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1

The properties of amylose-ethylcellulose films cast from organic-based solvents as potential coatings for colonic drug delivery.  

PubMed

The purpose of the study was to establish the physico-mechanical and digestibility properties of water-miscible organic solvent-based amylose-ethylcellulose films as potential coatings for colonic drug delivery. Free films containing different ratios of amylose to ethylcellulose were cast from the water-miscible organic solvent, ethyl lactate, in combination with the plasticiser, dibutyl sebacate. The resultant mixed films were characterised in terms of tensile strength and elasticity, polymer miscibility, permeability, and digestibility under simulated colonic conditions. Films containing higher concentrations of amylose displayed increasing weakness and softness and faster permeation to hydrogen ions compared to films with lower amylose content. No apparent miscibility was detected between the amylose and ethylcellulose, regardless of film composition. The films were found to be susceptible to digestion by bacterial enzymes within a simulated colonic environment. The extent of digestion was directly proportional to the amount of amylose present within the film. Overall, the results suggest that such amylose-ethylcellulose films could be used as coatings for drug delivery to the colon. PMID:10915961

Siew, L F; Basit, A W; Newton, J M

2000-08-01

2

Nickel based casting alloy  

Microsoft Academic Search

A nickel base casting alloy containing 10 to 25 percent chromium, 3 to 8 percent manganese, 3 to 10 percent niobium, 0 to 3.5 percent aluminum, 0.5 to 2.0 percent beryllium which exhibits lower melting characteristics allowing enhanced compatibility to gypsum bonded investments.

A. P. Burnett; W. C. Bollinger

1985-01-01

3

Diagnosis of oxide films in cast aluminum alloys  

Microsoft Academic Search

Aluminum (Al) alloy castings often contain many defects, such as micro-shrinkage, gas pores, shrinkage pores, hot tearing,\\u000a and oxide film entrapment. When oxide films are entrapped in Al alloy castings, they are very difficult to identify simply\\u000a by optical observation. In this study we used an auto-scanning eddy current testing method to detect oxide films entrapped\\u000a in Al alloy castings.

Yeong-Jern Chen; Hwei-Yuan Teng; Yuo-Tern Tsai

2004-01-01

4

Melting and casting of FeAl-based cast alloy  

Microsoft Academic Search

The FeAl-based intermetallic alloys are of great interest because of their low density, low raw material cost, and excellent resistance to high-temperature oxidation, sulfidation, carburization, and molten salts. The applications based on these unique properties of FeAl require methods to melt and cast these alloys into complex-shaped castings and centrifugal cast tubes. This paper addresses the melting-related issues and the

V. K. Sikka; D. Wilkening; J. Liebetrau; B. Mackey

1998-01-01

5

Melting and casting of FeAl-based cast alloy  

SciTech Connect

The FeAl-based intermetallic alloys are of great interest because of their low density, low raw material cost, and excellent resistance to high-temperature oxidation, sulfidation, carburization, and molten salts. The applications based on these unique properties of FeAl require methods to melt and cast these alloys into complex-shaped castings and centrifugal cast tubes. This paper addresses the melting-related issues and the effect of chemistry on the microstructure and hardness of castings. It is concluded that the use of the Exo-Melt{trademark} process for melting and the proper selection of the aluminum melt stock can result in porosity-free castings. The FeAl alloys can be melted and cast from the virgin and revert stock. A large variation in carbon content of the alloys is possible before the precipitation of graphite flakes occurs. Titanium is a very potent addition to refine the grain size of castings. A range of complex sand castings and two different sizes of centrifugal cast tubes of the alloy have already been cast.

Sikka, V.K. [Oak Ridge National Lab., TN (United States); Wilkening, D. [Columbia Falls Aluminum Co., Columbia Falls, MT (United States); Liebetrau, J.; Mackey, B. [AFFCO, L.L.C., Anaconda, MT (United States)

1998-11-01

6

Diagnosis of oxide films in cast aluminum alloys  

NASA Astrophysics Data System (ADS)

Aluminum (Al) alloy castings often contain many defects, such as micro-shrinkage, gas pores, shrinkage pores, hot tearing, and oxide film entrapment. When oxide films are entrapped in Al alloy castings, they are very difficult to identify simply by optical observation. In this study we used an auto-scanning eddy current testing method to detect oxide films entrapped in Al alloy castings. The detection signal and the measurement data were confirmed by scanning electron microscope (SEM) observation and partly backed-up by the ultrasonic-vibration method.

Chen, Yeong-Jern; Teng, Hwei-Yuan; Tsai, Yuo-Tern

2004-02-01

7

The Raman analysis of films cast from dissolved feather keratin  

Microsoft Academic Search

Raman spectroscopy was used to characterize films cast from dissolved feather keratin. Spectra obtained from the films were found to be very similar to those of the feather components from which they were derived. The protein structure of the films was dominated by ?-sheet conformation with possibly more disordered protein content and slightly less disulfide cross-linking compared to the feather.

J. S. Church; A. J. Poole; A. L. Woodhead

2010-01-01

8

Land-based turbine casting initiative  

SciTech Connect

To meet goals for the ATS program, technical advances developed for aircraft gas turbine engines need to be applied to land-based gas turbines. These advances include directionally solidified and single crystal castings, alloys tailored to exploit these microstructures, complex internal cooling schemes, and coatings. The proposed program to scale aircraft gas turbine casting technology up to land based gas turbine size components is based on low sulfur alloys, casting process development, post-cast process development, and establishing casting defect tolerance levels. The inspection side is also discussed.

Mueller, B.A.; Spicer, R.A. [Howmet Corp., Whitehall, MI (United States)

1995-12-31

9

Emulsion based cast booster - a priming system  

SciTech Connect

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

Gupta, R.N.; Mishra, A.K. [National Institute of Rock Mechanics, KGF (India)

2005-07-01

10

Bifilm Defects in Ni-Based Alloy Castings  

NASA Astrophysics Data System (ADS)

The Ni-base superalloys, which are normally melted and cast in a vacuum, entrain their surface-oxide film during turbulent pouring of the melt; unfortunately at this time, this process is universally practiced for investment castings of these materials. The entrained film becomes a bifilm crack automatically, so that cast alloys have a large population of cracks that controls their failure behavior. The problems of the growth of single crystals and the welding of polycrystalline alloys are reviewed to illustrate the central role of bifilms in the cracking of turbine blades, the heat-affected zones of welds, and the reliability of properties. It has been demonstrated that improved gravity pouring systems can reduce these problems significantly, but only countergravity filling of molds is expected to result in defect-free castings. Recent cases in which turbine blades failed in service are examined, and the central role of bifilm defects in these failures is discussed.

Campbell, John; Tiryakio?lu, Murat

2012-08-01

11

Electrochemical Response of Metallofullerene Films Casted on Electrodes  

NASA Astrophysics Data System (ADS)

We have studied solution casted films of the major isomer of DyatC82 (DyatC82(I)) by cyclic voltammetry (CV) in acetonitrile. The films are found to display pronounced and stable redox response in the solution. A pair of reversible oxidation and rereduction waves is observed after the reoxidation of a reduced film. The characteristics and the inter-relationship of these waves are uncovered by the CV technique, scanning electron microscopy (SEM), and UV-Vis-NIR spectra.

Fan, Louzhen; Yang, Shangfeng; Yang, Shihe

2003-10-01

12

Infiltration of Slag Film into the Grooves on a Continuous Casting Mold  

NASA Astrophysics Data System (ADS)

An analytical model is developed to clarify the slag film infiltration into grooves on a copper mold during the continuous casting of steel slabs. A grooved-type casting mold was applied to investigate the infiltration of slag film into the grooves of a pitch of 0.8 mm, width of 0.7 mm, and depth of 0.6 mm at the vicinity of a meniscus. The plant trial tests were carried out at a casting speed of 5.5 m min-1. The slag film captured at a commercial thin slab casting plant showed that both the overall and the liquid film thickness were decreased exponentially as the distance from the meniscus increases. In contrast, the infiltration of slag film into the grooves had been increased with increasing distance from the meniscus. A theoretic model has been derived based on the measured profile of slag film thickness to calculate the infiltration of slag film into the grooves. It successfully reproduces the empirical observation that infiltration ratio increased sharply along casting direction, about 80 pct at 50 mm and 95 pct at 150 mm below the meniscus. In the model calculation, the infiltration of slag film increases with increasing groove width and/or surface tension of the slag. The effect of groove depth is negligible when the width to depth ratio of the groove is larger than unity. It is expected that the developed model for slag film infiltration in this study will be widely utilized to optimize the design of groove dimensions in continuous casting molds.

Cho, Jung-Wook; Jeong, Hee-Tae

2013-02-01

13

Entrained oxide films in TiAl castings  

Microsoft Academic Search

Tilt pouring of TiAl alloy from an induction skull melting (ISM) furnace into a ceramic shell mould has been carried out in this research. Microstructures and casting defects entrained by surface turbulence have been examined using scanning electron microscopy and EDX analysis. Oxide films were found draped over the dendrites of shrinkage porosity and the inner surface of bubbles in

J Mi; R. A Harding; M Wickins; J Campbell

2003-01-01

14

Storage Stability and Antibacterial Activity against E. coli O157:H7 of Carvacrol in Edible Apple Films made by Two Different Casting Methods  

Technology Transfer Automated Retrieval System (TEKTRAN)

The antimicrobial activities against E. coli O157:H7, as well as the stability of carvacrol, the main constituent of oregano oil, were evaluated during the preparation and storage of apple-based edible films made by two different casting methods, continuous casting and batch casting. Antimicrobial ...

15

Filling system for investment cast Ni-base turbine blades  

Microsoft Academic Search

In investment foundries, it is usual to pay relatively little attention to the design of the filling system of a casting. Vacuum-cast turbine blades represent a typical case, where the mould filling process is poorly controlled, the mould cavities themselves often being top-filled. The consequential surface turbulence causes the entrapment of oxide film on the liquid surface, despite the use

D. Z Li; J Campbell; Y. Y Li

2004-01-01

16

Study of anisotropy of spin cast and vapor deposited polyimide films using internal reflection techniques  

SciTech Connect

We have compared anisotropy of spin cast and vapor deposited polyimide (VDP) films, using internal reflection infrared spectroscopy. The films were deposited directly on the internal reflection element. We find that spin cast films are more anisotropic than their VDP counterparts, with the polyimide chains tending to align parallel to the substrate. Both films are found to contain more and less ordered regions. Within the ordered regions, the plane of the phenyl ring tends to align parallel to the substrate.

Liberman, V.

1996-11-01

17

Advances in nickel-based cast superalloys  

Microsoft Academic Search

Nickel-based superalloys have served as the most competitive high temperature structural materials under highly stressed and\\u000a aggressive operating conditions in a variety of applications for more than 60 years. The most demanding among all the applications\\u000a has been the gas turbine aerofoil castings of modern aero-engines. These turbine parts operate in extremely aggressive environment\\u000a of high velocity hot combustion gas-air

Niranjan Das

2010-01-01

18

Aqueous suspensions for tape-casting based on acrylic binders  

Microsoft Academic Search

The use of water-based systems represents an interesting alternative to the widespread non-aqueous tape-casting but the low strength of water-based binders generally limits their applicability. A tape-casting slurry is a complex system where each organic component has a substantial effect on the rheological behaviour. In this study the effect of the dispersant and binders in alumina aqueous tape-casting slurries were

C. Pagnoux; T. Chartier; M. de F. Granja; F. Doreau; J. M. Ferreira; J. F. Baumard

1998-01-01

19

Chemical Properties and Film Casting of Radiation Grafted Ion-Containing Polymers.  

National Technical Information Service (NTIS)

A series of radiation grafted cation and anion exchange polymers have been studied with the intent of developing procedures for dissolving and film casting these polymers. Solvent swelling studies have shown that these polymers display two maxima in plots...

M. N. Szentirmay C. R. Martin

1984-01-01

20

QCM analyses on adsorption of gaseous guests to cast films of porphyrin-resorcinol derivatives  

Microsoft Academic Search

Bindings of fourteen kinds of gaseous guests to cast films of Zn-porphyrin-bis (resorcinol) have been investigated by gravimetric analysis using a quartz crystal microbalance (QCM). The Zn-porphyxin-bis (resorcinol) is known to form a hydrogen bonded inclusion complex with appropriate guests. When a QCM with the cast film of the Zn-poxphyrin-bis (resorcinol) was exposed to flow of guest gas, the QCM

Katsuhiko Ariga; Ken Endo; Yasuhiro Aoyama; Yoshio Okahata

2000-01-01

21

Oxide defects in a vacuum investment-cast ni-based turbine blade  

NASA Astrophysics Data System (ADS)

Samples from large turbine blades for power generation, investment-cast in vacuum from a nickel-based superalloy, were investigated. Samples were cut from regions near the top of the casting that contained freckle defects. The microstructures of these segregated regions were compared with those from nonsegregated adjacent regions using both optical microscopy and scanning electron microscopy (SEM). The segregated areas revealed a high density of carbides and a network of cracks. Samples were prepared by carefully fracturing along the cracks so as to observe the surfaces of the cracks. Observation by SEM revealed the presence of inclusions identified as films that appeared to have initiated the growth of carbides. Fractures of random areas of the nonsegregated alloy revealed that the films were numerous and widely distributed. In all cases, the films were principally oxides (and/or possibly nitrides) of aluminum and chromium. It was hypothesized that the films had originated by entrainment of the surface film on the liquid metal during the turbulent pouring of the casting. The films could, therefore, be assumed to be double, because the entrainment mechanism is a folding action. It follows that the doubled-over films constitute (1) the observed cracks and (2) the substrates for carbide precipitation. Evidence from other alloy systems is presented to support this conclusion.

Rashid, A. K. M. B.; Campbell, J.

2004-07-01

22

Sodium dodecyl sulfate treatment improves properties of cast films from soy protein isolate  

Microsoft Academic Search

The manufacture of edible\\/biodegradable films or coatings can potentially add value to soy protein. This study was conducted to determine the effect of sodium dodecyl sulfate (SDS) on selected physical properties of glycerin-plasticized soy protein isolate (SPI) films. Films were cast from heated (70°C for 20 min), alkaline (pH 10) aqueous solutions of SPI (5 g\\/100 ml water), glycerin (50%

Jong W. Rhim; Aristippos Gennadios; Curtis L. Weller; Milford A. Hanna

2002-01-01

23

DETAIL VIEW OF BASE OF CAST IRON TOWER SHOWING THE ...  

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

DETAIL VIEW OF BASE OF CAST IRON TOWER SHOWING THE FABRICATING MARK OF STARBUCK IRON WORKS, TROY, NY - Bidwell Bar Suspension Bridge & Stone Toll House, Near Lake Oroville (moved from fork of Feather River), Oroville, Butte County, CA

24

10. DETAIL OF CAST IRON COLUMN BASE ON FIRST FLOOR ...  

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

10. DETAIL OF CAST IRON COLUMN BASE ON FIRST FLOOR STOREFRONT, SHOWING MANUFACTURER'S STAMP: IOWA IRON WOKS CO. DUBUQUE. VIEW TO SOUTHWEST. - Commercial & Industrial Buildings, Dubuque Seed Company Warehouse, 169-171 Iowa Street, Dubuque, Dubuque County, IA

25

Study of oriented block copolymers films obtained by roll-casting  

Microsoft Academic Search

Roll-casting orientation of cylinder microphase separated poly(styrene-b-butadiene-b-styrene) triblock copolymers, was analyzed. The mechanical anisotropy of roll-cast films, defined as the ratio of Young's modulus obtained parallel and perpendicular to poly(styrene) cylinders, is similar for samples prepared using a dimensionless minimum gap between rolls higher than approximately 0.02. The orientation of samples was also characterized by measuring the full width at

Marcelo A Villar; Daniel R Rueda; Fernando Ania; Edwin L Thomas

2002-01-01

26

Rapid casting of turbine blades with abnormal film cooling holes using integral ceramic casting molds  

Microsoft Academic Search

Film cooling is an important cooling method to decrease the turbine blade surface temperature, and its average cooling efficiency\\u000a is mainly dependent on the cooling structures of internal passageways and the shapes of film cooling holes. Compared with\\u000a standard cylindrical film cooling holes, abnormal film cooling holes have higher average cooling efficiency. But it is difficult\\u000a to manufacture these holes

Haihua Wu; Dichen Li; Xiaojie Chen; Bo Sun; Dongyang Xu

2010-01-01

27

Undulation instability in drop-cast poly(3-hexylthiophene) film originated from self-assembly  

NASA Astrophysics Data System (ADS)

In this study, we characterize the undulated structures which appear at the edge of drop-cast regio-regular poly(3-hexylthiophene) (rr-P3HT, head-to-tail > 95%) film using optical microscopy and atomic force microscopy. We propose that these periodic structures originate from the undulations of the layered structure of liquid crystal-air interface. Evidence of rr-P3HT solution forming liquid crystalline phases at higher concentrations was obtained by the observation of distinct birefringence and characteristic textures under crossed polarizers using an optical microscope. Synchrotron x-ray diffraction pattern provides additional structural information at the undulated area compared with those at the area without undulated pattern. Based on these experimental results, we propose rr-P3HT solution can form a lyotropic liquid crystal at specific concentrations. This work was partially supported by NSF funding (DMR-0706235).

Park, Min Sang; Aiyar, Avishek; Park, Jung Ok; Reichmanis, Elsa; Srinivasarao, Mohan

2012-02-01

28

Functional properties of chitosan-based films.  

PubMed

Chitosan-based films plasticized with glycerol were prepared by casting with the aim to obtain environmentally friendly materials for packaging applications. Different contents of glycerol were incorporated into chitosan solutions to improve mechanical properties and all films obtained were flexible and transparent. It was observed that the transparency and good behaviour of the films against UV radiation were not affected by chitosan molecular weight or glycerol content. Moreover, chitosan-based films exhibited excellent barrier properties against water vapour and oxygen, even with the addition of glycerol. The effect of the plasticizer on the properties has been explained using Fourier transform infrared (FTIR) spectroscopic analysis. The changes observed in the intensity of the bands showed that glycerol interacts with chitosan, which could be confirmed by total soluble matter (TSM). PMID:23465939

Leceta, I; Guerrero, P; de la Caba, K

2012-04-20

29

Vacuum Casting of Thick Polymeric Films: New process produces uniform, bubble-free film from polymer solution.  

National Technical Information Service (NTIS)

This citation summarizes a one-page announcement of technology available for utilization. Uniform, bubble-free polymeric films, typically 0.2 cm in thickness, are formed from polymer solutions by a new vacuum-casting process. Segmented polyurethane elasto...

1981-01-01

30

Solution Casting and Transfer Printing Single-Walled Carbon Nanotube Films  

Microsoft Academic Search

This paper presents methods for solution casting and transfer printing collections of individual single-walled carbon nanotubes (SWNTs) onto a wide range of substrates, including plastic sheets. The deposition involves introduction of a solvent that removes surfactant from a suspension of SWNTs as it is applied to a substrate. The subsequent controlled flocculation (cF) produces films of SWNTs with densities that

Matthew A. Meitl; Yangxin Zhou; Anshu Gaur; Seokwoo Jeon; Monica L. Usrey; Michael S. Strano; John A. Rogers

2004-01-01

31

Antireflective polyimide based films  

NASA Astrophysics Data System (ADS)

The goal of this work was to prepare antireflective and anti-abrasion films using polyimide and organically modified silica nanoparticle thin films. A series of thin film were prepared from colorless and soluble polyimide with organically modified silica colloids via a solution casting method. The polyimide was selected for its optical properties. Three type of organically modified silica nanoparticles were prepared by grafting polysiloxane, polyfluoroester and fluoroalkyl groups onto silica nanoparticles. The molecular weight of the polysiloxane, polyfluoroester and the amount of fluorinated alkyl groups were varied. The organically modified silica colloids were characterized by TEM, DLS, FTIR, 1H NMR, solid state 13C NMR and solid state 29Si NMR. The coatings were characterized by UV-Vis transmittance spectra and SEM. The effect of modified silica loading, the molecular weight of polymer and type of solvent on AR properties were studied. An enhancement in antireflective activity was observed for 1 wt% LPDMS modified (low molecular weight) silica coatings, 3 wt% fluorosilica-10 and 3% L-MPS-PF-SILICA nanoparticles (low molecular weight polyfluoroester modified silica) in dimethylacetamide (DMAc). In comparison with cyclopentanone (CPT), DMAc favors migration of silica particles towards coating-air interface giving higher transmittance. The migration of particles to the surface and consequent increased surface roughness were observed by SEM. The present study suggested a roll to roll solution casting method to create antireflective coatings. This approach had potential to be used for a one-step large-scale manufacturing of antireflective coating. Four acrylated bismaleimide were made via two-step process. The first step involved the solution imidization to form hydroxylated bismaleimide. In the second step, hydroxylated bismaleimide was reacted with acryloyl chloride to form acrylated bismaleimide. The acrylated bismaleimide were characterized by FTIR, 1H NMR, 13C NMR, GPC and mass spectra. The acrylated bismaleimide was formulated with acryloyl morpholine and photoinitiator with or without addition of PDMS-silica nanoparticles to achieve UV-curable thin films. The photo-cure kinetics of four neat acrylated bismaleimide and the formulation were investigated by real-time FTIR, photo-DSC and rheometer. The kinetic analysis revealed that PDMS-silica accelerated the photocure rate and increased the conversion of both acrylate double bond and maleimide double bond. The dispersion of PDMS-silica nanoparticles affected the abrasion resistance. The optimal abrasion resistance was achieved with 3.0% wt PDMS modified silica nanoparticle loading.

Cao, Yuanmei

32

Cast thermally stable high temperature nickel-base alloys and casting made therefrom  

Microsoft Academic Search

A cast thermally stable high temperature nickel-base alloy characterized by superior oxidation resistance, sustainable hot strength and retention of ductility on aging is provided by maintaining the alloy chemistry within the composition molybdenum 13.7% to 15.5%; chromium 14.7% to 16.5%; carbon up to 0.1%, lanthanum in an effective amount to provide oxidation resistance up to 0.08%; boron up to 0.015%;

D. A. Acuncius; R. B. Herchenroeder; R. W. Kirchner; W. L. Silence

1977-01-01

33

Study on the Origin of Inverted Phase in Drying Solution-Cast Block Copolymer Films  

Microsoft Academic Search

ABSTRACT: In a previous study, we reported observation of the novel inverted phase (the minority blocks comprising,the continuum,phase) in kinetically,controlled,phase,separating,solution-cast,poly(styrene- b-butadiene-b-styrene) (SBS) triblock copolymer films [Zhang et al. Macromolecules 2000, 33, 9561-7]. In this study, we adopt the same approach to investigate the formation of inverted phase in a series of solution-cast,poly(styrene-b-butadiene) (SB) asymmetric,diblock,copolymers,having,nearly,equal,poly- styrene,(PS) weight,fraction,(about 30 wt %) but

Haiying Huang; Fajun Zhang; Zhijun Hu; Binyang Du; Tianbai HeFuk; Kay Lee; Yongjian Wang; Ophelia K. C. Tsui

2008-01-01

34

Mercuric iodide composite films using polyamide, polycarbonate and polystyrene fabricated by casting  

NASA Astrophysics Data System (ADS)

Mercuric iodide (HgI2) composite films were obtained by using the casting technique. Insulator polymers such as polyamide, polycarbonate and polystyrene were mixed to HgI2 crystallites forming a final sub-millimeter thick self-standing film. Fabrication temperature varied from 10 to 100 °C, and total fabrication time reached at most 5 min. The larger the fabrication temperature, the thinner the film and the smaller its electrical resistivity. Electrical characterization was performed in the dark, under UV illumination and under mammographic X-ray exposure. The final properties of the films are discussed and related to fabrication conditions. The optimized composite film might be a better candidate for use as X-ray detector for medical imaging, in place of the single HgI2 crystalline device.

Ugucioni, J. C.; Ghilardi Netto, T.; Mulato, M.

2010-10-01

35

The Effects on the Physical Property of the Chitin-Added Polyurethane Cast Films and Coated Fabrics  

Microsoft Academic Search

Chitin added to three types of polyurethane resins including hydrophilic, water in oil (w\\/o) emulsified, and wet-coagulated polyurethane resins for cast films and coated fabrics was investigated in this study The results showed that adding chitin to the hydrophilic and wet-coagulated polyurethane resins can effectively increase the water vapor permeability of the cast films or nylon coated fabrics. For the

Meng-Shung Yen; Kun-Lin Cheng

1995-01-01

36

Trace detection and differentiation of uranyl(VI) ion cast films utilizing aligned Ag nanorod SERS substrates  

Microsoft Academic Search

Aligned Ag nanorod arrays prepared by oblique angle vapor deposition (OAD) were utilized to observe the SERS response for cast films of adsorbed uranyl ion complexes. These nanorod arrays consisted of preferentially aligned and tilted cylindrically shaped nanorods (average nanorod length=858nm). Routine SERS spectra of cast films of uranyl nitrate resulted in 0.87pg of material analyzed with a detection limit

Chad L. Leverette; Eliel Villa-Aleman; Slade Jokela; Zhongyue Zhang; Yongjun Liu; Yiping Zhao; Sean A. Smith

2009-01-01

37

Dense polymer film and membrane formation via the dry-cast process part I. Model development  

Microsoft Academic Search

The dry-cast membrane-formation process is a major phase-inversion technique by which asymmetric membranes are manufactured. In this paper a fully predictive model which incorporates coupled heat and mass transfer is developed to describe the evaporation of both solvent and nonsolvent from an ini- tially homogeneous polymer\\/solvent\\/nonsolvent system. This unsteady-state, one-dimensional, coupled heat- and mass-transport model allows for local film shrinkage

Saeed S. Shojaie; William B. Krantz; Alan R. Greenberg

1994-01-01

38

UV–vis–infrared optical and AFM study of spin-cast chitosan films  

Microsoft Academic Search

Optical properties of spin-cast chitosan films have been determined in the infrared, visible, and ultraviolet region of the spectrum using spectroscopic ellipsometry. Optical constants for the UV–vis–near IR spectra from 130 to 1700nm were determined using Cauchy dispersion forms combined with Lorentzian oscillator models in the absorptive shorter wavelength regions. Infrared index of refraction and extinction coefficients from 750 to

W. H. Nosal; D. W. Thompson; L. Yan; S. Sarkar; A. Subramanian; J. A. Woollam

2005-01-01

39

Fatty acid-based polyurethane films for wound dressing applications.  

PubMed

Fatty acid-based polyurethane films were prepared for use as potential wound dressing material. The polymerization reaction was carried out with or without catalyst. Polymer films were prepared by casting-evaporation technique with or without crosslink-catalyst. The film prepared from uncatalyzed reaction product with crosslink-catalyst gave slightly higher crosslink density. The mechanical tests showed that, the increase in the tensile strength and decrease in the elongation at break is due to the increase in the degree of crosslinking. All films were flexible, and resisted to acid solution. The films prepared without crosslink-catalyst were more hydrophilic, absorbed more water. The highest permeability values were generally obtained for the films prepared without crosslink catalyst. Both the direct contact method and the MMT test were applied for determination of cytotoxicity of polymer films and the polyurethane film prepared from uncatalyzed reaction product without crosslink-catalyst showed better biocompatibility property, closest to the commercial product, Opsite. PMID:18839285

Gultekin, Guncem; Atalay-Oral, Cigdem; Erkal, Sibel; Sahin, Fikret; Karastova, Djursun; Tantekin-Ersolmaz, S Birgul; Guner, F Seniha

2008-10-07

40

Application in casting defect lossless examination based on surf  

NASA Astrophysics Data System (ADS)

Based on the study of measures of the algorithm casting defect lossless examination and characteristics of X-ray imaging, a new automatic detection based on SURF is presented. Firstly, the algorithm detects the interested points of specifically component model in the standard image samples by SURF. Then the interested points of inspection produce are detected when the rotary worktable makes one revolution, at the same time, the interested points between model and produce are matched. The number of matched points is the basis for whether the product contains the component. Experimental results show that this method is effective in determining the component model well or not, which provides a novel method for casting defect lossless examination.

Fan, Youchen; Sun, Huayan; Wang, Haoxiang

2013-08-01

41

The metallography of a nickel base casting alloy.  

PubMed

Three groups of tensile test pieces were produced using a nickel base partial denture casting alloy and employing induction fusion in each case. The first group was produced fro new metal, the second from metal which had been recast four times, and the third from new overheated metal. Samples of alloy were cut from each group, and together with a piece from an original ingot, were mounted, polished, etched, and examined under a metallurgical microscope. PMID:1108851

Lewis, A J

1975-10-01

42

Cast Fe-base cylinder\\/regenerator housing alloy  

Microsoft Academic Search

The development of an iron-base alloy that can meet the requirements of automotive Stirling engine cylinders and regenerator housings is described. Alloy requirements are as follows: a cast alloy, stress for 5000-hr rupture life of 200 MPa (29 ksi) at 775 C (1427 F), oxidation\\/corrosion resistance comparable to that of N-155, compatibility with hydrogen, and an alloy cost less than

F. Larson; L. Kindlimann

1980-01-01

43

Casting of particle-based hollow shapes  

DOEpatents

A method for the production of hollow articles made of a particle-based material; e.g., ceramics and sintered metals. In accordance with one aspect of the invention, a thermally settable slurry containing a relatively high concentration of the particles is coated onto a prewarmed continuous surface in a relatively thin layer so that the slurry is substantially uniformly coated on the surface. The heat of the prewarmed surface conducts to the slurry to initiate a reaction which causes the slurry to set or harden in a shape conforming to the surface. The hardened configurations may then be sintered to consolidate the particles and provide a high density product.

Menchhofer, Paul (Oak Ridge, TN)

1995-01-01

44

Fluid casting of particle-based articles  

DOEpatents

A method for the production of articles made of a particle-based material; e.g., ceramics and sintered metals. In accordance with one aspect of the invention, a thermally settable slurry containing a relatively high concentration of the particles is introduced into an immiscible, heated fluid. The slurry sets or hardens into a shape determined by the physical characteristics of the fluid and the manner of introduction of the slurry into the fluid. For example, the slurry is pulse injected into the fluid to provide spherical articles. The hardened spheres may then be sintered to consolidate the particles and provide a high density product.

Menchhofer, Paul (Oak Ridge, TN)

1995-01-01

45

Casting of particle-based hollow shapes  

DOEpatents

A method for the production of hollow articles made of a particle-based material; e.g., ceramics and sintered metals. In accordance with one aspect of the invention, a thermally settable slurry containing a relatively high concentration of the particles is coated onto a prewarmed continuous surface in a relatively thin layer so that the slurry is substantially uniformly coated on the surface. The heat of the prewarmed surface conducts to the slurry to initiate a reaction which causes the slurry to set or harden in a shape conforming to the surface. The hardened configurations may then be sintered to consolidate the particles and provide a high density product.

Menchhofer, Paul (Oak Ridge, TN)

1997-01-01

46

Fluid casting of particle-based articles  

DOEpatents

A method is disclosed for the production of articles made of a particle-based material; e.g., ceramics and sintered metals. In accordance with one aspect of the invention, a thermally settable slurry containing a relatively high concentration of the particles is introduced into an immiscible, heated fluid. The slurry sets hardens into a shape determined by the physical characteristics of the fluid and the manner of introduction of the slurry into the fluid. For example, the slurry is pulse injected into the fluid to provide spherical articles. The hardened spheres may then be sintered to consolidate the particles and provide a high density product. 1 figure.

Menchhofer, P.

1995-03-28

47

The recovery of latent fingermarks and DNA using a silicone-based casting material  

Microsoft Academic Search

There are many techniques available for the recovery of fingermarks at scenes of crime including the possibility of taking casts of the marks. Casts can be advantageous in cases where other destructive recovery techniques might not be suitable, such as when recovering finger marks deposited on valued or immobile items.In this research, Isomark™ (a silicone-based casting material) was used to

Rita Shalhoub; Ignacio Quinones; Carole Ames; Bryan Multaney; Stuart Curtis; Haj Seeboruth; Stephen Moore; Barbara Daniel

2008-01-01

48

Pure titanium casting into titanium-modified calcia-based and magnesia-based investment molds  

Microsoft Academic Search

Calcia is the most stable oxide for molten titanium at high temperature. In this study, pure titanium casting into calcia- and magnesia-based investments was investigated. Experimental results show that adding the proper amount of titanium powder into calcia- and magnesia-based investments can increase the thermal expansion value, at 800°C, of both investments. Pure titanium castings in the calcia-based group have

C. C. Hung; P. L. Lai; C. C. Tsai; T. K. Huang; Y. Y. Liao

2007-01-01

49

Flexible, transparent nanocomposite film with a large clay component and ordered structure obtained by a simple solution-casting method.  

PubMed

A flexible, transparent nanocomposite (NC) film with 57 wt % inorganic components was obtained by the simple casting of a solution of Laponite and modified organic molecules through a sol-gel reaction. The NC film has solvent resistance and a disco-nematic liquid-crystalline-like structure of Laponite that originates from the cross linking of Laponite by silanol agents and the large amount of Laponite in the film. PMID:20586428

Shikinaka, Kazuhiro; Aizawa, Kazuto; Fujii, Nozomu; Osada, Yoshihito; Tokita, Masatoshi; Watanabe, Junji; Shigehara, Kiyotaka

2010-08-01

50

In situ observation of cluster formation during nanoparticle solution casting on a colloidal film.  

PubMed

We present a real-time study of the nanostructuring and cluster formation of gold nanoparticles deposited in aqueous solution on top of a pre-structured polystyrene colloidal thin film. Cluster formation takes place at different length scales, from the agglomerations of the gold nanoparticles to domains of polystyrene colloids. By combining in situ imaging ellipsometry and microbeam grazing incidence small-angle x-ray scattering, we are able to identify different stages of nanocomposite formation, namely diffusion, roughness increase, layer build-up and compaction. The findings can serve as a guideline for nanocomposite tailoring by solution casting. PMID:21654049

Roth, S V; Herzog, G; Körstgens, V; Buffet, A; Schwartzkopf, M; Perlich, J; Abul Kashem, M M; Döhrmann, R; Gehrke, R; Rothkirch, A; Stassig, K; Wurth, W; Benecke, G; Li, C; Fratzl, P; Rawolle, M; Müller-Buschbaum, P

2011-06-09

51

Cast Fe-base cylinder/regenerator housing alloy  

SciTech Connect

The development of an iron-base alloy that can meet the requirements of automotive Stirling engine cylinders and regenerator housings is described. Alloy requirements are as follows: a cast alloy, stress for 5000-hr rupture life of 200 MPa (29 ksi) at 775 C (1427 F), oxidation/corrosion resistance comparable to that of N-155, compatibility with hydrogen, and an alloy cost less than or equal to that of 19-9DL. The preliminary screening and evaluation of ten alloys are described.

Larson, F.; Kindlimann, L.

1980-12-01

52

A ciliary based 8-legged walking micro robot using cast IPMC actuators  

Microsoft Academic Search

We have proposed a prototype model of walking micro robot using IPMC (Ionic Polymer Metal Composite) actuators. The stiffness of IPMC actuator is a key parameter to implement a walking robot. Therefore, the casting process is developed to increase the stiffness of the actuator by controlling thickness of ion-exchange polymer film. The process of fabricating a solid film front liquid

Byungkyu Kim; Jaewook Ryu; Younkoo Jeong; Younghun Tak; Byungmok Kim; Jong-oh Park

2003-01-01

53

Grain Refinement of Permanent Mold Cast Copper Base Alloys.  

National Technical Information Service (NTIS)

Grain refinement is a well established process for many cast and wrought alloys. The mechanical properties of various alloys could be enhanced by reducing the grain size. Refinement is also known to improve casting characteristics such as fluidity and hot...

M. Sadayappan J. P. Thomson M. Elboujdaini G. P. Gu M. Sahoo

2004-01-01

54

Vertical water distribution during the drying of polymer films cast from aqueous emulsions.  

PubMed

We present a systematic study of the vertical uniformity of water distribution during the drying of waterborne colloidal films, testing the predictions of a Peclet number Pe defined for this system. Pe indicates the relative contributions of water evaporation and Brownian diffusion in determining the concentration profile in the vertical direction ( i.e. normal to the substrate). When Pe < 1, the water concentration in films cast from an alkyd emulsion is found via magnetic-resonance profiling to be uniform with depth, which is consistent with expectations. When Pe > 1, a gradient in the water concentration develops, with less water near the interface with air. The water profiles reveal that the alkyd particles do not coalesce immediately upon contact in close-packing. At later times, a concentrated surface layer develops, but particles are not coalesced in this layer to form a continuous "skin", but rather the structure is likely to be that of a biliquid foam. PMID:15010943

Gorce, J-P; Bovey, D; McDonald, P J; Palasz, P; Taylor, D; Keddie, J L

2002-07-01

55

Vertical water distribution during the drying of polymer films cast from aqueous emulsions  

NASA Astrophysics Data System (ADS)

We present a systematic study of the vertical uniformity of water distribution during the drying of waterborne colloidal films, testing the predictions of a Peclet number Pe defined for this system. Pe indicates the relative contributions of water evaporation and Brownian diffusion in determining the concentration profile in the vertical direction (i.e. normal to the substrate). When textit{Pe} < 1, the water concentration in films cast from an alkyd emulsion is found via magnetic-resonance profiling to be uniform with depth, which is consistent with expectations. When textit{Pe} > 1, a gradient in the water concentration develops, with less water near the interface with air. The water profiles reveal that the alkyd particles do not coalesce immediately upon contact in close-packing. At later times, a concentrated surface layer develops, but particles are not coalesced in this layer to form a continuous “skin”, but rather the structure is likely to be that of a biliquid foam.

Gorce, J.-P.; Bovey, D.; McDonald, P. J.; Palasz, P.; Taylor, D.; Keddie, J. L.

2002-07-01

56

Influence of oxygen on solidification behaviour of cast TiAl-based alloys  

Microsoft Academic Search

The influence of oxygen on solidification behaviour of cast TiAl-based alloys containing 40–48at.% of Al was studied. Twelve alloys with fixed Ti:Al ratios ranging from 1.08 to 1.5 and oxygen content of 0.1, 0.8 and 1.5at.% were prepared by induction melting and casting in a cold crucible under protective atmosphere. Increasing oxygen content affects significantly the macrostructure of the as-cast

J. Zollinger; J. Lapin; D. Daloz; H. Combeau

2007-01-01

57

Texture and self-biased property of an oriented M-type barium ferrite thick film by tape casting  

NASA Astrophysics Data System (ADS)

In this paper, the oriented M-type barium ferrite (BaM) thick films with different thicknesses are prepared by tape casting. It is found that the crystallographic alignment degree (f), the pore and the squareness ratio (Mr/Ms) are not affected by the thickness of the film. XRD and SEM results show that the thick film has hexagonal morphology with a crystal texture of c-axis grains perpendicular to film plane. The hysteresis curve indicates that the BaM thick film exhibits a self-biased property with a remanent magnetization of 3.30 T, a squareness ratio (Mr/Ms) of 0.81, and a coercivity of 0.40 T. The results show that the BaM thick film has potential for use in self-biasing microwave devices, and also proves that the tape casting technique is capable of fabricating high-quality barium ferrite films, thus providing a unique opportunity to realize the large area production of thick film.

Chen, Da-Ming; Liu, Ying-Li; Li, Yuan-Xun; Yang, Kai; Zhang, Huai-Wu

2012-06-01

58

In vitro biocompatibility of schwann cells on surfaces of biocompatible polymeric electrospun fibrous and solution-cast film scaffolds.  

PubMed

The in vitro responses of Schwann cells (RT4-D6P2T, a schwannoma cell line derived from a chemically induced rat peripheral neurotumor) on various types of electrospun fibrous scaffolds of some commercially available biocompatible and biodegradable polymers, i.e., poly(3-hydroxybutyrate) (PHB), poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), polycaprolactone (PCL), poly(l-lactic acid) (PLLA), and chitosan (CS), were reported in comparison with those of the cells on corresponding solution-cast film scaffolds as well as on a tissue-culture polystyrene plate (TCPS), used as the positive control. At 24 h after cell seeding, the viability of the attached cells on the various substrates could be ranked as follows: PCL film > TCPS > PCL fibrous > PLLA fibrous > PHBV film > CS fibrous approximately CS film approximately PLLA film > PHB film > PHBV fibrous > PHB fibrous. At day 3 of cell culture, the viability of the proliferated cells on the various substrates could be ranked as follows: TCPS > PHBV film > PLLA film > PCL film > PLLA fibrous > PHB film approximately PCL fibrous > CS fibrous > CS film > PHB fibrous > PHBV fibrous. At approximately 8 h after cell seeding, the cells on the flat surfaces of all of the film scaffolds and that of the PCL nanofibrous scaffold appeared in their characteristic spindle shape, while those on the surfaces of the PHB, PHBV, and PLLA macrofibrous scaffolds also appeared in their characteristic spindle shape, but with the cells being able to penetrate to the inner side of the scaffolds. PMID:17429941

Sangsanoh, Pakakrong; Waleetorncheepsawat, Suchada; Suwantong, Orawan; Wutticharoenmongkol, Patcharaporn; Weeranantanapan, Oratai; Chuenjitbuntaworn, Boontharika; Cheepsunthorn, Poonlarp; Pavasant, Prasit; Supaphol, Pitt

2007-04-13

59

Development of microporous drug-releasing films cast from artificial nanosized latexes of poly(styrene-co-methyl methacrylate) or poly(styrene-co-ethyl methacrylate).  

PubMed

Two sets of copolymers comprising of styrene and either methyl or ethyl methacrylate as comonomer were conveniently synthesized by microemulsion copolymerization. The purified materials were characterized by GPC-MALLS and were shown to form artificial nanolatexes in THF. ATR-FTIR analysis revealed differences in copolymer composition and based on the copolymer properties, a selection of copolymers was chosen to cast drug-loaded, microporous films that exhibit microencapsulation of drug agglomerates. The contact angles of the copolymers suggested potential applications in medical devices to prevent the formation of bacterial biofilms that commonly result in infections. Additionally, the different copolymeric films showed two phases of drug release characterized by a rapid initial drug release followed by a zero-order phase. Depending on the application, one could select the copolymer films that best suited the application i.e. for short-term drug release applications such as urinary catheters or long-term applications such as artificial implants. PMID:18417330

Otto, Daniel P; Vosloo, Hermanus C M; Liebenberg, Wilna; de Villiers, Melgardt M

2008-02-14

60

Real-time measurement system for tracking birefringence, weight, thickness, and surface temperature during drying of solution cast coatings and films  

NASA Astrophysics Data System (ADS)

This paper describes the design and performance of a new instrument to track temporal changes in physical parameters during the drying behavior of solutions, as well as curing of monomers. This real-time instrument follows in-plane and out-of-plane birefringence, weight, thickness, and surface temperature during the course of solidification of coatings and films through solvent evaporation and thermal or photocuring in a controlled atmosphere. It is specifically designed to simulate behavior of polymer solutions inside an industrial size, continuous roll-to-roll solution casting line and other coating operations where resins are subjected to ultraviolet (UV) curing from monomer precursors. Controlled processing parameters include air speed, temperature, initial cast thickness, and solute concentration, while measured parameters are thickness, weight, film temperature, in-plane and out-of-plane birefringence. In this paper, we illustrate the utility of this instrument with solution cast and dried poly (amide-imide)/DMAc (Dimethylacetamide) solution, water based black paint, and organo-modified clay/NMP (N-Methylpyrrolidone) solution. In addition, the physical changes that take place during UV photo polymerization of a monomer are tracked. This instrument is designed to be generic and it can be used for tracking any drying/swelling/solidification systems including paper, foodstuffs such as; grains, milk as well as pharmaceutical thin paste and slurries.

Unsal, E.; Drum, J.; Yucel, O.; Nugay, I. I.; Yalcin, B.; Cakmak, M.

2012-02-01

61

Optimization of composition of as-cast chromium white cast iron based on wear-resistant performance  

Microsoft Academic Search

The wear-resistant performance of chromium white cast iron was performed by an L9 (34) orthogonal experiment. The differences between orthogonal design and radial base function artificial neural network (RBFANN) were investigated. The results show that Cu significantly influences the wear-resistant performance. The optimum compositions are 5.5%Cr, 2%Si, 3%Mn and 2%Cu. The predicted and simulated results indicate that the RBFANN can

Wei-ke An; An-hui Cai; Yun Luo; Hua Chen; Wei-xiang Liu; Tie-lin Li; Min Chen

2009-01-01

62

The metallography of heat treatment effects in a nickel-base casting alloy. A preliminary report.  

PubMed

A series of standard tensile specimens produced from a nickel-base removable partial denture casting alloy were subjected to heat treatments at three temperatures and three periods at each temperature. The microstructures developed within the castings disclose changes in both the matrix and interdendritic zones. PMID:296698

Goodall, T G; Lewis, A J

1979-08-01

63

The Influence of Cast Structure on Thermal Fatigue of Some Nickel-Base Superalloys.  

National Technical Information Service (NTIS)

A fluidized-bed thermal fatigue test used to determine the influence of foundry variables on cast structure and thermal fatigue resistance of four nickel-base superalloys (M 21, 713 LC, IN 738 LC and IN 939) indicates that specimens cast under conditions ...

J. C. Ashworth K. J. Williams

1977-01-01

64

Wear and Erosion Characteristics of a Cast Cobalt Base Alloy.  

National Technical Information Service (NTIS)

An investigation was conducted at the Research Directorate, Weapons Laboratory, USAWECOM, to determine the erosion and wear characteristics of a conventional-cast gun tube material, Haynes Stellite Alloy No. 21, (HS-21), and to relate mechanical propertie...

W. T. Ebihara

1973-01-01

65

High solids loading for water-based tape casting  

NASA Astrophysics Data System (ADS)

Tape Casting is a low cost process for making large-area, thin, flat ceramics, which traditionally utilizes organic solvents to allow fast drying.sp{1-4} However, some of the volatile organic compounds (VOC), such as toluene, methylethyl ketone (MEK), and cyclohexanone, are hazardous air pollutants, and their emissions need to be regulated. Therefore, using water as a solvent is desirable to avoid the need of trapping VOCs. Although water is of low cost, nonflammable and safe to the environment, its heat of vaporization is high, 540 kca/g, compared to that of toluene, 74 kca/g.sp7 This makes the drying slow when water is used. The use of water in a tape casting formulation has previously been practical just for applications which require very thin tape, 100-200 mum. A high solids loading of above 50 vol% is an alternative approach to obtain sufficiently rapid drying for a thicker tape (up to 0.8 mm) since the water content is originally minimized. In order to obtain a high solids loading, the dispersants and binder systems were carefully tailored during the present research project. Low molecular weight polyelectrolytes, such as polyacrylic acid PAA (M.W. 1800) and citric acid, were found to be effective for high solids loading of Alsb2Osb3 (A-16SG), for which the electrosteric stabilization played an important role to the stability of the suspension. The viscosity and flow behavior of the suspension strongly depended on pH and the amount of polyelectrolyte, which could be related to the configuration of the polyelectrolyte molecules on the powder surface. The high solids loading of 64.5 vol% could be obtained for the fine A-16SG powder which had a surface area of 9.3 msp2/g. For the coarser powder, A-152SG, the dilatancy was a major problem that obstructed a further rise in solids loading. The dilatancy could be minimized by modifying the size distribution with A-152SG plus A-16SG and using a proper pH and amount of dispersants. An extremely high solids loading of 71-73 vol% could be reached in an aqueous system for the size-modified powder, before binder addition. An emulsion binder (Duramaxsp{TM} B-1001) aided the reduction in viscosity of the high solids loading suspension, while the soluble binder aggravated the agglomeration and drastically raised the viscosity. The emulsion binder used also had high polymer content and, therefore, less water. The final solids loadings obtained were 55.7 vol% for A-16SG and 63 vol% for mixed A-152SG and A-16SG powder. The drying time was reduced by one third for the 63 vol% formulation compared to the 55.7 vol% formulation. Water-based tape casting of A1N was possible in a buffer solution. Polyacrylic acid, PAA (M.W. 1800), aided dispersion and also minimized hydrolysis of A1N in water. Poly(vinyl pyrrolidone), PVP (M.W. 160,000), gave a lower viscosity to suspension compared to poly(vinyl alcohol) and cellulose ether, and had less bubble formation. The suspension could be processed for more than 72 h without degradation. With optimization of dispersant and binder, a high solids loading formulation of 52 vol% could be obtained. When the organic components were burned out in the air, AlN with 3wt% Ysb2Osb3 could be sintered at 1800sp°C for 1 h without degradation. The thermal conductivity was up to 153 W/m.K.

Suwannasiri, Thitima

66

Sampled points decomposing based ray casting for virtual endoscopy  

NASA Astrophysics Data System (ADS)

In this paper, we presented a novel ray casting algorithm, which can escape time-consuming operation of truncating a floating-point number during resampling. By converting every sampled point into the vector sum of the vectors, which are comprised by the integer point and the floating-point vector point, and utilizing coherence between adjacent sampled points, we can completely escape the operation of truncating a floating-point number. Applied this algorithm, rendering speed can be improved obviously in ray casting algorithm with tri-linear interpolation. The algorithm is robust and can be easily combined with another fast ray casting algorithms to further speed up the rendering. Because this algorithm does not need additional memory consumption and other time-consuming preprocess, and moreover it does not degrade the image quality, it is very useful in the implementation of virtual endoscopy system.

Yuan, Feiniu; Zhou, Heqin; Zhao, He; Feng, Huanqing

2002-07-01

67

Influence of S. mutans on base-metal dental casting alloy toxicity.  

PubMed

We have highlighted that exposure of base-metal dental casting alloys to the acidogenic bacterium Streptococcus mutans significantly increases cellular toxicity following exposure to immortalized human TR146 oral keratinocytes. With Inductively Coupled Plasma-Mass Spectrometry (ICP-MS), S. mutans-treated nickel-based (Ni-based) and cobalt-chromium-based (Co-Cr-based) dental casting alloys were shown to leach elevated levels of metal ions compared with untreated dental casting alloys. We targeted several biological parameters: cell morphology, viable cell counts, cell metabolic activity, cell toxicity, and inflammatory cytokine expression. S. mutans-treated dental casting alloys disrupted cell morphology, elicited significantly decreased viable cell counts (p < 0.0001) and cell metabolic activity (p < 0.0001), and significantly increased cell toxicity (p < 0.0001) and inflammatory cytokine expression (p < 0.0001). S. mutans-treated Ni-based dental casting alloys induced elevated levels of cellular toxicity compared with S. mutans-treated Co-Cr-based dental casting alloys. While our findings indicated that the exacerbated release of metal ions from S. mutans-treated base-metal dental casting alloys was the likely result of the pH reduction during S. mutans growth, the exact nature of mechanisms leading to accelerated dissolution of alloy-discs is not yet fully understood. Given the predominance of S. mutans oral carriage and the exacerbated cytotoxicity observed in TR146 cells following exposure to S. mutans-treated base-metal dental casting alloys, the implications for the long-term stability of base-metal dental restorations in the oral cavity are a cause for concern. PMID:23103633

McGinley, E L; Dowling, A H; Moran, G P; Fleming, G J P

2012-10-26

68

Burnishability of a nickel and a cobalt base casting alloys.  

PubMed

A specially designed stainless steel split die capable of producing a total of 24 half cylindrical shaped wax patterns was used in this study. The burnishability of two non-precious casting alloys was evaluated following a proposed softening heat treatment technique. A practical easily applied burnishing tool was introduced. Results have shown that, both of the non-precious alloys were burnishable following softening heat treatment. However, nickel-chromium alloy was significantly more burnishable than the cobalt-chromium alloy. It is suggested that clinical implications of the developed technique in this study would be an important additive for more precision castings. PMID:2701428

Nasr, H H; Mosleh, I

1989-10-01

69

Percolation enhancement of conductivity in polyaniline films cast from volatile solvents  

NASA Astrophysics Data System (ADS)

There are numerous applications that could benefit from the use of conducting polymers. While great progress has been made in broadening the choice of materials and improving their transport properties, one is still rather limited in choices by the needs for both procesability and environmental stability. These requirements tend to narrow the choice of materials to various forms of polyaniline (PANI). Polyaniline can be solution processed retaining its conductivity after exposure to ambient conditions for exended periods. Although films cast from a CSA-PANI in m-cresol solution exhibit conductivities ranging from 100-200 S/cm, this solvent is unacceptable not only due to the high temperatures required for its removal but overall safety concerns due to operator exposure. We report on work to aliviate some of these issues by loading the PANI with highly conducting dispersable solids. The overall matrix can exhibit large enhancements of the conductivity with appropriate choice of the loading material and control of the dispersion properties. This allows one to obtain a highly conducting environmentally stable percolated matrix formed from appropriate solvents satisfying the needs of many applications.

Blanchet, Graciela; Fincher, Curtis; Gao, Feng; Hsu, Che

2001-03-01

70

The Status of Dalit Women in India's Caste Based System  

Microsoft Academic Search

In this paper I wish to present the devastating effects of the caste system on the educational, social, and economical status of Dalit women in modern India. My aim is to highlight the harsh reality of the suppression, struggle and torture Dalit women face every day of their miserable lives. The hardships of Dalit women are not simply due to

Sonia Mahey

71

Hardware-Based Ray Casting for Tetrahedral Meshes  

Microsoft Academic Search

We present the first implementation of a volume ray casting algorithm for tetrahedral meshes running on off-the-shelf programmable graphics hardware. Our implementation avoids the memory transfer bottleneck of the graphics bus since the complete mesh data is stored in the local memory of the graphics adapter and all computations, in particular ray traversal and ray integration, are performed by the

Manfred Weiler; Martin Kraus; Markus Merz; Thomas Ertl

2003-01-01

72

Three-dimensional microstructure simulation of Ni-based superalloy investment castings  

NASA Astrophysics Data System (ADS)

An integrated macro and micro multi-scale model for the three-dimensional microstructure simulation of Ni-based superalloy investment castings was developed, and applied to industrial castings to investigate grain evolution during solidification. A ray tracing method was used to deal with the complex heat radiation transfer. The microstructure evolution was simulated based on the Modified Cellular Automaton method, which was coupled with three-dimensional nested macro and micro grids. Experiments for Ni-based superalloy turbine wheel investment casting were carried out, which showed a good correspondence with the simulated results. It is indicated that the proposed model is able to predict the microstructure of the casting precisely, which provides a tool for the optimizing process.

Pan, Dong; Xu, Qingyan; Liu, Baicheng

2011-05-01

73

Physicochemical properties of the amorphous drug, cast films, and spray dried powders to predict formulation probability of success for solid dispersions: etravirine.  

PubMed

Solid dispersion technology represents an enabling approach to formulate poorly water-soluble drugs. While providing for a potentially increased oral bioavailability secondary to an increased drug dissolution rate, amorphous dispersions can be limited by their physical stability. The ability to assess formulation risk in this regard early in development programs can not only help in guiding development strategies but can also point to critical design elements in the configuration of the dosage form. Based on experience with a recently approved solid dispersion-based product, Intelence® (etravirine), a three part strategy is suggested to predict early formulate-ability of these systems. The components include an assessment of the amorphous form, a study of binary drug/carrier cast films and the evaluation of a powder of the drug and polymer processed in a manner relevant to the intended final dosage form. A variety of thermoanalytical, spectroscopic, and spectrophotometric approaches were applied to study the prepared materials. The data suggest a correlation between the glass forming ability and stability of the amorphous drug and the nature of the final formulation. Cast films can provide early information on miscibility and stabilization and assessment of processed powders can help define requirements and identify issues with potential final formulations. PMID:20575005

Weuts, Ilse; Van Dycke, Frederic; Voorspoels, Jody; De Cort, Steve; Stokbroekx, Sigrid; Leemans, Ruud; Brewster, Marcus E; Xu, Dawei; Segmuller, Brigitte; Turner, Ya Tsz A; Roberts, Clive J; Davies, Martyn C; Qi, Sheng; Craig, Duncan Q M; Reading, Mike

2010-06-22

74

The effects of remelting on the mechanical properties of a nickel base partial denture casting alloy.  

PubMed

Three series of tensile test pieces were produced using a nickel base partial denture casting alloy. For the first series induction heating was employed, for the second a resistance crucible, and for the third, an oxy-acetylene torch. In each series the same metal was cast sequentially a number of times and all test pieces so produced were subjected to mechanical testing. The mechanical properties were found to vary according to both the number of times the alloy was cast and the method of heating used to render the alloy molten. PMID:1100023

Lewis, A J

1975-04-01

75

High ductile as-cast Mg–RE based alloys at room temperature  

Microsoft Academic Search

A variety of novel single phase solid solution as-cast Mg–RE based alloys have been developed. The as-cast alloys exhibit high ductility at room temperature. Mg–0.32Y–0.46Gd–0.34Dy–0.16Zr (wt.%) alloy exhibits high ductility expanding known performance boundaries of as-cast Mg alloys. The average tensile elongation and compression ratio at room temperature is over 30%. Meanwhile, the yield strength of tension is nearly the

Qiuming Peng; Yongjun Tian; Yuanding Huang; Norbert Hort

76

Heat flux transients at the casting\\/chill interface during solidification of aluminum base alloys  

Microsoft Academic Search

Heat flow at the metal\\/chill interface of bar-type castings of aluminum base alloys was modeled as a function of thermophysical\\u000a properties of the chill material and its thickness. Experimental setup for casting square bars of Al-13.2 pct Si eutectic\\u000a and Al-3 pet Cu-4.5 pct Si long freezing range alloys with chill at one end exposed to ambient conditions was fabricated.

T. S. Prasanna Kumar; K. Narayan Prabhu

1991-01-01

77

A ciliary motion based 8-legged walking micro robot using cast IPMC actuators  

Microsoft Academic Search

In this paper, we present a micro robot using IPMC (Ionic Polymer Metal Composite) actuators. The IPMC actuator usually has been fabricated with commercially available ion-exchange polymer with the typical thickness of 100-300 ?m. By the casting of liquid ion-exchange polymer solution, the thickness of the IPMC actuator could increase up to a few millimeters. Based on the casting method,

Jaewook Ryu; Younkoo Jeong; Younghun Tak; Byungmok Kim; Byungkyu Kim; Jong-Oh Parkb

2002-01-01

78

Oxide defects in a vacuum investment-cast ni-based turbine blade  

Microsoft Academic Search

Samples from large turbine blades for power generation, investment-cast in vacuum from a nickel-based superalloy, were investigated.\\u000a Samples were cut from regions near the top of the casting that contained freckle defects. The microstructures of these segregated\\u000a regions were compared with those from nonsegregated adjacent regions using both optical microscopy and scanning electron microscopy\\u000a (SEM). The segregated areas revealed a

A. K. M. B. Rashid; J. Campbell

2004-01-01

79

Comparing GPU-based multi-volume ray casting techniques  

Microsoft Academic Search

The most essential technique to visualize 3D scalar data is direct volume rendering. For many applications it is necessary\\u000a that two or more 3D data are visualized simultaneously. We present an overview of data intermixing techniques for visualization\\u000a with the direct volume rendering technique ray casting. The techniques are Classification Level Intermixing, Accumulation\\u000a Level Intermixing and Image Level Intermixing. The

Nicole Schubert; Ingrid Scholl

2011-01-01

80

Investments for casting micro parts with base alloys  

Microsoft Academic Search

The production of micro parts made of alloys like Al-bronze by casting techniques requires specially designed investments\\u000a with sufficient mechanical and thermal stability. For damage free deflasking, good solubility of at least one component of\\u000a the burned mold is required. Furthermore, especially when the micro parts are meant to mechanically interact with each other\\u000a in a micro system, the surface

S. Rath; G. Baumeister; J. Hausselt

2006-01-01

81

High solids loading for water-based tape casting  

Microsoft Academic Search

Tape Casting is a low cost process for making large-area, thin, flat ceramics, which traditionally utilizes organic solvents to allow fast drying.sp{1-4} However, some of the volatile organic compounds (VOC), such as toluene, methylethyl ketone (MEK), and cyclohexanone, are hazardous air pollutants, and their emissions need to be regulated. Therefore, using water as a solvent is desirable to avoid the

Thitima Suwannasiri

1997-01-01

82

MoSiâ-based sandwich composite made by tape casting  

Microsoft Academic Search

The mechanical properties of a novel laminar composite made by tape casting have been studied. The composite consists of three layers in which an inner core of pure molybdenum disilicide (MoSiâ) is sandwiched between two layers of MoSiâ reinforced with alumina platelets. Monolithic MoSiâ exhibits poor room-temperature strength and a brittle indentation strength response, indicative of the absence of R-curve

Stephane Tuffe; David S. Wilkinson

1995-01-01

83

The fabrication of a thin, circular polymer film based phase shaper for generating doughnut modes.  

PubMed

We demonstrated the fabrication of a phase shaper for generating a 'doughnut mode' laser beam using a thin, circular polymer film on a substrate. The fabrication method is based on a combination of spin-coating and drop-casting. The alignment procedure to get ideal 'doughnut modes' is described. The intensity distribution at the focus is analyzed with single molecule spectroscopy. PMID:19516800

Hotta, Jun-Ichi; Uji-I, Hiroshi; Hofkens, Johan

2006-06-26

84

Die Casting.  

National Technical Information Service (NTIS)

Contents: Mechanical properties of creep resistant zinc die casting alloys; Studies on a gravity die cast zinc base alloy; Parashot system for turbulence-free injection of metal; Zinc--the versatile metal; Prevention of metal dribble on hot chamber die ca...

1977-01-01

85

Comparison of Release-Controlling Efficiency of Polymeric Coating Materials Using Matrix-type Casted Films and Diffusion-Controlled Coated Tablet  

PubMed Central

Polymeric coating materials have been widely used to modify release rate of drug. We compared physical properties and release-controlling efficiency of polymeric coating materials using matrix-type casted film and diffusion-controlled coated tablet. Hydroxypropylmethyl cellulose (HPMC) with low or high viscosity grade, ethylcellulose (EC) and Eudragit® RS100 as pH-independent polymers and Eudragit S100 for enteric coatings were chosen to prepare the casted film and coated tablet. Tensile strength and contact angle of matrix-type casted film were invariably in the decreasing order: EC> Eudragit S100> HPMC 100000> Eudragit RS100>HPMC 4000. There was a strong linear correlation between tensile strength and contact angle of the casted films. In contrast, weight loss (film solubility) of the matrix-type casted films in three release media (gastric, intestinal fluid and water) was invariably in the increasing order: EC?casted films was EC?>?HPMC 100000?>?Eudragit RS100?>?HPMC 4000?>?Eudragit S100. Interestingly, diffusion-controlled coated tablet also followed this rank order except Eudragit S100 although release profiles and lag time were highly dependent on the coating levels and type of polymeric coating materials. EC and Eudragit RS100 produced sustained release while HPMC and Eudragit S100 produced pulsed release. No molecular interactions occurred between drug and coating materials using 1H-NMR analysis. The current information on release-controlling power of five different coating materials as matrix carrier or diffusion-controlled film could be applicable in designing oral sustained drug delivery.

Piao, Zong-Zhu; Lee, Kyoung-Ho; Kim, Dong-Jin; Lee, Hong-Gu; Lee, Jaehwi; Oh, Kyung Taek

2010-01-01

86

Study on the solidification condition of exudation penetration occurrence in grey cast iron castings based on solidification simulation  

NASA Astrophysics Data System (ADS)

The solidification condition of eutectic exudation penetration occurrence, a kind of casting defect in grey cast-iron castings, is studied with computer solidification simulation and experiments on specially designed castings. A hot hole refers to the solidification condition when the temperature gradient or solidifying time gradient from the centre to the surface at some location in a casting is positive during the solidification process. It is a term proposed in this paper to better describe the condition of exudation penetration occurrence and for predicting its location at hot spots in a casting. The term is useful for improving the foundry technology used for solving the penetration problem with the help of computer simulation.

Han, Jianmin; Hansen, S. F.

2000-11-01

87

Spectral response of solvent-cast polyvinyl chloride (PVC) thin film used as a long-term UV dosimeter.  

PubMed

The spectral response of solvent-cast polyvinyl chloride (PVC) thin film suitable for use as a long-term UV dosimeter has been determined by measuring the UV induced change in the 1064 cm(-1) peak intensity of the PVC's infrared (IR) spectra as a function of the wavelength of the incident radiation. Measurements using cut-off filters, narrow band-pass filters and monochromatic radiation showed that the 16 ?m PVC film responds mainly to the UVB band. The maximum response was at 290 nm and decreasing exponentially with wavelength up to about 340 nm independent of temperature and exposure dose. The most suitable concentration (W/V%) of PVC/Tetrahydrofuran solution was found to be 10% and the best thickness for the dosimeter was determined as 16 ?m. PMID:23811159

Amar, Abdurazaq; Parisi, Alfio V

2013-06-10

88

Social exclusion, caste & health: a review based on the social determinants framework.  

PubMed

Poverty and social exclusion are important socio-economic variables which are often taken for granted while considering ill-health effects. Social exclusion mainly refers to the inability of our society to keep all groups and individuals within reach of what we expect as society to realize their full potential. Marginalization of certain groups or classes occurs in most societies including developed countries and perhaps it is more pronounced in underdeveloped countries. In the Indian context, caste may be considered broadly as a proxy for socio-economic status and poverty. In the identification of the poor, scheduled caste and scheduled tribes and in some cases the other backward castes are considered as socially disadvantaged groups and such groups have a higher probability of living under adverse conditions and poverty. The health status and utilization patterns of such groups give an indication of their social exclusion as well as an idea of the linkages between poverty and health. In this review, we examined broad linkages between caste and some select health/health utilization indicators. We examined data on prevalence of anaemia, treatment of diarrhoea, infant mortality rate, utilization of maternal health care and childhood vaccinations among different caste groups in India. The data based on the National Family Health Survey II (NFHS II) highlight considerable caste differentials in health. The linkages between caste and some health indicators show that poverty is a complex issue which needs to be addressed with a multi-dimensional paradigm. Minimizing the suffering from poverty and ill-health necessitates recognizing the complexity and adopting a perspective such as holistic epidemiology which can challenge pure technocentric approaches to achieve health status. PMID:18032810

Nayar, K R

2007-10-01

89

Efficacy of powder-based three-dimensional printing (3DP) technologies for rapid casting of light alloys  

Microsoft Academic Search

The aim of the present research was to compare the efficacy of two powder based 3D printing technologies for rapid casting\\u000a of light alloys. The technologies of ZCast process and investment casting were employed to cast aluminium A356 alloy and zinc\\u000a ZA-12 alloy. The split pattern shells were printed in ZCast501 powder and used directly as mould with outside sand

Simranpreet Singh Gill; Munish Kaplas

2011-01-01

90

Cast iron-base alloy for cylinder/regenerator housing: Final report  

SciTech Connect

The objective is to develop an Fe-base alloy that can meet the requirements of the automotive Stirling engine cylinders and regenerator housings. The scope of work was to test various alloys and select the one best demonstrating the following characteristics: It must be a cast alloy, using nonstrategic metals. It must withstand stresses for a 2500-hr rupture life at 200 MPa/775/degree/C. Oxidation/corrosion resistance must be comparable to that of N-155. It must be compatible with hydrogen. Fatigue properties must be superior to alloy XF 818. Cost must be less than or equal to that of 19-9DL. Major tests were designed to include the following: Selection, processing, and evaluation of candidate alloys within each alloy group system. Determination of casting parameters. Selection of a candidate alloy and establishment of a data base for this alloy. In the initial phase of the program designated as Round 1, a series of alloys representing each alloy system was cast and tested. In all there were 5 alloys of the nickel-manganese Group 1, 13 alloys of the nickel Group 2, and 3 alloys of the manganese Group 3. The aim was to maintain the chemistry of the major element(s) shown and vary the percentage of other elements to study their influence. Evaluation of results obtained from this series of tests enabled us to closely define the chemistry range for our candidate alloy, designated NASACC-1. A master heat was made to this composition. The heat was melted and poured under controlled casting conditions previously established and poured into investment shell molds. All castings and test bars were heat treated before actual testing. NASACC-1 proved to be an excellent alloy for casting. It could be melted in air and had good fluidity and fill characteristics. The alloy met or exceeded all program goals. 28 refs., 47 figs., 44 tabs.

Witter, S.L.; Simmons, H.E.; Woulds, M.J.

1985-08-01

91

Influence of Phenolic Compounds in the Combustion of Cast Double Base Propellants Containing Lead Stearate  

Microsoft Academic Search

The effect of different cresols (o, m, p), resorcinol and pyrogallol in the presence and absence of lead stearate on the burning rates of cast double base propellants has been studied in the 35?140 kg\\/cm pressure range. While their effect is not significant without lead stearate, these phenolic compounds increased burning rates in the presence of lead stearate. Their mode

HARIDWAR SINGH; K. V. RAMAN; K. R. K. RAO

1980-01-01

92

The effect of aluminium on the metallography of a nickel base removable partial denture casting alloy.  

PubMed

Three special nickel-chromium alloys were prepared in which the aluminum levels were adjusted both above and below that of a commercial nickel base dental casting alloy. Tensile and metallographic evaluation of representative samples of the alloys were made and the changes in the properties of the alloys are reported. PMID:285671

Lewis, A J

1978-12-01

93

Cast iron-base alloy for cylinder\\/regenerator housing: Final report  

Microsoft Academic Search

The objective is to develop an Fe-base alloy that can meet the requirements of the automotive Stirling engine cylinders and regenerator housings. The scope of work was to test various alloys and select the one best demonstrating the following characteristics: It must be a cast alloy, using nonstrategic metals. It must withstand stresses for a 2500-hr rupture life at 200

S. L. Witter; H. E. Simmons; M. J. Woulds

1985-01-01

94

Creep-rupture behavior of candidate stirling engine cast iron-base superalloys  

Microsoft Academic Search

The Stirling engine is under investigation jointly by the DOE and NASA as an alternate to the automotive internal combustion engine. Present design criteria require cast cylinder heads and regenerator housings to operate 3500 hours from ambient to 775 C while pressurized to 15 MPa with hydrogen. Creep-rupture tests in air and 15 MPa hydrogen were performed on candidate iron-base

Titran

2008-01-01

95

Dental magnesia-based investments for cast titanium crown: setting and fitness  

Microsoft Academic Search

Titanium crowns were cast using experimental magnesia-based investment mixed with hydrolysed sol. Ten types of hydrolysed sol were used, adding a catalyst to each sol whether the setting (hardening) of the magnesia investment powder appeared within 3 h after mixing. A penetration test using a Vicat needle to measure needle depth as setting was carried out after mixing of the

K. Wakasa; M. Yamaki

1995-01-01

96

Weld procedural effect on the performance of iron based hardfacing deposits on cast iron substrate  

Microsoft Academic Search

Two commercial and four formulated iron based high Cr high C type hardfacing electrodes were deposited on gray cast iron plate (ASTM grade 2500) using various welding procedures such as preheat and without preheat, single and double hardfacing layer as well as buffer or without buffer layer. The effect of welding procedural variation upon the cracking sensitivity and performance of

S. Chatterjee; T. K. Pal

2006-01-01

97

Intelligent Optimization-Based Production Planning and Simulation Analysis for Steelmaking and Continuous Casting Process  

Microsoft Academic Search

Aiming at the limitations of the traditional mathematical model for production planning, a novel optimization model is proposed to improve the efficiency and performance for production planning in steelmaking and continuous casting (SCC) process. The optimization model combined with parallel-backward inferring algorithm and genetic algorithm is described. To analyze and evaluate the production plans, a simulation model based on cellular

Dao-fei ZHU; Zhong ZHENG; Xiao-qiang GAO

2010-01-01

98

Casting Technology.  

ERIC Educational Resources Information Center

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

Wright, Michael D.; And Others

1992-01-01

99

Joining of NiAl to iron-based alloys by reactive casting  

Microsoft Academic Search

Nickel monoaluminide, NiAl, is exothermically synthesized from elemental liquids of aluminum and nickel and is simultaneously\\u000a joined to iron-based alloys, such as carbon steels and stainless steels, by the reactive casting method, which is based on\\u000a the pouring of the elemental liquids onto the base material. The exothermic reaction between the aluminum and nickel liquids\\u000a produces extremely superheated NiAl liquid.

Kiyotaka Matsuura; Masayuki Kudoh; Hiroshi Kinoshita; Heishichiro Takahashi

2002-01-01

100

On the weldability of grey cast iron using nickel based filler metal  

Microsoft Academic Search

Shielded metal arc welding process using nickel based filler metal was used to join grey cast iron. The effect of post weld heat treatment (PWHT) on the microstructure and hardness was studied. PWHT included heating up to 870°C, holding for 1h at 870°C and then furnace cooling. By using nickel based filler metal, formation of hard brittle phase (e.g. carbides

M. Pouranvari

2010-01-01

101

An evaluation of the CAST program using a conceptual model of school-based implementation  

Microsoft Academic Search

Therapeutic prevention and\\/or early intervention programs for children at risk of developing disruptive behaviour disorders are increasingly being implemented in schools. One such Australian school-based program is CAST: CAMHS (Child and Adolescent Mental Health Service) and Schools Together, an evidenced-based program treating children with emerging disruptive behaviour disorders in the early primary school years. The current evaluation examines the process

Denise Corboy; John McDonald

102

Microstructural Restoration by HIP and Heat Treatment Processes in Cast Nickel Based Superalloy, IN738  

Microsoft Academic Search

Inconel 738, as a cast nickel-based superalloy components for land-based gas turbine blades, utilized at elevated temperatures, expresses microstructural stability with excellent mechanical properties. In this study, the microstructural refurbishment by a hot isostatic pressing (HIP) and different heat treatment conditions after long-term service of the alloy was investigated. Although, the HIP temperature in the HIP process was high enough

Panyawat Wangyao; Nutthita Chuankrerkkul

2009-01-01

103

Effect of pore former on the properties of casted film prepared from blends of Eudragit NE 30 D and Eudragit L 30 D-55.  

PubMed

The casted films of aqueous dispersions of Eudragit NE30 D and Eudragit L30 D-55 containing pore former were prepared. The study investigated the influence of pore former on basic model drug clarithromycin release, water uptake and water vapor permeability from casted film prepared from the blends of neutral polymer dispersion of Eudragit NE30 D and enteric polymer dispersion of Eudragit L30 D-55. This study was concluded that pore former hydroxypropyl methyl cellulose, lactose, polyethylene glycol (PEG) and polyvinyl pyrrolidon (PVP) was released at the beginning of the release process, the rate and extent of water uptake of the polymeric films were much higher in phosphate buffer pH 6.8 than in pH 5.0 and the concentration of pore former have a significant influence on the permeability to water vapour. PMID:17666856

Zhang, Xiangrong; Wang, Yanjiao; Wang, Jing; Wang, Yan; Li, Sanming

2007-08-01

104

Moving through the phase diagram: morphology formation in solution cast polymer-fullerene blend films for organic solar cells.  

PubMed

The efficiency of organic bulk heterojunction solar cells strongly depends on the multiscale morphology of the interpenetrating polymer-fullerene network. Understanding the molecular assembly and the identification of influencing parameters is essential for a systematic optimization of such devices. Here, we investigate the molecular ordering during the drying of doctor-bladed polymer-fullerene blends on PEDOT:PSS-coated substrates simultaneously using in situ grazing incidence X-ray diffraction (GIXD) and laser reflectometry. In the process of blend crystallization, we observe the nucleation of well-aligned P3HT crystallites in edge-on orientation at the interface at the instant when P3HT solubility is crossed. A comparison of the real-time GIXD study at ternary blends with the binary phase diagrams of the drying blend film gives evidence of strong polymer-fullerene interactions that impede the crystal growth of PCBM, resulting in the aggregation of PCBM in the final drying stage. A systematic dependence of the film roughness on the drying time after crossing P3HT solubility has been shown. The highest efficiencies have been observed for slow drying at low temperatures which showed the strongest P3HT interchain ?-?-ordering along the substrate surface. By adding the "unfriendly" solvent cyclohexanone to a chlorobenzene solution of P3HT:PCBM, the solubility can be crossed prior to the drying process. Such solutions exhibit randomly orientated crystalline structures in the freshly cast film which results in a large crystalline orientation distribution in the dry film that has been shown to be beneficial for solar cell performance. PMID:22004659

Schmidt-Hansberg, Benjamin; Sanyal, Monamie; Klein, Michael F G; Pfaff, Marina; Schnabel, Natalie; Jaiser, Stefan; Vorobiev, Alexei; Müller, Erich; Colsmann, Alexander; Scharfer, Philip; Gerthsen, Dagmar; Lemmer, Uli; Barrena, Esther; Schabel, Wilhelm

2011-11-02

105

Mechanical and structural properties of solution-cast high-amylose maize starch films.  

PubMed

Environmental issues have forced the introduction of sustainable solutions such as annually renewable resources being used as a raw material for packaging and disposables. This paper examined the effects of time and temperature during manufacturing and plasticiser content on the molecular structure of high-amylose maize starch films. It also analysed how manufacturing conditions, plasticiser content and molecular structure of the films affected their material properties. It was found that increased time or temperature increased the degradation of amylose and of amylopectin, which in turn negatively affected film cohesiveness. However, neither time nor temperature had any effect on tensile properties. PMID:19828118

Koch, Kristine; Gillgren, Thomas; Stading, Mats; Andersson, Roger

2009-10-12

106

Patellar dislocation: cylinder cast, splint or brace? An evidence-based review of the literature.  

PubMed

Patellar dislocations are a common injury in the emergency department. The conservative management consists of immobilisation with a cylinder cast, posterior splint or removable knee brace. No consensus seems to exist on the most appropriate means of conservative treatment or the duration of immobilisation. Therefore the aims of this review were first to examine whether immobilisation with a cylinder cast causes less redislocation and joint movement restriction than a knee brace or posterior splint and second to compare the redislocation rates after conservative treatment with surgical treatment. A systematic search of Pubmed, Embase and the Cochrane Library was performed. We identified 470 articles. After applying the exclusion and inclusion criteria, only one relevant study comparing conservative treatment with a cylinder cast, brace and posterior splint remained (Mäenpää et al.). In this study, the redislocation frequency per follow-up year was significant higher in the brace group (0.29; p?cast group (0.12) and the posterior splint group (0.08). The proportion of loss of flexion and extension was the highest in the cylinder cast group and the lowest in the posterior splint group (not significant). The evidence level remained low because of the small study population, difference in duration of immobilisation between groups and use of old braces. Also, 12 studies comparing surgical with conservative treatment were assessed. Only one study reported significantly different redislocation rates after surgical treatment. In conclusion, a posterior splint might be the best therapeutic option because of the low redislocation rates and knee joint restrictions. However, this recommendation is based on only one study with significant limitations. Further investigation with modern braces and standardisation of immobilisation time is needed to find the most appropriate conservative treatment for patellar luxation. Furthermore, there is insufficient evidence to confirm the added value of surgical management. PMID:23273401

van Gemert, Johanna P; de Vree, Lisette M; Hessels, Roger A P A; Gaakeer, Menno I

2012-12-31

107

Patellar dislocation: cylinder cast, splint or brace? An evidence-based review of the literature  

PubMed Central

Patellar dislocations are a common injury in the emergency department. The conservative management consists of immobilisation with a cylinder cast, posterior splint or removable knee brace. No consensus seems to exist on the most appropriate means of conservative treatment or the duration of immobilisation. Therefore the aims of this review were first to examine whether immobilisation with a cylinder cast causes less redislocation and joint movement restriction than a knee brace or posterior splint and second to compare the redislocation rates after conservative treatment with surgical treatment. A systematic search of Pubmed, Embase and the Cochrane Library was performed. We identified 470 articles. After applying the exclusion and inclusion criteria, only one relevant study comparing conservative treatment with a cylinder cast, brace and posterior splint remained (Mäenpää et al.). In this study, the redislocation frequency per follow-up year was significant higher in the brace group (0.29; p?cast group (0.12) and the posterior splint group (0.08). The proportion of loss of flexion and extension was the highest in the cylinder cast group and the lowest in the posterior splint group (not significant). The evidence level remained low because of the small study population, difference in duration of immobilisation between groups and use of old braces. Also, 12 studies comparing surgical with conservative treatment were assessed. Only one study reported significantly different redislocation rates after surgical treatment. In conclusion, a posterior splint might be the best therapeutic option because of the low redislocation rates and knee joint restrictions. However, this recommendation is based on only one study with significant limitations. Further investigation with modern braces and standardisation of immobilisation time is needed to find the most appropriate conservative treatment for patellar luxation. Furthermore, there is insufficient evidence to confirm the added value of surgical management.

2012-01-01

108

A new method of fine grained casting for nickle-base superalloys  

Microsoft Academic Search

The grain structures and microscopic features of a nickle-base Inconel 738LC were examined under various melting and casting conditions. Results show that the gain size of the ? matrix is reduced significantly by a treatment of lowing melt superheat temperature (LMST). By the addition of a trace intermetallic compound A1xNiy to the melt together with LMST treatment, a remarkable refinement

Lin Liu; Rong Zhang; Liuding Wang; Shuxian Pang; Baolin Zhen

1998-01-01

109

Microstructure study of laser welding cast nickel-based superalloy K418  

Microsoft Academic Search

Experiments of laser welding cast nickel-based superalloy K418 were conducted. Microstructure of the welded seam was characterized by optical microscopy (OM), scanning electron microscopy (SEM), X-ray diffraction (XRD), and energy dispersive spectrometer (EDS). Mechanical properties of the welded seam were evaluated by microhardness. The corresponding mechanisms were discussed in detail. Results show that the laser welded seam have non-equilibrium solidified

Ming Pang; Gang Yu; Heng-Hai Wang; Cai-Yun Zheng

2008-01-01

110

Method of improving fatigue life of cast nickel based superalloys and composition  

Microsoft Academic Search

The invention consists of a method of producing a fine equiaxed grain structure (ASTM 2-4) in cast nickel-base superalloys which increases low cycle fatigue lives without detrimental effects on stress rupture properties to temperatures as high as 1800.degree. F. These superalloys are variations of the basic nickel-chromium matrix, hardened by gamma prime [Ni.sub.3 (Al, Ti)] but with optional additions of

Allen F. Denzine; Thomas A. Kolakowski; John F. Wallace

1978-01-01

111

Carbon nanotube based transparent conductive thin films.  

PubMed

Carbon nanotube (CNT) based optically transparent and electrically conductive thin films are fabricated on plastic substrates in this study. Single-walled carbon nanotubes (SWNTs) are chemically treated with a mixture of concentrated sulfuric acid and nitric acid before being dispersed in aqueous surfactant-contained solutions. SWNT thin films are prepared from the stable SWNT solutions using wet coating techniques. The 100 nm thick SWNT thin film exhibits a surface resistivity of 6 kohms/square nanometer with an average transmittance of 88% on the visible light range, which is three times better than the films prepared from the high purity as-received SWNTs. PMID:17025106

Yu, X; Rajamani, R; Stelson, K A; Cui, T

2006-07-01

112

Polyimide-based scintillating thin films  

Microsoft Academic Search

The production procedure and the scintillation characteristics of thin polyimide films containing rhodamine B are reported. Fluorinated polyimide has been chosen as host matrix for its well known radiation hardness, in order to improve the lifetime of detector systems based on plastic thin film scintillators, 6FDA (4,4'-hertafluoroisopropylidene diphthalic anhydride) and DAB (diaminobenzophenone) have been used as polyimide precursor monomers. The

A. Quaranta; S. Carturan; G. Maggioni; P. M. Milazzo; U. Abbondanno; G. Della Mea; F. Gramegna; U. Pieri

2001-01-01

113

Water-Based Solid Film Lubricants.  

National Technical Information Service (NTIS)

This report presents the initial results of an investigation to develop high temperature 538 deg C (1000 deg F) and moderate temperature 260 deg C (500 deg F) range water-based solid film lubricants for naval aircraft applications. Lithium silicate films ...

A. A. Conte

1982-01-01

114

Environmental damage of a cast nickel base superalloy  

NASA Astrophysics Data System (ADS)

Exposure in air in the temperature range 900 to 1100 °C produces a major loss in stress rupture life and ductility of IN738. The sensitivity to this environmental damage increases with decreasing test temperature in the range 1000 to 700 °C. Oxygen is identified as the source of the damage for air exposure and indirect evidence supports grain boundary penetration of the gas to considerable depth. It is argued that oxygen segregation can lead to grain boundary immobilization and unstable intergranular fracture at intermediate temperatures. It is shown that compositional modifications, particularly boron and hafnium additions, may reduce the oxygen damage susceptibility, and that a cobalt base coating effectively eliminates the susceptibility. The relevance of these observations in understanding the effect of test environment on creep-rupture and fatigue crack propagation is considered.

Woodford, D. A.

1981-02-01

115

Capacitor structures based on strontium titanate films  

NASA Astrophysics Data System (ADS)

The structural properties of strontium titanate films and the electrical parameters of the related capacitor structures have been investigated. It has been found that the deposition temperature exerts a direct effect on the phase composition of the films, the degree of perfection of the crystal structure, and the internal stresses in the lattice. The strontium titanate films deposited at a temperature of 800°C are single-phase, have a rather perfect crystal structure, and possess minimum internal stresses. It has been shown that the capacitor structures based on oriented strontium titanate films provide a twofold decrease in the level of dielectric loss as compared to similar structures based on barium strontium titanate solid solution films at a frequency of 1.5 GHz.

Tumarkin, A. V.; Gaidukov, M. M.; Razumov, S. V.; Gagarin, A. G.

2012-05-01

116

Aircraft Water-Based Solid Film Lubricants.  

National Technical Information Service (NTIS)

An improved MIL-L-81329 water based extreme temperature range solid film lubricant has been developed. This material provides corrosion protection and improved endurance life for steel on steel components while maintaining the other desirable properties s...

A. A. Conte

1983-01-01

117

Project CAST.  

ERIC Educational Resources Information Center

|The document outlines procedures for implementing Project CAST (Community and School Together), a community-based career education program for secondary special education students in Charles County, Maryland. Initial sections discuss the role of a learning coordinator, (including relevant travel reimbursement and mileage forms) and an overview of…

Charles County Board of Education, La Plata, MD. Office of Special Education.

118

Fennel waste-based films suitable for protecting cultivations.  

PubMed

Biodegradable, flexible, and moisture-resistant films were obtained by recycling fennel waste and adding to fennel homogenates the bean protein phaseolin that was modified or not modified by the enzyme transglutaminase. All films were analyzed for their morphology, mechanical properties, water vapor permeability, and susceptibility to biodegradation under soil-like conditions. Our experiments showed that transglutaminase treatment of the phaseolin-containing fennel waste homogenates allowed us to obtain films comparable in their mechanical properties and water vapor permeability to the commercial films Ecoflex and Mater-Bi. Furthermore, biodegradability tests demonstrated that the presence of the enzyme in the film-casting sample significantly influences the integrity of such a product that lasts longer than films obtained either with fennel waste alone or with a mixture of fennel waste and phaseolin. These findings indicate the fennel-phaseolin film prepared in the presence of transglutaminase to be a promising candidate for a new environmentally friendly mulching bioplastic. PMID:17877395

Mariniello, L; Giosafatto, C V L; Moschetti, G; Aponte, M; Masi, P; Sorrentino, A; Porta, R

2007-09-18

119

Corrosion behavior of cast and forged cobalt-based alloys for double-alloy joint endoprostheses.  

PubMed

An ideal combination of mechanical and corrosion properties of long-term implants such as joint endoprostheses has yet to be found. Besides being resistant to pitting and crevice attack, which can lead to corrosion fatigue and stress corrosion cracking failures, the implant material must be highly resistant to wear and abrasion. Two cobalt-based alloys, wrought CoNiMoTi and air-cast CoCrMo, were subjected to a number of selected in vitro electrochemically and chemically accelerated corrosion tests in chloride-containing solutions with wrought AISI-316L used as a reference alloy. A limited number of immersion tests in FeCl3 and acidified FeCl3 solutions were also conducted. It is found that the mechanical properties of wrought CoNiCrMoTi alloy qualify it as a substitute for cast CoCrMo alloy and wrought AISI-316L in anchorage shaft production for all types of joint endoprostheses. Wrought CoNiCrMoTi has a higher resistance to fatigue cracking compared with cast CoCrMo and is as resistant to selective corrosion phenomena such as stress corrosion cracking. PMID:701305

Süry, P; Semlitsch, M

1978-09-01

120

Influence of Molecular Rigidity on Interfacial Ordering in Diphenyl-Based Polysiloxane Films  

SciTech Connect

Synchrotron X-ray reflectivity (XRR) shows significant differences between the ordering in thin films of diphenyl-based siloxane oligomers with single versus double backbones of -Si-O- repeating groups. We show that the more restricted conformational arrangement of twofold-skeleton molecules results in a higher degree of molecular ordering indicated by 2-2.5 times higher value of intensity of the corresponding Bragg peak in thin solid films of poly(phenylsilsesquioxane) than in films of poly(diphenylsiloxane), regardless of the solvent used for film casting. In both cases, the ordered molecules are located within 40-50 Angstroms of the substrate surface. The results indicate unambiguously that the chain stiffness of siloxanes governs the degree of ordering in the restricted geometry of the interfacial region.

Evmenenko,G.; Kewalramani, S.; Dutta, P.

2007-01-01

121

The Preparation and Characterization of Glycerol Pseudo-Thermoplastic Starch\\/Glycerol Pseudo-Thermoplastic Polyvinyl Alcohol (GTPS\\/GTPVA) Biodegradable Films Using the Solution Casting Method  

Microsoft Academic Search

Starch and polyvinyl alcohol (PVA) are non-plasticized biodegradable materials. The purpose of this research was to transform starch and PVA into pseudo-thermoplastic starch (GTPS) and pseudo-thermoplastic PVA (GTPVA). Plasticizer (Glycerol) was used to reduce the molecular chain interactions and the melting temperatures, and then blended them via solution casting to form GTPS\\/GTPVA biodegradable films. Experimental tests evaluate the effect of

Chin-An Lin; Chi-Che Tung

2010-01-01

122

Origin of stress and enhanced carrier transport in solution-cast organic semiconductor films  

NASA Astrophysics Data System (ADS)

Molecular packing in laterally directed solution deposition is a strong function of variables such as printing speed, substrate temperature, and solution concentration. Knowledge of the ordering mechanisms impacts on the development of new processes and materials for improved electronic devices. Here, we present real-time synchrotron x-ray scattering results combined with optical video microscopy, revealing the stages of ordering during the deposition of organic thin films via hollow capillary writing. Limited long range ordering is observed during the initial crystallization, but it gradually develops over 3-4 s for a range of deposition conditions. Buckling of thin films is typically observed for deposition above room temperature. We infer that compressive stress originates from thermal transients related to solvent evaporation on timescales similar to the development of long range ordering. Under optimized conditions, elimination of cracks and other structural defects significantly improves the average charge carrier mobility in organic field-effect transistors.

Cour, Ishviene; Chinta, Priya V.; Schlepütz, Christian M.; Yang, Yongsoo; Clarke, Roy; Pindak, Ron; Headrick, Randall L.

2013-09-01

123

Vertical water distribution during the drying of polymer films cast from aqueous emulsions  

Microsoft Academic Search

:   We present a systematic study of the vertical uniformity of water distribution during the drying of waterborne colloidal films,\\u000a testing the predictions of a Peclet number Pe defined for this system. Pe indicates the relative contributions of water evaporation and Brownian diffusion in determining the concentration profile\\u000a in the vertical direction (i.e. normal to the substrate). When Pe via

J.-P. Gorce; D. Bovey; P. J. McDonald; P. Palasz; D. Taylor; J. L. Keddie

2002-01-01

124

Why do backward castes need their own gurus? The social and political significance of new caste-based monasteries in Karnataka  

Microsoft Academic Search

Jati matha, as people of Karnataka call it, is a monastery that culturally and religiously represents a specific caste or sub-caste group, most of which are non-Brahmin, backward castes. From the Kuruba (shepherd caste, the largest amongst other backward classes) to Dalits (former untouchables) and Adivasis (tribals), the number of such caste-mathas is believed to be more than 100 in

Aya Ikegame

2010-01-01

125

Novel gradient casting method provides high-throughput assessment of blended polyester poly(lactic-co-glycolic acid) thin films for parameter optimization.  

PubMed

Pure polymer films cannot meet the diverse range of controlled release and material properties demanded for the fabrication of medical implants or other devices. Additives are added to modulate and optimize thin films for the desired qualities. To characterize the property trends that depend on additive concentration, an assay was designed which involved casting a single polyester poly(lactic-co-glycolic acid) (PLGA) film that blends a linear gradient of any PLGA-soluble additive desired. Four gradient PLGA films were produced by blending polyethylene glycol or the more hydrophobic polypropylene glycol. The films were made using a custom glass gradient maker in conjunction with a 180 cm film applicator. These films were characterized in terms of thickness, percent additive, total polymer (PLGA+additive), and controlled drug release using drug-like fluorescent molecules such as coumarin 6 (COU) or fluorescein diacetate (FDAc). Material properties of elongation and modulus were also accessed. Linear gradients of additives were readily generated, with phase separation being the limiting factor. Additive concentration had a Pearson's correlation factor (R) of >0.93 with respect to the per cent total release after 30 days for all gradients characterized. Release of COU had a near zero-order release over the same time period, suggesting that coumarin analogs may be suitable for use in PLGA/polyethylene glycol or PLGA/polypropylene glycol matrices, with each having unique material properties while allowing tuneable drug release. The gradient casting method described has considerable potential in offering higher throughput for optimizing film or coating material properties for medical implants or other devices. PMID:22293582

Steele, Terry W J; Huang, Charlotte L; Kumar, Saranya; Irvine, Scott; Boey, Freddy Yin Chiang; Loo, Joachim S C; Venkatraman, Subbu S

2012-01-18

126

Plasticizer effects on physical-mechanical properties of solvent cast Soluplus® films.  

PubMed

Soluplus® is a novel amphiphilic polymer that has been shown to enhance the solubility and drug dissolution rate of poorly soluble drugs. However, there still is a lack of information regarding the physical mechanical properties of Soluplus® with addition of the plasticizers. This study characterized the mechanical properties of Soluplus® with four different plasticizers. The plasticizers selected were polyethylene glycol 6, triethyl citrate, propylene glycol, and glycerin; they were studied at three different levels (15%, 20%, and 25% w/w). The effects of these plasticizers on the glass transition temperature, tensile strength, percent elongation, and Young's modulus of free films made from Soluplus® were measured and the toughness and ratio of tensile strength to Young's modulus were calculated. These results showed these four plasticizers are capable to plasticizing Soluplus® as indicated by the glass transition temperature lowering, tensile strength, and Young's modulus while increasing the percent elongation and film toughness. Among the plasticizers tested, polyethylene glycol 6 showed greatest changed in the mechanical properties studied. PMID:23689959

Lim, Hanpin; Hoag, Stephen W

2013-05-21

127

Plane-based sampling for ray casting algorithm in sequential medical images.  

PubMed

This paper proposes a plane-based sampling method to improve the traditional Ray Casting Algorithm (RCA) for the fast reconstruction of a three-dimensional biomedical model from sequential images. In the novel method, the optical properties of all sampling points depend on the intersection points when a ray travels through an equidistant parallel plan cluster of the volume dataset. The results show that the method improves the rendering speed at over three times compared with the conventional algorithm and the image quality is well guaranteed. PMID:23424608

Lin, Lili; Chen, Shengyong; Shao, Yan; Gu, Zichun

2013-01-22

128

Sliding wear and friction characteristics of six Zn-based die-casting alloys  

Microsoft Academic Search

The friction and wear characteristics of zinc-based alloys in warm, oil-lubricated, sliding contact against mild steel were investigated. The alloys, their compositions, and their microstructures included: pure Zn (100% Zn, ? zinc), Zamak 3 (Zn?4Al?0.1Cu, ? zinc plus ?? eutectic), ZA 27 (Zn?31Al?2.3Cu, ? aluminum plus ?ga eutectic), ACuZinc 5 (Zn?3.0Al?5Cu) in die cast form, and ACuZinc 10 (Zn?3.5Al?10Cu, epsilon

M. D. Hanna; J. T. Carter; M. S. Rashid

1997-01-01

129

Improvement of the mechanical and barrier properties of methylcellulose-based films by treatment with HEMA and silane monomers under gamma radiation  

NASA Astrophysics Data System (ADS)

Methylcellulose (MC)-based films were prepared by casting from its 1% aqueous solution containing 0.5% vegetable oil, 0.25% glycerol and 0.025% Tween®-80. Puncture strength (PS), puncture deformation (PD) and water vapor permeability (WVP) of the films were found to be 147 N/mm, 3.46 mm, and 6.34 g mm/m2 day kPa, respectively. The monomer, 2-hydroxyethyl methacrylate (HEMA) (0.1-1%, w/w) was incorporated into the MC-based solution and films were prepared by casting. Films were then exposed to gamma radiation (5-25 kGy) and it revealed that 1% HEMA containing films showed the highest PS values (282 N/mm at 10 kGy). Silane monomer (3-aminopropyl tri-ethoxy silane) (0.1-1%, w/w) was also added into the MC-based films and were found to improve the strength of the films significantly. In comparison between HEMA and silane treatment onto MC-based films, it was observed that silane performed better strength and barrier properties. Surface morphology of the monomer treated films was examined by scanning electron microscopy and suggested better appearance than MC-based film.

Khan, Ruhul A.; Dussault, Dominic; Salmieri, Stephane; Safrany, Agnes; Lacroix, Monique

2012-08-01

130

Classification techniques based on AI application to defect classification in cast aluminum  

NASA Astrophysics Data System (ADS)

This paper describes the Artificial Intelligent techniques applied to the interpretation process of images from cast aluminum surface presenting different defects. The whole process includes on-line defect detection, feature extraction and defect classification. These topics are discussed in depth through the paper. Data preprocessing process, as well as segmentation and feature extraction are described. At this point, algorithms employed along with used descriptors are shown. Syntactic filter has been developed to modelate the information and to generate the input vector to the classification system. Classification of defects is achieved by means of rule-based systems, fuzzy models and neural nets. Different classification subsystems perform together for the resolution of a pattern recognition problem (hybrid systems). Firstly, syntactic methods are used to obtain the filter that reduces the dimension of the input vector to the classification process. Rule-based classification is achieved associating a grammar to each defect type; the knowledge-base will be formed by the information derived from the syntactic filter along with the inferred rules. The fuzzy classification sub-system uses production rules with fuzzy antecedent and their consequents are ownership rates to every defect type. Different architectures of neural nets have been implemented with different results, as shown along the paper. In the higher classification level, the information given by the heterogeneous systems as well as the history of the process is supplied to an Expert System in order to drive the casting process.

Platero, Carlos; Fernandez, Carlos; Campoy Cervera, Pascual; Aracil, Rafael

1994-11-01

131

Sand casting precision technology based on non-occupying coating technology  

Microsoft Academic Search

The current status of foundry technology is introduced. A suggestion of improving sand casting precision to realize precision casting by using rapid prototyping technology and non-occupying coating technology is put forward. Combining with making brake drum of sand casting mold, the key technology is analyzed. The advantages are pointed out by comparing with the common.

Shi Ying; Wang Liang

2010-01-01

132

Cast aluminized explosives (review)  

Microsoft Academic Search

This paper reviews the current status and future trends of aluminized explosives. The major focus is on cast compositions,\\u000a which encompass both the melt-cast trinitrotoluene (TNT) based and the slurry cast polymer-based compositions. Widely reported\\u000a RDX and HMX based aluminized compositions with TNT used as a binder are discussed in detail. Various researchers have suggested\\u000a a 15–20% Al content as

P. P. Vadhe; R. B. Pawar; R. K. Sinha; S. N. Asthana; A. Subhananda Rao

2008-01-01

133

New approaches in microcasting: permanent mold casting and composite casting  

Microsoft Academic Search

For several years, microcasting was based on investment casting. New approaches are now the permanent mold casting and composite\\u000a casting of micro parts. Casting was performed with aluminum bronze of the type CuAl10Ni5Fe4. Permanent mold casting was commenced with steel mold inserts in a lost mold. The development of a band heater enabled the\\u000a heating of permanent molds inside the

G. Baumeister; D. Buqezi-Ahmeti; J. Glaser; H.-J. Ritzhaupt-Kleissl

2011-01-01

134

Enhanced Performance Consistency in Nanoparticle/TIPS Pentacene-Based Organic Thin Film Transistors  

SciTech Connect

In this study, inorganic silica nanoparticles are used to manipulate the morphology of 6,13-bis(triisopropylsilylethynyl)-pentacene (TIPS pentacene) thin films and the performance of solution-processed organic thin-film transistors (OTFTs). This approach is taken to control crystal anisotropy, which is the origin of poor consistency in TIPS pentacene based OTFT devices. Thin film active layers are produced by drop-casting mixtures of SiO{sub 2} nanoparticles and TIPS pentacene. The resultant drop-cast films yield improved morphological uniformity at {approx}10% SiO{sub 2} loading, which also leads to a 3-fold increase in average mobility and nearly 4 times reduction in the ratio of measured mobility standard deviation ({mu}{sub Stdev}) to average mobility ({mu}{sub Avg}). Grazing-incidence X-ray diffraction, scanning and transmission electron microscopy as well as polarized optical microscopy are used to investigate the nanoparticle-mediated TIPS pentacene crystallization. The experimental results suggest that the SiO{sub 2} nanoparticles mostly aggregate at TIPS pentacene grain boundaries, and 10% nanoparticle concentration effectively reduces the undesirable crystal misorientation without considerably compromising TIPS pentacene crystallinity.

He, Zhengran [ORNL; Xiao, Kai [ORNL; Durant, William Mark [ORNL; Anthony, John E. [University of Kentucky, Lexington; Kilbey, II, S Michael [ORNL; Chen, Jihua [ORNL; Li, Dawen [ORNL

2011-01-01

135

Preparation of nano cellulose fibers and its application in kappa-carrageenan based film.  

PubMed

Bio-based nanocomposite films were successfully developed using nanofibrillated cellulose (NFC) as the reinforcing phase and kappa-carrageenan (KCRG) as the matrix. NFC was successfully synthesis from short stable cotton fibers by chemo-mechanical process. The bionanocomposites were prepared by incorporating 0.1, 0.2, 0.3, 0.4, 0.5, and 1wt% of the NFC into a KCRG matrix using a solution casting method there characterization was done in terms of thermal properties (DSC), morphology (SEM), water vapor transmission rate (WVTR), oxygen transmission rate (OTR), X-ray diffractograms (XRD), and tensile properties. The main conclusion arising from the analysis of the result is that the bionanocomposites containing 0.4wt% of NFC exhibited the highest enhancement in tensile strength it is almost 44% improvement. WVTR and OTR results showed improvement of all nanocomposite film compare to control KCRG film. PMID:22940239

Savadekar, N R; Karande, V S; Vigneshwaran, N; Bharimalla, A K; Mhaske, S T

2012-08-24

136

Thermally induced grinding damage in cast equiaxed nickel-based superalloys  

SciTech Connect

The overall objective of this program was to increase the understanding and productivity of conventional grinding operations utilized in the finishing of cast equiaxed nickel-based superalloy components. To achieve this overall goal a four phase approach was employed. Initially, a grinding energy partition relationship for conventional grinding of superalloys was developed. Secondly, the mechanisms and conditions that influence superalloy microcracking during abusive grinding were determined. Third, building on the above relationships, a means of readily predicting the onset of grinding damage in cast Rene-77 and B-1900 superalloys was established. Finally, the results were implemented in production surface grinding operations to increase superalloy grinding quality and productivity. Finite element analyses were utilized to determine the superalloy grinding zone temperatures and residual stresses. The results indicated that Rene-77 microcracks are not formed by the residual stresses alone. The effects of constitutional liquation or weakening of the grain boundaries due to rapid heating to such temperatures were shown to be significant. It was then demonstrated that workplace damage would occur when the combined conducted and convected heat flux exceeded a critical limit.

Kovach, J.A.

1986-01-01

137

Microstructure-based fatigue life prediction for cast A356-T6 aluminum-silicon alloys  

NASA Astrophysics Data System (ADS)

Fatigue life prediction and optimization is becoming a critical issue affecting the structural applications of cast aluminum-silicon alloys in the aerospace and automobile industries. In this study, a range of microstructure and porosity populations in A356 alloy was created by controlling the casting conditions and by applying a subsequent hot isostatic pressing (“hipping”) treatment. The microstructure and defects introduced during the processing were then quantitatively characterized, and their effects on the fatigue performance were examined through both experiment and modeling. The results indicated that whenever a pore is present at or near the surface, it initiates fatigue failure. In the absence of large pores, a microcell consisting of ?-Al dendrites and associated Si particles was found to be responsible for crack initiation. Crack initiation life was quantitatively assessed using a local plastic strain accumulation model. Moreover, the subsequent crack growth from either a pore or a microcell was found to follow a small-crack propagation law. Based on experimental observation and finite-element analysis, a unified model incorporating both the initiation and small crack growth stages was developed to quantitatively predict the dependency of fatigue life on the microstructure and porosity. Good agreement was obtained between the model and experiment.

Yi, J. Z.; Gao, Y. X.; Lee, P. D.; Lindley, T. C.

2006-04-01

138

The microstructural characteristics in a newly developed nickel-base cast superalloy  

SciTech Connect

A new cast superalloy with composition of 8.48 Cr, 9.68 W, 1.76 Mo, 4.52 Al, 0.95 Ti, 9.55 Co, 1.02 Nb, 5.16 Ta, 0.07 Hf, 0.082 Zr, 0.013 B, 0.11 C, Ni bal. (wt.%) was prepared by the investment casting process. The alloy was solution annealed at 1,553K for 2h and then air cooled, followed by a two-step aging treatment for 5h at 1,293K and then air cooled, followed by 1,143K and air cooled to room temperature. The microstructural characteristics were evaluated through optical and electron microscopic observations. Electron probe microanalysis and energy-dispersive analysis of X-rays were conducted to study the (W, Mo)-rich phase precipitated in the new alloy. The results showed that the alloy is coarse grained ({approximately}5mm) with serrated grain boundaries and a relatively homogeneous composition. This alloy contains uniform {gamma}-{gamma}{prime} microstructure and a fine, discrete W-Mo-containing phase together with discrete carbides M{sub 6}C and M{sub 23}C{sub 6}, which coexist at grain boundaries. All of these microstructural features are thought to be beneficial to the superior creep rupture life of the newly developed nickel-base superalloy.

Yao, X.X.; Fang, Y. [Shanghai Jiao Tong Univ. (China). Dept. of Materials Science; Kim, H.T.; Choi, J. [Korea Inst. of Science and Technology, Seoul (Korea, Republic of). Div. of Metals

1997-02-01

139

Development of model for barrier and optical properties of tapioca starch based edible films.  

PubMed

The film forming solutions composed of tapioca (cassava) starch (1-3 g), glycerol (0.5-1.0 ml), agar (0.5-1.0 g) and span 80 (0.1-0.5 ml) were prepared according to a three-level, four-factor Box-Behnken response surface experimental design. The films were obtained by casting method and they are homogenous and transparent. The influence of film composition (tapioca starch, glycerol, agar and span80) on the barrier and optical properties of the tapioca starch based edible films was evaluated. The results showed that, hydrophilic nature and plasticizing effect of glycerol increases the water vapor permeability, oxygen permeability, moisture content, solubility and swelling capacity of the films. But surfactant (span80) incorporation reduces the mobility of the polysaccharide matrix and decreases the barrier properties of the films. Transparency of the films was influenced by plasticizer and surfactant concentration due to the dilution effect of glycerol and span80. The results were analyzed by Pareto analysis of variance (ANOVA) and second-order polynomial models were developed using multiple regression analysis. The models developed from the experimental design were predictive and good fit with the experimental data with high coefficient of determination (R(2)) values (more than 0.95). The optimized conditions were obtained were tapioca starch of 1.95 g, glycerol of 0.8 ml, agar of 0.7 g and span 80 of 0.3 ml, respectively. PMID:23399163

Maran, J Prakash; Sivakumar, V; Sridhar, R; Thirugnanasambandham, K

2012-10-03

140

Context-based user grouping for multi-casting in heterogeneous radio networks  

NASA Astrophysics Data System (ADS)

Along with the rise of sophisticated smartphones and smart spaces, the availability of both static and dynamic context information has steadily been increasing in recent years. Due to the popularity of social networks, these data are complemented by profile information about individual users. Making use of this information by classifying users in wireless networks enables targeted content and advertisement delivery as well as optimizing network resources, in particular bandwidth utilization, by facilitating group-based multi-casting. In this paper, we present the design and implementation of a web service for advanced user classification based on user, network, and environmental context information. The service employs simple and advanced clustering algorithms for forming classes of users. Available service functionalities include group formation, context-aware adaptation, and deletion as well as the exposure of group characteristics. Moreover, the results of a performance evaluation, where the service has been integrated in a simulator modeling user behavior in heterogeneous wireless systems, are presented.

Mannweiler, C.; Klein, A.; Schneider, J.; Schotten, H. D.

2011-08-01

141

Thin film solar cells on glass based on the transfer of monocrystalline Si films  

Microsoft Academic Search

Thin film solar cells based on monocrystalline Si films are transferred onto a glass superstrate. Chemical vapor deposition serves to epitaxially deposit Si on quasi-monocrystalline Si films obtained from thermal crystallization of a double-layer porous Si film on a Si wafer. A separation layer that forms during this crystallization process allows one to separate the epitaxial layer on top of

R. B Bergmann; T. J Rinke; T. A Wagner; J. H Werner

2001-01-01

142

Structural and magnetic properties of free-standing Ni0.23Cu0.11Zn0.66Fe2O4 thick films prepared using a modified tape-casting method  

NASA Astrophysics Data System (ADS)

Free-standing Ni0.23Cu0.11Zn0.66Fe2O4 thick films have been prepared using a modified tape-casting method from a viscous paint. The surface morphology, saturation magnetization (Ms), coercivity (Hc) and complex permeability of the thick films were studied. It is demonstrated that the thick films have relatively larger complex permeability and higher resonance frequency as compared to their bulk material counterparts.

Yang, Z. H.; Li, Z. W.; Kong, L. B.

2010-03-01

143

Production and properties of nanocellulose-reinforced methylcellulose-based biodegradable films.  

PubMed

Methylcellulose (MC)-based films were prepared by casting from its 1% aqueous solution containing 0.5% vegetable oil, 0.25% glycerol, and 0.025% Tween 80. Puncture strength (PS), puncture deformation (PD), viscoelasticity coefficient, and water vapor permeability (WVP) were found to be 147 N/mm, 3.46 mm, 41%, and 6.34 g.mm/m(2).day.kPa, respectively. Aqueous nanocellulose (NC) solution (0.1-1%) was incorporated into the MC-based formulation, and it was found that PS was improved (117%) and WVP was decreased (26%) significantly. Films containing 0.25% NC were found to be the optimum. Then films were exposed to gamma radiation (0.5-50 kGy), and it was revealed that mechanical properties of the films were slightly decreased after irradiation, whereas barrier properties were further improved with a decrease of WVP to 28.8% at 50 kGy. Molecular interactions due to incorporation of NC were supported by FTIR spectroscopy. Thermal properties of the NC-containing films were improved, confirmed by TGA and DSC. Crystalline peaks appeared due to NC addition, found by XRD. Micrographs of films containing NC were investigated by SEM. PMID:20545366

Khan, Ruhul A; Salmieri, Stephane; Dussault, Dominic; Uribe-Calderon, Jorge; Kamal, Musa R; Safrany, Agnes; Lacroix, Monique

2010-07-14

144

Preparation and Characterization of Films Based on Alginate and Aloe Vera  

Microsoft Academic Search

Sodium alginate films with aloe vera extract were prepared by the casting\\/solvent evaporation technique. The resulting films were characterized by differential scanning calorimetry, Fourier transform-infrared spectroscopy, scanning electron microscopy, and mechanical and water absorption tests. The in vitro degradation of the films was also investigated over 14 days. Results show that aloe vera contributes to both enhancing the thermal and

Rúben Pereira; Ana Tojeira; Daniela C. Vaz; Ausenda Mendes; Paulo Bártolo

2011-01-01

145

Electrical properties of poly(vinyl alcohol) (PVA) based on LiFePO 4 complex polymer electrolyte films  

Microsoft Academic Search

Li ion conducting polymer electrolyte films were prepared based on poly(vinyl alcohol) (PVA) with 5, 10, 15, 20, 25 and 30 wt%\\u000a lithium iron phosphate (LiFePO4) salt using a solution-casting technique. X-ray diffraction (XRD) was used to determine the complexation of the polymer with\\u000a LiFePO4 salt. Differential scanning (DSC) calorimetry was used to determine the melting temperatures of the pure PVA

V. M. Mohan; Weiliang Qiu; Jie Shen; Wen Chen

2010-01-01

146

Ion conducting polymer electrolyte films based on (PEO+KNO 3) system and its application as an electrochemical cell  

Microsoft Academic Search

Ion conducting polymer electrolyte films based on poly (ethylene oxide) (PEO) complexed with potassium nitrate (KNO3) have been prepared by solution-cast technique. The complexation of KNO3 salt with the polymer PEO has been confirmed by X-ray diffraction (XRD) and Infrared (IR) studies. DC conductivity in the temperature range 303–373 K and transference number measurements have been employed to investigate the

T Sreekanth; M Jaipal Reddy; S Subramanyam; U. V Subba Rao

1999-01-01

147

[Cast structures and mechanical properties of Ir added to Ag-based alloys. (Part 1) (author's transl)].  

PubMed

The effect of very small quantity of Ir added to pure Agb or Ab-based casting alloys on the mechanical properties were investigated by microstructure observation, tensile test, XMA (electron probe micro analysis) and electrical resistivity measurement. 1) An addition of 0.005% Ir to pure Ag caused grain refinement, increased elongation, yield point, tensile strength. However, the refinement effect did not proportionally increase to the amount of additional Ir. 2) An addition of Ir to Ag alloy containing 7% Cu caused to finely dispersed beta phase in the as cast alloy and degraded the dendrite structure. As a result, homogenization and aging were accelerated. Mechanical properties i. e. elongation, yield point and tensile strength increased in castings and homogeneous state and yield point increased in aging state. The addition of about 0.05% Ir appeared optimum. 3) An addition of Ir to an Ag alloy containing 15% Cu caused grain refinement of the alloy as cast but its effect on the mechanical properties of the alloy was not clarified owing to casting defects. 4) 0.05% Ir added to an Ag alloy containing 20% Pd and 7% Cu did not show an apparent refinement effect. The optimum quantity of Ir is assumed to differ depending on the amount of Pd content. PMID:7033415

Honma, H; Iijima, K

1981-04-01

148

Development of NZP ceramic based {open_quotes}cast-in-place{close_quotes} diesel engine port liners  

SciTech Connect

BSX (Ba{sub 1+x}Zr{sub 4}P{sub 6-2x}Si{sub 2x}O{sub 24}) and CSX (Ca{sub l-x}Sr{sub x}Zr{sub 4}P{sub 6}O{sub 24}) type NZP ceramics were fabricated and characterized for: (i) thermal properties viz., thermal conductivity, thermal expansion, thermal stability and thermal shock resistance; (ii) mechanical properties viz., flexure strength and elastic modulus; and (iii) microstructures. Results of these tests and analysis indicated that the BS-25 (x=0.25 in BSX) and CS-50 (x=0.50 in CSX) ceramics had the most desirable properties for casting metal with ceramic in place. Finite element analysis (FEA) of metal casting (with ceramic in place) was conducted to analyze thermomechanical stresses generated and determine material property requirements. Actual metal casting trials were also conducted to verify the results of finite element analysis. In initial trials, the ceramic cracked because of the large thermal expansion mismatch (hoop) stresses (predicted by FEA also). A process for introduction of a compliant layer between the metal and ceramic to alleviate such destructive stresses was developed. The compliant layer was successful in preventing cracking of either the ceramic or the metal. In addition to these achievements, pressure slip casting and gel-casting processes for fabrication of NZP components; and acoustic emission and ultrasonics-based NDE techniques for detection of microcracks and internal flaws, respectively, were successfully developed.

Nagaswaran, R.; Limaye, S.Y.

1996-02-01

149

Influence of the deagglomeration procedure on aqueous dispersion, slip casting and sintering of Si 3N 4-based ceramics  

Microsoft Academic Search

The influence of the deagglomeration procedure on the rheological behaviour of Si3N4-based aqueous suspensions, the slip casting performance and the final properties after sintering were investigated. Ball milling and planetary milling performed deagglomeration of powders. The experimental results showed that the time required to obtain the same degree of deagglomeration was considerably shorter in the case of planetary milling. The

Marta I. L. L. Oliveira; Kexin Chen; José M. F. Ferreira

2002-01-01

150

Project CAST: Experience-Based Career Education Program for Secondary Level Handicapped Students Residing in a Rural Area. Final Report.  

ERIC Educational Resources Information Center

The final report of the 3 year Project CAST (an Appalachia Educational Laboratory adaptation of the Experience Based Career Education Model) in Charles County, Maryland, reviews accomplishments in the areas of student appraisal, individual educational programming (IEP), joint coordination and continuing education, and dissemination and…

Diep, Barbara J.; Welsh, Phil

151

Development of knowledge-based engineering module for diagnosis of defects in casting and interpretation of defects by nondestructive testing  

Microsoft Academic Search

The research presented in this paper has resulted in a knowledge-based engineering module, which was developed for the diagnosis of defects in cylinder block casting. The criteria for diagnosing these defects, which have been classified into different groups, include location, shape of defects and whether the defects appear before or after machining. The paper also develops an expert system adviser

S. N Dwivedi; A Sharan

2003-01-01

152

OM Study of Effect of HIP and Heat Treatments on Microstructural Restoration in Cast Nickel Based Superalloy, IN738  

Microsoft Academic Search

The present work aims at studying and searching for the most suitable and practicable repairing condition for microstructural restoration, which could provide the desired microstructural characteristics by rejuvenation method of hot isostatic pressing (HIP), followed by 12 heat treatment conditions for long-term serviced gas turbine blades made of cast nickel base superalloy grade IN-738 operated by Electricity Generating Authority of

Panyawat WANGYAO; Weerasak HOMKRAJAI; Viyaporn KRONGTONG; Nurot PANICH

153

Probabilistic simulation of hydrogen gas porosity formation in A356 base hypoeutectic alloy castings  

Microsoft Academic Search

Microporosity in cast aluminum alloy can be classified as gas porosity and\\/or shrinkage porosity. In prior research, two dimensional simulation programs employing a probabilistic modeling approach and cellular automaton method were developed to predict microporosity in cast aluminum alloys. In this research the 2D models were statistically compared with experimental data. Additionally, we investigated size and morphology distribution of grains

Jo Asada

2000-01-01

154

Feasibility of Squeeze Casting the Base for the PATRIOT Warhead XM248E1.  

National Technical Information Service (NTIS)

Squeeze casting is a hybrid of permanent mold casting and forging techniques. In this metalworking process molten metal is metered into a die cavity and pressure is applied to the solidifying metal. Suitable use of the optimized process parameters can eli...

A. Chakravartty

1979-01-01

155

Comparison of different binders for water-based tape casting of alumina  

Microsoft Academic Search

Three different types of binders, latexes, polyvinyl alcohol and cellulose ether were studied for tape casting of alumina. The rheological properties of the different systems were compared by continuous shear and oscillatory measurements. The cast tapes were evaluated with regard to particle packing, binder burnout and sintering behaviour. The microstructure of the final materials was investigated as well. Owing to

A. Kristoffersson; E. Roncari; C. Galassi

1998-01-01

156

Rheological characterization of water-based slurries for the tape casting process  

Microsoft Academic Search

Rheological properties of aqueous tape casting slurries have been investigated as they strongly affect the tape casting process and the quality of the final product. The aqueous slurries consist of yttria stabilized zirconia and a polymeric latex emulsion as the binder. The viscosity, its time dependent behavior and the strength of the internal structure of the slurry were characterized by

Bernd Bitterlich; Christiane Lutz; Andreas Roosen

2002-01-01

157

Casting Process Simulation Based of Interface Friction between Metallic Liquid and Die Wall  

Microsoft Academic Search

Rapid Tooling (RT) is a major field in rapid prototyping manufacturing (RPM). In order to obtain metallic molds for automobile industry, ceramic shell precision casting technology is being used. Models are used in this kind of casting technology in RT in our lab. Some main factors have been analysed and estimated. MARC nonlinear finite element analysis software has been used

Renji Zhang; Yuan Liu; Da Xu; Yongnian Yan

1998-01-01

158

A general and Robust Ray-Casting-Based Algorithm for Triangulating Surfaces at the Nanoscale  

PubMed Central

We present a general, robust, and efficient ray-casting-based approach to triangulating complex manifold surfaces arising in the nano-bioscience field. This feature is inserted in a more extended framework that: i) builds the molecular surface of nanometric systems according to several existing definitions, ii) can import external meshes, iii) performs accurate surface area estimation, iv) performs volume estimation, cavity detection, and conditional volume filling, and v) can color the points of a grid according to their locations with respect to the given surface. We implemented our methods in the publicly available NanoShaper software suite (www.electrostaticszone.eu). Robustness is achieved using the CGAL library and an ad hoc ray-casting technique. Our approach can deal with any manifold surface (including nonmolecular ones). Those explicitly treated here are the Connolly-Richards (SES), the Skin, and the Gaussian surfaces. Test results indicate that it is robust to rotation, scale, and atom displacement. This last aspect is evidenced by cavity detection of the highly symmetric structure of fullerene, which fails when attempted by MSMS and has problems in EDTSurf. In terms of timings, NanoShaper builds the Skin surface three times faster than the single threaded version in Lindow et al. on a 100,000 atoms protein and triangulates it at least ten times more rapidly than the Kruithof algorithm. NanoShaper was integrated with the DelPhi Poisson-Boltzmann equation solver. Its SES grid coloring outperformed the DelPhi counterpart. To test the viability of our method on large systems, we chose one of the biggest molecular structures in the Protein Data Bank, namely the 1VSZ entry, which corresponds to the human adenovirus (180,000 atoms after Hydrogen addition). We were able to triangulate the corresponding SES and Skin surfaces (6.2 and 7.0 million triangles, respectively, at a scale of 2 grids per Å) on a middle-range workstation.

Decherchi, Sergio; Rocchia, Walter

2013-01-01

159

A general and robust ray-casting-based algorithm for triangulating surfaces at the nanoscale.  

PubMed

We present a general, robust, and efficient ray-casting-based approach to triangulating complex manifold surfaces arising in the nano-bioscience field. This feature is inserted in a more extended framework that: i) builds the molecular surface of nanometric systems according to several existing definitions, ii) can import external meshes, iii) performs accurate surface area estimation, iv) performs volume estimation, cavity detection, and conditional volume filling, and v) can color the points of a grid according to their locations with respect to the given surface. We implemented our methods in the publicly available NanoShaper software suite (www.electrostaticszone.eu). Robustness is achieved using the CGAL library and an ad hoc ray-casting technique. Our approach can deal with any manifold surface (including nonmolecular ones). Those explicitly treated here are the Connolly-Richards (SES), the Skin, and the Gaussian surfaces. Test results indicate that it is robust to rotation, scale, and atom displacement. This last aspect is evidenced by cavity detection of the highly symmetric structure of fullerene, which fails when attempted by MSMS and has problems in EDTSurf. In terms of timings, NanoShaper builds the Skin surface three times faster than the single threaded version in Lindow et al. on a 100,000 atoms protein and triangulates it at least ten times more rapidly than the Kruithof algorithm. NanoShaper was integrated with the DelPhi Poisson-Boltzmann equation solver. Its SES grid coloring outperformed the DelPhi counterpart. To test the viability of our method on large systems, we chose one of the biggest molecular structures in the Protein Data Bank, namely the 1VSZ entry, which corresponds to the human adenovirus (180,000 atoms after Hydrogen addition). We were able to triangulate the corresponding SES and Skin surfaces (6.2 and 7.0 million triangles, respectively, at a scale of 2 grids per Å) on a middle-range workstation. PMID:23577073

Decherchi, Sergio; Rocchia, Walter

2013-04-05

160

Potentiometric biosensors based on polyaniline semiconductor films  

Microsoft Academic Search

Application of polyaniline (PAn) semiconductor films for potentiometric biosensor development provides certain advantages compared with the known systems. For enzyme immobilisation a pH sensitive matrix was used, which could improve sensor sensitivity. Indeed the limiting response value of the PAn based trypsin electrode in 1 mM buffer was 270 mV. The maximal slope of the calibration curve in semilogarithmic coordinates

Arkady A. Karyakin; Oksana A. Bobrova; Lylia V. Lukachova; Elena E. Karyakina

1996-01-01

161

Optically transparent superhydrophobic silica-based films  

Microsoft Academic Search

Optically transparent superhydrophobic silica-based films were obtained by means of sol–gel processing and self-assembly (SA). Desired surface roughness was obtained by tuning the microstructures of the sol–gels through careful control of hydrolysis and condensation reactions of various silica precursors during sol–gel processing, whereas modification of surface chemistry was done by introducing a monolayer through surface condensation reaction. Such coatings were

H. M. Shang; Y. Wang; S. J. Limmer; T. P. Chou; K. Takahashi; G. Z. Cao

2005-01-01

162

Electroslag Casting.  

National Technical Information Service (NTIS)

The report contains an examination of the most important characteristics of the physico-mechanical properties of electroslag cast metal in comparison with the properties of open hearth steel, subjected to deformation by forging or used in the cast form.

B. E. Paton B. I. Medovar G. A. Boiko

1975-01-01

163

Clad Cast Steel Strip.  

National Technical Information Service (NTIS)

A process for producing continuous cast hot band crystalline metal strips comprising feeding thin gauge metal strips and molten metal into a gap formed between opposed quenching surfaces. The film of molten metal is cooled while in contact with the quench...

R. L. Sheneman

1983-01-01

164

[Optimization of the ray-casting algorithm based on streaming single instruction multiple datum extension].  

PubMed

At present, ray-casting algorithm is the most widely used algorithm in the field of medical image visualization, and it can achieve the best image quality. Due to large amounts of computation like sampling, gradient, lighting and blending calculation, the cost of ray-casting algorithm is very large. The characteristic of Streaming single instruction multiple datum extensions (SSE) instruction--supporting vector computation--can satisfy the property of ray-casting algorithm well. Therefore, in this paper, we improved the implementation efficient significantly by vectorization of gradient, lighting and blending calculation, and still achieved a high quality image at the same time. PMID:22616160

Zou, Yunpeng; Qi, Ji; Kang, Yan

2012-04-01

165

Dimensional changes of one-piece frameworks cast from titanium, base metal, or noble metal alloys and supported on telescopic crowns  

Microsoft Academic Search

Statement of problem. The dimensional accuracy of 1-piece frameworks cast from commercially pure titanium and used to accommodate supporting telescopic crowns has not been demonstrated. Purpose. To compare dimensional changes incurred in frameworks cast from commercially pure titanium, a cobalt-chromium alloy, and a noble metal (gold) alloy. Material and Methods. This study was based on 2 different models, both prepared

Matthias Gebelein; Gert Richter; Ursula Range; Bernd Reitemeier

2003-01-01

166

Analysis of mechanical characteristics of the ionic polymer metal composite (IPMC) actuator using cast ion-exchange film  

Microsoft Academic Search

IPMC (Ionic Polymer Metal Composite) is a promising candidate actuator for bio-related applications mainly due to its biocompatibility, soft properties and operation in wet condition. The widely used and commercialized ion-exchange polymer film has limitation in thicknesses, but more various film thicknesses are required for extensive applications. Especially for the enhanced force as an actuator, acquisition of thick film is

Byungkyu Kim; Byung M. Kim; Jaewook Ryu; In-Hwan Oh; Seung-Ki Lee; Seung-Eun Cha; Jungho Pak

2003-01-01

167

Welding and mechanical properties of cast FAPY (Fe-16 at. % Al-based) alloy slabs  

SciTech Connect

This report deals with the welding procedure development and weldment properties of an Fe-16 at. % Al alloy known as FAPY. The welding procedure development was carried out on 12-, 25-, and 51-mm (0.5-, 1-, and 2-in.) -thick plates of the alloy in the as-cast condition. The welds were prepared by using the gas tungsten arc process and filler wire of composition matching the base-metal composition. The preheat temperatures varied from room temperature to 350{degrees}C, and the postweld heat treatment (PWHT) was limited only for 1 h at 750{degrees}C. The welds were characterized by microstructural. analysis and microhardness data. The weldment specimens were machined for Charpy-impact, tensile, and creep properties. The tensile and creep properties of the weldment specimens were essentially the same as that of the base metal. The Charpy-impact properties of the weldment specimens improved with the PWHT and were somewhat lower than previously developed data on the wrought material. Additional work is required on welding of thicker sections, development of PWHT temperatures as a function of section thickness, and mechanical properties.

Sikka, V.K.; Goodwin, G.M.; Alexander, D.J.; Howell, C.R.

1995-05-01

168

Feature-based imaging for cast stainless steel components: 1987 and 1988 field examinations: Final report  

SciTech Connect

Digital-based inspection systems were used for the ultrasonic examinations and analysis of the hot-leg elbow in the Trojan Nuclear Power Plant in 1987 and 1988. This was the first time advanced systems were utilized during successive plant outages to monitor inspection data. The hot-leg elbow is made of statically cast stainless steel known for its mechanical strength and corrosion resistance. However, it presents unique difficulties in ultrasonic inspection because the large grain sizes can cause severe signal attenuation and beam redirection. The 1987 examination was authorized by Portland General Electric of Portland, Oregon, based on a study in 1985 which revealed that the hot-leg elbow could have experienced maximum strain and loading conditions because of steam generator snubber lockup. Seven indications were discovered during this examination; none of them was larger than the expected grain size in this material. The data were digitally processed at the EPRI NDE Center utilizing a personal computer based system that was integrated to other commercial systems and capable of feature-based imaging. Bandpass filtering and spatial averaging were found to increase signal-to-noise-ratio by as much as a factor of 2, i.e., 6 decibels. The hot-leg elbow was reexamined in 1988 using similar apparatus and inspection procedures. In addition to the seven 1987 indications, three more indications were discovered. These were determined to be in the midwall region. The largest of all the indications as reported by the inspection vendor was comparable to the average grain size, approximately 0.50 inch. The data were digitally processed at the EPRI NDE Center using similar techniques. Feature-based imaging of 1987 and 1988 inspection data made it possible to evaluate elbow conditions more reliably. 15 refs., 52 figs., 2 tabs.

Shanker, R.; Jeong, P.; Williams, R.

1989-01-01

169

A study on green tapes for LOM with water-based tape casting processing  

Microsoft Academic Search

A commercial styrene-acrylic latex binder has been investigated as eligible binder for aqueous Al2O3 suspensions tape casting processing. This paper focuses on the rheological behavior and tape casting processing of aqueous slurries with latex binder system. In this experiment, the green tapes have a smooth surface, good toughness and homogeneous structure. Moreover, the green tapes can coil continuously by a

Xuemin Cui; Shixi Ouyang; Zhiyong Yu; Changan Wang; Yong Huang

2003-01-01

170

Analysis of ceramic shell cracking in stereolithography-based rapid casting of turbine blade  

Microsoft Academic Search

Rapid casting (RC) of freeform-surface parts can be realized via replacing wax patterns by stereolithography (SL) patterns\\u000a to overcome the disadvantage of time-and-cost consuming in traditional investment casting. It has a promising application\\u000a prospect in single and small batch production. But ceramic shell cracking during the pyrolyzing of SL patterns limits the\\u000a application and popularization of RC. In this paper,

Xiaojie Chen; Dichen Li; Haihua Wu; Yiping Tang; Lei Zhao

2011-01-01

171

A study of two refractories as mould materials for investment casting TiAl based alloys  

Microsoft Academic Search

Interfacial reactions between Ti-46Al (at.%) casting and ceramic shell mould made of ZrO2 and Al2O3 were studied using a range of techniques. On the surface of the TiAl casting, a reaction layer as thick as 230 ?m was found\\u000a in the case of the zirconia mould, whereas there was no visible reaction layer for the alumina mould. Electron probe microanalysis\\u000a indicated

Q. Jia; Y. Y. Cui; R. Yang

2006-01-01

172

Artificial neural network modeling of caste odor discrimination based on cuticular hydrocarbons in termites  

Microsoft Academic Search

Summary.   Individuals in an insect colony need to identify one another according to caste. Nothing is known about the sensory process\\u000a allowing nestmates to discriminate minute variations in the cuticular hydrocarbon mixture. The purpose of this study was to\\u000a attempt to model caste odors discrimination in four species of Reticulitermes termites for the first time by a non-linear mathematical approach

A.-G. Bagnères; G. Rivière; J.-L. Clément

1998-01-01

173

Photonic transistor based on bacteriorhodopsin films  

NASA Astrophysics Data System (ADS)

Light activated optical circuits have several key advantages over conventional electronics because they are free from electrical current losses, resistive heat dissipation, and friction forces that greatly diminish system performance and efficiency. The effects of current leakage and power loss are also crucial design constaints in developing micro-electromechanical (MEMS) technology. An essential device for creating viable micro-optical circuitry is a robust photonic transistor that can act as a small signal switch and amplifier. The proposed photonic transistor is based on the complementary suppression-modulated light transmission properties of thin bacteriorhodopsin (bR) films. The light transmission properties exhibited by the thin film are controlled using the variable wavelength and intensity of the impinging light soruces. The light transmisison properties of the bR film are illustrated using a mathematical model for the two-state photoreaction system. The two-state model represents the longest lifetime in the bR photocycle, largest change in absorption maxima, and high photochemical stability. The optical response is proportional to changes in the light transmission properties of the biometrical, and therefore represents a viable material for creating optoelectronic devices.

Wang, Wei W.; Knopf, George K.; Bassi, Amarjeet S.

2003-10-01

174

Thin film-based optical fiber sensors  

Microsoft Academic Search

Optical thin films can be deposited on side- and end-face of optical fiber, if these films are sensitive to ambient environments, optical refractive index changes in thin films will finally result to variation of optical signals transmitted in the optical fiber. Here thin films work as sensitive elements and transducer to get response and feedback from environments, optical fiber here

Minghong Yang; Dai Jixiang; Wang Min; Xinling Tong; Desheng Jiang

2010-01-01

175

Real-Time, Model-Based Spray-Cooling Control System for Steel Continuous Casting  

NASA Astrophysics Data System (ADS)

This article presents a new system to control secondary cooling water sprays in continuous casting of thin steel slabs (CONONLINE). It uses real-time numerical simulation of heat transfer and solidification within the strand as a software sensor in place of unreliable temperature measurements. The one-dimensional finite-difference model, CON1D, is adapted to create the real-time predictor of the slab temperature and solidification state. During operation, the model is updated with data collected by the caster automation systems. A decentralized controller configuration based on a bank of proportional-integral controllers with antiwindup is developed to maintain the shell surface-temperature profile at a desired set point. A new method of set-point generation is proposed to account for measured mold heat flux variations. A user-friendly monitor visualizes the results and accepts set-point changes from the caster operator. Example simulations demonstrate how a significantly better shell surface-temperature control is achieved.

Petrus, Bryan; Zheng, Kai; Zhou, X.; Thomas, Brian G.; Bentsman, Joseph

2010-12-01

176

Real-Time, Model-Based Spray-Cooling Control System for Steel Continuous Casting  

NASA Astrophysics Data System (ADS)

This article presents a new system to control secondary cooling water sprays in continuous casting of thin steel slabs (CONONLINE). It uses real-time numerical simulation of heat transfer and solidification within the strand as a software sensor in place of unreliable temperature measurements. The one-dimensional finite-difference model, CON1D, is adapted to create the real-time predictor of the slab temperature and solidification state. During operation, the model is updated with data collected by the caster automation systems. A decentralized controller configuration based on a bank of proportional-integral controllers with antiwindup is developed to maintain the shell surface-temperature profile at a desired set point. A new method of set-point generation is proposed to account for measured mold heat flux variations. A user-friendly monitor visualizes the results and accepts set-point changes from the caster operator. Example simulations demonstrate how a significantly better shell surface-temperature control is achieved.

Petrus, Bryan; Zheng, Kai; Zhou, X.; Thomas, Brian G.; Bentsman, Joseph

2011-02-01

177

Biphasic calcium phosphate coating on cobalt-base surgical alloy during investment casting.  

PubMed

The biphasic calcium phosphate (BCP) yields higher bioactivity and efficiency than the Hydroxyapatite (HA) alone. The HA/?-TCP ratio significantly affects BCP bioactivity as well as the extent of BCP resorption. In this study, the BCP coating on ASTM F-75 cobalt base alloy during the investment casting process was investigated. For this purpose, molten metal was poured at 1,470°C into previously coated investment molds preheated to 750, 850, 950, 1,050°C in order to investigate the effect of mold preheating temperatures on coating phase transformations. For in vitro evaluation, samples were immersed in the simulated body fluid (SBF) at 37°C for 4 weeks and characterized by XRD, SEM, EDS, and optical microscopy. The weight percentages of HA and ?-TCP of the specimens were calculated to find that the HA/?-TCP ratio significantly depended on the mold preheating temperature as it caused changes in the dissolution behavior of BCP coating and the bone-like apatite precipitation on coating during in vitro evaluation. PMID:21894538

Minouei, H; Meratian, M; Fathi, M H; Ghazvinizadeh, H

2011-09-06

178

Grain Selection During Casting Ni-Base, Single-Crystal Superalloys with Spiral Grain Selector  

NASA Astrophysics Data System (ADS)

The behavior of grain selection in a spiral grain selector during investment casting of a Ni-base, single-crystal (SX) superalloy, DD3, has been investigated by electron backscattered diffraction (EBSD) techniques and optical microscopy. The results indicated that the main function of starter block is to optimize the crystal orientation. During the process of grain selection in spiral passage, the grain near the inner wall of spiral passage was usually selected as the final single crystal. It was found that the dendrites near the inner wall could develop new tertiary dendritic arms that paralleled the primary dendrites from the secondary dendritic arms to overgrow the dendrites far away from the inner wall. The crystal orientation that was examined by X-ray diffraction revealed that (1) the crystal orientation did not change obviously with increasing spiral thickness or angle and (2) the crystal orientation could be optimized by increasing the withdrawal rate and ceramic mold temperature. The influence of pouring temperature on crystal orientation was also discussed.

Gao, S. F.; Liu, L.; Wang, N.; Zhao, X. B.; Zhang, J.; Fu, H. Z.

2012-10-01

179

Infrared optical properties and AFM of spin-cast chitosan films chemically modified with 1,2 Epoxy-3-phenoxy-propane.  

PubMed

Chemical modification of spin-cast chitosan films has been performed. This modification involves the attachment of 1,2 Epoxy-3-phenoxy-propane, commonly known as glycidyl phenyl ether (GPE), to the amine group of the chitosan molecule. Optical properties of modified films have been determined in the infrared region of the spectrum using spectroscopic ellipsometry, and are reported in this paper. Special attention is paid to the infrared region where the index of refraction and extinction coefficients from 750 to 4000 cm(-1) were determined. Difference plots of IR optical data before and after chemical modification were generated to confirm that modification had occurred. Optical modeling of infrared spectroscopic ellipsometry (IRSE) data with respect to chemical bond vibrations has also been performed. This modeling involved curve fitting of resonant chemical bond absorptions using Lorentz oscillators. These oscillator models allow for comparison of modified chitosan to unmodified chitosan. The purpose of this research was to determine infrared optical constants of chemically modified chitosan films This work shows that surface chemistry of biomaterials can be studied quite sensitively with spectroscopy ellipsometry, detecting as little as 100 ng/cm(2) of GPE. PMID:16199143

Nosal, W H; Thompson, D W; Yan, L; Sarkar, S; Subramanian, A; Woollam, J A

2005-09-30

180

Preparation and Characterization of Anode-Supported YSZ Thin Film Electrolyte by Co-Tape Casting and Co-Sintering Process  

NASA Astrophysics Data System (ADS)

In this study, a co-tape casting and co-sintering process has been developed to prepare yttria-stabilized zirconia (YSZ) electrolyte films supported on Ni-YSZ anode substrates in order to substantially reduce the fabrication cost of solid oxide fuel cells (SOFC). Through proper control of the process, the anode/electrolyte bilayer structures with a size of 7.8cm × 7.8cm were achieved with good flatness. Scanning electron microscopy (SEM) observation indicated that the YSZ electrolyte film was about 16 ?m in thickness, highly dense, crack free and well-bonded to the anode support. The electrochemical properties of the prepared anode-supported electrolyte film was evaluated in a button cell mode incorporating a (LaSr)MnO3-YSZ composite cathode. With humidified hydrogen as the fuel and stationary air as the oxidant, the cell demonstrated an open-circuit voltage of 1.081 V and a maximum power density of 1.01 W/cm2 at 800°C. The obtained results represent the important progress in the development of anode-supported intermediate temperature SOFC with reduced fabrication cost.

Liu, Q. L.; Fu, C. J.; Chan, S. H.; Pasciak, G.

2011-06-01

181

Surface abuse when machining cast iron (G-17) and nickel-base superalloy (Inconel 718) with ceramic tools  

Microsoft Academic Search

Single-point continuous-turning tests were carried out on a G-17 cast iron and a nickel base, Inconel 718, alloy using round and rhomboid-shape pure oxide (Al2O3 + ZrO2) and mixed oxide (Al2O3 + TiC) ceramic tools to study the extent of damage on the machined surfaces under optimum cutting conditions. The test results show that improved surface finish and lesser damage

E. O. Ezugwu; S. H. Tang

1995-01-01

182

Superhydrophobic cellulose-based bionanocomposite films from Pickering emulsions  

Microsoft Academic Search

Inherently superhydrophobic and flexible cellulose-based bionanocomposites were fabricated from solid stabilized (Pickering) emulsions. Emulsions were formed by dispersing cyclosiloxanes in water stabilized by layered silicate particles and were subsequently modified by blending into a zinc oxide nanofluid. The polymer matrix was a blend of cellulose nitrate and fluoroacrylic polymer (Zonyl 8740) precompatibilized in solution. Coatings were spray cast onto aluminum

Ilker S. Bayer; Adam Steele; Philip J. Martorana; Eric Loth; Lance Miller

2009-01-01

183

Measurement of concrete E-modulus evolution since casting: A novel method based on ambient vibration  

SciTech Connect

The use of ambient vibration tests to characterize the evolution of E-modulus of concrete right after casting is investigated in this paper. A new methodology is proposed, which starts by casting a concrete cylindrical beam inside a hollow acrylic formwork. This beam is then placed horizontally, simply supported at both extremities, and vertical accelerations resulting from ambient vibration are measured at mid-span. Processing these mid-span acceleration time series using power spectral density functions allows a continuous identification of the first flexural frequency of vibration of the composite beam, which in turn is correlated with the evolutive E-modulus of concrete since casting. Together with experiments conducted with the proposed methodology, a complementary validation campaign for concrete E-modulus determination was undertaken by static loading tests performed on the composite beam, as well as by standard compressive tests of concrete cylinders of the same batch loaded at different ages.

Azenha, Miguel, E-mail: miguel.azenha@civil.uminho.p [LABEST - Laboratory for the Concrete Technology and Structural Behaviour, Faculdade de Engenharia da Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto (Portugal); ISISE - Institute for Sustainability and Innovation in Structural Engineering, Universidade do Minho, Escola de Engenharia, Campus de Azurem, 4800-058 Guimaraes (Portugal); Magalhaes, Filipe [VIBEST - Laboratory of Vibrations and Structural Monitoring, Faculdade de Engenharia da Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto (Portugal); Faria, Rui [LABEST - Laboratory for the Concrete Technology and Structural Behaviour, Faculdade de Engenharia da Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto (Portugal); Cunha, Alvaro [VIBEST - Laboratory of Vibrations and Structural Monitoring, Faculdade de Engenharia da Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto (Portugal)

2010-07-15

184

Structurally Based Assessment of the Influence of Fluorides on the Characteristics of Continuous Casting Powder Slags  

NASA Astrophysics Data System (ADS)

The use of fluorides in continuous casting powder leads to the desired reduction of melting temperature to less than 1573 K (1300 °C) as well as to lowering the viscosity below 10 dPas. With an equilateral use of alkalis, the tendency to form volatile fluorine compounds rises. The effect of these components on the structure of the casting slags can be described with the NBO/T-ratio. Should the full effect of fluorides to be used for structural modification of the slags, the other components have to be inhibited by compound formation so as to prevent them from forming gaseous fluoride. If the fluoride content in the continuous casting slag is represented by means of fluorspar, the influence on the NBO/T-ratio can be described with the impact factor 4.0.

Schulz, Tilo; Lychatz, Bernd; Haustein, Nicole; Janke, Dieter

2013-04-01

185

In-situ observations of oxidation and phase stability in cast nickel-based intermetallic alloys  

SciTech Connect

The effects of the as-cast microstructure on the oxidation characteristics of two Ni-Al-Cr alloys with either gamma or gamma' primary solidification were investigated with an in-situ, time-resolved X-ray diffraction (TRXRD) technique using synchrotron radiation. The measurements, carried out during rapid heating and cooling, showed that a segregated microstructure in these cast alloys leads to the preferential formation of zirconium oxide before the formation of aluminum oxides is detected. The oxidation leads to a change in the phase stability and to the modification of surface microstructures. Computational thermodynamic models were used to explain the preferential formation of oxides in the as-cast microstructure.

Babu, Suresh S. [Edison Welding Institute; Specht, Eliot D [ORNL; Santella, Michael L [ORNL; Ice, Gene E [ORNL; David, Stan A [ORNL

2006-01-01

186

The microstructural characteristics in a newly developed nickel-base cast superalloy  

Microsoft Academic Search

A new cast superalloy with composition of 8.48 Cr, 9.68 W, 1.76 Mo, 4.52 Al, 0.95 Ti, 9.55 Co, 1.02 Nb, 5.16 Ta, 0.07 Hf, 0.082 Zr, 0.013 B, 0.11 C, Ni bal. (wt.%) was prepared by the investment casting process. The alloy was solution annealed at 1553K for 2h and then air cooled, followed by a two-step aging treatment

X. X. Yao; Y. Fang; H. T. Kim; J. Choi

1997-01-01

187

Vehicle routing problem based model and ant colony optimization algorithm for group charge problem of ingot casting  

Microsoft Academic Search

Group charge problem of ingot casting is one of iron & steel production planning and scheduling problems. Compares with the steel-making - continuous casting's group charge problem, the ingot casting's group charge problem has the difference in the process constraint and planning rules. On the basis of analyzing the difference between group charge problem of ingot casting and group charge

Huang Hui; Tu Nai-wei; Ma Tian-mu; Zheng Bing-lin; Chai Tian-you

2009-01-01

188

Effects of Block Length and Solution-Casting Conditions on the Final Morphology and Properties of Disulfonated Poly(arylene ether sulfone) Multiblock Copolymer Films for Proton Exchange Membranes  

SciTech Connect

The effects of block length and solution-casting conditions on the final microstructures and properties of disulfonated poly(arylene ether sulfone) multiblock copolymer (BPSH100-BPS0) films for proton exchange membranes were investigated based on the basic principles of microstructure formation of block copolymers. Morphological studies using transmission electron microscopy and small angle X-ray scattering demonstrated that as the block length increased, the inter-ionic-domain distance increased, with a subsequent increase in lamellar ordering and long-range continuity. Further enhancement in morphological order was achieved by simply utilizing a selective solvent, dimethylacetamide, which is good and marginal for the sulfonated and unsulfonated blocks, respectively, rather than a neutral solvent, N-metyl-2-pyrrolidone. These morphological enhancements led to higher proton conductivity and water uptake. Drying temperature and/or solvent removal rate were observed to have considerable effects on water uptake and swelling behavior, being coupled with solvent selectivity. Also, the multiblock copolymer consisting of longer blocks was found to be more sensitive to the variation of the processing conditions such as solvent type and film drying temperature.

Lee, M.; Park, J; Lee, H; Lane, O; Moore, R; McGrath, J; Baird, D

2009-01-01

189

Azobenzene-based surface relief gratings for thin film distributed feedback lasers  

NASA Astrophysics Data System (ADS)

Holographic surface relief gratings written in azobenzene containing films were studied for the use as masters for polymeric thin film distributed feedback (DFB) lasers. Light induced mass transport driven by E-Z isomerization in azobenzene containing materials have shown to be attractive for all optical and one-step fabrication of periodic surface structures with varying parameters for different optical applications. Based on new azobenzene materials and their holographic processing deep surface relief gratings were generated with grating pitches in the range of 400 nm as resonant structures for second order DFB lasers emitting in the VIS range. Nanoimprint techniques enabled multiple duplications of azobenzene master gratings in UV adhesives. The replicas were coated via spin casting with thin films of red light emitting polymer layers to form DFB thin film lasers. These active layers are guest-host-systems consisting of an UV-light absorbing conjugated polymer as host transferring its excitation via Förster resonant energy transfer to a red emitting conjugated polymer. Simple adjustment of grating depth via controlling of illumination time allowed it to investigate the influence of the corrugation depth and thereby the coupling of laser light and grating on the lasing behavior of second order DFB lasers in the red region. For this purpose multiple surface structures with different corrugation depths of up to 130 nm were generated holographically, duplicated and coated.

Döring, Sebastian; Rabe, Torsten; Rosenhauer, Regina; Kulikovska, Olga; Hildebrandt, Niko; Stumpe, Joachim

2010-04-01

190

Fabrication of integral ceramic mold for investment casting of hollow turbine blade based on stereolithography  

Microsoft Academic Search

Purpose – The purpose of this paper is to develop a novel process of integral ceramic molds for investment casting of hollow turbine blades. Design\\/methodology\\/approach – At first, a resin pattern of a hollow turbine blade prototype is fabricated by stereolithography (SL). And then aqueous gelcasting process is utilized to fill the resin pattern with ceramic slurry of low viscosity

Haihua Wu; Dichen Li; Nannan Guo

2009-01-01

191

ALEXSYS - A Prototype Knowledge Based Expert System for the Quality Assurance of High Pressure Die Castings  

Microsoft Academic Search

The ALEXSYS System is aimed to be used as an industrial tool for the identification, assessment and correction of defects in the aluminium high pressure die casting industry. ALEXSYS consists of three modules: the Diagnostic Module, the Machine Parameters Module and the Design Module. The expert system is tested within a real industrial environment, where a robotic cell fully equipped

C. A. G. Webster; M. Weller; M. M. Sfantsikopoulos; V. D. Tsoukalas

1993-01-01

192

Investment casting  

SciTech Connect

Materials and manufacturing technologies for investment casting have made impressive gains over the past several years, resulting in higher productivity, shorter lead times, and superior castings. To improve efficiency, investment casters have applied total quality control methods, new management concepts, and computer controls. Management and production efficiency improvements have been critical factors in maintaining and expanding market share.

Bidwell, H.T. [Investment Casting Inst., Dallas, TX (United States)

1996-04-01

193

Study on aluminium-based single films.  

PubMed

In the present paper the authors studied isolated metallic films made from the same material used for making metallic foams, and then characterised their properties. Metal films were made from a liquid aluminium alloy reinforced with ceramic particles of known concentration. Melts without such particles were also investigated. It is shown that stable films could not be made from Al-Si alloy having no particles, and just extremely thin and fragile films could be made from commercially-pure Al. In contrast, aluminium alloys containing particles such as SiC and TiB(2) allowed pulling thin, stable films, which did not rupture. Significant thinning of films was observed when the particle concentration in the melt decreased. By in situ X-ray monitoring of liquid films during pulling, film thickness and drainage effects within the liquid film could be studied. The morphology and microstructure of films was characterised after solidification. Our work shows that the question of how foams are stabilised can be studied using a simplified system such as a film, instead of having to deal with the multitude of different structural elements present in a foam. PMID:18060172

Vinod Kumar, G S; García-Moreno, F; Babcsán, N; Brothers, A H; Murty, B S; Banhart, J

2007-10-10

194

Clean Metal Casting  

SciTech Connect

The objective of this project is to develop a technology for clean metal processing that is capable of consistently providing a metal cleanliness level that is fit for a given application. The program has five tasks: Development of melt cleanliness assessment technology, development of melt contamination avoidance technology, development of high temperature phase separation technology, establishment of a correlation between the level of melt cleanliness and as cast mechanical properties, and transfer of technology to the industrial sector. Within the context of the first task, WPI has developed a standardized Reduced Pressure Test that has been endorsed by AFS as a recommended practice. In addition, within the context of task1, WPI has developed a melt cleanliness sensor based on the principles of electromagnetic separation. An industrial partner is commercializing the sensor. Within the context of the second task, WPI has developed environmentally friendly fluxes that do not contain fluorine. Within the context of the third task, WPI modeled the process of rotary degassing and verified the model predictions with experimental data. This model may be used to optimize the performance of industrial rotary degassers. Within the context of the fourth task, WPI has correlated the level of melt cleanliness at various foundries, including a sand casting foundry, a permanent mold casting foundry, and a die casting foundry, to the casting process and the resultant mechanical properties. This is useful in tailoring the melt cleansing operations at foundries to the particular casting process and the desired properties of cast components.

Makhlouf M. Makhlouf; Diran Apelian

2002-02-05

195

MEMS-based thick film PZT vibrational energy harvester  

Microsoft Academic Search

We present a MEMS-based unimorph silicon\\/PZT thick film vibrational energy harvester with an integrated proof mass. We have developed a process that allows fabrication of high performance silicon based energy harvesters with a yield higher than 90%. The process comprises a KOH etch using a mechanical front side protection of an SOI wafer with screen printed PZT thick film. The

A. Lei; R. Xu; A. Thyssen; A. C. Stoot; T. L. Christiansen; K. Hansen; R. Lou-Moller; E. V. Thomsen; K. Birkelund

2011-01-01

196

MOLDS FOR CASTING PLUTONIUM  

DOEpatents

A coated mold for casting plutonium comprises a mold base portion of a material which remains solid and stable at temperatures as high as the pouring temperature of the metal to be cast and having a thin coating of the order of 0.005 inch thick on the interior thereof. The coating is composed of finely divided calcium fluoride having a particle size of about 149 microns. (AEC)

Anderson, J.W.; Miley, F.; Pritchard, W.C.

1962-02-27

197

Influence of film structure and light on charge trapping and dissipation dynamics in spun-cast organic thin-film transistors measured by scanning Kelvin probe microscopy  

NASA Astrophysics Data System (ADS)

Herein, time-dependent scanning Kelvin probe microscopy of solution processed organic thin film transistors (OTFTs) reveals a correlation between film microstructure and OTFT device performance with the location of trapped charge within the device channel. The accumulation of the observed trapped charge is concurrent with the decrease in ISD during operation (VG = -40 V, VSD = -10 V). We discuss the charge trapping and dissipation dynamics as they relate to the film structure and show that application of light quickly dissipates the observed trapped charge.

Teague, L. C.; Loth, M. A.; Anthony, J. E.

2012-06-01

198

Cellulose Triacetate, Thin Film Dielectric Capacitor.  

National Technical Information Service (NTIS)

Very thin films of cellulose triacetate are cast from a solution containing a small amount of high boiling temperature, non-solvent which evaporates last and lifts the film from the casting surface. Stretched, oriented, crystallized films have high electr...

S. S. Yen T. R. Jow

1993-01-01

199

Microstructure-based fatigue modeling of cast A356-T6 alloy  

Microsoft Academic Search

High cycle fatigue (HCF) life in cast Al–Mg–Si alloys is particularly sensitive to the combination of microstructural inclusions and stress concentrations. Inclusions can range from large-scale shrinkage porosity with a tortuous surface profile to entrapped oxides introduced during the pour. When shrinkage porosity is controlled, the relevant microstructural initiation sites are often the larger Si particles within eutectic regions. In

D. L. McDowell; K. Gall; M. F. Horstemeyer; J. Fan

2003-01-01

200

Creep deformation mechanisms in high-pressure die-cast magnesium-aluminum-base alloys  

Microsoft Academic Search

Creep of die-cast Mg alloys is described as an integral part of their plastic deformation behavior in terms of stress-strain-rate-strain\\u000a relations. Creep tests yield information on yield stress, work hardening, maximum deformation resistance (minimum creep rate),\\u000a and work softening. Testing in compression avoids influences by fracture. Data on the alloy AJ52 (5Al, 2Sr) in the temperature\\u000a range between 135 °C

W. Blum; Y. J. Li; X. H. Zeng; P. Zhang; B. von Großmann; C. Haberling

2005-01-01

201

Rheological characterisation of water-based AlN slurries for the tape casting process  

Microsoft Academic Search

In the present work rheological properties of aqueous concentrated AlN suspensions have been investigated in the presence of a sintering aid, deffloculant, binder and plasticizers, in order to screen the most suitable experimental conditions to obtain a good rheological behaviour for tape casting thick and non-cracked tapes with good flexibility.Suspensions exhibiting the desired shear thinning behaviour could be prepared. Adding

S. M. Olhero; J. M. F. Ferreira

2005-01-01

202

A miniature PTC thermistor based sensor element fabricated by tape casting technique  

Microsoft Academic Search

Miniature Positive Temperature Coefficient thermistors measuring around 4 mm×4 mm×0.3 mm have been prepared from semiconducting barium titanate by tape casting technique. Their performance as sensor elements for sensing of temperature and related parameters is far superior due to their miniature size and therefore very low thermal mass. These elements have considerably high signal-to-noise ratio and their response is also

Suman Chatterjee; K Sengupta; H. S Maiti

1999-01-01

203

Quantitative evaluation of evaporation rate during spin-coating of polymer blend films: Control of film structure through defined-atmosphere solvent-casting.  

PubMed

Thin films of polymer mixtures made by spin-coating can phase separate in two ways: by forming lateral domains, or by separating into distinct layers. The latter situation (self-stratification or vertical phase separation) could be advantageous in a number of practical applications, such as polymer optoelectronics. We demonstrate that, by controlling the evaporation rate during the spin-coating process, we can obtain either self-stratification or lateral phase separation in the same system, and we relate this to a previously hypothesised mechanism for phase separation during spin-coating in thin films, according to which a transient wetting layer breaks up due to a Marangoni-type instability driven by a concentration gradient of solvent within the drying film. Our results show that rapid evaporation leads to a laterally phase-separated structure, while reducing the evaporation rate suppresses the interfacial instability and leads to a self-stratified final film. PMID:21086015

Mokarian-Tabari, P; Geoghegan, M; Howse, J R; Heriot, S Y; Thompson, R L; Jones, R A L

2010-11-18

204

Thick film CO 2 sensors based on Nasicon solid electrolyte  

Microsoft Academic Search

A planar miniaturised CO2 sensor based on thick films of Nasicon (Na+ conductor, Na3Zr2Si2PO12) electrolyte has been developed. The thick film was fabricated by screen printing Nasicon paste on an alumina substrate and then firing at 1543 K. scanning electron microscopy (SEM) analysis shows that the films achieved good densification, although reactions occur between Nasicon and alumina substrate, so conductivity

Ling Wang; R. V. Kumar

2003-01-01

205

Preparation of Se-doped polyaniline emeraldine base films  

Microsoft Academic Search

Our letter focuses on the preparation of polyaniline emeraldine base films doped with selenium. PANI EB and Se were dissolved in dimethylsulfoxide. Thin films of selenium-doped PANI EB were obtained by spin-coating of Si and ZnSe substrates with a PANI EB+Se solution in DMSO. We studied the distribution of the selenium in the PANI EB films using time-of-flight secondary ion

Edward Bormashenko; Roman Pogreb; Semion Sutovski; Alexander Shulzinger; Avigdor Sheshnev; Alexander Gladkikh

2003-01-01

206

Switchable mirrors based on nickel–magnesium films  

Microsoft Academic Search

An electrochromic mirror electrode based on reversible uptake of hydrogen in nickel magnesium alloy films is reported. Thin, magnesium-rich Ni–Mg films prepared on glass substrates by co-sputtering from Ni and Mg targets are mirror-like in appearance and have low visible transmittance. Upon exposure to hydrogen gas or on cathodic polarization in alkaline electrolyte, the films take up hydrogen and become

T. J. Richardson; J. L. Slack; R. D. Armitage; R. Kostecki; B. Farangis; M. D. Rubin

2001-01-01

207

Switchable mirrors based on nickel-magnesium films  

Microsoft Academic Search

An electrochromic mirror electrode based on reversible uptake of hydrogen in nickel magnesium alloy films is reported. Thin, magnesium-rich Ni-Mg films prepared on glass substrates by co-sputtering from Ni and Mg targets are mirror-like in appearance and have low visible transmittance. Upon exposure to hydrogen gas or on cathodic polarization in alkaline electrolyte, the films take up hydrogen and become

Thomas J. Richardson; Jonathan L. Slack; Robert D. Armitage; Robert Kostecki; Baker Farangis; Michael D. Rubin

2001-01-01

208

New Switchable Mirror Based on Magnesium-Niobium Thin Film  

Microsoft Academic Search

We found that palladium-capped magnesium-niobium alloy thin films show a good optical switching property when they are exposed to a hydrogen-containing atmosphere. A switchable mirror based on a magnesium-niobium thin film was prepared on a glass substrate by cosputtering of Mg and Nb targets. Mg1-xNbx thin films with a 4 nm Pd overlayer can be switched reversibly between shiny mirror

Shanhu Bao; Yasusei Yamada; Kazuki Tajima; Masahisa Okada; Kazuki Yoshimura

2007-01-01

209

Sensitivity of linear CCD array based film scanners used for film dosimetry  

SciTech Connect

Film dosimetry is commonly performed by using linear CCD array transmission optical densitometers. However, these devices suffer from a variation in response along the detector array. If not properly corrected for, this nonuniformity may lead to significant overestimations of the measured dose as one approaches regions close to the edges of the scanning region. In this note, we present measurements of the spatial response of an AGFA Arcus II document scanner used for radiochromic film dosimetry. Results and methods presented in this work can be generalized to other CCD based transmission scanners used for film dosimetry employing either radiochromic or radiographic films.

Devic, Slobodan; Wang Yizhen; Tomic, Nada; Podgorsak, Ervin B. [Medical Physics Department, McGill University Health Centre, Montreal, Quebec (Canada)

2006-11-15

210

Cells studies on PEO\\/PEG\\/NaClO 3 thin-film electrolyte system based on composite V 2 O 5 electrode  

Microsoft Academic Search

The thin-film solid polymer electrolyte based on polyethylene oxide (PEO) with sodium chlorite (NaClO3) has been prepared by a solution-cast technique. The electrolyte was characterized by X-ray diffraction (XRD), infrared (IR),\\u000a cyclic voltammetry, alternating current conductivity, and Wagner’s polarization studies. The complexation of NaClO3 with PEO was confirmed through the XRD and IR studies. The transference number measurement has shown

R. Chandrasekaran; R. Sathiyamoorthi; S. Selladurai

2008-01-01

211

Bioelectronic Imaging Array Based on Bacteriorhodopsin Film  

Microsoft Academic Search

A photoreceptor array that exploits the light sensitive bacteriorhodopsin (bR) films has been manufactured on a flexible indium-tin-oxide (ITO) coated plastic film using electrophoretic sedimentation technique (EPS). The effective sensing area of each photoreceptor is 2 ?? 2 mm2, separated by 1 mm and arranged in a 4 ?? 4 array. A switched integrator with gain on the order of

Wei Wei Wang; George K. Knopf; Amarjeet S. Bassi

2008-01-01

212

Film-based dual energy radiography  

SciTech Connect

Apparatus for reading out individual X-ray images recorded on a double-emulsion radiographic film or on separate films that were coincident when exposed simultaneously to a polyenergetic or broad X-ray photon energy spectrum beam emergent from a body and where an image corresponding to one obtained with a low energy part of the spectrum is formed on one film and an image corresponding to a higher energy part of the spectrum is formed on the other. One readout apparatus is for the case of two separate films which, after development, are illuminated from the back and optically scanned to derive analog signals representative of the intensities of spatially corresponding picture elements on each film. Another apparatus is for the case where the two images are on opposite sides of a film and are represented by alternate fine image information lines obtained by interposing a grid during the X-ray exposure. Another is for the case where a reflective layer is disposed between the film images during readout. In all cases the films are optically scanned and the resulting analog signals are digitized and variously processed to yield an image representative of that which is different between the two original different energy images.

Lambert, T. W.; Andrews, E. W.

1985-12-24

213

Electrocaloric devices based on thin-film heat switches  

NASA Astrophysics Data System (ADS)

We describe a new approach to refrigeration, heat pumping, and electrical generation that allows one to exploit the attractive properties of thin films of electrocaloric materials. Layers of electrocaloric material coupled with thin-film heat switches can work as either refrigerators and heat pumps or electrical generators, depending on the phasing of the applied voltages and heat switching. With heat switches based on thin layers of liquid crystals, the efficiency of electrocaloric thin-film devices can be at least as high as that of current thermoelectric devices. Advanced heat switches that may use carbon nanotubes would enable thin-film refrigerators and generators to outperform conventional vapor-compression devices.

Epstein, Richard I.; Malloy, Kevin J.

2009-09-01

214

Microelectromechanical switches based on amorphous diamondlike carbon films  

NASA Astrophysics Data System (ADS)

We report on the development and investigation of radio frequency (RF) switches (including complete relay pairs) that employ single-crystal microelectromechanical systems (MEMSs) with mobile elements based on high-ohmic amorphous diamondlike carbon films. The use of these films in RF-MEMS switches eliminates problems related to electrode sticking, significantly decreases signal losses (to 100 dB), and ensures short switching times (˜10 ns) for commutated signals at ultrahigh frequencies (up to 2 GHz for films on silicon substrates and above 10 GHz for films on gallium arsenide substrates).

Vlasenko, V. A.; Belyaev, S. N.; Efimov, A. G.; Il'Ichev, É. A.; Malenkovich, M. D.; Nemirovski?, V. É.; Poltoratski?, É. A.; Goryachev, A. V.; Popkov, A. F.; Frolova, G. V.; Shupegin, M. L.

2009-08-01

215

High-temperature fuel cell membranes based on mechanically stable para-ordered polybenzimidazole prepared by direct casting  

Microsoft Academic Search

Poly[2,2?-(p-phenylene)-5,5?-bibenzimidazole] (pPBI) is synthesized by mixing 3,3?-diaminobenzidine tetrahydrochloride and terephthalic acid in polyphosphoric acid (PPA) at 240°C for 12h. pPBI can be cast in membrane form directly from a polymerization solution (direct casting) or from a methanesulfonic acid solution (MSA casting). Membranes obtained by direct casting are almost amorphous and have much higher acid doping levels and larger water uptake

Tae-Ho Kim; Tae-Wook Lim; Jong-Chan Lee

2007-01-01

216

AC conductivity and electrochemical studies of PVA/PEG based polymer blend electrolyte films  

NASA Astrophysics Data System (ADS)

Polymer blend electrolyte films based on Polyvinyl alcohol(PVA)/Poly(ethylene glycol)(PEG) and magnesium nitrate (Mg(NO3)2) were prepared by solution casting technique. Conductivity in the temperature range 303-373 K and transference number measurements have been employed to investigate the charge transport in this polymer blend electrolyte system. The highest conductivity is found to be 9.63 × 10-5 S/cm at 30°C for sample with 30 weight percent of Mg(NO3)2 in PVA/PEG blend matrix. Transport number data shows that the charge transport in this polymer electrolyte system is predominantly due to ions. Using this electrolyte, an electrochemical cell with configuration Mg/(PVA+PEG+Mg(NO3)2)/(I2+C+electrolyte) was fabricated and its discharge characteristics profile has been studied.

Polu, Anji Reddy; Kumar, Ranveer; Dehariya, Harsha

2012-06-01

217

Bacteriorhodopsin-based biochromic films for chemical sensors  

Microsoft Academic Search

Biochromic films based on bacteriorhodopsin (BR) have been investigated, with especial regard to the creation of long-lived miniature optical vapour sensors working in real time, and exploiting the good reversibility of BR. Films were fabricated by dispersing nanosize fragments of BR in a hydrophilic matrix (gelatin) and their distribution was investigated using electron microscopy. It was shown that the composite

J. P. Sharkany; S. O. Korposh; Z. I. Batori-Tarci; I. I. Trikur; J. J. Ramsden

2005-01-01

218

Neighborhood Coherence and Edge Based Approaches to Film Scene Extraction  

Microsoft Academic Search

In order to enable high-level semantics-based video an- notation and interpretation, we tackle the problem of au- tomatic decomposition of motion pictures into meaningful story units, namely scenes. Since a scene is a complicated and subjective concept, we first propose guidelines from film production to determine when a scene change occurs in film. We examine different rules and conventions followed

Ba Tu Truongt; Svetha Venkatesht; Chitra Dorai

2002-01-01

219

Optical sensing of pH based on polypyrrole films  

Microsoft Academic Search

An optical sensor for pH is presented which is based on the use of a thin polypyrrole (PPy) film obtained by chemical oxidation of pyrrole and deposited as a < 1 ?m film on the walls of a polystyrene cuvette. The spectrum of PPy displays strong absorption in the near infrared at around 900 nm, and a characteristic minimum at

Susana de Marcos; Otto S. Wolfbeis

1996-01-01

220

Mechanical properties and biodegradation characteristics of PHB-based films  

Microsoft Academic Search

An effect of plasticizers on physical properties and biodegradation characteristics of polyhydroxybutyrate (PHB) based films have been investigated. Laprol was a good plasticizer for PHB and for PHB containing biomass (BM) of Azotobacter chroococcum23. A maximum plasticizing effect was attained with a LAP concentration up to 30% w\\/w. The biodegradation rate of PHB and BM films significantly decreased with an

L Savenkova; Z Gercberga; V Nikolaeva; A Dzene; I Bibers; M Kalnin

2000-01-01

221

Film based scatter measurement in mammography.  

PubMed

Film based measurements of scatter to primary ratio (s/p) have been made using the "beam stop" technique. Phantom material, radiographically equivalent to 100% glandular tissue, 100% adipose tissue and 50% glandular: 50% adipose tissue was used. These measurements have been made at 25 and 28 kVp for non grid and 28 and 30 kVp with grid for phantom thicknesses varying from 3 cm to 7 cm and 'D shaped' field sizes varying from 80 to 290 cm2. Results indicate that s/p is predominantly uniform across a mammographic image with a reduction towards the edge of the phantom. The values for s/p agree with previously published values determined from Monte Carlo calculation. Scatter primary ratio was found to be directly proportional to phantom thickness with little effect from field size. The effect of beam energy was significant in the non-grid case but reduced in significance with the use of a grid. The average measurement error was estimated at 4.5%. No variation in scatter primary ratio was detected between glandular and adipose phantom materials in this study. PMID:10921199

McLean, D; Ainley, L; Blackett, K

2000-03-01

222

Combination of bortezomib-based chemotherapy and extracorporeal free light chain removal for treating cast nephropathy in multiple myeloma  

Microsoft Academic Search

Besides amyloidosis and light chain deposition disease, the most common histological type of renal lesion is cast nephropathy in 30% of patients with multiple myeloma (2). In contrast to amyloidosis, cast nephropathy is believed to be potentially reversible when circulating light chains are rapidly reduced. We report on three patients with multiple myeloma and cast nephropathy treated with a bortezomib-

Ulrike Bachmann; Ralf Schindler; Markus Storr; Andreas Kahl; Achim Joerres; Isrid Sturm

2008-01-01

223

A novel method for vacuum casting titanium.  

PubMed

A new method for vacuum casting titanium is described. The device allows decontamination of the mold before placing it into the casting machine. After wax elimination, the mold is placed into the device and sealed with a thin film of titanium. The air is evacuated from the mold, and it is flushed with helium. The process is repeated, and the casting is made when convenient. PMID:2133381

Hruska, A R

224

Ion beam-based characterization of multicomponent oxide thin films and thin film layered structures  

SciTech Connect

Fabrication of thin film layered structures of multi-component materials such as high temperature superconductors, ferroelectric and electro-optic materials, and alloy semiconductors, and the development of hybrid materials requires understanding of film growth and interface properties. For High Temperature Superconductors, the superconducting coherence length is extremely short (5--15 [Angstrom]), and fabrication of reliable devices will require control of film properties at extremely sharp interfaces; it will be necessary to verify the integrity of thin layers and layered structure devices over thicknesses comparable to the atomic layer spacing. Analytical techniques which probe the first 1--2 atomic layers are therefore necessary for in-situ characterization of relevant thin film growth processes. However, most surface-analytical techniques are sensitive to a region within 10--40 [Angstrom] of the surface and are physically incompatible with thin film deposition and are typically restricted to ultra high vacuum conditions. A review of ion beam-based analytical methods for the characterization of thin film and multi-layered thin film structures incorporating layers of multicomponent oxides is presented. Particular attention will be paid to the use of time-of-flight techniques based on the use of 1- 15 key ion beams which show potential for use as nondestructive, real-time, in-situ surface diagnostics for the growth of multicomponent metal and metal oxide thin films.

Krauss, A.R.; Rangaswamy, M.; Lin, Yuping; Gruen, D.M. (Argonne National Lab., IL (United States)); Schultz, J.A. (Ionwerks, Inc., Houston, TX (United States)); Schmidt, H.K. (Schmidt Instruments, Inc., Houston, TX (United States)); Chang, R.P.H. (Northwestern Univ., Evanston, IL (United States). Dept. of Materials Science)

1992-01-01

225

Ion beam-based characterization of multicomponent oxide thin films and thin film layered structures  

SciTech Connect

Fabrication of thin film layered structures of multi-component materials such as high temperature superconductors, ferroelectric and electro-optic materials, and alloy semiconductors, and the development of hybrid materials requires understanding of film growth and interface properties. For High Temperature Superconductors, the superconducting coherence length is extremely short (5--15 {Angstrom}), and fabrication of reliable devices will require control of film properties at extremely sharp interfaces; it will be necessary to verify the integrity of thin layers and layered structure devices over thicknesses comparable to the atomic layer spacing. Analytical techniques which probe the first 1--2 atomic layers are therefore necessary for in-situ characterization of relevant thin film growth processes. However, most surface-analytical techniques are sensitive to a region within 10--40 {Angstrom} of the surface and are physically incompatible with thin film deposition and are typically restricted to ultra high vacuum conditions. A review of ion beam-based analytical methods for the characterization of thin film and multi-layered thin film structures incorporating layers of multicomponent oxides is presented. Particular attention will be paid to the use of time-of-flight techniques based on the use of 1- 15 key ion beams which show potential for use as nondestructive, real-time, in-situ surface diagnostics for the growth of multicomponent metal and metal oxide thin films.

Krauss, A.R.; Rangaswamy, M.; Lin, Yuping; Gruen, D.M. [Argonne National Lab., IL (United States); Schultz, J.A. [Ionwerks, Inc., Houston, TX (United States); Schmidt, H.K. [Schmidt Instruments, Inc., Houston, TX (United States); Chang, R.P.H. [Northwestern Univ., Evanston, IL (United States). Dept. of Materials Science

1992-11-01

226

Precipitation of ?-Al5FeSi Phase Platelets in Al-Si Based Casting Alloys  

NASA Astrophysics Data System (ADS)

The aim of the present work has been to investigate the factors affecting the precipitation of the ?-Al5FeSi iron intermetallic phase of directionally solidified A356- and 319-type alloys as a function of the iron content, a Sr addition of ~250 ppm, and superheating or cooling rates. The iron levels selected varied from 0.12 to 0.8 wt pct and cover the range of Fe levels in commercial casting alloys. The use of an end-chill mold provided different cooling rates along the height of the same casting, with dendritic arm spacing values that varied from ~15 to 85 ?m, corresponding to levels of 5, 10, 30, 50, and 100 mm above the chill end. The microstructure and phase identification were monitored using optical microscopy, scanning electron microscopy (SEM), thermal analysis, and electron probe microanalysis (EPMA) techniques. An image analyzer was used in conjunction with the optical microscope for quantification purposes. The results showed that, for the range of cooling rates covered in the present study, the highest cooling rate (at a 5-mm distance from the chill) is the more significant parameter in controlling the size and distribution of the ?-Al2FeSi intermetallic phase in the nonmodified 319 and 356 alloys. The addition of strontium leads to fragmentation of coeutectic or posteutectic ? platelets. This effect diminishes with an increase in the iron concentration, and further strontium addition leads to the precipitation of Al2Si2Sr phase particles, instead.

Liu, L.; Mohamed, A. M. A.; Samuel, A. M.; Samuel, F. H.; Doty, H. W.; Valtierra, S.

2009-10-01

227

Special Casting Techniques (Chapter 9).  

National Technical Information Service (NTIS)

Special casting techniques are progressive production methods. These casting techniques include the following: metal mold casting (chill mold casting), shell-mold casting, investment casting, centrifugal casting, and others. Each of these methods of casti...

N. P. Dubinin

1965-01-01

228

Morphology-dependent exciton emission and energy transfer in fluorene-polymer-related fluorescent and phosphorescent composite films spin cast from a mixture of two dissimilar organic solvents  

SciTech Connect

We report morphology-dependent exciton emission and energy transfer in fluorene-conjugated polymer poly(9,9-dioctylfluorenyl-2,7-diyl)-related fluorescent and phosphorescent materials by using a mixture of two dissimilar organic solvents for spin-cast film formation. The electron microscopic characterizations revealed that the mixture of a high-boiling-point orthodichlorobenzene and a low-boiling-point chloroform results in a formation of both crystalline and amorphous morphological structures in fluorene-conjugated polymers. The UV-visible absorption and photoluminescence studies indicated that the low-energy crystalline phase domains, randomly distributed in the continuous high-energy amorphous phase, function as potential quantum wells. As a consequence, the mixture of two dissimilar organic solvents significantly affects the exciton emission from fluorescent fluorene-conjugated polymer and the energy transfer in phosphorescent composite of fluorene polymer and iridium complex molecules, presenting a pathway to control fluorescent and phosphorescent processes in polymer light-emitting materials.

Wu, Yue [University of Tennessee, Knoxville (UTK); Hu, Bin [University of Tennessee, Knoxville (UTK); Howe, Jane Y [ORNL

2005-01-01

229

Instant Casting Movie Theater: The Future Cast System  

NASA Astrophysics Data System (ADS)

We have developed a visual entertainment system called “Future Cast” which enables anyone to easily participate in a pre-recorded or pre-created film as an instant CG movie star. This system provides audiences with the amazing opportunity to join the cast of a movie in real-time. The Future Cast System can automatically perform all the processes required to make this possible, from capturing participants' facial characteristics to rendering them into the movie. Our system can also be applied to any movie created using the same production process. We conducted our first experimental trial demonstration of the Future Cast System at the Mitsui-Toshiba pavilion at the 2005 World Exposition in Aichi Japan.

Maejima, Akinobu; Wemler, Shuhei; Machida, Tamotsu; Takebayashi, Masao; Morishima, Shigeo

230

Dimensional variability of production steel castings.  

National Technical Information Service (NTIS)

Work is ongoing to characterize the dimensional variability of steel casting features. Data are being collected from castings produced at representative Steel Founders' Society of America foundries. Initial results based on more than 12,500 production cas...

F. E. Peters J. W. Risteu W. G. Vaupel E. C. DeMeter R. C. Voigt

1994-01-01

231

Chitosan and gelatin based edible films: state diagrams, mechanical and permeation properties  

Microsoft Academic Search

Films of chitosan and gelatin were prepared by casting their aqueous solutions (pH?4.0) at 60°C and evaporating at 22 or 60°C (low- and high-temperature methods, respectively). The physical (thermal, mechanical and gas\\/water permeation) properties of these composite films, plasticized with water or polyols, were studied. An increase in the total plasticizer content resulted in a considerable decrease of elasticity modulus

Ioannis S. Arvanitoyannis; Atsuyoshi Nakayama; Sei-ichi Aiba

1998-01-01

232

Effect of surfactants on the functional properties of gelatin–polysaccharide-based films  

Microsoft Academic Search

The aim of this study was to evaluate the effects of the addition of surfactants sodium stearoyl lactate (SSL) and sucrose\\u000a ester (SE) on the functional properties of films produced with polysaccharides mixtures (methylcellulose\\/glucomannan\\/pectin\\u000a in 1\\/4\\/1 ratio, respectively) and gelatin. The films were produced by the casting method and characterized for their water\\u000a vapor permeability (WVP), mechanical (tensile strength and

Hulda Chambi; Carlos Grosso

2011-01-01

233

Cooling Process and Cast Structure of Zr-Al-Ni-Cu-Based Bulk Metallic Glasses Produced in Various Atmospheres  

NASA Astrophysics Data System (ADS)

Cooling process in the production of Zr65Al7.5Ni10Cu17.5-based bulk metallic glasses (BMGs) was investigated in various chamber atmospheres in Cu mold casting. Two different cooling modes, consisting of the direct heat transfer between the melt and Cu mold in the high temperature and indirect transfer via cavity in the low-temperature regions, are suggested. In the later case, the cooling effect should depend on the chamber atmosphere, which results in the formation of glassy structure with large relaxation enthalpy casting under the ambient Ar and He atmospheres due to a good thermal conductivity. The less relaxed BMGs produced by an improved cooling effect are also expected to contain a large amount of free volume for significant deformability. Actually, it is clarified that the compressive plastic deformation is improved with an increase of the relaxation enthalpy. The present study indicates a necessity of development of the glassy structure, i.e., relaxation state, and provides a new technique of the formation of less relaxed glassy structure for the improvement of plasticity in BMGs.

Saida, J.; Setyawan, A. D.; Kato, H.; Inoue, A.

2011-06-01

234

Gelatin-based films containing hydrophobic plasticizers and saponin from Yucca schidigera as the surfactant  

Microsoft Academic Search

The aim of this study was to evaluate the incorporation of hydrophobic plasticizers (acetyltributyl citrate – ATB, tributyl citrate – TB and acetyltriethyl citrate – ATC) in a matrix of gelatin, using the saponin extracted from Yucca schidigera (yucca) as emulsifier, in the production of biodegradable emulsified films using the casting technique. High levels of hydrophobic plasticizers were incorporated, reaching

Caroline Andreuccetti; Rosemary A. Carvalho; Carlos R. F. Grosso

2010-01-01

235

Preparation of refractive index matching polymer film alternative to oil for use in a portable surface-plasmon resonance phenomenon-based chemical sensor method.  

PubMed

In order to simplify the procedure for assembling a surface-plasmon resonance (SPR) sensor, a refractive index matching polymer film was prepared as an alternative to the conventionally used matching oil. The refractive index matching polymer film, the refractive index of which was nearly equal to the prism and sensor chip material (a cover glass) of the SPR sensor, was prepared by casting a tetrahydrofuran solution of poly (vinyl chloride) (PVC) containing equal weights of dioctyl phthalate and tricresyl phosphate. The refractive index matching polymer film was found to have a refractive index of 1.516, which is identical to that of the prism and the cover glass used for the present SPR sensor. The utility of the matching polymer film for the SPR sensor was confirmed by the detection of anti-human albumin, based on an antigen-antibody reaction. PMID:12110971

Masadome, Takashi; Asano, Yasukazu; Imato, Toshihiko; Ohkubo, Satoshi; Tobita, Tatsuya; Tabei, Hisao; Iwasaki, Yuzuru; Niwa, Osamu; Fushinuki, Yoshito

2002-05-24

236

MoSi{sub 2}-based sandwich composite made by tape casting  

SciTech Connect

The mechanical properties of a novel laminar composite made by tape casting have been studied. The composite consists of three layers in which an inner core of pure molybdenum disilicide (MoSi{sub 2}) is sandwiched between two layers of MoSi{sub 2} reinforced with alumina platelets. Monolithic MoSi{sub 2} exhibits poor room-temperature strength and a brittle indentation strength response, indicative of the absence of R-curve behavior. A 25 vol% Al{sub 2}O{sub 3} platelet reinforced MoSi{sub 2}, however, shows increased strength and strong R-curve behavior. The flexural behavior of the sandwich composite (both strength and toughness) is dominated by the properties of the outer layer, so long as the thickness of this layer exceeds a critical value. A model has been developed which successfully predicts the critical thickness required.

Tuffe, S.; Wilkinson, D.S. [McMaster Univ., Hamilton, Ontario (Canada). Dept. of Materials Science and Engineering

1995-11-01

237

Education and Caste in India  

ERIC Educational Resources Information Center

This paper analyses the policy of reservation for lower castes in India. This policy is similar to that of affirmative action in the United States. The paper provides a brief overview of the caste system and discusses the types of groups that are eligible for reservation, based on data from government reports. The stance of this paper is that…

Chauhan, Chandra Pal Singh

2008-01-01

238

Education and caste in India  

Microsoft Academic Search

This paper analyses the policy of reservation for lower castes in India. This policy is similar to that of affirmative action in the United States. The paper provides a brief overview of the caste system and discusses the types of groups that are eligible for reservation, based on data from government reports. The stance of this paper is that affirmative

Chandra Pal Singh Chauhan

2008-01-01

239

Surface carburization of steel castings  

Microsoft Academic Search

Shaping methods based on sand-resin mixtures have undoubted benefits and accordingly are increas? ingly used in the manufacture of highperformance iron, steel, and nonferrousalloy castings. However, they cannot be unconditionally recommended for lowcarbon steel castings. This is because heat from the molten metal destroys the organic components present in such molds. At low temperatures (150 °C), these mixtures mainly emit

E. B. Ten; O. A. Kol’; I. B. Badmazhapova; M. P. Klyuev

2011-01-01

240

Electroslag component casting. [Nickel aluminide  

Microsoft Academic Search

This project is directed toward the development of electroslag-casting (ESC) technology for use in coal conversion components such as valve bodies, pump housings, and pipe fittings. The aim is also to develop a sufficient data base to permit electroslag casting to become an ASME Code-accepted process. It is also intended to transfer the ESC process technology to private industry. A

Sikka

1986-01-01

241

Magnetism of Cobalt Base Artificial Lattice Films.  

National Technical Information Service (NTIS)

The Co/Pd and Co/Pd artificial lattice films have attracted much interest by their special magnetization properties. We discussed the effect of the Pt, Pd layer thickness on the magnetic anisotropy, and we showed the effect of the hydrogen ion implantatio...

K. Taka M. Masuda N. Yoshitake S. Matsumoto Y. Hayashi

2001-01-01

242

Effect of gamma radiation on the mechanical and barrier properties of HEMA grafted chitosan-based films  

NASA Astrophysics Data System (ADS)

Chitosan films were prepared by dissolving 1% (w/v) chitosan powder in 2% (w/v) aqueous acetic acid solution. Chitosan films were prepared by solution casting. The values of puncture strength (PS), viscoelasticity coefficient and water vapor permeability (WVP) of the films were found to be 565 N/mm, 35%, and 3.30 g mm/m2 day kPa, respectively. Chitosan solution was exposed to gamma irradiation (0.1-5 kGy) and it was revealed that PS values were reduced significantly (p?0.05) after 1 kGy dose and it was not possible to form films after 5 kGy. Monomer, 2-hydroxyethyl methacrylate (HEMA) solution (0.1-1%, w/v) was incorporated into the chitosan solution and the formulation was exposed to gamma irradiation (0.3 kGy). A 0.1% (w/v) HEMA concentration at 0.3 kGy dose was found optimal-based on PS values for chitosan grafting. Then radiation dose (0.1-5 kGy) was optimized for HEMA grafting. The highest PS values (672 N/mm) were found at 0.7 kGy. The WVP of the grafted films improved significantly (p?0.05) with the rise of radiation dose.

Khan, Avik; Huq, Tanzina; Khan, Ruhul A.; Dussault, Dominic; Salmieri, Stephane; Lacroix, Monique

2012-08-01

243

Development of Stronger and More Reliable Cast Austenitic Stainless Steels (H-Series) Based on Scientific Design Methodology  

SciTech Connect

The goal of this program was to increase the high-temperature strength of the H-Series of cast austenitic stainless steels by 50% and upper use temperature by 86 to 140 F (30 to 60 C). Meeting this goal is expected to result in energy savings of 38 trillion Btu/year by 2020 and energy cost savings of $185 million/year. The higher strength H-Series of cast stainless steels (HK and HP type) have applications for the production of ethylene in the chemical industry, for radiant burner tubes and transfer rolls for secondary processing of steel in the steel industry, and for many applications in the heat-treating industry. The project was led by Duraloy Technologies, Inc. with research participation by the Oak Ridge National Laboratory (ORNL) and industrial participation by a diverse group of companies. Energy Industries of Ohio (EIO) was also a partner in this project. Each team partner had well-defined roles. Duraloy Technologies led the team by identifying the base alloys that were to be improved from this research. Duraloy Technologies also provided an extensive creep data base on current alloys, provided creep-tested specimens of certain commercial alloys, and carried out centrifugal casting and component fabrication of newly designed alloys. Nucor Steel was the first partner company that installed the radiant burner tube assembly in their heat-treating furnace. Other steel companies participated in project review meetings and are currently working with Duraloy Technologies to obtain components of the new alloys. EIO is promoting the enhanced performance of the newly designed alloys to Ohio-based companies. The Timken Company is one of the Ohio companies being promoted by EIO. The project management and coordination plan is shown in Fig. 1.1. A related project at University of Texas-Arlington (UT-A) is described in Development of Semi-Stochastic Algorithm for Optimizing Alloy Composition of High-Temperature Austenitic Stainless Steels (H-Series) for Desired Mechanical and Corrosion Properties (ORNL/TM-2005/81/R1). The final report on another related project at the University of Tennessee by George Pharr, Easo George, and Michael Santella has been published as Development of Combinatorial Methods for Alloy Design and Optimization (ORNL/TM-2005-133). The goal of the project was to increase the high-temperature strength by 50% and upper use temperature by 86 to 140 F (30 to 60 C) of H-Series of cast austenitic stainless steels. Meeting such a goal is expected to result in energy savings of 38 trillion Btu/year by 2020 and energy cost savings of $185 million/year. The goal of the project was achieved by using the alloy design methods developed at ORNL, based on precise microcharacterization and identification of critical microstructure/properties relationships and combining them with the modern computational science-based tools that calculate phases, phase fractions, and phase compositions based on alloy compositions. The combined approach of microcharacterization of phases and computational phase prediction would permit rapid improvement of the current alloy composition of an alloy and provide the long-term benefit of customizing alloys within grades for specific applications. The project was appropriate for the domestic industry because the current H-Series alloys have reached their limits both in high-temperature-strength properties and in upper use temperature. The desire of Duraloy's industrial customers to improve process efficiency, while reducing cost, requires that the current alloys be taken to the next level of strength and that the upper use temperature limit be increased. This project addressed a specific topic from the subject call: to develop materials for manufacturing processes that will increase high-temperature strength, fatigue resistance, corrosion, and wear resistance. The outcome of the project would benefit manufacturing processes in the chemical, steel, and heat-treating industries.

Muralidharan, G.; Sikka, V.K.; Pankiw, R.I.

2006-04-15

244

CASTING FURNACES  

DOEpatents

A device is described for casting uranium which comprises a crucible, a rotatable table holding a plurality of molds, and a shell around both the crucible and the table. The bottom of the crucible has an eccentrically arranged pouring hole aligned with one of the molds at a time. The shell can be connected with a vacuum.

Ruppel, R.H.; Winters, C.E.

1961-01-01

245

High-temperature superconducting thin-film-based electronic devices  

SciTech Connect

This the final report of a one-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The project involved optimization of processing of Y123 and Tl-2212 thin films deposited on novel substrates for advanced electronic devices. The Y123 films are the basis for development of Josephson Junctions to be utilized in magnetic sensors. Microwave cavities based on the Tl-2212 films are the basis for subsequent applications as communication antennas and transmitters in satellites.

Wu, X.D; Finokoglu, A.; Hawley, M.; Jia, Q.; Mitchell, T.; Mueller, F.; Reagor, D.; Tesmer, J.

1996-09-01

246

New Switchable Mirror Based on Magnesium-Niobium Thin Film  

NASA Astrophysics Data System (ADS)

We found that palladium-capped magnesium-niobium alloy thin films show a good optical switching property when they are exposed to a hydrogen-containing atmosphere. A switchable mirror based on a magnesium-niobium thin film was prepared on a glass substrate by cosputtering of Mg and Nb targets. Mg1-xNbx thin films with a 4 nm Pd overlayer can be switched reversibly between shiny mirror and transparent states with the reversible uptake of 4% hydrogen gas at room temperature. In the hydride (transparent) state, they are almost color neutral.

Bao, Shanhu; Yamada, Yasusei; Tajima, Kazuki; Okada, Masahisa; Yoshimura, Kazuki

2007-01-01

247

Active microcantilevers based on piezoresistive ferromagnetic thin films  

NASA Astrophysics Data System (ADS)

We report the piezoresistivity in magnetic thin films of Fe0.7Ga0.3 and their use for fabricating self-transducing microcantilevers. The actuation occurs as a consequence of both the ferromagnetic and magnetostrictive properties of Fe0.7Ga0.3 thin films, while the deflection readout is achieved by exploiting the piezoresistivity of these films. This self-sensing self-actuating micromechanical system involves a very simple bilayer structure, which eliminates the need for the more complex piezoelectric stack that is commonly used in active cantilevers. Thus, it potentially opens opportunities for remotely actuated cantilever-based sensors.

Bhaskaran, Harish; Li, Mo; Garcia-Sanchez, Daniel; Zhao, Peng; Takeuchi, Ichiro; Tang, Hong X.

2011-01-01

248

Ultra-sensitive strain sensors based on piezoresistive nanographene films  

NASA Astrophysics Data System (ADS)

Graphene shows promise on strain sensor applications, but the piezoresistive sensitivity of perfect graphene is low due to its weak electrical conductivity response upon structural deformation. In this paper, we used nanographene films for ultra-sensitive strain sensors. The piezoresistive sensitivity of nanographene films with different thicknesses and conductivities was systematically investigated and a nearly inverse proportional correlation was found. A gauge factor over 300, the highest so far for graphene-based strain sensors, was achieved. A charge tunneling model was used to explain the piezoresistive characteristics of nanographene films, which indicates our results provide a different rout toward ultra-sensitive strain sensors.

Zhao, Jing; He, Congli; Yang, Rong; Shi, Zhiwen; Cheng, Meng; Yang, Wei; Xie, Guibai; Wang, Duoming; Shi, Dongxia; Zhang, Guangyu

2012-08-01

249

Visual information processing using bacteriorhodopsin-based complex LB films.  

PubMed

Image extraction and visual information processing using bacteriorhodopsin (bR)-based bioelectronic devices is presented. Image extraction was achieved using a photoreceptor consisting of bR and spiropyran films. The undesired signals from the photoreceptor were automatically eliminated from the whole signal by spiropyran films acting as an optical noise filter that increases the target signal to an undesired signal ratio. For the information processing, the photoreceptor consisting of bR and lipid films deposited with different configurations was used and the target signals were processed to achieve the pattern recognition. The pattern recognition was based on not only the response variability of bacteriorhodopsin, induced by different film configurations, but also on the initial learning process. The input patterns were predicted by simple calculation with the known signals through the initial learning process. PMID:11679271

Min, J; Choi, H G; Oh, B K; Lee, W H; Paek, S H; Choi, J W

2001-12-01

250

Development of an autocorrelator based on the organic polymer thin film  

NASA Astrophysics Data System (ADS)

Ultrafast lasers have many applications mainly due to its two properties, the ultrashort pulse width and the ultrahigh intensity. Because the former is the main cause of the latter, it is very important to exactly measure the pulse width of the ultrafast laser. Currently, there are several different kinds of experimental methods to measure the ultrashort pulse width. Among those systems for this measurement, the autocorrelator using the second harmonic generation (SHG) is by far the most simple and basic method. This type of autocorrelators usually uses inorganic crystals, such as BBO, as the SHG medium. The thinner medium is necessary for analyzing the shorter laser pulses. However, the polishing process which is necessary for obtaining the optically good surfaces makes it difficult to reduce the thickness of medium as desired. We present an autocorrelator system which overcomes these shortcomings. Our system is based on the SHG using organic polymer. Polymers can be easily prepared in the form of thin film on the strong substrate through the process of spin casting. Thickness less than 1 m can be obtained without difficulties. Furthermore, due to its high nonlinearity, thin film of polymer can produce the bright second harmonic light. Polyurea was used as the second harmonic generation material of the autocorrelator because it has the pretty good transparency. An autocorrelator system based on the 397nm-thick poled polyurea thin film has been developed and used to measure the pulse width of a home-made Ti:sapphire laser oscillator. Then, the system was compared with that based on a 100 ?m-thick BBO crystal, which is widely used. The pulse width of laser beam was measured to be 9.8 fs with the former. The value is believed to be more accurate than that of 7.2 fs measured with the latter.

Jung, Changsoo; Yu, Tae Jun; Bang, Han-Bae; Lee, Ju-Yeon; Lee, Yeung Lak; Byeon, Clare C.; Noh, Young-Chul; Choi, Il Woo; Ko, Do-Kyeong; Lee, Jongmin

2005-01-01

251

36 CFR 1237.30 - How do agencies manage records on nitrocellulose-base and cellulose-acetate base film?  

Code of Federal Regulations, 2011 CFR

...records on nitrocellulose-base and cellulose-acetate base film? (a) The nitrocellulose base, a substance akin to gun cotton, is chemically unstable and highly flammable. Agencies must handle nitrocellulose-base film (used in the...

2011-07-01

252

Slip casting under pressure  

NASA Astrophysics Data System (ADS)

The addition of a pressure during slip casting increases the rate of material deposition and enables larger pieces to be fabricated. In this study, this process has been further developed using monolithic Al2O3 and Al2O3-SiC composites. Slip casting formulations based on both dispersed and coagulated slurries have been analyzed. Excellent results are achieved using coagulated slurries, with no cracking present after drying. The effect of pressure is to increase the green density with a consequent increase in the fired density. In addition, homogeneous microstructures are achieved in the composite system, despite the large difference in particle size used.

Grazzini, H. H.; Wilkinson, D. S.

1992-08-01

253

Gas sensors based on nanoparticle WO3 thick films  

Microsoft Academic Search

The gas sensing properties of chemical sensors based on nanoparticle WO3 thick films, doped with indium and bismuth, are studied. Commercial WO3 nanopowder with spherical diameter up to 33.1 nm was mixed with either InCl3 or BiCl3. The sensing films of the sensors were prepared using three different concentrations of each doping metal (1.5 wt.%, 3.0 wt.% and 5.0 wt.%,

V. Khatko; R. Ionescu; E. Llobet; X. Vilanova; J. Brezmes; J. Hubalek; K. Malysz; X. Correig

2004-01-01

254

Optical information recording based on photochemical etching of aluminum films  

NASA Astrophysics Data System (ADS)

The publication describes optical information recording process based on the photochemical etching of the aluminum films using sandwich-type structures: substrate/aluminum film/polymer light-sensitive layer. The etchers are produced during the illumination of the light-sensitive polymer layers. Processes of the etching have a high light- sensitivity due to additional post-exposure autocatalytic accumulation of the etchers.

Grishina, Antonina D.; Tedoradze, Marine G.; Vannikov, Anatoly V.

1998-01-01

255

Raman measurements on Bi-based superconductor thin films  

Microsoft Academic Search

The copper-bismuth based superconductor has attracted much interest because of its high critical temperature, specially with the partial substitution of Pb in Bi sites, since it indicates stabilization in the 2223-phase. We present a Raman study in Bi-Pb-Sr-Ca-Cu-O thin films grown on MgO substrates by spray pyrolysis technique. The thin films were prepared by the two steps procedure: deposition of

Concepcion Mejia-Garcia; Elvia Diaz-Valdes; Gerardo Contreras-Puente; Milan Jergel

2000-01-01

256

Micro-structure evolution of wall based crystals after casting of model suspensions as obtained from Bragg microscopy  

NASA Astrophysics Data System (ADS)

Growth of heterogeneously nucleated, wall based crystals plays a major role in determining the micro-structure during melt casting. This issue is here addressed using a model system of charged colloidal spheres in deionized aqueous suspension observed by Bragg microscopy which is a combination of light scattering and microscopy. We examine the evolution of the three-dimensional size, shape, and orientation of twin domains in monolithic crystals growing from two opposing planar walls into a meta-stable (shear-) melt. At each wall crystal orientation and twinning emerges during nucleation with small domains. During growth these widen and merge. From image analysis we observe the lateral coarsening velocities to follow a power law behaviour LXY ~ t1/2 as long as the vertical growth continues at constant speed. Lateral coarsening terminates upon intersection of the two solids and hardly any further ripening is seen. Initial lateral coarsening velocities show a Wilson Frenkel type dependence on the melt meta-stability.

Palberg, Thomas; Maaroufi, Martin R.; Stipp, Andreas; Schöpe, Hans Joachim

2012-09-01

257

CONTROLLED DIFFUSION SOLIDIFICATION: APPLICATION TO METAL CASTING  

Microsoft Academic Search

Wrought aluminum-based alloys exhibit superior physical and mechanical properties compared to conventional cast alloys. However, wrought alloys cannot be cast because they develop hot tears and hot cracks during solidification. For this reason, these alloys are typically cast into ingots and are subsequently brought to final shape by mechanical processes such as rolling, extrusion, drawing and forging. Controlled Diffusion Solidification

K. Symeonidis; D. Apelian; M. M. Makhlouf

258

Multilayer metal-oxide composites based on cast plasticized films with powder fillers  

Microsoft Academic Search

This article reviews the production of a range of cermets consisting of the oxides of hafnium, magnesium, beryllium, aluminium, and zirconium and the metals molybdenum and tungsten and provides data on properties ranging from mechanical to thermal to structural to corrosional.

S. M. Kats; V. N. Bogin; S. S. Ordanyan; T. S. Basalaeva; N. G. Chubenko

1987-01-01

259

Development and Evaluation of Cefadroxil Drug Loaded Biopolymeric Films Based on Chitosan-Furfural Schiff Base  

PubMed Central

Cefadroxil drug loaded biopolymeric films of chitosan-furfural schiff base were prepared by reacting chitosan with furfural in presence of acetic acid and perchloric acid respectively for the external use. Prepared films were evaluated for their strength, swelling index, thickness, drug content, uniformity, tensile strength, percent elongation, FTIR spectral analysis and SEM. The results of in vitro diffusion studies revealed that the films exhibited enhanced drug diffusion as compared to the films prepared using untreated chitosan. The films also demonstrated good to moderate antibacterial activities against selective gram positive and gram negative bacteria.

Dixit, Ritu B.; Uplana, Rahul A.; Patel, Vishnu A.; Dixit, Bharat C.; Patel, Tarosh S.

2010-01-01

260

ShakeCast Manual  

USGS Publications Warehouse

ShakeCast is a freely available, post-earthquake situational awareness application that automatically retrieves earthquake shaking data from ShakeMap, compares intensity measures against users? facilities, and generates potential damage assessment notifications, facility damage maps, and other Web-based products for emergency managers and responders.

Lin, Kuo-Wan; Wald, David J.

2008-01-01

261

Superhydrophobic cellulose-based bionanocomposite films from Pickering emulsions  

NASA Astrophysics Data System (ADS)

Inherently superhydrophobic and flexible cellulose-based bionanocomposites were fabricated from solid stabilized (Pickering) emulsions. Emulsions were formed by dispersing cyclosiloxanes in water stabilized by layered silicate particles and were subsequently modified by blending into a zinc oxide nanofluid. The polymer matrix was a blend of cellulose nitrate and fluoroacrylic polymer (Zonyl 8740) precompatibilized in solution. Coatings were spray cast onto aluminum substrates from polymer blends dispersed in modified Pickering emulsions. No postsurface treatment was required to induce superhydrophobicity. Effect of antiseptic additives on bionanocomposite superhydrophobicity is also discussed. Replacing cellulose nitrate with commercial liquid bandage solutions produced identical superhydrophobic coatings.

Bayer, Ilker S.; Steele, Adam; Martorana, Philip J.; Loth, Eric; Miller, Lance

2009-04-01

262

Gating of Permanent Molds for ALuminum Casting  

SciTech Connect

This report summarizes a two-year project, DE-FC07-01ID13983 that concerns the gating of aluminum castings in permanent molds. The main goal of the project is to improve the quality of aluminum castings produced in permanent molds. The approach taken was determine how the vertical type gating systems used for permanent mold castings can be designed to fill the mold cavity with a minimum of damage to the quality of the resulting casting. It is evident that somewhat different systems are preferred for different shapes and sizes of aluminum castings. The main problems caused by improper gating are entrained aluminum oxide films and entrapped gas. The project highlights the characteristic features of gating systems used in permanent mold aluminum foundries and recommends gating procedures designed to avoid common defects. The study also provides direct evidence on the filling pattern and heat flow behavior in permanent mold castings.

David Schwam; John F. Wallace; Tom Engle; Qingming Chang

2004-03-30

263

Energy Consumption of Die Casting Operations  

SciTech Connect

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

Jerald Brevick; clark Mount-Campbell; Carroll Mobley

2004-03-15

264

Simulation-based prediction of microshrinkage porosity in aluminum casting: Fully-coupled numerical calculation vs. criteria functions  

Microsoft Academic Search

Micro-shrinkage porosity in aluminum casting is analysed by computer simulation using three criteria functions and a fully-coupled shrinkage porosity model. Three process simulations of different precision were executed as basis for the porosity prediction for investigation of the impact of simulation precision on porosity prediction. To validate the simulation predictions, three identical blocks were cast in a special experimental setup.

J Jakumeit; S Jana; B Böttger; R Laqua; M Y Jouani; A Bührig-Polaczek

2012-01-01

265

Identification of critical factors affecting shrinkage porosity in permanent mold casting using numerical simulations based on design of experiments  

Microsoft Academic Search

Vital process parameters affecting the size and location of a shrinkage pore defect in an aluminum alloy permanent mold casting of varying section thicknesses were sought. The aim was to either modify or eliminate the defect by manipulating those parameters so that the lower inlet manifold casting would pass a leak test. The study was carried out ‘off-line’ using numerical

D. R. Gunasegaram; D. J. Farnsworth; T. T. Nguyen

2009-01-01

266

Interaction of Interstitial Impurities with Iron Subgroup Metals in as-Cast Molybdenum-Based Dilute Solid Solutions.  

National Technical Information Service (NTIS)

The structure and properties of low-alloy Mo-Fe, Mo-Co, and Mo-Ni castings were examined in order to determine the nature of the positive influence exerted by small additions of iron-subgroup metals (Fe, Ni, Co) on the properties of cast molybdenum contai...

N. V. Ageyev N. N. Bokareva Z. A. Guts D. V. Ignatov M. M. Kantov

1974-01-01

267

ZnS-nanocrystals/polypyrrole nanocomposite film based immunosensor  

NASA Astrophysics Data System (ADS)

We report an electrochemically synthesized ZnS nanocrystals modified polypyrrole (PPy) nanocomposite film based immunosensor for the detection of C-reactive protein (?CRP). The ZnS-PPy composite film was characterized by transmission electron microscopy (TEM), atomic force microscopy (AFM) and electrochemical techniques. The modified film showed good biocompatibility with efficient binding to protein antibody (?CRP-Ab) molecules through ZnS nanocrystals, exhibited an attractive platform for immunosensor fabrication. The electrical and sensing properties of the polymer composite film of different thickness towards protein antigen (?CRP-Ag) were delineated. The immunosensor exhibited an impedance response to ?CRP-Ag concentration in a linear range from 10 ng to 10 ?g mL-1.

Mishra, Sujeet K.; Pasricha, Renu; Biradar, Ashok M.; Rajesh

2012-01-01

268

A kaolin based particle film to affect pepper yield  

Technology Transfer Automated Retrieval System (TEKTRAN)

Heat stress can limit yield in pepper (Capsicum spp.), generally through flower and fruit abortion. A kaolin based particle film, originally developed to protect fruit trees from insects, has been found to reduce temperatures in tissues of plants. The kaolin based material was tested to determine ...

269

Flexible and transparent electrothermal film heaters based on graphene materials.  

PubMed

High-performance and novel graphene-based electrothermal films are fabricated through a simple yet versatile solution process. Their electrothermal performances are studied in terms of applied voltage, heating rate, and input power density. The electrothermal films annealed at high temperature show high transmittance and display good heating performance. For example, the graphene-based film annealed at 800 °C, which shows transmittance of over 80% at 550 nm, can reach a saturated temperature of up to 42 °C when 60 V is applied for 2 min. Graphene-based films annealed at 900 and 1000 °C can exhibit high steady-state temperatures of 150 and 206 °C under an applied voltage of 60 V with a maximum heating rate of over 7 °C s(-1) . For flexible heating films patterned on polyimide, a steady-state temperature of 72 °C could be reached in less than 10 s with a maximum heating rate exceeding 16 °C s(-1) at 60 V. These excellent results, combined with the high chemical stability and mechanical flexibility of graphene, indicate that graphene-based electrothermal elements hold great promise for many practical applications, such as defrosting and antifogging devices. PMID:21990210

Sui, Dong; Huang, Yi; Huang, Lu; Liang, Jiajie; Ma, Yanfeng; Chen, Yongsheng

2011-10-11

270

Electroslag component casting. [Nickel aluminide  

SciTech Connect

This project is directed toward the development of electroslag-casting (ESC) technology for use in coal conversion components such as valve bodies, pump housings, and pipe fittings. The aim is also to develop a sufficient data base to permit electroslag casting to become an ASME Code-accepted process. It is also intended to transfer the ESC process technology to private industry. A total of 32 electroslag castings of 2.25Cr-1Mo, 9Cr-1Mo, type 316, and nickel aluminide were procured from four facilities for evaluation (Table 1). The most complex castings procured during this program were the valve bodies shown in Figure 2. The castings were subjected to various heat treatments (Table 2), checked for chemical composition uniformity from top to bottom, and subjected to macrostructural evaluation and mechanical properties testing. Results are discussed. 10 refs., 7 figs., 3 tabs.

Sikka, V.K.

1986-01-01

271

Bioelectronic imaging array based on bacteriorhodopsin film.  

PubMed

A photoreceptor array that exploits the light sensitive bacteriorhodopsin (bR) films has been manufactured on a flexible indium-tin-oxide (ITO) coated plastic film using electrophoretic sedimentation technique (EPS). The effective sensing area of each photoreceptor is 2 x 2 mm (2), separated by 1 mm and arranged in a 4 x 4 array. A switched integrator with gain on the order of 10(10) is used to amplify the signal to a suitable level. When exposed to light, the differential response characteristic is attributed to charge displacement and recombination within bR molecules, as well as loading effects of the attached amplifier. The peak spectral response occurs at 568 nm and is linear over the tested light power range of 200 mu W to 12 mW. The response remains linear at other tested wavelengths, but with reduced amplitude. Initial tests have indicated that responsivity among all photoreceptors is greater than 71% of the average value, 465.25 mV/mW. The differential nature of the signal generated by bR makes it a suitable sensing material for vision applications such as motion detection. The prototype array demonstrates this property by employing Reichardt's delay-and-correlate algorithm. Furthermore, fabricating sensor arrays on flexible substrates introduces a new design approach that enables non-planar imaging surfaces. PMID:19203868

Wang, Wei Wei; Knopf, George K; Bassi, Amarjeet S

2008-12-01

272

Directional solidification of large cross-section nickel-base superalloy castings via liquid-metal cooling  

NASA Astrophysics Data System (ADS)

The drive for higher efficiency in very large industrial gas turbines (IGTs) used in power generation applications has led to the need for directional solidification of large cross-section components, such as turbine blades, used in the hot gas path sections of the IGTs. The Bridgman directional solidification technique, which is currently used to produce these components, has been optimized for much smaller aero-engine components. The scale-up of this technique to produce large parts has resulted in numerous problems, and consequently low casting yield, which can all be related to the limited cooling capability of the Bridgman process. In this dissertation, a higher cooling efficiency process, liquid-metal cooling (LMC) using Sn as the cooling medium, has been evaluated for improved capability to cast large cross-section components. A series of castings were made for direct comparison using both the conventional Bridgman and the high thermal gradient LMC processes. Casting conditions were selected to simulate the state of the art for the Bridgman method and to assess the limits of casting with the less familiar LMC method. The experiments were evaluated through thermocouple analyses of casting conditions and post-casting analyses of grain defects, microstructural features, and mechanical behavior. Additionally, a finite element model of the solidification process was developed to further elucidate casting conditions. The casting parameters and elements of the LMC process that had the greatest influence on casting conditions were determined. Results indicated that the LMC process is capable of significantly enhancing cooling efficiency during directional solidification of large cross-section components. The enhanced cooling allowed much faster solidification withdrawal rates and resulted in substantially refined cast microstructure. The LMC process eliminated freckle-type defects in all cases and considerably reduced other casting defects under optimal conditions. It also was determined that the location of the solidification front during the LMC process is a crucial parameter that must be controlled to produce a high quality casting. Additionally, a floating thermal baffle used with the LMC-Sn process was established as an indispensable element of the LMC process.

Elliott, Andrew J.

273

Optimization of Gating System Design for Die Casting of Thin Magnesium Alloy-Based Multi-Cavity LCD Housings  

NASA Astrophysics Data System (ADS)

High-pressure die casting is the preferred process for manufacturing Mg-alloy components used for numerous applications. High-pressure die casting is suitable for mass production and has the advantage of also being suitable for accurately fashioning objects of complicated shapes. One disadvantage of high-speed die casting is the occurrence of defects such as shrinkage or air entrainment. Gating system design must be very effective in actual manufacturing facilities to avoid the occurrence of such defects. The objective of this study is to present a methodology for obtaining optimal designs of 4-cavity thin electronic component housings. The fluid behavior and amount of air entrainment caused by the overflows and air vent designs were analyzed using a computer fluid dynamics (CFD) simulator. The effectiveness of the proposed system was demonstrated through CFD simulations and experiments using an actual manufacturing process. Also, the effect of vacuum systems on the porosity and mechanical properties of the castings was studied. The volume of porosity in the casting was found to be significantly reduced using vacuum assistance during die casting. As a result, the tensile strength and the elongation of the die casting products are improved.

Lee, B. D.; Baek, U. H.; Han, J. W.

2012-09-01

274

Deshpande: The Grammar of Caste - Economic Discrimination in Contemporary India  

Microsoft Academic Search

This book examines the contemporary nature of caste disparities in India by using a framework that integrates discussions on caste from other social science disciplines with those from within economics. It brings together quantitative evidence on different dimensions of caste disparities based on two large national-level data sets, in order to analyse the degree of change in the caste system

Ashwini Deshpande

275

Photochromic polymer films based on a 14-F bacteriorhodopsin derivative.  

PubMed

Spectral and kinetic characteristics were measured for polymer (gelatin) films based on 14-F bacteriorhodopsin (BR), both wild-type (WT) and D96N mutant, to study the peculiarities of photo-induced transformation of the samples. It was demonstrated earlier that incorporation of 14-F retinal into the apomembrane of both 14-F WT and 14-F D96N produces pigments with drastically different photo-induced behavior, regarding the formation and decay of a red-shifted species at 660 nm. However, similar fundamental differences between 14-F WT and 14-F D96N, if embedded into gelatin matrix, were not observed. Results are discussed in the frame of the relationship between the kinetic rates of two photo-induced processes that occur in suspensions and gelatin films of corresponding pigments. These experimental results can possibly be explained by the difference in kinetics for gelatin films and water suspensions. The main factor in altering the kinetics is the relative humidity of gelatin samples. Therefore, the effect of relative humidity on performance of 14-F BR gelatin films, both WT and D96N, was studied. A range of humidity has been defined for each pigment, in which spectral and kinetic characteristics were changed in the desired direction. It was shown that 14-F WT gelatin films may offer a technological advantage relative to those based on 14-F D96N. PMID:19017472

Druzhko, Anna B; Alvarez, Rosana; de Lera, Angel R

2008-01-01

276

Si-based multilayered print circuit board for MEMS packaging fabricated by Si deep etching, bonding, and vacuum metal casting  

NASA Astrophysics Data System (ADS)

In our previous works, metal injection technique into small diameter (10 -100micrometers ) through holes was developed and applied for fabrication of Si based print circuit board. In the present work, we present the metal filling technology by vacuum casting into 3 dimensional through holes and trenches structure fabricated in stacked layered Si wafers prepared by fusion bonding of ICP etched Si wafers. Metal electrical feed through was successfully prepared by the method. Conventional print circuit boards have been fabricated with Epoxy resin based materials. In recent years Si is regarded as a candidate for next generation materials for print circuit board substrates, as the substrate whose thermal elongation same as the mounted chips is an ideal solution to residual stress problems in the elevated temperature application. In this report, we developed the double sided mountable stacked circuit board using Si deep etching technology and fusion bonding. This technology is expected to lead to the realization of the assembling of sensors, actuators and ICs, i.e. 3 dimensional MEMS packaging. In this report, we adopted micromachining technology to this application area and the special emphasis is placed on the low cost and reliable process development. The detailed items to be developed are shown as follows; 1) Development of Si wafer through holes penetration and trench formation by ICP etching. 2) Alignment and bonding of micromachined wafers. 3) Development of insulating layer with oxidation. 4) Development of formation of electrical feed through for stacked layers.

Murakoshi, Yoichi; Hanada, Kotaro; Li, Yaomin; Uchino, Kazuyoshi; Suzuki, Takaaki; Maeda, Ryutaro

2001-11-01

277

Elevated Temperature Tensile and Creep Properties of M-252 (Bar), Inconel 700 (Bar), and Inconel 713 (Cast) Nickel Base Alloys.  

National Technical Information Service (NTIS)

Room and elevated temperature tensile and elevated temperature creep properties to 1000 hours were determined at three representative application temperatures for M-252 (bar), Inconel 700 (bar), and Inconel 713 (cast). Tabulated tensile and creep data, de...

S. O. Davis

1964-01-01

278

Film Affective Content Recognition Based on Fuzzy Inference  

Microsoft Academic Search

Affective content plays an important role in film analysis and retrieval. However, the widely affective gap between the low-level features and the emotion recognition is still an unsolved problem. In order to recognize the affective type of a scene, a new algorithm is proposed based on fuzzy inference theory in this paper. It contains three main technologies. Firstly, two feature

Xinqi Lin; Xiangming Wen; Zhaoming Lu; Yong Sun

2008-01-01

279

Thin polymer film based rapid surface acoustic wave humidity sensors  

Microsoft Academic Search

Polyvinyl alcohol (PVA) and polyvinyl pyrrolidone (PVP) thin films, deposited on the surface of glass slides, were studied using transmission FTIR spectroscopy upon varying relative humidity (RH) from 2 to 70%. The obtained data revealed fast dynamics of water vapor adsorption–desorption with responses on the order of several seconds. Based on the fast FTIR signal intensity changes versus RH, it

Andrii Buvailo; Yangjun Xing; Jacqueline Hines; Eric Borguet

2011-01-01

280

Electrochemical biosensors based on enzymes immobilized in electropolymerized films  

Microsoft Academic Search

A review based on 135 references concerns the design and properties of electrochemical biosensors for 13 different substrates of enzymatic reactions. In the sensors discussed the enzymes are immobilized within or on the top of electropolymerized films, mostly of conducting polymers. Amperometric detection is most often used for internal electrochemical sensing.

Marek Trojanowicz; Tadeusz Krawczy?ski vel Krawczyk

1995-01-01

281

Quantitative fractographic analysis of variability in tensile ductility of a squeeze cast Al–Si–Mg base alloy  

Microsoft Academic Search

Cast Al-alloy components often exhibit significant variability in fracture-related mechanical properties, such as ductility and strength. In this contribution, the variability in the ductility of tensile test specimens of squeeze cast A356 Al-alloy is examined. The variability in ductility does not correlate to the global average microstructural parameters, such as dendrite cell size, Si particle size, and amount of porosity

A. M. Gokhale; G. R. Patel

2005-01-01

282

[Investigation of influencing variables on the computer-aided simulation of contacts in dynamic occlusion based on optically digitized plaster casts].  

PubMed

In dentistry, mechanical articulators with which mandibular movements can be reproduced in dentals casts play a major role. Commonly used semiadjustable articulators, however, have major limitations: On the one hand, the movement of the mandible is not reproduced exactly, on the other, they do not provide time-related information on jaw movement. Both problems can be solved by replacing the mechanical articulator by a digital simulation ("virtual articulator") based on digitized plaster casts and electronically recorded masticatory movements. We present a system for the 3D measurement of plaster casts in a skull-related, anatomical coordinate system using the fringe projection technique, and electronically recorded condylar movements. Using numerical algorithms, the contacts between upper and low jaw, and the angle of rotation of the temporomandibular joint can be computed for each movement in dynamic occlusion. Taking the data recorded from a patient as an example, the influence of the accuracy of the digitization of plaster casts on the computation of the rotation of the temporomandibular joint is discussed in relation to the anatomy of the masticatory apparatus. PMID:15212195

Böröcz, Z; Dirksen, D; Thomas, C; Runte, C; Bollmann, F; von Bally, G

2004-05-01

283

Casting Technology Relevant to the Production of High Strength Aluminum Sand Castings.  

National Technical Information Service (NTIS)

High-strength aluminum sand casting alloys such as type 201 and 224 offer yield strengths upwards of 55,000 psi on bars cut from castings. The range of properties represented expands the technical base and design strength range of aluminum castings; their...

A. G. Fleming G. B. Singh

1973-01-01

284

A comparison of the marginal adaptation of cathode-arc vapor-deposited titanium and cast base metal copings  

PubMed Central

Statement of problem A new fabrication process has been developed where a titanium coping, which has a gold colored titanium nitride outer layer can be reliably fused to porcelain, but the marginal adaptation characteristics are still undetermined. Purpose The primary purpose of this study is to compare the rate of Clinically Acceptable Marginal Adaptation (CAMA-defined as a marginal gap mean ?60 ?m) of cathode-arc vapor-deposited titanium with the CAMA rate for the cast base metal copings. In addition, the study will evaluate the marginal gap scores themselves to assess their mean difference between the two study groups. Finally, the study will present two analyses of group differences in variability to support the contention that the titanium copings perform more consistently than their base metal counterparts. Material and methods Thirty-seven cathode-arc vapor-deposited titanium copings and 40 cast base metal copings were evaluated by computer-based image analysis using an optical microscope. The conventional lost wax technique was used to fabricate the 40 cast base metal copings that were 0.3 mm thick. The titanium copings were 0.3 mm thick and were formed by a collection of atomic titanium vapor onto a refractory die duplicate in a high vacuum chamber. Fifty vertical marginal gap measurements were collected from each of the 77 copings and the mean of these measurements was computed to form a gap score for each coping. Next, the gap score was compared to the 60 ?m criterion to classify each coping as to whether it did or did not achieve Clinically Acceptable Marginal Adaption (CAMA). A comparison of the CAMA rates for each type of coping was used to address the primary purpose of this study. In addition, the gap scores themselves were used to test the (one-sided) hypothesis that the mean of the titanium gap scores is smaller than the mean of the base metal gap scores. Finally, the assertion that the titanium copings provide more consistency in their marginal gap performance was tested in two ways. First, the means of the titanium gap scores were compared to the means of the marginal gap scores for the base metal copings. Second, the standard deviations of the marginal gap scores for the titanium copings were compared with those for the base metal copings. Results Statistical comparison of the CAMA rates for each type of coping showed that the CAMA criterion was achieved by 24 of the 37 (64.86%) titanium copings, while 19 of the 40 (47.50%) base metal copings met this same standard. Noninferiority of the titanium copings was established by the 2-sided 90% Confidence Interval for the 17.36% difference in these rates (?0.95%, 35.68%) and noninferiority of titanium coping adaption was also demonstrated by the Wald Test rejection of the tentative hypothesis of inferiority (Z-score=1.9191, one-sided p=0.0275). The mean of the vertical marginal gap scores for the titanium copings (56.9025) was significantly less than the mean of the marginal gap scores for the base metal copings (71.9041) as shown by the Satterthwaite t-score=?2.29 (one-sided p=0.0126). To compare the adaption consistency of the titanium copings to the base metal counterparts the difference between the variance of the marginal gap scores for the titanium copings (594.843) and the variance of the marginal gap scores for the base metal copings (1510.901) was found to be statistically significant (Folded-F test score=2.63, p=0.0042). Our second method for showing that the titanium copings performed more consistently than the base metal comparisons was to use a one-sided test to show that the mean of the standard deviations of the vertical gap measurements for each titanium coping (29.9835) was significantly lower than the mean of the standard deviations of the vertical gap measurements for each base metal coping (36.1332). This test produced a Satterthwaite’s t-score of ?2.24 (one-sided p=0.0141), indicating the titanium adaption was significantly more consistent. Conclusions Cathode-arc vapor deposited titanium

Wu, JC; Lai, LC; Sheets, CG; Earthman, J; Newcomb, R

2011-01-01

285

Switchable mirrors based on nickel-magnesium films  

SciTech Connect

A new type of electrochromic mirror electrode based on reversible uptake of hydrogen in nickel magnesium alloy films is reported. Thin,magnesium-rich Ni-Mg films prepared on glass substrates by cosputtering from Ni and Mg targets are mirror-like in appearance and have low visible transmittance. Upon exposure to hydrogen gas or on reduction in alkaline electrolyte, the films take up hydrogen and become transparent. When hydrogen is removed, the mirror properties are recovered. The transition is believed to result from reversible formation of Mg2NiH4 and MgH2. A thin overlayer of palladium was found to enhance the kinetics of hydrogen insertion and extraction,and to protect the metal surface against oxidation.

Richardson,Thomas J.; Slack, Jonathan L.; Armitage, Robert D.; Kostecki, Robert; Farangis, Baker; Rubin, Michael D.

2001-01-16

286

Metallosupramolecular thin films using a tritopic cyclam-based ligand.  

PubMed

We present the preparation and characterization of novel metallosupramolecular thin films on solid substrates. These films incorporate metallosupramolecular polymers based on a tritopic cyclam bis-terpyridine ligand and are formed using different deposition techniques. From layer-by-layer (LBL) method, alternate thin multilayers of this metallosupramolecule along with oppositely charged polyelectrolyte are constructed by electrostatic self-assembly. Using dip-coating method, homogenous monolayers are deposited. The monolayer thickness is controlled by withdraw velocity of substrate. In a direct-assembly approach: Langmuir-Blodgett (LB), well-ordered metallosupramolecular monolayer is achieved by using a Metallosupramolecular Polyelectrolyte Amphiphile Complex (MPAC). The structures of these metallosupramolecular thin films are characterized by X-ray reflectivity (XRR), Atomic Force Microscopy (AFM), Langmuir isotherms, and UV/Vis absorption. The results open access to fabricate novel molecular materials such as sensors and memory devices. PMID:23540829

Yan, Minhao; Velu, Sabareesh K P; Royal, Guy; Terech, Pierre

2013-03-07

287

Cast Aluminum Structures Technology, Phase III (Cast).  

National Technical Information Service (NTIS)

The objective of CAST is to establish the necessary structural and manufacturing technologies and to demonstrate the validate the integrity, producibility, and viability of cast aluminum primary airframe structures. The baseline design is the AMST prototy...

D. Goehler

1978-01-01

288

Microstructure and mechanical properties of cast Ni-base superalloy K44  

Microsoft Academic Search

The Ni-base superalloy K44, developed recently in China, plays an important role in manufacturing blades of gas turbine engines due to its high temperature capability. The microstructure, deformation mechanism and mechanical properties of the Ni-base superalloy K44 have been investigated. Tensile properties and creep behaviors show abnormal variations with increasing temperatures, and the creep data can be fitted well with

J. S Hou; J. T Guo; L. Z Zhou; C Yuan; H. Q Ye

2004-01-01

289

Vertical Conducting Nanodomains Self-Assembled from Poly(3-hexylthiophene)-Based Diblock Copolymer Thin Films  

SciTech Connect

We have synthesized {pi}-conjugated poly(3-hexyl thiophene)-block-poly(methyl methacrylate) (P3HT-b-PMMA) with a P3HT molecular weight of 11 kDa and a PMMA volume fraction of 0.53, which potentially has several organic electronic applications. Its phase-separation behavior was investigated for various thicknesses cast from organic solvents. When cast onto 300 nm thick SiO{sub 2} dielectrics from toluene, in which the P3HT segments have limited solubility, the P3HT-b-PMMA films consist of nanofibrillar self-assemblies of laterally {pi}-stacked P3HT chains. In contrast, the P3HT segments were found to be highly mobile in chlorobenzene, generating a typical phase-separation morphology consisting of vertically conducting P3HT nanodomains on these dielectrics. As the thickness of the cast films increased, however, the topmost surface becomes covered with {pi}-conjugated nanofibrils that are laterally oriented with respect to the surface. Due to the anisotropic domain orientations of P3HT, top-gate organic field-effect transistors (OFETs) containing the P3HT-b-PMMA films exhibited enhanced electrical performance compared to bottom-gate OFETs.

Y Lee; S Kim; H Yang; M Jang; S Hwang; H Lee; K Baek

2011-12-31

290

USGS ShakeCast  

USGS Publications Warehouse

Automating, Simplifying, and Improving the Use of ShakeMap for Post-Earthquake Decisionmaking and Response. ShakeCast is a freely available, post-earthquake situational awareness application that automatically retrieves earthquake shaking data from ShakeMap, compares intensity measures against users facilities, and generates potential damage assessment notifications, facility damage maps, and other Web-based products for emergency managers and responders.

Wald, David; Lin, Kuo-Wan

2007-01-01

291

Preparation and Characterization of Modified Cellulose Fiber-Reinforced Polyvinyl Alcohol\\/Polypyrrolidone Hybrid Film Composites  

Microsoft Academic Search

In this work, cellulose was modified by using 2-(trifluromethyl)benzoylchloride by base catalyzed reaction. Modification of cellulose was confirmed by IR studies. The biodegradable composite films were developed by a film casting method using modified cellulose with poly(vinyl alcohol) and polypyrrolidone in different compositions. Film composites showed good biodegradability. Better barrier and mechanical properties showed by film composites as the percentage

Sandeep S. Laxmeshwar; S. Viveka; D. J. Madhu Kumar; Dinesha; R. F. Bhajanthri; G. K. Nagaraja

2012-01-01

292

Drying kinetics of water-based ceramic suspensions for tape casting  

Microsoft Academic Search

An experimental study is described which seeks to characterise the drying kinetics of water-based ceramic (alumina) suspensions in controlled environments. The drying process of the ceramic suspensions is shown, to a first approximation, to follow a two stage mechanism (initial stage: ‘external’ evaporation controlled process; and second stage: ‘internal’ diffusion-controlled process). It has been shown that the temperature, the humidity

B. J. Briscoe; G. Lo Biundo; N. Özkan

1998-01-01

293

Filmless versus film-based systems in radiographic examination costs: an activity-based costing method  

PubMed Central

Background Since the shift from a radiographic film-based system to that of a filmless system, the change in radiographic examination costs and costs structure have been undetermined. The activity-based costing (ABC) method measures the cost and performance of activities, resources, and cost objects. The purpose of this study is to identify the cost structure of a radiographic examination comparing a filmless system to that of a film-based system using the ABC method. Methods We calculated the costs of radiographic examinations for both a filmless and a film-based system, and assessed the costs or cost components by simulating radiographic examinations in a health clinic. The cost objects of the radiographic examinations included lumbar (six views), knee (three views), wrist (two views), and other. Indirect costs were allocated to cost objects using the ABC method. Results The costs of a radiographic examination using a filmless system are as follows: lumbar 2,085 yen; knee 1,599 yen; wrist 1,165 yen; and other 1,641 yen. The costs for a film-based system are: lumbar 3,407 yen; knee 2,257 yen; wrist 1,602 yen; and other 2,521 yen. The primary activities were "calling patient," "explanation of scan," "take photographs," and "aftercare" for both filmless and film-based systems. The cost of these activities cost represented 36.0% of the total cost for a filmless system and 23.6% of a film-based system. Conclusions The costs of radiographic examinations using a filmless system and a film-based system were calculated using the ABC method. Our results provide clear evidence that the filmless system is more effective than the film-based system in providing greater value services directly to patients.

2011-01-01

294

Humidity sensors based on polymer thin films  

Microsoft Academic Search

Studies on humidity sensors fabricated with organic polymers for the last 10 years are reviewed. Several useful methods for improving the characteristics of humidity sensors based on polymers are proposed. In the case of a resistive-type sensor, cross-linking of hydrophilic polymers or formation of interpenetrated polymer networks with a hydrophobic polymer makes the hydrophilic polymers durable at high humidities. Graft

Y Sakai; Y Sadaoka; M Matsuguchi

1996-01-01

295

Prediction of Part Distortion in Die Casting  

SciTech Connect

The die casting process is one of the net shape manufacturing techniques and is widely used to produce high production castings with tight tolerances for many industries. An understanding of the stress distribution and the deformation pattern of parts produced by die casting will result in less deviation from the part design specification, a better die design and eventually more productivity and cost savings. This report presents methods that can be used to simulate the die casting process in order to predict the deformation and stresses in the produced part and assesses the degree to which distortion modeling is practical for die casting at the current time. A coupled thermal-mechanical finite elements model was used to simulate the die casting process. The simulation models the effect of thermal and mechanical interaction between the casting and the die. It also includes the temperature dependant material properties of the casting. Based on a designed experiment, a sensitivity analysis was conducted on the model to investigate the effect of key factors. These factors include the casting material model, material properties and thermal interaction between casting and dies. To verify the casting distortion predictions, it was compared against the measured dimensions of produced parts. The comparison included dimensions along and across the parting plane and the flatness of one surface.

R. Allen Miller

2005-03-30

296

Friction and wear behaviour of cast Al 6063 based in situ metal matrix composites  

Microsoft Academic Search

Al 6063 based in situ composites were manufactured from Al–10%Ti and Al–3%B master alloys by liquid metallurgy route. The in situ TiB2 reinforced Al 6063 composites were synthesized through the exothermic reaction between Al–10%Ti and Al–3%B master alloys, which were used in the ratio of 1:2 respectively in Al 6063 matrix alloy. Tribological properties of both Al 6063 matrix alloy

C. S. Ramesh; Abrar Ahamed

2011-01-01

297

Planar electrochemical sensors based on tape-cast YSZ layers and oxide electrodes  

Microsoft Academic Search

Electrochemical planar sensors based on yttria-stabilized zirconia (YSZ) with semiconducting oxides (WO3 and LaFeO3) and mixed conductors (La0.8Sr0.2FeO3) as sensing electrodes were investigated. The electromotive force (EMF) of the sensors was measured at fixed temperature (450–700 °C) and different concentrations of NO2 and CO in air in the range 20–1000 ppm. The sensors were wholly exposed to the same gas

Elisabetta Di Bartolomeo; Narin Kaabbuathong; Maria Luisa Grilli; Enrico Traversa

2004-01-01

298

Adsorption behaviour of Schiff base and corrosion protection of resulting films to copper substrate  

Microsoft Academic Search

Self-assembled (SA) films of Schiff base were prepared on the copper surface. The corrosion protection abilities of SA films in chloride solution were evaluated using electrochemical impedance spectroscopy and polarization curves. A subsequent adsorption of 1-dodecanethiol on the original SA films of Schiff base improved significantly the protection ability to the copper substrate. The behavior of Schiff base adsorption on

Zhenlan Quan; Shenhao Chen; Ying Li; Xuegui Cui

2002-01-01

299

A casting based process to fabricate 3D alginate scaffolds and to investigate the influence of heat transfer on pore architecture during fabrication  

Microsoft Academic Search

The fabrication of 3-dimensional (3D) tissue scaffolds is a competitive approach to engineered tissues. An ideal tissue scaffold must be highly porous, biocompatible, biodegradable, easily processed and cost-effective, and have adequate mechanical properties. A casting based process has been developed in this study to fabricate 3D alginate tissue scaffolds. The alginate\\/calcium gluconate hydrogel was quenched in a glass mold and

W. M. Parks; Y. B. Guo

2008-01-01

300

Thermal behavior of hafnium-based ultrathin films on silicon  

NASA Astrophysics Data System (ADS)

We report here on the thermodynamical stability of ultrathin, hafnium-based dielectric films, namely hafnium oxide (HfO2), silicate (HfSixOy), and aluminum silicate (AlHfxSiyOz), deposited on silicon. These materials are promising candidates to replace the well established silicon oxide and oxynitride as gate dielectric materials in advanced Si-based complementary metal-oxide-semiconductor technology. Since there are mandatory requirements on the gate dielectric material, hafnium oxide is currently being modified, by adding silicon and aluminum into the matrix, increasing its thermal stability, and improving its electrical properties. Diffusion-reaction during thermal processing was investigated using isotopic substitution together with ion beam techniques such as Rutherford backscattering spectrometry, narrow nuclear resonance profiling, and nuclear reaction analysis. The chemical changes in the films were accessed by x-ray photoelectron spectroscopy.

Pezzi, R. P.; Morais, J.; Dahmen, S. R.; Bastos, K. P.; Miotti, L.; Soares, G. V.; Baumvol, I. J. R.; Freire, F. L.

2003-07-01

301

Quantification of ecotoxicological tests based on bioluminescence using Polaroid film.  

PubMed

Assays based on the measurement of bacterial luminescence are widely used in ecotoxicology. Bacterial strains responding either to general toxicity or specific pollutants are rapid, cost-effective and easy to use. However, quantification of the signal requires relatively expensive instrumentation. We show here that the detection of luminescence of BioTox, a Vibrio fischeri-based toxicity test, and of a specific recombinant bacterial strain for arsenic determination, is possible using common Polaroid film. The exposed films can be used for visual or computer-assisted quantification of the signal. Qualitative visual comparison to standards can be used in the rapid and relatively accurate estimation of toxicity or pollutant concentration. The computer-assisted method significantly improves the accuracy and quantification of the results. The results obtained by computer-assisted quantification were in good agreement with the values obtained with a luminometer. PMID:16949132

Tamminen, Manu V; Virta, Marko P J

2006-09-01

302

Simulation-based prediction of micro-shrinkage porosity in aluminum casting: Fully-coupled numerical calculation vs. criteria functions  

NASA Astrophysics Data System (ADS)

Micro-shrinkage porosity in aluminum casting is analysed by computer simulation using three criteria functions and a fully-coupled shrinkage porosity model. Three process simulations of different precision were executed as basis for the porosity prediction for investigation of the impact of simulation precision on porosity prediction. To validate the simulation predictions, three identical blocks were cast in a special experimental setup. Chill plates enforce shrinkage porosity, which was analyzed using computer tomography. The results demonstrate that both precise numerical simulations and precise porosity models are needed for reliable porosity prediction.

Jakumeit, J.; Jana, S.; Böttger, B.; Laqua, R.; Jouani, M. Y.; Bührig-Polaczek, A.

2012-01-01

303

Immunosensor systems with the Langmuir-film-based fluorescence detection  

SciTech Connect

A method is developed for detecting protein antigens for fluorescent immunoassay using a model system based on the technique for preparation of Langmuir films. Fluorescein isothiocyanate and donor-acceptor energy-transfer pairs of markers (the Yb complex of tetraphenyl porphyrin - benzoyl trifluoroacetoneisothiocyanate and derivatives of tetra(carboxyphenyl) porphyrin - cyanine dye containing a five-membered polyene chain), which were nor studied earlier, were used as markers for detecting the binding of an antigen on the surface of Langmuir films of antibodies. Fluorescence was detected in the near-IR region (for the first pair) and in the visible spectral range (for the second pair). To reduce the nonspecific sorption of a protein (antigen), a method was proposed for the preparation of a nonpolar surface by applying an even number of layers of stearic acid as a substrate for the Langmuir - Blodgett film. A high sensitivity of model systems to a protein antigen in solution was achieved ({approx}10{sup -11} M), the assay time being 6 - 8 min. The model system with the first donor - acceptor pair was tested in analysis of the blood plasma. The fluorescence of the Dy{sup 3+}, Tm{sup 3+}, and Yb{sup 3+} complexes of tetraphenyl porphyrin sensitised by diketonate complexes of lanthanides was studied for the first time and the enhancement of the IR fluorescence of these complexes in a Langmuir film was demonstrated. (papers devoted to the memory of academician a m prokhorov)

Chudinova, G K; Nagovitsyn, I A; Savranskii, V V [Natural Science Center, A.M. Prokhorov General Physics Institute, Russian Academy of Sciences, Moscow (Russian Federation); Karpov, R E [Photochemistry Center, Russian Academy of Sciences, Moscow (Russian Federation)

2003-09-30

304

All-optical logic-gates based on bacteriorhodopsin film  

Microsoft Academic Search

Based on self-diffraction in bacteriorhodopsin (bR) film, we propose all-optical NOT, XOR, half adder and XNOR logic operations. Using the relation between diffraction light and the polarization states of recording beams, we demonstrate NOT and XNOR logic operations. Studying the relation of polarization states among the diffracting, recording and reading beams, we implement XOR logic and half adder operations with

Gui-Ying Chen; Chun-Ping Zhang; Zong-Xia Guo; Jian-Guo Tian; Guang-Yin Zhang; Qi-Wang Song

2005-01-01

305

All-optical logic-gates based on bacteriorhodopsin film  

NASA Astrophysics Data System (ADS)

Based on self-diffraction in bacteriorhodopsin (bR) film, we propose all-optical NOT, XOR, half adder and XNOR logic operations. Using the relation between diffraction light and the polarization states of recording beams, we demonstrate NOT and XNOR logic operations. Studying the relation of polarization states among the diffracting, recording and reading beams, we implement XOR logic and half adder operations with three inputs. The methods are simple and practicable.

Chen, Gui-Ying; Zhang, Chun-Ping; Guo, Zong-Xia; Tian, Jian-Guo; Zhang, Guang-Yin; Song, Qi-Wang

2005-04-01

306

Acetone sensor based on Film Bulk Acoustic Resonator  

Microsoft Academic Search

This paper described acetone sensing using ZnO based Film Bulk Acoustic Resonator (FBAR). The resonant frequency of the FBAR increased as the concentration of acetone increased. The detection limit of acetone was around 4 ppm. The density decrease of the ZnO induced by releasing carbon dioxide generated from the reaction between acetone and the adsorbed oxygen ions on the ZnO

Xiaotun Qiu; Rui Tang; Jie Zhu; Hongyu Yu; Jon Oiler; Ziyu Wang

2010-01-01

307

Infrared optics applications of thin polyaniline emeraldine base films  

Microsoft Academic Search

The use of polyaniline emeraldine base films as antireflection coating for near and middle IR optics elements was studied. The optical quality of ZnSe substrates spin-coated with thin PANI EB layers were studied using a Linnik interferometer. The spectral properties of PANI coated ZnSe plates were investigated in broad IR band with FTIR spectrometer. It was shown that PANI coating

Edward Bormashenko; Roman Pogreb; Semion Sutovski; Alexander Shulzinger; Avigdor Sheshnev; Gregory Izakson; Abraham Katzir

2003-01-01

308

Infrared optics applications of thin polyaniline emeraldine base films  

Microsoft Academic Search

The use of polyaniline emeraldine base films as antireflection coating for near and middle IR optics elements was studied. The optical quality of ZnSe substrates spin-coated with thin PANI EB layers were studied using a Linnik interferometer. The spectral properties of PANI coated ZnSe plates were investigated with FTIR spectrometer. It was shown that PANI coating allows a significant decrease

Edward Bormashenko; Roman Pogreb; Semion Sutovski; Alexander Shulzinger; Avigdor Sheshnev; Gregory Izakson; Abraham Katzir

2004-01-01

309

Electron transport in Mo_2N Nanoparticle-Based Films  

Microsoft Academic Search

The resistance rho(T) of Mo_2N nanoparticle-based films in the temperature range 77 < T < 500 K has been studied as a function of particle surface treatment. The nanoparticles were synthesized via CO2 laser pyrolysis of Mo(CO)6 and NH3 , colloidally suspended in acetonitrile, and then injected under flowing N2 into a narrow groove cut into a silicon substrate with

Gamini U. Sumanasekera; Jan L. Allen; Peter C. Eklund

1997-01-01

310

Informing Selection of Nanomaterial Concentrations for ToxCast in Vitro Testing Based on Occupational Exposure Potential  

PubMed Central

Background: Little justification is generally provided for selection of in vitro assay testing concentrations for engineered nanomaterials (ENMs). Selection of concentration levels for hazard evaluation based on real-world exposure scenarios is desirable. Objectives: Our goal was to use estimates of lung deposition after occupational exposure to nanomaterials to recommend in vitro testing concentrations for the U.S. Environmental Protection Agency’s ToxCast™ program. Here, we provide testing concentrations for carbon nanotubes (CNTs) and titanium dioxide (TiO2) and silver (Ag) nanoparticles (NPs). Methods: We reviewed published ENM concentrations measured in air in manufacturing and R&D (research and development) laboratories to identify input levels for estimating ENM mass retained in the human lung using the multiple-path particle dosimetry (MPPD) model. Model input parameters were individually varied to estimate alveolar mass retained for different particle sizes (5–1,000 nm), aerosol concentrations (0.1 and 1 mg/m3), aspect ratios (2, 4, 10, and 167), and exposure durations (24 hr and a working lifetime). The calculated lung surface concentrations were then converted to in vitro solution concentrations. Results: Modeled alveolar mass retained after 24 hr is most affected by activity level and aerosol concentration. Alveolar retention for Ag and TiO2 NPs and CNTs for a working-lifetime (45 years) exposure duration is similar to high-end concentrations (~ 30–400 ?g/mL) typical of in vitro testing reported in the literature. Conclusions: Analyses performed are generally applicable for providing ENM testing concentrations for in vitro hazard screening studies, although further research is needed to improve the approach. Understanding the relationship between potential real-world exposures and in vitro test concentrations will facilitate interpretation of toxicological results.

Brown, James S.; Wang, Amy; Houck, Keith A.; Dix, David J.; Kavlock, Robert J.; Hubal, Elaine A. Cohen

2011-01-01

311

Team-based thin-film CIS research activities  

NASA Astrophysics Data System (ADS)

This paper describes the team-based thin-film copper indium diselenide (CIS) research activities. The CIS team was formed in December 1994 in Kona, Hawaii. Originally, the team had two working groups: the ``Junction'' and the ``Absorber'' groups. Currently, there are four working groups the Present Junction, New Junction, Substrate/Mo Impact, and the Transient Effect groups. We have completed extensive data compilation of CIS-based films and solar cells using various techniques such as Auger, photoluminescence, scanning electron microscopy, secondary-ion mass spectrometry, X-ray photoelectron spectroscopy, X-ray diffraction, capacitance-voltage, light and dark current-voltage, and quantum efficiency. Studies are under way to understand the fundamental mechanisms that demonstrate a total-area, high efficiency of 17.7% in CuInGaSe2 devices using chemical-bath deposition (CBD) CdS. Alternate buffer layers are also being investigated to replace the CBD CdS. The impact of various Mo substrates from the various industrial partners has been investigated, and the results are reported. A study is under way to investigate the transient effects in encapsulated/laminated thin-film CIS-based devices.

Ullal, Harin S.

1997-02-01

312

Optical properties of a long dynamic range chemical UV dosimeter based on solvent cast polyvinyl chloride (PVC).  

PubMed

The dosimetric properties of the recently introduced UV dosimeter based on 16?m PVC film have been fully characterised. Drying the thin film in air at 50°C for at least 28days was found to be necessary to minimise the temperature effects on the dosimeter response. This research has found that the dosimeter response, previously reported to be mainly to UVB, has no significant dependence on either exposure temperature or dose rate. The dosimeter has negligible dark reaction and responds to the UV radiation with high reproducibility. The dosimeter angular response was found to have a similar pattern as the cosine function but deviates considerably at angles larger than 70°. Dose response curves exhibit monotonically increasing shape and the dosimeter can measure more than 900 SED. This is about 3weeks of continuous exposure during summer at subtropical sites. Exposures measured by the PVC dosimeter for some anatomical sites exposed to solar radiation for twelve consecutive days were comparable with those concurrently measured by a series of PPO dosimeters and were in line with earlier results reported in similar studies. PMID:24084259

Amar, Abdurazaq; Parisi, Alfio V

2013-09-13

313

Antimicrobial food packaging film based on the release of LAE from EVOH.  

PubMed

The aim of this work was to develop antimicrobial films for active packaging applications containing the natural antimicrobial compound LAE (lauramide arginine ethyl ester) in EVOH copolymers with different mol % ethylene contents (i.e. EVOH-29 and EVOH-44). EVOH-29 and EVOH-44 films were made by casting and incorporating 0.25%, 1%, 5%, and 10% LAE in the film forming solution (w/w with respect to polymer weight). Previously, the minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) of LAE against Listeria monocytogenes, Escherichia coli, and Salmonella enterica were determined by a microdilution assay. The antimicrobial activity of the resulting films was tested in vitro against these microorganisms in liquid culture media. The activity of the films was also evaluated over time. The results showed that films containing 5% and 10% LAE produced total growth inhibition and viable counts decreased with 0.25% and 1% LAE. Finally, the effectiveness of the films was tested by applying them to an infant formula milk inoculated with L. monocytogenes and S. enterica and stored for 6 days at 4°C. The application of films with LAE to infant formula milk inoculated with L. monocytogenes reduced at the end of storage period about 4 log in case of 10% LAE and with S. enterica reduced 3.74 log and 3.95 log with EVOH 29 5% and 10%, respectively, and EVOH-44 5% and 10% LAE reduced 1 log and 3.27 log, respectively, at the end of storage. The antimicrobial capacity of EVOH-29 films was greater than that of EVOH-44 films in all the cases tested. In general, the films were more effective in inhibiting the growth of L. monocytogenes than S. enterica, this inhibition being more acute at the end of the storage time. PMID:22640726

Muriel-Galet, Virginia; López-Carballo, Gracia; Gavara, Rafael; Hernández-Muñoz, Pilar

2012-05-14

314

Measurement of Thermoelectric Properties of Amorphous Silicon Based Thin Films  

NASA Astrophysics Data System (ADS)

It is important to understand thermal transport behavior in materials for technological and fundamental physics applications. Many efforts have been made in the past for explaining thermal conduction in solids. It has been observed that thermal transport properties may change with reducing size of the sample, especially as sample size approaches the nanoscale regime. The deviation in these properties, mainly in thermal conductivity, may change the choice of the material for different applications such as thermoelectricity. Thermoelectric materials are a possible source of sustainable energy and can play an important role in the fight against the present energy crisis. Recently, better thermoelectric materials have become available in bulk form as compared to thin film form, with higher figure of merit (ZT = alpha2sigma T=k). ZT is a dimensionless quantity which is used to characterize the performance of thermoelectric materials in terms of the efficiency. Figure of merit (ZT) depends on three fundamental properties including thermal conductivity (k) which is challenging to measure for thin films. This is due to several reasons such as large or more than one background contribution and radiation heating above 100 K. Precise measurements of thermopower (alpha) also become critical for thin films in order to calculate ZT and the efficiency. For devices which rely on thin film technology it is important to have an accurate knowledge of how a material behaves as a thin film in a wide range of temperature. All three of these properties are a function of charge carrier concentration as well as of temperature. In my thesis, I will present novel experimental techniques and measurements of thermoelectric properties in amorphous based thin films over a wide range of temperature. Amorphous Si alloys are expected to have high efficiency for thermoelectric purposes because of their low thermal conductivity and the fact that we can control the charge carrier concentration for optimized thermopower(alpha) and electrical conductivity(sigma) by controlling the dopant concentration. Thermal properties of pure amorphous thin films are also potentially useful in micro- or nano fabrication techniques such as electrically insulating integrated devices. ii

Sultan, Rubina

315

Casts and crusts of the tympanic membrane.  

PubMed

Casts and crusts of the tympanic membrane were removed from patients with previous otitis media. Casts are formed of adherent keratinocytes in a matrix of dried exudate. Detachment from the drumhead leaves the underlying epidermis intact. Casts are defined as those crusts that have detached spontaneously from the surface of the drum. A mechanism based on epithelial proliferation induced by inflammation within the middle ear, with subsequent keratinocyte retention and thickening, is proposed. PMID:2426916

Weinberger, J; Proops, D W; Hawke, M

316

Elastohydrodynamic Film Thickness Formula Based on X-Ray Measurements with a Synthetic Paraffinic Oil.  

National Technical Information Service (NTIS)

An empirical elastohydrodynamic film thickness formula for heavily loaded contacts based upon X-ray film thickness measurements made with a synthetic paraffinic oil is presented. The deduced relation was found to adequately reflect the high load dependenc...

S. H. Loewenthal R. J. Parker E. V. Zaretsky

1973-01-01

317

Piezoelectric micromachined ultrasonic transducers based on PZT thin films.  

PubMed

This paper describes fabrication and characterization results of piezoelectric micromachined ultrasonic transducers (pMUTs) based on 2-microm-thick Pb(Zr0.53Ti0.47O3) (PZT) thin films. The applied structures are circular plates held at four bridges, thus partially unclamped. A simple analytical model for the fully clamped structure is used as a reference to optimize design parameters such as thickness relations and electrodes, and to provide approximate predictions for coupling coefficients related to previously determined thin film properties. The best coupling coefficient was achieved with a 270-microm plate and amounted to kappa2 = 5.3%. This value compares well with the calculated value based on measured small signal dielectric (epsilon = 1050) and piezoelectric (e3l,f = 15 Cm(-2)) properties of the PZT thin film at 100 kV/cm dc bias. The resonances show relatively large Q-factors, which can be partially explained by the small diameters as compared to the sound wavelength in air and in the test liquid (Fluorinert 77). A transmit-receive experiment with two quasi-identical pMUTs was performed showing significant signal transmission up to a distance of 20 cm in air and 2 cm in the test liquid. PMID:16463493

Muralt, Paul; Ledermann, Nicolas; Baborowski, Jacek; Barzegar, Abdolghaffar; Gentil, Sandrine; Belgacem, Brahim; Petitgrand, Sylvain; Bosseboeuf, Alain; Setter, Nava

2005-12-01

318

Photoluminescence enhancement of semiconducting-carbon-nanotubes-based thin films  

NASA Astrophysics Data System (ADS)

Semiconducting single wall carbon nanotubes (s-SWNT) are unique monodimensional material of particular interest in photonics for their direct band-gap, allowing tunable near-IR luminescence from electron-hole recombinaison. However, the presence of metallic nanotubes and impurities in real carbon nanotubes samples creates several non radiative relaxation mechanisms, leading to an effective quenching of s-SWNT photoluminescence and limiting their usability in photonics devices. Recently, we have developed a process to selectively extract s-SWNT and embedded them in polyfluorene (PFO) thin films. A removal of metallic nanotubes leads to an enhancement of the photoluminescence properties, with a 6-fold increase of the photoluminescence intensity of (8,6) s-SWNT. Development of nanotubes based photonics devices is also reported. The SWNT-based layer was inserted between two Bragg mirrors to form a Fabry-Perot cavity, leading to a huge photoluminescence enhancement by a factor of 30 in comparison with an identical film and by a factor of 180 in comparison with a non s-SWNT enriched film.

Gaufres, Etienne; Izard, Nicolas; Le Roux, Xavier; Marris-Morini, Delphine; Kazaoui, Said; Cassan, Eric; Vivien, Laurent

2010-04-01

319

The nucleation of Fe-Rich phases on oxide films in Al11.5Si0.4Mg cast alloys  

Microsoft Academic Search

The microstructures of Al-11.5Si-0.4Mg alloys with various Fe and Mn contents have been studied to investigate the potential\\u000a influence of oxide films on the precipitation of Fe-rich phases from the liquid metal. Oxide films are incorporated into melts\\u000a by an entrainment process. This is an enfolding mechanism of incorporation. Folded oxide films in melts have two sides: the\\u000a dry unbonded

X. Cao; J. Campbell

2003-01-01

320

Large displacement vertical translational actuator based on piezoelectric thin films  

NASA Astrophysics Data System (ADS)

A novel vertical translational microactuator based on thin-film piezoelectric actuation is presented, using a set of four compound bend-up/bend-down unimorphs to produce translational motion of a moving platform or stage. The actuation material is a chemical-solution deposited lead-zirconate-titanate (PZT) thin film. Prototype designs have shown as much as 120 µm of static displacement, with 80-90 µm displacements being typical, using four 920 µm long by 70 µm legs. Analytical models are presented that accurately describe nonlinear behavior in both static and dynamic operation of prototype stages when the dependence of piezoelectric coefficients on voltage is known. Resonance of the system is observed at a frequency of 200 Hz. The large displacement and high bandwidth of the actuators at low-voltage and low-power levels should make them useful to a variety of optical applications, including endoscopic microscopy.

Qiu, Zhen; Pulskamp, Jeffrey S.; Lin, Xianke; Rhee, Choong-Ho; Wang, Thomas; Polcawich, Ronald G.; Oldham, Kenn

2010-07-01

321

Effects of the Exposure to Corrosive Salts on the Frictional Behavior of Gray Cast Iron and a Titanium-Based Metal Matrix Composite  

SciTech Connect

The introduction of increasingly aggressive road-deicing chemicals has created significant and costly corrosion problems for the trucking industry. From a tribological perspective, corrosion of the sliding surfaces of brakes after exposure to road salts can create oxide scales on the surfaces that affect friction. This paper describes experiments on the effects of exposure to sodium chloride and magnesium chloride sprays on the transient frictional behavior of cast iron and a titanium-based composite sliding against a commercial brake lining material. Corrosion scales on cast iron initially act as abrasive third-bodies, then they become crushed, spread out, and behave as a solid lubricant. The composition and subsurface microstructures of the corrosion products on the cast iron were analyzed. Owing to its greater corrosion resistance, the titanium composite remained scale-free and its frictional response was markedly different. No corrosion scales were formed on the titanium composite after aggressive exposure to salts; however, a reduction in friction was still observed. Unlike the crystalline sodium chloride deposits that tended to remain dry, hygroscopic magnesium chloride deposits absorbed ambient moisture from the air, liquefied, and retained a persistent lubricating effect on the titanium surfaces.

Blau, Peter Julian [ORNL; Truhan, Jr., John J [ORNL; Kenik, Edward A [ORNL

2007-01-01

322

Cast iron (CI) based soft magnetic BMG Ci88.3Al2Ga1P4.35B4.35  

NASA Astrophysics Data System (ADS)

Thermal stability, structure, and magnetic properties of bulk type Ci88.3Al2Ga1P4.35B4.35 alloy in ribbon form have been studied using differential thermal analysis, x-ray diffraction and magnetic measurements. Results reveal that crystallization peak temperature (Tx) and Curie temperature (Tc) of the as-cast alloy are respectively 513 and 370 °C. Crystallization of the specimen starts after annealing at 460 °C and ?-Fe is precipitated out. Annealing at temperatures higher than 515 °C, produces apart from ?-Fe, hard magnetic precipitants (Fe2B, Fe3B), which deteriorate the soft magnetic properties. Lowest coercive field - 9.8 A/m, highest saturation of induction - 1.55 Tesla and best losses - 0.42 W/kg (at 50 Hz and 0.4 kA/m) were obtained for as-cast specimen. Observed good soft magnetic properties of these low cost cast-iron based alloys suggest perspective applications of these soft magnetic alloys as an alternative to the conventional Fe-Si electrical steel and Mn-Zn ferrites.

Kane, S. N.; Lee, H. J.; Jeong, Y. H.; Varga, L. K.

2009-01-01

323

Effects of samarium (Sm) additions on the microstructure and mechanical properties of as-cast and hot-extruded Mg5 wt%Al3 wt%Ca-based alloys  

Microsoft Academic Search

Samarium (Sm) additions to as-cast Mg-5Al-3Ca-based alloys result in changes, such as equiaxed grains and a refined grain size. The microstructure of as-cast Mg-5Al-3Ca-xSm alloys consists of an ?-Mg matrix, a (Mg, Al)2Ca eutectic phase, and an Al2Sm intermetallic compound. In as-cast alloys, the (Mg, Al)2Ca eutectic phase was located at grain boundaries with a chain structure, and the Al2Sm

Hyeon-Taek Son; Jae-Seol Lee; Dae-Guen Kim; Kyosuke Yoshimi; Kouichi Maruyama

2009-01-01

324

Importance and efficiency of in-depth antimicrobial activity for the control of listeria development with nisin-incorporated sodium caseinate films  

Microsoft Academic Search

The effect of antimicrobial sodium caseinate-based films was investigated on inhibition of Listeria innocua in cheese. Nisin was incorporated into sorbitol-plasticized sodium caseinate films at 1000IU\\/cm2 and the films were prepared by casting methods. Mini red Babybel® cheese was chosen as a semi-soft cheese model. The antimicrobial activity was studied based on the contact between antimicrobial films and surface-contaminated as

Lan Cao-Hoang; Lydie Grégoire; Aline Chaine; Yves Waché

2010-01-01

325

Efficacy of polyethylene-based antimicrobial films containing principal constituents of basil  

Microsoft Academic Search

The feasibility of low-density polyethylene (LDPE)-based films containing linalool or methylchavicol as antimicrobial (AM) packages to retard microbial growth on food surfaces was investigated. The AM LDPE-based films were tested for inhibition against selected microorganisms. Both compounds retained their AM activity, after an extrusion film-blowing process, against Escherichia coli in solid medium. Cheddar cheese was wrapped with the AM films

Panuwat Suppakul; Kees Sonneveld; Stephen W. Bigger; Joseph Miltz

2008-01-01

326

Usefulness of gel-casting method in the fabrication of nonstoichiometric CaZrO 3-based electrolytes for high temperature application  

Microsoft Academic Search

Hydrogels obtained from lower toxicity monomers of N-(hydroxymethyl)acrylamide and N,N?-methylenebisacrylamide were applied to form nonstoichiometric CaZrO3-based electrolytes. A coprecipitation-calcination method with ((NH4)2C2O4) in concentrated NH3 aqueous solution was used to synthesise CaZrO3 involving 51mol.% CaO (CZ-51) powder. The gas-tight CaZrO3-based rods were prepared by the gel-casting method with 45vol.% suspension and then sintered at 1500°C–2h. It was found that in

Magdalena Dudek

2009-01-01

327

The effect of hydrolysis degree on the properties of antibacterial polymeric films based on poly(vinyl alcohol) and zinc sulphate for biomedical applications.  

PubMed

Fully and partially hydrolyzed poly(vinyl alcohol) (PVA) was modified with zinc sulphate in the concentration range from 0 to 9 wt% of recalculated zinc content using the solvent cast technique. The resulting polymeric films were characterized by optical microscopy, stress-strain analysis, differential scanning calorimetry and Fourier transform infrared spectroscopy (FT-IR-ATR). In addition, agar diffusion test and dilution and spread plate technique were used for determination of antibacterial properties of the films against both Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli, Pseudomonas aeruginosa and Klebsiella pneumoniae) bacterial strains. A mathematical model was applied on the measured data and parameters characterizing the antibacterial efficiency of the material were calculated and discussed. The results revealed that the PVA hydrolysis degree can play an important role in all studied properties, including antibacterial activity of the all PVA-based materials. PMID:20534194

Sedlarik, Vladimir; Galya, Tsermaa; Sedlarikova, Jana; Valasek, Pavel; Saha, Petr

2010-06-08

328

Synthetic casting tapes: benefits and uses of Delta-Cast Conformable.  

PubMed

Casting is a traditional practice that has changed relatively little over thousands of years. Today, however, with the emphasis on evidence-based medicine, health professionals are examining the practice and investigating ways of improving it for the benefit of both patients and those who perform it. Most fractures and many soft tissue injuries are usually managed in a rigid cast, which brings with it complications and disadvantages. The ideal form of fracture fixation would stabilize the fracture while allowing some movement of the fracture site and soft tissue compression. This article explores the use of Delta-Cast Conformable (Johnson and Johnson), a synthetic casting tape, in both primary and secondary casting. The role of Delta-Cast Conformable with regard to focused rigidity casting, a new philosophy in fracture management, is discussed. PMID:9866464

Capper, C

329

INTERIOR VIEW WITH CASTING MACHINE AND CASTING FOREMAN OBSERVING OPERATION ...  

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

INTERIOR VIEW WITH CASTING MACHINE AND CASTING FOREMAN OBSERVING OPERATION TO ENSURE MAXIMUM PRODUCTION AND QUALITY. - McWane Cast Iron Pipe Company, Pipe Casting Area, 1201 Vanderbilt Road, Birmingham, Jefferson County, AL

330

Development of Stronger and More Reliable Cast Austenitic Stainless Steels (H-Series) Based on Scientific and Design Methodology  

SciTech Connect

The goal of this project was to increase the high-temperature strength of the H-Series of cast austenitic stainless steels by 50% and the upper use temperature by 86 to 140 degrees fahrenheit (30 to 60 degrees celsius). Meeting this goal is expected to result in energy savings of 35 trillion Btu/year by 2020 and energy cost savings of approximately $230 million/year. The higher-strength H-Series cast stainless steels (HK and HP type) have applications for the production of ethylene in the chemical industry, for radiant burner tubes and transfer rolls for secondary processing of steel in the steel industry, and for many applications in the heat treating industry, including radiant burner tubes. The project was led by Duraloy Technologies, Inc., with research participation by Oak Ridge National Laboratory (ORNL) and industrial participation by a diverse group of companies.

Pankiw, Roman I; Muralidharan, G. (Murali); Sikka, Vinod K.

2006-06-30

331

Finite element simulations of the deformation of fused-cast refractories based on X-ray computed tomography  

Microsoft Academic Search

This work consists in building a 3D numerical model of the microstructure of a fused-cast refractory (two-phase material). Creep tests at temperatures as high as 1400°C reveal a major influence of the morphology of the phases on the material behavior. A possible 3D connectivity of the zirconia grains, related to the fabrication process, may explain the observed high creep resistance.

Kamel Madi; Samuel Forest; Michel Boussuge; Sylvain Gailliègue; Emilie Lataste; Jean-Yves Buffière; Dominique Bernard; Dominique Jeulin

2007-01-01

332

A Novel Multi-Sender algorithm based on MultiCast Concept for P2P Networks  

Microsoft Academic Search

Unlike those on Internet, the media providers on P2P networks are ordinary nodes whose contribution bandwidth is limited. Multi-sender methods are the best solutions known to video streaming on P2P networks. In this paper, we propose use of a multi-cast method on the top of an arbitrary multi-sender method so that all requesting peers receive almost the same expected bit-rate.

M. H. Firooz; K. Ronasi; M. R. Pakravan; A. N. Avanaki

2006-01-01

333

Tensile, creep, and low-cycle fatigue behavior of a cast ? -TiAl-based alloy for gas turbine applications  

Microsoft Academic Search

The influence of chemical composition on the microstructure of the ?-titanium aluminide alloy Ti-48Al-2W-0.5Si (at. pct) and the accompanying tensile, low-cycle fatigue, and creep properties\\u000a has been evaluated. The study showed that small variations in chemical composition and casting procedures resulted in considerable\\u000a variations in the microstructure, yielding vastly different mechanical properties. Low contents of aluminum and tungsten led\\u000a to

V. Recina; D. Lundström; B. Karlsson

2002-01-01

334

Simultaneous Modification of Bottom-Contact Electrode and Dielectric Surfaces for Organic Thin-Film Transistors Through Single-Component Spin-Cast Monolayers  

SciTech Connect

An efficient process is developed by spin-coating a single-component, self-assembled monolayer (SAM) to simultaneously modify the bottom-contact electrode and dielectric surfaces of organic thin-film transistors (OTFTs). This efficient interface modification is achieved using n-alkyl phosphonic acid based SAMs to prime silver bottom-contacts and hafnium oxide (HfO{sub 2}) dielectrics in low-voltage OTFTs. Surface characterization using near edge X-ray absorption fine structure (NEXAFS) spectroscopy, X-ray photoelectron spectroscopy (XPS), attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy, atomic force microscopy (AFM), and spectroscopic ellipsometry suggest this process yields structurally well-defined phosphonate SAMs on both metal and oxide surfaces. Rational selection of the alkyl length of the SAM leads to greatly enhanced performance for both n-channel (C60) and p-channel (pentacene) based OTFTs. Specifically, SAMs of n-octylphos-phonic acid (OPA) provide both low-contact resistance at the bottom-contact electrodes and excellent interfacial properties for compact semiconductor grain growth with high carrier mobilities. OTFTs based on OPA modifi ed silver electrode/HfO{sub 2} dielectric bottom-contact structures can be operated using < 3V with low contact resistance (down to 700 Ohm-cm), low subthreshold swing (as low as 75 mV dec{sup -1}), high on/off current ratios of 107, and charge carrier mobilities as high as 4.6 and 0.8 cm{sup 2} V{sup -1} s{sup -1}, for C60 and pentacene, respectively. These results demonstrate that this is a simple and efficient process for improving the performance of bottom-contact OTFTs.

O Acton; M Dubey; t Weidner; K OMalley; T Kim; G Ting; D Hutchins; J Baio; T Lovejoy; et al.

2011-12-31

335

Effects of Vanadium Doping on Resistive Switching Characteristics and Mechanisms of Based Memory Films  

Microsoft Academic Search

The effects of vanadium doping on resistive switching (RS) characteristics and mechanisms of RF-sputtered SrZrO3 (SZO)-based thin films are investigated in this paper. The physical and electrical properties of SZO-based thin films are modulated by vanadium doping due to the Zr4+ ion replaced by V5+, further affecting the RS parameters of SZO-based thin films. The conduction mechanisms of SZO-based thin

Meng-Han Lin; Ming-Chi Wu; Chen-Hsi Lin; Tseung-Yuen Tseng

2010-01-01

336

Effect of casting methods on accuracy of peridental restorations.  

PubMed

The present study has shown that the accuracy of peridental gold alloy castings depends 1) on the type of casting machine used, 2) on the diameter of the casting sprue, and 3) on the strength properties of the investment material. The dependence between the accuracy and the three factors mentioned is based on erosion of the investment mold by the inflow of the liquid casting alloy. The vacuum casting technique proved to be a more gentle casting method than centrifugal and vacuum/pressure techniques. PMID:7051263

Finger, W; Kota, K

1982-06-01

337

Development of Advanced Coating Techniques for Highly-durable Casting Dies  

NASA Astrophysics Data System (ADS)

In order to improve the durability of aluminum die-casting molds, we applied microstructure-controlled PVD coating techniques. Single-layer and multilayer films consisting of chromium nitride (CrN) or titanium aluminum nitride (TiAlN) were prepared using an ion plating process. Structures of multilayer films were observed using transmission electron microscopy. Pin-shaped mold steel specimens coated with each of the films were soaked in the molten aluminum alloy at 953 K different periods of time, and the amount of weight loss due to erosion was evaluated. The weight losses for the multilayer CrN and TiAlN specimens were found to be less than those for the single-layer specimens. As a practical test, five specimens of core pins used in aluminum die casting of automobile parts were coated with multilayer films, and the number of maintenance operations required to remove aluminum alloy remaining on the specimen surfaces after several thousand castings was counted and compared with six control specimens (core pins treated using a commercial salt bath diffusion process). The number of maintenance operations for CrN- and TiAlN-based multilayer-coated core pins was found to be lower than for the control specimens.

Tanaka, S.; Takagi, M.; Mano, T.

2013-03-01

338

Titanium Castings Today.  

National Technical Information Service (NTIS)

Titanium castings weighing from a few grams to over half a ton are being produced. Three foundries produce castings in rammed graphite molds chiefly for applications where high resistance to corrosion is important. Three other foundries use investment mol...

J. G. Kura

1973-01-01

339

Casting Characteristics of Aluminum Die Casting Alloys  

Microsoft Academic Search

The research program investigates the casting characteristics of selected aluminum die casting alloys. Specifically, the alloys' tendencies towards die soldering and sludge formation, and the alloys' fluidity and machinability are evaluated. It was found that: When the Fe and Mn contents of the alloy are low; caution has to be taken against possible die soldering. When the alloy has a

Makhlouf M. Makhlouf; Diran Apelian

2002-01-01

340

Characterization of the surface free energy of cellulose ether films  

Microsoft Academic Search

The objective of this study was to determine the surface free energy components of aqueous-based cellulose ether films and compare these values with those of other cellulose polymers. The surface free energy parameters were calculated from the contact angles of sessile drops of apolar and polar liquids on cellulose ether films cast on glass slides using the Lifshitz–van der Waals\\/acid–base

Paul E Luner; Euichaul Oh

2001-01-01

341

Preparation of Highly Adhesive and Superhydrophobic Epoxy-Based Thin Film by Sol–Gel Process  

Microsoft Academic Search

In this study the preparation of a superhydrophobic epoxy-based thin film with excellent high adhesion properties was carried out by mixing epoxy polymer solution, MTMOS solution, and silica powder. It was found that the adhesion between the film and a substrate could be improved by adding PET fibers to the above solution. The characteristic properties of the as-prepared films were

Guan-Yu Wu; Shi-Sheng Wang; Jen-Chin Wu; Ming-Yau Hsu; Hui Chen

2011-01-01

342

Evaluation of a CCD-based film digitizer for digital mammography  

Microsoft Academic Search

Film digitalization is the process of mapping the optical densities of a radiographic film into a digital matrix. In this work, a film digitizer based on charge-coupled device was evaluated and optimized for digital mammography applications. The characteristics of the digital output were determined for various spatial resolutions and dynamic ranges. Furthermore, the reproducibility of the system was tested as

Maria Kallergi; Marios A. Gavrielides; William W. Gross; Laurence P. Clarke

1997-01-01

343

Development of Titanium Alloy Casting Technology.  

National Technical Information Service (NTIS)

This program was conducted to develop the technologies necessary to establish a low-cost approach for producing titanium investment castings. This approach was based on using simpler and cheaper melting and casting techniques, common to steel and super-al...

D. R. Schuyler G. S. Hall J. A. Petrusha S. R. Seagle

1976-01-01

344

LLNL casting technology  

NASA Astrophysics Data System (ADS)

Competition to produce cast parts of higher quality, lower rejection rate, and lower cost is a fundamental factor in the global economy. To gain an edge on foreign competitors, the US casting industry must cut manufacturing costs and reduce the time from design to market. Casting research and development (R&D) are the key to increasing US competiveness in the casting arena. Lawrence Livermore National Laboratory (LLNL) is the home of a wide range of R&D projects that push the boundaries of state-of-the art casting. LLNL casting expertise and technology include: casting modeling research and development, including numerical simulation of fluid flow, heat transfer, reaction/solidification kinetics, and part distortion with residual stresses; special facilities to cast toxic material; extensive experience casting metals and nonmetals; advanced measurement and instrumentation systems. Department of Energy (DOE) funding provides the leverage for LLNL to collaborate with industrial partners to share this advanced casting expertise and technology. At the same time, collaboration with industrial partners provides LLNL technologists with broader insights into casting industry issues, casting process data, and the collective experience of industry experts. Casting R&D is also an excellent example of dual-use technology; it is the cornerstone for increasing US industrial competitiveness and minimizing waste nuclear material in weapon component production. Annual funding for casting projects at LLNL is $10M, which represents 1% of the total LLNL budget. Metal casting accounts for about 80% of the funding. Funding is nearly equally divided between development directed toward US industrial competitiveness and weapon component casting.

Shapiro, A. B.; Comfort, W. J., III

1994-01-01

345

LLNL casting technology  

SciTech Connect

Competition to produce cast parts of higher quality, lower rejection rate, and lower cost is a fundamental factor in the global economy. To gain an edge on foreign competitors, the US casting industry must cut manufacturing costs and reduce the time from design to market. Casting research and development (R&D) are the key to increasing US compentiveness in the casting arena. Lawrence Livermore National Laboratory (LLNL) is the home of a wide range of R&D projects that push the boundaries of state-of-the art casting. LLNL casting expertise and technology include: casting modeling research and development, including numerical simulation of fluid flow, heat transfer, reaction/solidification kinetics, and part distortion with residual stresses; special facilities to cast toxic material; extensive experience casting metals and nonmetals; advanced measurement and instrumentation systems. Department of Energy (DOE) funding provides the leverage for LLNL to collaborate with industrial partners to share this advanced casting expertise and technology. At the same time, collaboration with industrial partners provides LLNL technologists with broader insights into casting industry issues, casting process data, and the collective, experience of industry experts. Casting R&D is also an excellent example of dual-use technology; it is the cornerstone for increasing US industrial competitiveness and minimizing waste nuclear material in weapon component production. Annual funding for casting projects at LLNL is $10M, which represents 1% of the total LLNL budget. Metal casting accounts for about 80% of the funding. Funding is nearly equally divided between development directed toward US industrial competitiveness and weapon component casting.

Shapiro, A.B.; Comfort, W.J. III [eds.

1994-01-01

346

Graphene-based flexible and stretchable thin film transistors.  

PubMed

Graphene has been attracting wide attention owing to its superb electronic, thermal and mechanical properties. These properties allow great applications in the next generation of optoelectronics, where flexibility and stretchability are essential. In this context, the recent development of graphene growth/transfer and its applications in field-effect transistors are involved. In particular, we provide a detailed review on the state-of-the-art of graphene-based flexible and stretchable thin film transistors. We address the principles of fabricating high-speed graphene analog transistors and the key issues of producing an array of graphene-based transistors on flexible and stretchable substrates. It provides a platform for future work to focus on understanding and realizing high-performance graphene-based transistors. PMID:22767356

Yan, Chao; Cho, Jeong Ho; Ahn, Jong-Hyun

2012-07-06

347

Analogy Between Heat and Mass Transfer for Constant-Rate Period During Non-Convective Drying: Application to Water-Based Alumina Suspension for Tape Casting  

NASA Astrophysics Data System (ADS)

Analogy between heat and mass transfer is proposed for the constant-rate period during non-convective drying process. The analogy is applied to predict a temperature-dependent heat-transfer coefficient from a temperature-dependent mass-transfer coefficient also presented for the constant-rate period during non-convective drying of water-based alumina suspension for tape casting. Predicted values of the temperature-dependent heat and mass transfer coefficients are compared with experimental data and good agreement is obtained.

Puyate, Y. T.

348

Yield Improvement in Steel Casting (Yield II)  

SciTech Connect

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

Richard A. Hardin; Christoph Beckermann; Tim Hays

2002-02-18

349

Effect of surfactants on the functional properties of gelatin-based edible films  

Microsoft Academic Search

The aim of this research was to evaluate the plasticizing effect of natural surfactants lecithin or yucca extract from Yucca schidigera on gelatin-based films. Films containing yucca extract showed higher tensile strength values (?90–40MPa) and moisture contents (?15%) and less elongation (?5%) and water vapor permeability values (?0.22–0.09gmmm?2h?1kPa?1) compared to films containing lecithin. Soluble films (?20–50%) were obtained when yucca

Caroline Andreuccetti; Rosemary A. Carvalho; Tomás Galicia-García; Fernando Martínez-Bustos; Carlos R. F. Grosso

2011-01-01

350

Ozone sensors on the base of SnO 2 films deposited by spray pyrolysis  

Microsoft Academic Search

The gas-sensing properties of SnO2-based thin films designed for ozone detection are discussed in this paper. The influence of film characteristics on sensor performance is analyzed. SnO2 films with thickness 30–200nm were deposited by spray pyrolysis. The SnO2 films have a response to ozone that is quantitative and rapid and sufficient for use in ozone control and monitoring applications. Sensor

G. Korotcenkov; I. Blinov; M. Ivanov; J. R. Stetter

2007-01-01

351

Vitreous tin oxide-based thin film electrodes for Li-ion micro-batteries  

Microsoft Academic Search

Sputter deposited thin films from a Sn\\/(SnO)(B2O3)0.3(P2O5)0.2 composite target are investigated as an alternative to the lithium metal anode for lithium-ion micro-batteries. Experimental conditions related to the manufacturing of the target and elaboration of the vitreous thin films are described. Chemical and physical properties of the thin layer films are presented. Regarding the electrochemical behavior, vitreous tin oxide-based thin films

C Branci; N Benjelloun; J Sarradin; M Ribes

2000-01-01

352

Growth of hierarchical based ZnO micro\\/nanostructured films and their tunable wettability behavior  

Microsoft Academic Search

Hierarchical zinc oxide (ZnO) micro\\/nanostructured thin films were grown onto as-prepared and different annealed ZnO seed layer films by a simple two step chemical process. A cost effective successive ionic layer adsorption and reaction (SILAR) method was employed to grow the seed layer films at optimal temperature (80°C) and secondly, different hierarchical based ZnO structured thin films were deposited over

P. Suresh Kumar; A. Dhayal Raj; D. Mangalaraj; D. Nataraj; N. Ponpandian; Lin Li; G. Chabrol

2011-01-01

353

Egyptian Caste System  

NSDL National Science Digital Library

Understand the culture, character, and societal characteristics of different classes in the ancient Egyptian caste system Understand the culture, character, and societal characteristics of different classes in the ancient Egyptian caste system Go to these sites to learn about the Egyptian Caste System ...

Issen, Ms.

2009-09-17

354

Solution-cast films of poly(3,4-ethylenedioxythiophene) as ion-to-electron transducers in all-solid-state ion-selective electrodes  

Microsoft Academic Search

An aqueous dispersion of poly(3,4-ethylenedioxythiophene) (PEDOT) doped with poly(styrenesulfonate) (PSS) was cast on screen-printed gold substrates. PEDOT(PSS) was ionically (physically) crosslinked by multivalent cations, including Mg2+, Ca2+, Fe2+\\/3+ and Ru(NH3)62+\\/3+ to form a hydrogel in order to decrease the water solubility of the PEDOT(PSS). The resulting Au\\/PEDOT(PSS) electrodes were characterized by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and energy-dispersive

Mercedes Vázquez; Petter Danielsson; Johan Bobacka; Andrzej Lewenstam; Ari Ivaska

2004-01-01

355

Sacrificial Mg film anode for cathodic protection of die cast Mg–9 wt.%Al–1 wt.%Zn alloy in NaCl aqueous solution  

Microsoft Academic Search

An Mg film was coated on one side of an Mg–9wt.%Al–1wt.%Zn (AZ91D) sample to form a galvanic couple in NaCl aqueous solution. The sacrificial Mg film anode cathodically protected the AZ91D substrate, because the mixed potential of the Mg coating\\/AZ91D couple was more anodic than the corrosion potential of the substrate.

Bing-Lung Yu; Jun-Yen Uan

2006-01-01

356

A sensor of alcohol vapours based on thin polyaniline base film and quartz crystal microbalance.  

PubMed

Thin films of polyaniline base, emeraldine base (EB), coating on the quartz crystal microbalance (QCM) electrode were used as a sensitive layer for the detection of a number of primary aliphatic alcohols such as ethanol, methanol, 2-propanol and 1-propanol vapours. The frequency shifts (Deltaf) of the QCM were increased due to the vapour adsorption into the EB film. Deltaf were found to be linearly correlated with the concentrations of alcohols vapour in part per million (ppm). The sensitivity of the sensor was found to be governed by the chemical structure of the alcohol. The sensor shows a good reproducibility and reversibility. The diffusions of different alcohols vapour were studied and the diffusion coefficients (D) were calculated. It is concluded that the diffusion of the vapours into the EB film follows Fickian kinetics. PMID:19264405

Ayad, Mohamad M; El-Hefnawey, Gad; Torad, Nagy L

2009-02-07

357

Release behavior and stability of encapsulated D-limonene from emulsion-based edible films.  

PubMed

Edible films may act as carriers of active molecules, such as flavors. This possibility confers to them the status of active packaging. Two different film-forming biopolymers, gluten and ?-carrageenans, have been compared. D-Limonene was added to the two film formulations, and its release kinetics from emulsion-based edible films was assessed with HS-SPME. Results obtained for edible films were compared with D-limonene released from the fatty matrix called Grindsted Barrier System 2000 (GBS). Comparing ?-carrageenans with gluten-emulsified film, the latter showed more interesting encapsulating properties: in fact, D-limonene was retained by gluten film during the process needed for film preparation, and it was released gradually during analysis time. D-Limonene did not show great affinity to ?-carrageenans film, maybe due to high aroma compound hydrophobicity. Carvone release from the three different matrices was also measured to verify the effect of oxygen barrier performances of edible films to prevent D-limonene oxidation. Further investigations were carried out by FT-IR and liquid permeability measurements. Gluten film seemed to better protect D-limonene from oxidation. Gluten-based edible films represent an interesting opportunity as active packaging: they could retain and release aroma compounds gradually, showing different mechanical and nutritional properties from those of lipid-based ingredients. PMID:23163743

Marcuzzo, Eva; Debeaufort, Frédéric; Sensidoni, Alessandro; Tat, Lara; Beney, Laurent; Hambleton, Alicia; Peressini, Donatella; Voilley, Andrée

2012-12-04

358

Fabrication of graphene-based films using remote plasma CVD  

NASA Astrophysics Data System (ADS)

Plasma-enhanced CVD (PECVD) employing methane/hydrogen gases has been used to grow diamond, diamond-like carbon, and carbon nanotubes. In the case of microwave PECVD with methane/hydrogen system without catalyst nanoparticles at temperatures of 700--850 ^oC, where the substrate is exposed to the plasma, vertical nano-graphenes and carbon nanoflakes have been easily grown even on Cu substrate due to the ion bombardment and local electric field forces. In this work, we demonstrate the synthesis of planar few-layer graphene-based film using PECVD with remote plasma configuration. In the case using microwave plasma of cylindrical resonant cavity type, by simply installing grounded grid over the substrate plate for obtaining remote plasma configuration, we have successfully fabricated graphene-based films on Cu substrate, which was confirmed by the Raman spectrum and SEM image of deposit. Similar method will be applied to other plasmas such as low-pressure inductively coupled plasma, in order to verify the effectiveness of remote plasma configuration for the growth of planar graphene using PECVD technique. We will discuss the planar graphene growth mechanism in terms of precursors and their surface reaction.

Hiramatsu, Mineo; Tsukada, Ryosuke; Kashima, Yohei; Naito, Masateru; Kondo, Hiroki; Hori, Masaru

2012-10-01

359

A comparison of mechanical properties of all-ceramic alumina dental crowns prepared from aqueous- and non-aqueous-based tape casting.  

PubMed

Alumina-glass dental composites were prepared by aqueous- and non-aqueous-based tape casting and sintering at 1120 degrees C, followed by glass infiltration at 1100 degrees C. Flexural strength and fracture toughness of the composites were investigated in terms of influence of tape constituents, namely, alumina powder, binder, and plasticizer on the mechanical properties. For the alumina-glass composites prepared from the aqueous-based tapes, both strength and toughness increased with increasing alumina fraction ratio in tape constituents including organic substances, a/a+o, and binder content ratio in binder/binder + plasticizer mixture, b/b+p. For the composites prepared from the non-aqueous-based tapes, on the other hand, both strength and toughness increased with increasing the a/a+o ratio but decreased with increasing the b/b+p ratio. These observations were consistent with influence of the constituents on mean alumina particle distance in tapes, suggesting that high strength of the glass infiltrated alumina composites is related to toughening by crack bowing. The optimized strength of the aqueous and nonaqueous tape cast composites was 559 and 508 MPa, and the fracture toughness was 3.3 and 3.1 MPam(1/2), respectively. PMID:10898872

Kim, D J; Lee, M H; Lee, D Y; Han, J S

2000-01-01

360

Biodegradability and mechanical properties of starch films from Andean crops.  

PubMed

Different Andean crops were used to obtain starches not previously reported in literature as raw material for the production of biodegradable polymers. The twelve starches obtained were used to prepare biodegradable films by casting. Water and glycerol were used as plasticizers. The mechanical properties of the starch based films were assessed by means of tensile tests. Compost tests and FTIR tests were carried out to assess biodegradability of films. The results show that the mechanical properties (UTS, Young's modulus and elongation at break) of starch based films strongly depend on the starch source used for their production. We found that all the starch films prepared biodegrade following a three stage process and that the weight loss rate of all the starch based films tested was higher than the weight loss rate of the cellulose film used as control. PMID:21300087

Torres, F G; Troncoso, O P; Torres, C; Díaz, D A; Amaya, E

2011-02-12

361

Mechanical properties and microstructures of cast Ti–Cu alloys  

Microsoft Academic Search

Objectives: This study evaluated the mechanical properties of cast Ti–Cu alloys with the hope of developing an alloy for dental casting with better mechanical properties than unalloyed titanium.Methods: Ti–Cu alloys with five concentrations of copper (0.5, 1.0, 2.0, 5.0 and 10.0mass%) were made in an argon-arc melting furnace. The alloys were cast into magnesia-based molds using a centrifugal casting machine.

Masafumi Kikuchi; Yukyo Takada; Seigo Kiyosue; Masanobu Yoda; Margaret Woldu; Zhuo Cai; Osamu Okuno; Toru Okabe

2003-01-01

362

Effect of Pressure Difference on the Quality of Titanium Casting  

Microsoft Academic Search

In casting titanium using a two-compartment casting machine, Herø et al. (1993) reported that the pressure difference between the melting chamber and the mold chamber affected the soundness of the castings. This study tested the hypothesis that differences in pressure produce castings with various amounts of porosity and different mechanical properties values. Plastic dumbbell-shaped patterns were invested with an alumina-based,

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

1997-01-01

363

Advances in aluminum casting technology  

SciTech Connect

This symposium focuses on the improvements of aluminum casting quality and reliability through a better understanding of processes and process variables, and explores the latest innovations in casting-process design that allow increasing use of the castings to replace complex assemblies and heavy steel and cast-iron components in aerospace and automotive applications. Presented are 35 papers by international experts in the various aspects of the subject. The contents include: Semisolid casting; Computer-aided designing of molds and castings; Casting-process modeling; Aluminum-matrix composite castings; HIPing of castings; Progress in the US car project; Die casting and die design; and Solidification and properties.

Tiryakioglu, M.; Campbell, J. (eds.)

1998-01-01

364

Process Modeling of Low-Pressure Die Casting of Aluminum Alloy Automotive Wheels  

NASA Astrophysics Data System (ADS)

Although on initial inspection, the aluminum alloy automotive wheel seems to be a relatively simple component to cast based on its shape, further insight reveals that this is not the case. Automotive wheels are in a select group of cast components that have strict specifications for both mechanical and aesthetic characteristics due to their important structural requirements and their visibility on a vehicle. The modern aluminum alloy automotive wheel continues to experience tightened tolerances relating to defects to improve mechanical performance and/or the physical appearance. Automotive aluminum alloy wheels are assessed against three main criteria: wheel cosmetics, mechanical performance, and air tightness. Failure to achieve the required standards in any one of these categories will lead to the wheel either requiring costly repair or being rejected and remelted. Manufacturers are becoming more reliant on computational process modeling as a design tool for the wheel casting process. This article discusses and details examples of the use of computational process modeling as a predictive tool to optimize the casting process from the standpoint of defect minimization with the emphasis on those defects that lead to failure of aluminum automotive wheels, namely, macroporosity, microporosity, and oxide films. The current state of applied computational process modeling and its limitations with regard to wheel casting are discussed.

Reilly, C.; Duan, J.; Yao, L.; Maijer, D. M.; Cockcroft, S. L.

2013-09-01

365

Enhanced SPR sensing based on micro-patterned thin films  

Microsoft Academic Search

Micro-patterned thin films interrogated in the Kretschmann configuration of SPR could extend the detection range to lower concentrations and small biomolecules due to a greater sensitivity. This was achieved with the same instrumentation and analysis methodologies developed for SPR with continuous films. The plasmonic properties of micro-patterned thin films composed of various layers of Ag and Au were investigated to

Ludovic S. Live; Julien Breault-Turcot; Kim-Ly Nguyen; Jean-Francois Masson

2011-01-01

366

Design of high frequency inductors based on magnetic films  

Microsoft Academic Search

Magnetically coated stripe inductors with conductor insulated from the magnetic film and with conductor in direct electrical contact with the magnetic film are analyzed. A simple equivalent circuit model shows that for the structure without insulation, regardless of the fact that the dc resistivity of the magnetic film is much higher than that of the conductor, most of the driving

V. Korenivski; R. B. van Dover

1998-01-01

367

A compositional based model for the tear film lipid layer.  

PubMed Central

BACKGROUND: The tear film lipid layer is formed from lipids secreted by meibomian glands of the eyelid. After initial analyses of these lipids we concluded that an understanding of the function of the various classes of lipids in a normal lipid layer could only be understood after detailed investigations of both polar and nonpolar lipids of the meibomian gland. METHODS: Meibomian gland secretions were obtained from normals. Lipids were separated by thin layer chromatography and high pressure liquid chromatography, and analyzed by UV absorbance, gas chromatography and mass spectroscopy. RESULTS: Based on our analyses we concluded that the current understanding of lipid layer composition and function were inadequate or misleading. We therefore propose that the more polar lipids function as a structure (with surfactant characteristics) upon which the functional stability of the more nonpolar lipids are dependent. We further suggest that the interrelationships between lipid classes present, length of fatty acids and alcohols, their unsaturation, and hydroxylation are important for maintaining proper thixotropic characteristics of the lipid layer as well as optimal barrier properties. CONCLUSION: The tear film lipid layer is composed of 2 phases: (1) a thin polar phase adjacent to the aqueous-mucin phase and (2) a thick nonpolar phase associated with both the polar phase and the air interface. The structural characteristics of the polar phase and the barrier functions of the nonpolar phase are a direct result of specific compositional parameters.

McCulley, J P; Shine, W

1997-01-01

368

Effect of plasticizer (DMF) on electrical properties of PMMA based polymer electrolyte films  

NASA Astrophysics Data System (ADS)

Solid polymer electrolyte films of PMMA with NaClO4 and NaClO4+ plasticizer (dimethyl foramide) have been prepared by solution cast technique. DC conductivity of the films was measured in the temperature range 303-393 K. The variation of ionic conductivity as a function of temperature in polymer electrolyte was analyzed. In the temperature range studied, three regions with different activation energies were observed. Transference number data showed that the charge transport in this system is predominantly due to ions only. Electrochemical cells of configuration Na/(PMMA+NaClO4+DMF)/(I2+C+electrolyte) were fabricated and the discharge characteristics of these cells were studied under a constant load of 100K?. Several cell parameters associated with the cells were evaluated and compared with earlier reports.

Sekhar, P. Chandra; Kumar, P. Naveen; Sasikala, U.; Sharma, A. K.

2013-06-01

369

Tape Casting Method and Tape Cast Materials.  

National Technical Information Service (NTIS)

A precursor tape casting method is one in which chemical precursors are converted into a final chemical phase from green tapes to products. Because chemical precursors are employed rather than the final powder materials, sintering is not required to form ...

D. Xiao M. Wu S. Hui Y. Zhang

2005-01-01

370

Size factor of a fast film photodetector based on the optical rectification effect  

NASA Astrophysics Data System (ADS)

The photodetector based on optical rectification effect (ORE) was created using nanostructured carbon (nanographite) films. Sensitivity of the photodetector was studied in dependence on the carbon films size. It is shown that amplitude of electrical pulses generated by the photodetector depends on the thickness, length and width of the film area. The maximal sensitivity is reached at the film thickness of about 2.5 micrometers. It is shown also that the photoelectrical pulses appearing on the nanographite film have different nature than those appearing in on the silicon substrate.

Mikheev, Gennady M.; Zonov, Ruslan G.; Obraztsov, Alexander N.

2006-03-01

371

The fractography of casting alloys  

SciTech Connect

Several types of casting alloys were fractured using various loading modes (uniaxial tension, bending, impact, and torsion, and cyclic stressing), and the corresponding mechanical properties were determined. The unetched and etched fracture surfaces and the microstructures were examined using conventional techniques. The types of casting alloys that were the subjects f these investigations include gray iron, ductile iron, cast steel, and aluminum-base alloys (A380, A356, and 319). The fractographic studies have yielded these generalizations regarding the topography of the fracture surfaces. In the case of low-ductility alloys such as gray iron and the aluminum-base alloys, the tensile edge of a fracture surface produced by a stress system with a strong bending-moment component has a highly irregular contour, whereas the compressive edge of the fracture surface is quite straight and parallel to the bend axis. On the other hand, the periphery of a fracture surface produced by uniaxial tension has a completely irregular contour. The fracture surface produced by cyclic loading of a gray iron does not display any macroscopic evidence (such as a thumb nail) of the loading mode. However, the fracture surface of each of the other casting alloys displays clear, macroscopic evidence of failure induced by fatigue. The aluminum-base alloys fracture completely within the interdendritic region of the microstructure when subjected to monotonic loading by uniaxial tension or bending, whereas a fatigue crack propagates predominantly through the primary crystals of the microstructure.

Powell, G.W. (Ohio State Univ., Columbus, OH (United States))

1994-10-01

372

Effect of Gamma Radiation on the Physico- and ThermoMechanical Properties of Gelatin-Based Films Using 2-Hydroxyethyl Methacrylate (HEMA)  

Microsoft Academic Search

Gelatin films were prepared from gelatin granules in aqueous medium by casting. Tensile strength, tensile modulus, elongation at break and the glass point of the gelatin films were found to be 27 MPa, 100 MPa, 4% and 51.7°C, respectively. After irradiated with gamma radiation tensile properties were increased due to denser network structure. Gelatin films were soaked in five different formulations containing

Sabrina Sultana; Ruhul A. Khan; Mubarak A. Khan; A. I. Mustafa; M. A. Gafur

2010-01-01

373

Fabrication and electrochemical characterization of cobalt-based layered double hydroxide nanosheet thin-film electrodes  

Microsoft Academic Search

A continuous cobalt-based layered double hydroxide (LDH) nanosheet thin-film electrode has been fabricated by drying a nearly transparent colloidal solution of cobalt-based LDH nanosheets on an indium tin oxide (ITO)-coated glass plate substrate. The effects of varying the Al content, the film thickness, and the heating temperature on the electrochemical properties of the as-deposited thin-film electrode have been investigated. A

Yi Wang; Wensheng Yang; Chen Chen; David G. Evans

2008-01-01

374

All-optical image switch based on bacteriorhodopsin film  

NASA Astrophysics Data System (ADS)

While two waves are coupled in bacteriorhodopsin (bR) film, a beam of incident light carrying the image is transferred to two diffraction beams whose intensities can increase from zero to a maximum and then decrease to a stable value with the increase of the writing time. Based on the relation among the polarization states of image in a recording beam and diffraction beams, we have proposed and demonstrated the all-optical image transfer switch which depends on the effective time and has the function that within the effective time, a polarization state image is automatically transferred to two images whose polarization states are perpendicular, and the transfer stops automatically beyond the effective time. A time-dependent all-optical image switch with muti-outputs is implemented.

Chen, Guiying; Liang, Xin; Yuan, Yizhe; Yang, Guang; Zhang, Chunping; Xu, Tang; Song, Q. W.

2007-08-01

375

Perylene Diimide Based "Nanofabric" Thin Films for Organic Photovoltaic Cells  

NASA Astrophysics Data System (ADS)

We report progress in using a perylene diimide (PDI) nanofabric as an effective electron accepting nanostructure for organic photovoltaics (OPV). A key challenge in OPV continues to be the recovery of electrons after charge separation due to the relatively poor mobility of C60 and related materials. A series of PDI compounds and complexes have been synthesized and used to fabricate nanofibers and thin films using solution and vacuum deposition techniques. Overlaping PDI-based nanofibers form a fast electron-transporting "nanofabric" that has been characterized (AFM, PL, UV-vis, etc.) and can be blended with electron donating materials. A solution-processible OPV configuration containing a nanofabric heterojunction (FHJ) of poly(3-hexylthiophene) and the PDI nanofabric was investigated. We observed a significant improvement in power-conversion efficiency due in part to expansion of the interfacial area and the presence of high mobility electron pathways to the LiF/Al electrode.

Carter, Austin; Park, June Hyoung; Min, Yong; Epstein, Arthur

2011-03-01

376

Property evaluations of dry-cast reconstituted bacterial cellulose/tamarind xyloglucan biocomposites.  

PubMed

We describe the mechanical defibrillation of bacterial cellulose (BC) followed by the dry-cast generation of reconstituted BC films (RBC). Xyloglucan (XGT), extracted from tamarind seeds, was incorporated into the defibrillated cellulose at various compositions, and new films were created using the same process. Microscopy and contact angle analyses of films revealed an increase in the microfibre adhesion, a reduced polydispersity in the diameters of the microfibrils and increased hydrophobic behaviour as a function of %XGT. X-ray diffraction analysis revealed changes to the crystallographic planes of the RBC and the biocomposite films with preferential orientation along the (110) plane. Compared with BC, RBC/XGT biocomposite with 10% XGT exhibited improvement in its thermal properties and in Young's modulus. These results indicated a reorganisation of the microfibres with mechanical treatment, which when combined with hydrocolloids, can create cellulose-based materials that could be applied as scaffolding for tissue engineering and drug release. PMID:23465913

de Souza, Clayton F; Lucyszyn, Neoli; Woehl, Marco A; Riegel-Vidotti, Izabel C; Borsali, Redouane; Sierakowski, Maria Rita

2012-05-04

377

Dimensional variability of production steel castings  

SciTech Connect

Work is ongoing to characterize the dimensional variability of steel casting features. Data are being collected from castings produced at representative Steel Founders` Society of America foundries. Initial results based on more than 12,500 production casting feature measurements are presented for carbon and low alloy steel castings produced in green sand, no-bake, and shell molds. A comprehensive database of casting, pattern, and feature variables has been developed so that the influence of the variables on dimensional variability can be determined. Measurement system analysis is conducted to insure that large measurement error is not reported as dimensional variability. Results indicate that the dimensional variability of production casting features is less than indicated in current US (SFSA) and international (ISO) standards. Feature length, casting weight, parting line and molding process all strongly influence dimensional variability. Corresponding pattern measurements indicate that the actual shrinkage amount for casting features varies considerably. This variation in shrinkage will strongly influence the ability of the foundry to satisfy customer dimensional requirements.

Peters, F.E.; Risteu, J.W.; Vaupel, W.G.; DeMeter, E.C.; Voigt, R.C.

1994-12-31

378

Films based on bacteriorhodopsin in sol-gel matrices  

NASA Astrophysics Data System (ADS)

The bacteriorhodopsin film in gelatin matrixes which are used as sensitive elements of integrated optic and fibre-optic sensors of various vapor and gases components will not be able to carry out the chemical control of aqueous solutions. In the given paper the results of technological development of obtaining the bacteriorhodopsin (bR) films in a sol-gel matrix are represented. The films are obtained in a broad thickness range (from 0.5 to 20 microns) with various bR concentrations and photosensitize additives. The optimal technological conditions of obtaining of uniform films with given optical parameters are defined. The surface morphology and cross section of the obtained films was studied using an AFM and SEM. The films have a reasonable surface roughness (~ 100 nm) and a uniform distribution of the purple membrane fragments in the nanostructured sol-gel glass matrix along the films surface and thickness. The transmission spectrums have the characteristic for bR the absorption band, the value of which depends on bR concentration and technological features of the films deposition. The investigated photosensitive properties of the obtained films and influence on them of chemical components of aqueous solutions, allow recommending the thin bR films in sol-gel matrixes for creation of planar waveguides in the role of components of the chemical sensors of liquid solutions.

Korposh, S. O.; Sichka, M. Y.; Trikur, I. I.; Sharkan, Y. P.; Yang, D. H.; Lee, S. W.; Ramsden, J. J.

2005-09-01

379

Amorphous Silicon(aSi:H) Thin Film Based Omnidirectional Control Solar Powered Vehicle  

Microsoft Academic Search

Through the paper, our goal is to drive a car with the help of thin film based solar cell. Mechanical and Electrical parts are assembled thereby. The main objective of this project is to collect maximum solar energy from the solar spectrum and use that solar energy to drive the car. Amorphous silicon based thin film solar panel has been

Abdullah Moinuddin; Jony C. Sarker; Akhter Zia

2012-01-01

380

High performance thin film transistors based on regioregular poly(3-dodecylthiophene)-sorted large diameter semiconducting single-walled carbon nanotubes  

NASA Astrophysics Data System (ADS)

In this work, a simple and rapid method to selectively sort semiconducting-SWCNTs (sc-SWCNTs) with large diameters using regioregular poly(3-dodecylthiophene) (rr-P3DDT) is presented. The absorption spectra and Raman spectra demonstrated that metallic species of arc discharge SWCNTs were effectively removed after interaction with rr-P3DDT in toluene with the aid of sonication and centrifugation. The sorted sc-SWCNT inks have been directly used to fabricate thin film transistors (TFTs) by dip-coating, drop-casting and inkjet printing. TFTs with an effective mobility of ~34 cm2 V-1 s-1 and on-off ratios of ~107 have been achieved by dip coating and drop casting the ink on SiO2/Si substrates with pre-patterned interdigitated gold electrode arrays. The printed devices also showed excellent electrical properties with a mobility of up to 6.6 cm2 V-1 s-1 and on-off ratios of up to 105. Printed inverters based on the TFTs have been constructed on glass substrates, showing a maximum voltage gain of 112 at a Vdd of -5 V. This work paves the way for making printable logic circuits for real applications.In this work, a simple and rapid method to selectively sort semiconducting-SWCNTs (sc-SWCNTs) with large diameters using regioregular poly(3-dodecylthiophene) (rr-P3DDT) is presented. The absorption spectra and Raman spectra demonstrated that metallic species of arc discharge SWCNTs were effectively removed after interaction with rr-P3DDT in toluene with the aid of sonication and centrifugation. The sorted sc-SWCNT inks have been directly used to fabricate thin film transistors (TFTs) by dip-coating, drop-casting and inkjet printing. TFTs with an effective mobility of ~34 cm2 V-1 s-1 and on-off ratios of ~107 have been achieved by dip coating and drop casting the ink on SiO2/Si substrates with pre-patterned interdigitated gold electrode arrays. The printed devices also showed excellent electrical properties with a mobility of up to 6.6 cm2 V-1 s-1 and on-off ratios of up to 105. Printed inverters based on the TFTs have been constructed on glass substrates, showing a maximum voltage gain of 112 at a Vdd of -5 V. This work paves the way for making printable logic circuits for real applications. Electronic supplementary information (ESI) available. See DOI: 10.1039/c3nr34304a

Wang, Chao; Qian, Long; Xu, Wenya; Nie, Shuhong; Gu, Weibing; Zhang, Jianhui; Zhao, Jianwen; Lin, Jian; Chen, Zheng; Cui, Zheng

2013-05-01

381

Predicting initial treatment failure of fiberglass casts in pediatric distal radius fractures: utility of the second metacarpal-radius angle  

PubMed Central

Purpose Recent literature comparing the effectiveness of above-elbow and below-elbow plaster casts appears to suggest that either cast type offers adequate immobilization for distal radius and ulna fractures. The idea that an appropriate mold placed on the cast is the most significant determinant of successful immobilization and, thereby, patient outcome has also been elucidated. The purpose of this study was to compare the effectiveness of above-elbow versus below-elbow fiberglass casts in maintaining distal radius/ulna fracture reduction and to identify factors associated with treatment failures. Methods We reviewed the radiographs and clinical data of 253 children with distal third forearm fractures requiring reduction under conscious sedation or a hematoma block. Outcome measures included rates of re-manipulation, loss of reduction, and cast complications. Results One hundred and nineteen children were treated with below-elbow fiberglass casts and 134 were treated with above-elbow fiberglass casts based on a clinical pathway created before the study period. There were no differences between the two groups in age, weight, fracture pattern, percentage of both-bone fractures, and initial fracture angulation. Of the 253 fractures in the study, 38 (15%) were considered to have less than ideal outcomes. There were no differences between the ‘ideal’ and ‘non-ideal’ groups in age, fracture pattern, presence of ulna fracture, cast index, or cast type. All immediate post-reduction measures (anterior-posterior [AP] and lateral displacement/angulation) were significantly correlated with treatment outcome, except angulation on AP films. The magnitude of reduction as measured by a newly described variable, the angle between the second metacarpal and long axis of the radius in the AP projection, was significantly correlated with treatment failure (r = ?0.139, P = 0.027). Binary logistic regression was performed and demonstrated that the success of the reduction, as determined by the AP radiograph second metacarpal-radius angle, was a significant predictor of treatment success (odds ratio 1.6, P < 0.001). Also, the change in lateral view angulation post-reduction was a significant predictor of treatment failure based on regression (odds ratio 1.2, P = 0.004). The above-elbow cast group had a slightly greater cast index (0.80) compared to the below-elbow cast group (0.77) (P = 0.003). Whereas below-elbow fiberglass casts appear to be equally effective in immobilizing pediatric distal third forearm fractures as above-elbow fiberglass casts, it seems that they have an increased risk for poor molding, particularly with regards to ulnar deviation. We did not find an association between the treatment ‘failure’ and cast index, likely because the number of poor molds (cast index >0.8) was nearly equal in each group (above-elbow with 61 and below-elbow with 45). However, the mold seen on the AP radiograph as determined by the second metacarpal-radius angle was a reproducible radiographic predictor of treatment success. If molded with ulnar deviation (second metacarpal-radius angle >0°), the outcome was considered to be ideal in 86.7% of cases compared to only 74.4% when it was <0°. Conclusion We agree with prior studies suggesting the equal efficacy of below-elbow versus above-elbow casts in distal radius and ulna fracture treatment using either plaster or fiberglass, but wish to emphasize the importance of not only the cast index, but also the ulnar deviation mold (for most dorsally displaced fractures), as measured by the second metacarpal-radius angle.

Edmonds, Eric W.; Capelo, Roderick M.; Stearns, Philip; Bastrom, Tracey P.; Wallace, C. Douglas

2009-01-01

382

Caste and Language in Jaffna Society.  

ERIC Educational Resources Information Center

|Caste and language in the Jaffna Hindu Tamil society were correlated based on data collected from sample villages in the Jaffna peninsula, where the political and economic ascendancy of the landlords was very dominant in the recent past. (SW)|

Suseendirarajah, S.

1978-01-01

383

Casting Design Knowledge Management  

Microsoft Academic Search

India has a global competitive advantage in medium-volume engineering-intensive metal products, such as automobile castings. To maintain and enhance this advantage, foundries need to adopt a systematic approach to preserve and reuse their in-house knowledge accumulated through years of experience. In this paper, we present a casting knowledge management system that facilitates: (1) capturing and updating casting knowledge in the

B. Ravi

384

Some Economic Implications of Caste  

Microsoft Academic Search

This paper compares outcomes across two types of villages in a poor region of rural India. The two types of villages systematically vary by which caste is dominant, i.e., the caste group which owns the majority of land. The dominant caste is either from an upper caste or a lower backward caste. The key finding is that income is substantially

Siwan Anderson

385

Evolution of halictine castes  

NASA Astrophysics Data System (ADS)

Social halictine bees have female castes that range from species with no size differences to those with a discrete bimodality. Female caste differences are inversely correlated with the number of males produced in the first brood. It is proposed that the sexual dimorphism of solitary forms is being usurped by the female caste system of species in the process of turning social. Thus, caste differences and summer male suppression are greatest in the social species originating from solitary precursors with distinct sexual dimorphism, and are least in species evolving from solitary ancestors with a continuous sexual polymorphism.

Knerer, Gerd

1980-03-01

386

Photoelectric properties of a detector based on dried bacteriorhodopsin film  

Microsoft Academic Search

The photoelectric response of a detector using dried bacteriorhodopsin (bR) film as the light sensing material is mathematically modeled and experimentally verified in this paper. The photocycle and proton transfer kinetics of dried bR film differ dramatically from the more commonly studied aqueous bR material because of the dehydration process. The photoelectric response of the dried film is generated by

Wei Wei Wang; George K. Knopf; Amarjeet S. Bassi

2006-01-01

387

Switchable mirror based on Mg-Zr-H thin films  

Microsoft Academic Search

A Mg-Zr thin film is prepared on a glass substrate by co-sputtering of Mg and Zr targets and in situ sputtering of a thin Pd overlayer. The structural and optical properties of Mg-Zr and Mg-Zr-H thin film are investigated induced by hydrogen absorption and\\/or desorption at room temperature. Optical transmission and reflection data indicated that Mg-Zr-H thin film is the

Shanhu Bao; Yasusei Yamada; Kazuki Tajima; Ping. Jin; Masahisa Okada; Kazuki Yoshimura

388

Cast Aluminum Structures Technology (CAST) Manufacturing Methods--Phase II.  

National Technical Information Service (NTIS)

The objective of CAST is to establish the necessary structural and manufacturing technologies and to demonstrate and validate the integrity, producibility, and viability of cast aluminum primary airframe structures. The necessary casting foundry practices...

D. D. Goehler R. G. Christner

1978-01-01

389

INTERIOR VIEW WITH LARGE PIPE CASTING MACHINE CASTING A 48' ...  

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

INTERIOR VIEW WITH LARGE PIPE CASTING MACHINE CASTING A 48' PIPE. - United States Pipe & Foundry Company Plant, Pipe Casting & Testing Area, 2023 St. Louis Avenue at I-20/59, Bessemer, Jefferson County, AL

390

INTERIOR VIEW WITH PIPE CASTING MACHINE CASTING A 24' PIPE ...  

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

INTERIOR VIEW WITH PIPE CASTING MACHINE CASTING A 24' PIPE AND OPERATOR JOHNNY NIXON. - United States Pipe & Foundry Company Plant, Pipe Casting & Testing Area, 2023 St. Louis Avenue at I-20/59, Bessemer, Jefferson County, AL

391

Organic Solar Cells Based on Electrodeposited Polyaniline Films  

NASA Astrophysics Data System (ADS)

Polyaniline thin films as hole transporting layers were fabricated on transparent indium--tin-oxide electrodes by electrodeposition of aniline in an aqueous H2SO4 electrolyte solution. Emerald-green polyaniline films were obtained, which showed stable redox waves. A mixed solution of polythiophene and fullerene derivative was spin-coated onto the electrodeposited polyaniline film. After the modification of titanium oxide film on the surface of the polythiophene/fullerene layer, an aluminum electrode was fabricated by vacuum deposition. The obtained solar cells generated stable photocurrent and photovoltage under light illumination.

Inoue, Kei; Akiyama, Tsuyoshi; Suzuki, Atsushi; Oku, Takeo

2012-04-01

392

Characterization and performance of carbon films deposited by plasma and ion beam based techniques  

SciTech Connect

Plasma and ion beam based techniques have been used to deposit carbon-based films. The ion beam based method, a cathodic arc process, used a magnetically mass analyzed beam and is inherently a line-of-sight process. Two hydrocarbon plasma-based, non-line-of-sight techniques were also used and have the advantage of being capable of coating complicated geometries. The self-bias technique can produce hard carbon films, but is dependent on rf power and the surface area of the target. The pulsed-bias technique can also produce hard carbon films but has the additional advantage of being independent of rf power and target surface area. Tribological results indicated the coefficient of friction is nearly the same for carbon films from each deposition process, but the wear rate of the cathodic arc film was five times less than for the self-bias or pulsed-bias films. Although the cathodic arc film was the hardest, contained the highest fraction of sp{sup 3} bonds and exhibited the lowest wear rate, the cathodic arc film also produced the highest wear on the 440C stainless steel counterface during tribological testing. Thus, for tribological applications requiring low wear rates for both counterfaces, coating one surface with a very hard, wear resistant film may detrimentally affect the tribological behavior of the counterface.

Walter, K.C.; Kung, H.; Levine, T. [and others

1994-12-31

393

Optical characteristics of polymer films based on bacteriorhodopsin for irreversible recording of optical information.  

PubMed

Bacteriorhodopsin (BR)-containing polymer films have been developed in which photoinduced transformations of BR molecules take place during the process of photoinduced hydroxylaminolysis (PHA). The routine simplified scheme of the phototransformation is B <--> M(412) in the case of polymer films based on nonmodified BR. In the case of polymer films based on BR modified by hydroxylamine (HA), this scheme is changed to [formula in text] where retinal oxime (RO) is a final product of chemical trapping of retinal by the HA molecule. Under certain conditions, the rate of RO to B regeneration is infinitely low. So, the irreversibility of RO formation allows one to use PHA for the preparation of films for irreversible write once recording. Some optical sensitometric characteristics are compared for polymer-BR films and polymer-BR-HA films. It has been shown that the photosensitivity level for polymer-BR-HA films depends on the time after film preparation. A method is offered to increase the photosensitivity of polymer-BR-HA films and to avoid the photosensitivity decrease with the time after film preparation. PMID:19222793

Druzhko, Anna B

394

Comparative study on micromorphology and humidity sensitive properties of thin-film and thick-film humidity sensors based on semiconducting MnWO 4  

Microsoft Academic Search

Based on our experience of developing thick-film MnWO4 humidity sensors, a thin-film humidity sensor with nano-sized MnWO4 grains has been fabricated using the sol–gel technique. The thin-film sensor shows smaller humidity sensitivity than that compared to a thick-film sensor. However, it exhibits a fast response to humidity change and also has a very low temperature coefficient within the temperature range

Wenmin Qu; Wojtek Wlodarski; Jörg-Uwe Meyer

2000-01-01

395

Glucose sensor based on organic thin film transistor using glucose oxidase and conducting polymer  

Microsoft Academic Search

An organic thin film transistor (OTFT)-based glucose sensor, with a channel consisting of glucose oxidase enzyme (GOx) immobilized with poly(3,4-ethylenedioxythiophene–poly(styrene-sulfonate) (PEDOT–PSS) conducting polymer film, has been investigated. GOx was immobilized on PEDOT–PSS conducting polymer film using a simple cost effective spin-coating technique, and was entrapped in the polymer matrix during electrochemical polymerization. Subsequently, the sensor was encapsulated within a cellulose

J. Liu; M. Agarwal; K. Varahramyan

2008-01-01

396

Laminated Head for VTR with Co-Based Super-Structured Nitride Alloy Films  

Microsoft Academic Search

The recording characteristics and wide-band playback characteristics of laminated heads composed of Co-base superstructured nitride alloy films were investigated. The superstructured alloy film was composed of 250 ?? thick nonnitride and nitride layers of Co-Nb-Zr, and had higher thermal stability, higher saturation flux density, and higher initial permeability at high frequencies than does conventional Co-Nb-Ta-Zr amorphous alloy film. Because of

H. Hasegawa; K. Takahashi; E. Sawai; S. Muraoka; H. Sakakima; K. Osano

1990-01-01

397

Evaluation of variational principle based model for LDPE large scale film blowing process  

NASA Astrophysics Data System (ADS)

In this work, variational principle based film blowing model combined with Pearson and Petrie formulation, considering non-isothermal processing conditions and novel generalized Newtonian model allowing to capture steady shear and uniaxial extensional viscosities has been validated by using experimentally determined bubble shape and velocity profile for LDPE sample on large scale film blowing line. It has been revealed that the minute change in the flow activation energy can significantly influence the film stretching level.

Kolarik, Roman; Zatloukal, Martin

2013-04-01

398

Deinking of water-based ink printing from plastic film using nonionic surfactants  

Microsoft Academic Search

When plastic film packaging is processed for reuse, residual ink colors the polymer and makes the polymer less stiff, weaker,\\u000a and denser than the original material. These problems can be avoided if the printing is removed from the plastic film surface.\\u000a In this study, a commercial polyethylene film with water-based ink printing was deinked (the ink was removed) using nonionic

Hatice Gecol; John F. Scamehorn; Sherril D. Christian; Brian P. Grady; Fred E. Riddell

2002-01-01

399

Novel biodegradable films made from chitosan and poly(lactic acid) with antifungal properties against mycotoxinogen strains  

Microsoft Academic Search

Composite films from chitosan and poly(lactic acid) (PLA) were prepared by solution mixing and a film casting procedure. The main objectives of this study were the elaboration and the characterization of chitosan\\/PLA based bio-packaging for potential food applications and the study of antifungal activity of coatings and films on three mycotoxinogen fungal strains, Fusarium proliferatum, Fusarium moniliforme and Aspergillus ochraceus.

Fimbeau Sébastien; Grelier Stéphane; Alain Copinet; Veronique Coma

2006-01-01

400

Cellulose triacetate, thin film dielectric capacitor  

NASA Astrophysics Data System (ADS)

Very thin films of cellulose triacetate are cast from a solution containing a small amount of high boiling temperature, non-solvent which evaporates last and lifts the film from the casting surface. Stretched, oriented, crystallized films have high electrical breakdown properties. Metallized films less than about 2 microns in thickness form self-healing electrodes for high energy density, pulsed power capacitors. Thicker films can be utilized as a dielectric for a capacitor.

Yen, Shiao-Ping S.; Jow, T. Richard

1993-05-01

401

Cellulose triacetate, thin film dielectric capacitor  

NASA Astrophysics Data System (ADS)

Very thin films of cellulose triacetate are cast from a solution containing a small amount of high boiling temperature, non-solvent which evaporates last and lifts the film from the casting surface. Stretched, oriented, crystallized films have high electrical breakdown properties. Metallized films less than about 2 microns in thickness form self-healing electrodes for high energy density, pulsed power capacitors. Thicker films can be utilized as a dielectric for a capacitor.

Yen, Shiao-Ping S.; Jow, T. Richard

1995-08-01

402

The Effect of Casting Conditions on the High-Cycle Fatigue Properties of the Single-Crystal Nickel-Base Superalloy PWA 1483  

NASA Astrophysics Data System (ADS)

Different solidification conditions are employed to produce sets of single-crystal samples with different primary dendrite arm spacings, i.e., 600 ?m, 400 ?m, and 250 ?m. The material with the smaller dendrite arm spacing is shown to possess considerably increased high-cycle fatigue life. Fatigue cracks are found to originate from shrinkage porosity rather than from carbides, in which the size of the largest pores in the samples scales with the primary dendrite arm spacing. Fatigue life can be rationalized using a fracture mechanics approach based on a Kitagawa Takahashi plot. The impact of the results with respect to the development of new commercial casting processes that produce higher temperature gradients and cooling rates will be discussed.

Lamm, M.; Singer, R. F.

2007-06-01

403

High Power Storage System Based on Thin Film Solid Ionics.  

National Technical Information Service (NTIS)

Thin film insertion cathode have been obtained in the In-Se system and Hall mobility up to 50 sq cm have been measured on annealed films. Electrochemical lithium intercalation has been performed and shows that a plateau appears at 1.8V. The redox stabilit...

M. Balkanski C. Julien

1988-01-01

404

Electrocaloric devices based on thin-film heat switches  

Microsoft Academic Search

We describe a new approach to refrigeration, heat pumping, and electrical generation that allows one to exploit the attractive properties of thin films of electrocaloric materials. Layers of electrocaloric material coupled with thin-film heat switches can work as either refrigerators and heat pumps or electrical generators, depending on the phasing of the applied voltages and heat switching. With heat switches

Richard I. Epstein; Kevin J. Malloy

2009-01-01

405

Effect of adhesive primers on bonding strength of heat cure denture base resin to cast titanium and cobalt-chromium alloy  

PubMed Central

STATEMENT OF PROBLEM The poor chemical bonding of a denture base resin to cast titanium framework often introduces adhesive failure and increases microleakage. PURPOSE This study evaluated the shear bond strengths of a heat cure denture base resin to commercially pure titanium, Ti-6Al-4V alloy and a cobalt-chromium alloy using two adhesive primers. MATERIAL AND METHODS Disks of commercially pure titanium, Ti-6Al-4V alloy and a cobalt-chromium alloy were cast. Specimens without the primer were also prepared and used as the controls. The shear bond strengths were measured on a screw-driven universal testing machine. RESULTS The primers significantly (P < .05) improved the shear bond strengths of the heat cure resin to all metals. However, the specimens primed with the Alloy primer® (MDP monomer) showed higher bond strength than those primed with the MR bond® (MAC-10 monomer) on titanium. Only adhesive failure was observed at the metal-resin interface in the non-primed specimens, while the primed specimens showed mixed failure of adhesive and cohesive failure. CONCLUSIONS The use of appropriate adhesive metal primers makes it possible not only to eliminate the need for surface preparation of the metal framework before applying the heat cure resins, but also reduce the need for retentive devices on the metal substructure. In particular, the Alloy primer®, which contains the phosphoric acid monomer, MDP, might be clinically more acceptable for bonding a heat cure resin to titanium than a MR bond®, which contains the carboxylic acid monomer, MAC-10.

Kim, Su-Sung; Yang, Hong-So; Park, Sang-Won; Lim, Hyun-Pil

2009-01-01

406

Spin-Cast and Patterned Organophosphonate Self-Assembled Monolayer Dielectrics on Metal-Oxide-Activated Si  

SciTech Connect

An efficient process is developed for modifying Si with self-assembled monolayers (SAMs) through in situ metal oxide surface activation and microcontact printing or spin-coating of phosphonic-acid-based molecules. The utility of this process is demonstrated by fabricating self-organized and solution-processed low-voltage organic thin-film transistors enabled by patterned and spin-cast phosphonate SAM/metal oxide hybrid dielectrics.

O Acton; D Hutchins; L Arnadottir; T Weidner; N Cernetic; G Ting; T Kim; D Castner; H Ma; A Jen

2011-12-31

407

LLNL casting technology.  

National Technical Information Service (NTIS)

Competition to produce cast parts of higher quality, lower rejection rate, and lower cost is a fundamental factor in the global economy. To gain an edge on foreign competitors, the US casting industry must cut manufacturing costs and reduce the time from ...

A. B. Shapiro W. J. Comfort

1994-01-01

408

Expendable Pattern Casting Technology  

NASA Astrophysics Data System (ADS)

The expendable pattern casting (EPC) process is a potential casting process breakthrough which could dramatically improve the competitiveness of the U.S. foundry industry. Cooperatively supported by U.S. Industry and the Department of Energy and managed by the American Foundrymen's Society, a project was started in May 1989 to develop and optimize expendable pattern casting technology. Four major tasks were conducted in the first phase of the project. Those tasks involved: (1) reviewing published literature to determine the major problems in the EPC process; (2) evaluating factors influencing sand flow and compaction; (3) evaluating and comparing casting precision obtained in the EPC process with that obtained in other processes; and (4) identifying critical parameters that control dimensional precision and defect formation in EP castings.

1990-07-01

409

Versatile fluoride substrates for Fe-based superconducting thin films  

NASA Astrophysics Data System (ADS)

We demonstrate the growth of Co-doped BaFe2As2 (Ba-122) thin films on CaF2 (001), SrF2 (001), and BaF2 (001) single crystal substrates using pulsed laser deposition. All films are grown epitaxially despite of a large misfit of -10.6% for BaF2 substrate. For all films, a reaction layer is formed at the interface confirmed by X-ray diffraction and for the films grown on CaF2 and BaF2 additionally by transmission electron microscopy. The superconducting transition temperature of the film on CaF2 is around 27 K, whereas the corresponding values of the films on SrF2 and BaF2 are around 22 K and 21 K, respectively. The Ba-122 on CaF2 shows almost identical crystalline quality and superconducting properties as films on Fe-buffered MgO.

Kurth, F.; Reich, E.; Hänisch, J.; Ichinose, A.; Tsukada, I.; Hühne, R.; Trommler, S.; Engelmann, J.; Schultz, L.; Holzapfel, B.; Iida, K.

2013-04-01

410

Development of VOC analyzer using a WO3 thick film based gas sensor  

Microsoft Academic Search

This paper describes a VOC gas analyzer system developed using an original gas sensor and gas chromatography for the detection of aromatic hydrocarbon gases. The sensor is based on a WO3 thick film where Pd and Pt are applied as catalyst to a limited area of the film to promote sensitivity and improve gas selectivity. The sensor shows extremely high

K. Kanda; T. Kuse

2004-01-01

411

Fabrication and testing of a microstrip particle detector based on highly oriented diamond films  

Microsoft Academic Search

A particle detector for high flux applications has been fabricated based on highly oriented diamond (HOD) films. Relatively thick HOD films were achieved by combining the bias enhanced nucleation (BEN) in a microwave plasma chemical vapor deposition (MPCVD) reactor and high rate growth process in a low pressure combustion flame (LPCF) reactor. Following the diamond deposition, Si substrate was etched

S. K. Han; M. T. McClure; C. A. Wolden; B. Vlahovic; A. Soldi; S. Sitar

2000-01-01

412

Achromatic circular polarizer in the 482-535 nm range based on polypropylene films  

NASA Astrophysics Data System (ADS)

We present a design for an achromatic circular polarizer based on polypropylene films. The circular polarizer, having eccentricity ?0.92 in the 482-535 nm range and ideally circular for the wavelength of ~505 nm, is obtained by combining BOPP C2-25 and BOPP C2-35 films of thickness 23 m and 33 ?m.

Muravsky, Al. A.; Murauski, An. A.; Agabekov, V. E.; Chuvasheva, O. O.; Ivanova, N. A.

2012-11-01

413

Low-cost portable respiration monitor based on micro hot-film flow sensor  

Microsoft Academic Search

We present a portable, low cost, sensitive respiration monitoring system based on a micro hot-film flow sensor. The sensitive component of the flow sensor is a patterned thin-film with nanometer thickness fabricated on a flexible polyimide substrate by incorporating printed circuit technique with micromachining technique. The respiratory flow measurement is under a constanttemperature mode, and the measured signals are sampled

Zhe Cao; Rong Zhu; Ruiyi Que

2010-01-01

414

Residual stress and fracture in thick tetraethylorthosilicate (TEOS) and silane-based PECVD oxide films  

Microsoft Academic Search

This paper reports residual stress measurements and fracture analysis in thick tetraethylorthosilicate (TEOS) and silane-based plasma enhanced chemical vapor deposition (PECVD) oxide films. The measured residual stress depended strongly on thermal process parameters; dissolved hydrogen gases played an important role in governing intrinsic stress. The tendency to form cracks was found to be a strong function of film thickness and

X. Zhang; K.-S. Chen; R. Ghodssi; A. A. Ayón; S. M. Spearing

2001-01-01

415

Electrodeposited Fe-Co films prepared from a citric-acid-based plating bath  

NASA Astrophysics Data System (ADS)

Electrodeposited Fe-Co films are commonly prepared in a boric-acid-based bath. In this research, we applied citric acid instead of boric acid for the plating of Fe-Co films because boron in the waste bath is restricted by environmental-protection regulations in Japan. We evaluated the effect of citric acid on the magnetic and structural properties of the films. The saturation magnetization of the Fe-Co films slightly increased while the Fe content in the Fe-Co films decreased with increasing citric acid concentration. The lowest coercivity value of 240 A/m was obtained at a citric acid concentration of 100 g/L. The plating bath with this citric acid concentration enabled us to obtain Fe-Co films with high saturation magnetizations and smooth surface morphologies.

Yanai, T.; Uto, H.; Shimokawa, T.; Nakano, M.; Fukunaga, H.; Suzuki, K.

2013-06-01

416

Hysteresis in pentacene-based organic thin-film transistors  

NASA Astrophysics Data System (ADS)

Memory effects are commonly seen in organic thin-film transistor (OTFT) characteristics. In the absence of memory effects associated with the gate dielectric, the hysteresis in p-channel pentacene-based OTFTs, as measured in air and under illumination, was found to be dominated by trapped electrons, rather than trapped holes, in the semiconductor. The responsible acceptor type traps have very long lifetime. The immobile, previously stored negative charge requires extra holes to balance it, resulting in early establishment of the channel and extra drain current. This model is unique in that it discusses the majority carrier population influenced by trapped charge opposite in sign to the majority carriers in a simple electrostatic manner, to explain history dependence. The model was supported by drain current transient decay data. This memory effect is ambient and illumination sensitive. We studied the presence or absence of this effect under various ambient and illumination conditions, and found the responsible acceptor type traps mostly extrinsic and their formation reversible. Efforts were taken in the quantitative analysis to exclude the bias stress effect from the memory effect due to the charged acceptors.

Gu, Gong; Kane, Michael G.

2006-09-01

417

Photoelectric properties of a detector based on dried bacteriorhodopsin film.  

PubMed

The photoelectric response of a detector using dried bacteriorhodopsin (bR) film as the light sensing material is mathematically modeled and experimentally verified in this paper. The photocycle and proton transfer kinetics of dried bR film differ dramatically from the more commonly studied aqueous bR material because of the dehydration process. The photoelectric response of the dried film is generated by charge displacement and recombination instead of transferring a proton from the cytoplasmic side to the extracellular side of the cell membrane. In this work, the wild-type bR samples are electrophoretically deposited onto an indium tin oxide (ITO) electrode to construct a simple multiple layered photo-detector with high sensitivity to small changes in incident illumination. The light absorption characteristics of the thin bR film are mathematically represented using the kinetics of the bR photocycle and the charge displacement theorem. An electrically equivalent RC circuit is used to describe the intrinsic photoelectric properties of the film and external measurement circuitry to analyze the detector's response characteristics. Simulated studies and experimental results show that the resistance of the dried bR film is in the order of 10(11) Omega. When the input impedance of the measurement circuitry is one order of magnitude smaller than the dried film, the detector exhibits a strong differential response to the original time-varying light signal. An analytical solution of the equivalent circuit also reveals that the resistance and capacitance values exhibited by the dried bR film, in the absence of incident light, are almost twice as large as the values obtained while the material is under direct illumination. Experimental observations and a predictive model both support the notion that dried bR film can be used in simple highly sensitive photo-detector designs. PMID:16039842

Wang, Wei Wei; Knopf, George K; Bassi, Amarjeet S

2005-07-21

418

Ion beam analysis of HTc superconducting Tl-based films  

NASA Astrophysics Data System (ADS)

The elemental composition, film thickness and concentration depth profiles of superconducting Tl-Ba-Ca-Cu-O and precursor Ba-Ca-Cu-O thin films were studied by IBA techniques such as RBS and NRA. The precursor Ba-Ca-Cu-O films were prepared by deposition of an aerosol (spray pyrolysis) atomized from aqueous nitrate solutions by ultrasonic excitations. The substrates were single crystal MgO and yttrium-stabilized zirconia (YSZ). The precursor Ba-Ca-Cu-O films were thallinated in a single-zone reaction chamber to produce the superconductor. The critical temperature values, Tc, of the superconducting films ranged from 101 to 103 K and were found to consist of more than 95 vol.% of the Tl2Ba2CaCu2Ox phase. IBA studies revealed that the superconducting films were well oxygenated but slightly thallium deficient, with the Tl depth profile decreasing from the bulk of the film to the surface. The phase composition was found to be different from the elemental one determined by IBA techniques. Moreover, residual carbon was found in both the superconducting and precursor films. Thermogravimetric studies revealed that it is highly probable that the carbon contamination was caused by exposure of the precursor oxide films to the ambient atmosphere prior to the thallination procedure. In regard to the optimization of the thallium content, the most important parameters of the dynamical thallination process were found to be the initial amount of Tl, the partial pressures pTl2O and pO2, the time of thallination and the reaction rate.

Andrade, E.; Cheang-Wong, J. C.; Jergel, M.; Conde-Gallardo, A.; Falcony, C.

1997-03-01

419

Fatigue of Iron Base Alloys HY-80 Steel Cast Tees Butt Welded to Rolled Section Single and Double Weld Joint Design.  

National Technical Information Service (NTIS)

The average fatigue life of 1 5/8 in. thick cast tee butt welded to rolled plate is approximately the same as that of cast plate butt welded to rolled plate and rolled plate butt welded to rolled plate. At 80,000 psi nominal stress range the fatigue life ...

1964-01-01

420

Neutron radiography inspection of investment castings.  

PubMed

Investment casting, also known as the lost wax process, is a manufacturing method employed to produce near net shape metal articles. Traditionally, investment casting has been used to produce structural titanium castings for aero-engine applications with wall thickness less than 1 in (2.54 cm). Recently, airframe manufacturers have been exploring the use of titanium investment casting to replace components traditionally produced from forgings. Use of titanium investment castings for these applications reduces weight, cost, lead time, and part count. Recently, the investment casting process has been selected to produce fracture critical structural titanium airframe components. These airframe components have pushed the traditional inspection techniques to their physical limits due to cross sections on the order of 3 in (7.6 cm). To overcome these inspection limitations, a process incorporating neutron radiography (n-ray) has been developed. In this process, the facecoat of the investment casting mold material contains a cocalcined mixture of yttrium oxide and gadolinium oxide. The presence of the gadolinium oxide, allows for neutron radiographic imaging (and eventual removal and repair) of mold facecoat inclusions that remain within these thick cross sectional castings. Probability of detection (POD) studies have shown a 3 x improvement of detecting a 0.050 x 0.007 in2 (1.270 x 0.178 mm2) inclusion of this cocalcined material using n-ray techniques when compared to the POD using traditional X-ray techniques. Further, it has been shown that this n-ray compatible mold facecoat material produces titanium castings of equal metallurgical quality when compared to the traditional materials. Since investment castings can be very large and heavy, the neutron radiography facilities at the University of California, Davis McClellan Nuclear Radiation Center (UCD/MNRC) were used to develop the inspection techniques. The UCD/MNRC has very unique facilities that can handle large parts up to 39 ft (12 m) in length and 13 ft (4 m) high weighing up to 5000 lbs (2300 kg). These handling systems are robotically driven. The neutron radiographic system consists of a highly thermalized neutron beam. The neutron beam has an intensity of 5.6 x 10(6) n/cm2 s, with a L/D = 200 at a power of 2 MW. A divergent beam collimator is used which provides a beam of approximately 22 in (56 cm) in diameter at the film plane. A vacuum cassette with a gadolinium vapor deposited screen is used to collect the image. Exposure times can be as short as 3 min, or up to 30 min. PMID:15246417

Richards, W J; Barrett, J R; Springgate, M E; Shields, K C

2004-10-01

421

Electrochromic multilayer films based on trilacunary Dawson-type polyoxometalate  

Microsoft Academic Search

A new ultrathin multilayer film consisting of polyoxometalate (POM) cluster Na12[P2W15O56]·18H2O (P2W15) and polyallylamine hydrochloride (PAH) were fabricated on quartz and ITO substrates by layer-by-layer self-assembly method. The multilayer films, PSS\\/PAH\\/(P2W15\\/PAH)n, were characterized by UV–vis spectra, cyclic voltammetry (CV) and chronoamperometric (CA) measurements. The electrochromic film exhibits both suitable response time and low power consumption due to the presence of

Guanggang Gao; Lin Xu; Wenju Wang; Zhenqing Wang; Yunfeng Qiu; Enbo Wang

2005-01-01

422

One-dimensional semiconductor nanostructure based thin-film partial composite formed by transfer implantation for high-performance flexible and printable electronics at low temperature.  

PubMed

Having high bending stability and effective gate coupling, the one-dimensional semiconductor nanostructures (ODSNs)-based thin-film partial composite was demonstrated, and its feasibility was confirmed through fabricating the Si NW thin-film partial composite on the poly(4-vinylphenol) (PVP) layer, obtaining uniform and high-performance flexible field-effect transistors (FETs). With the thin-film partial composite optimized by controlling the key steps consisting of the two-dimensional random dispersion on the hydrophilic substrate of ODSNs and the pressure-induced transfer implantation of them into the uncured thin dielectric polymer layer, the multinanowire (NW) FET devices were simply fabricated. As the NW density increases, the on-current of NW FETs increases linearly, implying that uniform NW distribution can be obtained with random directions over the entire region of the substrate despite the simplicity of the drop-casting method. The implantation of NWs by mechanical transfer printing onto the PVP layer enhanced the gate coupling and bending stability. As a result, the enhancements of the field-effect mobility and subthreshold swing and the stable device operation up to a 2.5 mm radius bending situation were achieved without an additional top passivation. PMID:21174391

Moon, Kyeong-Ju; Lee, Tae-Il; Choi, Ji-Hyuk; Jeon, Joohee; Kang, Youn Hee; Kar, Jyoti Prakash; Kang, Jung Han; Yun, Ilgu; Myoung, Jae-Min

2010-12-21

423

STARCH\\/PULP-FIBER BASED PACKAGING FOAMS AND CAST FILMS CONTAINING ALASKAN FISH BY-PRODUCTS (WASTE)  

Microsoft Academic Search

Baked starch\\/pulp foams were prepared from formulations containing zero to 25 weight percent of processed Alaskan fish by-products that consisted mostly of salmon heads, pollock heads, and pollock frames (bones and associated remains produced in the filleting operation). Fish by-products thermoformed well along with starch and pulp fiber, and the foam product (panels) exhibited useful mechanical properties. Foams with all

Syed H. Imam; Bor-Sen Chiou; Delilah Woods; Justin Shey; Gregory M. Glenn; William J. Orts; Robert J. Avena-Bustillos; Tara H. McHugh; Alberto Pantoja; Peter J. Bechtel

424

Tape casting of lanthanum chromite  

Microsoft Academic Search

Solid oxide fuel cells (SOFCs) are currently being developed for a variety of applications such as stationary on-site power plants and cogeneration. The effects of process additives, ball milling, and solids loading were evaluated for tape casting suspensions of glycine-nitrate-synthesized La{sub 0.7}Ca{sub 0.31}CrOâ powder. An optimized formulation was obtained based on rheological characterization, electrokinetic sonic amplitude measurements, qualitative examination of

Michael W. Murphy; Timothy R. Armstrong; Peter A. Smith

1997-01-01

425

Feeding of high-nickel alloy castings  

Microsoft Academic Search

Feeding of the nickel-based alloys CZ-100, M-35-1, and CW-12MW, as well as of the austenitic stainless steel CN-7M, is investigated,\\u000a using a combination of casting experiments and simulation. Casting trials are performed at five foundries, to produce a total\\u000a of 55 plates of varying lengths and radiographic soundness levels. In order to develop the property databases necessary to\\u000a simulate the

Kent D. Carlson; Shouzhu Qu; Christoph Beckermann

2005-01-01

426

Tape casting of non-aqueous silicon nitride slips  

Microsoft Academic Search

Tape casting is a powerful method for the manufacturing of flat, large area ceramic components. Silicon nitride is a reference material for high temperature structural applications. Between them, thick film\\/coating technologies and ceramic–ceramic joining are receiving an increased attention. In this work, the rheological behavior on non-aqueous silicon nitride slips for tape casting was investigated considering different solvent and binding

C. A Gutiérrez; R Moreno

2000-01-01

427

High performance thin film transistors based on regioregular poly(3-dodecylthiophene)-sorted large diameter semiconducting single-walled carbon nanotubes.  

PubMed

In this work, a simple and rapid method to selectively sort semiconducting-SWCNTs (sc-SWCNTs) with large diameters using regioregular poly(3-dodecylthiophene) (rr-P3DDT) is presented. The absorption spectra and Raman spectra demonstrated that metallic species of arc discharge SWCNTs were effectively removed after interaction with rr-P3DDT in toluene with the aid of sonication and centrifugation. The sorted sc-SWCNT inks have been directly used to fabricate thin film transistors (TFTs) by dip-coating, drop-casting and inkjet printing. TFTs with an effective mobility of ?34 cm(2) V(-1) s(-1) and on-off ratios of ?10(7) have been achieved by dip coating and drop casting the ink on SiO2/Si substrates with pre-patterned interdigitated gold electrode arrays. The printed devices also showed excellent electrical properties with a mobility of up to 6.6 cm(2) V(-1) s(-1) and on-off ratios of up to 10(5). Printed inverters based on the TFTs have been constructed on glass substrates, showing a maximum voltage gain of 112 at a V(dd) of -5 V. This work paves the way for making printable logic circuits for real applications. PMID:23595234

Wang, Chao; Qian, Long; Xu, Wenya; Nie, Shuhong; Gu, Weibing; Zhang, Jianhui; Zhao, Jianwen; Lin, Jian; Chen, Zheng; Cui, Zheng

2013-05-21

428

Radon in Water Measurements Based on Thin Film Adsorption  

Microsoft Academic Search

Radium adsorbing MnO2 thin films developed for water analysis show to adsorb radon daughters as well. A 12 µm polyethylene-terephtalate foil is covered on the water side with a MnO2 film. On the opposite side a semiconductor detector counts on-line during adsorption alpha particles passing through the foil. 218Po and 214Po are well separated in the alpha spectrum measured that

Heinz Surbeck; Jean-Louis Andrey

429

Conducting polymer soft actuators based on polypyrrole films  

Microsoft Academic Search

Electrochemomechanical deformation (ECMD) of a conducting polymer, polypyrrole (PPy) has been studied to attain better performance as soft actuators. The PPy films were electrochemically prepared from methyl benzoate solution of tetra butyl ammonium (TBA) trifluoromethansulfonate, TBACF3SO3 and TBA bis(perfluoroalkylsufonil)imid, TBA (CnF2n+1SO2)2 N) (n = 1- 4). The PPy films prepared from TBACF3SO3 are tough and flexible with the conductivity of

Keiichi Kaneto

2006-01-01

430

Biosensors based on acetylcholinesterase immobilized on mesoporous silica thin films  

Microsoft Academic Search

Using tetraethoxysilane and 3-aminopropyltriethoxysilane as the silica sources, amino-functionalized mesoporous silica thin\\u000a films with 3-dimensional cubic structure have been deposited on conducting ITO substrate in the presence of surfactant F127\\u000a templates under acid conditions. The acetylcholinesterase (AchE) and cytochrome c (Cyt c) were incorporated into the pores\\u000a of mesoporous thin films, and an amperometric biosensor was obtained. After adsorption of

XueAo Zhang; HongHui Jia; XiaoFeng Wang; HaiLiang Zhang; HongWei Yin; ShengLi Chang; JianFang Wang; WenJian Wu

2009-01-01

431

Casting in Sport  

PubMed Central

Attempts by sports medicine professionals to return high school athletes with hand and wrist injuries to competition quickly and safely have been the source of confusion and debate on many playing fields around the country. In addition to the differing views regarding the appropriateness of playing cast usage in high school football, a debate exists among sports medicine professionals as to which material is best suited for playing cast construction. Materials used in playing cast construction should be hard enough to provide sufficient stabilization to the injured area and include adequate padding to absorb blunt impact forces. The purpose of the biomechanical portion of this investigation was to attempt to determine the most appropriate materials for use in constructing playing casts for the hand and wrist by assessing different materials for: 1) hardness using a Shore durometer, and 2) ability to absorb impact using a force platform. Results revealed that RTV11 and Scotchcast were the “least hard” of the underlying casting materials and that Temper Stick foam greatly increased the ability of RTV11 to absorb impact. Assessment of the mechanical properties of playing cast materials and review of current developments in high school football rules are used to aid practitioners in choosing the most appropriate materials for playing cast construction. ImagesFig 1.Fig 2.Fig 3.

DeCarlo, Mark; Malone, Kathy; Darmelio, John; Rettig, Arthur

1994-01-01

432

Three Social Distance Measures for Film Rankings.  

ERIC Educational Resources Information Center

|Describes the use of three alternative methods for ranking films for information retrieval (IR). A large film-person incidence matrix is generated using the principle cast, directors, producers and screenwriters for each film. These attributes are used to measure film-film distances by creating a distance matrix. Distance, product distance, and…

Leazer, Gregory H.; Furner, Jonathan; Napper, Rachel

2003-01-01

433

CENTRIFUGAL CASTING MACHINE  

DOEpatents

A device is described that is specifically designed to cast uraniumn fuel rods in a vacuunn, in order to obtain flawless, nonoxidized castings which subsequently require a maximum of machining or wastage of the expensive processed material. A chamber surrounded with heating elements is connected to the molds, and the entire apparatus is housed in an airtight container. A charge of uranium is placed in the chamber, heated, then is allowed to flow into the molds While being rotated. Water circulating through passages in the molds chills the casting to form a fine grained fuel rod in nearly finished form.

Shuck, A.B.

1958-04-01

434

Oxide-based method of making compound semiconductor films and making related electronic devices  

SciTech Connect

A method for forming a compound film includes the steps of preparing a source material, depositing the source material on a base and forming a preparatory film from the source material, heating the preparatory film in a suitable atmosphere to form a precursor film, and providing suitable material to said precursor film to form the compound film. The source material includes oxide-containing particles including Group IB and IIIA elements. The precursor film includes non-oxide Group IB and IIIA elements. The compound film includes a Group IB-IIIA-VIA compound. The oxides may constitute greater than about 95 molar percent of the Group IB elements and greater than about 95 molar percent of the Group IIIA elements in the source material. Similarly, non-oxides may constitute greater than about 95 molar percent of the Group IB elements and greater than about 95 molar percent of the Group IIIA elements in the precursor film. The molar ratio of Group IB to Group IIIA elements in the source material may be greater than about 0.6 and less than about 1.0, or substantially greater that 1.0, in which case this ratio in the compound film may be reduced to greater than about 0.6 and less than about 1.0. The source material may be prepared as an ink from particles in powder form. The oxide-containing particles may include a dopant, as may the compound film. Compound films including a Group IIB-IVA-VA compound may be substituted using appropriate substitutions in the method. The method, also, is applicable to fabrication of solar cells and other electronic devices.

Kapur, Vijay K. (Tarzana, CA); Basol, Bulent M. (Manhattan Beach, CA); Leidholm, Craig R. (Woodland Hills, CA); Roe, Robert A. (Glendale, CA)

2000-01-01

435

Distal radius fractures: a prospective randomized comparison of fibreglass tape with QuickCast.  

PubMed

Cast immobilization remains the most commonly employed method in the treatment of distal radius fractures. In an effort to test a new shrinkable polymer-coated casting material (QuickCast), a prospective randomized study was performed on 30 consecutive distal radius fractures. Fractures were divided into three groups based on the severity of fracture and treated with either a conventional short-arm fibreglass tape cast or a QuickCast. Results showed no significant differences in minor cast complications or maintenance of fracture reduction between conventional fibreglass tape and the QuickCast material. The shrinkable QuickCast, however, resulted in an average of one less cast change in all groups. This reduction in time and labour must be weighed against the slightly increased cost of the QuickCast immobilizer. PMID:9282188

Cohen, M S; Frillman, T

1997-05-01

436

Roll Casting of Aluminum Alloy Clad Strip  

SciTech Connect

Casting of aluminum alloy three layers of clad strip was tried using the two sets of twin roll casters, and effects of the casting parameters on the cladding conditions were investigated. One twin roll caster was mounted on the other twin roll caster. Base strip was 8079 aluminum alloy and overlay strips were 6022 aluminum alloy. Effects of roll-load of upper and lower casters and melt temperature of the lower caster were investigated. When the roll-load of the upper and lower caster was large enough, the overlay strip could be solidified and be connected. The overlay strip could be connected when the melt of the overlay strip cast by the lower caster was low enough. Sound three layers of clad strip could be cast by proper conditions.

Nakamura, R.; Tsuge, H. [Graduate School of Osaka Institute of Technology (Japan); Haga, T. [Osaka Institute of Technology, 5-16-1 Omiya Asahiku Osaka city 535-8585 (Japan); Watari, H. [Tokyo Institute of Technology, 4259 Nagatsuda Midoriku Yokohama city 226-8502 (Japan); Kumai, S. [Gunma University, 1-5-1 tenjin cho Kiryu city 376-8515 (Japan)

2011-01-17

437

Effect of oleic acid–beeswax mixtures on mechanical, optical and water barrier properties of soy protein isolate based films  

Microsoft Academic Search

Soy protein isolate (SPI) based films are effective barriers to oxygen, lipids and aroma compounds but they provide yellowish films and are not effective water vapour barriers. Different ratios of lipid mixtures (oleic acid and beeswax at different ratios) were incorporated into the SPI based films to improve their properties. Oleic acid, pure or mixed with beeswax, had a plasticizing

F. María Monedero; Maria José Fabra; Pau Talens; Amparo Chiralt

2009-01-01

438

Protection of copper corrosion by modification of self-assembled films of Schiff bases with alkanethiol  

Microsoft Academic Search

The corrosion protection of self-assembled films derived from Schiff bases, including N-2-hydroxyphenyl-(3-methoxy-salicylidenimine) (V-bso), N-2-hydroxyphenyl-(salicylidenimine) (S-bso) and N,N?-o-phenylen-bis(salicylidenimine) (S-o-ph-S), on copper surfaces have been probed by electrochemical techniques in an aqueous electrolyte. These studies suggest that the pure films of Schiff bases possess some unfilled defect sites. However, when the films were modified by 1-dodecanethiol (C12H25SH, abbreviated as DT), the quality

Zhenlan Quan; Shenhao Chen; Shulan Li

2001-01-01

439

Effect of molding temperature on the properties of nanocomposite films based on low-density polyethylene  

NASA Astrophysics Data System (ADS)

The influence of the molding temperature on the density and porosity of nanocomposite films based on low-density polyethylene (LDPE) filled with CdS and MnO nanoparticles has been studied. It is established that molding at temperatures of about 110°C ensures the formation of nanocomposite films with a minimum porosity, (i.e., maximum density). The results open ways to the modification of some other macroscopic parameters of LDPE-based nanocomposite films by varying the molding temperature, since the properties dependent on the material porosity include dielectric permittivity, refractive index, elastic modulus, and some other.

Za?tsev, B. D.; Kuznetsova, I. E.; Shikhabudinov, A. M.; Razumov, K. A.

2008-06-01

440

Enhanced SPR sensing based on micro-patterned thin films  

NASA Astrophysics Data System (ADS)

Micro-patterned thin films interrogated in the Kretschmann configuration of SPR could extend the detection range to lower concentrations and small biomolecules due to a greater sensitivity. This was achieved with the same instrumentation and analysis methodologies developed for SPR with continuous films. The plasmonic properties of micro-patterned thin films composed of various layers of Ag and Au were investigated to find an optimal structure for biosensing application. The analytical parameters and biosensing performances were also evaluated for analysis of biological samples. Au microhole arrays of 3.2 ?m periodicity and 1.6 ?m hole diameter were prepared using a modified nanosphere lithography (NSL) technique. These microstructures showed optimal plasmonic properties for biosensing applications as they exhibit a 50% increase in sensitivity to refractive index changes compared to continuous thin films of the same thickness. Moreover, microhole arrays presented a faster response time to refractive index changes while analytical parameters such as the resolution and the noise in biosensing measurement were comparable to continuous films. When combined to the appropriate surface chemistry, a greater SPR response was measured for proteins using microhole arrays. Although microhole arrays required an additional preparation step, a cleaning step using oxygen plasma allowed multiple measurements with the same metallic surface with great repeatability. Hence, microhole arrays proved to be a simple approach to improve current SPR biosensing technique. Further investigations to understand the plasmonic properties of microhole were performed using an angle scanning SPR instrument.

Live, Ludovic S.; Breault-Turcot, Julien; Nguyen, Kim-Ly; Masson, Jean-Francois

2011-02-01

441

Metal-organic chemical vapor deposition of cadmium oxide-based transparent conductors: Precursor design, film growth, and film characterization  

NASA Astrophysics Data System (ADS)

The growing importance of cadmium containing thin films and the desire for their efficient deposition has necessitated the development of high performance MOCVD precursors. To this end, a series of low-melting, and thermally-stable cadmium MOCVD precursors has been synthesized, characterized, and implemented in the growth of highly conductive and transparent CdO-based thin films. One member of the series, bis(1,1,1,5,5,5-hexafluoro-2,4-pentanedionato)(N,N-diethyl-N ', N'-dimethyl-ethylenediamine)cadmium(II), Cd(hfa)2(N,N-DE-N' ,N'-DMEDA), represents a particularly significant improvement over previously available Cd precursors owing to its low melting point, and robust thermal stability. This precursor will allow careful control of composition and growth rates in complex cadmium-containing oxide systems owing to the elimination of sintering effects detrimental to reproducible growth with solid precursors. Materials with high electrical conductivity and optical transparency are needed for future flat panel display, solar energy, and other opto-electronic technologies. High quality Cd1-xInxO films with been deposited utilizing our new class of MOCVD precursors. The x = 0.05 film, with conductivity of 17,000 S/cm, carrier mobility of 70 cm2/V·s, and wide visible region optical transparency window considerably exceed the corresponding parameters for commercial indium-tin oxide (ITO). A detailed understanding of the fundamental aspects of charge transport in degenerate semiconductors is of great interest. In order to elucidate the importance of individual scattering mechanisms in TCO materials, high-quality CdO films were grown by MOCVD in parallel on glass and single-crystal MgO (100) between 300°C and 412°C. Enhanced mobilities observed for highly biaxially textured films grown on MgO (100) vs. glass are attributed, on the basis of DC charge transport measurements and microstructure analysis, to a reduction in neutral impurity scattering and/or to a more densely packed grain microstructure. Although single grained films grown on MgO (100) exhibit greater mobilities than analogues with discrete ˜100 nm grains and similar texture, this effect is attributed, on the basis of charge transport and Hall effect measurements as well as optical reflectivity analysis to small differences in carrier concentration, rather than to a reduction in grain boundary scattering. Conductivities and mobilities as high as 11,000 S/cm and 307 cm2/V·s, respectively, are obtained for epitaxial single-grained CdO films grown in situ on MgO (100).

Metz, Andrew William

2003-07-01

442

External electro-optic measurement utilizing poled polymer-based asymmetric Fabry–Perot reflection film  

Microsoft Academic Search

An external linear electro-optic measuring system based on a poled polymer asymmetric Fabry–Perot multiple reflection film has been built, and the electric signals propagating on an indium tin oxide coplanar strip transmission line have been successfully measured. The nonlinear polymer spin coated on the high-reflectivity glass substrate was corona poled, thus an asymmetric Fabry–Perot film was fabricated based on polymer

D. M. Zhang; M. B. Yi; X. J. Tian; W. Sun; A. L. Hou; J. Z. Sun; Y. G. Ma; W. J. Tian; J. C. Shen

1999-01-01

443

External electro-optic measurement utilizing poled polymer-based asymmetric Fabry-Perot reflection film  

Microsoft Academic Search

An external linear electro-optic measuring system based on a poled polymer asymmetric Fabry- Perot multiple reflection film has been built, and the electric signals propagating on an indium tin oxide coplanar strip transmission line have been successfully measured. The nonlinear polymer spin coated on the high-reflectivity glass substrate was corona poled, thus an asymmetric Fabry-Perot film was fabricated based on

D. M. Zhang; M. B. Yi; X. J. Tian; W. Sun; A. L. Hou; J. Z. Sun; Y. G. Ma; W. J. Tian; J. C. Shen

2006-01-01

444

Sensitivity of linear CCD array based film scanners used for film dosimetry  

Microsoft Academic Search

Film dosimetry is commonly performed by using linear CCD array transmission optical densitometers. However, these devices suffer from a variation in response along the detector array. If not properly corrected for, this nonuniformity may lead to significant overestimations of the measured dose as one approaches regions close to the edges of the scanning region. In this note, we present measurements

Slobodan Devic; Yi-Zhen Wang; Nada Tomic; Ervin B. Podgorsak

2006-01-01

445

Ethanol-assisted graphene oxide-based thin film formation at pentane-water interface.  

PubMed

Graphene oxide (GO) can be viewed as an amphiphilic soft material, which form thin films at organic solvent-water interfaces. However, organic solvent evaporation provides little driving force, which results in slow GO transfer in aqueous phase, thus dawdling GO film formation processes for various potential applications. We present an ethanol-assisted self-assembly method for the quick formation of GO or GO-based composite thin films with tunable composition, transmittance, and surface resistivity at pentane-water interface. The thickness of pure GO and reduced GO (rGO) films ranging from ~1 nm to more than 10 nm can be controlled by the concentration of GO in bulk solution. The transmittance of rGO films can be tuned from 72% to 97% at 550 nm while the surface resistivity changes from 8.3 to 464.6 k? sq(-1). Ethanol is essential for achieving quick formation of GO thin films. When ethanol is injected into GO aqueous dispersion, it serves as a nonsolvent, compromising the stability of GO and providing driving force to allow GO sheets aggregate at the water-pentane interface. On the other hand, neither the evaporation of pentane nor the mixing between ethanol and water provides sufficient driving forces to allow noteworthy amount of GO sheets to migrate from the bulk aqueous phase to the interface. This method can also be extended to prepare GO-based composites thin films with tunable composition, such as GO/single walled carbon nanotube (SWCNT) composite thin films investigated in this work. Reduced GO/SWCNT composite films show much lower surface resistivity compared to pure rGO thin films. This ethanol-assisted self-assembly method opens opportunities to design and fabricate new functional GO-based hybrid materials for various potential applications. PMID:21714517

Chen, Fuming; Liu, Shaobin; Shen, Jianmin; Wei, Li; Liu, Andong; Chan-Park, Mary B; Chen, Yuan

2011-06-29

446

Effect of Addition of Halloysite Nanoclay and SiO 2 Nanoparticles on Barrier and Mechanical Properties of Bovine Gelatin Films  

Microsoft Academic Search

Casting method was used to prepare bovine gelatin based bio-nanocomposite films with halloysite nanoclay and nano-SiO2 as the reinforcing materials. The composition included gelatin with 20% (w\\/w) of glycerol (as plasticizer) compounded with\\u000a halloysite nanoclay and nano-SiO2 (0%, 2%, 3%, 4%, 5% w\\/w), respectively. Both types of nanocomposite films showed better mechanical and water solubility than\\u000a the pristine gelatin films.

Han Ching Voon; Rajeev Bhat; Azhar Mat Easa; M. T. Liong; A. A. Karim

447

Predicting Pattern Tooling and Casting Dimensions for Investment Casting - Phase II  

SciTech Connect

The investment casting process allows the production of complex-shape parts and close dimensional tolerances. One of the most important phases in the investment casting process is the design of the pattern die. Pattern dies are used to create wax patterns by injecting wax into dies. The wax patterns are used to create a ceramic shell by the application of a series of ceramic coatings, and the alloy is cast into the dewaxed shell mold (Fig. 1.1). However, the complexity of shape and the close dimensional tolerances required in the final casting make it difficult to determine tooling dimensions. The final linear dimension of the casting depends on the cumulative effects of the linear expansions or contractions in each step of the investment casting process (Fig. 1.2). In most cases, the mold geometry or cores restrict the shrinkage of the pattern or the cast part, and the final casting dimensions may be affected by time-dependent processes such as viscoelastic deformation of the wax, and viscoplastic creep and plastic deformations of the shell and alloy. The pattern die is often reworked several times to produce castings whose dimensions are within acceptable tolerances. To date, investment casting technology has been based on hands-on training and experience. Technical literature is limited to experimental, phenomenological studies aimed at obtaining empirical correlations for quick and easy application in industry. The goal of this project was to predict casting dimensions for investment castings in order to meet blueprint nominal during the first casting run. Several interactions have to be considered in a coupled manner to determine the shrinkage factors: these are the die-wax, wax-shell, and shell-alloy interactions (as illustrated in Fig. 1.3). In this work, the deformations of the die-wax and shell-alloy systems were considered in a coupled manner, while the coupled deformation of the wax-shell system was not considered. Future work is needed in order to deliver to industry a computer program in which all three systems are coupled for determining the dimensions of the wax pattern, the shell mold, and casting in a sequential but coupled manner.

Sabau, Adrian S [ORNL

2005-09-01

448

High power storage system based on thin film solid ionics  

NASA Astrophysics Data System (ADS)

Thin film insertion cathodes obtained in the In-Se system and with a Hall mobility up to 50 sq cm (V sub s) have been measured on annealed films. Electrochemical lithium intercalation has been performed and shows that a plateau appears at 1.8V. The redox stability range has been determined by cyclic voltametry for different preparation conditions of the films. Lithium solid state hybrid systems using borate glasses as electrolyte and lamellar compounds as intercalated electrodes have been tested from the point of view of storage applications. The secondary prototype built with a composite electrode including NiPS3, carbon and powdered electrolyte have been set up and checked. Both thermodynamic and kinetic parameters are given under high power storage conditions.

Balkanski, M.; Julien, C.

1988-02-01

449

Laser-Based Growth of Nanostructured Thin Films  

NASA Astrophysics Data System (ADS)

The development of powerful, pulsed lasers with immense power has drastically changed our perception of light-matter interactions and opened new ways of implementing laser sources for the growth and processing of nanostructured materials, making Pulsed Laser Deposition (PLD) as one of the most important techniques in the nanotechnology era. In this work, we describe the main parts of a PLD system and the basic physical processes involved, as well as some laser processes for microstructural control of the grown materials. In order to establish firm understanding of the PLD processes, three case studies are presented as examples: (a) External Control of Ablated Species and Application to Tetrahedral Amorphous Carbon (ta-C) Films, (b) Self-assembled nanoparticles (NPs) into dielectric-matrix films and superlattices, (c) Controlling of the atomic structure and nanostructure of intermetallic and glassy films.

Patsalas, P.

450

Method of casting aerogels  

DOEpatents

The invention describes a method for making monolithic castings of transparent silica aerogel with densities in the range from 0.001 g/cm[sup 3] to 0.6 g/cm[sup 3]. Various shapes of aerogels are cast in flexible polymer molds which facilitate removal and eliminate irregular surfaces. Mold dimensions are preselected to account for shrinkage of aerogel which occurs during the drying step of supercritical extraction of solvent. 2 figures.

Poco, J.F.

1993-09-07

451

Aluminum Fluidity in Casting  

NASA Astrophysics Data System (ADS)

The understanding and control of fluidity is, and has been, a major aspect of foundry technology development. This paper reviews the progress made in this area over the years as it applies to aluminum castings. As a result of this development, thin-wall, high-integrity aluminum castings which were previously not thought possible have been produced. Further work in this area is expected to allow metal-matrix composites to fulfill their technical and economic promise.

Mollard, Francois R.; Flemings, Merton C.; Niyama, Eisuke F.

1987-11-01

452

Casting critical components  

NASA Astrophysics Data System (ADS)

Investment casting is an essential processing route for critical rotating and static aero gas turbine components and for a wide spectrum of high integrity parts. These must perform reliably under arduous operating conditions involving high stresses and, frequently, extremely hostile environments. The advanced technology, in-process controls, rigorous specifications, and stringent testing and inspection procedures required for high integrity investment castings are considered along with some examples of the technological 'spin-off' into diverse industry sectors.

McCallum, R.

1982-06-01

453

Casting Characteristics of Aluminum Die Casting Alloys  

SciTech Connect

The research program investigates the casting characteristics of selected aluminum die casting alloys. Specifically, the alloys' tendencies towards die soldering and sludge formation, and the alloys' fluidity and machinability are evaluated. It was found that: When the Fe and Mn contents of the alloy are low; caution has to be taken against possible die soldering. When the alloy has a high sludge factor, particularly a high level of Fe, measures must be taken to prevent the formation of large hardspots. For this kind of alloy, the Fe content should be kept at its lowest allowable level and the Mn content should be at its highest possible level. If there are problems in die filling, measures other than changing the alloy chemistry need to be considered first. In terms of alloy chemistry, the elements that form high temperature compounds must be kept at their lowest allowable levels. The alloys should not have machining problems when appropriate machining techniques and machining parameters are used.

Makhlouf M. Makhlouf; Diran Apelian

2002-02-05

454

Evaluation and improvement in the accuracy of a charge-coupled-device-based pyrometer for temperature field measurements of continuous casting billets  

NASA Astrophysics Data System (ADS)

This paper presents a radiometric high-temperature field measurement model based on a charge-coupled-device (CCD). According to the model, an intelligent CCD pyrometer with a digital signal processor as the core is developed and its non-uniformity correction algorithm for reducing the differences in accuracy between individual pixel sensors is established. By means of self-adaptive adjustment for the light-integration time, the dynamic range of the CCD is extended and its accuracy in low-temperature range is improved. The non-uniformity correction algorithm effectively reduces the accuracy differences between different pixel sensors. The performance of the system is evaluated through a blackbody furnace and an integrating sphere, the results of which show that the dynamic range of 400 K is obtained and the accuracy in low temperature range is increased by 7 times compared with the traditional method based on the fixed light-integration time. In addition, the differences of accuracy between the on-axis pixel and the most peripheral pixels are decreased from 19.1 K to 2.8 K. Therefore, this CCD pyrometer ensures that the measuring results of all pixels tend to be equal-accuracy distribution across the entire measuring ranges. This pyrometric system has been successfully applied to the temperature field measurements in continuous casting billets.

Bai, Haicheng; Xie, Zhi; Zhang, Yuzhong; Hu, Zhenwei

2013-06-01

455

Theoretical investigation of acoustic wave devices based on different piezoelectric films deposited on silicon carbide  

NASA Astrophysics Data System (ADS)

Performances of acoustic wave (AW) devices based on silicon carbide (SiC) substrates are theoretically studied, in which two types of piezoelectric films of ZnO and AlN deposited on 4H-SiC and 3C-SiC substrates are adopted. The phase velocities (PV), electromechanical coupling coefficients (ECC), and temperature coefficients of frequency (TCF) for three AW modes (Rayleigh wave, A0 and S0 modes of Lamb wave) often used in AW devices are calculated based on four types of configurations of interdigital transducers (IDTs). It is found that that the ZnO piezoelectric film is proper for the AW device operating in the low-frequency range because a high ECC can be realized using a thin ZnO film. The AlN piezoelectric film is proper for the device operating in the high-frequency range in virtue of the high PV of AlN, which can increase the finger width of the IDT. Generally, in the low-frequency Lamb wave devices using ZnO piezoelectric films with small normalized thicknesses of films to wavelengths hf/?, thin SiC substrates can increase ECCs but induce high TCFs simultaneously. In the high-frequency device with a large hf/?, the S0 mode of Lamb wave based on the AlN piezoelectric film deposited on a thick SiC substrate exhibits high performances by simultaneously considering the PV, ECC, and TCF.

Fan, Li; Zhang, Shu-yi; Ge, Huan; Zhang, Hui

2013-07-01

456

Stress Relaxation in Sn-Based Films: Effects of Pb Alloying, Grain Size, and Microstructure  

NASA Astrophysics Data System (ADS)

Stress is believed to provide the driving force for growth of Sn whiskers, so stress relaxation in the Sn layer plays a key role in their formation. To understand and enhance stress relaxation in Sn-based films, the effects of Pb alloying and microstructure on their mechanical properties have been studied by observing the relaxation of thermal expansion-induced strain. The relaxation rate is found to increase with film thickness and grain size in pure Sn films, and it depends on the microstructure in Pb-alloyed Sn films. Measurements of multilayered structures (Sn on Pb-Sn and Pb-Sn on Sn) show that changing the surface layer alone is not sufficient to enhance the relaxation, indicating that the Pb enhances relaxation in the bulk of the film and not by surface modification. Implications of our results for whisker mitigation strategies are discussed.

Jadhav, Nitin; Wasserman, Jacob; Pei, Fei; Chason, Eric

2011-12-01

457

Controllable optical, electrical, and morphologic properties of 3,4-ethylenedioxythiophene based electrocopolymerization films.  

PubMed

This contribution presents a kind of novel and neutral network films based on EDOT formed by in situ electrocopolymerization (ECP). The ECP films which are neutral and colorless exhibit the conductivity of 0.2-0.5 S·cm(-1), W(F) of 4.79-5.20 eV, and RMS roughness of 3.51-5.26 nm. The electroluminescent devices where ECP films acted as hole-transport layer (HTL) exhibit higher brightness, current density, efficiency (20-30% improvement), and stability than that of PEDOT:PSS HTL device. The ECP films also significantly benefit the stability of neighboring organic layer compared to PEDOT:PSS. This kind of new ECP films affords more opportunities to develop organic light-emitting diodes (OLEDs) with high performances and stability. PMID:21644242

Gu, Cheng; Liu, He; Hu, Dehua; Zhang, Wensi; Lv, Ying; Lu, Ping; Lu, Dan; Ma, Yuguang

2011-06-03

458

Wet Etching of TiO2-Based Precursor Amorphous Films for Transparent Electrodes  

NASA Astrophysics Data System (ADS)

We investigated wet etching of Nb-doped anatase TiO2 (TNO) transparent conducting thin films and their precursors in an amorphous phase deposited by rf sputtering on glass substrates. The polycrystalline TNO films showed a very low etching rate of less than 0.06 nm/min in concentrated sulfuric acid (H2SO4) even at elevated temperatures up to 95 °C. In contrast, H2SO4 etched the precursor films at a rate of 1.4 nm/min at 95 °C. The etching rate of the amorphous films followed the Arrhenius equation, leading us to conjecture that a much higher etching rate of ˜230 nm/min can be achieved at 170 °C. These results indicate that wet-etching of precursor amorphous films prior to crystallization represents a practical and low-cost lithographic technique for patterning TiO2-based transparent electrodes.

Ohkubo, Junpei; Hirose, Yasushi; Sakai, Enju; Nakao, Shoichiro; Hitosugi, Taro; Hasegawa, Tetsuya

2011-01-01

459

H2S sensors based on chemically treated SnO2:Pd thin films  

NASA Astrophysics Data System (ADS)

Preparation and characterization of gas sensors based on thin films of SnO2:Pd to monitor trace amounts of H2S in air are reported. Sensors have been exposed to 100% relative humidity to study the incorporation of hydroxyl group (-OH) in the film and its effects on gas sensing properties. Films have been subsequently treated with dilute sulphuric acid and characterized using different techniques such as X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, IR spectroscopy and electrical resistance measurements. IR studies reveal the presence of two types of hydroxyl groups (-OH) in the film; as 'free surface -OH' and hydrogen bonded -OH. The two types of -OH have been found to affect the gas sensing properties in different ways. Chemical treatment of films with dilute sulphuric acid has been found to improve the H2S sensing properties of the sensor by modifying the concentrations of the two types of hydroxyl groups.

Katti, V. R.; Kaur, Manmeet; Muthe, K. P.; Dua, A. K.; Gadkari, S. C.; Gupta, S. K.; Sahni, Vinod C.

2003-10-01

460

Radiation dose dependent change in physiochemical, mechanical and barrier properties of guar gum based films.  

PubMed

Mechanical and water vapor barrier properties of biodegradable films prepared from radiation processed guar gum were investigated. Films prepared from GG irradiated up to 500Gy demonstrated significantly higher tensile strength as compared to non-irradiated control films. This improvement in tensile strength observed was demonstrated to be due to the ordering of polymer structures as confirmed by small angle X-ray scattering analysis. Exposure to doses higher than 500Gy, however, resulted in a dose dependent decrease in tensile strength. A dose dependent decrease in puncture strength with no significant differences in the percent elongation was also observed at all the doses studied. Water vapor barrier properties of films improved up to 15% due to radiation processing. Radiation processing at lower doses for improving mechanical and barrier properties of guar based packaging films is demonstrated here for the first time. PMID:24053847

Saurabh, Chaturbhuj K; Gupta, Sumit; Bahadur, Jitendra; Mazumder, S; Variyar, Prasad S; Sharma, Arun

2013-07-25

461

Tape casting of lanthanum chromite  

SciTech Connect

Solid oxide fuel cells (SOFCs) are currently being developed for a variety of applications such as stationary on-site power plants and cogeneration. The effects of process additives, ball milling, and solids loading were evaluated for tape casting suspensions of glycine-nitrate-synthesized La{sub 0.7}Ca{sub 0.31}CrO{sub 3} powder. An optimized formulation was obtained based on rheological characterization, electrokinetic sonic amplitude measurements, qualitative examination of green tapes, and the sintered microstructure. The tape casting formulation incorporated 66:34 methyl ethyl ketone/ethyl alcohol solvent, an aliphatic phosphate ester dispersant, and 80 wt% (35 vol%) solids. The best binder/plasticizer system was 12 wt% (15 vol%) poly(isobutyl methacrylate) and 5 wt% (6.3 vol%) benzyl butyl phthalate plasticizer (binder:plasticizer = 2.3). Cast tapes were sintered at 1300 C for 2 h, producing a bulk density of 96.2% theoretical, with linear shrinkage of 22% and an approximate grain size of 1.3 {micro}m.

Murphy, M.W.; Armstrong, T.R.; Smith, P.A. [Pacific Northwest National Lab., Richland, WA (United States)

1997-01-01