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Sample records for extruding dl-1375 silica

  1. Extrudate versus powder silica alumina as support for Re₂O₇ catalyst in the metathesis of seed oil-derivatives - a comparison.

    PubMed

    Marvey, Bassie B

    2009-01-01

    Self- and cross-metathesis of fatty acid methyl esters (FAMEs) was investigated using a silica alumina supported Re(2)O(7) catalyst. Although a 3 wt% Re(2)O(7)/SiO(2)-Al(2)O(3)/SnBu(4) is already active for the metathesis of unsaturated FAMEs, the results have shown that particle size of silica alumina support has a profound influence on its activity and selectivity. Consequently, high substrate conversions coupled with improved product yields (for mono- and diesters) and reaction rates were obtained upon using powder, as opposed to extrudate silica alumina as the support material. Diesters are platform compounds for the synthesis of polymers and fragrances. In this paper a comparative outline of the influence of particle size of silica alumina (extrudate versus powder) on catalytic performance of a 3 wt% Re(2)O(7)/SiO(2)-Al(2)O(3)/SnBu(4) for self- and cross-metathesis of FAMEs is made. Low surface area and diffusion constraints associated with extrudates were identified as some of the factors leading to low catalytic activity and selectivity. PMID:19333442

  2. Intelligent Extruder

    SciTech Connect

    AlperEker; Mark Giammattia; Paul Houpt; Aditya Kumar; Oscar Montero; Minesh Shah; Norberto Silvi; Timothy Cribbs

    2003-04-24

    ''Intelligent Extruder'' described in this report is a software system and associated support services for monitoring and control of compounding extruders to improve material quality, reduce waste and energy use, with minimal addition of new sensors or changes to the factory floor system components. Emphasis is on process improvements to the mixing, melting and de-volatilization of base resins, fillers, pigments, fire retardants and other additives in the :finishing'' stage of high value added engineering polymer materials. While GE Plastics materials were used for experimental studies throughout the program, the concepts and principles are broadly applicable to other manufacturers materials. The project involved a joint collaboration among GE Global Research, GE Industrial Systems and Coperion Werner & Pleiderer, USA, a major manufacturer of compounding equipment. Scope of the program included development of a algorithms for monitoring process material viscosity without rheological sensors or generating waste streams, a novel detection scheme for rapid detection of process upsets and an adaptive feedback control system to compensate for process upsets where at line adjustments are feasible. Software algorithms were implemented and tested on a laboratory scale extruder (50 lb/hr) at GE Global Research and data from a production scale system (2000 lb/hr) at GE Plastics was used to validate the monitoring and detection software. Although not evaluated experimentally, a new concept for extruder process monitoring through estimation of high frequency drive torque without strain gauges is developed and demonstrated in simulation. A plan to commercialize the software system is outlined, but commercialization has not been completed.

  3. Orbital foamed material extruder

    NASA Technical Reports Server (NTRS)

    Tucker, Dennis S. (Inventor)

    2009-01-01

    This invention is a process for producing foamed material in space comprising the steps of: rotating the material to simulate the force of gravity; heating the rotating material until it is molten; extruding the rotating, molten material; injecting gas into the extruded, rotating, molten material to produce molten foamed material; allowing the molten foamed material to cool to below melting temperature to produce the foamed material. The surface of the extruded foam may be heated to above melting temperature and allowed to cool to below melting temperature. The extruded foam may also be cut to predetermined length. The starting material may be metal or glass. Heating may be accomplished by electrical heating elements or by solar heating.

  4. Extruded plastic scintillation detectors

    SciTech Connect

    Anna Pla-Dalmau, Alan D. Bross and Kerry L. Mellott

    1999-04-16

    As a way to lower the cost of plastic scintillation detectors, commercially available polystyrene pellets have been used in the production of scintillating materials that can be extruded into different profiles. The selection of the raw materials is discussed. Two techniques to add wavelength shifting dopants to polystyrene pellets and to extrude plastic scintillating strips are described. Data on light yield and transmittance measurements are presented.

  5. Extruded ceramic honeycomb and method

    DOEpatents

    Day, J. Paul

    1995-04-04

    Extruded low-expansion ceramic honeycombs comprising beta-spodumene solid solution as the principal crystal phase and with less than 7 weight percent of included mullite are produced by compounding an extrusion batch comprising a lithium aluminosilicate glass powder and a clay additive, extruding a green honeycomb body from the batch, and drying and firing the green extruded cellular honeycomb to crystallize the glass and clay into a low-expansion spodumene ceramic honeycomb body.

  6. Physical properties of extrudates containing distillers grains extruded in a twin screw extruder

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Extrusion trials were conducted with varying levels of distillers dried grains with solubles (DDGS) along with soy flour, corn flour, fish meal, vitamin mix, mineral mix and net protein content adjusted to 28% using a Wenger TX-52 twin screw extruder. The properties of extrudates obtained with exper...

  7. About NICADD extruded scintillating strips

    SciTech Connect

    Dyshkant, A.; Beznosko, D.; Blazey, G.; Chakraborty, D.; Francis, K.; Kubik, D.; Lima, J.G.; Rykalin, V.; Zutshi, v.; Baldina, E.; Bross, A.; Deering, P.; Nebel, T.; Pla-Dalmau, A.; Schellpfeffer, J.; Serritella, C.; Zimmerman, J.; /Fermilab

    2005-04-01

    The results of control measurements of extruded scintillating strip responses to a radioactive source Sr-90 are provided, and details of strip choice, preparation, and method of measurement are included. About four hundred one meter long extruded scintillating strips were measured at four different points. These results were essential for prototyping a tail catcher and muon tracker for a future international electron positron linear collider detector.

  8. Extruded scintillator for the calorimetry applications

    SciTech Connect

    Dyshkant, A.; Rykalin, V.; Pla-Dalmau, A.; Beznosko, D.; /SUNY, Stony Brook

    2006-08-01

    An extrusion line has been installed and successfully operated at FNAL (Fermi National Accelerator Laboratory) in collaboration with NICADD (Northern Illinois Center for Accelerator and Detector Development). This new Facility will serve to further develop and improve extruded plastic scintillator. Recently progress has been made in producing co-extruded plastic scintillator, thus increasing the potential HEP applications of this Facility. The current R&D work with extruded and co-extruded plastic scintillator for a potential ALICE upgrade, the ILC calorimetry program and the MINERvA experiment show the attractiveness of the chosen strategy for future experiments and calorimetry. We extensively discuss extruded and co-extruded plastic scintillator in calorimetry in synergy with new Solid State Photomultipliers. The characteristics of extruded and co-extruded plastic scintillator will be presented here as well as results with non-traditional photo read-out.

  9. Extruded scintillator for the Calorimetry applications

    SciTech Connect

    Dyshkant, A.; Rykalin, V.; Pla-Dalmau, A.; Beznosko, D.

    2006-10-27

    An extrusion line has been installed and successfully operated at FNAL (Fermi National Accelerator Laboratory) in collaboration with NICADD (Northern Illinois Center for Accelerator and Detector Development). This new Facility will serve to further develop and improve extruded plastic scintillator. Recently progress has been made in producing co-extruded plastic scintillator, thus increasing the potential HEP applications of this Facility. The current R and D work with extruded and co-extruded plastic scintillator for a potential ALICE upgrade, the ILC calorimetry program and the MINERvA experiment show the attractiveness of the chosen strategy for future experiments and calorimetry. We extensively discuss extruded and co-extruded plastic scintillator in calorimetry in synergy with new Solid State Photomultipliers. The characteristics of extruded and co-extruded plastic scintillator will be presented here as well as results with non-traditional photo read-out.

  10. FNAL-NICADD extruded scintillator

    SciTech Connect

    Beznosko, D.; Bross, A.; Dyshkant, A.; Pla-Dalmau, A.; Rykalin, V.; /Northern Illinois U.

    2005-09-01

    The possibility to produce a scintillator that satisfies the demands of physicists from different science areas has emerged with the installation of an extrusion line at Fermi National Accelerator Laboratory (FNAL). The extruder is the product of the fruitful collaboration between FNAL and Northern Illinois Center for Accelerator and Detector Development (NICADD) at Northern Illinois University (NIU). The results from the light output, light attenuation length and mechanical tolerance indicate that FNAL-NICADD scintillator is of high quality. Improvements in the extrusion die will yield better scintillator profiles and decrease the time needed for initial tuning. This paper will present the characteristics of the FNAL-NICADD scintillator based on the measurements performed. They include the response to MIPs from cosmic rays for individual extruded strips and irradiation studies where extruded samples were irradiated up to 1 Mrad. We will also discuss the results achieved with a new die design. The attractive perspective of using the extruded scintillator with MRS (Metal Resistive Semiconductor) photodetector readout will also be shown.

  11. Extruding plastic scintillator at Fermilab

    SciTech Connect

    Anna Pla-Dalmau; Alan D. Bross; Victor V. Rykalin

    2003-10-31

    An understanding of the costs involved in the production of plastic scintillators and the development of a less expensive material have become necessary with the prospects of building very large plastic scintillation detectors. Several factors contribute to the high cost of plastic scintillating sheets, but the principal reason is the labor-intensive nature of the manufacturing process. In order to significantly lower the costs, the current casting procedures had to be abandoned. Since polystyrene is widely used in the consumer industry, the logical path was to investigate the extrusion of commercial-grade polystyrene pellets with dopants to yield high quality plastic scintillator. This concept was tested and high quality extruded plastic scintillator was produced. The D0 and MINOS experiments are already using extruded scintillator strips in their detectors. An extrusion line has recently been installed at Fermilab in collaboration with NICADD (Northern Illinois Center for Accelerator and Detector Development). This new facility will serve to further develop and improve extruded plastic scintillator. This paper will discuss the characteristics of extruded plastic scintillator and its raw materials, the different manufacturing techniques and the current R&D program at Fermilab.

  12. Properties of extruded expandable breadfruit products

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Dried breadfruit was extruded with a twin screw extruder to develop a value-added expanded fruit product. This research studied the effects of barrel temperature (120-160°C), moisture content (13-25%), feeding rate (13-25 kg/h) and screw speed (115-175rpm) on physicochemical properties (bulk densit...

  13. Improvements to the single screw extruder

    NASA Technical Reports Server (NTRS)

    Hiemenz, C.; Ziegmann, G.; Franzkoch, B.; Hoffmanns, W.; Michaeli, W.

    1977-01-01

    The extrusion on a single screw extruder is examined. The process is divided into several steps: the dosage of the materials to be conveyed; the modification of the shape of the feeding opening which influences the feeding process and consequently the throughput of the extruder; optimizing the shape of the feeding zone to meet the specific material requirements; and plasticizing and homogenizing.

  14. Extruded plastic scintillator for MINERvA

    SciTech Connect

    Pla-Dalmau, Anna; Bross, Alan D.; Rykalin, Victor V.; Wood, Brian M.; /NICADD, DeKalb

    2005-11-01

    An extrusion line has recently been installed at Fermilab in collaboration with NICADD (Northern Illinois Center for Accelerator and Detector Development). This new facility will serve to further develop and improve extruded plastic scintillator. Since polystyrene is widely used in the consumer industry, the logical path was to investigate the extrusion of commercial-grade polystyrene pellets with dopants to yield high quality plastic scintillator. The D0 and MINOS experiments are already using extruded scintillator strips in their detectors. A new experiment at Fermilab is pursuing the use of extruded plastic scintillator. A new plastic scintillator strip is being tested and its properties characterized. The initial results are presented here.

  15. Completely extruded talus without soft tissue attachments.

    PubMed

    Choi, Young Rak; Jeong, Jae Jung; Lee, Ho Seong; Kim, Sang Woo; Suh, Jin-Soo

    2011-03-29

    A completely extruded talus without any remaining soft tissue attachments is extremely rare. The present report describes treatment of a 45-year-old man who sustained a completely extruded talus injury following a rock-climbing fall. Upon admission, the extruded talus was deep-frozen in our bone bank. The open ankle joint underwent massive wound debridement and irrigation for 3 days. Four days later we performed a primary subtalar fusion between the extruded talus and the calcaneus, anticipating revascularization from the calcaneus. However, aseptic loosening and osteolysis developed around the screw and talus. At 12 months post-trauma we performed a tibiocalcaneal ankle fusion with a femoral head allograft to fill the talar defect. Follow-up at 24 months post-trauma showed the patient had midfoot motion, tibio-talar-calcaneal fusion, and was able partake in 4-hour physical activity twice per week. PMID:24765266

  16. RHEOLOGY OF EXTRUDED WHEY PROTEIN ISOLATE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Whey protein isolate (WPI), a high-quality protein used to fortify a number of foods, may be texturized with a twin-screw extruder. Since extrusion of food is commonly performed above 70°C, which causes whey protein to denature, cold extrusion below 70°C was investigated to determine the effects on...

  17. PHYSICOCHEMICAL PROPERTIES OF STARCH IN EXTRUDED RICE FLOURS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The effects of extruding temperatures and subsequent drying conditions on X-ray diffractionpatterns (XRD) and differential scanning calorimetry (DSC) of long grain (LG) and short grain (SG) rice flours were investigated. The rice flours were extruded in a twin-screw extruder at 70-120degreesC and 22...

  18. Extruder analysis, modeling, and dynamic matrix control

    SciTech Connect

    Sribuangam, D.

    1991-01-01

    The Modern Plastics extruder of the Material Science and Engineering Department is used to extrude high density polyethylene (Alathon 7040). Diameter sensor characterization is done due to the fiber positioning sensitivity of the sensor (Zimmer) and observed variations in the sensor signal. Detailed step test transfer function models are developed where the input variables are take-up speed, screw speed, gear pump speed, and die temperature set point. The output variables are die temperature, die pressure, end of the barrel temperature and pressure. A total of 18 transfer functions are obtained. The relationships between known periodic input variations and the output variations are analyzed by the power spectrum analysis. Due to the dominance of the draw resonance-like variation, the main control objective is to eliminate this variation. Results show that all control methods can handle set point tracking but achieve only a limited reduction in amplitude of the fiber diameter variation.

  19. Method for extruding pitch based foam

    DOEpatents

    Klett, James W.

    2002-01-01

    A method and apparatus for extruding pitch based foam is disclosed. The method includes the steps of: forming a viscous pitch foam; passing the precursor through an extrusion tube; and subjecting the precursor in said extrusion tube to a temperature gradient which varies along the length of the extrusion tube to form an extruded carbon foam. The apparatus includes an extrusion tube having a passageway communicatively connected to a chamber in which a viscous pitch foam formed in the chamber paring through the extrusion tube, and a heating mechanism in thermal communication with the tube for heating the viscous pitch foam along the length of the tube in accordance with a predetermined temperature gradient.

  20. Extruded plastic scintillator including inorganic powders

    DOEpatents

    Bross, Alan D.; Mellott, Kerry L.; Pla-Dalmau, Anna

    2006-06-27

    A method for producing a plastic scintillator is disclosed. A plurality of nano-sized particles and one or more dopants can be combined with a plastic material for the formation of a plastic scintillator thereof. The nano-sized particles, the dopant and the plastic material can be combined within the dry inert atmosphere of an extruder to produce a reaction that results in the formation of a plastic scintillator thereof and the deposition of energy within the plastic scintillator, such that the plastic scintillator produces light signifying the detection of a radiative element. The nano-sized particles can be treated with an inert gas prior to processing the nano-sized particles, the dopant and the plastic material utilizing the extruder. The plastic scintillator can be a neutron-sensitive scintillator, x-ray sensitive scintillator and/or a scintillator for the detection of minimum ionizing particles.

  1. Studies of NICADD Extruded Scintillator Strips

    SciTech Connect

    Dychkant, Alexandre; et al.

    2005-03-01

    About four hundred one meter long, 10 cm wide and 5 mm thick extruded scintillating strips were measured at four different points. The results of measurements strip responses to a radioactive source {sup 90}Sr are provided, and details of strip choice, preparation, and method of measurement are included. This work was essential for prototyping a tail catcher and muon tracker for a future international electron positron linear collider detector.

  2. Physicochemical Properties of Flaxseed Fortified Extruded Bean Snack

    PubMed Central

    Vadukapuram, Naveen; Hall, Clifford

    2014-01-01

    Milled flaxseed was incorporated (0–20%) into a combination of bean-corn flours and extruded in a twin screw extruder using corn curl method. Physicochemical parameters such as water activity, color, expansion ratio, bulk density, lipid content, and peroxide values of extruded snack were analyzed. Scanning electron micrographs were taken. Peroxide values and propanal contents were measured over four months of storage. Rancidity scores of extruded snack were measured using a trained panel. As expected, omega-3 fatty acids and bulk density increased with increasing flaxseed fortification levels. Extrudates with more flaxseed had decreased lightness values and expansion ratios. However, only the 15 and 20% flaxseed containing extrudates had expansion ratios that were significantly (P ≤ 0.05) different from the control. In general, no significant difference (P > 0.05) in water activity values was observed in the flaxseed fortified extrudates, except in the navy-corn based extrudates. Peroxide values increased with increased flaxseed levels and over a storage period. However, propanal values did not change significantly in the 5–10% flaxseed fortified extrudates but increased in extrudates with higher levels of flaxseed. Rancidity scores were correlated with peroxide values and did not increase significantly during storage under nitrogen flushed conditions. PMID:26904633

  3. Extrusion of electrode material by liquid injection into extruder barrel

    DOEpatents

    Keller, D.G.; Giovannoni, R.T.; MacFadden, K.O.

    1998-03-10

    An electrode sheet product is formed using an extruder having a feed throat and a downstream section by separately mixing an active electrode material and a solid polymer electrolyte composition that contains lithium salt. The active electrode material is fed into the feed throat of the extruder, while a portion of at least one fluid component of the solid polymer electrolyte composition is introduced to the downstream section. The active electrode material and the solid polymer electrolyte composition are compounded in a downstream end of the extruder. The extruded sheets, adhered to current collectors, can be formed into battery cells. 1 fig.

  4. Extrusion of electrode material by liquid injection into extruder barrel

    DOEpatents

    Keller, David Gerard; Giovannoni, Richard Thomas; MacFadden, Kenneth Orville

    1998-01-01

    An electrode sheet product is formed using an extruder having a feed throat and a downstream section by separately mixing an active electrode material and a solid polymer electrolyte composition that contains lithium salt. The active electrode material is fed into the feed throat of the extruder, while a portion of at least one fluid component of the solid polymer electrolyte composition is introduced to the downstream section. The active electrode material and the solid polymer electrolyte composition are compounded in a downstream end of the extruder. The extruded sheets, adhered to current collectors, can be formed into battery cells.

  5. Preferred orientations in extruded nickel and iron aluminides

    NASA Astrophysics Data System (ADS)

    Khadkikar, P. S.; Michal, G. M.; Vedula, K.

    1990-01-01

    Preferred orientations in both powder-extruded and cast and extruded binary NiAl (≃45 at. pet Al), FeAl (≃40 at. pet Al), and Ni3Al (≃24 at. pet Al) have been characterized by plotting inverse pole figures. The preferred orientation, [111], was observed along the extrusion direction in both powder-extruded and cast and extruded NiAl. Powder-extruded FeAl also exhibited [111] as the preferred orientation in the as-extruded condition. However, [110] was observed to be the preferred orientation in the cast and extruded FeAl and was replaced by a [211] orientation preference upon annealing. Annealing did not change the preferred orientations in NiAl or in powder-extruded FeAl. In contrast to the B2 NiAl and FeAl alloys, the Ll2 Ni3Al alloy exhibited nearly random orientations with only a minor preference for a [111] orientation in the as-extruded condition.

  6. Method and apparatus for extruding large honeycombs

    SciTech Connect

    Kragle, Harry A.; Lambert, David W.; Lipp, G. Daniel

    1996-09-03

    Extrusion die apparatus and an extrusion method for extruding large-cross-section honeycomb structures from plasticized ceramic batch materials are described, the apparatus comprising a die having a support rod connected to its central portion, the support rod being anchored to support means upstream of the die. The support rod and support means act to limit die distortion during extrusion, reducing die strain and stress to levels permitting large honeycomb extrusion without die failure. Dies of optimal thickness are disclosed which reduce the maximum stresses exerted on the die during extrusion.

  7. Extruding Kolmogorov-type phase screen ribbons.

    PubMed

    Fried, David L; Clark, Tim

    2008-02-01

    A phase screen ribbon extrusion process is presented that allows a phase screen ribbon of any specified width to be extruded, one column at a time, producing a ribbon of any desired length, with Kolmogorov statistics (i.e., having a five-thirds power-law-dependent structure function) for all separations up to some selected upper limit--which upper limit can be as large as desired. The method is an adaptation of the method described by [Assémat et al. Opt. Express 14, 988 (2006)]. PMID:18246180

  8. Dissolution from solid lipid extrudates containing release modifiers.

    PubMed

    Güres, Sinan; Kleinebudde, Peter

    2011-06-30

    The influence of different types of release modifiers on the dissolution from solid lipid extrudates was investigated. Diprophylline was extruded together with 45% tristearin and 5% (w/w) of a release modifier to suitable extrudates. Three groups of release modifiers were defined: Hydrocolloids, disintegrants and pore formers. All of the release modifier-containing extrudates showed a faster release compared to the reference extrudate, which contained 50% (w/w) of each, API and lipid. Increasing the amount of diprophylline in the binary mixture up to 55% (w/w) also increased its release rate. Compared to this new reference, not all of the release modifier-containing extrudates exhibited an increased dissolution rate. Within the group of pore formers, there was a great discrepancy concerning the dissolution rates. Extrudates containing polyethylene glycol (PEG) exhibited a much higher release rate compared with extrudates containing sodium chloride or mannitol. This behaviour was assumed to be based on the extrusion temperature of 65°C at which PEG exists in the molten state. The hypothesis was tested using different PEGs and another solid lipid. PMID:21515350

  9. Properties of extruded chia-corn meal puffs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study investigated the properties of extruded corn meal puffs containing chia. Mixtures of corn meal and chia seeds (0-20%) were processed in a laboratory-scale twin-screw extruder at different moisture contents (18-22%) and final heating zone temperatures (120-160 °C). Extrusion processing pro...

  10. Polyphenolic composition and antioxidant capacity of extruded cranberry pomace

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cranberry pomace was mixed with corn starch in various ratios (30/70, 40/60, 50/50 pomace/corn starch), and extruded using a twin-screw extruder at three temperatures (150, 170, 190 C), and two screw speeds (150, 200 rpm). Changes in the anthocyanin, flavonol, and procyanidin contents due to extrus...

  11. Silica nephropathy.

    PubMed

    Ghahramani, N

    2010-07-01

    Occupational exposure to heavy metals, organic solvents and silica is associated with a variety of renal manifestations. Improved understanding of occupational renal disease provides insight into environmental renal disease, improving knowledge of disease pathogenesis. Silica (SiO2) is an abundant mineral found in sand, rock, and soil. Workers exposed to silica include sandblasters, miners, quarry workers, masons, ceramic workers and glass manufacturers. New cases of silicosis per year have been estimated in the US to be 3600-7300. Exposure to silica has been associated with tubulointerstitial disease, immune-mediated multisystem disease, chronic kidney disease and end-stage renal disease. A rare syndrome of painful, nodular skin lesions has been described in dialysis patients with excessive levels of silicon. Balkan endemic nephropathy is postulated to be due to chronic intoxication with drinking water polluted by silicates released during soil erosion. The mechanism of silica nephrotoxicity is thought to be through direct nephrotoxicity, as well as silica-induced autoimmune diseases such as scleroderma and systemic lupus erythematosus. The renal histopathology varies from focal to crescentic and necrotizing glomerulonephritis with aneurysm formation suggestive of polyarteritis nodosa. The treatment for silica nephrotoxicity is non-specific and depends on the mechanism and stage of the disease. It is quite clear that further research is needed, particularly to elucidate the pathogenesis of silica nephropathy. Considering the importance of diagnosing exposure-related renal disease at early stages, it is imperative to obtain a thorough occupational history in all patients with renal disease, with particular emphasis on exposure to silica, heavy metals, and solvents. PMID:23022796

  12. Study on profile measurement of extruding tire tread by laser

    NASA Astrophysics Data System (ADS)

    Wang, LiangCai; Zhang, Wanping; Zhu, Weihu

    1996-10-01

    This paper presents a new 2D measuring system-profile measurement of extruding tire tread by laser. It includes the thickness measurement of extruding tire tread by laser and the width measurement of extruding tire tread using Moire Fringe. The system has been applied to process line of extruding tire tread. Two measuring results have been obtained. One is a standard profile picture of extruding tire tread including seven measuring values. Another one is a series of thickness and width values. When the scanning speed < 100mm/sec and total width < 800mm. The measuring errors of width < +/- 0.5mm. While the thickness range is < 40mm. The measuring errors of thickness < +/- 0.1mm.

  13. Extruder system and method for treatment of a gaseous medium

    DOEpatents

    Silvi, Norberto; Perry, Robert James; Singh, Surinder Prabhjot; Balch, Gary Stephen; Westendorf, Tiffany Elizabeth Pinard

    2016-04-05

    A system for treatment of a gaseous medium, comprises an extruder having a barrel. The extruder further comprises a first inlet port, a second inlet port, and a plurality of outlet ports coupled to the barrel. The first inlet port is configured for feeding a lean sorbent, the second inlet port is configured for feeding a gaseous medium, and the plurality of outlet ports are configured for releasing a plurality of components removed from the gaseous medium. Further, the extruder comprises a plurality of helical elements coupled to a plurality of kneading elements, mounted on a shaft, and disposed within the barrel. The barrel and the plurality of helical and kneading elements together form an absorption unit and a desorption unit. The first and second inlet ports are formed in the absorption unit and the plurality of outlet ports are formed in the absorption and desorption units.

  14. Physical and functional properties of arrowroot starch extrudates.

    PubMed

    Jyothi, A N; Sheriff, J T; Sajeev, M S

    2009-03-01

    Arrowroot starch, a commercially underexploited tuber starch but having potential digestive and medicinal properties, has been subjected to extrusion cooking using a single screw food extruder. Different levels of feed moisture (12%, 14%, and 16%) and extrusion temperatures (140, 150, 160, 170, 180, and 190 degrees C) were used for extrusion. The physical properties--bulk density, true density, porosity, and expansion ratio; functional properties such as water absorption index, water solubility index, oil absorption index, pasting, rheological, and textural properties; and in vitro enzyme digestibility of the extrudates were determined. The expansion ratio of the extrudates ranged from 3.22 to 6.09. The water absorption index (6.52 to 8.85 g gel/g dry sample), water solubility index (15.92% to 41.31%), and oil absorption index (0.50 to 1.70 g/g) were higher for the extrudates in comparison to native starch (1.81 g gel/g dry sample, 1.16% and 0.60 g/g, respectively). The rheological properties, storage modulus, and loss modulus of the gelatinized powdered extrudates were significantly lower (P < 0.05) and these behaved like solutions rather than a paste or a gel. Hardness and toughness were more for the samples extruded at higher feed moisture and lower extrusion temperature, whereas snap force and energy were higher at lower feed moisture and temperature. There was a significant decrease in the percentage digestibility of arrowroot starch (30.07% after 30 min of incubation with the enzyme) after extrusion (25.27% to 30.56%). Extrusion cooking of arrowroot starch resulted in products with very good expansion, color, and lower digestibility, which can be exploited for its potential use as a snack food. PMID:19323747

  15. Quality improvement of melt extruded laminar systems using mixture design.

    PubMed

    Hasa, D; Perissutti, B; Campisi, B; Grassi, M; Grabnar, I; Golob, S; Mian, M; Voinovich, D

    2015-07-30

    This study investigates the application of melt extrusion for the development of an oral retard formulation with a precise drug release over time. Since adjusting the formulation appears to be of the utmost importance in achieving the desired drug release patterns, different formulations of laminar extrudates were prepared according to the principles of Experimental Design, using a design for mixtures to assess the influence of formulation composition on the in vitro drug release from the extrudates after 1h and after 8h. The effect of each component on the two response variables was also studied. Ternary mixtures of theophylline (model drug), monohydrate lactose and microcrystalline wax (as thermoplastic binder) were extruded in a lab scale vertical ram extruder in absence of solvents at a temperature below the melting point of the binder (so that the crystalline state of the drug could be maintained), through a rectangular die to obtain suitable laminar systems. Thanks to the desirability approach and a reliability study for ensuring the quality of the formulation, a very restricted optimal zone was defined within the experimental domain. Among the mixture components, the variation of microcrystalline wax content played the most significant role in overall influence on the in vitro drug release. The formulation theophylline:lactose:wax, 57:14:29 (by weight), selected based on the desirability zone, was subsequently used for in vivo studies. The plasma profile, obtained after oral administration of the laminar extruded system in hard gelatine capsules, revealed the typical trend of an oral retard formulation. The application of the mixture experimental design associated to a desirability function permitted to optimize the extruded system and to determine the composition space that ensures final product quality. PMID:25912827

  16. Characterization of modified 9 Cr-1 Mo steel extruded pipe

    SciTech Connect

    Sikka, V.K.; Hart, M.D.

    1985-04-01

    The fabrication of hot-extruded pipe of modified 9 Cr-1 Mo steel at Cameron Iron Works is described. The report also deals with the tempering response; tensile, Charpy impact, and creep properties; and microstructure of the hot-extruded pipe. The tensile properties of the pipe are compared with the average and average -1.65 standard error of estimate curves for various product forms of several commercial heats of this alloy. The creep-rupture properties are compared with the average curve for various product forms of the commercial heats.

  17. Buckling of a beam extruded into highly viscous fluid.

    PubMed

    Gosselin, F P; Neetzow, P; Paak, M

    2014-11-01

    Inspired by microscopic Paramecia which use trichocyst extrusion to propel themselves away from thermal aggression, we propose a macroscopic experiment to study the stability of a slender beam extruded in a highly viscous fluid. Piano wires were extruded axially at constant speed in a tank filled with corn syrup. The force necessary to extrude the wire was measured to increase linearly at first until the compressive viscous force causes the wire to buckle. A numerical model, coupling a lengthening elastica formulation with resistive-force theory, predicts a similar behavior. The model is used to study the dynamics at large time when the beam is highly deformed. It is found that at large time, a large deformation regime exists in which the force necessary to extrude the beam at constant speed becomes constant and length independent. With a proper dimensional analysis, the beam can be shown to buckle at a critical length based on the extrusion speed, the bending rigidity, and the dynamic viscosity of the fluid. Hypothesizing that the trichocysts of Paramecia must be sized to maximize their thrust per unit volume as well as avoid buckling instabilities, we predict that their bending rigidity must be about 3×10^{-9}Nμm^{2}. The verification of this prediction is left for future work. PMID:25493827

  18. 99. 99% Al/ 6063 Alloy Co-extruded beam chamber

    SciTech Connect

    Ishimaru, H.; Narushima, K.; Kanazawa, K.

    1988-09-30

    In an electron storage ring, synchrotron radiation causes stimulated gas desorption from the vacuum chamber wall. It raises the operating pressure far above the ultrahigh vacuum range needed for long beam lifetimes. In order to determine an ideal material for low dynamic gas desorption we have studied the properties of co-extruded 99.99%Al/ 6063 alloy. (AIP)

  19. Effect of starch sources on extruded aquaculture feed containing DDGS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aquaculture is one of the most rapidly growing sectors of agriculture, and is a reliable growth market for the prepared feeds. A Brabender laboratory-scale single screw extruder was used to study the effect of various starch sources (cassava, corn, and potato), DDGS levels (20, 30, and 40% (wb)), an...

  20. Buckling of a beam extruded into highly viscous fluid

    NASA Astrophysics Data System (ADS)

    Gosselin, F. P.; Neetzow, P.; Paak, M.

    2014-11-01

    Inspired by microscopic Paramecia which use trichocyst extrusion to propel themselves away from thermal aggression, we propose a macroscopic experiment to study the stability of a slender beam extruded in a highly viscous fluid. Piano wires were extruded axially at constant speed in a tank filled with corn syrup. The force necessary to extrude the wire was measured to increase linearly at first until the compressive viscous force causes the wire to buckle. A numerical model, coupling a lengthening elastica formulation with resistive-force theory, predicts a similar behavior. The model is used to study the dynamics at large time when the beam is highly deformed. It is found that at large time, a large deformation regime exists in which the force necessary to extrude the beam at constant speed becomes constant and length independent. With a proper dimensional analysis, the beam can be shown to buckle at a critical length based on the extrusion speed, the bending rigidity, and the dynamic viscosity of the fluid. Hypothesizing that the trichocysts of Paramecia must be sized to maximize their thrust per unit volume as well as avoid buckling instabilities, we predict that their bending rigidity must be about 3 ×10-9N μ m2 . The verification of this prediction is left for future work.

  1. PHYSICAL PROPERTIES OF EXTRUDED AND INJECTION MOLDED CORN GLUTEN MEAL

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study was performed to investigate the compounding of corn gluten meal (CGM) and decanoic acid and to evaluate their mechanical properties. The mixture of CGM and 30% decanoic acid was compounded in a twin screw extruder, followed by injection molding. Scanning electron microscopy (SEM), tens...

  2. Extruded Self-Lubricating Solid For High-Temperature Use

    NASA Technical Reports Server (NTRS)

    Sliney, H. E.; Waters, W. J.; Soltis, R. F.; Bemis, K.

    1996-01-01

    "EX-212" denotes high-density extruded form of composite solid material self-lubricating over wide range of temperatures. Properties equal or exceed those of powder-metallurgy version of this material. Developed for use in advanced engines at high temperatures at which ordinary lubricants destroyed.

  3. Carbohydrate Composition of Raw and Extruded Pulse Flours

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Extrusion cooking technology is commercially used in the fabrication of a variety of snack-type and ready-to-eat foods made from cereals grains. However, with the exception of soybean, other pulses such as lentil, dry pea and chickpea have not been used for the development of extruded food products...

  4. A New Extrudable Form of Hypromellose: AFFINISOL™ HPMC HME.

    PubMed

    Huang, Siyuan; O'Donnell, Kevin P; Keen, Justin M; Rickard, Mark A; McGinity, James W; Williams, Robert O

    2016-02-01

    Hypromellose is a hydrophilic polymer widely used in immediate- and modified-release oral pharmaceutical dosage forms. However, currently available grades of hypromellose are difficult, if not impossible, to process by hot melt extrusion (HME) because of their high glass transition temperature, high melt viscosity, and low degradation temperature. To overcome these challenges, a modified grade of hypromellose, AFFINISOL™ HPMC HME, was recently introduced. It has a significantly lower glass transition temperature and melt viscosity as compared to other available grades of hypromellose. The objective of this paper is to assess the extrudability and performance of AFFINISOL™ HPMC HME (100LV and 4M) as compared to other widely used polymers in HME, including HPMC 2910 100cP (the currently available hypromellose), Soluplus®, Kollidon® VA 64, and EUDRAGIT® E PO. Formulations containing polymer and carbamazepine (CBZ) were extruded on a co-rotating 16-mm twin-screw extruder, and the effect of temperature, screw speed, and feed rate was investigated. The performance of the solid dispersions was evaluated based on Flory-Huggins modeling and characterized by differential scanning calorimetry (DSC), X-ray powder diffraction (XRD), Raman spectroscopy, Fourier-transform infrared (FTIR) spectroscopy, and dissolution. All formulations extruded well except for HPMC 2910 100cP, which resulted in over-torqueing the extruder (machine overloading because the motor cannot provide efficient energy to rotate the shaft). Among the HME extrudates, only the EUDRAGIT® E PO formulation was crystalline as confirmed by DSC, XRD, and Raman, which agreed with predictions from Flory-Huggins modeling. Dissolution testing was conducted under both sink and non-sink conditions. Sink dissolution testing in neutral media revealed that amorphous CBZ in the HME extrudates completely dissolved within 15 min, which was much more rapid than the time for complete dissolution of bulk CBZ (60 min) and

  5. Microstructure and Mechanical Properties of Extruded Gamma Met PX

    NASA Technical Reports Server (NTRS)

    Draper, S. L.; Das, G.; Locci, I.; Whittenberger, J. D.; Lerch, B. A.; Kestler, H.

    2003-01-01

    A gamma TiAl alloy with a high Nb content is being assessed as a compressor blade material. The microstructure and mechanical properties of extruded Ti-45Al-X(Nb,B,C) (at %) were evaluated in both an as-extruded condition and after a lamellar heat treatment. Tensile behavior of both as-extruded and lamellar heat treated specimens was studied in the temperature range of RT to 926 C. In general, the yield stress and ultimate tensile strength reached relatively high values at room temperature and decreased with increasing deformation temperature. The fatigue strength of both microstructures was characterized at 650 C and compared to a baseline TiAl alloy and to a Ni-base superalloy. Tensile and fatigue specimens were also exposed to 800 C for 200 h in air to evaluate the alloy's environmental resistance. A decrease in ductility was observed at room temperature due to the 800 C exposure but the 650 C fatigue properties were unaffected. Compressive and tensile creep testing between 727 and 1027 C revealed that the creep deformation was reproducible and predictable. Creep strengths reached superalloy-like levels at fast strain rates and lower temperatures but deformation at slower strain rates and/or higher temperature indicated significant weakening for the as-extruded condition. At high temperatures and low stresses, the lamellar microstructure had improved creep properties when compared to the as-extruded material. Microstructural evolution during heat treatment, identification of various phases, and the effect of microstructure on the tensile, fatigue, and creep behaviors is discussed.

  6. Microstructure and Mechanical Properties of Extruded Gamma Microstructure Met PX

    NASA Technical Reports Server (NTRS)

    Draper, S. L.; Das, G.; Locci, J.; Whittenberger, J. D.; Lerch, B. A.; Kestler, H.

    2003-01-01

    A gamma TiAl alloy with a high Nb content is being assessed as a compressor blade material. The microstructure and mechanical properties of extruded Ti-45Al-X(Nb,B,C) (at.%) were evaluated in both an as-extruded condition and after a lamellar heat treatment. Tensile behavior of both as-extruded and lamellar heat treated specimens was studied in the temperature range of RT to 926 C. In general, the yield stress and ultimate tensile strength reached relatively high values at room temperature and decreased with increasing deformation temperature. The fatigue strength of both microstructures was characterized at 650 C and compared to a baseline TiAl alloy and to a Ni-base superalloy. Tensile and fatigue specimens were also exposed to 800 C for 200 h in air to evaluate the alloy's environmental resistance. A decrease in ductility was observed at room temperature due to the 800 C. exposure but the 650 C fatigue properties were unaffected. Compressive and tensile creep testing between 727 and 1027 C revealed that the creep deformation was reproducible and predictable. Creep strengths reached superalloy-like levels at fast strain rates and lower temperatures but deformation at slower strain rates and/or higher temperature indicated significant weakening for the as-extruded condition. At high temperatures and low stresses, the lamellar microstructure had improved creep properties when compared to the as-extruded material. Microstructural evolution during heat treatment, identification of various phases, and the effect of microstructure on the tensile, fatigue, and creep behaviors is discussed.

  7. Processing and characterization of extruded zein-based biodegradable films

    NASA Astrophysics Data System (ADS)

    Wang, Ying

    The objectives of this study were to prepare biodegradable zein films by extrusion processing and to evaluate relevant physical properties of resulting films with respect to their potential as packaging materials. The manufacture of protein-based packaging films by extrusion has remained a challenge. In this study, a zein resin was prepared by combining zein and oleic acid. This resin was formed into films by blown extrusion at the bench-top scale. Resin moisture content and extruder barrel temperature profile were identified as major parameters controlling the process. The optimum temperature of the blowing head was determined to be 40--45°C, while optimum moisture at film collection was 14--15%. Physico-chemical properties of the extruded products were characterized. Extruded products exhibited plastic behavior and ductility. Morphology characterization by SEM showed micro voids in extruded zein sheets, caused by entrapped air bubbles or water droplets. DSC characterization showed that zein was effectively plasticized by oleic acid as evidenced by the lowered glass transition temperature of zein films. X-ray scattering was used to investigate changes in zein molecular aggregation during processing. It was observed that higher mechanical energy treatment progressively disrupted zein molecular aggregates, resulting in a more uniform distribution of individual zein molecules. With the incorporation of oleic acid as plasticizer and monoglycerides as emulsifier, zein formed structures with long-range periodicity which varied depending on the formulation and processing methods. Processing methods for film formation affected the binding of oleic acid to zein with higher mechanical energy treatment resulting in better interaction between the two components. The moisture sorption capacity of extruded zein films was reduced due to the compact morphology caused by extrusion. Plasticization with oleic acid further reduced moisture sorption of zein films. The overall

  8. Development of a Tritium Extruder for ITER Pellet Injection

    SciTech Connect

    M.J. Gouge; P.W. Fisher

    1998-09-01

    As part of the International Thermonuclear Experimental Reactor (ITER) plasma fueling development program, Oak Ridge National Laboratory (ORNL) has fabricated a pellet injection system to test the mechanical and thermal properties of extruded tritium. Hydrogenic pellets will be used in ITER to sustain the fusion power in the plasma core and may be crucial in reducing first-wall tritium inventories by a process of "isotopic fueling" in which tritium-rich pellets fuel the burning plasma core and deuterium gas fuels the edge. This repeating single-stage pneumatic pellet injector, called the Tritium-Proof-of-Principle Phase II (TPOP-II) Pellet Injector, has a piston-driven mechanical extruder and is designed to extrude and accelerate hydrogenic pellets sized for the ITER device. The TPOP-II program has the following development goals: evaluate the feasibility of extruding tritium and deuterium-tritium (D-T) mixtures for use in future pellet injection systems; determine the mechanical and thermal properties of tritium and D-T extrusions; integrate, test, and evaluate the extruder in a repeating, single-stage light gas gun that is sized for the ITER application (pellet diameter -7 to 8 mm); evaluate options for recycling propellant and extruder exhaust gas; and evaluate operability and reliability of ITER prototypical fueling systems in an environment of significant tritium inventory that requires secondary and room containment systems. In tests with deuterium feed at ORNL, up to 13 pellets per extrusion have been extruded at rates up to 1 Hz and accelerated to speeds of 1.0 to 1.1 km/s, using hydrogen propellant gas at a supply pressure of 65 bar. Initially, deuterium pellets 7.5 mm in diameter and 11 mm in length were produced-the largest cryogenic pellets produced by the fusion program to date. These pellets represent about a 10% density perturbation to ITER. Subsequently, the extruder nozzle was modified to produce pellets that are almost 7.5-mm right circular

  9. A Novel cooked extruded lentils analog: physical and chemical properties.

    PubMed

    Abu-Ghoush, Mahmoud; Alavi, Sajid; Al-Shathri, Abdulaziz

    2015-07-01

    Developing an extruded lentil analog is our aim. Lentil analog with six formulations were produced using a pilot-scale single (SS) and twin screw (TS) extruders. Texture analysis of lentil analogs prepared for consumption revealed that the products formulated with 60:40 and 70:30 soy: wheat ratios exhibited a significantly higher hardness, adhesiveness and lower springiness as compared to all other treatments. Differential Scanning Calorimeter (DSC) results indicated that all starches in dry blend are completely 100 % gelatinized by extrusion for all treatments at 100 °C. The maximum peak of viscosity for TS was formed after 5.58 min. from the run at 89.9 °C for the best treatment. However, this lentil analog product can provide a high quality lentil which can be used as a substitute for regular lentils. PMID:26139886

  10. Early-age volume changes of extrudable reactive powder concrete

    NASA Astrophysics Data System (ADS)

    Cherkaoui, K.; Courtial, M.; Dunstetter, F.; Khelidj, A.; Mounanga, P.; de Noirfontaine, M. N.

    2010-06-01

    This article presents a study on the early-age autogenous deformations of Extrudable Reactive Powder Concretes (ERPCs), especially designed for the making of concrete pipes by extrusion. Different ERPC mixtures, with variable amounts of polycarboxylate superplasticizer (SP), have been investigated. Results on 28-day mechanical properties, early-age hydration rate, autogenous shrinkage and premature cracking risk are analyzed and discussed in relation with the ERPC mix parameters.

  11. Production of aluminum-lithium near net shape extruded cylinders

    NASA Technical Reports Server (NTRS)

    Hartley, Paula J.

    1995-01-01

    In the late 1980's, under funding from the Advanced Launch System Program, numerous near net shape technologies were investigated as a means for producing high quality, low cost Aluminum-Lithium (Al-Li) hardware. Once such option was to extrude near net shape barrel panels instead of producing panels by machining thick plate into a final tee-stiffened configuration (which produced up to 90% scrap). This method offers a reduction in the volume of scrap and consequently reduces the buy-to-fly cost. Investigation into this technology continued under Shuttle-C funding where four Al alloys 2219, 2195, 2096, and RX 818 were extruded. Presented herein are the results of that program. Each alloy was successfully extruded at Wyman Gordon, opened and flattened at Ticorm, and solution heat treated and stretched at Reynolds Metals Company. The first two processes were quite successful while the stretching process did offer some challenges. Due to the configuration of the panels and the stretch press set-up, it was difficult to induce a consistent percentage of cold work throughout the length and width of each panel. The effects of this variation will be assessed in the test program to be conducted at a future date.

  12. Conjugated linoleic acid content of milk and cheese from cows fed extruded oilseeds.

    PubMed

    Dhiman, T R; Helmink, E D; McMahon, D J; Fife, R L; Pariza, M W

    1999-02-01

    Extruded oilseeds were fed to 24 dairy cows to study the influence on the conjugated linoleic acid content of milk and cheese. Cows were fed one of three diets that contained forage and grain in a ratio of 47:53. A control diet containing 13.5% soybean meal was compared with diets containing 12% full fat extruded soybeans or 12% full fat extruded cottonseed. The control, extruded soybean, and extruded cottonseed diets contained 2.73, 4.89, and 4.56% fatty acids, respectively. Measurements were made during the last 5 wk of the 8-wk experiment. The DM intakes and 3.5% fat-corrected milk yields were higher for cows fed the extruded soybean and extruded cottonseed diets than for cows fed the control diet. A tendency for lower fat and protein contents in the milk of cows fed the extruded soybean and extruded cottonseed diets was detected. Most of the C18 fatty acids were increased in the milk and cheese when extruded soybeans and cottonseeds were fed. The conjugated linoleic acid content in milk and cheese increased a mean of 109% when full fat extruded soybeans were fed and increased 77% when cottonseeds were fed compared with the conjugated linoleic acid content when the control diet was fed. Processing the milk into cheese did not alter the conjugated linoleic acid content. The conjugated linoleic acid content of milk and cheese can be increased by the inclusion of full fat extruded soybeans and full fat extruded cottonseeds in the diets of dairy cows. PMID:10068962

  13. What Is Crystalline Silica?

    MedlinePlus

    ... silica, and requires a repirator protection program until engineering controls are implemented. Additionally, OSHA has a National ... silica materials with safer substitutes, whenever possible. ■ Provide engineering or administrative controls, where feasible, such as local ...

  14. Multifunctional mesoporous silica catalyst

    DOEpatents

    Lin, Victor Shang-Yi; Tsai, Chih-Hsiang; Chen, Hung-Ting; Pruski, Marek; Kobayashi, Takeshi

    2015-03-31

    The present invention provides bifunctional silica mesoporous materials, including mesoporous silica nanoparticles ("MSN"), having pores modified with diarylammonium triflate and perfluoroaryl moieties, that are useful for the acid-catalyzed esterification of organic acids with organic alcohols.

  15. Silica extraction from geothermal water

    SciTech Connect

    Bourcier, William L; Bruton, Carol J

    2014-09-23

    A method of producing silica from geothermal fluid containing low concentration of the silica of less than 275 ppm includes the steps of treating the geothermal fluid containing the silica by reverse osmosis treatment thereby producing a concentrated fluid containing the silica, seasoning the concentrated fluid thereby producing a slurry having precipitated colloids containing the silica, and separating the silica from the slurry.

  16. Rheological and nutritional quality of selected dehulled legumes blended rice extrudates.

    PubMed

    Balasubramanian, S; Borah, Anjan; Singh, K K; Patil, R T

    2012-10-01

    Rheological and nutritional quality of ready-to-eat rice (Oryza sativa ) -legume viz. black gram (Vigna mungo), green gram (Vigna radiata), lentil (Lens culinaris) and peas (Pisum sativum) based extrudates were studied using low cost collet extruder. Extrudates were prepared keeping constant feed rate (25 kg/h) and moisture content (14% wb) at 0, 5, 10 and 15% legume incorporation levels. Rheological properties of porridge made of extrudate flour were evaluated using Rapid Visco Analyser (RVA). Maximum and minimum peak viscosity for rice extrudates alone and rice extrudates blended with 15% peas were 697 cp and 523 cp, respectively. There was a decreasing trend in degree of gelatinization with increase in legume incorporation level. Other RVA rheological parameters like trough break down and final viscosity were in the range of 266-226 cp, 431-297 cp and 452-375 cp respectively. Maximum values of protein, fat, fibre and ash contents were found in rice extrudates at 15% legumes blend levels. There was an increasing trend in nutrient contents with legume content in rice extrudates. Degree of gelatinization for rice alone extrudate was 29.4% and showed a decrease in gelatinization with increase in legumes extrudate and was minimum (22.4%) for rice blended with 15% dehulled green gram. Sensory evaluation scores for all extrudates showed the most acceptable range of 6 to 8. Thus, legume blend level (up to 15%) of dehulled legumes fetched good scores and showed promising trend for the production of low cost expanded extrudates and its instant flour. PMID:24082277

  17. Material wear and failure mode analysis of breakfast cereal extruder barrels and screw elements

    NASA Astrophysics Data System (ADS)

    Mastio, Michael Joseph, Jr.

    2005-11-01

    Nearly seventy-five years ago, the single screw extruder was introduced as a means to produce metal products. Shortly after that, the extruder found its way into the plastics industry. Today much of the world's polymer industry utilizes extruders to produce items such as soda bottles, PVC piping, and toy figurines. Given the significant economical advantages of extruders over conventional batch flow systems, extruders have also migrated into the food industry. Food applications include the meat, pet food, and cereal industries to name just a few. Cereal manufacturers utilize extruders to produce various forms of Ready-to-Eat (RTE) cereals. These cereals are made from grains such as rice, oats, wheat, and corn. The food industry has been incorrectly viewed as an extruder application requiring only minimal energy control and performance capability. This misconception has resulted in very little research in the area of material wear and failure mode analysis of breakfast cereal extruders. Breakfast cereal extruder barrels and individual screw elements are subjected to the extreme pressures and temperatures required to shear and cook the cereal ingredients, resulting in excessive material wear and catastrophic failure of these components. Therefore, this project focuses on the material wear and failure mode analysis of breakfast cereal extruder barrels and screw elements, modeled as a Discrete Time Markov Chain (DTMC) process in which historical data is used to predict future failures. Such predictive analysis will yield cost savings opportunities by providing insight into extruder maintenance scheduling and interchangeability of screw elements. In this DTMC wear analysis, four states of wear are defined and a probability transition matrix is determined based upon 24,041 hours of operational data. This probability transition matrix is used to predict when an extruder component will move to the next state of wear and/or failure. This information can be used to determine

  18. Effect of blend moisture and extrusion temperature on physical properties of everlasting pea-wheat extrudates.

    PubMed

    Zarzycki, P; Kasprzak, M; Rzedzicki, Z; Sobota, A; Wirkijowska, A; Sykut-Domańska, E

    2015-10-01

    The effect of everlasting pea in combination with wheat on physical properties and microstructure of extrudates were studied. The share of everlasting pea (Lathyrus sativus) was variable, at 35, 50 and 65 %, respectively. The everlasting pea-wheat mixtures were moistened to the required level (18, 21, and 24 %), homogenized, conditioned and extruded in twin-screw extruder with counter-rotating conical screws. All of the obtained extrudates were characterised by a slow degree of radial expansion and high specific density. The Pearson correlation analysis indicated a statistically significant linear Pearson correlation (p < 0.05) between chemical compositions of the blends and physical properties of the extrudates. The expansion ratio increased as the concentration of the fibers and proteins increased, while specific density and hardness decreased. Inverse relationship was observed for crude fat. The microstructure of the extrudates was determined by both the moisture of the blend and the process temperature. The differences observed in the size, number of air cells and in the cell wall shapes and thickness indicate possibilities of the modification of physical properties of everlasting pea-wheat extrudates. The extrudates produced from everlasting pea-wheat blends (50:50) at higher barrel temperature (110/140/180/170/130 °C) were characterised by more numerous air cells of smaller diameters. Increasing moisture content of extruded blends results in extrudates with a higher porosity. No significant effect was shown in the chemical compositions on the level of metal contamination in the extrudates. The application of a counter-rotating twin-screw extrusion-cooker in the study permitted the production of compact, hard everlasting pea-wheat extrudates for use in vegetarian lunch dishes. PMID:26396414

  19. Development of a Twin-Screw D-2 Extruder for the ITER Pellet Injection System

    SciTech Connect

    Meitner, Steven J; Baylor, Larry R; Carbajo, Juan J; Combs, Stephen Kirk; Fehling, Dan T; Foust, Charles R; McFee, Marshall T; McGill, James M; Rasmussen, David A; Sitterson, R G; Sparks, Dennis O; Qualls, A L

    2009-07-01

    A twin-screw extruder for the ITER pellet injection system is under development at the Oak Ridge National Laboratory. The extruder will provide a stream of solid hydrogen isotopes to a secondary section, where pellets are cut and accelerated with single-stage gas gun into the plasma. A one-fifth ITER scale prototype extruder has been built to produce a continuous solid deuterium extrusion. Deuterium gas is precooled and liquefied before being introduced into the extruder. The precooler consists of a copper vessel containing liquid nitrogen surrounded by a deuterium gas filled copper coil. The liquefier is comprised of a copper cylinder connected to a Cryomech AL330 cryocooler, which is surrounded by a copper coil that the precooled deuterium flows through. The lower extruder barrel is connected to a Cryomech GB-37 cryocooler to solidify the deuterium (at approximate to 15 K) before it is forced through the extruder nozzle. A viewport located below the extruder nozzle provides a direct view of the extrusion. A camera is used to document the extrusion quality and duration. A data acquisition system records the extruder temperatures, torque, and speed, upstream, and downstream pressures. This paper will describe the prototype twin-screw extruder and initial extrusion results.

  20. Development of clad boiler tubes extruded from bimetallic centrifugal castings

    NASA Astrophysics Data System (ADS)

    Sponseller, D. L.; Timmons, G. A.; Bakker, W. T.

    1998-04-01

    Wrought tubes of T-11 steel, externally clad with SS310, have been produced by a new method (U.S. Patent 5,558,150). The alloys were united directly from the molten state by centrifugal casting. In the optimum process, temperatures were controlled to prevent meltback of the SS310 outer layer by the higher melting T-11 stream. Hollow extrusion billets were prepared from the heavy-walled cast bimetallic tubes and successfully hot extruded (at a ratio of 13.4) to 84-mm (3.3 in.) OD X 64-mm (2.5-in.) ID tubes, and (at a ratio of 37.6) to 51-mm (2-in.) OD X 38-mm (1.5-in.) ID tubes. In all, 10 castings were produced, and 12 billets were extruded to tubes. For the most part, thicknesses of the cladding and of the tube wall are rather uniform around the circumference and from end to end of the tubes. Hardness and tensile properties of annealed 51-mm (2-in.) tubes are uniform from end to end of a tube, and between tubes, and readily conform to ASTM A 213; tubes satisfy the flattening and flaring requirements of ASTM A 450. The cladding is metallurgically bonded to the base metal, as revealed by metallography, and by two tests developed for this study: a bond shear strength test and a twist test. In the latter test, rings 3.1 mm (0.125 in.) in thickness are slotted and severely twisted with a special tool. In tubes made by the optimum process, minute fissures that form adjacent to some of the pressure points during twist testing occupy just 3 % of the bond-line length. Cost estimates for commercial production of 51-mm (2-in.) tubes via the centrifugal casting route suggest that such tubes should be considerably less expensive than conventionally clad tubes (extruded from composite billets assembled from heavy-walled wrought tubes).

  1. Development of an extruder-feeder biomass direct liquefaction process

    SciTech Connect

    White, D.H.; Wolf, D. . Dept. of Chemical Engineering)

    1991-10-01

    As an abundant, renewable, domestic energy resource, biomass could help the United States reduce its dependence on imported oil. Biomass is the only renewable energy technology capable of addressing the national need for liquid transportation fuels. Thus, there is an incentive to develop economic conversion processes for converting biomass, including wood, into liquid fuels. Through research sponsored by the US DOE's Biomass Thermochemical Conversion Program, the University of Arizona has developed a unique biomass direct liquefaction system. The system features a modified single-screw extruder capable of pumping solid slurries containing as high as 60 wt% wood flour in wood oil derived vacuum bottoms at pressures up to 3000 psi. The extruder-feeder has been integrated with a unique reactor by the University to form a system which offers potential for improving high pressure biomass direct liquefaction technology. The extruder-feeder acts simultaneously as both a feed preheater and a pumping device for injecting wood slurries into a high pressure reactor in the biomass liquefaction process. An experimental facility was constructed and following shakedown operations, wood crude oil was produced by mid-1985. By July 1988, a total of 57 experimental continuous biomass liquefaction runs were made using White Birch wood feedstock. Good operability was achieved at slurry feed rates up to 30 lb/hr, reactor pressures from 800 to 3000 psi and temperatures from 350{degree}C to 430{degree}C under conditions covering a range of carbon monoxide feed rates and sodium carbonate catalyst addition. Crude wood oils containing as little as 6--10 wt% residual oxygen were produced. 38 refs., 82 figs., 26 tabs.

  2. Development of an extruder-feeder biomass direct liquefaction process

    SciTech Connect

    White, D.H.; Wolf, D. . Dept. of Chemical Engineering)

    1991-10-01

    As an abundant, renewable, domestic energy resource, biomass could help the United States reduce its dependence on imported oil. Biomass is the only renewable energy technology capable of addressing the national need for liquid transportation fuels. Thus, there is an incentive to develop economic conversion processes for converting biomass, including wood, into liquid fuels. Through research sponsored by the US DOE's Biomass Thermochemical Conversion Program, the University of Arizona has developed a unique biomass direct liquefaction system. The system features a modified single-screw extruder capable of pumping solid slurries containing as high as 60 wt % wood flour in wood oil derived vacuum bottoms at pressures up to 3,000 psi. By comparison, conventional pumping systems are capable of pumping slurries containing only 10--20 wt % wood flour in wood oil under similar conditions. The extruder-feeder has been integrated with a unique reactor to form a system which offers potential for improving high pressure biomass direct liquefaction technology. The extruder-feeder acts simultaneously as both a feed preheater and a pumping device for injecting wood slurries into a 3,000 psi pressure reactor in the biomass liquefaction process. An experimental facility was constructed during 1983--84. Following shakedown operations, wood crude oil was produced by mid-1985. During the period January 1985 through July 1988, a total of 57 experimental continuous biomass liquefaction runs were made using White Birch wood feedstock. Good operability was achieved at slurry feed rates up to 30 lb/hr, reactor pressures from 800 to 3,000 psi and temperatures from 350{degrees}C to 430{degrees}C under conditions covering a range of carbon monoxide feed rates and sodium carbonate catalyst addition. Crude wood oils containing as little as 6--10 wt % residual oxygen were produced. 43 refs., 81 figs., 52 tabs.

  3. Dislocations in extruded Co-49.3 at. pct Al

    NASA Technical Reports Server (NTRS)

    Yaney, D. L.; Nix, W. D.; Pelton, A. R.

    1986-01-01

    Polycrystalline Co-49.3 at. pct Al, which had been extruded at 1505 K, was examined using transmission electron microscopy. Diffraction contrast analysis showed that b = 100 as well as b = 111 line dislocations contribute to elevated temperature deformation in CoAl. Therefore, it was concluded that sufficient slip systems exist in CoAl to allow for general plasticity in the absence of diffusional mechanisms. Line dislocations of the type b = 001 were observed on both 110 and 100 planes while b = 111 line dislocations were observed on 1 -1 0 planes.

  4. MRS Photodiode, LED and extruded scintillator performance in magnetic field

    SciTech Connect

    Beznosko, D.; Blazey, G.; Dyshkant, A.; Francis, K.; Kubik, D.; Rykalin, V.; Zutshi, V.; /Northern Illinois U.

    2005-05-01

    The experimental results on the performance of the MRS (Metal/Resistor/Semiconductor) photodiode in the strong magnetic field of 4.4T, and the possible impact of the quench of the magnet at 4.5T on sensor's operation are reported. In addition, the experimental results on the performance of the extruded scintillator and WLS fiber, and various LEDs in the magnetic fields of 1.8T and 2.3T respectively, are detailed. The measurement method used is being described.

  5. Encapsulation of liquids using a counter rotating twin screw extruder.

    PubMed

    Tackenberg, Markus W; Krauss, Ralph; Marmann, Andreas; Thommes, Markus; Schuchmann, Heike P; Kleinebudde, Peter

    2015-01-01

    Until now extrusion is not applied for pharmaceutical encapsulation processes, whereas extrusion is widely used for encapsulation of flavours within food applications. Based on previous mixing studies, a hot melt counter-rotating extrusion process for encapsulation of liquid active pharmaceutical ingredients (APIs) was investigated. The mixing ratio of maltodextrin to sucrose as matrix material was adapted in first extrusion trials. Then the number of die holes was investigated to decrease expansion and agglutination of extrudates to a minimum. At a screw speed of 180 min(-1) the product temperature was decreased below 142 °C, resulting in extrudates of cylindrical shape with a crystalline content of 9-16%. Volatile orange terpenes and the nonvolatile α-tocopherol were chosen as model APIs. Design of experiments were performed to investigate the influences of barrel temperature, powder feed rate, and API content on the API retentions. A maximum of 9.2% α-tocopherol was encapsulated, while the orange terpene encapsulation rate decreased to 6.0% due to evaporation after leaving the die. During 12 weeks of storage re-crystallization of sucrose occurred; however, the encapsulated orange terpene amount remained unchanged. PMID:25460584

  6. Silica-Ceria Hybrid Nanostructures

    SciTech Connect

    Munusamy, Prabhakaran; Sanghavi, Shail P.; Nachimuthu, Ponnusamy; Baer, Donald R.; Thevuthasan, Suntharampillai

    2012-04-25

    A new hybrid material system that consists of ceria attached silica nanoparticles has been developed. Because of the versatile properties of silica and versatile properties of silica and versatile properties of silica and versatile properties of silica and versatile properties of silica and versatile properties of silica and versatile properties of silica and versatile properties of silica and versatile properties of silica and versatile properties of silica and versatile properties of silica and versatile properties of silica and antioxidant properties of ceria nanoparticles, this material system is ideally suited for biomedical applications. The silica particles of size ~50nm were synthesized by the Stöber synthesis method and ceria nanoparticles of size ~2-3nm was attached to the silica surface using a hetrocoagulation method. The presence of silanol groups on the surface of silica particles mediated homogenous nucleation of ceria which were attached to silica surface by Si-O-Ce bonding. The formations of silica-ceria hybrid nanostructures were characterized by X-photoelectron spectroscopy (XPS) and high resolution transmission electron microscopy (HRTEM). The HRTEM image confirms the formation of individual crystallites of ceria nanoparticles attached to the silica surface. The XPS analysis indicates that ceria nanoparticles are chemically bonded to surface of silica and possess mixture of +3 and +4 chemical states.

  7. Silazane to silica

    NASA Technical Reports Server (NTRS)

    Harvey, Gale A.

    1992-01-01

    Thin film silica and/or methyl silicone were detected on most external surfaces of the retrieved LDEF. Known sources of silicone in or on the LDEF appear inadequate to explain the ubiquitous presence of the silica and silicone films. Hexamethyldisilazane (HMDS) was used as the Challenger tile waterproofing compound for the Challenger/LDEF deployment mission. HMDS releases NH3 which depolymerizes silicone RTV's. Polyurethanes were also attacked. Much of the silica/silicone contamination of LDEF resulted from HMDS.

  8. Physical characteristics of extrudates from corn flour and dehulled carioca bean flour blend

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Extruded products were prepared from a corn flour and dehulled carioca bean (Phaseolus vulgaris, L.) flour blend using a single-screw extruder. A central composite rotate design was used to evaluate the effects of extrusion process variables: screw speed (318.9-392.9 rpm), feed moisture (10.9-21.0 g...

  9. [Physico-chemical evaluation of products extruded with sorghum-corn-soybean blends].

    PubMed

    Gutiérrez, R R; Gómez, M H

    1988-03-01

    Yellow corn grits (M), brown sorghum (SM), white sorghum (SB) and full fat soy flour (S) blends were extruded in an autogenous Brady Crop Cooker extruder at 195-200 degrees C and 11% moisture content. Binary blends (70:30) made up of M:S, SM:S and SB:S; and ternary blends (30:40:30) made up of SM:M:S and SB:M:S were extruded. Under these conditions, extrudates contained about 19% protein and 6% fat, which are within the specifications given for cereal/oil seed blends. Raw and extruded samples were analyzed for ES, WQI, WSI, MD and paste viscosity. All blends underwent modifications in the starch fraction at granular and molecular level. Brown sorghum extrudates presented higher degradation than those of white sorghum and corn:soy blends, although the last ones gave similar responses to analitical techniques. Extrudates greatly increased their ES, SWI and MD values, suggesting that degradation products, like dextrins, were present. Cooked paste low viscosities (50 degrees C) and micrographs support these findings. Because of their functional characteristics, extrudates could be used in beverages. PMID:3256283

  10. Effects of extrusion conditions on the physicochemical properties of extruded red ginseng.

    PubMed

    Gui, Ying; Gil, Sun Kuk; Ryu, Gi Hyung

    2012-09-01

    The effects of variable moisture content, screw speed and barrel temperature on the physicochemical properties of red ginseng powder extrudates were investigated. The raw red ginseng powders were processed in a co-rotating intermeshing twin-screw extruder. Primary extrusion variables were feed moisture content (20 and 30%), screw speed (200 and 250 rpm) and barrel temperature (115 and 130°C). Extruded red ginseng showed higher crude saponin contents (6.72~7.18%) than raw red ginseng (5.50%). Tested extrusion conditions did not significantly affect the crude saponin content of extrudates. Increased feed moisture content resulted in increased bulk density, specific length, water absorption index (WAI), breaking strength, elastic modulus and crude protein content and decreased water solubility index (WSI) and expansion (p<0.05). Increased barrel temperature resulted in increased total sugar content, but decreased reducing sugar content in the extrudate (p<0.05). Furthermore, increased barrel temperature resulted in increased amino acid content and specific length and decreased expansion and bulk density of extrudates only at a higher feed moisture content. The physicochemical properties of extrudates were mainly dependent on the feed moisture content and barrel temperature, whereas the screw speed showed a lesser effect. These results will be used to help define optimized process conditions for controlling and predicting qualities and characteristics of extruded red ginseng. PMID:24471085

  11. RELATIVE EFFECT OF PARTICLE SIZE ON QUANTITATIVE AND QUALITATIVE FEATURES OF CORN MEAL EXTRUDATES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Corn meal of various particle sizes ranging from 180 to 710 µm was processed in a twin-screw extruder at 16% moisture content, screw speed (300 rpm), and fixed temperature profile, to produce directly expanded extrudates with different physical properties. The extrusion process effects on the specif...

  12. Highly CO2 sensitive extruded fluorescent plastic indicator film based on HPTS.

    PubMed

    Mills, Andrew; Yusufu, Dilidaer

    2016-02-01

    Highly-sensitive optical fluorescent extruded plastic films are reported for the detection of gaseous and dissolved CO2. The pH-sensitive fluorescent dye used is 8-hydroxypyrene-1,3,6-trisulfonic acid trisodium salt (HPTS, PTS(-)) coated on the surface of hydrophilic fumed silica and the base is tetrabutylammonium hydroxide (TBAH). The above components are used to create an HPTS pigment (i.e. HPTS/SiO2/TBAH) with a high CO2 sensitivity (%CO2 (S = 1/2) = 0.16%) and fast 50% response (t50↓) = 2 s and recovery (t50↑) = 5 s times. Highly CO2-sensitive plastic films are then fabricated, via the extrusion of the HPTS pigment powder in low-density polyethylene (LDPE). As with the HPTS-pigment, the luminescence intensity (at 515 nm) and absorbance (at 475 nm) of the HPTS plastic film decreases as the %CO2 in the ambient gas phase increases. The HPTS plastic film exhibits a high CO2 sensitivity, %CO2 (S = 1/2), of 0.29%, but a response time <2 min and recovery time <40 min, which is slower than that of the HPTS pigment. The HPTS plastic film is very stable under ambient conditions, (with a shelf life >six month when stored in the dark but under otherwise ambient conditions). Moreover, the HPTS-LDPE film is stable in water, salt solution and even in acid (pH = 2), and in each of these media it can be used to detect dissolved CO2. PMID:26677800

  13. Silazine to silica

    NASA Technical Reports Server (NTRS)

    Harvey, Gale A.

    1993-01-01

    Thin film silica and/or methyl silicone were detected on most external surfaces of the retrieved LDEF. Both solar ultraviolet radiation and atomic oxygen can convert silicones to silica. Known sources of silicone in or on the LDEF appear inadequate to explain the ubiquitous presence of the silica and silicone films. Hexamethyldisilazane (HMDS) was used as the Challenger tile waterproofing compound for the Challenger/LDEF deployment mission. HMDS is both volatile and chemically reactive at STP. In addition, HMDS releases NH3 which depolymerizes silicone RTV's. Polyurethanes are also depolymerized. Experiments are reported that indicate much of the silicone and silica contamination of LDEF resulted directly or indirectly from HMDS.

  14. Lycopene bioaccessibility and starch digestibility for extruded snacks enriched with tomato derivatives.

    PubMed

    Dehghan-Shoar, Zeinab; Mandimika, Tafadzwa; Hardacre, Allan K; Reynolds, Gordon W; Brennan, Charles S

    2011-11-23

    To improve the nutritional value of energy-dense extruded snacks, corn grits were replaced with tomato paste and/or tomato skin powder at ratios of 5, 10, and 20% and extruded to make expanded snack foodlike products. Using a model digestion system, lycopene bioaccessibility and uptake from the snacks into Caco-2 cells were determined. The digestibility of the starch, the main nutrient component of the snacks, was also investigated. While extrusion cooking reduced the lycopene content of the snacks, the proportion of bioaccessible lycopene increased. Lycopene uptake by the Caco-2 cells from the extruded snacks exceeded that of the control in which the lycopene was not extruded, by 5% (p < 0.05). The digestibility of starch in the snacks varied depending on the type of tomato derivative and its concentration. Optimization of the extrusion cooking process and the ingredients can yield functional extruded snack products that contain bioavailable lycopene. PMID:21981281

  15. Effect of Extrusion Variables on the Hardness of Lentil Semolina Extrudates

    NASA Astrophysics Data System (ADS)

    Petrova, Todorka; Ruskova, Milena; Tzonev, Panayot; Zsivanovits, Gabor; Penov, Nikolay

    2010-01-01

    Lentil semolina was extruded in a laboratory single screw extruder (Brabender 20 DN, Germany) with screw diameter 19 mm and die diameter 5 mm. Effects of moisture content, barrel temperature, metering zone temperature, screw speed, and screw compression ratio on hardness of the extruded products were studied. Response surface methodology with combinations of moisture content (18, 22, 25, 28, 32%), metering zone temperature (136, 150, 160, 170, 184° C), barrel temperature (136, 150, 160, 170, 184° C), screw speed (132, 160, 180, 200, 228 rpm), and screw compression ratio (1:1, 2:1, 3:1, 4:1, 5:1) was applied. Feed screw speed was fixed at 70 rpm. Feed zone temperature was kept constant at 150° C. The hardness of the extrudates was measured with a TA.XT Plus Texture Analyser, Stable Micro Systems. The textural profiles of the extrudates showed that feed moisture had the highest effect on the hardness.

  16. Optimization of weaning mix based on malted and extruded pearl millet and barley.

    PubMed

    Balasubramanian, S; Kaur, Jaspreet; Singh, Deepak

    2014-04-01

    Weaning mix was developed using extrudates of plain and malted pearl millet (Pennisetum typhoides) and barley (Hordeum vulgare) flour. Central composite rotatable design (CCRD) with four independent variables PME (pearl millet extrudates), PMME (pearl millet malt extrudates), BE (barley extrudates), BME (barley malt extrudates) at five level and five dependent variables, i.e. lightness, peak viscosity (PV), water solubility index (WSI), water absorption index (WAI) and overall acceptability (OAA) scores, were used to conduct the experiments. Highly acceptable weaning mix was obtained by combining optimized ingredients with constant level of skim milk powder (SMP) 25%, WPC-70 5%, sugar 6% and refined vegetable oil 4 ml 100 g(-1) mix. The optimized level of ingredients was PME 20.77%, PMME 7.39%, BE 20.99%, BME 6.53% with 81.3% desirability. The nutrient content of optimized weaning mix was in accordance with the standards specified by PFA, 2004. PMID:24741161

  17. An advanced extruder-feeder biomass liquefaction reactor system

    NASA Astrophysics Data System (ADS)

    White, Don H.; Wolf, D.; Davenport, G.; Mathews, S.; Porter, M.; Zhao, Y.

    1987-11-01

    A unique method of pumping concentrated, viscous biomass slurries that are characteristic of biomass direct liquefaction systems was developed. A modified single-screw extruder was shown to be capable of pumping solid slurries as high as 60 weight percent wood flour in wood oil derived vacuum bottoms, as compared to only 10 to 20 weight percent wood flour in wood oil in conventional systems. During the period August, 1985 to April, 1987, a total of 18 experimental continuous biomass liquefaction runs were made using white birch feedstock. Good operability with feed rates up to 30 lb/hr covering a range of carbon monoxide, sodium carbonate catalyst, pressures from 800 to 3000 psi and temperatures from 350 C to 430 C was achieved. Crude wood oils containing 6 to 10 weight percent residual oxygen were obtained. Other wood oil characteristics are reported.

  18. Homogenization of EN AW 6005A Alloy for Improved Extrudability

    NASA Astrophysics Data System (ADS)

    Birol, Yucel

    2013-01-01

    The homogenization practice for EN AW 6005A was investigated. It requires an 8-hour soaking at 853 K (580 °C) to even out the Mg and Si distribution in the aluminum matrix and to fully transform the monoclinic β-Al5FeSi plates into relatively small round αc-Al12(Fe,Mn)3Si particles with a "necklace" type configuration. It is predominantly the equilibrium β-Mg2Si phase that precipitates during subsequent cooling at 1000 K h-1 while orthogonal β'-Mg2Si platelets are also noted starting at 500 K h-1. The hardness decreases with decreasing cooling rate from 41.1 ± 1 HV to 35.8 ± 0.8 HV, by 15 pct, over the range investigated. The precipitation capacity retained in homogenized samples cooled to room temperature at less than 250 K h-1 is reduced substantially. The solvus temperatures of these samples are below 773 K (500 °C) ensuring full solutionizing of the Mg2Si precipitates below the press exit temperatures typically employed by extruders. An 8-hour soaking at 853 K (580 °C) followed by cooling at 250 K h-1 is identified to be the optimum homogenization treatment as it gives a homogeneous structure with predominantly spherical-shaped αc-Al12(Fe,Mn)3Si particles and sufficiently low hardness for improved extrudability and a solvus temperature below 773 K (500 °C) to ensure adequate age-hardening capacity.

  19. Aligning carbon fibers in micro-extruded composite ink

    NASA Astrophysics Data System (ADS)

    Mahajan, Chaitanya G.

    Direct write processes include a wide range of additive manufacturing techniques with the ability to fabricate structures directly onto planar and non-planar surfaces. Most additive manufacturing techniques use unreinforced polymers to produce parts. By adding carbon fiber as a reinforcing material, properties such as mechanical strength, electrical conductivity, and thermal conductivity can be enhanced. Carbon fibers can be long and continuous, or short and discontinuous. The strength of carbon fiber composite parts is greatly increased when the fibers are preferentially aligned. This research focuses on increasing the strength of additively manufactured parts reinforced using discontinuous carbon fibers that have been aligned during the micro extrusion process. A design of experiments (DOE) approach was used to identify significant process parameters affecting fiber alignment. Factors such as the length of carbon fibers, nozzle diameter, fiber loading fraction, air pressure, translational speed and standoff distance were considered. A two dimensional Fast Fourier Transform (2D FFT) was used to quantify the degree of fiber alignment in the extruded composite inks. ImageJ software supported by an oval profile plugin was used with micrographs of printed samples to obtain the carbon fiber alignment values. The optimal value for the factors was derived by identifying the significant main and interaction effects. Based on the results of the DOE, tensile test samples were printed with fibers aligned parallel and perpendicular to the tensile axis. A standard test method for tensile properties of plastic revealed that the extruded parts with fibers aligned along the tensile axis were better in tensile strength and modulus.

  20. Autocalibrating Tiled Projectors on Piecewise Smooth Vertically Extruded Surfaces.

    PubMed

    Sajadi, Behzad; Majumder, Aditi

    2011-09-01

    In this paper, we present a novel technique to calibrate multiple casually aligned projectors on fiducial-free piecewise smooth vertically extruded surfaces using a single camera. Such surfaces include cylindrical displays and CAVEs, common in immersive virtual reality systems. We impose two priors to the display surface. We assume the surface is a piecewise smooth vertically extruded surface for which the aspect ratio of the rectangle formed by the four corners of the surface is known and the boundary is visible and segmentable. Using these priors, we can estimate the display's 3D geometry and camera extrinsic parameters using a nonlinear optimization technique from a single image without any explicit display to camera correspondences. Using the estimated camera and display properties, the intrinsic and extrinsic parameters of each projector are recovered using a single projected pattern seen by the camera. This in turn is used to register the images on the display from any arbitrary viewpoint making it appropriate for virtual reality systems. The fast convergence and robustness of this method is achieved via a novel dimension reduction technique for camera parameter estimation and a novel deterministic technique for projector property estimation. This simplicity, efficiency, and robustness of our method enable several coveted features for nonplanar projection-based displays. First, it allows fast recalibration in the face of projector, display or camera movements and even change in display shape. Second, this opens up, for the first time, the possibility of allowing multiple projectors to overlap on the corners of the CAVE-a popular immersive VR display system. Finally, this opens up the possibility of easily deploying multiprojector displays on aesthetic novel shapes for edutainment and digital signage applications. PMID:21301026

  1. Silica, Silicosis, and Autoimmunity

    PubMed Central

    Pollard, Kenneth Michael

    2016-01-01

    Inhalation of dust containing crystalline silica is associated with a number of acute and chronic diseases including systemic autoimmune diseases. Evidence for the link with autoimmune disease comes from epidemiological studies linking occupational exposure to crystalline silica dust with the systemic autoimmune diseases systemic lupus erythematosus, systemic sclerosis, and rheumatoid arthritis. Although little is known regarding the mechanism by which silica exposure leads to systemic autoimmune disease, there is a voluminous literature on silica exposure and silicosis that may help identify immune processes that precede development of autoimmunity. The pathophysiology of silicosis consists of deposition of silica particles in the alveoli of the lung. Ingestion of these particles by macrophages initiates an inflammatory response, which stimulates fibroblasts to proliferate and produce collagen. Silica particles are encased by collagen leading to fibrosis and the nodular lesions characteristic of the disease. The steps in the development of silicosis, including acute and chronic inflammation and fibrosis, have different molecular and cellular requirements, suggesting that silica-induced inflammation and fibrosis may be mechanistically separate. Significantly, it is unclear whether silica-induced inflammation and fibrosis contribute similarly to the development of autoimmunity. Nonetheless, the findings from human and animal model studies are consistent with an autoimmune pathogenesis that begins with activation of the innate immune system leading to proinflammatory cytokine production, pulmonary inflammation leading to activation of adaptive immunity, breaking of tolerance, and autoantibodies and tissue damage. The variable frequency of these immunological features following silica exposure suggests substantial genetic involvement and gene/environment interaction in silica-induced autoimmunity. However, numerous questions remain unanswered. PMID:27014276

  2. Silica, Silicosis, and Autoimmunity.

    PubMed

    Pollard, Kenneth Michael

    2016-01-01

    Inhalation of dust containing crystalline silica is associated with a number of acute and chronic diseases including systemic autoimmune diseases. Evidence for the link with autoimmune disease comes from epidemiological studies linking occupational exposure to crystalline silica dust with the systemic autoimmune diseases systemic lupus erythematosus, systemic sclerosis, and rheumatoid arthritis. Although little is known regarding the mechanism by which silica exposure leads to systemic autoimmune disease, there is a voluminous literature on silica exposure and silicosis that may help identify immune processes that precede development of autoimmunity. The pathophysiology of silicosis consists of deposition of silica particles in the alveoli of the lung. Ingestion of these particles by macrophages initiates an inflammatory response, which stimulates fibroblasts to proliferate and produce collagen. Silica particles are encased by collagen leading to fibrosis and the nodular lesions characteristic of the disease. The steps in the development of silicosis, including acute and chronic inflammation and fibrosis, have different molecular and cellular requirements, suggesting that silica-induced inflammation and fibrosis may be mechanistically separate. Significantly, it is unclear whether silica-induced inflammation and fibrosis contribute similarly to the development of autoimmunity. Nonetheless, the findings from human and animal model studies are consistent with an autoimmune pathogenesis that begins with activation of the innate immune system leading to proinflammatory cytokine production, pulmonary inflammation leading to activation of adaptive immunity, breaking of tolerance, and autoantibodies and tissue damage. The variable frequency of these immunological features following silica exposure suggests substantial genetic involvement and gene/environment interaction in silica-induced autoimmunity. However, numerous questions remain unanswered. PMID:27014276

  3. Defatted flaxseed meal incorporated corn-rice flour blend based extruded product by response surface methodology.

    PubMed

    Ganorkar, Pravin M; Patel, Jhanvi M; Shah, Vrushti; Rangrej, Vihang V

    2016-04-01

    Considering the evidence of flaxseed and its defatted flaxseed meal (DFM) for human health benefits, response surface methodology (RSM) based on three level four factor central composite rotatable design (CCRD) was employed for the development of DFM incorporated corn - rice flour blend based extruded snack. The effect of DFM fortification (7.5-20 %), moisture content of feed (14-20 %, wb), extruder barrel temperature (115-135 °C) and screw speed (300-330 RPM) on expansion ratio (ER), breaking strength (BS), overall acceptability (OAA) score and water solubility index (WSI) of extrudates were investigated using central composite rotatable design (CCRD). Significant regression models explained the effect of considered variables on all responses. DFM incorporation level was found to be most significant independent variable affecting on extrudates characteristics followed by extruder barrel temperature and then screw rpm. Feed moisture content did not affect extrudates characteristics. As DFM level increased (7.5 % to 20 %), ER and OAA value decreased. However, BS and WSI values were found to increase with increase in DFM level. Based on the defined criteria for numerical optimization, the combination for the production of DFM incorporated extruded snack with desired sensory attributes was achieved by incorporating 10 % DFM (replacing rice flour in flour blend) and by keeping 20 % moisture content, 312 screw rpm and 125 °C barrel temperature. PMID:27413213

  4. Development of flaxseed fortified rice - corn flour blend based extruded product by response surface methodology.

    PubMed

    Ganorkar, P M; Jain, R K

    2015-08-01

    Flaxseed imparted the evidence of health benefits in human being. Response surface methodology (RSM) was employed to develop flaxseed fortified rice - corn flour blend based extruded product using twin screw extruder. The effect of roasted flaxseed flour (RFF) fortification (15-25 %), moisture content of feed (12-16 %, wb), extruder barrel temperature (120-140 °C) and screw speed (300-330 RPM) on expansion ratio (ER), breaking strength (BS), bulk density (BD) and overall acceptability (OAA) score of extrudates were investigated using central composite rotatable design (CCRD). Increased RFF level decreased the ER and OAA score significantly while increased BS and BD of extrudates (p < 0.01). Moisture content of extruder feed was positively related to ER (p < 0.01) and OAA (p < 0.05) and negatively related to BD (p < 0.01). Extruder barrel temperature was found to be negatively related to ER and OAA (p < 0.05) and positively related to BD (p < 0.1). Quadratic effect of screw speed was significantly positively related to ER (p < 0.01), BS (p < 0.05) and negatively related to BD (p < 0.01). 15 % RFF fortification with rice flour, 16 % moisture content (wb) of extruder feed, 120 °C extruder barrel temperature and 330 RPM of screw speed gave an optimized product of high desirability with corresponding responses as 3.08 ER, 0.53 kgf BS, 0.106 g.cm(-3) BD and 7.86 OAA. PMID:26243928

  5. Application of silica nanoparticles for increased silica availability in maize

    NASA Astrophysics Data System (ADS)

    Suriyaprabha, R.; Karunakaran, G.; Yuvakkumar, R.; Prabu, P.; Rajendran, V.; Kannan, N.

    2013-02-01

    Silica nanoparticles were extracted from rice husk and characterised comprehensively. The synthesised silica powders were amorphous in size with 99.7% purity (20-40 nm). Nanosilica was amended with red soil at 15 kg ha-1 along with micron silica. The influence of nanoscale on silica uptake, accumulation and nutritional variations in maize roots were evaluated through the studies such as root sectioning, elemental analysis and physiological parameters (root length and silica content) and compared with micron silica and control. Nanosilica treated soil reveals enhanced silica uptake and elongated roots which make the plant to resist in stress conditions like drought.

  6. The use of twin screw extruders for feeding coal against pressures of up to 1500 PSI

    NASA Technical Reports Server (NTRS)

    Wiedmann, W.; Mack, W. A.

    1977-01-01

    Recent tests with a twin-screw, co-rotating extruder which was successfully used to convey and feed coal against pressures of up to 1500 psi are described. Intermeshing and self-wiping, co-rotating twin-screws give greatly improved conveying and pressure built-up capabilities and avoid hangup and eventual decomposition of coal particles in the screw flights. The conveying action of intermeshing, self-wiping, co-rotating extruder systems approaches that of a positive displacement pump. With this feature, it is possible to maintain very accurate control over all aspects of product conveyance in the extruder, i.e., intake, conveyance and pressure buildup.

  7. New antifouling silica hydrogel.

    PubMed

    Beltrán-Osuna, Ángela A; Cao, Bin; Cheng, Gang; Jana, Sadhan C; Espe, Matthew P; Lama, Bimala

    2012-06-26

    In this work, a new antifouling silica hydrogel was developed for potential biomedical applications. A zwitterionic polymer, poly(carboxybetaine methacrylate) (pCBMA), was produced via atom-transfer radical polymerization and was appended to the hydrogel network in a two-step acid-base-catalyzed sol-gel process. The pCBMA silica aerogels were obtained by drying the hydrogels under supercritical conditions using CO(2). To understand the effect of pCBMA on the gel structure, pCBMA silica aerogels with different pCBMA contents were characterized using scanning electron microscopy (SEM), nuclear magnetic resonance (NMR) spectroscopy, and the surface area from Brauner-Emmet-Teller (BET) measurements. The antifouling property of pCBMA silica hydrogel to resist protein (fibrinogen) adsorption was measured using enzyme-linked immunosorbent assay (ELISA). SEM images revealed that the particle size and porosity of the silica network decreased at low pCBMA content and increased at above 33 wt % of the polymer. The presence of pCBMA increased the surface area of the material by 91% at a polymer content of 25 wt %. NMR results confirmed that pCBMA was incorporated completely into the silica structure at a polymer content below 20 wt %. A protein adsorption test revealed a reduction in fibrinogen adsorption by 83% at 25 wt % pCBMA content in the hydrogel compared to the fibrinogen adsorption in the unmodified silica hydrogel. PMID:22607091

  8. Oxygen configurations in silica

    SciTech Connect

    Chelikowsky, James R.; Chadi, D. J.; Binggeli, N.

    2000-07-15

    We propose a transition state for oxygen in silica. This state is produced by the insertion of an oxygen molecule into the Si-O-Si bond, i.e., it consists of producing a Si-O-O-O-Si bond. This state allows molecular oxygen diffusion in silica without breaking the molecular O{sub 2} bond and it is energetically more stable than a peroxy configuration. This configuration may allow for exchange of molecular oxygen with the oxygen in the silica framework. (c) 2000 The American Physical Society.

  9. Silica Embedded Metal Hydrides

    SciTech Connect

    Heung, L.K.; Wicks, G.G.

    1998-08-01

    A method to produce silica embedded metal hydride was developed. The product is a composite in which metal hydride particles are embedded in a matrix of silica. The silica matrix is highly porous. Hydrogen gas can easily reach the embedded metal hydride particles. The pores are small so that the metal hydride particles cannot leave the matrix. The porous matrix also protects the metal hydride particles from larger and reactive molecules such as oxygen, since the larger gas molecules cannot pass through the small pores easily. Tests show that granules of this composite can absorb hydrogen readily and withstand many cycles without making fines.

  10. Development of clad boiler tubes extruded from bimetallic centrifugal castings

    SciTech Connect

    Sponseller, D.L.; Bakker, W.T.; Timmons, G.A.

    1998-04-01

    Wrought tubes of T-11 steel, externally clad with SS310, have been produced by a new method. The alloys were united directly from the molten state by centrifugal casting. In the optimum process, temperatures were controlled to prevent meltback of the SS310 outer layer by the higher melting T-11 stream. Hollow extrusion billets were prepared from the heavy-walled cast bimetallic tubes and successfully hot extruded to 84-mm OD x 64-mm ID tubes, and to 51-mm OD x 38-mm ID tubes. For the most part, thicknesses of the cladding and of the tube wall are rather uniform around the circumference and from end to end of the tubes. Hardness and tensile properties of annealed 51-mm tubes are uniform from end to end of a tube, and between tubes, and readily conform to ASTM A 213; tubes satisfy the flattening and flaring requirements of ASTM A 450. The cladding is metallurgically bonded to be base metal, as revealed by metallography, and by two tests developed for this study: a bond shear strength test and a twist test. In the latter test, rings 3.1 mm in thickness are slotted and severely twisted with a special tool. In tubes made by the optimum process, minute fissures that form adjacent to some of the pressure points during twist testing occupy just 3% of the bond-line length. Cost estimates for commercial production of 51-mm tubes via the centrifugal casting route suggest that such tubes should be considerably less expensive than conventionally clad tubes (extruded from composite billets assembled from heavy-walled wrought tubes). Such tubes should be attractive for the following applications in utility boilers: high-corrosion areas of existing coal-fired boilers, in both steam-generating tubes and superheaters; water walls, screen tubes, and superheater tubes of municipal waste-incineration boilers; future ultra super-critical boilers operating a higher temperatures and pressures; and steam-generating tubes of Syngas coolers of integrated coal gasification power plants.

  11. Cellulose-silica aerogels.

    PubMed

    Demilecamps, Arnaud; Beauger, Christian; Hildenbrand, Claudia; Rigacci, Arnaud; Budtova, Tatiana

    2015-05-20

    Aerogels based on interpenetrated cellulose-silica networks were prepared and characterised. Wet coagulated cellulose was impregnated with silica phase, polyethoxydisiloxane, using two methods: (i) molecular diffusion and (ii) forced flow induced by pressure difference. The latter allowed an enormous decrease in the impregnation times, by almost three orders of magnitude, for a sample with the same geometry. In both cases, nanostructured silica gel was in situ formed inside cellulose matrix. Nitrogen adsorption analysis revealed an almost threefold increase in pores specific surface area, from cellulose aerogel alone to organic-inorganic composite. Morphology, thermal conductivity and mechanical properties under uniaxial compression were investigated. Thermal conductivity of composite aerogels was lower than that of cellulose aerogel due to the formation of superinsulating mesoporous silica inside cellulose pores. Furthermore, composite aerogels were stiffer than each of reference aerogels. PMID:25817671

  12. Measuring response of extruded scintillator to UV LED in magnetic field

    SciTech Connect

    Beznosko, D.; Blazey, G.; Dyshkant, A.; Francis, K.; Kubik, D.; Rykalin, V.; Tartaglia, M.; Zutshi, V.; /Northern Illinois U.

    2005-05-01

    The experimental results on the performance of the extruded scintillator and WLS fiber, and various LEDs in the magnetic fields of 1.8T and 2.3T respectively, are reported. The methodic used is being described.

  13. Investigations of the mixing behaviour of pin-type rubber extruders

    NASA Astrophysics Data System (ADS)

    Schöppner, Volker; Schadomsky, Michael; Hopmann, Christian; Lemke, Florian

    2016-03-01

    This paper deals with investigations of the mixing behaviour of rubber extruders. The requirement to obtain a high-quality elastomer product is a thermally and materially homogenous rubber mixture. Because of the highly viscous and multicomponent nature of rubber mixture, extruders require a thoroughly distributive and dispersive mixing behaviour. The current state of the art is the pin-type rubber extruder with cylindrical pins which extend radially into the screw channel, causing a constant deformation and reorientation of the rubber melt. As mixing is of crucial importance, the mixing behaviour of pin-type rubber extruders is analysed with the goal of optimising it. The starting point of the optimisation is the current cylindrical pins. Over the course of the investigation, new pin designs and geometrical arrangements are investigated.

  14. Moffatt eddies in the single screw extruder: Numerical and analytical study

    NASA Astrophysics Data System (ADS)

    Fodor, Petru S.; Kaufman, Miron

    2015-05-01

    A detailed analysis of the fluid flow in the single screw extruder is performed by combining numerical and analytical methods. While finite element analysis numerical models are used to extract the transversal velocity field, an analytical model in the limit of zero Reynolds numbers is used to determine the longitudinal component of the fluid velocities. The high resolution 3D model developed for the fluid flow in single screw extruders with aspect ratios (i.e. depth/width) ranging from 1 to 0.1, allows the identification of the position and extent of Moffatt eddies that impede the fluid mixing through the entire extruder's volume. This information is used to estimate the extent by which the Moffatt eddies formation affects the mixing in the extruder, and also to develop strategies to prevent their formation.

  15. Extraction of light filth from rice flours, extruded rice products, and rice paper: collaborative study.

    PubMed

    Dent, R G

    1982-09-01

    Two new methods were developed for the extraction of rodent hairs and insect fragments from rice products: one for rice flour and one for extruded rice products and rice paper. A 100 g sample of rice flour was extracted with mineral oil-40% isopropanol, followed by a water phase as needed for additional cycles. For extruded rice products and rice paper, a 225 g sample of each was initially extracted as above, followed by a single extraction with mineral oil-20% isopropanol. Both methods used an acid hydrolysis pretreatment followed by wet sieving and a percolator extraction. Average rodent hair recoveries were 77.8% for rice flour and 82.2% for extruded rice products and rice paper. Average insect fragment recoveries were 89.6% for rice flour and 91.9% for extruded rice products and rice paper. Both methods were adopted official first action. PMID:7130079

  16. Crystalline Silica Primer

    USGS Publications Warehouse

    Staff- Branch of Industrial Minerals

    1992-01-01

    substance and will present a nontechnical overview of the techniques used to measure crystalline silica. Because this primer is meant to be a starting point for anyone interested in learning more about crystalline silica, a list of selected readings and other resources is included. The detailed glossary, which defines many terms that are beyond the scope of this publication, is designed to help the reader move from this presentation to a more technical one, the inevitable next step.

  17. Preparation and properties of PA6/CSW composites via vane extruder

    NASA Astrophysics Data System (ADS)

    Haichen, Zhang; Jianbo, Li; Li, Yang; Guizhen, Zhang; Jinping, Qu

    2016-03-01

    The PA6/CSW composites were prepared with a vane extruder in this work, which is a novel polymer processing equipment dominated by elongational flow field. SEM microphotographs indicate that the whiskers were well dispersed in the polymer matrix under the elongational flow field of the vane extruder.The PA6/CSW composites were also characterized by DSC, Mechanical testing and Rheological measurements. The results show that the PA6/CSW composites have improved their tensile strength and modulus greatly.

  18. Interparticle movement and the mechanical behavior of extruded powder aluminum at elevated temperature

    SciTech Connect

    Peacock, H.B.

    1996-09-01

    This paper proposes a model and mechanism, based on relative motion of the extruded aluminum particles, to explain these effects. Quantitative stereology is used to support the concept. Stress-strain relations are derived for the uniaxial and biaxial behavior of powder aluminum and they are seen to fit the data from a number of uniaxial and tension-torsion test specimens. Implications of the model for forming of extruded powder metal products are discussed

  19. Insensitive explosive composition and method of fracturing rock using an extrudable form of the composition

    DOEpatents

    Davis, Lloyd L

    2013-11-05

    Insensitive explosive compositions were prepared by reacting di-isocyanate and/or poly-isocyanate monomers with an explosive diamine monomer. Prior to a final cure, the compositions are extrudable. The di-isocyanate monomers tend to produce tough, rubbery materials while polyfunctional monomers (i.e. having more than two isocyanate groups) tend to form rigid products. The extrudable form of the composition may be used in a variety of applications including rock fracturing.

  20. Insensitive explosive composition and method of fracturing rock using an extrudable form of the composition

    DOEpatents

    Davis, Lloyd L.

    2015-07-28

    Insensitive explosive compositions were prepared by reacting di-isocyanate and/or poly-isocyanate monomers with an explosive diamine monomer. Prior to a final cure, the compositions are extrudable. The di-isocyanate monomers tend to produce tough, rubbery materials while polyfunctional monomers (i.e. having more than two isocyanate groups) tend to form rigid products. The extrudable form of the composition may be used in a variety of applications including rock fracturing.

  1. Silica, hybrid silica, hydride silica and non-silica stationary phases for liquid chromatography.

    PubMed

    Borges, Endler M

    2015-04-01

    Free silanols on the surface of silica are the "villains", which are responsible for detrimental interactions of those compounds and the stationary phase (i.e., bad peak shape, low efficiency) as well as low thermal and chemical stability. For these reasons, we began this review describing new silica and hybrid silica stationary phases, which have reduced and/or shielded silanols. At present, in liquid chromatography for the majority of analyses, reversed-phase liquid chromatography is the separation mode of choice. However, the needs for increased selectivity and increased retention of hydrophilic bases have substantially increased the interest in hydrophilic interaction chromatography (HILIC). Therefore, stationary phases and this mode of separation are discussed. Then, non-silica stationary phases (i.e., zirconium oxide, titanium oxide, alumina and porous graphitized carbon), which afford increased thermal and chemical stability and also selectivity different from those obtained with silica and hybrid silica, are discussed. In addition, the use of these materials in HILIC is also reviewed. PMID:25234386

  2. Hot extruded carbon nanotube reinforced aluminum matrix composite materials.

    PubMed

    Kwon, Hansang; Leparoux, Marc

    2012-10-19

    Carbon nanotube (CNT) reinforced aluminum (Al) matrix composite materials were successfully fabricated by mechanical ball milling followed by powder hot extrusion processes. Microstructural analysis revealed that the CNTs were well dispersed at the boundaries and were aligned with the extrusion direction in the composites obtained. Although only a small quantity of CNTs were added to the composite (1 vol%), the Vickers hardness and the tensile strength were significantly enhanced, with an up to three-fold increase relative to that of pure Al. From the fractography of the extruded Al-CNT composite, several shapes were observed in the fracture surface, and this unique morphology is discussed based on the strengthening mechanism. The damage in the CNTs was investigated with Raman spectroscopy. However, the Al-CNT composite materials were not only strengthened by the addition of CNTs but also enhanced by several synergistic effects. The nanoindentation stress-strain curve was successfully constructed by setting the effective zero-load and zero-displacement points and was compared with the tensile stress-strain curve. The yield strengths of the Al-CNT composites from the nanoindentation and tensile tests were compared and discussed. We believe that the yield strength can be predicted using a simple nanoindentation stress/strain curve and that this method will be useful for materials that are difficult to machine, such as complex ceramics. PMID:23011263

  3. Laboratory composting of extruded poly(lactic acid) sheets.

    PubMed

    Ghorpade, V M; Gennadios, A; Hanna, M A

    2001-01-01

    Composting of extruded poly(lactic acid) (PLA) in combination with pre-composted yard waste in a laboratory composting system was studied. Yard waste and PLA mixtures containing 0%, 10%, or 30% PLA (dry weight basis) were placed in composting vessels for four weeks. Exhaust gases were analyzed for carbon dioxide concentration twice per week. After the first week, significantly greater (P < 0.05) amounts of carbon dioxide were generated in vessels with 10% or 30% PLA than in control (0% PLA) vessels. Data indicated that microbial degradation of PLA occurred. There was no significant difference (P > 0.05) in carbon dioxide emission between 10% and 30% PLA mixtures. Compost pH dropped (from 6.0 to 4.0) after 4 weeks of composting for 30% PLA, but remained unchanged (6.3) for 0% or 10% PLA. Most likely, in the case of 30% PLA, substantial chemical hydrolysis and lactic acid generation lowered the compost pH. The lowered pH likely suppressed microbial activity, thus explaining the lack of difference in carbon dioxide emissions between 10% and 30% PLA mixtures. Gel permeation chromatography showed a notable decrease in PLA molecular weight as a result of composting. It was demonstrated that PLA can be efficiently composted when added in small amounts (<30% by weight) to pre-composted yard waste. PMID:11315811

  4. Hot extruded carbon nanotube reinforced aluminum matrix composite materials

    NASA Astrophysics Data System (ADS)

    Kwon, Hansang; Leparoux, Marc

    2012-10-01

    Carbon nanotube (CNT) reinforced aluminum (Al) matrix composite materials were successfully fabricated by mechanical ball milling followed by powder hot extrusion processes. Microstructural analysis revealed that the CNTs were well dispersed at the boundaries and were aligned with the extrusion direction in the composites obtained. Although only a small quantity of CNTs were added to the composite (1 vol%), the Vickers hardness and the tensile strength were significantly enhanced, with an up to three-fold increase relative to that of pure Al. From the fractography of the extruded Al-CNT composite, several shapes were observed in the fracture surface, and this unique morphology is discussed based on the strengthening mechanism. The damage in the CNTs was investigated with Raman spectroscopy. However, the Al-CNT composite materials were not only strengthened by the addition of CNTs but also enhanced by several synergistic effects. The nanoindentation stress-strain curve was successfully constructed by setting the effective zero-load and zero-displacement points and was compared with the tensile stress-strain curve. The yield strengths of the Al-CNT composites from the nanoindentation and tensile tests were compared and discussed. We believe that the yield strength can be predicted using a simple nanoindentation stress/strain curve and that this method will be useful for materials that are difficult to machine, such as complex ceramics.

  5. Properties of Extruded PS-212 Type Self-Lubricating Materials

    NASA Technical Reports Server (NTRS)

    Waters, W. J.; Sliney, H. E.; Soltis, R. F.

    1993-01-01

    Research has been underway at the NASA Lewis Research Center since the 1960's to develop high temperature, self-lubricating materials. The bulk of the research has been done in-house by a team of researchers from the Materials Division. A series of self-lubricating solid material systems has been developed over the years. One of the most promising is the composite material system referred to as PS-212 or PM-212. This material is a powder metallurgy product composed of metal bonded chromium carbide and two solid lubricating materials known to be self-lubricating over a wide temperature range. NASA feels this material has a wide potential in industrial applications. Simplified processing of this material would enhance its commercial potential. Processing changes have the potential to reduce processing costs, but tribological and physical properties must not be adversely affected. Extrusion processing has been employed in this investigation as a consolidation process for PM-212/PS-212. It has been successful in that high density bars of EX-212 (extruded PM-212) can readily be fabricated. Friction and strength data indicate these properties have been maintained or improved over the P.M. version. A range of extrusion temperatures have been investigated and tensile, friction, wear, and microstructural data have been obtained. Results indicate extrusion temperatures are not critical from a densification standpoint, but other properties are temperature dependent.

  6. Production and characterization of cornstarch/cellulose acetate/silver sulfadiazine extrudate matrices.

    PubMed

    Zepon, Karine Modolon; Petronilho, Fabricia; Soldi, Valdir; Salmoria, Gean Vitor; Kanis, Luiz Alberto

    2014-11-01

    The production and evaluation of cornstarch/cellulose acetate/silver sulfadiazine extrudate matrices are reported herein. The matrices were melt extruded under nine different conditions, altering the temperature and the screw speed values. The surface morphology of the matrices was examined by scanning electron microscopy. The micrographs revealed the presence of non-melted silver sulfadiazine microparticles in the matrices extruded at lower temperature and screw speed values. The thermal properties were evaluated and the results for both the biopolymer and the drug indicated no thermal degradation during the melt extrusion process. The differential scanning analysis of the extrudate matrices showed a shift to lower temperatures for the silver sulfadiazine melting point compared with the non-extruded drug. The starch/cellulose acetate matrices containing silver sulfadiazine demonstrated significant inhibition of the growth of Pseudomonas aeruginosa and Staphylococcus aureus. In vivo inflammatory response tests showed that the extrudate matrices, with or without silver sulfadiazine, did not trigger chronic inflammatory processes. PMID:25280700

  7. Nanostructure Characterization of Bismuth Telluride-Based Powders and Extruded Alloys by Various Experimental Methods

    NASA Astrophysics Data System (ADS)

    Vasilevskiy, D.; Bourbia, O.; Gosselin, S.; Turenne, S.; Masut, R. A.

    2011-05-01

    High-resolution transmission electron microscopy (HRTEM) observations of mechanically alloyed powders and bulk extruded alloys give experimental evidence of nanosized grains in bismuth telluride-based materials. In this study we combine HRTEM observations and x-ray diffraction (XRD) measurements, of both mechanically alloyed powders and extruded samples, with mechanical spectroscopy (MS) of extruded rods. Both HRTEM and XRD show that nanostructures with an average grain size near 25 nm can be achieved within 2 h of mechanical alloying from pure elements in an attritor-type milling machine. Residual strain orthogonal to the c-axis of powder nanoparticles has been evaluated at about 1.2% by XRD peak broadening. In contrast, XRD has been found unreliable for evaluation of grain size in highly textured extruded materials for which diffraction conditions are similar to those of single crystals, while MS appears promising for study of bulk extruded samples. Nanostructured extruded alloys at room temperature exhibit an internal friction (IF) background that is one order of magnitude higher than that of conventional zone-melted material with a grain size of several millimeters. IF as a function of sample temperature gives activation energies that are also different between bulk materials having nano- and millimeter-size grains, a result that is attributed to different creep mechanisms. Nanograin size, as well as orientation and volumetric proportion, provide valuable information for optimization of technological parameters of thermoelectric alloys and should be carefully cross-examined by various independent methods.

  8. Differences in time-dependent mechanical properties between extruded and molded hydrogels.

    PubMed

    Ersumo, N; Witherel, C E; Spiller, K L

    2016-01-01

    The mechanical properties of hydrogels used in biomaterials and tissue engineering applications are critical determinants of their functionality. Despite the recent rise of additive manufacturing, and specifically extrusion-based bioprinting, as a prominent biofabrication method, comprehensive studies investigating the mechanical behavior of extruded constructs remain lacking. To address this gap in knowledge, we compared the mechanical properties and swelling properties of crosslinked gelatin-based hydrogels prepared by conventional molding techniques or by 3D bioprinting using a BioBots Beta pneumatic extruder. A preliminary characterization of the impact of bioprinting parameters on construct properties revealed that both Young's modulus and optimal extruding pressure increased with polymer content, and that printing resolution increased with both printing speed and nozzle gauge. High viability (>95%) of encapsulated NIH 3T3 fibroblasts confirmed the cytocompatibility of the construct preparation process. Interestingly, the Young's moduli of extruded and molded constructs were not different, but extruded constructs did show increases in both the rate and extent of time-dependent mechanical behavior observed in creep. Despite similar polymer densities, extruded hydrogels showed greater swelling over time compared to molded hydrogels, suggesting that differences in creep behavior derived from differences in microstructure and fluid flow. Because of the crucial roles of time-dependent mechanical properties, fluid flow, and swelling properties on tissue and cell behavior, these findings highlight the need for greater consideration of the effects of the extrusion process on hydrogel properties. PMID:27550945

  9. Comparison of the creep properties of cast and powder metallurgy-extruded binary NiAl

    SciTech Connect

    Raj, S.V.; Garg, A.; Bieler, T.R.

    1997-12-31

    The current emphasis in developing NiAl-based alloys for use in gas-turbine aircraft engines requires a fundamental understanding of the creep mechanisms dominant in these materials. Here, a comparison of published creep data on binary NiAl showed that there is a discrepancy in the reported magnitudes of the stress exponents, n, which usually vary between about 4.5 and 6.5. In general, a close examination of the data suggested that n {approx} 4.5 for cast materials and 6.5 for powder-metallurgy extruded NiAl. Constant load compression creep tests were conducted on a cast and extruded binary NiAl between 800 and 1,200 K over a wide range of initial applied stresses varying between 4.0 and 200 MPa. The microstructures were characterized by transmission electron microscopy. The observed variations in the creep behavior of the extruded cast and powder-metallurgy NiAl appeared to be due to a grain size effect. Despite similarities in the values of n, no significant substructure was observed in most of the grains in the cast and extruded specimens at 1,100 and 1,200 K in contrast to the PM-extruded alloy, which revealed a wide range of substructural features in the power-law creep region. However, extensive subgrain formation and dislocations were widely observed at lower temperatures and higher stresses in the cast and extruded material.

  10. Characterization of laminar extrudates manufactured at room temperature in the absence of solvents for the delivery of drugs.

    PubMed

    Oliveira, G; Wahl, M A; Pinto, J F

    2013-09-15

    Extrudates with laminar shape for delivery of drugs were manufactured at room temperature and without solvents. Different lipidic materials, formulations and extrusion conditions were studied, as well as the influence of the size of particles of coumarin on the release from the extrudates. Materials were mixed prior to feeding an in-house built ram extruder with a rectangular shaped die. The process of extrusion was characterized for the force at steady state whereas extrudates were characterized immediately after production and over storage for density, porosity, bending strength, elasticity, stiffness, deformation, thermal behavior and release performance of coumarin, the model drug. The variety of lipid excipients and their proportions in the formulations directly influenced the properties of the extrudates, namely the bending strength, stiffness, deformation and elasticity and, the density and porosity, which changed over storage time: in general, the bending strength, stiffness and porosity increased over time, whereas deformation, elasticy and density decreased. The thermal analysis supported these observations as there was an increase in the enthalpies of fusion of the extrudates over time. The release of coumarin from the extrudates occured both by diffusion within the extrudates and by structural alterations of the extrudates and an increase of the coumarin particle size corresponded to a decrease of the release rate. The study has proved the ability to manufacture extrudates in a continuous fashion, with laminar shape using a green technology. PMID:23845856

  11. ORC4 surrounds extruded chromatin in female meiosis.

    PubMed

    Nguyen, Hieu; Ortega, Michael A; Ko, Myungjun; Marh, Joel; Ward, W Steven

    2015-05-01

    Six proteins, ORC1-6, make up the origin recognition complex (ORC) that initiates licensing of DNA replication origins. We have previously reported that subunit ORC2 is localized between the separating maternal chromosomes at anaphase II just after fertilization and is present in zygotic pronuclei at G1. Here, we found that ORC1, 3, and 5 all localize between the chromosomes at anaphase II, but could not be detected in zygotic G1. ORC6 localized to the periphery of the nucleoli at all zygotic stages. We identified an unexpected potential role for ORC4 in polar body formation. We found that in both female meiotic divisions, ORC4 surrounds the set of chromosomes, as a sphere-like structure, that will eventually be discarded in the polar bodies, but not the chromosomes that segregate into the oocyte. None of the other five ORC proteins are involved in this structure. In Zygotic G1, ORC4 surrounds the nuclei of the polar bodies, but was not detectable in the pronuclei. When the zygote entered mitosis ORC4 was only detected in the polar body. However, ORC4 appeared on both sets of separating chromosomes at telophase. At this point, the ORC4 that was in the polar body also migrated into the nuclei, suggesting that ORC4 or an associated protein is modified during the first embryonic cell cycle to allow it to bind DNA. Our results suggest that ORC4 may help identify the chromosomes that are destined to be expelled in the polar body, and may play a role in polar body extrusion. ORC4 surrounds the chromatin that will be extruded in the polar body in both female meiotic divisions, then makes a transition from the cytoplasm to the chromosomes at zygotic anaphase, suggesting multiple roles for this replication licensing protein. PMID:25502171

  12. ORC4 Surrounds Extruded Chromatin in Female Meiosis

    PubMed Central

    Nguyen, Hieu; Ortega, Michael A.; Ko, Myungjun; Marh, Joel; Ward, W. Steven

    2014-01-01

    Six proteins, ORC1-6, make up the origin recognition complex (ORC) that initiates licensing of DNA replication origins. We have previously reported that subunit ORC2 is localized between the separating maternal chromosomes at anaphase II just after fertilization and is present in zygotic pronuclei at G1. Here, we found that ORC1, 3, and 5 all localize between the chromosomes at anaphase II, but could not be detected in zygotic G1. ORC6 localized to the periphery of the nucleoli at all zygotic stages. We identified an unexpected potential role for ORC4 in polar body formation. We found that in both female meiotic divisions, ORC4 surrounds the set of chromosomes, as a sphere-like structure, that will eventually be discarded in the polar bodies, but not the chromosomes that segregate into the oocyte. None of the other five ORC proteins are involved in this structure. In Zygotic G1, ORC4 surrounds the nuclei of the polar bodies, but was not detectable in the pronuclei. When the zygote entered mitosis ORC4 was only detected in the polar body. However, ORC4 appeared on both sets of separating chromosomes at telophase. At this point, the ORC4 that was in the polar body also migrated into the nuclei, suggesting that ORC4 or an associated protein is modified during the first embryonic cell cycle to allow it to bind DNA. Our results suggest that ORC4 may help identify the chromosomes that are destined to be expelled in the polar body, and may play a role in polar body extrusion. extrusion. ORC4 surrounds the chromatin that will be extruded in the polar body in both female meiotic divisions, then makes a transition from the cytoplasm to the chromosomes at zygotic anaphase, suggesting multiple roles for this replication licensing protein. PMID:25502171

  13. Kinetics of silica polymerization

    SciTech Connect

    Weres, O.; Yee, A.; Tsao, L.

    1980-05-01

    The polymerization of silicic acid in geothermal brine-like aqueous solutions to produce amorphous silica in colloidal form has been studied experimentally and theoretically. A large amount of high quality experimental data has been generated over the temperature rang 23 to 100{sup 0}C. Wide ranges of dissolved silica concentration, pH, and sodium chloride concentration were covered. The catalytic effects of fluoride and the reaction inhibiting effects of aluminum and boron were studied also. Two basic processes have been separately studied: the formation of new colloidal particles by the homogeneous nucleation process and the deposition of dissolved silica on pre-existing colloidal particles. A rigorous theory of the formation of colloidal particles of amorphous silica by homogeneous nucleation was developed. This theory employs the Lothe-Pound formalism, and is embodied in the computer code SILNUC which quantitatively models the homogeneous nucleation and growth of colloidal silica particles in more than enough detail for practical application. The theory and code were extensively used in planning the experimental work and analyzing the data produced. The code is now complete and running in its final form. It is capable of reproducing most of the experimental results to within experimental error. It is also capable of extrapolation to experimentally inaccessible conditions, i.e., high temperatures, rapidly varying temperature and pH, etc.

  14. Twin-Screw Extruder Development for the ITER Pellet Injection System

    SciTech Connect

    Meitner, Steven J; Baylor, Larry R; Combs, Stephen Kirk; Fehling, Dan T; McGill, James M; Rasmussen, David A; Leachman, J. W.

    2009-01-01

    The ITER pellet injection system is comprised of devices to form and accelerate pellets, and will be connected to inner wall guide tubes for fueling, and outer wall guide tubes for ELM pacing. An extruder will provide a stream of solid hydrogen isotopes to a secondary section, where pellets are cut and accelerated with a gas gun into the plasma. The ITER pellet injection system is required to provide a plasma fueling rate of 120 Pa-m3/s (900 mbar-L/s) and durations of up to 3000 s. The fueling pellets will be injected at a rate up to 10 Hz and pellets used to trigger ELMs will be injected at higher rates up to 20 Hz. A twin-screw extruder for the ITER pellet injection system is under development at the Oak Ridge National Laboratory. A one-fifth ITER scale prototype has been built and has demonstrated the production of a continuous solid deuterium extrusion. The 27 mm diameter, intermeshed, counter-rotating extruder screws are rotated at a rate up to ≈5 rpm. Deuterium gas is pre-cooled and liquefied and solidified in separate extruder barrels. The precooler consists of a deuterium gas filled copper coil suspended in a separate stainless steel vessel containing liquid nitrogen. The liquefier is comprised of a copper barrel connected to a Cryomech AL330 cryocooler, which has a machined helical groove surrounded by a copper jacket, through which the pre-cooled deuterium condenses. The lower extruder barrel is connected to a Cryomech GB-37 cryocooler to solidify the deuterium (at ≈15 K) before it is forced through the extruder die. The die forms the extrusion to a 3 mm x 4 mm rectangular cross section. Design improvements have been made to improve the pre-cooler and liquefier heat exchangers, to limit the loss of extrusion through gaps in the screws. This paper will describe the design improvements for the next iteration of the extruder prototype.

  15. Continuously graded extruded polymer composites for energetic applications fabricated using twin-screw extrusion processing technology

    NASA Astrophysics Data System (ADS)

    Gallant, Frederick M.

    A novel method of fabricating functionally graded extruded composite materials is proposed for propellant applications using the technology of continuous processing with a Twin-Screw Extruder. The method is applied to the manufacturing of grains for solid rocket motors in an end-burning configuration with an axial gradient in ammonium perchlorate volume fraction and relative coarse/fine particle size distributions. The fabrication of functionally graded extruded polymer composites with either inert or energetic ingredients has yet to be investigated. The lack of knowledge concerning the processing of these novel materials has necessitated that a number of research issues be addressed. Of primary concern is characterizing and modeling the relationship between the extruder screw geometry, transient processing conditions, and the gradient architecture that evolves in the extruder. Recent interpretations of the Residence Time Distributions (RTDs) and Residence Volume Distributions (RVDs) for polymer composites in the TSE are used to develop new process models for predicting gradient architectures in the direction of extrusion. An approach is developed for characterizing the sections of the extrudate using optical, mechanical, and compositional analysis to determine the gradient architectures. The effects of processing on the burning rate properties of extruded energetic polymer composites are characterized for homogeneous formulations over a range of compositions to determine realistic gradient architectures for solid rocket motor applications. The new process models and burning rate properties that have been characterized in this research effort will be the basis for an inverse design procedure that is capable of determining gradient architectures for grains in solid rocket motors that possess tailored burning rate distributions that conform to user-defined performance specifications.

  16. Silica in alkaline brines

    USGS Publications Warehouse

    Jones, B.F.; Rettig, S.L.; Eugster, H.P.

    1967-01-01

    Analysis of sodium carbonate-bicarbonate brines from closed basins in volcanic terranes of Oregon and Kenya reveals silica contents of up to 2700 parts per million at pH's higher than 10. These high concentrations of SiO 2 can be attributed to reaction of waters with silicates, and subsequent evaporative concentration accompanied by a rise in pH. Supersaturation with respect to amorphous silica may occur and persist for brines that are out of contact with silicate muds and undersaturated with respect to trona; correlation of SiO2 with concentration of Na and total CO2 support this interpretation. Addition of moredilute waters to alkaline brines may lower the pH and cause inorganic precipitation of substantial amounts of silica.

  17. Silica Precipitation and Lithium Sorption

    SciTech Connect

    Jay Renew

    2015-09-20

    This file contains silica precipitation and lithium sorption data from the project. The silica removal data is corrected from the previous submission. The previous submission did not take into account the limit of detection of the ICP-MS procedure.

  18. Epoxy Grout With Silica Thickener

    NASA Technical Reports Server (NTRS)

    Mcclung, C. E.

    1984-01-01

    Grout cures quickly, even in presence of hydraulic oil. Grout is mixture of aggregate particles, finely-divided silica, epoxy resin, and triethylenetetramine curing agent, with mixture containing about 85 percent silica and aggregate particle sand 15 percent resin and curing agent. Silica is thickening agent and keeps grout from sagging.

  19. Characteristics of milk and reduced fat cheddar cheese from cows fed extruded soybeans and niacin.

    PubMed

    Baer, R J; Lentsch, M R; Schingoethe, D J; Madison-Anderson, R J; Kasperson, K M

    1996-07-01

    A control diet and three experimental diets were fed to midlactation Holstein cows to evaluate the effects of dietary unsaturated fatty acids and niacin on milk and reduced fat Cheddar cheese. The diet consisted mainly of rolled corn and soybean meal in the concentrate mixture. Experimental diets consisted of the control diet with added niacin and the control diet but with extruded soybeans substituted for part of the corn and soybean meal, with and without added niacin. Milks from cows fed diets of extruded soybean and extruded soybeans with added niacin contained lower concentrations of short- and medium-chain fatty acids and higher concentrations of long-chain fatty acids. Cheese milks consisted of a control, a homogenized control (3.45 MPa), and unhomogenized and homogenized milks (3.45 MPa) from cows fed extruded soybeans with added niacin. Reduced fat Cheddar cheeses produced from unhomogenized and homogenized milks from the cows fed extruded soybeans with added niacin contained higher concentrations of unsaturated fatty acids. The reduced fat Cheddar cheeses maintained acceptable flavor, body, and texture during storage. Homogenization of cheese milk had little effect on cheese properties. Cheeses manufactured from milks with high amounts of unsaturated fatty acids were softer; however, this difference was not detected by the sensory panel. PMID:8872710

  20. Influence of Instruments Used in Root Canal Preparation on Amount of Apically Extruded Debris.

    PubMed

    Karataş, Ertuğrul; Ersoy, İbrahim; Gündüz, Hicran Ateş; Uygun, Ahmet Demirhan; Kol, Elif; Çakıcı, Fatih

    2016-08-01

    The aim of the present study was to compare the effects of ProTaper Gold, WaveOne Gold, ProTaper Universal, and WaveOne instruments on the amount of apically extruded debris. Eighty mandibular premolar teeth with straight root canals were selected and assigned to four groups (n = 20). The root canals were instrumented using ProTaper Gold, WaveOne Gold, ProTaper Universal, and WaveOne systems. Eppendorf tubes containing apically extruded debris were weighed three times, and mean values were calculated. The net mass of the extruded debris was calculated by subtracting the initial mass from the final mass. The groups were compared using one-way analysis of variance and Tukey's post hoc tests at a significance level of P < 0.05. The PTG group extruded less debris than the PTU group, and the WOG group extruded less debris than the WO group (P < 0.05). All the instrumentation systems tested in the present study were associated with apical extrusion of debris. PMID:26814380

  1. Upscaling and in-line process monitoring via spectroscopic techniques of ethylene vinyl acetate hot-melt extruded formulations.

    PubMed

    Almeida, A; Saerens, L; De Beer, T; Remon, J P; Vervaet, C

    2012-12-15

    The aim of the present work was to evaluate drug release and quality of EVA/drug matrices at different PEO 7M concentrations (5 and 15%), manufactured using two different hot-melt extruders: a lab-scale mini extruder and a pilot-scale extruder. The process parameters used on both extruders (temperature and screw speed) and drug release from the matrices were compared. On the lab-scale extruder all formulations were extruded at 90 °C, whereas on the pilot-scale extruder the temperature of the die was adjusted to 100 °C in order to achieve a constant pressure at the extrusion die, hence constant material flow through the die to yield smooth extrudates. Screw speed was also adjusted from 60 rpm (lab-scale extruder) to 90 rpm (pilot-scale extruder) in order to obtain a balance between feeding rate and screw speed. Drug release from the obtained matrices on both extruders was also assessed. Despite the differences in diameter (diameter of 2 and 3mm for the lab-scale extruder and pilot-scale extruder, respectively), temperature and screw speed, drug release per surface area was similar. DSC analysis of a formulation [EVA40/MPT (50/50, w/w) with 5% PEO] indicated small changes in its solid state after extrusion on both extruders: drug crystallinity was reduced by max. 20%, PEO recrystallized after cooling and EVA remained semi-crystalline. Extrusion experiments on the pilot-scale extruder of EVA/MPT, 50/50 (w/w) formulations were also monitored in-line using Raman and NIR spectroscopy in order to evaluate the material behavior at a molecular level in the extrusion barrel as function of the process settings (extrusion temperature: 90, 110 and 140 °C; screw speed: 90 and 110 rpm). At 90 and 110 °C the crystallinity of the drug was reduced, but the majority of MPT remained in its crystalline state as specific peaks in the Raman spectra of the drug became broader. These differences were accentuated when extrusion was performed at 140 °C as the drug completely melted

  2. Development of baked and extruded functional foods from metabolic syndrome specific ingredient mix.

    PubMed

    Miglani, Neetu; Bains, Kiran; Kaur, Harpreet

    2015-09-01

    The study was aimed to develop baked and extruded functional foods from Metabolic Syndrome (MS) specific designed ingredient mixes with optimum amino acid makeup using key food ingredients with functional properties such as whole cereals, legumes, skimmed milk powder, along with flaxseeds and fenugreek seeds. Two cereals viz. barley and oats and four pulses viz. mung bean, cowpea, bengal gram and soybean were blended in different proportions in order to balance the limiting amino acid lysine in the wheat flour. Three products namely bread, extruded snack and noodles prepared from twenty five ingredient mixes. Six ingredient mixes of breads and four ingredient mixes each of extruded snack and noodles specifically designed for MS patients were organoleptically at par with control wheat flour products. The acceptable products had significantly (p ≤ 0.05) higher lysine, crude protein, ash and fibre and low carbohydrates in compare control whole wheat flour products, hence appropriate for MS patients. PMID:26345000

  3. The mechanical behavior of extruded powder aluminum subjected to biaxial loadings at elevated temperature

    SciTech Connect

    Woods, T.O.; Berghaus, D.G.; Peacock, H.B.

    1990-12-31

    The goal of this investigation is to develop a description of the biaxial behavior of extruded powder aluminum at elevated temperature. Specimens made of extruded 101 ALCOA (Aluminum Company of America) powder aluminum and specimens made from 1100 commercial aluminum rod are tested biaxially in tension-torsion and compression-torsion loadings at the extrusion temperature. The powder aluminum is examined microscopically and stereological methods are used to give a quantified description of the material behavior in terms of changes in the laminar powder material structure. A model for the biaxial (tension-torsion) behavior of extruded powder aluminum is developed. This description is consistent with a previous analysis of behavior in pure tension.

  4. The mechanical behavior of extruded powder aluminum subjected to biaxial loadings at elevated temperature

    SciTech Connect

    Woods, T.O.; Berghaus, D.G. ); Peacock, H.B. )

    1990-01-01

    The goal of this investigation is to develop a description of the biaxial behavior of extruded powder aluminum at elevated temperature. Specimens made of extruded 101 ALCOA (Aluminum Company of America) powder aluminum and specimens made from 1100 commercial aluminum rod are tested biaxially in tension-torsion and compression-torsion loadings at the extrusion temperature. The powder aluminum is examined microscopically and stereological methods are used to give a quantified description of the material behavior in terms of changes in the laminar powder material structure. A model for the biaxial (tension-torsion) behavior of extruded powder aluminum is developed. This description is consistent with a previous analysis of behavior in pure tension.

  5. Comparison of waste pumpkin material and its potential use in extruded snack foods.

    PubMed

    Norfezah, M N; Hardacre, A; Brennan, C S

    2011-08-01

    Material was produced from Crown pumpkin (Cucurbita maxima) processed from fractions of the fruit which are regarded as waste stream products (peel, flesh and seed). The flour from the three different fractions (peel, flesh and seed) of Crown pumpkin flour was incorporated into an extruded snack product formulation at levels 10%, 30% and 50% (w/w with corn grit) and processed in a twin-screw extruder to make 10 expanded snack products. Proximate analysis was carried out to determine the nutritional value of the raw pumpkin and pumpkin flour. A physical analysis of the product was used to determine its color, the expansion ratio, bulk density and texture. Inclusion of waste stream material (peel and seed) at 10%, yielded extruded products with similar expansion and density characteristics to the control sample; however, an inclusion of greater than 10% yielded significant challenges to product quality (hardness of the product). PMID:21813596

  6. Physicochemical characterization and drug-release properties of celecoxib hot-melt extruded glass solutions.

    PubMed

    Andrews, Gavin P; Abu-Diak, Osama; Kusmanto, Febe; Hornsby, Peter; Hui, Zhai; Jones, David S

    2010-11-01

    The interest in hot-melt extrusion (HME) as a drug delivery technology for the production of glass solutions is growing rapidly. HME glass solutions have a tendency to recrystallize during storage and also typically have a very dense structure, restricting the ingress of dissolution fluid and retarding drug release. In this study, we have used HME to manufacture glass solutions containing celecoxib (CX) and polyvinylpyrrolidone (PVP) and have assessed the use of supercritical carbon dioxide (scCO2) as a pore-forming agent to enhance drug release. Differential scanning calorimetry confirmed the formation of glass solutions following extrusion. All extrudates exhibited a single glass transition temperature (Tg), positioned between the Tg values of CX and PVP. The instability of glass solutions is a significant problem during storage. Stabilization may be improved through the appropriate choice of excipient to facilitate drug–polymer interactions. The Gordon–Taylor equation showed that the Tg values of all extrudates expected on ideal mixing were lower than those observed experimentally. This may be indicative of drug–polymer interactions that decrease free volume and elevate the Tg. Molecular interactions between CX and PVP were further confirmed using Fourier transform infrared and Raman spectroscopy. Storage stability of the extrudates was shown to be dependent on drug loading. Samples containing a higher CX loading were less stable, which we ascribed to decreased Tg and hence increased mobility within the drug–polymer matrix. The solubility of CX was improved through the formulation of extruded glass solutions, but release rate was relatively slow. Exposure of extrudates to scCO2 had no effect on the solid-state properties of CX but did produce a highly porous structure. The drug-release rate from extrudates after scCO2 exposure was significantly higher. PMID:21072971

  7. Assessment of apically extruded debris and irrigant produced by different nickel-titanium instrument systems.

    PubMed

    Küçükyilmaz, Ebru; Savas, Selcuk; Saygili, Gokhan; Uysal, Banu

    2015-01-01

    The aim of this study was to evaluate the preparation time and the amounts of apically extruded debris and irrigant using different nickel-titanium instrumentation systems. Forty-five extracted single-rooted mandibular premolar teeth were selected and divided into three groups. The root canals were instrumented according to the manufacturers' instructions, using a reciprocating single-file system, a single-file rotary system and a multiple-file rotary system. Bidistilled water was used as the irrigant solution. The apically extruded debris and irrigant were collected into preweighed Eppendorf tubes. The amounts of extruded debris and irrigant were assessed with a precision micro-balance. The Eppendorf tubes were incubated at 37°C for 15 days. After the incubation period, they were weighed again to assess the debris extrusion. The time required to prepare the canals was also recorded. The results were statistically analyzed using MANOVA and Bonferroni's adjustment. Considering the apically extruded debris and irrigant, there were no statistically significant differences among the groups (p > 0.05). The Reciproc group produced the highest debris (0.000632 ± 0.000162 gr) and irrigant (0.844587 ± 0.437814 ml) extrusion values. While the least extruded debris was observed with OneShape (0,000431 ± 0,000171 gr), the least extruded irrigant was observed with ProTaper system (0.564147 ± 0.370596 ml). Instrumentation was faster using the Reciproc than the other two instruments (70.27 ± 13.38 s) (p < 0.05). All of the instrumentation systems used in this study produced apical debris and irrigant extrusion. The reciprocating single-file system tended to produce more debris and irrigant extrusion, compared with the rotary systems. Considering the preparation time, the single-file systems appeared to be advantageous due to their working time. PMID:25387860

  8. Aerodynamic performance of a 5-metre-diameter Darrieus turbine with extruded aluminum NACA-0015 blades

    SciTech Connect

    Sheldahl, R.E.; Klimas, P.C.; Feltz, L.V.

    1980-03-01

    A 5-metre-diameter vertical-axis wind turbine has undergone continued testing since 1976 at the Sandia Laboratories Wind Turbine site. The latest tests of this machine have been with extruded aluminum blades of NACA-0015 airfoil cross section. The results of these tests at several turbine rotational speeds are presented and compared with earlier test results. A performance comparison is made with a vortex/lifting line computational code. The performance of the turbine with the extruded blades met all expectations.

  9. The Column Strength of Two Extruded Aluminum-Alloy H-Sections

    NASA Technical Reports Server (NTRS)

    Osgood, William R; Holt, Marshall

    1939-01-01

    Extruded aluminum-alloy members of various cross sections are used in aircraft as compression members either singly or as stiffeners for aluminum-alloy sheet. In order to design such members, it is necessary to know their column strength or, in the case of stiffeners, the value of the double modulus, which is best obtained for practical purposes from column tests. Column tests made on two extruded h-sections are described, and column formulas and formulas for the ratio of the double modulus to Young's modulus, based on the tests, are given.

  10. 40 CFR 428.60 - Applicability; description of the medium-sized general molded, extruded, and fabricated rubber...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... medium-sized general molded, extruded, and fabricated rubber plants subcategory. 428.60 Section 428.60... RUBBER MANUFACTURING POINT SOURCE CATEGORY Medium-Sized General Molded, Extruded, and Fabricated Rubber... fabricated rubber plants subcategory. The following provisions of this subpart are applicable to...

  11. 40 CFR 428.50 - Applicability; description of the small-sized general molded, extruded, and fabricated rubber...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... small-sized general molded, extruded, and fabricated rubber plants subcategory. 428.50 Section 428.50... (CONTINUED) RUBBER MANUFACTURING POINT SOURCE CATEGORY Small-Sized General Molded, Extruded, and Fabricated Rubber Plants Subcategory § 428.50 Applicability; description of the small-sized general molded,...

  12. 40 CFR 428.50 - Applicability; description of the small-sized general molded, extruded, and fabricated rubber...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... small-sized general molded, extruded, and fabricated rubber plants subcategory. 428.50 Section 428.50... (CONTINUED) RUBBER MANUFACTURING POINT SOURCE CATEGORY Small-Sized General Molded, Extruded, and Fabricated Rubber Plants Subcategory § 428.50 Applicability; description of the small-sized general molded,...

  13. 40 CFR 428.70 - Applicability; description of the large-sized general molded, extruded, and fabricated rubber...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... large-sized general molded, extruded, and fabricated rubber plants subcategory. 428.70 Section 428.70... (CONTINUED) RUBBER MANUFACTURING POINT SOURCE CATEGORY Large-Sized General Molded, Extruded, and Fabricated Rubber Plants Subcategory § 428.70 Applicability; description of the large-sized general molded,...

  14. 40 CFR 428.60 - Applicability; description of the medium-sized general molded, extruded, and fabricated rubber...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... medium-sized general molded, extruded, and fabricated rubber plants subcategory. 428.60 Section 428.60... (CONTINUED) RUBBER MANUFACTURING POINT SOURCE CATEGORY Medium-Sized General Molded, Extruded, and Fabricated Rubber Plants Subcategory § 428.60 Applicability; description of the medium-sized general...

  15. 40 CFR 428.50 - Applicability; description of the small-sized general molded, extruded, and fabricated rubber...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... small-sized general molded, extruded, and fabricated rubber plants subcategory. 428.50 Section 428.50... (CONTINUED) RUBBER MANUFACTURING POINT SOURCE CATEGORY Small-Sized General Molded, Extruded, and Fabricated Rubber Plants Subcategory § 428.50 Applicability; description of the small-sized general molded,...

  16. 40 CFR 428.70 - Applicability; description of the large-sized general molded, extruded, and fabricated rubber...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... large-sized general molded, extruded, and fabricated rubber plants subcategory. 428.70 Section 428.70... RUBBER MANUFACTURING POINT SOURCE CATEGORY Large-Sized General Molded, Extruded, and Fabricated Rubber... fabricated rubber plants subcategory. The following provisions of this subpart are applicable to...

  17. 40 CFR 428.60 - Applicability; description of the medium-sized general molded, extruded, and fabricated rubber...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... medium-sized general molded, extruded, and fabricated rubber plants subcategory. 428.60 Section 428.60... RUBBER MANUFACTURING POINT SOURCE CATEGORY Medium-Sized General Molded, Extruded, and Fabricated Rubber... fabricated rubber plants subcategory. The following provisions of this subpart are applicable to...

  18. 40 CFR 428.50 - Applicability; description of the small-sized general molded, extruded, and fabricated rubber...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... small-sized general molded, extruded, and fabricated rubber plants subcategory. 428.50 Section 428.50... RUBBER MANUFACTURING POINT SOURCE CATEGORY Small-Sized General Molded, Extruded, and Fabricated Rubber... fabricated rubber plants subcategory. The following provisions of this subpart are applicable to...

  19. 40 CFR 428.60 - Applicability; description of the medium-sized general molded, extruded, and fabricated rubber...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... medium-sized general molded, extruded, and fabricated rubber plants subcategory. 428.60 Section 428.60... (CONTINUED) RUBBER MANUFACTURING POINT SOURCE CATEGORY Medium-Sized General Molded, Extruded, and Fabricated Rubber Plants Subcategory § 428.60 Applicability; description of the medium-sized general...

  20. 40 CFR 428.70 - Applicability; description of the large-sized general molded, extruded, and fabricated rubber...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... large-sized general molded, extruded, and fabricated rubber plants subcategory. 428.70 Section 428.70... (CONTINUED) RUBBER MANUFACTURING POINT SOURCE CATEGORY Large-Sized General Molded, Extruded, and Fabricated Rubber Plants Subcategory § 428.70 Applicability; description of the large-sized general molded,...

  1. 40 CFR 428.50 - Applicability; description of the small-sized general molded, extruded, and fabricated rubber...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... small-sized general molded, extruded, and fabricated rubber plants subcategory. 428.50 Section 428.50... RUBBER MANUFACTURING POINT SOURCE CATEGORY Small-Sized General Molded, Extruded, and Fabricated Rubber... fabricated rubber plants subcategory. The following provisions of this subpart are applicable to...

  2. 40 CFR 428.70 - Applicability; description of the large-sized general molded, extruded, and fabricated rubber...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... large-sized general molded, extruded, and fabricated rubber plants subcategory. 428.70 Section 428.70... RUBBER MANUFACTURING POINT SOURCE CATEGORY Large-Sized General Molded, Extruded, and Fabricated Rubber... fabricated rubber plants subcategory. The following provisions of this subpart are applicable to...

  3. 40 CFR 428.60 - Applicability; description of the medium-sized general molded, extruded, and fabricated rubber...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... medium-sized general molded, extruded, and fabricated rubber plants subcategory. 428.60 Section 428.60... (CONTINUED) RUBBER MANUFACTURING POINT SOURCE CATEGORY Medium-Sized General Molded, Extruded, and Fabricated Rubber Plants Subcategory § 428.60 Applicability; description of the medium-sized general...

  4. 40 CFR 428.70 - Applicability; description of the large-sized general molded, extruded, and fabricated rubber...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... large-sized general molded, extruded, and fabricated rubber plants subcategory. 428.70 Section 428.70... (CONTINUED) RUBBER MANUFACTURING POINT SOURCE CATEGORY Large-Sized General Molded, Extruded, and Fabricated Rubber Plants Subcategory § 428.70 Applicability; description of the large-sized general molded,...

  5. Modeling vitreous silica bilayers

    NASA Astrophysics Data System (ADS)

    Kumar, Avishek; Wilson, Mark; Sherrington, David; Thorpe, Michael

    2014-03-01

    The recent synthesis and imaging of bilayers of vitreous silica has led to a wealth of new information. We have modeled the experimentally-observed bilayer using a computer assembly procedure to form a network of corner-sharing tetrahedra, which is then mirror-reflected to form a bilayer. We show that the vitreous silica bilayer has additional macroscopic degrees of freedom iff there is a symmetry plane through the center of the bilayer going through the central layer of oxygen ions that join the upper and lower monolayers. We have computer-refined the experimental coordinates to determine the density, and other structural characteristics such as the Si-Si pair distribution function, Si-O-Si bond angle distribution and the Aboav-Weaire law.

  6. Viscoelasticity of silica gels

    SciTech Connect

    Scherer, G.W.

    1995-12-01

    The response of silica gels to mechanical loads depends on the properties of the solid phase and the permeability of the network. Understanding this behavior is essential for modeling of stresses developed during drying or heating of gels. The permeability and the mechanical properties are readily determined from a simple beam-bending experiment, by measuring the load relaxation that occurs at constant deflection. Load decay results from movement of the liquid within the network; in addition, there may be viscoelastic relaxation of the network itself. Silica gel is viscoelastic in chemically aggressive media, but in inert liquids (such as ethanol or acetone) it is elastic. Experiments show that the viscoelastic relaxation time decreases as the concentration and pH of the water in the pore liquid increase. During drying, the permeability decreases and the viscosity increases, both exhibiting a power-law dependence on density of the gel network.

  7. 21 CFR 182.1711 - Silica aerogel.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Silica aerogel. 182.1711 Section 182.1711 Food and... GENERALLY RECOGNIZED AS SAFE Multiple Purpose GRAS Food Substances § 182.1711 Silica aerogel. (a) Product. Silica aerogel as a finely powdered microcellular silica foam having a minimum silica content of...

  8. 21 CFR 582.1711 - Silica aerogel.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Silica aerogel. 582.1711 Section 582.1711 Food and....1711 Silica aerogel. (a) Product. Silica aerogel as a finely powdered microcellular silica foam having a minimum silica content of 89.5 percent. (b) (c) Limitations, restrictions, or explanation....

  9. 21 CFR 582.1711 - Silica aerogel.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Silica aerogel. 582.1711 Section 582.1711 Food and....1711 Silica aerogel. (a) Product. Silica aerogel as a finely powdered microcellular silica foam having a minimum silica content of 89.5 percent. (b) (c) Limitations, restrictions, or explanation....

  10. 21 CFR 182.1711 - Silica aerogel.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Silica aerogel. 182.1711 Section 182.1711 Food and....1711 Silica aerogel. (a) Product. Silica aerogel as a finely powdered microcellular silica foam having a minimum silica content of 89.5 percent. (b) (c) Limitations, restrictions, or explanation....

  11. 21 CFR 582.1711 - Silica aerogel.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Silica aerogel. 582.1711 Section 582.1711 Food and....1711 Silica aerogel. (a) Product. Silica aerogel as a finely powdered microcellular silica foam having a minimum silica content of 89.5 percent. (b) (c) Limitations, restrictions, or explanation....

  12. 21 CFR 582.1711 - Silica aerogel.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Silica aerogel. 582.1711 Section 582.1711 Food and....1711 Silica aerogel. (a) Product. Silica aerogel as a finely powdered microcellular silica foam having a minimum silica content of 89.5 percent. (b) (c) Limitations, restrictions, or explanation....

  13. 21 CFR 182.1711 - Silica aerogel.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Silica aerogel. 182.1711 Section 182.1711 Food and....1711 Silica aerogel. (a) Product. Silica aerogel as a finely powdered microcellular silica foam having a minimum silica content of 89.5 percent. (b) (c) Limitations, restrictions, or explanation....

  14. 21 CFR 182.1711 - Silica aerogel.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Silica aerogel. 182.1711 Section 182.1711 Food and....1711 Silica aerogel. (a) Product. Silica aerogel as a finely powdered microcellular silica foam having a minimum silica content of 89.5 percent. (b) (c) Limitations, restrictions, or explanation....

  15. Physical and mechanical properties of extruded poly(lactic acid)-based Paulownia elongata biocomposites

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Paulownia wood flour (PWF), a byproduct of milling lumber, was tested as bio-filler with polylactic acid (PLA). Paulownia wood (PW) shavings were milled and separated into particle fractions and then blended with PLA with a single screw extruder. Mechanical and thermal properties were tested. Dif...

  16. Neural Network and Regression Modeling of Extrusion processing Parameters and Properties of Extrudates containing DDGS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Two extrusion experiments using a single screw extruder were conducted with an ingredient blend containing 40% DDGS, along with soy flour, corn flour, fish meal, vitamin mix, and mineral mix, with the net protein content adjusted to 28%. The variables controlled in the first experiment included 7 le...

  17. Aerodynamic performance of a 5-metre-diameter Darrieus turbine with extruded aluminum NACA-0015 blades

    NASA Astrophysics Data System (ADS)

    Sheldahl, R. E.; Klimas, P. C.; Feltz, L. V.

    1980-03-01

    A 5 metric-diameter vertical-axis wind turbine with extruded aluminum blades of NACA-0015 airfoil cross section was tested. Several turbine rotational speeds are presented and compared with earlier test results. Performance comparison is made with a vortex/lifting line computational code.

  18. Apparent Amino Acid Availability from Feedstuffs in Extruded Diets for Rainbow Trout Oncorhynchus mykiss.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Apparent amino acid availability coefficients of several typical and novel feed ingredients were determined in rainbow trout using extruded diets and the fecal stripping technique. The ingredients tested included five fish meals, three terrestrial animal by products, five plant protein concentrates...

  19. Effect of Starch Sources and Protein Content on Extruded Aquaculture Feed Containing DDGS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A 3x3 completely randomized design was used to investigate the extrusion cooking and product characteristics of DDGS, protein levels, and various starch sources in a laboratory scale single screw extruder. Cassava, corn, and potato starches with varying levels of DDGS (20, 30, and 40% wb) were extru...

  20. Characterization of Peptides Found in Unprocessed and Extruded Amaranth (Amaranthus hypochondriacus) Pepsin/Pancreatin Hydrolysates

    PubMed Central

    Montoya-Rodríguez, Alvaro; Milán-Carrillo, Jorge; Reyes-Moreno, Cuauhtémoc; González de Mejía, Elvira

    2015-01-01

    The objectives of this study were to characterize peptides found in unprocessed amaranth hydrolysates (UAH) and extruded amaranth hydrolysates (EAH) and to determine the effect of the hydrolysis time on the profile of peptides produced. Amaranth grain was extruded in a single screw extruder at 125 °C of extrusion temperature and 130 rpm of screw speed. Unprocessed and extruded amaranth flour were hydrolyzed with pepsin/pancreatin enzymes following a kinetic at 10, 25, 60, 90, 120 and 180 min for each enzyme. After 180 min of pepsin hydrolysis, aliquots were taken at each time during pancreatin hydrolysis to characterize the hydrolysates by MALDI-TOF/MS-MS. Molecular masses (MM) (527, 567, 802, 984, 1295, 1545, 2034 and 2064 Da) of peptides appeared consistently during hydrolysis, showing high intensity at 10 min (2064 Da), 120 min (802 Da) and 180 min (567 Da) in UAH. EAH showed high intensity at 10 min (2034 Da) and 120 min (984, 1295 and 1545 Da). Extrusion produced more peptides with MM lower than 1000 Da immediately after 10 min of hydrolysis. Hydrolysis time impacted on the peptide profile, as longer the time lower the MM in both amaranth hydrolysates. Sequences obtained were analyzed for their biological activity at BIOPEP, showing important inhibitory activities related to chronic diseases. These peptides could be used as a food ingredient/supplement in a healthy diet to prevent the risk to develop chronic diseases. PMID:25894223

  1. Physical, textural, and antioxidant properties of extruded waxy wheat bran snack utilizing several varieties of bran

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Wheat represents a ubiquitous commodity and while industries valorize 10% of wheat bran, most of this antioxidant-rich byproduct gets discarded. The objective of this study was to incorporate wheat bran into an extruded snack. Bran varieties from hard red spring, white club Bruehl, and purple whea...

  2. Characterisation and potential application of pineapple pomace in an extruded product for fibre enhancement.

    PubMed

    Selani, Miriam Mabel; Brazaca, Solange Guidolin Canniatti; Dos Santos Dias, Carlos Tadeu; Ratnayake, Wajira S; Flores, Rolando A; Bianchini, Andreia

    2014-11-15

    This study characterised pineapple pomace (PP) and evaluated its application in extrusion to enhance fibre content of the final product. The pomace had low fat (0.61%) and high dietary fibre (45.22%), showing its potential for fibre enrichment of nutritionally poor products, as some extruded snacks. Results also showed low microbiological counts, water activity, and pH indicating good microbiological quality and low risk of physicochemical deterioration. During extrusion, pomace (0%, 10.5% and 21%), moisture (14%, 15% and 16%) and temperature (140 and 160°C) were evaluated. The PP addition decreased expansion and luminosity; while increasing redness of the extrudates compared to the control (0% pomace/14% moisture/140°C). When hardness, yellowness, water absorption, and bulk density were compared to the control, there was no effect (p>0.05) of 10.5% PP addition on the extrudates, indicating that, at this level, PP could be added without affecting the properties of the final extruded product. PMID:24912691

  3. Functional properties of plantain, cowpea flours and oat fiber in extruded products

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Drying effect on functional properties of two plantain and cowpea varieties and suitability of their flour blends in extruded snacks was determined. The functional and rheological behaviors of (plantain: cowpea): 90:10, 80:20, 70:30, 60:40 and 50:50 blends were evaluated. The extrusion product melt ...

  4. Characterization of peptides found in unprocessed and extruded amaranth (Amaranthus hypochondriacus) pepsin/pancreatin hydrolysates.

    PubMed

    Montoya-Rodríguez, Alvaro; Milán-Carrillo, Jorge; Reyes-Moreno, Cuauhtémoc; González de Mejía, Elvira

    2015-01-01

    The objectives of this study were to characterize peptides found in unprocessed amaranth hydrolysates (UAH) and extruded amaranth hydrolysates (EAH) and to determine the effect of the hydrolysis time on the profile of peptides produced. Amaranth grain was extruded in a single screw extruder at 125 °C of extrusion temperature and 130 rpm of screw speed. Unprocessed and extruded amaranth flour were hydrolyzed with pepsin/pancreatin enzymes following a kinetic at 10, 25, 60, 90, 120 and 180 min for each enzyme. After 180 min of pepsin hydrolysis, aliquots were taken at each time during pancreatin hydrolysis to characterize the hydrolysates by MALDI-TOF/MS-MS. Molecular masses (MM) (527, 567, 802, 984, 1295, 1545, 2034 and 2064 Da) of peptides appeared consistently during hydrolysis, showing high intensity at 10 min (2064 Da), 120 min (802 Da) and 180 min (567 Da) in UAH. EAH showed high intensity at 10 min (2034 Da) and 120 min (984, 1295 and 1545 Da). Extrusion produced more peptides with MM lower than 1000 Da immediately after 10 min of hydrolysis. Hydrolysis time impacted on the peptide profile, as longer the time lower the MM in both amaranth hydrolysates. Sequences obtained were analyzed for their biological activity at BIOPEP, showing important inhibitory activities related to chronic diseases. These peptides could be used as a food ingredient/supplement in a healthy diet to prevent the risk to develop chronic diseases. PMID:25894223

  5. Chemical and toxicological evaluation of fumonisin B1 in extruded corn grits.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Extrusion cooking reduces fumonisin concentrations in corn but its effect on fumonisin toxicity is unknown. Batches of corn grits were contaminated by spiking with fumonisin B1 (FB1) (SG, 43 ppm) or by fermentation (FG1, 46 ppm FB1; FG2 48 ppm FB1) and then extruded with and without the addition of ...

  6. Neural network and regression modeling of extrusion processing parameters and properties of extrudates containing DDGS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Two extrusion experiments using a single screw extruder were conducted with an ingredient blend containing 40% DDGS, along with soy flour, corn flour, fish meal, vitamin mix, and mineral mix, with the net protein content adjusted to 28%. The variables controlled in the first experiment included 7 le...

  7. Quench sensitivity of hot extruded 6061-T6 and 6069-T6 aluminum alloys

    SciTech Connect

    Bergsma, S C; Kassner, M E; Li, X; Rosen, R S

    2000-08-08

    The purpose of this study is to investigate the quench sensitivity of mechanical properties of hot extruded 6061 and 6069 aluminum alloys. The relationship between mechanical properties and quench delzty time at various temperatures between 200-500 C was determined. It was concluded that the 6069-T6 was somewhat more quench sensitive than 6061, which may be consistent with the composition difference.

  8. Mechanical-Acoustic and Sensory Evaluations of Corn Starch-Whey Protein Isolate Extrudates

    Technology Transfer Automated Retrieval System (TEKTRAN)

    To study the mechanism that relates sensory perception of brittle food foams to their mechanical and acoustic properties during crushing, corn starch was extruded with four levels (0, 6, 12, and 18%) of whey protein isolate (WPI) and two levels of in-barrel moisture (23 and 27%). Texture of the exp...

  9. Dissolving cellulose with twin-screw extruder in a NaOH complex aqueous solution

    NASA Astrophysics Data System (ADS)

    Yang, Y. P.; Zhang, Y.; Dawelbeit, A.; Yu, M. H.

    2016-07-01

    Novel cellulose dissolution method with twin-screw extruder was developed in order to improve the dissolution property, to simplify production procedure and to produce cellulose spinning dope which is stable and which has a higher concentration of cellulose. Therefore, the extrusion conditions on the cellulose dissolution in NaOH/thiourea/urea were extensively studied in this work. The resulted extrudates of twin-screw extruder dissolution method were characterized by polarized optical microscope image, the solubility experiment and the apparent viscosity. The results revealed that the screw revolution speed of such process could improve the solubility value (S a) of cellulose, and the solubility of cellulose reached a maximum value of 7.5 wt% at higher revolutions 450 rpm. On the other hand, the cellulose solutions were more transparent and balanced with its apparent viscosity values lower and more stable compare to stirring method, which indicated dissolving cellulose with twin-screw extruder was reliable. Moreover, the whole dissolving time is quite short, and the process is simple. The soluble effect of twin screw extrusion was far superior to traditional stirring, and the most suitable temperature was -2°C.

  10. Apparent digestibility of gross nutrients from feedstuffs in extruded feeds for rainbow trout, Oncorhynchus mykiss

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The current experiment was performed to determine apparent protein and energy digestibility coefficients of feed ingredients by the fecal stripping technique using extruded diets. The ingredients tested included five fish meals, three terrestrial animal by-products, five plant protein concentrates,...

  11. Texture Evolution and Twinning During the Expansion of Hot Extruded AZ31 + Sr Seamless Tubes

    NASA Astrophysics Data System (ADS)

    Sadeghi, Alireza; Martin, Étienne; Pekguleryuz, Mihriban

    2014-12-01

    Seamless tubes of AZ31, AZ31 + 0.4, and 0.8 wt pctSr were extruded at elevated temperatures. By compressing pure copper inserts inside the tubes, the extruded tubes were expanded at room and elevated temperatures [373 K and 473 K (100 °C and 200 °C)]. Microstructural examinations reveal the formation of twining in the as-extruded and expanded tubes. The amount of twinning decreased with increasing level of Sr in the expanded microstructures as a result of grain refinement and of decreasing Al in solution that facilitates dislocation motion. During expansion at room temperature, AZ31 shows higher elongation and lower strength than the alloys containing Sr. At 473 K (200 °C), compared to the lower temperatures, the Sr containing alloys exhibit lower flow stress and no fracture in the strain range investigated (40 pct reduction in cylinder height). The textures of the extruded alloys contain two main components named as RD ( c-axis parallel to the radial direction) and HD ( c-axis parallel to the hoop direction) based on their orientation with the sample coordinates. During expansion, extension twinning in the HD grains reorients the lattice to strengthen the RD and form a new ED ( c-axis parallel to the extrusion direction) component. By increasing the temperature or level of Sr, the ED component is weakened due to the decrease in twinning. During expansion, the RD grains undergo contraction and double twining which reduce the overall texture strength.

  12. Texture Evolution and Twinning During the Expansion of Hot Extruded AZ31 + Sr Seamless Tubes

    NASA Astrophysics Data System (ADS)

    Sadeghi, Alireza; Martin, Étienne; Pekguleryuz, Mihriban

    2014-09-01

    Seamless tubes of AZ31, AZ31 + 0.4, and 0.8 wt pctSr were extruded at elevated temperatures. By compressing pure copper inserts inside the tubes, the extruded tubes were expanded at room and elevated temperatures [373 K and 473 K (100 °C and 200 °C)]. Microstructural examinations reveal the formation of twining in the as-extruded and expanded tubes. The amount of twinning decreased with increasing level of Sr in the expanded microstructures as a result of grain refinement and of decreasing Al in solution that facilitates dislocation motion. During expansion at room temperature, AZ31 shows higher elongation and lower strength than the alloys containing Sr. At 473 K (200 °C), compared to the lower temperatures, the Sr containing alloys exhibit lower flow stress and no fracture in the strain range investigated (40 pct reduction in cylinder height). The textures of the extruded alloys contain two main components named as RD (c-axis parallel to the radial direction) and HD (c-axis parallel to the hoop direction) based on their orientation with the sample coordinates. During expansion, extension twinning in the HD grains reorients the lattice to strengthen the RD and form a new ED (c-axis parallel to the extrusion direction) component. By increasing the temperature or level of Sr, the ED component is weakened due to the decrease in twinning. During expansion, the RD grains undergo contraction and double twining which reduce the overall texture strength.

  13. A preliminary study on edible, antimicrobial extruded films made from pectin and other food hydrocolloids

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Antimicrobial edible films were prepared from the natural fibers, pectin and other food hydrocolloids e. g., poly(ethylene oxide), for food packaging or wrapping by extrusion followed by the compression or the blown film method. Microscopic analysis revealed extruded pellets with well-mixed integra...

  14. Cryogenic strength and microstructure of a hydrostatically extruded austenitic steel 1.4429 (AISI 316LN)

    NASA Astrophysics Data System (ADS)

    Czarkowski, P.; Krawczyńska, A. T.; Brynk, T.; Nowacki, M.; Lewandowska, M.; Kurzydłowski, K. J.

    2014-11-01

    The as-received material with the average equivalent grain diameter of 45 μm was subjected to a hydrostatic extrusion process to a total true strain of 0.25, 0.84 and 1.36. Static tensile tests of the extruded material, performed at the room temperature, in liquid nitrogen and liquid helium. The material extruded to the strain of 1.36 and tested in liquid helium revealed ultimate strength 2.6 GPa. The results obtained for strengthened material were compared with the properties of as-received state. The effect of extrusion on the structure of this material was examined by transmission and scanning electron microscopy. The presence of necking and the nature of fracture surfaces in the specimens subjected to tensile tests confirm ductile behaviour of the extruded material even at liquid helium temperature, despite limited ductility. The results show that the hydrostatically extruded austenitic stainless steel is a promising material for relatively small, heavy loaded components working at cryogenic conditions.

  15. Prediction of Residual Stresses and Distortion in Quenched Extruded Shapes Using Generalized Plane Strain Theory

    NASA Astrophysics Data System (ADS)

    Cherukuri, Harish P.; Ulysse, Patrick; Smelser, Ronald E.; Subramanian, Kannan; Kotaru, Deepti

    2010-06-01

    Rapid quenching of aluminum extrusions often results in residual stresses and distortion. The out-of-plane normal component of the residual stress is typically very large and results in undesirable bending (bowing) of the extruded shape. Three-dimensional models to predict the residual stresses and bending of extruded thin-walled shapes are difficult to implement since the wall-thicknesses are often very small compared with the axial dimensions. In this paper, a generalized plane-strain model is presented to predict the residual stresses and distortion. For illusrative purposes of the model, a Z-shaped extrusion is chosen. The model predicts the bowing of the extruded shape along with the in-plane and out-of-plane stress components. An internal state-variable model is used for the constitutive description. The residual stresses and distortion are studied for cold and warm water quenching and three different cases of spray quenching. The numerical results indicate that cold water quenching and the two spray quenching cases with the higher discharge rates lead to significantly larger residual stresses compared to the remaining two cases. For each case, the out-of-plane bows of the extruded shapes are also shown to be significant.

  16. Compositional profiling and sensorial analysis of multi-wholegrain extruded puffs as affected by fructan inclusion.

    PubMed

    Handa, C; Goomer, S

    2015-09-01

    Rice grits, corn grits, pulse, wholegrain - finger millet and sorghum were utilized in the production of multigrain extruded puffs using a single screw extruder. The effect of inclusion of fructan - fructoligosaccharide in multi-wholegrain (MWG) extruded puffs was examined. MWG fructan enriched puffs puffs had 450 % higher dietary fiber content than the control puff (CP). These puffs can be categorized as 'Good Source' of fiber as it suffices 17.2 % DV of fiber. Puffs were rated 8.1 ± 0.6, 8.3 ± 0.7, 8.1 ± 0.6, 7.5 ± 0.5 and 8.2 ± 0.6 for color, flavor, texture, appearance and overall acceptability respectively. The scores for all the attributes were found to be not significantly different (p < 0.05) from CP. The MWG fructan puffs were rated higher on flavor than the CP having a score of 8.3 ± 0.7 as opposed to 8.2 ± 0.4 for CP. This indicates that the nutritional quality and acceptability of MWG extruded puffs could be improved by the inclusion of fructans. PMID:26345016

  17. Impact of different file systems on the amount of apically extruded debris during endodontic retreatment

    PubMed Central

    Uzunoglu, Emel; Turker, Sevinc Aktemur

    2016-01-01

    Objective: The goal of present study was to determine the effect of different nickel–titanium file systems on the amount of apically extruded debris during endodontic retreatment: D-RaCe retreatment systems, EdgeFile XR retreatment rotary files, and Reciproc R40. Materials and Methods: Thirty-six single-rooted prepared mandibular premolar teeth were filled with Gutta-percha and AH Plus sealer. The teeth were then randomly assigned into three groups (n = 12) for retreatment. The endodontic retreatment was performed as follows: D-RaCe, EdgeFile XR, Reciproc 40. Debris extruded apically during the retreatment was collected into preweighed Eppendorf tubes. An incubator was used to store tubes at 70° C for 5 days. The initial weight was subtracted from final weight of the Eppendorf tubes to calculate the weight of the dry extruded debris for each group. The data obtained were evaluated using Welch analysis of variance and Games-Howell post-hoc tests (P < 0.05). Results: All files resulted in apical extrusion of debris. Reciproc caused significantly less debris extrusion compared to D-RaCe and EdgeFile XR (P < 0.05). Conclusions: The findings revealed that during endodontic retreatment, number, and taper of files might have an influence on the amount of apically extruded debris during endodontic retreatment. PMID:27095898

  18. Effect of extrusion on the antioxidant capacity and color attributes of expanded extrudates prepared from purple potato and yellow pea flour mixes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The effect of extrusion cooking on the antioxidant capacity and color attributes of extruded products prepared from three selected formulations of purple potato and yellow pea flours using a co-rotating twin screw extruder were studied. Expansion ratios of the extruded products varied from 3.93 to 4...

  19. Nanoscale plasticity in silica glass

    SciTech Connect

    Glosli, J.N.; Boercker, D.B.; Tesar, A.; Belak, J.

    1993-10-01

    Mechanisms of nano-scale plasticity and damage initiation in silica glass is examined using molecular dynamics simulation. Computer experiments are carried out by indenting a sharp diamond-like tool, containing 4496 atoms, into a silica slab consisting of 12288 atoms. Both elastic and plastic deformation of silica is observed during nanoindentation simulation; this transition occurs at an indentation of 1.25 nm, and the calculated hardness (15GPa for 1.5 nm indentation) agrees with experiment.

  20. Cyclic Deformation Behavior of a Rare-Earth Containing Extruded Magnesium Alloy: Effect of Heat Treatment

    NASA Astrophysics Data System (ADS)

    Mirza, F. A.; Chen, D. L.; Li, D. J.; Zeng, X. Q.

    2015-03-01

    The present study was aimed at evaluating strain-controlled cyclic deformation behavior of a rare-earth (RE) element containing Mg-10Gd-3Y-0.5Zr (GW103K) alloy in different states (as-extruded, peak-aged (T5), and solution-treated and peak-aged (T6)). The addition of RE elements led to an effective grain refinement and weak texture in the as-extruded alloy. While heat treatment resulted in a grain growth modestly in the T5 state and significantly in the T6 state, a high density of nano-sized and bamboo-leaf/plate-shaped β' (Mg7(Gd,Y)) precipitates was observed to distribute uniformly in the α-Mg matrix. The yield strength and ultimate tensile strength, as well as the maximum and minimum peak stresses during cyclic deformation in the T5 and T6 states were significantly higher than those in the as-extruded state. Unlike RE-free extruded Mg alloys, symmetrical hysteresis loops in tension and compression and cyclic stabilization were present in the GW103K alloy in different states. The fatigue life of this alloy in the three conditions, which could be well described by the Coffin-Manson law and Basquin's equation, was equivalent within the experimental scatter and was longer than that of RE-free extruded Mg alloys. This was predominantly attributed to the presence of the relatively weak texture and the suppression of twinning activities stemming from the fine grain sizes and especially RE-containing β' precipitates. Fatigue crack was observed to initiate from the specimen surface in all the three alloy states and the initiation site contained some cleavage-like facets after T6 heat treatment. Crack propagation was characterized mainly by the characteristic fatigue striations.

  1. A mathematical model describing the solid conveying and melting behavior of planetary roller extruders

    NASA Astrophysics Data System (ADS)

    Rudloff, J.; Lang, M.; Kretschmer, K.; Heidemeyer, P.; Bastian, M.; Koch, M.

    2014-05-01

    Due to increased quality requirements and the trend to cost reduction by process optimization, the modeling of plastic processing by means of simulation software becomes more and more important to predict process behavior. Most tools are based on a physical analysis of the process conditions and a reflection of those in a mathematical model, either based on FE methods or an approach to approximation or complete analytical models. First models were published for planetary roller extruders. However, these models deal primarily with the melt conveying behavior and have not yet been developed for the melting process which in many cases is critical to address homogenization features of such machines in the melt phase. This paper presents an approach to calculate the melting degree along the barrel of a planetary roller extruder. Therefore, models that are used to describe the melting process of single and twin screw extruders are adjusted to the conditions in the planetary roller extruder. At first the relevant process was divided in the three steps solid conveying, melting initiation and melting propagation. The solid conveying is described by the Archimedes solid conveying model. In order to estimate the melting initiation the solid particles temperature increase was used for partial filled sections. Further, it was assumed that the melting cannot start later than at the point where the extruder flow channels are fully filled for the first time. The melting propagation was described by a modified disperse melting model. The developed models were implemented into a simulation tool. The models were verified by experimental investigations. A comparison between simulated results and experimental data shows a good agreement.

  2. Biogeochemistry: Silica cycling over geologic time

    NASA Astrophysics Data System (ADS)

    Conley, Daniel J.; Carey, Joanna C.

    2015-06-01

    The Earth's long-term silica cycle is intimately linked to weathering rates and biogenic uptake. Changes in weathering rates and the retention of silica on land have altered silica availability in the oceans for hundreds of millions of years.

  3. ZBLAN, Silica Fiber Comparison

    NASA Technical Reports Server (NTRS)

    1998-01-01

    This graph depicts the increased signal quality possible with optical fibers made from ZBLAN, a family of heavy-metal fluoride glasses (fluorine combined zirconium, barium, lanthanum, aluminum, and sodium) as compared to silica fibers. NASA is conducting research on pulling ZBLAN fibers in the low-g environment of space to prevent crystallization that limits ZBLAN's usefulness in optical fiber-based communications. In the graph, a line closer to the black theoretical maximum line is better. Photo credit: NASA/Marshall Space Flight Center

  4. Silica Fillers for elastomer Reinforement

    SciTech Connect

    Kohls, D.J.; Schaefer, D.W.

    2009-08-26

    This article summarizes recent work on the structure of precipitated silica used in the reinforcement of elastomers. Silica has a unique morphology, consisting of multiple structural levels that can be controlled through processing. The ability to control and characterize the multiple structures of precipitated silica is an example of morphological engineering for reinforcement applications. In this summary of some recent research efforts using precipitated silica, small-angle scattering techniques are described and their usefulness for determining the morphology of silica in terms of primary particles, aggregates, and agglomerates are discussed. The structure of several different precipitated silica powders is shown as well as the mechanical properties of elastomers reinforced with these silica particles. The study of the mechanical properties of filled elastomer systems is a challenging and exciting topic for both fundamental science and industrial application. It is known that the addition of hard particulates to a soft elastomer matrix results in properties that do not follow a straightforward rule of mixtures. Research efforts in this area have shown that the properties of filled elastomers are influenced by the nature of both the filler and the matrix, as well as the interactions between them. Several articles have reviewed the influence of fillers like silica and carbon black on the reinforcement of elastomers. In general, the structure-property relationships developed for filled elastomers have evolved into the following major areas: Filler structure, hydrodynamic reinforcement, and interactions between fillers and elastomers.

  5. Silica Fillers for elastomer Reinforement

    SciTech Connect

    Kohls, D.J.; Schaefer, D.W.

    2012-09-10

    This article summarizes recent work on the structure of precipitated silica used in the reinforcement of elastomers. Silica has a unique morphology, consisting of multiple structural levels that can be controlled through processing. The ability to control and characterize the multiple structures of precipitated silica is an example of morphological engineering for reinforcement applications. In this summary of some recent research efforts using precipitated silica, small-angle scattering techniques are described and their usefulness for determining the morphology of silica in terms of primary particles, aggregates, and agglomerates are discussed. The structure of several different precipitated silica powders is shown as well as the mechanical properties of elastomers reinforced with these silica particles. The study of the mechanical properties of filled elastomer systems is a challenging and exciting topic for both fundamental science and industrial application. It is known that the addition of hard particulates to a soft elastomer matrix results in properties that do not follow a straightforward rule of mixtures. Research efforts in this area have shown that the properties of filled elastomers are influenced by the nature of both the filler and the matrix, as well as the interactions between them. Several articles have reviewed the influence of fillers like silica and carbon black on the reinforcement of elastomers. In general, the structure-property relationships developed for filled elastomers have evolved into the following major areas: Filler structure, hydrodynamic reinforcement, and interactions between fillers and elastomers.

  6. Modeling flow, melting, solid conveying and global behavior in intermeshing counter-rotating twin screw extruders

    NASA Astrophysics Data System (ADS)

    Jiang, Qibo

    Intermeshing counter-rotating twin screw extruders are widely applied in polymer processing industry, especially in compounding and PVC profile processing. However, the design of this type of machines is generally based on experiences and error-and-try. In addition, most of the investigations on intermeshing counter-rotating twin screw extruders were made on the melt conveying region. There is a lack of adequate study on a complete extrusion process to this type of machines. In this study, models were developed to simulate the extrusion processes, including solid conveying, melting and metering, evaluate the performance of intermeshing counter-rotating twin screw extruders, and optimize the design of machines and operating conditions. Experiments were carried out on a laboratory modular intermeshing counter-rotating twin screw extruder to observe solid conveying, the melting process and the global behavior of this type of machine. The solid bed is formed in the solid conveying region. The inter-screw region plays a dominant role in the melting process. Based on our observations, models were developed to describe both the solid conveying and the melting process. Based on hydrodynamic lubrication theory, a melt conveying model was developed to characterize the pumping capacity of screw elements in intermeshing counter-rotating twin screw extruders. The effect of screw channel aspect ratio (screw channel depth/width) was incorporated into the melt conveying model to improve the prediction of screw pumping capacity. Calculations were made to investigate the effect of geometrical parameter on screw pumping capacity. Models of solid conveying, the melting process and melt conveying were integrated together and a global composite model was developed to characterize the whole intermeshing counter-rotating twin screw extrusion process. The global model is intended for both flood fed and metered starved fed conditions. This is the first composite model designed for this type

  7. Silaffins in Silica Biomineralization and Biomimetic Silica Precipitation

    PubMed Central

    Lechner, Carolin C.; Becker, Christian F. W.

    2015-01-01

    Biomineralization processes leading to complex solid structures of inorganic material in biological systems are constantly gaining attention in biotechnology and biomedical research. An outstanding example for biomineral morphogenesis is the formation of highly elaborate, nano-patterned silica shells by diatoms. Among the organic macromolecules that have been closely linked to the tightly controlled precipitation of silica in diatoms, silaffins play an extraordinary role. These peptides typically occur as complex posttranslationally modified variants and are directly involved in the silica deposition process in diatoms. However, even in vitro silaffin-based peptides alone, with and without posttranslational modifications, can efficiently mediate biomimetic silica precipitation leading to silica material with different properties as well as with encapsulated cargo molecules of a large size range. In this review, the biomineralization process of silica in diatoms is summarized with a specific focus on silaffins and their in vitro silica precipitation properties. Applications in the area of bio- and nanotechnology as well as in diagnostics and therapy are discussed. PMID:26295401

  8. Silaffins in Silica Biomineralization and Biomimetic Silica Precipitation.

    PubMed

    Lechner, Carolin C; Becker, Christian F W

    2015-08-01

    Biomineralization processes leading to complex solid structures of inorganic material in biological systems are constantly gaining attention in biotechnology and biomedical research. An outstanding example for biomineral morphogenesis is the formation of highly elaborate, nano-patterned silica shells by diatoms. Among the organic macromolecules that have been closely linked to the tightly controlled precipitation of silica in diatoms, silaffins play an extraordinary role. These peptides typically occur as complex posttranslationally modified variants and are directly involved in the silica deposition process in diatoms. However, even in vitro silaffin-based peptides alone, with and without posttranslational modifications, can efficiently mediate biomimetic silica precipitation leading to silica material with different properties as well as with encapsulated cargo molecules of a large size range. In this review, the biomineralization process of silica in diatoms is summarized with a specific focus on silaffins and their in vitro silica precipitation properties. Applications in the area of bio- and nanotechnology as well as in diagnostics and therapy are discussed. PMID:26295401

  9. A novel modeling approach to the mixing process in twin-screw extruders

    NASA Astrophysics Data System (ADS)

    Kennedy, Amedu Osaighe; Penlington, Roger; Busawon, Krishna; Morgan, Andy

    2014-05-01

    In this paper, a theoretical model for the mixing process in a self-wiping co-rotating twin screw extruder by combination of statistical techniques and mechanistic modelling has been proposed. The approach was to examine the mixing process in the local zones via residence time distribution and the flow dynamics, from which predictive models of the mean residence time and mean time delay were determined. Increase in feed rate at constant screw speed was found to narrow the shape of the residence time distribution curve, reduction in the mean residence time and time delay and increase in the degree of fill. Increase in screw speed at constant feed rate was found to narrow the shape of the residence time distribution curve, decrease in the degree of fill in the extruder and thus an increase in the time delay. Experimental investigation was also done to validate the modeling approach.

  10. Physical properties and sixth graders' acceptance of an extruded ready-to-eat sweetpotato breakfast cereal

    NASA Technical Reports Server (NTRS)

    Dansby, M. Y.; Bovell-Benjamin, A. C.

    2003-01-01

    Extruded ready-to-eat breakfast cereals (RTEBCs) were made from varying levels of sweetpotato flour (SPF), whole-wheat bran (WWB), and extrusion cooking. Moisture, protein, and ash contents were lower in the 100% SPF than the 100% WWB. Carbohydrate, beta-carotene, and ascorbic acid contents were higher in the 100% SPF. Fat, thiamin, riboflavin contents, bulk densities, and the water absorption index were similar for the cereals. However, the expansion ratio was highest in the 100% SPF cereal. The 100% WWB had the lightest color and most fibrous morphology. Extruded RTEBC containing 100% SPF and 75%/25% SPF/WWB were well-liked and acceptable to sixth graders attending an elementary school in Auburn, Alabama, but the 100% WWB was unacceptable.

  11. The column strength of aluminum alloy 75S-T extruded shapes

    NASA Technical Reports Server (NTRS)

    Holt, Marshall; Leary, J R

    1946-01-01

    Because the tensile strength and tensile yield strength of alloy 75S-T are appreciably higher than those of the materials used in the tests leading to the use of the straight-line column curve, it appeared advisable to establish the curve of column strength by test rather than by extrapolation of relations determined empirically in the earlier tests. The object of this investigation was to determine the curve of column strength for extruded aluminum alloy 75S-T. In addition to three extruded shapes, a rolled-and-drawn round rod was included. Specimens of various lengths covering the range of effective slenderness ratios up to about 100 were tested.

  12. Scanning probe acoustic microscopy of extruded starch materials: direct visual evidence of starch crystal.

    PubMed

    Liu, Zhongdong; Liu, Boxiang; Li, Mengxing; Wei, Min; Li, Hua; Liu, Peng; Wan, Tuo

    2013-10-15

    Scanning probe acoustic microscopy (SPAM) has been successfully used to study inorganic and keratin biomaterials. However, few studies have attempted to apply SPAM to structural study of non-keratin organic materials such as starch based materials. This study investigated hardness and surface finish to establish sample preparation method suitable for SPAM imaging and acquired clear acoustic images of extruded starch materials. Acquired acoustic images directly exhibited certain structure of starch materials and provided visual evidence of starch material components and aggregates. In addition, through correlating acoustic images with X-ray diffraction data, crystal-structural information in nano-scale was obtained and acoustic image contrast showed a linear relationship with starch amylose content in extruded starch materials. PMID:23987357

  13. A model for the biaxial post-yield behavior of extruded powder aluminum at elevated temperature

    SciTech Connect

    Woods, T.O.; Berghaus, D.G. ); Peacock, H.B. )

    1990-01-01

    A model has been developed which describes the post-yield behavior of extruded powder aluminum tested biaxially in tension and torsion at elevated temperature. Plots of shear stress versus shear strain for the powder aluminum loaded in simple torsion show that the shear stress increases linearly to the yield point, then remains relatively constant in a pure plastic type of behavior. For the tension-torsion tests, there is an initial linear region up to the yield point followed by a fairly linear decrease in shear stress. A similar linear decrease in axial stress with increasing axial strain is observed in uniaxial tension tests. The model for post-yield behavior of extruded powder aluminum gives a quantified description of the macroscopic material behavior in terms of changes in the laminar powder aluminum structure.

  14. A model for the biaxial post-yield behavior of extruded powder aluminum at elevated temperature

    SciTech Connect

    Woods, T.O.; Berghaus, D.G.; Peacock, H.B.

    1990-12-31

    A model has been developed which describes the post-yield behavior of extruded powder aluminum tested biaxially in tension and torsion at elevated temperature. Plots of shear stress versus shear strain for the powder aluminum loaded in simple torsion show that the shear stress increases linearly to the yield point, then remains relatively constant in a pure plastic type of behavior. For the tension-torsion tests, there is an initial linear region up to the yield point followed by a fairly linear decrease in shear stress. A similar linear decrease in axial stress with increasing axial strain is observed in uniaxial tension tests. The model for post-yield behavior of extruded powder aluminum gives a quantified description of the macroscopic material behavior in terms of changes in the laminar powder aluminum structure.

  15. Use of extruded alloys Bi-Sb in low temperature thermoelements

    NASA Astrophysics Data System (ADS)

    Banaga, M. P.; Buimistr, B. S.; Moloshnik, E. F.

    1988-10-01

    Values of thermoelectric factor of quality for extruded alloys Bi_88Sb_12 of n-type in the temperatures interval 200-100K and a magnetic field induction 0-0.3Tl has been given. Temperature dependencies of optimal ratios of crossections of frames of thermoelements, containing extruded n-frame for various values of the induction of the transversal magnetic field has been analysed. Temperature dependencies of the quality factors of the thermoelements has been given. Calculated and experimental temperature falls on thermoelements and their dependenices on the crossections frames ratios for various temperatures of the heat evacuation has been analysed. Thermoelements examined are designed for application in low-temperature coolers.

  16. Chemical and functional characterization of Kañiwa (Chenopodium pallidicaule) grain, extrudate and bran.

    PubMed

    Repo-Carrasco-Valencia, Ritva; Acevedo de La Cruz, Alexander; Icochea Alvarez, Julio Cesar; Kallio, Heikki

    2009-06-01

    Cereals provide a good source of dietary fibre and other important compounds with nutritional potential, such as phenolic compounds, antioxidants, minerals and vitamins. Although native Andean cereals are known to have high nutritional value, their minor components have not been studied thoroughly. In this study, two varieties of a native Andean crop, kañiwa (Chenopodium pallidicaule), were investigated as sources of dietary fibre and specific antioxidant compounds. Two products, an extrudate and bran, were also prepared and their functional properties and bioactive compounds were determined. Both varieties were rich in total dietary fibre and lignin, and the phenolic components analyzed had high antioxidant activity. The extrudates had good functional properties, such as degree of gelatinization, sectional expansion index and water solubility index; the bran was high in bioactive compounds, such as total phenolics. In conclusion, kañiwa may offer an alternative to traditional cereals as a health-promoting food ingredient. PMID:19424801

  17. Microstructures of rapidly solidified powder and extruded rod of Ni{sub 3}Ge

    SciTech Connect

    Fang, J.; Schulson, E.M.

    1996-07-01

    Rapidly solidified powders and extruded rods of Ni{sub 3}Ge with and without 0.06 at. % boron were characterized using optical microscopy, scanning electron microscopy, transmission electron microscopy, and X-ray diffraction. The powders were generally spherical and exhibited both dendritic and lamellar structures. The increase in lattice parameter per atom fraction of boron, {var_epsilon}, was estimated to be 0.33. Extrusion of the powders produced fine grains of about 2 {micro}m in diameter. The extruded materials were partially recrystallized and showed a minor preference for [111] orientation. Annealing at 950 C resulted in a fully recrystallized structure and a nearly random orientation. The addition of 0.06 at. % boron had no observable effect on the morphology, microstructure, and texture. Precipitates of borides were observed in the annealed boron-doped alloy, suggesting that the solubility of boron in Ni{sup 3}Ge may be below about 0.06 at. %.

  18. The effect of moisture content on physicochemical properties of extruded waxy and non-waxy rice flour.

    PubMed

    Jongsutjarittam, Ornpicha; Charoenrein, Sanguansri

    2014-12-19

    The properties of waxy rice flour (WRF) and non-waxy rice flour (RF) were modified using an extrusion process with different feeding material moisture contents. WRF was more affected by the thermomechanical stress from extrusion; consequently, it had a lower glass transition temperature but higher water solubility index (WSI) indicating higher molecular degradation than extruded RF. The lower moisture content of the feeding flour caused more severe flour damage (coarser surface of the extruded flour) and lowered relative crystallinity compared to higher moisture content processing. Moreover, low moisture content processing led to complete gelatinization, whereas, partial gelatinization occurred in the higher moisture content extrusion. Consequently, the extruded flours had a lower peak viscosity and gelatinization enthalpy but a higher water absorption index and WSI than native flour. In conclusion, the rice flour type and the moisture content of the extrusion feeding flour affected the physicochemical properties of the extruded flour. PMID:25263873

  19. Melt-Extruded Eudragit® FS-Based Granules for Colonic Drug Delivery.

    PubMed

    Zhang, Feng

    2016-02-01

    The purpose of this study is to characterize the properties of Eudragit® FS-based granules prepared using melt extrusion process for colonic drug delivery. 5-Aminosalicylic acid (5-ASA), theophylline, and diclofenac sodium were used as the model compounds. Drug and polymer blends were melt-extruded into thin rods using a single screw extruder. Drugs were found to be dispersed as crystalline particles in the granules. A hammer mill was used to reduce the extrudate into 16-40 mesh granules, which were mixed with lactose and filled into hard gelatin capsules. Three-stage dissolution testing performed using USP paddle method was used to simulate drug release in gastrointestinal tract. In this study, melt extrusion has been demonstrated to be a suitable process to prepare granules for colonic delivery of 5-amino salicylic acid. At 30% drug loading, less than 25% 5-ASA was released from melt-extruded granules of 20-30 mesh in the first two stages (0.1 N hydrochloric acid solution and phosphate buffer pH 6.8) of the dissolution testing. All 5-ASA was released within 4 h when dissolution medium was switched to phosphate buffer pH 7.4. Drug loading, granule size, and microenvironment pH induced by the solubilized drug were identified as the key factors controlling drug release. Granules prepared with melt extrusion demonstrated lower porosity, smaller pore size, and higher physical strength than those prepared with conventional compression process. Eudragit® FS was found to be stable even when processed at 200°C. PMID:26162974

  20. Development of a pilot-scale kinetic extruder feeder system and test program. Phase I report

    SciTech Connect

    1982-03-01

    This report describes the work done under Phase I, the moisture tolerance testing of the Kinetic Extruder. The following coals were used in the test program: Western Bituminous (Utah), Eastern Bituminous (Pennsylvania), North Dakota Lignite, Sub-Bituminous (Montana), and Eastern Bituminous coal mixed with 20-percent Limestone. The coals were initially tested at the as-received moisture level and subsequently tested after surface moisture was added by water spray. Test results and recommendations for future research and development work are presented.

  1. Extrusion Conditions and Amylose Content Affect Physicochemical Properties of Extrudates Obtained from Brown Rice Grains

    PubMed Central

    González, Rolando José; Pastor Cavada, Elena; Vioque Peña, Javier; Torres, Roberto Luis; De Greef, Dardo Mario; Drago, Silvina Rosa

    2013-01-01

    The utilization of whole grains in food formulations is nowadays recommended. Extrusion cooking allows obtaining precooked cereal products and a wide range of ready-to-eat foods. Two rice varieties having different amylose content (Fortuna 16% and Paso 144, 27%) were extruded using a Brabender single screw extruder. Factorial experimental design was used to study the effects of extrusion temperature (160, 175, and 190°C) and grits moisture content (14%, 16.5%, and 19%) on extrudate properties. Specific mechanical energy consumption (SMEC), radial expansion (E), specific volume (SV), water absorption (WA), and solubility (S) were determined on each extrudate sample. In general, Fortuna variety showed higher values of SMEC and S (703–409 versus 637–407 J/g; 33.0–21.0 versus 20.1–11.0%, resp.) than those of Paso 144; on the contrary SV (8.64–3.47 versus 8.27–4.53 mL/g) and WA tended to be lower (7.7–5.1 versus 8.4–6.6 mL/g). Both varieties showed similar values of expansion rate (3.60–2.18). Physical characteristics depended on extrusion conditions and rice variety used. The degree of cooking reached by Paso rice samples was lower than that obtained for Fortuna. It is suggested that the presence of germ and bran interfered with the cooking process, decreasing friction level and broadening residence time distribution. PMID:26904605

  2. Effect of carbamazepine on viscoelastic properties and hot melt extrudability of Soluplus ®.

    PubMed

    Gupta, Simerdeep Singh; Parikh, Tapan; Meena, Anuprabha K; Mahajan, Nidhi; Vitez, Imre; Serajuddin, Abu T M

    2015-01-15

    The purpose of this study was to apply viscoelastic properties of polymer and drug-polymer mixtures to determine processing conditions for the preparation of amorphous solid dispersion by melt extrusion. A poorly water-soluble drug, carbamazepine (CBZ), was mixed with Soluplus(®) as the carrier. Torque analysis using a melt extruder was performed at 10, 20 and 30% w/w drug concentrations and the effect of barrel temperature was studied. Viscosity of the mixtures either at fixed temperatures with different angular frequencies or as a function of temperature with the same frequency was studied using a rheometer. The viscosity of Soluplus(®) and the torque exerted on the twin screws decreased with the increase in CBZ concentration. The viscosity versus temperature plots for different CBZ concentrations were parallel to each other, without the drug melting transition, indicating complete drug-polymer miscibility. Thus, the drug-polymer mixtures could be extruded at temperature as low as 140°C with 10% w/w drug load, 135°C with 20% w/w drug and 125°C with 30% w/w drug, which were, respectively, ∼ 50°C, 55°C and 65°C below the melting point of 191°C for CBZ. The differential scanning calorimetry (DSC) and powder X-ray diffraction (XRD) analyses of the binary mixtures extruded at 125-150°C showed absence of crystalline drug. A systematic study of miscibility and extrudability of drug-polymer mixtures by rheological and torque analysis as a function of temperature will help formulators select optimal melt extrusion processing conditions to develop solid dispersions. PMID:25448585

  3. Research on flow mechanism of material for spur gear in closed extruding fine blanking process

    NASA Astrophysics Data System (ADS)

    Deng, Ming; Liu, Lu-zhou

    2013-05-01

    The finite element method (FEM) is applied to analyze closed extruding fine blanking gear. The reason of engendering corner collapse is the friction between blank and die. Meanwhile, this paper analyzes effects of various counterpunch forces on the flow characteristics, obtains the fiber distribution on different sections of the gear. The effects of counterpunch forces on material flow characteristics in deformation zone and the swirling flow in scrap are also obtained.

  4. Silica research in Glasgow

    NASA Astrophysics Data System (ADS)

    Barr, B. W.; Cagnoli, G.; Casey, M. M.; Clubley, D.; Crooks, D. R. M.; Danzmann, K.; Elliffe, E. J.; Goßler, S.; Grant, A.; Grote, H.; Heptonstall, A.; Hough, J.; Jennrich, O.; Lück, H.; McIntosh, S. A.; Newton, G. P.; Palmer, D. A.; Plissi, M. V.; Robertson, D. I.; Robertson, N. A.; Rowan, S.; Skeldon, K. D.; Sneddon, P.; Strain, K. A.; Torrie, C. I.; Ward, H.; Willems, P. A.; Willke, B.; Winkler, W.

    2002-04-01

    The Glasgow group is involved in the construction of the GEO600 interferometer as well as in R&D activity on technology for advanced gravitational wave detectors. GEO600 will be the first GW detector using quasi-monolithic silica suspensions in order to decrease thermal noise significantly with respect to steel wire suspensions. The results concerning GEO600 suspension mounting and performance will be shown in the first section. Section 2 is devoted to the present results from the direct measurement of thermal noise in mirrors mounted in the 10 m interferometer in Glasgow which has a sensitivity limit of 4 × 10-19 m Hz-1/2 above 1 kHz. Section 3 presents results on the measurements of coating losses. R&D activity has been carried out to understand better how thermal noise in the suspensions affects the detector sensitivity, and in section 4 a discussion on the non-linear thermoelastic effect is presented.

  5. Silica aerogel core waveguide.

    PubMed

    Grogan, M D W; Leon-Saval, S G; England, R; Birks, T A

    2010-10-11

    We have selectively filled the core of hollow photonic crystal fibre with silica aerogel. Light is guided in the aerogel core, with a measured attenuation of 0.2 dB/cm at 1540 nm comparable to that of bulk aerogel. The structure guides light by different mechanisms depending on the wavelength. At long wavelengths the effective index of the microstructured cladding is below the aerogel index of 1.045 and guidance is by total internal reflection. At short wavelengths, where the effective cladding index exceeds 1.045, a photonic bandgap can guide the light instead. There is a small region of crossover, where both index- and bandgap-guided modes were simultaneously observed. PMID:20941148

  6. Experimental Studies on Dynamic Mechanical Behaviors and Anti-Projectile Capabilities of Extruded Magnesium Alloy

    NASA Astrophysics Data System (ADS)

    Fan, Yafu; Zhao, Baorong

    Dynamic mechanical behaviors of Mg-Gd-Y series extruded magnesium alloy and its σ-ɛcurves are measured by using of Hopkinson pressure bar technique. According to the concept of efficiency of absorption energy, this thesis compares Mg-Gd-Y series extruded alloy with ZK60 extruded magnesium alloy. Being obtained similitude numbers by means of normalizing processing for governing equations of the continuum mechanics and according to the viewpoint of equal density of area, the comparative experiment of anti-projectile capabilities is elaborately designed between Mg-Gd-Y alloy and the 7A52 aluminum alloy. The result has validated that anti-projectile capability of Mg-Gd-Y alloy is better than those of 7A52 alloy under the condition of equal density of area. The relative technique approaches for improving anti-projectile capability of Mg-Gd-Y alloy are put forward making use of similitude numbers. Finally, the basic characters of effect of adiabatic shear are revealed by micro analysis.

  7. Dungeness crab, Cancer magister, do not extrude eggs annually in southeastern Alaska: An in situ study

    USGS Publications Warehouse

    Swiney, K.M.; Shirley, T.C.; Taggart, S.J.; O'Clair, C. E.

    2003-01-01

    The reproductive biology of female Dungeness crabs was studied with crab-pot and dive-transect sampling in five bays within or near Glacier Bay National Park and Preserve, southeastern Alaska, in April and September yearly from 1992 to 1998. A large percentage of nonovigerous, mature females was found in April, a time when females were expected to be brooding eggs that hatch in May and June. Our study examined differences between ovigerous and nonovigerous females collected in April and September samples to corroborate our previous laboratory study in which we found nonannual egg extrusion among Dungeness crabs. Seasonal differences in the catches of ovigerous and nonovigerous females, crab sizes, shell condition, and appendage injury were examined. Additionally, all crabs collected from two bays were tagged beginning in the fall of 1995; tagging was conducted twice annually. Our pot and dive data indicate that females, particularly larger ones, do not extrude eggs annually. Larger females have lower molting probabilities, which limits mating potential and increases reliance on stored sperm. The tagging study confirmed that at least some females do not extrude eggs in one year and then extrude eggs at a later time without molting, thus skipping at least one reproductive season. A reproductive cycle of Dungeness crabs in Alaska is introduced which includes earlier egg extrusion by larger females and nonannual egg extrusion.

  8. Direct Forming of All-Polypropylene Composites Products from Fabrics made of Co-Extruded Tapes

    NASA Astrophysics Data System (ADS)

    Alcock, B.; Cabrera, N. O.; Barkoula, N. M.; Peijs, T.

    2009-04-01

    Many technologies presented in literature for the forming of self-reinforced or all-polymer composites are based on manufacturing processes involving thermoforming of pre-consolidated sheets. This paper describes novel direct forming routes to manufacture simple geometries of self-reinforced, all-polypropylene (all-PP) composites, by moulding fabrics of woven co-extruded polypropylene tapes directly into composite products, without the need for pre-consolidated sheet. High strength co-extruded PP tapes have potential processing advantages over mono-extruded fibres or tapes as they allow for a larger temperature processing window for consolidation. This enlarged temperature processing window makes direct forming routes feasible, without the need for an intermediate pre-consolidated sheet product. Thermoforming studies show that direct forming is an interesting alternative to stamping of pre-consolidated sheets, as it eliminates an expensive belt-pressing step which is normally needed for the manufacturing of semi-finished sheets products. Moreover, results from forming studies shows that only half the energy was required to directly form a simple dome geometry from a stack of fabrics compared to stamping the same shape from a pre-consolidated sheet.

  9. Starch-based extruded cereals enriched in fibers: a behavior of composite solid foams.

    PubMed

    Chanvrier, Hélène; Desbois, Fabrice; Perotti, Fabienne; Salzmann, Claire; Chassagne, Sophie; Gumy, Jean-Claude; Blank, Imre

    2013-10-15

    Extruded cereals mainly composed of starch and enriched in fibers were produced with two types of base recipes: (i) one recipe mainly composed of wheat flour and (ii) one recipe mainly composed of corn and soya flours. The addition of fibers was performed through the use of oat bran concentrate or wheat bran, up to 32% of the recipe. The structure of the extrudates, assessed by X-ray tomography, pointed out the decrease of porosity and of mean cells size with the increase of the total dietary fibers content of the recipe. The hardness of the products, i.e. the maximum stress determined by a compression test, was linked to their porosity. The Gibson-Ashby relationship could be applied and the fit was even improved when considering the walls of the solid foam as composite materials. Fibers and proteins can be indeed considered as particles dispersed in the starchy phase. This work thus shows the impact of the structure of the extrudates on their mechanical properties. The structure is taken into account at different length scales; at the level of the porous structure and at the level of the phase of the main biopolymers present in the recipe (starch, proteins and fibers). The mechanical behavior of these products is then discussed according to their characteristics of composite solid foams. PMID:23987420

  10. Microstructural Changes in High-Protein Nutrition Bars Formulated with Extruded or Toasted Milk Protein Concentrate.

    PubMed

    Banach, J C; Clark, S; Lamsal, B P

    2016-02-01

    Milk protein concentrates with more than 80% protein (that is, MPC80) are underutilized as the primary protein source in high-protein nutrition bars as they impart crumbliness and cause hardening during storage. High-protein nutrition bar texture changes are often associated with internal protein aggregations and macronutrient phase separation. These changes were investigated in model high-protein nutrition bars formulated with MPC80 and physically modified MPC80s. High-protein nutrition bars formulated with extruded MPC80s hardened slower than those formulated with toasted or unmodified MPC80. Extruded MPC80 had reduced free sulfhydryl group exposure, whereas measurable increases were seen in the toasted MPC80. High-protein nutrition bar textural performance may be related to the number of exposed free sulfhydryl groups in MPC80. Protein aggregations resulting from ingredient modification and high-protein nutrition bar storage were studied with sodium dodecyl sulfate polyacrylamide gel electrophoresis. Disulfide-based protein aggregations and changes in free sulfhydryl concentration were not consistently relatable to high-protein nutrition bar texture change. However, the high-protein nutrition bars formulated with extruded MPC80 were less prone to phase separations, as depicted by confocal laser scanning microscopy, and underwent less texture change during storage than those formulated with toasted or unmodified MPC80. PMID:26748454

  11. Starch-guar gum extrudates: microstructure, physicochemical properties and in-vitro digestion.

    PubMed

    von Borries-Medrano, Erich; Jaime-Fonseca, Mónica R; Aguilar-Méndez, Miguel A

    2016-03-01

    Starch-guar gum mixtures were obtained by extrusion using a three-variable Box-Behnken statistic design. Morphology, expansion index, viscosity, crystallinity and digestion in vitro of the extruded samples were analyzed through response surface methodology (RSM). The extrusion temperature and the moisture content were the factors that significantly affected the physicochemical properties of the samples. Starch-guar gum samples showed expansion index and viscosity up to 1.55 and 1400mPas, respectively. The crystallinity of the samples was modified by adding guar gum to the extrudates, showing correlation between long-range order (X-ray diffraction) and short-range order (FTIR spectroscopy). Guar induced microstructural changes and its role in gelatinization-melting processes was significant. The rate of glucose release decreased from 0.47 to 0.43mM/min when the extrusion temperature decreased. However, adding guar gum to starch had no significant effect on glucose release. Overall, the extrusion temperature and the moisture content were the factors that significantly affected the physicochemical properties of the extruded samples. PMID:26471632

  12. Physico-chemical, nutritional and infrared spectroscopy evaluation of an optimized soybean/corn flour extrudate.

    PubMed

    Guzmán-Ortiz, Fabiola Araceli; Hernández-Sánchez, Humberto; Yee-Madeira, Hernani; San Martín-Martínez, Eduardo; Robles-Ramírez, María Del Carmen; Rojas-López, Marlon; Berríos, Jose De J; Mora-Escobedo, Rosalva

    2015-07-01

    A central composite design using RMS (Response Surface Methodology) successfully described the effect of independent variables (feed moisture, die temperature and soybean proportion) on the specific parameters of product quality as expansion index (EI), water absorption index (WAI), water solubility index (WSI) and total color difference (ΔE) studied. The regression model indicated that EI, WAI, WSI and ΔE were significant (p < 0.05) with coefficients of determination (R(2)) of 0.7371, 0.7588, 0.7622, 0.8150, respectively. The optimized processing conditions were obtained with 25.8 % feed moisture, 160 °C die temperature and 58 %/42 % soybean/corn proportion. It was not found statistically changes in amino acid profile due to extrusion process. The electrophoretic profile of extruded soybean/corn mix presented low intensity molecular weight bands, compared to the unprocessed sample. The generation of low molecular weight polypeptides was associated to an increased in In vitro protein digestibility (IVPD) of the extrudate. The FTIR spectra of the soybean/corn mix before and after extrusion showed that the α-helix structure remained unchanged after extrusion. However, the band associated with β-sheet structure showed to be split into two bands at 1624 and 1640 cm(-1) . The changes in the β-sheet structures may be also associated to the increased in IVPD in the extruded sample. PMID:26139872

  13. Effect of extruded wheat flour as a fat replacer on batter characteristics and cake quality.

    PubMed

    Román, Laura; Santos, Isabel; Martínez, Mario M; Gómez, Manuel

    2015-12-01

    The effects of three levels of fat replacement (1/3, 2/3, and 3/3) by extruded flour paste and the effects of the presence of emulsifier on layer cake batter characteristics and final cake quality were studied. Replacement of oil by extruded flour paste modified the batter density and microscopy, reducing the number of air bubbles and increasing their size, while emulsifier incorporation facilitated air entrapment in batter. Emulsifier addition also increased the elastic and viscous moduli of the batter, while oil reduction resulted in a less structured batter. Emulsifier incorporation leads to good quality cakes, minimizing the negative effect of oil reduction, maintaining the volume and reducing the hardness of cakes. Furthermore, consumer acceptability of the reduced fat cakes was improved by the addition of emulsifier. Thus, the results confirmed the positive effect of partial oil substitution (up to 2/3) by extruded flour paste on the quality of reduced fat cakes when emulsifier was incorporated. PMID:26604393

  14. Investigation of functional properties and color changes of corn extrudates enriched with broccoli or olive paste.

    PubMed

    Bisharat, Ghassan I; Katsavou, Ioanna D; Panagiotou, Nikolaos M; Krokida, Magdalini K; Maroulis, Zacharias B

    2015-12-01

    Following the tendency of replacing common food snacks with healthier food products, extruded snacks with corn flour and broccoli (4-10%) or olive paste (4-8%) were investigated in this study. The effect of material characteristics, including feed moisture content (14-19%), and broccoli or olive paste concentration, and extrusion conditions, including screw speed (150-250 r/min), and extrusion temperature (140-180 ℃), on the functional properties (water absorption index, water solubility index, and oil absorption index), as well as color change (ΔE) of the extruded snacks was studied. Regression analysis showed that screw speed did not significantly influence (p > 0.05) the properties. After mathematical modelling it was found that broccoli and olive paste concentration, as well as temperature increment, caused a decrease in water absorption index (minimum of 5.6 and 6.4 g/g sample, respectively) and an increase in water solubility index (maximum of 18.7 and 10.9 g/100 g sample, respectively), while feed moisture presented opposite tendency. Higher extrusion temperature led to an increment of oil absorption index (approximately to 1.2 and 1 mL/g sample) and decrement of color changes. Finally, feed moisture and broccoli concentration lowered oil absorption index and color of corn/broccoli extrudates, while olive paste concentration caused their increment. PMID:25406135

  15. Effect of Ca(OH)2 pretreatment on extruded rice straw anaerobic digestion.

    PubMed

    Gu, Yu; Zhang, Yalei; Zhou, Xuefei

    2015-11-01

    It has been proven that extrusion can change the structure of rice straw and increase biogas production, but the effect of a single pretreatment is limited. Ca(OH)2 pretreatment was used to enhance the enzyme hydrolysis and biogas production of extruded rice straw. After Ca(OH)2 pretreatment, the glucose and xylose conversion rates in enzymatic hydrolysis increased from 36.0% and 22.4% to 66.8% and 50.2%, respectively. The highest biogas production observed in 8% and 10% Ca(OH)2 pretreated rice straw reached 564.7mL/g VS and 574.5mL/g VS, respectively, which are 34.3% and 36.7% higher than the non-Ca(OH)2-loaded sample. The Ca(OH)2 pretreatment can effectively remove the lignin and increase the fermentable sugar content. The structural changes in the extruded rice straw have also been analyzed by XRD, FTIR, and SEM. Considering all of the results, an 8% Ca(OH)2 loading rate is the best option for the pretreatment of extruded rice straw. PMID:26231131

  16. Drug structural features affect drug delivery from hyperbranched polyesteramide hot melt extrudates.

    PubMed

    Raviña-Eirin, Elena; Azuaje, Jhonny; Sotelo, Eddy; Gomez-Amoza, Jose Luis; Martinez-Pacheco, Ramon

    2016-05-01

    The aim of this study was firstly to evaluate the utility of Hybrane S1200 as a hot melt extrusion (HME) carrier to prepare instant-release multiparticulate systems for very poorly-soluble drugs such as ketoconazole or nifedipine. Hybrane S1200 allows an easy extrusion of its drug mixtures at a relatively low temperature, not higher than 90°C, and with no need of any additional aid. Extrudates containing 10% of nifedipine or ketoconazole form monophasic systems. Nifedipine extrudate shows no drug release in drug dissolution rate tests while ketoconazole extrudate release reaches only 60% of drug content. Additionally, a turbidity in the dissolution medium due to the formation of a kind of polymer vesicles (ranging 3-0.2μm in size) is observed. These facts could suggest a chemical interaction between the polymer and both drugs, triggered by the HME process. Both nifedipine and ketoconazole share characteristic acid-base profiles that could facilitate a degradation processes within the polymer, thus modifying Hybrane's water-solubility and polar nature. Such modified polymer structure, when in aqueous medium, forms the aforementioned stable vesicles that may encapsulate the drugs, thus making its delivery difficult or even preventing it. PMID:26912462

  17. The effect of extrusion processing on the physiochemical properties of extruded orange pomace.

    PubMed

    Huang, Ya-Ling; Ma, Ya-Sheng

    2016-02-01

    Soluble dietary fibre (SDF) is considered the most effective fraction of dietary fibre (DF) for human health. In this study, extrusion technology was applied to enhance the SDF obtained from orange pomace, a byproduct of juice extraction containing a high level of DF. The pomace was processed in a single-screw extruder at various barrel temperatures (X1; 115-135 °C), feed moistures (X2; 10-18 g/100g), and screw speeds (X3; 230-350 rpm). Based on response surface methodology, the optimum extrusion conditions, which produced a maximum SDF value of 30.36%, were as follows: barrel temperature, 129 °C; feed moisture, 15%; and screw speed, 299 rpm. Compared with unextruded pomace, SDF fraction in extrudate had a higher level of uronic acid. Furthermore, the extrusion process improved the physicochemical properties of extrudate, increasing the water-holding capacity, swelling, water solubility index, and cation-exchange capacity and decreasing the oil-holding capacity. PMID:26304360

  18. 21 CFR 584.700 - Hydrophobic silicas.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Hydrophobic silicas. 584.700 Section 584.700 Food... DRINKING WATER OF ANIMALS Listing of Specific Substances Affirmed as GRAS § 584.700 Hydrophobic silicas. (a) Product. Amorphous fumed hydrophobic silica or precipitated hydrophobic silica (CAS Reg. No....

  19. 21 CFR 584.700 - Hydrophobic silicas.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Hydrophobic silicas. 584.700 Section 584.700 Food... DRINKING WATER OF ANIMALS Listing of Specific Substances Affirmed as GRAS § 584.700 Hydrophobic silicas. (a) Product. Amorphous fumed hydrophobic silica or precipitated hydrophobic silica (CAS Reg. No....

  20. 21 CFR 584.700 - Hydrophobic silicas.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Hydrophobic silicas. 584.700 Section 584.700 Food... DRINKING WATER OF ANIMALS Listing of Specific Substances Affirmed as GRAS § 584.700 Hydrophobic silicas. (a) Product. Amorphous fumed hydrophobic silica or precipitated hydrophobic silica (CAS Reg. No....

  1. 21 CFR 584.700 - Hydrophobic silicas.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Hydrophobic silicas. 584.700 Section 584.700 Food... DRINKING WATER OF ANIMALS Listing of Specific Substances Affirmed as GRAS § 584.700 Hydrophobic silicas. (a) Product. Amorphous fumed hydrophobic silica or precipitated hydrophobic silica (CAS Reg. No....

  2. 21 CFR 582.1711 - Silica aerogel.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Silica aerogel. 582.1711 Section 582.1711 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS....1711 Silica aerogel. (a) Product. Silica aerogel as a finely powdered microcellular silica foam...

  3. 21 CFR 182.1711 - Silica aerogel.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Silica aerogel. 182.1711 Section 182.1711 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN....1711 Silica aerogel. (a) Product. Silica aerogel as a finely powdered microcellular silica foam...

  4. Development of molybdena catalysts supported on. gamma. -alumina extrudates with four different Mo profiles: Preparation, characterization, and catalytic properties

    SciTech Connect

    Goula, M.A.; Kordulis, Ch.; Lycourghiotis, A. ); Fierro, J.L.G. )

    1992-10-01

    The main goal of this work is to prepare, characterize, and determine the catalytic properties of molybdena supported {gamma}-alumina extrudates with four Mo profiles. Concerning preparation, a procedure was established allowing the authors to prepare (both axially and radially) egg-shell, egg-white, egg-yolk, and uniform profiles with the same, relatively high, Mo loading. The preparation of the egg-shell and uniform profiles was achieved by impregnating {gamma}-alumina extrudates with acidic and alkaline ammonium heptamolybdate solution, respectively. Moreover, it was found that an egg-white (egg-yolk) profile nondry impregnations of the Mo-supported extrudes with NH{sub 4}OH aqueous solutions. Kinetic experiments were done, using the HDS of thiophene as a probe reaction, over the characterized samples being in the form of extrudates and powders produced by crushing the extrudates. It was found that HDS activity was mainly determined by the number and the quality of active centers and not by the type of Mo profile, though these suggested the presence of no significant diffusional effects. The relative yield of butane, produced by the hydrogenation of the unsaturated hydrocarbons formed during HDS, increased with the distance of the maximum of the Mo profile from the periphery of the extrude to its center. Finally, it is important to note that the most active radial profile proved to be the egg-white for HDS and the egg-yolk for hydrogenation.

  5. Silica/Polymer and Silica/Polymer/Fiber Composite Aerogels

    NASA Technical Reports Server (NTRS)

    Ou, Danny; Stepanian, Christopher J.; Hu, Xiangjun

    2010-01-01

    Aerogels that consist, variously, of neat silica/polymer alloys and silica/polymer alloy matrices reinforced with fibers have been developed as materials for flexible thermal-insulation blankets. In comparison with prior aerogel blankets, these aerogel blankets are more durable and less dusty. These blankets are also better able to resist and recover from compression . an important advantage in that maintenance of thickness is essential to maintenance of high thermal-insulation performance. These blankets are especially suitable as core materials for vacuum- insulated panels and vacuum-insulated boxes of advanced, nearly seamless design. (Inasmuch as heat leakage at seams is much greater than heat leakage elsewhere through such structures, advanced designs for high insulation performance should provide for minimization of the sizes and numbers of seams.) A silica/polymer aerogel of the present type could be characterized, somewhat more precisely, as consisting of multiply bonded, linear polymer reinforcements within a silica aerogel matrix. Thus far, several different polymethacrylates (PMAs) have been incorporated into aerogel networks to increase resistance to crushing and to improve other mechanical properties while minimally affecting thermal conductivity and density. The polymethacrylate phases are strongly linked into the silica aerogel networks in these materials. Unlike in other organic/inorganic blended aerogels, the inorganic and organic phases are chemically bonded to each other, by both covalent and hydrogen bonds. In the process for making a silica/polymer alloy aerogel, the covalent bonds are introduced by prepolymerization of the methacrylate monomer with trimethoxysilylpropylmethacrylate, which serves as a phase cross-linker in that it contains both organic and inorganic monomer functional groups and hence acts as a connector between the organic and inorganic phases. Hydrogen bonds are formed between the silanol groups of the inorganic phase and the

  6. Skin penetration of silica microparticles.

    PubMed

    Boonen, J; Baert, B; Lambert, J; De Spiegeleer, B

    2011-06-01

    Knowledge about skin penetration of nano- and microparticles is essential for the development of particle-core drug delivery systems and toxicology. A large number of studies have been devoted to metallic particle penetration. However, little work has been published about the importance of chemical material properties of the particles and the skin penetration effect of the applied formulation. Here, we investigated the penetration of 3 microm silica particles in water and in a 65% ethanolic plant extract on ex vivo human skin using scanning electron microscopy. Contrary to most other microsphere skin studies, we observed for the first time that 3 microm silica particles can penetrate the living epidermis. Moreover, when formulated in the ethanolic medium, particles even reach the dermis. The deviating chemical properties of silica compared to previously investigated microparticles (titanium dioxide, zinc oxide) and confounding effect of the formulation in which the silica microparticles are presented, is thus demonstrated. PMID:21699089

  7. Impact of extruded flaxseed meal supplemented diet on growth performance, oxidative stability and quality of broiler meat and meat products

    PubMed Central

    2013-01-01

    This study was intended to explore the effect of extruded flaxseed meal supplemented diet on broiler growth performance, oxidative stability and organoleptic characteristics of broiler meat and meat products. 120 (day old) broiler chicks were randomly allotted to 12 experimental groups and fed on diets containing extruded flaxseed meal at 0, 5, 10 and 15%. The supplementation of extruded flaxseed in the diet decreases the body weight gain, feed intake and increased feed conversion ratio (FCR) values of broilers. The antioxidant enzymes were strongly influenced by different levels of extruded flaxseed supplementation among treatments. The TBARS assay revealed that maximum malondialdehyde were produced in T3 containing highest extruded flaxseed level (15%) and minimum malondialdehyde were produced in T0 treatment having no extruded flaxseed. The TBARS values ranged from 0.850-2.106 and 0.460-1.052 in leg and breast met respectively. The Free radical scavenging activity varied significantly and DPPH values of breast meat ranged from 20.70% to 39.09% and in leg meat 23.53% to 43.09% respectively. The sensory acceptability of broiler meat nuggets was decreased with the increase in the level of flaxseeds due to the lipid peroxidation of polyunsaturated fatty acids (PUFA) which generated off flavors and bad odors. Feeding extruded flaxseed to chicken through feed strongly inflated the quality and functional properties, fatty acid contents and reduced the oxidative stability of broiler meat and meat products. The present study concludes that up to 10% of flaxseed meal may be used in broiler diet to enhance the omega 3 fatty acids content in the broiler meat. PMID:23391137

  8. Enhancing anaerobic digestion of high-pressure extruded food waste by inoculum optimization.

    PubMed

    Kong, Xin; Xu, Shuang; Liu, Jianguo; Li, Huan; Zhao, Ke; He, Liang

    2016-01-15

    The inoculation for extruded food waste anaerobic digestion (AD) was optimized to improve methane (CH4) yield. The inoculum of acclimated anaerobic sludge resulted in high biodegradability, producing CH4 yields from 580 mLCH4 g(-1)·VSadded to 605 mLCH4 g(-1)·VSadded, with corresponding BDCH4 ranging from 90% to 94%. We also investigated inoculum to substrate ratios (ISRs). With regards to digested slurry as inoculum, we found that a decrease in ISR improved CH4 yield, while a lower ISR prolonged the lag time of the initial AD stage due to lipid inhibition caused by excessive food waste. These results demonstrate that minimal inocula are required to start the AD system for high-pressure extruded food waste because it is easily biodegraded. High ammonia concentration had a negative effect on CH4 production (i.e., when free ammonia nitrogen [FAN] increased from 20 to 30 mg L(-1) to 120-140 mg L(-1), the CH4 yield decreased by 25%), suggesting that FAN was a significant inhibitor in CH4 yield reduction. In terms of CH4 yield and lag time of the AD process, the optimal inoculation of digested slurry for the extruded food waste had an ISR of 0.33 with CH4 yield of 505 mLCH4 g(-1)VSadded, which was 20% higher than what was found for higher ISR controls of 2, 1 and 0.5. PMID:26468605

  9. Simulation of Peptide Binding to Silica and Silica Mineralization

    NASA Astrophysics Data System (ADS)

    Emami, F. S.; Heinz, H.; Berry, R. J.; Varshney, V.; Farmer, B. L.; Naik, R. R.; Patwardhan, S. V.; Perry, C. C.

    2009-03-01

    The purpose of this study is to identify the nature of the interaction of peptides with silica surfaces and their effect on mineralization. Classical force fields (CVFF, PCFF) have been extended for silica aiming at the computation of surface properties in quantitative agreement with experiment, taking explicitly into account water molecules, pH, and surface coverage with peptides. We focus on the interaction of five short peptides (pep1, pep4, 82-4, H4, R5) identified by biopanning with regular and amorphous silica surfaces (Q3 and Q2) to understand the relation between peptide sequence and affinity to the surface. Results of the atomistic molecular dynamics simulation indicate adsorption energies, binding constants and conformational changes upon adsorption. The comparison of NMR chemical shifts in solution and on the surface in computation and experiment further aids in understanding the mechanism of binding.

  10. The effect of extrusion on the functional components and in vitro lycopene bioaccessibility of tomato pulp added corn extrudates.

    PubMed

    Tonyali, Bade; Sensoy, Ilkay; Karakaya, Sibel

    2016-02-01

    The effect of processing on functional ingredients and their in vitro bioaccessibility should be investigated to develop better food products. Tomato pulp was added as a functional ingredient to extrudates. The effects of extrusion on the functional properties of the extrudates and the in vitro bioaccessibility of lycopene were investigated. Two different temperature sets were applied during extrusion: 80 °C, 90 °C, 100 °C and 130 °C and 80 °C, 100 °C, 130 °C and 160 °C. Screw speed and feed rate were kept constant at 225 rpm and 36 ± 1 g min(-1), respectively. The feed moisture content was adjusted to 30 ± 1% by mixing the tomato pulp to the corn grit. Antioxidant activity and the total phenolic content decreased after the extrusion process. High performance liquid chromatography (HPLC) analysis indicated that the lycopene content decreased after the extrusion process when feed and extrudates were compared. In vitro bioaccessibility of lycopene for the extruded samples with 160 °C last zone treatment temperature was higher than the feed and extruded samples with 130 °C last zone treatment temperature. The results indicate that extrusion affects the food matrix and the release of functional components. PMID:26674172

  11. Physicochemical Changes and Resistant-Starch Content of Extruded Cornstarch with and without Storage at Refrigerator Temperatures.

    PubMed

    Neder-Suárez, David; Amaya-Guerra, Carlos A; Quintero-Ramos, Armando; Pérez-Carrillo, Esther; Alanís-Guzmán, María G de J; Báez-González, Juan G; García-Díaz, Carlos L; Núñez-González, María A; Lardizábal-Gutiérrez, Daniel; Jiménez-Castro, Jorge A

    2016-01-01

    Effects of extrusion cooking and low-temperature storage on the physicochemical changes and resistant starch (RS) content in cornstarch were evaluated. The cornstarch was conditioned at 20%-40% moisture contents and extruded in the range 90-130 °C and at screw speeds in the range 200-360 rpm. The extrudates were stored at 4 °C for 120 h and then at room temperature. The water absorption, solubility index, RS content, viscoelastic, thermal, and microstructural properties of the extrudates were evaluated before and after storage. The extrusion temperature and moisture content significantly affected the physicochemical properties of the extrudates before and after storage. The RS content increased with increasing moisture content and extrusion temperature, and the viscoelastic and thermal properties showed related behaviors. Microscopic analysis showed that extrusion cooking damaged the native starch structure, producing gelatinization and retrogradation and forming RS. The starch containing 35% moisture and extruded at 120 °C and 320 rpm produced the most RS (1.13 g/100 g) after to storage at low temperature. Although the RS formation was low, the results suggest that extrusion cooking could be advantageous for RS production and application in the food industry since it is a pollution less, continuous process requiring only a short residence time. PMID:27537864

  12. Instrumental and Sensory Texture Attributes of High-Protein Nutrition Bars Formulated with Extruded Milk Protein Concentrate.

    PubMed

    Banach, J C; Clark, S; Lamsal, B P

    2016-05-01

    Previous instrumental study of high-protein nutrition (HPN) bars formulated with extruded milk protein concentrate (MPC) indicated slower hardening compared to bars formulated with unmodified MPC. However, hardness, and its change during storage, insufficiently characterizes HPN bar texture. In this study, MPC80 was extruded at 2 different conditions and model HPN bars were prepared. A trained sensory panel and instrumental techniques were used to measure HPN bar firmness, crumbliness, fracturability, hardness, cohesiveness, and other attributes to characterize texture change during storage. Extrusion modification, storage temperature, and storage time significantly affected the instrumental and sensory panel measured texture attributes. The HPN bars became firmer and less cohesive during storage. When evaluated at the same storage conditions, the texture attributes of the HPN bars formulated with the different extrudates did not differ significantly from each other. However, textural differences were noted most of the time between the control and the HPN bars formulated with extruded MPC80. An adapted HPN bar crumbliness measurement technique produced results that were correlated with sensory panel measured crumbliness (r = 0.85) and cohesiveness (r = -0.84). Overall, the HPN bars formulated with extruded MPC80 were significantly softer, less crumbly, and more cohesive than the control during storage. PMID:27037608

  13. Effect of incorporation of corn byproducts on quality of baked and extruded products from wheat flour and semolina.

    PubMed

    Sharma, Savita; Gupta, Jatinder Pal; Nagi, H P S; Kumar, Rakesh

    2012-10-01

    The effect of blending level (0, 5, 10, 15 and 20%) of corn bran, defatted germ and gluten with wheat flour on the physico-chemical properties (protein, crude fiber, phosphorus, iron and calcium), baking properties of bread, muffins and cookies, and extrusion properties of noodles and extruded snacks prepared from semolina were examined. Blending of wheat flour and corn byproducts significantly increased the protein, crude fiber, phosphorus, iron and calcium contents. Breads from gluten blends had higher loaf volume as compared to bran and germ breads. Among corn byproducts, gluten cookies were rated superior with respect to top grain. Muffins from germ blends and gluten blends had higher acceptability scores than the bran muffins. Blending of corn bran, defatted germ and gluten at 5 and 10% with wheat flour resulted in satisfactory bread, cookie, and muffin score. Quality of noodles was significantly influenced by addition of corn byproducts and their levels. Corn byproducts blending had significant influence on cooking time, however, gruel solid loss affected non-significantly in case of noodles. Expansion ratio and density of extruded snacks was affected non significantly by blending source and blending level. However, significant effect was observed on amperage, pressure, yield and overall acceptability of extruded snacks. Acceptable extruded products (noodles and extruded snacks) could be produced by blending corn byproducts with semolina upto 10% level. PMID:24082269

  14. Development of extruded Ready-To-Eat (RTE) snacks using corn, black gram, roots and tuber flour blends.

    PubMed

    Reddy, M Kavya; Kuna, Aparna; Devi, N Lakshmi; Krishnaiah, N; Kaur, Charanjit; Nagamalleswari, Y

    2014-09-01

    Extruded RTE snacks were prepared from flour blends made with corn flour, Bengal gram flour, roots and tuber flours in a proportion of 60-80: 20: 20 respectively and moisture was adjusted to 17-20 %. The roots and tubers flours were developed from potato (Solanum tuberosum), yam (Dioscorea spp.), sweet potato (Ipomoea batatas L.), taro (Colocassia esculenta) and beet root (Beta vulgaris). Different formulations were extruded at 80 ± 5 °C (heater I) and 95-105 °C (heater II) temperature, 300-350 rpm screw speed, 100 ± 10 °C die temperature and 15 ± 2 kg/h feed rate. The exit diameter of the circular die was 3 mm. Sensory acceptability, physical parameters and nutrient analysis along with storage stability of the products was conducted. The fiber and energy content of the RTE extruded snack improved in experimental samples prepared using root and tuber flours. A serving of 100 g of the snack can provide more than 400 Kcal and 10 g of protein. The overall acceptability of RTE extruded products made with potato and taro were highly acceptable compared to yam and sweet potato. The study demonstrates utilization of roots and tuber flours as potential and diverse ingredients to enhance the appearance and nutritional properties in RTE extruded snack. PMID:25190848

  15. Column and Plate Compressive Strengths of Aircraft Structural Materials: Extruded 24S-T Aluminum Alloy

    NASA Technical Reports Server (NTRS)

    Heimerl, George J.; Roy, J Albert

    1945-01-01

    Column and plate compressive strengths of extruded 24S-T aluminum alloy were determined both within and beyond the elastic range from tests of thin-strip columns and local-instability tests of H-, Z-,and channel-section columns. These tests are part of an extensive research investigation to provide data on the' structural strength of various aircraft materials. The results are presented in the form of curves and charts that are suitable for use in the design and analysis of aircraft structures.

  16. Microstructure and properties of cryomilled nickel aluminide extruded with chromium or molybdenum

    NASA Technical Reports Server (NTRS)

    Aikin, Beverly J. M.; Dickerson, Robert M.; Dickerson, Patricia O.

    1995-01-01

    Previous results from high energy, attrition milled NiAl in liquid nitrogen (cryomilled) indicate that this process can produce high temperature, creep resistant AlN particulate reinforced materials. However, the low temperature toughness of such materials is below that preferred for structural applications in aerospace engines. In order to improve the toughness of these materials, prealloyed nickel aluminide (Ni-53 atomic percent Al) powder was cryomilled and mixed with chromium or molybdenum powders. The resulting materials were hot extruded and tested for room temperature toughness and 1300 K compressive strength.

  17. Plastification of polymers in twin-screw-extruders: New visualization technic using high-speed imaging

    NASA Astrophysics Data System (ADS)

    Knieper, A.; Beinert, C.

    2014-05-01

    The initial melting of the first granules through plastic energy dissipation (PED) at the beginning of the melting zone, in the co-rotating twin-screw extruder is visualized in this work. The visualization was created through the use of a high speed camera in the cross section of the melting zone. The parameters screw speed, granule-temperature, temperature-profile, type of polymer and back pressure were examined. It was shown that the screw speed and the temperature-profile have significant influence on the rate of initial melting.

  18. Two-layer flow of polymer melts in extruder die channel

    NASA Astrophysics Data System (ADS)

    Sharafutdinov, R. F.; Snigerev, B. A.; Galimov, E. R.; Galimova, N. Ya

    2016-06-01

    The paper discusses numerical modeling of two-layer flow of viscous non-Newtonian fluids in extruder die channels. Fluid motion is described by mass and momentum conservation equations supplemented by the rheological equation of state of a viscous non-Newtonian fluid according to the Carreau model. Technique of numerical solution of the problem based on the finite element method is presented. Distribution pattern of fluid velocities, pressure, stresses, positions of the interface in the two-layer flow depending on the rheological properties of a fluid and flow regimes is investigated.

  19. Indomethacin-Kollidon VA64 Extrudates: A Mechanistic Study of pH-Dependent Controlled Release.

    PubMed

    Tres, Francesco; Treacher, Kevin; Booth, Jonathan; Hughes, Leslie P; Wren, Stephen A C; Aylott, Jonathan W; Burley, Jonathan C

    2016-03-01

    Because of its weakly acidic nature (pKa of 4.5), indomethacin presents an aqueous solubility that significantly increases when changing from acidic to neutral/alkaline pH (1.5 μg/mL at pH 1.2 and 105.2 μg/mL at pH 7.4). We have therefore investigated the impact of the dissolution medium pH on the dissolution performance of indomethacin:Kollidon VA64 extrudates. The impact of the drug loading on the dissolution properties of these systems was also examined (5%, 15%, 30%, 50%, 70%, and 90% drug loading). Time-resolved Raman spectroscopy along with in-line UV-vis spectrophotometry was employed to directly relate changes in dissolution behavior to physicochemical changes that occur to the extrudate during the test. The dissolution tests were performed in pH 2 HCl (to mimic the stomach conditions), and this was then switched during the experiment to pH 6.8 phosphate buffer (to simulate the poststomach conditions). The rotating disc dissolution rate test was also used to simultaneously measure the dissolution rate of both the drug and the polymer. We found that in pH 2 HCl buffer, for the 15% or higher drug-loaded extrudates, Kollidon VA64 preferentially dissolves from the exterior of the compact leaving an amorphous drug-rich hydrophobic shell, which, similarly to an enteric coating, inhibits the drug release. The in situ formation of an enteric coating has been previously hypothesized, and this has been the first time that is directly observed in a pH-variable dissolution test. The dissolution medium switch to pH 6.8 phosphate buffer, due to the large increase of the aqueous solubility of indomethacin at this pH, leads to rapid dissolution of the material forming the coating and therefore total drug release. In contrast, the 5% extrudate is fully hydrated and quickly dissolves at low pH pointing to a dissolution performance dependent on highly water-soluble Kollidon VA64. PMID:26845251

  20. Plastification of polymers in twin-screw-extruders: New visualization technic using high-speed imaging

    SciTech Connect

    Knieper, A. E-mail: Christian.Beinert@lbf.fraunhofer.de; Beinert, C. E-mail: Christian.Beinert@lbf.fraunhofer.de

    2014-05-15

    The initial melting of the first granules through plastic energy dissipation (PED) at the beginning of the melting zone, in the co-rotating twin-screw extruder is visualized in this work. The visualization was created through the use of a high speed camera in the cross section of the melting zone. The parameters screw speed, granule-temperature, temperature-profile, type of polymer and back pressure were examined. It was shown that the screw speed and the temperature-profile have significant influence on the rate of initial melting.

  1. Column and Plate Compressive Strengths of Aircraft Structural Martials Extruded 0-1HTA Magnesium Alloy

    NASA Technical Reports Server (NTRS)

    Heimerl, George J; Niles, Donald E

    1947-01-01

    Column and plate compressive strengths of extruded 0-1HTA magnesium alloy were determined both within and beyond the elastic range from tests of flat end H-section columns and from local instability tests of H-, Z-, and channel section columns. These tests are part of an extensive research investigation to provide data on the structural strength of various aircraft materials. The results are presented in the form of curves and charts that are suitable for use in the design and analysis of aircraft structures.

  2. Surface modification of silica nanoparticles

    NASA Astrophysics Data System (ADS)

    Ranjan, Rajesh

    Surface modification of nanosized silica particles by polymer grafting is gaining attention. This can be attributed to the fact that it provides a unique opportunity to engineer the interfacial properties of these modified particles; at the same time the mechanical and thermal properties of the polymers can be improved. Controlled free radical polymerization is a versatile technique which affords control over molecular weight, molecular weight distribution, architecture and functionalities of the resulting polymer. Three commonly used controlled free radical polymerizations include nitroxide-mediated polymerization (NMP), atom transfer radical polymerization (ATRP) and reversible addition fragmentation transfer (RAFT) polymerization. ATRP and RAFT polymerization were explored in order to modify the silica surface with well-defined polymer brushes. A novel click-functionalized RAFT chain transfer agent (RAFT CTA) was synthesized which opened up the possibility of using RAFT polymerization and click chemistry together in surface modification. Using this RAFT CTA, the surface of silica nanoparticles was modified with polystyrene and polyacrylamide brushes via the "grafting to" approach. Both tethered polystyrene and polyacrylamide chains were found in the brush regime. The combination of ATRP and click chemistry was also explored for surface modification. A combination of RAFT polymerization and click chemistry was also studied to modify the surface via the "grafting from" approach. Our strategy included the (1) "grafting from" approach for brush formation (2) facile click reaction to immobilize the RAFT agent (3) synthesis of R-supported chain transfer agent and (4) use of the more active trithiocarbonate RAFT agent. Grafting density obtained by this method was significantly higher than reported values in the literature. Polystyrene (PS) grafted silica nanoparticles were also prepared by a tandem process that simultaneously employs reversible addition fragmentation

  3. Precipitated silica as flow regulator.

    PubMed

    Müller, Anne-Kathrin; Ruppel, Joanna; Drexel, Claus-Peter; Zimmermann, Ingfried

    2008-08-01

    Flow regulators are added to solid pharmaceutical formulations to improve the flow properties of the powder mixtures. The primary particles of the flow regulators exist in the form of huge agglomerates which are broken down into smaller aggregates during the blending process. These smaller aggregates adsorb at the surface of the solid's grains and thus diminish attractive Van-der-Waals-forces by increasing the roughness of the host's surface. In most cases amorphous silica is used as flow additive but material properties like particle size or bond strength influence the desagglomeration tendency of the agglomerates and thus the flow regulating potency of each silica. For some silica types we will show that the differences in their flow regulating potency are due to the rate and extent by which they are able to cover the surface of the host particles. Binary powder mixtures consisting of a pharmaceutical excipient and an added flow regulator were blended in a Turbula mixer for a defined period of time. As pharmaceutical excipient corn starch was used. The flow regulators were represented by a selection of amorphous silicon dioxide types like a commercial fumed silica and various types of SIPERNAT precipitated silica provided by Evonik-Degussa GmbH, Hanau, Germany. Flowability parameters of the mixtures were characterized by means of a tensile strength tester. The reduction of tensile strength with the blending time can be correlated with an increase in fragmentation of the flow regulator. PMID:18595668

  4. Exposure to crystalline silica in abrasive blasting operations where silica and non-silica abrasives are used.

    PubMed

    Radnoff, Diane L; Kutz, Michelle K

    2014-01-01

    Exposure to respirable crystalline silica is a hazard common to many industries in Alberta but particularly so in abrasive blasting. Alberta occupational health and safety legislation requires the consideration of silica substitutes when conducting abrasive blasting, where reasonably practicable. In this study, exposure to crystalline silica during abrasive blasting was evaluated when both silica and non-silica products were used. The crystalline silica content of non-silica abrasives was also measured. The facilities evaluated were preparing metal products for the application of coatings, so the substrate should not have had a significant contribution to worker exposure to crystalline silica. The occupational sampling results indicate that two-thirds of the workers assessed were potentially over-exposed to respirable crystalline silica. About one-third of the measurements over the exposure limit were at the work sites using silica substitutes at the time of the assessment. The use of the silica substitute, by itself, did not appear to have a large effect on the mean airborne exposure levels. There are a number of factors that may contribute to over-exposures, including the isolation of the blasting area, housekeeping, and inappropriate use of respiratory protective equipment. However, the non-silica abrasives themselves also contain silica. Bulk analysis results for non-silica abrasives commercially available in Alberta indicate that many contain crystalline silica above the legislated disclosure limit of 0.1% weight of silica per weight of product (w/w) and this information may not be accurately disclosed on the material safety data sheet for the product. The employer may still have to evaluate the potential for exposure to crystalline silica at their work site, even when silica substitutes are used. Limited tests on recycled non-silica abrasive indicated that the silica content had increased. Further study is required to evaluate the impact of product recycling

  5. Admicellar polymerization of precipated silica

    SciTech Connect

    Reynolds, J.L.; Grady, B.P.; Harwell, J.H.

    1996-10-01

    The tendency of a surfactant molecule to adsorb at a solid-liquid interface is the basis for an in situ surface modification process, termed admicellar polymerization. The four-step admicellar polymerization process includes: (1) adsorption of surfactant at the solid-liquid interface, (2) adsolubilization of monomer into the surfactant bilayer, (3) polymerization using free-radical initiators and heat, (4) removal of excess surfactant to expose the polymer modified surface. The process is used to apply polymer to precipitated silica to enhance the compatibility of the silica when added to filled rubber. The adsorption isotherms were first determined for particular surfactant/silica combinations to find the surfactant concentration that would sufficiently adsolubilize the monomer, while remaining below the critical micelle concentration. A series of experiments were then devised for the polymerization reactions in which the surfactant and monomer amounts were varied over three levels to establish the optimal combination.

  6. Optimization of light yield by injecting an optical filler into the co-extruded hole of the plastic scintillation bar

    NASA Astrophysics Data System (ADS)

    Artikov, A.; Baranov, V.; Budagov, Ju.; Chokheli, D.; Davydov, Yu.; Glagolev, V.; Kharzheev, Yu.; Kolomoetz, V.; Shalugin, A.; Simonenko, A.; Tereshchenko, V.

    2016-05-01

    The light yield of 2-m long extruded scintillation bars (strips) are measured with cosmic muons as a function of the distance for different options of the light collection technique. The strips with a 2.6-mm diameter central co-extruded hole were made of polystyrene with the 2% PTP and 0.03% POPOP dopants at ISMA (Kharkov, Ukraine). It is shown that the optical transparent BC-600 or CKTN-MED(E) resin injected by a special technique into the co-extruded hole with a 1.0-mm or 1.2-mm Kuraray Y11 (200) MC wave-length shifting (WLS) fiber in it improves light collection by a factor of 1.6–1.9 against the ``dry'' case.

  7. Effect of selected dehulled legume incorporation on functional and nutritional properties of protein enriched sorghum and wheat extrudates.

    PubMed

    Balasubramanian, Subramanian; Borah, A; Singh, K K; Patil, R T

    2012-10-01

    The effect of legume incorporation (5%, 10% and 15%) on functional and nutritional properties of sorghum and wheat extrudates was investigated. Sorghum extrudates incorporated with legumes showed lower water absorption index water solubility index and pasting properties viz., peak viscosity, minimum viscosity, breakdown viscosity, final viscosity and total set back and similar degree of gelatinization and nutritional profile. At 15% incorporation level, water absorption index and water solubility index found to be maximum while degree of gelatinization and all the pasting properties showed lowest values for both sorghum and wheat extrudates. Similarly nutritional profile observed to be significantly higher for 15% as compared to 10% and 15% incorporation levels. Incorporation of legumes at 15% could be effective in producing high energy dense food products having better functional and nutritional properties. PMID:24082268

  8. 21 CFR 584.700 - Hydrophobic silicas.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...: (i) Amorphous fumed hydrophobic silica: Not less than 99.0 percent silicon dioxide after ignition... dichlorodimethylsilane. (ii) Precipated hydrophobic silica: Not less than 94.0 percent silicon dioxide after...

  9. Physisorbed Water on Silica at Mars Temperatures

    NASA Technical Reports Server (NTRS)

    Sutter, B.; Sriwatanapongse, W.; Quinn, R.; Klug, C.; Zent, A.

    2002-01-01

    The usefulness of nuclear magnetic resonance spectroscopy in probing water interactions on silica at Mars temperatures is discussed. Results indicate that two types of water occur with silica at Mars temperatures. Additional information is contained in the original extended abstract.

  10. Photon stimulated desorption measurement of an extruded aluminum beam chamber for the Advanced Photon Source

    SciTech Connect

    Foerster, C.L.; Lanni, C.; Noonan, J.R.; Rosenberg, R.A.

    1995-12-31

    The Advanced Photon Source (APS), presently being commisioned, will produce X-ray s of unprecedented brightness. The high energy ring of the APS is a 7 GeV positron storage ring, 1104 meters in circumference designed to operate at less than 10{sup {minus}9} Torr with 300 ma of beam and a greater than 10 hour lifetime. The storage ring vacuum chamber is constructed from an extruded 6063 aluminum alloy. During the construction phase, a 2.34 m long section of the APS extruded aluminum chamber was set up on National Synchrotron Light Source (NSLS) X-ray Beamlline X28A and Photon Stimulated Desorption (PSD) was measured. Cleaning and preparation of the chamber was identical to that of the APS construction. In addition to the chamber, small samples of M, Be, and Cu were also exposed to white light having a critical energy of 5 keV. In addition to PSD, measurements were made of specular and diffuse scattering of photons. The chamber and samples were each exposed to a dose greater than 10{sup 23} photons per meter. Desorption yields for H{sub 2}, CO, CO{sub 2}, CH{sub 4} and H{sub 2}0 are reported as a function of accumulated flux, critical energy, incidence angle, and preparation. These results are compared with previous results for aluminum on NSLS Beamlline U1OB and PSD results of other laboratories published for aluminum.