the Get Away Special program for a future orbital space flight in the U.S. Space Shuttle. Semi-permeable polymer membranes have important applications in a variety of fields, such as medicine, energy, and pharmaceuticals and in general fluid separation processes, such as reverse osmosis, ultrafiltration, and electrodialysis. The casting of semi-permeable membranes in space will help to identify the roles of convection in determining the structure of these membranes.

Gas separation membranes

DOEpatents

Schell, William J.

1979-01-01

A dry, fabric supported, polymeric gas separation membrane, such as cellulose acetate, is prepared by casting a solution of the polymer onto a shrinkable fabric preferably formed of synthetic polymers such as polyester or polyamide filaments before washing, stretching or calendering (so called griege goods). The supported membrane is then subjected to gelling, annealing, and drying by solvent exchange. During the processing steps, both the fabric support and the membrane shrink a preselected, controlled amount which prevents curling, wrinkling or cracking of the membrane in flat form or when spirally wound into a gas separation element.

Organic fluid permeation through fluoropolymer membranes

DOEpatents

Nemser, Stuart M.; Kosaraju, Praveen; Bowser, John

2015-07-14

Separation of the components of liquid mixtures is achieved by contacting a liquid mixture with a nonporous membrane having a fluoropolymer selectively permeable layer and imposing a pressure gradient across the membrane from feed side to permeate side. Unusually high transmembrane flux is obtained when the membrane is subjected to one or more process conditions prior to separation. These include (a) leaving some residual amount of membrane casting solvent in the membrane, and (b) contacting the membrane with a component of the mixture to be separated for a duration effective to saturate the membrane with the component.

Analysis of surface scale on the Ni-based superalloy CMSX-10N and proposed mechanism of formation

NASA Astrophysics Data System (ADS)

Simmonds, S.; D'Souza, N.; Ryder, K. S.; Dong, H.

2012-01-01

There is a continuing demand to raise the operating temperature of jet engine turbine blades to meet the need for higher turbine entry temperatures (TET) in order to increase thermal efficiency and thrust. Modern, high-pressure turbine blades are made from Ni-based superalloys in single-crystal form via the investment casting process. One important post-cast surface defect, known as 'surface scale', has been investigated on the alloy CMSX-10N. This is an area of distinct discolouration of the aerofoil seen after casting. Auger electron and X-ray photoelectron spectroscopy analysis were carried out on both scaled and un-scaled areas. In the scaled region, a thin layer (~800nm) of Ni oxide is evident. In the un-scaled regions there is a thicker Al2O3 layer. It is shown that, as the blade cools during casting, differential thermal contraction of mould and alloy causes the solid blade to 'detach' from the mould in these scaled areas. The formation of Ni Oxides is facilitated by this separation.

Effect of simulated hyperemia on the flow field in a mildly atherosclerotic coronary artery casting of man

NASA Technical Reports Server (NTRS)

Cho, Y. I.; Back, L. H.; Crawford, D. W.

1985-01-01

Changes in an arterial flow field due to mild atherosclerosis were determined using a main coronary artery casting with a maximum obstruction of about 50 percent by area. Local pressure changes were measured using six pressure tap holes along the wall of the casting. The test-fluid was a 33 percent sugar-water solution of approximately the same viscosity as human blood. Flow visualization results were obtained by injecting blue-dye through the pressure tap holes. Measurement of local pressure demonstrated a significant Reynolds number effect. At Reynolds numbers of 80-710, a local pressure rise was observed downstream of the mild atherosclerotic constriction due to momentum changes. The Reynolds number necessary for flow separation in the divergent region of the coronary casting was about 330. The experimental results can be used to obtain a quantitative relation between coronary morphology and the fluid dynamic consequences of mild diffuse disease under conditions of maximum cardiac demand i.e., higher coronary flow rates and Reynolds numbers associated with space and atmospheric flight.

40 CFR 63.542 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... to monitor relative particulate matter loadings. Battery breaking area means the plant location at which lead-acid batteries are broken, crushed, or disassembled and separated into components. Blast...) Casting operations occur. High efficiency particulate air (HEPA) filter means a filter that has been...

40 CFR 63.542 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... to monitor relative particulate matter loadings. Battery breaking area means the plant location at which lead-acid batteries are broken, crushed, or disassembled and separated into components. Blast...) Casting operations occur. High efficiency particulate air (HEPA) filter means a filter that has been...

Mechanical Properties of Be-Al Alloys

DTIC Science & Technology

2000-02-22

technology (sand and mold casting) producing a coarse dendritic structure that did not produce mechanical properties appropriate for structural ... Mechanical Properties of Be-AI Alloys 2. REPORT TYPE Technical Report 6. AUTHOR(S) E. U. Lee K. George V. V. Agarwala H. Sanders 3. DATES...SUPPLEMENTARY NOTES 14. ABSTRACT ~ — — This study was conducted to define the mechanical properties of a wrought 62Be-38A1 alloy and a cast 65Be-32A1

Parallel volume ray-casting for unstructured-grid data on distributed-memory architectures

NASA Technical Reports Server (NTRS)

Ma, Kwan-Liu

1995-01-01

As computing technology continues to advance, computational modeling of scientific and engineering problems produces data of increasing complexity: large in size and unstructured in shape. Volume visualization of such data is a challenging problem. This paper proposes a distributed parallel solution that makes ray-casting volume rendering of unstructured-grid data practical. Both the data and the rendering process are distributed among processors. At each processor, ray-casting of local data is performed independent of the other processors. The global image composing processes, which require inter-processor communication, are overlapped with the local ray-casting processes to achieve maximum parallel efficiency. This algorithm differs from previous ones in four ways: it is completely distributed, less view-dependent, reasonably scalable, and flexible. Without using dynamic load balancing, test results on the Intel Paragon using from two to 128 processors show, on average, about 60% parallel efficiency.

Commercialization of NASA's High Strength Cast Aluminum Alloy for High Temperature Applications

NASA Technical Reports Server (NTRS)

Lee, Jonathan A.

2003-01-01

In this paper, the commercialization of a new high strength cast aluminum alloy, invented by NASA-Marshall Space Flight Center, for high temperature applications will be presented. Originally developed to meet U.S. automotive legislation requiring low- exhaust emission, the novel NASA aluminum alloy offers dramatic improvement in tensile and fatigue strengths at elevated temperatures (450 F-750 F), which can lead to reducing part weight and cost as well as improving performance for automotive engine applications. It is an ideal low cost material for cast components such as pistons, cylinder heads, cylinder liners, connecting rods, turbo chargers, impellers, actuators, brake calipers and rotors. NASA alloy also offers greater wear resistance, dimensional stability, and lower thermal expansion compared to conventional aluminum alloys, and the new alloy can be produced economically from sand, permanent mold and investment casting. Since 2001, this technology was licensed to several companies for automotive and marine internal combustion engines applications.

Ni{sub 3}Al technology transfer

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

Sikka, V.K.; Viswanathan, S.; Santella, M.L.

1997-04-01

Ductile Ni{sub 3}Al and Ni{sub 3}Al-based alloys have been identified for a range of applications. These applications require the use of material in a variety of product forms such as sheet, plate, bar, wire, tubing, piping, and castings. Although significant progress has been made in the melting, casting, and near-net-shape forming of nickel aluminides, some issues still remain. These include the need for: (1) high-strength castable composition for many applications that have been identified; (2) castability (mold type, fluidity, hot-shortness, porosity, etc.); (3) weld reparability of castings; and (4) workability of cast or powder metallurgy product to sheet, bar, andmore » wire. The four issues listed above can be {open_quotes}show stoppers{close_quotes} for the commercial application of nickel aluminides. This report describes the work completed to address some of these issues during FY 1996.« less

Influence of processing factors over concrete strength.

NASA Astrophysics Data System (ADS)

Kara, K. A.; Dolzhenko, A. V.; Zharikov, I. S.

2018-03-01

Construction of facilities of cast in-situ reinforced concrete poses additional requirements to quality of material, peculiarities of the construction process may sometimes lead to appearance of lamination planes and inhomogeneity of concrete, which reduce strength of the material and structure as a whole. Technology compliance while working with cast in-situ concrete has a significant impact onto the concrete strength. Such process factors as concrete curing, vibration and compaction of the concrete mixture, temperature treatment, etc., when they are countered or inadequately followed lead to a significant reduction in concrete strength. Here, the authors experimentally quantitatively determine the loss of strength in in-situ cast concrete structures due to inadequate following of process requirements, in comparison with full compliance.

Research on High-efficient Remanufacturing Technologies and Application of Electric Motor

NASA Astrophysics Data System (ADS)

Liu, Ren; Zhao, Yuejin; Yang, Xu; Wang, Gen

2017-09-01

The energy conservation of electric motor system is the key of industrial energy conservation. With the implementation and acceleration of electric motor energy efficiency improvement plan, more and more electric motors are knocked out. High-efficient remanufacturing of electric motor refers to improving the efficiency of electric motor and recycling the resources by replacing the winding, iron core and other components of electric motor on the basis of the low-efficient/outdated electric motors, which conforms to China’s policy of circular economy and resource recovery. The remanufacturing of electric motor not only maximizes the use of resources, but also reduces the energy consumption generated by reprocessing of cast iron, silicon steel sheet and other materials in dismantling of electric motor. However, structures and iron core materials used in design and manufacture of electric motors are different, and the degrees of wear of electric motors are also different under different operating conditions, which further result in diversified design schemes, increased remanufacturing cost and reduced remanufacturing efficiency. This paper analyzes the key process technologies for remanufacturing of electric motors are researched by analyzing the remanufacturing technologies of electric motors, and presents the feasibility to replace the cast-aluminum rotor with cast-copper rotor in high-efficient remanufacturing process of electric motor.

Anion exchange membranes composed of a poly(2,6-dimethyl-1,4-phenylene oxide) random copolymer functionalized with a bulky phosphonium cation

DOE PAGES

Liu, Ye; Zhang, Bingzi; Kinsinger, Corey L.; ...

2016-01-22

A random copolymer, tris(2,4,6-trimethoxyphenyl) phosphonium functionalized poly(2,6-dimethyl-1,4-phenylene oxide) (PPO-TPQP) was cast from three different solvents: dimethyl sulfoxide (DMSO), ethyl lactate, or a 41:59 vol% mixture of DMSO and ethyl lactate. Solvents were selected via analysis of the Hansen solubility parameters to vary the phase separation of the polymer in the films. An optimized mixture of DMSO and ethyl lactate chosen for film fabrication and this film was contrasted with films cast from the neat constituent solvents. Atomic force microscopy identified domains from nanometer to tens of nanometer sizes, while the light microscopy showed features on the order of micron. SAXSmore » revealed a cation scattering peak with a d-spacing from 7 to 15 Å. Trends in conductivity and water diffusion for the membranes vary depending on the solvent from which they are cast. The mixed solvent cast membrane shows a linear Arrhenius behavior indicating fully dissociated cationic/anionic groups, and has the highest bromide conductivity of 3 mS/cm at 95% RH, 90 °C. The ethyl lactate cast membrane shows a linear Arrhenius relation in conductivity, but a Vogel-Tamman-Fulcher behavior in its water self-diffusion. While water increases bromide dissociation, water and bromide transport in these films seems to be decoupled. Lastly, this is particularly true for the film cast from ethyl lactate.« less

Anion exchange membranes composed of a poly(2,6-dimethyl-1,4-phenylene oxide) random copolymer functionalized with a bulky phosphonium cation

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

Liu, Ye; Zhang, Bingzi; Kinsinger, Corey L.

A random copolymer, tris(2,4,6-trimethoxyphenyl) phosphonium functionalized poly(2,6-dimethyl-1,4-phenylene oxide) (PPO-TPQP) was cast from three different solvents: dimethyl sulfoxide (DMSO), ethyl lactate, or a 41:59 vol% mixture of DMSO and ethyl lactate. Solvents were selected via analysis of the Hansen solubility parameters to vary the phase separation of the polymer in the films. An optimized mixture of DMSO and ethyl lactate chosen for film fabrication and this film was contrasted with films cast from the neat constituent solvents. Atomic force microscopy identified domains from nanometer to tens of nanometer sizes, while the light microscopy showed features on the order of micron. SAXSmore » revealed a cation scattering peak with a d-spacing from 7 to 15 A. Trends in conductivity and water diffusion for the membranes vary depending on the solvent from which they are cast. The mixed solvent cast membrane shows a linear Arrhenius behavior indicating fully dissociated cationic/anionic groups, and has the highest bromide conductivity of 3 mS/cm at 95% RH, 90 degrees C. The ethyl lactate cast membrane shows a linear Arrhenius relation in conductivity, but a Vogel-Tamman-Fulcher behavior in its water self-diffusion. While water increases bromide dissociation, water and bromide transport in these films seems to be decoupled. This is particularly true for the film cast from ethyl lactate.« less

Anion exchange membranes composed of a poly(2,6-dimethyl-1,4-phenylene oxide) random copolymer functionalized with a bulky phosphonium cation

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

Liu, Ye; Zhang, Bingzi; Kinsinger, Corey L.

A random copolymer, tris(2,4,6-trimethoxyphenyl) phosphonium functionalized poly(2,6-dimethyl-1,4-phenylene oxide) (PPO-TPQP) was cast from three different solvents: dimethyl sulfoxide (DMSO), ethyl lactate, or a 41:59 vol% mixture of DMSO and ethyl lactate. Solvents were selected via analysis of the Hansen solubility parameters to vary the phase separation of the polymer in the films. An optimized mixture of DMSO and ethyl lactate chosen for film fabrication and this film was contrasted with films cast from the neat constituent solvents. Atomic force microscopy identified domains from nanometer to tens of nanometer sizes, while the light microscopy showed features on the order of micron. SAXSmore » revealed a cation scattering peak with a d-spacing from 7 to 15 Å. Trends in conductivity and water diffusion for the membranes vary depending on the solvent from which they are cast. The mixed solvent cast membrane shows a linear Arrhenius behavior indicating fully dissociated cationic/anionic groups, and has the highest bromide conductivity of 3 mS/cm at 95% RH, 90 °C. The ethyl lactate cast membrane shows a linear Arrhenius relation in conductivity, but a Vogel-Tamman-Fulcher behavior in its water self-diffusion. While water increases bromide dissociation, water and bromide transport in these films seems to be decoupled. Lastly, this is particularly true for the film cast from ethyl lactate.« less

Membrane separation of hydrocarbons

DOEpatents

Funk, Edward W.; Kulkarni, Sudhir S.; Chang, Y. Alice

1986-01-01

Mixtures of heavy oils and light hydrocarbons may be separated by passing the mixture over a polymeric membrane which comprises a polymer capable of maintaining its integrity in the presence of hydrocarbon compounds at temperature ranging from about ambient to about 100.degree. C. and pressures ranging from about 50 to about 1000 psi. The membranes which possess pore sizes ranging from about 10 to about 500 Angstroms are cast from a solvent solution and recovered.

Getters for improved technetium containment in cementitious waste forms

DOE PAGES

Asmussen, R. Matthew; Pearce, Carolyn I.; Miller, Brian W.; ...

2017-07-26

A cementitious waste form, Cast Stone, is a possible candidate technology for the immobilization of low activity nuclear waste (LAW) at the Hanford site. This paper focuses on the addition of getter materials to Cast Stone that can sequester Tc from the LAW, and in turn, lower Tc release from the Cast Stone. Two getters which produce different products upon sequestering Tc from LAW were tested: Sn(II) apatite (Sn-A) that removes Tc as a Tc(IV)-oxide and potassium metal sulfide (KMS-2) that removes Tc as a Tc(IV)-sulfide species, allowing for a comparison of stability of the form of Tc upon enteringmore » the waste form. The Cast Stone with KMS-2 getter had the best performance with addition equivalent to ~0.08 wt% of the total waste form mass. The observed diffusion (D obs) of Tc decreased from 4.6 ± 0.2 × 10 -12 cm 2/s for Cast Stone that did not contain a getter to 5.4 ± 0.4 × 10 -13 cm 2/s for KMS-2 containing Cast Stone. Finally, it was found that Tc-sulfide species are more stable against re-oxidation within getter containing Cast Stone compared with Tc-oxide and is the origin of the decrease in Tc D obs when using the KMS-2.« less

Getters for improved technetium containment in cementitious waste forms.

PubMed

Asmussen, R Matthew; Pearce, Carolyn I; Miller, Brian W; Lawter, Amanda R; Neeway, James J; Lukens, Wayne W; Bowden, Mark E; Miller, Micah A; Buck, Edgar C; Serne, R Jeffery; Qafoku, Nikolla P

2018-01-05

A cementitious waste form, Cast Stone, is a possible candidate technology for the immobilization of low activity nuclear waste (LAW) at the Hanford site. This work focuses on the addition of getter materials to Cast Stone that can sequester Tc from the LAW, and in turn, lower Tc release from the Cast Stone. Two getters which produce different products upon sequestering Tc from LAW were tested: Sn(II) apatite (Sn-A) that removes Tc as a Tc(IV)-oxide and potassium metal sulfide (KMS-2) that removes Tc as a Tc(IV)-sulfide species, allowing for a comparison of stability of the form of Tc upon entering the waste form. The Cast Stone with KMS-2 getter had the best performance with addition equivalent to ∼0.08wt% of the total waste form mass. The observed diffusion (D obs ) of Tc decreased from 4.6±0.2×10 -12 cm 2 /s for Cast Stone that did not contain a getter to 5.4±0.4×10 -13 cm 2 /s for KMS-2 containing Cast Stone. It was found that Tc-sulfide species are more stable against re-oxidation within getter containing Cast Stone compared with Tc-oxide and is the origin of the decrease in Tc D obs when using the KMS-2. Copyright © 2017 Elsevier B.V. All rights reserved.

Addressing Learning Disabilities with UDL and Technology: Strategic Reader

ERIC Educational Resources Information Center

Hall, Tracey E.; Cohen, Nicole; Vue, Ge; Ganley, Patricia

2015-01-01

CAST created "Strategic Reader," a technology-based system blending Universal Design for Learning (UDL) and Curriculum-Based Measurement (CBM) in a digital learning environment to improve reading comprehension instruction. This experimental study evaluates the effectiveness of Strategic Reader using two treatment conditions for measuring…

Quantitative Experimental Study of Defects Induced by Process Parameters in the High-Pressure Die Cast Process

NASA Astrophysics Data System (ADS)

Sharifi, P.; Jamali, J.; Sadayappan, K.; Wood, J. T.

2018-05-01

A quantitative experimental study of the effects of process parameters on the formation of defects during solidification of high-pressure die cast magnesium alloy components is presented. The parameters studied are slow-stage velocity, fast-stage velocity, intensification pressure, and die temperature. The amount of various defects are quantitatively characterized. Multiple runs of the commercial casting simulation package, ProCAST™, are used to model the mold-filling and solidification events. Several locations in the component including knit lines, last-to-fill region, and last-to-solidify region are identified as the critical regions that have a high concentration of defects. The area fractions of total porosity, shrinkage porosity, gas porosity, and externally solidified grains are separately measured. This study shows that the process parameters, fluid flow and local solidification conditions, play major roles in the formation of defects during HPDC process.

Phosphorus Segregation in Meta-Rapidly Solidified Carbon Steels

NASA Astrophysics Data System (ADS)

Li, Na; Qiao, Jun; Zhang, Junwei; Sha, Minghong; Li, Shengli

2017-09-01

Twin-roll strip casters for near-net-shape manufacture of steels have received increased attention in the steel industry. Although negative segregation of phosphorus occurred in twin-roll strip casting (TRSC) steels in our prior work, its mechanism is still unclear. In this work, V-shaped molds were designed and used to simulate a meta-rapid solidification process without roll separating force during twin roll casting of carbon steels. Experimental results show that no obvious phosphorus segregation exist in the V-shaped mold casting (VMC) steels. By comparing TRSC and the VMC, it is proposed that the negative phosphorus segregation during TRSC results from phosphorus redistribution driven by recirculating and vortex flow in the molten pool. Meanwhile, solute atoms near the advancing interface are overtaken and incorporated into the solid because of the high solidification speed. The high rolling force could promote the negative segregation of alloying elements in TRSC.

Relating hydrogen-bonding interactions with the phase behavior of naproxen/PVP K 25 solid dispersions: evaluation of solution-cast and quench-cooled films.

PubMed

Paudel, Amrit; Nies, Erik; Van den Mooter, Guy

2012-11-05

In this work, we investigated the relationship between various intermolecular hydrogen-bonding (H-bonding) interactions and the miscibility of the model hydrophobic drug naproxen with the hydrophilic polymer polyvinylpyrrolidone (PVP) across an entire composition range of solid dispersions prepared by quasi-equilibrium film casting and nonequilibrium melt quench cooling. The binary phase behavior in solid dispersions exhibited substantial processing method dependence. The solid state solubility of crystalline naproxen in PVP to form amorphous solid dispersions was 35% and 70% w/w naproxen in solution-cast films and quench-cooled films, respectively. However, the presence of a single mixed phase glass transition indicated the amorphous miscibility to be 20% w/w naproxen for the films, beyond which amorphous-amorphous and/or crystalline phase separations were apparent. This was further supported by the solution state interactions data such as PVP globular size distribution and solution infrared spectral profiles. The borderline melt composition showed cooling rate dependence of amorphization. The glass transition and melting point depression profiles of the system were treated with the analytical expressions based on Flory-Huggins mixing theory to interpolate the equilibrium solid solubility. FTIR analysis and subsequent spectral deconvolution revealed composition and miscibility dependent variations in the strength of drug-polymer intermolecular H-bonding. Two types of H-bonded populations were evidenced from 25% w/w and 35% w/w naproxen in solution-cast films and quench-cooled films, respectively, with the higher fraction of strongly H-bonded population in the drug rich domains of phase separated amorphous film compositions and highly drug loaded amorphous quench-cooled dispersions.

Centrifugal casting of ZA8 zinc alloy and composite A356/silicon carbide: Study and modeling of phases' and particles' segregation

NASA Astrophysics Data System (ADS)

Balout, Bahaa

Centrifugation is a casting technology that allows the production of cylindrical and graduated parts with different mechanical properties through the section. The need for materials with good quality and specific mechanical properties has been driven this technology in order to produce different types of materials such as zinc alloys and graduated metal matrix composites reinforced by hard and wear resistant particles. The goal of this research project is to study and model the eutectic macrosegregation, the solidification speed, and the speeds of solidification fronts during centrifugal casting of ZA8 zinc-aluminum alloy in order to improve the part quality and increase its strength and field reliability. Moreover, the segregation of the particles during centrifugal casting of an aluminum matrix composite reinforced by silicon carbide particles (A356/SiC) is also studied to improve and control the graduation of the parts. The cooling rate, the speed, acceleration/deceleration, displacement, and segregation of the particles across the section will be modeled by discretization of Stokes' law in time in order to take into consideration the change in the centrifugal radius and melt viscosity during cooling process. This study will allow the control of the graduation degree of particles across the section in order to improve the properties and wear resistance of the composite. This composite can be used in systems where friction is critical and load is high (reinforcements of parts for the cylinders of pneumatic systems). The results show that the maximum macrosegregation zone of the eutectic across the casting section corresponds to the last point of solidification. The eutectic macrosegregation produced during centrifugal casting of thin walled part is a normal segregation which varies depending on the solidification speed and the ratio between the speeds of solidification fronts. On the other hand, it was found that the position and volume fraction of the particles on the outer/inner casting surface and across the section varies whether the viscosity of the liquid metal used and the centrifugal radius are considered constant or variable during the modeling. Modeling the particles' segregation while discretizing, in time, the particles' velocities gives more consistent results compared to those obtained experimentally. Key-words: centrifugal casting, composite, macrosegregation, solidification.

Vermicomposting of source-separated human faeces for nutrient recycling.

PubMed

Yadav, Kunwar D; Tare, Vinod; Ahammed, M Mansoor

2010-01-01

The present study examined the suitability of vermicomposting technology for processing source-separated human faeces. Since the earthworm species Eisenia fetida could not survive in fresh faeces, modification in the physical characteristics of faeces was necessary before earthworms could be introduced to faeces. A preliminary study with six different combinations of faeces, soil and bulking material (vermicompost) in different layers was conducted to find out the best condition for biomass growth and reproduction of earthworms. The results indicated that SVFV combination (soil, vermicompost, faeces and vermicompost - bottom to top layers) was the best for earthworm biomass growth indicating the positive role of soil layer in earthworm biomass growth. Further studies with SVFV and VFV combinations, however, showed that soil layer did not enhance vermicompost production rate. Year-long study conducted with VFV combination to assess the quality and quantity of vermicompost produced showed an average vermicompost production rate of 0.30kg-cast/kg-worm/day. The vermicompost produced was mature as indicated by low dissolved organic carbon (2.4+/-0.43mg/g) and low oxygen uptake rate (0.15+/-0.09mg O(2)/g VS/h). Complete inactivation of total coliforms was noted during the study, which is one of the important objectives of human faeces processing. Results of the study thus indicated the potential of vermicomposting for processing of source-separated human faeces.

Timing of Getter Material Addition in Cementitious Wasteforms

NASA Astrophysics Data System (ADS)

Lawter, A.; Qafoku, N. P.; Asmussen, M.; Neeway, J.; Smith, G. L.

2015-12-01

A cementitious waste form, Cast Stone, is being evaluated as a possible supplemental immobilization technology for the Hanford sites's low activity waste (LAW), which contains radioactive 99Tc and 129I, as part of the tank waste cleanup mission. Cast Stone is made of a dry blend 47% blast furnace slag, 45% fly ash, and 8% ordinary Portland cement, mixed with a low-activity waste (LAW). To improve the retention of Tc and/or I in Cast Stone, materials with a high affinity for Tc and/or I, termed "getters," can be added to provide a stable domain for the radionuclides of concern. Previous testing conducted with a variety of getters has identified Tin(II)-Apatite and Silver Exchanged Zeolite as promising candidates for Tc and I, respectively. Investigation into the sequence in which getters are added to Cast Stone was performed following two methods: 1) adding getters to the Cast Stone dry blend, and then mixing with liquid waste, and 2) adding getters to the liquid waste first, followed by addition of the Cast Stone dry blend. Cast Stone monolith samples were prepared with each method and leach tests, following EPA method 1315, were conducted in either distilled water or simulated vadose zone porewater for a period of up to 63 days. The leachate was analyzed for Tc, I, Na, NO3-, NO2- and Cr with ICP-MS, ICP-OES and ion chromatography and the results indicated that the Cast Stone with getter addition in the dry blend mix (method 1) has lower rates of Tc and I leaching. The mechanisms of radionuclide release from the Cast Stone were also investigated with a variety of solid phase characterization techniques of the monoliths before and after leaching, such as XRD, SEM/EDS, TEM/SAED and other spectroscopic techniques.

High-resistant castable corrosion-resistant nickel alloy for monocrystalline casting by the directional crystallization method

NASA Astrophysics Data System (ADS)

Belikov, S. B.; Andrienko, A. G.; Gaiduk, S. V.; Kononov, V. V.; Zamkovoi, V. E.

2008-01-01

A high-resistant corrosion-resistant nickel-based alloy has been developed for monocrystalline casting using the directional crystallization method. Its mechanical properties are close to those of aircraft alloys ZhS6K-VI and ZhS6U-VI with an equiaxial structure and ZhS26-VI with an oriented structure. The technology of producing blades for turboprop engines from the new alloy has been developed and tested.

Potential Technology Transfer to the DoD Unmanned Ground Vehicle Program.

DTIC Science & Technology

1996-10-01

Germany. This process combines x-ray lithography, galvanic casting, and micromolding technology and can be used to produce a variety of sensors and...whether circulation is being obstructed by atherosclerosis . Finally, work is being done at the University of Minnesota on a microrobotic device

Use of freeze-casting in advanced burner reactor fuel design

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

Lang, A. L.; Yablinsky, C. A.; Allen, T. R.

2012-07-01

This paper will detail the modeling of a fast reactor with fuel pins created using a freeze-casting process. Freeze-casting is a method of creating an inert scaffold within a fuel pin. The scaffold is created using a directional solidification process and results in open porosity for emplacement of fuel, with pores ranging in size from 300 microns to 500 microns in diameter. These pores allow multiple fuel types and enrichments to be loaded into one fuel pin. Also, each pore could be filled with varying amounts of fuel to allow for the specific volume of fission gases created by thatmore » fuel type. Currently fast reactors, including advanced burner reactors (ABR's), are not economically feasible due to the high cost of operating the reactors and of reprocessing the fuel. However, if the fuel could be very precisely placed, such as within a freeze-cast scaffold, this could increase fuel performance and result in a valid design with a much lower cost per megawatt. In addition to competitive costs, freeze-cast fuel would also allow for selective breeding or burning of actinides within specific locations in fast reactors. For example, fast flux peak locations could be utilized on a minute scale to target specific actinides for transmutation. Freeze-cast fuel is extremely flexible and has great potential in a variety of applications. This paper performs initial modeling of freeze-cast fuel, with the generic fast reactor parameters for this model based on EBR-II. The core has an assumed power of 62.5 MWt. The neutronics code used was Monte Carlo N-Particle (MCNP5) transport code. Uniform pore sizes were used in increments of 100 microns. Two different freeze-cast scaffold materials were used: ceramic (MgO-ZrO{sub 2}) and steel (SS316L). Separate models were needed for each material because the freeze-cast ceramic and metal scaffolds have different structural characteristics and overall porosities. Basic criticality results were compiled for the various models. Preliminary results show that criticality is achievable with freeze-cast fuel pins despite the significant amount of inert fuel matrix. Freeze casting is a promising method to achieve very precise fuel placement within fuel pins. (authors)« less

Enhanced heat transfer surface for cast-in-bump-covered cooling surfaces and methods of enhancing heat transfer

DOEpatents

Chiu, Rong-Shi Paul; Hasz, Wayne Charles; Johnson, Robert Alan; Lee, Ching-Pang; Abuaf, Nesim

2002-01-01

An annular turbine shroud separates a hot gas path from a cooling plenum containing a cooling medium. Bumps are cast in the surface on the cooling side of the shroud. A surface coating overlies the cooling side surface of the shroud, including the bumps, and contains cooling enhancement material. The surface area ratio of the cooling side of the shroud with the bumps and coating is in excess of a surface area ratio of the cooling side surface with bumps without the coating to afford increased heat transfer across the element relative to the heat transfer across the element without the coating.

Low-Impedance Compact Modulators Capable of Generating Intense Ultra-fast Rising Nanosecond Waveforms

DTIC Science & Technology

2006-10-31

spark gap is shown in Fig. 1. The Blumleins were constructed from copper plates separated by laminated layered Kapton (polyimide) dielectrics. Scaling... convolution factor. The diamond/GaAs heterojunction response is limited to a very thin layer across the cross section between amorphic diamond and GaAs...were fastened to electrode mounts and passed through the cast material of the base before it hardened. A thick kapton laminate 1.2 cm wide separated

In vitro investigation of marginal accuracy of implant-supported screw-retained partial dentures.

PubMed

Koke, U; Wolf, A; Lenz, P; Gilde, H

2004-05-01

Mismatch occurring during the fabrication of implant-supported dentures may induce stress to the peri-implant bone. The purpose of this study was to investigate the influence of two different alloys and the fabrication method on the marginal accuracy of cast partial dentures. Two laboratory implants were bonded into an aluminium block so that the distance between their longitudinal axes was 21 mm. Frameworks designed for screw-retained partial dentures were cast either with pure titanium (rematitan) or with a CoCr-alloy (remanium CD). Two groups of 10 frameworks were cast in a single piece. The first group was made of pure titanium, and the second group of a CoCr-alloy (remanium CD). A third group of 10 was cast in two pieces and then laser-welded onto a soldering model. This latter group was also made of the CoCr-alloy. All the frameworks were screwed to the original model with defined torque. Using light microscopy, marginal accuracy was determined by measuring vertical gaps at eight defined points around each implant. Titanium frameworks cast in a single piece demonstrated mean vertical gaps of 40 microm (s.d. = 11 microm) compared with 72 microm (s.d. = 40 microm) for CoCr-frameworks. These differences were not significant (U-test, P = 0.124) because of a considerable variation of the values for CoCr-frameworks (minimum: 8 microm and maximum: 216 microm). However, frameworks cast in two pieces and mated with a laser showed significantly better accuracy in comparison with the other experimental groups (mean: 17 microm +/- 6; P < 0.01). (i) The fit of implant-supported partial dentures cast with pure titanium in a single piece is preferable to that of those made with the CoCr-alloy and (ii) the highest accuracy can be achieved by using a two-piece casting technique combined with laser welding. Manufacturing the framework pieces separately and then welding them together provides the best marginal fit.

Materials for advanced ultrasupercritical steam turbines

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

Purgert, Robert; Shingledecker, John; Saha, Deepak

The U.S. Department of Energy (DOE) and the Ohio Coal Development Office (OCDO) have sponsored a project aimed at identifying, evaluating, and qualifying the materials needed for the construction of the critical components of coal-fired power plants capable of operating at much higher efficiencies than the current generation of supercritical plants. This increased efficiency is expected to be achieved principally through the use of advanced ultrasupercritical (A-USC) steam conditions. A limiting factor in this can be the materials of construction for boilers and for steam turbines. The overall project goal is to assess/develop materials technology that will enable achieving turbinemore » throttle steam conditions of 760°C (1400°F)/35MPa (5000 psi). This final technical report covers the research completed by the General Electric Company (GE) and Electric Power Research Institute (EPRI), with support from Oak Ridge National Laboratory (ORNL) and the National Energy Technology Laboratory (NETL) – Albany Research Center, to develop the A-USC steam turbine materials technology to meet the overall project goals. Specifically, this report summarizes the industrial scale-up and materials property database development for non-welded rotors (disc forgings), buckets (blades), bolting, castings (needed for casing and valve bodies), casting weld repair, and casting to pipe welding. Additionally, the report provides an engineering and economic assessment of an A-USC power plant without and with partial carbon capture and storage. This research project successfully demonstrated the materials technology at a sufficient scale and with corresponding materials property data to enable the design of an A-USC steam turbine. The key accomplishments included the development of a triple-melt and forged Haynes 282 disc for bolted rotor construction, long-term property development for Nimonic 105 for blading and bolting, successful scale-up of Haynes 282 and Nimonic 263 castings using traditional sand foundry practices, and a techno-economic study of an A-USC plant including cost estimates for an A-USC turbine which showed A-USC to be economically attractive for partial carbon and capture compared to today’s USC technology. Based on this successful materials research and a review with U.S. utility stakeholders, a new project to develop a component test facility (ComTest) including the world’s first A-USC turbine has been proposed to continue the technology development.« less

Physicochemical and Microstructural Characterization of Corn Starch Edible Films Obtained by a Combination of Extrusion Technology and Casting Technique.

PubMed

Fitch-Vargas, Perla Rosa; Aguilar-Palazuelos, Ernesto; de Jesús Zazueta-Morales, José; Vega-García, Misael Odín; Valdez-Morales, Jesús Enrique; Martínez-Bustos, Fernando; Jacobo-Valenzuela, Noelia

2016-09-01

Starch edible films (EFs) have been widely studied due to their potential in food preservation; however, their application is limited because of their poor mechanical and barrier properties. Because of that, the aim of this work was to use the extrusion technology (Ex T) as a pretreatment of casting technique to change the starch structure in order to obtain EFs with improved physicochemical properties. To this, corn starch and a mixture of plasticizers (sorbitol and glycerol, in different ratios) were processed in a twin screw extruder to generate the starch modification and subsequently casting technique was used for EFs formation. The best conditions of the Ex T and plasticizers concentration were obtained using response surface methodology. All the response variables evaluated, were affected significatively by the Plasticizers Ratio (Sorbitol:Glycerol) (PR (S:G)) and Extrusion Temperature (ET), while the Screw Speed (SS) did not show significant effect on any of these variables. The optimization study showed that the appropriate conditions to obtain EFs with the best mechanical and barrier properties were ET = 89 °C, SS = 66 rpm and PR (S:G) = 79.7:20.3. Once the best conditions were obtained, the optimal treatment was characterized according to its microstructural properties (X-ray diffraction, Scanning Electron Microscopy and Atomic Force Microscopy) to determine the damage caused in the starch during Ex T and casting technique. In conclusion, with the combination of Ex T and casting technique were obtained EFs with greater breaking strength and deformation, as well as lower water vapor permeability than those reported in the literature. © 2016 Institute of Food Technologists®

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

Induction hardening treatment and simulation for a grey cast iron used in engine cylinder liners

NASA Astrophysics Data System (ADS)

Castellanos-Leal, E. L.; Miranda, D. A.; Coy, A. E.; Barrero, J. G.; González, J. A.; Vesga Rueda, O. P.

2017-01-01

In this research, a technical study of induction hardening in a grey cast iron used in engine cylinder liners manufactured by LAVCO Ltda., a Colombian foundry company, was carried out. Metallurgical parameters such as austenitization temperature, cooling rate, and quenching severity were determined. These factors are exclusively dependent on chemical composition and initial microstructure of grey cast iron. Simulations of induction heating through finite elements method were performed and, the most appropriate experimental conditions to achieve the critical transformation temperature was evaluated to reach a proper surface hardening on the piece. Preliminary results revealed an excellent approximation between simulation and heating test performed with a full bridge inverter voltage adapted with local technology.

SeqAPASS to evaluate conservation of high-throughput screening targets across non-mammalian species

EPA Science Inventory

Cell-based high-throughput screening (HTS) and computational technologies are being applied as tools for toxicity testing in the 21st century. The U.S. Environmental Protection Agency (EPA) embraced these technologies and created the ToxCast Program in 2007, which has served as a...

Syndicated RSS Feeds for Course Information Distribution

ERIC Educational Resources Information Center

Glotzbach, Ronald J.; Mordkovich, Dorina A.; Radwan, Jaime E.

2008-01-01

Students in higher education today are technologically savvy and expect faculty to use myriad web technologies for course delivery. This includes taking advantage of email, course web sites, and online learning communities. However, expectations now also include RSS, blogs, web-, pod-, and vod-casting, extending the classroom experience to provide…

Really Simple Syndication (RSS): An Educational Approach

ERIC Educational Resources Information Center

Glotzbach, Ronald J.; Mohler, James L.; Radwan, Jaime E.

2009-01-01

Today's post-secondary students are technologically savvy and they expect faculty to use myriad web technologies for course delivery. This includes taking advantage of email, course web sites, and online learning communities. However, expectations now also include RSS, blogs, web- and pod-casting, extending the classroom experience to provide…

Manufacturing and Characterization of Ultra Pure Ferrous Alloys Final Report CRADA No. TC02069.0

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

Lesuer, D.; McGreevy, T. E.

This CRADA was a.collaborative effort between the Lawrence Livermore National Security LLC (formerly University of California)/Lawrence Livermore National Laboratory (LLNL),and Caterpillar Inc. (CaterpiHar), to further advance levitation casting techniques (developed at the Central Research Institute for Material (CRIM) in St. Petersburg, Russia) for use in manufacturing high purity metal alloys. This DOE Global Initiatives for Proliferation Prevention Program (IPP) project was to develop and demonstrate the levitation casting technology for producing ultra-pure alloys.

Photophysical Studies of Spin Cast Polymer Films

DTIC Science & Technology

1988-07-13

Polymeric Materials contained research presentations on fundamental radiation chemistry and physics as well as on technological applications of polymer ...on Polymeric Materials," X~os Hoos. ueensland. Australia., August 16-19, 1987 ,7 COSAII CODES I&. SUBJECT TEAMS (Conuo an itwre it r~,*Ctzy Mid od@0ty...by biOck mumblrJ _ILO GR UP SU8 -GaOUP 9. AaSTkRAC7T (COn1nue an r*"wne it noatamey and iwaf by bWok nuffltr) Snim casting is a commonly used technique

Combination of microscopic model and VoF-multiphase approach for numerical simulation of nodular cast iron solidification

NASA Astrophysics Data System (ADS)

Subasic, E.; Huang, C.; Jakumeit, J.; Hediger, F.

2015-06-01

The ongoing increase in the size and capacity of state-of-the-art wind power plants is highlighting the need to reduce the weight of critical components, such as hubs, main shaft bearing housings, gear box housings and support bases. These components are manufactured as nodular iron castings (spheroid graphite iron, or SGI). A weight reduction of up to 20% is achievable by optimizing the geometry to minimize volume, thus enabling significant downsizing of wind power plants. One method for enhancing quality control in the production of thick-walled SGI castings, and thus reducing tolerances and, consequently, enabling castings of smaller volume is via a casting simulation of mould filling and solidification based on a combination of microscopic model and VoF-multiphase approach. Coupled fluid flow with heat transport and phase transformation kinetics during solidification is described by partial differential equations and solved using the finite volume method. The flow of multiple phases is described using a volume of fluid approach. Mass conservation equations are solved separately for both liquid and solid phases. At the micro-level, the diffusion-controlled growth model for grey iron eutectic grains by Wetterfall et al. is combined with a growth model for white iron eutectic grains. The micro-solidification model is coupled with macro-transport equations via source terms in the energy and continuity equations. As a first step the methodology was applied to a simple geometry to investigate the impact of mould-filling on the grey-to-white transition prediction in nodular cast iron.

Influence of heat treatment and hot extrusion on the microstructure and tensile properties of rare earth modified Mg-Zn based alloy

NASA Astrophysics Data System (ADS)

Sheng, L. Y.; Wang, B. J.; Du, B. N.; Lai, C.; Xi, T. F.

2018-01-01

In the present paper, the Mg-Zn-Y-Nd alloy was prepared by casting, heat treatment and hot extrusion. The microstructure and mechanical properties of the alloys were tested by OM, SEM, TEM and tensile test. The results showed that the Mg3Zn2Y3 phase is the main strengthening phase and forms the eutectic structure with α-Mg matrix in the as cast alloy. The strengthening phases semi-continuously connect and separate the α-Mg matrix into cell structure. The average grain size of the as cast alloy is about 60 μm. The heat treatment promotes the solid solution of the strengthening phase and precipitation of small particles inside grain.Compared with the as cast alloy, the heat treatment increases grain size a little and mechanical properties more than 30%. The hot extrusion refines the grain and strengthening phase, which increase the mechanical properties significantly. Moreover, the great deformation by the hot extrusion results in the ultrafine structure and abundant of crystal defects. The intersection of micro-twins lead to the special region with nanometer size.

Corrosion cast study of the canine hepatic veins.

PubMed

Uršič, M; Vrecl, M; Fazarinc, G

2014-11-01

This study presents a detailed description of the distribution, diameters and drainage patterns of hepatic veins on the basis of the corrosion cast analysis in 18 dogs. We classified the hepatic veins in three main groups: the right hepatic veins of the caudate process and right lateral liver lobe, the middle hepatic veins of the right medial and quadrate lobes and the left hepatic veins of both left liver lobes and the papillary process. The corrosion cast study showed that the number of the veins in the Nomina Anatomica Veterinaria and most anatomical textbooks is underestimated. The number of various-sized hepatic veins of the right liver division ranged from 3 to 5 and included 1 to 4 veins from the caudate process and 2 to 4 veins from the right lateral liver lobe. Generally, in all corrosion casts, one middle-sized vein from the right part of the right medial lobe, which emptied separately in the caudal vena cava, was established. The other vein was a large-sized vein from the remainder of the central division, which frequently joined the common left hepatic vein from the left liver lobes. The common left hepatic vein was the largest of all the aforementioned hepatic veins.

The importance of new processing techniques in tissue engineering

NASA Technical Reports Server (NTRS)

Lu, L.; Mikos, A. G.; McIntire, L. V. (Principal Investigator)

1996-01-01

The use of polymer scaffolds in tissue engineering is reviewed and processing techniques are examined. The discussion of polymer-scaffold processing explains fiber bonding, solvent casting and particulate leaching, membrane lamination, melt molding, polymer/ceramic fiber composite-foam processing, phase separation, and high-pressure processing.

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

Experimental studies of the rotor flow downwash on the Stability of multi-rotor crafts in descent

NASA Astrophysics Data System (ADS)

Veismann, Marcel; Dougherty, Christopher; Gharib, Morteza

2017-11-01

All rotorcrafts, including helicopters and multicopters, have the inherent problem of entering rotor downwash during vertical descent. As a result, the craft is subject to highly unsteady flow, called vortex ring state (VRS), which leads to a loss of lift and reduced stability. To date, experimental efforts to investigate this phenomenon have been largely limited to analysis of a single, fixed rotor mounted in a horizontal wind tunnel. Our current work aims to understand the interaction of multiple rotors in vertical descent by mounting a multi-rotor craft in a low speed, vertical wind tunnel. Experiments were performed with a fixed and rotationally free mounting; the latter allowing us to better capture the dynamics of a free flying drone. The effect of rotor separation on stability, generated thrust, and rotor wake interaction was characterized using force gauge data and PIV analysis for various descent velocities. The results obtained help us better understand fluid-craft interactions of drones in vertical descent and identify possible sources of instability. The presented material is based upon work supported by the Center for Autonomous Systems and Technologies (CAST) at the Graduate Aerospace Laboratories of the California Institute of Technology (GALCIT).

JPRS Report, Science & Technology, USSR: Science & Technology Policy

DTIC Science & Technology

1989-12-07

technologies. —The restoration of the biosphere and its return to an ecologically clean, healthy state; the preservation and reproduction of soils and the...and Geochemistry of Combustible Materials Institute, Casting Problems Institute, Technical Thermal Physics Institute, Gas Insti- tute, Social and...academician, honorary director of the Institute of Geochemistry imeni A.P. Vinogradov of the Siberian Department of the USSR Academy of Sciences

Electrochromatography on acrylate-based monolith in cyclic olefin copolymer microchip: a cost-effective and easy-to-use technology.

PubMed

Ladner, Yoann; Crétier, Gérard; Faure, Karine

2012-10-01

This article shows that there is great interest in using an electrochromatographic microchip made of hexyl acrylate (HA) based porous monolith cast within the channel of a cyclic olefin copolymer (COC) device. The monolith is simultaneously in situ synthesized and anchored to the inner walls of the channel in less than 10 min. By appropriate choice of light intensity used during the synthesis, the separation efficiency obtained for nonpolar solutes such as polycyclic aromatic hydrocarbons (PAH) is increased up to 250 000 plates/m. The performance of this HA-filled COC microchip was investigated for a wide range of analytes of varying nature. The reversed-phase separation of four aflatoxins is obtained in less than 2 min. The baseline separation of a mixture of neurotransmitters including six amino acids and two catecholamines is possible thanks to the superimposition of the differences in electrophoretic mobility on the chromatographic process. The durability of the system at pH 13 allows the separation of five biogenic amines and the quantitative determination of two of them in numerous wine samples. The feasibility of on-line preconcentration is also demonstrated. Hydrophilic surface modification of COC channel via UV-photografting with poly(ethylene glycol) methacrylate (PEGMA) before in situ synthesis of HA, is necessary to reduce the adsorption of very hydrophobic solutes such as PAH during enrichment. The detection limit of fluoranthene is decreased down to less than 1 ppb with a preconcentration of 4.5 h on the HA-filled PEGMA functionalized COC microchip. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Secondary Waste Simulant Development for Cast Stone Formulation Testing

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

Russell, Renee L.; Westsik, Joseph H.; Rinehart, Donald E.

Washington River Protection Solutions, LLC (WRPS) funded Pacific Northwest National Laboratory (PNNL) to conduct a waste form testing program to implement aspects of the Secondary Liquid Waste Treatment Cast Stone Technology Development Plan (Ashley 2012) and the Hanford Site Secondary Waste Roadmap (PNNL 2009) related to the development and qualification of Cast Stone as a potential waste form for the solidification of aqueous wastes from the Hanford Site after the aqueous wastes are treated at the Effluent Treatment Facility (ETF). The current baseline is that the resultant Cast Stone (or grout) solid waste forms would be disposed at the Integratedmore » Disposal Facility (IDF). Data and results of this testing program will be used in the upcoming performance assessment of the IDF and in the design and operation of a solidification treatment unit planned to be added to the ETF. The purpose of the work described in this report is to 1) develop simulants for the waste streams that are currently being fed and future WTP secondary waste streams also to be fed into the ETF and 2) prepare simulants to use for preparation of grout or Cast Stone solid waste forms for testing.« less

Scalable Production Method for Graphene Oxide Water Vapor Separation Membranes

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

Fifield, Leonard S.; Shin, Yongsoon; Liu, Wei

ABSTRACT Membranes for selective water vapor separation were assembled from graphene oxide suspension using techniques compatible with high volume industrial production. The large-diameter graphene oxide flake suspensions were synthesized from graphite materials via relatively efficient chemical oxidation steps with attention paid to maintaining flake size and achieving high graphene oxide concentrations. Graphene oxide membranes produced using scalable casting methods exhibited water vapor flux and water/nitrogen selectivity performance meeting or exceeding that of membranes produced using vacuum-assisted laboratory techniques. (PNNL-SA-117497)

Apparatus for obtaining silicon from fluosilicic acid

DOEpatents

Sanjurjo, Angel

1986-05-20

Apparatus for producing low cost, high purity solar grade silicon ingots in single crystal or quasi single crystal ingot form in a substantially continuous operation in a two stage reactor starting with sodium fluosilicate and a metal more electropositive than silicon (preferably sodium) in separate compartments having easy vapor transport therebetween and thermally decomposing the sodium fluosilicate to cause formation of substantially pure silicon and a metal fluoride which may be continuously separated in the melt and silicon may be directly and continuously cast from the melt.

Marginal discrepancy of noble metal-ceramic fixed dental prosthesis frameworks fabricated by conventional and digital technologies.

PubMed

Afify, Ahmed; Haney, Stephan; Verrett, Ronald; Mansueto, Michael; Cray, James; Johnson, Russell

2018-02-01

Studies evaluating the marginal adaptation of available computer-aided design and computer-aided manufacturing (CAD-CAM) noble alloys for metal-ceramic prostheses are lacking. The purpose of this in vitro study was to evaluate the vertical marginal adaptation of cast, milled, and direct metal laser sintered (DMLS) noble metal-ceramic 3-unit fixed partial denture (FDP) frameworks before and after fit adjustments. Two typodont teeth were prepared for metal-ceramic FDP abutments. An acrylic resin pattern of the prepared teeth was fabricated and cast in nickel-chromium (Ni-Cr) alloy. Each specimen group (cast, milled, DMLS) was composed of 12 casts made from 12 impressions (n=12). A single design for the FDP substructure was created on a laboratory scanner and used for designing the specimens in the 3 groups. Each specimen was fitted to its corresponding cast by using up to 5 adjustment cycles, and marginal discrepancies were measured on the master Ni-Cr model before and after laboratory fit adjustments. The milled and DMLS groups had smaller marginal discrepancy measurements than those of the cast group (P<.001). Significant differences were found in the number of adjustments among the groups, with the milled group requiring the minimum number of adjustments, followed by the DMLS and cast groups (F=30.643, P<.001). Metal-ceramic noble alloy frameworks fabricated by using a CAD-CAM workflow had significantly smaller marginal discrepancies compared with those with a traditional cast workflow, with the milled group demonstrating the best marginal fit among the 3 test groups. Manual refining significantly enhanced the marginal fit of all groups. All 3 groups demonstrated marginal discrepancies within the range of clinical acceptability. Copyright © 2017 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

FIELD DEMONSTRATION OF INNOVATIVE LEAK DETECTION/LOCATION TECHNOLOGIES COUPLED WITH WALL-THICKNESS SCREENING FOR WATER MAINS

EPA Science Inventory

The U.S. Environmental Protection Agency sponsored a large-scale field demonstration of innovative leak detection/location and condition assessment technologies on a 76-year old, 2,500-ft long, cement-lined, 24-in. cast iron water main in Louisville, KY from July through Septembe...

Field Demonstration of Innovative Condition Assessment Technologies for Water Mains: Leak Detection and Location

EPA Science Inventory

Three leak detection/location technologies were demonstrated on a 76-year-old, 2,057-ft-long portion of a cement-lined, 24-in. cast iron water main in Louisville, KY. This activity was part of a series of field demonstrations of innovative leak detection/location and condition a...

An improved method for collecting and monitoring pine oleoresin

Treesearch

Dick Karsky; Brian Strom; Harold Thistle

2004-01-01

A new method for collecting and monitoring pine oleoresin has been developed through a cooperative project involving the Missoula Technology Development Center (MTDC), Southern Research Station (Brian Strom, research entomologist), and the Forest Health Technology Enterprise Team. The new sampling unit (figure 1) is cast from rugged plastic. It provides a closed system...

Accuracy verification of magnetic resonance imaging (MRI) technology for lower-limb prosthetic research: utilising animal soft tissue specimen and common socket casting materials.

PubMed

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

2012-01-01

Lower limb prosthetic socket shape and volume consistency can be quantified using MRI technology. Additionally, MRI images of the residual limb could be used as an input data for CAD-CAM technology and finite element studies. However, the accuracy of MRI when socket casting materials are used has to be defined. A number of six, 46 mm thick, cross-sections of an animal leg were used. Three specimens were wrapped with Plaster of Paris (POP) and the other three with commercially available silicone interface liner. Data was obtained by utilising MRI technology and then the segmented images compared to corresponding calliper measurement, photographic imaging, and water suspension techniques. The MRI measurement results were strongly correlated with actual diameter, surface area, and volume measurements. The results show that the selected scanning parameters and the semiautomatic segmentation method are adequate enough, considering the limit of clinical meaningful shape and volume fluctuation, for residual limb volume and the cross-sectional surface area measurements.

Accuracy Verification of Magnetic Resonance Imaging (MRI) Technology for Lower-Limb Prosthetic Research: Utilising Animal Soft Tissue Specimen and Common Socket Casting Materials

PubMed Central

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

2012-01-01

Lower limb prosthetic socket shape and volume consistency can be quantified using MRI technology. Additionally, MRI images of the residual limb could be used as an input data for CAD-CAM technology and finite element studies. However, the accuracy of MRI when socket casting materials are used has to be defined. A number of six, 46 mm thick, cross-sections of an animal leg were used. Three specimens were wrapped with Plaster of Paris (POP) and the other three with commercially available silicone interface liner. Data was obtained by utilising MRI technology and then the segmented images compared to corresponding calliper measurement, photographic imaging, and water suspension techniques. The MRI measurement results were strongly correlated with actual diameter, surface area, and volume measurements. The results show that the selected scanning parameters and the semiautomatic segmentation method are adequate enough, considering the limit of clinical meaningful shape and volume fluctuation, for residual limb volume and the cross-sectional surface area measurements. PMID:22619599

Concept of a small satellite for sub-MeV and MeV all sky survey: the CAST mission

NASA Astrophysics Data System (ADS)

Nakazawa, Kazuhiro; Takahashi, Tadayuki; Ichinohe, Yuto; Takeda, Shin'ichiro; Tajima, Hiroyasu; Kamae, Tuneyoshi; Kokubun, Motohide; Takashima, Takeshi; Tashiro, Makoto; Tamagawa, Toru; Terada, Yukikatsu; Nomachi, Masaharu; Fukazawa, Yasushi; Makishima, Kazuo; Mizuno, Tsunefumi; Mitani, Takefumi; Yoshimitsu, Tetsuo; Watanabe, Shin

2012-09-01

MeV and sub-MeV energy band from ~200 keV to ~2 MeV contains rich information of high-energy phenomena in the universe. The CAST (Compton Telescope for Astro and Solar Terrestrial) mission is planned to be launched at the end of 2010s, and aims at providing all-sky map in this energy-band for the first time. It is made of a semiconductor Compton telescope utilizing Si as a scatterer and CdTe as an absorber. CAST provides allsky sub-MeV polarization map for the first time, as well. The Compton telescope technology is based on the design used in the Soft Gamma-ray Detector (SGD) onboard ASTRO-H, characterized by its tightly stacked semiconductor layers to obtain high Compton reconstruction efficiency. The CAST mission is currently planned as a candidate for the small scientific satellite series in ISAS/JAXA, weighting about 500 kg in total. Scalable detector design enables us to consider other options as well. Scientific outcome of CAST is wide. It will provide new information from high-energy sources, such as AGN and/or its jets, supernova remnants, magnetors, blackhole and neutron-star binaries and others. Polarization map will tell us about activities of jets and reflections in these sources, as well. In addition, CAST will simultaneously observe the Sun, and depending on its attitude, the Earth.

PDMS free-flow electrophoresis chips with integrated partitioning bars for bubble segregation.

PubMed

Köhler, Stefan; Weilbeer, Claudia; Howitz, Steffen; Becker, Holger; Beushausen, Volker; Belder, Detlev

2011-01-21

In this work, a microfluidic free-flow electrophoresis device with a novel approach for preventing gas bubbles from entering the separation area is presented. This is achieved by integrating partitioning bars to reduce the channel depth between electrode channels and separation chamber in order to obtain electrical contact and simultaneously prevent bubbles from entering the separation area. The three-layer sandwich chip features a reusable carrier plate with integrated ports for fluidic connection combined with a softlithographically cast microfluidic PDMS layer and a sealing glass slide. This design allows for a straightforward and rapid chip prototyping process. The performance of the device is demonstrated by free-flow zone electrophoretic separations of fluorescent dye mixtures as well as by the separation of labeled amines and amino acids with separation voltages up to 297 V.

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.

Manufacturing Processes for Long-Life Gas Turbines

NASA Astrophysics Data System (ADS)

Hoppin, G. S.; Danesi, W. P.

1986-07-01

Dual-alloy turbine wheels produced by solid-state diffusion bonding of vacuum investment cast blade rings of one superalloy to preconsolidated powder metal hubs of a second superalloy have the long cyclic lives characteristic of wrought or powder superalloys combined with the high creep strength and net-shape blades characteristic of cast superalloys. A wide variety of superalloys and turbine configurations are compatible with this technology. Improved temperature capability turbine blades and vanes of the MAR-M 247 alloy made by directional solidification casting processes are now in volume production for Garrett gas turbines. Single-crystal alloys derivative to MAR-M 247 further extend the temperature capability of turbine blades and have been successfully engine tested. These blades are produced by a relatively simple modification of the processes used to manufacture directionally solidified blades.

The role of heat transfer in strip casting

NASA Astrophysics Data System (ADS)

Misra, Paretosh

The last few years have witnessed rapid developments in the area of strip casting of steel. It involves smaller capital and operating cost, lower greenhouse gas emissions, and an opportunity to create newer products due to a faster solidification rate that leads to a different solidification structure. Thus, ample reasons for interest in the technology exist. At the same time, it needs to be determined if the properties of a strip cast product can match those of a conventional product and if it is possible to produce steel strip at high production rates. The first objective of this work was to characterize the quality, structure, and properties of strip cast material of different chemistries and cast at different machines, to identify the critical operating conditions that would result in the best properties. Determination of the possible range of properties was also aimed, given that the structure of the material is different from the traditional material. The second objective was to investigate ways to increase the rate of heat transfer in strip casting, as that will also enhance the productivity of a strip caster. It was also envisaged to see what effect a high rate of heat transfer will have on the properties of the strip cast material. Results from the strip cast material characterization that was carried out to achieve the first objective indicated that an effective control of heat transfer is very important to get the best properties. Samples that showed best properties had a uniform solidification structure consisting of columnar grains running from the edge of a strip to the centerline, indicating a good control of heat transfer, and their dendrite spacings pointed towards a relatively faster rate of cooling between the rolls. These findings indicated that heat transfer is a core issue in strip casting. The mechanism of increase in the rate of heat transfer in strip casting due to the presence of liquid oxide films at the metal-mold interface was examined. It was discovered that these films originate from the metal itself. A high degree of interdendritic supersaturation can lead to the formation of low melting point oxide phases by the deoxidizing agents in the steel. As the temperature lowers further the film may get ejected out of the metal due to the non-wetting of the metal by the oxide phase. If enough oxide film can be generated then this can result in an almost two-fold increase in the rate of heat transfer during initial solidification---the first 20 milliseconds. The results indicate that if a proper control of these films is ensured then it provides an attractive alternative to increasing the roll diameter as a mechanism of increasing the rate of production of a strip caster. This mechanism will work even with smaller diameter rolls, in fact, perhaps better in that case due to a smaller interface area over which uniformity of heat transfer has to be ensured, thus leveraging its full advantages. If successfully implemented at a plant, this technique can help the strip casting machines to increase their productivity and emerge as a competitive technology to produce steel strip.

Facile preparation of high density polyethylene superhydrophobic/superoleophilic coatings on glass, copper and polyurethane sponge for self-cleaning, corrosion resistance and efficient oil/water separation.

PubMed

Cheng, Yuanyuan; Wu, Bei; Ma, Xiaofan; Lu, Shixiang; Xu, Wenguo; Szunerits, Sabine; Boukherroub, Rabah

2018-04-18

Inspired by the lotus effect and water-repellent properties of water striders' legs, superhydrophobic surfaces have been intensively investigated from both fundamental and applied perspectives for daily and industrial applications. Various techniques are available for the fabrication of artificial superoleophilic/superhydrophobic (SS). However, most of these techniques are tedious and often require hazardous or expensive equipment, which hampers their implementation for practical applications. In the present work, we used a versatile and straightforward technique based on polymer drop-casting for the preparation SS materials that can be implemented on any substrate. High density polyethylene (HDPE) SS coatings were prepared on different substrates (glass, copper mesh and polyurethane (PU) sponge) by drop casting the parent polymer xylene-ethanol solution at room temperature. All the substrates exhibited a superhydrophobic behavior with a water contact angle (WCA) greater than 150°. Furthermore, the corrosion resistance, stability, self-cleaning property, and water/oil separation of the developed materials were also assessed. While copper mesh and PU sponge exhibited good ability for oil and organic solvents separation from water, the HDPE-functionalized PU sponge displayed good adsorption capacity, 32-90 times the weight of adsorbed substance vs. the weight of adsorbent. Copyright © 2018 Elsevier Inc. All rights reserved.

Aluminium alloys in municipal solid waste incineration bottom ash.

PubMed

Hu, Yanjun; Rem, Peter

2009-05-01

With the increasing growth of incineration of household waste, more and more aluminium is retained in municipal solid waste incinerator bottom ash. Therefore recycling of aluminium from bottom ash becomes increasingly important. Previous research suggests that aluminium from different sources is found in different size fractions resulting in different recycling rates. The purpose of this study was to develop analytical and sampling techniques to measure the particle size distribution of individual alloys in bottom ash. In particular, cast aluminium alloys were investigated. Based on the particle size distribution it was computed how well these alloys were recovered in a typical state-of-the-art treatment plant. Assessment of the cast alloy distribution was carried out by wet physical separation processes, as well as chemical methods, X-ray fluorescence analysis and electron microprobe analysis. The results from laboratory analyses showed that cast alloys tend to concentrate in the coarser fractions and therefore are better recovered in bottom ash treatment plants.

Casting core for a cooling arrangement for a gas turbine component

DOEpatents

Lee, Ching-Pang; Heneveld, Benjamin E

2015-01-20

A ceramic casting core, including: a plurality of rows (162, 166, 168) of gaps (164), each gap (164) defining an airfoil shape; interstitial core material (172) that defines and separates adjacent gaps (164) in each row (162, 166, 168); and connecting core material (178) that connects adjacent rows (170, 174, 176) of interstitial core material (172). Ends of interstitial core material (172) in one row (170, 174, 176) align with ends of interstitial core material (172) in an adjacent row (170, 174, 176) to form a plurality of continuous and serpentine shaped structures each including interstitial core material (172) from at least two adjacent rows (170, 174, 176) and connecting core material (178).

Fabrication of U-10 wt.%Zr Metallic Fuel Rodlets for Irradiation Test in BOR-60 Fast Reactor

DOE PAGES

Kim, Ki-Hwan; Kim, Jong-Hwan; Oh, Seok-Jin; ...

2016-01-01

The fabrication technology for metallic fuel has been developed to produce the driver fuel in a PGSFR in Korea since 2007. In order to evaluate the irradiation integrity and validate the in-reactor of the starting metallic fuel with FMS cladding for the loading of the metallic fuel, U-10 wt.%Zr fuel rodlets were fabricated and evaluated for a verification of the starting driver fuel through an irradiation test in the BOR-60 fast reactor. The injection casting method was applied to U-10 wt.%Zr fuel slugs with a diameter of 5.5 mm. Consequently, fuel slugs per melting batch without casting defects were fabricated through the developmentmore » of advanced casting technology and evaluation tests. The optimal GTAW welding conditions were also established through a number of experiments. In addition, a qualification test was carried out to prove the weld quality of the end plug welding of the metallic fuel rodlets. The wire wrapping of metallic fuel rodlets was successfully accomplished for the irradiation test. Thus, PGSFR fuel rodlets have been soundly fabricated for the irradiation test in a BOR-60 fast reactor.« less

A Review of Permanent Magnet Stirring During Metal Solidification

NASA Astrophysics Data System (ADS)

Zeng, Jie; Chen, Weiqing; Yang, Yindong; Mclean, Alexander

2017-12-01

Rather than using conventional electromagnetic stirring (EMS) with three-phase alternating current, permanent magnet stirring (PMS), based on the use of sintered NdFeB material which has excellent magnetic characteristics, can be employed to generate a magnetic field for the stirring of liquid metal during solidification. Recent experience with steel casting indicates that PMS requires less than 20 pct of the total energy compared with EMS. Despite the excellent magnetic density properties and low power consumption, this relatively new technology has received comparatively little attention by the metal casting community. This paper reviews simulation modeling, experimental studies, and industrial trials of PMS conducted during recent years. With the development of magnetic simulation software, the magnetic field and associated flow patterns generated by PMS have been evaluated. Based on the results obtained from laboratory experiments, the effects of PMS on metal solidification structures and typical defects such as surface pinholes and center cavities are summarized. The significance of findings obtained from trials of PMS within the metals processing sector, including the continuous casting of steel, are discussed with the aim of providing an overview of the relevant parameters that are of importance for further development and industrial application of this innovative technology.

Clinical marginal and internal fit of metal ceramic crowns fabricated with a selective laser melting technology.

PubMed

Huang, Zhuoli; Zhang, Lu; Zhu, Jingwei; Zhang, Xiuyin

2015-06-01

Selective laser melting (SLM) technology has been introduced to fabricate dental restorations. However, the fit of these restorations still needs further study. The purpose of this in vivo investigation was to compare the marginal and internal fit of SLM metal ceramic crowns with 2 lost-wax cast metal ceramic crowns and to evaluate the influence of tooth type on the marginal and internal fit of these crowns. A total of 330 metal ceramic crowns were evaluated. The metal copings were fabricated with SLM Co-Cr, cast Au-Pt, and cast Co-Cr alloy (n=110). The marginal and internal gaps of crowns were recorded by using a replica technique. The anterior and premolar replicas were sectioned 2 times, and molar replicas were sectioned 4 times. The marginal and internal gap width of each cross section was examined by stereomicroscope at ×30 magnification. Two-way analysis of variance was performed to identify the statistical difference among the groups. The marginal fit of the SLM Co-Cr group (75.6 ±32.6 μm) was not different from the cast Au-Pt group (76.8 ±32.1 μm) (P>.05) but was better than the cast Co-Cr group (91.0 ±36.3 μm) (P<.01). No significant difference was found among the SLM Co-Cr group (127.3 ±45.8 μm), cast Au-Pt group (129.9 ±61.1 μm). and cast Co-Cr group (142.5 ±63.7 μm) (P>.05). The mean occlusal gap width of the SLM Co-Cr group (309.8 ±106.6 μm) was significantly higher than that of the cast Au-Pt group (254.6 ±109.6 μm) and the cast Co-Cr group (249.6 ±110.4 μm) (P<.005). No significant difference was found in the marginal fit among the anterior group (84.4 ±35.1 μm), the premolar group (80.6 ±26.3 μm), and the molar group (82.7 ±38.0 μm) (P>.05). Also, no significant difference was found in the axial fit among the anterior group (138.3 ±52.5 μm), the premolar group (132.9 ±50.4 μm), and the molar group (134.4 ±52.5 μm) (P>.05). The anterior group (267.6 ±110.2 μm) did not differ from the premolar group (270.2 ±112.8 μm) and the molar group (268.6 ±110.5 μm) in occlusal fit (P>.05). The marginal fit of SLM Co-Cr metal ceramic crowns was similar to that of the cast Au-Pt metal ceramic crowns and was better than that of the cast Co-Cr metal ceramic crowns. The SLM Co-Cr metal ceramic crowns were not significantly different from the 2 cast metal ceramic crowns in axial fit but were less accurate in occlusal fit. Tooth type did not influence the marginal and internal fit of the metal ceramic crowns. Copyright © 2015 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

FY97 Materials & Processes Technology Area Plan

DTIC Science & Technology

1996-09-01

Offices ess has Center Technology Coun- ings, the first use ever of gamma (SPOs). In addition, we provide cil (CTCs) technology needs Titanium Aluminide ...300,000 in form- structive evaluation (NDE). Four Agreements (CRDAs) with 7 ing of Titanium Aluminide with Data EAchange Agreements more in negotiation and...Systems Aircraft Range with r 50% Decrease in Fuel Propulsion Syste s =Consumption Titanium Aluminides Cast Titanium 25000F Ceramic Matrix Transition

Design of experiments to optimize an in vitro cast to predict human nasal drug deposition.

PubMed

Shah, Samir A; Dickens, Colin J; Ward, David J; Banaszek, Anna A; George, Chris; Horodnik, Walter

2014-02-01

Previous studies showed nasal spray in vitro tests cannot predict in vivo deposition, pharmacokinetics, or pharmacodynamics. This challenge makes it difficult to assess deposition achieved with new technologies delivering to the therapeutically beneficial posterior nasal cavity. In this study, we determined best parameters for using a regionally divided nasal cast to predict deposition. Our study used a model suspension and a design of experiments to produce repeatable deposition results that mimic nasal deposition patterns of nasal suspensions from the literature. The seven-section (the nozzle locator, nasal vestibule, front turbinate, rear turbinate, olfactory region, nasopharynx, and throat filter) nylon nasal cast was based on computed tomography images of healthy humans. It was coated with a glycerol/Brij-35 solution to mimic mucus. After assembling and orienting, airflow was applied and nasal spray containing a model suspension was sprayed. After disassembling the cast, drug depositing in each section was assayed by HPLC. The success criteria for optimal settings were based on nine in vivo studies in the literature. The design of experiments included exploratory and half factorial screening experiments to identify variables affecting deposition (angles, airflow, and airflow time), optimization experiments, and then repeatability and reproducibility experiments. We found tilt angle and airflow time after actuation affected deposition the most. The optimized settings were flow rate of 16 L/min, postactuation flow time of 12 sec, a tilt angle of 23°, nozzle angles of 0°, and actuation speed of 5 cm/sec. Neither cast nor operator caused significant variation of results. We determined cast parameters to produce results resembling suspension nasal sprays in the literature. The results were repeatable and unaffected by operator or cast. These nasal spray parameters could be used to assess deposition from new devices or formulations. For human deposition studies using radiolabeled formulations, this cast could show that radiolabel deposition represents drug deposition. Our methods could also be used to optimize settings for other casts.

Manufacturing technology methodology for propulsion system parts

NASA Astrophysics Data System (ADS)

McRae, M. M.

1992-07-01

A development history and a current status evaluation are presented for lost-wax casting of such gas turbine engine components as turbine vanes and blades. The most advanced such systems employ computer-integrated manufacturing methods for high process repeatability, reprogramming versatility, and feedback monitoring. Stereolithography-based plastic model 3D prototyping has also been incorporated for the wax part of the investment casting; it may ultimately be possible to produce the 3D prototype in wax directly, or even to create a ceramic mold directly. Nonintrusive inspections are conducted by X-radiography and neutron radiography.

Physics Teacher Candidates' Opinions on Fiber Optics and New Technologies in This Field

ERIC Educational Resources Information Center

Çildir, Sema

2016-01-01

Factors such as innovations brought in by the developing technology, also rapidly changing social structures casted various roles to both the student and the teacher. Therefore, it is necessary to associate such knowledge acquired in courses with implications of the knowledge in our real lives and to constantly enrich course contents, namely to…

"A Dance with the Butterflies:" A Metamorphosis of Teaching and Learning through Technology

ERIC Educational Resources Information Center

McPherson, Sarah

2009-01-01

This paper describes a web-based collaborative project called "A Dance with the Butterflies" that applied the brain-based research of the Center for Applied Special Technologies (CAST) and principles of Universal Design for Learning (UDL) to Pre-K-4 science curriculum. Learning experiences were designed for students to invoke the Recognition,…

Manufacturing Technology Support (MATES II) Task Order 0005: Manufacturing Integration and Technology Evaluation to Enable Technology Transition. Subtask Phase 0 Study Task: Manufacturing Technology (ManTech) and Systems Engineering For Quick Reaction Systems

DTIC Science & Technology

2014-10-01

Porosity from gas entrapment & shrinkage 4 Continuous Fiber Ti Metal Matrix Composites (Aircraft panels and rotor components) [14...process models for casting, forging, and welding , and software capability to integrate various independent models with design, thermal, and structural...Applications, Ph.D. Thesis, Queen’s College, University of Oxford, (2007). 14. S.A. Singerman and J.J. Jackson, Titanium Metal Matrix Composites for

Influence of Solutocapillary Convection on Macrovoid Defect Formation in Polymeric Membranes

NASA Technical Reports Server (NTRS)

Greenberg, Alan R.; Krantz, William B.; Todd, Paul

2003-01-01

The focus of this research project involved the dry-cast process for polymeric membrane formation, whereby evaporation of solvent from an initially homogeneous polymer/solvent/ nonsolvent solution results in phase separation and the formation of polymer-rich and polymer-lean phases. Under certain conditions the polymer-lean phase gives rise to very large and usually undesirable, tear-drop-shaped pores (size approx. 10 - 50 microns) termed macrovoids (MVs). Although in many cases the presence of MV pores has deleterious effects on membrane performance, there are a number of innovative applications where the presence of such pores is highly desirable. Although researchers have proposed a variety of mechanisms for MV formation over the past three decades, two main hypotheses are currently favored: one asserts that MV growth can be attributed solely to diffusion (the diffusive growth hypothesis), whereas the other states that solutocapillary convection (the SC hypothesis) at the MV interface contributes to growth. The overall goal of this research was to obtain a more comprehensive understanding of the fundamental mechanism of MV growth. This research incorporates a coupled modeling and experimental approach to test a solutocapillary convection hypothesis for the growth of macrovoid pores in polymeric membranes. Specifically, we utilized a modification of the first principles model developed by two of the PIs (ARG and WBK) for dry-cast CA membranes. For the experimental component, two separate and mutually complementary approaches were used to study MV growth. In the first, membranes cast in a zero-g environment aboard the NASA KC-135 aircraft were compared with those cast on the ground to assess the effect of the buoyancy force on membrane morphology and MV size and shape. In the second approach, videomicroscopy flow visualization (VMFV) was utilized to observe MV formation and growth in real time and to assess the effect of surface tension on the MV growth dynamics. As a result of these fundamental studies, our research group advanced a new hypothesis for MV pore development in polymeric membranes.

PREFACE: International Conference on Advancement in Science and Technology 2012 (iCAST): Contemporary Mathematics, Mathematical Physics and their Applications

NASA Astrophysics Data System (ADS)

Ganikhodjaev, Nasir; Mukhamedov, Farrukh; Hee, Pah Chin

2013-04-01

The 4th International Conference on the Advancement of Science and Technology 2012 (iCAST 2012), with theme 'Contemporary Mathematics, Mathematical Physics and their Applications', took place in Kuantan, Malaysia, from Wednesday 7 to Friday 9 November 2012. The conference was attended by more than 100 participants, and hosted about 160 oral and poster papers by more than 140 pre-registered authors. The key topics of the 4th iCAST 2012 include Pure Mathematics, Applied Mathematics, Theoretical/Mathematical Physics, Dynamical Systems, Statistics and Financial Mathematics. The scientific program was rather full since after the Keynote and Invited Talks in the morning, four parallel sessions ran every day. However, according to all attendees, the program was excellent with a high level of talks and the scientific environment was fruitful; thus all attendees had a creative time. The conference aimed to promote the knowledge and development of high-quality research in mathematical fields concerned with the application of other scientific fields as well as modern technological trends in physics, chemistry, biology, medicine, economics, sociology and environmental sciences. We would like to thank the Keynote and the Invited Speakers for their significant contributions to 4th iCAST 2012. We would also like to thank the members of the International Scientific Committee and the members of the Organizing Committee. We cannot end without expressing our many thanks to International Islamic University Malaysia and our sponsors for their financial support . This volume presents selected papers which have been peer-reviewed. The editors hope that it may be useful and fruitful for scholars, researchers, and advanced technical members of the industrial laboratory facilities for developing new tools and products. Guest Editors Nasir Ganikhodjaev, Farrukh Mukhamedov and Pah Chin Hee The PDF contains the committee lists, board list and biographies of the plenary speakers.

Advances in Gammalloy Materials-Processes-Application Technology: Successes, Dilemmas, and Future

NASA Astrophysics Data System (ADS)

Kim, Young-Won; Kim, Sang-Lan

2018-04-01

For the last several years, gamma titanium aluminide ( γ-TiAl)-based alloys, called "gammalloys," in specific alloy-microstructure forms began to be implemented in civil aero-engines as cast or wrought low-pressure turbine (LPT) blades and in select ground vehicle engines as cast turbocharger rotors and wrought exhaust valves. Their operation temperatures are approximately up to 750°C for LPT blades and around 1000°C for turbocharger rotors. This article critically assesses current engineering gammalloys and their limitations and introduces eight strengthening pathways that can be adopted immediately for the development of advanced, higher temperature gammalloys. Intelligent integration of the pathways into the emerging application-specific research and development processes is emphasized as the key to the advancement of the gammalloy technology to the next higher engineering performance levels.

Female Literacy in India: The Urban Dimension.

ERIC Educational Resources Information Center

Raju, Saraswati

This paper presents a sociogeographic analysis of female literacy in India and compares literacy rates of females and males in scheduled (reported separately on the census) and nonscheduled (reported as one group on the census) castes. In Indian cities, male literacy is higher than female literacy, and literacy rates are higher for nonscheduled…

Cast Iron Inoculation Enhanced by Supplementary Oxy-sulfides Forming Elements

NASA Astrophysics Data System (ADS)

Riposan, Iulian; Stan, Stelian; Uta, Valentin; Stefan, Ion

2017-09-01

Inoculation is one of the most important metallurgical treatments applied to the molten cast iron immediately prior to casting, to promote solidification without excessive eutectic undercooling, which favors carbides formation usually with undesirable graphite morphologies. The paper focused on the separate addition of an inoculant enhancer alloy [S, O, oxy-sulfides forming elements] with a conventional Ca-FeSi alloy, in the production of gray and ductile cast irons. Carbides formation tendency decreased with improved graphite characteristics as an effect of the [Ca-FeSi + Enhancer] inoculation combination, when compared to other Ca/Ca, Ba/Ca, RE-FeSi alloy treatments. Adding an inoculant enhancer greatly enhances inoculation, lowers inoculant consumption up to 50% or more and avoids the need to use more costly inoculants, such as a rare earth bearing alloy. The Inoculation Specific Factor [ISF] was developed as a means to more realistically measure inoculant treatment efficiency. It compares the ratio between the improved characteristic level and total inoculant consumption for this effect. Addition of any of the commercial inoculants plus the inoculant enhancer offered outstanding inoculation power [increased ISF] even at higher solidification cooling rates, even though the total enhancer addition was at a small fraction of the amount of commercial inoculant used.

Compacted graphite iron: Cast iron makes a comeback

NASA Astrophysics Data System (ADS)

Dawson, S.

1994-08-01

Although compacted graphite iron has been known for more than four decades, the absence of a reliable mass-production technique has resulted in relatively little effort to exploit its operational benefits. However, a proven on-line process control technology developed by SinterCast allows for series production of complex components in high-quality CGI. The improved mechanical properties of compacted graphite iron relative to conventional gray iron allow for substantial weight reduction in gasoline and diesel engines or substantial increases in horsepower, or an optimal combination of both. Concurrent with these primary benefits, CGI also provides significant emissions and fuel efficiency benefits allowing automakers to meet legislated performance standards. The operational and environmental benefits of compacted graphite iron together with its low cost and recyclability reinforce cast iron as a prime engineering material for the future.

Thermophysical property sensitivity effects in steel solidification

NASA Technical Reports Server (NTRS)

Overfelt, Tony

1993-01-01

The simulation of advanced solidification processes via digital computer techniques has gained widespread acceptance during the last decade or so. Models today can predict transient temperature fields, fluid flow fields, important microstructural parameters, and potential defects in castings. However, the lack of accurate thermophysical property data on important industrial alloys threatens to limit the ability of manufacturers to fully capitalize on the technology's benefits. A study of the sensitivity of one such numerical model of a steel plate casting to imposed variations in the data utilized for the thermal conductivity, specific heat, density, and heat of fusion is described. The sensitivity of the data's variability is characterized by its effects on the net solidification time of various points along the centerline of the plate casting. Recommendations for property measurements are given and the implications of data uncertainty for modelers are discussed.

Transtibial Prosthetic Socket Shape in a Developing Country: A study to compare initial outcomes in Pressure Cast hydrostatic and Patella Tendon Bearing designs.

PubMed

Laing, Sheridan; Lythgo, Noel; Lavranos, Jim; Lee, Peter Vee Sin

2017-10-01

This study compared the physical function and comfort level of patients with unilateral transtibial amputation after being fitted with a hand-cast Patella Tendon Bearing (PTB) socket and a pressure-cast (PCAST) hydrocast socket. The latter technique aims to reduce the skill dependency currently required for socket manufacture and fit. The study was conducted at the Vietnamese Training Centre for Orthopaedic Technologies and involved seventeen Vietnamese participants with unilateral transtibial amputation, all of whom were long term users of prosthetics. All participants were fitted with two sockets manufactured using both hand-cast and PCAST techniques with International Committee of the Red Cross components. Walking tests (timed up and go test and six-minute-walk-test), spatio-temporal gait analyses and subjective comfort assessments were completed after a short acclimatisation period with each socket. The participant-preferred socket was also noted. No significant differences were found for the measures of mobility, functional capacity, spatio-temporal gait parameters, gait symmetry, perceived comfort or participant socket preference. The results show the initial patient outcomes are similar when participants are fitted with a hand-cast PTB socket and a PCAST hydrocast sockets. Future work should confirm these findings in a longer trial. Copyright © 2017 Elsevier B.V. All rights reserved.

Knowledge Acquisition and Job Training for Advanced Technical Skills Using Immersive Virtual Environment

NASA Astrophysics Data System (ADS)

Watanuki, Keiichi; Kojima, Kazuyuki

The environment in which Japanese industry has achieved great respect is changing tremendously due to the globalization of world economies, while Asian countries are undergoing economic and technical development as well as benefiting from the advances in information technology. For example, in the design of custom-made casting products, a designer who lacks knowledge of casting may not be able to produce a good design. In order to obtain a good design and manufacturing result, it is necessary to equip the designer and manufacturer with a support system related to casting design, or a so-called knowledge transfer and creation system. This paper proposes a new virtual reality based knowledge acquisition and job training system for casting design, which is composed of the explicit and tacit knowledge transfer systems using synchronized multimedia and the knowledge internalization system using portable virtual environment. In our proposed system, the education content is displayed in the immersive virtual environment, whereby a trainee may experience work in the virtual site operation. Provided that the trainee has gained explicit and tacit knowledge of casting through the multimedia-based knowledge transfer system, the immersive virtual environment catalyzes the internalization of knowledge and also enables the trainee to gain tacit knowledge before undergoing on-the-job training at a real-time operation site.

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

Chandler, H.E.

The predictions of a special Metal Progress round table spanning the next 20 years in materials and process engineering in North America are given. Subjects discussed include the energy crunch, impact of computer technology, new roles for testing and inspection, happenings in non ferrous technology, materials substitution, composites and non metallics, people aspects of technology, materials availability, powder metallurgy changes, casting, welding and joining, heat treatments, carbon and alloy steels, new and improved materials, forming, coatings and conservation, and metal production. (FS)

Process and apparatus for obtaining silicon from fluosilicic acid

DOEpatents

Sanjurjo, Angel

1988-06-28

Process and apparatus for producing low cost, high purity solar grade silicon ingots in single crystal or quasi single crystal ingot form in a substantially continuous operation in a two stage reactor starting with sodium fluosilicate and a metal more electropositive than silicon (preferably sodium) in separate compartments having easy vapor transport therebetween and thermally decomposing the sodium fluosilicate to cause formation of substantially pure silicon and a metal fluoride which may be continuously separated in the melt and silicon may be directly and continuously cast from the melt.

The many selves of social insects.

PubMed

Queller, David C; Strassmann, Joan E

2002-04-12

Social insects show multiple levels of self identity. Most individuals are sterile workers who selflessly labor for their colony, which is often viewed as a superorganism. The superorganism protects itself with colony recognition systems based on learned odors, typically cuticular hydrocarbons. Transfer of these odors within the colony obscures separate clan identities. Residual individual interests do appear to cause conflicts within colonies over sex ratio, male production, caste, and reproductive dominance. However, genomic imprinting theory predicts that the individual's maternal and paternal genes will evolve separate infraorganismal identities, perhaps leaving virtually no coherent individual identity.

High Cycle Fatigue Crack Initiation Study of Case Blade Alloy Rene 125

NASA Technical Reports Server (NTRS)

Kantzos, P.; Gayda, J.; Miner, R. V.; Telesman, J.; Dickerson, P.

2000-01-01

This study was conducted in order to investigate and document the high cycle fatigue crack initiation characteristics of blade alloy Rene 125 as cast by three commercially available processes. This alloy is typically used in turbine blade applications. It is currently being considered as a candidate alloy for high T3 compressor airfoil applications. This effort is part of NASA's Advanced Subsonic Technology (AST) program which aims to develop improved capabilities for the next generation subsonic gas turbine engine for commercial carriers. Wrought alloys, which are customarily used for airfoils in the compressor, cannot meet the property goals at the higher compressor exit temperatures that would be required for advanced ultra-high bypass engines. As a result cast alloys are currently being considered for such applications. Traditional blade materials such as Rene 125 have the high temperature capabilities required for such applications. However, the implementation of cast alloys in compressor airfoil applications where airfoils are typically much thinner does raise some issues of concern such as thin wall castability, casting cleaningness, and susceptibility to high-cycle fatigue (HCF) loading.

Energy Saving Melting and Revert Reduction Technology (E-SMARRT): Development of Surface Engineered Coating Systems for Aluminum Pressure Die Casting Dies: Towards a 'Smart' Die Coating

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

Dr. John J. Moore; Dr. Jianliang Lin,

2012-07-31

The main objective of this research program was to design and develop an optimal coating system that extends die life by minimizing premature die failure. In high-pressure aluminum die-casting, the die, core pins and inserts must withstand severe processing conditions. Many of the dies and tools in the industry are being coated to improve wear-resistance and decrease down-time for maintenance. However, thermal fatigue in metal itself can still be a major problem, especially since it often leads to catastrophic failure (i.e. die breakage) as opposed to a wear-based failure (parts begin to go out of tolerance). Tooling costs remain themore » largest portion of production costs for many of these parts, so the ability prevent catastrophic failures would be transformative for the manufacturing industry.The technology offers energy savings through reduced energy use in the die casting process from several factors, including increased life of the tools and dies, reuse of the dies and die components, reduction/elimination of lubricants, and reduced machine down time, and reduction of Al solder sticking on the die. The use of the optimized die coating system will also reduce environmental wastes and scrap parts. Current (2012) annual energy saving estimates, based on initial dissemination to the casting industry in 2010 and market penetration of 80% by 2020, is 3.1 trillion BTU's/year. The average annual estimate of CO2 reduction per year through 2020 is 0.63 Million Metric Tons of Carbon Equivalent (MM TCE).« less

The Release of Elements from Dental Casting Alloy into Cell-Culture Medium and Artificial Saliva

PubMed Central

Can, Gülşen; Akpınar, Gül; Aydın, Ahmet

2007-01-01

Objectives The biocompatibility of dental casting alloys is a critical issue because these alloys are in long-term intimate contact with oral tissues. Since the biocompatibility of alloys is not completely known; the release of elements from the alloys has been studied. The aim of this study was to compare the elemental release from dental casting alloy during exposure to artificial saliva and cell-culture medium. Materials and Methods Twenty specimens made from Ni-Cr alloy were provided in the form of 5 mm diameter discs, 2 mm in thickness with a 7 mm stem attached to one face to facilitate handling. Ten of twenty samples were polished separately using a conventional technique. The remaining ten samples were left sandblasted with 50 μm Al203. Ten samples (5 polished, 5 sandblasted) were separately placed into cell-culture wells with Dulbecco’s Modified Eagle’s Medium. The other ten samples were placed separately into cell-culture wells with artificial saliva. The samples were subjected in contact with these medium for 30 days. These medium were collected every 7 days. The cell-culture medium and artificial saliva without alloy samples were subjected to elemental analyses as a control. At the end of the exposure time, Atomic Absorption Spectrometry (AAS) was used to determine the release of elements from the alloys into all collected medium. Statistical analyses were assessed with two-way ANOVA. Results In general, the elemental release occurred with in all medium. The elemental releases of sandblasted alloys were higher than polished alloys. Artificial saliva was found to cause more release from the samples. In both media, Ni released from polished and sandblasted alloys were higher than Cr and Mo. Conlusions The results suggest that the release of elements from the alloys might have correlated with the environments and the surface of dental alloy. PMID:19212482

The release of elements from dental casting alloy into cell-culture medium and artificial saliva.

PubMed

Can, Gülşen; Akpınar, Gül; Aydın, Ahmet

2007-04-01

The biocompatibility of dental casting alloys is a critical issue because these alloys are in long-term intimate contact with oral tissues. Since the biocompatibility of alloys is not completely known; the release of elements from the alloys has been studied. The aim of this study was to compare the elemental release from dental casting alloy during exposure to artificial saliva and cell-culture medium. Twenty specimens made from Ni-Cr alloy were provided in the form of 5 mm diameter discs, 2 mm in thickness with a 7 mm stem attached to one face to facilitate handling. Ten of twenty samples were polished separately using a conventional technique. The remaining ten samples were left sandblasted with 50 mum Al(2)0(3). Ten samples (5 polished, 5 sandblasted) were separately placed into cell-culture wells with Dulbecco's Modified Eagle's Medium. The other ten samples were placed separately into cell-culture wells with artificial saliva. The samples were subjected in contact with these medium for 30 days. These medium were collected every 7 days. The cell-culture medium and artificial saliva without alloy samples were subjected to elemental analyses as a control. At the end of the exposure time, Atomic Absorption Spectrometry (AAS) was used to determine the release of elements from the alloys into all collected medium. Statistical analyses were assessed with two-way ANOVA. In general, the elemental release occurred with in all medium. The elemental releases of sandblasted alloys were higher than polished alloys. Artificial saliva was found to cause more release from the samples. In both media, Ni released from polished and sandblasted alloys were higher than Cr and Mo. The results suggest that the release of elements from the alloys might have correlated with the environments and the surface of dental alloy.

Utilization of the International Space Station for Crew Autonomous Scheduling Test (CAST)

NASA Technical Reports Server (NTRS)

Healy, Matthew; Marquez, Jesica; Hillenius, Steven; Korth, David; Bakalyar, Laure Rush; Woodbury, Neil; Larsen, Crystal M.; Bates, Shelby; Kockler, Mikayla; Rhodes, Brooke;

Electrospun Polymer Blend Nanofibers for Tunable Drug Delivery: The Role of Transformative Phase Separation on Controlling the Release Rate.

PubMed

Tipduangta, Pratchaya; Belton, Peter; Fábián, László; Wang, Li Ying; Tang, Huiru; Eddleston, Mark; Qi, Sheng

2016-01-04

Electrospun fibrous materials have a wide range of biomedical applications, many of them involving the use of polymers as matrices for incorporation of therapeutic agents. The use of polymer blends improves the tuneability of the physicochemical and mechanical properties of the drug loaded fibers. This also benefits the development of controlled drug release formulations, for which the release rate can be modified by altering the ratio of the polymers in the blend. However, to realize these benefits, a clear understanding of the phase behavior of the processed polymer blend is essential. This study reports an in depth investigation of the impact of the electrospinning process on the phase separation of a model partially miscible polymer blend, PVP K90 and HPMCAS, in comparison to other conventional solvent evaporation based processes including film casting and spin coating. The nanoscale stretching and ultrafast solvent removal of electrospinning lead to an enhanced apparent miscibility between the polymers, with the same blends showing micronscale phase separation when processed using film casting and spin coating. Nanoscale phase separation in electrospun blend fibers was confirmed in the dry state. Rapid, layered, macroscale phase separation of the two polymers occurred during the wetting of the fibers. This led to a biphasic drug release profile from the fibers, with a burst release from PVP-rich phases and a slower, more continuous release from HPMCAS-rich phases. It was noted that the model drug, paracetamol, had more favorable partitioning into the PVP-rich phase, which is likely to be a result of greater hydrogen bonding between PVP and paracetamol. This led to higher drug contents in the PVP-rich phases than the HPMCAS-rich phases. By alternating the proportions of the PVP and HPMCAS, the drug release rate can be modulated.

ScienceCast 202: Escape of the Destructive Electrons

NASA Image and Video Library

2015-12-14

Earth is surrounded by electrons that can be disruptive to our technology. NASA is using high-altitude balloons and spacecraft to monitor and understand these particles in the radiation belts surrounding our planet.

Effect of Thermal and Chemical Treatment on the Microstructural, Mechanical and Machining Performance of W319 Al-Si-Cu Cast Alloy Engine Blocks and Directionally Solidified Machinability Test Blocks

NASA Astrophysics Data System (ADS)

Szablewski, Daniel

The research presented in this work is focused on making a link between casting microstructural, mechanical and machining properties for 319 Al-Si sand cast components. In order to achieve this, a unique Machinability Test Block (MTB) is designed to simulate the Nemak V6 Al-Si engine block solidification behavior. This MTB is then utilized to cast structures with in-situ nano-alumina particle master alloy additions that are Mg based, as well as independent in-situ Mg additions, and Sr additions to the MTB. The Universal Metallurgical Simulator and Analyzer (UMSA) Technology Platform is utilized for characterization of each cast structure at different Secondary Dendrite Arm Spacing (SDAS) levels. The rapid quench method and Jominy testing is used to assess the capability of the nano-alumina master alloy to modify the microstructure at different SDAS levels. Mechanical property assessment of the MTB is done at different SDAS levels on cast structures with master alloy additions described above. Weibull and Quality Index statistical analysis tools are then utilized to assess the mechanical properties. The MTB is also used to study single pass high speed face milling and bi-metallic cutting operations where the Al-Si hypoeutectic structure is combined with hypereutectoid Al-Si liners and cast iron cylinder liners. These studies are utilized to aid the implementation of Al-Si liners into the Nemak V6 engine block and bi-metallic cutting of the head decks. Machining behavior is also quantified for the investigated microstructures, and the Silicon Modification Level (SiML) is utilized for microstructural analysis as it relates to the machining behavior.

Genetic variation, climate models and the ecological genetics of Larix occidentalis

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

Rehfeldt, G.E.

1995-12-31

Provenance tests of 138 populations of Larix occidentalis revealed genetic differentiation for eight variables describing growth, phenology, tolerance to spring frosts, effects of Meria laricis needle cast, and survival. Geographic variables accounted for as much as 34% of the variance among Rocky Mountain populations. Patterns of genetic variation were dominated by the effects of latitude and elevation, with populations from the north and from high elevations having the lowest growth potential, the least tolerance to the needle cast, and the lowest survival. However, the slope of the geographic clines was relatively flat. Populations in the same geographic area, for instance,more » need to be separated by about 500 m in elevation before genetic differentiation can be expected.« less

Testing a Variety of Encryption Technologies

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

Henson, T J

2001-04-09

Review and test speeds of various encryption technologies using Entrust Software. Multiple encryption algorithms are included in the product. Algorithms tested were IDEA, CAST, DES, and RC2. Test consisted of taking a 7.7 MB Word document file which included complex graphics and timing encryption, decryption and signing. Encryption is discussed in the GIAC Kickstart section: Information Security: The Big Picture--Part VI.

Energy Saving Melting and Revert Reduction Technology: Innovative Semi-Solid Metal (SSM) Processing

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

Diran Apelian

2012-08-15

Semi-solid metal (SSM) processing has emerged as an attractive method for near-net-shape manufacturing due to the distinct advantages it holds over conventional near-net-shape forming technologies. These advantages include lower cycle time, increased die life, reduced porosity, reduced solidification shrinkage, improved mechanical properties, etc. SSM processing techniques can not only produce the complex dimensional details (e.g. thin-walled sections) associated with conventional high-pressure die castings, but also can produce high integrity castings currently attainable only with squeeze and low-pressure permanent mold casting processes. There are two primary semi-solid processing routes, (a) thixocasting and (b) rheocasting. In the thixocasting route, one starts frommore » a non-dendritic solid precursor material that is specially prepared by a primary aluminum manufacturer, using continuous casting methods. Upon reheating this material into the mushy (a.k.a. "two-phase") zone, a thixotropic slurry is formed, which becomes the feed for the casting operation. In the rheocasting route (a.k.a. "slurry-on-demand" or "SoD"), one starts from the liquid state, and the thixotropic slurry is formed directly from the melt via careful thermal management of the system; the slurry is subsequently fed into the die cavity. Of these two routes, rheocasting is favored in that there is no premium added to the billet cost, and the scrap recycling issues are alleviated. The CRP (Trade Marked) is a process where the molten metal flows through a reactor prior to casting. The role of the reactor is to ensure that copious nucleation takes place and that the nuclei are well distributed throughout the system prior to entering the casting cavity. The CRP (Trade Marked) has been successfully applied in hyper-eutectic Al-Si alloys (i.e., 390 alloy) where two liquids of equal or different compositions and temperatures are mixed in the reactor and creating a SSM slurry. The process has been mostly used for hypo-eutectic Al-Si alloys (i.e., 356, 357, etc.) where a single melt passes through the reactor. In addition, the CRP (Trade Marked) was designed to be flexible for thixocasting or rheocasting applications as well as batch or continuous casting. Variable heat extraction rates can be obtained by controlling either the superheat of the melt, the temperature of the channel system, or the temperature of the reactor. This program had four main objectives all of which were focused on a mechanistic understanding of the process in order to be able to scale it up, to develop it into a robust process,and for SSM processing to be commercially used.« less

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

Asmussen, Robert M.; Lawter, Amanda R.; Stephenson, John R.

Washington River Protection Solutions (WRPS) is collecting relevant available data on waste forms for use as a supplemental immobilization technology, to provide the additional capacity needed to treat low-activity waste (LAW) in Hanford Site tanks and complete the tank waste cleanup mission in a timely and cost-effective manner. One candidate supplemental waste form, fabricated using a low-temperature process, is a cementitious grout called Cast Stone. Cast Stone has been under investigation for this application at Pacific Northwest National Laboratory (PNNL) since initial screening tests in FY13. This report is the culmination of work to lower the diffusivities of Tc andmore » I from Cast Stone using getters. Getters are compounds added to a system designed to selectively sequester a species of interest to provide increased stability to the species. The work contained within this report is related to waste form development and testing, and does not directly support the 2017 integrated disposal facility (IDF) performance assessment. However, this work contains valuable information which may be used in performance assessment maintenance past FY17, and in future waste form development. This report on performance characterization of Tc and I getters in Cast Stone fabricated with simulated LAW covers several areas of interest and major findings to WRPS: investigating performance of potassium metal sulfide (KMS-2-SS) and tin (II) apatite (Sn-A) as Tc getters when incorporated into Cast Stone; investigating performance of silver exchanged zeolite (Ag-Z) and argentite (Arg) as I getters when incorporated into Cast Stone; utilizing sequential addition of Tc and I getters to overcome any deleterious interactions between the getters in solution; determining, for the first time, Tc distribution within the cured Cast Stone and its evolution during leaching; and performing solid state characterization of getters and Cast Stone samples to support leach test findings and develop a mechanistic understanding of the processes that control Tc and I release into solution.« less

Spray-on polyvinyl alcohol separators and impact on power production in air-cathode microbial fuel cells with different solution conductivities.

PubMed

Hoskins, Daniel L; Zhang, Xiaoyuan; Hickner, Michael A; Logan, Bruce E

2014-11-01

Separators are used to protect cathodes from biofouling and to avoid electrode short-circuiting, but they can adversely affect microbial fuel cell (MFC) performance. A spray method was used to apply a polyvinyl alcohol (PVA) separator to the cathode. Power densities were unaffected by the PVA separator (339±29mW/m(2)), compared to a control lacking a separator in a low conductivity solution (1mS/cm) similar to wastewater. Power was reduced with separators in solutions typical of laboratory tests (7-13mS/cm), compared to separatorless controls. The PVA separator produced more power in a separator assembly (SEA) configuration (444±8mW/m(2)) in the 1mS/cm solution, but power was reduced if a PVA or wipe separator was used in higher conductivity solutions with either Pt or activated carbon catalysts. Spray and cast PVA separators performed similarly, but the spray method is preferred as it was easier to apply and use. Copyright © 2014 Elsevier Ltd. All rights reserved.

MedCast: a discussion support system for cooperative work

NASA Astrophysics Data System (ADS)

Moreno, Ramon A.; Lima, Vinícius; Lopes, Isidro; Gutierrez, Marco A.

2012-02-01

The availability of low cost Internet connections and specialized hardware, like webcams and headsets, makes possible the development of solutions for remote collaborative work. These solutions can provide advantages compared to presential meetings, such as: availability of experts on remote locations; lower price compared to presential meetings; creation of online didactic material (e.g. video-classes); richer forms of interaction between participants. These technologies are particularly interesting for continent-sized countries where typically there is a short number of skilled people in remote areas. However, the application of these technologies in medical field represents a special challenge due to the more complex requirements of this area, such as: Provide confidentiality (patient de-identification) and integrity of patient data; Guarantee availability of the system; Guarantee authenticity of data and users; Provide simple and effective user interface; Be compliant with medical standards such as DICOM and HL7. In order to satisfy those requirements a prototype called MedCast is under development whose architecture allows the integration of the Hospital Information System (HIS) with a collaborative tool in compliance with the HIPAA rules. Some of the MedCast features are: videoconferencing, chat, recording of the sessions, sharing of documents and reports and still and dynamic images presentation. Its current version allows the remote discussion of clinical cases and the remote ECG evaluation.

Magnesium Front End Research and Development: A Canada-China-USA Collaboration

NASA Astrophysics Data System (ADS)

Luo, Alan A.; Nyberg, Eric A.; Sadayappan, Kumar; Shi, Wenfang

The Magnesium Front End Research & Development (MFERD) project is an effort jointly sponsored by the United States Department of Energy, the United States Automotive Materials Partnership (USAMP), the Chinese Ministry of Science and Technology and Natural Resources Canada (NRCan) to demonstrate the technical and economic feasibility of a magnesium-intensive automotive front end body structure which offers improved fuel economy and performance benefits in a multi-material automotive structure. The project examines novel magnesium automotive body applications and processes, beyond conventional die castings, including wrought components (sheet or extrusions) and high-integrity body castings. This paper outlines the scope of work and organization for the collaborative (tri-country) task teams. The project has the goals of developing key enabling technologies and knowledge base for increased magnesium automotive body applications. The MFERD project began in early 2007 by initiating R&D in the following areas: crashworthiness, NVH, fatigue and durability, corrosion and surface finishing, extrusion and forming, sheet and forming, high-integrity body casting, as well as joining and assembly. Additionally, the MFERD project is also linked to the Integrated Computational Materials Engineering (ICME) project that will investigate the processing/structure/properties relations for various magnesium alloys and manufacturing processes utilizing advanced computer-aided engineering and modeling tools.

Ventriculostomy Simulation Using Patient-Specific Ventricular Anatomy, 3D Printing, and Hydrogel Casting.

PubMed

Ryan, Justin R; Chen, Tsinsue; Nakaji, Peter; Frakes, David H; Gonzalez, L Fernando

2015-11-01

Educational simulators provide a means for students and experts to learn and refine surgical skills. Educators can leverage the strengths of medical simulators to effectively teach complex and high-risk surgical procedures, such as placement of an external ventricular drain. Our objective was to develop a cost-effective, patient-derived medical simulacrum for cerebral lateral ventriculostomy. A cost-effective, patient-derived medical simulacrum was developed for placement of an external lateral ventriculostomy. Elastomeric and gel casting techniques were used to achieve realistic brain geometry and material properties. 3D printing technology was leveraged to develop accurate cranial properties and dimensions. An economical, gravity-driven pump was developed to provide normal and abnormal ventricular pressures. A small pilot study was performed to gauge simulation efficacy using a technology acceptance model. An accurate geometric representation of the brain was developed with independent lateral cerebral ventricular chambers. A gravity-driven pump pressurized the ventricular cavities to physiologic values. A qualitative study illustrated that the simulation has potential as an educational tool to train medical professionals in the ventriculostomy procedure. The ventricular simulacrum can improve learning in a medical education environment. Rapid prototyping and multi-material casting techniques can produce patient-derived models for cost-effective and realistic surgical training scenarios. Copyright © 2015 Elsevier Inc. All rights reserved.

Campanella, Tommaso [Giovan Domenico] (1568-1639)

NASA Astrophysics Data System (ADS)

Murdin, P.

2000-11-01

Born in Stilo, Calabria, Italy. A Dominican, he wrote on Telesian philosophy and astrology, and cast flattering horoscopes for the influential. A great admirer of Galileo, in 1622 he published his Apologia pro Galileo (`Defense of Galileo'), defending the Copernican system and the separate paths of scripture and nature to knowledge of the Creator. He adopted an animistic, yet empirical, interpret...

Silvical characteristics of paper birch (Betula papyrifera

Treesearch

Russell J. Hutnik; Frank E. Cunningham

1961-01-01

Paper birch (Betula papyrifera Marsh) is commonly known also as white birch. The bark, which gives not only name but also unique character to this tree, is distinguishable from the white bark of other species by its pearly surface, its creamy cast, and its chalky whiteness that rubs off onto clothing. This bark separates easily into papery thin...

Defect-free ultrahigh flux asymmetric membranes

DOEpatents

Pinnau, Ingo; Koros, William J.

1990-01-01

Defect-free, ultrahigh flux integrally-skinned asymmetric membranes having extremely thin surface layers (<0.2 .mu.m) comprised of glassy polymers are disclosed. The membranes are formed by casting an appropriate drope followed by forced convective evaporation of solvent to obtain a dry phase separated asymmetrical structure. The structure is then washed in a precipitation liquid and dried.

Creep-rupture behavior of a developmental cast-iron-base alloy for use up to 800 deg C

NASA Technical Reports Server (NTRS)

Titran, Robert H.; Scheuermann, Coulson M.

1987-01-01

A promising iron-base cast alloy is being developed as part of the DOE/NASA Stirling Engine Systems Project under contract DEN 3-282 with the United Technologies Research Center. This report presents the results of a study at the Lewis Research Center of the alloy's creep-rupture properties. The alloy was tested under a variety of conditions and was found to exhibit the normal 3-stage creep response. The alloy compared favorably with others being used or under consideration for the automotive Stirling engine cylinder/regenerator housing.

Development of Thixomolded{reg_sign} magnesium products

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

Ghosh, D.; Fan, R.; Kang, K.

1995-10-01

Thixomolding{reg_sign} is a racial new process which merges the technologies of die-casting and plastic injection molding for the net shape molding of magnesium based alloys. Properties of Thixomolded{reg_sign} magnesium alloys are discussed and compared with those of traditional die casting. Magnesium alloys are of great interest to automobile manufacturers because of the potential weight savings and corresponding energy savings due to increased fuel economy. For this reason, one of the first target markets for Thixomolded{reg_sign} products is the automotive industry. The use of Thixomolding{reg_sign} in the production of an automobile part is examined.

Rapid bridge construction technology : precast elements for substructures.

DOT National Transportation Integrated Search

2011-06-01

The goal of this research was to propose an alternate system of precast bridge substructures which can : substitute for conventional cast in place systems in Wisconsin to achieve accelerated construction. : Three types of abutment modules (hollow wal...

An Innovative Speech-Based User Interface for Smarthomes and IoT Solutions to Help People with Speech and Motor Disabilities.

PubMed

Malavasi, Massimiliano; Turri, Enrico; Atria, Jose Joaquin; Christensen, Heidi; Marxer, Ricard; Desideri, Lorenzo; Coy, Andre; Tamburini, Fabio; Green, Phil

2017-01-01

A better use of the increasing functional capabilities of home automation systems and Internet of Things (IoT) devices to support the needs of users with disability, is the subject of a research project currently conducted by Area Ausili (Assistive Technology Area), a department of Polo Tecnologico Regionale Corte Roncati of the Local Health Trust of Bologna (Italy), in collaboration with AIAS Ausilioteca Assistive Technology (AT) Team. The main aim of the project is to develop experimental low cost systems for environmental control through simplified and accessible user interfaces. Many of the activities are focused on automatic speech recognition and are developed in the framework of the CloudCAST project. In this paper we report on the first technical achievements of the project and discuss future possible developments and applications within and outside CloudCAST.

Water-soluble nanocrystalline cellulose films with highly transparent and oxygen barrier properties

NASA Astrophysics Data System (ADS)

Cheng, Shaoling; Zhang, Yapei; Cha, Ruitao; Yang, Jinliang; Jiang, Xingyu

2015-12-01

By mixing a guar gum (GG) solution with a nanocrystalline cellulose (NCC) dispersion using a novel circular casting technology, we manufactured biodegradable films as packaging materials with improved optical and mechanical properties. These films could act as barriers for oxygen and could completely dissolve in water within 5 h. We also compared the effect of nanocomposite films and commercial food packaging materials on the preservation of food.By mixing a guar gum (GG) solution with a nanocrystalline cellulose (NCC) dispersion using a novel circular casting technology, we manufactured biodegradable films as packaging materials with improved optical and mechanical properties. These films could act as barriers for oxygen and could completely dissolve in water within 5 h. We also compared the effect of nanocomposite films and commercial food packaging materials on the preservation of food. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr07647a

Production of footbridge with double curvature made of UHPC

NASA Astrophysics Data System (ADS)

Kolísko, J.; Čítek, D.; Tej, P.; Rydval, M.

2017-09-01

This article present a mix design, preparation and production of thin-walled footbridge made from UHPFRC. In this case an experimental pedestrian bridge was design and prepared. Bridge with span of 10 m and the clear width of 1.50 m designed as single-span bridge. Optimization of UHPFRC matrix and parameters of this material leads to the design of very thin structures. Total thickness of shell structure 30 - 45 mm. Bridge was cast as a prefabricated element in one piece. Self-compacting character of UHPFRC with high flowability allows the production of the final structure. Extensive research was done before production of footbridge. Experimental reached data were compared with extensive numerical analysis and the final design of structure and UHPFRC matrix were optimized in many details. Two versions of large scale mock-ups were casted and tested. According to the complexity of whole experiment a casting technology and production of formwork were tested and optimized many times.

The fuzzy algorithm in the die casting mould for the application of multi-channel temperature control

NASA Astrophysics Data System (ADS)

Sun, Jin-gen; Chen, Yi; Zhang, Jia-nan

2017-01-01

Mould manufacturing is one of the most basic elements in the production chain of China. The mould manufacturing technology has become an important symbol to measure the level of a country's manufacturing industry. The die-casting mould multichannel intelligent temperature control method is studied by cooling water circulation, which uses fuzzy control to realize, aiming at solving the shortcomings of slow speed and big energy consumption during the cooling process of current die-casting mould. At present, the traditional PID control method is used to control the temperature, but it is difficult to ensure the control precision. While , the fuzzy algorithm is used to realize precise control of mould temperature in cooling process. The design is simple, fast response, strong anti-interference ability and good robustness. Simulation results show that the control method is completely feasible, which has higher control precision.

Application of superalloy powder metallurgy for aircraft engines

NASA Technical Reports Server (NTRS)

Dreshfield, R. L.; Miner, R. V., Jr.

1980-01-01

In the last decade, Government/Industry programs have advanced powder metallurgy-near-net-shape technology to permit the use of hot isostatic pressed (HIP) turbine disks in the commercial aircraft fleet. These disks offer a 30% savings of input weight and an 8% savings in cost compared in cast-and-wrought disks. Similar savings were demonstrated for other rotating engine components. A compressor rotor fabricated from hot-die-forged-HIP superalloy billets revealed input weight savings of 54% and cost savings of 35% compared to cast-and-wrought parts. Engine components can be produced from compositions such as Rene 95 and Astroloy by conventional casting and forging, by forging of HIP powder billets, or by direct consolidation of powder by HIP. However, each process produces differences in microstructure or introduces different defects in the parts. As a result, their mechanical properties are not necessarily identical. Acceptance methods should be developed which recognize and account for the differences.

Microstructure formation and fracturing characteristics of grey cast iron repaired using laser.

PubMed

Yi, Peng; Xu, Pengyun; Fan, Changfeng; Yang, Guanghui; Liu, Dan; Shi, Yongjun

2014-01-01

The repairing technology based on laser rapid fusion is becoming an important tool for fixing grey cast iron equipment efficiently. A laser repairing protocol was developed using Fe-based alloy powders as material. The microstructure and fracturing feature of the repaired zone (RZ) were analyzed. The results showed that regionally organized RZ with good density and reliable metallurgical bond can be achieved by laser repairing. At the bottom of RZ, dendrites existed in similar direction and extended to the secondary RZ, making the grains grow extensively with inheritance with isometric grains closer to the surface substrate. The strength of the grey cast iron base material was maintained by laser repairing. The base material and RZ were combined with robust strength and fracture resistance. The prevention and deflection of cracking process were analyzed using a cracking process model and showed that the overall crack toughness of the materials increased.

Microstructure Formation and Fracturing Characteristics of Grey Cast Iron Repaired Using Laser

PubMed Central

Liu, Dan; Shi, Yongjun

2014-01-01

The repairing technology based on laser rapid fusion is becoming an important tool for fixing grey cast iron equipment efficiently. A laser repairing protocol was developed using Fe-based alloy powders as material. The microstructure and fracturing feature of the repaired zone (RZ) were analyzed. The results showed that regionally organized RZ with good density and reliable metallurgical bond can be achieved by laser repairing. At the bottom of RZ, dendrites existed in similar direction and extended to the secondary RZ, making the grains grow extensively with inheritance with isometric grains closer to the surface substrate. The strength of the grey cast iron base material was maintained by laser repairing. The base material and RZ were combined with robust strength and fracture resistance. The prevention and deflection of cracking process were analyzed using a cracking process model and showed that the overall crack toughness of the materials increased. PMID:25032230

Casting of weldable graphite/magnesium metal matrix composites with built-in metallic inserts

NASA Technical Reports Server (NTRS)

Lee, Jonathan A.; Kashalikar, Uday; Majkowski, Patricia

1994-01-01

Technology innovations directed at the advanced development of a potentially low cost and weldable graphite/magnesium metal matrix composites (MMC) through near net shape pressure casting are described. These MMC components uniquely have built-in metallic inserts to provide an innovative approach for joining or connecting other MMC components through conventional joining techniques such as welding, brazing, mechanical fasteners, etc. Moreover, the metallic inserts trapped within the MMC components can be made to transfer the imposed load efficiently to the continuous graphite fiber reinforcement thus producing stronger, stiffer, and more reliable MMC components. The use of low pressure near net shape casting is economical compared to other MMC fabrication processes. These castable and potentially weldable MMC components can provide great payoffs in terms of high strength, high stiffness, low thermal expansion, lightweight, and easily joinable MMC components for several future NASA space structural, industrial, and commercial applications.

Leveraging metal matrix composites to reduce costs in space mechanisms

NASA Technical Reports Server (NTRS)

Nye, Ted; Claridge, Rex; Walker, Jim

1994-01-01

Advanced metal matrix composites may be one of the most promising technologies for reducing cost in structural components without compromise to strength or stiffness. A microlight 12.50 N (2.81 lb), two-axis, solar array drive assembly (SADA) was made for the Advanced Materials Applications to Space Structures (AMASS) Program flight experiment. The SADA had both its inner and outer axis housings fabricated from silicon carbide particulate reinforced alumimun. Two versions of the housings were made. The first was machined from a solid billet of material. The second was plaster cast to a near net shape that required minimal finish machining. Both manufacturing methods were compared upon completion. Results showed a cost savings with the cast housing was possible for quantities greater than one and probable for quantities greater than two. For quantities approaching ten, casting resulted in a reduction factor of almost three in the cost per part.

Investigation of Wear and Friction Properties Under Sliding Conditions of Some Materials Suitable for Cages of Rolling-Contact Bearings

NASA Technical Reports Server (NTRS)

Johnson, Robert L; Swikert, Max A; Bisson, Edmond E

1952-01-01

An investigation of wear and friction properties of a number of materials sliding against SAE 52100 steel was conducted. These materials included brass, bronze, beryllium copper, monel, nichrome v, 24s-t aluminum, nodular iron, and gray cast iron. The metals investigated may be useful as possible cage (separator or retainer) materials for rolling-contact bearings of high-speed turbine engines. The ability of materials to form surface films that prevent welding is a most important factor in both dry friction and boundary lubrication. On the basis of wear and resistance to welding only, the cast irons were the most promising materials investigated; they showed the least wear and the least tendency to surface failure when run dry, and when boundary lubricated they showed the highest load capacity. On the basis of mechanical properties, nodular iron is superior to gray cast iron. Bronze had the lowest friction coefficient under dry sliding conditions. The results with brass, beryllium copper, and aluminum were poor and these materials do not appear, with regard to friction and wear, to be suitable for cages.

U.S. Geological Survey's ShakeCast: A cloud-based future

USGS Publications Warehouse

Wald, David J.; Lin, Kuo-Wan; Turner, Loren; Bekiri, Nebi

2014-01-01

When an earthquake occurs, the U. S. Geological Survey (USGS) ShakeMap portrays the extent of potentially damaging shaking. In turn, the ShakeCast system, a freely-available, post-earthquake situational awareness application, automatically retrieves earthquake shaking data from ShakeMap, compares intensity measures against users’ facilities, sends notifications of potential damage to responsible parties, and generates facility damage assessment maps and other web-based products for emergency managers and responders. ShakeCast is particularly suitable for earthquake planning and response purposes by Departments of Transportation (DOTs), critical facility and lifeline utilities, large businesses, engineering and financial services, and loss and risk modelers. Recent important developments to the ShakeCast system and its user base are described. The newly-released Version 3 of the ShakeCast system encompasses advancements in seismology, earthquake engineering, and information technology applicable to the legacy ShakeCast installation (Version 2). In particular, this upgrade includes a full statistical fragility analysis framework for general assessment of structures as part of the near real-time system, direct access to additional earthquake-specific USGS products besides ShakeMap (PAGER, DYFI?, tectonic summary, etc.), significant improvements in the graphical user interface, including a console view for operations centers, and custom, user-defined hazard and loss modules. The release also introduces a new adaption option to port ShakeCast to the "cloud". Employing Amazon Web Services (AWS), users now have a low-cost alternative to local hosting, by fully offloading hardware, software, and communication obligations to the cloud. Other advantages of the "ShakeCast Cloud" strategy include (1) Reliability and robustness of offsite operations, (2) Scalability naturally accommodated, (3), Serviceability, problems reduced due to software and hardware uniformity, (4) Testability, freely available for new users, (5) Remotely supported, allowing expert-facilitated maintenance, (6) Adoptability, simplified with disk images, and (7) Security, built in at the very high level associated with AWS. The ShakeCast user base continues to expand and broaden. For example, Caltrans, the prototypical ShakeCast user and development supporter, has been providing guidance to other DOTs on the use of the National Bridge Inventory (NBI) database to implement fully-functional ShakeCast systems in their states. A long-term goal underway is to further "connect the DOTs" via a Transportation Pooled Fund (TPF) with participating state DOTs. We also review some of the many other users and uses of ShakeCast. Lastly, on the hazard input front, we detail related ShakeMap improvements and ongoing advancements in estimating the likelihood of shaking-induced secondary hazards at structures, facilities, bridges, and along roadways due to landslides and liquefaction, and implemented within the ShakeCast framework.

Has NICE got it right? An international perspective considering the case of Technology Appraisal No. 98 by the National Institute for Health and Clinical Excellence (NICE).

PubMed

Schlander, Michael

2008-04-01

The National Institute for Health and Clinical Excellence (NICE) has been widely recognised as setting an international standard for high-quality health technology assessments (HTAs) including economic evaluation. A previous critical analysis of NICE Technology Appraisal No. 98 (TA98), evaluating methylphenidate, dexamphetamine and atomoxetine for the treatment of attention-deficit/hyperactivity disorder (ADHD) in children, revealed a number of issues, which must cast doubt on the robustness of the NICE approach when addressing a complex clinical decision problem. The exploration of potential underlying problems will be followed by a discussion of lessons for international healthcare policy-makers, and is intended to be an invitation to further debate and inquiry, not a presentation of definitive conclusions. Pertaining to the technology assessment report, potential problems were identified relating to an unnecessarily narrow scope, data search and selection strategy, the distinction between efficacy and effectiveness, data synthesis across studies and clinical effect measures, and limitations of the economic model. The appraisal process moderated the asserted 'clear conclusions' of the assessment but could not compensate for some of its gaps. It is suggested that key issues contributing to these problems may have included a separation of clinical and economic perspectives, a highly standardised reference case analysis that was followed schematically, the absence of an effective system for quality assurance of technology assessments, and transparency deficits of the economic evaluation. Further considerations for international policy-makers looking at NICE as a potential role model for HTAs are discussed, such as institutional context, the objectives of collectively financed healthcare and related value judgments, the reliance on QALYs as a universal and comprehensive measure of health benefits, the appropriate perspective for analysis, and process-related implications.

Presurgical nasoalveolar molding for cleft lip and palate: the application of digitally designed molds.

PubMed

Shen, Congcong; Yao, Caroline A; Magee, William; Chai, Gang; Zhang, Yan

2015-06-01

The authors present a novel nasoalveolar molding protocol by prefabricating sets of nasoalveolar molding appliances using three-dimensional technology. Prospectively, 17 infants with unilateral complete cleft lip and palate underwent the authors' protocol before primary cheiloplasty. An initial nasoalveolar molding appliance was created based on the patient's first and only in-person maxillary cast, produced from a traditional intraoral dental impression. Thereafter, each patient's molding course was simulated using computer software that aimed to narrow the alveolar gap by 1 mm each week by rotating the greater alveolar segment. A maxillary cast of each predicted molding stage was created using three-dimensional printing. Subsequent appliances were constructed in advance, based on the series of computer-generated casts. Each patient had a total three clinic visits spaced 1 month apart. Anthropometric measurements and bony segment volumes were recorded before and after treatment. Alveolar cleft widths narrowed significantly (p < 0.01), soft-tissue volume of each segment expanded (p < 0.01), and the arc of the alveolus became more contiguous across the cleft (p < 0.01). One patient required a new appliance at the second visit because of bleeding and discomfort. Eleven patients had mucosal irritation and two experienced minor mucosal ulceration. Three-dimensional technology can precisely represent anatomic structures in pediatric clefts. Results from the authors' algorithm are equivalent to those of traditional nasoalveolar molding therapies; however, the number of required clinic visits and appliance adjustments decreased. As three-dimensional technology costs decrease, multidisciplinary teams may design customized nasoalveolar molding treatment with improved efficiency and less burden to medical staff, patients, and families. Therapeutic, IV.

Materials Selection and Their Characteristics as Used in Rapid Prototyping

NASA Technical Reports Server (NTRS)

Cooper, K.; Salvail, P.; Vesely, E.; Wells, D.

1999-01-01

NASA's Marshall Space Flight Center (MSFC) conducted a program to evaluate six technologies used in Rapid Prototyping (RP) to produce investment casting patterns. In this paper, RP refers to the collective additive fabrication technologies known as Solid Free-Form Fabrication. Such technologies are being used with increasing frequency in manufacturing applications, due in part to their rapidly expanding capabilities to fabricate models from many types of materials. This study used ABS plastic, polycarbonate, TrueForm PM6, epoxy resin, paper, starch, and wax. The baseline model was a semi-complex prototype fuel pump housing, intended for use in the X-33 reusable launch vehicle. All models were shelled in a production- grade colloidal silica ceramic. Primary coats were zircon-base flour with zircon backup, while secondary coats were silica grains with a tabular alumina backup. Each model was shelled in an identical manner, using the same atmospheric conditions and drying times, as well as the same number of layers. Bake-outs and firing cycles were consistent with the leach ability of each material. Preheat and bath temperatures were also kept consistent. All molds were cast in vacuum using a hydrogen-resistant superalloy (NASA- 23) that was developed in-house. The final technical evaluation included detailed measurements of the model and the final casting, in order to determine any dimensional changes caused by different pattern materials, as well as documentation of all defects and any obvious refractory/model reactions. Prototype production costs were estimated for each method and taken into consideration during trade-off analysis.

FIELD DEMONSTRATION OF INNOVATIVE CONDITION ASSESSMENT TECHNOLOGIES FOR WATER MAINS: ACOUSTIC PIPE WALL ASSESSMENT, INTERNAL INSPECTION, AND EXTERNAL INSPECTIONVOLUME 1: TECHNICAL REPORT AND VOLUME 2: APPENDICES

EPA Science Inventory

Nine pipe wall integrity assessment technologies were demonstrated on a 76-year-old, 2,057-ft-long portion of a cement-lined, 24-in. cast iron water main in Louisville, KY. This activity was part of a series of field demonstrations of innovative leak detection/location and condi...

76 FR 47144 - In the Matter of: Jianwei Ding, 51 Bukit Batok Crescent, #0828 Unity Centre, Singapore 658077...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-08-04

... the China Academy of Space Technology (``CAST''), participated in a scheme whereby he directed... instructions and informed Ding that he ``had to make up the story [when] I call for [a] rate quote.'' On or... kilograms of Toray M40 material to New Bluesky Technology Co. Ltd. in Hong Kong. These exports were destined...

Automotive Manufacturing Processes. Volume III - Casting and Forging Processes

DOT National Transportation Integrated Search

1981-02-01

Extensive material substitution and resizing of the domestic automotive fleet, as well as the introduction of new technologies, will require major changes in the techniques and equipment used in the various manufacturing processes employed in the pro...

Arsenic Removal from Drinking Water

EPA Science Inventory

Web cast presentation covered six topics: 1), Arsenic Chemistry, 2), Technology Selection/Arsenic Demonstration Program, 3), Case Study 1, 4), Case Study 2,5), Case Study 3, and 6), Media Regeneration Project. The presentation consists of material presented at other training sess...

Caste-specific differences in hindgut microbial communities of honey bees (Apis mellifera).

PubMed

Kapheim, Karen M; Rao, Vikyath D; Yeoman, Carl J; Wilson, Brenda A; White, Bryan A; Goldenfeld, Nigel; Robinson, Gene E

2015-01-01

Host-symbiont dynamics are known to influence host phenotype, but their role in social behavior has yet to be investigated. Variation in life history across honey bee (Apis mellifera) castes may influence community composition of gut symbionts, which may in turn influence caste phenotypes. We investigated the relationship between host-symbiont dynamics and social behavior by characterizing the hindgut microbiome among distinct honey bee castes: queens, males and two types of workers, nurses and foragers. Despite a shared hive environment and mouth-to-mouth food transfer among nestmates, we detected separation among gut microbiomes of queens, workers, and males. Gut microbiomes of nurses and foragers were similar to previously characterized honey bee worker microbiomes and to each other, despite differences in diet, activity, and exposure to the external environment. Queen microbiomes were enriched for bacteria that may enhance metabolic conversion of energy from food to egg production. We propose that the two types of workers, which have the highest diversity of operational taxonomic units (OTUs) of bacteria, are central to the maintenance of the colony microbiome. Foragers may introduce new strains of bacteria to the colony from the environment and transfer them to nurses, who filter and distribute them to the rest of the colony. Our results support the idea that host-symbiont dynamics influence microbiome composition and, reciprocally, host social behavior.

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

Carpenter, J.A.; Swanson, D.E; Chango, R.F.

Bethlehem Steel's Burns Harbor Div. operates two 89,000-cu ft blast furnaces, D and C, built in 1969 and 1972. These furnaces have been in the forefront of blast furnace performance since they were blown-in. To maintain a credible operation throughout the past 25 years their performance has been improved continuously. Production was increased approximately 3%/year while fuel rate decreased 1%/year. This presentation summarizes the early repairs, relines and improvements that have sustained and enhanced the furnace's performance. The fourth reline of both furnaces will be discussed in detail. As part of the 1991 reline of D furnace its lines weremore » improved and modern penstocks installed. The bosh, tuyere jacket, hearth jacket and both cast floors were replaced. The furnace now has a larger hearth making it easier to control and, liquid level is no longer a problem when pulling the wind to shut down. The new cast floor with its increased trough length has much improved separation of slag from iron and lowered refractory consumption. Since the cast floors on D furnace were changed, there has been a reduction in accidents and absenteeism. This may be related to the change in work practices on the new cast floors. The 1994 reline of C furnace incorporates those improvements made on D furnace in 1991. In addition, C furnace will have high-density cooling which is expected to double its campaign from 6 to 12 years, without interim repairs.« less

Terrestrial applications from space technology

NASA Technical Reports Server (NTRS)

Clarks, H.

1985-01-01

NASA's Technology Utilization Program, which is concerned with transferring aerospace technologies to the public and private sectors, is described. The strategy for transferring the NASA technologies to engineering projects includes: (1) identification of the problem, (2) selection of an appropriate aerospace technology, (3) development of a partnership with the company, (4) implementation of the project, and (5) commercialization of the product. Three examples revealing the application of aerospace technologies to projects in biomedical engineering, materials, and automation and robotics are presented; the development of a programmable, implantable medication system and a programmable, mask-based optical correlator, and the improvement of heat and erosion resistance in continuous casting are examined.

Classrooms of the Future. A Thirty-Three Act Play with an Ever-Changing Cast; Out of the Spotlight; Selected Acts; The Perils and Promises of Technological Literacy: Three Case Studies; The Producers, the Critics, and the Glitch Factor.

ERIC Educational Resources Information Center

Landsberger, Joe; Krey, Cynthia L.; Moorhead, Alice

2001-01-01

This special section on the history and creators of COTF VII describe the process for creating a conference on technology in education using the example of the Minnesota-based Classrooms of the Future Symposia presented by colleges and universities in the Twin Cities area. Highlights include the role of technology in instruction; promotional…

Progress of Crew Autonomous Scheduling Test (CAST) On the ISS

NASA Technical Reports Server (NTRS)

Healy, Matthew; Marquez, Jessica; Hillenius, Steven; Korth, David; Bakalyar, Lauren Rush; Woodbury, Neil; Larsen, Crystal M.; Bates, Shelby; Kockler, Mikayla; Rhodes, Brooke;

High-Performance All-Solid-State Na-S Battery Enabled by Casting-Annealing Technology.

PubMed

Fan, Xiulin; Yue, Jie; Han, Fudong; Chen, Ji; Deng, Tao; Zhou, Xiuquan; Hou, Singyuk; Wang, Chunsheng

2018-04-24

Room-temperature all-solid-state Na-S batteries (ASNSBs) using sulfide solid electrolytes are a promising next-generation battery technology due to the high energy, enhanced safety, and earth abundant resources of both sodium and sulfur. Currently, the sulfide electrolyte ASNSBs are fabricated by a simple cold-pressing process leaving with high residential stress. Even worse, the large volume change of S/Na 2 S during charge/discharge cycles induces additional stress, seriously weakening the less-contacted interfaces among the solid electrolyte, active materials, and the electron conductive agent that are formed in the cold-pressing process. The high and continuous increase of the interface resistance hindered its practical application. Herein, we significantly reduce the interface resistance and eliminate the residential stress in Na 2 S cathodes by fabricating Na 2 S-Na 3 PS 4 -CMK-3 nanocomposites using melting-casting followed by stress-release annealing-precipitation process. The casting-annealing process guarantees the close contact between the Na 3 PS 4 solid electrolyte and the CMK-3 mesoporous carbon in mixed ionic/electronic conductive matrix, while the in situ precipitated Na 2 S active species from the solid electrolyte during the annealing process guarantees the interfacial contact among these three subcomponents without residential stress, which greatly reduces the interfacial resistance and enhances the electrochemical performance. The in situ synthesized Na 2 S-Na 3 PS 4 -CMK-3 composite cathode delivers a stable and highly reversible capacity of 810 mAh/g at 50 mA/g for 50 cycles at 60 °C. The present casting-annealing strategy should provide opportunities for the advancement of mechanically robust and high-performance next-generation ASNSBs.

Characterization of a 12-pdr wrought-iron cannonball from the Akko 1 shipwreck

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

Cvikel, D.; Ashkenazi, D., E-mail: dana@eng.tau.ac.il; Stern, A.

2013-09-15

The Akko 1 shipwreck, discovered in Akko harbor, Israel, is the remains of an eastern Mediterranean brig built at the beginning of the 19th century. Among other finds, eleven cannonballs were found in the shipwreck and three of them were retrieved. Two of the cannonballs, the 9- and 24-pdrs, have been studied previously. The present study of the 12-pdr cannonball included γ-rays radiographic testing, XRF analysis, density measurements, optical microscopy and SEM-EDS observation, OES analysis and microhardness tests. The investigation included characterization of the composition, microstructure and slag analysis. The results revealed a quite homogenous microstructure of α-ferrite phase, withmore » glassy, wüstite and fayalite slags, as typical for a wrought-iron—annealed product, a more complicated and an earlier technology, compared to the 9- and 24-pdr that were made of cast-iron. Ferritic cannonballs are extremely rare, especially in the 19th century, when cannonballs were manufactured of cast iron by the sand casting process. The different manufacturing methods may indicate a different place of fabrication, and an apparently earlier production date for the 12-pdr, which might have even been used as ballast. - Highlights: • Three cannonballs were retrieved from the 19th century Akko 1 shipwreck. • The 12-pdr differs from the 9- and 24-pdr cannonballs previously studied. • The 12-pdr was made of high quality annealed wrought-iron, not of cast-iron. • The technology used indicates a date earlier than the middle of the 19th century. • Perhaps the 12-pdr belonged to another navy than the other two or used as ballast.« less

Energy Saving Melting and Revert Reduction Technology (Energy SMARRT): Development of CCT Diagrams

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

Chumbley, L Scott

2011-08-20

One of the most energy intensive industries in the U.S. today is in the melting and casting of steel alloys for use in our advanced technological society. While the majority of steel castings involve low or mild carbon steel for common construction materials, highly-alloyed steels constitute a critical component of many industries due to their excellent properties. However, as the amount of alloying additions increases, the problems associated with casting these materials also increases, resulting in a large waste of energy due to inefficiency and a lack of basic information concerning these often complicated alloy systems. Superaustenitic stainless steels constitutemore » a group of Fe-based alloys that are compositionally balanced to have a purely austenitic matrix and exhibit favorable pitting and crevice corrosion resistant properties and mechanical strength. However, intermetallic precipitates such as sigma (³) and Laves can form during casting or exposure to high-temperature processing, which degrade the corrosion and mechanical properties of the material. Knowledge of the times and temperatures at which these detrimental phases form is imperative if a company is to efficiently produce castings of high quality in the minimum amount of time, using the lowest amount of energy possible, while producing the least amount of material waste. Anecdotal evidence from company representatives revealed that large castings frequently had to be scrapped due to either lower than expected corrosion resistance or extremely low fracture toughness. It was suspected that these poor corrosion and / or mechanical properties were directly related to the type, amount, and location of various intermetallic phases that formed during either the cooling cycle of the castings or subsequent heat treatments. However, no reliable data existed concerning either the time-temperature-transformation (TTT) diagrams or the continuous-cooling-transformation (CCT) diagrams of the super-austenitics. The goal of this study was to accurately characterize the solid-solid phase transformations seen in cast superaustenitic stainless steels. Heat treatments were performed to understand the time and temperature ranges for intermetallic phase formations in alloys CN3MN and CK3McuN. Microstructures were characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), and energy and wavelength dispersive spectroscopy (EDS, WDS). In this way TTT and CCT diagrams could be developed for the matrix of samples chosen. As this study consisted of basic research into the development of TTT and CCT diagrams as an aid to the US steel casting industry, there is no formal commercialization plan associated with this task other than presentations and publications via the Steel Founders Society of America to their members. The author is confident that the data contained in this report can be used by steel foundries to refine their casting procedures in such a way as to reduce the amount of waste produced and energy wasted by significantly reducing or eliminating the need for remelting or recasting of material due to unwanted, premature intermetallic formation. This development of high alloy steel CCT diagrams was predicted to result in an average energy savings of 0.05 trillion BTU's/year over a 10 year period (with full funding). With 65% of the proposed funding, current (2011) annual energy saving estimates, based on initial dissemination to the casting industry in 2011and market penetration of 97% by 2020, is 0.14 trillion BTU's/year. The reduction of scrap and improvement in casting yield will also result in a reduction of environmental emissions associated with the melting and pouring of the steel. The average annual estimate of CO2 reduction per year through 2020 is 0.003 Million Metric Tons of Carbon Equivalent (MM TCE)« less

Energy Saving Melting and Revert Reduction Technology: Improved Die Casting Process to Preserve the Life of the Inserts

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

David Schwam, PI; Xuejun Zhu, Sr. Research Associate

2012-09-30

The goal of this project was to study the combined effects of die design, proper internal cooling and efficient die lubricants on die life. The project targeted improvements in die casting insert life by: Optomized Die Design for Reduced Surface Temperature: The life of die casting dies is significantly shorter when the die is exposed to elevated temperature for significant periods of time. Any die operated under conditions leading to surface temperature in excess of 1050oF undergoes structural changes that reduce its strength. Optimized die design can improve die life significantly. This improvement can be accomplished by means of coolingmore » lines, baffles and bubblers in the die. A key objective of the project was to establish criteria for the minimal distance of the cooling lines from the surface. This effort was supported with alloys and machining by BohlerUddeholm, Dunn Steel, HH Stark and Rex Buckeye. In plant testing and evaluation was conducted as in-kind cost share at St. Clair Die Casting. The Uddeholm Dievar steel evaluated in this program showed superior resistance to thermal fatigue resistance. Based on the experimental evidence, cooling lines could be placed as close as 0.5" from the surface. Die Life Extension by Optimized Die Lubrication: The life of die casting dies is affected by additions made to its surface with the proper lubricants. These lubricants will protect the surface from the considerable temperature peaks that occur when the molten melt enters the die. Dies will reach a significantly higher temperature without this lubricant being applied. The amount and type of the lubricant are critical variables in the die casting process. However, these lubricants must not corrode the die surface. This effort was supported with alloys and machining by BohlerUddeholm, Dunn Steel, HH Stark and Rex Buckeye. In plant testing and evaluation was conducted as in-kind cost share at St. Clair Die Casting. Chem- Trend participated in the program with die lubricants and technical support. Experiments conducted with these lubricants demonstrated good protection of the substrate steel. Graphite and boron nitride used as benchmarks are capable of completely eliminating soldering and washout. However, because of cost and environmental considerations these materials are not widely used in industry. The best water-based die lubricants evaluated in this program were capable of providing similar protection from soldering and washout. In addition to improved part quality and higher production rates, improving die casting processes to preserve the life of the inserts will result in energy savings and a reduction in environmental wastes. Improving die life by means of optimized cooling line placement, baffles and bubblers in the die will allow for reduced die temperatures during processing, saving energy associated with production. The utilization of optimized die lubricants will also reduce heat requirements in addition to reducing waste associated with soldering and washout. This new technology was predicted to result in an average energy savings of 1.1 trillion BTU's/year over a 10 year period. Current (2012) annual energy saving estimates, based on commercial introduction in 2010, a market penetration of 70% by 2020 is 1.26 trillion BTU's/year. Along with these energy savings, reduction of scrap and improvement in casting yield will result in a reduction of the environmental emissions associated with the melting and pouring of the metal which will be saved as a result of this technology. The average annual estimate of CO2 reduction per year through 2020 is 0.025 Million Metric Tons of Carbon Equivalent (MM TCE).« less

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

Energy Saving Melting and Revert Reduction Technology: Melting Efficiency in Die Casting Operations

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

David Schwam

2012-12-15

This project addressed multiple aspects of the aluminum melting and handling in die casting operations, with the objective of increasing the energy efficiency while improving the quality of the molten metal. The efficiency of melting has always played an important role in the profitability of aluminum die casting operations. Consequently, die casters need to make careful choices in selecting and operating melting equipment and procedures. The capital cost of new melting equipment with higher efficiency can sometimes be recovered relatively fast when it replaces old melting equipment with lower efficiency. Upgrades designed to improve energy efficiency of existing equipment maymore » be well justified. Energy efficiency is however not the only factor in optimizing melting operations. Melt losses and metal quality are also very important. Selection of melting equipment has to take into consideration the specific conditions at the die casting shop such as availability of floor space, average quantity of metal used as well as the ability to supply more metal during peaks in demand. In all these cases, it is essential to make informed decisions based on the best available data.« less

Synthesis, Characterization and Cold Workability of Cast Copper-Magnesium-Tin Alloys

NASA Astrophysics Data System (ADS)

Bravo Bénard, Agustín Eduardo; Martínez Hernández, David; González Reyes, José Gonzalo; Ortiz Prado, Armando; Schouwenaars Franssens, Rafael

2014-02-01

The use of Mg as an alloying element in copper alloys has largely been overlooked in scientific literature and technological applications. Its supposed tribological compatibility with iron makes it an interesting option to replace Pb in tribological alloys. This work describes the casting process of high-quality thin slabs of Cu-Mg-Sn alloys with different compositions by means of conventional methods. The resulting phases were analyzed using X-ray diffraction, scanning electron microscopy, optical microscopy, and energy dispersive X-ray spectroscopy techniques. Typical dendritic α-Cu, eutectic Cu2Mg(Sn) and eutectoid non-equilibrium microstructures were found. Tensile tests and Vickers microhardness show the excellent hardening capability of Mg as compared to other copper alloys in the as-cast condition. For some of the slabs and compositions, cold rolling reductions of over 95 pct have been easily achieved. Other compositions and slabs have failed during the deformation process. Failure analysis after cold rolling reveals that one cause for brittleness is the presence of casting defects such as microshrinkage and inclusions, which can be eliminated. However, for high Mg contents, a high volume fraction of the intermetallic phase provides a contiguous path for crack propagation through the connected interdendritic regions.

Aspectos ecologicos, toxicologicos y agricolas de la hormiga brasileña Solenopsis invicta

Treesearch

J. A. Torres

1990-01-01

The fire ant Solenopsis invicta recently invaded in Puerto Rico. Its presence has created great alarm among farmers and the public. This work reviews the ecology of this ant in the United States, Brazil and Puerto Rico in order to clarify some misconceptions. Information is provided to separate Solenopsis invicta from S. geminata. Colony foundation, caste...

19. WHILE AUTOMATION REDUCED SOME LABORINTENSIVE POSITIONS, THESE LARGE ROTATING ...

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

19. WHILE AUTOMATION REDUCED SOME LABOR-INTENSIVE POSITIONS, THESE LARGE ROTATING CLEANING MACHINES WHICH TUMBLED CASTINGS OVER EACH OTHER TO BREAK OFF EXCESS MATERIAL WHILE QUICKLY COOLING THE METALS IN THE MALLEABLE FOUNDRY PRIOR TO ANNEALING, STILL REQUIRED HAND SEPARATION OF THE EXCESS MATERIAL, CA. 1950. - Stockham Pipe & Fittings Company, 4000 Tenth Avenue North, Birmingham, Jefferson County, AL

Development of Integrated Die Casting Process for Large Thin-Wall Magnesium Applications

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

Carter, Jon T.; Wang, Gerry; Luo, Alan

The purpose of this project was to develop a process and product which would utilize magnesium die casting and result in energy savings when compared to the baseline steel product. The specific product chosen was a side door inner panel for a mid-size car. The scope of the project included: re-design of major structural parts of the door, design and build of the tooling required to make the parts, making of parts, assembly of doors, and testing (both physical and simulation) of doors. Additional work was done on alloy development, vacuum die casting, and overcasting, all in order to improvemore » the performance of the doors and reduce cost. The project achieved the following objectives: 1. Demonstrated ability to design a large thin-wall magnesium die casting. 2. Demonstrated ability to manufacture a large thin-wall magnesium die casting in AM60 alloy. 3. Tested via simulations and/or physical tests the mechanical behavior and corrosion behavior of magnesium die castings and/or lightweight experimental automotive side doors which incorporate a large, thin-wall, powder coated, magnesium die casting. Under some load cases, the results revealed cracking of the casting, which can be addressed with re-design and better material models for CAE analysis. No corrosion of the magnesium panel was observed. 4. Using life cycle analysis models, compared the energy consumption and global warming potential of the lightweight door with those of a conventional steel door, both during manufacture and in service. Compared to a steel door, the lightweight door requires more energy to manufacture but less energy during operation (i.e., fuel consumption when driving vehicle). Similarly, compared to a steel door, the lightweight door has higher global warming potential (GWP) during manufacture, but lower GWP during operation. 5. Compared the conventional magnesium die casting process with the “super-vacuum” die casting process. Results achieved with cast tensile bars suggest some improvement in tensile properties with vacuum casting. Plant trials with large castings revealed cavity fill issues attributed to cooling and partial solidification of metal in the shot sleeve while waiting for vacuum to be established in the die cavity. 6. Developed age-hardenable Mg-based alloys as potential alternatives to the AM60 and AZ91 alloys typically used in automotive applications. Mg-7%Al-based alloys having Sn or Sn+Si additions exhibited significant age hardening, but more work is needed to demonstrate significant improvement in tensile properties. Corrosion behavior of these alloys is between those of AM60 and AZ91 alloys. 7. Evaluated the die casting of magnesium directly onto either steel or aluminum tubes as a potential process to make large lightweight subassemblies. Samples were free of gross defects, but additional work is needed to increase the interfacial shear strength. Overall, the project demonstrated that an automotive door-in-white design incorporating a die cast magnesium inner panel and a stamped aluminum outer panel can achieve approximately 50% mass reduction compared to the stamped steel baseline door-in-white. This leads to reduced energy consumption when driving the vehicle, which should more than offset the increased embedded energy of manufacture associated with the lighter metals. However, additional design work would be needed in order to meet the mechanical performance required of a door. Development of high-strength, high-ductility magnesium alloy castings would help make this technology more attractive for potential use in the side doors on automobiles. Also, increased use of recycled magnesium and aluminum would reduce the embedded energy and greenhouse gas emissions associated with the manufacture of this type of lightweight door. Commercialization planning of the type of lightweight door technology addressed in this project would be contingent upon the doors meeting all technical performance requirements of the car maker. The specific lightweight door developed in this project didn’t meet some of those requirements, but a preliminary business case study was conducted anyhow. This study considered the ratio of cost increase to mass decrease when the lightweight door is compared to a baseline steel door. The ratio was found to be in an acceptable range for some vehicle programs, especially if the number of such vehicles to be produced is equal to or slightly less than the estimated 250,000-shot life of the die set. This would allow for the investment in the dies to be spread across many parts and thereby help minimize the cost increase.« less

High Throughput Transcriptomics: From screening to pathways

EPA Science Inventory

The EPA ToxCast effort has screened thousands of chemicals across hundreds of high-throughput in vitro screening assays. The project is now leveraging high-throughput transcriptomic (HTTr) technologies to substantially expand its coverage of biological pathways. The first HTTr sc...

JPRS Report, Science & Technology, Japan

DTIC Science & Technology

1987-12-02

casting nathod —.ntnoshar ic sintering nethod _Reaotion sintering nethod .Btlf-iintering nethod „Recrystallizing sintering nathod -Hot Porning ...was completed by photo- graphically recalling even such things as how bolts were fastened to achieve a complete copy similar to a video replay of

ExpoCast: Exposure Science for Prioritization and Toxicity Testing (T)

EPA Science Inventory

The US EPA National Center for Computational Toxicology (NCCT) has a mission to integrate modern computing and information technology with molecular biology to improve Agency prioritization of data requirements and risk assessment of chemicals. Recognizing the critical need for ...

A polymeric master replication technology for mass fabrication of poly(dimethylsiloxane) microfluidic devices.

PubMed

Li, Hai-Fang; Lin, Jin-Ming; Su, Rong-Guo; Cai, Zong Wei; Uchiyama, Katsumi

2005-05-01

A protocol of producing multiple polymeric masters from an original glass master mold has been developed, which enables the production of multiple poly(dimethylsiloxane) (PDMS)-based microfluidic devices in a low-cost and efficient manner. Standard wet-etching techniques were used to fabricate an original glass master with negative features, from which more than 50 polymethylmethacrylate (PMMA) positive replica masters were rapidly created using the thermal printing technique. The time to replicate each PMMA master was as short as 20 min. The PMMA replica masters have excellent structural features and could be used to cast PDMS devices for many times. An integration geometry designed for laser-induced fluorescence (LIF) detection, which contains normal deep microfluidic channels and a much deeper optical fiber channel, was successfully transferred into PDMS devices. The positive relief on seven PMMA replica masters is replicated with regard to the negative original glass master, with a depth average variation of 0.89% for 26-microm deep microfluidic channels and 1.16% for the 90 mum deep fiber channel. The imprinted positive relief in PMMA from master-to-master is reproducible with relative standard deviations (RSDs) of 1.06% for the maximum width and 0.46% for depth in terms of the separation channel. The PDMS devices fabricated from the PMMA replica masters were characterized and applied to the separation of a fluorescein isothiocyanate (FITC)-labeled epinephrine sample.

Evaluation of a 3D stereophotogrammetric technique to measure the stone casts of patients with unilateral cleft lip and palate.

PubMed

Sforza, Chiarella; De Menezes, Marcio; Bresciani, Elena; Cerón-Zapata, Ana M; López-Palacio, Ana M; Rodriguez-Ardila, Myriam J; Berrio-Gutiérrez, Lina M

2012-07-01

To assess a three-dimensional stereophotogrammetric method for palatal cast digitization of children with unilateral cleft lip and palate. As part of a collaboration between the University of Milan (Italy) and the University CES of Medellin (Colombia), 96 palatal cast models obtained from neonatal patients with unilateral cleft lip and palate were obtained and digitized using a three-dimensional stereophotogrammetric imaging system. Three-dimensional measurements (cleft width, depth, length) were made separately for the longer and shorter cleft segments on the digital dental cast surface between landmarks, previously marked. Seven linear measurements were computed. Systematic and random errors between operators' tracings, and accuracy on geometric objects of known size were calculated. In addition, mean measurements from three-dimensional stereophotographs were compared statistically with those from direct anthropometry. The three-dimensional method presented good accuracy error (<0.9%) on measuring geometric objects. No systematic errors between operators' measurements were found (p > .05). Statistically significant differences (p < 5%) were noted for different methods (caliper versus stereophotogrammetry) for almost all distances analyzed, with mean absolute difference values ranging between 0.22 and 3.41 mm. Therefore, rates for the technical error of measurement and relative error magnitude were scored as moderate for Ag-Am and poor for Ag-Pg and Am-Pm distances. Generally, caliper values were larger than three-dimensional stereophotogrammetric values. Three-dimensional stereophotogrammetric systems have some advantages over direct anthropometry, and therefore the method could be sufficiently precise and accurate on palatal cast digitization with unilateral cleft lip and palate. This would be useful for clinical analyses in maxillofacial, plastic, and aesthetic surgery.

Does powdering of the dentition increase the accuracy of fusing 3D stereophotographs and digital dental casts.

PubMed

Rangel, Frits A; Chiu, Yu-Ting; Maal, Thomas J J; Bronkhorst, Ewald M; Bergé, Stefaan J; Kuijpers-Jagtman, Anne Marie

2016-08-01

The shiny vestibular surfaces of teeth make it difficult to match digital dental casts to 3D stereophotogrammetric images of patient teeth. This study tested whether reducing this shininess by coating the teeth with titanium-oxide powder might improve the accuracy of the matching procedure. Twenty patients participated in the study. For each patient, 3D stereophotogrammetric images were taken without and with a powder coating. Separately, digital dental casts were created. Next, the digital dental casts were fused with the 3D stereophotogrammetric images of either non-powdered or powdered dentition. Distance maps were created to evaluate the inter-surface distance between the digital dental cast and the 3D images. The matching accuracy was compared for dentition with and without powdering. Of all recorded distances between corresponding points, 95% was smaller than 0.84mm for the powdered dentition and smaller than 0.90mm for the non-powdered dentition. Although powdered dentition showed significantly better matching than non-powdered dentition, the difference was less than 0.1mm. Intra-observer statistics showed that five out of 24 repetitions gave significantly different results, but only for dentition that was not powdered. The patients did not have any major malocclusions. Severe malocclusions might cause greater difficulty in matching the dentition without powder. Only one type of powder was used, but it effectively reduced shininess. Powdering the dentition had a small, but significant, positive effect on matching. However, this effect was of minor clinical importance. Therefore, we do not recommend powdering the dentition for 3D stereophotogrammetric images used for matching procedures. © The Author 2016. Published by Oxford University Press on behalf of the European Orthodontic Society. All rights reserved. For permissions, please email: journals.permissions@oup.com.

The effect of water-soluble polymers on the microstructure and properties of freeze-cast alumina ceramics

NASA Astrophysics Data System (ADS)

Pekor, Christopher Michael

Porous ceramics can be divided into three separate classes based on their pore size: microporous ceramics with pores less than 2 nm, mesoporous ceramics with pores in the range of 2--50 nm and macroporous ceramics with pores that are greater than 50 nm. In particular, macroporous ceramics are used in a variety of applications such as refractories, molten metal filtration, diesel particulate filters, heterogeneous catalyst supports and biomedical scaffolds. Freeze casting is a novel method used to create macroporous ceramics. In this method growing ice crystals act as a template for the pores and are solidified, often directionally, through a ceramic dispersion and removed from the green body through a freeze drying procedure. This method has attracted some attention over the past few years due to its relative simplicity, flexibility and environmental friendliness. On top of this freeze casting is capable of producing materials with high pore volume fractions, which is an advantage over processing by packing and necking of particles, where the pore volume fraction is typically less than 50%. Many of the basic processing variables that affect the freeze cast microstructure, such as the temperature gradient, interfacial velocity and solid loading of the dispersion have been well established in the literature. On the other hand, areas such as the effect of additives on the microstructure and mechanical properties have not been covered in great detail. In this study the concept of constitutional supercooling from basic solidification theory is used to explain the effects of two water-soluble polymers, polyethylene glycol and polyvinyl alcohol, on the microstructure of freeze cast alumina ceramics. In addition, changes in the observed microstructure will be related to experimentally determined values of permeability and compressive strength.

Cellularized Cellular Solids via Freeze-Casting.

PubMed

Christoph, Sarah; Kwiatoszynski, Julien; Coradin, Thibaud; Fernandes, Francisco M

2016-02-01

The elaboration of metabolically active cell-containing materials is a decisive step toward the successful application of cell based technologies. The present work unveils a new process allowing to simultaneously encapsulate living cells and shaping cell-containing materials into solid-state macroporous foams with precisely controlled morphology. Our strategy is based on freeze casting, an ice templating materials processing technique that has recently emerged for the structuration of colloids into macroporous materials. Our results indicate that it is possible to combine the precise structuration of the materials with cellular metabolic activity for the model organism Saccharomyces cerevisiae. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Manufacturing Methods and Technology Project Summary Reports

DTIC Science & Technology

1982-12-01

aluminide was used to eliminate adhesive failures. A doctor blade and expandable ring segment were selected as the tooling to apply the 0.010 inch...contractual effort is to develop manu- facturing technology for the production of integrally bladed impellers using titanium pre-alloyed powder and...Projectiles in Modernized Plants 1-16 METALS Abstracts ME-1 Projects 176 7046, 17T 7046 and 177 7046 - Precision Cast Titanium Compressor Casing ME

Future requirements for advanced materials

NASA Technical Reports Server (NTRS)

Olstad, W. B.

1980-01-01

Recent advances and future trends in aerospace materials technology are reviewed with reference to metal alloys, high-temperature composites and adhesives, tungsten fiber-reinforced superalloys, hybrid materials, ceramics, new ablative materials, such as carbon-carbon composite and silica tiles used in the Shuttle Orbiter. The technologies of powder metallurgy coupled with hot isostatic pressing, near net forging, complex large shape casting, chopped fiber molding, superplastic forming, and computer-aided design and manufacture are emphasized.

Letter Report: LAW Simulant Development for Cast Stone Screening Test

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

Russell, Renee L.; Westsik, Joseph H.; Swanberg, David J.

2013-03-27

More than 56 million gallons of radioactive and hazardous waste are stored in 177 underground storage tanks at the U.S. Department of Energy’s (DOE’s) Hanford Site in southeastern Washington State. The Hanford Tank Waste Treatment and Immobilization Plant (WTP) is being constructed to treat the wastes and immobilize them in a glass waste form. The WTP includes a pretreatment facility to separate the wastes into a small volume of high-level waste (HLW) containing most of the radioactivity and a larger volume of low-activity waste (LAW) containing most of the nonradioactive chemicals. The HLW will be converted to glass in themore » HLW vitrification facility for ultimate disposal at an offsite federal repository. At least a portion (~35%) of the LAW will be converted to glass in the LAW vitrification facility and will be disposed of onsite at the Integrated Disposal Facility (IDF). The pretreatment and HLW vitrification facilities will have the capacity to treat and immobilize the wastes destined for each facility. However, a second facility will be needed for the expected volume of additional LAW requiring immobilization. A cementitious waste form known as Cast Stone is being considered to provide the required additional LAW immobilization capacity. The Cast Stone waste form must be acceptable for disposal in the IDF. The Cast Stone waste form and immobilization process must be tested to demonstrate that the final Cast Stone waste form can comply with waste acceptance criteria for the IDF disposal facility and that the immobilization processes can be controlled to consistently provide an acceptable waste form product. Further, the waste form must be tested to provide the technical basis for understanding the long term performance of the waste form in the IDF disposal environment. These waste form performance data are needed to support risk assessment and performance assessment (PA) analyses of the long-term environmental impact of the waste disposal in the IDF. A testing program was developed in fiscal year (FY) 2012 describing in some detail the work needed to develop and qualify Cast Stone as a waste form for the solidification of Hanford LAW (Westsik et al. 2012). Included within Westsik et al. (2012) is a section on the near-term needs to address Tri-Party Agreement Milestone M-062-40ZZ. The objectives of the testing program to be conducted in FY 2013 and FY 2014 are to: • Determine an acceptable formulation for the LAW Cast Stone waste form. • Evaluate sources of dry materials for preparing the LAW Cast Stone. • Demonstrate the robustness of the Cast Stone waste form for a range of LAW compositions. • Demonstrate the robustness of the formulation for variability in the Cast Stone process. • Provide Cast Stone contaminant release data for PA and risk assessment evaluations. The first step in determining an acceptable formulation for the LAW Cast Stone waste form is to conduct screening tests to examine expected ranges in pretreated LAW composition, waste stream concentrations, dry-materials sources, and mix ratios of waste feed to dry blend. A statistically designed test matrix will be used to evaluate the effects of these key parameters on the properties of the Cast Stone as it is initially prepared and after curing. The second phase of testing will focus on selection of a baseline Cast Stone formulation for LAW and demonstrating that Cast Stone can meet expected waste form requirements for disposal in the IDF. It is expected that this testing will use the results of the screening tests to define a smaller suite of tests to refine the composition of the baseline Cast Stone formulation (e.g. waste concentration, water to dry mix ratio, waste loading).« less

Accuracy of a separating foil impression using a novel polyolefin foil compared to a custom tray and a stock tray technique

PubMed Central

Pastoret, Marie-Hélène; Bühler, Julia; Weiger, Roland

2017-01-01

PURPOSE To compare the dimensional accuracy of three impression techniques- a separating foil impression, a custom tray impression, and a stock tray impression. MATERIALS AND METHODS A machined mandibular complete-arch metal model with special modifications served as a master cast. Three different impression techniques (n = 6 in each group) were performed with addition-cured silicon materials: i) putty-wash technique with a prefabricated metal tray (MET) using putty and regular body, ii) single-phase impression with custom tray (CUS) using regular body material, and iii) two-stage technique with stock metal tray (SEP) using putty with a separating foil and regular body material. All impressions were poured with epoxy resin. Six different distances (four intra-abutment and two inter-abutment distances) were gauged on the metal master model and on the casts with a microscope in combination with calibrated measuring software. The differences of the evaluated distances between the reference and the three test groups were calculated and expressed as mean (± SD). Additionally, the 95% confidence intervals were calculated and significant differences between the experimental groups were assumed when confidence intervals did not overlap. RESULTS Dimensional changes compared to reference values varied between -74.01 and 32.57 µm (MET), -78.86 and 30.84 (CUS), and between -92.20 and 30.98 (SEP). For the intra-abutment distances, no significant differences among the experimental groups were detected. CUS showed a significantly higher dimensional accuracy for the inter-abutment distances with -0.02 and -0.08 percentage deviation compared to MET and SEP. CONCLUSION The separation foil technique is a simple alternative to the custom tray technique for single tooth restorations, while limitations may exist for extended restorations with multiple abutment teeth. PMID:28874996

20180311 - High Throughput Transcriptomics: From screening to pathways (SOT 2018)

EPA Science Inventory

The EPA ToxCast effort has screened thousands of chemicals across hundreds of high-throughput in vitro screening assays. The project is now leveraging high-throughput transcriptomic (HTTr) technologies to substantially expand its coverage of biological pathways. The first HTTr sc...

South Africa’s Technology Sector

DTIC Science & Technology

2007-08-01

Somchem’s rocket motor propellant casting pits were destroyed and sealed with concrete .135 In taking this step, South Africa became the only country...principles of restraint, responsibility, and translucence .163 Translucence or semi-transparency is distinct from the more rigorous concept of total

ExpoCastDB: A Publicly Accessible Database for Observational Exposure Data

EPA Science Inventory

The application of environmental informatics tools for human health risk assessment will require the development of advanced exposure information technology resources. Exposure data for chemicals is often not readily accessible. There is a pressing need for easily accessible, che...

Multivariate research in areas of phosphorus cast-iron brake shoes manufacturing using the statistical analysis and the multiple regression equations

NASA Astrophysics Data System (ADS)

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

2017-05-01

The braking system is one of the most important and complex subsystems of railway vehicles, especially when it comes for safety. Therefore, installing efficient safe brakes on the modern railway vehicles is essential. Nowadays is devoted attention to solving problems connected with using high performance brake materials and its impact on thermal and mechanical loading of railway wheels. The main factor that influences the selection of a friction material for railway applications is the performance criterion, due to the interaction between the brake block and the wheel produce complex thermos-mechanical phenomena. In this work, the investigated subjects are the cast-iron brake shoes, which are still widely used on freight wagons. Therefore, the cast-iron brake shoes - with lamellar graphite and with a high content of phosphorus (0.8-1.1%) - need a special investigation. In order to establish the optimal condition for the cast-iron brake shoes we proposed a mathematical modelling study by using the statistical analysis and multiple regression equations. Multivariate research is important in areas of cast-iron brake shoes manufacturing, because many variables interact with each other simultaneously. Multivariate visualization comes to the fore when researchers have difficulties in comprehending many dimensions at one time. Technological data (hardness and chemical composition) obtained from cast-iron brake shoes were used for this purpose. In order to settle the multiple correlation between the hardness of the cast-iron brake shoes, and the chemical compositions elements several model of regression equation types has been proposed. Because a three-dimensional surface with variables on three axes is a common way to illustrate multivariate data, in which the maximum and minimum values are easily highlighted, we plotted graphical representation of the regression equations in order to explain interaction of the variables and locate the optimal level of each variable for maximal response. For the calculation of the regression coefficients, dispersion and correlation coefficients, the software Matlab was used.

Examination of the Position Accuracy of Implant Abutments Reproduced by Intra-Oral Optical Impression

PubMed Central

Odaira, Chikayuki; Kobayashi, Takuya; Kondo, Hisatomo

2016-01-01

An impression technique called optical impression using intraoral scanner has attracted attention in digital dentistry. This study aimed to evaluate the accuracy of the optical impression, comparing a virtual model reproduced by an intraoral scanner to a working cast made by conventional silicone impression technique. Two implants were placed on a master model. Working casts made of plaster were fabricated from the master model by silicone impression. The distance between the ball abutments and the angulation between the healing abutments of 5 mm and 7 mm height at master model were measured using Computer Numerical Control Coordinate Measuring Machine (CNCCMM) as control. Working casts were then measured using CNCCMM, and virtual models via stereo lithography data of master model were measured by a three-dimensional analyzing software. The distance between ball abutments of the master model was 9634.9 ± 1.2 μm. The mean values of trueness of the Lava COS and working casts were 64.5 μm and 22.5 μm, respectively, greater than that of control. The mean of precision values of the Lava COS and working casts were 15.6 μm and 13.5 μm, respectively. In the case of a 5-mm-height healing abutment, mean angulation error of the Lava COS was greater than that of the working cast, resulting in significant differences in trueness and precision. However, in the case of a 7-mm-height abutment, mean angulation errors of the Lava COS and the working cast were not significantly different in trueness and precision. Therefore, distance errors of the optical impression were slightly greater than those of conventional impression. Moreover, the trueness and precision of angulation error could be improved in the optical impression using longer healing abutments. In the near future, the development of information technology could enable improvement in the accuracy of the optical impression with intraoral scanners. PMID:27706225

Technetium Getters to Improve Cast Stone Performance

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

Neeway, James J.; Lawter, Amanda R.; Serne, R. Jeffrey

2015-10-15

The cementitious material known as Cast Stone has been selected as the preferred waste form for solidification of aqueous secondary liquid effluents from the Hanford Tank Waste Treatment and Immobilization Plant (WTP) process condensates and low-activity waste (LAW) melter off-gas caustic scrubber effluents. Cast Stone is also being evaluated as a supplemental immobilization technology to provide the necessary LAW treatment capacity to complete the Hanford tank waste cleanup mission in a timely and cost effective manner. Two radionuclides of particular concern in these waste streams are technetium-99 (99Tc) and iodine-129 (129I). These radioactive tank waste components contribute the most tomore » the environmental impacts associated with the cleanup of the Hanford site. A recent environmental assessment of Cast Stone performance, which assumes a diffusion controlled release of contaminants from the waste form, calculates groundwater in excess of the allowable maximum permissible concentrations for both contaminants. There is, therefore, a need and an opportunity to improve the retention of both 99Tc and 129I in Cast Stone. One method to improve the performance of Cast Stone is through the addition of “getters” that selectively sequester Tc and I, therefore reducing their diffusion out of Cast Stone. In this paper, we present results of Tc and I removal from solution with various getters with batch sorption experiments conducted in deionized water (DIW) and a highly caustic 7.8 M Na Ave LAW simulant. In general, the data show that the selected getters are effective in DIW but their performance is comprised when experiments are performed with the 7.8 M Na Ave LAW simulant. Reasons for the mitigated performance in the LAW simulant may be due to competition with Cr present in the 7.8 M Na Ave LAW simulant and to a pH effect.« less

A comparison of the accuracy of polyether, polyvinyl siloxane, and plaster impressions for long-span implant-supported prostheses.

PubMed

Hoods-Moonsammy, Vyonne J; Owen, Peter; Howes, Dale G

2014-01-01

The purpose of this study was to compare the capacity of different impression materials to accurately reproduce the positions of five implant analogs on a master model by comparing the resulting cast with the stainless steel master model. The study was motivated by the knowledge that distortions can occur during impression making and the pouring of casts and that this distortion may produce inaccuracies of subsequent restorations, especially long-span castings for implant superstructures. The master model was a stainless steel model with five implant analogs. The impression materials used were impression plaster (Plastogum, Harry J Bosworth), a polyether (Impregum Penta, 3M ESPE), and two polyvinyl siloxane (PVS) materials (Aquasil Monophase and Aquasil putty with light-body wash, Dentsply). Five impressions were made with each impression material and cast in die stone under strictly controlled laboratory conditions. The positions of the implants on the master model, the impression copings, and the implant analogs in the subsequent casts were measured using a coordinate measuring machine that measures within 4 μm of accuracy. Statistical analyses indicated that distortion occurred in all of the impression materials, but inconsistently. The PVS monophase material reproduced the master model most accurately. Although there was no significant distortion between the impressions and the master model or between the impressions and their casts, there were distortions between the master model and the master casts, which highlighted the cumulative effects of the distortions. The polyether material proved to be the most reliable in terms of predictability. The impression plaster displayed cumulative distortion, and the PVS putty with light body showed the least reliability. Some of the distortions observed are of clinical significance and likely to contribute to a lack of passive fit of any superstructure. The inaccuracy of these analog materials and procedures suggested that greater predictability may lie in digital technology.

Development of volume deposition on cast iron by additive manufacturing

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

Sridharan, Niyanth; Dehoff, Ryan R.; Jordan, Brian H.

2016-11-10

ORNL partnered with Cummins to demonstrate the feasibility of using additive manufacturing techniques to help develop repair techniques for refurbished cast iron engine blocks. Cummins is interested in the refurbished engine business due to the increased cost savings and reduced emissions. It is expected that by refurbishing engines could help reduce the green house gas emissions by as much as 85%. Though such repair techniques are possible in principle there has been no major industry in the automotive sector that has deployed this technology. Therefore phase-1 would seek to evaluate the feasibility of using the laser directed energy deposition techniquemore » to repair cast iron engine blocks. The objective of the phase-1 would be to explore various strategies and understand the challenges involved. During phase-1 deposits were made using Inconel-718, Nickel, Nr-Cr-B braze filler. Inconel 718 builds showed significant cracking in the heat-affected zone in the cast iron. Nickel was used to reduce the cracking in the cast iron substrate, however the Ni builds did not wet the substrate sufficiently resulting in poor dimensional tolerance. In order to increase wetting the Ni was alloyed with the Ni-Cr-B braze to decrease the surface tension of Ni. This however resulted in significant cracks in the build due to shrinkage stresses associated with multiple thermal cycling. Hence to reduce the residual stresses in the builds the DMD-103D equipment was modified and the cast iron block was pre heated using cartridge heaters. Inconel-718 alloyed with Ni was deposited on the engine block. The pre-heated deposits showed a reduced susceptibility to cracking. If awarded the phase-2 of the project would aim to develop process parameters to achieve a crack free deposit engine block.« less

Population differentiation of southern Indian male lineages correlates with agricultural expansions predating the caste system.

PubMed

Arunkumar, Ganeshprasad; Soria-Hernanz, David F; Kavitha, Valampuri John; Arun, Varatharajan Santhakumari; Syama, Adhikarla; Ashokan, Kumaran Samy; Gandhirajan, Kavandanpatti Thangaraj; Vijayakumar, Koothapuli; Narayanan, Muthuswamy; Jayalakshmi, Mariakuttikan; Ziegle, Janet S; Royyuru, Ajay K; Parida, Laxmi; Wells, R Spencer; Renfrew, Colin; Schurr, Theodore G; Smith, Chris Tyler; Platt, Daniel E; Pitchappan, Ramasamy

2012-01-01

Previous studies that pooled Indian populations from a wide variety of geographical locations, have obtained contradictory conclusions about the processes of the establishment of the Varna caste system and its genetic impact on the origins and demographic histories of Indian populations. To further investigate these questions we took advantage that both Y chromosome and caste designation are paternally inherited, and genotyped 1,680 Y chromosomes representing 12 tribal and 19 non-tribal (caste) endogamous populations from the predominantly Dravidian-speaking Tamil Nadu state in the southernmost part of India. Tribes and castes were both characterized by an overwhelming proportion of putatively Indian autochthonous Y-chromosomal haplogroups (H-M69, F-M89, R1a1-M17, L1-M27, R2-M124, and C5-M356; 81% combined) with a shared genetic heritage dating back to the late Pleistocene (10-30 Kya), suggesting that more recent Holocene migrations from western Eurasia contributed <20% of the male lineages. We found strong evidence for genetic structure, associated primarily with the current mode of subsistence. Coalescence analysis suggested that the social stratification was established 4-6 Kya and there was little admixture during the last 3 Kya, implying a minimal genetic impact of the Varna (caste) system from the historically-documented Brahmin migrations into the area. In contrast, the overall Y-chromosomal patterns, the time depth of population diversifications and the period of differentiation were best explained by the emergence of agricultural technology in South Asia. These results highlight the utility of detailed local genetic studies within India, without prior assumptions about the importance of Varna rank status for population grouping, to obtain new insights into the relative influences of past demographic events for the population structure of the whole of modern India.

Light weight and high strength materials made of recycled steel and aluminum

NASA Astrophysics Data System (ADS)

Nounezi, Thomas

Recycling has proven not only to address today's economical, environmental and social issues, but also to be imperative for the sustainability of human technology. The current thesis has investigated the feasibility of a new philosophy for Recycling (Alloying-Recycling) using steel 1020 and aluminum 6061T6. The study was limited to the metallurgical aspects only and has highlighted the potential of recycled alloys made of recycled aluminum and steel to exhibit substantially increased wear resistance and strength-to-weight ratio as compared to initial primary materials. Three alloy-mixtures are considered: TN3 (5wt% 1020 +95wt% 6061T6); TN5 (0.7wt% 1020 + 99.3wt% 6061T6); and TN4 (10wt% 6061T6 + 90wt% 1020). A Tucker induction power supply system (3kW; 135-400 kHz) is used to melt the alloy mixtures for casting in graphite crucibles. Heat treatment of the cast samples is done using a radiation box furnace. Microscopy, Vickers hardness and pin-on-disc abrasive wear tests are performed. Casting destroyed the initial microstructures of the alloys leading to a hardness reduction in the as-cast and solution heat-treated aluminum rich samples to 60 Hv from 140 Hv. Ageing slightly increased the hardness of the cast samples and provided a wear resistance two times higher than that of the initial 6061T6 material. On the steel rich side, the hardness of the as-cast TN4 was 480 Hv, which is more than twice as high as the initial hardness of steel 1020 of 202 Hv; this hints to strong internal and residual stress, probably martensite formation during fast cooling following casting. Solution heat treatment lowered the hardness to the original value of steel 1020, but provided about ten (10) times higher wear resistance; this suggests higher ductility and toughness of normalised TN4 as compared to 1020. In addition, TN4 exhibits about 25% weight reduction as compared to 1020. The actual recycling process and the effect of non-metallic impurities shall be investigated in future works. Also, the casting and heat treatment processes need to be improved.

Tutorial Video Series: Using Stakeholder Outreach to Increase ...

EPA Pesticide Factsheets

The limited amount of toxicity data on thousands of chemicals found in consumer products has led to the development of research endeavors such as the U.S. EPA’s Toxicity Forecaster (ToxCast). ToxCast uses high-throughput screening technology to evaluate thousands of chemicals for potential toxicity. At the end of 2013, U.S. EPA released ToxCast chemical data on almost 2,000 chemicals through the interactive Chemical Safety for Sustainability (iCSS) Dashboard. The iCSS Dashboard provides public access to the high-throughput screening data that can be used to inform the evaluation of the safety of chemicals. U.S. EPA recognized early in the development of ToxCast that stakeholder outreach was needed in order to translate the complex scientific information featured in the iCSS Dashboard and data, with the goal of educating the diverse user community through targeted efforts to increase data usage and analysis. Through survey feedback and the request of stakeholders, a series of tutorial videos to demonstrate how to access and use the data has been planned, and the first video of the series has been released to guide data usage. This presentation will describe the video tutorial strategy including an overview of: 1) Stakeholder outreach goals and approach; 2) Planning, production, and dissemination of tutorial videos; 3) Overview of Survey Feedback; 4) Overview of tutorial video usage statistics and usage of the ToxCast data. This stakeholder-outreach approach

Multiphase materials with lignin. VI. Effect of cellulose derivative structure on blend morphology with lignin

Treesearch

Timothy G. Rials; Wolfgang G. Glasser

1989-01-01

Polymeric blends of lignin with ethyl cellulose (EC) and cellulose acetate/butyrate (CAB) prepared by solution casting from dioxane. Fracture surface analysis by scanning electron microscopy revealed phase separation when the lignin content exceeded 10% for blends with EC and 5% in the CAB system. While this phase behavior is as predicted for the EC blends, a greater...

In Situ Cross-Linking of Polyvinyl Alcohol Films

NASA Technical Reports Server (NTRS)

Philipp, W. H.; Shu, L. C.; May, C. E.

1984-01-01

Films or impregnated matrices readily made from aqueous polyvinyl alcohol solution. Controlled thickness films made by casting precise quantities of aqueous polymer solution on smooth surface, allowing water to evaporate and then removing film. Composite separators formed in similar fashion by impregnating cloth matrix with polyvinyl alcohol solution and drying composite. Insoluble thin hydrophilic membranes made from aqueous systems, and use of undesirable organic solvents not required.

Directional Unfolded Source Term (DUST) for Compton Cameras.

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

Mitchell, Dean J.; Horne, Steven M.; O'Brien, Sean

2018-03-01

A Directional Unfolded Source Term (DUST) algorithm was developed to enable improved spectral analysis capabilities using data collected by Compton cameras. Achieving this objective required modification of the detector response function in the Gamma Detector Response and Analysis Software (GADRAS). Experimental data that were collected in support of this work include measurements of calibration sources at a range of separation distances and cylindrical depleted uranium castings.

Enhanced protein electrophoresis technique for separating human skeletal muscle myosin heavy chain isoforms

NASA Technical Reports Server (NTRS)

Bamman, M. M.; Clarke, M. S.; Talmadge, R. J.; Feeback, D. L.

1999-01-01

Talmadge and Roy (J. Appl. Physiol. 1993, 75, 2337-2340) previously established a sodium dodecyl sulfate - polyacrylamide gel electrophoresis (SDS-PAGE) protocol for separating all four rat skeletal muscle myosin heavy chain (MHC) isoforms (MHC I, IIa, IIx, IIb); however, when applied to human muscle, the type II MHC isoforms (Ila, IIx) are not clearly distinguished. In this brief paper we describe a modification of the SDS-PAGE protocol which yields distinct and consistent separation of all three adult human MHC isoforms (MHC I, IIa, IIx) in a minigel system. MHC specificity of each band was confirmed by Western blot using three monoclonal IgG antibodies (mAbs) immunoreactive against MHCI (mAb MHCs, Novacastra Laboratories), MHCI+IIa (mAb BF-35), and MHCIIa+IIx (mAb SC-71). Results provide a valuable SDS-PAGE minigel technique for separating MHC isoforms in human muscle without the difficult task of casting gradient gels.

[Bonding agent influence on shear bond strength of titanium/polyglass interface].

PubMed

Oyafuso, Denise Kanashiro; Bottino, Marco Antonio; Itinoche, Marcos Koiti; Nasraui, Anna Paula; Costa, Elza Maria Valadares da

2003-09-01

There is little information regarding bond strengths of polyglass to metal alloys. This study evaluated the influence of bonding system on shear bond strength of a composite resin (Artglass/Heraeus Kulzer) to cast titanium (Ti). Twenty metallic structures (4mm in diameter, 5mm thick) of titanium grade I were cast shaped and abraded with 250mm aluminum oxide and separated into two groups. For each group was applied one bonding system (Siloc or Retention Flow) before opaque and dentin polymer superposition. This procedure was managed using teflon matrices. They were manipulated and polymerized according to the manufacturer's recommendations. The samples were stored in distilled water for 24 hours at 37º and thermocycled (5º and 55ºC/500 cycles). Shear bond strength tests were performed by using an Instron Universal testing machine at a crosshead speed of 5mm/min. Results were analyzed statistically with one-way ANOVA (a=0,5) and they indicated that the Retention Flow system was statistically better than Siloc (20.74 MPa and 11.65 MPa , respectively). It was possible to conclude that the bonding agent influenced the adhesion between polymer and cast titanium.

Magnetically assisted slip casting of bioinspired heterogeneous composites

NASA Astrophysics Data System (ADS)

Le Ferrand, Hortense; Bouville, Florian; Niebel, Tobias P.; Studart, André R.

2015-11-01

Natural composites are often heterogeneous to fulfil functional demands. Manufacturing analogous materials remains difficult, however, owing to the lack of adequate and easily accessible processing tools. Here, we report an additive manufacturing platform able to fabricate complex-shaped parts exhibiting bioinspired heterogeneous microstructures with locally tunable texture, composition and properties, as well as unprecedentedly high volume fractions of inorganic phase (up to 100%). The technology combines an aqueous-based slip-casting process with magnetically directed particle assembly to create programmed microstructural designs using anisotropic stiff platelets in a ceramic, metal or polymer functional matrix. Using quantitative tools to control the casting kinetics and the temporal pattern of the applied magnetic fields, we demonstrate that this approach is robust and can be exploited to design and fabricate heterogeneous composites with thus far inaccessible microstructures. Proof-of-concept examples include bulk composites with periodic patterns of microreinforcement orientation, and tooth-like bilayer parts with intricate shapes exhibiting site-specific composition and texture.

Genetic variations in the Dravidian population of South West coast of India: Implications in designing case-control studies.

PubMed

D'Cunha, Anitha; Pandit, Lekha; Malli, Chaithra

2017-06-01

Indian data have been largely missing from genome-wide databases that provide information on genetic variations in different populations. This hinders association studies for complex disorders in India. This study was aimed to determine whether the complex genetic structure and endogamy among Indians could potentially influence the design of case-control studies for autoimmune disorders in the south Indian population. A total of 12 single nucleotide variations (SNVs) related to genes associated with autoimmune disorders were genotyped in 370 healthy individuals belonging to six different caste groups in southern India. Allele frequencies were estimated; genetic divergence and phylogenetic relationship within the various caste groups and other HapMap populations were ascertained. Allele frequencies for all genotyped SNVs did not vary significantly among the different groups studied. Wright's FSTwas 0.001 per cent among study population and 0.38 per cent when compared with Gujarati in Houston (GIH) population on HapMap data. The analysis of molecular variance results showed a 97 per cent variation attributable to differences within the study population and <1 per cent variation due to differences between castes. Phylogenetic analysis showed a separation of Dravidian population from other HapMap populations and particularly from GIH population. Despite the complex genetic origins of the Indian population, our study indicated a low level of genetic differentiation among Dravidian language-speaking people of south India. Case-control studies of association among Dravidians of south India may not require stratification based on language and caste.

LOCATING LEAKS WITH ACOUSTIC TECHNOLOGY

EPA Science Inventory

Many water distribution systems in this country are almost 100 years old. About 26 percent of piping in these systems is made of unlined cast iron or steel and is in poor condition. Many methods that locate leaks in these pipes are time-consuming, costly, disruptive to operations...

Ultra-Light Precision Membrane Optics

NASA Technical Reports Server (NTRS)

Moore, Jim; Gunter, Kent; Patrick, Brian; Marty, Dave; Bates, Kevin; Gatlin, Romona; Clayton, Bill; Rood, Bob; Brantley, Whitt (Technical Monitor)

2001-01-01

SRS Technologies and NASA Marshall Space Flight Center have conducted a research effort to explore the possibility of developing ultra-lightweight membrane optics for future imaging applications. High precision optical flats and spherical mirrors were produced under this research effort. The thin film mirrors were manufactured using surface replication casting of CPI(Trademark), a polyimide material developed specifically for UV hardness and thermal stability. In the course of this program, numerous polyimide films were cast with surface finishes better than 1.5 nanometers rms and thickness variation of less than 63 nanometers. Precision membrane optical flats were manufactured demonstrating better than 1/13 wave figure error when measured at 633 nanometers. The aerial density of these films is 0.037 kilograms per square meter. Several 0.5-meter spherical mirrors were also manufactured. These mirrors had excellent surface finish (1.5 nanometers rms) and figure error on the order of tens of microns. This places their figure error within the demonstrated correctability of advanced wavefront correction technologies such as real time holography.

A new lead alloy for automotive batteries operating under high-temperature conditions

NASA Astrophysics Data System (ADS)

Albert, L.; Goguelin, A.; Jullian, E.

The operating conditions of automotive and some industrial batteries are involving increasingly higher temperatures and heavier duty cycles. These place stress on the positive-grid materials which are presently not sufficiently resistant to corrosion and to creep. Conventional lead-calcium-tin-aluminium alloys can usually be optimized by a proper choice of calcium and tin contents for each specific manufacturing technology. With the new requirements of customers and the typical behaviour of these conventional alloys, however, there is no more room for improvement without searching for additional alloying elements. The work reported here shows how the doping of conventional lead-calcium-tin-aluminium alloys with barium improves mechanical properties (tensile strength and creep resistance) and increases corrosion resistance at temperatures between 50 and 75°C. Grid materials prepared by two manufacturing technologies (gravity cast; continuous cast followed by expansion) are investigated. Both the mechanical properties and the corrosion behaviour of the resulting grids are evaluated.

Nanostructured membranes based on polysulfone homopolymers and copolymers

NASA Astrophysics Data System (ADS)

Nunes, Suzana

Polyethersulfone is one of the most successful polymers for membranes with applications varying from seawater desalination to hemodialysis. Their manufacture however is traditionally done by solution casting and phase inversion using solvents, which are now considered negative for the environment. We have been working on the membrane manufacture using ionic liquids as green solvent alternative. Polyethersulfone, and polyetherimide sulfone membranes, as flat-sheet and hollow fibers, were prepared from solutions in different ionic liquids. Thermodynamic and rheological investigation were conducted to optimize the membrane morphology, leading to permeances of 20-65 Lm-2h-1bar-1 useful for instance for separations of peptides with molecular weight in the range of 800 to 3500 gmol-1. We also synthesized block copolymers with polysulfone segments and explored them for membrane preparation with low fouling, high porosity and narrow pore size distribution. The self-assembly of the copolymer in solution, leading to the membrane formation was investigated by cryo electron microscopy, supported by modeling (dissipative particle dynamics). In collaboration with: Dooli Kim, Yihui xie, Burhannudin Sutisna, King Abdullah University of Science and Technology

Skylab observations of X-ray loops connecting separate active regions. [solar activity

NASA Technical Reports Server (NTRS)

Chase, R. C.; Krieger, A. S.; Svestka, Z.; Vaiana, G. S.

1976-01-01

One hundred loops interconnecting 94 separate active solar regions detectable in soft X-rays were identified during the Skylab mission. While close active regions are commonly interconnected with loops, the number of such interconnections decreases steeply for longer distances; the longest interconnecting loop observed in the Skylab data connected regions separated by 37 deg. Several arguments are presented which support the point of view that this is the actual limit of the size of magnetic interconnections between active regions. No sympathetic flares could be found in the interconnected regions. These results cast doubt on the hypothesis that accelerated particles can be guided in interconnecting loops from one active region to another over distances of 100 deg or more and eventually produce sympathetic flares in them.

Hybrid digital-analog video transmission in wireless multicast and multiple-input multiple-output system

NASA Astrophysics Data System (ADS)

Liu, Yu; Lin, Xiaocheng; Fan, Nianfei; Zhang, Lin

2016-01-01

Wireless video multicast has become one of the key technologies in wireless applications. But the main challenge of conventional wireless video multicast, i.e., the cliff effect, remains unsolved. To overcome the cliff effect, a hybrid digital-analog (HDA) video transmission framework based on SoftCast, which transmits the digital bitstream with the quantization residuals, is proposed. With an effective power allocation algorithm and appropriate parameter settings, the residual gains can be maximized; meanwhile, the digital bitstream can assure transmission of a basic video to the multicast receiver group. In the multiple-input multiple-output (MIMO) system, since nonuniform noise interference on different antennas can be regarded as the cliff effect problem, ParCast, which is a variation of SoftCast, is also applied to video transmission to solve it. The HDA scheme with corresponding power allocation algorithms is also applied to improve video performance. Simulations show that the proposed HDA scheme can overcome the cliff effect completely with the transmission of residuals. What is more, it outperforms the compared WSVC scheme by more than 2 dB when transmitting under the same bandwidth, and it can further improve performance by nearly 8 dB in MIMO when compared with the ParCast scheme.

Manufacturing and operational issues with lead-acid batteries

NASA Astrophysics Data System (ADS)

Rand, D. A. J.; Boden, D. P.; Lakshmi, C. S.; Nelson, R. F.; Prengaman, R. D.

An expert panel replies to questions on lead-acid technology and performance asked by delegates to the Ninth Asian Battery Conference. The subjects are as follows. Grid alloys: effects of calcium and tin levels on microstructure, corrosion, mechanical and electrochemical properties; effect of alloy-fabrication process on mechanical strength and corrosion resistance; low dross-make during casting of lead-calcium-tin alloys; future of book-mould casting; effect of increasing levels of silver; stability of continuously processed grids at high temperature. Negative-plate expanders: function of lignosulfonates and barium sulfate; benefits of pre-blended expanders; optimum expander formulations. Valve-regulated batteries: effect of oxygen cycle; optimum methods for float charging; charging and deep-cycle lifetimes; reliability testing.

12 CFR 611.100 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-01-01

... means a ballot cast by regular or electronic mail. (d) Online meeting means a meeting that is conducted over the Internet through the use of mediating technologies, such as online services, computer hardware... way during the course of the meeting. (e) Online meeting space means an online environment where Farm...

12 CFR 611.100 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-01-01

... means a ballot cast by regular or electronic mail. (d) Online meeting means a meeting that is conducted over the Internet through the use of mediating technologies, such as online services, computer hardware... way during the course of the meeting. (e) Online meeting space means an online environment where Farm...

Defining the taxonomic domain of applicability for mammalian-based high-throughput screening assays

EPA Science Inventory

Cell-based high throughput screening (HTS) technologies are becoming mainstream in chemical safety evaluations. The US Environmental Protection Agency (EPA) Toxicity Forecaster (ToxCastTM) and the multi-agency Tox21 Programs have been at the forefront in advancing this science, m...

Manufacturing Methods and Technology Project Summary Reports

DTIC Science & Technology

1983-06-01

Proposal will be prepared by Solar Turbines, Inc. for introduction of cast titanium impellers into T62T-40 production. Detroit Diesel Allison will...microprocessor con- trol, RS 232 serial zommunications ports, binary I/O ports, floppy disk mass storage and cor.-rol panal . A component pickup

[Optimization theory and practical application of membrane science technology based on resource of traditional Chinese medicine residue].

PubMed

Zhu, Hua-Xu; Duan, Jin-Ao; Guo, Li-Wei; Li, Bo; Lu, Jin; Tang, Yu-Ping; Pan, Lin-Mei

2014-05-01

Resource of traditional Chinese medicine residue is an inevitable choice to form new industries characterized of modem, environmental protection and intensive in the Chinese medicine industry. Based on the analysis of source and the main chemical composition of the herb residue, and for the advantages of membrane science and technology used in the pharmaceutical industry, especially membrane separation technology used in improvement technical reserves of traditional extraction and separation process in the pharmaceutical industry, it is proposed that membrane science and technology is one of the most important choices in technological design of traditional Chinese medicine resource industrialization. Traditional Chinese medicine residue is a very complex material system in composition and character, and scientific and effective "separation" process is the key areas of technology to re-use it. Integrated process can improve the productivity of the target product, enhance the purity of the product in the separation process, and solve many tasks which conventional separation is difficult to achieve. As integrated separation technology has the advantages of simplified process and reduced consumption, which are in line with the trend of the modern pharmaceutical industry, the membrane separation technology can provide a broad platform for integrated process, and membrane separation technology with its integrated technology have broad application prospects in achieving resource and industrialization process of traditional Chinese medicine residue. We discuss the principles, methods and applications practice of effective component resources in herb residue using membrane separation and integrated technology, describe the extraction, separation, concentration and purification application of membrane technology in traditional Chinese medicine residue, and systematically discourse suitability and feasibility of membrane technology in the process of traditional Chinese medicine resource industrialization in this paper.

Ultrasonically assisted single screw extrusion, film blowing and film casting of LLDPE/clay and PA6/clay nanocomposites

NASA Astrophysics Data System (ADS)

Niknezhad, Setareh

The major objective of this study was to investigate the effect of ultrasonic treatment on the dispersion of modified clay particles in LLDPE and PA6 matrices and the final properties of nanocomposites. LLDPE and PA6 are two polymers that are widely used in packaging industry. Blown and cast films were manufactured from the prepared nanocomposites. To achieve one step film processing, an online ultrasonic film casting was developed. Ultrasonic waves caused high-energy mixing and dispersion due to the acoustic cavitation, causing the clay agglomorates to separate into individual platelets in polymer matrix. Ultrasonic waves also broke down the polymer molecular chains reducing viscosity of the melt, facilating dispersion of the clay platelets throughout the matrix. Ultrasound also led to a breakage of the clay platelets reducing the particle size and improving their distribution. Clay particles acted as a heterogenous nucleation agent generating smaller size polymer crystals. In turn, these improved different properties including mechanical properties, oxygen permeability and transparency of films. In LLDPE/clay 20A nanocomposites, the effect of ultrasound was more obvious at higher clay loadings. Exfoliated structure for ultrasonically treated nanocomposites containing 2.5, 5 and 7.5 wt% of clay 20A and highly intercalated structure for ultrasonically treated nanocomposites containing 10 wt% of clay 20A were achieved. However, in blown films, the exfoliated structure transferred to the intercalated structure due to the addition of more shear and thermal degradation of surfactants of the clay particles. While, manufacturing cast films using the new developed online ultrasonic cast film machine revealed the exfoliated structure with ultrasonic treatment till 7.5 wt% of clay loadings. Cast films of nanocomposites containing 5 wt% of clay loadings were also prepared with addition of different compatibilizers. The compatibilizer containing higher amount of grafted maleic anhydride (MA) affected mechanical properties and oxygen permeability with ultrasonic treatment to higher extent. However, use of compatibilizers led to a higher die pressure and resulted in opaque cast films. The mechanical properties were in agreement with crystallinity of samples. The exfoliated structure was achieved for PA6/clay 30B nanocomposites prepared using ultrasonically assisted single screw extrusion except for untreated nanocomposites containing 10 wt% of clay 30B. Untreated 92.5/7.5 and 90/10 PA6/clay 30B blown films showed the intercalated structure, but the exfoliated structure was achieved with ultrasonic treatment. All cast films of PA6/clay 30B showed the exfoliated structure. FTIR spectroscopy along with XRD results confirmed the existence of alpha and gamma-type crystals in the cast films, with clay particles favoring the formation of gamma-type crystals, and ultrasonic treatment favoring the formation of alpha-type crystals. Both parameters increased crystallinity of cast films improving their mechanical properties and oxygen permeability.

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

Bullion to B-fields: The Silver Program of the Manhattan Project

NASA Astrophysics Data System (ADS)

Reed, Cameron

2010-04-01

Between October 1942 and September 1944, over 14,000 tons of silver bullion bars withdrawn form the U.S. Treasury were melted and cast into magnet coils and busbar pieces for the ``calutron'' electromagnetic isotope-separators constructed at Oak Ridge. Based on Manhattan Engineer District documents, this paper will review the history of this ``Silver Program,'' including discussions of the contractors, production methods, and quantities of materials involved.

Bullion to B-fields: The Silver Program of the Manhattan Project

NASA Astrophysics Data System (ADS)

Reed, Cameron

2010-02-01

Between October 1942 and September 1944, over 14,000 tons of silver bullion bars withdrawn from the U. S. Treasury were melted and cast into magnet coils and busbar pieces for the ``calutron'' electromagnetic isotope-separators constructed at Oak Ridge. Based on Manhattan Engineer District documents, this paper will review the history of this ``Silver Program,'' including discussions of the contractors, production methods, and quantities of material involved. )

Honeycomb Films with Core-Shell Dispersed Phases Prepared by the Combination of Breath Figures and Phase Separation Process of Ternary Blends.

PubMed

Del Campo, A; de León, A S; Rodríguez-Hernández, J; Muñoz-Bonilla, A

2017-03-21

Herein, we propose a strategy to fabricate core-shell microstructures ordered in hexagonal arrays by combining the breath figures approach and phase separation of immiscible ternary blends. This simple strategy to fabricate these structures involves only the solvent casting of a ternary polymer blend under moist atmosphere, which provides a facile and low-cost fabrication method to obtain the porous structures with a core-shell morphology. For this purpose, blends consisting of polystyrene (PS) as a major component and PS 40 -b-P(PEGMA300) 48 amphiphilic copolymer and polydimethylsiloxane (PDMS) as minor components were dissolved in tetrahydrofuran and cast onto glass wafers under humid conditions, 70% of relative humidity. The resulting porous morphologies were characterized by optical and confocal Raman microscopy. In particular, confocal Raman results demonstrated the formation of core-shell morphologies into the ordered pores, in which the PS forms the continuous matrix, whereas the other two phases are located into the cavities (PDMS is the core while the amphiphilic copolymer is the shell). Besides, by controlling the weight ratio of the polymer blends, the structural parameters of the porous structure such as pore diameter and the size of the core can be effectively tuned.

Negatively charged polysulfone membranes with hydrophilicity and antifouling properties based on in situ cross-linked polymerization.

PubMed

Zhu, Lijing; Song, Haiming; Zhang, Dawei; Wang, Gang; Zeng, Zhixiang; Xue, Qunji

2017-07-15

Polysulfone (PSf) membrane has been widely used in water separation and purification, although, membrane fouling is still a serious problem limiting its potential. We aim to improve the antifouling of PSf membranes via a very simple and efficient method. In this work, antifouling PSf membranes were fabricated via in situ cross-linked polymerization coupled with non-solvent induced phase separation. In brief, acrylic acid (AA) and vinyltriethoxysilane (VTEOS) were copolymerized in PSf solution, then directly casted into membranes without purification. With the increase of monomers concentration, the morphology of the as-cast membranes changed from a finger-like morphology to a fully sponge-like structure due to the increased viscosity and decreased precipitation rate of the polymer solutions. Meanwhile, the hydrophilicity and electronegativity of modified membranes were highly improved leading to inhibited protein adsorption and improved antifouling property. Furthermore, in order to further find out the different roles player by AA and VTESO, the modified membrane without VTEOS was prepared and characterized. The results indicated that AA is more effective in the membrane hydrophilicity improvement, VTEOS is more crucial to improve membrane stability. This work provides valuable guidance for fabricating PSf membranes with hydrophilicity and antifouling property via in situ cross-linked polymerization. Copyright © 2017 Elsevier Inc. All rights reserved.

Advanced Industrial Materials (AIM) program. Annual progress report. FY 1996

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

NONE

1997-04-01

The Advanced Industrial Materials (AIM) Program underwent a major transformation in Fiscal Year 1995 and these changes have continued to the present. When the Program was established in 1990 as the Advanced Industrial Concepts (AIC) Materials Program, the mission was to conduct applied research and development to bring materials and processing technologies from the knowledge derived from basic research to the maturity required for the end use sectors for commercialization. In 1995, the Office of Industrial Technologies (OIT) made radical changes in structure and procedures. All technology development was directed toward the seven `Vision Industries` that use about 80% ofmore » industrial energy and generated about 90% of industrial wastes. These are: aluminium; chemical; forest products; glass; metal casting; refineries; and steel. OIT is working with these industries, through appropriate organizations, to develop Visions of the desired condition of each industry some 20 or 25 years in the future and then to prepare Road Maps and Implementation Plans to enable them to reach their goals. The mission of AIM has, therefore, changed to `Support development and commercialization of new or improved materials to improve productivity, product quality, and energy efficiency in the major process industries.` Though AIM remains essentially a National Laboratory Program, it is necessary that each project have industrial partners, including suppliers to, and customers of, the seven industries. Now, well into FY 1996, the transition is nearly complete and the AIM Program remains healthy and productive, thanks to the superb investigators and Laboratory Program Managers. Separate abstracts have been indexed into the energy database for articles from this report.« less

Development and Technology of Large Thickness TMCP Steel Plate with 390MPA Grade Used for Engineering Machinery

NASA Astrophysics Data System (ADS)

Wang, Xiaoshu; Zhang, Zhijun; Zhang, Peng

Recently, with the rapid upgrading of the equipment in the steel Corp, the rolling technology of TMCP has been rapidly developed and widely applied. A large amount of steel plate has been produced by using the TMCP technology. The TMCP processes have been used more and more widely and replaced the heat treatment technology of normalizing, quenching and tempering heat process. In this paper, low financial input is considered in steel plate production and the composition of the steel has been designed with low C component, a limited alloy element of the Nb, and certain amounts of Mn element. During the continuous casting process, the size of the continuous casting slab section is 300 mm × 2400 mm. The rolling technology of TMCP is controlled at a lower rolling and red temperature to control the transformation of the microstructure. Four different rolling treatments are chosen to test its effects on the 390MPa grade low carbon steel of bainitic microstructure and properties. This test manages to produce a proper steel plate fulfilling the standard mechanical properties. Specifically, low carbon bainite is observed in the microstructure of the steel plate and the maximum thickness of steel plate under this TMCP technology is up to 80mm. The mechanical property of the steel plate is excellent and the KV2 at -40 °C performs more than 200 J. Moreover, the production costs are greatly reduced when the steel plate is produced by this TMCP technology when replacing the current production process of quenching and tempering. The low cost steel plate could well meet the requirements of producing engineering machinery in the steel market.

Re-Casting the U.S.-Mexico Border Security Net

DTIC Science & Technology

2014-03-01

the best fence money can buy , and they counter us with a 2,500-year-old technology.214 The incident proved that these organizations are extremely...created a demand that has attracted illicit activity. DTOs have expanded their franchises to increase the size of their profits. Border security

Student Cooperative Training Units. Business Partnerships Final Performance Report.

ERIC Educational Resources Information Center

Wheeles, Rebecca

The North Clackamas School District (Oregon) conducted the Student Cooperative Training Units (CTU) program. The CTU program addressed two key issues that disrupted the development and maintenance of local high technology businesses: (1) The aerospace parts casting, health care, and graphic reproduction industries have experienced a shortage of…

Using ToxCast data to reconstruct dynamic cell state trajectories and estimate toxicological points of departure

EPA Science Inventory

AbstractBackground. High-throughput in vitro screening is an important tool for evaluating the potential biological activity of the thousands of existing chemicals in commerce and the hundreds more introduced each year. Among the assay technologies available, high-content imaging...

Industrial Location Research Studies: Reports 17-25.

ERIC Educational Resources Information Center

Fantus Co., Inc., New York, NY.

Nine industrial-location research studies of the Appalachian region are presented in this document. These studies relate to the casting, plastic, metal, and food industries. Each study devotes sections to (1) a profile of the industry, (2) the industry's prospects for growth, (3) technology and trends, (4) primary factors influencing selection of…

Internet's Potential to Affect Social Studies and Democracy

ERIC Educational Resources Information Center

Friedman, Adam M.

2006-01-01

Technology, and the Internet in particular, is bringing constant change to American society, including the potential to enhance democracy by fostering participation in the electoral process. Because of the wealth of information available on candidates, issues, and policies, the Internet may foster citizens' ability to cast a more informed vote. As…

Extrapolating toxicity data across species using U.S. EPA SeqAPASS tool

EPA Science Inventory

In vitro high-throughput screening (HTS) and in silico technologies have emerged as 21st century tools for chemical hazard identification. In 2007 the U.S. Environmental Protection Agency (EPA) launched the ToxCast Program, which has screened thousands of chemicals in hundreds of...

Effect of forging on mechanical properties of rice husk ash-silicon carbide reinforced Al1100 hybrid composites

NASA Astrophysics Data System (ADS)

Ghanaraja, S.; Gireesha, B. L.; Ravikumar, K. S.; Likith, P.

2018-04-01

During the past few years, material design has changed prominence to pursue light weight, environment friendliness, low cost, quality, higher service temperature, higher elastic modulus, improved wear resistance and performance. Straight monolithic materials have limitations in achieving the above decisive factors. To overcome these limitations and to convince the ever increasing demand of modern day technology, Attention has been shifted towards Metal Matrix Composites (MMC). Stir casting route is most hopeful for synthesizing discontinuous reinforcement aluminium matrix composites because of its relative simplicity and easy adaptability with all shape casting process used in metal casting industry. Hybridization of metal matrix composites is the introduction of more than one type/kind, size and shape of reinforcement during processing of composites. It is carried out to obtain synergistic properties of different reinforcements and matrix used, which may not be rea1ised in monolithic alloy or in conventional monocomposites. The present study involves synthesis of hybrid composites by addition of the desired amount of Silicon Carbide (SiC) and Rice Husk Ash (RHA) particles in to the molten Al 1100-Mg alloy through stir casting technique fallowed by hot forging of the cast composites. The influence of increasing in the wt% (3, 6, 9, 12 and 15 wt%) of SiC particles addition (3 wt% Rice husk ash kept constant) on evolution of microstructure is studied through XRD and SEM and their impact on the mechanical properties like hardness and tensile strength of the resulting forged hybrid composites has been investigated.

Energy Saving Melting and Revert Reduction Technology: Aging of Graphitic Cast Irons and Machinability

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

Richards, Von L.

2012-09-19

The objective of this task was to determine whether ductile iron and compacted graphite iron exhibit age strengthening to a statistically significant extent. Further, this effort identified the mechanism by which gray iron age strengthens and the mechanism by which age-strengthening improves the machinability of gray cast iron. These results were then used to determine whether age strengthening improves the machinability of ductile iron and compacted graphite iron alloys in order to develop a predictive model of alloy factor effects on age strengthening. The results of this work will lead to reduced section sizes, and corresponding weight and energy savings.more » Improved machinability will reduce scrap and enhance casting marketability. Technical Conclusions: Age strengthening was demonstrated to occur in gray iron ductile iron and compacted graphite iron. Machinability was demonstrated to be improved by age strengthening when free ferrite was present in the microstructure, but not in a fully pearlitic microstructure. Age strengthening only occurs when there is residual nitrogen in solid solution in the Ferrite, whether the ferrite is free ferrite or the ferrite lamellae within pearlite. Age strengthening can be accelerated by Mn at about 0.5% in excess of the Mn/S balance Estimated energy savings over ten years is 13.05 trillion BTU, based primarily on yield improvement and size reduction of castings for equivalent service. Also it is estimated that the heavy truck end use of lighter castings for equivalent service requirement will result in a diesel fuel energy savings of 131 trillion BTU over ten years.« less

Comparison of Fit of Dentures Fabricated by Traditional Techniques Versus CAD/CAM Technology.

PubMed

McLaughlin, J Bryan; Ramos, Van; Dickinson, Douglas P

2017-11-14

To compare the shrinkage of denture bases fabricated by three methods: CAD/CAM, compression molding, and injection molding. The effect of arch form and palate depth was also tested. Nine titanium casts, representing combinations of tapered, ovoid, and square arch forms and shallow, medium, and deep palate depths, were fabricated using electron beam melting (EBM) technology. For each base fabrication method, three poly(vinyl siloxane) impressions were made from each cast, 27 dentures for each method. Compression-molded dentures were fabricated using Lucitone 199 poly methyl methacrylate (PMMA), and injection molded dentures with Ivobase's Hybrid Pink PMMA. For CAD/CAM, denture bases were designed and milled by Avadent using their Light PMMA. To quantify the space between the denture and the master cast, silicone duplicating material was placed in the intaglio of the dentures, the titanium master cast was seated under pressure, and the silicone was then trimmed and recovered. Three silicone measurements per denture were recorded, for a total of 243 measurements. Each silicone measurement was weighed and adjusted to the surface area of the respective arch, giving an average and standard deviation for each denture. Comparison of manufacturing methods showed a statistically significant difference (p = 0.0001). Using a ratio of the means, compression molding had on average 41% to 47% more space than injection molding and CAD/CAM. Comparison of arch/palate forms showed a statistically significant difference (p = 0.023), with shallow palate forms having more space with compression molding. The ovoid shallow form showed CAD/CAM and compression molding had more space than injection molding. Overall, injection molding and CAD/CAM fabrication methods produced equally well-fitting dentures, with both having a better fit than compression molding. Shallow palates appear to be more affected by shrinkage than medium or deep palates. Shallow ovoid arch forms appear to benefit from the use of injection molding compared to CAD/CAM and compression molding. © 2017 by the American College of Prosthodontists.

Women's Political Empowerment and Investments in Primary Schooling in India.

PubMed

Halim, Nafisa; Yount, Kathryn M; Cunningham, Solveig A; Pande, Rohini P

2016-02-01

Using a national district-level dataset of India composed of information on investments in primary schooling (data from the District Information Survey for Education [DISE, 2007/8]) and information on demographic characteristics of elected officials (data from the Election Commission of India [ECI, 2000/04]), we examined the relationship between women's representation in State Legislative Assembly (SLA) seats and district-level investments in primary schooling. We used OLS regressions adjusting for confounders and spatial autocorrelation, and estimated separate models for North and South India. Women's representation in general SLA seats typically was negatively associated with investments in primary-school amenities and teachers; women's representation in SLA seats reserved for under-represented minorities, i.e., scheduled castes and scheduled tribes, typically was positively associated with investments in primary schooling, especially in areas addressing the basic needs of poor children. Women legislators' gender and caste identities may shape their decisions about redistributive educational policies.

Designing novel bulk metallic glass composites with a high aluminum content

PubMed Central

Chen, Z. P.; Gao, J. E.; Wu, Y.; Wang, H.; Liu, X. J.; Lu, Z. P.

2013-01-01

The long-standing challenge for forming Al-based BMGs and their matrix composites with a critical size larger than 1 mm have not been answered over the past three decades. In this paper, we reported formation of a series of BMG matrix composites which contain a high Al content up to 55 at.%. These composites can be cast at extraordinarily low cooling rates, compatible with maximum rod diameters of over a centimetre in copper mold casting. Our results indicate that proper additions of transition element Fe which have a positive heat of mixing with the main constituents La and Ce can appreciably improve the formability of the BMG matrix composites by suppressing the precipitation of Al(La,Ce) phase resulted from occurrence of the phase separation. However, the optimum content of Fe addition is strongly dependant on the total amount of the Al content in the Al-(CoCu)-(La,Ce) alloys. PMID:24284800

Designing novel bulk metallic glass composites with a high aluminum content.

PubMed

Chen, Z P; Gao, J E; Wu, Y; Wang, H; Liu, X J; Lu, Z P

2013-11-27

The long-standing challenge for forming Al-based BMGs and their matrix composites with a critical size larger than 1 mm have not been answered over the past three decades. In this paper, we reported formation of a series of BMG matrix composites which contain a high Al content up to 55 at.%. These composites can be cast at extraordinarily low cooling rates, compatible with maximum rod diameters of over a centimetre in copper mold casting. Our results indicate that proper additions of transition element Fe which have a positive heat of mixing with the main constituents La and Ce can appreciably improve the formability of the BMG matrix composites by suppressing the precipitation of Al(La,Ce) phase resulted from occurrence of the phase separation. However, the optimum content of Fe addition is strongly dependant on the total amount of the Al content in the Al-(CoCu)-(La,Ce) alloys.

Feasibility of Actively Cooled Silicon Nitride Airfoil for Turbine Applications Demonstrated

NASA Technical Reports Server (NTRS)

Bhatt, Ramakrishna T.

2001-01-01

Nickel-base superalloys currently limit gas turbine engine performance. Active cooling has extended the temperature range of service of nickel-base superalloys in current gas turbine engines, but the margin for further improvement appears modest. Therefore, significant advancements in materials technology are needed to raise turbine inlet temperatures above 2400 F to increase engine specific thrust and operating efficiency. Because of their low density and high-temperature strength and thermal conductivity, in situ toughened silicon nitride ceramics have received a great deal of attention for cooled structures. However, the high processing costs and low impact resistance of silicon nitride ceramics have proven to be major obstacles for widespread applications. Advanced rapid prototyping technology in combination with conventional gel casting and sintering can reduce high processing costs and may offer an affordable manufacturing approach. Researchers at the NASA Glenn Research Center, in cooperation with a local university and an aerospace company, are developing actively cooled and functionally graded ceramic structures. The objective of this program is to develop cost-effective manufacturing technology and experimental and analytical capabilities for environmentally stable, aerodynamically efficient, foreign-object-damage-resistant, in situ toughened silicon nitride turbine nozzle vanes, and to test these vanes under simulated engine conditions. Starting with computer aided design (CAD) files of an airfoil and a flat plate with internal cooling passages, the permanent and removable mold components for gel casting ceramic slips were made by stereolithography and Sanders machines, respectively. The gel-cast part was dried and sintered to final shape. Several in situ toughened silicon nitride generic airfoils with internal cooling passages have been fabricated. The uncoated and thermal barrier coated airfoils and flat plates were burner rig tested for 30 min without and with air cooling. Without cooling, the surface temperature of the flat plate reached approximately 2350 F. Starting with computer aided design (CAD) files of an airfoil and a flat plate with internal cooling passages, the permanent and removable mold components for gel casting ceramic slips were made by stereolithography and Sanders machines, respectively. The gel-cast part was dried and sintered to final shape. Several in situ toughened silicon nitride generic airfoils with internal cooling passages have been fabricated. The uncoated and thermal barrier coated airfoils and flat plates were burner rig tested for 30 min without and with air cooling. Without cooling, the surface temperature of the flat plate reached approximately 2350 F. With cooling, the surface temperature decreased to approximately 1910 F--a drop of approximately 440 F. This preliminary study demonstrates that a near-net-shape silicon nitride airfoil can be fabricated and that silicon nitride can sustain severe thermal shock and the thermal gradients induced by cooling and, thus, is a viable candidate for cooled components.

Non-Magnetic, Tough, Corrosion- and Wear-Resistant Knives From Bulk Metallic Glasses and Composites

NASA Technical Reports Server (NTRS)

Hoffman, Douglas C.; Potter, Benjamin

2013-01-01

Quality knives are typically fabricated from high-strength steel alloys. Depending on the application, there are different requirements for mechanical and physical properties that cause problems for steel alloys. For example, diver's knives are generally used in salt water, which causes rust in steel knives. Titanium diver's knives are a popular alternative due to their salt water corrosion resistance, but are too soft to maintain a sharp cutting edge. Steel knives are also magnetic, which is undesirable for military applications where the knives are used as a tactical tool for diffusing magnetic mines. Steel is also significantly denser than titanium (8 g/cu cm vs. 4.5 g/cu cm), which results in heavier knives for the same size. Steel is hard and wear-resistant, compared with titanium, and can keep a sharp edge during service. A major drawback of both steel and titanium knives is that they must be ground or machined into the final knife shape from a billet. Since most knives have a mirrored surface and a complex shape, manufacturing them is complex. It would be more desirable if the knife could be cast into a net or near-net shape in a single step. The solution to the deficiencies of titanium, steel, and ceramic knives is to fabricate them using bulk metallic glasses (or composites). These alloys can be cast into net or near-net shaped knives with a combination of properties that exceed both titanium and steel. A commercially viable BMG (bulk metallic glass) or composite knife is one that exhibits one or all of the following properties: It is based on titanium, has a self-sharpening edge, can retain an edge during service, is hard, is non-magnetic, is corrosion-resistant against a variety of corrosive environments, is tough (to allow for prying), can be cast into a net-shape with a mirror finish and a complex shape, has excellent wear resistance, and is low-density. These properties can be achieved in BMG and composites through alloy chemistry and processing. For each desired property for knife fabrication and performance, there is an alloy development strategy that optimizes behavior. Although BMG knives have been demonstrated as far back as 1995, they never found commercial success because they had to be ground (which presented problems because the alloys contained beryllium), they weren't low cost (because they weren't cast to a net-shape), they were brittle (because they were made with a low-quality commercial material), and they had extremely poor corrosion resistance (because corrosion was not well-understood in these materials). Ultimately, these shortcomings prevented the widespread commercialization. In the current work, the inventors have applied more than a decade of research on BMGs from Caltech and JPL to develop a better understanding of how to make BMG knives that exhibit an optimal combination of properties, processing and cost. Alloys have been developed based in titanium (and other metals), that exhibit high toughness, high hardness, excellent corrosion resistance, no ferromagnetism, edge-retaining selfsharpening, and the ability to be cast like a plastic using commercially available casting techniques (currently used by commercial companies such as Liquidmetal Technologies and Visser Precision Casting). The inventors argue that depending on the application (diving, military, tactical, utility, etc.) there is an optimal combination of design and alloy composition. Moreover, with new casting technologies not available at the inception of these materials, net-shaped knives can be cast into complex shapes that require no aftermarket forming, except for sharpening using water-cooled polishing wheel. These combinations of discoveries seek to make low-cost BMG knives commercially viable products that have no equal among metal or ceramic knives. Current work at JPL focuses on net-shape casting of these alloys and testing their mechanical properties versus commercially available knives to demonstrate their benefits.

In-situ cross linking of polyvinyl alcohol. [application to battery separator films

NASA Technical Reports Server (NTRS)

Philipp, W. H.; Hsu, L. C.; Sheibley, D. W. (Inventor)

1981-01-01

A method of producing a crosslinked polyvinyl alcohol structure, such as a battery separator membrane or electrode envelope is described. An aqueous solution of a film-forming polyvinyl alcohol is admixed with an aldehyde crosslinking agent a basic pH to inhibit crosslinking. The crosslinking agent, perferably a dialdehyde such as glutaraldehyde, is used in an amount of from about 1/2 to about 20% of the theoretical amount required to crosslink all of the hydroxyl groups of the polymer. The aqueous admixture is formed into a desired physical shape, such as by casting a sheet of the solution. The sheet is then dried to form a self-supporting film. Crosslinking is then effected by immersing the film in aqueous acid solution. The resultant product has excellent properties for use as a battery separator.

Evaluation of Technetium Getters to Improve the Performance of Cast Stone

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

Neeway, James J.; Qafoku, Nikolla P.; Serne, R. Jeffrey

2015-11-01

Cast Stone has been selected as the preferred waste form for solidification of aqueous secondary liquid effluents from the Hanford Tank Waste Treatment and Immobilization Plant (WTP) process condensates and low-activity waste (LAW) melter off-gas caustic scrubber effluents. Cast Stone is also being evaluated as a supplemental immobilization technology to provide the necessary LAW treatment capacity to complete the Hanford tank waste cleanup mission in a timely and cost effective manner. One of the major radionuclides that Cast Stone has the potential to immobilize is technetium (Tc). The mechanism for immobilization is through the reduction of the highly mobile Tc(VII)more » species to the less mobile Tc(IV) species by the blast furnace slag (BFS) used in the Cast Stone formulation. Technetium immobilization through this method would be beneficial because Tc is one of the most difficult contaminants to address at the U.S. Department of Energy (DOE) Hanford Site due to its complex chemical behavior in tank waste, limited incorporation in mid- to high-temperature immobilization processes (vitrification, steam reformation, etc.), and high mobility in subsurface environments. In fact, the Tank Closure and Waste Management Environmental Impact Statement for the Hanford Site, Richland, Washington (TC&WM EIS) identifies technetium-99 ( 99Tc) as one of the radioactive tank waste components contributing the most to the environmental impact associated with the cleanup of the Hanford Site. The TC&WM EIS, along with an earlier supplemental waste-form risk assessment, used a diffusion-limited release model to estimate the release of different contaminants from the WTP process waste forms. In both of these predictive modeling exercises, where effective diffusivities based on grout performance data available at the time, groundwater at the 100-m down-gradient well exceeded the allowable maximum permissible concentrations for 99Tc. (900 pCi/L). Recent relatively short-term (63 day) leach tests conducted on both LAW and secondary waste Cast Stone monoliths indicated that 99Tc diffusivities were at or near diffusivities where the groundwater at the 100-m down-gradient well would exceed the allowable maximum permissible 99Tc concentrations. There is, therefore, a need and an opportunity to improve the retention of Tc in the Cast Stone waste form. One method to improve the performance of the Cast Stone waste form is through the addition of “getters” that selectively sequester Tc inside Cast Stone.« less

Program Evaluation - Automotive Lightweighting Materials Program Research and Development Projects Assessment of Benefits - Case Studies No. 2

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

Das, S.

This report is the second of a series of studies to evaluate research and development (R&D) projects funded by the Automotive Lightweighting Materials (ALM) Program of the Office of Advanced Automotive Technologies (OAAT) of the U.S. Department of Energy (DOE). The objectives of the program evaluation are to assess short-run outputs and long-run outcomes that may be attributable to the ALM R&D projects. The ALM program focuses on the development and validation of advanced technologies that significantly reduce automotive vehicle body and chassis weight without compromising other attributes such as safety, performance, recyclability, and cost. Funded projects range from fundamentalmore » materials science research to applied research in production environments. Collaborators on these projects include national laboratories, universities, and private sector firms, such as leading automobile manufacturers and their suppliers. Three ALM R&D projects were chosen for this evaluation: Design and Product Optimization for Cast Light Metals, Durability of Lightweight Composite Structures, and Rapid Tooling for Functional Prototyping of Metal Mold Processes. These projects were chosen because they have already been completed. The first project resulted in development of a comprehensive cast light metal property database, an automotive application design guide, computerized predictive models, process monitoring sensors, and quality assurance methods. The second project, the durability of lightweight composite structures, produced durability-based design criteria documents, predictive models for creep deformation, and minimum test requirements and suggested test methods for establishing durability properties and characteristics of random glass-fiber composites for automotive structural composites. The durability project supported Focal Project II, a validation activity that demonstrates ALM program goals and reduces the lead time for bringing new technology into the marketplace. Focal projects concentrate on specific classes of materials and nonproprietary components and are done jointly by DOE and the Automotive Composites Consortium of U.S. Council for Automotive Research (USCAR). The third project developed a rapid tooling process that reduces tooling time, originally some 48-52 weeks, to less than 12 weeks by means of rapid generation of die-casting die inserts and development of generic holding blocks, suitable for use with large casting applications. This project was conducted by the United States Automotive Materials Partnership, another USCAR consortium.« less

Correlation of laser-Doppler-velocity measurements and endothelial cell shape in a stenosed dog aorta.

PubMed

Liepsch, D W; Levesque, M; Nerem, R M; Moravec, S T

1988-01-01

Laser-Doppler-velocity measurements were carried out in an elastic 1:1 true-to-scale silicone rubber model of a dog aorta with stenosis. The model was constructed from a cast of a severely stenosed dog aorta (71% of its area). The stenosis in the dog aorta was prepared by wrapping a cotton band around the aorta. This band was tightened until the presence of a thrill or a bruit was felt distal to the band. Twelve weeks later the animal was sacrificed and a cast was prepared from the aorta. From this vascular cast, the cross-sectional area was calculated. Endothelial cell geometry and orientation was studied using computerized analysis to determine the cell area and shape index. An elastic silicone rubber model was prepared from the cast to measure the velocity profiles and to estimate the local wall shear stress. Velocity measurements were done at steady and pulsatile flow using a Newtonian aqueous-glycerol solution and a non-Newtonian blood-like fluid. From those velocity measurements the velocity gradients near the wall were determined and the shear stress calculated. The flow distal to the stenosis separates from the wall at physiological conditions. The endothelial cells are smaller and more elongated in the throat; distal to the stenosis they are larger and rounder. The shape index distribution along the stenosed aorta is correlated with the level of wall shear stress. It is shown that even low changes in the wall shear stress have an influence on the orientation of the endothelial cells.

Three-Dimensional Printing in Orthopedic Surgery.

PubMed

Eltorai, Adam E M; Nguyen, Eric; Daniels, Alan H

2015-11-01

Three-dimensional (3D) printing is emerging as a clinically promising technology for rapid prototyping of surgically implantable products. With this commercially available technology, computed tomography or magnetic resonance images can be used to create graspable objects from 3D reconstructed images. Models can enhance patients' understanding of their pathology and surgeon preoperative planning. Customized implants and casts can be made to match an individual's anatomy. This review outlines 3D printing, its current applications in orthopedics, and promising future directions. Copyright 2015, SLACK Incorporated.

Functionalized low defect graphene nanoribbons and polyurethane composite film for improved gas barrier and mechanical performances.

PubMed

Xiang, Changsheng; Cox, Paris J; Kukovecz, Akos; Genorio, Bostjan; Hashim, Daniel P; Yan, Zheng; Peng, Zhiwei; Hwang, Chih-Chau; Ruan, Gedeng; Samuel, Errol L G; Sudeep, Parambath M; Konya, Zoltan; Vajtai, Robert; Ajayan, Pulickel M; Tour, James M

2013-11-26

A thermoplastic polyurethane (TPU) composite film containing hexadecyl-functionalized low-defect graphene nanoribbons (HD-GNRs) was produced by solution casting. The HD-GNRs were well distributed within the polyurethane matrix, leading to phase separation of the TPU. Nitrogen gas effective diffusivity of TPU was decreased by 3 orders of magnitude with only 0.5 wt % HD-GNRs. The incorporation of HD-GNRs also improved the mechanical properties of the composite films, as predicted by the phase separation and indicated by tensile tests and dynamic mechanical analyses. The improved properties of the composite film could lead to potential applications in food packaging and lightweight mobile gas storage containers.

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

Young, D.A.

The carboxyl-terminated butadiene/acrylonitrile copolymer (CTBN)/epoxy adduct, BKC 20102, which is used for encapsulating electronic devices, was studied to improve its quality and reliability. The average chemical, physical, and mechanical properties were obtained by testing 16 batches of adduct prepared from 13 separate lots of CTBN. Three methods were determined to prepare a clear, soluble liquid adduct that does not separate in storage or transit. Two of these methods also produce a clear epoxy casting and a filled potting compound with improved impact and flexural, compressive, and tensile strengths. Study of the temperature-viscosity profile during the cure of the liquid adductmore » has shown that a slight change in the degassing time can significantly reduce foaming during degassing.« less

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

Young, D.A.; Smith, C.H.

A carboxyl-terminated butadiene/acrylonitrile (CTBN)/epoxy resin adduct, used to encapsulate electronic devices, was studied to improve its quality and reliability. The average physical and mechanical properties of the amine-cured product were obtained by testing 16 batches of adduct prepared from 13 separate lots of CTBN. It was found that by using a CTBN with a higher acrylonitrile content (or one in which the chemical structure includes carboxyl groups in the chain backbone, in addition to end termination), a clear, soluble liquid adduct that does not separate in storage or transit could be prepared. These materials also produced clear epoxy castings andmore » filled potting compounds with improved impact, flexural, compressive, and tensile strengths.« less

Initial Mechanical Testing of Superalloy Lattice Block Structures Conducted

NASA Technical Reports Server (NTRS)

Krause, David L.; Whittenberger, J. Daniel

2002-01-01

The first mechanical tests of superalloy lattice block structures produced promising results for this exciting new lightweight material system. The testing was performed in-house at NASA Glenn Research Center's Structural Benchmark Test Facility, where small subelement-sized compression and beam specimens were loaded to observe elastic and plastic behavior, component strength levels, and fatigue resistance for hundreds of thousands of load cycles. Current lattice block construction produces a flat panel composed of thin ligaments arranged in a three-dimensional triangulated trusslike structure. Investment casting of lattice block panels has been developed and greatly expands opportunities for using this unique architecture in today's high-performance structures. In addition, advances made in NASA's Ultra-Efficient Engine Technology Program have extended the lattice block concept to superalloy materials. After a series of casting iterations, the nickel-based superalloy Inconel 718 (IN 718, Inco Alloys International, Inc., Huntington, WV) was successfully cast into lattice block panels; this combination offers light weight combined with high strength, high stiffness, and elevated-temperature durability. For tests to evaluate casting quality and configuration merit, small structural compression and bend test specimens were machined from the 5- by 12- by 0.5-in. panels. Linear elastic finite element analyses were completed for several specimen layouts to predict material stresses and deflections under proposed test conditions. The structural specimens were then subjected to room-temperature static and cyclic loads in Glenn's Life Prediction Branch's material test machine. Surprisingly, the test results exceeded analytical predictions: plastic strains greater than 5 percent were obtained, and fatigue lives did not depreciate relative to the base material. These assets were due to the formation of plastic hinges and the redundancies inherent in lattice block construction, which were not considered in the simplified computer models. The fatigue testing proved the value of redundancies since specimen strength was maintained even after the fracture of one or two ligaments. This ongoing test program is planned to continue through high-temperature testing. Also scheduled for testing are IN 718 lattice block panels with integral face sheets, as well as specimens cast from a higher temperature alloy. The initial testing suggests the value of this technology for large panels under low and moderate pressure loadings and for high-risk, damage-tolerant structures. Potential aeropropulsion uses for lattice blocks include turbine-engine actuated panels, exhaust nozzle flaps, and side panel structures.

Integrally cored ceramic investment casting mold fabricated by ceramic stereolithography

NASA Astrophysics Data System (ADS)

Bae, Chang-Jun

Superalloy airfoils are produced by investment casting (IC), which uses ceramic cores and wax patterns with ceramic shell molds. Hollow cored superalloy airfoils in a gas turbine engine are an example of complex IC parts. The complex internal hollow cavities of the airfoil are designed to conduct cooling air through one or more passageways. These complex internal passageways have been fabricated by a lost wax process requiring several processing steps; core preparation, injection molding for wax pattern, and dipping process for ceramic shell molds. Several steps generate problems such as high cost and decreased accuracy of the ceramic mold. For example, costly tooling and production delay are required to produce mold dies for complex cores and wax patterns used in injection molding, resulting in a big obstacle for prototypes and smaller production runs. Rather than using separate cores, patterns, and shell molds, it would be advantageous to directly produce a mold that has the casting cavity and the ceramic core by one process. Ceramic stereolithography (CerSLA) can be used to directly fabricate the integrally cored ceramic casting mold (ICCM). CerSLA builds ceramic green objects from CAD files from many thin liquid layers of powder in monomer, which are solidified by polymerization with a UV laser, thereby "writing" the design for each slice. This dissertation addresses the integrally cored casting ceramic mold (ICCM), the ceramic core with a ceramic mold shell in a single patternless construction, fabricated by ceramic stereolithography (CerSLA). CerSLA is considered as an alternative method to replace lost wax processes, for small production runs or designs too complex for conventional cores and patterns. The main topic is the development of methods to successfully fabricate an ICCM by CerSLA from refractory silica, as well as related issues. The related issues are the segregation of coarse fused silica powders in a layer, the degree of segregation parameter to prevent segregation, and sintering and cristobalite transformation in fused silica compacts.

Who is excluded and how? An analysis of community spaces for maternal and child health in Pakistan.

PubMed

Aziz, Ayesha; Khan, Fazal Ali; Wood, Geof

2015-11-25

The maternal, newborn, and child health (MNCH) indicators of Pakistan depict the deplorable state of the poor and rural women and children. Many MNCH programmes stress the need to engage the poor in community spaces. However, caste and class based hierarchies and gendered social norms exclude the lower caste poor women from accessing healthcare. To find pathways for improving the lives of the excluded, this study considers the social system as a whole and describes the mechanisms of exclusion in the externally created formal community spaces and their interaction with the indigenous informal spaces. The study used a qualitative case study design to identify the formal and informal community spaces in three purposively selected villages of Thatta, Rajanpur, and Ghizer districts. Community perspectives were gathered by conducting 37 focus group discussions, based on participatory rural appraisal tools, with separate groups of women and men. Relevant documents of six MNCH programmes were reviewed and 25 key informant interviews were conducted with programme staff. We found that lower caste poor tenants and nomadic peasants were excluded from formal and informal spaces. The formal community spaces formed by MNCH programmes across Pakistan included fixed, small transitory, large transitory, and emerging institutional spaces. Programme guidelines mandated selection of community notables in groups/committees and used criteria that prevented registration of nomadic groups as eligible clients. The selection criteria and adverse attitude of healthcare workers, along with inadequacy of programmatic resources to sustain outreach activities also contributed to exclusion of the lower caste poor women from formal spaces. The informal community spaces were mostly gender segregated. Infrequently, MNCH information trickled down from the better-off to the lower caste poor women through transitory interactions in the informal domestic sphere. A revision of the purpose and implementation mechanisms for MNCH programmes is mandated to transform formal health spaces into sites of equitable healthcare.

FY2017 Materials Annual Progress Report

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

Wu, Felix; Gibbs, Jerry; Kleinbaum, Sarah

The Materials Technology subprogram supports the Vehicle Technology Office’s mission to help consumers and businesses reduce their transportation energy costs while meeting or exceeding vehicle performance expectations. The Propulsion Materials research portfolio seeks to develop higher performance materials that can withstand increasingly extreme environments and address the future properties needs of a variety of high efficiency powertrain types, sizes, fueling concepts, and combustion modes. Advanced Lightweight Materials research enables improvements in fuel economy by providing properties that are equal to or better than traditional materials at a lower weight. Because it takes less energy to accelerate a lighter object, replacingmore » cast iron and traditional steel components with lightweight materials such as high-strength steel, magnesium (Mg), aluminum (Al), and polymer composites can directly reduce a vehicle’s fuel consumption. Materials technology activities focus on the following cost and performance targets: (1) enable a 25 percent weight reduction for light-duty vehicles including body, chassis, and interior as compared to a 2012 baseline at no more than a $5/lb-saved increase in cost; and (2) validate a 25 percent improvement in high temperature (300°C) component strength relative to components made with 2010 baseline cast Al alloys (A319 or A356) for improved efficiency light-duty engines.« less

Microstructure, Friction and Wear of Aluminum Matrix Composites

NASA Astrophysics Data System (ADS)

Florea, R. M.

2018-06-01

MMCs are made by dispersing a reinforcing material into a metal matrix. They are prepared by casting, although several technical challenges exist with casting technology. Achieving a homogeneous distribution of reinforcement within the matrix is one such challenge, and this affects directly on the properties and quality of composite. The aluminum alloy composite materials consist of high strength, high stiffness, more thermal stability, more corrosion and wear resistance, and more fatigue life. Aluminum alloy materials found to be the best alternative with its unique capacity of designing the materials to give required properties. In this work a composite is developed by adding silicon carbide in Aluminum metal matrix by mass ratio 5%, 10% and 15%. Mechanical tests such as hardness test and microstructure test are conducted.

Using special additions to preparation of the moulding mixture for casting steel parts of drive wheel type

NASA Astrophysics Data System (ADS)

Josan, A.; Pinca Bretotean, C.

2015-06-01

The paper presents the possibility of using special additions to the execution of moulding mixtures for steel castings, drive wheel type. Critical analysis of moulding technology leads to the idea that most defects appear due to using improper moulding mixture. Using a improper moulding mixture leads to penetration of steel in moulding mixture, resulting in the formation of adherences, due to inadequate refractarity of the mould and core mixtures. Using only the unique mixture to the moulding leads to increasing consumption of new sand, respectively to the increase of price of piece. Acording to the dates registered in the industrial practice is necessary to use the special additions to obtain the moulding mixtures, carbonaceous materials respectively.

76 FR 5507 - Airworthiness Directives; Airbus Model A300 B4-601, B4-603, B4-605R, C4-605R Variant F, and F4...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-02-01

...-80C2 forward engine mounts (skinny cast yoke) does not meet the Design Service Goal (DSG) requirements... forward engine mount. * * * * * The unsafe condition is possible separation of the engine from the engine... that, among the types of yokes in service, one component on the CF6-80C2 forward engine mounts (skinny...

Studies on wettability of polypropylene/methyl-silicone composite film and polypropylene monolithic material.

PubMed

Hou, Weixin; Mu, Bo; Wang, Qihua

2008-11-01

A polypropylene/methyl-silicone superhydrophobic surface was prepared using a simple casting method. Varying the ratio of polypropylene and methyl-silicone results in different surface microstructure. The wetting behavior of the as-prepared surface was investigated. A polypropylene monolithic material was also prepared. Its superhydrophobicity still retains when the material was cut or abraded. The as-prepared material can also be used to separate some organic solvents from water.

Adaptation and micro-structure of Co-Cr alloy maxillary complete denture base plates fabricated by selective laser melting technique.

PubMed

Ye, Ye; Jiao, Ting; Zhu, Jiarui; Sun, Jian

2018-01-24

The purpose of the study was to evaluate the adaptation and micro-structure of Co-Cr alloy maxillary complete denture base plates fabricated by the selective laser melting (SLM) technique. Twenty pairs of edentulous casts were randomly and evenly divided into two groups, and manufacturing of the Co-Cr alloy maxillary complete denture base was conducted either by the SLM technique or by the conventional method. The base-cast sets were transversally sectioned into three sections at the distal canines, mesial of the first molars and the posterior palatal zone. The gap between the metal base and cast was measured in these three sections with a stereoscopic microscope, and the data were analysed using t tests. A total of five specimens of 5 mm diameter were fabricated with the Co-Cr alloy by SLM and the traditional casting technology. A scanning electron microscope (SEM) was used to evaluate the differences in microstructure between these specimens. There was no statistical difference between the three sections in all four groups (P > 0.05). At the region of the canines, the clearance value for the SLM Co-Cr alloy group was larger than that of the conventional method group (P < 0.05). At the mesial of the first molar region and the posterior palatal zone, there was no statistical difference between the gaps observed in the two groups (P > 0.05). The SLM Co-Cr alloy has a denser microstructure behaviour and less casting defect than the cast Co-Cr alloy. The SLM technique showed initial feasibility for the manufacture of dental bases of complete dentures, but large sample studies are needed to prove its reliability in clinical applications. The mechanical properties and microstructure of the denture frameworks prepared by selective laser melting indicate that these dentures are appropriate for clinical use.

Freeze cast porous barium titanate for enhanced piezoelectric energy harvesting

NASA Astrophysics Data System (ADS)

Roscow, J. I.; Zhang, Y.; Kraśny, M. J.; Lewis, R. W. C.; Taylor, J.; Bowen, C. R.

2018-06-01

Energy harvesting is an important developing technology for a new generation of self-powered sensor networks. This paper demonstrates the significant improvement in the piezoelectric energy harvesting performance of barium titanate by forming highly aligned porosity using freeze casting. Firstly, a finite element model demonstrating the effect of pore morphology and angle with respect to poling field on the poling behaviour of porous ferroelectrics was developed. A second model was then developed to understand the influence of microstructure-property relationships on the poling behaviour of porous freeze cast ferroelectric materials and their resultant piezoelectric and energy harvesting properties. To compare with model predictions, porous barium titanate was fabricated using freeze casting to form highly aligned microstructures with excellent longitudinal piezoelectric strain coefficients, d 33. The freeze cast barium titanate with 45 vol.% porosity had a d 33  =  134.5 pC N‑1 compared to d 33  =  144.5 pC N‑1 for dense barium titanate. The d 33 coefficients of the freeze cast materials were also higher than materials with uniformly distributed spherical porosity due to improved poling of the aligned microstructures, as predicted by the models. Both model and experimental data indicated that introducing porosity provides a large reduction in the permittivity () of barium titanate, which leads to a substantial increase in energy harvesting figure of merit, , with a maximum of 3.79 pm2 N‑1 for barium titanate with 45 vol.% porosity, compared to only 1.40 pm2 N‑1 for dense barium titanate. Dense and porous barium titanate materials were then used to harvest energy from a mechanical excitation by rectification and storage of the piezoelectric charge on a capacitor. The porous barium titanate charged the capacitor to a voltage of 234 mV compared to 96 mV for the dense material, indicating a 2.4-fold increase that was similar to that predicted by the energy harvesting figures of merit.

Population Differentiation of Southern Indian Male Lineages Correlates with Agricultural Expansions Predating the Caste System

PubMed Central

Arun, Varatharajan Santhakumari; Syama, Adhikarla; Ashokan, Kumaran Samy; Gandhirajan, Kavandanpatti Thangaraj; Vijayakumar, Koothapuli; Narayanan, Muthuswamy; Jayalakshmi, Mariakuttikan; Ziegle, Janet S.; Royyuru, Ajay K.; Parida, Laxmi; Wells, R. Spencer; Renfrew, Colin; Schurr, Theodore G.; Smith, Chris Tyler; Platt, Daniel E.; Pitchappan, Ramasamy

2012-01-01

Previous studies that pooled Indian populations from a wide variety of geographical locations, have obtained contradictory conclusions about the processes of the establishment of the Varna caste system and its genetic impact on the origins and demographic histories of Indian populations. To further investigate these questions we took advantage that both Y chromosome and caste designation are paternally inherited, and genotyped 1,680 Y chromosomes representing 12 tribal and 19 non-tribal (caste) endogamous populations from the predominantly Dravidian-speaking Tamil Nadu state in the southernmost part of India. Tribes and castes were both characterized by an overwhelming proportion of putatively Indian autochthonous Y-chromosomal haplogroups (H-M69, F-M89, R1a1-M17, L1-M27, R2-M124, and C5-M356; 81% combined) with a shared genetic heritage dating back to the late Pleistocene (10–30 Kya), suggesting that more recent Holocene migrations from western Eurasia contributed <20% of the male lineages. We found strong evidence for genetic structure, associated primarily with the current mode of subsistence. Coalescence analysis suggested that the social stratification was established 4–6 Kya and there was little admixture during the last 3 Kya, implying a minimal genetic impact of the Varna (caste) system from the historically-documented Brahmin migrations into the area. In contrast, the overall Y-chromosomal patterns, the time depth of population diversifications and the period of differentiation were best explained by the emergence of agricultural technology in South Asia. These results highlight the utility of detailed local genetic studies within India, without prior assumptions about the importance of Varna rank status for population grouping, to obtain new insights into the relative influences of past demographic events for the population structure of the whole of modern India. PMID:23209694

Vertical misfit of laser-sintered and vacuum-cast implant-supported crown copings luted with definitive and temporary luting agents.

PubMed

Castillo-de-Oyagüe, Raquel; Sánchez-Turrión, Andrés; López-Lozano, José-Francisco; Albaladejo, Alberto; Torres-Lagares, Daniel; Montero, Javier; Suárez-García, Maria-Jesús

2012-07-01

This study aimed to evaluate the vertical discrepancy of implant-supported crown structures constructed with vacuum-casting and Direct Metal Laser Sintering (DMLS) technologies, and luted with different cement types. Crown copings were fabricated using: (1) direct metal laser sintered Co-Cr (LS); (2) vacuum-cast Co-Cr (CC); and (3) vacuum-cast Ti (CT). Frameworks were luted onto machined implant abutments under constant seating pressure. Each alloy group was randomly divided into 5 subgroups (n = 10 each) according to the cement system utilized: Subgroup 1 (KC) used resin-modified glass-ionomer Ketac Cem Plus; Subgroup 2 (PF) used Panavia F 2.0 dual-cure resin cement; Subgroup 3 (RXU) used RelyX Unicem 2 Automix self-adhesive dual-cure resin cement; Subgroup 4 (PIC) used acrylic/urethane-based temporary Premier Implant Cement; and Subgroup 5 (DT) used acrylic/urethane-based temporary DentoTemp cement. Vertical misfit was measured by scanning electron microscopy (SEM). Two-way ANOVA and Student-Newman-Keuls tests were run to investigate the effect of alloy/fabrication technique, and cement type on vertical misfit. The statistical significance was set at α = 0.05. The alloy/manufacturing technique and the luting cement affected the vertical discrepancy (p < 0.001). For each cement type, LS samples exhibited the best fit (p < 0.01) whereas CC and CT frames were statistically similar. Within each alloy group, PF and RXU provided comparably greater discrepancies than KC, PIC, and DT, which showed no differences. Laser sintering may be an alternative to vacuum-casting of base metals to obtain passive-fitting implant-supported crown copings. The best marginal adaptation corresponded to laser sintered structures luted with glass-ionomer KC, or temporary PIC or DT cements. The highest discrepancies were recorded for Co-Cr and Ti cast frameworks bonded with PF or RXU resinous agents. All groups were within the clinically acceptable misfit range.

Mathematical Modeling of High-Temperature Constitutive Equations and Hot Processing Maps for As-Cast SA508-3 Steel

NASA Astrophysics Data System (ADS)

Sui, Dashan; Wang, Tao; Zhu, Lingling; Gao, Liang; Cui, Zhenshan

2016-11-01

The hot deformation behavior and hot workability characteristics of as-cast SA508-3 steel were studied by modeling the constitutive equations and developing hot processing maps. The isothermal compression experiments were carried out at temperatures of 950°C, 1050°C, 1150°C, and 1250°C and strain rates of 0.001 s-1, 0.01 s-1, 0.1 s-1, and 1 s-1 respectively. The two-stage flow stress models were established through the classical theories on work hardening and softening, and the solution of activation energy for hot deformation was 355.0 kJ mol-1 K-1. Based on the dynamic material model, the power dissipation and instability maps were developed separately at strains of 0.2, 0.4, 0.6 and 0.8. The power dissipation rate increases with both the increase of temperature and the decrease of strain rate, and the instable region mainly appears on the conditions of low temperature and high strain rate. The optimal hot working parameters for as-cast SA508-3 steel are 1050-1200°C/0.001-0.1 s-1, with about 25-40% peak efficiency of power dissipation.

A Scalable Route to Nanoporous Large-Area Atomically Thin Graphene Membranes by Roll-to-Roll Chemical Vapor Deposition and Polymer Support Casting.

PubMed

Kidambi, Piran R; Mariappan, Dhanushkodi D; Dee, Nicholas T; Vyatskikh, Andrey; Zhang, Sui; Karnik, Rohit; Hart, A John

2018-03-28

Scalable, cost-effective synthesis and integration of graphene is imperative to realize large-area applications such as nanoporous atomically thin membranes (NATMs). Here, we report a scalable route to the production of NATMs via high-speed, continuous synthesis of large-area graphene by roll-to-roll chemical vapor deposition (CVD), combined with casting of a hierarchically porous polymer support. To begin, we designed and built a two zone roll-to-roll graphene CVD reactor, which sequentially exposes the moving foil substrate to annealing and growth atmospheres, with a sharp, isothermal transition between the zones. The configurational flexibility of the reactor design allows for a detailed evaluation of key parameters affecting graphene quality and trade-offs to be considered for high-rate roll-to-roll graphene manufacturing. With this system, we achieve synthesis of uniform high-quality monolayer graphene ( I D / I G < 0.065) at speeds ≥5 cm/min. NATMs fabricated from the optimized graphene, via polymer casting and postprocessing, show size-selective molecular transport with performance comparable to that of membranes made from conventionally synthesized graphene. Therefore, this work establishes the feasibility of a scalable manufacturing process of NATMs, for applications including protein desalting and small-molecule separations.

Accelerating Adverse Outcome Pathway (AOP) development ...

EPA Pesticide Factsheets

The Adverse Outcome Pathway (AOP) framework is increasingly being adopted as a tool for organizing and summarizing the mechanistic information connecting molecular perturbations by environmental stressors with adverse outcomes relevant for ecological and human health outcomes. However, the conventional process for assembly of these AOPs is time and resource intensive, and has been a rate limiting step for AOP use and development. Therefore computational approaches to accelerate the process need to be developed. We previously developed a method for generating computationally predicted AOPs (cpAOPs) by association mining and integration of data from publicly available databases. In this work, a cpAOP network of ~21,000 associations was established between 105 phenotypes from TG-GATEs rat liver data from different time points (including microarray, pathological effects and clinical chemistry data), 994 REACTOME pathways, 688 High-throughput assays from ToxCast and 194 chemicals. A second network of 128,536 associations was generated by connecting 255 biological target genes from ToxCast to 4,980 diseases from CTD using either HT screening activity from ToxCast for 286 chemicals or CTD gene expression changes in response to 2,330 chemicals. Both networks were separately evaluated through manual extraction of disease-specific cpAOPs and comparison with expert curation of the relevant literature. By employing data integration strategies that involve the weighting of n

Development of High-Performance Cast Crankshafts. Final Technical Report

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

Bauer, Mark E

The objective of this project was to develop technologies that would enable the production of cast crankshafts that can replace high performance forged steel crankshafts. To achieve this, the Ultimate Tensile Strength (UTS) of the new material needs to be 850 MPa with a desired minimum Yield Strength (YS; 0.2% offset) of 615 MPa and at least 10% elongation. Perhaps more challenging, the cast material needs to be able to achieve sufficient local fatigue properties to satisfy the durability requirements in today’s high performance gasoline and diesel engine applications. The project team focused on the development of cast steel alloysmore » for application in crankshafts to take advantage of the higher stiffness over other potential material choices. The material and process developed should be able to produce high-performance crankshafts at no more than 110% of the cost of current production cast units, perhaps the most difficult objective to achieve. To minimize costs, the primary alloy design strategy was to design compositions that can achieve the required properties with minimal alloying and post-casting heat treatments. An Integrated Computational Materials Engineering (ICME) based approach was utilized, rather than relying only on traditional trial-and-error methods, which has been proven to accelerate alloy development time. Prototype melt chemistries designed using ICME were cast as test specimens and characterized iteratively to develop an alloy design within a stage-gate process. Standard characterization and material testing was done to validate the alloy performance against design targets and provide feedback to material design and manufacturing process models. Finally, the project called for Caterpillar and General Motors (GM) to develop optimized crankshaft designs using the final material and manufacturing processing path developed. A multi-disciplinary effort was to integrate finite element analyses by engine designers and geometry-specific casting simulations with existing materials models to optimize crankshaft cost and performance. Prototype crankshafts of the final design were to be produced and validated using laboratory bench testing and on-engine durability testing. ICME process simulation tools were used to investigate a broad range of processing concepts. These concepts included casting orientation, various mold and core materials, and various filling and feeding strategies. Each crankshaft was first simulated without gating and risers, which is termed natural solidification. The natural solidification results were used as a baseline for strategy development of each concept. Casting process simulations and ICME tools were proven to be reasonable predictors of real world results. Potential alloys were developed that could meet the project material property goals with appropriate normalization and temper treatments. For the alloys considered, post-normalization temper treatments proved to be necessary to achieve the desired yield strengths and elongations and appropriate heat treatments were designed using ICME tools. The experimental data of all the alloys were analyzed in combination with ICME tools to establish chemistry-process-structure relations. Several GM small gas engine (SGE) crankshafts were successfully cast in sand molds using two different sprue, runner, gate, riser, chill designs. These crankshafts were cast in two different steel alloys developed during the project, but casting finishing (e.g. riser removal) remains a cost challenge. A long list of future work was left unfinished when this project was unexpectedly terminated.« less

Cognitive and sociocultural aspects of robotized technology: innovative processes of adaptation

NASA Astrophysics Data System (ADS)

Kvesko, S. B.; Kvesko, B. B.; Kornienko, M. A.; Nikitina, Y. A.; Pankova, N. M.

2018-05-01

The paper dwells upon interaction between socio-cultural phenomena and cognitive characteristics of robotized technology. The interdisciplinary approach was employed in order to cast light on the manifold and multilevel identity of scientific advance in terms of robotized technology within the mental realm. Analyzing robotized technology from the viewpoint of its significance for the modern society is one of the upcoming trends in the contemporary scientific realm. The robots under production are capable of interacting with people; this results in a growing necessity for the studies on social status of robotized technological items. Socio-cultural aspect of cognitive robotized technology is reflected in the fact that the nature becomes ‘aware’ of itself via human brain, a human being tends to strives for perfection in their intellectual and moral dimensions.

Mechanical Testing of IN718 Lattice Block Structures

NASA Technical Reports Server (NTRS)

Krause, David L.; Whittenberger, John D.; Kantzos, Pete T.; Hebsur, Mohan G.

2002-01-01

Lattice block construction produces a flat, structurally rigid panel composed of thin ligaments of material arranged in a three-dimensional triangulated truss-like structure. Low-cost methods of producing cast metallic lattice block panels are now available that greatly expand opportunities for using this unique material system in today's high-performance structures. Additional advances are being made in NASA's Ultra Efficient Engine Technology (UEET) program to extend the lattice block concept to superalloy materials. Advantages offered by this combination include high strength, light weight, high stiffness, and elevated temperature capabilities. Recently under UEET, the nickel-based superalloy Inconel 718 (IN718) was investment cast into lattice block panels with great success. To evaluate casting quality and lattice block architecture merit, individual ligaments, and structural subelement specimens were extracted from the panels. Tensile tests, structural compression, and bending strength tests were performed on these specimens. Fatigue testing was also completed for several bend test specimens. This paper first presents metallurgical and optical microscopy analysis of the castings. This is followed by mechanical test results for the tensile ligament tests and the subelement compression and bending strength tests, as well as for the fatigue tests that were performed. These tests generally showed comparable properties to base IN718 with the same heat treatment, and they underscored the benefits offered by lattice block materials. These benefits might be extended with improved architecture such as face sheets.

Thermal Stress and Heat Transfer Coefficient for Ceramics Stalk Having Protuberance Dipping into Molten Metal

NASA Astrophysics Data System (ADS)

Noda, Nao-Aki; Hendra; Li, Wenbin; Takase, Yasushi; Ogura, Hiroki; Higashi, Yusuke

Low pressure die casting is defined as a net shape casting technology in which the molten metal is injected at high speeds and pressure into a metallic die. The low pressure die casting process plays an increasingly important role in the foundry industry as a low-cost and high-efficiency precision forming technique. In the low pressure die casting process is that the permanent die and filling systems are placed over the furnace containing the molten alloy. The filling of the cavity is obtained by forcing the molten metal, by means of a pressurized gas, to rise into a ceramic tube having protuberance, which connects the die to the furnace. The ceramics tube, called stalk, has high temperature resistance and high corrosion resistance. However, attention should be paid to the thermal stress when the stalk having protuberance is dipped into the molten aluminum. It is important to reduce the risk of fracture that may happen due to the thermal stresses. In this paper, thermo-fluid analysis is performed to calculate surface heat transfer coefficient. The finite element method is applied to calculate the thermal stresses when the stalk having protuberance is dipped into the crucible with varying dipping speeds. It is found that the stalk with or without protuberance should be dipped into the crucible slowly to reduce the thermal stress.

Marginal adaptation and CAD-CAM technology: A systematic review of restorative material and fabrication techniques.

PubMed

Papadiochou, Sofia; Pissiotis, Argirios L

2018-04-01

The comparative assessment of computer-aided design and computer-aided manufacturing (CAD-CAM) technology and other fabrication techniques pertaining to marginal adaptation should be documented. Limited evidence exists on the effect of restorative material on the performance of a CAD-CAM system relative to marginal adaptation. The purpose of this systematic review was to investigate whether the marginal adaptation of CAD-CAM single crowns, fixed dental prostheses, and implant-retained fixed dental prostheses or their infrastructures differs from that obtained by other fabrication techniques using a similar restorative material and whether it depends on the type of restorative material. An electronic search of English-language literature published between January 1, 2000, and June 30, 2016, was conducted of the Medline/PubMed database. Of the 55 included comparative studies, 28 compared CAD-CAM technology with conventional fabrication techniques, 12 contrasted CAD-CAM technology and copy milling, 4 compared CAD-CAM milling with direct metal laser sintering (DMLS), and 22 investigated the performance of a CAD-CAM system regarding marginal adaptation in restorations/infrastructures produced with different restorative materials. Most of the CAD-CAM restorations/infrastructures were within the clinically acceptable marginal discrepancy (MD) range. The performance of a CAD-CAM system relative to marginal adaptation is influenced by the restorative material. Compared with CAD-CAM, most of the heat-pressed lithium disilicate crowns displayed equal or smaller MD values. Slip-casting crowns exhibited similar or better marginal accuracy than those fabricated with CAD-CAM. Cobalt-chromium and titanium implant infrastructures produced using a CAD-CAM system elicited smaller MD values than zirconia. The majority of cobalt-chromium restorations/infrastructures produced by DMLS displayed better marginal accuracy than those fabricated with the casting technique. Compared with copy milling, the majority of zirconia restorations/infrastructures produced by CAD-CAM milling exhibited better marginal adaptation. No clear conclusions can be drawn about the superiority of CAD-CAM milling over the casting technique and DMLS regarding marginal adaptation. Copyright © 2017 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

DEVELOPING AND IMPLEMENTING A BIRD MIGRATION MONITORING, ASSESSMENT AND PUBLIC OUTREACH PROGRAM FOR YOUR COMMUNITY - THE BIRDCAST PROJECT

EPA Science Inventory

The USEPA has developed a technology transfer handbook for the EMPACt BirdCast bird migration monitoring project. The document is essentially a "How-To" Handbook that addresses the planning and implementation steps that were needed to develop, operate and maintain a program simil...

A Primer on Applying Monte Carlo Simulation, Real Options Analysis, Knowledge Value Added, Forecasting, and Portfolio Optimization

DTIC Science & Technology

2010-02-08

popular pastime. Even in Biblical accounts, Roman soldiers cast lots for Christ’s robes. In earlier times, chance was something that occurred in nature...with the advent of blazing fast computing technology, our modern world of uncertainty can be explained with much more elegance through

Aluminum space frame technology

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

Birch, S.

This article examines the increased application of aluminum to the construction of automobile frames. The topics of the article include a joint venture between Audi and Alcoa, forms in which aluminum is used, new alloys and construction methods, meeting rigidity and safety levels, manufacturing techniques, the use of extrusions, die casting, joining techniques, and pollution control during manufacturing.

Field Demonstration of Innovative Leak Detection/Location in Conjunction with Pipe Wall Thickness Testing for Water Mains

EPA Science Inventory

The U.S. Environmental Protection Agency (EPA) sponsored a large-scale field demonstration of innovative leak detection/location and condition assessment technologies on a 76-year old, 2,000-ft long, cement-lined, 24-in. cast iron water main in Louisville, KY from July through Se...

Universal Design for Learning: A Blueprint for Success for All Learners

ERIC Educational Resources Information Center

Brand, Susan Trostle; Favazza, Antoinette E.; Dalton, Elizabeth M.

2012-01-01

The Center for Applied Special Technology, Inc. (CAST), an educational research organization, introduced Universal Design for Learning (UDL) in its earliest form nearly 25 years ago. According to Orkwis and McLane (1998), UDL is a tangible means by which educators implement the special education requirements and sustain the gains that were…

Knowledge Maps for E-Literacy in ICT-Rich Learning Environments

ERIC Educational Resources Information Center

Taha, Ahmed

2005-01-01

The Web-based information and communication technology (w-ICT) has become a powerful means for delivery and dissemination of digitised information among the emerging virtual learning and business communities. The w-ICT has engendered a growing cybersphere paradigm to accommodate a huge mass of e-resources cast over the Web. Such abundance of…

Energy requirement for the production of silicon solar arrays

NASA Technical Reports Server (NTRS)

Lindmayer, J.; Wihl, M.; Scheinine, A.; Morrison, A.

1977-01-01

An assessment of potential changes and alternative technologies which could impact the photovoltaic manufacturing process is presented. Topics discussed include: a multiple wire saw, ribbon growth techniques, silicon casting, and a computer model for a large-scale solar power plant. Emphasis is placed on reducing the energy demands of the manufacturing process.

A Biologically Informed Framework for the Analysis of the PPAR Signaling Pathway using a Bayesian Network

EPA Science Inventory

The US EPA’s ToxCastTM program seeks to combine advances in high-throughput screening technology with methodologies from statistics and computer science to develop high-throughput decision support tools for assessing chemical hazard and risk. To develop new methods of analysis of...

All Aboard--Destination Unknown: A Sociological Discussion of Online Learning

ERIC Educational Resources Information Center

Goldberg, Andra K.; Riemer, Frances Julia

2006-01-01

This paper is an attempt to describe the emergence and growing popularity of online distance education over the past 30 years through changing sociological lenses. Examining the re-casting of the electronic classroom through the euphoria of techno-positivism, the power-embedded analysis of Critical Theory of Technology (CTT), and the critique of…

Some methods of increasing the density of metal in order to increase him corrosion resistance

NASA Astrophysics Data System (ADS)

Chumanov, I. V.; Anikeev, A. N.; Sergeev, D. V.; Maltseva, A. N.

2017-11-01

Methods to increase the density of metal in order to increase its corrosion resistance in an aggressive environment are examined in the article. Two steel grades, differing in the content of alloying elements, increasing the resistance to corrosion are selected for the manufacture of experimental metallic materials. Two technologies are chosen as methods for increasing the density, and as a result, corrosion resistance, of the experimental materials obtained: the first is electroslag remelting with rotation of the consumable electrode, the second is centrifugal casting with modification. The microstructure of the metal becomes more homogeneous, the degree of metal refining from non-metallic inclusions increases, the rate of crystallization during metal smelting by the ESR method increases with rotation of the consumable electrode. When ingots are produced by the method of centrifugal casting, they are modified with dispersed WC and TiC particles, which increases the crystallization rate, increases the metal density, corrosion and mechanical properties. The evaluation of their corrosion resistance with the help of the autoclaved test complex “Cortest” is made after obtaining ingots by various technologies.

Formwork pressure exerted by self-consolidating concrete

NASA Astrophysics Data System (ADS)

Omran, Ahmed Fathy

Self-consolidating concrete (SCC) is an emerging technology that utilizes flowable concrete that eliminates the need for consolidation. The advantages of SCC lie in a remarkable reduction of the casting time, facilitating the casting of congested and complex structural elements, possibility to reduce labor demand, elimination of mechanical vibrations and noise, improvement of surface appearance, producing a better and premium concrete product. The research focussed on capturing existing knowledge and making recommendations for current practice. An experimental program was undertaken at the Universite de Sherbrooke to evaluate the lateral pressure developed by SCC mixtures. A portable devise (UofS2 pressure column) for measuring and predicting lateral pressure and its rate of decay of SCC was developed and validated. The UofS2 pressure column is cast with 0.5 m high fresh concrete and air pressure is introduced from the top to simulate casting depth up to 13 m. Then, develop and implement test method for field evaluation of relevant plastic and thixotropic properties of SCC that affect formwork pressure were done. Portable vane (PV) test based on the hand-held vane test method used to determine the undrained shear strength property of clay soil was the first setup as well as the inclined plane (IP) test. The IP device involves slumping a small concrete cylinder on a horizontal plate and then lifting up the plate at different durations of rest until the slumped sample starts to move. Identifying role of material constituents, mix design, concrete placement characteristics (casting rate, waiting periods between lifts, and casting depth), temperature, and formwork characteristics that have major influence on formwork pressure exerted by SCC were evaluated in laboratory and validated by actual field measurements. Relating the maximum lateral pressure and its rate of decay to the plastic properties of SCC were established. In the analytical part of the research, effective ways to reduce lateral pressure by developing formulation expertise and practical guidelines to lower lateral pressure of SCC were proposed. Various design equations as well as chart diagrams to predict formwork pressure that can be exerted by SCC on column and wall elements were derived and reported. In general, the results obtained show that measured lateral pressure is lower than corresponding hydrostatic pressure. The study has shown that lateral pressure exerted by SCC is closely related to the structural build-up at rest (or thixotropy) of SCC. The latter can be controlled using different mixture proportionings, material constituents, and chemical admixtures. SCC mixture with a high rate of structural build-up at rest can develop low lateral pressure on formwork. Increased rate of structural build-up at rest can be ensured by incorporating a greater volume of coarse aggregate, lower paste volume, and/or lower sand-to-total aggregate ratio. Incorporating coarse aggregate of larger maximum size could also increase the thixotropy and hence reduce the lateral pressure. This can also be achieved by reducing the workability of SCC using less HRWRA concentration. Indeed, all mixture factors have been replaced by measuring the rate of structural build-up at rest (or thixotropy) using the developed portable vane and inclined plane field-oriented test as well as the modified Tattersall MK-III concrete rheometer. On the other hand, increasing or maintaining the concrete temperature at a certain level plays an important role to reduce the lateral pressure. The higher concrete temperature can accelerate the heat of hydration of cement with water and increase the internal friction leading to higher thixotropy. Controlling the placement rate has a great impact on the resultant lateral pressure of SCC. The lateral pressure can be reduced by slowing down the casting rate, as concrete has more time to build-up. However, this can slow down the rate of construction. The casting rate should be optimized to yield a cost effective formwork system. Pausing the continuous casting by a waiting period can reduce the exerted lateral pressure. The research investigation could accelerate the acceptance and implementation of SCC technology in cast-in-place applications, which is the preponderate business of the ready mixed concrete suppliers. The research findings could also contribute to the removal of some of the major barriers hindering the acceptance of SCC in cast-in-place applications and provide the industry with much needed guidelines on formwork pressure. (Abstract shortened by UMI.)

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.

Approaches to Design and Evaluation of Sandwich Composites

NASA Technical Reports Server (NTRS)

Shivakumar, Kunigal; Raju, I. S. (Technical Monitor); Ambur, D. (Technical Monitor)

2001-01-01

This report describes research during the period June 15, 1997 to October 31, 2000. This grant yielded a low cast manufacturing of composite sandwich structures technology and characterization interfacial and subinterfacial cracks in foam core sandwich panels. The manufacturing technology is called the vacuum assisted resin transfer (VARTM). The VARTM is suitable for processing composite materials both at ambient and elevated temperatures and of unlimited component size. This technology has been successfully transferred to a small business fiber preform manufacturing company 3TEX located in Cary, North Carolina. The grant also supported one Ph.D, one M.S and a number of under graduate students, and nine publications and Presentations.

Slip casting nano-particle powders for making transparent ceramics

DOEpatents

Kuntz, Joshua D [Livermore, CA; Soules, Thomas F [Livermore, CA; Landingham, Richard Lee [Livermore, CA; Hollingsworth, Joel P [Oakland, CA

2011-04-12

A method of making a transparent ceramic including the steps of providing nano-ceramic powders in a processed or unprocessed form, mixing the powders with de-ionized water, the step of mixing the powders with de-ionized water producing a slurry, sonifing the slurry to completely wet the powder and suspend the powder in the de-ionized water, separating very fine particles from the slurry, molding the slurry, and curing the slurry to produce the transparent ceramic.

Separation and Depleted Uranium Fragments from Gun Test Catchment. Volume 2. Catchment System and Separations Methods

DTIC Science & Technology

1993-12-30

projectile fragments from target materials, principally sand. Phase I activities included (1) literature review of separations technology , (2) site visits, (3...the current operation, evaluation of alternative means for separation of DU from sand, a review of uranium mining technology for v possible...the current operation, evaluation of alternative means for separation of DU from sand, a review of uranium mining technology for possible

Mixed Matrix PVDF Membranes With in Situ Synthesized PAMAM Dendrimer-Like Particles: A New Class of Sorbents for Cu(II) Recovery from Aqueous Solutions by Ultrafiltration.

PubMed

Kotte, Madhusudhana Rao; Kuvarega, Alex T; Cho, Manki; Mamba, Bhekie B; Diallo, Mamadou S

2015-08-18

Advances in industrial ecology, desalination, and resource recovery have established that industrial wastewater, seawater, and brines are important and largely untapped sources of critical metals and elements. A Grand Challenge in metal recovery from industrial wastewater is to design and synthesize high capacity, recyclable and robust chelating ligands with tunable metal ion selectivity that can be efficiently processed into low-energy separation materials and modules. In our efforts to develop high capacity chelating membranes for metal recovery from impaired water, we report a one-pot method for the preparation of a new family of mixed matrix polyvinylidene fluoride (PVDF) membranes with in situ synthesized poly(amidoamine) [PAMAM] particles. The key feature of our new membrane preparation method is the in situ synthesis of PAMAM dendrimer-like particles in the dope solutions prior to membrane casting using low-generation dendrimers (G0 and G1-NH2) with terminal primary amine groups as precursors and epichlorohydrin (ECH) as cross-linker. By using a combined thermally induced phase separation (TIPS) and nonsolvent induced phase separation (NIPS) casting process, we successfully prepared a new family of asymmetric PVDF ultrafiltration membranes with (i) neutral and hydrophilic surface layers of average pore diameters of 22-45 nm, (ii) high loadings (∼48 wt %) of dendrimer-like PAMAM particles with average diameters of ∼1.3-2.4 μm, and (iii) matrices with sponge-like microstructures characteristics of membranes with strong mechanical integrity. Preliminary experiments show that these new mixed matrix PVDF membranes can serve as high capacity sorbents for Cu(II) recovery from aqueous solutions by ultrafiltration.

Malignant tumors of the maxilla: virtual planning and real-time rehabilitation with custom-made R-zygoma fixtures and carbon-graphite fiber-reinforced polymer prosthesis.

PubMed

Ekstrand, Karl; Hirsch, Jan-M

2008-03-01

Oral cancer is a mutilating disease. Because of the expanding application of computer technology in medicine, new methods are constantly evolving. This project leads into a new technology in maxillofacial reconstructive therapy using a redesigned zygoma fixture. Previous development experiences showed that the procedure was time-consuming and painful for the patients. Frequent episodes of sedation or general anesthetics were required and the rehabilitation is costly. The aim of our new treatment goal was to allow the patients to wake up after tumor surgery with a functional rehabilitation in place. Stereolithographic models were introduced to produce a model from the three-dimensional computed tomography (CT). A guide with the proposed resection was fabricated, and the real-time maxillectomy was performed. From the postoperative CT, a second stereolithographic model was manufactured and in addition, a stent for the optimal position of the implants. Customized zygoma implants were installed (R-zygoma, Integration AB, Göteborg, Sweden). A fixed construction was fabricated by using a new material based on poly(methylacrylate) reinforced with carbon/graphite fibers and attached to the implants. On the same master cast, a separate obturator was fabricated in permanent soft silicon. The result of this project showed that it was possible to create a virtual plan preoperatively to apply during surgery in order for the patient to wake up functionally rehabilitated. From a quality-of-life perspective, it is an advantage to be rehabilitated fast. By using new computer technology, pain and discomfort are less and the total rehabilitation is faster, which in turn reduces days in hospital and thereby total costs.

THE INFLUENCE OF SCREW TYPE, ALLOY AND CYLINDER POSITION ON THE MARGINAL FIT OF IMPLANT FRAMEWORKS BEFORE AND AFTER LASER WELDING

PubMed Central

Castilio, Daniela; Pedreira, Ana Paula Ribeiro do Vale; Rossetti, Paulo Henrique Orlato; Rossetti, Leylha Maria Nunes; Bonachela, Wellington Cardoso

2006-01-01

Misfit at the abutment-prosthetic cylinder interface can cause loss of preload, leading to loosening or fracture of gold and titanium screws. Objectives: To evaluate the influence of screw type, alloy, and cylinder position on marginal fit of implant frameworks before and after laser welding. Methods: After Estheticone-like abutments were screwed to the implants, thirty plastic prosthetic cylinders were mounted and waxed-up to fifteen cylindrical bars. Each specimen had three interconnected prosthetic components. Five specimens were one-piece cast in titanium and five in cobalt-chromium alloy. On each specimen, tests were conducted with hexagonal titanium and slotted gold screws separately, performing a total of thirty tested screws. Measurements at the interfaces were performed using an optical microscope with 5 μm accuracy. After sectioning, specimens were laser welded and new measurements were obtained. Data were submitted to a four-way ANOVA and Tukey's multiple comparisons test (α =0.05). Results: Slotted and hexagonal screws did not present significant differences regarding to the fit of cylinders cast in titanium, either in one-piece casting framework or after laser welding. When slotted and hexagonal screws were tested on the cobalt-chromium specimens, statistically significant differences were found for the one-piece casting condition, with the slotted screws presenting better fit (24.13μm) than the hexagonal screws (27.93 μm). Besides, no statistically significant differences were found after laser welding. Conclusions: 1) The use of different metal alloys do exert influence on the marginal fit, 2) The slotted and hexagonal screws play the exclusive role of fixing the prosthesis, and did not improve the fit of cylinders, and 3) cylinder position did not affect marginal fit values. PMID:19089035

The University Münster Model Surgery System for Orthognathic Surgery. Part II -- KD-MMS.

PubMed

Ehmer, Ulrike; Joos, Ulrich; Ziebura, Thomas; Flieger, Stefanie; Wiechmann, Dirk

2013-01-04

Model surgery is an integral part of the planning procedure in orthognathic surgery. Most concepts comprise cutting the dental cast off its socket. The standardized spacer plates of the KD-MMS provide for a non-destructive, reversible and reproducible means of maxillary and/or mandibular plaster cast separation. In the course of development of the system various articulator types were evaluated with regard to their capability to provide a means of realizing the concepts comprised of the KD-MMS. Special attention was dedicated to the ability to perform three-dimensional displacements without cutting of plaster casts. Various utilities were developed to facilitate maxillary displacement in accordance to the planning. Objectives of this development comprised the ability to implement the values established in the course of two-dimensional ceph planning. The system - KD-MMS comprises a set of hardware components as well as a defined procedure. Essential hardware components are red spacer and blue mounting plates. The blue mounting plates replace the standard yellow SAM mounting elements. The red spacers provide for a defined leeway of 8 mm for three-dimensional movements. The non-destructive approach of the KD-MMS makes it possible to conduct different model surgeries with the same plaster casts as well as to restore the initial, pre-surgical situation at any time. Thereby, surgical protocol generation and gnathologic splint construction are facilitated. The KD-MMS hardware components in conjunction with the defined procedures are capable of increasing efficiency and accuracy of model surgery and splint construction. In cases where different surgical approaches need to be evaluated in the course of model surgery, a significant reduction of chair time may be achieved.

The influence of screw type, alloy and cylinder position on the marginal fit of implant frameworks before and after laser welding.

PubMed

Castilio, Daniela; Pedreira, Ana Paula Ribeiro do Vale; Rossetti, Paulo Henrique Orlato; Rossetti, Leylha Maria Nunes; Bonachela, Wellington Cardoso

2006-04-01

Misfit at the abutment-prosthetic cylinder interface can cause loss of preload, leading to loosening or fracture of gold and titanium screws. To evaluate the influence of screw type, alloy, and cylinder position on marginal fit of implant frameworks before and after laser welding. After Estheticone-like abutments were screwed to the implants, thirty plastic prosthetic cylinders were mounted and waxed-up to fifteen cylindrical bars. Each specimen had three interconnected prosthetic components. Five specimens were one-piece cast in titanium and five in cobalt-chromium alloy. On each specimen, tests were conducted with hexagonal titanium and slotted gold screws separately, performing a total of thirty tested screws. Measurements at the interfaces were performed using an optical microscope with 5mm accuracy. After sectioning, specimens were laser welded and new measurements were obtained. Data were submitted to a four-way ANOVA and Tukey's multiple comparisons test (alpha=0.05). Slotted and hexagonal screws did not present significant differences regarding to the fit of cylinders cast in titanium, either in one-piece casting framework or after laser welding. When slotted and hexagonal screws were tested on the cobalt-chromium specimens, statistically significant differences were found for the one-piece casting condition, with the slotted screws presenting better fit (24.13 microm) than the hexagonal screws (27.93 microm). Besides, no statistically significant differences were found after laser welding. 1) The use of different metal alloys do exert influence on the marginal fit, 2) The slotted and hexagonal screws play the exclusive role of fixing the prosthesis, and did not improve the fit of cylinders, and 3) cylinder position did not affect marginal fit values.

Viscosity Meaurement Technique for Metal Fuels

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

Ban, Heng; Kennedy, Rory

2015-02-09

Metallic fuels have exceptional transient behavior, excellent thermal conductivity, and a more straightforward reprocessing path, which does not separate out pure plutonium from the process stream. Fabrication of fuel containing minor actinides and rare earth (RE) elements for irradiation tests, for instance, U-20Pu-3Am-2Np-1.0RE-15Zr samples at the Idaho National Laboratory, is generally done by melt casting in an inert atmosphere. For the design of a casting system and further scale up development, computational modeling of the casting process is needed to provide information on melt flow and solidification for process optimization. Therefore, there is a need for melt viscosity data, themore » most important melt property that controls the melt flow. The goal of the project was to develop a measurement technique that uses fully sealed melt sample with no Americium vapor loss to determine the viscosity of metallic melts and at temperatures relevant to the casting process. The specific objectives of the project were to: develop mathematical models to establish the principle of the measurement method, design and build a viscosity measurement prototype system based on the established principle, and calibrate the system and quantify the uncertainty range. The result of the project indicates that the oscillation cup technique is applicable for melt viscosity measurement. Detailed mathematical models of innovative sample ampoule designs were developed to not only determine melt viscosity, but also melt density under certain designs. Measurement uncertainties were analyzed and quantified. The result of this project can be used as the initial step toward the eventual goal of establishing a viscosity measurement system for radioactive melts.« less

Kr/Xe Separation over a Chabazite Zeolite Membrane

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

Feng, Xuhui; Zong, Zhaowang; Elsaidi, Sameh K.

2016-08-10

Cryogenic distillation, the current conventional technology to separate Krypton and Xenon from air, and from nuclear reprocessing technologies, is an energy-intensive and expensive process. Membrane technology could potentially make this challenging industrial separation less energy intensive and economically viable. We demonstrate that chabazite zeolite SAPO-34 membranes effectively separated Kr/Xe gas mixtures at industrially relevant compositions. Control over membrane thickness and average crystal size led to industrial range permeances and high separation selectivities. Specifically, SAPO-34 membranes can separate Kr/Xe mixtures with Kr permeances as high as 361.4 GPU and separation selectivities of 34.8 for molar compositions close to typical concentrations ofmore » these two gases in air. In addition, SAPO-34 membranes separated Kr/Xe mixtures with Kr permeances as high as 525.7 GPU and separation selectivities up to 45.1 for molar compositions as might be encountered in nuclear reprocessing technologies. Molecular sieving and differences in diffusivities were identified as the dominant separation mechanisms.« less

Ohno continuous casting

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

Soda, H.; McLean, A.; Motoyasu, G.

1995-04-01

Production of net-shape products directly from the liquid is an attractive manufacturing route for alloys that are difficult to process or that cannot be rolled, drawn, or extruded. Developed at the Chiba Institute of Technology in Japan, the Ohno Continuous Casting (OCC) approach not only provides significant cost savings, but also has the potential to create new products. OCC process equipment includes a melting furnace, crucible, mold level-control block, cooling device, and pinch rolls. OCC is currently used to produce copper rods and wires for audio and video cables, and aluminum alloy welding rods for hard-surfacing applications. For example, Mitsuimore » Engineering and Ship Building Co. has used OCC to produce copper tubing products with internal fins and partitions for applications such as heat exchanger tubes and induction coils.« less

HEU Holdup Measurements in 321-M B and Spare U-Al Casting Furnaces

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

Salaymeh, S.R.

The Analytical Development Section of Savannah River Technology Center (SRTC) was requested by the Facilities Decontamination Division (FDD) to determine the holdup of enriched uranium in the 321-M facility as part of an overall deactivation project of the facility. The 321-M facility was used to fabricate enriched uranium fuel assemblies, lithium-aluminum target tubes, neptunium assemblies, and miscellaneous components for the production reactors. This report covers holdup measurements in two uranium aluminum alloy (U-Al) casting furnaces. Our results indicate an upper limit of 235U content for the B and Spare furnaces of 51 and 67 g respectively. This report discusses themore » methodology, non-destructive assay (NDA) measurements, and results of the uranium holdup on the two furnaces.« less

Multiple structured light system for the 3D measurement of feet

NASA Astrophysics Data System (ADS)

Gaertner, Hansjoerg; Lavoie, Jean-Francois; Vermette, Eric; Houle, Pascal-Simon

1999-03-01

In the field of custom foot orthosis bio-mechanics specialists take negative casts of the patient's feet and produce a positive on which they apply corrective elements. The corrected positive cast is then used to thermoform an orthosis. Several production steps can be simplified or eliminated by a 3D-acquisition of the underside of the foot. Such a complete custom footwear system, developed by Neogenix Technologies Inc., has been reported last year in IS and T/SPIE's symposium. A major improvement aimed at maximizing the coverage of the underside of foot surface has been achieved since by using multiple structured light projection technique. A description of a patent pending hardware set-up and range data extraction by software will be given in this paper.

Implementation of Metal Casting Best Practices

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

Eppich, Robert; Naranjo, Robert D.

2007-01-01

The project examined cases where metal casters had implemented ITP research results and the benefits they received due to that implementation. In cases where casters had not implemented those results, the project examined the factors responsible for that lack of implementation. The project also informed metal casters of the free tools and service offered by the ITP Technology Delivery subprogram.

Developments in metallic materials for aerospace applications

NASA Astrophysics Data System (ADS)

Wadsworth, J.; Froes, F. H.

1989-05-01

High-performance aerospace systems are creating a demand for new materials, not only for airframe and engine applications, but for missile and space systems as well. Recently, advances have been made in metallic materials systems based on magnesium, aluminum, titanium and niobium using a variety of processing methods, including ingot casting, powder metallurgy, rapid solidification and composite technology.

3 CFR 8790 - Proclamation 8790 of April 2, 2012. National Cancer Control Month, 2012

Code of Federal Regulations, 2013 CFR

2013-01-01

... and grandparents, children and cherished friends; the disease touches almost all of us and casts a... promising technologies and treatments. During National Cancer Control Month, we pay tribute to the men, women, and children we have lost to cancer, and we look ahead to a future in which more Americans have...

Casting the Net: The Development of a Resource Collection for an Internet Database.

ERIC Educational Resources Information Center

McKiernan, Gerry

CyberStacks(sm), a demonstration prototype World Wide Web information service, was established on the home page server at Iowa State University with the intent of facilitating identification and use of significant Internet resources in science and technology. CyberStacks(sm) was created in response to perceived deficiencies in early efforts to…

Evaluating Learning Management System (LMS)-Facilitated Delivery of Universal Design for Learning (UDL)

ERIC Educational Resources Information Center

Bryans Bongey, Sarah

2012-01-01

This quantitative study involved 157 students in two sections of an undergraduate class in general biology, as well as one instructor who taught both sections of the course. It used resources from the Center for Applied Special Technologies (CAST) to evaluate the viability of a Learning Management System (LMS) to provide Universal Design for…

Patio Stone Project Gives Students a Concrete Learning Experience

ERIC Educational Resources Information Center

Fitzgerald, Mike

2005-01-01

In this article, the author presents an overview of concrete as a building material and as an example of a particle composite, and discusses the origins of concrete in ancient Rome. He then describes an activity in which students can cast a concrete patio stone. Students can apply the technological design process, as well as the elements of…

A novel technology coupling extraction and foam fractionation for separating the total saponins from Achyranthes bidentata.

PubMed

Ding, Linlin; Wang, Yanji; Wu, Zhaoliang; Liu, Wei; Li, Rui; Wang, Yanyan

2016-10-02

A novel technology coupling extraction and foam fractionation was developed for separating the total saponins from Achyranthes bidentata. In the developed technology, the powder of A. bidentata was loaded in a nylon filter cloth pocket with bore diameter of 180 µm. The pocket was fixed in the bulk liquid phase for continuously releasing saponins. Under the optimal conditions, the concentration and the extraction rate of the total saponins in the foamate by the developed technology were 73.5% and 416.2% higher than those by the traditional technology, respectively. The foamates obtained by the traditional technology and the developed technology were analyzed by ultraperformance liquid chromatography-mass spectrometry to determine their ingredients, and the results appeared that the developed technology exhibited a better performance for separating saponins than the traditional technology. The study is expected to develop a novel technology for cost effectively separating plant-derived materials with surface activity.

Synthesis and crystalline properties of CdS incorporated polyvinylidene fluoride (PVDF) composite film

NASA Astrophysics Data System (ADS)

Patel, Arunendra Kumar; Sunder, Aishwarya; Mishra, Shweta; Bajpai, Rakesh

2018-05-01

This paper gives an insight on the synthesis and crystalline properties of Polyvinylidene Fluoride (PVDF) (host matrix) composites impregnated with Cadmium Sulphide (CdS) using Dimethyl formamide (DMF) as the base, prepared by the well known solvent casting technique. The effect of doping concentration of CdS in to the PVDF matrix was studied using X-ray diffraction technique. The structural properties like crystallinity Cr, interplanar distance d, average size of the crystalline region (D), and average inter crystalline separation (R) have been estimated for the developed composite. The crystallinity index, crystallite size and inter crystalline separation is increasing with increase in the concentration of CdS in to the PVDF matrix while the interplanar distance d is decreasing.

Supplemental Immobilization of Hanford Low-Activity Waste: Cast Stone Screening Tests

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

Westsik, Joseph H.; Piepel, Gregory F.; Lindberg, Michael J.

2013-09-30

More than 56 million gallons of radioactive and hazardous waste are stored in 177 underground storage tanks at the U.S. Department of Energy’s (DOE’s) Hanford Site in southeastern Washington State. The Hanford Tank Waste Treatment and Immobilization Plant (WTP) is being constructed to treat the wastes and immobilize them in a glass waste form. The WTP includes a pretreatment facility to separate the wastes into a small volume of high-level waste (HLW) containing most of the radioactivity and a larger volume of low-activity waste (LAW) containing most of the nonradioactive chemicals. The HLW will be converted to glass in themore » HLW vitrification facility for ultimate disposal at an offsite federal repository. At least a portion (~35%) of the LAW will be converted to glass in the LAW vitrification facility and will be disposed of onsite at the Integrated Disposal Facility (IDF). The pretreatment and HLW vitrification facilities will have the capacity to treat and immobilize the wastes destined for each facility. However, a second LAW immobilization facility will be needed for the expected volume of LAW requiring immobilization. A cementitious waste form known as Cast Stone is being considered to provide the required additional LAW immobilization capacity. The Cast Stone waste form must be acceptable for disposal in the IDF. The Cast Stone waste form and immobilization process must be tested to demonstrate that the final Cast Stone waste form can comply with the waste acceptance criteria for the disposal facility and that the immobilization processes can be controlled to consistently provide an acceptable waste form product. Further, the waste form must be tested to provide the technical basis for understanding the long-term performance of the waste form in the disposal environment. These waste form performance data are needed to support risk assessment and performance assessment (PA) analyses of the long-term environmental impact of the waste disposal in the IDF. The PA is needed to satisfy both Washington State IDF Permit and DOE Order requirements. Cast Stone has been selected for solidification of radioactive wastes including WTP aqueous secondary wastes treated at the Effluent Treatment Facility (ETF) at Hanford. A similar waste form called Saltstone is used at the Savannah River Site (SRS) to solidify its LAW tank wastes.« less

Periodic Cellular Structure Technology for Shape Memory Alloys

NASA Technical Reports Server (NTRS)

Chen, Edward Y.

2015-01-01

Shape memory alloys are being considered for a wide variety of adaptive components for engine and airframe applications because they can undergo large amounts of strain and then revert to their original shape upon heating or unloading. Transition45 Technologies, Inc., has developed an innovative periodic cellular structure (PCS) technology for shape memory alloys that enables fabrication of complex bulk configurations, such as lattice block structures. These innovative structures are manufactured using an advanced reactive metal casting technology that offers a relatively low cost and established approach for constructing near-net shape aerospace components. Transition45 is continuing to characterize these structures to determine how best to design a PCS to better exploit the use of shape memory alloys in aerospace applications.

A comparison of forming technologies for ceramic gas-turbine engine components

NASA Technical Reports Server (NTRS)

Hengst, R. R.; Heichel, D. N.; Holowczak, J. E.; Taglialavore, A. P.; Mcentire, B. J.

1990-01-01

For over ten years, injection molding and slip casting have been actively developed as forming techniques for ceramic gas turbine components. Co-development of these two processes has continued within the U.S. DOE-sponsored Advanced Turbine Technology Application Project (ATTAP). Progress within ATTAP with respect to these two techniques is summarized. A critique and comparison of the two processes are given. Critical aspects of both processes with respect to size, dimensional control, material properties, quality, cost, and potential for manufacturing scale-up are discussed.

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.

Separators - Technology review: Ceramic based separators for secondary batteries

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

Nestler, Tina; Schmid, Robert; Münchgesang, Wolfram

Besides a continuous increase of the worldwide use of electricity, the electric energy storage technology market is a growing sector. At the latest since the German energy transition ('Energiewende') was announced, technological solutions for the storage of renewable energy have been intensively studied. Storage technologies in various forms are commercially available. A widespread technology is the electrochemical cell. Here the cost per kWh, e. g. determined by energy density, production process and cycle life, is of main interest. Commonly, an electrochemical cell consists of an anode and a cathode that are separated by an ion permeable or ion conductive membranemore » - the separator - as one of the main components. Many applications use polymeric separators whose pores are filled with liquid electrolyte, providing high power densities. However, problems arise from different failure mechanisms during cell operation, which can affect the integrity and functionality of these separators. In the case of excessive heating or mechanical damage, the polymeric separators become an incalculable security risk. Furthermore, the growth of metallic dendrites between the electrodes leads to unwanted short circuits. In order to minimize these risks, temperature stable and non-flammable ceramic particles can be added, forming so-called composite separators. Full ceramic separators, in turn, are currently commercially used only for high-temperature operation systems, due to their comparably low ion conductivity at room temperature. However, as security and lifetime demands increase, these materials turn into focus also for future room temperature applications. Hence, growing research effort is being spent on the improvement of the ion conductivity of these ceramic solid electrolyte materials, acting as separator and electrolyte at the same time. Starting with a short overview of available separator technologies and the separator market, this review focuses on ceramic-based separators. Two prominent examples, the lithium-ion and sodium-sulfur battery, are described to show the current stage of development. New routes are presented as promising technologies for safe and long-life electrochemical storage cells.« less

Separators - Technology review: Ceramic based separators for secondary batteries

NASA Astrophysics Data System (ADS)

Nestler, Tina; Schmid, Robert; Münchgesang, Wolfram; Bazhenov, Vasilii; Schilm, Jochen; Leisegang, Tilmann; Meyer, Dirk C.

2014-06-01

Besides a continuous increase of the worldwide use of electricity, the electric energy storage technology market is a growing sector. At the latest since the German energy transition ("Energiewende") was announced, technological solutions for the storage of renewable energy have been intensively studied. Storage technologies in various forms are commercially available. A widespread technology is the electrochemical cell. Here the cost per kWh, e. g. determined by energy density, production process and cycle life, is of main interest. Commonly, an electrochemical cell consists of an anode and a cathode that are separated by an ion permeable or ion conductive membrane - the separator - as one of the main components. Many applications use polymeric separators whose pores are filled with liquid electrolyte, providing high power densities. However, problems arise from different failure mechanisms during cell operation, which can affect the integrity and functionality of these separators. In the case of excessive heating or mechanical damage, the polymeric separators become an incalculable security risk. Furthermore, the growth of metallic dendrites between the electrodes leads to unwanted short circuits. In order to minimize these risks, temperature stable and non-flammable ceramic particles can be added, forming so-called composite separators. Full ceramic separators, in turn, are currently commercially used only for high-temperature operation systems, due to their comparably low ion conductivity at room temperature. However, as security and lifetime demands increase, these materials turn into focus also for future room temperature applications. Hence, growing research effort is being spent on the improvement of the ion conductivity of these ceramic solid electrolyte materials, acting as separator and electrolyte at the same time. Starting with a short overview of available separator technologies and the separator market, this review focuses on ceramic-based separators. Two prominent examples, the lithium-ion and sodium-sulfur battery, are described to show the current stage of development. New routes are presented as promising technologies for safe and long-life electrochemical storage cells.