Ceramic gas turbine shroud

DOEpatents

Shi, Jun; Green, Kevin E.

2014-07-22

An example gas turbine engine shroud includes a first annular ceramic wall having an inner side for resisting high temperature turbine engine gasses and an outer side with a plurality of radial slots. A second annular metallic wall is positioned radially outwardly of and enclosing the first annular ceramic wall and has a plurality of tabs in communication with the slot of the first annular ceramic wall. The tabs of the second annular metallic wall and slots of the first annular ceramic wall are in communication such that the first annular ceramic wall and second annular metallic wall are affixed.

Floating air riding seal for a turbine

DOEpatents

Ebert, Todd A

2016-08-16

A floating air riding seal for a gas turbine engine with a rotor and a stator, an annular piston chamber with an axial moveable annular piston assembly within the annular piston chamber formed in the stator, an annular cavity formed on the annular piston assembly that faces a seal surface on the rotor, where the axial moveable annular piston includes an inlet scoop on a side opposite to the annular cavity that scoops up the swirling cooling air and directs the cooling air to the annular cavity to form an air cushion with the seal surface of the rotor.

Fuel Pin Behavior Under the Slow Power Ramp Transients in the CABRI-2 Experiments

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

Charpenel, Jean; Lemoine, Francette; Sato, Ikken

Slow ramp-type transient-overpower tests were performed within the framework of the international CABRI-2 experimental program. The implemented power transients of {approx}1% nominal power/s correspond to a control rod withdrawal-type accident in a liquid-metal-cooled fast breeder reactor (FBR). The analysis of the tests includes the information elements derived from the hodoscope signals, which were assessed quantitatively and supported by destructive and nondestructive posttest examinations. These tests, performed with fuels of various geometries, demonstrated the high margin to failure of such FBR fuel pins within the expected power level before the emergency reactor shutdown. At the same time, these tests performed withmore » high- and low-smear-density industrial pins led to clarification of the influence of pellet design on fuel pin behavior under high overpower condition. With the high-smear-density solid fuel pellet pin of high burnup level, the retained gaseous fission products played an important role in the solid fuel swelling, leading to clad deformation and failure at a maximum heating rate of 81 kW.m{sup -1}, which is much greater than the end-of-life (EOL) linear rating of the pin. With the low smear-density annular pellet pin, an important fuel swelling takes place, leading to degradation of the fuel thermal conductivity. This effect was detected at the power level around 73 kW.m{sup -1}, which is also much higher than the EOL value of the pin. Furthermore, the absence of clad deformation, and consequently of failure even at the power level going up to 134.7 kW.m{sup -1}, confirmed the very high margin to failure. In consequence, it was clarified that gaseous fission products have significant effects on failure threshold as well as on thermal performance during overpower condition, and such effects are significantly dependent on fuel design and power operation conditions.« less

Link module for a downhole drilling network

DOEpatents

Hall, David R [Provo, UT; Fox, Joe [Provo, UT

2007-05-29

A repeater is disclosed in one embodiment of the present invention as including a cylindrical housing, characterized by a proximal end and a distal end, and having a substantially cylindrical wall, the cylindrical wall defining a central bore passing therethrough. The cylindrical housing is formed to define at least one recess in the cylindrical wall, into which a repeater is inserted. The cylindrical housing also includes an annular recess formed into at least one of the proximal end and the distal end. An annular transmission element, operably connected to the repeater, is located in the annular recess. In selected embodiments, the annular transmission element inductively converts electrical energy to magnetic energy. In other embodiments, the annular transmission element includes an electrical contact to transmit electrical energy directly to another contact.

Improved Electrical Contact For Dowhhole Drilling Networks

DOEpatents

Hall, David R.; Hall, Jr., H. Tracy; Pixton, David S.; Dahlgren, Scott; Fox, Joe; Sneddon, Cameron

2005-08-16

An electrical contact system for transmitting information across tool joints while minimizing signal reflections that occur at the tool joints includes a first electrical contact comprising an annular resilient material. An annular conductor is embedded within the annular resilient material and has a surface exposed from the annular resilient material. A second electrical contact is provided that is substantially equal to the first electrical contact. Likewise, the second electrical contact has an annular resilient material and an annular conductor. The two electrical contacts configured to contact one another such that the annular conductors of each come into physical contact. The annular resilient materials of each electrical contact each have dielectric characteristics and dimensions that are adjusted to provide desired impedance to the electrical contacts.

Three cases of subcutaneous granuloma annulare of the penis: a rare presentation of a common disease.

PubMed

Toepfer, Nicholas J; Wessner, Scott R; Elston, Dirk M; Simmons, Jennifer; Sumfest, Joel M

2011-09-01

To describe three patients who presented to a single institution within four years of each other with isolated granuloma annulare of the penis. Granuloma annulare is an inflammatory disease of the dermis that can affect men of any age including childhood. Granuloma annulare of the penis is a remarkably uncommon presentation with only 12 cases previously reported. A retrospective review of pathologic records was conducted confirming three cases of penile granuloma annulare diagnosed at our institution. The three cases are described in detail including the history, presentation, histological findings and treatment of each patient. The clinical variants, characteristic histology, classic clinical presentation, differential diagnosis and recurrence following surgery of granuloma annulare are reviewed. We describe three individuals from a single institution with isolated granuloma annulare of the penis suggesting this condition is more common than previously thought. Patients with penile granuloma annulare may present to practicing urologists and it is important to be familiar with this idiopathic subcutaneous disorder in order to avoid unnecessary aggressive surgery. Copyright © 2011 Elsevier Inc. All rights reserved.

Ingestion resistant seal assembly

DOEpatents

Little, David A [Chuluota, FL

2011-12-13

A seal assembly limits gas leakage from a hot gas path to one or more disc cavities in a gas turbine engine. The seal assembly includes a seal apparatus associated with a blade structure including a row of airfoils. The seal apparatus includes an annular inner shroud associated with adjacent stationary components, a wing member, and a first wing flange. The wing member extends axially from the blade structure toward the annular inner shroud. The first wing flange extends radially outwardly from the wing member toward the annular inner shroud. A plurality of regions including one or more recirculation zones are defined between the blade structure and the annular inner shroud that recirculate working gas therein back toward the hot gas path.

Fast-Acting Valve

NASA Technical Reports Server (NTRS)

Wojciechowski, Bogdan V. (Inventor); Pegg, Robert J. (Inventor)

2003-01-01

A fast-acting valve includes an annular valve seat that defines an annular valve orifice between the edges of the annular valve seat, an annular valve plug sized to cover the valve orifice when the valve is closed, and a valve-plug holder for moving the annular valve plug on and off the annular valve seat. The use of an annular orifice reduces the characteristic distance between the edges of the valve seat. Rather than this distance being equal to the diameter of the orifice, as it is for a conventional circular orifice, the characteristic distance equals the distance between the inner and outer radii (for a circular annulus). The reduced characteristic distance greatly reduces the gap required between the annular valve plug and the annular valve seat for the valve to be fully open, thereby greatly reducing the required stroke and corresponding speed and acceleration of the annular valve plug. The use of a valve-plug holder that is under independent control to move the annular valve plug between its open and closed positions is important for achieving controllable fast operation of the valve.

Damping device for a stationary labyrinth seal

NASA Technical Reports Server (NTRS)

El-Aini, Yehia M. (Inventor); Mitchell, William S. (Inventor); Roberts, Lawrence P. (Inventor); Montgomery, Stuart K. (Inventor); Davis, Gary A. (Inventor)

2010-01-01

A stationary labyrinth seal system includes a seal housing having an annular cavity, a plurality of damping devices, and a retaining ring. The damping devices are positioned within the annular cavity and are maintained within the annular cavity by the retaining ring.

Design of a fuel element for a lead-cooled fast reactor

NASA Astrophysics Data System (ADS)

Sobolev, V.; Malambu, E.; Abderrahim, H. Aït

2009-03-01

The options of a lead-cooled fast reactor (LFR) of the fourth generation (GEN-IV) reactor with the electric power of 600 MW are investigated in the ELSY Project. The fuel selection, design and optimization are important steps of the project. Three types of fuel are considered as candidates: highly enriched Pu-U mixed oxide (MOX) fuel for the first core, the MOX containing between 2.5% and 5.0% of the minor actinides (MA) for next core and Pu-U-MA nitride fuel as an advanced option. Reference fuel rods with claddings made of T91 ferrite-martensitic steel and two alternative fuel assembly designs (one uses a closed hexagonal wrapper and the other is an open square variant without wrapper) have been assessed. This study focuses on the core variant with the closed hexagonal fuel assemblies. Based on the neutronic parameters provided by Monte-Carlo modeling with MCNP5 and ALEPH codes, simulations have been carried out to assess the long-term thermal-mechanical behaviour of the hottest fuel rods. A modified version of the fuel performance code FEMAXI-SCK-1, adapted for fast neutron spectrum, new fuels, cladding materials and coolant, was utilized for these calculations. The obtained results show that the fuel rods can withstand more than four effective full power years under the normal operation conditions without pellet-cladding mechanical interaction (PCMI). In a variant with solid fuel pellets, a mild PCMI can appear during the fifth year, however, it remains at an acceptable level up to the end of operation when the peak fuel pellet burnup ∼80 MW d kg-1 of heavy metal (HM) and the maximum clad damage of about 82 displacements per atom (dpa) are reached. Annular pellets permit to delay PCMI for about 1 year. Based on the results of this simulation, further steps are envisioned for the optimization of the fuel rod design, aiming at achieving the fuel burnup of 100 MW d kg-1 of HM.

Polished Downhole Transducer Having Improved Signal Coupling

DOEpatents

Hall, David R.; Fox, Joe

2006-03-28

Apparatus and methods to improve signal coupling in downhole inductive transmission elements to reduce the dispersion of magnetic energy at the tool joints and to provide consistent impedance and contact between transmission elements located along the drill string. A transmission element for transmitting information between downhole tools is disclosed in one embodiment of the invention as including an annular core constructed of a magnetically conductive material. The annular core forms an open channel around its circumference and is configured to form a closed channel by mating with a corresponding annular core along an annular mating surface. The mating surface is polished to provide improved magnetic coupling with the corresponding annular core. An annular conductor is disposed within the open channel.

Statistical assessment of normal mitral annular geometry using automated three-dimensional echocardiographic analysis.

PubMed

Pouch, Alison M; Vergnat, Mathieu; McGarvey, Jeremy R; Ferrari, Giovanni; Jackson, Benjamin M; Sehgal, Chandra M; Yushkevich, Paul A; Gorman, Robert C; Gorman, Joseph H

2014-01-01

The basis of mitral annuloplasty ring design has progressed from qualitative surgical intuition to experimental and theoretical analysis of annular geometry with quantitative imaging techniques. In this work, we present an automated three-dimensional (3D) echocardiographic image analysis method that can be used to statistically assess variability in normal mitral annular geometry to support advancement in annuloplasty ring design. Three-dimensional patient-specific models of the mitral annulus were automatically generated from 3D echocardiographic images acquired from subjects with normal mitral valve structure and function. Geometric annular measurements including annular circumference, annular height, septolateral diameter, intercommissural width, and the annular height to intercommissural width ratio were automatically calculated. A mean 3D annular contour was computed, and principal component analysis was used to evaluate variability in normal annular shape. The following mean ± standard deviations were obtained from 3D echocardiographic image analysis: annular circumference, 107.0 ± 14.6 mm; annular height, 7.6 ± 2.8 mm; septolateral diameter, 28.5 ± 3.7 mm; intercommissural width, 33.0 ± 5.3 mm; and annular height to intercommissural width ratio, 22.7% ± 6.9%. Principal component analysis indicated that shape variability was primarily related to overall annular size, with more subtle variation in the skewness and height of the anterior annular peak, independent of annular diameter. Patient-specific 3D echocardiographic-based modeling of the human mitral valve enables statistical analysis of physiologically normal mitral annular geometry. The tool can potentially lead to the development of a new generation of annuloplasty rings that restore the diseased mitral valve annulus back to a truly normal geometry. Copyright © 2014 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

Gas turbine sealing apparatus

DOEpatents

Wiebe, David J; Wessell, Brian J; Ebert, Todd; Beeck, Alexander; Liang, George; Marussich, Walter H

2013-02-19

A gas turbine includes forward and aft rows of rotatable blades, a row of stationary vanes between the forward and aft rows of rotatable blades, an annular intermediate disc, and a seal housing apparatus. The forward and aft rows of rotatable blades are coupled to respective first and second portions of a disc/rotor assembly. The annular intermediate disc is coupled to the disc/rotor assembly so as to be rotatable with the disc/rotor assembly during operation of the gas turbine. The annular intermediate disc includes a forward side coupled to the first portion of the disc/rotor assembly and an aft side coupled to the second portion of the disc/rotor assembly. The seal housing apparatus is coupled to the annular intermediate disc so as to be rotatable with the annular intermediate disc and the disc/rotor assembly during operation of the gas turbine.

Durable regenerable sorbent pellets for removal of hydrogen sulfide from coal gas

DOEpatents

Siriwardane, R.V.

1999-02-02

Pellets for removing hydrogen sulfide from a coal gasification stream at an elevated temperature are prepared in durable form, usable over repeated cycles of absorption and regeneration. The pellets include a material reactive with hydrogen sulfide, in particular zinc oxide, a binder, and an inert material, in particular calcium sulfate (drierite), having a particle size substantially larger than other components of the pellets. A second inert material and a promoter may also be included. Preparation of the pellets may be carried out by dry, solid-state mixing of components, moistening the mixture, and agglomerating it into pellets, followed by drying and calcining. Pellet size is selected, depending on the type of reaction bed for which the pellets are intended. The use of inert material with a large particle size provides a stable pellet structure with increased porosity, enabling effective gas contact and prolonged mechanical durability.

Durable regenerable sorbent pellets for removal of hydrogen sulfide from coal gas

DOEpatents

Siriwardane, R.V.

1997-12-30

Pellets for removing hydrogen sulfide from a coal gasification stream at an elevated temperature are prepared in durable form usable over repeated cycles of absorption and regeneration. The pellets include a material reactive with hydrogen sulfide, in particular zinc oxide, a binder, and an inert material, in particular calcium sulfate (drierite), having a particle size substantially larger than other components of the pellets. A second inert material and a promoter may also be included. Preparation of the pellets may be carried out by dry, solid-state mixing of components, moistening the mixture, and agglomerating it into pellets, followed by drying and calcining. Pellet size is selected, depending on the type of reaction bed for which the pellets are intended. The use of inert material with a large particle size provides a stable pellet structure with increased porosity, enabling effective gas contact and prolonged mechanical durability.

Durable regenerable sorbent pellets for removal of hydrogen sulfide from coal gas

DOEpatents

Siriwardane, Ranjani V.

1997-01-01

Pellets for removing hydrogen sulfide from a coal gasification stream at an elevated temperature are prepared in durable form usable over repeated cycles of absorption and regeneration. The pellets include a material reactive with hydrogen sulfide, in particular zinc oxide, a binder, and an inert material, in particular calcium sulfate (drierite), having a particle size substantially larger than other components of the pellets. A second inert material and a promoter may also be included. Preparation of the pellets may be carried out by dry, solid-state mixing of components, moistening the mixture, and agglomerating it into pellets, followed by drying and calcining. Pellet size is selected, depending on the type of reaction bed for which the pellets are intended. The use of inert material with a large particle size provides a stable pellet structure with increased porosity, enabling effective gas contact and prolonged mechanical durability.

Durable regenerable sorbent pellets for removal of hydrogen sulfide coal gas

DOEpatents

Siriwardane, Ranjani V.

1999-01-01

Pellets for removing hydrogen sulfide from a coal gasification stream at an elevated temperature are prepared in durable form, usable over repeated cycles of absorption and regeneration. The pellets include a material reactive with hydrogen sulfide, in particular zinc oxide, a binder, and an inert material, in particular calcium sulfate (drierite), having a particle size substantially larger than other components of the pellets. A second inert material and a promoter may also be included. Preparation of the pellets may be carried out by dry, solid-state mixing of components, moistening the mixture, and agglomerating it into pellets, followed by drying and calcining. Pellet size is selected, depending on the type of reaction bed for which the pellets are intended. The use of inert material with a large particle size provides a stable pellet structure with increased porosity, enabling effective gas contact and prolonged mechanical durability.

Annular Solar Eclipse of 10 May 1994

NASA Technical Reports Server (NTRS)

Espenak, Fred; Anderson, Jay

1993-01-01

An annular eclipse of the Sun will be widely visible from the Western Hemisphere on 10 May 1994. The path of the Moon's shadow passes through Mexico, the United States of America, maritime Canada, the North Atlantic, the Azores and Morocco. Detailed predictions for this event are presented and include tables of geographic coordinates of the annular path, local circumstances for hundreds of cities, maps of the path of annular and partial eclipse, weather prospects, and the lunar limb profile.

Electron beam diagnostic system using computed tomography and an annular sensor

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

Elmer, John W.; Teruya, Alan T.

2015-08-11

A system for analyzing an electron beam including a circular electron beam diagnostic sensor adapted to receive the electron beam, the circular electron beam diagnostic sensor having a central axis; an annular sensor structure operatively connected to the circular electron beam diagnostic sensor, wherein the sensor structure receives the electron beam; a system for sweeping the electron beam radially outward from the central axis of the circular electron beam diagnostic sensor to the annular sensor structure wherein the electron beam is intercepted by the annular sensor structure; and a device for measuring the electron beam that is intercepted by themore » annular sensor structure.« less

Electron beam diagnostic system using computed tomography and an annular sensor

DOEpatents

Elmer, John W.; Teruya, Alan T.

2014-07-29

A system for analyzing an electron beam including a circular electron beam diagnostic sensor adapted to receive the electron beam, the circular electron beam diagnostic sensor having a central axis; an annular sensor structure operatively connected to the circular electron beam diagnostic sensor, wherein the sensor structure receives the electron beam; a system for sweeping the electron beam radially outward from the central axis of the circular electron beam diagnostic sensor to the annular sensor structure wherein the electron beam is intercepted by the annular sensor structure; and a device for measuring the electron beam that is intercepted by the annular sensor structure.

Inductive coupler for downhole components and method for making same

DOEpatents

Hall, David R.; Hall, Jr., H. Tracy; Pixton, David S.; Dahlgren, Scott; Briscoe, Michael A.; Sneddon, Cameron; Fox, Joe

2006-05-09

The present invention includes a method of making an inductive coupler for downhole components. The method includes providing an annular housing, preferably made of steel, the housing having a recess. A conductor, preferably an insulated wire, is also provided along with a plurality of generally U-shaped magnetically conducting, electrically insulating (MCEI) segments. Preferably, the MCEI segments comprise ferrite. An assembly is formed by placing the plurality of MCEI segments within the recess in the annular housing. The segments are aligned to form a generally circular trough. A first portion of the conductor is placed within the circular trough. This assembly is consolidated with a meltable polymer which fills spaces between the segments, annular housing and the first portion of the conductor. The invention also includes an inductive coupler including an annular housing having a recess defined by a bottom portion and two opposing side wall portions. At least one side wall portion includes a lip extending toward but not reaching the other side wall portion. A plurality of generally U-shaped MCEI segments, preferably comprised of ferrite, are disposed in the recess and aligned so as to form a circular trough. The coupler further includes a conductor disposed within the circular trough and a polymer filling spaces between the segments, the annular housing and the conductor.

Probe with integrated heater and thermocouple pack

DOEpatents

McCulloch, Reg W.; Dial, Ralph E.; Finnell, Wilber K. R.

1990-01-01

A probe for measuring heat includes an elongate rod fitted within a sheath, and a plurality of annular recesses are formed on the surface of the rod in a spaced-apart relationship to form annular chambers that are resistant to heat flow. A longitudinal bore extends axially into the rod and within the cylinders defined by the annular chambers, and an integrated heater and thermocouple pack is dimensioned to fit within the bore. In construction, the integrated pack includes a plurality of wires disposed in electrical insulation within a sheath and a heater cable. These wires include one common wire and a plurality of thermocuple wires. The common wire is constructed of one type of conductive material while the thermocouple wires are each constructed of two types of materials so that at least one thermocouple junction is formed therein. All of the wires extend the length of the integrated pack and are connected together at their ends. The thermocouple wires are constructed to form thermocouple junctions proximate to each annular chamber for producing electromotive forces corresponding to the temperature of the rod within the annular chambers relative to outside the chambers. In the preferred embodiment, each thermocouple wire forms two thermocouple junctions, one junction being disposed within an annular chamber and the second junction being disposed outside of, but proximate to, the same annular chamber. In one embodiment two thermocouple wires are configured to double the sensitivity of the probe in one region.

Probe with integrated heater and thermocouple pack

DOEpatents

McCulloch, Reginald W.; Dial, Ralph E.; Finnell, Wilber K. R.

1988-01-01

A probe for measuring heat includes an elongate rod fitted within a sheath, and a plurality of annular recesses are formed on the surface of the rod in a spaced-apart relationship to form annular chambers that are resistant to heat flow. A longitudinal bore extends axially into the rod and within the cylinders defined by the annular chambers, and an integrated heater and thermocouple pack is dimensioned to fit within the bore. In construction, the integrated pack includes a plurality of wires disposed in electrical insulation within a sheath and a heater cable. These wires include one common wire and a plurality of thermocouple wires. The common wire is constructed of one type of conductive material while the thermocouple wires are each constructed of two types of materials so that at least one thermocouple junction is formed therein. All of the wires extend the length of the integrated pack and are connected together at their ends. The thermocouple wires are constructed to form thermocouple junctions proximate to each annular chamber for producing electromotive forces corresponding to the temperature of the rod within the annular chambers relative to outside the chambers. In the preferred embodiment, each thermocouple wire forms two thermocouple junctions, one junction being disposed within an annular chamber and the second junction being disposed outside of, but proximate to, the same annular chamber. In one embodiment two thermocouple wires are configured to double the sensitivity of the probe in one region.

Effect of hydrothermal carbonization on storage process of woody pellets: Pellets' properties and aldehydes/ketones emission.

PubMed

Li, Hui; Wang, Siyuan; Huang, Zhongliang; Yuan, Xingzhong; Wang, Ziliang; He, Rao; Xi, Yanni; Zhang, Xuan; Tan, Mengjiao; Huang, Jing; Mo, Dan; Li, Changzhu

2018-07-01

Effect of hydrothermal carbonization (HTC) on the hydrochar pelletization and the aldehydes/ketones emission from pellets during storage was investigated. Pellets made from the hydrochar were stored in sealed apparatuses for sampling. The energy consumption during pelletization and the pellets' properties before/after storage, including dimension, density, moisture content, hardness, aldehyde/ketones emission amount/rate and unsaturated fatty acid amount, were analyzed. Compared with untreated-sawdust-pellets, the hydrochar-pellets required more energy consumption for pelletization, and achieved the improved qualities, resulting in the higher stability degree during storage. The species and amount of unsaturated fatty acids in the hydrochar-pellets were higher than those in the untreated-sawdust-pellets. The unsaturated fatty acids content in the hydrochar-pellets was decreased with increasing HTC temperature. Higher aldehydes/ketones emission amount and rates with a longer emission period were found for the hydrochar-pellets, associated with variations of structure and unsaturated fatty acid composition in pellets. Copyright © 2018 Elsevier Ltd. All rights reserved.

Gas turbine combustor

NASA Technical Reports Server (NTRS)

Burd, Steven W. (Inventor); Cheung, Albert K. (Inventor); Dempsey, Dae K. (Inventor); Hoke, James B. (Inventor); Kramer, Stephen K. (Inventor); Ols, John T. (Inventor); Smith, Reid Dyer Curtis (Inventor); Sowa, William A. (Inventor)

2011-01-01

A gas turbine engine has a combustor module including an annular combustor having a liner assembly that defines an annular combustion chamber having a length, L. The liner assembly includes a radially inner liner, a radially outer liner that circumscribes the inner liner, and a bulkhead, having a height, H1, which extends between the respective forward ends of the inner liner and the outer liner. The combustor has an exit height, H3, at the respective aft ends of the inner liner and the outer liner interior. The annular combustor has a ratio H1/H3 having a value less than or equal to 1.7. The annular combustor may also have a ration L/H3 having a value less than or equal to 6.0.

Assembly for directing combustion gas

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

Charron, Richard C.; Little, David A.; Snyder, Gary D.

2016-04-12

An arrangement is provided for delivering gases from a plurality of combustors of a can-annular gas turbine combustion engine to a first row of turbine blades including a first row of turbine blades. The arrangement includes a gas path cylinder, a cone and an integrated exit piece (IEP) for each combustor. Each IEP comprises an inlet chamber for receiving a gas flow from a respective combustor, and includes a connection segment. The IEPs are connected together to define an annular chamber extending circumferentially and concentric to an engine longitudinal axis, for delivering the gas flow to the first row ofmore » blades. A radiused joint extends radially inward from a radially outer side of the inlet chamber to an outer boundary of the annular chamber, and a flared fillet extends radially inward from a radially inner side of the inlet chamber to an inner boundary of the annular chamber.« less

Development of a neutronics calculation method for designing commercial type Japanese sodium-cooled fast reactor

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

Takeda, T.; Shimazu, Y.; Hibi, K.

2012-07-01

Under the R and D project to improve the modeling accuracy for the design of fast breeder reactors the authors are developing a neutronics calculation method for designing a large commercial type sodium- cooled fast reactor. The calculation method is established by taking into account the special features of the reactor such as the use of annular fuel pellet, inner duct tube in large fuel assemblies, large core. The Verification and Validation, and Uncertainty Qualification (V and V and UQ) of the calculation method is being performed by using measured data from the prototype FBR Monju. The results of thismore » project will be used in the design and analysis of the commercial type demonstration FBR, known as the Japanese Sodium fast Reactor (JSFR). (authors)« less

Thermal protection system and related methods

NASA Technical Reports Server (NTRS)

Garbe, Duane J. (Inventor)

2012-01-01

A thermal protection system and a method of manufacturing are disclosed. The thermal protection system may be configured to protect a movable joint, for example, a flexible bearing of a rocket motor nozzle. The thermal protection system includes a series of annular shims separated by a plurality of discrete spacers. Each shim of the series of annular shims may have a larger diameter than the previous shim, and the shims may nest. The shims may comprise a thermally stable material, and the discrete spacers may comprise an elastomer. Optionally, an annular bearing protector may separate the annular shims from the flexible bearing.

Effect of pelleting process variables on physical properties and sugar yields of ammonia fiber expansion pretreated corn stover

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

Amber N. Hoover; Jaya Shankar Tumuluru; Farzaneh Teymouri

Pelletization process variables including grind size (4, 6 mm), die speed (40, 50, 60 Hz), and preheating (none, 70 degrees C) were evaluated to understand their effect on pellet quality attributes and sugar yields of ammonia fiber expansion (AFEX) pretreated biomass. The bulk density of the pelletized AFEX corn stover was three to six times greater compared to untreated and AFEX-treated corn stover. Also the durability of the pelletized AFEX corn stover was >97.5% for all pelletization conditions studied except for preheated pellets. Die speed had no effect on enzymatic hydrolysis sugar yields of pellets. Pellets produced with preheating ormore » a larger grind size (6 mm) had similar or lower sugar yields. Pellets generated with 4 mm AFEX-treated corn stover, a 60 Hz die speed, and no preheating resulted in pellets with similar or greater density, durability, and sugar yields compared to other pelletization conditions.« less

Arthroscopic Treatment of Annular Drive Through and Radial Lateral Collateral Ligament Articular-Side Tear of the Elbow.

PubMed

Arrigoni, Paolo; D'Ambrosi, Riccardo; Randelli, Pietro

2015-12-01

An elongation or partial articular-sided tear of the radial lateral collateral ligament (R-LCL) is a rare injury causing disability and instability of the elbow. In our experience this condition is often associated with a pathologic sign of the annular ligament named the "annular drive through" caused by a redundancy of the ligament. The benefits of performing an arthroscopic procedure for surgical stabilization of the R-LCL include smaller incisions with less soft-tissue dissection, better visualization of the joint, better repair accessibility, and elimination of the annular drive-through sign. The main steps of the operation are as follows: evaluation of annular drive through, inspection of the radial side of the joint, anterior capsulotomy, insertion of a suture anchor through the anterolateral portal, shuttling of the suture anchor through the ligament, and elimination of the annular drive-through sign. By use of this technique, it is possible to repair a lesion of the R-LCL with a suture anchor that ensures an anatomic repair and, at the same time, returns the annular ligament to its physiological tension.

Electric Propulsion Apparatus

NASA Technical Reports Server (NTRS)

Patterson, Michael J. (Inventor)

2013-01-01

An electric propulsion machine includes an ion thruster having an annular discharge chamber housing an anode having a large surface area. The ion thruster includes flat annular ion optics with a small span to gap ratio. Optionally, a second electric propulsion thruster may be disposed in a cylindrical space disposed within an interior of the annulus.

Material distribution in light water reactor-type bundles tested under severe accident conditions

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

Noack, V.; Hagen, S.J.L.; Hofmann, P.

1997-02-01

Severe fuel damage experiments simulating small-break loss-of-coolant accidents have been carried out in the CORA out-of-pile test facility at Forschungszentrum Karlsruhe. Rod bundles with electrically heated fuel rod simulators containing annular UO{sub 2} pellets, UO{sub 2} full pellet rods, and absorber rods of two kinds (Ag/In/Cd to represent pressurized water reactor conditions and B{sub 4}C to represent boiling water reactor and VVER-1000 fuel elements) were subjected to temperature transients up to 2,300 K. A special method was applied to determine the axial mass distribution of bundle materials. The low-temperature melt formation by various interactions between zirconium and components of absorbermore » and spacer grids strongly influences the bundle degradation and material relocation. Absorber materials can separate from the fuel by a noncoherent relocation of the materials at different temperatures. The distributions of solidified materials in the different test bundles show a clear dependence on the axial temperature profile. Coolant channel blockages are observed mainly at the lower end of the bundle, i.e., near the lowest elevation at which an oxidation excursion resulting from the highly exothermic zirconium-steam reaction had been experienced. This elevation corresponds with a steep axial temperature gradient in the maximum temperature attained. Oxide layers on Zircaloy result in reduced melt formation.« less

Looking Northeast Along Hallway between Pellet Plant and Oxide Building, ...

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

Looking Northeast Along Hallway between Pellet Plant and Oxide Building, including Virgin Hopper Bins - Hematite Fuel Fabrication Facility, Pellet Plant, 3300 State Road P, Festus, Jefferson County, MO

Portable compton gamma-ray detection system

DOEpatents

Rowland, Mark S [Alamo, CA; Oldaker, Mark E [Pleasanton, CA

2008-03-04

A Compton scattered gamma-ray detector system. The system comprises a gamma-ray spectrometer and an annular array of individual scintillators. The scintillators are positioned so that they are arrayed around the gamma-ray spectrometer. The annular array of individual scintillators includes a first scintillator. A radiation shield is positioned around the first scintillator. A multi-channel analyzer is operatively connected to the gamma-ray spectrometer and the annular array of individual scintillators.

Effects of thermal treatment on energy density and hardness of torrefied wood pellets

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

Peng, Jianghong; Wang, Jingsong; Bi, Xiaotao T.

Here, three types of wood pellets samples, including two types of commercial pellets and one type of lab-made control pellets were torrefied in a fixed bed unit to study the effect of thermal pretreatment on the quality of wood pellets. The quality of wood pellets was mainly characterized by the pellet density, bulk density, higher heating value, Meyer hardness, saturated moisture uptake, volumetric energy density, and energy yield. Results showed that torrefaction significantly decreased the pellet density, hardness, volumetric energy density, and energy yield. The higher heating value increased and the saturated moisture content decreased after torrefaction. In view ofmore » the lower density, lower hardness, lower volumetric energy density, and energy yield of torrefied pellets, it is recommended that biomass should be torrefied and then compressed to make strong pellets of high hydrophobicity and volumetric energy density.« less

Effects of thermal treatment on energy density and hardness of torrefied wood pellets

DOE PAGES

Peng, Jianghong; Wang, Jingsong; Bi, Xiaotao T.; ...

2014-09-27

Here, three types of wood pellets samples, including two types of commercial pellets and one type of lab-made control pellets were torrefied in a fixed bed unit to study the effect of thermal pretreatment on the quality of wood pellets. The quality of wood pellets was mainly characterized by the pellet density, bulk density, higher heating value, Meyer hardness, saturated moisture uptake, volumetric energy density, and energy yield. Results showed that torrefaction significantly decreased the pellet density, hardness, volumetric energy density, and energy yield. The higher heating value increased and the saturated moisture content decreased after torrefaction. In view ofmore » the lower density, lower hardness, lower volumetric energy density, and energy yield of torrefied pellets, it is recommended that biomass should be torrefied and then compressed to make strong pellets of high hydrophobicity and volumetric energy density.« less

Zooplankton fecal pellets, marine snow, phytodetritus and the ocean's biological pump

NASA Astrophysics Data System (ADS)

Turner, Jefferson T.

2015-01-01

The 'biological pump' is the process by which photosynthetically-produced organic matter in the ocean descends from the surface layer to depth by a combination of sinking particles, advection or vertical mixing of dissolved organic matter, and transport by animals. Particulate organic matter that is exported downward from the euphotic zone is composed of combinations of fecal pellets from zooplankton and fish, organic aggregates known as 'marine snow' and phytodetritus from sinking phytoplankton. Previous reviews by Turner and Ferrante (1979) and Turner (2002) focused on publications that appeared through late 2001. Since that time, studies of the biological pump have continued, and there have been >300 papers on vertical export flux using sediment traps, large-volume filtration systems and other techniques from throughout the global ocean. This review will focus primarily on recent studies that have appeared since 2001. Major topics covered in this review are (1) an overview of the biological pump, and its efficiency and variability, and the role of dissolved organic carbon in the biological pump; (2) zooplankton fecal pellets, including the contribution of zooplankton fecal pellets to export flux, epipelagic retention of zooplankton fecal pellets due to zooplankton activities, zooplankton vertical migration and fecal pellet repackaging, microbial ecology of fecal pellets, sinking velocities of fecal pellets and aggregates, ballasting of sinking particles by mineral contents, phytoplankton cysts, intact cells and harmful algae toxins in fecal pellets, importance of fecal pellets from various types of zooplankton, and the role of zooplankton fecal pellets in picoplankton export; (3) marine snow, including the origins, abundance, and distributions of marine snow, particles and organisms associated with marine snow, consumption and fragmentation of marine snow by animals, pathogens associated with marine snow; (4) phytodetritus, including pulsed export of phytodetritus, phytodetritus from Phaeocystis spp., picoplankton in phytodetritus, the summer export pulse (SEP) of phytodetritus in the subtropical North Pacific, benthic community responses to phytodetritus; (5) other components of the biological pump, including fish fecal pellets and fish-mediated export, sinking carcasses of animals and macrophytes, feces from marine mammals, transparent exopolymer particles (TEP); (6) the biological pump and climate, including origins of the biological pump, the biological pump and glacial/interglacial cycles, the biological pump and contemporary climate variations, and the biological pump and anthropogenic climate change. The review concludes with potential future modifications in the biological pump due to climate change.

Fusion reactor pumped laser

DOEpatents

Jassby, D.L.

1987-09-04

A nuclear pumped laser capable of producing long pulses of very high power laser radiation is provided. A toroidal fusion reactor provides energetic neutrons which are slowed down by a moderator. The moderated neutrons are converted to energetic particles capable of pumping a lasing medium. The lasing medium is housed in an annular cell surrounding the reactor. The cell includes an annular reflecting mirror at the bottom and an annular output window at the top. A neutron reflector is disposed around the cell to reflect escaping neutrons back into the cell. The laser radiation from the annular window is focused onto a beam compactor which generates a single coherent output laser beam. 10 figs.

Fusion reactor pumped laser

DOEpatents

Jassby, Daniel L.

1988-01-01

A nuclear pumped laser capable of producing long pulses of very high power laser radiation is provided. A toroidal fusion reactor provides energetic neutrons which are slowed down by a moderator. The moderated neutrons are converted to energetic particles capable of pumping a lasing medium. The lasing medium is housed in an annular cell surrounding the reactor. The cell includes an annular reflecting mirror at the bottom and an annular output window at the top. A neutron reflector is disposed around the cell to reflect escaping neutrons back into the cell. The laser radiation from the annular window is focused onto a beam compactor which generates a single coherent output laser beam.

Manufacture of annular cermet articles

DOEpatents

Forsberg, Charles W.; Sikka, Vinod K.

2004-11-02

A method to produce annular-shaped, metal-clad cermet components directly produces the form and avoids multiple fabrication steps such as rolling and welding. The method includes the steps of: providing an annular hollow form with inner and outer side walls; filling the form with a particulate mixture of ceramic and metal; closing, evacuating, and hermetically sealing the form; heating the form to an appropriate temperature; and applying force to consolidate the particulate mixture into solid cermet.

Irradiation performance of PFBR MOX fuel after 112 GWd/t burn-up

NASA Astrophysics Data System (ADS)

Venkiteswaran, C. N.; Jayaraj, V. V.; Ojha, B. K.; Anandaraj, V.; Padalakshmi, M.; Vinodkumar, S.; Karthik, V.; Vijaykumar, Ran; Vijayaraghavan, A.; Divakar, R.; Johny, T.; Joseph, Jojo; Thirunavakkarasu, S.; Saravanan, T.; Philip, John; Rao, B. P. C.; Kasiviswanathan, K. V.; Jayakumar, T.

2014-06-01

The 500 MWe Prototype Fast Breeder Reactor (PFBR) which is in advanced stage of construction at Kalpakkam, India, will use mixed oxide (MOX) fuel with a target burnup of 100 GWd/t. The fuel pellet is of annular design to enable operation at a peak linear power of 450 W/cm with the requirement of minimum duration of pre-conditioning. The performance of the MOX fuel and the D9 clad and wrapper material was assessed through Post Irradiation Examinations (PIE) after test irradiation of 37 fuel pin subassembly in Fast Breeder Test Reactor (FBTR) to a burn-up of 112 GWd/t. Fission product distribution, swelling and fuel-clad gap evolution, central hole diameter variation, restructuring, fission gas release and clad wastage due to fuel-clad chemical interaction were evaluated through non-destructive and destructive examinations. The examinations have indicated that the MOX fuel can safely attain the desired target burn-up in PFBR.

Freeze chromatography method and apparatus

DOEpatents

Scott, C.D.

1987-04-16

A freeze chromatography method and apparatus are provided which enable separation of the solutes contained in a sample. The apparatus includes an annular column construction comprising cylindrical inner and outer surfaces defining an annular passage therebetween. One of the surfaces is heated and the other cooled while passing an eluent through the annular passageway so that the eluent in contact with the cooled surface freezes and forms a frozen eluent layer thereon. A mixture of solutes dissolved in eluent is passed through the annular passageway in contact with the frozen layer so that the sample solutes in the mixture will tend to migrate either toward or away the frozen layer. The rate at which the mixture flows through the annular passageway is controlled so that the distribution of the sample solutes approaches that at equilibrium and thus a separation between the sample solutes occurs. 3 figs.

Annular feed air breathing fuel cell stack

DOEpatents

Wilson, Mahlon S.

1996-01-01

A stack of polymer electrolyte fuel cells is formed from a plurality of unit cells where each unit cell includes fuel cell components defining a periphery and distributed along a common axis, where the fuel cell components include a polymer electrolyte membrane, an anode and a cathode contacting opposite sides of the membrane, and fuel and oxygen flow fields contacting the anode and the cathode, respectively, wherein the components define an annular region therethrough along the axis. A fuel distribution manifold within the annular region is connected to deliver fuel to the fuel flow field in each of the unit cells. In a particular embodiment, a single bolt through the annular region clamps the unit cells together. In another embodiment, separator plates between individual unit cells have an extended radial dimension to function as cooling fins for maintaining the operating temperature of the fuel cell stack.

A novel HTS magnetic levitation dining table

NASA Astrophysics Data System (ADS)

Lu, Yiyun; Huang, Huiying

2018-05-01

High temperature superconducting (HTS) bulk can levitate above or suspend below a permanent magnet stably. Many magnificent potential applications of HTS bulk are proposed by researchers. Until now, few reports have been found for real applications of HTS bulk. A complete set of small-scale HTS magnetic levitation table is proposed in the paper. The HTS magnetic levitation table includes an annular HTS magnetic levitation system which is composed of an annular HTS bulk array and an annular permanent magnet guideway (PMG). The annular PMG and the annular cryogenics vessel which used to maintain low temperature environment of the HTS bulk array are designed. 62 YBCO bulks are used to locate at the bottom of the annular vessel. A 3D-model finite element numerical method is used to design the HTS bulk magnetic levitation system. Equivalent magnetic levitation and guidance forces calculation rules are proposed aimed at the annular HTS magnetic levitation system stability. Based on the proposed method, levitation and guidance forces curves of the one YBCO bulk magnetic above PMG could be obtained. This method also can use to assist PMG design to check whether the designed PMG could reach the basic demand of the HTS magnetic levitation table.

Prediction of the mechanical properties of zeolite pellets for aerospace molecular decontamination applications.

PubMed

Rioland, Guillaume; Dutournié, Patrick; Faye, Delphine; Daou, T Jean; Patarin, Joël

2016-01-01

Zeolite pellets containing 5 wt % of binder (methylcellulose or sodium metasilicate) were formed with a hydraulic press. This paper describes a mathematical model to predict the mechanical properties (uniaxial and diametric compression) of these pellets for arbitrary dimensions (height and diameter) using a design of experiments (DOE) methodology. A second-degree polynomial equation including interactions was used to approximate the experimental results. This leads to an empirical model for the estimation of the mechanical properties of zeolite pellets with 5 wt % of binder. The model was verified by additional experimental tests including pellets of different dimensions created with different applied pressures. The optimum dimensions were found to be a diameter of 10-23 mm, a height of 1-3.5 mm and an applied pressure higher than 200 MPa. These pellets are promising for technological uses in molecular decontamination for aerospace-based applications.

Segmented annular combustor

DOEpatents

Reider, Samuel B.

1979-01-01

An industrial gas turbine engine includes an inclined annular combustor made up of a plurality of support segments each including inner and outer walls of trapezoidally configured planar configuration extents and including side flanges thereon interconnected by means of air cooled connector bolt assemblies to form a continuous annular combustion chamber therebetween and wherein an air fuel mixing chamber is formed at one end of the support segments including means for directing and mixing fuel within a plenum and a perforated header plate for directing streams of air and fuel mixture into the combustion chamber; each of the outer and inner walls of each of the support segments having a ribbed lattice with tracks slidably supporting porous laminated replaceable panels and including pores therein for distributing combustion air into the combustion chamber while cooling the inner surface of each of the panels by transpiration cooling thereof.

Electron microscope aperture system

NASA Technical Reports Server (NTRS)

Heinemann, K. (Inventor)

1976-01-01

An electron microscope including an electron source, a condenser lens having either a circular aperture for focusing a solid cone of electrons onto a specimen or an annular aperture for focusing a hollow cone of electrons onto the specimen, and an objective lens having an annular objective aperture, for focusing electrons passing through the specimen onto an image plane are described. The invention also entails a method of making the annular objective aperture using electron imaging, electrolytic deposition and ion etching techniques.

Pellets for fusion reactor refueling. Annual progress report, January 1, 1976--December 31, 1976

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

Turnbull, R. J.; Kim, K.

1977-01-01

The purpose of this research is to test the feasibility of refueling fusion reactors using solid pellets composed of fuel elements. A solid hydrogen pellet generator has been constructed and experiments have been done to inject the pellets into the ORMAK Tokamak. A theory has been developed to describe the pellet ablation in the plasma, and an excellent agreement has been found between the theory and the experiment. Techniques for charging the pellets have been developed in order to accelerate and control them. Other works currently under way include the development of techniques for accelerating the pellets for refueling purpose.more » Evaluation of electrostatic acceleration has also been performed.« less

Nuclear reactor neutron shielding

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

Speaker, Daniel P; Neeley, Gary W; Inman, James B

A nuclear reactor includes a reactor pressure vessel and a nuclear reactor core comprising fissile material disposed in a lower portion of the reactor pressure vessel. The lower portion of the reactor pressure vessel is disposed in a reactor cavity. An annular neutron stop is located at an elevation above the uppermost elevation of the nuclear reactor core. The annular neutron stop comprises neutron absorbing material filling an annular gap between the reactor pressure vessel and the wall of the reactor cavity. The annular neutron stop may comprise an outer neutron stop ring attached to the wall of the reactormore » cavity, and an inner neutron stop ring attached to the reactor pressure vessel. An excore instrument guide tube penetrates through the annular neutron stop, and a neutron plug comprising neutron absorbing material is disposed in the tube at the penetration through the neutron stop.« less

Method of forming aperture plate for electron microscope

NASA Technical Reports Server (NTRS)

Heinemann, K. (Inventor)

1974-01-01

An electron microscope is described with an electron source a condenser lens having either a circular aperture for focusing a solid cone of electrons onto a specimen or an annular aperture for focusing a hollow cone of electrons onto the specimen. It also has objective lens with an annular objective aperture, for focusing electrons passing through the specimen onto an image plane. A method of making the annular objective aperture using electron imaging, electrolytic deposition and ion etching techniques is included.

Radial electron-beam-breakup transit-time oscillator

DOEpatents

Kwan, Thomas J. T.; Mostrom, Michael A.

1998-01-01

A radial electron-beam-breakup transit-time oscillator (RBTO) provides a compact high power microwave generator. The RBTO includes a coaxial vacuum transmission line having an outer conductor and an inner conductor. The inner conductor defines an annular cavity with dimensions effective to support an electromagnetic field in a TEM.sub.00m mode. A radial field emission cathode is formed on the outer conductor for providing an electron beam directed toward the annular cavity electrode. Microwave energy is then extracted from the annular cavity electrode.

Terrain Traversing Device Having a Wheel with Microhooks

NASA Technical Reports Server (NTRS)

Parness, Aaron (Inventor); McKenzie, Clifford F. (Inventor)

2014-01-01

A terrain traversing device includes an annular rotor element with a plurality of co-planar microspine hooks arranged on the periphery of the annular rotor element. Each microspine hook has an independently flexible suspension configuration that permits the microspine hook to initially engage an irregularity in a terrain surface at a preset initial engagement angle and subsequently engage the irregularity with a continuously varying engagement angle when the annular rotor element is rotated for urging the terrain traversing device to traverse a terrain surface.

Composite Pressure Vessel Including Crack Arresting Barrier

NASA Technical Reports Server (NTRS)

DeLay, Thomas K. (Inventor)

2013-01-01

A pressure vessel includes a ported fitting having an annular flange formed on an end thereof and a tank that envelopes the annular flange. A crack arresting barrier is bonded to and forming a lining of the tank within the outer surface thereof. The crack arresting barrier includes a cured resin having a post-curing ductility rating of at least approximately 60% through the cured resin, and further includes randomly-oriented fibers positioned in and throughout the cured resin.

Owl Pellets.

ERIC Educational Resources Information Center

Thompson, Craig D.

1987-01-01

Provides complete Project WILD lesson plans for 20-45-minute experiential science learning activity for grades 3-7 students. Describes how students construct a simple food chain through examination of owl pellets. Includes lesson objective, method, background information, materials, procedure, evaluation, and sources of owl pellets and posters.…

Formation and dispersion of mycelial pellets of Streptomyces coelicolor A3(2).

PubMed

Kim, Yul-Min; Kim, Jae-heon

2004-03-01

The pellets from a culture of Streptomyces coelicolor A3(2) that were submerged shaken were disintegrated into numerous hyphal fragments by DNase treatment. The pellets were increasingly dispersed by hyaluronidase treatment, and mycelial fragments were easily detached from the pellets. The submerged mycelium grew by forming complexes with calcium phosphate precipitates or kaolin, a soil particle. Therefore, the pellet formation of Streptomyces coelicolor A3(2) can be considered a biofilm formation, including the participation of adhesive extracellular polymers and the insoluble substrates.

Summary of Pellet Technology Program Activities

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

Gebhart, III, Gerald E.; Baylor, Larry R.; Bell, Gary L.

This report summarizes the activities and budget information of ORNL’s pellet technology program from the start of FY2014 through FY2017. Cost summaries are broken down by year and spending category. Milestone activities are outlined and described by year and further described in the project narrative. The project narrative outlines the main pellet injection technology advances enabled by the pellet technology program. A list of published research products is included, along with biographies of personnel involved. This document was prepared in support of the April 24, 2018, review of the pellet technology program at ORNL.

Oxidizing Roasting Performances of Coke Fines Bearing Brazilian Specularite Pellets

NASA Astrophysics Data System (ADS)

Chun, Tiejun; Zhu, Deqing

2016-06-01

Oxidized pellets, consisting of Brazilian specularite fines and coke fines, were prepared by disc pelletizer using bentonite as binder. The roasting process of pellets includes preheating stage and firing stage. The compressive strength of preheated pellets and fired pellets reached the peak value at 1.5% coke fines dosage. During the initial stage of preheating, some original Fe2O3 was reduced to Fe3O4 because of partial reduction atmosphere in pellet. During the later stage of preheating and firing stage, coke fines were burnt out, and the secondary Fe2O3 (new generation Fe2O3) was generated due to the re-oxidization of Fe3O4, which improved the recrystallization of Fe2O3. Compared with the fired pellets without adding coke fines, fired pellets with 1.5% coke fines exhibited the comparable RSI (reduction swelling index) and RDI+3.15 mm (reduction degradation index), and slightly lower RI (reducibility index).

Annular fuel and air co-flow premixer

DOEpatents

Stevenson, Christian Xavier; Melton, Patrick Benedict; York, William David

2013-10-15

Disclosed is a premixer for a combustor including an annular outer shell and an annular inner shell. The inner shell defines an inner flow channel inside of the inner shell and is located to define an outer flow channel between the outer shell and the inner shell. A fuel discharge annulus is located between the outer flow channel and the inner flow channel and is configured to inject a fuel flow into a mixing area in a direction substantially parallel to an outer airflow through the outer flow channel and an inner flow through the inner flow channel. Further disclosed are a combustor including a plurality of premixers and a method of premixing air and fuel in a combustor.

Reuse potential of low-calcium bottom ash as aggregate through pelletization.

PubMed

Geetha, S; Ramamurthy, K

2010-01-01

Coal combustion residues which include fly ash, bottom ash and boiler slag is one of the major pollutants as these residues require large land area for their disposal. Among these residues, utilization of bottom ash in the construction industry is very low. This paper explains the use of bottom ash through pelletization. Raw bottom ash could not be pelletized as such due to its coarseness. Though pulverized bottom ash could be pelletized, the pelletization efficiency was low, and the aggregates were too weak to withstand the handling stresses. To improve the pelletization efficiency, different clay and cementitious binders were used with bottom ash. The influence of different factors and their interaction effects were studied on the duration of pelletization process and the pelletization efficiency through fractional factorial design. Addition of binders facilitated conversion of low-calcium bottom ash into aggregates. To achieve maximum pelletization efficiency, the binder content and moisture requirements vary with type of binder. Addition of Ca(OH)(2) improved the (i) pelletization efficiency, (ii) reduced the duration of pelletization process from an average of 14-7 min, and (iii) reduced the binder dosage for a given pelletization efficiency. For aggregate with clay binders and cementitious binder, Ca(OH)(2) and binder dosage have significant effect in reducing the duration of pelletization process. 2010 Elsevier Ltd. All rights reserved.

Annular feed air breathing fuel cell stack

DOEpatents

Wilson, Mahlon S.; Neutzler, Jay K.

1997-01-01

A stack of polymer electrolyte fuel cells is formed from a plurality of unit cells where each unit cell includes fuel cell components defining a periphery and distributed along a common axis, where the fuel cell components include a polymer electrolyte membrane, an anode and a cathode contacting opposite sides of the membrane, and fuel and oxygen flow fields contacting the anode and the cathode, respectively, wherein the components define an annular region therethrough along the axis. A fuel distribution manifold within the annular region is connected to deliver fuel to the fuel flow field in each of the unit cells. The fuel distribution manifold is formed from a hydrophilic-like material to redistribute water produced by fuel and oxygen reacting at the cathode. In a particular embodiment, a single bolt through the annular region clamps the unit cells together. In another embodiment, separator plates between individual unit cells have an extended radial dimension to function as cooling fins for maintaining the operating temperature of the fuel cell stack.

Neutron economic reactivity control system for light water reactors

DOEpatents

Luce, Robert G.; McCoy, Daniel F.; Merriman, Floyd C.; Gregurech, Steve

1989-01-01

A neutron reactivity control system for a LWBR incorporating a stationary seed-blanket core arrangement. The core arrangement includes a plurality of contiguous hexagonal shaped regions. Each region has a central and a peripheral blanket area juxapositioned an annular seed area. The blanket areas contain thoria fuel rods while the annular seed area includes seed fuel rods and movable thoria shim control rods.

ELM mitigation with pellet ELM triggering and implications for PFCs and plasma performance in ITER

DOE PAGES

Baylor, Larry R.; Lang, P. T.; Allen, Steve L.; ...

2014-10-05

The triggering of rapid small edge localized modes (ELMs) by high frequency pellet injection has been proposed as a method to prevent large naturally occurring ELMs that can erode the ITER plasma facing components. Deuterium pellet injection has been used to successfully demonstrate the on-demand triggering of edge localized modes (ELMs) at much higher rates and with much smaller intensity than natural ELMs. The proposed hypothesis for the triggering mechanism of ELMs by pellets is the local pressure perturbation resulting from reheating of the pellet cloud that can exceed the local high-n ballooning mode threshold where the pellet is injected.more » Nonlinear MHD simulations of the pellet ELM triggering show destabilization of high-n ballooning modes by such a local pressure perturbation. A review of the recent pellet ELM triggering results from ASDEX Upgrade (AUG), DIII-D, and JET reveals that a number of uncertainties about this ELM mitigation technique still remain. These include the heat flux impact pattern on the divertor and wall from pellet triggered and natural ELMs, the necessary pellet size and injection location to reliably trigger ELMs, and the level of fueling to be expected from ELM triggering pellets and synergy with larger fueling pellets. The implications of these issues for pellet ELM mitigation in ITER and its impact on the PFCs are presented along with the design features of the pellet injection system for ITER.« less

ELM mitigation with pellet ELM triggering and implications for PFCs and plasma performance in ITER

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

Baylor, Larry R.; Lang, P.; Allen, S. L.

2015-08-01

The triggering of rapid small edge localized modes (ELMs) by high frequency pellet injection has been proposed as a method to prevent large naturally occurring ELMs that can erode the ITER plasma facing components (PFCs). Deuterium pellet injection has been used to successfully demonstrate the on-demand triggering of edge localized modes (ELMs) at much higher rates and with much smaller intensity than natural ELMs. The proposed hypothesis for the triggering mechanism of ELMs by pellets is the local pressure perturbation resulting from reheating of the pellet cloud that can exceed the local high-n ballooning mode threshold where the pellet ismore » injected. Nonlinear MHD simulations of the pellet ELM triggering show destabilization of high-n ballooning modes by such a local pressure perturbation.A review of the recent pellet ELM triggering results from ASDEX Upgrade (AUG), DIII-D, and JET reveals that a number of uncertainties about this ELM mitigation technique still remain. These include the heat flux impact pattern on the divertor and wall from pellet triggered and natural ELMs, the necessary pellet size and injection location to reliably trigger ELMs, and the level of fueling to be expected from ELM triggering pellets and synergy with larger fueling pellets. The implications of these issues for pellet ELM mitigation in ITER and its impact on the PFCs are presented along with the design features of the pellet injection system for ITER.« less

Grain Size and Phase Purity Characterization of U 3Si 2 Pellet Fuel

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

Hoggan, Rita E.; Tolman, Kevin R.; Cappia, Fabiola

Characterization of U 3Si 2 fresh fuel pellets is important for quality assurance and validation of the finished product. Grain size measurement methods, phase identification methods using scanning electron microscopes equipped with energy dispersive spectroscopy and x-ray diffraction, and phase quantification methods via image analysis have been developed and implemented on U 3Si 2 pellet samples. A wide variety of samples have been characterized including representative pellets from an initial irradiation experiment, and samples produced using optimized methods to enhance phase purity from an extended fabrication effort. The average grain size for initial pellets was between 16 and 18 µm.more » The typical average grain size for pellets from the extended fabrication was between 20 and 30 µm with some samples exhibiting irregular grain growth. Pellets from the latter half of extended fabrication had a bimodal grain size distribution consisting of coarsened grains (>80 µm) surrounded by the typical (20-30 µm) grain structure around the surface. Phases identified in initial uranium silicide pellets included: U 3Si 2 as the main phase composing about 80 vol. %, Si rich phases (USi and U 5Si 4) composing about 13 vol. %, and UO 2 composing about 5 vol. %. Initial batches from the extended U 3Si 2 pellet fabrication had similar phases and phase quantities. The latter half of the extended fabrication pellet batches did not contain Si rich phases, and had between 1-5% UO 2: achieving U 3Si 2 phase purity between 95 vol. % and 98 vol. % U 3Si 2. The amount of UO 2 in sintered U 3Si 2 pellets is correlated to the length of time between U 3Si 2 powder fabrication and pellet formation. These measurements provide information necessary to optimize fabrication efforts and a baseline for future work on this fuel compound.« less

Simulations of Neon Pellets for Plasma Disruption Mitigation in Tokamaks

NASA Astrophysics Data System (ADS)

Bosviel, Nicolas; Samulyak, Roman; Parks, Paul

2017-10-01

Numerical studies of the ablation of neon pellets in tokamaks in the plasma disruption mitigation parameter space have been performed using a time-dependent pellet ablation model based on the front tracking code FronTier-MHD. The main features of the model include the explicit tracking of the solid pellet/ablated gas interface, a self-consistent evolving potential distribution in the ablation cloud, JxB forces, atomic processes, and an improved electrical conductivity model. The equation of state model accounts for atomic processes in the ablation cloud as well as deviations from the ideal gas law in the dense, cold layers of neon gas near the pellet surface. Simulations predict processes in the ablation cloud and pellet ablation rates and address the sensitivity of pellet ablation processes to details of physics models, in particular the equation of state.

Gimbaled-shoulder friction stir welding tool

NASA Technical Reports Server (NTRS)

Carter, Robert W. (Inventor); Lawless, Kirby G. (Inventor)

2010-01-01

A gimbaled-shoulder friction stir welding tool includes a pin and first and second annular shoulders coupled to the pin. At least one of the annular shoulders is coupled to the pin for gimbaled motion with respect thereto as the tool is rotated by a friction stir welding apparatus.

Vacuum encapsulated, high temperature diamond amplified cathode capsule and method for making same

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

Rao, Triveni; Walsh, Josh; Gangone, Elizabeth

2015-12-29

A vacuum encapsulated, hermetically sealed cathode capsule for generating an electron beam of secondary electrons, which generally includes a cathode element having a primary emission surface adapted to emit primary electrons, an annular insulating spacer, a diamond window element comprising a diamond material and having a secondary emission surface adapted to emit secondary electrons in response to primary electrons impinging on the diamond window element, a first high-temperature solder weld disposed between the diamond window element and the annular insulating spacer and a second high-temperature solder weld disposed between the annular insulating spacer and the cathode element. The cathode capsulemore » is formed by a high temperature weld process under vacuum such that the first solder weld forms a hermetical seal between the diamond window element and the annular insulating spacer and the second solder weld forms a hermetical seal between the annular spacer and the cathode element whereby a vacuum encapsulated chamber is formed within the capsule.« less

Annular lichenoid dermatitis of youth ... and beyond: a series of 6 cases.

PubMed

Cesinaro, Anna Maria; Sighinolfi, Pamela; Greco, Antonietta; Garagnani, Lorella; Conti, Andrea; Fantini, Fabrizio

2009-05-01

Annular lichenoid dermatitis of youth (ALDY) is a clinico-pathologic entity described in children and young patients, clinically reminiscent of morphea, annular erythema, vitiligo or mycosis fungoides. We report on six patients presenting single or multiple lesions, distributed particularly on the flanks and abdomen, with clinical and histologic features consistent with ALDY. Two patients were young girls and four were adults males. Three patients received topical therapy and four showed complete resolution of the lesions after a 24-65 months follow-up. Analogously to the cases reported so far, immunohistochemistry showed a T cell infiltrate with a predominance of CD8+ lymphocytes, while T cell receptor rearrangement was absent in all cases. It seems appropriate to include annular lichenoid dermatitis of youth among the dermatoses with a lichenoid pattern. For the first time, we found that it can affect also adult patients, therefore we propose to rename the disease annular lichenoid dermatitis. The differential diagnosis with mycosis fungoides, especially in adult patients, is particularly crucial for their proper management and treatment.

Vacuum encapsulated hermetically sealed diamond amplified cathode capsule and method for making same

DOEpatents

Rao, Triveni; Walsh, John; Gangone, Elizabeth

2014-12-30

A vacuum encapsulated, hermetically sealed cathode capsule for generating an electron beam of secondary electrons, which generally includes a cathode element having a primary emission surface adapted to emit primary electrons, an annular insulating spacer, a diamond window element comprising a diamond material and having a secondary emission surface adapted to emit secondary electrons in response to primary electrons impinging on the diamond window element, a first cold-weld ring disposed between the cathode element and the annular insulating spacer and a second cold-weld ring disposed between the annular insulating spacer and the diamond window element. The cathode capsule is formed by a vacuum cold-weld process such that the first cold-weld ring forms a hermetical seal between the cathode element and the annular insulating spacer and the second cold-weld ring forms a hermetical seal between the annular spacer and the diamond window element whereby a vacuum encapsulated chamber is formed within the capsule.

Gas turbine structural mounting arrangement between combustion gas duct annular chamber and turbine vane carrier

DOEpatents

Wiebe, David J.; Charron, Richard C.; Morrison, Jay A.

2016-10-18

A gas turbine engine ducting arrangement (10), including: an annular chamber (14) configured to receive a plurality of discrete flows of combustion gases originating in respective can combustors and to deliver the discrete flows to a turbine inlet annulus, wherein the annular chamber includes an inner diameter (52) and an outer diameter (60); an outer diameter mounting arrangement (34) configured to permit relative radial movement and to prevent relative axial and circumferential movement between the outer diameter and a turbine vane carrier (20); and an inner diameter mounting arrangement (36) including a bracket (64) secured to the turbine vane carrier, wherein the bracket is configured to permit the inner diameter to move radially with the outer diameter and prevent axial deflection of the inner diameter with respect to the outer diameter.

Trial production of fuel pellet from Acacia mangium bark waste biomass

NASA Astrophysics Data System (ADS)

Amirta, R.; Anwar, T.; Sudrajat; Yuliansyah; Suwinarti, W.

2018-04-01

Fuel pellet is one of the innovation products that can be produced from various sources of biomass such as agricultural residues, forestry and also wood industries including wood bark. Herein this paper, the potential fuel pellet production using Acacia mangium bark that abundant wasted from chip mill industry was studied. Fuel pellet was produced using a modified animal feed pellet press machine equipped with rotating roller-cylinders. The international standards quality of fuel pellet such as ONORM (Austria), SS (Sweden), DIN (Germany), EN (European) and ITEBE (Italy) were used to evaluate the optimum composition of feedstock and additive used. Theresults showed the quality offuel pellet produced were good compared to commercial sawdust pellet. Mixed of Acacia bark (dust) with 10% of tapioca and 20% of glycerol (w/w) was increased the stable form of pellet and the highest heating value to reached 4,383 Kcal/kg (calorific value). Blending of Acacia bark with tapioca and glycerol was positively improved its physical, chemical and combustion properties to met the international standards requirement for export market. Based on this finding, production of fuel pellet from Acacia bark waste biomass was promising to be developed as an alternative substitution of fossil energy in the future.

PELLETS AND PELLETIZATION: EMERGING TRENDS IN THE PHARMA INDUSTRY.

PubMed

Zaman, Muhammad; Saeed-Ul-Hassan, Syed; Sarfraz, Rai Muhammad; Batool, Nighat; Qureshi, Muhammad Junaid; Akram, Muhammad Abdullah; Munir, Saiqa; Danish, Zeeshan

2016-11-01

The present time is considered as an era of advancements in drug delivery systems. Different novel approaches are under investigation that range from uniparticulate to multi particulate system, macro to micro and nano particulate systems. Pelletization is one of the novel drug delivery technique that provides an effective way to deliver the drug in modified pattern. It is advantageous in providing site specific delivery of the drug. Drugs with unpleasant taste, poor bioavailability and short biological half-life can be delivered efficiently through pellets. Their reduced size makes them more valuable as compared to the conventional drug deliv- ery system. Different techniques are used to fabricate the pellets such as extrusion and spheronization, hot melt extrusion, powder layering, suspension or solution layering, freeze pelletization and pelletization by direct compression method. Various natural polymers including xanthan gum, guar gum, tragacanth and gum acacia, semisynthetic polymers like cellulose derivatives, synthetic polymers like derivatives of acrylamides, can be used in pellets formulation. Information provided in this review is collected from various national and intemational research articles, review articles and literature available in the books. The purpose of the current review is to discuss pellets, their characterizations, different techniques of pelletization and the polymers with potential of being suitable for pellets formulation.

Laser Doppler velocimeter measurements and laser sheet imaging in an annular combustor model. M.S. Thesis, Final Report

NASA Technical Reports Server (NTRS)

Dwenger, Richard Dale

1995-01-01

An experimental study was conducted in annular combustor model to provide a better understanding of the flowfield. Combustor model configurations consisting of primary jets only, annular jets only, and a combination of annular and primary jets were investigated. The purpose of this research was to provide a better understanding of combustor flows and to provide a data base for comparison with computational models. The first part of this research used a laser Doppler velocimeter to measure mean velocity and statistically calculate root-mean-square velocity in two coordinate directions. From this data, one Reynolds shear stress component and a two-dimensional turbulent kinetic energy term was determined. Major features of the flowfield included recirculating flow, primary and annular jet interaction, and high turbulence. The most pronounced result from this data was the effect the primary jets had on the flowfield. The primary jets were seen to reduce flow asymmetries, create larger recirculation zones, and higher turbulence levels. The second part of this research used a technique called marker nephelometry to provide mean concentration values in the combustor. Results showed the flow to be very turbulent and unsteady. All configurations investigated were highly sensitive to alignment of the primary and annular jets in the model and inlet conditions. Any imbalance between primary jets or misalignment of the annular jets caused severe flow asymmetries.

Southeastern United States wood pellets as a global energy resource: a cradle-to-gate life cycle assessment derived from empirical data

NASA Astrophysics Data System (ADS)

Morrison, Brandon; Golden, Jay S.

2018-02-01

Given increased policies driving renewable electricity generation and insufficient local production of woody biomass, many countries are reliant upon the importation of wood pellets. Of current wood pellet exports, the vast majority originates from the Southeastern United States (US). In this paper we present results from a cradle-to-gate, attributional process life cycle assessment in which two production scenarios of wood pellets were modelled for the Southeastern US: one utilising roundwood from a silviculture operation and the other utilising sawmill residues. The system boundary includes all steps from harvesting of the wood biomass, through delivery of the finished wood pellets to a US port facility. For each of the impact categories assessed, wood pellets from sawmill residues resulted in higher values, ranging from 5% to 31%. In relation to Global Warming Potential, roundwood pellets resulted in a 13-21% lower value than pellets produced from sawmill residues, depending upon the allocation method.

DETERMINATION OF THE STRONG ACIDITY OF ATMOSPHERIC FINE PARTICLES (<2.5 UM) USING ANNULAR DENUDER TECHNOLOGY

EPA Science Inventory

This report is a standardized methodology description for the determination of strong acidity of fine particles (less than 2.5 microns) in ambient air using annular denuder technology. his methodology description includes two parts: art A - Standard Method and Part B - Enhanced M...

Design of the Annular Suspension and Pointing System (ASPS) (including design addendum)

NASA Technical Reports Server (NTRS)

Cunningham, D.; Gismondi, T.; Hamilton, B.; Kendig, J.; Kiedrowski, J.; Vroman, A.; Wilson, G.

1980-01-01

The Annular Suspension and Pointing System is an experiment pointing mount designed for extremely precise 3 axis orientation of shuttle experiments. It utilizes actively controlled magnetic bearing to provide noncontacting vernier pointing and translational isolation of the experiment. The design of the system is presented and analyzed.

Pressure-actuated joint system

NASA Technical Reports Server (NTRS)

McGuire, John R. (Inventor)

2004-01-01

A pressure vessel is provided that includes first and second case segments mated with one another. First and second annular rubber layers are disposed inboard of the first and second case segments, respectively. The second annular rubber layer has a slot extending from the radial inner surface across a portion of its thickness to define a main body portion and a flexible portion. The flexible portion has an interfacing surface portion abutting against an interfacing surface portion of the first annular rubber layer to follow movement of the first annular rubber layer during operation of the pressure vessel. The slot receives pressurized gas and establishes a pressure-actuated joint between the interfacing surface portions. At least one of the interfacing surface portions has a plurality of enclosed and sealed recesses formed therein.

Tracer-Encapsulated Solid Pellet (TESPEL) Injection System for the TJ-II Stellarator

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

Tamura, N.; McCarthy, K. J.; Hayashi, H.

2016-01-01

A tracer-encapsulated solid pellet (TESPEL) injection system for the TJ-II stellarator was recently developed. In order to reduce the time and cost for the development, we combined a TESPEL injector provided by National Institute for Fusion Science with an existing TJ-II cryogenic pellet injection system. Consequently, the TESPEL injection into the TJ-II plasma was successfully achieved, which was confirmed by several pellet diagnostics including a normal-incidence spectrometer for monitoring a tracer impurity behavior.

Support mechanism for a mirrored surface or other arrangement

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

Cutburth, R.W.

1987-02-03

A mechanism is described for supporting first means including a planer surface for movement relative to a vertical plane defined by particular intersecting x and y axes which extend horizontally and vertically, respectively, the mechanism comprising: (a) second means including a plurality of segments of an annular surface which forms part of a sphere whose center defines the intersection of the x and y axes. The annular surface defines a z axis extending through the intersection of the x and y axes perpendicular to the vertical plane; (b) third means connecting the planer surface including first means with the secondmore » means such that the planer surface is positionably within the vertical plane and is itself intersected by the z axis at a particular point thereon. The third means includes bearing means disposed between the first means and the segments of the annular surface of the second means for allowing the first means to move in any direction on the annular surface segments including certain specific directions which allow the planer surface to pivot back and forth to a limited extent about both the x and y axes relative to the vertical plane; and (c) fourth means interconnecting the first and second means and cooperating with the third means for limiting the movement of the first means to the certain specific directions.« less

Universal cell frame for high-pressure water electrolyzer and electrolyzer including the same

DOEpatents

Schmitt, Edwin W.; Norman, Timothy J.

2013-01-08

Universal cell frame generic for use as an anode frame and as a cathode frame in a water electrolyzer. According to one embodiment, the universal cell frame includes a unitary annular member having a central opening. Four trios of transverse openings are provided in the annular member, each trio being spaced apart by about 90 degrees. A plurality of internal radial passageways fluidly interconnect the central opening and each of the transverse openings of two diametrically-opposed trios of openings, the other two trios of openings lacking corresponding radial passageways. Sealing ribs are provided on the top and bottom surfaces of the annular member. The present invention is also directed at a water electrolyzer that includes two such cell frames, one being used as the anode frame and the other being used as the cathode frame, the cathode frame being rotated 90 degrees relative to the anode frame.

Concentric tube support assembly

DOEpatents

Rubio, Mark F.; Glessner, John C.

2012-09-04

An assembly (45) includes a plurality of separate pie-shaped segments (72) forming a disk (70) around a central region (48) for retaining a plurality of tubes (46) in a concentrically spaced apart configuration. Each segment includes a support member (94) radially extending along an upstream face (96) of the segment and a plurality of annularly curved support arms (98) transversely attached to the support member and radially spaced apart from one another away from the central region for receiving respective upstream end portions of the tubes in arc-shaped spaces (100) between the arms. Each segment also includes a radial passageway (102) formed in the support member for receiving a fluid segment portion (106) and a plurality of annular passageways (104) formed in the support arms for receiving respective arm portions (108) of the fluid segment portion from the radial passageway and for conducting the respective arm portions into corresponding annular spaces (47) formed between the tubes retained by the disk.

Dryout-type critical heat flux in vertical upward annular flow: effects of entrainment rate, initial entrained fraction and diameter

NASA Astrophysics Data System (ADS)

Wu, Zan; Wadekar, Vishwas; Wang, Chenglong; Sunden, Bengt

2018-01-01

This study aims to reveal the effects of liquid entrainment, initial entrained fraction and tube diameter on liquid film dryout in vertical upward annular flow for flow boiling. Entrainment and deposition rates of droplets were included in mass conservation equations to estimate the local liquid film mass flux in annular flow, and the critical vapor quality at dryout conditions. Different entrainment rate correlations were evaluated using flow boiling data of water and organic liquids including n-pentane, iso-octane and R134a. Effect of the initial entrained fraction (IEF) at the churn-to-annular flow transition was also investigated. A transitional Boiling number was proposed to separate the IEF-sensitive region at high Boiling numbers and the IEF-insensitive region at low Boiling numbers. Besides, the diameter effect on dryout vapor quality was studied. The dryout vapor quality increases with decreasing tube diameter. It needs to be pointed out that the dryout characteristics of submillimeter channels might be different because of different mechanisms of dryout, i.e., drying of liquid film underneath long vapor slugs and flow boiling instabilities.

Removal of atmospheric oxidants with annular denuders

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

Williams, E.L. II; Grosjean, D.

1990-06-01

Annular denuders have been tested for their ability to remove atmospheric photochemical oxidants including ozone (150-170 ppb), nitrogen dioxide (40-200 ppb), nitric acid (35 ppb), and peroxyacetyl nitrate (PAN, 6-25 ppb). Formaldehyde (80-140 ppb) was also tested as a copollutant. Tests were carried out at low rates of 1,2, and 20 L/min, with oxidants tested singly or as part of photochemical mixtures in purified air. Efficient collection was obtained with annular denuders coated with potassium iodide (O{sub 3}), phenoxamine (O{sub 3}), sodium carbonate (HNO{sub 3}), potassium hydroxide (PAN), and 2,4-dinitrophenylhydrazine (HCHO).

Concentric Coplanar Capacitive Sensor System with Quantitative Model

NASA Technical Reports Server (NTRS)

Chen, Tianming (Inventor); Bowler, Nicola (Inventor)

2014-01-01

A concentric coplanar capacitive sensor includes a charged central disc forming a first electrode, an outer annular ring coplanar with and outer to the charged central disc, the outer annular ring forming a second electrode, and a gap between the charged central disc and the outer annular ring. The first electrode and the second electrode may be attached to an insulative film. A method provides for determining transcapacitance between the first electrode and the second electrode and using the transcapacitance in a model that accounts for a dielectric test piece to determine inversely the properties of the dielectric test piece.

Micro-Fresnel Zone Plate Optical Devices Using Densely Accumulated Ray Points

NASA Technical Reports Server (NTRS)

Choi, Sang H. (Inventor); Park, Yeonjoon (Inventor); King, Glen C. (Inventor); Elliott, James R. (Inventor)

2011-01-01

An embodiment generally relates to an optical device suitable for use with an optical medium for the storage and retrieval of data. The optical device includes an illumination means for providing a beam of optical radiation of wavelength .lamda. and an optical path that the beam of optical radiation follows. The optical device also includes a diffractive optical element defined by a plurality of annular sections. The plurality of annular sections having a first material alternately disposed with a plurality of annular sections comprising a second material. The diffractive optical element generates a plurality of focal points and densely accumulated ray points with phase contrast phenomena and the optical medium is positioned at a selected focal point or ray point of the diffractive optical element.

Dual annular rotating "windowed" nuclear reflector reactor control system

DOEpatents

Jacox, Michael G.; Drexler, Robert L.; Hunt, Robert N. M.; Lake, James A.

1994-01-01

A nuclear reactor control system is provided in a nuclear reactor having a core operating in the fast neutron energy spectrum where criticality control is achieved by neutron leakage. The control system includes dual annular, rotatable reflector rings. There are two reflector rings: an inner reflector ring and an outer reflector ring. The reflectors are concentrically assembled, surround the reactor core, and each reflector ring includes a plurality of openings. The openings in each ring are capable of being aligned or non-aligned with each other. Independent driving means for each of the annular reflector rings is provided so that reactor criticality can be initiated and controlled by rotation of either reflector ring such that the extent of alignment of the openings in each ring controls the reflection of neutrons from the core.

Pellet microfossils: Possible evidence for metazoan life in Early Proterozoic time

PubMed Central

Robbins, Eleanora Iberall; Porter, Karen Glaus; Haberyan, Kurt A.

1985-01-01

Microfossils resembling fecal pellets occur in acid-resistant residues and thin sections of Middle Cambrian to Early Proterozoic shale. The cylindrical microfossils average 50 × 110 μm and are the size and shape of fecal pellets produced by microscopic animals today. Pellets occur in dark gray and black rocks that were deposited in the facies that also preserves sulfide minerals and that represent environments analogous to those that preserve fecal pellets today. Rocks containing pellets and algal microfossils range in age from 0.53 to 1.9 gigayears (Gyr) and include Burgess Shale, Greyson and Newland Formations, Rove Formation, and Gunflint Iron-Formation. Similar rock types of Archean age, ranging from 2.68 to 3.8 Gyr, were barren of pellets. If the Proterozoic microfossils are fossilized fecal pellets, they provide evidence of metazoan life and a complex food chain at 1.9 Gyr ago. This occurrence predates macroscopic metazoan body fossils in the Ediacaran System at 0.67 Gyr, animal trace fossils from 0.9 to 1.3 Gyr, and fossils of unicellular eukaryotic plankton at 1.4 Gyr. Images PMID:16593599

Characterization of Residential Scale Biofuel Boilers and Fuels

NASA Astrophysics Data System (ADS)

Chandrasekaran, Sriraam R.

The objectives of this study were to: 1) characterize commercially available wood pellets and wood chips for basic properties such as calorific, ash, moisture contents; 2) analyze elements and ions and other possible contamination during the pellet manufacturing processes; 3) characterize the chemical and thermo-chemical property of grass pellets for their combustion potential; 4) characterize the emissions from 6 different residential scale boiler/furnace appliances burning grass and wood pellets; 5) characterize the emitted particulate matter for toxic and marker species with respect to combustion appliance and combustion conditions; and 6) determine the effects of the biomass fuel properties of 5 different grass pellets on particulate and gaseous emissions from a single type of boiler. The results from characterization of wood pellets and chips indicated that the wood pellet samples generally meet the quality standards. However, there are some samples that would fail the ash content requirements. Only the German standards have extensive trace element limits. Most of the samples would meet these standards, but some samples failed to meet these standards based on their lead, arsenic, cadmium, and copper concentrations. It is likely that inclusion of extraneous materials such as painted or pressure treated lumber led to the observed high concentrations. Given increasing use of pellets and chips as a renewable fuel, standards for the elemental composition of commercial wood pellets and chips are needed in United States to avoid the inclusion of extraneous materials. Such standards would reduce the environmental impact of toxic species that would be released when the wood is burned. Grass pellets were characterized for chemical and thermochemical properties. Switch grass pellets were studied for it thermal degradation process under inert and oxidizing atmosphere using TGA. The thermal degradation of grass pellet measured the activation energy and pre-exponential factors for switch grass decomposition. Two major losses occurred due to volatilization of cellulose, hemicelluloses, and lignin and burning or slow oxidation of residual char. The parameters were high for oxidative environment indicating high temperature sensitivity of the charcoal formation reaction. There was a substantial effect of heating rate on the mass loss and mass loss rate. The TG curve shifted to higher temperature ranges on increasing the heating rate. In both pyrolyzing and oxidizing conditions, average combustion and devolatlization rates increased. Emissions measurements and efficiency estimation were conducted on six commercially available residential scale appliances that utilize different technologies including direct combustion, gasification, lambda control, or fixed air flow rates that were designed to burn low ash wood (less than 1%). The grass has high ash and chlorine content producing more PM and chlorinated hydrocarbons including dioxins and furans. The results also indicated that the air supply and geometry of the furnace, and the type of furnace are also major influencing factors that affect the pollutant formation. To determine the effect of fuel properties on emissions formation, gaseous and particulate characterization was conducted of six fuels that include five different grass pellets types with ash content ranging from 3% to 13% and a premium wood pellet with ash content 0.6% on a boiler. Emissions from grass pellets were found to be higher than wood pellets and the PM; SO2 and NOx emissions were strongly related to the fuel properties such as ash content, sulfur and nitrogen content, respectively. CO emissions that indicate the completeness of reactions were higher for grass pellets and were strongly correlated to PAHs emissions. The PCDD/F emission was clearly a function of chlorine content of the fuel. A strong correlation existed between levoglucosan and PM2.5 concentrations indicated that levoglucosan is also a molecular marker for grass pellet combustion. All of the emissions were found to be higher for grass pellets when compared to the wood pellets and are higher at high loads than at low loads. These results show that the grass pellets cannot be used as a fuel in current generation wood pellet systems. It will be necessary to design systems that effectively deal with the higher ash and chlorine content if grass pellets are to be a significant fuel for home heating. (Abstract shortened by UMI.)

Nonlinear distortion of thin liquid sheets

NASA Astrophysics Data System (ADS)

Mehring, Carsten Ralf

Thin planar, annular and conical liquid sheets or films are analyzed, in a unified manner, by means of a reduced- dimension approach providing governing equations for the nonlinear motion of planar and swirling annular thin inviscid and incompressible liquid sheets in zero gravity and with axial disturbances only. Temporal analyses of periodically disturbed infinite sheets are considered, as well as spatial analyses of semi-infinite sheets modulated at the nozzle exit. Results on planar and swirling annular or conical sheets are presented for a zero density ambient gas. Here, conical sheets are obtained in the nearfield of the nozzle exit by considering sheets or films with swirl in excess of that needed to stabilize the discharging stream in its annular configuration. For nonswirling annular sheets a spatially and/or temporally constant gas-core pressure is assumed. A model extension considering the influence of aerodynamic effects on planar sheets is proposed. For planar and annular sheets, linear analyses of the pure initial- and pure boundary-value problem provide insight into the propagation characteristics of dilational and sinuous waves, the (linear) coupling between both wave modes, the stability limits for the annular configuration, as well as the appearance of particular waves on semi-infinite modulated sheets downstream from the nozzle exit. Nonlinear steady-state solutions for the conical configuration (without modulation) are illustrated. Comparison between nonlinear and linear numerical and linear analytical solutions for temporally or spatially developing sheets provides detailed information on the nonlinear distortion characteristics including nonlinear wave propagation and mode-coupling for all the considered geometric configurations and for a variety of parameter configurations. Sensitivity studies on the influence of Weber number, modulation frequency, annular radius, forcing amplitude and sheet divergence on breakup or collapse length and times are reported for modulated semi-infinite annular and conical sheets. Comparisons between the different geometric configurations are made. For periodically disturbed planar sheets, accuracy of the employed reduced-dimension approach is demonstrated by comparison with more accurate two-dimensional vortex dynamics simulations.

Cleaning By Blasting With Pellets Of Dry Ice

NASA Technical Reports Server (NTRS)

Fody, Jody

1993-01-01

Dry process strips protective surface coats from parts to be cleaned, without manual scrubbing. Does not involve use of flammable or toxic solvents. Used to remove coats from variety of materials, including plastics, ceramics, ferrous and nonferrous metals, and composites. Adds no chemical-pollution problem to problem of disposal of residue of coating material. Process consists of blasting solid carbon dioxide (dry ice) pellets at surface to be cleaned. Pellets sublime on impact and pass into atmosphere as carbon dioxide gas. Size, harness, velocity, and quantity of pellets adjusted to suit coating material and substrate.

Monitoring of a wide range of organic micropollutants on the Portuguese coast using plastic resin pellets.

PubMed

Mizukawa, Kaoruko; Takada, Hideshige; Ito, Maki; Geok, Yeo Bee; Hosoda, Junki; Yamashita, Rei; Saha, Mahua; Suzuki, Satoru; Miguez, Carlos; Frias, João; Antunes, Joana Cepeda; Sobral, Paula; Santos, Isabelina; Micaelo, Cristina; Ferreira, Ana Maria

2013-05-15

We analyzed polychlorinated biphenyls (PCBs), dichlorodiphenyl dichloroethane and its metabolites, hexachlorocyclohexanes (HCHs), polycyclic aromatic hydrocarbons (PAHs), and hopanes, in plastic resin pellets collected from nine locations along the Portuguese coast. Concentrations of a sum of 13 PCBs were one order of magnitude higher in two major cities (Porto: 307 ng/g-pellet; Lisboa: 273 ng/g-pellet) than in the seven rural sites. Lower chlorinated congeners were more abundant in the rural sites than in the cities, suggesting atmospheric dispersion. At most of the locations, PAH concentrations (sum of 33 PAH species) were ∼100 to ∼300 ng/g-pellet; however, three orders of magnitude higher concentrations of PAHs, with a petrogenic signature, were detected at a small city (Sines). Hopanes were detected in the pellets at all locations. This study demonstrated that multiple sample locations, including locations in both urban and remote areas, are necessary for country-scale pellet watch. Copyright © 2013 Elsevier Ltd. All rights reserved.

Operating experience with 100% pellet burden on Amanda blast furnace

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

Keaton, D.E.; Minakawa, T.

1993-01-01

A number of significant changes in operations at the Ashland Works of the Armco Steel Company occurred in 1992 which directly impacted the Amanda Blast Furnace operation. These changes included the shutdown of the hot strip mill which resulted in coke oven gas enrichment of the Amanda stoves and an increase of 75 C in hot blast temperature, transition to 100% continuous cast operation which resulted in increased variation of the hot metal demand, and the July idling of the sinter plant. Historically, the Amanda Blast Furnace burden was 30% fluxed sinter and 70% acid pellet. It was anticipated thatmore » the change to 100% pellet burden would require changes in charging practice and alter furnace performance. The paper gives a general furnace description and then describes the burden characteristics, operating practice with 30% sinter/70% acid pellet burden, preparations for the 100% acid pellet burden operation, the 100% acid pellet operation, and the 100% fluxed pellet burden operation.« less

Correlation of combustor acoustic power levels inferred from internal fluctuating pressure measurements

NASA Technical Reports Server (NTRS)

Vonglahn, U. H.

1978-01-01

Combustion chamber acoustic power levels inferred from internal fluctuating pressure measurements are correlated with operating conditions and chamber geometries over a wide range. The variables include considerations of chamber design (can, annular, and reverse-flow annular) and size, number of fuel nozzles, burner staging and fuel split, airflow and heat release rates, and chamber inlet pressure and temperature levels. The correlated data include those obtained with combustion component development rigs as well as engines.

Recent high-speed ballistics experiments at ORNL

NASA Astrophysics Data System (ADS)

Combs, S. K.; Gouge, M. J.; Baylor, L. R.; Fisher, P. W.; Foster, C. A.; Foust, C. R.; Milora, S. L.; Qualls, A. L.

Oak Ridge National Laboratory (ORNL) has been developing pellet injectors for plasma fueling experiments on magnetic confinement devices for almost 20 years. With these devices, pellets (1 to 8 mm in diameter) composed of hydrogen isotopes are formed (at temperatures less than 20 K) and typically accelerated to speeds of (approximately) 1.0 to 2.0 km/s for injection into plasmas of experimental fusion devices. A variety of pellet injector designs have been developed at ORNL, including repeating pneumatic injectors (single- and multiple-barrel light gas guns) that can inject up to hundreds of pellets for long-pulse plasma operation. The repeating pneumatic injectors are of particular importance because long-pulse fueling is required for present large experimental fusion devices, with steady-state operation the objective for future fusion reactors. In this paper, recent advancements in the development of repeating pneumatic injectors are described, including (1) a small-bore (1.8-mm), high-firing-rate (10-Hz) version of a single-stage light gas gun; (2) a repeating single-stage light gas gun for 8-mm-diam tritium pellets; (3) a repeating two-stage light gas gun for operation at higher pellet velocities; and (4) a steady-state hydrogen extruder feed system.

Recent high-speed ballistics experiments at ORNL

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

Combs, S.K.; Gouge, M.J.; Baylor, L.R.

1994-12-31

Oak Ridge National Laboratory (ORNL) has been developing pellet injectors for plasma fueling experiments on magnetic confinement devices for almost 20 years. With these devices, pellets (1 to 8 mm in diameter) composed of hydrogen isotopes are formed (at temperatures <20 K) and typically accelerated to speeds of {approximately} 1.0 to 2.0 km/s for injection into plasmas of experimental fusion devices. A variety of pellet injector designs have been developed at ORNL, including repeating pneumatic injectors (single- and multiple-barrel light gas guns) that can inject up to hundreds of pellets for long-pulse plasma operation. The repeating pneumatic injectors are ofmore » particular importance because long-pulse fueling is required for present large experimental fusion devices, with steady-state operation the objective for future fusion reactors. In this paper, recent advancements in the development of repeating pneumatic injectors are described, including (1) a small-bore (1.8-mm), high-firing-rate (10-Hz) version of a single-stage light gas gun; (2) a repeating single-stage light gas gun for 8-mm-diam tritium pellets; (3) a repeating two-stage light gas gun for operation at higher pellet velocities; and (4) a steady-state hydrogen extruder feed system.« less

Pellet inspection apparatus

DOEpatents

Wilks, Robert S.; Taleff, Alexander; Sturges, Jr., Robert H.

1982-01-01

Apparatus for inspecting nuclear fuel pellets in a sealed container for diameter, flaws, length and weight. The apparatus includes, in an array, a pellet pick-up station, four pellet inspection stations and a pellet sorting station. The pellets are delivered one at a time to the pick-up station by a vibrating bowl through a vibrating linear conveyor. Grippers each associated with a successive pair of the stations are reciprocable together to pick up a pellet at the upstream station of each pair and to deposit the pellet at the corresponding downstream station. The gripper jaws are opened selectively depending on the state of the pellets at the stations and the particular cycle in which the apparatus is operating. Inspection for diameter, flaws and length is effected in each case by a laser beam projected on the pellets by a precise optical system while each pellet is rotated by rollers. Each laser and its optical system are mounted in a container which is free standing on a precise surface and is provided with locating buttons which engage locating holes in the surface so that each laser and its optical system is precisely set. The roller stands are likewise free standing and are similarly precisely positioned. The diameter optical system projects a thin beam of light which scans across the top of each pellet and is projected on a diode array. The fl GOVERNMENT CONTRACT CLAUSE The invention herein described was made in the course of or under a contract or subcontract thereunder with the Department of Energy bearing No. EY-67-14-C-2170.

Mixer assembly for a gas turbine engine having a pilot mixer with a corner flame stabilizing recirculation zone

NASA Technical Reports Server (NTRS)

Dai, Zhongtao (Inventor); Cohen, Jeffrey M. (Inventor); Fotache, Catalin G. (Inventor)

2012-01-01

A mixer assembly for a gas turbine engine is provided, including a main mixer, and a pilot mixer having an annular housing in which a corner is formed between an aft portion of the housing and a bulkhead wall in which a corner recirculation zone is located to stabilize and anchor the flame of the pilot mixer. The pilot mixer can further include features to cool the annular housing, including in the area of the corner recirculation zone.

Dry pulverized solid material pump

DOEpatents

Meyer, John W.; Bonin, John H.; Daniel, Jr., Arnold D.

1984-07-31

Apparatus is shown for substantially increasing the feed rate of pulverized material into a pressurized container. The apparatus includes a rotor that is mounted internal to the pressurized container. The pulverized material is fed into an annular chamber defined by the center of the rotor. A plurality of impellers are mounted within the annular chamber for imparting torque to the pulverized material.

Data transmission element for downhole drilling components

DOEpatents

Hall, David R.; Hall, Jr., H. Tracy; Pixton, David S.; Dahlgren, Scott; Fox, Joe; Sneddon, Cameron; Briscoe, Michael

2006-01-31

A robust data transmission element for transmitting information between downhole components, such as sections of drill pipe, in the presence of hostile environmental conditions, such as heat, dirt, rocks, mud, fluids, lubricants, and the like. The data transmission element components include a generally U-shaped annular housing, a generally U-shaped magnetically conductive, electrically insulating element such as ferrite, and an insulated conductor. Features on the magnetically conducting, electrically insulating element and the annular housing create a pocket when assembled. The data transmission element is filled with a polymer to retain the components within the annular housing by filling the pocket with the polymer. The polymer can bond with the annular housing and the insulated conductor but preferably not the magnetically conductive, electrically insulating element. A data transmission element is mounted within a recess proximate a mating surface of a downhole drilling component, such as a section of drill pipe.

High Thrust-to-Power Annular Engine Technology

NASA Technical Reports Server (NTRS)

Patterson, Michael J.; Thomas, Robert E.; Crofton, Mark W.; Young, Jason A.; Foster, John E.

2015-01-01

Gridded ion engines have the highest efficiency and total impulse of any mature electric propulsion technology, and have been successfully implemented for primary propulsion in both geocentric and heliocentric environments with excellent ground/in-space correlation of performance. However, they have not been optimized to maximize thrust-to-power, an important parameter for Earth orbit transfer applications. This publication discusses technology development work intended to maximize this parameter. These activities include investigating the capabilities of a non-conventional design approach, the annular engine, which has the potential of exceeding the thrust-to-power of other EP technologies. This publication discusses the status of this work, including the fabrication and initial tests of a large-area annular engine. This work is being conducted in collaboration among NASA Glenn Research Center, The Aerospace Corporation, and the University of Michigan.

High Thrust-to-Power Annular Engine Technology

NASA Technical Reports Server (NTRS)

Patterson, Michael; Thomas, Robert; Crofton, Mark; Young, Jason A.; Foster, John E.

2015-01-01

Gridded ion engines have the highest efficiency and total impulse of any mature electric propulsion technology, and have been successfully implemented for primary propulsion in both geocentric and heliocentric environments with excellent ground-in-space correlation of performance. However, they have not been optimized to maximize thrust-to-power, an important parameter for Earth orbit transfer applications. This publication discusses technology development work intended to maximize this parameter. These activities include investigating the capabilities of a non-conventional design approach, the annular engine, which has the potential of exceeding the thrust-to-power of other EP technologies. This publication discusses the status of this work, including the fabrication and initial tests of a large-area annular engine. This work is being conducted in collaboration among NASA Glenn Research Center, The Aerospace Corporation, and the University of Michigan.

Centrifugally activated bearing for high-speed rotating machinery

DOEpatents

Post, Richard F.

1994-01-01

A centrifugally activated bearing is disclosed. The bearing includes an annular member that extends laterally and radially from a central axis. A rotating member that rotates about the central axis relative to the annular member is also included. The rotating member has an interior chamber that surrounds the central axis and in which the annular member is suspended. Furthermore, the interior chamber has a concave shape for retaining a lubricant therein while the rotating member is at rest and for retaining a lubricant therein while the rotating member is rotating. The concave shape is such that while the rotating member is rotating a centrifugal force causes a lubricant to be forced away from the central axis to form a cylindrical surface having an axis collinear with the central axis. This centrifugally displaced lubricant provides restoring forces to counteract lateral displacement during operation.

Dual annular rotating [open quotes]windowed[close quotes] nuclear reflector reactor control system

DOEpatents

Jacox, M.G.; Drexler, R.L.; Hunt, R.N.M.; Lake, J.A.

1994-03-29

A nuclear reactor control system is provided in a nuclear reactor having a core operating in the fast neutron energy spectrum where criticality control is achieved by neutron leakage. The control system includes dual annular, rotatable reflector rings. There are two reflector rings: an inner reflector ring and an outer reflector ring. The reflectors are concentrically assembled, surround the reactor core, and each reflector ring includes a plurality of openings. The openings in each ring are capable of being aligned or non-aligned with each other. Independent driving means for each of the annular reflector rings is provided so that reactor criticality can be initiated and controlled by rotation of either reflector ring such that the extent of alignment of the openings in each ring controls the reflection of neutrons from the core. 4 figures.

Generation of annular, high-charge electron beams at the Argonne wakefield accelerator

NASA Astrophysics Data System (ADS)

Wisniewski, E. E.; Li, C.; Gai, W.; Power, J.

2012-12-01

We present and discuss the results from the experimental generation of high-charge annular(ring-shaped)electron beams at the Argonne Wakefield Accelerator (AWA). These beams were produced by using laser masks to project annular laser profiles of various inner and outer diameters onto the photocathode of an RF gun. The ring beam is accelerated to 15 MeV, then it is imaged by means of solenoid lenses. Transverse profiles are compared for different solenoid settings. Discussion includes a comparison with Parmela simulations, some applications of high-charge ring beams,and an outline of a planned extension of this study.

Terrain Traversing Device Having a Wheel with Microhooks

NASA Technical Reports Server (NTRS)

Wiltsie, Nicholas (Inventor); Carpenter, Kalind C. (Inventor); Parness, Aaron (Inventor)

2015-01-01

A terrain traversing device is described. The device includes an annular rotor element with a plurality of co-planar microspine hooks arranged on the periphery of the annular rotor element. Each microspine hook has an independently flexible suspension configuration that permits the microspine hook to initially engage an irregularity in a terrain surface at a preset initial engagement angle and subsequently engage the irregularity with a continuously varying engagement angle when the annular rotor element is rotated for urging the terrain traversing device to traverse a terrain surface. Improvements related to the design, fabrication and use of the microspine hooks in the device are also described.

Trap seal for open circuit liquid cooled turbines

DOEpatents

Grondahl, Clayton M.; Germain, Malcolm R.

1980-01-01

An improved trap seal for open circuit liquid cooled turbines is disclosed. The trap seal of the present invention includes an annular recess formed in the supply conduit of cooling channels formed in the airfoil of the turbine buckets. A cylindrical insert is located in the annular recesses and has a plurality of axial grooves formed along the outer periphery thereof and a central recess formed in one end thereof. The axial grooves and central recess formed in the cylindrical insert cooperate with the annular recess to define a plurality of S-shaped trap seals which permit the passage of liquid coolant but prohibit passage of gaseous coolant.

Turbomachinery Laboratory Texas A and M University research progress on annular gas seals

NASA Technical Reports Server (NTRS)

Childs, Dara W.

1994-01-01

Three helically-grooved seals were tested and the results were compared to the MTI code SPIRALG. A smooth annular seal was tested at six eccentricity ratios from 0 to 0.5. The following are concluded in this viewgraph presentation: (1) Helical-grooved seals provide a substantial reduction in cross-coupled stiffness coefficients. Negative k(sub xy) values are obtained for no-swirl or low-swirl cases. (2) SPIRALG is completely unsuitable for the type of seal tested, namely, turbulent flow, wide grooves and lands, etc. (3) A good analysis code is needed to guide the design of helically-grooved annular seals including groove and smooth sections.

Internal impacted screw-locking pellet

NASA Technical Reports Server (NTRS)

MacMartin, Malcolm J. (Inventor)

1994-01-01

An elongate fastener having an engaging surface engageable with an engaging surface of a fastener's mate includes a hole extending through a portion of the fastener and having a top opening and a bottom floor, a locking pellet disposed near the bottom floor, a discharge channel communicating between the pellet and through the engaging surface of the fastener and opening out toward the engaging surface of the fastener's mate, and an impact pin in the hole having a top portion protruding through the top opening and a bottom portion near the locking pellet, whereby the pin drives the locking pellet through the discharge channel against the engaging surfaces of the fastener and the fastener's mate whereby to lock the fastener against the fastener's mate.

Split ring floating air riding seal for a turbine

DOEpatents

Mills, Jacob A

2015-11-03

A floating air riding seal for a gas turbine engine with a rotor and a stator, an annular piston chamber with an axial moveable annular piston assembly within the annular piston chamber, an annular cavity formed on the annular piston assembly that faces a seal surface on the rotor, and a central passage connecting the annular cavity to the annular piston chamber to supply compressed air to the seal face, where the annular piston assembly is a split piston assembly to maintain a tight seal as coning of the rotor disk occurs.

The UO2 ex-ADU powder preparation and pellet sintering for optimum efficiency: experimental and modeling studies

NASA Astrophysics Data System (ADS)

Hung, Nguyen Trong; Thuan, Le Ba; Van Tung, Nguyen; Thuy, Nguyen Thanh; Lee, Jin-Young; Jyothi, Rajesh Kumar

2017-12-01

The UO2 nuclear fuel pellet process for light water reactors (LWR) includes the conversion of uranium hexafluoride (UF6) into UO2 powder and the fabrication of UO2 pellets from such UO2 powder. In the paper, studies on UO2 pellet process from ammonium diuranate-derived uranium dioxide powder (UO2 ex-ADU powder) were reported. The UO2 ex-ADU powders were converted from ADU at various temperatures of 973 K, 1023 K and 1073 K and then UO2 pellets prepared from the powders were sintered at temperatures of 1923 K, 1973 K and 2023 K for times of 4 h, 6 h and 8 h. Response surface methodology (RSM) based on quadratic central composite design (CCD) type of face centered (CCF) improved by Box and Hunter was used to model the UO2 pellet process, using MODDE 5.0 software as an assessing tool. On the base of the proposed model, the relationship between the technological parameters and density of the UO2 pellet product was suggested to control the UO2 ex-ADU pellet process as desired levels.

Pharmaceutical approaches to preparing pelletized dosage forms using the extrusion-spheronization process.

PubMed

Trivedi, Namrata R; Rajan, Maria Gerald; Johnson, James R; Shukla, Atul J

2007-01-01

Pelletized dosage forms date back to the 1950s, when the first product was introduced to the market. Since then, these dosage forms have gained considerable popularity because of their distinct advantages, such as ease of capsule filling because of better flow properties of the spherical pellets; enhancement of drug dissolution; ease of coating; sustained, controlled, or site-specific delivery of the drug from coated pellets; uniform packing; even distribution in the GI tract; and less GI irritation. Pelletized dosage forms can be prepared by a number of techniques, including drug layering on nonpareil sugar or microcrystalline cellulose beads, spray drying, spray congealing, rotogranulation, hot-melt extrusion, and spheronization of low melting materials or extrusion-spheronization of a wet mass. This review discusses recent developments in the pharmaceutical approaches that have been used to prepare pelletized dosage forms using the extrusion-spheronization process over the last decade. The review is divided into three parts: the first part discusses the extrusion-spheronization process, the second part discusses the effect of varying formulation and process parameters on the properties of the pellets, and the last part discusses the different approaches that have been used to prepare pelletized dosage forms using the extrusion-spheronization process.

Geometrically nonlinear resonance of higher-order shear deformable functionally graded carbon-nanotube-reinforced composite annular sector plates excited by harmonic transverse loading

NASA Astrophysics Data System (ADS)

Gholami, Raheb; Ansari, Reza

2018-02-01

This article presents an attempt to study the nonlinear resonance of functionally graded carbon-nanotube-reinforced composite (FG-CNTRC) annular sector plates excited by a uniformly distributed harmonic transverse load. To this purpose, first, the extended rule of mixture including the efficiency parameters is employed to approximately obtain the effective material properties of FG-CNTRC annular sector plates. Then, the focus is on presenting the weak form of discretized mathematical formulation of governing equations based on the variational differential quadrature (VDQ) method and Hamilton's principle. The geometric nonlinearity and shear deformation effects are considered based on the von Kármán assumptions and Reddy's third-order shear deformation plate theory, respectively. The discretization process is performed via the generalized differential quadrature (GDQ) method together with numerical differential and integral operators. Then, an efficient multi-step numerical scheme is used to obtain the nonlinear dynamic behavior of the FG-CNTRC annular sector plates near their primary resonance as the frequency-response curve. The accuracy of the present results is first verified and then a parametric study is presented to show the impacts of CNT volume fraction, CNT distribution pattern, geometry of annular sector plate and sector angle on the nonlinear frequency-response curve of FG-CNTRC annular sector plates with different edge supports.

A thickness-mode piezoelectric micromachined ultrasound transducer annular array using a PMN–PZT single crystal

NASA Astrophysics Data System (ADS)

Kang, Woojin; Jung, Joontaek; Lee, Wonjun; Ryu, Jungho; Choi, Hongsoo

2018-07-01

Micro-electromechanical system (MEMS) technologies were used to develop a thickness-mode piezoelectric micromachined ultrasonic transducer (Tm-pMUT) annular array utilizing a lead magnesium niobate–lead zirconate titanate (PMN–PZT) single crystal prepared by the solid-state single-crystal-growth method. Dicing is a conventional processing method for PMN–PZT single crystals, but MEMS technology can be adopted for the development of Tm-pMUT annular arrays and has various advantages, including fabrication reliability, repeatability, and a curved element shape. An inductively coupled plasma–reactive ion etching process was used to etch a brittle PMN–PZT single crystal selectively. Using this process, eight ring-shaped elements were realized in an area of 1  ×  1 cm2. The resonance frequency and effective electromechanical coupling coefficient of the Tm-pMUT annular array were 2.66 (±0.04) MHz, 3.18 (±0.03) MHz, and 30.05%, respectively, in the air. The maximum positive acoustic pressure in water, measured at a distance of 7.27 mm, was 40 kPa from the Tm-pMUT annular array driven by a 10 Vpp sine wave at 2.66 MHz without beamforming. The proposed Tm-pMUT annular array using a PMN–PZT single crystal has the potential for various applications, such as a fingerprint sensor, and for ultrasonic cell stimulation and low-intensity tissue stimulation.

Tritium pellet injector for the tokamak fusion test reactor

NASA Astrophysics Data System (ADS)

Gouge, M. J.; Baylor, L. R.; Combs, S. K.; Fisher, P. W.; Foust, C. R.; Milora, S. L.

The tritium pellet injector (TPI) for the Tokamak Fusion Test Reactor (TFTR) will provide a tritium pellet fueling capability with pellet speeds in the 1- to 3-km/s range for the TFTR deuterium-tritium (D-T) plasma phase. An existing deuterium pellet injector (DPI) was modified at Oak Ridge National Laboratory (ORNL) to provide a four-shot, tritium-compatible, pipe-gun configuration with three upgraded single-stage pneumatic guns and a two-stage light gas gun driver. The TPI was designed for frozen pellets ranging in size from 3 to 4 mm in diameter in arbitrarily programmable firing sequences at tritium pellet speeds up to approximately 1.5 km/s for the three single-stage drivers and 2.5 to 3 km/s for the two-stage driver. Injector operation is controlled by a programmable logic controller (PLC). The new pipe-gun injector assembly was installed in the modified DPI guard vacuum box, and modifications were also made to the internals of the DPI vacuum injection line, including a new pellet diagnostics package. Assembly of these modified parts with existing DPI components was then completed and the TPI was tested at ORNL with deuterium pellets. Results of the testing program at ORNL are described. The TPI has been installed and operated on TFTR in support of the FY-92 deuterium plasma run period. In 1993, the tritium pellet injector will be retrofitted with a D-T fuel manifold and tritium gloveboxes and integrated into TFTR tritium processing systems to provide full tritium pellet capability.

Feeding soywaste or pellet on performance and carcass characteristics of post-weaning kids.

PubMed

Rahman, Mohammad Mijanur; Khadijah, Wan Embong Wan; Abdullah, Ramli Bin

2016-08-01

Twelve Jermasia kids were individually housed in pens to study the effects of soywaste on growth performance and carcass characteristics and to compare such effects with commercial pellet. Kids were divided into a pellet group and a soywaste group, including six kids (3 males and 3 females) in each group. Pellet or soywaste was offered to kids at a rate of 2.0 % dry matter (DM) of body weight/day in addition to Napier grass ad libitum. In last 10 days of experiment, kids were housed in metabolism crates for faeces collection. At the end of the experiment, three males from each group were slaughtered. Kids fed soywaste diet consumed more grass and neutral detergent fibre (NDF) than those fed pellet. The same trend was found for the digestibilities of DM, organic matter (OM) and NDF. Conversely, kids fed soywaste diet consumed less soywaste supplement than kids fed pellet. No treatment effects were observed on total intakes of DM, OM and crude protein (CP) including CP digestibility. Similarly, no effects were found on carcass and non-carcass components, except for lean, lean to fat ratio and kidney weight which were higher for kids fed soywaste diet. Results indicate that soywaste is effective as a feed for growing kids.

Rotary union for use with ultrasonic thickness measuring probe

DOEpatents

Nachbar, H.D.

1992-09-15

A rotary union for rotatably supporting an ultrasonic probe operable to nondestructively measure the thickness of steam generator tubes to determine the amount of corrosion experienced by the tubes includes a stationary body having a bore therethrough and an outlet drain, and a fitting rotatably mounted within the upper end of the body. The fitting has a bore aligned with the bore of the body. An electrical cable positioned within a water supply tube in an annular arrangement passes through the bore of the body and the bore of the fitting. This annular arrangement, in turn, is positioned within a connector element which extends outwardly from the fitting bore and is connected to the ultrasonic probe. An elastomeric lower bushing seals the annular arrangement to the lower end of the rotary union body and an elastomeric upper bushing seals the connector element to the fitting to permit the connector element and the ultrasonic probe connected thereto to rotate with the fitting relative to the body. The lower and upper bushings permit water to be passed through the annular arrangement and into the ultrasonic probe and thereafter discharged between the annular arrangement and the connector element to the outlet drain of the rotary union body. 5 figs.

Right ventricular remodeling and dysfunction with subsequent annular dilatation and tethering as a mechanism of isolated tricuspid regurgitation.

PubMed

Seo, Hye-Sun; Ha, Jong-Won; Moon, Jae Youn; Choi, Eui-Young; Rim, Se-Joong; Jang, Yangsoo; Chung, Namsik; Shim, Won-Heum; Cho, Seung-Yun; Kim, Sung Soon

2008-10-01

Secondary tricuspid regurgitation (TR) as a result of pulmonary hypertension and/or left-sided heart disease is caused by tricuspid valve (TV) annular dilatation and tethering of the tricuspid leaflet after right ventricular (RV) dilatation. However, the mechanism of isolated TR without significant pulmonary hypertension remains unknown. The present study investigated the RV function and TV deformations in patients with isolated TR to find out the mechanism and etiology of the disease. Twelve patients with isolated, severe TR were included. RV area, volume, ejection fraction (EF), tenting distance and tenting area were measured. These parameters were compared with 12 age-and gender-matched controls and 12 patients with secondary TR. The cause of isolated TR was incomplete coaptation associated with annular dilatation without other problems. Compared with the controls, RV end-diastolic volumes and annular diameters were significantly larger and RVEF was significantly lower in patients with isolated TR. Tenting area and tenting distance were also significantly higher. However, there were no significant differences in these parameters between patients with isolated and secondary TR. Isolated TR was associated with RV remodeling, systolic dysfunction and resultant annular dilatation and tethering of tricuspid leaflets.

Rotary union for use with ultrasonic thickness measuring probe

DOEpatents

Nachbar, Henry D.

1992-01-01

A rotary union for rotatably supporting an ultrasonic probe operable to nondestructively measure the thickness of steam generator tubes to determine the amount of corrosion experienced by the tubes includes a stationary body having a bore therethrough and an outlet drain, and a fitting rotatably mounted within the upper end of the body. The fitting has a bore aligned with the bore of the body. An electrical cable positioned within a water supply tube in an annular arrangement passes through the bore of the body and the bore of the fitting. This annular arrangement, in turn, is positioned within a connector element which extends outwardly from the fitting bore and is connected to the ultrasonic probe. An elastomeric lower bushing seals the annular arrangement to the lower end of the rotary union body and an elastomeric upper bushing seals the connector element to the fitting to permit the connector element and the ultrasonic probe connected thereto to rotate with the fitting relative to the body. The lower and upper bushings permit water to be passed through the annular arrangement and into the ultrasonic probe and thereafter discharged between the annular arrangement and the connector element to the outlet drain of the rotary union body.

Apparatus and method for classifying fuel pellets for nuclear reactor

DOEpatents

Wilks, Robert S.; Sternheim, Eliezer; Breakey, Gerald A.; Sturges, Jr., Robert H.; Taleff, Alexander; Castner, Raymond P.

1984-01-01

Control for the operation of a mechanical handling and gauging system for nuclear fuel pellets. The pellets are inspected for diameters, lengths, surface flaws and weights in successive stations. The control includes, a computer for commanding the operation of the system and its electronics and for storing and processing the complex data derived at the required high rate. In measuring the diameter, the computer enables the measurement of a calibration pellet, stores that calibration data and computes and stores diameter-correction factors and their addresses along a pellet. To each diameter measurement a correction factor is applied at the appropriate address. The computer commands verification that all critical parts of the system and control are set for inspection and that each pellet is positioned for inspection. During each cycle of inspection, the measurement operation proceeds normally irrespective of whether or not a pellet is present in each station. If a pellet is not positioned in a station, a measurement is recorded, but the recorded measurement indicates maloperation. In measuring diameter and length a light pattern including successive shadows of slices transverse for diameter or longitudinal for length are projected on a photodiode array. The light pattern is scanned electronically by a train of pulses. The pulses are counted during the scan of the lighted diodes. For evaluation of diameter the maximum diameter count and the number of slices for which the diameter exceeds a predetermined minimum is determined. For acceptance, the maximum must be less than a maximum level and the minimum must exceed a set number. For evaluation of length, the maximum length is determined. For acceptance, the length must be within maximum and minimum limits.

Chemical methods in the development of eco-efficient wood-based pellet production and technology.

PubMed

Kuokkanen, Matti; Kuokkanen, Toivo; Stoor, Tuomas; Niinimäki, Jouko; Pohjonen, Veli

2009-09-01

Up to 20 million tons of waste wood biomass per year is left unused in Finland, mainly in the forests during forestry operations, because supply and demand does not meet. As a consequence of high heat energy prices, the looming threat of climate change, the greenhouse effect, and due to global as well as national demands to considerably increase the proportion of renewable energy, there is currently tremendous enthusiasm in Finland to substantially increase pellet production. As part of this European objective to increase the eco- and cost-efficient utilization of bio-energy from the European forest belt, the aim of our research group is - by means of multidisciplinary research, especially through chemical methods - to promote the development of Nordic wood-based pellet production in both the qualitative and the quantitative sense. Wood-based pellets are classified as an emission-neutral fuel, which means that they are free from emission trading in the European Union. The main fields of pellet research and the chemical toolbox that has been developed for these studies, which includes a new specific staining and optical microscope method designed to determine the cross-linking of pellets in the presence of various binding compounds, are described in this paper. As model examples illustrating the benefits of this toolbox, experimental data is presented concerning Finnish wood pellets and corresponding wood-based pellets that include the use of starch-containing waste potato peel residue and commercial lignosulfonate as binding materials. The initial results concerning the use of the developed and optimized specific staining and microscopic method using starch-containing potato peel residue as binding material are presented.

Inductive coupler for downhole components and method for making same

DOEpatents

Hall, David R.; Hall, Jr., H. Tracy; Pixton, David S.; Dahlgren, Scott; Sneddon, Cameron; Fox, Joe; Briscoe, Michael A.

2006-10-03

An inductive coupler for downhole components. The inductive coupler includes an annular housing having a recess defined by a bottom portion and two opposing side wall portions. At least one side wall portion includes a lip extending toward but not reaching the other side wall portion. A plurality of generally U-shaped MCEI segments, preferably comprised of ferrite, are disposed in the recess and aligned so as to form a circular trough. The coupler further includes a conductor disposed within the circular trough and a polymer filling spaces between the segments, the annular housing and the conductor.

Auxiliary reactor for a hydrocarbon reforming system

DOEpatents

Clawson, Lawrence G.; Dorson, Matthew H.; Mitchell, William L.; Nowicki, Brian J.; Bentley, Jeffrey M.; Davis, Robert; Rumsey, Jennifer W.

2006-01-17

An auxiliary reactor for use with a reformer reactor having at least one reaction zone, and including a burner for burning fuel and creating a heated auxiliary reactor gas stream, and heat exchanger for transferring heat from auxiliary reactor gas stream and heat transfer medium, preferably two-phase water, to reformer reaction zone. Auxiliary reactor may include first cylindrical wall defining a chamber for burning fuel and creating a heated auxiliary reactor gas stream, the chamber having an inlet end, an outlet end, a second cylindrical wall surrounding first wall and a second annular chamber there between. The reactor being configured so heated auxiliary reactor gas flows out the outlet end and into and through second annular chamber and conduit which is disposed in second annular chamber, the conduit adapted to carry heat transfer medium and being connectable to reformer reaction zone for additional heat exchange.

Centrifugally activated bearing for high-speed rotating machinery

DOEpatents

Post, R.F.

1994-02-15

A centrifugally activated bearing is disclosed. The bearing includes an annular member that extends laterally and radially from a central axis. A rotating member that rotates about the central axis relative to the annular member is also included. The rotating member has an interior chamber that surrounds the central axis and in which the annular member is suspended. Furthermore, the interior chamber has a concave shape for retaining a lubricant therein while the rotating member is at rest and for retaining a lubricant therein while the rotating member is rotating. The concave shape is such that while the rotating member is rotating a centrifugal force causes a lubricant to be forced away from the central axis to form a cylindrical surface having an axis collinear with the central axis. This centrifugally displaced lubricant provides restoring forces to counteract lateral displacement during operation. 4 figures.

Lens fiber organization in four avian species: a scanning electron microscopic study.

PubMed

Willekens, B; Vrensen, G

1985-01-01

The three-dimensional organization of the eye lenses of the chicken, the canary, the song-thrush and the kestrel was studied using light and scanning electron microscopy. The lenses of birds are characterized by the presence of two distinct compartments: the annular pad and the main lens body, separated by a cavum lenticuli. The annular pad fibers had a hexagonal circumference all contained a round nucleus and except for the canary were smooth-surfaced and lacking anchoring devices. In the canary, however, the annular pad fibers were studded with edge protrusions and ball-and-socket junctions. The semicircular main lens body fibers of all four species were studded with ball-and-socket junctions and edge protrusions. In contrast with mammals these anchoring devices were present throughout the lens up to the embryonal nucleus. Superficially the main lens body fibers were extremely flat. Additionally membrane elevations and depressions and globular elements were found on these central fibers in three species, the kestrel being the exception. At the transition between annular pad and main lens body the fibers turned their course and the nuclei became oval and disappeared in the deeper aspect of the main lens body. The cavum lenticuli was filled with globules tied off from the annular pad fibers. It seems attractive to assume that the presence of a separated annular pad, a cavum lenticuli filled with globular elements, the extreme flatness of the superficial central fibers and the studding of these central fibers with anchoring devices up to the embryonal nucleus are morphological expressions of the mouldability of the bird's eye lenses and consequently would explain their efficient accommodative mechanism including formation of a lenticonus. The presence of nuclei in the annular pad fibers and their typical change at the transitional zone between annular pad and main lens body are suggestive for a two-phased differentiation in bird's lens fibers: differentiation of the germinative epithelial cells to annular pad fibers which migrate to the main lens body after which they differentiate further to main lens body fibers.

Pellet injection into H-mode ITER plasma with the presence of internal transport barriers

NASA Astrophysics Data System (ADS)

Leekhaphan, P.; Onjun, T.

2011-04-01

The impacts of pellet injection into ITER type-1 ELMy H-mode plasma with the presence of internal transport barriers (ITBs) are investigated using self-consistent core-edge simulations of 1.5D BALDUR integrated predictive modeling code. In these simulations, the plasma core transport is predicted using a combination of a semi-empirical Mixed B/gB anomalous transport model, which can self-consistently predict the formation of ITBs, and the NCLASS neoclassical model. For simplicity, it is assumed that toroidal velocity for ω E× B calculation is proportional to local ion temperature. In addition, the boundary conditions are predicted using the pedestal temperature model based on magnetic and flow shear stabilization width scaling; while the density of each plasma species, including both hydrogenic and impurity species, at the boundary are assumed to be a large fraction of its line averaged density. For the pellet's behaviors in the hot plasma, the Neutral Gas Shielding (NGS) model by Milora-Foster is used. It was found that the injection of pellet could result in further improvement of fusion performance from that of the formation of ITB. However, the impact of pellet injection is quite complicated. It is also found that the pellets cannot penetrate into a deep core of the plasma. The injection of the pellet results in a formation of density peak in the region close to the plasma edge. The injection of pellet can result in an improved nuclear fusion performance depending on the properties of pellet (i.e., increase up to 5% with a speed of 1 km/s and radius of 2 mm). A sensitivity analysis is carried out to determine the impact of pellet parameters, which are: the pellet radius, the pellet velocity, and the frequency of injection. The increase in the pellet radius and frequency were found to greatly improve the performance and effectiveness of fuelling. However, changing the velocity is observed to exert small impact.

Levitation pressure and friction losses in superconducting bearings

DOEpatents

Hull, John R.

2001-01-01

A superconducting bearing having at least one permanent magnet magnetized with a vertical polarization. The lower or stator portion of the bearing includes an array of high-temperature superconducting elements which are comprised of a plurality of annular rings. An annular ring is located below each permanent magnet and an annular ring is offset horizontally from at least one of the permanent magnets. The rings are composed of individual high-temperature superconducting elements located circumferentially along the ring. By constructing the horizontally-offset high-temperature superconducting ring so that the c-axis is oriented in a radial direction, a higher levitation force can be achieved. Such an orientation will also provide substantially lower rotational drag losses in the bearing.

Gas flow path for a gas turbine engine

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

Montgomery, Matthew D.; Charron, Richard C.; Snyder, Gary D.

A duct arrangement in a can annular gas turbine engine. The gas turbine engine has a gas delivery structure for delivering gases from a plurality of combustors to an annular chamber that extends circumferentially and is oriented concentric to a gas turbine engine longitudinal axis for delivering the gas flow to a first row of blades A gas flow path is formed by the duct arrangement between a respective combustor and the annular chamber for conveying gases from each combustor to the first row of turbine blades The duct arrangement includes at least one straight section having a centerline thatmore » is misaligned with a centerline of the combustor.« less

Effect of Pellet Boiler Exhaust on Secondary Organic Aerosol Formation from α-Pinene.

PubMed

Kari, Eetu; Hao, Liqing; Yli-Pirilä, Pasi; Leskinen, Ari; Kortelainen, Miika; Grigonyte, Julija; Worsnop, Douglas R; Jokiniemi, Jorma; Sippula, Olli; Faiola, Celia L; Virtanen, Annele

2017-02-07

Interactions between anthropogenic and biogenic emissions, and implications for aerosol production, have raised particular scientific interest. Despite active research in this area, real anthropogenic emission sources have not been exploited for anthropogenic-biogenic interaction studies until now. This work examines these interactions using α-pinene and pellet boiler emissions as a model test system. The impact of pellet boiler emissions on secondary organic aerosol (SOA) formation from α-pinene photo-oxidation was studied under atmospherically relevant conditions in an environmental chamber. The aim of this study was to identify which of the major pellet exhaust components (including high nitrogen oxide (NO x ), primary particles, or a combination of the two) affected SOA formation from α-pinene. Results demonstrated that high NO x concentrations emitted by the pellet boiler reduced SOA yields from α-pinene, whereas the chemical properties of the primary particles emitted by the pellet boiler had no effect on observed SOA yields. The maximum SOA yield of α-pinene in the presence of pellet boiler exhaust (under high-NO x conditions) was 18.7% and in the absence of pellet boiler exhaust (under low-NO x conditions) was 34.1%. The reduced SOA yield under high-NO x conditions was caused by changes in gas-phase chemistry that led to the formation of organonitrate compounds.

Technoeconomic analysis of wheat straw densification in the Canadian Prairie Province of Manitoba.

PubMed

Mupondwa, Edmund; Li, Xue; Tabil, Lope; Phani, Adapa; Sokhansanj, Shahab; Stumborg, Mark; Gruber, Margie; Laberge, Serge

2012-04-01

This study presents a technoeconomic analysis of wheat straw densification in Canada's prairie province of Manitoba as an integral part of biomass-to-cellulosic-ethanol infrastructure. Costs of wheat straw bale and pellet transportation and densification are analysed, including densification plant profitability. Wheat straw collection radius increases nonlinearly with pellet plant capacity, from 9.2 to 37km for a 2-35tonnesh(-1) plant. Bales are cheaper under 250km, beyond which the cheapest feedstocks are pellets from the largest pellet plant that can be built to exploit economies of scale. Feedstocks account for the largest percentage of variable costs. Marginal and average cost curves suggest Manitoba could support a pellet plant up to 35tonnesh(-1). Operating below capacity (75-50%) significantly erodes a plant's net present value (NPV). Smaller plants require higher NPV break-even prices. Very large plants have considerable risk under low pellet prices and increased processing costs. Crown Copyright © 2012. Published by Elsevier Ltd. All rights reserved.

Reductions in Emissions of Carbonaceous Particulate Matter and Polycyclic Aromatic Hydrocarbons from Combustion of Biomass Pellets in Comparisonwith Raw Fuel Burning

PubMed Central

SHEN, Guofeng; TAO, Shu; WEI, Siye; ZHANG, Yanyan; WANG, Rong; WANG, Bin; LI, Wei; SHEN, Huizhong; HUANG, Ye; CHEN, Yuanchen; CHEN, Han; YANG, Yifeng; WANG, Wei; WEI, Wen; WANG, Xilong; LIU, Wenxing; WANG, Xuejun; SIMONICH, Staci L. Massey

2012-01-01

Biomass pellets are emerging as a cleaner alternative to traditional biomass fuels. The potential benefits of using biomass pellets include improving energy utilization efficiency and reducing emissions of air pollutants. To assess the environmental, climate, and health significance of replacing traditional fuels with biomass pellets, it is critical to measure the emission factors (EFs) of various pollutants from pellet burning. However, only a few field measurements have been conducted on the emissions of carbon monoxide (CO), particulate matter (PM), and polycyclic aromatic hydrocarbons (PAHs) from the combustion of pellets. In this study, pine wood and corn straw pellets were burned in a pellet burner (2.6 kW) and the EFs of CO, organic carbon, elemental carbon, PM, and PAHs (EFCO, EFOC, EFEC, EFPM, and EFPAH) were determined. The average EFCO, EFOC, EFEC, and EFPM were 1520±1170, 8.68±11.4, 11.2±8.7, and 188±87 mg/MJ for corn straw pellets, and 266±137, 5.74±7.17, 2.02±1.57, and 71.0±54.0 mg/MJ for pine wood pellets, respectively. Total carbonaceous carbon constituted 8 to 14% of the PM mass emitted. The measured values of EFPAH for the two pellets were 1.02±0.64 and 0.506±0.360 mg/MJ, respectively. The secondary side air supply in the pellet burner did not change the EFs of most pollutants significantly (p > 0.05). The only exceptions were EFOC and EFPM for pine wood pellets because of reduced combustion temperatures with the increased air supply. In comparison with EFs for the raw pine wood and corn straw, EFCO, EFOC, EFEC, and EFPM for pellets were significantly lower than those for raw fuels (p < 0.05). However, the differences in EFPAH were not significant (p > 0.05). Based on the measured EFs and thermal efficiencies, it was estimated that 95, 98, 98, 88, and 71% reductions in the total emissions of CO, OC, EC, PM, and PAHs could be achieved by replacing the raw biomass fuels combusted in traditional cooking stoves with pellets burned in modern pellet burners. PMID:22568759

Reductions in emissions of carbonaceous particulate matter and polycyclic aromatic hydrocarbons from combustion of biomass pellets in comparison with raw fuel burning.

PubMed

Shen, Guofeng; Tao, Shu; Wei, Siye; Zhang, Yanyan; Wang, Rong; Wang, Bin; Li, Wei; Shen, Huizhong; Huang, Ye; Chen, Yuanchen; Chen, Han; Yang, Yifeng; Wang, Wei; Wei, Wen; Wang, Xilong; Liu, Wenxing; Wang, Xuejun; Masse Simonich, Staci L y

2012-06-05

Biomass pellets are emerging as a cleaner alternative to traditional biomass fuels. The potential benefits of using biomass pellets include improving energy utilization efficiency and reducing emissions of air pollutants. To assess the environmental, climate, and health significance of replacing traditional fuels with biomass pellets, it is critical to measure the emission factors (EFs) of various pollutants from pellet burning. However, only a few field measurements have been conducted on the emissions of carbon monoxide (CO), particulate matter (PM), and polycyclic aromatic hydrocarbons (PAHs) from the combustion of pellets. In this study, pine wood and corn straw pellets were burned in a pellet burner (2.6 kW), and the EFs of CO, organic carbon, elemental carbon, PM, and PAHs (EF(CO), EF(OC), EF(EC), EF(PM), and EF(PAH)) were determined. The average EF(CO), EF(OC), EF(EC), and EF(PM) were 1520 ± 1170, 8.68 ± 11.4, 11.2 ± 8.7, and 188 ± 87 mg/MJ for corn straw pellets and 266 ± 137, 5.74 ± 7.17, 2.02 ± 1.57, and 71.0 ± 54.0 mg/MJ for pine wood pellets, respectively. Total carbonaceous carbon constituted 8 to 14% of the PM mass emitted. The measured values of EF(PAH) for the two pellets were 1.02 ± 0.64 and 0.506 ± 0.360 mg/MJ, respectively. The secondary side air supply in the pellet burner did not change the EFs of most pollutants significantly (p > 0.05). The only exceptions were EF(OC) and EF(PM) for pine wood pellets because of reduced combustion temperatures with the increased air supply. In comparison with EFs for the raw pine wood and corn straw, EF(CO), EF(OC), EF(EC), and EF(PM) for pellets were significantly lower than those for raw fuels (p < 0.05). However, the differences in EF(PAH) were not significant (p > 0.05). Based on the measured EFs and thermal efficiencies, it was estimated that 95, 98, 98, 88, and 71% reductions in the total emissions of CO, OC, EC, PM, and PAHs could be achieved by replacing the raw biomass fuels combusted in traditional cooking stoves with pellets burned in modern pellet burners.

Cooling supply system for stage 3 bucket of a gas turbine

DOEpatents

Eldrid, Sacheverel Quentin; Burns, James Lee; Palmer, Gene David; Leone, Sal Albert; Drlik, Gary Joseph; Gibler, Edward Eugene

2002-01-01

In a land based gas turbine including a compressor, a combustor and turbine section including at least three stages, an improvement comprising an inlet into a third stage nozzle from the compressor for feeding cooling air from the compressor to the third stage nozzle; at least one passageway running substantially radially through each airfoil of the third stage nozzle and an associated diaphragm, into an annular space between the rotor and the diaphragm; and passageways communicating between the annular space and individual buckets of the third stage.

Plastic phase change material and articles made therefrom

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

Abhari, Ramin

The present invention generally relates to a method for manufacturing phase change material (PCM) pellets. The method includes providing a melt composition, including paraffin and a polymer. The paraffin has a melt point of between about 10.degree. C. and about 50.degree. C., and more preferably between about 18.degree. C. and about 28.degree. C. In one embodiment, the melt composition includes various additives, such as a flame retardant. The method further includes forming the melt composition into PCM pellets. The method further may include the step of cooling the melt to increase the melt viscosity before pelletizing. Further, PCM compounds aremore » provided having an organic PCM and a polymer. Methods are provided to convert the PCM compounds into various form-stable PCMs. A method of coating the PCMs is included to provide PCMs with substantially no paraffin seepage and with ignition resistance properties.« less

Experimental equipment for measuring physical properties of the annular hydrostatic thrust bearing

NASA Astrophysics Data System (ADS)

Kozdera, Michal; Drábková, Sylva; Bojko, Marian

2014-03-01

The hydraulic circuit, through which the mineral oil is brought, is an important part of hydrostatic bearings. The annular hydrostatic thrust bearing consists of two sliding plates divided by a layer of mineral oil. In the lower plate, there are oil grooves which distribute the liquid between the sliding areas. The hydraulic circuit is made of two basic parts: the energy source and the controlling part. The hydraulic pump, which brings the liquid into the sliding bearing, is the source of the pressure energy. The sliding bearing is weighted down by axial force, which can be changed during the process. That's why in front of the particular oil grooves control components adjusting pressure and flow size are located. This paper deals with a project of a hydraulic circuit for regulation of fluid layer in the annular hydrostatic thrust bearing and the testing equipment for measuring its physical properties. It will include the issue of measuring loading capacity and height of the fluid layer in the annular hydrostatic thrust bearing.

Microstructure of agglomerated suspended sediments in northern chesapeake bay estuary.

PubMed

Zabawa, C F

1978-10-06

Suspended sediments in the turbidity maximum of Chesapeake Bay include composite particles which contain platy mineral grains, arranged both in pellets (attributable to fecal pelletization) and in networks of angular configuration (attributable to electrochemical flocculation and coagulation).

NEUTRONIC REACTOR

DOEpatents

Fraas, A.P.; Mills, C.B.

1961-11-21

A neutronic reactor in which neutron moderation is achieved primarily in its reflector is described. The reactor structure consists of a cylindrical central "island" of moderator and a spherical moderating reflector spaced therefrom, thereby providing an annular space. An essentially unmoderated liquid fuel is continuously passed through the annular space and undergoes fission while contained therein. The reactor, because of its small size, is particularly adapted for propulsion uses, including the propulsion of aircraft. (AEC)

Liner mounting assembly

NASA Technical Reports Server (NTRS)

Halila, Ely E. (Inventor)

1994-01-01

A mounting assembly includes an annular supporting flange disposed coaxially about a centerline axis which has a plurality of circumferentially spaced apart supporting holes therethrough. An annular liner is disposed coaxially with the supporting flange and includes a plurality of circumferentially spaced apart mounting holes aligned with respective ones of the supporting holes. Each of a plurality of mounting pins includes a proximal end fixedly joined to the supporting flange through a respective one of the supporting holes, and a distal end disposed through a respective one of the liner mounting holes for supporting the liner to the supporting flange while unrestrained differential thermal movement of the liner relative to the supporting flange.

Shaft seal system

DOEpatents

Kapich, Davorin D.

1985-01-01

A shaft seal system is disclosed for isolating two regions of different fluid mediums through which a rotatable shaft extends. The seal system includes a seal housing through which the shaft extends and which defines an annular land and an annular labyrinth both of which face on the shaft so that each establishes a corresponding fluid sealing annulus. A collection cavity is formed in communication with the annular sealing spaces, and fluids compatible with the fluids in each of the two regions to be isolated are introduced, respectively, into the annular sealing spaces and collected in the collection cavity from which the fluid mixture is removed and passed to a separator which separates the fluids and returns them to their respective annular sealing spaces in a recycling manner. In the illustrated embodiment, the isolated fluid mediums comprise a liquid region and a gas region. Gas is removed from the gas region and passed through a purifier and a gas pump operative to introduce the purified gas through the labyrinth sealing annulus to the collection cavity. After passing to the separator, the separated gas is passed through a dryer from which the dried gas is caused to pass through the labyrinth sealing annulus into the collection cavity independently of the purified gas so as to insure isolation of the gas region in the event of sealing gas pump malfunction.

Bottom head to shell junction assembly for a boiling water nuclear reactor

DOEpatents

Fife, Alex Blair; Ballas, Gary J.

1998-01-01

A bottom head to shell junction assembly which, in one embodiment, includes an annular forging having an integrally formed pump deck and shroud support is described. In the one embodiment, the annular forging also includes a top, cylindrical shaped end configured to be welded to one end of the pressure vessel cylindrical shell and a bottom, conical shaped end configured to be welded to the disk shaped bottom head. Reactor internal pump nozzles also are integrally formed in the annular forging. The nozzles do not include any internal or external projections. Stubs are formed in each nozzle opening to facilitate welding a pump housing to the forging. Also, an upper portion of each nozzle opening is configured to receive a portion of a diffuser coupled to a pump shaft which extends through the nozzle opening. Diffuser openings are formed in the integral pump deck to provide additional support for the pump impellers. The diffuser opening is sized so that a pump impeller can extend at least partially therethrough. The pump impeller is connected to the pump shaft which extends through the nozzle opening.

Bottom head to shell junction assembly for a boiling water nuclear reactor

DOEpatents

Fife, A.B.; Ballas, G.J.

1998-02-24

A bottom head to shell junction assembly which, in one embodiment, includes an annular forging having an integrally formed pump deck and shroud support is described. In the one embodiment, the annular forging also includes a top, cylindrical shaped end configured to be welded to one end of the pressure vessel cylindrical shell and a bottom, conical shaped end configured to be welded to the disk shaped bottom head. Reactor internal pump nozzles also are integrally formed in the annular forging. The nozzles do not include any internal or external projections. Stubs are formed in each nozzle opening to facilitate welding a pump housing to the forging. Also, an upper portion of each nozzle opening is configured to receive a portion of a diffuser coupled to a pump shaft which extends through the nozzle opening. Diffuser openings are formed in the integral pump deck to provide additional support for the pump impellers. The diffuser opening is sized so that a pump impeller can extend at least partially therethrough. The pump impeller is connected to the pump shaft which extends through the nozzle opening. 5 figs.

The Penetration Behavior of an Annular Gas-Solid Jet Impinging on a Liquid Bath: The Effects of the Density and Size of Solid Particles

NASA Astrophysics Data System (ADS)

Chang, J. S.; Sohn, H. Y.

2012-08-01

Top-blow injection of a gas-solid jet through a circular lance is used in the Mitsubishi Continuous Smelting Process. One problem associated with this injection is the severe erosion of the hearth refractory below the lances. A new configuration of the lance to form an annular gas-solid jet rather than the circular jet was designed in this laboratory. With this new configuration, the solid particles fed through the center tube leave the lance at a much lower velocity than the gas, and the penetration behavior of the jet is significantly different from that with a circular lance where the solid particles leave the lance at the same high velocity as the gas. In previous cold-model investigations in this laboratory, the effects of the gas velocity, particle feed rate, lance height of the annular lance, and the cross-sectional area of the gas jet were studied and compared with the circular lance. This study examined the effect of the density and size of the solid particles on the penetration behavior of the annular gas-solid jet, which yielded some unexpected results. The variation in the penetration depth with the density of the solid particles at the same mass feed rate was opposite for the circular lance and the annular lance. In the case of the circular lance, the penetration depth became shallower as the density of the solid particles increased; on the contrary, for the annular lance, the penetration depth became deeper with the increasing density of particles. However, at the same volumetric feed rate of the particles, the density effect was small for the circular lance, but for the annular lance, the jets with higher density particles penetrated more deeply. The variation in the penetration depth with the particle diameter was also different for the circular and the annular lances. With the circular lance, the penetration depth became deeper as the particle size decreased for all the feed rates, but with the annular lance, the effect of the particle size was small. The overall results including the previous work indicated that the penetration behavior of an annular jet is much less sensitive to the variations in operating variables than that of a circular jet. Correlation equations for the penetration depth that show good agreements with the measured values have been developed.

[Multiple cephalic deep granuloma annulare of children].

PubMed

Bulinckx, A; Cambier, N; Wayllace Gaspar, L; Théate, I; Roquet-Gravy, P P; Bessis, D

2017-10-01

Deep granuloma annulare is a fairly rare variety of granuloma annulare. It is seen predominantly in children and mainly affects the anterior aspect of the legs and the top of the feet; cephalic presentation is rare. Below, we report three cases of deep granuloma annulare in children presenting solely at the cephalic extremity. Case 1: a six-year-old boy presented 7 cutaneous nodules measuring 1 to 2cm that were flesh-coloured, insensitive to palpation, of hard consistency and deeply attached. The lesions were grouped together on the anterior half of the left temporal fossa. While spontaneous regression of the three nodules was noted in the month following cutaneous biopsy, these nodules recurred a few months later. Case 2: a four-year-old girl with five deep cephalic nodules measuring around one centimetre and the colour of normal skin were seen on her right temporal fossa. The child was lost to follow-up after biopsy. Case 3: a four-month-old infant was presenting some 15 deep cutaneous nodules arranged in linear fashion on the forehead next to the left temporal fossa. These nodules regressed spontaneously one month after biopsy. In all three cases, histological examination confirmed the diagnosis of deep granuloma annulare. There have been few published cases of multiple, cephalic, deep granuloma annulare at a single site in children. The condition has an extensive differential diagnosis that includes malignant tumours; in addition, histological confirmation is normally essential. Treatment is not qualified and therapeutic extension with clinical monitoring alone may frequently be recommended. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Minimising alkalinity and pH spikes from Portland cement-bound Bauxsol (seawater-neutralized red mud) pellets for pH circum-neutral waters.

PubMed

Despland, Laure M; Clark, Malcolm W; Aragno, Michel; Vancov, Tony

2010-03-15

Bauxsol reagents (powder, slurry, or pellet forms) are powerful tools in environmental remediation and water and sewage treatment However, when used in circum-neutral water treatments, cement-bound Bauxsol pellets produce a sustained pH and alkalinity spike due to the presence of unreacted CaO in the cement binder. This study developed a pellet treatment system to minimize the alkalinity/pH spike. The recipe for pelletization consisted of Bauxsol powder, ordinary Portland cement (OPC), hydrophilic fumed silica, aluminum powder, a viscosity modifier, and water. Several batches (including different ratios and sizes) were run using modified makeup waters (H(2)0 + CO(2) or NaHCO(3)) or curing brines (CO(2), NaHCO(3), or Mg/CaCl(2)). Alkalinity, pH stability, and slake durability tests were performed on pellets before and/or after curing. The best result for reducing the alkalinity/pH spike was obtained from a MgCl(2), CaCl(2) bath treatment using a Bauxsol:cement ratio of 2.8:1 (pH 8.28; alkalinity 75.1 mg/L) for a 100 g batch or 245:1 (pH 8.05; alkalinity 35.4 mg/L) for a 1 kg batch. Although brine curing does provide a control on pH/alkalinity release, the pellets may still contain unreacted CaO. Therefore, a freshwater rinse of pellets before treating circum-neutral waters is recommended as is the continued investigation of alternative pellet binders.

Occupational exposure of aldehydes resulting from the storage of wood pellets.

PubMed

Rahman, Mohammad Arifur; Rossner, Alan; Hopke, Philip K

2017-06-01

An exposure assessment was conducted to investigate the potential for harmful concentrations of airborne short chain aldehydes emitted from recently stored wood pellets. Wood pellets can emit a number of airborne aldehydes include acetaldehyde, formaldehyde, propionaldehyde, butyraldehyde, valeraldehyde, and hexanal. Exposure limits have been set for these compounds since they can result in significant irritation of the upper respiratory system at elevated concentrations. Formaldehyde is a recognized human carcinogen and acetaldehyde is an animal carcinogen. Thus, air sampling was performed in a wood pellet warehouse at a pellet mill, two residential homes with bulk wood pellet storage bins, and in controlled laboratory experiments to evaluate the risk to occupants. Using NIOSH method 2539, sampling was conducted in five locations in the warehouse from April-June 2016 when it contained varying quantities of bagged pellets as well as two homes with ten ton bulk storage bins. The aldehyde concentrations were found to increase with the amount of stored pellets. Airborne concentrations of formaldehyde were as high as 0.45 ppm in the warehouse exceeding the NIOSH REL-C, and ACGIH TLV-C occupational exposure limits (OELs). The concentrations of aldehydes measured in the residential bins were also elevated indicating emissions may raise indoor air quality concerns for occupants. While individual exposures are of concern the combined irritant effect of all the aldehydes is a further raise the concerns for building occupants. To minimize exposure and the risk of adverse health effects to a building's occupants in storage areas with large quantities of pellets, adequate ventilation must be designed into storage areas.

Air riding seal for a turbine

DOEpatents

Mills, Jacob A; Brown, Wesley D; Sexton, Thomas D; Jones, Russell B

2016-07-19

An air riding seal between a rotor and a stator in a turbine of a gas turbine engine, where an annular piston is movable in an axial direction within a housing that extends from the stator, and a bellows is secured to the annular piston to form a flexible air passageway from a compressed air inlet through the annular piston and into a cushion cavity that forms an air riding seal between the annular piston and the rotor sealing surface. In another embodiment, a flexible seal secured to and extending from the annular piston forms a sealing surface between the annular piston chamber and the annular piston to provide a seal and allow for axial movement.

A comparison of experimental and theoretical results for leakage, pressure gradients, and rotordynamic coefficients for tapered annular gas seal

NASA Technical Reports Server (NTRS)

Elrod, D. A.; Childs, D. W.

1986-01-01

A brief review of current annular seal theory and a discussion of the predicted effect on stiffness of tapering the seal stator are presented. An outline of Nelson's analytical-computational method for determining rotordynamic coefficients for annular compressible-flow seals is included. Modifications to increase the maximum rotor speed of an existing air-seal test apparatus at Texas A&M University are described. Experimental results, including leakage, entrance-loss coefficients, pressure distributions, and normalized rotordynamic coefficients, are presented for four convergent-tapered, smooth-rotor, smooth-stator seals. A comparison of the test results shows that an inlet-to-exit clearance ratio of 1.5 to 2.0 provides the maximum direct stiffness, a clearance ratio of 2.5 provides the greatest stability, and a clearance ratio of 1.0 provides the least stability. The experimental results are compared to theoretical results from Nelson's analysis with good agreement. Test results for cross-coupled stiffness show less sensitivity of fluid prerotation than predicted.

Solidification and Acceleration of Large Cryogenic Pellets Relevant for Plasma Disruption Mitigation

DOE PAGES

Combs, Stephen Kirk; Meitner, S. J.; Gebhart, T. E.; ...

2016-01-01

The technology for producing, accelerating, and shattering large pellets (before injection into plasmas) for disruption mitigation has been under development at the Oak Ridge National Laboratory for several years, including a system on DIII-D that has been used to provide some significant experimental results. The original proof-of-principle testing was carried out using a pipe gun injector cooled by a cryogenic refrig- erator (temperatures ~8-20 K) and equipped with a stainless steel tube to produce 16.5-mm pellets composed of either pure D 2, pure Ne, or a dual layer with a thin outer shell of D 2 and core of Ne.more » Recently, significant progress has been made in the laboratory using that same pipe gun and a new injector that is an ITER test apparatus cooled with liquid helium. The new injector operates at ~5-8 K, which is similar to temperatures expected with cooling provided by the flow of supercritical helium on ITER. An alternative technique for producing/solidifying large pellets directly from a premixed gas has now been successfully tested in the laboratory. Also, two additional pellet sizes have been tested recently (nominal 24.4 and 34.0 mm diameters). With larger pellets, the number of injectors required for ITER disruption mitigation can be reduced, resulting in less cost and a smaller footprint for the hardware. An attractive option is longer pellets, and 24.4-mm pellets with a length/diameter ratio of ~3 have been successfully tested. Since pellet speed is the key parameter in determining the response time of a shattered pellet system to a plasma disruption event, recent tests have concentrated on documenting the speeds with different hardware configurations and operating parameters; speeds of ~100-800 m/s have been recorded. The data and results from laboratory testing are presented and discussed, and a simple model for the pellet solidification process is described.« less

Ringlight for use in high radiation

DOEpatents

Baylor, G.A.; Jacket, H.S.

1992-09-01

A ringlight having an annular array of light-emitting elements centered about a viewing passage has an outer annular body with an inner annular body fitted concentrically within the outer body to form an annular void and a light-emitting aperture therebetween. A plurality of optical fibers extends into the void with end portions of the optical fibers secured therein to form an annular array at the light-emitting aperture. The first and second annular bodies cooperate to angle the end portions of the optical fibers towards a central axis of the viewing passage. 3 figs.

Direct imaging of the tricuspid valve annular motions by fiberoptic cardioscopy in dogs. I. Does De Vega's annuloplasty preserve the annular motions?

PubMed

Minato, N; Itoh, T

1992-12-01

Applying the technology of direct imaging by fiberoptic cardioscopy, physiologic and pathophysiologic motions of the tricuspid valve anulus were studied in 10 anesthetized normal dogs (control group) and in 9 dogs that had chronic tricuspid regurgitation (TR group). The heart was perfused with transparent modified Tyrode's solution by working heart method, and the anuli, outlined by sutured beads, were observed and recorded on a high-speed video system in real time. Tricuspid valve annular area was calculated at 14 points during the cardiac cycle. The control group was studied in the normal condition, and the tricuspid regurgitation group was studied during four interventions: nontricuspid annuloplasty group and three tricuspid annuloplasty groups with reducing tricuspid valve annular area to 80%, 65%, and 50% of that of the non-tricuspid annuloplasty group by De Vega's procedure. Tricuspid valve annular area in the control group increased by 7% during atrial systole and was reduced by 34% mainly during ventricular systole, in which the free wall annular area and the septal annular area narrowed by an equal 34%. Chronic tricuspid regurgitation lessened tricuspid valve annular area narrowing to 20% in percent reduction (p < 0.01). In the TR group the decrease in tricuspid valve annular area narrowing was attributed mainly to lessened narrowing of the free wall anulus (percent reduction of tricuspid valve annular area, 19%; p < 0.01). The amplitudes in tricuspid valve annular area narrowing were unchanged in the tricuspid annuloplasty groups even when tricuspid valve annular area, was reduced to 50% by De Vega's tricuspid annuloplasty (percent reduction of tricuspid valve annular area, 16%; not significant). These findings suggest that De Vega's tricuspid annuloplasty is a reasonable method that does preserve the physiologic annular motions in the opening and closing mechanism of the tricuspid valve.

Production of zinc pellets

DOEpatents

Cooper, J.F.

1996-11-26

Uniform zinc pellets are formed for use in batteries having a stationary or moving slurry zinc particle electrode. The process involves the cathodic deposition of zinc in a finely divided morphology from battery reaction product onto a non-adhering electrode substrate. The mossy zinc is removed from the electrode substrate by the action of gravity, entrainment in a flowing electrolyte, or by mechanical action. The finely divided zinc particles are collected and pressed into pellets by a mechanical device such as an extruder, a roller and chopper, or a punch and die. The pure zinc pellets are returned to the zinc battery in a pumped slurry and have uniform size, density and reactivity. Applications include zinc-air fuel batteries, zinc-ferricyanide storage batteries, and zinc-nickel-oxide secondary batteries. 6 figs.

Production of zinc pellets

DOEpatents

Cooper, John F.

1996-01-01

Uniform zinc pellets are formed for use in batteries having a stationary or moving slurry zinc particle electrode. The process involves the cathodic deposition of zinc in a finely divided morphology from battery reaction product onto a non-adhering electrode substrate. The mossy zinc is removed from the electrode substrate by the action of gravity, entrainment in a flowing electrolyte, or by mechanical action. The finely divided zinc particles are collected and pressed into pellets by a mechanical device such as an extruder, a roller and chopper, or a punch and die. The pure zinc pellets are returned to the zinc battery in a pumped slurry and have uniform size, density and reactivity. Applications include zinc-air fuel batteries, zinc-ferricyanide storage batteries, and zinc-nickel-oxide secondary batteries.

Effects of pelleting conditioner retention time on nursery pig growth performance.

PubMed

Lewis, L L; Stark, C R; Fahrenholz, A C; Goncalves, M A D; DeRouchey, J M; Jones, C K

2015-03-01

A total of 180 nursery pigs (PIC 327 × 1050; initially 12.6 kg) were used in an 18-d study to determine the effects of pellet mill conditioning parameters and feed form on pig performance. All diets were similar, and different feed processing parameters were used to create experimental treatments. Factors considered were conditioning time (15, 30, or 60 s) and feed form (mash or pelleted). To remove the confounding factor of feed form, pelleted samples were reground to a similar particle size as the mash diet. Treatments included: 1) mash diet without thermal processing (negative control), 2) pelleted diet conditioned for 30 s (positive control), 3) pelleted diet conditioned for 15 s and reground, 4) pelleted diet conditioned for 30 s and reground, and 5) pelleted diet conditioned for 60 s and reground. Pigs were weaned and fed a common acclimation diet for 21 d before the start of the experiment. Growth and feed disappearance were then measured for 18 d. All diets had similar levels of percentage total starch, but thermally processed diets had a 1.67 to 1.87-fold increase in percentage gelatinized starch compared to the mash diet. Average daily gain and G:F did not differ between treatments overall, but pigs fed the positive control pelleted diet had decreased ADFI ( < 0.05) compared to pigs fed all other diets. Preplanned contrasts revealed that pigs fed mash diets tended to have greater ADG ( < 0.10) compared to those fed pelleted and reground diets. This suggests that processing may have had a negative influence on feed utilization, which is further supported by the finding that pigs fed mash diets tended to have greater ADG ( < 0.10) compared to those fed diets that were thermally processed, regardless of regrinding. Considering these results, it was not surprising that pigs fed mash diets had greater ADG and ADFI ( < 0.05) than those fed pelleted diets. When directly comparing diets conditioned at 60 rpm, fed either as whole pellets or reground to mash consistency, pigs fed pelleted diets had improved G:F ( < 0.05) due to lower ADFI ( < 0.05) but similar ADG. The expected improvement in G:F from pelleting (6.8%) was observed but lost when diets were reground to near original mash particle size. This may indicate that diet form from the actual pelleting process impacts G:F more than conditioner retention time.

Treatment of Annular Elastolytic Giant Cell Granuloma With Topical Tretinoin.

PubMed

Wagenseller, Aubrey; Larocca, Cecilia; Vashi, Neelam A

2017-07-01

Annular elastolytic giant cell granuloma, also known as actinic granuloma, is a rare skin condition with a chronic course that is often resistant to treatment. Literature is sparse, and only a handful of case reports are available to guide treatment decisions. Typical first line treatment options include topical and intralesional steroids, topical pimecrolimus, and cryotherapy. Resistant cases have been treated with cyclosporine, systemic steroids, antimalarials, and oral retinoids. In particular, acitretin and isotretinoin have shown success in three cases. However, these medications can have side effects and require frequent lab monitoring. We present a case of a 47-year-old woman with bilateral forearm lesions consistent with annular elastolytic giant cell granuloma who was successfully treated with topical tretinoin.

J Drugs Dermatol. 2017;16(7):699-700.

Multi-cylinder hot gas engine

DOEpatents

Corey, John A.

1985-01-01

A multi-cylinder hot gas engine having an equal angle, V-shaped engine block in which two banks of parallel, equal length, equally sized cylinders are formed together with annular regenerator/cooler units surrounding each cylinder, and wherein the pistons are connected to a single crankshaft. The hot gas engine further includes an annular heater head disposed around a central circular combustor volume having a new balanced-flow hot-working-fluid manifold assembly that provides optimum balanced flow of the working fluid through the heater head working fluid passageways which are connected between each of the cylinders and their respective associated annular regenerator units. This balanced flow provides even heater head temperatures and, therefore, maximum average working fluid temperature for best operating efficiency with the use of a single crankshaft V-shaped engine block.

A High Frequency Model of Cascade Noise

NASA Technical Reports Server (NTRS)

Envia, Edmane

1998-01-01

Closed form asymptotic expressions for computing high frequency noise generated by an annular cascade in an infinite duct containing a uniform flow are presented. There are two new elements in this work. First, the annular duct mode representation does not rely on the often-used Bessel function expansion resulting in simpler expressions for both the radial eigenvalues and eigenfunctions of the duct. In particular, the new representation provides an explicit approximate formula for the radial eigenvalues obviating the need for solutions of the transcendental annular duct eigenvalue equation. Also, the radial eigenfunctions are represented in terms of exponentials eliminating the numerical problems associated with generating the Bessel functions on a computer. The second new element is the construction of an unsteady response model for an annular cascade. The new construction satisfies the boundary conditions on both the cascade and duct walls simultaneously adding a new level of realism to the noise calculations. Preliminary results which demonstrate the effectiveness of the new elements are presented. A discussion of the utility of the asymptotic formulas for calculating cascade discrete tone as well as broadband noise is also included.

Annular and central heavy pigment deposition on the posterior lens capsule in the pigment dispersion syndrome: pigment deposition on the posterior lens capsule in the pigment dispersion syndrome.

PubMed

Turgut, Burak; Türkçüoğlu, Peykan; Deniz, Nurettin; Catak, Onur

2008-12-01

To report annular and central heavy pigment deposition on the posterior lens capsule in a case of pigment dispersion syndrome. Case report. A 36-year-old female with bilateral pigment dispersion syndrome presented with progressive decrease in visual acuity in the right eye over the past 1-2 years. Clinical examination revealed the typical findings of pigment dispersion syndrome including bilateral Krunkenberg spindles, iris transillumination defects, and dense trabecular meshwork pigmentation. Remarkably, annular and central dense pigmentation of the posterior lens capsule was noted in the right eye. Annular pigment deposition on the posterior lens capsule may be a rare finding associated with pigment dispersion syndrome. Such a finding suggests that there may be aqueous flow into the retrolental space in some patients with this condition. The way of central pigmentation is the entrance of aqueous to Berger's space. In our case, it is probable that spontaneous detachment of the anterior hyaloid membrane aided this entrance.

Improved compaction of dried tannery wastewater sludge.

PubMed

Della Zassa, M; Zerlottin, M; Refosco, D; Santomaso, A C; Canu, P

2015-12-01

We quantitatively studied the advantages of improving the compaction of a powder waste by several techniques, including its pelletization. The goal is increasing the mass storage capacity in a given storage volume, and reducing the permeability of air and moisture, that may trigger exothermic spontaneous reactions in organic waste, particularly as powders. The study is based on dried sludges from a wastewater treatment, mainly from tanneries, but the indications are valid and useful for any waste in the form of powder, suitable to pelletization. Measurements of bulk density have been carried out at the industrial and laboratory scale, using different packing procedures, amenable to industrial processes. Waste as powder, pellets and their mixtures have been considered. The bulk density of waste as powder increases from 0.64 t/m(3) (simply poured) to 0.74 t/m(3) (tapped) and finally to 0.82 t/m(3) by a suitable, yet simple, packing procedure that we called dispersion filling, with a net gain of 28% in the compaction by simply modifying the collection procedure. Pelletization increases compaction by definition, but the packing of pellets is relatively coarse. Some increase in bulk density of pellets can be achieved by tapping; vibration and dispersion filling are not efficient with pellets. Mixtures of powder and pellets is the optimal packing policy. The best compaction result was achieved by controlled vibration of a 30/70 wt% mixture of powders and pellets, leading to a final bulk density of 1t/m(3), i.e. an improvement of compaction by more than 54% with respect to simply poured powders, but also larger than 35% compared to just pellets. That means increasing the mass storage capacity by a factor of 1.56. Interestingly, vibration can be the most or the least effective procedure to improve compaction of mixtures, depending on characteristics of vibration. The optimal packing (30/70 wt% powders/pellets) proved to effectively mitigate the onset of smouldering, leading to self-heating, according to standard tests, whereas the pure pelletization totally removes the self-heating hazard. Copyright © 2015 Elsevier Ltd. All rights reserved.

Improved enzyme production by bio-pellets of Aspergillus niger: targeted morphology engineering using titanate microparticles.

PubMed

Driouch, Habib; Hänsch, Robert; Wucherpfennig, Thomas; Krull, Rainer; Wittmann, Christoph

2012-02-01

The present study describes the design of bio-pellet morphologies of the industrial working horse Aspergillus niger strains in submerged culture. The novel approach recruits the intended addition of titanate microparticles (TiSiO(4), 8 µm) to the growth medium. As tested for two recombinant strains producing fructofuranosidase and glucoamylase, the enzyme titer by the titanate-enhanced cultures in shake flasks was increased 3.7-fold to 150 U/mL (for fructofuranosidase) and 9.5-fold to 190 U/mL (for glucoamylase) as compared to the control. This could be successfully utilized for improved enzyme production in stirred tank reactors. Stimulated by the particles, the achieved final glucoamylase activity of 1,080 U/mL (fed-batch) and 320 U/mL (batch) was sevenfold higher as compared to the conventional processes. The major reason for the enhanced production was the close association between the titanate particles and the fungal cells. Already below 2.5 g/L the micromaterial was found inside the pellets, including single particles embedded as 50-150 µm particle aggregates in the center resulting in core shell pellets. With increasing titanate levels the pellet size decreased from 1,700 µm (control) to 300 µm. Fluorescence based resolution of GFP expression revealed that the large pellets of the control were only active in a 200 µm surface layer. This matches with the critical penetration depth for nutrients and oxygen typically observed for fungal pellets. The biomass within the titanate derived fungal pellets, however, was completely active. This was due a reduced thickness of the biomass layer via smaller pellets as well as the core shell structure. Moreover, also the created loose inner pellet structure enabled a higher mass transfer and penetration depths for up to 500 µm. The creation of core-shell pellets has not been achieved previously by the addition of microparticles, for example, made of talc or alumina. Due to this, the present work opens further possibilities to use microparticles for tailor-made morphology design of filamentous fungi, especially for pellet based processes which have a long and strong industrial relevance for industrial production. Copyright © 2011 Wiley Periodicals, Inc.

Acceleration of small, light projectiles (including hydrogen isotopes) to high speeds using a two-stage light gas gun

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

Combs, S.K.; Foust, C.R.; Gouge, M.J.

1990-05-01

Small, light projectiles have been accelerated to high speeds using a two-stage light gas gun at Oak Ridge National Laboratory. With 35-mg plastic projectiles (4 mm in diameter), speeds of up to 4.5 km/s have been recorded. The pipe gun'' technique for freezing hydrogen isotopes {ital in} {ital situ} in the gun barrel has been used to accelerate deuterium pellets (nominal diameter of 4 mm) to velocities of up to 2.85 km/s. The primary application of this technology is for plasma fueling of fusion devices via pellet injection of hydrogen isotopes. Conventional pellet injectors are limited to pellet speeds inmore » the range 1--2 km/s. Higher velocities are desirable for plasma fueling applications, and the two-stage pneumatic technique offers performance in a higher velocity regime. However, experimental results indicate that the use of sabots to encase the cryogenic pellets and protect them from the high peak pressures will be required to reliably attain intact pellets at speeds of {approx}3 km/s or greater. In some limited tests, lithium hydride pellets were accelerated to speeds up to 4.2 km/s. Also, repetitive operation of the two-stage gun (four plastic pellets fired at {approx}0.5 Hz) was demonstrated for the first time in preliminary tests. The equipment and operation are described, and experimental results and some comparisons with a theoretical model are presented.« less

Acceleration of small, light projectiles (including hydrogen isotopes) to high speeds using a two-stage light gas gun

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

Combs, S.K.; Foust, C.R.; Gouge, M.J.

1989-01-01

Small, light projectiles have been accelerated to high speeds using a two-stage light gas gun at Oak Ridge National Laboratory. With 35-mg plastic projectiles (4 mm in diameter), speeds of up to 4.5 km/s have been recorded. The pipe gun'' technique for freezing hydrogen isotopes in situ in the gun barrel has been used to accelerate deuterium pellets (nominal diameter of 4 mm) to velocities of up to 2.85 km/s. The primary application of this technology is for plasma fueling of fusion devices via pellet injection of hydrogen isotopes. Conventional pellet injectors are limited to pellet speeds in the rangemore » 1-2 km/s. Higher velocities are desirable for plasma fueling applications, and the two-stage pneumatic technique offers performance in a higher velocity regime. However, experimental results indicate that the use of sabots to encase the cryogenic pellets and protect them for the high peak pressures will be required to reliably attain intact pellets at speeds of {approx}3 km/s or greater. In some limited tests, lithium hydride pellets were accelerated to speeds of up to 4.2 km/s. Also, repetitive operation of the two-stage gun (four plastic pellets fired at {approx}0.5 Hz) was demonstrated for the first time in preliminary tests. The equipment and operation are described, and experimental results and some comparisons with a theoretical model are presented. 17 refs., 6 figs., 2 tabs.« less

Radial midframe baffle for can-annular combustor arrangement having tangentially oriented combustor cans

DOEpatents

Rodriguez, Jose L.

2015-09-15

A can-annular gas turbine engine combustion arrangement (10), including: a combustor can (12) comprising a combustor inlet (38) and a combustor outlet circumferentially and axially offset from the combustor inlet; an outer casing (24) defining a plenum (22) in which the combustor can is disposed; and baffles (70) configured to divide the plenum into radial sectors (72) and configured to inhibit circumferential motion of compressed air (16) within the plenum.

Low coke fuel injector for a gas turbine engine

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

Taylor, J.R.

This patent describes a gas turbine carbureting device for disposal in a down-stream flowing compressor discharge air flow. It comprises: a spin chamber defined by a generally annular housing including a closed forward end having a continuous unobstructed inner surface and an open aft end wherein the forward end is upstream of the aft end with respect tot he compressor discharge airflow; at least one exhaust tube having an inlet disposed within the spin chamber wherein the exhaust tube is radially spaced apart from the annular housing and which together with the annular housing forms at least in part amore » first annular air passage leading to the forward end; the housing having a fuel entrance and a swirling air entrance to the first annular air passage and spaced axially apart from each other, and wherein the swirling air entrance and fuel entrance are downstream of the closer forward end with respect to the compressor discharge flow; and wherein the first air passage is formed for flowing swirling air from the swirling air passage to the aft end in an upstream direction with respect to the compressor discharge flow and the exhaust tube inlet is disposed within the swirl chamber so as to reverse the axial direction of the swirling air off the forward end from an upstream direction to a downstream direction through the exhaust tube.« less

Effect of processing sorghum grain on dairy calf performance.

PubMed

Abdelgadir, I E; Morrill, J L

1995-09-01

Two trials evaluated the effect of sorghum grain processing on dairy calf performance. In trial 1, Holstein calves (n = 76; .5 to 8 wk of age) were fed one of three calf starters that contained either raw, roasted (exit temperature of 135 degrees C), or conglomerated sorghum grain. The conglomeration process consisted of grinding the grain, adding water, pelleting the mixture, and then roasting it. Raw and roasted sorghum grains were ground through a 3.2-mm screen and then included in complete pelleted starters; conglomerated sorghum grain pellets were mixed with the other pelleted ingredients of the starter. Processing did not enhance calf performance or affect selected ruminal and blood metabolites. In trial 2, roasted and conglomerated sorghum grains were ground through a 3.2-mm screen, and each was included in a pelleted starter fed for ad libitum intake to Holstein calves (n = 48) from .5 to 8 wk of age. Calf performance was not affected by method of grain processing, and ruminal and blood metabolites were similar; however, 22% of calves on the conglomerated sorghum grain starter bloated during the postweaning period, which probably resulted in reduced feed intake from wk 6 to 8. Measures to prevent bloat may be necessary to realize a potential benefit of conglomerating sorghum grain for calves.

Flaw detection and evaluation

DOEpatents

Wilks, Robert S.; Sturges, Jr., Robert H.

1983-01-01

The invention provides a method of and apparatus for optically inspecting nuclear fuel pellets for surface flaws. The inspection system includes a prism and lens arrangement for scanning the surface of each pellet as the same is rotated. The resulting scan produces data indicative of the extent and shape of each flaw which is employed to generate a flaw quality index for each detected flaw. The flaw quality indexes from all flaws are summed and compared with an acceptable surface quality index. The result of the comparison is utilized to control the acceptance or rejection of the pellet.

Short Communication: Emission of Oxygenated Polycyclic Aromatic Hydrocarbons from Biomass Pellet Burning in a Modern Burner for Cooking in China

PubMed Central

Shen, Guofeng; Wei, Siye; Zhang, Yanyan; Wang, Rong; Wang, Bin; Li, Wei; Shen, Huizhong; Huang, Ye; Chen, Yuanchen; Chen, Han; Wei, Wen; Tao, Shu

2015-01-01

Biomass pellets are undergoing fast deployment widely in the world, including China. To this stage, there were limited studies on the emissions of various organic pollutants from the burning of those pellets. In addition to parent polycyclic aromatic hydrocarbons, oxygenated PAHs (oPAHs) have been received increased concerns. In this study, emission factors of oPAHs (EFoPAHs) were measured for two types of pellets made from corn straw and pine wood, respectively. Two combustion modes with (mode II) and without (mode I) secondary side air supply in a modern pellet burner were investigated. For the purpose of comparison, EFoPAHs for raw fuels combusted in a traditional cooking stove were also measured. EFoPAHs were 348±305 and 396±387 µg/kg in the combustion mode II for pine wood and corn straw pellets, respectively. In mode I, measured EFoPAHs were 77.7±49.4 and 189±118 µg/kg, respectively. EFs in mode II were higher (2–5 times) than those in mode I mainly due to the decreased combustion temperature under more excess air. Compared to EFoPAHs for raw corn straw and pine wood burned in a traditional cooking stove, total EFoPAHs for the pellets in mode I were significantly lower (p < 0.05), likely due to increased combustion efficiencies and change in fuel properties. However, the difference between raw biomass fuels and the pellets burned in mode II was not statistically significant. Taking both the increased thermal efficiencies and decreased EFs into consideration, substantial reduction in oPAH emission can be expected if the biomass pellets can be extensively used by rural residents. PMID:25678836

Emission of oxygenated polycyclic aromatic hydrocarbons from biomass pellet burning in a modern burner for cooking in China

NASA Astrophysics Data System (ADS)

Shen, Guofeng; Wei, Siye; Zhang, Yanyan; Wang, Rong; Wang, Bin; Li, Wei; Shen, Huizhong; Huang, Ye; Chen, Yuanchen; Chen, Han; Wei, Wen; Tao, Shu

2012-12-01

Biomass pellets are undergoing fast deployment widely in the world, including China. To this stage, there were limited studies on the emissions of various organic pollutants from the burning of those pellets. In addition to parent polycyclic aromatic hydrocarbons, oxygenated PAHs (oPAHs) have been received increased concerns. In this study, emission factors of oPAHs (EFoPAHs) were measured for two types of pellets made from corn straw and pine wood, respectively. Two combustion modes with (mode II) and without (mode I) secondary side air supply in a modern pellet burner were investigated. For the purpose of comparison, EFoPAHs for raw fuels combusted in a traditional cooking stove were also measured. EFoPAHs were 348 ± 305 and 396 ± 387 μg kg-1 in the combustion mode II for pine wood and corn straw pellets, respectively. In mode I, measured EFoPAHs were 77.7 ± 49.4 and 189 ± 118 μg kg-1, respectively. EFs in mode II were higher (2-5 times) than those in mode I mainly due to the decreased combustion temperature under more excess air. Compared to EFoPAHs for raw corn straw and pine wood burned in a traditional cooking stove, total EFoPAHs for the pellets in mode I were significantly lower (p < 0.05), likely due to increased combustion efficiencies and change in fuel properties. However, the difference between raw biomass fuels and the pellets burned in mode II was not statistically significant. Taking both the increased thermal efficiencies and decreased EFs into consideration, substantial reduction in oPAH emission can be expected if the biomass pellets can be extensively used by rural residents.

Short Communication: Emission of Oxygenated Polycyclic Aromatic Hydrocarbons from Biomass Pellet Burning in a Modern Burner for Cooking in China.

PubMed

Shen, Guofeng; Wei, Siye; Zhang, Yanyan; Wang, Rong; Wang, Bin; Li, Wei; Shen, Huizhong; Huang, Ye; Chen, Yuanchen; Chen, Han; Wei, Wen; Tao, Shu

2012-12-01

Biomass pellets are undergoing fast deployment widely in the world, including China. To this stage, there were limited studies on the emissions of various organic pollutants from the burning of those pellets. In addition to parent polycyclic aromatic hydrocarbons, oxygenated PAHs (oPAHs) have been received increased concerns. In this study, emission factors of oPAHs (EF oPAHs ) were measured for two types of pellets made from corn straw and pine wood, respectively. Two combustion modes with (mode II) and without (mode I) secondary side air supply in a modern pellet burner were investigated. For the purpose of comparison, EF oPAHs for raw fuels combusted in a traditional cooking stove were also measured. EF oPAHs were 348±305 and 396±387 µg/kg in the combustion mode II for pine wood and corn straw pellets, respectively. In mode I, measured EF oPAHs were 77.7±49.4 and 189±118 µg/kg, respectively. EFs in mode II were higher (2-5 times) than those in mode I mainly due to the decreased combustion temperature under more excess air. Compared to EF oPAHs for raw corn straw and pine wood burned in a traditional cooking stove, total EF oPAHs for the pellets in mode I were significantly lower ( p < 0.05 ), likely due to increased combustion efficiencies and change in fuel properties. However, the difference between raw biomass fuels and the pellets burned in mode II was not statistically significant. Taking both the increased thermal efficiencies and decreased EFs into consideration, substantial reduction in oPAH emission can be expected if the biomass pellets can be extensively used by rural residents.

Improved Screw-Thread Lock

NASA Technical Reports Server (NTRS)

Macmartin, Malcolm

1995-01-01

Improved screw-thread lock engaged after screw tightened in nut or other mating threaded part. Device does not release contaminating material during tightening of screw. Includes pellet of soft material encased in screw and retained by pin. Hammer blow on pin extrudes pellet into slot, engaging threads in threaded hole or in nut.

Owls On Silent Wings. The Wonder Series.

ERIC Educational Resources Information Center

Cooper, Ann C.

This curriculum guide is all about owls and provides information on the folklore related to owls, present populations, explanations of physical characteristics, exploring owl pellets, burrowing owls, snowy owls, and great horned owls. Included are eight activities using owl cards, owl pellets, puzzles, and origami. This guide aims to increase…

Enhancing cadmium bioremediation by a complex of water-hyacinth derived pellets immobilized with Chlorella sp.

PubMed

Shen, Ying; Zhu, Wenzhe; Li, Huan; Ho, Shih-Hsin; Chen, Jianfeng; Xie, Youping; Shi, Xinguo

2018-06-01

A complex of water-hyacinth derived pellets immobilized with Chlorella sp. was applied, for the first time, in the bioremediation of Cadmium (Cd). The Cd(II) removal efficiency of the complex was optimized by investigating several parameters, including the pellet materials, algal culture age, and light intensity. Results showed that the Cd(II) removal efficiency was positively related to the algal immobilization efficiency and the algal bioaccumulation capacity. Since higher surface hydrophilicity leads to higher immobilization efficiency, the water-hyacinth leaf biochar pellet (WLBp) was selected as the optimal carrier. A maximum Cd(II) removal efficiency of 92.45% was obtained by the complex of WLBp immobilized with algal cells in stationary growth phase and illuminated with a light intensity of 119 μmol m -2  s -1 . Recovery tests on both microalgal cells and the WLBp demonstrated that the algal cells and the biochar pellet can be economically recycled and reused. Copyright © 2018 Elsevier Ltd. All rights reserved.

Experimental investigation of the dynamics of pellet ablation on the Texas Experimental Tokamak

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

Durst, R.D.

1988-01-01

Rapid fluctuations in the ablation of hydrogen pellets in the Texas Experimental Tokamak were studied using fast photographic techniques. It is proposed that the fluctuations are a type of relaxation oscillation driven by the motion of the particle across the magnetic field. This is shown to be consistent with a time-dependent model of plasma shielding due to Kaufmann et al. A technique to include this effect in calculations of pellet ablation is discussed. Spatially resolved measurements of the temperature and density in the pellet-ablation cloud were obtained by line-to-continuum ratios and Stark broadening, respectively. Typical parameters in the pellet-ablation cloudmore » are 5-6 eV and 1.0-1.5 {times} 10{sup 17} cm{sup {minus}3}. The flow along the magnetic field is found to be isobaric. The heating of the expanding ablatant is strongly asymmetric, being stronger on the side facing the electron-drift direction. This may be due to suprathermal electrons.« less

mirRICH, a simple method to enrich the small RNA fraction from over-dried RNA pellets.

PubMed

Choi, Cheolwon; Yoon, Seulgi; Moon, Hyesu; Bae, Yun-Ui; Kim, Chae-Bin; Diskul-Na-Ayudthaya, Penchatr; Ngu, Trinh Van; Munir, Javaria; Han, JaeWook; Park, Se Bin; Moon, Jong-Seok; Song, Sujung; Ryu, Seongho

2018-04-11

Techniques to isolate the small RNA fraction (<200nt) by column-based methods are commercially available. However, their use is limited because of the relatively high cost. We found that large RNA molecules, including mRNAs and rRNAs, are aggregated together in the presence of salts when RNA pellets are over-dried. Moreover, once RNA pellets are over-dried, large RNA molecules are barely soluble again during the elution process, whereas small RNA molecules (<100nt) can be eluted. We therefore modified the acid guanidinium thiocyanate-phenol-chloroform (AGPC)-based RNA extraction protocol by skipping the 70% ethanol washing step and over-drying the RNA pellet for 1 hour at room temperature. We named this novel small RNA isolation method "mirRICH." The quality of the small RNA sequences was validated by electrophoresis, next-generation sequencing, and quantitative PCR, and the findings support that our newly developed column-free method can successfully and efficiently isolate small RNAs from over-dried RNA pellets.

Ceria-thoria pellet manufacturing in preparation for plutonia-thoria LWR fuel production

NASA Astrophysics Data System (ADS)

Drera, Saleem S.; Björk, Klara Insulander; Sobieska, Matylda

2016-10-01

Thorium dioxide (thoria) has potential to assist in niche roles as fuel for light water reactors (LWRs). One such application for thoria is its use as the fertile component to burn plutonium in a mixed oxide fuel (MOX). Thor Energy and an international consortium are currently irradiating plutonia-thoria (Th-MOX) fuel in an effort to produce data for its licensing basis. During fuel-manufacturing research and development (R&D), surrogate materials were utilized to highlight procedures and build experience. Cerium dioxide (ceria) provides a good surrogate platform to replicate the chemical nature of plutonium dioxide. The project's fuel manufacturing R&D focused on powder metallurgical techniques to ensure manufacturability with the current commercial MOX fuel production infrastructure. The following paper highlights basics of the ceria-thoria fuel production including powder milling, pellet pressing and pellet sintering. Green pellets and sintered pellets were manufactured with average densities of 67.0% and 95.5% that of theoretical density respectively.

An equivalent network representation of a clamped bimorph piezoelectric micromachined ultrasonic transducer with circular and annular electrodes using matrix manipulation techniques.

PubMed

Sammoura, Firas; Smyth, Katherine; Kim, Sang-Gook

2013-09-01

An electric circuit model for a clamped circular bimorph piezoelectric micromachined ultrasonic transducer (pMUT) was developed for the first time. The pMUT consisted of two piezoelectric layers sandwiched between three thin electrodes. The top and bottom electrodes were separated into central and annular electrodes by a small gap. While the middle electrode was grounded, the central and annular electrodes were biased with two independent voltage sources. The strain mismatch between the piezoelectric layers caused the plate to vibrate and transmit a pressure wave, whereas the received echo generated electric charges resulting from plate deformation. The clamped pMUT plate was separated into a circular and an annular plate, and the respective electromechanical transformation matrices were derived. The force and velocity vectors were properly selected using Hamilton's principle and the necessary boundary conditions were invoked. The electromechanical transformation matrix for the clamped circular pMUT was deduced using simple matrix manipulation techniques. The pMUT performance under three biasing schemes was elaborated: 1) central electrode only, 2) central and annular electrodes with voltages of the same magnitude and polarity, and 3) central and annular electrodes with voltages of the same magnitude and opposite polarity. The circuit parameters of the pMUT were extracted for each biasing scheme, including the transformer ratio, the clamped electric impedance, and the open-circuit mechanical impedance. Each pMUT scheme was characterized under different acoustic loadings using the theoretically developed model, which was verified with finite element modeling (FEM) simulation. The electrode size was optimized to maximize the electromechanical transformer ratio. As such, the developed model could provide more insight into the design, optimization, and characterization of pMUTs and allow for performance comparison with their cMUT counterparts.

Gyrokinetic simulations of particle transport in pellet fuelled JET discharges

NASA Astrophysics Data System (ADS)

Tegnered, D.; Oberparleiter, M.; Nordman, H.; Strand, P.; Garzotti, L.; Lupelli, I.; Roach, C. M.; Romanelli, M.; Valovič, M.; Contributors, JET

2017-10-01

Pellet injection is a likely fuelling method of reactor grade plasmas. When the pellet ablates, it will transiently perturb the density and temperature profiles of the plasma. This will in turn change dimensionless parameters such as a/{L}n,a/{L}T and plasma β. The microstability properties of the plasma then changes which influences the transport of heat and particles. In this paper, gyrokinetic simulations of a JET L-mode pellet fuelled discharge are performed. The ion temperature gradient/trapped electron mode turbulence is compared at the time point when the effect from the pellet is the most pronounced with a hollow density profile and when the profiles have relaxed again. Linear and nonlinear simulations are performed using the gyrokinetic code GENE including electromagnetic effects and collisions in a realistic geometry in local mode. Furthermore, global nonlinear simulations are performed in order to assess any nonlocal effects. It is found that the positive density gradient has a stabilizing effect that is partly counteracted by the increased temperature gradient in the this region. The effective diffusion coefficients are reduced in the positive density region region compared to the intra pellet time point. No major effect on the turbulent transport due to nonlocal effects are observed.

Larval diet affects mosquito development and permissiveness to Plasmodium infection.

PubMed

Linenberg, Inbar; Christophides, George K; Gendrin, Mathilde

2016-12-02

The larval stages of malaria vector mosquitoes develop in water pools, feeding mostly on microorganisms and environmental detritus. Richness in the nutrient supply to larvae influences the development and metabolism of larvae and adults. Here, we investigated the effects of larval diet on the development, microbiota content and permissiveness to Plasmodium of Anopheles coluzzii. We tested three fish diets often used to rear mosquitoes in the laboratory, including two pelleted diets, Dr. Clarke's Pool Pellets and Nishikoi Fish Pellets, and one flaked diet, Tetramin Fish-Flakes. Larvae grow and develop faster and produce bigger adults when feeding on both types of pellets compared with flakes. This correlates with a higher microbiota load in pellet-fed larvae, in agreement with the known positive effect of the microbiota on mosquito development. Larval diet also significantly influences the prevalence and intensity of Plasmodium berghei infection in adults, whereby Nishikoi Fish Pellets-fed larvae develop into adults that are highly permissive to parasites and survive longer after infection. This correlates with a lower amount of Enterobacteriaceae in the midgut microbiota. Together, our results shed light on the influence of larval feeding on mosquito development, microbiota and vector competence; they also provide useful data for mosquito rearing.

Segmented trapped vortex cavity

NASA Technical Reports Server (NTRS)

Grammel, Jr., Leonard Paul (Inventor); Pennekamp, David Lance (Inventor); Winslow, Jr., Ralph Henry (Inventor)

2010-01-01

An annular trapped vortex cavity assembly segment comprising includes a cavity forward wall, a cavity aft wall, and a cavity radially outer wall there between defining a cavity segment therein. A cavity opening extends between the forward and aft walls at a radially inner end of the assembly segment. Radially spaced apart pluralities of air injection first and second holes extend through the forward and aft walls respectively. The segment may include first and second expansion joint features at distal first and second ends respectively of the segment. The segment may include a forward subcomponent including the cavity forward wall attached to an aft subcomponent including the cavity aft wall. The forward and aft subcomponents include forward and aft portions of the cavity radially outer wall respectively. A ring of the segments may be circumferentially disposed about an axis to form an annular segmented vortex cavity assembly.

Assembly and method for testing the integrity of stuffing tubes

DOEpatents

Morrison, Edward Francis

1997-01-01

A stuffing tube integrity checking assembly includes first and second annular seals, with each seal adapted to be positioned about a stuffing tube penetration component. An annular inflation bladder is provided, the bladder having a slot extending longitudinally therealong and including a separator for sealing the slot. A first valve is in fluid communication with the bladder for introducing pressurized fluid to the space defined by the bladder when mounted about the tube. First and second releasible clamps are provided. Each clamp assembly is positioned about the bladder for securing the bladder to one of the seals for thereby establishing a fluid-tight chamber about the tube.

Mount assembly for porous transition panel at annular combustor outlet

NASA Technical Reports Server (NTRS)

Sweeney, Ralph B. (Inventor); Verdouw, Albert J. (Inventor)

1980-01-01

A gas turbine engine combustor assembly of annular configuration has outer and inner walls made up of a plurality of axially extending multi-layered porous metal panels joined together at butt joints therebetween and each outer and inner wall including a transition panel of porous metal defining a combustor assembly outlet supported by a combustor mount assembly including a stiffener ring having a side undercut thereon fit over a transition panel end face; and wherein an annular weld joins the ring to the end face to transmit exhaust heat from the end face to the stiffener ring for dissipation from the combustor; a combustor pilot member is located in axially spaced, surrounding relationship to the end face and connector means support the stiffener ring in free floating relationship with the pilot member to compensate for both radial and axial thermal expansion of the transition panel; and said connector means includes a radial gap for maintaining a controlled flow of coolant from outside of the transition panel into cooling relationship with the stiffener ring and said weld to further cool the end face against excessive heat build-up therein during flow of hot gas exhaust through said outlet.

Turbofan aft duct suppressor study program listing and user's guide

NASA Technical Reports Server (NTRS)

Joshi, M. C.; Kraft, R. E.

1983-01-01

A description of the structure of the Annular Flow Duct Program (AFDP) for the calculation of acoustic suppression due to treatment in a finite length annular duct carrying sheared flow is presented. Although most appropriate for engine exhaust ducts, this program can be used to study sound propagation in any duct that maintains annular geometry over a considerable length of the duct. The program is based on the modal analysis of sound propagation in ducts with axial segments of different wall impedances. For specified duct geometry, wall impedance, flow and acoustic conditions in the duct (including mode amplitude distribution of the source) and duct termination reflection characteristics, the program calculates the suppression due to the treatment in the duct. The presence of forward and backward traveling modes in the duct due to the reflection and redistribution of modes at segment interfaces and duct end terminations are taken into account in the calculations. The effects of thin wall boundary layers (with a linear or mean flow velocity profile) on the acoustic propagation are also included in the program. A functional description of the major subroutines is included and a sample run is provided with an explanation of the output.

Heat exchanger with ceramic elements

DOEpatents

Corey, John A.

1986-01-01

An annular heat exchanger assembly includes a plurality of low thermal growth ceramic heat exchange members with inlet and exit flow ports on distinct faces. A mounting member locates each ceramic member in a near-annular array and seals the flow ports on the distinct faces into the separate flow paths of the heat exchanger. The mounting member adjusts for the temperature gradient in the assembly and the different coefficients of thermal expansion of the members of the assembly during all operating temperatures.

Connector tube for a turbine rotor cooling circuit

DOEpatents

Li, Ming Cheng

2003-06-24

A tubular connector adapted to extend between two tubular components comprising a tubular body having an internal diameter, a first free end including an annular radial flange having a tapered surface adapted to engage a complementary seating surface on a first of the two tubular components, the internal diameter remaining constant through the first free end; and a second free end having an annular bulbous shape adapted to seat within a cylindrical end of a second of the two tubular components.

Connector tube for a turbine rotor cooling circuit

DOEpatents

Li, Ming Cheng

2002-01-01

A tubular connector adapted to extend between two tubular components comprising a tubular body having an internal diameter, a first free end including an annular radial flange having a tapered surface adapted to engage a complementary seating surface on a first of the two tubular components, the internal diameter remaining constant through the first free end; and a second free end having an annular bulbous shape adapted to seat within a cylindrical end of a second of the two tubular components.

Packer arrangements for oil wells and the like

DOEpatents

Harvey, Andrew C.; McFadden, David H.

1981-11-24

The packer includes an elongated tubular casing, and a metal ring is disposed in its entirety within an annular recess in the casing. The recess has a circumferential opening extending entirely around the peripheral outer surface of the casing. Hydraulic fluid is flowed into the recess to apply pressure to the inner peripheral surface of the metal ring to expand the ring radially outwardly and force its outer peripheral surface through the circumferential opening and into annular sealing engagement with the opposed surface of the well casing.

Analysis and simulation of a magnetic bearing suspension system for a laboratory model annular momentum control device

NASA Technical Reports Server (NTRS)

Groom, N. J.; Woolley, C. T.; Joshi, S. M.

1981-01-01

A linear analysis and the results of a nonlinear simulation of a magnetic bearing suspension system which uses permanent magnet flux biasing are presented. The magnetic bearing suspension is part of a 4068 N-m-s (3000 lb-ft-sec) laboratory model annular momentum control device (AMCD). The simulation includes rigid body rim dynamics, linear and nonlinear axial actuators, linear radial actuators, axial and radial rim warp, and power supply and power driver current limits.

Apparatus for Leak Testing Pressurized Hoses

NASA Technical Reports Server (NTRS)

Underwood, Steve D. (Inventor); Garrison, Steve G. (Inventor); Gant, Bobby D. (Inventor); Palmer, John R. (Inventor)

2015-01-01

A hose-attaching apparatus for leak-testing a pressurized hose may include a hose-attaching member. A bore may extend through the hose-attaching member. An internal annular cavity may extend coaxially around the bore. At least one of a detector probe hole and a detector probe may be connected to the internal annular cavity. At least a portion of the bore may have a diameter which is at least one of substantially equal to and less than a diameter of a hose to be leak-tested.

Using the Auditory Hazard Assessment Algorithm for Humans (AHAAH) With Hearing Protection Software, Release MIL-STD-1474E

DTIC Science & Technology

2013-12-01

points in the waveform. This is useful if the digitization rate is unnecessarily high and the waveform content remains unchanged at lower sampling...there is a precursor acoustic event not included in the waveform, like another impulse or high background noise. MIL-STD-1474E defines an exposure as...Breaking strain of annular ligament filaments Ramp 6 unitless ratio Ratio of resistance to stiffness of annular ligament at high loads So 1.00E+09

Air riding seal with purge cavity

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

Sexton, Thomas D; Mills, Jacob A

An air riding seal for a turbine in a gas turbine engine, where an annular piston is axial moveable within an annular piston chamber formed in a stator of the turbine and forms a seal with a surface on the rotor using pressurized air that forms a cushion in a pocket of the annular piston. A purge cavity is formed on the annular piston and is connected to a purge hole that extends through the annular piston to a lower pressure region around the annular piston or through the rotor to an opposite side. The annular piston is sealed alsomore » with inner and outer seals that can be a labyrinth seal to form an additional seal than the cushion of air in the pocket to prevent the face of the air riding seal from overheating.« less

Effects of annulus defects and implantation of poly(lactic-co-glycolic acid) (PLGA)/fibrin gel scaffolds on nerves ingrowth in a rabbit model of annular injury disc degeneration.

PubMed

Xin, Long; Xu, Weixing; Yu, Leijun; Fan, Shunwu; Wang, Wei; Yu, Fang; Wang, Zhenbin

2017-05-12

Growth of nerve fibers has been shown to occur in a rabbit model of intravertebral disc degeneration (IVD) induced by needle puncture. As nerve growth may underlie the process of chronic pain in humans affected by disc degeneration, we sought to investigate the factors underlying nerve ingrowth in a minimally invasive annulotomy rabbit model of IVD by comparing the effects of empty disc defects with those of defects filled with poly(lactic-co-glycolic acid)/fibrin gel (PLGA) plugs. New Zealand white rabbits (n = 24) received annular injuries at three lumbar levels (L3/4, L4/5, and L5/6). The discs were randomly assigned to four groups: (a) annular defect (1.8-mm diameter; 4-mm depth) by mini-trephine, (b) annular defect implanted with a PLGA scaffold containing a fibrin gel, (c) annular puncture by a 16G needle (5-mm depth), and (d) uninjured L2/3 disc (control). Disc degeneration was evaluated by radiography, MRI, histology, real-time PCR, and analysis of proteoglycan (PG) content. Nerve ingrowth into the discs was assessed by immunostaining with the nerve marker protein gene product 9.5. Injured discs showed a progressive disc space narrowing with significant disc degeneration and proteoglycan loss, as confirmed by imaging results, molecular and compositional analysis, and histological examinations. In 16G punctured discs, nerve ingrowth was observed on the surface of scar tissue. In annular defects, nerve fibers were found to be distributed along small fissures within the fibrocartilaginous-like tissue that filled the AF. In discs filled with PLGA/ fibrin gel, more nerve fibers were observed growing deeper into the inner AF along the open annular track.  In addition, innervations scores showed significantly higher than those of punctured discs and empty defects. A limited vascular proliferation was found in the injured sites and regenerated tissues. Nerve ingrowth was significantly higher in PLGA/fibrin-filled discs than in empty defects. Possible explanations include (i) annular fissures along the defect and early loss of proteoglycan may facilitate the ingrowth process and (ii) biodegradable PLGA/fibrin gel may promote adverse growth of nerves and blood vessels into deeper parts of injured disc. The rabbit annular defect model of disc degeneration appears suitable to investigate the effects of nerve ingrowth in relation to pain generation.

CO2 (dry ice) cleaning system

NASA Technical Reports Server (NTRS)

Barnett, Donald M.

1995-01-01

Tomco Equipment Company has participated in the dry ice (solid carbon dioxide, CO2) cleaning industry for over ten years as a pioneer in the manufacturer of high density, dry ice cleaning pellet production equipment. For over four years Tomco high density pelletizers have been available to the dry ice cleaning industry. Approximately one year ago Tomco introduced the DI-250, a new dry ice blast unit making Tomco a single source supplier for sublimable media, particle blast, cleaning systems. This new blast unit is an all pneumatic, single discharge hose device. It meters the insertion of 1/8 inch diameter (or smaller), high density, dry ice pellets into a high pressure, propellant gas stream. The dry ice and propellant streams are controlled and mixed from the blast cabinet. From there the mixture is transported to the nozzle where the pellets are accelerated to an appropriate blasting velocity. When directed to impact upon a target area, these dry ice pellets have sufficient energy to effectively remove most surface coatings through dry, abrasive contact. The meta-stable, dry ice pellets used for CO2 cleaning, while labeled 'high density,' are less dense than alternate, abrasive, particle blast media. In addition, after contacting the target surface, they return to their equilibrium condition: a superheated gas state. Most currently used grit blasting media are silicon dioxide based, which possess a sharp tetrahedral molecular structure. Silicon dioxide crystal structures will always produce smaller sharp-edged replicas of the original crystal upon fracture. Larger, softer dry ice pellets do not share the same sharp-edged crystalline structures as their non-sublimable counterparts when broken. In fact, upon contact with the target surface, dry ice pellets will plastically deform and break apart. As such, dry ice cleaning is less harmful to sensitive substrates, workers and the environment than chemical or abrasive cleaning systems. Dry ice cleaning system components include: a dry ice pellet supply, a non-reactive propellant gas source, a pellet and propellant metering device, and a media transport and acceleration hose and nozzle arrangement. Dry ice cleaning system operating parameters include: choice of propellant gas, its pressure and temperature, dry ice mass flow rate, dry ice pellet size and shape, and acceleration nozzle configuration. These parameters may be modified to fit different applications. The growth of the dry ice cleaning industry will depend upon timely data acquisition of the effects that independent changes in these parameters have on cleaning rates, with respect to different surface coating and substrate combinations. With this data, optimization of cleaning rates for particular applications will be possible. The analysis of the applicable range of modulation of these parameters, within system component mechanical constraints, has just begun.

Cylindrical geometry hall thruster

DOEpatents

Raitses, Yevgeny; Fisch, Nathaniel J.

2002-01-01

An apparatus and method for thrusting plasma, utilizing a Hall thruster with a cylindrical geometry, wherein ions are accelerated in substantially the axial direction. The apparatus is suitable for operation at low power. It employs small size thruster components, including a ceramic channel, with the center pole piece of the conventional annular design thruster eliminated or greatly reduced. Efficient operation is accomplished through magnetic fields with a substantial radial component. The propellant gas is ionized at an optimal location in the thruster. A further improvement is accomplished by segmented electrodes, which produce localized voltage drops within the thruster at optimally prescribed locations. The apparatus differs from a conventional Hall thruster, which has an annular geometry, not well suited to scaling to small size, because the small size for an annular design has a great deal of surface area relative to the volume.

Hot-melt extrusion of sugar-starch-pellets.

PubMed

Yeung, Chi-Wah; Rein, Hubert

2015-09-30

Sugar-starch-pellets (syn. sugar spheres) are usually manufactured through fluidized bed granulation or wet extrusion techniques. This paper introduces hot-melt extrusion (HME) as an alternative method to manufacture sugar-starch-pellets. A twin-screw extruder coupled with a Leistritz Micro Pelletizer (LMP) cutting machine was utilized for the extrusion of different types (normal-, waxy-, and high-amlyose) of corn starch, blended with varying amounts of sucrose. Pellets were characterized for their physicochemical properties including crystallinity, particle size distribution, tensile strength, and swelling expansion. Furthermore, the influence of sugar content and humidity on the product was investigated. Both sucrose and water lowered the Tg of the starch system allowing a convenient extrusion process. Mechanical strength and swelling behavior could be associated with varying amylose and amylopectin. X-ray powder diffractometric (XRPD) peaks of increasing sucrose contents appeared above 30%. This signified the oversaturation of the extruded starch matrix system with sucrose. Otherwise, had the dissolved sucrose been embedded into the molten starch matrix, no crystalline peak could have been recognized. The replacement of starch with sucrose reduced the starch pellets' swelling effect, which resulted in less sectional expansion (SEI) and changed the surface appearance. Further, a nearly equal tensile strength could be detected for sugar spheres with more than 40% sucrose. This observation stands in good relation with the analyzed values of the commercial pellets. Both techniques (fluidized bed and HME) allowed a high yield of spherical pellets (less friability) for further layering processes. Thermal influence on the sugar-starch system is still an obstacle to be controlled. Copyright © 2015 Elsevier B.V. All rights reserved.

Gas Gun Model and Comparison to Experimental Performance of Pipe Guns Operating with Light Propellant Gases and Large Cryogenic Pellets

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

Reed, J. R.; Carmichael, J. R.; Gebhart, T. E.

Injection of multiple large (~10 to 30 mm diameter) shattered pellets into ITER plasmas is presently part of the scheme planned to mitigate the deleterious effects of disruptions on the vessel components. To help in the design and optimize performance of the pellet injectors for this application, a model referred to as “the gas gun simulator” has been developed and benchmarked against experimental data. The computer code simulator is a Java program that models the gas-dynamics characteristics of a single-stage gas gun. Following a stepwise approach, the code utilizes a variety of input parameters to incrementally simulate and analyze themore » dynamics of the gun as the projectile is launched down the barrel. Using input data, the model can calculate gun performance based on physical characteristics, such as propellant-gas and fast-valve properties, barrel geometry, and pellet mass. Although the model is fundamentally generic, the present version is configured to accommodate cryogenic pellets composed of H2, D2, Ne, Ar, and mixtures of them and light propellant gases (H2, D2, and He). The pellets are solidified in situ in pipe guns that consist of stainless steel tubes and fast-acting valves that provide the propellant gas for pellet acceleration (to speeds ~200 to 700 m/s). The pellet speed is the key parameter in determining the response time of a shattered pellet system to a plasma disruption event. The calculated speeds from the code simulations of experiments were typically in excellent agreement with the measured values. With the gas gun simulator validated for many test shots and over a wide range of physical and operating parameters, it is a valuable tool for optimization of the injector design, including the fast valve design (orifice size and volume) for any operating pressure (~40 bar expected for the ITER application) and barrel length for any pellet size (mass, diameter, and length). Key design parameters and proposed values for the pellet injectors for the ITER disruption mitigation systems are discussed.« less

Gas Gun Model and Comparison to Experimental Performance of Pipe Guns Operating with Light Propellant Gases and Large Cryogenic Pellets

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

Combs, S. K.; Reed, J. R.; Lyttle, M. S.

2016-01-01

Injection of multiple large (~10 to 30 mm diameter) shattered pellets into ITER plasmas is presently part of the scheme planned to mitigate the deleterious effects of disruptions on the vessel components. To help in the design and optimize performance of the pellet injectors for this application, a model referred to as “the gas gun simulator” has been developed and benchmarked against experimental data. The computer code simulator is a Java program that models the gas-dynamics characteristics of a single-stage gas gun. Following a stepwise approach, the code utilizes a variety of input parameters to incrementally simulate and analyze themore » dynamics of the gun as the projectile is launched down the barrel. Using input data, the model can calculate gun performance based on physical characteristics, such as propellant-gas and fast-valve properties, barrel geometry, and pellet mass. Although the model is fundamentally generic, the present version is configured to accommodate cryogenic pellets composed of H2, D2, Ne, Ar, and mixtures of them and light propellant gases (H2, D2, and He). The pellets are solidified in situ in pipe guns that consist of stainless steel tubes and fast-acting valves that provide the propellant gas for pellet acceleration (to speeds ~200 to 700 m/s). The pellet speed is the key parameter in determining the response time of a shattered pellet system to a plasma disruption event. The calculated speeds from the code simulations of experiments were typically in excellent agreement with the measured values. With the gas gun simulator validated for many test shots and over a wide range of physical and operating parameters, it is a valuable tool for optimization of the injector design, including the fast valve design (orifice size and volume) for any operating pressure (~40 bar expected for the ITER application) and barrel length for any pellet size (mass, diameter, and length). Key design parameters and proposed values for the pellet injectors for the ITER disruption mitigation systems are discussed.« less

Multi-functional annular fairing for coupling launch abort motor to space vehicle

NASA Technical Reports Server (NTRS)

Camarda, Charles J. (Inventor); Scotti, Stephen J. (Inventor); Buning, Pieter G. (Inventor); Bauer, Steven X. S. (Inventor); Engelund, Walter C. (Inventor); Schuster, David M. (Inventor)

2011-01-01

An annular fairing having aerodynamic, thermal, structural and acoustic attributes couples a launch abort motor to a space vehicle having a payload of concern mounted on top of a rocket propulsion system. A first end of the annular fairing is fixedly attached to the launch abort motor while a second end of the annular fairing is attached in a releasable fashion to an aft region of the payload. The annular fairing increases in diameter between its first and second ends.

Food habits of Northern Goshawks nesting in south central Wyoming

Treesearch

John R. Squires

2000-01-01

Northern Goshawks (Accipiter gentiles) nesting in south central Wyoming consumed at least 33 species of prey; 14 were mammals and 19 were birds. Based on percent occurrence in regurgitated pellets, dominant (>10% frequency) prey species included: red squirrel (Tamiasciurus hudsonicus; present in 50% of pellets), Northern Flicker (Colaptes auratus; 34...

Mitral Annular Dynamics in Mitral Annular Calcification: A Three-Dimensional Imaging Study.

PubMed

Pressman, Gregg S; Movva, Rajesh; Topilsky, Yan; Clavel, Marie-Annick; Saldanha, Jason A; Watanabe, Nozomi; Enriquez-Sarano, Maurice

2015-07-01

The mitral annulus displays complex conformational changes during the cardiac cycle that can now be quantified by three-dimensional echocardiography. Mitral annular calcification (MAC) is increasingly encountered, but its structural and dynamic consequences are largely unexplored. The objective of this study was to describe alterations in mitral annular dimensions and dynamics in patients with MAC. Transthoracic three-dimensional echocardiography was performed in 43 subjects with MAC and 36 age- and sex-matched normal control subjects. Mitral annular dimensions were quantified, using dedicated software, at six time points (three diastolic, three systolic) during the cardiac cycle. In diastole, the calcified annulus was larger and flatter than normal, with increased anteroposterior diameter (29.4 ± 0.6 vs 27.8 ± 0.6 mm, P = .046), reduced height (2.8 ± 0.2 vs 3.6 ± 0.2 mm, P = .006), and decreased saddle shape (8.9 ± 0.6% vs 11.4 ± 0.6%, P = .005). In systole, patients with MAC had greater annular area at all time points (P < .05 for each) compared with control subjects, because of reduced contraction along the anteroposterior diameter (P < .001). Saddle shape increased in early systole (from 10.5% to 13.5%, P = .04) in control subjects but not in those with MAC (P = NS). Valvular alterations were also noted; although mitral valve tent length decreased during systole in both groups, decreases were less in patients with MAC (P < .05 for mid- and late systole). For certain parameters (e.g., annular area), changes were confined largely to those patients with moderate to severe MAC (P = .006 vs control subjects, but nonsignificant for patients with mild MAC). Quantitative three-dimensional echocardiography provides new insights into the dynamic consequences of MAC. This imaging technique demonstrates that the mitral annulus is not made smaller by calcification. However, there is loss of annular contraction, particularly along the anteroposterior diameter, and loss of early systolic folding along the intercommissural diameter. Associated valvular alterations include smaller than usual declines in tenting during systole. These quantitative three-dimensional echocardiographic data provide new insights into the dynamic physiology of the calcified mitral annulus. Copyright © 2015 American Society of Echocardiography. Published by Elsevier Inc. All rights reserved.

De Vega Annuloplasty for Functional Tricupsid Regurgitation: Concept of Tricuspid Valve Orifice Index to Optimize Tricuspid Valve Annular Reduction

PubMed Central

Hwang, Ho Young; Chang, Hyoung Woo; Jeong, Dong Seop

2013-01-01

We evaluated long-term results of De Vega annuloplasty measured by cylindrical sizers for functional tricuspid regurgitation (FTR) and analyzed the impact of measured annular size on the late recurrence of tricuspid valve regurgitation. Between 2001 and 2011, 177 patients (57.9±10.5 yr) underwent De Vega annuloplasty for FTR. Three cylindrical sizers (actual diameters of 29.5, 31.5, and 33.5 mm) were used to reproducibly reduce the tricuspid annulus. Long-term outcomes were evaluated and risk factor analyses for the recurrence of FTR ≥3+ were performed. Measured annular diameter indexed by patient's body surface area was included in the analyses as a possible risk factor. Operative mortality occurred in 8 patients (4.5%). Ten-year overall and cardiac death-free survivals were 80.5% and 90.8%, respectively. Five and 10-yr freedom rates from recurrent FTR were 96.5% and 93.1%, respectively. Cox proportional hazard model revealed that higher indexed annular size was the only risk factor for the recurrence of FTR (P=0.006). A minimal P value approach demonstrated that indexed annular diameter of 22.5 mm/m2 was a cut-off value predicting the recurrence of FTR. De Vega annuloplasty for FTR results in low rates of recurrent FTR in the long-term. Tricuspid annulus should be reduced appropriately considering patients' body size to prevent recurrent FTR. PMID:24339705

Annular convective-radiative fins with a step change in thickness, and temperature-dependent thermal conductivity and heat transfer coefficient

NASA Astrophysics Data System (ADS)

Barforoush, M. S. M.; Saedodin, S.

2018-01-01

This article investigates the thermal performance of convective-radiative annular fins with a step reduction in local cross section (SRC). The thermal conductivity of the fin's material is assumed to be a linear function of temperature, and heat transfer coefficient is assumed to be a power-law function of surface temperature. Moreover, nonzero convection and radiation sink temperatures are included in the mathematical model of the energy equation. The well-known differential transformation method (DTM) is used to derive the analytical solution. An exact analytical solution for a special case is derived to prove the validity of the obtained results from the DTM. The model provided here is a more realistic representation of SRC annular fins in actual engineering practices. Effects of many parameters such as conduction-convection parameters, conduction-radiation parameter and sink temperature, and also some parameters which deal with step fins such as thickness parameter and dimensionless parameter describing the position of junction in the fin on the temperature distribution of both thin and thick sections of the fin are investigated. It is believed that the obtained results will facilitate the design and performance evaluation of SRC annular fins.

Look away: arterial and venous intravascular embolisation following shotgun injury.

PubMed

Vedelago, John; Dick, Elizabeth; Thomas, Robert; Jones, Brynmor; Kirmi, Olga; Becker, Jennifer; Alavi, Afshin; Gedroyc, Wladyslaw

2014-01-01

We describe two cases of intravascular embolization of shotgun pellets found distant to the entry site of penetrating firearm injury. The cases demonstrate antegrade embolization of a shotgun pellet from neck to right middle cerebral artery, and antegrade followed by retrograde venous embolization through the left lower limb to pelvis. Radiologists and Trauma Physicians should be aware that post shotgun injury, the likelihood of an embolised shot pellet is increased compared to other types of firearm missile injury, and should therefore search away from the site of injury to find such missiles. Shotgun pellets may travel in an antegrade or a retrograde intravascular direction - both were seen in these cases - and may not be clinically obvious. This underscores the importance of a meticuluous search through all images, including CT scout images, for evidence of their presence.

Characterization and evaluation of self-nanoemulsifying sustained-release pellet formulation of ziprasidone with enhanced bioavailability and no food effect.

PubMed

Miao, Yanfei; Chen, Guoguang; Ren, Lili; Pingkai, Ouyang

2016-09-01

The purpose of this work was to develop self-nanomulsifying drug delivery systems (SNEDDS) in sustained-release pellets of ziprasidone to enhance the oral bioavailability and overcome the food effect of ziprasidone. Preformulation studies including screening of excipients for solubility and pseudo-ternary phase diagrams suggested the suitability of Capmul MCM as oil phase, Labrasol as surfactant, and PEG 400 as co-surfactant for preparation of self-nanoemulsifying formulations. Preliminary composition of the SNEDDS formulations were selected from the pseudo-ternary phase diagrams. The prepared ziprasidone-SNEDDS formulations were characterized for self-emulsification time, effect of pH and robustness to dilution, droplet size analysis and zeta potential. The optimized ziprasidone-SNEDDS were used to prepare ziprasidone-SNEDDS sustained-release pellets via extrusion-spheronization method. The pellets were characterized for SEM, particle size, droplet size distribution and zeta potential. In vitro drug release studies indicated the ziprsidone-SNEDDS sustained-release pellets showed sustained release profiles with 90% released within 10 h. The ziprsidone-SNEDDS sustained-release pellets were administered to fasted and fed beagle dogs and their pharmacokinetics were compared to commercial formulation of Zeldox as a control. Pharmacokinetic studies in beagle dogs showed ziprasidone with prolonged actions and enhanced bioavailability with no food effect was achieved simultaneously in ziprsidone-SNEDDS sustained-release pellets compared with Zeldox in fed state. The results indicated a sustained release with prolonged actions of schizophrenia and bipolar disorder treatment.

Orbital volume augmentation using expandable hydrogel implants in acquired anophthalmia and phthisis bulbi.

PubMed

Kim, Esther Lee; Bernardino, Carlo Rob; Levin, Flora

2016-01-01

The purpose of this study is to describe our experience using expandable spherical hydrogel implants and injectable hydrogel pellets for orbital volume augmentation in cases of post-enucleation socket syndrome after acquired anophthalmia or phthisis bulbi. We retrospectively reviewed the clinical records of all adult patients who received an expandable hydrogel implant for orbital volume loss following enucleation or phthisis bulbi at the Emory Eye Center between 2004 and January 2007 and the Yale Eye Center between 2009 and 2011. The study included 9 women and 5 men with a mean age of 51.2 years old (range 35-76 years old). Follow-up spanned 6 to 71 months (median of 18.5 months). Four patients received spherical hydrogel implants and 10 patients received hydrogel pellet injections. On average, nine pellets (range 5-16) were placed in each patient over an average of 1.7 injections (range 1-3). Most commonly, five pellets were injected per session, as was the case for 13 of the 17 treatment sessions. Post-operative complications included 2 cases of pellet migration, one subcutaneously and one anteriorly due to insufficiently posterior implant placement, and 1 hospital admission for pain after injection of 10 pellets in one visit. All patients experienced an overall subjective improvement in cosmesis. Self-expandable hydrogel implants appear to offer several advantages over other existing options for orbital volume augmentation, as they are easy to place, generally well-tolerated, volume-titratable, and to the extent that our follow-up shows, may be a safe and durable means of treating orbital volume loss in patients with acquired anophthalmia and phthisis bulbi.

Apparatus for converting hydrocarbon fuel into hydrogen gas and carbon dioxide

DOEpatents

Clawson, Lawrence G.; Mitchell, William L.; Bentley, Jeffrey M.; Thijssen, Johannes H. J.

2001-01-01

A hydrocarbon fuel reformer (200) is disclosed suitable for producing synthesis hydrogen gas from reactions with hydrocarbons fuels, oxygen, and steam. The reformer (200) comprises first and second tubes (208,218). The first tube (208) includes a first catalyst (214) and receives a first mixture of steam and a first fuel. The second tube (218) is annularly disposed about the first tube (208) and receives a second mixture of an oxygen-containing gas and a second fuel. In one embodiment, a third tube (224) is annularly disposed about the second tube (218) and receives a first reaction reformate from the first tube (208) and a second reaction reformate from the second tube (218). A catalyst reforming zone (260) annularly disposed about the third tube (224) may be provided to subject reformate constituents to a shift reaction. In another embodiment, a fractionator is provided to distill first and second fuels from a fuel supply source.

Optical transmission through silver film with compound periodic array of annular apertures

NASA Astrophysics Data System (ADS)

Zhang, Yue; Yao, Wen-jie; Yu, Hong

2015-03-01

Recently, some kinds of structures have been found to show the property of extraordinary optical transmission (EOT). In this paper, we present a novel composite structure based on array of annular apertures (AAA) with compound lattice. The lattice includes two kinds of annular apertures with the same outer radius and different inner radii. The transmission spectrum of this compound periodic AAA can be achieved by adding up the spectra of two corresponding simple periodic AAAs, and the transmission shows EOT property. The transmission peaks of this kind of structure can be adjusted to desire wavelengths by changing the inner radius of aperture or the index of the dielectric material in the aperture. This structure can be used as a filter with dual pass bands when the difference between inner radii or indices of dielectric inside is large enough for two kinds of apertures.

Annular pancreas

MedlinePlus

... page: //medlineplus.gov/ency/article/001142.htm Annular pancreas To use the sharing features on this page, please enable JavaScript. An annular pancreas is a ring of pancreatic tissue that encircles ...

Development of sustained-release lipophilic calcium stearate pellets via hot melt extrusion.

PubMed

Roblegg, Eva; Jäger, Evelyn; Hodzic, Aden; Koscher, Gerold; Mohr, Stefan; Zimmer, Andreas; Khinast, Johannes

2011-11-01

The objective of this study was the development of retarded release pellets using vegetable calcium stearate (CaSt) as a thermoplastic excipient. The matrix carrier was hot melt extruded and pelletized with a hot-strand cutter in a one step continuous process. Vegetable CaSt was extruded at temperatures between 100 and 130°C, since at these temperatures cutable extrudates with a suitable melt viscosity may be obtained. Pellets with a drug loading of 20% paracetamol released 11.54% of the drug after 8h due to the great densification of the pellets. As expected, the drug release was influenced by the pellet size and the drug loading. To increase the release rate, functional additives were necessary. Therefore, two plasticizers including glyceryl monostearate (GMS) and tributyl citrate (TBC) were investigated for plasticization efficiency and impact on the in vitro drug release. GMS increased the release rate due to the formation of pores at the surface (after dissolution) and showed no influence on the process parameters. The addition of TBC increased the drug release to a higher extent. After dissolving, the pellets exhibited pores at the surface and in the inner layer. Small- and Wide-Angle X-ray Scattering (SWAXS) revealed no major change in crystalline peaks. The results demonstrated that (nearly) spherical CaSt pellets could be successfully prepared by hot melt extrusion using a hot-strand cutter as downstreaming system. Paracetamol did not melt during the process indicating a solid suspension. Due to the addition of plasticizers, the in vitro release rate could be tailored as desired. Copyright © 2011 Elsevier B.V. All rights reserved.

Influence of pellet diameter and length on the quality of pellets and performance, nutrient utilisation and digestive tract development of broilers fed on wheat-based diets.

PubMed

Abdollahi, M R; Ravindran, V; Wester, T J; Ravindran, G; Thomas, D V

2013-06-01

1. The influence of pellet diameter and length on the quality of pellets and performance, nutrient utilisation and digestive tract development of broilers given wheat-based diets was examined from 10 to 42 d of age. The experimental design was a 2 × 2 factorial arrangement of treatments evaluating two pellet diameters (3 and 4.76 mm) and two pellet lengths (3 and 6 mm). From 0 to 9 d of age, all birds were offered a common starter diet pelleted with a 3-mm diameter die and 3-mm length. Broiler grower (d 10 to 21) and finisher (d 22 to 42) diets, based on wheat, were formulated and then subjected to the 4 different treatments. 2. In grower diets, increasing pellet diameter and pellet length reduced the gelatinised starch (GS) content of the diets. In finisher diets, GS content of 3-mm diameter pellets did not change with increasing pellet length but decreased in 4.76-mm diameter pellets. 3. In grower and finisher diets, increments in intact pellet weight, pellet durability index and pellet hardness with increasing pellet length were greater in 3-mm diameter pellets than those with 4.76-mm diameter. 4. Increasing pellet length from 3 to 6 mm increased apparent metabolisable energy values. Neither the interaction nor main effects were significant for the ileal digestibility of nitrogen and starch. 5. During the grower period (d 10 to 21), birds given pellets of 6-mm length had greater body-weight gain than those given 3-mm length pellets. Feeding 6-mm length pellets decreased feed per body-weight gain compared to 3-mm length pellets. During the finisher (d 22 to 42) and whole grow-out (d 10 to 42) periods, while different pellet lengths had no effect on feed per body-weight gain values at 3-mm pellet diameter, increasing the pellet length decreased feed per body-weight gain at 4.76-mm pellet diameter. 6. Increasing pellet diameter and pellet length reduced the relative length of duodenum. Birds given 3-mm diameter pellets had heavier proventriculus compared to those given 4.76-mm diameter pellets. 7. Overall, the data suggest that increasing the pellet length from 3 to 6 mm improved the body-weight gain and feed per body-weight gain during the grower period (d 10 to 21). While the positive effect on body-weight gain disappeared as the birds grew older, improvements in feed per body-weight gain were maintained over the finisher and whole grow-out periods only in 4.76-mm diameter pellets. Small diameter die holes and longer pellet lengths may be considered as potential manipulations to manufacture high-quality pellets under low conditioning temperatures.

Assembly and method for testing the integrity of stuffing tubes

DOEpatents

Morrison, E.F.

1997-08-26

A stuffing tube integrity checking assembly includes first and second annular seals, with each seal adapted to be positioned about a stuffing tube penetration component. An annular inflation bladder is provided, the bladder having a slot extending longitudinally there along and including a separator for sealing the slot. A first valve is in fluid communication with the bladder for introducing pressurized fluid to the space defined by the bladder when mounted about the tube. First and second releasible clamps are provided. Each clamp assembly is positioned about the bladder for securing the bladder to one of the seals for thereby establishing a fluid-tight chamber about the tube. 5 figs.

[Serum pharmacochemistry of Qinbai Qingfei concentrated pellets based on UPLC-Q-TOF-MS].

PubMed

Liu, Ye; Wei, Wen-Feng; Huo, Jin-Hai; Wang, Wei-Ming

2017-02-01

To analyze the main components of Qinbai Qingfei concentrated pellets in rat serum with UPLC-Q-TOF-MS technology and serum pharmacochemistry theory. After gavage administration with Qinbai Qingfei concentrated pellets, blood was collected from hepatic portal vein. ACQUITY UPLC BEH C₁₈(2.1 mm×100 mm, 1.7 μm) was used, with 0.1% formic acid agueous solution(A)-0.1%formic acid and acetonitrile(B) as the mobile phase for gradient elution. The flow rate was 0.3 mL•min⁻¹, the column temperature was maintained at 35 ℃. Through the comparative analysis fingerprints of Qinbai Qingfei concentrated pellets, drug containing-serum and blank serum, and with the help Peakview and Metabolitepilot software, components in serum were defined. A total of 28 compounds were identified, including 18 prototypes and 10 metabolites. As a result, UPLC-Q-TOF-MS technology and serum pharmacochemistry theory were applied to comprehensively expound Qinbai Qingfei concentrated pellets'constituents migrating to rat serum, and provide scientific basis for further studies for in vivo metabolic process and effective material base. Copyright© by the Chinese Pharmaceutical Association.

Method for directly recovering fluorine from gas streams

DOEpatents

Orlett, Michael J.; Saraceno, Anthony J.

1981-01-01

This invention is a process for the direct recovery of gaseous fluorine from waste-gas streams or the like. The process comprises passing the gas stream through a bed of anhydrous K.sub.3 NiF.sub.6 pellets to fluorinate the same to K.sub.3 NiF.sub.7 and subsequently desorbing the fluorine by heating the K.sub.3 NiF.sub.7 pellets to a temperature re-converting them to K.sub.3 NiF.sub.6. The efficiency of the fluorine-absorption step is maximized by operating in a selected and conveniently low temperature. The desorbed fluorine is highly pure and is at a pressure of several atmospheres. Preferably, the K.sub.3 NiF.sub.6 pellets are prepared by a method including the steps of forming agglomerates of hydrated K.sub.3 NiF.sub.5, sintering the agglomerates to form K.sub.3 NiF.sub.5 pellets of enhanced reactivity with respect to fluorine, and fluorinating the sintered pellets to K.sub.3 NiF.sub.6.

FUEL ELEMENT

DOEpatents

Bean, R.W.

1963-11-19

A ceramic fuel element for a nuclear reactor that has improved structural stability as well as improved cooling and fission product retention characteristics is presented. The fuel element includes a plurality of stacked hollow ceramic moderator blocks arranged along a tubular raetallic shroud that encloses a series of axially apertured moderator cylinders spaced inwardly of the shroud. A plurality of ceramic nuclear fuel rods are arranged in the annular space between the shroud and cylinders of moderator and appropriate support means and means for directing gas coolant through the annular space are also provided. (AEC)

Continuous spin detonation of poorly detonable fuel-air mixtures in annular combustors

NASA Astrophysics Data System (ADS)

Bykovskii, F. A.; Zhdan, S. A.

2017-09-01

This paper reports on the results of experimental investigations of continuous spin detonation of three fuel-air mixtures (syngas-air, CH4/H2-air, and kerosene/H2-air in a flow-type annular cylindrical combustor 503 mm in diameter. The limits of existence of continuous detonation in terms of the specific flow rates of the mixtures (minimum values) are determined. It is found that all gas mixtures, including the least detonable methane-air mixture, with addition of hydrogen can be burned in the continuous spin detonation regime.

Pelletizing/reslurrying as a means of distributing and firing clean coal

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

Conkle, H.N.; Raghavan, J.K.; Smit, F.J.

1991-11-21

The objective of this study is to develop technology that permits the practical and economic preparation, storage, handling, and transportation of coal pellets, which can be reslurried into Coal water fuels (CWF) suitable for firing in small- and medium-size commercial and industrial boilers, furnaces, and engines. The project includes preparing coal pellets and capsules from wet filter cake that can be economically stored, handled, transported, and reslurried into a CWF that can be suitably atomized and fired at the user site. The wet cakes studied were prepared from ultra-fine (95% -325 mesh) coal beneficiated by advanced froth-flotation techniques. The coalsmore » studied included two eastern bituminous coals, one from Virginia (Elkhorn) and one from Illinois (Illinois No. 6) and one western bituminous coal from Utah (Sky Line coal).« less

Device for controlling the pouring of molten materials

DOEpatents

Moore, A.F.; Duncan, A.L.

1994-02-15

A device is described for controlling the pouring of a molten material from a crucible or other container. The device includes an annular retainer ring for mounting in the drain opening in the bottom of a conventional crucible, the retainer ring defining a opening there through. The device also includes a plug member having an annular forward end portion for force-fit reception in the opening of the retainer ring to selectively seal the opening and for being selectively forced through the opening. The plug member has a rear end portion for being positioned within the crucible, the rear end portion including stop means for prohibiting the rear end portion from passing through the opening in the retainer ring when the forward end portion is selectively forced through the opening. The plug member defines at least one, and preferably a plurality of flutes, each extending from a point rearward the annular forward end portion of the plug member, and forward the stop means, to a point rearward of the stop means. The flutes permit fluid communication between the interior and exterior of the crucible when the forward end portion of the plug member is forced through the opening in the retaining ring such that the molten material is allowed to flow from the crucible. 5 figures.

The Design and Performance of a Twenty Barrel Hydrogen Pellet Injector for Alcator C-Mod

NASA Astrophysics Data System (ADS)

Urbahn, John A.

A twenty barrel hydrogen pellet injector has been designed, built and tested both in the laboratory and on the Alcator C-Mod Tokamak at MIT. The injector functions by firing pellets of frozen hydrogen or deuterium deep into the plasma discharge for the purpose of fueling the plasma, modifying the density profile and increasing the global energy confinement time. The design goals of the injector are: (1) Operational flexibility, (2) High reliability, (3) Remote operation with minimal maintenance. These requirements have led to a single stage, pipe gun design with twenty barrels. Pellets are formed by in-situ condensation of the fuel gas, thus avoiding moving parts at cryogenic temperatures. The injector is the first to dispense with the need for cryogenic fluids and instead uses a closed cycle refrigerator to cool the thermal system components. The twenty barrels of the injector produce pellets of four different size groups and allow for a high degree of flexibility in fueling experiments. Operation of the injector is under PLC control allowing for remote operation, interlocked safety features and automated pellet manufacturing. The injector has been extensively tested and shown to produce pellets reliably with velocities up to 1400 m/sec. During the period from September to November of 1993, the injector was successfully used to fire pellets into over fifty plasma discharges. Experimental results include data on the pellet penetration into the plasma using an advanced pellet tracking diagnostic with improved time and spatial response. Data from the tracker indicates pellet penetrations were between 30 and 86 percent of the plasma minor radius. Line averaged density increases of up to 300 percent were recorded with peak densities of just under 1 times 10^ {21} / m^3, the highest achieved on C-Mod to date. A comparison is made between the ablation source function derived from tracker data with that predicted by four different variations of the neutral shield model. Results suggest rapid heat flow from the interior of the plasma maintains temperatures on the ablation flux surface. Localized density perturbations with a specific m = 1,n = 1 structure and location on the q = 1 flux surface were observed following injection. (Copies available exclusively from MIT Libraries, Rm. 14-0551, Cambridge, MA 02139-4307. Ph. 617-253-5668; Fax 617-253 -1690.).

Method and system including a double rotary kiln pyrolysis or gasification of waste material

DOEpatents

McIntosh, M.J.; Arzoumanidis, G.G.

1997-09-02

A method is described for destructively distilling an organic material in particulate form wherein the particulates are introduced through an inlet into one end of an inner rotating kiln ganged to and coaxial with an outer rotating kiln. The inner and outer kilns define a cylindrical annular space with the inlet being positioned in registry with the axis of rotation of the ganged kilns. During operation, the temperature of the wall of the inner rotary kiln at the inlet is not less than about 500 C to heat the particulate material to a temperature in the range of from about 200 C to about 900 C in a pyrolyzing atmosphere to reduce the particulate material as it moves from the one end toward the other end. The reduced particulates including char are transferred to the annular space between the inner and the outer rotating kilns near the other end of the inner rotating kiln and moved longitudinally in the annular space from near the other end toward the one end in the presence of oxygen to combust the char at an elevated temperature to produce a waste material including ash. Also, heat is provided which is transferred to the inner kiln. The waste material including ash leaves the outer rotating kiln near the one end and the pyrolysis vapor leaves through the particulate material inlet. 5 figs.

Method and system including a double rotary kiln pyrolysis or gasification of waste material

DOEpatents

McIntosh, Michael J.; Arzoumanidis, Gregory G.

1997-01-01

A method of destructively distilling an organic material in particulate form wherein the particulates are introduced through an inlet into one end of an inner rotating kiln ganged to and coaxial with an outer rotating kiln. The inner and outer kilns define a cylindrical annular space with the inlet being positioned in registry with the axis of rotation of the ganged kilns. During operation, the temperature of the wall of the inner rotary kiln at the inlet is not less than about 500.degree. C. to heat the particulate material to a temperature in the range of from about 200.degree. C. to about 900.degree. C. in a pyrolyzing atmosphere to reduce the particulate material as it moves from the one end toward the other end. The reduced particulates including char are transferred to the annular space between the inner and the outer rotating kilns near the other end of the inner rotating kiln and moved longitudinally in the annular space from near the other end toward the one end in the presence of oxygen to combust the char at an elevated temperature to produce a waste material including ash. Also, heat is provided which is transferred to the inner kiln. The waste material including ash leaves the outer rotating kiln near the one end and the pyrolysis vapor leaves through the particulate material inlet.

Possibilities for preservation of coarse particles in pelleting process to improve feed quality characteristics.

PubMed

Vukmirović, D; Fišteš, A; Lević, J; Čolović, R; Rakić, D; Brlek, T; Banjac, V

2017-10-01

Poultry diets are mainly used in pelleted form because pellets have many advantages compared to mash feed. On the other hand, pelleting causes reduction of feed particle size. The aim of this research was to investigate the possibility of increasing the content of coarse particles in pellets, and, at the same time, to produce pellets with satisfactory quality. In this research, the three grinding treatments of corn were applied using hammer mill with three sieve openings diameter: 3 mm (HM-3), 6 mm (HM-6) and 9 mm (HM-9). These grinding treatments were combined in pelleting process with three gaps between rollers and the die of pellet press (roller-die gap, RDG) (0.30, 1.15 and 2.00 mm) and three moisture contents of the pelleted material (14.5, 16.0 and 17.5%). The increased coarseness of grinding by the hammer mill resulted in the increased amount of coarse particles in pellets, especially when the smallest RDG was applied (0.30 mm), but pellet quality was greatly reduced. Increasing of RDG improved the quality of pellets produced from coarsely ground corn, but reduced the content of coarse particles in pellets and increased specific energy consumption of the pellet press. Increasing the moisture content of material to be pelleted (MC) significantly reduced energy consumption of the pellet press, but there was no significant influence of MC on particle size after pelleting and on the pellet quality. The optimal values of the pelleting process parameters were determined using desirability function method. The results of optimization process showed that to achieve the highest possible quantity of coarse particles in the pellets, and to produce pellets of satisfactory quality, with the lowest possible energy consumption of the pellet press, the coarsest grinding on hammer mill (HM-9), the largest RDG (2 mm) and the highest MC (17.5%) should be applied. Journal of Animal Physiology and Animal Nutrition © 2016 Blackwell Verlag GmbH.

Survival characteristics of diarrheagenic Escherichia coli pathotypes and Helicobacter pylori during passage through the free-living ciliate, Tetrahymena sp.

USDA-ARS?s Scientific Manuscript database

Ciliates prey on bacteria in water and waste water systems. Compartmentalization of ingested material (including bacteria) in the food vacuoles of Tetrahymena and its egestion in the fecal pellet has been described and the survival of Salmonella enterica and E. coli O157:H7 in such fecal pellets ha...

Individual identification of Sitka black-tailed deer (Odocoileus hemionus sitkensis) using DNA from fecal pellets

Treesearch

Todd J. Brinkman; David K. Person; Michael K. Schwartz; Kristine L. Pilgrim; Kevin E. Colson; Kris J. Hundertmark

2010-01-01

We tested a protocol for extracting DNA from fecal pellets from Sitka black-tailed deer (Odocoileus hemionus sitkensis) and evaluated genotyping performance of previously developed microsatellite markers as well as a suite of new markers designed specifically for this study. We screened 30 microsatellites, and identified 7 (23%) loci including 4 new markers, that fit...

Testing large aspheric surfaces with complementary annular subaperture interferometric method

NASA Astrophysics Data System (ADS)

Hou, Xi; Wu, Fan; Lei, Baiping; Fan, Bin; Chen, Qiang

2008-07-01

Annular subaperture interferometric method has provided an alternative solution to testing rotationally symmetric aspheric surfaces with low cost and flexibility. However, some new challenges, particularly in the motion and algorithm components, appear when applied to large aspheric surfaces with large departure in the practical engineering. Based on our previously reported annular subaperture reconstruction algorithm with Zernike annular polynomials and matrix method, and the experimental results for an approximate 130-mm diameter and f/2 parabolic mirror, an experimental investigation by testing an approximate 302-mm diameter and f/1.7 parabolic mirror with the complementary annular subaperture interferometric method is presented. We have focused on full-aperture reconstruction accuracy, and discuss some error effects and limitations of testing larger aspheric surfaces with the annular subaperture method. Some considerations about testing sector segment with complementary sector subapertures are provided.

Prognostication of valvular aortic stenosis using tissue Doppler echocardiography: underappreciated importance of late diastolic mitral annular velocity.

PubMed

Poh, Kian-Keong; Chan, Mark Yan-Yee; Yang, Hong; Yong, Quek-Wei; Chan, Yiong-Huak; Ling, Lieng H

2008-05-01

Intact left atrial booster pump function helps maintain cardiac compensation in patients with aortic valve stenosis (AS). Because late diastolic mitral annular (A') velocity reflects left atrial systolic function, we hypothesized that A' velocity correlates with plasma N-terminal pro-B-type natriuretic peptide (NT-proBNP) level and clinical outcome in AS. We prospectively enrolled 53 consecutive patients (median age 74 years) with variable degrees of AS, in sinus rhythm, and left ventricular ejection fraction greater than 50%. Indices of valvular stenosis, left ventricular diastolic dysfunction, and mitral annular motion were correlated with plasma NT-proBNP and a composite clinical end point comprising cardiac death and symptom-driven aortic valve replacement. Tissue Doppler echocardiographic parameters, including early diastolic (E') velocity and A' velocity and ratio of early diastolic transmitral (E) to E' velocity (E/E') at the annular septum correlated better with NT-proBNP levels than body surface area-indexed aortic valve area. Eighteen patients had the composite end point, which was univariately predicted by body surface area-indexed aortic valve area, NT-proBNP, and all tissue Doppler echocardiographic indices. This outcome was most strongly predicted by the combination of septal A' velocity and E/E' ratio in bivariate Cox modeling. Septal annular A' velocity less than 9.6 cm/s was associated with significantly reduced event-free survival (Kaplan Meier log rank = 27.3, P < .0001) and predicted the end point with a sensitivity, specificity, and accuracy of 94%, 80%, and 85%, respectively. In patients with AS and normal ejection fraction, annular tissue Doppler echocardiographic indices may better reflect the physiologic consequences of afterload burden on the left ventricle than body surface area-indexed aortic valve area. Lower A' velocity is a predictor of cardiac death and need for valve surgery, suggesting an important role for compensatory left atrial booster pump function.

Annular and Total Solar Eclipses of 2003

NASA Technical Reports Server (NTRS)

Espenak, Fred; Anderson, Jay

2002-01-01

On Saturday, 2003 May 31, an annular eclipse of the Sun will be visible from a broad corridor that traverses the North Atlantic. The path of the Moon's antumbral shadow begins in northern Scotland, crosses Iceland and central Greenland, and ends at sunrise in Baffin Bay (Canada). A partial eclipse will be seen within the much broader path of the Moon's penumbral shadow, which includes most of Europe, the Middle East, central and northern Asia, and northwestern North America. The trajectory of the Moon's shadow is quite unusual during this event. The shadow axis passes to the far north where it barely grazes Earth's surface. In fact, the northern edge of the antumbra actually misses Earth so that one path limit is defined by the day/night terminator rather than by the shadow's upper edge. As a result, the track of annularity has a peculiar "D" shape that is nearly 1200 kilometers wide. Since the eclipse occurs just three weeks prior to the northern summer solstice, Earth's northern axis is pointed sunwards by 22.8 deg. As seen from the Sun, the antumbral shadow actually passes between the North Pole and the terminator. As a consequence of this extraordinary geometry, the path of annularity runs from east to west rather than the more typical west to east. The event transpires near the Moon's ascending node in Taurus five degrees north of Aldebaran. Since apogee occurs three days earlier (May 28 at 13 UT), the Moon's apparent diameter (29.6 arc-minutes) is still too small to completely cover the Sun (31.6 arc-minutes) resulting in an annular eclipse.

Use of pelleted sericea lespedeza (Lespedeza cuneata) for natural control of coccidia and gastrointestinal nematodes in weaned goats.

PubMed

Kommuru, D S; Barker, T; Desai, S; Burke, J M; Ramsay, A; Mueller-Harvey, I; Miller, J E; Mosjidis, J A; Kamisetti, N; Terrill, T H

2014-08-29

Infection with Eimeria spp. (coccidia) can be devastating in goats, particularly for young, recently-weaned kids, resulting in diarrhea, dehydration, and even death. Feeding dried sericea lespedeza [SL; Lespedeza cuneata (Dum.-Cours.) G. Don.] to young goats has been reported to reduce the effects of internal parasites, including gastrointestinal nematodes (GIN) but there have been no reports of the effects of feeding this forage on Eimeria spp. in goats. Two confinement feeding experiments were completed on recently-weaned intact bucks (24 Kiko-cross, Exp. 1; 20 Spanish, Exp. 2) to determine effects of SL pellets on an established infection of GIN and coccidia. The bucks were assigned to 1 of 2 (Exp. 1) or 3 (Exp. 2) treatment groups based upon the number of Eimeria spp. oocysts per gram (OPG) of feces. In Exp. 1, the kids were fed 1 of 2 pelleted rations ad libitum; 90% SL leaf meal+10% of a liquid molasses/lignin binder mix and a commercial pellet with 12% crude protein (CP) and 24% acid detergent fiber (n=12/treatment group, 2 animals/pen). For Exp. 2, treatment groups were fed (1) 90% SL leaf meal pellets from leaves stored 3 years (n=7), (2) 90% SL pellets from leaf meal stored less than 6 months, (n=7), and the commercial pellets (n=6) ad libitum. For both trials, fecal and blood samples were taken from individual animals every 7 days for 28 days to determine OPG and GIN eggs per gram (EPG) and packed cell volume (PCV), respectively. In Exp. 2, feces were scored for consistency (1=solid pellets, 5=slurry) as an indicator of coccidiosis. In Exp. 1, EPG (P<0.001) and OPG (P<0.01) were reduced by 78.7% and 96.9%, respectively, 7 days after initiation of feeding in goats on the SL pellet diet compared with animals fed the control pellets. The OPG and EPG remained lower in treatment than control animals until the end of the trial. In Exp. 2, goats fed new and old SL leaf meal pellets had 66.2% and 79.2% lower (P<0.05) EPG and 92.2% and 91.2% lower (P<0.05) OPG, respectively, than control animals within 7 days, and these differences were maintained or increased throughout the trial. After 4 weeks of pellet feeding in Exp. 2, fecal scores were lower (P<0.01) in both SL-fed groups compared with control animals, indicating fewer signs of coccidiosis. There was no effect of diet on PCV values throughout either experiment. Dried, pelleted SL has excellent potential as a natural anti-coccidial feed for weaned goats. Copyright © 2014 Elsevier B.V. All rights reserved.

Assessing bat droppings and predatory bird pellets for vector-borne bacteria: molecular evidence of bat-associated Neorickettsia sp. in Europe.

PubMed

Hornok, Sándor; Szőke, Krisztina; Estók, Péter; Krawczyk, Aleksandra; Haarsma, Anne-Jifke; Kováts, Dávid; Boldogh, Sándor A; Morandini, Pál; Szekeres, Sándor; Takács, Nóra; Kontschán, Jenő; Meli, Marina L; Fernández de Mera, Isabel G; de la Fuente, José; Gyuranecz, Miklós; Sulyok, Kinga M; Weibel, Beatrice; Gönczi, Enikő; de Bruin, Arnout; Sprong, Hein; Hofmann-Lehmann, Regina

2018-02-28

In Europe, several species of bats, owls and kestrels exemplify highly urbanised, flying vertebrates, which may get close to humans or domestic animals. Bat droppings and bird pellets may have epidemiological, as well as diagnostic significance from the point of view of pathogens. In this work 221 bat faecal and 118 bird pellet samples were screened for a broad range of vector-borne bacteria using PCR-based methods. Rickettsia DNA was detected in 13 bat faecal DNA extracts, including the sequence of a rickettsial insect endosymbiont, a novel Rickettsia genotype and Rickettsia helvetica. Faecal samples of the pond bat (Myotis dasycneme) were positive for a Neorickettsia sp. and for haemoplasmas of the haemofelis group. In addition, two bird pellets (collected from a Long-eared Owl, Asio otus, and from a Common Kestrel, Falco tinnunculus) contained the DNA of a Rickettsia sp. and Anaplasma phagocytophilum, respectively. In both of these bird pellets the bones of Microtus arvalis were identified. All samples were negative for Borrelia burgdorferi s.l., Francisella tularensis, Coxiella burnetii and Chlamydiales. In conclusion, bats were shown to pass rickettsia and haemoplasma DNA in their faeces. Molecular evidence is provided for the presence of Neorickettsia sp. in bat faeces in Europe. In the evaluated regions bat faeces and owl/kestrel pellets do not appear to pose epidemiological risk from the point of view of F. tularensis, C. burnetii and Chlamydiales. Testing of bird pellets may provide an alternative approach to trapping for assessing the local occurrence of vector-borne bacteria in small mammals.

Development of a Feedstock-to-Product Chain Model for Densified Biomass Pellets

NASA Astrophysics Data System (ADS)

McPherrin, Daniel

The Q’Pellet is a spherical, torrefied biomass pellet currently under development. It aims to improve on the shortcomings of commercially available cylindrical white and torrefied pellets. A spreadsheet-based model was developed to allow for techno-economic analysis and simplified life cycle analysis of Q’Pellets, torrefied pellets and white pellets. A case study was developed to compare the production of white, torrefied and Q’Pellet production based on their internal rates of return and life cycle greenhouse gas emissions. The case study was based on a commercial scale plant built in Williams Lake BC with product delivery in Rotterdam, Netherlands. Q’Pellets had the highest modelled internal rate of return, at 12.7%, with white pellets at 11.1% and torrefied pellets at 8.0%. The simplified life cycle analysis showed that Q’Pellets had the lowest life cycle greenhouse gas emissions of the three products, 6.96 kgCO2eq/GJ, compared to 21.50 kgCO2eq/GJ for white pellets and 10.08 kgCO2eq/GJ for torrefied pellets. At these levels of life cycle greenhouse gas emissions, white pellets are above the maximum life cycle emissions to be considered sustainable under EU regulations. Sensitivity analysis was performed on the model by modifying input variables, and showed that white pellets are more sensitive to uncontrollable market variables, especially pellet sale prices, raw biomass prices and transportation costs. Monte Carlo analysis was also performed, which showed that white pellet production is less predictable and more likely to lead to a negative internal rate of return compared to Q’Pellet production.

46 CFR 148.04-21 - Coconut meal pellets (also known as copra pellets).

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 5 2010-10-01 2010-10-01 false Coconut meal pellets (also known as copra pellets). 148.04-21 Section 148.04-21 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) DANGEROUS... § 148.04-21 Coconut meal pellets (also known as copra pellets). (a) Coconut meal pellets; (1) Must...

Flow-field characteristics of high-temperature annular buoyant jets and their development laws influenced by ventilation system.

PubMed

Wang, Yi; Huang, Yanqiu; Liu, Jiaping; Wang, Hai; Liu, Qiuhan

2013-01-01

The flow-field characteristics of high-temperature annular buoyant jets as well as the development laws influenced by ventilation system were studied using numerical methods to eliminate the pollutants effectively in this paper. The development laws of high-temperature annular buoyant jets were analyzed and compared with previous studies, including radial velocity distribution, axial velocity and temperature decay, reattachment position, cross-section diameter, volumetric flow rate, and velocity field characteristics with different pressures at the exhaust hood inlet. The results showed that when the ratio of outer diameter to inner diameter of the annulus was smaller than 5/2, the flow-field characteristics had significant difference compared to circular buoyant jets with the same outer diameter. For similar diameter ratios, reattachment in this paper occurred further downstream in contrast to previous study. Besides, the development laws of volumetric flow rate and cross-section diameter were given with different initial parameters. In addition, through analyzing air distribution characteristics under the coupling effect of high-temperature annular buoyant jets and ventilation system, it could be found that the position where maximum axial velocity occurred was changing gradually when the pressure at the exhaust hood inlet changed from 0 Pa to -5 Pa.

Flow-Field Characteristics of High-Temperature Annular Buoyant Jets and Their Development Laws Influenced by Ventilation System

PubMed Central

Liu, Jiaping; Wang, Hai; Liu, Qiuhan

2013-01-01

The flow-field characteristics of high-temperature annular buoyant jets as well as the development laws influenced by ventilation system were studied using numerical methods to eliminate the pollutants effectively in this paper. The development laws of high-temperature annular buoyant jets were analyzed and compared with previous studies, including radial velocity distribution, axial velocity and temperature decay, reattachment position, cross-section diameter, volumetric flow rate, and velocity field characteristics with different pressures at the exhaust hood inlet. The results showed that when the ratio of outer diameter to inner diameter of the annulus was smaller than 5/2, the flow-field characteristics had significant difference compared to circular buoyant jets with the same outer diameter. For similar diameter ratios, reattachment in this paper occurred further downstream in contrast to previous study. Besides, the development laws of volumetric flow rate and cross-section diameter were given with different initial parameters. In addition, through analyzing air distribution characteristics under the coupling effect of high-temperature annular buoyant jets and ventilation system, it could be found that the position where maximum axial velocity occurred was changing gradually when the pressure at the exhaust hood inlet changed from 0 Pa to −5 Pa. PMID:24000278

Gas flow stabilized megavolt spark gap for repetitive pulses

DOEpatents

Lawson, R.N.; O'Malley, M.W.; Rohwein, G.J.

A high voltage spark gap switch is disclosed including a housing having first and second end walls being spaced apart by a predetermined distance. A first electrode is positioned on the first end wall and a second electrode is positioned on the second end wall. The first and second electrodes are operatively disposed relative to each other and are spaced apart by a predetermined gap. An inlet conduit is provided for supplying gas to the first electrode. The conduit includes a nozzle for dispersing the gas in the shape of an annular jet. The gas is supplied into the housing at a predetermined velocity. A venturi housing is disposed within the second electrode. An exhaust conduit is provided for discharging gas and residue from the housing. The gas supplied at the predetermined velocity to the housing through the inlet conduit and the nozzle in an annular shape traverses the gap between the first and second electrodes and entrains low velocity gas within the housing decreasing the velocity of the gas supplied to the housing and increasing the diameter of the annular shape. The venturi disposed within the second electrode recirculates a large volume of gas to clean and cool the surface of the electrodes.

Gas flow stabilized megavolt spark gap for repetitive pulses

DOEpatents

Lawson, Robert N.; O'Malley, Martin W.; Rohwein, Gerald J.

1986-01-01

A high voltage spark gap switch including a housing having first and second end walls being spaced apart by a predetermined distance. A first electrode is positioned on the first end wall and a second electrode is positioned on the second end wall. The first and second electrodes are operatively disposed relative to each other and are spaced apart by a predetermined gap. An inlet conduit is provided for supplying gas to the first electrode. The conduit includes a nozzle for dispersing the gas in the shape of an annular jet. The gas is supplied into the housing at a predetermined velocity. A venturi housing is disposed within the second electrode. An exhaust conduit is provided for discharging gas and residue from the housing. The gas supplied at the predetermined velocity to the housing through the inlet conduit and the nozzle in an annular shape traverses the gap between the first and second electrodes and entrains low velocity gas within the housing decreasing the velocity of the gas supplied to the housing and increasing the diameter of the annular shape. The venturi disposed within the second electrode recirculates a large volume of gas to clean and cool the surface of the electrodes.

Pelletizing/reslurrying as a means of distributing and firing clean coal. Final quarterly technical progress report No. 5, July 1, 1991--September 30, 1991

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

Conkle, H.N.; Raghavan, J.K.; Smit, F.J.

1991-11-21

The objective of this study is to develop technology that permits the practical and economic preparation, storage, handling, and transportation of coal pellets, which can be reslurried into Coal water fuels (CWF) suitable for firing in small- and medium-size commercial and industrial boilers, furnaces, and engines. The project includes preparing coal pellets and capsules from wet filter cake that can be economically stored, handled, transported, and reslurried into a CWF that can be suitably atomized and fired at the user site. The wet cakes studied were prepared from ultra-fine (95% -325 mesh) coal beneficiated by advanced froth-flotation techniques. The coalsmore » studied included two eastern bituminous coals, one from Virginia (Elkhorn) and one from Illinois (Illinois No. 6) and one western bituminous coal from Utah (Sky Line coal).« less

Axial seal system for a gas turbine steam-cooled rotor

DOEpatents

Mashey, Thomas Charles

2002-01-01

An axial seal assembly is provided at the interface between adjacent wheels and spacers of a gas turbine rotor and disposed about tubes passing through openings in the rotor adjacent the rotor rim and carrying a thermal medium. Each seal assembly includes a support bushing for supporting a land of the thermal medium carrying tube, an axially registering seat bushing disposed in the opposed opening and a frustoconical seal between the seal bushing and seat. The seal bushing includes a radial flange having an annular recess for retaining the outer diameter edge of the seal, while the seat bushing has an axially facing annular surface forming a seat for engagement by the inner diameter edge of the seal.

Mechanical swirler for a low-NO{sub x}, weak-swirl burner

DOEpatents

Cheng, R.K.; Yegian, D.T.

1999-03-09

Disclosed is a mechanical swirler for generating diverging flow in lean premixed fuel burners. The swirler of the present invention includes a central passage with an entrance for accepting a feed gas, a flow balancing insert that introduces additional pressure drop beyond that occurring in the central passage in the absence of the flow balancing insert, and an exit aligned to direct the feed gas into a combustor. The swirler also has an annular passage about the central passage and including one or more vanes oriented to impart angular momentum to feed gas exiting the annular passage. The diverging flow generated by the swirler stabilizes lean combustion thus allowing for lower production of pollutants, particularly oxides of nitrogen. 16 figs.

Mechanical swirler for a low-NO.sub.x, weak-swirl burner

DOEpatents

Cheng, Robert K.; Yegian, Derek T.

1999-01-01

Disclosed is a mechanical swirler for generating diverging flow in lean premixed fuel burners. The swirler of the present invention includes a central passage with an entrance for accepting a feed gas, a flow balancing insert that introduces additional pressure drop beyond that occurring in the central passage in the absence of the flow balancing insert, and an exit aligned to direct the feed gas into a combustor. The swirler also has an annular passage about the central passage and including one or more vanes oriented to impart angular momentum to feed gas exiting the annular passage. The diverging flow generated by the swirler stabilizes lean combustion thus allowing for lower production of pollutants, particularly oxides of nitrogen.

Integrated field emission array for ion desorption

DOEpatents

Resnick, Paul J; Hertz, Kristin L.; Holland, Christopher; Chichester, David

2016-08-23

An integrated field emission array for ion desorption includes an electrically conductive substrate; a dielectric layer lying over the electrically conductive substrate comprising a plurality of laterally separated cavities extending through the dielectric layer; a like plurality of conically-shaped emitter tips on posts, each emitter tip/post disposed concentrically within a laterally separated cavity and electrically contacting the substrate; and a gate electrode structure lying over the dielectric layer, including a like plurality of circular gate apertures, each gate aperture disposed concentrically above an emitter tip/post to provide a like plurality of annular gate electrodes and wherein the lower edge of each annular gate electrode proximate the like emitter tip/post is rounded. Also disclosed herein are methods for fabricating an integrated field emission array.

Integrated field emission array for ion desorption

DOEpatents

Resnick, Paul J; Hertz, Kristin L; Holland, Christopher; Chichester, David; Schwoebel, Paul

2013-09-17

An integrated field emission array for ion desorption includes an electrically conductive substrate; a dielectric layer lying over the electrically conductive substrate comprising a plurality of laterally separated cavities extending through the dielectric layer; a like plurality of conically-shaped emitter tips on posts, each emitter tip/post disposed concentrically within a laterally separated cavity and electrically contacting the substrate; and a gate electrode structure lying over the dielectric layer, including a like plurality of circular gate apertures, each gate aperture disposed concentrically above an emitter tip/post to provide a like plurality of annular gate electrodes and wherein the lower edge of each annular gate electrode proximate the like emitter tip/post is rounded. Also disclosed herein are methods for fabricating an integrated field emission array.

46 CFR 148.325 - Wood chips; wood pellets; wood pulp pellets.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 5 2014-10-01 2014-10-01 false Wood chips; wood pellets; wood pulp pellets. 148.325... § 148.325 Wood chips; wood pellets; wood pulp pellets. (a) This part applies to wood chips and wood pulp... cargo hold. (b) No person may enter a cargo hold containing wood chips, wood pellets, or wood pulp...

46 CFR 148.325 - Wood chips; wood pellets; wood pulp pellets.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 5 2012-10-01 2012-10-01 false Wood chips; wood pellets; wood pulp pellets. 148.325... § 148.325 Wood chips; wood pellets; wood pulp pellets. (a) This part applies to wood chips and wood pulp... cargo hold. (b) No person may enter a cargo hold containing wood chips, wood pellets, or wood pulp...

46 CFR 148.325 - Wood chips; wood pellets; wood pulp pellets.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 5 2013-10-01 2013-10-01 false Wood chips; wood pellets; wood pulp pellets. 148.325... § 148.325 Wood chips; wood pellets; wood pulp pellets. (a) This part applies to wood chips and wood pulp... cargo hold. (b) No person may enter a cargo hold containing wood chips, wood pellets, or wood pulp...

46 CFR 148.325 - Wood chips; wood pellets; wood pulp pellets.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 5 2011-10-01 2011-10-01 false Wood chips; wood pellets; wood pulp pellets. 148.325... § 148.325 Wood chips; wood pellets; wood pulp pellets. (a) This part applies to wood chips and wood pulp... cargo hold. (b) No person may enter a cargo hold containing wood chips, wood pellets, or wood pulp...

Coaxial fuel and air premixer for a gas turbine combustor

DOEpatents

York, William D; Ziminsky, Willy S; Lacy, Benjamin P

2013-05-21

An air/fuel premixer comprising a peripheral wall defining a mixing chamber, a nozzle disposed at least partially within the peripheral wall comprising an outer annular wall spaced from the peripheral wall so as to define an outer air passage between the peripheral wall and the outer annular wall, an inner annular wall disposed at least partially within and spaced from the outer annular wall, so as to define an inner air passage, and at least one fuel gas annulus between the outer annular wall and the inner annular wall, the at least one fuel gas annulus defining at least one fuel gas passage, at least one air inlet for introducing air through the inner air passage and the outer air passage to the mixing chamber, and at least one fuel inlet for injecting fuel through the fuel gas passage to the mixing chamber to form an air/fuel mixture.

Percutaneous endoscopic intra-annular subligamentous herniotomy for large central disc herniation: a technical case report.

PubMed

Lee, Sang-Ho; Choi, Kyung-Chul; Baek, Oon Ki; Kim, Ho Jin; Yoo, Seung-Hwa

2014-04-01

Technical case report. To describe the novel technique of percutaneous endoscopic herniotomy using a unilateral intra-annular subligamentous approach for the treatment of large centrally herniated discs. Open discectomy for large central disc herniations may have poor long-term prognosis due to heavy loss of intervertebral disc tissue, segmental instability, and recurrence of pain. Six consecutive patients who presented with back and leg pain, and/or weakness due to a large central disc herniation were treated using percutaneous endoscopic herniotomy with a unilateral intra-annular subligamentous approach. The patients experienced relief of symptoms and intervertebral disc spaces were well maintained. The annular defects were noted to be in the process of healing and recovery. Percutaneous endoscopic unilateral intra-annular subligamentous herniotomy was an effective and affordable minimally invasive procedure for patients with large central disc herniations, allowing preservation of nonpathological intradiscal tissue through a concentric outer-layer annular approach.

Method of making an aero-derivative gas turbine engine

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

Wiebe, David J.

A method of making an aero-derivative gas turbine engine (100) is provided. A combustor outer casing (68) is removed from an existing aero gas turbine engine (60). An annular combustor (84) is removed from the existing aero gas turbine engine. A first row of turbine vanes (38) is removed from the existing aero gas turbine engine. A can annular combustor assembly (122) is installed within the existing aero gas turbine engine. The can annular combustor assembly is configured to accelerate and orient combustion gasses directly onto a first row of turbine blades of the existing aero gas turbine engine. Amore » can annular combustor assembly outer casing (108) is installed to produce the aero-derivative gas turbine engine (100). The can annular combustor assembly is installed within an axial span (85) of the existing aero gas turbine engine vacated by the annular combustor and the first row of turbine vanes.« less

Annular core liquid-salt cooled reactor with multiple fuel and blanket zones

DOEpatents

Peterson, Per F.

2013-05-14

A liquid fluoride salt cooled, high temperature reactor having a reactor vessel with a pebble-bed reactor core. The reactor core comprises a pebble injection inlet located at a bottom end of the reactor core and a pebble defueling outlet located at a top end of the reactor core, an inner reflector, outer reflector, and an annular pebble-bed region disposed in between the inner reflector and outer reflector. The annular pebble-bed region comprises an annular channel configured for receiving pebble fuel at the pebble injection inlet, the pebble fuel comprising a combination of seed and blanket pebbles having a density lower than the coolant such that the pebbles have positive buoyancy and migrate upward in said annular pebble-bed region toward the defueling outlet. The annular pebble-bed region comprises alternating radial layers of seed pebbles and blanket pebbles.

Twin-Screw Extruder and Pellet Accelerator Integration Developments for ITER

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

Meitner, Steven J; Baylor, Larry R; Combs, Stephen Kirk

The ITER pellet injection system consisting of a twinscrew frozen hydrogen isotope extruder, coupled to a combination solenoid actuated pellet cutter and pneumatic pellet accelerator, is under development at the Oak Ridge National Laboratory. A prototype extruder has been built to produce a continuous solid deuterium extrusion and will be integrated with a secondary section, where pellets are cut, chambered, and launched with a single-stage pneumatic accelerator into the plasma through a guide tube. This integrated pellet injection system is designed to provide 5 mm fueling pellets, injected at a rate up to 10 Hz, or 3 mm edge localizedmore » mode (ELM) triggering pellets, injected at higher rates up to 20 Hz. The pellet cutter, chamber mechanism, and the solenoid operated pneumatic valve for the accelerator are optimized to provide pellet velocities between 200-300 m/s to ensure high pellet survivability while traversing the inner wall fueling guide tubes, and outer wall ELMpacing guide tubes. This paper outlines the current twin-screwextruder design, pellet accelerator design, and the integrationrequired for both fueling and ELM pacing pellets.« less

Thermo-Chemical Conversion of Microwave Activated Biomass Mixtures

NASA Astrophysics Data System (ADS)

Barmina, I.; Kolmickovs, A.; Valdmanis, R.; Vostrikovs, S.; Zake, M.

2018-05-01

Thermo-chemical conversion of microwave activated wheat straw mixtures with wood or peat pellets is studied experimentally with the aim to provide more effective application of wheat straw for heat energy production. Microwave pre-processing of straw pellets is used to provide a partial decomposition of the main constituents of straw and to activate the thermo-chemical conversion of wheat straw mixtures with wood or peat pellets. The experimental study includes complex measurements of the elemental composition of biomass pellets (wheat straw, wood, peat), DTG analysis of their thermal degradation, FTIR analysis of the composition of combustible volatiles entering the combustor, the flame temperature, the heat output of the device and composition of the products by comparing these characteristics for mixtures with unprocessed and mw pre-treated straw pellets. The results of experimental study confirm that mw pre-processing of straw activates the thermal decomposition of mixtures providing enhanced formation of combustible volatiles. This leads to improvement of the combustion conditions in the flame reaction zone, completing thus the combustion of volatiles, increasing the flame temperature, the heat output from the device, the produced heat energy per mass of burned mixture and decreasing at the same time the mass fraction of unburned volatiles in the products.

Feeding steam-pelleted rapeseed affects expression of genes involved in hepatic lipid metabolism and fatty acid composition of chicken meat.

PubMed

Li, S; Vestergren, A Schiller; Wall, H; Trattner, S; Pickova, J; Ivarsson, E

2017-08-01

This study investigated the dietary effect of steam-pelleted rapeseed (RS) diets with different inclusion levels on the fatty acid composition of chicken meat and the expression of lipid metabolism-related genes in the liver. Experimental diets included 6 different wheat-soybean meal based diets either in nonpelleted or steam-pelleted form supplemented with 80, 160, and 240 g RS/kg feed and one nonpelleted wheat-soybean meal based diet without RS supplementation as the control. These diets were fed to newly hatched broiler chickens (Ross 308) for 34 days. Compared to the control diet, steam-pelleted diets containing 160 or 240 g/kg RS significantly increased the content of omega-3 long chain polyunsaturated fatty acids (n-3 LC-PUFA) in the breast and drumstick, while their meat yields were not affected. Moreover, the mRNA levels of fatty acid desaturase 1 (FADS1) and acyl-coenzyme A oxidase 1 (ACOX1) in their livers increased. Therefore, steam-pelleted diets with 160 or 240 g/kg RS can be used to increase the n-3 LC-PUFA content in chicken meat without compromising meat yield. © 2017 Poultry Science Association Inc.

Modelling explicit fracture of nuclear fuel pellets using peridynamics

NASA Astrophysics Data System (ADS)

Mella, R.; Wenman, M. R.

2015-12-01

Three dimensional models of explicit cracking of nuclear fuel pellets for a variety of power ratings have been explored with peridynamics, a non-local, mesh free, fracture mechanics method. These models were implemented in the explicitly integrated molecular dynamics code LAMMPS, which was modified to include thermal strains in solid bodies. The models of fuel fracture, during initial power transients, are shown to correlate with the mean number of cracks observed on the inner and outer edges of the pellet, by experimental post irradiation examination of fuel, for power ratings of 10 and 15 W g-1 UO2. The models of the pellet show the ability to predict expected features such as the mid-height pellet crack, the correct number of radial cracks and initiation and coalescence of radial cracks. This work presents a modelling alternative to empirical fracture data found in many fuel performance codes and requires just one parameter of fracture strain. Weibull distributions of crack numbers were fitted to both numerical and experimental data using maximum likelihood estimation so that statistical comparison could be made. The findings show P-values of less than 0.5% suggesting an excellent agreement between model and experimental distributions.

An X-band high-impedance relativistic klystron amplifier with an annular explosive cathode

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

Zhu, Danni; Zhang, Jun, E-mail: zhangjun@nudt.edu.cn; Zhong, Huihuang

2015-11-15

The feasibility of employing an annular beam instead of a solid one in the X-band high-impedance relativistic klystron amplifier (RKA) is investigated in theory and simulation. Small-signal theory analysis indicates that the optimum bunching distance, fundamental current modulation depth, beam-coupling coefficient, and beam-loaded quality factor of annular beams are all larger than the corresponding parameters of solid beams at the same beam voltage and current. An annular beam RKA and a solid beam RKA with almost the same geometric parameters are compared in particle-in-cell simulation. Output microwave power of 100 MW, gain of 50 dB, and power conversion efficiency of 42% aremore » obtained in an annular beam RKA. The annular beam needs a 15% lower uniform guiding magnetic field than the solid beam. Our investigations demonstrate that we are able to use a simple annular explosive cathode immersed in a lower uniform magnetic field instead of a solid thermionic cathode in a complicated partially shielding magnetic field for designing high-impedance RKA, which avoids high temperature requirement, complicated electron-optical system, large area convergence, high current density, and emission uniformity for the solid beam. An equivalent method for the annular beam and the solid beam on bunching features is proposed and agrees with the simulation. The annular beam has the primary advantages over the solid beam that it can employ the immersing uniform magnetic field avoiding the complicated shielding magnetic field system and needs a lower optimum guiding field due to the smaller space charge effect.« less

Tricuspid Annular Geometry: A Three-Dimensional Transesophageal Echocardiographic Study

PubMed Central

Mahmood, Feroze; Kim, Han; Chaudary, Bilal; Bergman, Remco; Matyal, Robina; Gerstle, Jeniffer; Gorman, Joseph H.; Gorman, Robert C.; Khabbaz, Kamal R.

2013-01-01

Objective To demonstrate the clinical feasibility of accurately measuring tricuspid annular area by 3-dimensional (3D) transesophageal echocardiography (TEE) and to assess the geometric differences based on the presence of tricuspid regurgitation (TR). Also, the shape of the tricuspid annulus was compared with previous descriptions in the literature. Design Prospective. Setting Tertiary care university hospital. Interventions Three-dimensional TEE. Participants Patients undergoing cardiac surgery. Measurements and Main Results Volumetric data sets from 20 patients were acquired by 3D TEE and prospectively analyzed. Comparisons in annular geometry were made between groups based on the presence of TR. The QLab (Philips Medical Systems, Andover, MA) software package was used to calculate tricuspid annular area by both linear elliptical dimensions and planimetry. Further analyses were performed in the 4D Cardio-View (TomTec Corporation GmBH, Munich, Germany) and MATLAB (Natick, MA) software environments to accurately assess annular shape. It was found that patients with greater TR had an eccentrically dilated annulus with a larger annular area. Also, the area as measured by the linear ellipse method was overestimated as compared to the planimetry method. Furthermore, the irregular saddle-shaped geometry of the tricuspid annulus was confirmed through the mathematic model developed by the authors. Conclusions Three-dimensional TEE can be used to measure the tricuspid annular area in a clinically feasible fashion, with an eccentric dilation seen in patients with TR. The tricuspid annulus shape is complex, with annular high and low points, and annular area calculation based on linear measurements significantly overestimates 3D planimetered area. PMID:23725682

Extended residence time centrifugal contactor design modification and centrifugal contactor vane plate valving apparatus for extending mixing zone residence time

DOEpatents

Wardle, Kent E.

2017-06-06

The present invention provides an annular centrifugal contactor, having a housing adapted to receive a plurality of flowing liquids; a rotor on the interior of the housing; an annular mixing zone, wherein the annular mixing zone has a plurality of fluid retention reservoirs with ingress apertures near the bottom of the annular mixing zone and egress apertures located above the ingress apertures of the annular mixing zone; and an adjustable vane plate stem, wherein the stem can be raised to restrict the flow of a liquid into the rotor or lowered to increase the flow of the liquid into the rotor.

Comparison of cryogenic (hydrogen) and TESPEL (polystyrene) pellet particle deposition in a magnetically confined plasma

NASA Astrophysics Data System (ADS)

McCarthy, K. J.; Tamura, N.; Combs, S. K.; Panadero, N.; Ascabíbar, E.; Estrada, T.; García, R.; Hernández Sánchez, J.; López Fraguas, A.; Navarro, M.; Pastor, I.; Soleto, A.; TJ-II Team

2017-10-01

A cryogenic pellet injector (PI) and tracer encapsulated solid pellet (TESPEL) injector system has been operated in combination on the stellarator TJ-II. This unique arrangement has been created by piggy-backing a TESPEL injector onto the backend of a pipe-gun-type PI. The combined injector provides a powerful new tool for comparing ablation and penetration of polystyrene TESPEL pellets and solid hydrogen pellets, as well as for contrasting subsequent pellet particle deposition and plasma perturbation under analogous plasma conditions. For instance, a significantly larger increase in plasma line-averaged electron density, and electron content, is observed after a TESPEL pellet injection compared with an equivalent cryogenic pellet injection. Moreover, for these injections from the low-magnetic-field side of the plasma cross-section, TESPEL pellets deposit electrons deeper into the plasma core than cryogenic pellets. Finally, the physics behind these observations and possible implications for pellet injection studies are discussed.

Gasification of Wood and Non-wood Waste of Timber Production as Perspectives for Development of Bioenergy

NASA Astrophysics Data System (ADS)

Kislukhina, Irina A.; Rybakova, Olga G.

2018-03-01

The article deals with biomass gasification technology using the gasification plant running on wood chips and pellets, produced from essential oils waste (waste of coniferous boughs). During the study, the authors solved the process task of improving the quality of the product gas derived from non-wood waste of timber production (coniferous boughs) due to the extraction of essential oils and the subsequent thermal processing of spent coniferous boughs at a temperature of 250-300°C degrees without oxygen immediately before pelleting. The paper provides the improved biomass gasification process scheme including the grinding of coniferous boughs, essential oil distillation and thermal treatment of coniferous boughs waste and pelletizing.

Cooling system for rotating machine

DOEpatents

Gerstler, William Dwight [Niskayuna, NY; El-Refaie, Ayman Mohamed Fawzi [Niskayuna, NY; Lokhandwalla, Murtuza [Clifton Park, NY; Alexander, James Pellegrino [Ballston Lake, NY; Quirion, Owen Scott [Clifton Park, NY; Palafox, Pepe [Schenectady, NY; Shen, Xiaochun [Schenectady, NY; Salasoo, Lembit [Schenectady, NY

2011-08-09

An electrical machine comprising a rotor is presented. The electrical machine includes the rotor disposed on a rotatable shaft and defining a plurality of radial protrusions extending from the shaft up to a periphery of the rotor. The radial protrusions having cavities define a fluid path. A stationary shaft is disposed concentrically within the rotatable shaft wherein an annular space is formed between the stationary and rotatable shaft. A plurality of magnetic segments is disposed on the radial protrusions and the fluid path from within the stationary shaft into the annular space and extending through the cavities within the radial protrusions.

Laser-induced retinal damage thresholds for annular retinal beam profiles

NASA Astrophysics Data System (ADS)

Kennedy, Paul K.; Zuclich, Joseph A.; Lund, David J.; Edsall, Peter R.; Till, Stephen; Stuck, Bruce E.; Hollins, Richard C.

2004-07-01

The dependence of retinal damage thresholds on laser spot size, for annular retinal beam profiles, was measured in vivo for 3 μs, 590 nm pulses from a flashlamp-pumped dye laser. Minimum Visible Lesion (MVL)ED50 thresholds in rhesus were measured for annular retinal beam profiles covering 5, 10, and 20 mrad of visual field; which correspond to outer beam diameters of roughly 70, 160, and 300 μm, respectively, on the primate retina. Annular beam profiles at the retinal plane were achieved using a telescopic imaging system, with the focal properties of the eye represented as an equivalent thin lens, and all annular beam profiles had a 37% central obscuration. As a check on experimental data, theoretical MVL-ED50 thresholds for annular beam exposures were calculated using the Thompson-Gerstman granular model of laser-induced thermal damage to the retina. Threshold calculations were performed for the three experimental beam diameters and for an intermediate case with an outer beam diameter of 230 μm. Results indicate that the threshold vs. spot size trends, for annular beams, are similar to the trends for top hat beams determined in a previous study; i.e., the threshold dose varies with the retinal image area for larger image sizes. The model correctly predicts the threshold vs. spot size trends seen in the biological data, for both annular and top hat retinal beam profiles.

Growth response of broilers to spray-dried plasma in pelleted or expanded feed processed at high temperature.

PubMed

Campbell, J M; Russell, L E; Crenshaw, J D; Behnke, K C; Clark, P M

2006-09-01

A series of 4 experiments evaluated effects of mash conditioning temperature from a pellet mill or expander on performance of broilers fed pelleted diets containing spray-dried plasma (SDP). All experiments utilized Ross x Ross 308 male broilers randomly assigned to their respective treatments (6 or 10 broilers/pen and 8 or 10 pens/treatment). Treatments in Exp. 1 consisted of a control (0% SDP), SDP coated postpelleting, or SDP blended into the meal prepelleting. Experiment 2 and 3 included the same 3 treatments as in Exp. 1 but with additional treatments of SDP blended into the meal and conditioned at 90 or 95 degrees C before pelleting. In Exp. 4, treatments consisted of a control (0% SDP) or SDP blended into the meal and pelleted (85 degrees C conditioning temperature) or expanded (149 degrees C final effective temperature) and then pelleted. Corn-soybean meal-based diets were formulated to be equal in lysine and ME in all experiments. Pelleted diets were conditioned for 15 s at 85 degrees C, and expanded diets were conditioned at 95 degrees C, 29.7 MJ/t, 13.95 kg/cm2 cone pressure, exit temperature of 149 degrees C, and then pelleted through a 4 x 32-mm die. In Exp. 1, ADG and feed intake were improved (P < 0.05) for broilers fed SDP from d 1 to 28 of age, with greater BW at d 42. In Exp. 2, both in early (d 1 to 28 of age) phases, and overall (d 1 to 42 of age), broilers fed SDP had improved (P < 0.05) gain and efficiency. In Exp. 3, ADG, feed intake, efficiency of gain, and BW were improved (P < 0.01) for broilers fed SDP from d 1 to 21 of age, regardless of conditioning temperature. In Exp. 4, broilers fed SDP had improved (P < 0.05) gain, BW, and feed intake regardless of processing method. Overall, the results of all of the experiments demonstrated that pellet conditioning temperature from 85 to 95 degrees C and expander temperatures to 149 degrees C did not impair the positive growth effects of SDP in pelleted or expanded broiler feed.

Domain-adaptive finite difference methods for collapsing annular liquid jets

NASA Astrophysics Data System (ADS)

Ramos, J. I.

1993-01-01

A domain-adaptive technique which maps a time-dependent, curvilinear geometry into a unit square is used to determine the steady state mass absorption rate and the collapse of annular liquid jets. A method of lines is used to solve the one-dimensional fluid dynamics equations written in weak conservation-law form, and upwind differences are employed to evaluate the axial convective fluxes. The unknown, time-dependent, axial location of the downstream boundary is determined from the solution of an ordinary differential equation which is nonlinearly coupled to the fluid dynamics and gas concentration equations. The equation for the gas concentration in the annular liquid jet is written in strong conservation-law form and solved by means of a method of lines at high Peclet numbers and a line Gauss-Seidel method at low Peclet numbers. The effects of the number of grid points along and across the annular jet, time step, and discretization of the radial convective fluxes on both the steady state mass absorption rate and the jet's collapse rate have been analyzed on staggered and non-staggered grids. The steady state mass absorption rate and the collapse of annular liquid jets are determined as a function of the Froude, Peclet and Weber numbers, annular jet's thickness-to-radius ratio at the nozzle exit, initial pressure difference across the annular jet, nozzle exit angle, temperature of the gas enclosed by the annular jet, pressure of the gas surrounding the jet, solubilities at the inner and outer interfaces of the annular jet, and gas concentration at the nozzle exit. It is shown that the steady state mass absorption rate is proportional to the inverse square root of the Peclet number except for low values of this parameter, and that the possible mathematical incompatibilities in the concentration field at the nozzle exit exert a great influence on the steady state mass absorption rate and on the jet collapse. It is also shown that the steady state mass absorption rate increases as the Weber number, nozzle exit angle, gas concentration at the nozzle exit, and temperature of the gases enclosed by the annular liquid jet are increased, but it decreases as the Froude and Peclet numbers, and annular liquid jet's thickness-to-radius ratio at the nozzle exit are increased. It is also shown that the annular liquid jet's collapse rate increases as the Weber number, nozzle exit angle, temperature of the gases enclosed by the annular liquid jet, and pressure of the gases which surround the jet are increased, but decreases as the Froude and Peclet numbers, and annular liquid jet's thickness-toradius ratio at the nozzle exit are increased. It is also shown that both the ratio of the initial pressure of the gas enclosed by the jet to the pressure of the gas surrounding the jet and the ratio of solubilities at the annular liquid jet's inner and outer interfaces play an important role on both the steady state mass absorption rate and the jet collapse. If the product of these ratios is greater or less than one, both the pressure and the mass of the gas enclosed by the annular liquid jet decrease or increase, respectively, with time. It is also shown that the numerical results obtained with the conservative, domain-adaptive method of lines technique presented in this paper are in excellent agreement with those of a domain-adaptive, iterative, non-conservative, block-bidiagonal, finite difference method which uncouples the solution of the fluid dynamics equations from that of the convergence length.

Design and performance of a punch mechanism based pellet injector for alternative injection in the large helical device

NASA Astrophysics Data System (ADS)

Mishra, J. S.; Sakamoto, R.; Motojima, G.; Matsuyama, A.; Yamada, H.

2011-02-01

A low speed single barrel pellet injector, using a mechanical punch device has been developed for alternative injection in the large helical device. A pellet is injected by the combined operation of a mechanical punch and a pneumatic propellant system. The pellet shape is cylindrical, 3 mm in diameter and 3 mm in length. Using this technique the speed of the pellet can be controlled flexibly in the range of 100-450 m/s, and a higher speed can be feasible for a higher gas pressure. The injector is equipped with a guide tube selector to direct the pellet to different injection locations. Pellets are exposed to several curved parts with the curvature radii Rc = 0.8 and 0.3 m when they are transferred in guided tubes to the respective injection locations. Pellet speed variation with pressure at different pellet formation temperatures has been observed. Pellet intactness tests through these guide tubes show a variation in the intact speed limit over a range of pellet formation temperatures from 6.5 to 9.8 K. Pellet speed reduction of less than 6% has been observed after the pellet moves through the curved guide tubes.

Fabrication of micro-cell UO2-Mo pellet with enhanced thermal conductivity

NASA Astrophysics Data System (ADS)

Kim, Dong-Joo; Rhee, Young Woo; Kim, Jong Hun; Kim, Keon Sik; Oh, Jang Soo; Yang, Jae Ho; Koo, Yang-Hyun; Song, Kun-Woo

2015-07-01

As one of accident tolerant fuel pellets which should have features of good thermal conductivity and high fission product retention, a micro-cell UO2-Mo pellet has been studied in the aspect of fabrication and thermal property. It was intended to develop the compatible process with conventional UO2 pellet fabrication process. The effects of processing parameters such as the size and density of UO2 granule and the size of Mo powder have been studied to produce sound and dense pellet with completely connected uniform Mo cell-walls. The micro-cell UO2-Mo pellet consists of many Mo micro-cells and UO2 in them. The thermal conductivity of the micro-cell UO2-Mo pellet was measured and compared to those of the UO2 pellet and the UO2-Mo pellet with dispersed form of Mo particles. The thermal conductivity of the micro-cell UO2-Mo pellet was much enhanced and was found to be influenced by the Mo volumetric fraction and pellet integrity. A continuous Mo micro-cell works as a heat conducting channel in the pellet, greatly enhancing the thermal conductivity of the micro cell UO2-Mo pellet.

High moisture corn stover pelleting in a flat die pellet mill fitted with a 6 mm die: physical properties and specific energy consumption

DOE PAGES

Tumuluru, Jaya Shankar

2015-06-15

The quality and specific energy consumption (SEC) of the biomass pellets produced depend upon pelleting process conditions. The present study includes understanding the effect of feedstock moisture in the range of 28–38% (wet basis [w.b.]) and preheating in the range of 30–110°C at two die speeds of 40 and 60 Hz on the physical properties and SEC. A flat die pellet mill fitted with a 6 mm die was used in the present study. The physical properties of pellets such as moisture content, unit, bulk and tapped density, durability, and expansion ratio and SEC of the pelleting process are measured.more » The results indicate that the pellets produced have durability values in the range of 87–98%, and unit bulk and tapped density in the range of 670–1100, 375–575, and 420–620 kg/m³. Increasing the feedstock moisture content from 33% to 38% (w.b) decreased the unit, bulk and tapped density by about 30–40%. Increasing feedstock moisture content increased the expansion ratio and decreased the density values. A higher feedstock moisture content of 38% (w.b.) and higher preheating temperature of 110°C resulted in lower density and a higher expansion ratio, which can be attributed to flash off of moisture as the material extrudes out of the die. The SEC was in the range of 75–275 kWh/ton. Higher feedstock moisture content of 38% (w.b.) and a lower die speed of 40 Hz increased the SEC, whereas lower to medium preheating temperature (30–70°C), medium feedstock moisture content of 33% (w.b.), and a higher die speed of 60 Hz minimized the SEC to <100 kWh/ton.« less

Research on Annular Frictional Pressure Loss of Hydraulic-Fracturing in Buckling Coiled Tubing

NASA Astrophysics Data System (ADS)

Liu, Bin; Cai, Meng; Li, Junliang; Xu, Yongquan; Wang, Peng

2018-01-01

Compared with conventional hydraulic fracturing, coiled tubing (CT) annular delivery sand fracturing technology is a new method to enhance the recovery ratio of low permeability reservoir. Friction pressure loss through CT has been a concern in fracturing. The small diameter of CT limits the cross-sectional area open to flow, therefore, to meet large discharge capacity, annular delivery sand technology has been gradually developed in oilfield. Friction pressure is useful for determining the required pump horsepower and fracturing construction design programs. Coiled tubing can buckle when the axial compressive load acting on the tubing is greater than critical buckling load, then the geometry shape of annular will change. Annular friction pressure loss elevates dramatically with increasing of discharge capacity, especially eccentricity and CT buckling. Despite the frequency occurrence of CT buckling in oilfield operations, traditionally annular flow frictional pressure loss considered concentric and eccentric annuli, not discussing the effects of for discharge capacity and sand ratio varying degree of CT buckling. The measured data shows that the factors mentioned above cannot be ignored in the prediction of annular pressure loss. It is necessary to carry out analysis of annulus flow pressure drop loss in coiled tubing annular with the methods of theoretical analysis and numerical simulation. Coiled tubing buckling has great influence on pressure loss of fracturing fluid. Therefore, the correlations have been developed for turbulent flow of Newtonian fluids and Two-phase flow (sand-liquid), and that improve the friction pressure loss estimation in coiled tubing operations involving a considerable level of buckling. Quartz sand evidently increases pressure loss in buckling annular, rising as high as 40%-60% more than fresh water. Meanwhile, annulus flow wetted perimeter increases with decreasing helical buckling pitch of coiled tubing, therefore, the annulus flow frictional pressure loss rapidly increases with decreasing helical buckling pitch. The research achievement provides theoretical guidance for coiled tubing annular delivery sand fracturing operation and design.

Statistical analysis and modeling of pelletized cultivation of Mucor circinelloides for microbial lipid accumulation.

PubMed

Xia, Chunjie; Wei, Wei; Hu, Bo

2014-04-01

Microbial oil accumulation via oleaginous fungi has some potential benefits because filamentous fungi can form pellets during cell growth and these pellets are easier to harvest from the culture broth than individual cells. This research studied the effect of various culture conditions on the pelletized cell growth of Mucor circinelloides and its lipid accumulation. The results showed that cell pelletization was positively correlated to biomass accumulation; however, pellet size was negatively correlated to the oil content of the fungal biomass, possibly due to the mass transfer barriers generated by the pellet structure. How to control the size of the pellet is the key to the success of the pelletized microbial oil accumulation process.

Jet Mixing and Emission Characteristics of Transverse Jets in Annular and Cylindrical Confined Crossflow

NASA Technical Reports Server (NTRS)

Bain, D. B.; Smith, C. E.; Holdeman, J. D.

1995-01-01

Three dimensional turbulent reacting CFD analyses were performed on transverse jets injected into annular and cylindrical (can) confined crossflows. The goal was to identify and assess mixing differences between annular and can geometries. The approach taken was to optimize both annular and can configurations by systematically varying orifice spacing until lowest emissions were achieved, and then compare the results. Numerical test conditions consisted of a jet-to-mainstream mass-flow ratio of 3.2 and a jet-to-mainstream momentum-flux ratio (J) of 30. The computational results showed that the optimized geometries had similar emission levels at the exit of the mixing section although the annular configuration did mix-out faster. For lowest emissions, the density correlation parameter (C = (S/H) square root of J) was 2.35 for the annular geometry and 3.5 for the can geometry. For the annular geometry, the constant was about twice the value seen for jet mixing at low mass-flow ratios (i.e., MR less than 0.5). For the can geometry, the constant was about 1 1/2 times the value seen for low mass-flow ratios.

Molecular mechanisms regulating formation, trafficking and processing of annular gap junctions.

PubMed

Falk, Matthias M; Bell, Cheryl L; Kells Andrews, Rachael M; Murray, Sandra A

2016-05-24

Internalization of gap junction plaques results in the formation of annular gap junction vesicles. The factors that regulate the coordinated internalization of the gap junction plaques to form annular gap junction vesicles, and the subsequent events involved in annular gap junction processing have only relatively recently been investigated in detail. However it is becoming clear that while annular gap junction vesicles have been demonstrated to be degraded by autophagosomal and endo-lysosomal pathways, they undergo a number of additional processing events. Here, we characterize the morphology of the annular gap junction vesicle and review the current knowledge of the processes involved in their formation, fission, fusion, and degradation. In addition, we address the possibility for connexin protein recycling back to the plasma membrane to contribute to gap junction formation and intercellular communication. Information on gap junction plaque removal from the plasma membrane and the subsequent processing of annular gap junction vesicles is critical to our understanding of cell-cell communication as it relates to events regulating development, cell homeostasis, unstable proliferation of cancer cells, wound healing, changes in the ischemic heart, and many other physiological and pathological cellular phenomena.

Kelly mud saver valve sub

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

Reddoch, J.A.

1986-12-02

A mud saver valve is described for preventing drilling mud from escaping from a kelly when a drill string is broken below the kelly, the valve comprising: a tubular valve body having first and second ends, the first end being provided with means for attachment in fluid communicating relationship with the kelly, the second end being provided with means for attachment to the drill string; an annular seat fixed in the interior of the valve body adjacent its first end; a tubular closure member within the valve body. The closure member is provided with a selectively closed seating end formore » seating in valve closing engagement with the annular seat, an open non-seating end in fluid communicating relationship with the drill string, and an annular expansion in the outer diameter of the closure member adjacent the seating end; a top and bottom spacer ring disposed in sliding relationship around the tubular closure member intermediate the annular expansion and the non-seating end of the closure member. The spacer ring and annular expansion cooperatively define an annular chamber around the closure member; and a helical spring disposed around the closure member towards the annular seat.« less

Experimental Investigation of Shock-Cell Noise Reduction for Single Stream Nozzles in Simulated Flight

NASA Technical Reports Server (NTRS)

Yamamoto, K.; Brausch, J. F.; Balsa, T. F.; Janardan, B. A.; Knott, P. R.

1984-01-01

Seven single stream model nozzles were tested in the Anechoic Free-Jet Acoustic Test Facility to evaluate the effectiveness of convergent divergent (C-D) flowpaths in the reduction of shock-cell noise under both static and mulated flight conditions. The test nozzles included a baseline convergent circular nozzle, a C-D circular nozzle, a convergent annular plug nozzle, a C-D annular plug nozzle, a convergent multi-element suppressor plug nozzle, and a C-D multi-element suppressor plug nozzle. Diagnostic flow visualization with a shadowgraph and aerodynamic plume measurements with a laser velocimeter were performed with the test nozzles. A theory of shock-cell noise for annular plug nozzles with shock-cells in the vicinity of the plug was developed. The benefit of these C-D nozzles was observed over a broad range of pressure ratiosin the vicinity of their design conditions. At the C-D design condition, the C-D annual nozzle was found to be free of shock-cells on the plug.

Broad specification fuels combustion technology program

NASA Technical Reports Server (NTRS)

Dodds, W. J.; Ekstedt, E. E.

1984-01-01

Design and development efforts to evolve promising aircraft gas turbine combustor configurations for burning broadened-properties fuels were discussed. Design and experimental evaluations of three different combustor concepts in sector combustor rig tests was conducted. The combustor concepts were a state of the art single-annular combustor, a staged double-annular combustor, and a short single-annular combustor with variable geometry to control primary zone stoichiometry. A total of 25 different configurations of the three combustor concepts were evaluated. Testing was conducted over the full range of CF6-80A engine combustor inlet conditions, using four fuels containing between 12% and 14% hydrogen by weight. Good progress was made toward meeting specific program emissions and performance goals with each of the three combustor concepts. The effects of reduced fuel hydrogen content, including increased flame radiation, liner metal temperature, smoke, and NOx emissions were documented. The most significant effect on the baseline combustor was a projected 33% life reduction, for a reduction from 14% to 13% fuel hydrogen content, due to increased liner temperatures.

Ionic Conductivity and Air Stability of Al-Doped Li₇La₃Zr₂O₁₂ Sintered in Alumina and Pt Crucibles.

PubMed

Xia, Wenhao; Xu, Biyi; Duan, Huanan; Guo, Yiping; Kang, Hongmei; Li, Hua; Liu, Hezhou

2016-03-02

Li7La3Zr2O12 (LLZO) is a promising electrolyte material for all-solid-state battery due to its high ionic conductivity and good stability with metallic lithium. In this article, we studied the effect of crucibles on the ionic conductivity and air stability by synthesizing 0.25Al doped LLZO pellets in Pt crucibles and alumina crucibles, respectively. The results show that the composition and microstructure of the pellets play important roles influencing the ionic conductivity, relative density, and air stability. Specifically, the 0.25Al-LLZO pellets sintered in Pt crucibles exhibit a high relative density (∼96%) and high ionic conductivity (4.48 × 10(-4) S cm(-1)). The ionic conductivity maintains 3.6 × 10(-4) S cm(-1) after 3-month air exposure. In contrast, the ionic conductivity of the pellets from alumina crucibles is about 1.81 × 10(-4) S cm(-1) and drops to 2.39 × 10(-5) S cm(-1) 3 months later. The large grains and the reduced grain boundaries in the pellets sintered in Pt crucibles are favorable to obtain high ionic conductivity and good air stability. X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy results suggest that the formation of Li2CO3 on the pellet surface is probably another main reason, which is also closely related to the relative density and the amount of grain boundary within the pellets. This work stresses the importance of synthesis parameters, crucibles included, to obtain the LLZO electrolyte with high ionic conductivity and good air stability.

Castration, dopamine and food choice: a cost/benefit test in male hamsters.

PubMed

Chu, Lucy; Wood, Ruth I

2002-10-17

Testosterone is essential for copulation, and contributes to sexual motivation. In addition, castrated males are fatter and less active, suggesting that androgens may play a role in non-sexual behaviors, including food-related responses. To test this hypothesis, male hamsters were trained with a cost/benefit test, which compares operant responding for more-preferred food versus ad libitum consumption of lab chow. Males were tested before and after castration. The effect of the dopamine antagonist, haloperidol, on instrumental responses in intact and castrated males was also determined. Food-deprived hamsters responded vigorously for 45 mg Bio-Serv pellets in daily 30-min tests (665 presses, 6.0+/-0.9 g). When lab chow was available, males continued to respond for pellets (3.6+/-0.6 g) over chow ad libitum (1.2+/-0.3 g). Dopamine is central to this response because haloperidol (1.0 mg/kg i.p.) reversed food intake (pellets: 0.5+/-0.1 g; chow 2.0+/-0.5 g). Castration had no effect on operant responding for pellets alone (6.6+/-0.7 g). When chow was present, castrates consumed an even greater proportion of their total food intake as pellets [6.0+/-0.4 g pellets (92%), 1.6+/-0.5 g chow (8%), vs. 75 and 25%, respectively, for intact males]. This is contrary to our original hypothesis. In addition, castration did not change the effects of haloperidol on food intake: (0.4+/-0.1 g pellets; 1.6+/-0.5 g chow). These results support previous findings in rats that dopamine affects response allocation in a cost/benefit test. However, they do not support the hypothesis that testosterone modifies the allocation of food-related responses.

Annular dynamics after mitral valve repair with different prosthetic rings: A real-time three-dimensional transesophageal echocardiography study.

PubMed

Nishi, Hiroyuki; Toda, Koichi; Miyagawa, Shigeru; Yoshikawa, Yasushi; Fukushima, Satsuki; Kawamura, Masashi; Yoshioka, Daisuke; Saito, Tetsuya; Ueno, Takayoshi; Kuratani, Toru; Sawa, Yoshiki

2016-09-01

We assessed the effects of different types of prosthetic rings on mitral annular dynamics using real-time three-dimensional echocardiography (RT3DE). RT3DE was performed in 44 patients, including patients undergoing mitral annuloplasty using the Cosgrove-Edwards flexible band (Group A, n = 10), the semi-rigid Sorin Memo 3D ring (Group B, n = 17), the semi-rigid Edwards Physio II ring (Group C, n = 7) and ten control subjects. Various annular diameters were measured throughout the cardiac cycle. We observed flexible anterior annulus motion in all of the groups except Group C. A flexible posterior annulus was only observed in Group B and the Control group. The mitral annular area changed during the cardiac cycle by 8.4 ± 3.2, 6.3 ± 2.0, 3.2 ± 1.3, and 11.6 ± 5.0 % in Group A, Group B, Group C, and the Control group, respectively. The dynamic diastolic to systolic change in mitral annular diameters was lost in Group C, while it was maintained in Group A, and to a good degree in Group B. In comparison to the Control group, the mitral annulus shape was more ellipsoid in Group B and Group C, and more circular in Group A. Although mitral regurgitation was well controlled by all of the types of rings that were utilized in the present study, we demonstrated that the annulus motion and annulus shape differed according to the type of prosthetic ring that was used, which might provide important information for the selection of an appropriate prosthetic ring.

"Ductal adenocarcinoma in anular pancreas".

PubMed

Benassai, Giacomo; Perrotta, Stefano; Furino, Ermenegildo; De Werra, Carlo; Aloia, Sergio; Del Giudice, Roberto; Amato, Bruno; Vigliotti, Gabriele; Limite, Gennaro; Quarto, Gennaro

2015-09-01

The annular pancreas is a congenital anomaly in which pancreatic tissue partially or completely surrounds the second portion of the duodenum. Its often located above of papilla of Vater (85%), rarely below (15%). This pancreatic tissue is often easily dissociable to the duodenum but there is same cases where it the tissue is into the muscolaris wall of the duodenum. We describe three case of annular pancreas hospitalized in our facility between January 2004 and January 2009. There were 2 male 65 and 69 years old respectively and 1 female of 60 years old, presented complaining of repeated episodes of mild epigastric pain. Laboratory tests (including tumor markers), a direct abdomen X-ray with enema, EGDS and total body CT scan were performed to study to better define the diagnosis. EUS showed the presence of tissue infiltrating the muscle layer all around the first part of duodenum. Biopsies performed found the presence of pancreatic tissue with focal areas of adenocarcinoma. Subtotal gastrectomy with Roux was performed. The histological examinations shows an annular pancreas of D1 with multiple focal area of adenocarcinoma. (T1aN0M0). We performed a follow up at 5 years. One patients died after 36 months for cardiovascular hit. Two patients, one male and one female, was 5-years disease-free. Annular pancreas is an uncommon congenital anomaly which usually presents itself in infants and newborn. Rarely it can present in late adult life with wide range of clinical severities thereby making its diagnosis difficult. Pre-operative diagnosis is often difficult. CT scan can illustrate the pancreatic tissue encircling the duodenum. ERCP and MRCP are useful in outlining the annular pancreatic duct. Surgery still remains necessary to confirm diagnosis and bypassing the obstructed segment. Copyright © 2015 IJS Publishing Group Limited. Published by Elsevier Ltd. All rights reserved.

Method to Produce Durable Pellets at Lower Energy Consumption Using High Moisture Corn Stover and a Corn Starch Binder in a Flat Die Pellet Mill

PubMed Central

Tumuluru, Jaya Shankar; Conner, Craig C.; Hoover, Amber N.

2016-01-01

A major challenge in the production of pellets is the high cost associated with drying biomass from 30 to 10% (w.b.) moisture content. At Idaho National Laboratory, a high-moisture pelleting process was developed to reduce the drying cost. In this process the biomass pellets are produced at higher feedstock moisture contents than conventional methods, and the high moisture pellets produced are further dried in energy efficient dryers. This process helps to reduce the feedstock moisture content by about 5-10% during pelleting, which is mainly due to frictional heat developed in the die. The objective of this research was to explore how binder addition influences the pellet quality and energy consumption of the high-moisture pelleting process in a flat die pellet mill. In the present study, raw corn stover was pelleted at moistures of 33, 36, and 39% (w.b.) by addition of 0, 2, and 4% pure corn starch. The partially dried pellets produced were further dried in a laboratory oven at 70 °C for 3-4 hr to lower the pellet moisture to less than 9% (w.b.). The high moisture and dried pellets were evaluated for their physical properties, such as bulk density and durability. The results indicated that increasing the binder percentage to 4% improved pellet durability and reduced the specific energy consumption by 20-40% compared to pellets with no binder. At higher binder addition (4%), the reduction in feedstock moisture during pelleting was <4%, whereas the reduction was about 7-8% without the binder. With 4% binder and 33% (w.b.) feedstock moisture content, the bulk density and durability values observed of the dried pellets were >510 kg/m3 and >98%, respectively, and the percent fine particles generated was reduced to <3%. PMID:27340875

Method to Produce Durable Pellets at Lower Energy Consumption Using High Moisture Corn Stover and a Corn Starch Binder in a Flat Die Pellet Mill.

PubMed

Tumuluru, Jaya Shankar; Conner, Craig C; Hoover, Amber N

2016-06-15

A major challenge in the production of pellets is the high cost associated with drying biomass from 30 to 10% (w.b.) moisture content. At Idaho National Laboratory, a high-moisture pelleting process was developed to reduce the drying cost. In this process the biomass pellets are produced at higher feedstock moisture contents than conventional methods, and the high moisture pellets produced are further dried in energy efficient dryers. This process helps to reduce the feedstock moisture content by about 5-10% during pelleting, which is mainly due to frictional heat developed in the die. The objective of this research was to explore how binder addition influences the pellet quality and energy consumption of the high-moisture pelleting process in a flat die pellet mill. In the present study, raw corn stover was pelleted at moistures of 33, 36, and 39% (w.b.) by addition of 0, 2, and 4% pure corn starch. The partially dried pellets produced were further dried in a laboratory oven at 70 °C for 3-4 hr to lower the pellet moisture to less than 9% (w.b.). The high moisture and dried pellets were evaluated for their physical properties, such as bulk density and durability. The results indicated that increasing the binder percentage to 4% improved pellet durability and reduced the specific energy consumption by 20-40% compared to pellets with no binder. At higher binder addition (4%), the reduction in feedstock moisture during pelleting was <4%, whereas the reduction was about 7-8% without the binder. With 4% binder and 33% (w.b.) feedstock moisture content, the bulk density and durability values observed of the dried pellets were >510 kg/m(3) and >98%, respectively, and the percent fine particles generated was reduced to <3%.

Adaptive optics scanning ophthalmoscopy with annular pupils

PubMed Central

Sulai, Yusufu N.; Dubra, Alfredo

2012-01-01

Annular apodization of the illumination and/or imaging pupils of an adaptive optics scanning light ophthalmoscope (AOSLO) for improving transverse resolution was evaluated using three different normalized inner radii (0.26, 0.39 and 0.52). In vivo imaging of the human photoreceptor mosaic at 0.5 and 10° from fixation indicates that the use of an annular illumination pupil and a circular imaging pupil provides the most benefit of all configurations when using a one Airy disk diameter pinhole, in agreement with the paraxial confocal microscopy theory. Annular illumination pupils with 0.26 and 0.39 normalized inner radii performed best in terms of the narrowing of the autocorrelation central lobe (between 7 and 12%), and the increase in manual and automated photoreceptor counts (8 to 20% more cones and 11 to 29% more rods). It was observed that the use of annular pupils with large inner radii can result in multi-modal cone photoreceptor intensity profiles. The effect of the annular masks on the average photoreceptor intensity is consistent with the Stiles-Crawford effect (SCE). This indicates that combinations of images of the same photoreceptors with different apodization configurations and/or annular masks can be used to distinguish cones from rods, even when the former have complex multi-modal intensity profiles. In addition to narrowing the point spread function transversally, the use of annular apodizing masks also elongates it axially, a fact that can be used for extending the depth of focus of techniques such as adaptive optics optical coherence tomography (AOOCT). Finally, the positive results from this work suggest that annular pupil apodization could be used in refractive or catadioptric adaptive optics ophthalmoscopes to mitigate undesired back-reflections. PMID:22808435

Impact of Annular Size on Outcomes After Surgical or Transcatheter Aortic Valve Replacement.

PubMed

Deeb, G Michael; Chetcuti, Stanley J; Yakubov, Steven J; Patel, Himanshu J; Grossman, P Michael; Kleiman, Neal S; Heiser, John; Merhi, William; Zorn, George L; Tadros, Peter N; Petrossian, George; Robinson, Newell; Mumtaz, Mubashir; Gleason, Thomas G; Huang, Jian; Conte, John V; Popma, Jeffrey J; Reardon, Michael J

2018-04-01

This analysis evaluates the relationship of annular size to hemodynamics and the incidence of prosthesis-patient mismatch (PPM) in surgical aortic valve replacement (SAVR) and transcatheter aortic valve replacement (TAVR) patients. The CoreValve US Pivotal High Risk Trial, described previously, compared TAVR using a self-expanding valve with SAVR. Multislice computed tomography was used to categorize TAVR and SAVR subjects according to annular perimeter-derived diameter: large (≥26 mm), medium (23 to <26 mm), and small (<23 mm). Hemodynamics, PPM, and clinical outcomes were assessed. At all postprocedure visits, mean gradients were significantly lower for TAVR compared with SAVR in small and medium size annuli (p < 0.001). Annular size was significantly associated with mean gradient after SAVR, with small annuli having the highest gradients (p < 0.05 at all timepoints); gradients were similar across all annular sizes after TAVR. In subjects receiving SAVR, the frequency of PPM was significantly associated with annular size, with small annuli having the greatest incidence. No difference in PPM incidence by annular sizing was observed with TAVR. In addition, TAVR subjects had significantly less PPM than SAVR subjects in small and medium annuli (p < 0.001), with no difference in the incidence of PPM between TAVR and SAVR in large annuli (p = 0.10). Annular size has a significant effect on hemodynamics and the incidence of PPM in SAVR subjects, not observed in TAVR subjects. With respect to annular size, TAVR results in better hemodynamics and less PPM for annuli less than 26 mm and should be strongly considered when choosing a tissue valve for small and medium size annuli. Copyright © 2018 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

Adaptive optics scanning ophthalmoscopy with annular pupils.

PubMed

Sulai, Yusufu N; Dubra, Alfredo

2012-07-01

Annular apodization of the illumination and/or imaging pupils of an adaptive optics scanning light ophthalmoscope (AOSLO) for improving transverse resolution was evaluated using three different normalized inner radii (0.26, 0.39 and 0.52). In vivo imaging of the human photoreceptor mosaic at 0.5 and 10° from fixation indicates that the use of an annular illumination pupil and a circular imaging pupil provides the most benefit of all configurations when using a one Airy disk diameter pinhole, in agreement with the paraxial confocal microscopy theory. Annular illumination pupils with 0.26 and 0.39 normalized inner radii performed best in terms of the narrowing of the autocorrelation central lobe (between 7 and 12%), and the increase in manual and automated photoreceptor counts (8 to 20% more cones and 11 to 29% more rods). It was observed that the use of annular pupils with large inner radii can result in multi-modal cone photoreceptor intensity profiles. The effect of the annular masks on the average photoreceptor intensity is consistent with the Stiles-Crawford effect (SCE). This indicates that combinations of images of the same photoreceptors with different apodization configurations and/or annular masks can be used to distinguish cones from rods, even when the former have complex multi-modal intensity profiles. In addition to narrowing the point spread function transversally, the use of annular apodizing masks also elongates it axially, a fact that can be used for extending the depth of focus of techniques such as adaptive optics optical coherence tomography (AOOCT). Finally, the positive results from this work suggest that annular pupil apodization could be used in refractive or catadioptric adaptive optics ophthalmoscopes to mitigate undesired back-reflections.

Do CTA measurements of annular diameter, perimeter and area result in different TAVI prosthesis sizes?

PubMed

Horehledova, Barbora; Mihl, Casper; Hendriks, Babs M F; Eijsvoogel, Nienke G; Vainer, Jindrich; Veenstra, Leo F; Wildberger, Joachim E; Das, Marco

2018-06-16

Incorrect prosthesis size has direct impact on patient outcome after transcatheter aortic valve implantation (TAVI) procedure. Currently, annular diameter, area or perimeter may be used for prosthesis size selection. The aim was to evaluate whether the use different annular dimensions would result in the selection of different prosthesis sizes, when assessed in the same TAVI-candidate during the same phase of a cardiac cycle. Fifty consecutive TAVI-candidates underwent retrospectively ECG-gated computed tomography angiography (CTA). Aortic root dimensions were assessed in the 20% phase of the R-R interval. Annular short diameter, perimeter and area were used to select the prosthesis size, based on the industry recommendations for a self-expandable (Medtronic CoreValve; MCV) and balloon-expandable (Edwards Sapien XT Valve; ESV) valve. Complete agreement on selected prosthesis size amongst all three annular dimensions was observed in 62% (31/50; ESV) and 30% (15/50; MCV). Short aortic annulus measurement resulted in a smaller prosthesis size in 20% (10/50; ESV) and in 60% of cases (30/50; MCV) compared to the size suggested by both annular perimeter and area. In 18% (9/50; ESV) and 10% of cases (5/50; MCV) a larger prosthesis would have been selected based on annular perimeter compared to annular diameter and area. Prosthesis size derived from area was always in agreement with at least one other parameter in all cases. Aortic annulus area appears to be the most robust parameter for TAVI-prosthesis size selection, regardless of the specific prosthesis size. Short aortic annulus diameter may underestimate the prosthesis size, while use of annular perimeter may lead to size overestimation in some cases.

Plastic in Cassin's Auklets (Ptychoramphus aleuticus) from the 2014 stranding on the Northeast Pacific Coast.

PubMed

Floren, Hannah P; Shugart, Gary W

2017-04-15

Oceanic plastic debris found in the digestive tracts of seabirds includes industrial plastic pellets and post-consumer user plastics. We examined whether the amount and type of plastic ingested by Cassin's Auklets (Ptychoramphus aleuticus) is changing by surveying the stomach contents of 171 Cassin's Auklets stranded along the Washington and Oregon coasts in 2014. We found that 41.5% of the birds contained plastic in their ventriculi, similar to values from the North Subarctic Pacific reported in the 1980s. Industrial pellets were found in 22.8% of our samples, and accounted for 28.1% of all the plastic pieces found. Industrial pellets tended to be larger than pieces of user plastic and accounted for 40.2% of total plastic weight. These industrial pellets were significantly smaller than those found in other species, suggesting either that Cassin's Auklets selected smaller plastic particles or that plastic was retained in ventriculi and worn down. Copyright © 2017 Elsevier Ltd. All rights reserved.

Comparison of cryogenic (hydrogen) and TESPEL (polystyrene) pellet particle deposition in a magnetically confined plasma

DOE PAGES

McCarthy, K. J.; Tamura, N.; Combs, S. K.; ...

2018-01-05

Here, a cryogenic pellet injector (PI) and tracer encapsulated solid pellet (TESPEL) injector system has been operated in combination on the stellarator TJ-II. This unique arrangement has been created by piggy-backing a TESPEL injector onto the backend of a pipe-gun–type PI. The combined injector provides a powerful new tool for comparing ablation and penetration of polystyrene TESPEL pellets and solid hydrogen pellets, as well as for contrasting subsequent pellet particle deposition and plasma perturbation under analogous plasma conditions. For instance, a significantly larger increase in plasma line-averaged electron density, and electron content, is observed after a TESPEL pellet injection comparedmore » with an equivalent cryogenic pellet injection. Moreover, for these injections from the low-magnetic-field side of the plasma cross-section, TESPEL pellets deposit electrons deeper into the plasma core than cryogenic pellets. Finally, the physics behind these observations and possible implications for pellet injection studies are discussed.« less

Comparison of cryogenic (hydrogen) and TESPEL (polystyrene) pellet particle deposition in a magnetically confined plasma

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

McCarthy, K. J.; Tamura, N.; Combs, S. K.

Here, a cryogenic pellet injector (PI) and tracer encapsulated solid pellet (TESPEL) injector system has been operated in combination on the stellarator TJ-II. This unique arrangement has been created by piggy-backing a TESPEL injector onto the backend of a pipe-gun–type PI. The combined injector provides a powerful new tool for comparing ablation and penetration of polystyrene TESPEL pellets and solid hydrogen pellets, as well as for contrasting subsequent pellet particle deposition and plasma perturbation under analogous plasma conditions. For instance, a significantly larger increase in plasma line-averaged electron density, and electron content, is observed after a TESPEL pellet injection comparedmore » with an equivalent cryogenic pellet injection. Moreover, for these injections from the low-magnetic-field side of the plasma cross-section, TESPEL pellets deposit electrons deeper into the plasma core than cryogenic pellets. Finally, the physics behind these observations and possible implications for pellet injection studies are discussed.« less

Air Revitalization Using Superoxides

NASA Technical Reports Server (NTRS)

Wydeven, Theodore; Wood, Peter C.; Spitze, L. A.

1988-01-01

Pellets made from powder mixtures of potassium superoxide, KO2, and calcium superoxide, Ca(O2)2, proven markedly superior to pellets of pure KO2 for adding O2 to and removing CO2 from atmospheric-pressure flow of humidified CO2 in He. Superoxides used extensively to supply O2 and scrub CO2 in variety of ambient-pressure life-support applications, including portable self-contained breathing apparatuses, spacecraft, and undersea submersible craft.

Lignite pellets and methods of agglomerating or pelletizing

DOEpatents

Baker, Albert F.; Blaustein, Eric W.; Deurbrouck, Albert W.; Garvin, John P.; McKeever, Robert E.

1981-01-01

The specification discloses lignite pellets which are relatively hard, dust resistant, of generally uniform size and free from spontaneous ignition and general degradation. Also disclosed are methods for making such pellets which involve crushing as mined lignite, mixing said lignite with a binder such as asphalt, forming the lignite binder mixture into pellets, and drying the pellets.

Bronchocarcinogenic properties of welding and thermal spraying fumes containing chromium in the rat.

PubMed

Berg, N O; Berlin, M; Bohgard, M; Rudell, B; Schütz, A; Warvinge, K

1987-01-01

The possible bronchocarcinogenic effects of fumes released during the shielded metal arc welding of stainless steel and the thermal spraying of chromium oxide (Cr2O3) have been studied on the rat. The fume particles were shown to contain tri- and hexavalent chromium in soluble and low soluble forms; they were collected and implanted as pellets in the bronchi of groups of 100 rats by the method of Laskin et al. A negative control group of 100 rats was included, as well as positive controls receiving pellets containing benz(a)pyrene. The experiment was continued for 34 months; no differences of biological significance were noted between the growth rates, survival times, and terminal organ weights of the test and negative control groups. At autopsy, the macroscopic and microscopic appearance of the organs in the three groups, including the local reaction to the implanted pellet, were similar. No precancerous changes were observed at the implantation sites; one rat, who received a pellet containing welding fumes, showed squamous cell carcinoma remote from the implantation site and not associated with the bronchus. It had the appearance of a metastasis. All three benz(a)pyrene control rats developed cancer at the implantation site. The occupational health implications of these findings are discussed.

Perioperative Ruminal pH Changes in Domestic Sheep (Ovis aries) Housed in a Biomedical Research Setting

PubMed Central

Jasmin, Bambi H; Boston, Ray C; Modesto, Rolf B; Schaer, Thomas P

2011-01-01

Little information is available on normal ruminal pH values for domestic sheep (Ovis aries) housed in a research setting and fed a complete pelleted ration. Sheep maintained on pelleted diets undergoing surgical procedures often present with postoperative anorexia and rumen atony. To determine the relationship between diet and postoperative rumen acidosis and associated atony, we studied dietary effects on ruminal pH in an ovine surgical model. Sheep undergoing orthopedic surgical procedures were randomized into 2 diet groups. Group 1 (n = 6) was fed complete pelleted diet during the pre- and postoperative period, and group 2 (n = 6) was fed timothy grass hay exclusively throughout the study. Measures included ruminal pH, ruminal motility, and rate of feed refusal, which was monitored throughout the pre- and postoperative periods. The 2 groups did not differ significantly before surgery, and the ruminal parameters remained largely within normal limits. However, a downward trend in the strength and frequency of rumen contractions was observed in pellet-fed sheep. After surgery, the pellet-fed group showed clinical signs consistent with ruminal acidosis, supported by decreased ruminal motility, anorexia, putrid-smelling ruminal material, and death of ruminal protozoa. Intervention by transfaunation in clinically affected sheep resulted in resolution of signs. Our findings suggest that sheep fed grass hay appear to have a more stable ruminal pH, are less likely to experience anorexia and rumen atony, and thereby exhibit fewer postoperative gastrointestinal complications than do sheep on a pellet diet. PMID:21333159

Lead pollution from waterfowl hunting in wetlands and rice fields in Argentina.

PubMed

Romano, Marcelo; Ferreyra, Hebe; Ferreyroa, Gisele; Molina, Fernando V; Caselli, Andrea; Barberis, Ignacio; Beldoménico, Pablo; Uhart, Marcela

2016-03-01

The pollution of wetlands by lead derived from waterfowl hunting with lead shot was investigated. We determined soil pellet density and Pb concentration in soil, water and vegetation in natural wetlands and rice fields in central-eastern Santa Fe province, Argentina. Pellet density varied greatly among hunting sites (between 5.5-141 pellets/m(2)) and pellets were present in some control sites. Soil Pb concentration in most hunting sites (approximately 10-20 mg kg(-1)) was not much higher than in control sites (~5-10 mg kg(-1)), with the exception of the site with highest pellet density, which also had a high Pb soil concentration. In water, on the other hand, Pb concentration was similar in all sites (~4-7 μg L(-1)), both control and hunting, and higher than reference values for aquatic media. Lead was also present in vegetation, including grasses and rice crops, in almost all cases. Most soil-collection sites were slightly acidic, and were frequently flooded. These results strongly suggest that metallic Pb from spent shot is oxidized and dissolved due to wetland conditions. Thus, the pollutant is readily mobilized and distributed across all wetland areas, effectively homogenizing its concentration in locations with and without hunting activities. The replacement of lead by nontoxic materials in pellets appears to be the only effective way to prevent Pb pollution in wetlands. Copyright © 2015 Elsevier B.V. All rights reserved.

Perioperative ruminal pH changes in domestic sheep (Ovis aries) housed in a biomedical research setting.

PubMed

Jasmin, Bambi H; Boston, Ray C; Modesto, Rolf B; Schaer, Thomas P

2011-01-01

Little information is available on normal ruminal pH values for domestic sheep (Ovis aries) housed in a research setting and fed a complete pelleted ration. Sheep maintained on pelleted diets undergoing surgical procedures often present with postoperative anorexia and rumen atony. To determine the relationship between diet and postoperative rumen acidosis and associated atony, we studied dietary effects on ruminal pH in an ovine surgical model. Sheep undergoing orthopedic surgical procedures were randomized into 2 diet groups. Group 1 (n = 6) was fed complete pelleted diet during the pre- and postoperative period, and group 2 (n = 6) was fed timothy grass hay exclusively throughout the study. Measures included ruminal pH, ruminal motility, and rate of feed refusal, which was monitored throughout the pre- and postoperative periods. The 2 groups did not differ significantly before surgery, and the ruminal parameters remained largely within normal limits. However, a downward trend in the strength and frequency of rumen contractions was observed in pellet-fed sheep. After surgery, the pellet-fed group showed clinical signs consistent with ruminal acidosis, supported by decreased ruminal motility, anorexia, putrid-smelling ruminal material, and death of ruminal protozoa. Intervention by transfaunation in clinically affected sheep resulted in resolution of signs. Our findings suggest that sheep fed grass hay appear to have a more stable ruminal pH, are less likely to experience anorexia and rumen atony, and thereby exhibit fewer postoperative gastrointestinal complications than do sheep on a pellet diet.

Entrance and exit region friction factor models for annular seal analysis. Ph.D. Thesis

NASA Technical Reports Server (NTRS)

Elrod, David Alan

1988-01-01

The Mach number definition and boundary conditions in Nelson's nominally-centered, annular gas seal analysis are revised. A method is described for determining the wall shear stress characteristics of an annular gas seal experimentally. Two friction factor models are developed for annular seal analysis; one model is based on flat-plate flow theory; the other uses empirical entrance and exit region friction factors. The friction factor predictions of the models are compared to experimental results. Each friction model is used in an annular gas seal analysis. The seal characteristics predicted by the two seal analyses are compared to experimental results and to the predictions of Nelson's analysis. The comparisons are for smooth-rotor seals with smooth and honeycomb stators. The comparisons show that the analysis which uses empirical entrance and exit region shear stress models predicts the static and stability characteristics of annular gas seals better than the other analyses. The analyses predict direct stiffness poorly.

High Pressure Rotary Shaft Sealing Mechanism

DOEpatents

Dietle, Lannie; Gobeli, Jeffrey D.

2001-05-08

A laterally translatable pressure staged rotary shaft sealing mechanism having a seal housing with a shaft passage therein being exposed to a fluid pressure P1 and with a rotary shaft being located within the shaft passage. At least one annular laterally translatable seal carrier is provided. First and second annular resilient sealing elements are supported in axially spaced relation by the annular seal carriers and have sealing relation with the rotary shaft. The seal housing and at least one seal carrier define a first pressure staging chamber exposed to the first annular resilient sealing element and a second pressure staging chamber located between and exposed to the first and second annular resilient sealing elements. A first fluid is circulated to the first pressure chamber at a pressure P1, and a second staging pressure fluid is circulated to the second pressure chamber at a fraction of pressure P1 to achieve pressure staging, cooling of the seals. Seal placement provides hydraulic force balancing of the annular seal carriers.

Effect of balloon mitral valvotomy on left ventricular function in rheumatic mitral stenosis.

PubMed

Rajesh, Gopalan Nair; Sreekumar, Pradeep; Haridasan, Vellani; Sajeev, C G; Bastian, Cicy; Vinayakumar, D; Kadermuneer, P; Mathew, Dolly; George, Biju; Krishnan, M N

Mitral stenosis (MS) is found to produce left ventricular (LV) dysfunction in some studies. We sought to study the left ventricular function in patients with rheumatic MS undergoing balloon mitral valvotomy (BMV). Ours is the first study to analyze effect of BMV on mitral annular plane systolic excursion (MAPSE), and to quantify prevalence of longitudinal left ventricular dysfunction in rheumatic MS. In this prospective cohort study, we included 43 patients with severe rheumatic mitral stenosis undergoing BMV. They were compared to twenty controls whose distribution of age and gender were similar to that of patients. The parameters compared were LV ejection fraction (EF) by modified Simpson's method, mitral annular systolic velocity (MASV), MAPSE, mitral annular early diastolic velocity (E'), and myocardial performance index (MPI). These parameters were reassessed immediately following BMV and after 3 months of procedure. MASV, MAPSE, E', and EF were significantly lower and MPI was higher in mitral stenosis group compared to controls. Impaired longitudinal LV function was present in 77% of study group. MAPSE and EF did not show significant change after BMV while MPI, MASV, and E' improved significantly. MASV and E' showed improvement immediately after BMV, while MPI decreased only at 3 months follow-up. There were significantly lower mitral annular motion parameters including MAPSE in patients with rheumatic mitral stenosis. Those with atrial fibrillation had higher MPI. Immediately after BMV, there was improvement in LV long axis function with a gradual improvement in global LV function. There was no significant change of MAPSE after BMV. Copyright © 2015 Cardiological Society of India. Published by Elsevier B.V. All rights reserved.

Prediction of slug-to-annular flow pattern transition (STA) for reducing the risk of gas-lift instabilities and effective gas/liquid transport from low-pressure reservoirs

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

Toma, P.R.; Vargas, E.; Kuru, E.

Flow-pattern instabilities have frequently been observed in both conventional gas-lifting and unloading operations of water and oil in low-pressure gas and coalbed reservoirs. This paper identifies the slug-to-annular flow-pattern transition (STA) during upward gas/liquid transportation as a potential cause of flow instability in these operations. It is recommended that the slug-flow pattern be used mainly to minimize the pressure drop and gas compression work associated with gas-lifting large volumes of oil and water. Conversely, the annular flow pattern should be used during the unloading operation to produce gas with relatively small amounts of water and condensate. New and efficient artificialmore » lifting strategies are required to transport the liquid out of the depleted gas or coalbed reservoir level to the surface. This paper presents held data and laboratory measurements supporting the hypothesis that STA significantly contributes to flow instabilities and should therefore be avoided in upward gas/liquid transportation operations. Laboratory high-speed measurements of flow-pressure components under a broad range of gas-injection rates including STA have also been included to illustrate the onset of large STA-related flow-pressure oscillations. The latter body of data provides important insights into gas deliquification mechanisms and identifies potential solutions for improved gas-lifting and unloading procedures. A comparison of laboratory data with existing STA models was performed first. Selected models were then numerically tested in field situations. Effective field strategies for avoiding STA occurrence in marginal and new (offshore) field applications (i.e.. through the use of a slug or annular flow pattern regimen from the bottomhole to wellhead levels) are discussed.« less

Distinct Annular Oligomers Captured along the Assembly and Disassembly Pathways of Transthyretin Amyloid Protofibrils

PubMed Central

Pires, Ricardo H.; Karsai, Árpád; Saraiva, Maria J.; Damas, Ana M.; Kellermayer, Miklós S. Z.

2012-01-01

Background Defects in protein folding may lead to severe degenerative diseases characterized by the appearance of amyloid fibril deposits. Cytotoxicity in amyloidoses has been linked to poration of the cell membrane that may involve interactions with amyloid intermediates of annular shape. Although annular oligomers have been detected in many amyloidogenic systems, their universality, function and molecular mechanisms of appearance are debated. Methodology/Principal Findings We investigated with high-resolution in situ atomic force microscopy the assembly and disassembly of transthyretin (TTR) amyloid protofibrils formed of the native protein by pH shift. Annular oligomers were the first morphologically distinct intermediates observed in the TTR aggregation pathway. Morphological analysis suggests that they can assemble into a double-stack of octameric rings with a 16±2 nm diameter, and displaying the tendency to form linear structures. According to light scattering data coupled to AFM imaging, annular oligomers appeared to undergo a collapse type of structural transition into spheroid oligomers containing 8–16 monomers. Disassembly of TTR amyloid protofibrils also resulted in the rapid appearance of annular oligomers but with a morphology quite distinct from that observed in the assembly pathway. Conclusions/Significance Our observations indicate that annular oligomers are key dynamic intermediates not only in the assembly but also in the disassembly of TTR protofibrils. The balance between annular and more compact forms of aggregation could be relevant for cytotoxicity in amyloidogenic disorders. PMID:22984597

The Asian Wood Pellet Markets

Treesearch

Joseph A. Roos; Allen Brackley

2012-01-01

This study examines the three major wood pellet markets in Asia: China, Japan, and South Korea. In contrast to the United States, where most wood pellets are used for residential heating with pellet stoves, a majority of the wood pellets in Asia are used for co-firing at coal-fired power plants. Our analysis indicated that Japan is the largest importer of wood pellets...

The effect of pulmonary hypertension on ovine tricuspid annular dynamics.

PubMed

Malinowski, Marcin; Wilton, Penny; Khaghani, Asghar; Langholz, David; Hooker, Victoria; Eberhart, Lenora; Hooker, Robert L; Timek, Tomasz A

2016-01-01

Pulmonary hypertension (PHT) is associated with tricuspid annular dilatation, but the effect of acute increase of pulmonary pressure on three-dimensional (3D) tricuspid annular dynamics and shape is unknown. Better understanding of tricuspid annular dynamics may lead to improved and more durable surgical reparative techniques. In nine open-chest anaesthetized sheep nine sonomicrometry crystals were implanted on the right ventricle while on cardiopulmonary bypass. Additional nine crystals were implanted around the tricuspid annulus (TA) with one crystal at each commissure defining three separate annular regions: anterior, posterior and septal. Two additional equidistant crystals were implanted between each commissure, creating three segments for every region. Pressure transducers were placed in the left ventricular (LV), right ventricular (RV) and right atrium. PHT was induced by acute pulmonary artery constriction with a pneumatic occluder. Sonomicrometry and echocardiographic data were collected before and after induction of PHT. TA area, regional and total perimeter, and 3D annular geometry were calculated from 3D crystal coordinates. Regional annular contraction was defined as the percentage difference between maximal and minimal region length during the cardiac cycle. PHT increased RV pressure from 31 ± 9 mmHg to 46 ± 13 mmHg (P = 0.001) and decreased left ventricular (LV) pressure from 111 ± 24 mmHg to 78 ± 36 mmHg (P = 0.018). There was no significant tricuspid regurgitation observed with PHT. During PHT, the TA area increased by 12 ± 13% from 641 ± 139 mm(2) to 721 ± 177 mm(2) (P = 0.037). The total perimeter increased from 103 ± 11 mm to 109 ± 13 mm (P = 0.02). All annular regions dilated significantly with PHT with 8 ± 10, 5 ± 5 and 5 ± 5% increase in anterior, posterior and septal annular length, respectively (P < 0.05). PHT reduced regional annular contraction in the anterior region only (17 ± 7 vs 14 ± 8%; P = 0.02). The TA had a complex 3D saddle geometry and the shape of the annulus was altered during PHT only in the antero-posterior region. The changes in tricuspid annular conformation, contractility and its 3D geometry observed during acute ovine PHT may help in the design of new pathology-specific tricuspid annular rings. © The Author 2015. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

Production and characterization of pellets using Avicel CL611 as spheronization aid.

PubMed

Puah, Sin Yee; Yap, Hsiu Ni; Chaw, Cheng Shu

2014-03-01

The study looked into the feasibility of producing pellet using Avicel CL611 as spheronization aid by the extrusion/spheronization technique. Pellets were formulated to contain either 20% or 40% Avicel CL611 and lactose monohydrate as the other sole ingredient. Water is used as liquid binder. Quality of pellets and extrudates were analyzed for size distribution, shape, surface tensile strength and disintegration profile. More water was needed when higher Avicel CL611 fraction was used during the production of pellets. The pellets of larger size were obtained by increasing the water content. Pellets with aspect ratios of ∼1.1 were produced with high spheronization speed at short residence time. Higher tensile strength was achieved when increasing the water content and the fraction of Avicel CL611 during pellet production. These pellets also took longer time to disintegrate, nonetheless all the pellets disintegrated within 15 min. A positive linear relationship was obtained between the tensile strength and time for pellets to disintegrate. Strong but round pellets that disintegrate rapidly could be produced with Avicel CL611 as spheronization aid using moderately soluble compounds such as lactose.

Radial flow nuclear thermal rocket (RFNTR)

DOEpatents

Leyse, Carl F.

1995-11-07

A radial flow nuclear thermal rocket fuel assembly includes a substantially conical fuel element having an inlet side and an outlet side. An annular channel is disposed in the element for receiving a nuclear propellant, and a second, conical, channel is disposed in the element for discharging the propellant. The first channel is located radially outward from the second channel, and separated from the second channel by an annular fuel bed volume. This fuel bed volume can include a packed bed of loose fuel beads confined by a cold porous inlet frit and a hot porous exit frit. The loose fuel beads include ZrC coated ZrC-UC beads. In this manner, nuclear propellant enters the fuel assembly axially into the first channel at the inlet side of the element, flows axially across the fuel bed volume, and is discharged from the assembly by flowing radially outward from the second channel at the outlet side of the element.

Radial flow nuclear thermal rocket (RFNTR)

DOEpatents

Leyse, Carl F.

1995-01-01

A radial flow nuclear thermal rocket fuel assembly includes a substantially conical fuel element having an inlet side and an outlet side. An annular channel is disposed in the element for receiving a nuclear propellant, and a second, conical, channel is disposed in the element for discharging the propellant. The first channel is located radially outward from the second channel, and separated from the second channel by an annular fuel bed volume. This fuel bed volume can include a packed bed of loose fuel beads confined by a cold porous inlet frit and a hot porous exit frit. The loose fuel beads include ZrC coated ZrC-UC beads. In this manner, nuclear propellant enters the fuel assembly axially into the first channel at the inlet side of the element, flows axially across the fuel bed volume, and is discharged from the assembly by flowing radially outward from the second channel at the outlet side of the element.

Simulation of reduction of iron-oxide-carbon composite pellets in a rotary hearth furnace

NASA Astrophysics Data System (ADS)

Halder, Sabuj

The primary motivation of this work is to evaluate a new alternative ironmaking process which involves the combination of a Rotary Hearth Furnace (RHF) with an iron bath smelter. This work is concerned primarily, with the productivity of the RHF. It is known that the reduction in the RHF is controlled by chemical kinetics of the carbon oxidation and wustite reduction reactions as well as by heat transfer to the pellet surface and within the pellet. It is heat transfer to the pellet which limits the number of layers of pellets in the pellet bed in the RHF and thus, the overall productivity. Different types of carbon like graphite, coal-char and wood charcoal were examined. Part of the research was to investigate the chemical kinetics by de-coupling it from the influence of heat and mass transfer. This was accomplished by carrying out reduction experiments using small iron-oxide-carbon powder composite mixtures. The reaction rate constants were determined by fitting the experimental mass loss with a mixed reaction model. This model accounts for the carbon oxidation by CO2 and wustite reduction by CO, which are the primary rate controlling surface-chemical reactions in the composite system. The reaction rate constants have been obtained using wustite-coal-char powder mixtures and wustite-wood-charcoal mixtures. The wustite for these mixtures was obtained from two iron-oxide sources: artificial porous analytical hematite (PAH) and hematite ore tailings. In the next phase of this study, larger scale experiments were conducted in a RHF simulator using spherical composite pellets. Measurement of the reaction rates was accomplished using off-gas analysis. Different combinations of raw materials for the pellets were investigated. These included artificial ferric oxide as well as naturally existing hematite and taconite ores. Graphite, coal-char and wood-charcoal were the reductants. Experiments were conducted using a single layer, a double layer and a triple layer of composite pellets to look into the different aspects associated with multi-layer reduction in the RHF. The reduced pellets were examined for morphology and phase distribution using Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray (EDX) analysis. Efforts were made to interpret the differences in the observed rates from one kind of pellet to the other on the grounds of chemical kinetics of the carbon oxidation and wustite reduction reactions and the issues of external and internal heat transport to and within the pellets. It was concluded from the experiments that in the ore containing pellets, wood-charcoal appeared to be a faster reductant than coal-char. However, in the PAH containing pellets, the reverse was found to be true. This is because of the internal heat transport limitations imposed by two factors (a) lower thermal conductivity of wood-charcoal in comparison to coal-char and (b) swelling of the PAH-Wood-Charcoal pellets during the initial heat-up stage. For the same type of reductant, hematite containing pellets were observed to reduce faster than taconite containing pellets. This is in accordance with the higher reducibility of hematite because of development of internal porosity due to cracking and fissure formation during the Fe2O3 to Fe 3O4 transformation stage. This is however, absent during the reduction of taconite, which is primarily Fe3O4. The PAH-Wood-Charcoal pellets were found to undergo significant amounts of swelling under low temperature conditions. This behavior of the PAH-Wood-Charcoal pellets of a certain layer impeded the external heat transport to the lower layer and consequently, resulted in a relatively lower reduction rate for a multi-layer bed. The volume change phenomena associated with the reduction of composites were also studied. Volume changes influence the external heat transport, especially to the lower layers of a multi-layer bed. The volume change of the different kinds of composite pellets was studied as a function of reduction temperature and time. Empirical correlations were developed associating the volume shrinkage to the fractional mass loss of the pellets. The estimation of the change in the amount of external heat transport with varying pellet sizes for a particular layer of a multi-layer bed was obtained by conducting heat transport tests using inert low carbon steel spheres. The experimental temperature data for the spheres of different layers was interpreted using a simple mathematical model. It was found through this exercise, that if the spheres of the top layer of the bed shrink by 30%, the external heat transfer to the second layer increases by almost 6 times. This is because of the decrease in the shielded area of the second layer due to the decreasing size of the top layer spheres. If the average degree of reduction targeted in a RHF is reduced from 95% to about 70% by coupling the RHF with a bath smelter, the productivity of the RHF can be enhanced by 1.5 to 2 times. The use of a 2 or 3 layer bed was found to be far superior to that of a single layer for higher productivities under the current experimental conditions. Sometimes, a 2 layer bed is more advantageous than a 3 layer bed, as was found to be the case with hematite-wood-charcoal pellets. The choice of the optimal number of layers depends upon several factors like pellet size, kind of pellet and shrinking characteristics of the pellet.

Right ventricular involvement in patients with inferior myocardial infarction, correlation of electrocardiographic findings with echocardiography data.

PubMed

Javed, Sumbul; Rajani, Ali Raza; Govindaswamy, Pushparani; Radaideh, Ghazi Ahmed; Abubaraka, Harb Ahmed; Qureshi, Tariq Ilyas; Arshad, Hassaan Bin

2017-03-01

To determine the right ventricular involvement in patients with inferior myocardial infarction by echocardiography in relation to electrocardiographic findings. This observational, prospective study was conducted at Rashid Hospital, Dubai, the United Arab Emirates, from January to September 2013, and comprised patients with inferior myocardial infarction. All patients aged above 18 years were included. Right ventricular myocardial infarction was defined by the electrocardiographic criteria of > 1mV ST elevation in V4R-V5R leads. RV infarction was assessed on echocardiography by fractional area change, tricuspid annular plane systolic excursion and tricuspid annular systolic velocity by tissue Doppler imaging. SPSS 21 was used for data analysis. Of the 73 patients, there were 68(93%) men and 5(7%) women. The three modalities used to assess the right ventricular infarction showed right ventricular involvement in 36(49.3%) cases by fractional area change, 28(38.4%) cases by tricuspid annular plane systolic excursion and 31(42.5%) cases by tissue Doppler imaging in patients with inferior myocardial infarction. Tissue Doppler imaging and right ventricular function showed low degree of negative correlation (p=0.16) while the correlation between tricuspid annular plane systolic excursion and right ventricular function showed significant positive correlation (p<0.0001). Assessment of right ventricular infarction by echocardiography helped to diagnose right ventricular infarction in greater number of cases compared to surface electrocardiogram.

Mitral annular calcification associated with impaired coronary microvascular function.

PubMed

Bozbas, Huseyin; Pirat, Bahar; Yildirir, Aylin; Simşek, Vahide; Sade, Elif; Altin, Cihan; Muderrisoglu, Haldun

2008-05-01

Mitral annular calcification (MAC) has been shown to be associated with atherosclerosis, and is a predictor of cardiovascular events. Coronary flow reserve (CFR) determined by transthoracic echocardiography has been introduced as a reliable indicator for coronary microvascular function. In this study we sought to investigate CFR in patients with and without MAC. Seventy patients (mean age, 68.2+/-6.6 years) who were free of coronary artery disease or diabetes mellitus were involved; 35 patients with MAC constituted the experimental group while 35 patients without MAC served as controls. Using transthoracic Doppler echocardiography coronary peak flow velocities were measured at baseline and after dipyridamole infusion. CFR was calculated as the ratio of hyperemic to baseline diastolic peak flow velocities. The clinical and demographic characteristics including age, sex, and traditional coronary risk factors did not differ between the groups (P>.05). The mean value of CFR was significantly lower in participants with mitral annular calcification than it was in controls (2.25+/-0.41 vs. 2.64+/-0.57; P<.0001). Multivariable regression analysis identified MAC (beta=-0.40, P=.004), smoking (beta=-0.36, P=.007), and C-reactive protein levels (beta=-0.28, P=.04) as the independent variables significantly associated with CFR. Our results demonstrate that CFR is impaired in patients with mitral annular calcification suggesting that coronary microvascular-endothelial dysfunction, an early finding of atherosclerosis, is present in these patients.

Probing RFP Density Limits and the Interaction of Pellet Fueling and NBI Heating on MST

NASA Astrophysics Data System (ADS)

Caspary, K. J.; Chapman, B. E.; Anderson, J. K.; Limbach, S. T.; Oliva, S. P.; Sarff, J. S.; Waksman, J.; Combs, S. K.; Foust, C. R.

2013-10-01

Pellet fueling on MST has previously achieved Greenwald fractions of up to 1.5 in 200 kA improved confinement discharges. Additionally, pellet fueling to densities above the Greenwald limit in 200 kA standard discharges resulted in early termination of the plasma, but pellet size was insufficient to exceed the limit for higher current discharges. To this end, the pellet injector on MST has been upgraded to increase the maximum fueling capability by increasing the size of the pellet guide tubes, which constrain the lateral motion of the pellet in flight, to accommodate pellets of up to 4.0 mm in diameter. These 4.0 mm pellets are capable of triggering density limit terminations for MST's peak current of 600 kA. An unexpected improvement in the pellet speed and mass control was also observed compared to the smaller diameter pellets. Exploring the effect of increased density on NBI particle and heat deposition shows that for MST's 1 MW tangential NBI, core deposition of 25 keV neutrals is optimized for densities of 2-3 × 1019 m-3. This is key for beta limit studies in pellet fueled discharges with improved confinement where maximum NBI heating is desired. An observed toroidal deflection of pellets injected into NBI heated discharges is consistent with asymmetric ablation due to the fast ion population. In 200 kA improved confinement plasmas with NBI heating, pellet fueling has achieved a Greenwald fraction of 2.0. Work supported by US DoE.

COMPARING FIELD PERFORMANCES OF DENUDER TECHNIQUES IN THE HIGH ARCTIC

EPA Science Inventory

A field evaluation between two annular denuder system configurations was conducted during the spring of 2003 in the marine Arctic (Ny-Ålesund, Svalbard). The IIA annular denuder system (ADS) employs a series of five single channel annular denuders, a cyclone and a filter pack to ...

Multiple discharge cylindrical pump collector

DOEpatents

Dunn, Charlton; Bremner, Robert J.; Meng, Sen Y.

1989-01-01

A space-saving discharge collector 40 for the rotary pump 28 of a pool-type nuclear reactor 10. An annular collector 50 is located radially outboard for an impeller 44. The annular collector 50 as a closed outer periphery 52 for collecting the fluid from the impeller 44 and producing a uniform circumferential flow of the fluid. Turning means comprising a plurality of individual passageways 54 are located in an axial position relative to the annular collector 50 for receiving the fluid from the annular collector 50 and turning it into a substantially axial direction.

Mechanically expandable annular seal

DOEpatents

Gilmore, R.F.

1983-07-19

A mechanically expandable annular reusable seal assembly to form an annular hermetic barrier between two stationary, parallel, and planar containment surfaces is described. A rotatable ring, attached to the first surface, has ring wedges resembling the saw-tooth array of a hole saw. Matching seal wedges are slidably attached to the ring wedges and have their motion restricted to be perpendicular to the second surface. Each seal wedge has a face parallel to the second surface. An annular elastomer seal has a central annular region attached to the seal wedges' parallel faces and has its inner and outer circumferences attached to the first surface. A rotation of the ring extends the elastomer seal's central region perpendicularly towards the second surface to create the fluid tight barrier. A counter rotation removes the barrier. 6 figs.

Experimental verification of the flow characteristics of an active controlled microfluidic valve with annular boundary

NASA Astrophysics Data System (ADS)

Pan, Chun-Peng; Wang, Dai-Hua

2014-03-01

The principle and structural configuration of an active controlled microfluidic valve with annular boundary is presented in this paper. The active controlled flowrate model of the active controlled microfluidic valve with annular boundary is established. The prototypes of the active controlled microfluidic valves with annular boundaries with three different combinations of the inner and outer radii are fabricated and tested on the established experimental setup. The experimental results show that: (1) The active controlled microfluidic valve with annular boundary possesses the on/off switching and the continuous control capability of the fluid with simple structure and easy fabrication processing; (2) When the inner and outer diameters of the annular boundary are 1.5 mm and 3.5 mm, respectively, the maximum flowrate of the valve is 0.14 ml/s when the differential pressure of the inlet and outlet of the valve is 1000 Pa and the voltage applied to circular piezoelectric unimorph actuator is 100 V; (3) The established active controlled flowrate model can accurately predict the controlled flowrate of the active controlled microfluidic valves with the maximum relative error of 6.7%. The results presented in this paper lay the foundation for designing and developing the active controlled microfluidic valves with annular boundary driven by circular piezoelectric unimorph actuators.

Annular Mode Dynamics: Eddy Feedbacks and the Underlying Mechanisms

NASA Astrophysics Data System (ADS)

Hassanzadeh, P.; Ma, D.; Kuang, Z.

2017-12-01

Annular modes are the leading modes the extratropical circulation variability in both hemispheres on intraseasonal to interannual timescales. Temporal persistence and an equivalent-barotropic dipolar wind anomaly are the key spatio-temporal characteristics of the annular modes. The potential source(s) of this persistence, and in particular, whether there is a contribution from a positive eddy-jet feedback, are still unclear (e.g., Lorenz and Hartmann, 2001; Byrne et al., 2016). The mechanism of this feedback, and how it depends on processes such as surface friction, is also not well understood (e.g., Robinson, 2000; Gerber et al., 2007). In this study, we utilize the recently calculated Linear Response Function (LRF) of an idealized GCM (Hassanzadeh and Kuang, 2016). The LRF enables us to accurately calculate the response of eddy momentum/heat fluxes to the zonal-mean zonal wind and temperature anomalies of the annular mode. Using this information: 1) We confirm the existence of a positive eddy-jet feedback in the annular mode of the idealized GCM and accurately quantify the magnitude of this feedback; 2) We quantify the contribution of key processes (e.g., eddy momentum/heat fluxes and surface friction) to the annular mode dynamics in the idealized GCM. We show that as proposed by Robinson (2000), the baroclinic component of the annular mode and surface friction are essential for the positive eddy-jet feedback. Results show that this feedback increases the persistence of the annular mode by a factor of two. We also show that the barotropic component of the annular mode alone does not lead to persistence. In fact, the eddy-jet feedback for the barotropic component is negative because of the dominance of the barotropic governor effect. 3) Using the results of 1, we evaluate the underlying assumptions and accuracy of the statistical methods previously developed for quantifying the eddy-jet feedback (Lorenz and Hartmann, 2001; Simpson et al., 2013) and introduce a new statistical method that shows superior accuracy. We apply the new method to reanalysis data to quantify the eddy-jet feedback for the Southern Annular Mode. The key findings of 1-3 and their implications for our understanding of the annular mode dynamics will be discussed in this presentation.

Controlling Properties of Agglomerates for Chemical Processes

NASA Astrophysics Data System (ADS)

Halt, Joseph A.

Iron ore pellets are hard spheres made from powdered ore and binders. Pellets are used to make iron, mainly in blast furnaces. Around the time that the pelletizing process was developed, starch was proposed as a binder because it's viscous, adheres well to iron oxides, does not contaminate pellets and is relatively cheap. In practice, however, starch leads to weak pellets with rough surfaces - these increase the amount of dust generated within process equipment and during pellet shipping and handling. Thus, even though the usual binder (bentonite clay) contaminates pellets, pelletizers prefer it to starch or other organics. This dissertation describes three ways to make good starch-based binders for pellets. Importantly, they solve the usual problems of weak rough pellets and lots of dust. The three approaches are: (1) Addition of clay to starch. This is not a novel idea. In fact, it is the standard method used for their improvement. However, it has not been tested extensively with starch. This approach was expected to be - and indeed was - successful. (2) Addition of a clay-rich layer to green ball surfaces. This approach is a novel idea. The coating's purpose was to mimic the good surface properties of standard bentonite-clay bonded pellets; as a benefit, clay consumption was significantly reduced. This approach was successful. (3) Addition of dispersants to starch. This approach was a novel idea. The intent of the dispersants was to enable pelletization to occur at lower moisture contents, thus leading to denser particle packing and lower porosity. The dispersants resulted in significantly stronger, smoother pellets without contaminating them with silica. Using approaches 1 and 3, starch can be used directly in traditional pelletizing operations, and importantly, in new pelletizing processes for new iron making operations. For approach 2, new application methods must be developed. Future engineering work is suggested as follows: design better dispersants for magnetic magnetite ores; incorporate the dispersing agent and starch into bead form for easy use; design a simple way to add coatings in existing drum-based pelletizing circuits; and optimize the coating composition to decrease both abrasion losses and pellet clustering (for new Direct Reduction pellets).

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

Hayes, S. L.; Harp, J. M.; Chichester, H. J. M.

Research and development activities on metallic fuels in the US are focused on their potential use for actinide transmutation in future sodium fast reactors. As part of this application, there is a desire to demonstrate a multifold increase in burnup potential. A number of metallic fuel design innovations are under investigation with a view toward significantly increasing the burnup potential of metallic fuels, since higher discharge burnups equate to lower potential actinide losses during recycle. Promising innovations under investigation include: 1) lowering the fuel smeared density in order to accommodate the additional swelling expected as burnups increase, 2) utilizing anmore » annular fuel geometry for better geometrical stability at low smeared densities, as well as the potential to eliminate the need for a sodium bond, and 3) minor alloy additions to immobilize lanthanide fission products inside the metallic fuel matrix and prevent their transport to the cladding resulting in fuel-cladding chemical interaction. This paper presents results from these efforts to advance metallic fuel technology in support of high burnup and actinide transmutation objectives. Highlights include examples of fabrication of low smeared density annular metallic fuels, experiments to identify alloy additions effective in immobilizing lanthanide fission products, and early postirradiation examinations of annular metallic fuels having low smeared densities and palladium additions for fission product immobilization.« less

High-rate behaviour of iron ore pellet

NASA Astrophysics Data System (ADS)

Gustafsson, Gustaf; Häggblad, Hans-Åke; Jonsén, Pär; Nishida, Masahiro

2015-09-01

Iron ore pellets are sintered, centimetre-sized spheres of ore with high iron content. Together with carbonized coal, iron ore pellets are used in the production of steel. In the transportation from the pelletizing plants to the customers, the iron ore pellets are exposed to different loading situations, resulting in degradation of strength and in some cases fragmentation. For future reliable numerical simulations of the handling and transportation of iron ore pellets, knowledge about their mechanical properties is needed. This paper describes the experimental work to investigate the dynamic mechanical properties of blast furnace iron ore pellets. To study the dynamic fracture of iron ore pellets a number of split Hopkinson pressure bar tests are carried out and analysed.

A comparison of experimental and theoretical results for rotordynamic coefficients of four annular gas seals

NASA Technical Reports Server (NTRS)

Childs, D. W.; Nelson, C. C.; Elrod, D.; Nicks, C.

1985-01-01

The test facility and initial test program developed to experimentally measure the fluid forces induced by annular gas seals is described. A comparison of theoretically predicted and experimentally obtained data for smooth and honeycomb seals is provided. And a comparison of experimental data from the tests of three smooth-rotor/smooth-stator seals is provided. The leakage of the working fluid through the seal, the pressure gradient along the seal length, entrance pressure-loss data, and rotordynamic coefficients provide a basis for comparison. A short discussion on seal theory is included, and various rotordynamic coefficient identification schemes are described.

Eccentricity and misalignment effects on the performance of high-pressure annular seals

NASA Technical Reports Server (NTRS)

Chen, W. C.; Jackson, E. D.

1985-01-01

Annular pressure seals act as powerful hydrostatic bearings and influence the dynamic characteristics of rotating machinery. This work, using the existing concentric seal theories, provides a simple approximate method for calculation of both seal leakage and the dynamic coefficients for short seals with large eccentricity and/or misalignment of the shaft. Rotation and surface roughness effects are included for leakage and dynamic force calculation. The leakage calculations for both laminar and turbulent flow are compared with experimental results. The dynamic coefficients are compared with analytical results. Excellent agreement between the present work and published results have been observed up to the eccentricitiy ratio of 0.8.

Transcatheter mitral direct annuloplasty: state of the art.

PubMed

Maisano, F; Kuck, K H

2014-06-01

Transcatheter mitral interventions are emerging as a novel therapy for patients with severe symptomatic mitral regurgitation who are deemed to be high risk or inoperable. Surgical treatment of mitral regurgitation includes a wide spectrum of therapies, ranging from leaflet and annular repair, to mitral valve replacement. Annuloplasty plays a fundamental role in open heart mitral valve repair, since it is associated with longer durability and higher degree of mitral regurgitation reduction. Direct annuloplasty is the interventional methodology most closely reproducing open heart annular repair. We describe the challenges and opportunities of the most promising technologies currently under development which will become available in clinical practice in the next future.

Transducer for downhole drilling components

DOEpatents

Hall, David R; Fox, Joe R

2006-05-30

A robust transmission element for transmitting information between downhole tools, such as sections of drill pipe, in the presence of hostile environmental conditions, such as heat, dirt, rocks, mud, fluids, lubricants, and the like. The transmission element maintains reliable connectivity between transmission elements, thereby providing an uninterrupted flow of information between drill string components. A transmission element is mounted within a recess proximate a mating surface of a downhole drilling component, such as a section of drill pipe. The transmission element may include an annular housing forming a trough, an electrical conductor disposed within the trough, and an MCEI material disposed between the annular housing and the electrical conductor.

Locking support for nuclear fuel assemblies

DOEpatents

Ledin, Eric

1980-01-01

A locking device for supporting and locking a nuclear fuel assembly within a cylindrical bore formed by a support plate, the locking device including a support and locking sleeve having upwardly extending fingers forming wedge shaped contact portions arranged for interaction between an annular tapered surface on the fuel assembly and the support plate bore as well as downwardly extending fingers having wedge shaped contact portions arranged for interaction between an annularly tapered surface on the support plate bore and the fuel assembly whereby the sleeve tends to support and lock the fuel assembly in place within the bore by its own weight while facilitating removal and/or replacement of the fuel assembly.

BB and pellet guns--toys or deadly weapons?

PubMed

Harris, W; Luterman, A; Curreri, P W

1983-07-01

BB and pellet weapons are not included in gun control laws and are often sold as children's toys. Injuries caused by these weapons have been considered trivial unless they involve vulnerable surface organs such as the eye. The purpose of this study was to review the management of six cases of pellet or BB gun injuries that required abdominal exploration at the University of South Alabama Medical Center from January 1980 through June 1982. Five of the six patients had significant internal injuries including perforations of the stomach, jejunum, liver, and pancreas. The ballistics of pneumatic weapons are reviewed. The muzzle velocities of many of these weapons necessitate that wounds caused by these weapons be handled with the same principles as for any small-caliber, low-velocity (less than 1,200 feet/second) weapons. Public education programs are urgently needed to educate parents as to the potential danger involved in purchasing these weapons for unsupervised use as toys by children.

Dung, diet, and the paleoenvironment of the extinct shrub-ox ( Euceratherium collinum) on the Colorado Plateau, USA

NASA Astrophysics Data System (ADS)

Kropf, Manny; Mead, Jim I.; Scott Anderson, R.

2007-01-01

Fossil remains of Euceratherium collinum (extinct shrub-ox) have been found throughout North America, including the Grand Canyon. Recent finds from the Escalante River Basin in southern Utah further extend the animal's range into the heart of the Colorado Plateau. E. collinum teeth and a metapodial condyle (foot bone) have been recovered in association with large distinctively shaped dung pellets, a morphology similar to a 'Hershey's Kiss' (HK), from a late Pleistocene dung layer in Bechan Cave. HK dung pellets have also been recovered from other alcoves in the Escalante River Basin including Willow and Fortymile canyons. Detailed analyses of the HK pellets confirmed them to be E. collinum and indicate a browser-type diet dominated (> 95%) by trees and shrubs: Artemisia tridentata (big sagebrush), Acacia sp. (acacia), Quercus (oak), and Chrysothamnus (rabbit brush). The retrieval of spring and fall pollen suggests E. collinum was a year-round resident in the Escalante River Basin.

Element for use in an inductive coupler for downhole drilling components

DOEpatents

Hall, David R.; Hall, Jr., H. Tracy; Pixton, David S.; Dahlgren, Scott; Fox, Joe; Sneddon, Cameron

2006-08-29

The present invention includes an element for use in an inductive coupler in a downhole component. The element includes a plurality of ductile, generally U-shaped leaves that are electrically conductive. The leaves are less than about 0.0625" thick and are separated by an electrically insulating material. These leaves are aligned so as to form a generally circular trough. The invention also includes an inductive coupler for use in downhole components, the inductive coupler including an annular housing having a recess with a magnetically conductive, electrically insulating (MCEI) element disposed in the recess. The MCEI element includes a plurality of segments where each segment further includes a plurality of ductile, generally U-shaped electrically conductive leaves. Each leaf is less than about 0.0625" thick and separated from the otherwise adjacent leaves by electrically insulating material. The segments and leaves are aligned so as to form a generally circular trough. The inductive coupler further includes an insulated conductor disposed within the generally circular trough. A polymer fills spaces between otherwise adjacent segments, the annular housing, insulated conductor, and further fills the circular trough.

Microwave sensing of moisture in flowing biomass pellets

USDA-ARS?s Scientific Manuscript database

Production of pelleted biomass is a significant emerging industry in the United States. A primary quality attribute of pelleted biomass is moisture content. This parameter is critical in pricing, binding, combustion, and storage of pelleted biomass. In order to produce pellets of a high quality mois...

Cu(II) promotes amyloid pore formation

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

Zhang, Hangyu, E-mail: hangyuz@uw.edu; Rochet, Jean-Christophe; Stanciu, Lia A.

2015-08-14

The aggregation of α-synuclein is associated with dopamine neuron death in Parkinson's disease. There is controversy in the field over the question of which species of the aggregates, fibrils or protofibrils, are toxic. Moreover, compelling evidence suggested the exposure to heavy metals to be a risk of PD. Nevertheless, the mechanism of metal ions in promoting PD remains unclear. In this research, we investigated the structural basis of Cu(II) induced aggregation of α-synuclein. Using transmission electron microscopy experiments, Cu(II) was found to promote in vitro aggregation of α-synuclein by facilitating annular protofibril formation rather than fibril formation. Furthermore, neuroprotective baicalein disaggregatedmore » annular protofibrils accompanied by considerable decrease of β-sheet content. These results strongly support the hypothesis that annular protofibrils are the toxic species, rather than fibrils, thereby inspiring us to search novel therapeutic strategies for the suppression of the toxic annular protofibril formation. - Highlights: • Cu(II) promoted the annular protofibril formation of α-synuclein in vitro. • Cu(II) postponed the in vitro fibrillization of α-synuclein. • Neuroprotective baicalein disaggregated annular protofibrils.« less

Dissolver vessel bottom assembly

DOEpatents

Kilian, Douglas C.

1976-01-01

An improved bottom assembly is provided for a nuclear reactor fuel reprocessing dissolver vessel wherein fuel elements are dissolved as the initial step in recovering fissile material from spent fuel rods. A shock-absorbing crash plate with a convex upper surface is disposed at the bottom of the dissolver vessel so as to provide an annular space between the crash plate and the dissolver vessel wall. A sparging ring is disposed within the annular space to enable a fluid discharged from the sparging ring to agitate the solids which deposit on the bottom of the dissolver vessel and accumulate in the annular space. An inlet tangential to the annular space permits a fluid pumped into the annular space through the inlet to flush these solids from the dissolver vessel through tangential outlets oppositely facing the inlet. The sparging ring is protected against damage from the impact of fuel elements being charged to the dissolver vessel by making the crash plate of such a diameter that the width of the annular space between the crash plate and the vessel wall is less than the diameter of the fuel elements.

Modeling of Thermochemical Behavior in an Industrial-Scale Rotary Hearth Furnace for Metallurgical Dust Recycling

NASA Astrophysics Data System (ADS)

Wu, Yu-Liang; Jiang, Ze-Yi; Zhang, Xin-Xin; Xue, Qing-Guo; Yu, Ai-Bing; Shen, Yan-Song

2017-10-01

Metallurgical dusts can be recycled through direct reduction in rotary hearth furnaces (RHFs) via addition into carbon-based composite pellets. While iron in the dust is recycled, several heavy and alkali metal elements harmful for blast furnace operation, including Zn, Pb, K, and Na, can also be separated and then recycled. However, there is a lack of understanding on thermochemical behavior related to direct reduction in an industrial-scale RHF, especially removal behavior of Zn, Pb, K, and Na, leading to technical issues in industrial practice. In this work, an integrated model of the direct reduction process in an industrial-scale RHF is described. The integrated model includes three mathematical submodels and one physical model, specifically, a three-dimensional (3-D) CFD model of gas flow and heat transfer in an RHF chamber, a one-dimensional (1-D) CFD model of direct reduction inside a pellet, an energy/mass equilibrium model, and a reduction physical experiment using a Si-Mo furnace. The model is validated by comparing the simulation results with measurements in terms of furnace temperature, furnace pressure, and pellet indexes. The model is then used for describing in-furnace phenomena and pellet behavior in terms of heat transfer, direct reduction, and removal of a range of heavy and alkali metal elements under industrial-scale RHF conditions. The results show that the furnace temperature in the preheating section should be kept at a higher level in an industrial-scale RHF compared with that in a pilot-scale RHF. The removal rates of heavy and alkali metal elements inside the composite pellet are all faster than iron metallization, specifically in the order of Pb, Zn, K, and Na.

Electrodes for high-definition transcutaneous DC stimulation for applications in drug delivery and electrotherapy, including tDCS.

PubMed

Minhas, Preet; Bansal, Varun; Patel, Jinal; Ho, Johnson S; Diaz, Julian; Datta, Abhishek; Bikson, Marom

2010-07-15

Transcutaneous electrical stimulation is applied in a range of biomedical applications including transcranial direct current stimulation (tDCS). tDCS is a non-invasive procedure where a weak direct current (<2 mA) is applied across the scalp to modulate brain function. High-definition tDCS (HD-tDCS) is a technique used to increase the spatial focality of tDCS by passing current across the scalp using <12 mm diameter electrodes. The purpose of this study was to design and optimize "high-definition" electrode-gel parameters for electrode durability, skin safety and subjective pain. Anode and cathode electrode potential, temperature, pH and subjective sensation over time were assessed during application of 2 mA direct current, for up to 22 min on agar gel or subject forearms. A selection of five types of solid-conductors (Ag pellet, Ag/AgCl pellet, rubber pellet, Ag/AgCl ring and Ag/AgCl disc) and seven conductive gels (Signa, Spectra, Tensive, Redux, BioGel, Lectron and CCNY-4) were investigated. The Ag/AgCl ring in combination with CCNY-4 gel resulted in the most favorable outcomes. Under anode stimulations, electrode potential and temperature rises were generally observed in all electrode-gel combinations except for Ag/AgCl ring and disc electrodes. pH remained constant for all solid-conductors except for both Ag and rubber pellet electrodes with Signa and CCNY-4 gels. Sensation ratings were independent of stimulation polarity. Ag/AgCl ring electrodes were found to be the most comfortable followed by Ag, rubber and Ag/AgCl pellet electrodes across all gels. Copyright 2010 Elsevier B.V. All rights reserved.

Electrodes for high-definition transcutaneous DC stimulation for applications in drug-delivery and electrotherapy, including tDCS

PubMed Central

Minhas, Preet; Bansal, Varun; Patel, Jinal; Ho, Johnson S.; Diaz, Julian; Datta, Abhishek; Bikson, Marom

2010-01-01

Transcutaneous electrical stimulation is applied in a range of biomedical applications including Transcranial Direct Current Stimulation (tDCS). tDCS is a non-invasive procedure where a weak direct current (<2 mA) is applied across the scalp to modulate brain function. High-Definition tDCS (HD-tDCS) is a technique used to increase the spatial focality of tDCS by passing current across the scalp using <12 mm diameter electrodes. The purpose of this study was to design and optimize “high-definition” electrode-gel parameters for electrode durability, skin safety, and subjective pain. Anode and cathode electrode potential, temperature, pH, and subjective sensation over time were assessed during application of 2 mA direct current, for up to 22 minutes on agar gel or subject forearms. A selection of 5 types of solid-conductors (Ag pellet, Ag/AgCl pellet, Rubber pellet, Ag/AgCl ring, and Ag/AgCl disc) and 7 conductive gels (Signa, Spectra, Tensive, Redux, BioGel, Lectron, and CCNY-4) were investigated. The Ag/AgCl ring in combination with CCNY-4 gel resulted in the most favorable outcomes. Under anode stimulations, electrode potential and temperature rises were generally observed in all electrode-gel combinations except for Ag/AgCl ring and disc electrodes. pH remained constant for all solid-conductors except for both Ag and Rubber pellet electrodes with Signa and CCNY-4 gels. Sensation ratings were independent of stimulation polarity. Ag/AgCl ring electrodes were found to be the most comfortable followed by Ag, Rubber, and Ag/AgCl pellet electrodes across all gels. PMID:20488204

Multi-Thruster Propulsion Apparatus

NASA Technical Reports Server (NTRS)

Patterson, Michael J. (Inventor)

2016-01-01

An electric propulsion machine includes an ion thruster having a discharge chamber housing a large surface area anode. The ion thruster includes flat annular ion optics with a small span to gap ratio. Optionally, at least a second thruster may be disposed radially offset from the ion thruster.

Modeling pellet impact drilling process

NASA Astrophysics Data System (ADS)

Kovalyov, A. V.; Ryabchikov, S. Ya; Isaev, Ye D.; Ulyanova, O. S.

2016-03-01

The paper describes pellet impact drilling which could be used to increase the drilling speed and the rate of penetration when drilling hard rocks. Pellet impact drilling implies rock destruction by metal pellets with high kinetic energy in the immediate vicinity of the earth formation encountered. The pellets are circulated in the bottom hole by a high velocity fluid jet, which is the principle component of the ejector pellet impact drill bit. The experiments conducted has allowed modeling the process of pellet impact drilling, which creates the scientific and methodological basis for engineering design of drilling operations under different geo-technical conditions.

Formation of particulate matter monitoring during combustion of wood pellete with additives

NASA Astrophysics Data System (ADS)

Palacka, Matej; Holubčík, Michal; Vician, Peter; Jandačka, Jozef

2016-06-01

Application additives into the material for the production of wood pellets achieve an improvement in some properties such as pellets ash flow temperature and abrasion resistance. Additives their properties influence the course of combustion, and have an impact on the results of issuance. The experiment were selected additives corn starch and dolomite. Wood pellets were produced in the pelleting press and pelletizing with the additives. Selected samples were tested for the production of particulate matter (PM) during their direct burn. The paper analyzing a process of producing wood pellets and his effect on the final properties.

Techno-economic assessment of pellets produced from steam pretreated biomass feedstock

DOE PAGES

Shahrukh, Hassan; Oyedun, Adetoyese Olajire; Kumar, Amit; ...

2016-03-10

Minimum production cost and optimum plant size are determined for pellet plants for three types of biomass feedstock e forest residue, agricultural residue, and energy crops. The life cycle cost from harvesting to the delivery of the pellets to the co-firing facility is evaluated. The cost varies from 95 to 105 t -1 for regular pellets and 146–156 t -1 for steam pretreated pellets. The difference in the cost of producing regular and steam pretreated pellets per unit energy is in the range of 2e3 GJ -1. The economic optimum plant size (i.e., the size at which pellet production costmore » is minimum) is found to be 190 kt for regular pellet production and 250 kt for steam pretreated pellet. Furthermore, sensitivity and uncertainty analyses were carried out to identify sensitivity parameters and effects of model error.« less

Compacted Multiparticulate Systems for Colon-Specific Delivery of Ketoprofen.

PubMed

de Alencar, Rodrigo Gomes; de Oliveira, Aline Carlos; Lima, Eliana Martins; da Cunha-Filho, Marcílio Sérgio Soares; Taveira, Stephânia Fleury; Marreto, Ricardo Neves

2017-08-01

Pellet-containing tablets for colon-specific drug delivery present higher targeting efficiency and lower costs when compared with monolithic tablets and pellet-filled capsules, respectively. In this study, pellets containing ketoprofen were coated with different acrylic polymers and submitted to compaction. The influence of formulation and process factors on film integrity was then evaluated. Pellets were prepared via extrusion-spheronization and coated using two acrylic polymers (Eudragit® FS 30 D and Opadry® 94 k28327, PMMA and PMA, respectively). The resulting pellets were mixed with placebo granules and compressed in a hydraulic press. Multiple regression showed that ketoprofen release from pellet-containing tablets is predominantly influenced by pellet content, hardness, friability, and disintegration time. PMA-containing tablets prepared under low compaction force or with low pellet content showed rapid disintegration (<1 min) and ketoprofen release similar to those of uncompressed coated pellets (∼30% at 360 min of experiment). On the other hand, PMMA-containing tablets showed a higher rupture level, and those prepared with higher pellet content gave rise to a non-disintegrating matrix. Coated pellets were shown to be able to target ketoprofen to the colonic region. Targeting capacity was dependent on the physicochemical characteristics of the tablets.

Cryogenic pellet production developments for long-pulse plasma operation

NASA Astrophysics Data System (ADS)

Meitner, S. J.; Baylor, L. R.; Combs, S. K.; Fehling, D. T.; McGill, J. M.; Duckworth, R. C.; McGinnis, W. D.; Rasmussen, D. A.

2014-01-01

Long pulse plasma operation on large magnetic fusion devices require multiple forms of cryogenically formed pellets for plasma fueling, on-demand edge localized mode (ELM) triggering, radiative cooling of the divertor, and impurity transport studies. The solid deuterium fueling and ELM triggering pellets can be formed by extrusions created by helium cooled, twin-screw extruder based injection system that freezes deuterium in the screw section. A solenoid actuated cutter mechanism is activated to cut the pellets from the extrusion, inserting them into the barrel, and then fired by the pneumatic valve pulse of high pressure gas. Fuel pellets are injected at a rate up to 10 Hz, and ELM triggering pellets are injected at rates up to 20 Hz. The radiative cooling and impurity transport study pellets are produced by introducing impurity gas into a helium cooled section of a pipe gun where it deposits in-situ. A pneumatic valve is opened and propellant gas is released downstream where it encounters a passive punch which initially accelerates the pellet before the gas flow around the finishes the pellet acceleration. This paper discusses the various cryogenic pellet production techniques based on the twin-screw extruder, pipe gun, and pellet punch designs.

Cryogenic pellet production developments for long-pulse plasma operation

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

Meitner, S. J.; Baylor, L. R.; Combs, S. K.

Long pulse plasma operation on large magnetic fusion devices require multiple forms of cryogenically formed pellets for plasma fueling, on-demand edge localized mode (ELM) triggering, radiative cooling of the divertor, and impurity transport studies. The solid deuterium fueling and ELM triggering pellets can be formed by extrusions created by helium cooled, twin-screw extruder based injection system that freezes deuterium in the screw section. A solenoid actuated cutter mechanism is activated to cut the pellets from the extrusion, inserting them into the barrel, and then fired by the pneumatic valve pulse of high pressure gas. Fuel pellets are injected at amore » rate up to 10 Hz, and ELM triggering pellets are injected at rates up to 20 Hz. The radiative cooling and impurity transport study pellets are produced by introducing impurity gas into a helium cooled section of a pipe gun where it deposits in-situ. A pneumatic valve is opened and propellant gas is released downstream where it encounters a passive punch which initially accelerates the pellet before the gas flow around the finishes the pellet acceleration. This paper discusses the various cryogenic pellet production techniques based on the twin-screw extruder, pipe gun, and pellet punch designs.« less

Contributions to advances in blend pellet products (BPP) research on molecular structure and molecular nutrition interaction by advanced synchrotron and globar molecular (Micro)spectroscopy.

PubMed

Guevara-Oquendo, Víctor H; Zhang, Huihua; Yu, Peiqiang

2018-04-13

To date, advanced synchrotron-based and globar-sourced techniques are almost unknown to food and feed scientists. There has been little application of these advanced techniques to study blend pellet products at a molecular level. This article aims to provide recent research on advanced synchrotron and globar vibrational molecular spectroscopy contributions to advances in blend pellet products research on molecular structure and molecular nutrition interaction. How processing induced molecular structure changes in relation to nutrient availability and utilization of the blend pellet products. The study reviews Utilization of co-product components for blend pellet product in North America; Utilization and benefits of inclusion of pulse screenings; Utilization of additives in blend pellet products; Application of pellet processing in blend pellet products; Conventional evaluation techniques and methods for blend pellet products. The study focus on recent applications of cutting-edge vibrational molecular spectroscopy for molecular structure and molecular structure association with nutrient utilization in blend pellet products. The information described in this article gives better insight on how advanced molecular (micro)spectroscopy contributions to advances in blend pellet products research on molecular structure and molecular nutrition interaction.

Volume measurement of cryogenic deuterium pellets by Bayesian analysis of single shadowgraphy images

NASA Astrophysics Data System (ADS)

Szepesi, T.; Kálvin, S.; Kocsis, G.; Lang, P. T.; Wittmann, C.

2008-03-01

In situ commissioning of the Blower-gun injector for launching cryogenic deuterium pellets at ASDEX Upgrade tokamak was performed. This injector is designed for high repetitive launch of small pellets for edge localised modes pacing experiments. During the investigation the final injection geometry was simulated with pellets passing to the torus through a 5.5m long guiding tube. For investigation of pellet quality at launch and after tube passage laser flash camera shadowgraphy diagnostic units before and after the tube were installed. As indicator of pellet quality we adopted the pellet mass represented by the volume of the main remaining pellet fragment. Since only two-dimensional (2D) shadow images were obtained, a reconstruction of the full three-dimensional pellet body had to be performed. For this the image was first converted into a 1-bit version prescribing an exact 2D contour. From this contour the expected value of the volume was calculated by Bayesian analysis taking into account the likely cylindrical shape of the pellet. Under appropriate injection conditions sound pellets with more than half of their nominal mass are detected after acceleration; the passage causes in average an additional loss of about 40% to the launched mass. Analyzing pellets arriving at tube exit allowed for deriving the injector's optimized operational conditions. For these more than 90% of the pellets were arriving with sound quality when operating in the frequency range 5-50Hz.

Particle fueling experiments with a series of pellets in LHD

NASA Astrophysics Data System (ADS)

Baldzuhn, J.; Damm, H.; Dinklage, A.; Sakamoto, R.; Motojima, G.; Yasuhara, R.; Ida, K.; Yamada, H.; LHD Experiment Group; Wendelstein 7-X Team

2018-03-01

Ice pellet injection is performed in the heliotron Large Helical Device (LHD). The pellets are injected in short series, with up to eight individual pellets. Parameter variations are performed for the pellet ice isotopes, the LHD magnetic configurations, the heating scenario, and some others. These experiments are performed in order to find out whether deeper fueling can be achieved with a series of pellets compared to single pellets. An increase of the fueling efficiency is expected since pre-cooling of the plasma by the first pellets within a series could aid deeper penetration of later pellets in the same series. In addition, these experiments show which boundary conditions must be fulfilled to optimize the technique. The high-field side injection of pellets, as proposed for deep fueling in a tokamak, will not be feasible with the same efficiency in a stellarator or heliotron because there the magnetic field gradient is smaller than in a tokamak of comparable size. Hence, too shallow pellet fueling, in particular in a large device or a fusion reactor, will be an issue that can be overcome only by extremely high pellet velocities, or other techniques that will have to be developed in the future. It turned out by our investigations that the fueling efficiency can be enhanced by the injection of a series of pellets to some extent. However, further investigations will be needed in order to optimize this approach for deep particle fueling.

Effect of process variables on the quality characteristics of pelleted wheat distiller's dried grains with solubles

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

Jaya Shankar Tumuluru; Lope Tabil; Anthony Opoku

2011-04-01

The rapid expansion of ethanol processing plants in Canada has resulted in a significant increase in the production of wheat-based distiller's dried grains with solubles (DDGS). Transportation and flowability problems associated with DDGS necessitate investigations on pelleting. In the present study, the effect of process variables like die temperature (T) and feed moisture content (Mw) on the pellet properties like pellet moisture content, durability and pellet density was explored using a single pelleting machine; further studies on pelleting DDGS using a pilot-scale pellet mill were also conducted to understand the effect of die diameter and steam conditioning on durability andmore » bulk density of pellets. Proximate analysis of DDGS indicated that crude protein and dry matter were in the range of 37.37–40.33% and 91.27–92.60%, respectively. Linear regression models developed for pellet quality attributes like pellet moisture content, pellet density and durability adequately described the single pelleting process with R2 value of 0.97, 0.99 and 0.7, respectively. ANOVA results have indicated that linear terms T and Mw and the interaction term T × Mw were statistically significant at P < 0.01 and P < 0.1 for pellet moisture content and pellet density. Based on the trends of the surface plots, a medium T of about 50–80 °C and a low Mw of about 5.1% resulted in maximum pellet density and durability and minimum pellet moisture content. Results from pilot-scale studies indicated that bulk density, durability and throughput values were 436.8–528.9 kg m-3, 60.3–92.7% and 45.52–68.77 kg h-1, respectively. It was observed that both die diameter and steam addition had a significant effect on the bulk density and the durability values. The highest bulk density and durability were achieved with 6.4 mm die diameter with steam addition compared to 7.9 mm die with or without steam addition.« less

Design and characteristic analysis of shaping optics for optical trepanning

NASA Astrophysics Data System (ADS)

Zeng, D.; Latham, W. P.; Kar, A.

2005-08-01

Optical trepanning is a new laser drilling method using an annular beam. The annular beams allow numerous irradiance profiles to supply laser energy to the workpiece and thus provide more flexibility in affecting the hole quality than a traditional circular laser beam. The refractive axicon system has been designed to generating a collimated annular beam. In this article, calculations of intensity distributions produced by this refractive system are made by evaluating the Kirchhoff-Fresnel diffraction. It is shown that the refractive system is able to transform a Gaussian beam into a full Gaussian annular beam. The base angle of the axicon lens, input laser beam diameter and intensity profiles are found to be important factors for the axcion refractive system. Their effects on the annular beam profiles are analyzed based on the numerical solutions of the diffraction patterns.

A Novel Approach for Dry Powder Coating of Pellets with Ethylcellulose. Part II: Evaluation of Caffeine Release.

PubMed

Albertini, Beatrice; Melegari, Cecilia; Bertoni, Serena; Dolci, Luisa Stella; Passerini, Nadia

2018-04-01

The objective of this study was to assess the efficacy and the capability of a novel ethylcellulose-based dry-coating system to obtain prolonged and stable release profiles of caffeine-loaded pellets. Lauric and oleic acids at a suitable proportion were used to plasticize ethylcellulose. The effect of coating level, percentage of drug loading, inert core particle size, and composition of the coating formulation including the anti-sticking agent on the drug release profile were fully investigated. A coating level of 15% w/w was the maximum layered amount which could modify the drug release. The best controlled drug release was obtained by atomizing talc (2.5% w/w) together with the solid plasticizer during the dry powder-coating process. SEM pictures revealed a substantial drug re-crystallization on the pellet surface, and the release studies evidenced that caffeine diffused through the plasticized polymer acting as pore former. Therefore, the phenomenon of caffeine migration across the coating layer had a strong influence on the permeability of the coating membrane. Comparing dry powder-coated pellets to aqueous film-coated ones, drug migration happened during storage, though more sustained release profiles were obtained. The developed dry powder-coating process enabled the production of stable caffeine sustained release pellets. Surprisingly, the release properties of the dry-coated pellets were mainly influenced by the way of addition of talc into the dry powder-coating blend and by the drug nature and affinity to the coating components. It would be interesting to study the efficacy of novel coating system using a different API.

Dangerous (toxic) atmospheres in UK wood pellet and wood chip fuel storage.

PubMed

Simpson, Andrew T; Hemingway, Michael A; Seymour, Cliff

2016-09-01

There is growing use of wood pellet and wood chip boilers in the UK. Elsewhere fatalities have been reported, caused by carbon monoxide poisoning following entry into wood pellet storage areas. The aim of this work was to obtain information on how safely these two fuels are being stored in the UK. Site visits were made to six small-scale boiler systems and one large-scale pellet warehouse, to assess storage practice, risk management systems and controls, user knowledge, and potential for exposure to dangerous atmospheres. Real time measurements were made of gases in the store rooms and during laboratory tests on pellets and chips. Volatile organic compounds (VOCs) emitted and the microbiological content of the fuel was also determined. Knowledge of the hazards associated with these fuels, including confined space entry, was found to be limited at the smaller sites, but greater at the large pellet warehouse. There has been limited risk communication between companies supplying and maintaining boilers, those manufacturing and supplying fuel, and users. Risk is controlled by restricting access to the store rooms with locked entries; some store rooms have warning signs and carbon monoxide alarms. Nevertheless, some store rooms are accessed for inspection and maintenance. Laboratory tests showed that potentially dangerous atmospheres of carbon monoxide and carbon dioxide, with depleted levels of oxygen may be generated by these fuels, but this was not observed at the sites visited. Unplanned ventilation within store rooms was thought to be reducing the build-up of dangerous atmospheres. Microbiological contamination was confined to wood chips.

Dangerous (toxic) atmospheres in UK wood pellet and wood chip fuel storage

PubMed Central

Simpson, Andrew T.; Hemingway, Michael A.; Seymour, Cliff

2016-01-01

ABSTRACT There is growing use of wood pellet and wood chip boilers in the UK. Elsewhere fatalities have been reported, caused by carbon monoxide poisoning following entry into wood pellet storage areas. The aim of this work was to obtain information on how safely these two fuels are being stored in the UK. Site visits were made to six small-scale boiler systems and one large-scale pellet warehouse, to assess storage practice, risk management systems and controls, user knowledge, and potential for exposure to dangerous atmospheres. Real time measurements were made of gases in the store rooms and during laboratory tests on pellets and chips. Volatile organic compounds (VOCs) emitted and the microbiological content of the fuel was also determined. Knowledge of the hazards associated with these fuels, including confined space entry, was found to be limited at the smaller sites, but greater at the large pellet warehouse. There has been limited risk communication between companies supplying and maintaining boilers, those manufacturing and supplying fuel, and users. Risk is controlled by restricting access to the store rooms with locked entries; some store rooms have warning signs and carbon monoxide alarms. Nevertheless, some store rooms are accessed for inspection and maintenance. Laboratory tests showed that potentially dangerous atmospheres of carbon monoxide and carbon dioxide, with depleted levels of oxygen may be generated by these fuels, but this was not observed at the sites visited. Unplanned ventilation within store rooms was thought to be reducing the build-up of dangerous atmospheres. Microbiological contamination was confined to wood chips. PMID:27030057

Persistent increase of blood lead level and suppression of δ-ALAD activity in northern bobwhite quail orally dosed with even a single 2-mm spent lead shot.

PubMed

Holladay, S D; Kerr, R; Holladay, J P; Meldrum, B; Williams, S M; Gogal, R M

2012-10-01

Birds that display grit ingestion behavior are potentially at risk of lead (Pb) poisoning from mistaken ingestion of spent Pb shot pellets. The majority of available studies designed to assess such risk have used unspent shot pellets rather than field-obtained spent shot, which is oxidized and otherwise changed by weathering. Available studies also often administered more or heavier shot pellets to a bird than it might be expected to ingest. The current study dosed northern bobwhite quail (Colinus virginianus) weighing 194.6 ± 23.1 g (female birds) and 199.3 ± 12.2 g (male birds) with one to three spent no. 9 Pb shot collected from a skeet range, with particular interest in the toxicity that may occur from ingestion of a single 2-mm, 50 mg shot. An 8 week post-dosing clinical observation period was employed, over which feed consumption, body weight, blood Pb levels, and a battery of blood physiological parameters were made. Weight loss occurred in the birds, including male birds dosed with one Pb pellet. Erythrocyte delta aminolevulinic acid dehydratase (δ-ALAD) levels were decreased for the duration of the study across exposures and to levels associated with injury in wild bird populations. Decreased ALAD was particularly severe in female birds dosed with one Pb pellet and was still 92 % decreased at 8 weeks after dosing. Together, these results suggest that inadvertent ingestion of a single no. 9 Pb shot pellet can adversely affect the health of northern bobwhite quail.

Glove port retrofit assembly and method of replacing components

DOEpatents

Giesen, Isaac M; Cournoyer, Michael E; Rael, David G

2014-11-18

What is disclosed is a system for retrofitting a sealed enclosure for performing work therein having an outer enclosure assembly configured to be clamped to the outer annular face of a port ring and form a sealed engagement with the outer annular surface of the port ring, a change assembly having an inner ring and an access element wherein the inner ring has a first annular cylinder body that is sized to be slidably received by the port ring and the access element is configured to be sealably and slidably positioned within the first annular cylinder body of the inner ring.

Stage 3 bucket shank bypass holes and related method

DOEpatents

Leone, Sal Albert; Eldrid, Sacheverel Quentin; Lupe, Douglas Arthur

2002-01-01

In a multi-stage turbine wherein at least one turbine wheel supports a row of buckets for rotation, and wherein the turbine wheel is located axially between first and second annular fixed arrays of nozzles, a cooling air circuit for purging a wheelspace between the turbine wheel and the second fixed annular array of nozzles comprising a flowpath through a shank portion of one or more buckets connecting a wheelspace between the turbine wheel and the first fixed annular array of nozzles with the wheelspace between the turbine wheel and the second fixed annular array of nozzles.

Sinkers or floaters? Contribution from salp pellets to the export flux during a large bloom event in the Southern Ocean

NASA Astrophysics Data System (ADS)

Iversen, Morten H.; Pakhomov, Evgeny A.; Hunt, Brian P. V.; van der Jagt, Helga; Wolf-Gladrow, Dieter; Klaas, Christine

2017-04-01

Salp fecal pellets are rich in organic matter and have been shown to sink at very high velocities. In recent years, salp abundances have been increasing in the Southern Ocean where they seem to be replacing krill as the dominant grazers on phytoplankton. As salps can form large swarms with high pellet production rates, it has been suggested that they will become increasingly important for the vertical export of particulate organic matter in the Southern Ocean. However, detailed studies combining both investigations of pellet production rates, turnover, and export are still needed in order to determine whether salp pellets are important for export ('sinkers') or recycling ('floaters') of organic matter. Our results suggest that pellets are produced at high rates in the upper few hundred meters of the water column. Although we observed high sinking velocities and low microbial degradation rates of the produced salp pellets, only about one third of the produced pellets were captured in sediment traps placed at 100 m and about 13% of the produced pellets were exported to sediment traps placed at 300 m. The high retention of these fast-settling pellets seems to be caused by break-up and loosening of the pellets, possibly by zooplankton and salps themselves. We measured 3-fold lower size-specific sinking velocities in loosened and fragmented compared to freshly produced intact pellets-. This enhanced the residence times (>1 day) of both small and large pellets in the upper water column. We postulate that the fragile nature of salp pellets make them more important for recycling of organic matter in the upper mesopelagic layer rather than as a conduit for export of particulate organic matter to the seafloor.

Wax-based sustained release matrix pellets prepared by a novel freeze pelletization technique II. In vitro drug release studies and release mechanisms.

PubMed

Cheboyina, Sreekhar; Wyandt, Christy M

2008-07-09

A novel freeze pelletization technique was evaluated for the preparation of wax-based sustained release matrix pellets. Pellets containing water-soluble drugs were successfully prepared using a variety of waxes. The drug release significantly depended on the wax type used and the aqueous drug solubility. The drug release decreased as the hydrophobicity of wax increased and the drug release increased as the aqueous drug solubility increased. In glyceryl monostearate (GMS) pellets, drug release rate decreased as the loading of theophylline increased. On the contrary, the release rate increased as the drug loading of diltiazem HCl increased in Precirol pellets. Theophylline at low drug loads existed in a dissolved state in GMS pellets and the release followed desorption kinetics. At higher loads, theophylline existed in a crystalline state and the release followed dissolution-controlled constant release for all the waxes studied. However, with the addition of increasing amounts of Brij 76, theophylline release rate increased and the release mechanism shifted to diffusion-controlled square root time kinetics. But the release of diltiazem HCl from Precirol pellets at all drug loads, followed diffusion-controlled square root time kinetics. Therefore, pellets capable of providing a variety of release profiles for different drugs can be prepared using this freeze pelletization technique by suitably modifying the pellet forming matrix compositions.

Visualizing the effect of dynamin inhibition on annular gap vesicle formation and fission

PubMed Central

Nickel, Beth; Boller, Marie; Schneider, Kimberly; Shakespeare, Teresa; Gay, Vernon; Murray, Sandra A.

2013-01-01

Summary Although gap junction plaque assembly has been extensively studied, mechanisms involved in plaque disassembly are not well understood. Disassembly involves an internalization process in which annular gap junction vesicles are formed. These vesicles undergo fission, but the molecular machinery needed for these fissions has not been described. The mechanoenzyme dynamin has been previously demonstrated to play a role in gap junction plaque internalization. To investigate the role of dynamin in annular gap junction vesicle fission, immunocytochemical, time-lapse and transmission electron microscopy were used to analyze SW-13 adrenocortical cells in culture. Dynamin was demonstrated to colocalize with gap junction plaques and vesicles. Dynamin inhibition, by siRNA knockdown or treatment with the dynamin GTPase inhibitor dynasore, increased the number and size of gap junction ‘buds’ suspended from the gap junction plaques. Buds, in control populations, were frequently released to form annular gap junction vesicles. In dynamin-inhibited populations, the buds were larger and infrequently released and thus fewer annular gap junction vesicles were formed. In addition, the number of annular gap junction vesicle fissions per hour was reduced in the dynamin-inhibited populations. We believe this to be the first report addressing the details of annular gap junction vesicle fissions and demonstrating a role of dynamin in this process. This information is crucial for elucidating the relationship between gap junctions, membrane regulation and cell behavior. PMID:23591819

Visualizing the effect of dynamin inhibition on annular gap vesicle formation and fission.

PubMed

Nickel, Beth; Boller, Marie; Schneider, Kimberly; Shakespeare, Teresa; Gay, Vernon; Murray, Sandra A

2013-06-15

Although gap junction plaque assembly has been extensively studied, mechanisms involved in plaque disassembly are not well understood. Disassembly involves an internalization process in which annular gap junction vesicles are formed. These vesicles undergo fission, but the molecular machinery needed for these fissions has not been described. The mechanoenzyme dynamin has been previously demonstrated to play a role in gap junction plaque internalization. To investigate the role of dynamin in annular gap junction vesicle fission, immunocytochemical, time-lapse and transmission electron microscopy were used to analyze SW-13 adrenocortical cells in culture. Dynamin was demonstrated to colocalize with gap junction plaques and vesicles. Dynamin inhibition, by siRNA knockdown or treatment with the dynamin GTPase inhibitor dynasore, increased the number and size of gap junction 'buds' suspended from the gap junction plaques. Buds, in control populations, were frequently released to form annular gap junction vesicles. In dynamin-inhibited populations, the buds were larger and infrequently released and thus fewer annular gap junction vesicles were formed. In addition, the number of annular gap junction vesicle fissions per hour was reduced in the dynamin-inhibited populations. We believe this to be the first report addressing the details of annular gap junction vesicle fissions and demonstrating a role of dynamin in this process. This information is crucial for elucidating the relationship between gap junctions, membrane regulation and cell behavior.

High temperature solid electrolyte fuel cell configurations and interconnections

DOEpatents

Isenberg, Arnold O.

1984-01-01

High temperature fuel cell configurations and interconnections are made including annular cells having a solid electrolyte sandwiched between thin film electrodes. The cells are electrically interconnected along an elongated axial outer surface.

STEAM GENERATOR FOR NUCLEAR REACTOR

DOEpatents

Kinyon, B.W.; Whitman, G.D.

1963-07-16

The steam generator described for use in reactor powergenerating systems employs a series of concentric tubes providing annular passage of steam and water and includes a unique arrangement for separating the steam from the water. (AEC)

Dosing of adult pigeons with as little as one #9 lead pellet caused severe δ-ALAD depression, suggesting potential adverse effects in wild populations.

PubMed

Holladay, Jeremy P; Nisanian, Mandy; Williams, Susan; Tuckfield, R Cary; Kerr, Richard; Jarrett, Timothy; Tannenbaum, Lawrence; Holladay, Steven D; Sharma, Ajay; Gogal, Robert M

2012-11-01

Avian wildlife species commonly ingest lead (Pb) spent shot or bullet fragments as grit or mistakenly as food. In previous studies in our laboratory and others, the toxicity varied based on the diet as well as type and quantity of Pb ingested. In the current study, domestic pigeons were gavaged with 1, 2, or 3 Pb pellets and then followed with weekly radiographs and blood physiologic endpoints for 28 days. Pellet retention decreased by roughly 50 % per week as pellets were either absorbed or excreted, except for week 4 where pellet number no longer was diminished. Size of retained pellets visually decreased over retention time. Birds dosed with a single #9 pellet showed mean blood Pb levels over 80 times higher than those of the controls, verifying Pb pellet absorption from the gut. A single Pb pellet also reduced plasma δ-aminolevulinic acid dehydratase (δ-ALAD) activity by over 80 % compared to controls, suggesting the potential for population injury in Pb pellet-exposed pigeons.

Energy Input and Quality of Pellets Made from Steam-Exploded Douglas Fir (Pseudotsuga menziesii)

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

Sokhansanj, Shahabaddine; Bi, X.T.; Lim, C. Jim

Ground softwood Douglas fir (Pseudotsuga menziesii) was treated with pressurized saturated steam at 200-220 C (1.6-2.4 MPa) for 5-10 min in a sealed container. The contents of the container were released to the atmosphere for a sudden decompression. The steam-exploded wood particles were dried to 10% moisture content and pelletized in a single-piston-cylinder system. The pellets were characterized for their mechanical strength, chemical composition, and moisture sorption. The steamtreated wood required 12-81% more energy to compact into pellets than the untreated wood. Pellets made from steam-treated wood had a breaking strength 1.4-3.3 times the strength of pellets made from untreatedmore » wood. Steam-treated pellets had a reduced equilibrium moisture content of 2-4% and a reduced expansion after pelletization. There was a slight increase in the high heating value from 18.94 to 20.09 MJ/kg for the treated samples. Steam-treated pellets exhibited a higher lengthwise rigidity compared to untreated pellets.« less

Structural support bracket for gas flow path

DOEpatents

None

2016-08-02

A structural support system is provided in a can annular gas turbine engine having an arrangement including a plurality of integrated exit pieces (IEPs) forming an annular chamber for delivering gases from a plurality of combustors to a first row of turbine blades. A bracket structure is connected between an IEP and an inner support structure on the engine. The bracket structure includes an axial bracket member attached to an IEP and extending axially in a forward direction. A transverse bracket member has an end attached to the inner support structure and extends circumferentially to a connection with a forward end of the axial bracket member. The transverse bracket member provides a fixed radial position for the forward end of the axial bracket member and is flexible in the axial direction to permit axial movement of the axial bracket member.

Measurement of Persistent Organic Pollutants (POPs) in plastic resin pellets from remote islands : Toward establishment of baseline level for International Pellet Watch

NASA Astrophysics Data System (ADS)

Takada, H.; Heskett, M.; Yamashita, R.; Yuyama, M.; Itoh, M.; Geok, Y. B.; Ogata, Y.

2011-12-01

Plastic resin pellets collected from remote islands in open oceans (Canary, St. Helena, Cocos, Hawaii, Maui Islands and Barbados) were sorted and yellowing polyethylene (PE) pellets were measured for polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloroethane and the degradation products (DDTs), and hexachlorocyclohexanes (HCHs) by gas chromatograph equipped with mass spectrometer (GC-MS) and with electron capture detector (GC-ECD). PCBs were detected from all the pellet samples, confirming the global dispersion of PCBs. Median concentrations of PCBs (sum of 13 congeners : CB-66, CB-101, CB-110, CB-118, CB-105, CB-149, CB-153, CB-138, CB-128, CB-187, CB-180, CB-170, CB-206) in the remote island pellets ranged from 0.1 to 10 ng/g-pellet. These were one to three orders of magnitude lower than those observed for pellets from industrialized coastal zones (hundreds ng/g in Los Angeles, Boston, Tokyo; Ogata et al., 2009). Because these remote islands are far (>100 km) from industrialized zones, these concentrations (i.e., 0.1 to 10 ng/g-pellet) can be regarded as global "baseline" level of PCB pollution. Concentrations of DDTs in the remote island pellets ranged from 0.2 to 5.5 ng/g-pellet. At some locations, DDT was dominant over the degradation products (DDE and DDD), suggesting current usage of the pesticides in the islands. HCHs concentrations were 0.4 - 1.8 ng/g-pellet and lower than PCBs and DDTs, except for St. Helena Island at 18.8 ng/g-pellet where the current usage of the pesticides are of concern. The analyses of pellets from the remote islands provided "baseline" level of POPs (PCBs < 10 ng/g-pellet, DDTs < 6 ng/g-pellet, HCHs < 2 ng/g-pellet). However, the present samples were from tropical and subtropical areas. To establish global baseline, especially to understand the effects of global distillation, pellet samples from remote islands in higher latitude regions are necessary. From the eco-toxicological point of view, the fact that sporadic high concentrations of POPs were detected in some pellet samples from the remote islands is underscored. Some plastic debris which were contaminated in industrialized coastal zones may have rapidly transported to the remote islands before they would reach equilibrium (i.e., desorption completed). Because POPs concentrations in the other media are at trace levels in these remote environments, the sporadic high concentrations of POPs in the plastic debris may pose threat to the ecosystem in the remote islands.

Novel naproxen/esomeprazole magnesium compound pellets based on acid-independent mechanism: in vitro and in vivo evaluation.

PubMed

Lu, Jing; Kan, Shuling; Zhao, Yi; Zhang, Wenli; Liu, Jianping

2016-09-01

The purpose of this study was to develop the novel naproxen/esomeprazole magnesium compound pellets (novel-NAP/EMZ) depending on EMZ acid-independent mechanism which has been proved to be predominate in the mechanism of co-therapy with nonsteroidal anti-inflammatory drug. The novel-NAP/EMZ compound pellets, composed of NAP colon-specific pellets (NAP-CSPs) and EMZ modified-release pellets (EMZ-MRPs), were prepared by fluid-bed coating technology with desired in vitro release profiles. The resulting pellets were filled into hard gelatin capsules for in vivo evaluation in rats and compared with the reference compound pellets, consisted of NAP enteric-coated pellets (NAP-ECPs) and EMZ immediate-release pellets (EMZ-IRPs). The reference compound pellets were prepared simulating the drug delivery system of VIMOVO(®). In vivo pharmacokinetics, EMZ-MRPs had significantly larger AUC0-t (p < 0.01), 1.67 times more than that of EMZ-IRPs, and prolonged mean residence time (7.55 ± 0.12 h) than that of IRPs (1.46 ± 0.39 h). NAP-CSPs and NAP-ECPs showed similar AUC0-t. Compared to the reference compound pellets, the novel-NAP/EMZ compound pellets did not show distinct differences in histological mucosal morphology. However, biochemical tests exhibited enhanced total antioxidant capacity, increased nitric oxide content and reduced malondialdehyde level for novel-NAP/EMZ compound pellets, indicating that the acid-independent action took effect. The gastric pH values of novel-NAP/EMZ compound pellets were at a low and stable level, which could ensure normal physiological range of human gastric pH. As a result, the novel-NAP/EMZ compound pellets may be a more suitable formulation with potential advantages by improving bioavailability of drug and further reducing undesirable gastrointestinal damages.

Co-culture of Adult Mesenchymal Stem Cells and Nucleus Pulposus Cells in Bilaminar Pellets for Intervertebral Disc Regeneration.

PubMed

Allon, Aliza A; Schneider, Richard A; Lotz, Jeffrey C

2009-01-01

Our goal is to optimize stem cell-based tissue engineering strategies in the context of the intervertebral disc environment. We explored the benefits of co-culturing nucleus pulposus cells (NPC) and adult mesenchymal stem cells (MSC) using a novel spherical bilaminar pellet culture system where one cell type is enclosed in a sphere of the other cell type. Our 3D system provides a structure that exploits embryonic processes such as tissue induction and condensation. We observed a unique phenomenon: the budding of co-culture pellets and the formation of satellite pellets that separate from the main pellet. MSC and NPC co-culture pellets were formed with three different structural organizations. The first had random organization. The other two had bilaminar organization with either MSC inside and NPC outside or NPC inside and MSC outside. By 14 days, all co-culture pellets exhibited budding and spontaneously generated satellite pellets. The satellite pellets were composed of both cell types and, surprisingly, all had the same bilaminar organization with MSC on the inside and NPC on the outside. This organization was independent of the structure of the main pellet that the satellites stemmed from. The main pellets generated satellite pellets that spontaneously organized into a bilaminar structure. This implies that structural organization occurs naturally in this cell culture system and may be inherently favorable for cell-based tissue engineering strategies. The occurrence of budding and the organization of satellite pellets may have important implications for the use of co-culture pellets in cell-based therapies for disc regeneration. From a therapeutic point of view, the generation of satellite pellets may be a beneficial feature that would serve to spread donor cells throughout the host matrix and restore normal matrix composition in a sustainable way, ultimately renewing tissue function.

Controlling the pressure within an annular volume of a wellbore

DOEpatents

Hermes, Robert E.; Gonzalez, Manuel E.; Llewellyn, Brian C.; Bloys, James B.

2008-10-28

A process is described for replacing at least a portion of the liquid within the annular volume of a casing system within a wellbore with a second liquid. The second liquid is preselected to provide a measure of control of the pressure within the annular volume as the fluid within the volume is being heated.

Controlling the pressure within an annular volume of a wellbore

DOEpatents

Hermes, Robert E [Los Alamos, NM; Gonzalez, Manuel E [Kingwood, TX; Llewellyn, Brian C [Kingwood, TX; Bloys, James B [Katy, TX; Coates, Don M [Santa Fe, NM

2011-05-31

A process is described for replacing at least a portion of the liquid within the annular volume of a casing system within a wellbore with a second liquid. The second liquid is preselected to provide a measure of control of the pressure within the annular volume as the fluid within the volume is being heated.

Controlling the pressure within an annular volume of a wellbore

DOEpatents

Hermes, Robert E [Los Alamos, NM; Gonzalez, Manuel E [Kingwood, TX; Llewellyn, Brian C [Kingwood, TX; Bloys, James B [Katy, TX

2011-01-18

A process is described for replacing at least a portion of the liquid within the annular volume of a casing system within a wellbore with a second liquid. The second liquid is preselected to provide a measure of control of the pressure within the annular volume as the fluid within the volume is being heated.

Controlling the pressure within an annular volume of a wellbore

DOEpatents

Hermes, Robert E.; Gonzalez, Manuel E.; Llewellyn, Brian C.; Bloys, James B.

2010-06-29

A process is described for replacing at least a portion of the liquid within the annular volume of a casing system within a wellbore with a second liquid. The second liquid is preselected to provide a measure of control of the pressure within the annular volume as the fluid within the volume is being heated.

Controlling the pressure within an annular volume of a wellbore

DOEpatents

Hermes, Robert E [Los Alamos, NM; Gonzalez, Manuel E [Kingwood, NM; Llewellyn, Brian C [Kingwood, TX; Bloys, James B [Katy, TX; Coates, Don M [Santa Fe, NM

2011-06-21

A process is described for replacing at least a portion of the liquid within the annular volume of a casing system within a wellbore with a second liquid. The second liquid is preselected to provide a measure of control of the pressure within the annular volume as the fluid within the volume is being heated.

You're Blocking the Light

ERIC Educational Resources Information Center

Riddle, Bob

2005-01-01

Eclipses typically occur in pairs twice each year, and the second pair for this year will be this month, starting with an annular solar eclipse on October 3, and two weeks later a partial lunar eclipse on October 17. The path of annularity will travel from the North Atlantic Ocean to Spain, where the annular phase will last for more than four…

Critical Science Issues for Direct Drive Inertial Fusion Energy

NASA Astrophysics Data System (ADS)

Dahlburg, Jill P.; Gardner, John H.; Schmitt, Andrew J.; Obenschain, S. P.

1998-09-01

There are several topics that require resolution prior to the construction of an Inertial Fusion Energy [IFE] laboratory Engineering Test Facility [ETF]: a pellet that produces high gain; a pellet fabrication system that cost-effectively and rapidly manufactures these pellets; a sufficiently uniform and durable high repetition-rate laser pellet driver; a practical target injection system that provides accurate pellet aiming; and, a target chamber that will survive the debris and radiation of repeated high-gain pellet implosions. In this summary we describe the science issues and opportunities that are involved in the design of a successful high gain direct drive Inertial Confinement Fusion [ICF] pellet.

Hidden plastics of Lake Ontario, Canada and their potential preservation in the sediment record.

PubMed

Corcoran, Patricia L; Norris, Todd; Ceccanese, Trevor; Walzak, Mary Jane; Helm, Paul A; Marvin, Chris H

2015-09-01

Microplastics are a source of environmental pollution resulting from degradation of plastic products and spillage of resin pellets. We report the amounts of microplastics from various sites of Lake Ontario and evaluate their potential for preservation in the sediment record. A total of 4635 pellets were sampled from the Humber Bay shoreline on three sampling dates. Pellet colours were similar to those from the Humber River bank, suggesting that the river is a pathway for plastics transport into Lake Ontario. Once in the lake, high density microplastics, including mineral-polyethylene and mineral-polypropylene mixtures, sink to the bottom. The minerals may be fillers that were combined with plastics during production, or may have adsorbed to the surfaces of the polymers in the water column or on the lake bottom. Based on sediment depths and accumulation rates, microplastics have accumulated in the offshore region for less than 38 years. Their burial increases the chance of microplastics preservation. Shoreline pellets may not be preserved because they are mingled with organic debris that is reworked during storm events. Copyright © 2015 Elsevier Ltd. All rights reserved.

Influence of apple pomace inclusion on the process of animal feed pelleting.

PubMed

Maslovarić, Marijana D; Vukmirović, Đuro; Pezo, Lato; Čolović, Radmilo; Jovanović, Rade; Spasevski, Nedeljka; Tolimir, Nataša

2017-08-01

Apple pomace (AP) is the main by-product of apple juice production. Large amounts of this material disposed into landfills can cause serious environmental problems. One of the solutions is to utilise AP as animal feed. The aim of this study was to investigate the impact of dried AP inclusion into model mixtures made from conventional feedstuffs on pellet quality and pellet press performance. Three model mixtures, with different ratios of maize, sunflower meal and AP, were pelleted. Response surface methodology (RSM) was applied when designing the experiment. The simultaneous and interactive effects of apple pomace share (APS) in the mixtures, die thickness (DT) of the pellet press and initial moisture content of the mixtures (M), on pellet quality and production parameters were investigated. Principal component analysis (PCA) and standard score (SS) analysis were applied for comprehensive analysis of the experimental data. The increase in APS led to an improvement of pellet quality parameters: pellet durability index (PDI), hardness (H) and proportion of fines in pellets. The increase in DT and M resulted in pellet quality improvement. The increase in DT and APS resulted in higher energy consumption of the pellet press. APS was the most influential variable for PDI and H calculation, while APS and DT were the most influential variables in the calculation of pellet press energy consumption. PCA showed that the first two principal components could be considered sufficient for data representation. In conclusion, addition of dried AP to feed model mixtures significantly improved the quality of the pellets.

[Chronic recurrent annular neutrophilic dermatosis].

PubMed

Croci-Torti, A; Guillot, B; Rigau, V; Bessis, D

2017-05-01

Chronic recurrent annular neutrophilic dermatosis (CRAND) is a rare form of neutrophilic dermatosis characterised by chronic annular progression, histological impairment similar to that seen in Sweet's syndrome and the absence of association with generalised signs, abnormal laboratory values or underlying systemic disease. Herein we report two new cases. Case n o  1. A 41-year-old woman had presented with four annular lesions on the forearms and neckline which she had had for one year. Examination revealed a 5-cm annular lesion on the right forearm and four similar adjacent lesions. The condition spontaneously resolved after 4 weeks. Treatment with hydroxychloroquine 400mg per day for three months proved ineffective in preventing a further episode. However, following treatment with colchicine at a daily dose of 1mg for two months, no further relapses in the rash occurred over a 10-year observation period. Case n o  2. A 38-year-old woman consulted for recurrent annular erythema confined to the legs. Examination showed the presence of a red papular annular lesion on the right leg, encircling a yellowish macule with a central ring of fine scale; the lesion had been present for three weeks. Treatment with colchicine was initiated but the patient was lost to follow-up. In both cases, histological examination was evocative of Sweet's syndrome but no inflammatory or neutrophilic syndrome and no underlying systemic disease were demonstrated. CRAND presents as a stereotypical and benign form of neutrophilic dermatosis. A diagnosis of chronic recurrent annular dermatosis with gyrate progression should be considered in the absence of general signs, neutrophilia or underlying systemic disease. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Annular and Total Solar Eclipses of 2010

NASA Technical Reports Server (NTRS)

Espenak, Fred; Anderson, J.

2008-01-01

While most NASA eclipse bulletins cover a single eclipse, this publication presents predictions for two solar eclipses during 2010. This has required a different organization of the material into the following sections. Section 1 -- Eclipse Predictions: The section consists of a general discussion about the eclipse path maps, Besselian elements, shadow contacts, eclipse path tables, local circumstances tables, and the lunar limb profile. Section 2 -- Annular Solar Eclipse of 2010 Ja n 15: The section covers predictions and weather prospects for the annular eclipse. Section 3 -- Total Solar Eclipse of 2010 Jul 11: The se ction covers predictions and weather prospects for the total eclipse. Section 4 -- Observing Eclipses: The section provides information on eye safety, solar filters, eclipse photography, and making contact timings from the path limits. Section 5 -- Eclipse Resources: The final section contains a number of resources including information on the IAU Working Group on Eclipses, the Solar Eclipse Mailing List, the NASA eclipse bulletins on the Internet, Web sites for the two 2010 eclipses, and a summary identifying the algorithms, ephemerides, and paramete rs used in the eclipse predictions.

Analysis and optimization of surface profile correcting mechanism of the pitch lap in large-aperture annular polishing

NASA Astrophysics Data System (ADS)

Zhang, Huifang; Yang, Minghong; Xu, Xueke; Wu, Lunzhe; Yang, Weiguang; Shao, Jianda

2017-10-01

The surface figure control of the conventional annular polishing system is realized ordinarily by the interaction between the conditioner and the lap. The surface profile of the pitch lap corrected by the marble conditioner has been measured and analyzed as a function of kinematics, loading conditions, and polishing time. The surface profile measuring equipment of the large lap based on laser alignment was developed with the accuracy of about 1μm. The conditioning mechanism of the conditioner is simply determined by the kinematics and fully fitting principle, but the unexpected surface profile deviation of the lap emerged frequently due to numerous influencing factors including the geometrical relationship, the pressure distribution at the conditioner/lap interface. Both factors are quantitatively evaluated and described, and have been combined to develop a spatial and temporal model to simulate the surface profile evolution of pitch lap. The simulations are consistent with the experiments. This study is an important step toward deterministic full-aperture annular polishing, providing a beneficial guidance for the surface profile correction of the pitch lap.

The Role of Biomass Composition and Steam Treatment on Durability of Pellets

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

Tang, Yong; Chandra, Richard P.; Sokhansanj, Shahab

Steam treatment has been reported to improve the durability of wood pellet likely by changing the physical and chemical structures of wood particles, but published literature is inconclusive about which structure change is the major reason for enhanced durability. Here, in this paper, steam treatment was combined either with alkaline or with SO 2 to study. The solids obtained after steam treatments along with a control sample were dried and each was compacted into pellets. The pellets were then tested for durability. Steam treatment alone dominated improvements in durability. The pellet durability increased with the amount of xylose, but xylosemore » performed better in the pellet from raw poplar than did in the pellet from treated poplar. Water-soluble components contributed a maximum 4% of the durability of poplar pellets. The addition of lignin and sugars to substrates after steam treatment did not improve durability significantly. The surface modification that took place as a result of size reduction during steam treatment was the major reason, contributing about 50% of the durability of the pellet from steam-treated poplar. The acidity of steam treatment slightly affected the relative contributions of these structure changes on the durability. Lastly, the new knowledge helps tailor the chemical and/or mechanical pretreatment involved in pelleting biomass to durable pellets.« less

The Role of Biomass Composition and Steam Treatment on Durability of Pellets

DOE PAGES

Tang, Yong; Chandra, Richard P.; Sokhansanj, Shahab; ...

2018-03-03

Steam treatment has been reported to improve the durability of wood pellet likely by changing the physical and chemical structures of wood particles, but published literature is inconclusive about which structure change is the major reason for enhanced durability. Here, in this paper, steam treatment was combined either with alkaline or with SO 2 to study. The solids obtained after steam treatments along with a control sample were dried and each was compacted into pellets. The pellets were then tested for durability. Steam treatment alone dominated improvements in durability. The pellet durability increased with the amount of xylose, but xylosemore » performed better in the pellet from raw poplar than did in the pellet from treated poplar. Water-soluble components contributed a maximum 4% of the durability of poplar pellets. The addition of lignin and sugars to substrates after steam treatment did not improve durability significantly. The surface modification that took place as a result of size reduction during steam treatment was the major reason, contributing about 50% of the durability of the pellet from steam-treated poplar. The acidity of steam treatment slightly affected the relative contributions of these structure changes on the durability. Lastly, the new knowledge helps tailor the chemical and/or mechanical pretreatment involved in pelleting biomass to durable pellets.« less

Electrochemical fecal pellet sensor for simultaneous real-time ex vivo detection of colonic serotonin signalling and motility

NASA Astrophysics Data System (ADS)

Morris, Rachel; Fagan-Murphy, Aidan; MacEachern, Sarah J.; Covill, Derek; Patel, Bhavik Anil

2016-03-01

Various investigations have focused on understanding the relationship between mucosal serotonin (5-HT) and colonic motility, however contradictory studies have questioned the importance of this intestinal transmitter. Here we described the fabrication and use of a fecal pellet electrochemical sensor that can be used to simultaneously detect the release of luminal 5-HT and colonic motility. Fecal pellet sensor devices were fabricated using carbon nanotube composite electrodes that were housed in 3D printed components in order to generate a device that had shape and size that mimicked a natural fecal pellet. Devices were fabricated where varying regions of the pellet contained the electrode. Devices showed that they were stable and sensitive for ex vivo detection of 5-HT, and no differences in the fecal pellet velocity was observed when compared to natural fecal pellets. The onset of mucosal 5-HT was observed prior to the movement of the fecal pellet. The release of mucosal 5-HT occurred oral to the fecal pellet and was linked to the contraction of the bowel wall that drove pellet propulsion. Taken, together these findings provide new insights into the role of mucosal 5-HT and suggest that the transmitter acts as a key initiator of fecal pellet propulsion.

Axisymmetric whole pin life modelling of advanced gas-cooled reactor nuclear fuel

NASA Astrophysics Data System (ADS)

Mella, R.; Wenman, M. R.

2013-06-01

Thermo-mechanical contributions to pellet-clad interaction (PCI) in advanced gas-cooled reactors (AGRs) are modelled in the ABAQUS finite element (FE) code. User supplied sub-routines permit the modelling of the non-linear behaviour of AGR fuel through life. Through utilisation of ABAQUS's well-developed pre- and post-processing ability, the behaviour of the axially constrained steel clad fuel was modelled. The 2D axisymmetric model includes thermo-mechanical behaviour of the fuel with time and condition dependent material properties. Pellet cladding gap dynamics and thermal behaviour are also modelled. The model treats heat up as a fully coupled temperature-displacement study. Dwell time and direct power cycling was applied to model the impact of online refuelling, a key feature of the AGR. The model includes the visco-plastic behaviour of the fuel under the stress and irradiation conditions within an AGR core and a non-linear heat transfer model. A multiscale fission gas release model is applied to compute pin pressure; this model is coupled to the PCI gap model through an explicit fission gas inventory code. Whole pin, whole life, models are able to show the impact of the fuel on all segments of cladding including weld end caps and cladding pellet locking mechanisms (unique to AGR fuel). The development of this model in a commercial FE package shows that the development of a potentially verified and future-proof fuel performance code can be created and used. The usability of a FE based fuel performance code would be an enhancement over past codes. Pre- and post-processors have lowered the entry barrier for the development of a fuel performance model to permit the ability to model complicated systems. Typical runtimes for a 5 year axisymmetric model takes less than one hour on a single core workstation. The current model has implemented: Non-linear fuel thermal behaviour, including a complex description of heat flow in the fuel. Coupled with a variety of different FE and finite difference models. Non-linear mechanical behaviour of the fuel and cladding including, fuel creep and swelling and cladding creep and plasticity each with dependencies on a variety of different properties. A fission gas release model which takes inputs from first principles calculations. Explicitly integrated inventory calculations performed in a coupled manner. Freedom to model steady state and transient behaviour using implicit time integration. The whole pin geometry is considered over an entire typical fuel life. The model showed by examination of normal operation and a subsequent transient chosen for software demonstration purposes: ABAQUS may be a sufficiently flexible platform to develop a complete and verified fuel performance code. The importance and effectiveness of the geometry of the fuel spacer pellets was characterised. The fuels performance under normal conditions (high friction no power spikes) would not suggest serious degradation of the cladding in fuel life. Large plastic strains were found when pellet bonding was strong, these would appear at all pellets cladding triple points and all pellet radial crack and cladding interfaces thus showing a possible axial direction to cracks forming from ductility exhaustion.

Monolith catalysts for closed-cycle carbon dioxide lasers

NASA Technical Reports Server (NTRS)

Herz, Richard K.; Badlani, Ajay

1991-01-01

The objective was to explore ways of making a monolithic form of catalyst for CO2 lasers. The approach chosen was to pelletize the catalyst material, Au/MnO2 powder, and epoxy the pellets to stainless steel sheets as structural supports. The CO oxidation reaction over Au/MnO2 powder was found to be first overall, and the reaction rate constant at room temperature was 4.4 +/- 0.3 cc/(g x sec). The activation energy was 5.7 kcal/mol. The BET surface area of the pellets was found to vary from 125 to 140 sq m/g between different batches of catalyst. Pellets epoxied to stainless steel strips showed no sign of fracture or dusting when subjected to thermal tests. Pellets can be dropped onto hard surfaces with chipping of edges but no breakage of the pellets. Mechanical strength tests performed on the pellets showed that the crush strength is roughly one-fourth of the pelletizing force. The apparent activity and activation energy over the pellets were found to be less than over the powdered form of the catalyst. The lower apparent activity and activation energy of the pellets are due to the fact that the internal surface area of a pellet is not exposed to the reactant concentration present in the flowing gas as a result of intrapellet diffusion resistance. Effectiveness factors varied from 0.44, for pellets having thickness of 2 mm and attached with epoxy to a stainless steel strip. The epoxy and the stainless steel strip were found to simply block off one of the circular faces of the pellets. The epoxy did not penetrate the pellets and block the active sites. The values of the effective diffusivities were estimated to be between 2.3 x 10(exp -3) and 4.9 x 10(exp -3) sq cm/s. With measurements performed on one powder sample and one pellet configuration, reasonable accurate predictions can be made of conversions that would be obtained with other pellet thickness and configurations.

Comparative Properties of Bamboo and Rice Straw Pellets

Treesearch

Xianmiao Liu; Zhijia Liu; Benhua Fei; Zhiyong Cai; Zehui Jiang; Xing' e Liu

2013-01-01

Bamboo is a potential major bio-energy resource. Tests were carried out to compare and evaluate the property of bamboo and rice straw pellets, rice straw being the other main source of biomass solid fuel in China. All physical properties of untreated bamboo pellets (UBP), untreated rice straw pellets (URP), carbonized bamboo pellets (CBP), and carbonized rice straw...

Encapsulation of thermal energy storage media

DOEpatents

Dhau, Jaspreet; Goswami, Dharendra; Jotshi, Chand K.; Stefanakos, Elias K.

2017-09-19

In one embodiment, a phase change material is encapsulated by forming a phase change material pellet, coating the pellet with flexible material, heating the coated pellet to melt the phase change material, wherein the phase change materials expands and air within the pellet diffuses out through the flexible material, and cooling the coated pellet to solidify the phase change material.

Annular mode changes in the CMIP5 simulations

NASA Astrophysics Data System (ADS)

Gillett, N. P.; Fyfe, J. C.

2013-03-01

We investigate simulated changes in the annular modes in historical and RCP 4.5 scenario simulations of 37 models from the fifth Coupled Model Intercomparison Project (CMIP5), a much larger ensemble of models than has previously been used to investigate annular mode trends, with improved resolution and forcings. The CMIP5 models on average simulate increases in the Northern Annular Mode (NAM) and Southern Annular Mode (SAM) in every season by 2100, and no CMIP5 model simulates a significant decrease in either the NAM or SAM in any season. No significant increase in the NAM or North Atlantic Oscillation (NAO) is simulated in response to volcanic aerosol, and no significant NAM or NAO response to solar irradiance variations is simulated. The CMIP5 models simulate a significant negative SAM response to volcanic aerosol in MAM and JJA, and a significant positive SAM response to solar irradiance variations in MAM, JJA and DJF.

Virtual cathode microwave generator having annular anode slit

DOEpatents

Kwan, Thomas J. T.; Snell, Charles M.

1988-01-01

A microwave generator is provided for generating microwaves substantially from virtual cathode oscillation. Electrons are emitted from a cathode and accelerated to an anode which is spaced apart from the cathode. The anode has an annular slit therethrough effective to form the virtual cathode. The anode is at least one range thickness relative to electrons reflecting from the virtual cathode. A magnet is provided to produce an optimum magnetic field having the field strength effective to form an annular beam from the emitted electrons in substantial alignment with the annular anode slit. The magnetic field, however, does permit the reflected electrons to axially diverge from the annular beam. The reflected electrons are absorbed by the anode in returning to the real cathode, such that substantially no reflexing electrons occur. The resulting microwaves are produced with a single dominant mode and are substantially monochromatic relative to conventional virtual cathode microwave generators.

Principle of radial transport in low temperature annular plasmas

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

Zhang, Yunchao, E-mail: yunchao.zhang@anu.edu.au; Charles, Christine; Boswell, Rod

2015-07-15

Radial transport in low temperature annular plasmas is investigated theoretically in this paper. The electrons are assumed to be in quasi-equilibrium due to their high temperature and light inertial mass. The ions are not in equilibrium and their transport is analyzed in three different situations: a low electric field (LEF) model, an intermediate electric field (IEF) model, and a high electric field (HEF) model. The universal IEF model smoothly connects the LEF and HEF models at their respective electric field strength limits and gives more accurate results of the ion mobility coefficient and effective ion temperature over the entire electricmore » field strength range. Annular modelling is applied to an argon plasma and numerical results of the density peak position, the annular boundary loss coefficient and the electron temperature are given as functions of the annular geometry ratio and Paschen number.« less

Radiation Effects on the Thermodiffusive Instability of Premixed Flames on a Cylindrical Porous Flame Holder

NASA Astrophysics Data System (ADS)

Du, Minglong; Yang, Lijun

2017-10-01

A linear analysis method was used to investigate the mechanics of radiation heat loss and mass transfer in the porous wall of premixed annular flames and their effect on thermodiffusive instability. The dispersion relation between the disturbance wave growth rate and wavenumber was calculated numerically. Results showed that radiation heat loss elevated the annular flame slightly away from the porous wall. In the annular flame with small Lewis numbers, radiation heat loss changed the thermodiffusive instability from a pulsating to a cellular state, while for the large Lewis numbers, only the pulsating instability was represented. Increasing radiation heat loss and the radius of the porous wall enhanced the instability of the annular flames. Heat losses decreased with the continued increase in thickness of the porous wall and the decrease in porosity. Annular flames with long-wave mode along the angular direction were more unstable than the shortwave mode.

Assessment of microplastic toxicity to embryonic development of the sea urchin Lytechinus variegatus (Echinodermata: Echinoidea).

PubMed

Nobre, C R; Santana, M F M; Maluf, A; Cortez, F S; Cesar, A; Pereira, C D S; Turra, A

2015-03-15

Apart from the physiological impacts on marine organisms caused by ingesting microplastics, the toxicity caused by substances leaching from these particles into the environment requires investigation. To understand this potential risk, we evaluated the toxicity of virgin (raw) and beach-stranded plastic pellets to the development of embryos of Lytechinus variegatus, simulating transfers of chemical compounds to interstitial water and water column by assays of pellet-water interface and elutriate, respectively. Both assays showed that virgin pellets had toxic effects, increasing anomalous embryonic development by 58.1% and 66.5%, respectively. The toxicity of stranded pellets was lower than virgin pellets, and was observed only for pellet-water interface assay. These results show that (i) plastic pellets act as a vector of pollutants, especially for plastic additives found on virgin particles; and that (ii) the toxicity of leached chemicals from pellets depends on the exposure pathway and on the environmental compartment in which pellets accumulate. Copyright © 2015 Elsevier Ltd. All rights reserved.

Immobilization of an L-aminoacylase-producing strain of Aspergillus oryzae into gelatin pellets and its application in the resolution of D,L-methionine.

PubMed

Yuan Yj, Ying-jin; Wang Sh, Shu-hao; Song Zx, Zheng-xiao; Gao Rc, Rui-chang

2002-04-01

The conditions for immobilization of an l-aminoacylase-producing strain of Aspergillus oryzae in gelatin and the enzymic characteristics of the immobilized pellets were studied. The optimal concentrations of gelatin, glutaraldehyde and ethyldiamine and time of immobilization were determined. Scanning electron micrographs reveal the cross-linked structure differences between the native and immobilized pellets. Optimum pH and temperature of the native and immobilized pellets were determined. Effects of ionic strength and substrate concentration on relative activity of the native and immobilized pellets were investigated in detail. The immobilized pellets were more stable over broader temperature and pH ranges. In addition, the immobilized pellets showed stable activity under operational and storage conditions. The immobilized pellets lost about 20% of their initial activity after five cycles of reuse. The results reported in this paper show the potential for using the immobilized A. oryzae pellets to resolve d,l-methionine.

Co-combustion of anthracite coal and wood pellets: Thermodynamic analysis, combustion efficiency, pollutant emissions and ash slagging.

PubMed

Guo, Feihong; Zhong, Zhaoping

2018-08-01

This work presents studies on the co-combustion of anthracite coal and wood pellets in fluidized bed. Prior to the fluidized bed combustion, thermogravimetric analysis are performed to investigate the thermodynamic behavior of coal and wood pellets. The results show that the thermal decomposition of blends is divided into four stages. The co-firing of coal and wood pellets can promote the combustion reaction and reduce the emission of gaseous pollutants, such as SO 2 and NO. It is important to choose the proportion of wood pellets during co-combustion due to the low combustion efficiency caused by large pellets with poor fluidization. Wood pellets can inhibit the volatilization of trace elements, especially for Cr, Ni and V. In addition, the slagging ratio of wood pellets ash is reduced by co-firing with coal. The research on combustion of coal and wood pellets is of great significance in engineering. Copyright © 2018 Elsevier Ltd. All rights reserved.

A data mining approach to optimize pellets manufacturing process based on a decision tree algorithm.

PubMed

Ronowicz, Joanna; Thommes, Markus; Kleinebudde, Peter; Krysiński, Jerzy

2015-06-20

The present study is focused on the thorough analysis of cause-effect relationships between pellet formulation characteristics (pellet composition as well as process parameters) and the selected quality attribute of the final product. The shape using the aspect ratio value expressed the quality of pellets. A data matrix for chemometric analysis consisted of 224 pellet formulations performed by means of eight different active pharmaceutical ingredients and several various excipients, using different extrusion/spheronization process conditions. The data set contained 14 input variables (both formulation and process variables) and one output variable (pellet aspect ratio). A tree regression algorithm consistent with the Quality by Design concept was applied to obtain deeper understanding and knowledge of formulation and process parameters affecting the final pellet sphericity. The clear interpretable set of decision rules were generated. The spehronization speed, spheronization time, number of holes and water content of extrudate have been recognized as the key factors influencing pellet aspect ratio. The most spherical pellets were achieved by using a large number of holes during extrusion, a high spheronizer speed and longer time of spheronization. The described data mining approach enhances knowledge about pelletization process and simultaneously facilitates searching for the optimal process conditions which are necessary to achieve ideal spherical pellets, resulting in good flow characteristics. This data mining approach can be taken into consideration by industrial formulation scientists to support rational decision making in the field of pellets technology. Copyright © 2015 Elsevier B.V. All rights reserved.

Starlight: A stationary inertial-confinement-fusion reactor with nonvaporizing walls

NASA Astrophysics Data System (ADS)

Pitts, John H.

1989-09-01

The Starlight concept for an inertial-confinement-fusion (ICF) reactor utilizes a softball-sized solid-lithium x ray and debris shield that surrounds each fuel pellet as it is injected into the reactor. The shield is sacrificial and vaporizes as it absorbs x ray and ion-debris energy emanating from the fusion reactions in the fuel pellets. However, the energy deposition time at the surface if the first wall is lengthened by four orders of magnitude (to greater than 100 microns) which allows the energy to be conducted into the wall fast enough to prevent vaporization. Starlight operates at 5 Hz with 300-MJ-yield fuel pellets. It features a stationary, nonvaporizing first wall that eliminates erosion and shock waves which can destroy the wall; also, it allows arbitrary fuel pellet illumination geometries so that efficient coupling of either laser or heavy ion beam driver energy to the fuel pellet can be achieved. When neutrons penetrate the shield, the wall experiences neutron damage that limits its lifetime. Hence, we must choose wall materials that have ab economic lifetime. We describe the general concept and a specific design for laser drivers using a 6-m-radius, 2 1/4 Cr 1 Mo steel first wall. We include heat transfer calculations used to establish the radius and structural analysis that shows stresses are within allowable limits. A wall lifetime of over six years is predicted.

Extraction of Organochlorine Pesticides from Plastic Pellets and Plastic Type Analysis.

PubMed

Pflieger, Marilyne; Makorič, Petra; Kovač Viršek, Manca; Koren, Špela

2017-07-01

Plastic resin pellets, categorized as microplastics (≤5 mm in diameter), are small granules that can be unintentionally released to the environment during manufacturing and transport. Because of their environmental persistence, they are widely distributed in the oceans and on beaches all over the world. They can act as a vector of potentially toxic organic compounds (e.g., polychlorinated biphenyls) and might consequently negatively affect marine organisms. Their possible impacts along the food chain are not yet well understood. In order to assess the hazards associated with the occurrence of plastic pellets in the marine environment, it is necessary to develop methodologies that allow for rapid determination of associated organic contaminant levels. The present protocol describes the different steps required for sampling resin pellets, analyzing adsorbed organochlorine pesticides (OCPs) and identifying the plastic type. The focus is on the extraction of OCPs from plastic pellets by means of a pressurized fluid extractor (PFE) and on the polymer chemical analysis applying Fourier Transform-InfraRed (FT-IR) spectroscopy. The developed methodology focuses on 11 OCPs and related compounds, including dichlorodiphenyltrichloroethane (DDT) and its two main metabolites, lindane and two production isomers, as well as the two biologically active isomers of technical endosulfan. This protocol constitutes a simple and rapid alternative to existing methodology for evaluating the concentration of organic contaminants adsorbed on plastic pieces.

Modeling the effects of pelleting on the logistics of distillers grains shipping.

PubMed

Rosentrater, Kurt A; Kongar, Elif

2009-12-01

The energy security needs of energy importing nations continue to escalate. It is clear that biofuels can help meet some of the increasing need for energy. Theoretically, these can be produced from a variety of biological materials, including agricultural residues (such as corn stover and wheat straw), perennial grasses, legumes, algae, and other biological materials. Currently, however, the most heavily utilized material is corn starch. Industrial fuel ethanol production in the US primarily uses corn, because it is readily converted into fuel at a relatively low cost compared to other biomass sources. The production of corn-based ethanol in the US is dramatically increasing. As the industry continues to grow, the amount of byproducts and coproducts also increases. At the moment, the nonfermentable residues (which are dried and sold as distillers dried grains with solubles--DDGS) are utilized only as livestock feed. The sale of coproducts provides ethanol processors with a substantial revenue source and significantly increases the profitability of the production process. Even though these materials are used to feed animals in local markets, as the size and scope of the industry continues to grow, the need to ship large quantities of coproducts grows as well. This includes both domestic as well as international transportation. Value-added processing options offer the potential to increase the sustainability of each ethanol plant, and thus the industry overall. However, implementation of new technologies will be dependent upon how their costs interact with current processing costs and the logistics of coproduct deliveries. The objective of this study was to examine some of these issues by developing a computer model to determine potential cost ramifications of using various alternative technologies during ethanol processing. This paper focuses specifically on adding a densification unit operation (i.e., pelleting) to produce value-added DDGS at a fuel ethanol manufacturing plant. We have examined the economic implications of pelleting DDGS for varying DDGS production rates (100-1000 tons/d) and pelleting rates (0-100%), for a series of DDGS sales prices ($50-$200/ton). As the proportion of pelleting increases, the cost of transporting DDGS to distant markets drastically declines, because the rail cars can be filled to capacity. For example, at a DDGS sales price of $50/ton, 100% pelleting will reduce shipping costs (both direct and indirect) by 89% compared to shipping the DDGS in bulk form (i.e., no pelleting), whereas at a DDGS sales price of $200/ton, it will reduce costs by over 96%. It is clear that the sustainability of the ethanol industry can be improved by implementing pelleting technology for the coproducts, especially at those plants that ship their DDGS via rail.

A curious pellet from a great horned owl (Bubo virginianus)

USGS Publications Warehouse

Woodman, N.; Dove, C.J.; Peurach, S.C.

2005-01-01

One of the traditional methods of determining the dietary preferences of owls relies upon the identification of bony remains of prey contained in regurgitated pellets. Discovery of a pellet containing a large, complete primary feather from an adult, male Ring-necked Pheasant (Phasianus colchicus) prompted us to examine in detail a small sample of pellets from a Great Horned Owl (Bubo virginianus). Our analyses of feather and hair remains in these pellets documented the presence of three species of birds and two species of mammals, whereas bones in the pellets represented only mammals. This finding indicates an important bias that challenges the reliability of owl pellet studies making use of only osteological remains.

Annular-Cross-Section CFE Chamber

NASA Technical Reports Server (NTRS)

Sharnez, Rizwan; Sammons, David W.

1994-01-01

Proposed continuous-flow-electrophoresis (CFE) chamber of annular cross section offers advantages over conventional CFE chamber, and wedge-cross-section chamber described in "Increasing Sensitivity in Continuous-Flow Electrophoresis" (MFS-26176). In comparison with wedge-shaped chamber, chamber of annular cross section virtually eliminates such wall effects as electro-osmosis and transverse gradients of velocity. Sensitivity enhanced by incorporating gradient maker and radial (collateral) flow.

Supersonic coal water slurry fuel atomizer

DOEpatents

Becker, Frederick E.; Smolensky, Leo A.; Balsavich, John

1991-01-01

A supersonic coal water slurry atomizer utilizing supersonic gas velocities to atomize coal water slurry is provided wherein atomization occurs externally of the atomizer. The atomizer has a central tube defining a coal water slurry passageway surrounded by an annular sleeve defining an annular passageway for gas. A converging/diverging section is provided for accelerating gas in the annular passageway to supersonic velocities.

Phase-locking of annular-combination CO2 laser

NASA Astrophysics Data System (ADS)

Qi, Tingxiang; Chen, Mei; Zhang, Rongzhu; Xiao, Qianyi

2015-07-01

A new annular-combination resonator structure adopting the external-injection phase-locking technology is presented theoretically for that the beam quality of stable annular resonator is not satisfying. The phase-locking principle and feasibility are characterized by energy density of injection beam and coupling coefficient. Based on the diffraction theory, output mode of the resonator with phase-locking is deduced and simulated. Results also confirm that injection beam have a good control effect on output mode. The intensity distributions of output beam are studied briefly and indicate that this new resonator which is adaptable to annular gain media can produce high-power laser beam with high quality.

Characterization of annular two-phase gas-liquid flows in microgravity

NASA Technical Reports Server (NTRS)

Bousman, W. Scott; Mcquillen, John B.

1994-01-01

A series of two-phase gas-liquid flow experiments were developed to study annular flows in microgravity using the NASA Lewis Learjet. A test section was built to measure the liquid film thickness around the perimeter of the tube permitting the three dimensional nature of the gas-liquid interface to be observed. A second test section was used to measure the film thickness, pressure drop and wall shear stress in annular microgravity two-phase flows. Three liquids were studied to determine the effects of liquid viscosity and surface tension. The result of this study provide insight into the wave characteristics, pressure drop and droplet entrainment in microgravity annular flows.

Measuring Orbital Angular Momentum (OAM) States of Vortex Beams with Annular Gratings

PubMed Central

Zheng, Shuang; Wang, Jian

2017-01-01

Measuring orbital angular momentum (OAM) states of vortex beams is of great importance in diverse applications employing OAM-carrying vortex beams. We present a simple and efficient scheme to measure OAM states (i.e. topological charge values) of vortex beams with annular gratings. The magnitude of the topological charge value is determined by the number of dark fringes after diffraction, and the sign of the topological charge value is distinguished by the orientation of the diffraction pattern. We first theoretically study the diffraction patterns using both annular amplitude and phase gratings. The annular phase grating shows almost 10-dB better diffraction efficiency compared to the annular amplitude grating. We then experimentally demonstrate the OAM states measurement of vortex beams using annular phase grating. The scheme works well even for high-order vortex beams with topological charge value as high as ± 25. We also experimentally show the evolution of diffraction patterns when slightly changing the fractional topological charge value of vortex beam from 0.1 to 1.0. In addition, the proposed scheme shows potential large tolerance of beam alignment during the OAM states measurement of vortex beams. PMID:28094325

Measuring Orbital Angular Momentum (OAM) States of Vortex Beams with Annular Gratings.

PubMed

Zheng, Shuang; Wang, Jian

2017-01-17

Measuring orbital angular momentum (OAM) states of vortex beams is of great importance in diverse applications employing OAM-carrying vortex beams. We present a simple and efficient scheme to measure OAM states (i.e. topological charge values) of vortex beams with annular gratings. The magnitude of the topological charge value is determined by the number of dark fringes after diffraction, and the sign of the topological charge value is distinguished by the orientation of the diffraction pattern. We first theoretically study the diffraction patterns using both annular amplitude and phase gratings. The annular phase grating shows almost 10-dB better diffraction efficiency compared to the annular amplitude grating. We then experimentally demonstrate the OAM states measurement of vortex beams using annular phase grating. The scheme works well even for high-order vortex beams with topological charge value as high as ± 25. We also experimentally show the evolution of diffraction patterns when slightly changing the fractional topological charge value of vortex beam from 0.1 to 1.0. In addition, the proposed scheme shows potential large tolerance of beam alignment during the OAM states measurement of vortex beams.

Ultrasonographic assessment of the proximal digital annular ligament in the equine forelimb.

PubMed

Dik, K J; Boroffka, S; Stolk, P

1994-01-01

Ultrasonography was used with 6 normal cadaver forelimbs of Dutch Warmblood horses to delineate the ultrasonographic anatomy of the palmar pastern region, with emphasis on the proximal digital annular ligament. Using a 5.5 MHz sector scanner, the thin proximal digital annular ligament was not visible on offset sonograms. Only if the digital sheath in the normal limb was distended was the distal border of this ligament outlined. In all normal limbs the palmarodistal thickness of the combined skin-proximal digital annular ligament layer in the mid-pastern region was 2 mm. The flexor tendons and distal sesamoidean ligaments were easily identified as hyperechoic structures. Distension of the digital sheath in the normal limbs clearly outlined the anechoic digital sheath pouches. In 4 lame horses ultrasonography aided the diagnosis of functional proximal digital annular ligament constriction. In all 4 diseased forelimbs ultrasonography demonstrated thickening of the skin-proximal digital annular ligament layer and distension of the digital sheath. In one of these limbs the distended digital sheath was also thickened. The flexor tendons and distal sesamoidean ligaments were normal. There was no radiographic evidence of additional bone or joint lesions.

Development of Impregnated Agglomerate Pelletization (IAP) process for fabrication of (Th,U)O 2 mixed oxide pellets

NASA Astrophysics Data System (ADS)

Khot, P. M.; Nehete, Y. G.; Fulzele, A. K.; Baghra, Chetan; Mishra, A. K.; Afzal, Mohd.; Panakkal, J. P.; Kamath, H. S.

2012-01-01

Impregnated Agglomerate Pelletization (IAP) technique has been developed at Advanced Fuel Fabrication Facility (AFFF), BARC, Tarapur, for manufacturing (Th, 233U)O 2 mixed oxide fuel pellets, which are remotely fabricated in hot cell or shielded glove box facilities to reduce man-rem problem associated with 232U daughter radionuclides. This technique is being investigated to fabricate the fuel for Indian Advanced Heavy Water Reactor (AHWR). In the IAP process, ThO 2 is converted to free flowing spheroids by powder extrusion route in an unshielded facility which are then coated with uranyl nitrate solution in a shielded facility. The dried coated agglomerate is finally compacted and then sintered in oxidizing/reducing atmosphere to obtain high density (Th,U)O 2 pellets. In this study, fabrication of (Th,U)O 2 mixed oxide pellets containing 3-5 wt.% UO 2 was carried out by IAP process. The pellets obtained were characterized using optical microscopy, XRD and alpha autoradiography. The results obtained were compared with the results for the pellets fabricated by other routes such as Coated Agglomerate Pelletization (CAP) and Powder Oxide Pelletization (POP) route.

Effective adsorption of phosphate from wastewaters by big composite pellets made of reduced steel slag and iron ore concentrate.

PubMed

Wang, Hongjuan; Shen, Shaobo; Liu, Longhui; Ji, Yilong; Wang, Fuming

2015-01-01

In order to remove phosphate from wastewater, a large plastic adsorption column filled with big phosphate-adsorbing pellets with diameters of 10 mm, heated by electromagnetic induction coils, was conceived. It was found that the prepared big pellets, which were made of reduced steel slag and iron ore concentrate, contain magnetic Fe and Fe3O4. The thermodynamics and kinetics of adsorption of phosphate from synthetic wastewaters on the pellets were studied in this work. The phosphate adsorption on the pellets followed three models of Freundlich, Langmuir and Dubinin-Kaganer-Radushkevick. The maximum phosphate adsorption capacity Qmax of the pellets were 2.46, 2.74 and 2.77 mg/g for the three temperatures of 20°C, 30°C and 40°C, respectively, based on the Langmuir model. The apparent adsorption energies were -12.9 kJ/mol for the three temperatures. It implied that ion exchange was the main mechanism involved in the adsorption processes. The adsorbed phosphate existed on the pellet surface mainly in the form of Fe3(PO4)2. A reduction pre-treatment of the pellet precursor with H2 greatly enhanced pellet adsorption for phosphate. The adsorption kinetics is better represented by a pseudo-first-order model. The adsorbed phosphate amounts were similar for both real and synthetic wastewaters under similar adsorption conditions. The percentage of adsorbed phosphate for a real wastewater increased with increasing pellet concentration and reached 99.2% at a pellet concentration of 64 (g/L). Some specific phosphate adsorption mechanisms for the pellets were revealed and the pellets showed the potential to efficiently adsorb phosphate from a huge amount of real wastewaters in an industrial scale.

Mounting for ceramic scroll

DOEpatents

Petty, Jack D.

1993-01-01

A mounting for a ceramic scroll on a metal engine block of a gas turbine engine includes a first ceramic ring and a pair of cross key connections between the first ceramic ring, the ceramic scroll, and the engine block. The cross key connections support the scroll on the engine block independent of relative radial thermal growth and for bodily movement toward an annular mounting shoulder on the engine. The scroll has an uninterrupted annular shoulder facing the mounting shoulder on the engine block. A second ceramic ring is captured between mounting shoulder and the uninterrupted shoulder on the scroll when the latter is bodily shifted toward the mouting shoulder to define a gas seal between the scroll and the engine block.

Atomic bonding effects in annular dark field scanning transmission electron microscopy. II. Experiments

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

Odlyzko, Michael L.; Held, Jacob T.; Mkhoyan, K. Andre, E-mail: mkhoyan@umn.edu

2016-07-15

Quantitatively calibrated annular dark field scanning transmission electron microscopy (ADF-STEM) imaging experiments were compared to frozen phonon multislice simulations adapted to include chemical bonding effects. Having carefully matched simulation parameters to experimental conditions, a depth-dependent bonding effect was observed for high-angle ADF-STEM imaging of aluminum nitride. This result is explained by computational predictions, systematically examined in the preceding portion of this study, showing the propagation of the converged STEM beam to be highly sensitive to net interatomic charge transfer. Thus, although uncertainties in experimental conditions and simulation accuracy remain, the computationally predicted experimental bonding effect withstands the experimental testing reportedmore » here.« less

Oral vaccination of brushtail possums with BCG: Investigation into factors that may influence vaccine efficacy and determination of duration of protection.

PubMed

Buddle, B M; Aldwell, F E; Keen, D L; Parlane, N A; Hamel, K L; de Lisle, G W

2006-10-01

To determine factors that may influence the efficacy of an oral pelleted vaccine containing Mycobacterium bovis bacille Calmette-Guérin (BCG) to induce protection of brushtail possums against tuberculosis. To determine the duration of protective immunity following oral administration of BCG. In Study 1, a group of possums (n=7) was immunised by feeding 10 pellets containing dead Pasteur BCG, followed 15 weeks later with a single pellet of live Pasteur BCG. At that time, four other groups of possums (n=7 per group) were given a single pellet of live Pasteur BCG orally, a single pellet of live Danish BCG orally, 10 pellets of live Pasteur BCG orally, or a subcutaneous injection of live Pasteur BCG. For the oral pelleted vaccines, BCG was formulated into a lipid matrix, and each pellet contained approximately 107 colony forming units (cfu) of BCG, while the vaccine injected subcutaneously contained 106 cfu of BCG. A sixth, non-vaccinated, group (n=7) served as a control. All possums were challenged by the aerosol route with a low dose of virulent M. bovis 7 weeks after vaccination, and killed 7-8 weeks after challenge. Protection against challenge with M. bovis was assessed from pathological and bacteriological findings. In Study 2, lipid-formulated live Danish BCG was administered orally to three groups of possums (10-11 per group), and these possums were challenged with virulent M. bovis 8, 29 or 54 weeks later. The possums were killed 7 weeks after challenge, to assess protection in comparison to a non-vaccinated group. The results from Study 1 showed that vaccine efficacy was not adversely affected by feeding dead BCG prior to live BCG. Feeding 10 vaccine pellets induced a level of protection similar to feeding a single pellet. Protection was similar when feeding possums a single pellet containing the Pasteur or Danish strains of BCG. All vaccinated groups had significantly reduced pathological changes or bacterial counts when compared to the non-vaccinated group. In Study 2, oral administration of Danish BCG induced protection against challenge with M. bovis, which persisted for at least 54 weeks after vaccination. Some protection was observed in possums challenged 54 weeks after vaccination, but this protection was significantly less than that observed in groups vaccinated 29 or 8 weeks prior to challenge. There was a strong relationship between the proportion of animals producing positive lymphocyte proliferation responses to M. bovis antigens and protection against challenge with M. bovis. Factors considered potentially capable of interfering with vaccination, including feeding dead BCG to possums prior to feeding live BCG, feeding multiple doses of BCG at one time, and changing strains of BCG, were shown not to interfere with the acquisition of protective immune responses in possums. Protection against tuberculosis was undiminished up to 29 weeks after vaccination with BCG administered orally. It is concluded that vaccination of possums by feeding pellets containing BCG is a robust and efficient approach to enhance the resistance of these animals to tuberculosis.

Fusion welding process

DOEpatents

Thomas, Kenneth C.; Jones, Eric D.; McBride, Marvin A.

1983-01-01

A process for the fusion welding of nickel alloy steel members wherein a ferrite containing pellet is inserted into a cavity in one member and melted by a welding torch. The resulting weld nugget, a fusion of the nickel containing alloy from the members to be welded and the pellet, has a composition which is sufficiently low in nickel content such that ferrite phases occur within the weld nugget, resulting in improved weld properties. The steel alloys encompassed also include alloys containing carbon and manganese, considered nickel equivalents.

Engineered Structured Sorbents for the Adsorption of Carbon Dioxide and Water Vapor from Manned Spacecraft Atmospheres: Applications and Testing 2008/2009

NASA Technical Reports Server (NTRS)

Howard, David F.; Perry, Jay L.; Knox, James C.; Junaedi, Christian

2009-01-01

This paper describes efforts to improve on typical packed beds of sorbent pellets by making use of structured sorbents and alternate bed configurations to improve system efficiency and reliability. The benefits of the alternate configurations include increased structural stability gained by eliminating clay bound zeolite pellets that tend to fluidize and erode, and better thermal control during sorption to increase process efficiency. Test results that demonstrate such improvements are described and presented.

Pellet imaging techniques in the ASDEX tokamak

NASA Astrophysics Data System (ADS)

Wurden, G. A.; Büchl, K.; Hofmann, J.; Lang, R.; Loch, R.; Rudyj, A.; Sandmann, W.

1990-11-01

As part of a USDOE/ASDEX collaboration, a detailed examination of pellet ablation in ASDEX with a variety of diagnostics has allowed a better understanding of a number of features of hydrogen ice pellet ablation in a plasma. In particular, fast-gated photos with an intensified Xybion CCD video camera allow in situ velocity measurements of the pellet as it penetrates the plasma. With time resolution of typically 100 ns and exposures every 50 μs, the evolution of each pellet in a multipellet ASDEX tokamak plasma discharge can be followed. When the pellet cloud track has striations, the light intensity profile through the cloud is hollow (dark near the pellet), whereas at the beginning or near the end of the pellet trajectory the track is typically smooth (without striations) and has a gaussian-peaked light emission profile. New, single pellet Stark broadened Dα, Dβ, and Dγ spectra, obtained with a tangentially viewing scanning mirror/spectrometer with Reticon array readout, are consistent with cloud densities of 2×1017 cm-3 or higher in the regions of strongest light emission. A spatially resolved array of Dα detectors shows that the light variations during the pellet ablation are not caused solely by a modulation of the incoming energy flux as the pellet crosses rational q surfaces, but instead are a result of dynamic, nonstationary, ablation process.

Pellet imaging techniques in the ASDEX tokamak (abstract)

NASA Astrophysics Data System (ADS)

Wurden, G. A.; Büchl, K.; Hofmann, J.; Lang, R.; Loch, R.; Rudyj, A.; Sandmann, W.

1990-10-01

As part of a USDOE/ASDEX collaboration, a detailed examination of pellet ablation in ASDEX with a variety of diagnostics has allowed a better understanding of a number of features of hydrogen ice pellet ablation in a plasma. In particular, fast-gated photos with an intensified Xybion CCD video camera allow in situ velocity measurements of the pellet as it penetrates the plasma. With time resolution of typically 100 ns and exposures every 50 μs, the evolution of each pellet in a multipellet ASDEX tokamak plasma discharge can be followed. When the pellet cloud track has striations, the light intensity profile through the cloud is hollow (dark near the pellet), whereas at the beginning or near the end of the pellet trajectory the track is typically smooth (without striations) and has a gaussian-peaked light emission profile. New, single pellet Stark broadened Dα, Dβ, and Dγ spectra, obtained with a tangentially viewing scanning mirror/spectrometer with Reticon array readout, are consistent with cloud densities of 2×1017 cm-3 or higher in the regions of strongest light emission. A spatially resolved array of Dα detectors shows that the light variations during the pellet ablation are not caused solely by a modulation of the incoming energy flux as the pellet crosses rational q surfaces, but instead are a result of dynamic, nonstationary, ablation process.

Influences on particle shape in underwater pelletizing processes

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

Kast, O., E-mail: oliver.kast@ikt.uni-stuttgart.de, E-mail: matthias.musialek@ikt.uni-stuttgart.de, E-mail: kalman.geiger@ikt.uni-stuttgart.de, E-mail: christian.bonten@ikt.uni-stuttgart.de; Musialek, M., E-mail: oliver.kast@ikt.uni-stuttgart.de, E-mail: matthias.musialek@ikt.uni-stuttgart.de, E-mail: kalman.geiger@ikt.uni-stuttgart.de, E-mail: christian.bonten@ikt.uni-stuttgart.de; Geiger, K., E-mail: oliver.kast@ikt.uni-stuttgart.de, E-mail: matthias.musialek@ikt.uni-stuttgart.de, E-mail: kalman.geiger@ikt.uni-stuttgart.de, E-mail: christian.bonten@ikt.uni-stuttgart.de

2014-05-15

Underwater pelletizing has gained high importance within the last years among the different pelletizing technologies, due to its advantages in terms of throughput, automation, pellet quality and applicability to a large variety of thermoplastics. The resulting shape and quality of pellets, however, differ widely, depending on material characteristics and effects not fully understood yet. In an experimental set-up, pellets of different volumes and shapes were produced and the medium pellet mass, the pellet surface and the bulk density were analyzed in order to identify the influence of material properties and process parameters. Additionally, the shaping kinetics at the die openingmore » were watched with a specially developed camera system. It was found that rheological material properties correlate with process parameters and resulting particle form in a complex way. Higher cutting speeds were shown to have a deforming influence on the pellets, leading to less spherical s and lower bulk densities. More viscous materials, however, showed a better resistance against this. Generally, the viscous properties of polypropylene proofed to be dominant over the elastic ones in regard to their influence on pellet shape. It was also shown that the shapes filmed at the die opening and the actual form of the pellets after a cooling track do not always correlate, indicating a significant influence of thermodynamic properties during the cooling.« less

Mycelial pellet formation by edible ascomycete filamentous fungi, Neurospora intermedia.

PubMed

Nair, Ramkumar B; Lennartsson, Patrik R; Taherzadeh, Mohammad J

2016-12-01

Pellet formation of filamentous fungi in submerged culture is an imperative topic of fermentation research. In this study, we report for the first time the growth of filamentous ascomycete fungus, Neurospora intermedia in its mycelial pellet form. In submerged culture, the growth morphology of the fungus was successfully manipulated into growing as pellets by modifying various cultivation conditions. Factors such as pH (2.0-10.0), agitation rate (100-150 rpm), carbon source (glucose, arabinose, sucrose, and galactose), the presence of additive agents (glycerol and calcium chloride) and trace metals were investigated for their effect on the pellet formation. Of the various factors screened, uniform pellets were formed only at pH range 3.0-4.0, signifying it as the most influential factor for N. intermedia pellet formation. The average pellet size ranged from 2.38 ± 0.12 to 2.86 ± 0.38 mm. The pellet formation remained unaffected by the inoculum type used and its size showed an inverse correlation with the agitation rate of the culture. Efficient glucose utilization was observed with fungal pellets, as opposed to the freely suspended mycelium, proving its viability for fast-fermentation processes. Scale up of the pelletization process was also carried out in bench-scale airlift and bubble column reactors (4.5 L).

The effect of sodium alginate on physical and dissolution properties of Surelease-matrix pellets prepared by a novel pelletizer.

PubMed

Kim, Min-Soo; Kim, Jeong-Soo; Hwang, Sung-Joo

2007-11-01

The aim of this study was to investigate the effect of sodium alginate on the physical and dissolution properties of Surelease-matrix pellets prepared by a novel pelletizer-equipped piston extruder and double-arm counter-rotating rollers. The mean values of the shape factor (e(R)) and the aspect ratio of Surelease-matrix pellets were 0.615-0.625 and 1.06-1.070, respectively, indicating good sphericity of the pellets. The drug release rate increased as the amount of sodium alginate increased due to hydration, swelling, and erosion within the Surelease-matrix pellets. In addition, the porosity of pellets also increased with increasing sodium alginate content. The results of this study show that sodium alginate has a greater effect on the drug release rate than the drug release mechanism within the Surelease-matrix for sparingly water-soluble drug, such as tamsulosin hydrochloride.

Experimental Study on Application of Boron Mud Secondary Resource to Oxidized Pellets Production

NASA Astrophysics Data System (ADS)

Fu, Xiao-Jiao; Chu, Man-Sheng; Zhao, Jia-Qi; Chen, Shuang-Yin; Liu, Zheng-Gen; Wang, Si-Yuan

2017-07-01

In order to realize comprehensive and massive treatment of boron mud secondary resource, fundamental study on boron mud applied to oxidized pellets production as additive was carried out in the paper under laboratory conditions. The effects of boron mud on the performance of oxidized pellets were investigated systemically, and boron mud was combined with other boron-rich material innovatively. The results showed that, within certain limits, boron mud can improve properties of oxidized pellets. The bentonite content decreased to 0.3 % when adding 1.0 % boron mud additive and the pellets met blast furnace requirements. With the combination additive content 0.8 %, bentonite content can be further decreased to 0.2 %, and the pellets properties were better than base pellet. Therefore, it was an effective way to reduce environmental pollution and optimize blast furnace operation by developing boron mud secondary resource as pellets additive.

[Distribution and origin of plastic resin pellets as environmental pollutants at the East China Sea area].

PubMed

Kaminuma, T; Ohtake, C; Kabuyama, N

2000-01-01

Plastic debris are important marine pollutants. Plastic debris consist of resin pellets and waste plastics. We are particularly interested in resin pellets. We made field survey of resin pellets at nearly 400 sites in 200 beaches in Japan and neighboring countries. The pellets were found at all most all Japan coasts we surveyed and at some beaches of Macao, Hong Kong, Xiamen, the north of Taipei, and Cheju Island in Korea. The number of pellets was more than 1000 pieces per m2 on the most abundant beach in Japan. Through further analysis using GC/ECD, endocrine disrupting chemicals, PCBs, DDTs, HCHs and Nonylphenol were detected in selected samples. Biota such as Bryozoa were observed on the surface of pellets washed up on the beaches in subtropical areas. Pellets has been suspected to affect wildlife and human health, but we have no report on affection to human.

Grid Effects on LES Thermo-Acoustic Limit-Cycle of a Full Annular Aeronautical Engine

NASA Astrophysics Data System (ADS)

Wolf, Pierre; Gicquel, Laurent Y. M.; Staffelbach, Gabriel; Poinsot, Thierry

Recent developments in large scale computer architectures allow Large Eddy Simulation (LES) to be considered for the prediction of turbulent reacting flows in geometries encountered in industry. To do so, various difficulties must be overcome and the first one is to ensure that proper meshes can be used for LES. Indeed, the quality of meshes is known to be a critical factor in LES of reacting flows. This issue becomes even more crucial when LES is used to compute large configurations such as full annular combustion chambers. Various analysis of mesh effects on LES results have been published before but all are limited to single-sector computational domains. However, real annular gas-turbine engines contain ten to twenty of such sectors and LES must also be used in such full chambers for the study of ignition or azimuthal thermo-acoustic interactions. Instabilities (mostly azimuthal modes involving the full annular geometry) remain a critical issue to aeronautical or power-generation industries and LES seems to be a promising path to properly apprehend such complex unsteady couplings. Based on these observations, mesh effects on LES in a full annular gas-turbine combustion chamber (including its casing) is studied here in the context of its azimuthal thermo-acoustic response. To do so, a fully compressible, multi-species reacting LES is used on two meshes yielding two fully unsteady turbulent reacting predictions of the same configuration. The two tetrahedra meshes contain respectively 38 and 93 millions cells. Limit-cycles as obtained by the two LES are gauged against each other for various flow quantities such as mean velocity profiles, flame position and temperature fields. The thermo-acoustic limit-cycles are observed to be relatively indepedent of the grid resolution which comforts the use of LES tools to provide insights and understanding of the mechanisms triggering the coupling between the system acoustic eigenmodes and combustion.

Functional Tricuspid Regurgitation Caused by Chronic Atrial Fibrillation: A Real-Time 3-Dimensional Transesophageal Echocardiography Study.

PubMed

Utsunomiya, Hiroto; Itabashi, Yuji; Mihara, Hirotsugu; Berdejo, Javier; Kobayashi, Sayuki; Siegel, Robert J; Shiota, Takahiro

2017-01-01

Functional tricuspid regurgitation (TR) with a structurally normal tricuspid valve (TV) may occur secondary to chronic atrial fibrillation (AF). However, the clinical and echocardiographic differences according to functional TR subtypes are unclear. Therefore, characterization of functional TR because of chronic AF (AF-TR) remains undetermined. To investigate the prevalence of AF-TR, 437 patients with moderate to severe TR underwent 3-dimensional (3D) transesophageal echocardiography. TR severity was determined by the averaged vena contracta width on apical and parasternal inflow views. The prevalence of AF-TR was 9.2%, whereas that of functional TR because of left-sided heart disease was 45.3%. Clinical features of AF-TR included advanced age, female sex, greater right atrial than left atrial enlargement and lower systolic pulmonary artery pressure compared with left-sided heart disease-TR with sinus rhythm (all P<0.05). In 3D TV assessment, patients with AF-TR had a larger TV annular area with weaker annular contraction (both P<0.001) but a smaller tethering angle (P<0.001) despite a similar leaflet coaptation status compared with patients with left-sided heart disease-TR with sinus rhythm. On multivariable analysis, only the TV annular area in midsystole (coefficient, 0.059; 95% confidence interval, 0.041-0.078 per 100 mm 2 ; P<0.001) was associated with TR severity in AF-TR. The annular area was more closely correlated with the right atrial volume than right ventricular end-systolic volume in AF-TR (P<0.001). AF-TR is not rare and is associated with advanced age and right atrial enlargement. TV deformations and their association with right heart remodeling differ between AF-TR and left-sided heart disease-TR. Our results suggest that in patients with TR secondary to AF, TV annuloplasty should be effective because this entity has annular dilatation without leaflet deformation. © 2017 American Heart Association, Inc.

Effect of auricular pellet acupressure on antioxidative systems in high-risk diabetes mellitus.

PubMed

Liu, Chi-Feng; Yu, Lee-Fen; Lin, Chia-Hsien; Lin, Song-Chow

2008-04-01

Free radicals and lipid peroxides, both of which are easily formed in the diabetic state, play an important role in the development of diabetic complications. Antioxidative therapy may help prevent diabetic complications caused by lipoperoxidation and free-radical formation in diabetes mellitus (DM). A number of findings suggest that oxidative stress exists in persons with high-risk DM. Auricular pellet acupressure has reportedly been an effective treatment method for a variety of medical conditions, including anxiety, juvenile myopia, essential hypertension, and senile vascular dementia. However, its effects on antioxidative enzymes have not been elucidated. We therefore evaluated the impact of auricular pellet acupressure on antioxidative status in persons with high-risk DM. Our study involved 69 persons with high-risk DM, who were allocated either to undergo acupressure as active treatment for the experimental group or to a control group. The experimental group in the study received auricular pellet acupressure three times daily for 5 consecutive days. After a 2-day rest period, the procedure was performed on the contralateral ear. Acupressure was performed twice on each ear, with each application followed by its application to the contralateral ear, over a total treatment period of 20 days. The control groups did not undergo auricular pellet acupressure. At the end of the 20-day period of treatment of the experimental group, blood was collected from all of the study participants for assay of serum superoxide dismutase (SOD) and catalase concentrations, as was also done for the control group. Serum concentrations of SOD (p < 0.05) and catalase (p < 0.0001) were significantly higher in the experimental group than in the control group. Our findings suggest that auricular pellet acupressure can increase the concentration of antioxidative enzymes in persons with high-risk DM.

Development of a two-stage light gas gun to accelerate hydrogen pellets to high speeds for plasma fueling applications

NASA Astrophysics Data System (ADS)

Combs, S. K.; Milora, S. L.; Foust, C. R.; Gouge, M. J.; Fehling, D. T.; Sparks, D. O.

1988-08-01

The development of a two-stage light gas gun to accelerate hydrogen isotope pellets to high speeds is under way at Oak Ridge National Laboratory. High velocities are desirable for plasma fueling applications, since the faster pellets can penetrate more deeply into large, hot plasmas and deposit atoms of fuel directly in a larger fraction of the plasma volume. In the initial configuration of the two-stage device, a 2.2-l volume provides the gas to accelerate a 25.4-mm-diam piston in a 1-m-long pump tube; a burst disk or a fast valve initiates the acceleration process in the first stage. As the piston travels the length of the pump tube, the downstream gas is compressed (to pressures up to 2600 bar) and thus is driven to high temperature (approx. 5000 K). This provides the driving force for acceleration of a 4-mm pellet in a 1-m-long gun barrel. In preliminary tests using helium as the driver in both stages, 35-mg plastic pellets have been accelerated to speeds as high as 3.8 km/s. Projectiles composed of hydrogen ice will have a mass in the range from 5 to 20 mg. However, the use of sabots to encase and protect the cryogenic pellets from the high peak pressures will probably be required to realize speeds of approx. 3 km/s or greater. The experimental plan includes acceleration of hydrogen isotopes as soon as the gun geometry and operating parameters are optimized; theoretical models are being used to aid in this process. The hardware is being designed to accommodate repetitive operation, which is the objective of this research and is required for future applications.

Polycyclic Aromatic Hydrocarbons (PAHs) and Hopanes in Plastic Resin Pellets as Markers of Oil Pollution via International Pellet Watch Monitoring.

PubMed

Yeo, Bee Geok; Takada, Hideshige; Hosoda, Junki; Kondo, Atsuko; Yamashita, Rei; Saha, Mahua; Maes, Thomas

2017-08-01

Oil pollution in the marine environment is an unavoidable problem due to chronic input from local sources, particularly in urban areas and oil spills. Oil pollution not only causes immediate physical damages to surrounding wildlife but also some components, including higher molecular weight PAHs, can persist in the environment for many years and pose insidious threats to the ecosystem. Long-term and nontargeted monitoring of oil pollution is important. This paper examines the ability of International Pellet Watch (IPW) for initial identification and monitoring of oil pollution by analysing PAHs and hopanes in plastic pellet samples collected globally by volunteers. PAH concentrations with the sum of 28 parent and methyl PAHs vary geographically, ranging from 0.035 to 24.4 µg/g-pellet, in line with the presence or absence of local oil pollution sources, such as oil refineries or oil spill sites. This suggests that PAHs can be used to monitor petroleum pollution in IPW. A colour-coded categorization for PAH concentrations within IPW monitoring also is established to facilitate data presentation and understanding. PAH concentrations are generally higher in Western Europe, especially around the North Sea shorelines, moderate in East Asia and North America, and lower in South East Asia, Oceania, South America, and Africa. Hopane concentrations, with a smaller spatial variation (1.7-101 µg/g-pellet), showed no spatial pattern. This result and the poor correlation between hopanes and PAHs suggest that hopane concentrations alone are unsuited to identify petroleum pollution. However, hopane compositions can be used for fingerprinting sources of oil pollution. Thus, both PAHs and hopanes in IPW allow for low cost, remote monitoring of global oil pollution.

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

Tumuluru, Jaya Shankar

The quality and specific energy consumption (SEC) of the biomass pellets produced depend upon pelleting process conditions. The present study includes understanding the effect of feedstock moisture in the range of 28–38% (wet basis [w.b.]) and preheating in the range of 30–110°C at two die speeds of 40 and 60 Hz on the physical properties and SEC. A flat die pellet mill fitted with a 6 mm die was used in the present study. The physical properties of pellets such as moisture content, unit, bulk and tapped density, durability, and expansion ratio and SEC of the pelleting process are measured.more » The results indicate that the pellets produced have durability values in the range of 87–98%, and unit bulk and tapped density in the range of 670–1100, 375–575, and 420–620 kg/m³. Increasing the feedstock moisture content from 33% to 38% (w.b) decreased the unit, bulk and tapped density by about 30–40%. Increasing feedstock moisture content increased the expansion ratio and decreased the density values. A higher feedstock moisture content of 38% (w.b.) and higher preheating temperature of 110°C resulted in lower density and a higher expansion ratio, which can be attributed to flash off of moisture as the material extrudes out of the die. The SEC was in the range of 75–275 kWh/ton. Higher feedstock moisture content of 38% (w.b.) and a lower die speed of 40 Hz increased the SEC, whereas lower to medium preheating temperature (30–70°C), medium feedstock moisture content of 33% (w.b.), and a higher die speed of 60 Hz minimized the SEC to <100 kWh/ton.« less

Solar Eclipses Observed from Antarctica

NASA Astrophysics Data System (ADS)

Pasachoff, Jay M.

2013-01-01

Aspects of the solar corona are still best observed during totality of solar eclipses, and other high-resolution observations of coronal active regions can be observed with radio telescopes by differentiation of occultation observations, as we did with the Jansky Very Large Array for the annular solar eclipse of 2012 May 20 in the US. Totality crossing Antarctica included the eclipse of 2003 November 23, and will next occur on 2021 December 4; annularity crossing Antarctica included the eclipse of 2008 February 7, and will next occur on 2014 April 29. Partial phases as high as 87% coverage were visible and were imaged in Antarctica on 2011 November 25, and in addition to partial phases of the total and annular eclipses listed above, partial phases were visible in Antarctica on 2001 July 2011, 2002 December 4, 2004 April 19, 2006 September 22, 2007 September 11, and 2009 January 26, and will be visible on 2015 September 13, 2016 September 1, 2017 February 26, 2018 February 15, and 2020 December 14. On behalf of the Working Group on Solar Eclipses of the IAU, the poster showed the solar eclipses visible from Antarctica and this article shows a subset (see www.eclipses.info for the full set). A variety of investigations of the Sun and of the response of the terrestrial atmosphere and ionosphere to the abrupt solar cutoff can be carried out at the future eclipses, making the Antarctic observations scientifically useful.

Resurgence and alternative-reinforcer magnitude.

PubMed

Craig, Andrew R; Browning, Kaitlyn O; Nall, Rusty W; Marshall, Ciara M; Shahan, Timothy A

2017-03-01

Resurgence is defined as an increase in the frequency of a previously reinforced target response when an alternative source of reinforcement is suspended. Despite an extensive body of research examining factors that affect resurgence, the effects of alternative-reinforcer magnitude have not been examined. Thus, the present experiments aimed to fill this gap in the literature. In Experiment 1, rats pressed levers for single-pellet reinforcers during Phase 1. In Phase 2, target-lever pressing was extinguished, and alternative-lever pressing produced either five-pellet, one-pellet, or no alternative reinforcement. In Phase 3, alternative reinforcement was suspended to test for resurgence. Five-pellet alternative reinforcement produced faster elimination and greater resurgence of target-lever pressing than one-pellet alternative reinforcement. In Experiment 2, effects of decreasing alternative-reinforcer magnitude on resurgence were examined. Rats pressed levers and pulled chains for six-pellet reinforcers during Phases 1 and 2, respectively. In Phase 3, alternative reinforcement was decreased to three pellets for one group, one pellet for a second group, and suspended altogether for a third group. Shifting from six-pellet to one-pellet alternative reinforcement produced as much resurgence as suspending alternative reinforcement altogether, while shifting from six pellets to three pellets did not produce resurgence. These results suggest that alternative-reinforcer magnitude has effects on elimination and resurgence of target behavior that are similar to those of alternative-reinforcer rate. Thus, both suppression of target behavior during alternative reinforcement and resurgence when conditions of alternative reinforcement are altered may be related to variables that affect the value of the alternative-reinforcement source. © 2017 Society for the Experimental Analysis of Behavior.

Resurgence and Alternative-Reinforcer Magnitude

PubMed Central

Craig, Andrew R.; Browning, Kaitlyn O.; Nall, Rusty W.; Marshall, Ciara M.; Shahan, Timothy A.

2017-01-01

Resurgence is defined as an increase in the frequency of a previously reinforced target response when an alternative source of reinforcement is suspended. Despite an extensive body of research examining factors that affect resurgence, the effects of alternative-reinforcer magnitude have not been examined. Thus, the present experiments aimed to fill this gap in the literature. In Experiment 1, rats pressed levers for single-pellet reinforcers during Phase 1. In Phase 2, target-lever pressing was extinguished, and alternative-lever pressing produced either five-pellet, one-pellet, or no alternative reinforcement. In Phase 3, alternative reinforcement was suspended to test for resurgence. Five-pellet alternative reinforcement produced faster elimination and greater resurgence of target-lever pressing than one-pellet alternative reinforcement. In Experiment 2, effects of decreasing alternative-reinforcer magnitude on resurgence were examined. Rats pressed levers and pulled chains for six-pellet reinforcers during Phases 1 and 2, respectively. In Phase 3, alternative reinforcement was decreased to three pellets for one group, one pellet for a second group, and suspended altogether for a third group. Shifting from six-pellet to one-pellet alternative reinforcement produced as much resurgence as suspending alternative reinforcement altogether, while shifting from six pellets to three pellets did not produce resurgence. These results suggest that alternative-reinforcer magnitude has effects on elimination and resurgence of target behavior that are similar to those of alternative-reinforcer rate. Thus, both suppression of target behavior during alternative reinforcement and resurgence when conditions of alternative reinforcement are altered may be related to variables that affect the value of the alternative-reinforcement source. PMID:28194793

[Effects of different excipients on properties of Tongsaimai mixture and pellet molding].

PubMed

Wang, Jin; Lv, Zhiyang; Wu, Xiaoyan; Di, Liuqing; Dong, Yu; Cai, Baochang

2011-01-01

To study preliminarily on the relationship between properties of the mixture composed of Tongsaimai extract and different excipients and pellet molding. The multivariate regression analysis was used to investigate the correlation of different mixture and pellet molding by measuring the cohesion, liquid-plastic limit of mixture, and the powder properties of pellets. The weighted coefficients of the powder properties were determined by analytic hierarchy process combined with criteria importance through intercriteria correlation. The results showed that liquid-plastic limit seemed to be a major factor, which had positive correlation with pellet molding, while cohesion had negative correlation with pellet molding in the measured range. The physical properties of the mixture has marked influence on pellet molding.

Effects of a completely pelleted diet on growth performance in Holstein heifers.

PubMed

Bonfante, E; Palmonari, A; Mammi, L; Canestrari, G; Fustini, M; Formigoni, A

2016-12-01

Forage neutral detergent fiber (NDF) content and particle size are important factors that affect rumen function. The aim of the current study was to evaluate the effects on rumen health, NDF digestibility, and animal performance of pelleting a forage-based diet. Eight Holstein heifers (age 336±30d, body weight 346±35kg) were randomly assigned to a repeated crossover design. Animals were housed in tie-stalls and fed for ad libitum intake. The study included 4 periods of 3 wk, the first 2 wk for adaptation to the diet and the last wk for data collection. Diets had the same ingredients but had a different physical form: total mixed ration (TMR) and pellet (diameter=8mm). The physically effective NDF (peNDF) differed between the 2 treatments (39.8 and 11.8% of NDF in the TMR and pellet diets, respectively). During the trial, dry matter intake (DMI), water intake, rumination time, rumen temperature, and pH were evaluated daily. Fecal samples were collected in wk3 of each period to determine total-tract digestibility of the potential digestible (pd)NDF. Average daily gain and feed conversion ratio were calculated at the end of each period. With the pellet diet, DMI, DMI/body weight, and water consumption were higher. We observed no significant difference in average daily gain or feed conversion ratio. Rumination time was lower for the pellet diet than for the TMR diet (241 vs. 507min/d, respectively). Diet had no effect on rumen temperature or rumen pH. The total-tract digestibility of the pdNDF was greater with the TMR diet than with the pellet diet (90.25 vs. 86.82% pdNDF, respectively). The results of the current study suggest that a complete-feed pellet diet was well accepted by the animals, as demonstrated by higher DMI. Rumination time was reduced with the pellet diet, but rumen pH was not different. The pdNDF digestibility was high for both diets, but significantly higher for the TMR diet. Given that animal performance was similar between the 2 diets, although they differed with respect to DMI and fiber digestion, we hypothesize that the 2 diets had different retention times, related to their physical form. A complete-feed pellet diet formulated to provide a sufficient level of NDF from forages could be fed to growing ruminants without apparent negative effects on rumen health and animal productivity, at least for a short period. More research over a longer growing period is needed before recommending this feeding strategy for growing heifers. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Effect of pelleting on survival of porcine epidemic diarrhea virus-contaminated feed.

PubMed

Cochrane, R A; Schumacher, L L; Dritz, S S; Woodworth, J C; Huss, A R; Stark, C R; DeRouchey, J M; Tokach, M D; Goodband, R D; Bia, J; Chen, Q; Zhang, J; Gauger, P C; Derscheid, R J; Magstadt, D R; Main, R G; Jones, C K

2017-03-01

Porcine epidemic diarrhea virus (PEDV) is a heat-sensitive virus that has devastated the U.S. swine industry. Because of its heat sensitivity, we hypothesized that a steam conditioner and pellet mill mimicking traditional commercial thermal processing may mitigate PEDV infectivity. Pelleting, a common feed processing method, includes the use of steam and shear forces, resulting in increased temperature of the processed feed. Two thermal processing experiments were designed to determine if different pellet mill conditioner retention times and temperatures would impact PEDV quantity and infectivity by analysis of quantitative reverse transcription PCR and bioassay. In Exp. 1, a 3 × 3 × 2 factorial design was used with 3 pelleting temperatures (68.3, 79.4, and 90.6°C), 3 conditioning times (45, 90, or 180 s), and 2 doses of viral inoculation (low, 1 × 10 tissue culture infectious dose (the concentration used to see cytopathic effect in 50% of the cells)/g, or high, 1 × 10 tissue culture infectious dose/g). Noninoculated and PEDV-inoculated unprocessed mash were used as controls. The low-dose PEDV-infected mash had 6.8 ± 1.8 cycle threshold (Ct) greater ( < 0.05) PEDV than the high-dose mash. Regardless of time or temperature, pelleting reduced ( < 0.05) the quantity of detectable viral PEDV RNA compared with the PEDV-inoculated unprocessed mash. Fecal swabs from pigs inoculated with the PEDV-positive unprocessed mash, regardless of dose, were clinically PEDV positive from 2 to 7 d (end of the trial) after inoculation. However, if either PEDV dose of inoculated feed was pelleted at any of the 9 tested conditioning time × temperature combinations, no PEDV RNA was detected in fecal swabs or cecum content. Based on Exp. 1 results, a second experiment was developed to determine the impact of lower processing temperatures on PEDV quantity and infectivity. In Exp. 2, PEDV-inoculated feed was pelleted at 1 of 5 conditioning temperatures (37.8, 46.1, 54.4, 62.8, and 71.1°C) for 30 s. The 5 increasing processing temperatures led to feed with respective mean Ct values of 32.5, 34.6, 37.0, 36.5, and 36.7, respectively. All samples had detectable PEDV RNA. However, infectivity was detected by bioassay only in pigs from the 37.8 and 46.1°C conditioning temperatures. Experiment 2 results suggest conditioning and pelleting temperatures above 54.4°C could be effective in reducing the quantity and infectivity of PEDV in swine feed. However, additional research is needed to prevent subsequent recontamination after pelleting as it is a point-in-time mitigation step.

The synthesis, characterisation and in vivo study of a bioceramic for potential tissue regeneration applications

PubMed Central

Poinern, Gérrard Eddy Jai; Brundavanam, Ravi Krishna; Thi Le, Xuan; Nicholls, Philip K.; Cake, Martin A.; Fawcett, Derek

2014-01-01

Hydroxyapatite (HAP) is a biocompatible ceramic that is currently used in a number of current biomedical applications. Recently, nanometre scale forms of HAP have attracted considerable interest due to their close similarity to the inorganic mineral component of the bone matrix found in humans. In this study ultrafine nanometre scale HAP powders were prepared via a wet precipitation method under the influence of ultrasonic irradiation. The resulting powders were compacted and sintered to form a series of ceramic pellets with a sponge-like structure with varying density and porosity. The crystalline structure, size and morphology of the powders and the porous ceramic pellets were investigated using advanced characterization techniques. The pellets demonstrated good biocompatibility, including mixed cell colonisation and matrix deposition, in vivo following surgical implantation into sheep M. latissimus dorsi. PMID:25168046

A new tritiated water measurement method with plastic scintillator pellets.

PubMed

Furuta, Etsuko; Iwasaki, Noriko; Kato, Yuka; Tomozoe, Yusuke

2016-01-01

A new tritiated water measurement method with plastic scintillator pellets (PS-pellets) by using a conventional liquid scintillation counter was developed. The PS-pellets used were 3 mm in both diameter and length. A low potassium glass vial was filled full with the pellets, and tritiated water was applied to the vial from 5 to 100 μl. Then, the sample solution was scattered in the interstices of the pellets in a vial. This method needs no liquid scintillator, so no liquid organic waste fluid is generated. The counting efficiency with the pellets was approximately 48 % when a 5 μl solution was used, which was higher than that of conventional measurement using liquid scintillator. The relationship between count rate and activity showed good linearity. The pellets were able to be used repeatedly, so few solid wastes are generated with this method. The PS-pellets are useful for tritiated water measurement; however, it is necessary to develop a new device which can be applied to a larger volume and measure low level concentration like an environmental application.

Studying Pellet Formation of a Filamentous Fungus Rhizopus oryzae to Enhance Organic Acid Production

NASA Astrophysics Data System (ADS)

Liao, Wei; Liu, Yan; Chen, Shulin

Using pelletized fungal biomass can effectively improve the fermentation performance for most of fugal strains. This article studied the effects of inoculum and medium compositions such as potato dextrose broth (PDB) as carbon source, soybean peptone, calcium carbonate, and metal ions on pellet formation of Rhizopus oryzae. It has been found that metal ions had significantly negative effects on pellet formation whereas soybean peptone had positive effects. In addition PDB and calcium carbonate were beneficial to R. oryzae for growing small smooth pellets during the culture. The study also demonstrated that an inoculum size of less than 1.5×109 spores/L had no significant influence on pellet formation. Thus, a new approach to form pellets has been developed using only PDB, soybean peptone, and calcium carbonate. Meanwhile, palletized fungal fermentation significantly enhanced organic acid production. Lactic acid concentration reached 65.0 g/L in 30 h using pelletized R. oryzae NRRL 395, and fumeric acid concentration reached 31.0 g/L in 96 h using pelletized R. oryzae ATCC 20344.

Drug-beta-cyclodextrin containing pellets prepared with a high-shear mixer.

PubMed

Gainotti, Alessandro; Bettini, Ruggero; Gazzaniga, Andrea; Colombo, Paolo; Giordano, Ferdinando

2004-01-01

This work was aimed at investigating the preparation of beta-cyclodextrin-microcrystalline cellulose pellets by means of a high-shear mixer, both in the absence or in the presence of ibuprofen as model drug. Drug loading of pellets was accomplished by means of two alternative techniques: 1) solution layering or 2) powder layering. The prepared pellets were characterised in terms of size distribution, shape factor, friability and dissolution rate. The interaction between ibuprofen and beta-cyclodextrin was monitored by Differential Scanning Calorimetry (DSC). Micro Fourier Transform Infrared spectroscopy (MicroFTIR) was applied to determine the distribution of components within each pellet on a micro scale. Pellets with narrow size distribution and containing up to about 90% of BCD were prepared using water as binder. The process yield resulted around 84 and 63% for drug-free and medicate pellets respectively. Drug loaded pellets with favourable technological and biopharmaceutical characteristics can be obtained both by powder or solution layering techniques. The latter proved to be more suitable for producing pellets with high drug contents, reduced friability and high drug dissolution rates.

Near-limit propagation of gaseous detonations in narrow annular channels

NASA Astrophysics Data System (ADS)

Gao, Y.; Ng, H. D.; Lee, J. H. S.

2017-03-01

New results on the near-limit behaviors of gaseous detonations in narrow annular channels are reported in this paper. Annular channels of widths 3.2 and 5.9 mm were made using circular inserts in a 50.8 mm-diameter external tube. The length of each annular channel was 1.8 m. Detonations were initiated in a steel driver tube where a small volume of a sensitive C2H2+ 2.5O2 mixture was injected to facilitate detonation initiation. A 2 m length of circular tube with a 50.8 mm diameter preceded the annular channel so that a steady Chapman-Jouguet (CJ) detonation was established prior to entering the annular channel. Four detonable mixtures of C2H2 {+} 2.5O2 {+} 85 % Ar, C2H2 {+} 2.5O2 {+} 70 % Ar, C3H8 {+} 5O2, and CH4 {+} 2O2 were used in the present study. Photodiodes spaced 10 cm throughout the length of both the annular channel and circular tube were used to measure the detonation velocity. In addition, smoked foils were inserted into the annular channel to monitor the cellular structure of the detonation wave. The results show that, well within the detonability limits, the detonation wave propagates along the channel with a small local velocity fluctuation and an average global velocity can be deduced. The average detonation velocity has a small deficit of 5-15 % far from the limits and the velocity rapidly decreases to 0.7V_{CJ}-0.8V_{CJ} when the detonation propagates near the limit. Subsequently, the fluctuation of local velocity also increases as the decreasing initial pressure approaches the limit. In the two annular channels used in this work, no galloping detonations were observed for both the stable and unstable mixtures tested. The present study also confirms that single-headed spinning detonation occurs at the limit, as in a circular tube, rather than the up and down "zig zag" mode in a two-dimensional, rectangular channel.

Hatch assembly

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

Marshall, J.R.; Hardin, R.T. Jr.

1987-07-07

This patent describes a nuclear reactor installation including means defining a fuel handling area and means defining a containment area separated from the fuel handling area and including a refuelling cavity; the improvement comprising: (a) a fuel transfer tube connecting the refuelling cavity with the fuel handling area; the fuel transfer tube having a first end in the fuel handling area and a second end in the refueling cavity; (b) valve means for opening and closing the first end; and (c) a hatch assembly mounted on the second end; the hatch assembly including (1) a hatch ring affixed to themore » fuel transfer tube at the second end the hatch ring has an integral annular seat surrounded by the hatch ring and defines a hatch opening in the second end of the fuel transfer tube; (2) a hatch cover adapts to be positioned on the annular seat for covering the hatch opening; (3) latching units are supported on the hatch ring about the hatch opening, each latching unit.« less

Paraformaldehyde pellet not necessary in vacuum-pumped maple sap system

Treesearch

H. Clay Smith; Carter B. Gibbs

1970-01-01

In a study of sugar maple sap collection through a vacuum-pumped plastic tubing system, yields were compared between tapholes in which paraformaldehyde pellets were used and tapholes without pellets, Use of the pellets did not increase yield.

Cradle-to-Gate Life-Cycle Inventory and Impact Assessment of Wood Fuel Pellet Manufacturing from Hardwood Flooring Residues in the Southeastern United States

Treesearch

Daniel Reed; Richard Bergman; Jae-Woo Kim; Adam Tayler; David Harper; David Jones; Chris Knowles; Maureen E. Puettmann

2012-01-01

In this article, we present cradle-to-gate life-cycle inventory (LCI) data for wood fuel pellets manufactured in the Southeast United States. We surveyed commercial pellet manufacturers in 2010, collecting annual production data for 2009. Weighted-average inputs to, and emissions from, the pelletization process were determined. The pellet making unit process was...

Fuel Pellets from Wheat Straw: The Effect of Lignin Glass Transition and Surface Waxes on Pelletizing Properties

Treesearch

Wolfgang Stelte; Craig Clemons; Jens K. Holm; Jesper Ahrenfeldt; Ulrik B. Henriksen; Anand R. Sanadi

2012-01-01

The utilization of wheat straw as a renewable energy resource is limited due to its low bulk density. Pelletizing wheat straw into fuel pellets of high density increases its handling properties but is more challenging compared to pelletizing wood biomass. Straw has a lower lignin content and a high concentration of hydrophobic waxes on its outer surface that may limit...

Engineering and functional properties of biodegradable pellets developed from various agro-industrial wastes using extrusion technology.

PubMed

Jan, Kulsum; Riar, C S; Saxena, D C

2015-12-01

Different agro-industrial wastes were mixed with different plasticizers and extruded to form the pellets to be used further for development of biodegradable molded pots. Bulk density and macro-porosity are the important engineering properties used to determine the functional characteristics of the biodegradable pellets viz., expansion volume, water solubility, product colour, flowability and compactness. Significant differences in the functional properties of pellets with varying bulk densities (loose and tapped) and macro-porosities (loose, tapped) were observed. The observed mean bulk density of biodegradable pellets made from different formulations ranged between 0.213 and 0.560 g/ml for loose fill conditions and 0.248 to 0.604 g/ml for tapped fill conditions. Biodegradable pellets bear a good compaction for both loose and tapped fill methods. The mean macro-porosity of biodegradable pellets ranged between 1.19 and 54.48 % for loose fill condition and 0.29 to 53.35 % for tapped fill condition. Hausner ratio (HR) for biodegradable pellets varied from 1.026 to 1.328, indicating a good flowability of biodegradable pellets. Pearson's correlation between engineering properties and functional properties of biodegradable pellets revealed that from engineering properties functional properties can be predicted.

Circular economy in drinking water treatment: reuse of ground pellets as seeding material in the pellet softening process.

PubMed

Schetters, M J A; van der Hoek, J P; Kramer, O J I; Kors, L J; Palmen, L J; Hofs, B; Koppers, H

2015-01-01

Calcium carbonate pellets are produced as a by-product in the pellet softening process. In the Netherlands, these pellets are applied as a raw material in several industrial and agricultural processes. The sand grain inside the pellet hinders the application in some high-potential market segments such as paper and glass. Substitution of the sand grain with a calcite grain (100% calcium carbonate) is in principle possible, and could significantly improve the pellet quality. In this study, the grinding and sieving of pellets, and the subsequent reuse as seeding material in pellet softening were tested with two pilot reactors in parallel. In one reactor, garnet sand was used as seeding material, in the other ground calcite. Garnet sand and ground calcite performed equally well. An economic comparison and a life-cycle assessment were made as well. The results show that the reuse of ground calcite as seeding material in pellet softening is technologically possible, reduces the operational costs by €38,000 (1%) and reduces the environmental impact by 5%. Therefore, at the drinking water facility, Weesperkarspel of Waternet, the transition from garnet sand to ground calcite will be made at full scale, based on this pilot plant research.

In-line monitoring of pellet coating thickness growth by means of visual imaging.

PubMed

Oman Kadunc, Nika; Sibanc, Rok; Dreu, Rok; Likar, Boštjan; Tomaževič, Dejan

2014-08-15

Coating thickness is the most important attribute of coated pharmaceutical pellets as it directly affects release profiles and stability of the drug. Quality control of the coating process of pharmaceutical pellets is thus of utmost importance for assuring the desired end product characteristics. A visual imaging technique is presented and examined as a process analytic technology (PAT) tool for noninvasive continuous in-line and real time monitoring of coating thickness of pharmaceutical pellets during the coating process. Images of pellets were acquired during the coating process through an observation window of a Wurster coating apparatus. Image analysis methods were developed for fast and accurate determination of pellets' coating thickness during a coating process. The accuracy of the results for pellet coating thickness growth obtained in real time was evaluated through comparison with an off-line reference method and a good agreement was found. Information about the inter-pellet coating uniformity was gained from further statistical analysis of the measured pellet size distributions. Accuracy and performance analysis of the proposed method showed that visual imaging is feasible as a PAT tool for in-line and real time monitoring of the coating process of pharmaceutical pellets. Copyright © 2014 Elsevier B.V. All rights reserved.

Modeling of Focused Acoustic Field of a Concave Multi-annular Phased Array Using Spheroidal Beam Equation

NASA Astrophysics Data System (ADS)

Yu, Li-Li; Shou, Wen-De; Hui, Chun

2012-02-01

A theoretical model of focused acoustic field for a multi-annular phased array on concave spherical surface is proposed. In this model, the source boundary conditions of the spheroidal beam equation (SBE) for multi-annular phased elements are studied. Acoustic field calculated by the dynamic focusing model of SBE is compared with numerical results of the O'Neil and Khokhlov—Zabolotskaya—Kuznetsov (KZK) model, respectively. Axial dynamic focusing and the harmonic effects are presented. The results demonstrate that the dynamic focusing model of SBE is good valid for a concave multi-annular phased array with a large aperture angle in the linear or nonlinear field.

Compact Low Frequency Radio Antenna

DOEpatents

Punnoose, Ratish J.

2008-11-11

An antenna is disclosed that comprises a pair of conductive, orthogonal arches and a pair of conductive annular sector plates, wherein adjacent legs of each arch are fastened to one of the annular sector plates and the opposite adjacent pair of legs is fastened to the remaining annular sector plate. The entire antenna structure is spaced apart from a conductive ground plane by a thin dielectric medium. The antenna is driven by a feed conduit passing through the conductive ground plane and dielectric medium and attached to one of the annular sector plates, wherein the two orthogonal arched act as a pair of crossed dipole elements. This arrangement of elements provides a radiation pattern that is largely omni-directional above the horizon.

On the Motion of an Annular Film in Microgravity Gas-Liquid Flow

NASA Technical Reports Server (NTRS)

McQuillen, John B.

2002-01-01

Three flow regimes have been identified for gas-liquid flow in a microgravity environment: Bubble, Slug, and Annular. For the slug and annular flow regimes, the behavior observed in vertical upflow in normal gravity is similar to microgravity flow with a thin, symmetrical annular film wetting the tube wall. However, the motion and behavior of this film is significantly different between the normal and low gravity cases. Specifically, the liquid film will slow and come to a stop during low frequency wave motion or slugging. In normal gravity vertical upflow, the film has been observed to slow, stop, and actually reverse direction until it meets the next slug or wave.

[Diarrhoea and oedema in two show horses after feeding a pelleted supplemental feed for horses according to VDLUFA's perspective of microbial quality classified as safe for use in horses].

PubMed

Büsing, Kirsten; Mietke-Hofmann, Henriette; Dibbert, Regina; Donandt, Dietz; Maier, Thomas; Zeyner, Annette

2013-01-01

A new batch of a supplemental feed was fed as pellets (diameter 8 mm) to two Warmblood-type horses. One horse developed watery diarrhoea within two days. Pronounced oedema due to hypalbuminemia was seen about ten days later. The feed was replaced by pellets of identical composition and mixing process, but lower diameter (5 mm). After one week of feeding, oedema regressed and faeces were normally formed. At refeeding the larger sized pellets, the symptoms recurred, but now both horses were affected. After a change to the smaller pellets, the horses recovered soon. Water activity (aw-value) of the larger and the smaller sized pellets was 0.68 and 0.56, respectively. In the larger sized pellets crude fat increased, whereas crude protein and nitrogen-free extracts decreased, giving a hint to microbial activity. Samples of both pellets were examined by VDLUFA methods and the microbial quality was classified in quality step 1. Though the quality parameters complied with recommendations for the product, it contained large numbers of spoilage indicating bacteria. The content of sulfite-reducing clostridia was higher in the 8 mm pellets than in the 5 mm pellets, with 3.3 x 10(2) and 1.1 x 10(2) colony forming units, respectively. The larger sized pellets produced remarkable quantities of gas. Bacillus cereus of non probiotic origin was identified.

Impact of AFEX™ Pretreatment and Extrusion Pelleting on Pellet Physical Properties and Sugar Recovery from Corn Stover, Prairie Cord Grass, and Switchgrass.

PubMed

Sundaram, Vijay; Muthukumarappan, Kasiviswanathan

2016-05-01

The effects of AFEX™ pretreatment, feedstock moisture content (5,10, and 15 % wb), particle size (screen sizes of 2, 4, and 8 mm), and extrusion temperature (75, 100, and 125 °C) on pellet bulk density, pellet hardness, and sugar recovery from corn stover, prairie cord grass, and switchgrass were investigated. Pellets were produced from untreated and AFEX™ pretreated feedstocks using a laboratory-scale extruder. AFEX™ pretreatment increased subsequent pellet bulk density from 453.0 to 650.6 kg m(-3) for corn stover from 463.2 to 680.1 kg m(-3) for prairie cord grass, and from 433.9 to 627.7 kg m(-3) for switchgrass. Maximum pellet hardness of 2342.8, 2424.3, and 1298.6 N was recorded for AFEX™ pretreated corn stover, prairie cord grass, and switchgrass, respectively. Glucose yields of AFEX™ corn stover pellets, prairie cord grass, and switchgrass pellets varied from 88.9 to 94.9 %, 90.1 to 94.9 %, and 87.0 to 92.9 %, respectively. Glucose and xylose yields of AFEX™ pellets were not affected by the extruder barrel temperature and the hammer mill screen size. The results obtained showed that low temperature and large particle size during the extrusion pelleting process can be employed for AFEX™-treated biomass without compromising sugar yields.

Annular beam with segmented phase gradients

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

Cheng, Shubo; Wu, Liang; Tao, Shaohua, E-mail: eshtao@csu.edu.cn

2016-08-15

An annular beam with a single uniform-intensity ring and multiple segments of phase gradients is proposed in this paper. Different from the conventional superposed vortices, such as the modulated optical vortices and the collinear superposition of multiple orbital angular momentum modes, the designed annular beam has a doughnut intensity distribution whose radius is independent of the phase distribution of the beam in the imaging plane. The phase distribution along the circumference of the doughnut beam can be segmented with different phase gradients. Similar to a vortex beam, the annular beam can also exert torques and rotate a trapped particle owingmore » to the orbital angular momentum of the beam. As the beam possesses different phase gradients, the rotation velocity of the trapped particle can be varied along the circumference. The simulation and experimental results show that an annular beam with three segments of different phase gradients can rotate particles with controlled velocities. The beam has potential applications in optical trapping and optical information processing.« less

Dynamic-Receive Focusing with High-Frequency Annular Arrays

NASA Astrophysics Data System (ADS)

Ketterling, J. A.; Mamou, J.; Silverman, R. H.

High-frequency ultrasound is commonly employed for ophthalmic and small-animal imaging because of the fine-resolution images it affords. Annular arrays allow improved depth of field and lateral resolution versus commonly used single-element, focused transducers. The best image quality from an annular array is achieved by using synthetic transmit-to-receive focusing while utilizing data from all transmit-to-receive element combinations. However, annular arrays must be laterally scanned to form an image and this requires one pass for each of the array elements when implementing full synthetic transmit-to-receive focusing. A dynamic-receive focusing approach permits a single pass, although at a sacrifice of depth of field and lateral resolution. A five-element, 20-MHz annular array is examined to determine the acoustic beam properties for synthetic and dynamic-receive focusing. A spatial impulse response model is used to simulate the acoustic beam properties for each focusing case and then data acquired from a human eye-bank eye are processed to demonstrate the effect of each approach on image quality.

Design of radial phononic crystal using annular soft material with low-frequency resonant elastic structures

NASA Astrophysics Data System (ADS)

Gao, Nansha; Wu, Jiu Hui; Yu, Lie; Xin, Hang

2016-10-01

Using FEM, we theoretically study the vibration properties of radial phononic crystal (RPC) with annular soft material. The band structures, transmission spectra, and displacement fields of eigenmode are given to estimate the starting and cut-off frequency of band gaps. Numerical calculation results show that RPC with annular soft material can yield low-frequency band gaps below 350 Hz. Annular soft material decreases equivalent stiffness of the whole structure effectively, and makes corresponding band gaps move to the lower frequency range. Physical mechanism behind band gaps is the coupling effect between long or traveling wave in plate matrix and the vibrations of corrugations. By changing geometrical dimensions of plate thickness e, the length of silicone rubber h2, and the corrugation width b, we can control the location and width of the first band gap. These research conclusions of RPC structure with annular soft material can potentially be applied to optimize band gaps, generate filters, and design acoustic devices.

Molecular Validation of Chondrogenic Differentiation and Hypoxia Responsiveness of Platelet-Lysate Expanded Adipose Tissue-Derived Human Mesenchymal Stromal Cells.

PubMed

Galeano-Garces, Catalina; Camilleri, Emily T; Riester, Scott M; Dudakovic, Amel; Larson, Dirk R; Qu, Wenchun; Smith, Jay; Dietz, Allan B; Im, Hee-Jeong; Krych, Aaron J; Larson, A Noelle; Karperien, Marcel; van Wijnen, Andre J

2017-07-01

To determine the optimal environmental conditions for chondrogenic differentiation of human adipose tissue-derived mesenchymal stromal/stem cells (AMSCs). In this investigation we specifically investigate the role of oxygen tension and 3-dimensional (3D) culture systems. Both AMSCs and primary human chondrocytes were cultured for 21 days in chondrogenic media under normoxic (21% oxygen) or hypoxic (2% oxygen) conditions using 2 distinct 3D culture methods (high-density pellets and poly-ε-caprolactone [PCL] scaffolds). Histologic analysis of chondro-pellets and the expression of chondrocyte-related genes as measured by reverse transcriptase quantitative polymerase chain reaction were used to evaluate the efficiency of differentiation. AMSCs are capable of expressing established cartilage markers including COL2A1, ACAN, and DCN when grown in chondrogenic differentiation media as determined by gene expression and histologic analysis of cartilage markers. Expression of several cartilage-related genes was enhanced by low oxygen tension, including ACAN and HAPLN1. The pellet culture environment also promoted the expression of hypoxia-inducible cartilage markers compared with cells grown on 3D scaffolds. Cell type-specific effects of low oxygen and 3D environments indicate that mesenchymal cell fate and differentiation potential is remarkably sensitive to oxygen. Genetic programming of AMSCs to a chondrocytic phenotype is effective under hypoxic conditions as evidenced by increased expression of cartilage-related biomarkers and biosynthesis of a glycosaminoglycan-positive matrix. Lower local oxygen levels within cartilage pellets may be a significant driver of chondrogenic differentiation.

Tritium proof-of-principle pellet injector: Phase 2

NASA Astrophysics Data System (ADS)

Fisher, P. W.; Gouge, M. J.

1995-03-01

As part of the International Thermonuclear Engineering 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. This repeating, single-stage, pneumatic injector, called the Tritium-Proof-of-Principle Phase-2 (TPOP-2) Pellet Injector, has a piston-driven mechanical extruder and is designed to extrude hydrogenic pellets sized for the ITER device. The TPOP-II program has the following development goals: evaluate the feasibility of extruding tritium and DT mixtures for use in future pellet injection systems; determine the mechanical and thermal properties of tritium and DT extrusions; integrate, test and evaluate the extruder in a repeating, single-stage light gas gun sized for the ITER application (pellet diameter approximately 7-8 mm); evaluate options for recycling propellant and extruder exhaust gas; evaluate operability and reliability of ITER prototypical fueling systems in an environment of significant tritium inventory requiring secondary and room containment systems. In initial tests with deuterium feed at ORNL, up to thirteen pellets have been extruded at rates up to 1 Hz and accelerated to speeds of order 1.0-1.1 km/s using hydrogen propellant gas at a supply pressure of 65 bar. The pellets are typically 7.4 mm in diameter and up to 11 mm in length and are the largest cryogenic pellets produced by the fusion program to date. These pellets represent about a 11% density perturbation to ITER. 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 called isotopic fueling where tritium-rich pellets fuel the burning plasma core and deuterium gas fuels the edge.

Annular gel reactor for chemical pattern formation

DOEpatents

Nosticzius, Zoltan; Horsthemke, Werner; McCormick, William D.; Swinney, Harry L.; Tam, Wing Y.

1990-01-01

The present invention is directed to an annular gel reactor suitable for the production and observation of spatiotemporal patterns created during a chemical reaction. The apparatus comprises a vessel having at least a first and second chamber separated one from the other by an annular polymer gel layer (or other fine porous medium) which is inert to the materials to be reacted but capable of allowing diffusion of the chemicals into it.

Elastic-plastic analysis of annular plate problems using NASTRAN

NASA Technical Reports Server (NTRS)

Chen, P. C. T.

1983-01-01

The plate elements of the NASTRAN code are used to analyze two annular plate problems loaded beyond the elastic limit. The first problem is an elastic-plastic annular plate loaded externally by two concentrated forces. The second problem is stressed radially by uniform internal pressure for which an exact analytical solution is available. A comparison of the two approaches together with an assessment of the NASTRAN code is given.

GAS BEARING

DOEpatents

Skarstrom, C.W.

1960-09-01

A gas lubricated bearing for a rotating shaft is described. The assembly comprises a stationary collar having an annular member resiliently supported thereon. The collar and annular member are provided with cooperating gas passages arranged for admission of pressurized gas which supports and lubricates a bearing block fixed to the rotatable shaft. The resilient means for the annular member support the latter against movement away from the bearing block when the assembly is in operation.

Method to produce durable pellets at lower energy consumption using high moisture corn stover and a corn starch binder in a flat die pellet mill

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

Tumuluru, Jaya Shankar; Conner, Craig C.; Hoover, Amber N.

Biomass from plants can serve as an alternative renewable energy resources for energy production. Low densities of 40–60 kg/m3 for ground lignocellulosic biomass like corn stover limit its operation for energy purposes. The common drawbacks are inefficient transportation, a bigger storage foot print, and handling problems. Densification of biomass using pellet mill helps to overcome these limitations. This study helps to understand the effect of binder on high moisture biomass with a focus on the quality (density and durability), the pelleting efficiency and the specific energy consumption of its pelleting process. Raw corn stover was pelleted at high moisture ofmore » 33% (w.b.) at both varying preheating temperatures and binder percentage. The die speed of the pellet mill was set at 60Hz. The pellets produced were analyzed and showed higher moisture content. They were further dried in a laboratory oven at 70°C for 3-4 hr bringing the pellet moisture to <9%. The dried pellets were evaluated for their physical properties like unit, bulk and tapped density, and durability. Furthermore, the results indicated increasing the binder percentage to 4% improved the physical properties of the pellets and reduced the specific energy consumption. Higher binder addition of 4% reduced the feedstock moisture loss during pelleting to <4%, which can be due reduced residence time of the material in the die. On the other hand the physical properties like density and durability improved significantly with binder addition. At 4% binder and 33% feedstock moisture content, the bulk density and durability values observed were >510 kg/m3 and >98% and the percent fines generation has reduced to <3%. Also at these conditions the specific energy consumption was reduced by about 30-40% compared no binder pelleting test.« less

Method to produce durable pellets at lower energy consumption using high moisture corn stover and a corn starch binder in a flat die pellet mill

DOE PAGES

Tumuluru, Jaya Shankar; Conner, Craig C.; Hoover, Amber N.

2016-06-15

Biomass from plants can serve as an alternative renewable energy resources for energy production. Low densities of 40–60 kg/m3 for ground lignocellulosic biomass like corn stover limit its operation for energy purposes. The common drawbacks are inefficient transportation, a bigger storage foot print, and handling problems. Densification of biomass using pellet mill helps to overcome these limitations. This study helps to understand the effect of binder on high moisture biomass with a focus on the quality (density and durability), the pelleting efficiency and the specific energy consumption of its pelleting process. Raw corn stover was pelleted at high moisture ofmore » 33% (w.b.) at both varying preheating temperatures and binder percentage. The die speed of the pellet mill was set at 60Hz. The pellets produced were analyzed and showed higher moisture content. They were further dried in a laboratory oven at 70°C for 3-4 hr bringing the pellet moisture to <9%. The dried pellets were evaluated for their physical properties like unit, bulk and tapped density, and durability. Furthermore, the results indicated increasing the binder percentage to 4% improved the physical properties of the pellets and reduced the specific energy consumption. Higher binder addition of 4% reduced the feedstock moisture loss during pelleting to <4%, which can be due reduced residence time of the material in the die. On the other hand the physical properties like density and durability improved significantly with binder addition. At 4% binder and 33% feedstock moisture content, the bulk density and durability values observed were >510 kg/m3 and >98% and the percent fines generation has reduced to <3%. Also at these conditions the specific energy consumption was reduced by about 30-40% compared no binder pelleting test.« less

A centrifuge CO2 pellet cleaning system

NASA Technical Reports Server (NTRS)

Foster, C. A.; Fisher, P. W.; Nelson, W. D.; Schechter, D. E.

1995-01-01

An advanced turbine/CO2 pellet accelerator is being evaluated as a depaint technology at Oak Ridge National Laboratory (ORNL). The program, sponsored by Warner Robins Air Logistics Center (ALC), Robins Air Force Base, Georgia, has developed a robot-compatible apparatus that efficiently accelerates pellets of dry ice with a high-speed rotating wheel. In comparison to the more conventional compressed air 'sandblast' pellet accelerators, the turbine system can achieve higher pellet speeds, has precise speed control, and is more than ten times as efficient. A preliminary study of the apparatus as a depaint technology has been undertaken. Depaint rates of military epoxy/urethane paint systems on 2024 and 7075 aluminum panels as a function of pellet speed and throughput have been measured. In addition, methods of enhancing the strip rate by combining infra-red heat lamps with pellet blasting and by combining the use of environmentally benign solvents with the pellet blasting have also been studied. The design and operation of the apparatus will be discussed along with data obtained from the depaint studies.

Complete reduction of high-density UO2 to metallic U in molten Li2O-LiCl

NASA Astrophysics Data System (ADS)

Choi, Eun-Young; Lee, Jeong

2017-10-01

The large size and high density of spent fuel pellets make it difficult to use the pellets directly in electrolytic reduction (also called as oxide reduction, OR) for pyroprocessing owing to the slow diffusion of molten Li2O-LiCl salt electrolyte into the pellets. In this study, we investigated complete OR of high-density UO2 to metallic U without any remaining UO2. Only partial reductions near the surface of high-density UO2 pellets were observed under operation conditions employing fast electrolysis rate that allowed previously complete reduction of low-density UO2 pellets. Complete reduction of high-density UO2 pellets was observed at fast electrolysis rate when the pellet size was reduced. The complete reduction of high-density UO2 pellets without size reduction was achieved at slow electrolysis rate, which allowed sufficient chemical reduction of UO2 with the lithium metal generated by the cathode reaction.

The impact of interface bonding efficiency on high-burnup spent nuclear fuel dynamic performance

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

Jiang, Hao; Wang, Jy-An John; Wang, Hong

Finite element analysis (FEA) was used to investigate the impact of interfacial bonding efficiency at pellet-pellet and pellet-clad interfaces of high-burnup (HBU) spent nuclear fuel (SNF) on system dynamic performance. Bending moments M were applied to FEA model to evaluate the system responses. From bending curvature, κ, flexural rigidity EI can be estimated as EI = M/κ. The FEA simulation results were benchmarked with experimental results from cyclic integrated reversal bending fatigue test (CIRFT) of HBR fuel rods. The consequence of interface debonding between fuel pellets and cladding is a redistribution of the loads carried by the fuel pellets tomore » the clad, which results in a reduction in composite rod system flexural rigidity. Furthermore, the interface bonding efficiency at the pellet-pellet and pellet-clad interfaces can significantly dictate the SNF system dynamic performance. With the consideration of interface bonding efficiency, the HBU SNF fuel property was estimated with CIRFT test data.« less

Adsorption of trace metals to plastic resin pellets in the marine environment.

PubMed

Holmes, Luke A; Turner, Andrew; Thompson, Richard C

2012-01-01

Plastic production pellets collected from beaches of south west England contain variable concentrations of trace metals (Cr, Co, Ni, Cu, Zn, Cd and Pb) that, in some cases, exceed concentrations reported for local estuarine sediments. The rates and mechanisms by which metals associate with virgin and beached polyethylene pellets were studied by adding a cocktail of 5 μg L(-1) of trace metals to 10 g L(-1) pellet suspensions in filtered seawater. Kinetic profiles were modelled using a pseudo-first-order equation and yielded response times of less than about 100 h and equilibrium partition coefficients of up to about 225 ml g(-1) that were consistently higher for beached pellets than virgin pellets. Adsorption isotherms conformed to both the Langmuir and Freundlich equations and adsorption capacities were greater for beached pellets than for virgin pellets. Results suggest that plastics may represent an important vehicle for the transport of metals in the marine environment. Copyright © 2011 Elsevier Ltd. All rights reserved.

The impact of interface bonding efficiency on high-burnup spent nuclear fuel dynamic performance

DOE PAGES

Jiang, Hao; Wang, Jy-An John; Wang, Hong

2016-09-26

Finite element analysis (FEA) was used to investigate the impact of interfacial bonding efficiency at pellet-pellet and pellet-clad interfaces of high-burnup (HBU) spent nuclear fuel (SNF) on system dynamic performance. Bending moments M were applied to FEA model to evaluate the system responses. From bending curvature, κ, flexural rigidity EI can be estimated as EI = M/κ. The FEA simulation results were benchmarked with experimental results from cyclic integrated reversal bending fatigue test (CIRFT) of HBR fuel rods. The consequence of interface debonding between fuel pellets and cladding is a redistribution of the loads carried by the fuel pellets tomore » the clad, which results in a reduction in composite rod system flexural rigidity. Furthermore, the interface bonding efficiency at the pellet-pellet and pellet-clad interfaces can significantly dictate the SNF system dynamic performance. With the consideration of interface bonding efficiency, the HBU SNF fuel property was estimated with CIRFT test data.« less

Diffuse pollution by persistent organic pollutants as measured in plastic pellets sampled from various beaches in Greece.

PubMed

Karapanagioti, H K; Endo, S; Ogata, Y; Takada, H

2011-02-01

Plastic pellets found stranded on beaches are hydrophobic organic materials and thus, they are a favourable medium for persistent organic pollutants to absorb to. In the present study, plastic pellets are used to determine the diffuse pollution of selected Greek beaches. Samples of pellets were taken from these beaches and were analyzed for PCBs, DDTs, HCHs, and PAHs. The observed differences among pellets from various sampling sites are related to the pollution occurring at each site. Plastic pellets collected in Saronikos Gulf beaches demonstrate much higher pollutant loading than the ones collected in a remote island or close to an agricultural area. Based on data collected in this study and the International Pellet Watch program, pollution in Saronikos Gulf, Greece, is comparable to other heavily industrialized places of the world. The present study demonstrates the potential of pellet watch to be utilized as a detailed-scale monitoring tool within a single country. Copyright © 2010 Elsevier Ltd. All rights reserved.

Upgrading nickel content of limonite nickel ore through pelletization, selective reduction and magnetic separation

NASA Astrophysics Data System (ADS)

Mayangsari, W.; Prasetyo, A. B.; Prasetiyo, Puguh

2018-04-01

Limonite nickel ore has potency to utilize as raw material for ferronickel or nickel matte, since it has low grade nickel content, thus process development is needed to find the acceptable process for upgrading nickel. The aim of this research is to determine upgrading of Ni content as result of selective reduction of limonite nickel pellet continued by magnetic separation as effect of temperature and time reduction as well as coal and CaSO4 addition. There are four steps to perform this research, such as preparation including characterization of raw ore and pelletization, selective reduction, magnetic separation and characterization of products by using AAS, XRD and SEM. Based on the result study, pellet form can upgrade 77.78% higher than powder form. Upgrading of Ni and Fe content was up to 3fold and 1.5fold respectively from raw ore used when reduced at 1100°C for 60 minutes with composition of coal and CaSO4, both 10%. The excess of CaSO4 addition caused fayalite formation. Moreover, S2 from CaSO4 also support to reach low melting point and enlardge particle size of metal formed.

Simulation and parametric study of a film-coated controlled-release pharmaceutical.

PubMed

Borgquist, Per; Zackrisson, Gunnar; Nilsson, Bernt; Axelsson, Anders

2002-04-23

Pharmaceutical formulations can be designed as Multiple Unit Systems, such as Roxiam CR, studied in this work. The dose is administrated as a capsule, which contains about 100 individual pellets, which in turn contain the active drug remoxipride. Experimental data for a large number of single pellets can be obtained by studying the release using microtitre plates. This makes it possible to study the release of the individual subunits making up the total dose. A mathematical model for simulating the release of remoxipride from single film-coated pellets is presented including internal and external mass transfer hindrance apart from the most important film resistance. The model can successfully simulate the release of remoxipride from single film-coated pellets if the lag phase of the experimental data is ignored. This was shown to have a minor influence on the release rate. The use of the present model is demonstrated by a parametric study showing that the release process is film-controlled, i.e. is limited by the mass transport through the polymer coating. The model was used to fit the film thickness and the drug loading to the experimental release data. The variation in the fitted values was similar to that obtained in the experiments.

The effect of acute mechanical left ventricular unloading on ovine tricuspid annular size and geometry.

PubMed

Malinowski, Marcin; Wilton, Penny; Khaghani, Asghar; Brown, Michael; Langholz, David; Hooker, Victoria; Eberhart, Lenora; Hooker, Robert L; Timek, Tomasz A

2016-09-01

Left ventricular assist device (LVAD) implantation may alter right ventricular shape and function and lead to tricuspid regurgitation. This in turn has been reported to be a determinant of right ventricular (RV) failure after LVAD implantation, but the effect of mechanical left ventricular (LV) unloading on the tricuspid annulus is unknown. The aim of the study was to provide insight into the effect of LVAD support on tricuspid annular geometry and dynamics that may help to optimize LV unloading with the least deleterious effect on the right-sided geometry. In seven open-chest anaesthetized sheep, nine sonomicrometry crystals were implanted on the right ventricle. Additional nine crystals were implanted around the tricuspid annulus, with one crystal at each commissure defining three separate annular regions: anterior, posterior and septal. Left ventricular unloading was achieved by connecting a cannula in the left atrium and the aorta to a continuous-flow pump. The pump was used for 15 min at a full flow of 3.8 ± 0.3 l/min. Epicardial echocardiography was used to assess the degree of tricuspid insufficiency. Haemodynamic, echocardiographic and sonomicrometry data were collected before and during full unloading. Tricuspid annular area, and the regional and total perimeter were calculated from crystal coordinates, while 3D annular geometry was expressed as the orthogonal distance of each annular crystal to the least squares plane of all annular crystals. There was no significant tricuspid regurgitation observed either before or during LV unloading. Right ventricular free wall to septum diameter increased significantly at end-diastole during unloading from 23.6 ± 5.8 to 26.3 ± 6.5 mm (P = 0.009), but the right ventricular volume, tricuspid annular area and total perimeter did not change from baseline. However, the septal part of the annulus significantly decreased its maximal length (38.6 ± 8.1 to 37.9 ± 8.2 mm, P = 0.03). Annular contraction was not altered. The tricuspid annulus had a complex 3D saddle-shaped geometry that was unaffected during experimental conditions. In healthy sheep hearts, left ventricular unloading increased septal-free wall RV diameter and reduced the length of the septal annulus, without altering the motion or geometry of the tricuspid annulus. Acute left ventricular unloading alone in healthy sheep was not sufficient to significantly perturb tricuspid annular dynamics and result in tricuspid insufficiency. © The Author 2016. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

Pelletizing lignite

DOEpatents

Goksel, Mehmet A.

1983-11-01

Lignite is formed into high strength pellets having a calorific value of at least 9,500 Btu/lb by blending a sufficient amount of an aqueous base bituminous emulsion with finely-divided raw lignite containing its inherent moisture to form a moistened green mixture containing at least 3 weight % of the bituminous material, based on the total dry weight of the solids, pelletizing the green mixture into discrete green pellets of a predetermined average diameter and drying the green pellets to a predetermined moisture content, preferrably no less than about 5 weight %. Lignite char and mixture of raw lignite and lignite char can be formed into high strength pellets in the same general manner.

A microwave cavity for measurement of the mass of hydrogen pellets

NASA Astrophysics Data System (ADS)

Sørensen, H.; Hansen, J. E.; Michelsen, P.; Sass, B.; Weisberg, K.-V.; Knudsen, O.; Michelsen, E.

1990-11-01

A description is given of a nondestructive method utilizing a microwave cavity for measuring the mass of high-speed pellets of solid hydrogen. The cavity is designed for use on a multishot pellet injector, where eight pellets are fired successively with trajectories being parallel and symmetrical around the injector axis. The cavity is cylindrical with the axis coinciding with the injector axis. When a pellet passes through the cavity through holes of 15-16 mm diameter, the change in resonant frequency is proportional to the pellet mass. As a result of the cylindrical symmetry the sensitivity will be identical for all pellets. The frequency shift is measured directly and is converted to a signal proportional to the size of the pellet. The cavity was calibrated with pellets of H2 and D2 containing around 6×1020 atoms and with velocities between 1200 and 1500 m/s. The sensitivity was found to be 300±15 mV/1020 atoms in both cases. This is in fair agreement with estimates made from the dielectric constants of solid H2 and D2. The cavity is built together with two optical detectors for time of flight measurements to form an integrated diagnostic unit.

The effect of pelleting on in situ rumen degradability of compound feed containing brown rice for dairy cows.

PubMed

Tagawa, Shin-Ichi; Yoshida, Norio; Iino, Yukihiro; Horiguchi, Ken-Ichi; Takahashi, Toshiyoshi; Watanabe, Maria; Takemura, Kei; Ito, Syuhei; Mikami, Toyoji

2017-01-01

This study was conducted to determine the effect of pelleting on in situ dry matter degradability of pelleted compound feed containing brown rice for dairy cows. Mash feed of the same composition was used as a control and the in situ study was conducted using three non-lactating Holstein steers fitted with a rumen cannula. The feeds contained 32.3% brown rice, 19.4% rapeseed meal, 11.4% wheat bran and 10.6% soybean meal (fresh weight basis). Except for moisture content, the chemical composition of the feed was not affected by pelleting. In situ dry matter disappearance of the feed increased from 0 to 2 h and after 72 h of incubation with pellet processing. Integration of the dry matter disappearance values over time revealed that degradability parameter a (soluble fraction) increased with pellet processing, whereas parameter b (potentially degradable fraction) decreased. Parameter c (fractional rate of degradation) and effective degradability (5% passage rate) were not affected by pellet processing. We concluded that pellet processing promotes rumen degradability at early incubation hours when the pelleted feed contains brown rice. © 2016 Japanese Society of Animal Science.

Automatic control system for uniformly paving iron ore pellets

NASA Astrophysics Data System (ADS)

Wang, Bowen; Qian, Xiaolong

2014-05-01

In iron and steelmaking industry, iron ore pellet qualities are crucial to end-product properties, manufacturing costs and waste emissions. Uniform pellet pavements on the grate machine are a fundamental prerequisite to ensure even heat-transfer and pellet induration successively influences performance of the following metallurgical processes. This article presents an automatic control system for uniformly paving green pellets on the grate, via a mechanism mainly constituted of a mechanical linkage, a swinging belt, a conveyance belt and a grate. Mechanism analysis illustrates that uniform pellet pavements demand the frontend of the swinging belt oscillate at a constant angular velocity. Subsequently, kinetic models are formulated to relate oscillatory movements of the swinging belt's frontend to rotations of a crank link driven by a motor. On basis of kinetic analysis of the pellet feeding mechanism, a cubic B-spline model is built for numerically computing discrete frequencies to be modulated during a motor rotation. Subsequently, the pellet feeding control system is presented in terms of compositional hardware and software components, and their functional relationships. Finally, pellet feeding experiments are carried out to demonstrate that the control system is effective, reliable and superior to conventional methods.

Determination of surface energies of hot-melt extruded sugar-starch pellets.

PubMed

Yeung, Chi-Wah; Rein, Hubert

2018-02-01

Hot-melt extruded sugar-starch pellets are an alternative for commercial sugar spheres, but their coating properties remain to be studied. Both the European Pharmcopoeia 8.6 and the United States Pharmacopoeia 40 specify the composition of sugar-starch pellets without giving requirements for the manufacturing process. Due to various fabrication techniques, the physicochemical properties of pellets may differ. Therefore, the adhesion energies of three coating dispersions (sustained, enteric and immediate release) on different types of pellets were investigated. In this context, the surface energies of various kinds of corn starch (normal, waxy, high-amylose) and sucrose pellets were analyzed using the sessile drop method, whereas the surface tensions of the coating dispersions were examined using the pendant drop method. The adhesion forces were calculated from the results of these studies. Furthermore, sugar spheres were characterized in terms of particle size distribution, porosity and specific surface area. An increase of the pellets' sucrose content leads to a more porous surface structure, which gives them an enhanced wetting behavior with coating dispersions. The adhesion energies of extruded sugar-starch pellets are similar to those of commercial sugar spheres, which comply with pharmacopeial requirements. Both types of pellets are equally suited for coating.

Re-usable electrochemical glucose sensors integrated into a smartphone platform.

PubMed

Bandodkar, Amay J; Imani, Somayeh; Nuñez-Flores, Rogelio; Kumar, Rajan; Wang, Chiyi; Mohan, A M Vinu; Wang, Joseph; Mercier, Patrick P

2018-03-15

This article demonstrates a new smartphone-based reusable glucose meter. The glucose meter includes a custom-built smartphone case that houses a permanent bare sensor strip, a stylus that is loaded with enzyme-carbon composite pellets, and sensor instrumentation circuits. A custom-designed Android-based software application was developed to enable easy and clear display of measured glucose concentration. A typical test involves the user loading the software, using the stylus to dispense an enzymatic pellet on top of the bare sensor strip affixed to the case, and then introducing the sample. The electronic module then acquires and wirelessly transmits the data to the application software to be displayed on the screen. The deployed pellet is then discarded to regain the fresh bare sensor surface. Such a unique working principle allows the system to overcome challenges faced by previously reported reusable sensors, such as enzyme degradation, leaching, and hysteresis effects. Studies reveal that the enzyme loaded in the pellets are stable for up to 8 months at ambient conditions, and generate reproducible sensor signals. The work illustrates the significance of the pellet-based sensing system towards realizing a reusable, point-of-care sensor that snugly fits around a smartphone and which does not face issues usually common to reusable sensors. The versatility of this system allows it to be easily modified to detect other analytes for application in a wide range of healthcare, environmental and defense domains. Copyright © 2017 Elsevier B.V. All rights reserved.

Owl Pellet Analysis--A Useful Tool in Field Studies

ERIC Educational Resources Information Center

Medlin, G. C.

1977-01-01

Describes a technique by which the density and hunting habits of owls can be inferred from their pellets. Owl pellets--usually small, cylindrical packages of undigested bone, hair, etc.--are regurgitated by a roosting bird. A series of activities based on owl pellets are provided. (CP)

Monitoring of carbon monoxide in residences with bulk wood pellet storage in the Northeast United States.

PubMed

Rossner, Alan; Jordan, Carolyn E; Wake, Cameron; Soto-Garcia, Lydia

2017-10-01

The interest in biomass fuel is continuing to expand globally and in the northeastern United States as wood pellets are becoming a primary source of fuel for residential and small commercial systems. Wood pellets for boilers are often stored in basement storage rooms or large bag-type containers. Due to the enclosed nature of these storage areas, the atmosphere may exhibit increased levels of carbon monoxide. Serious accidents in Europe have been reported over the last decade in which high concentrations of carbon monoxide (CO) have been found in or near bulk pellet storage containers. The aim of this study was to characterize the CO concentrations in areas with indoor storage of bulk wood pellets. Data was obtained over approximately 7 months (December 2013 to June 2014) at 25 sites in New Hampshire and Massachusetts: 16 homes using wood pellet boilers with indoor pellet storage containers greater than or equal to 3 ton capacity; 4 homes with wood pellet heating systems with outdoor pellet storage; 4 homes using other heating fuels; and a university laboratory site. CO monitors were set up in homes to collect concentrations of CO in the immediate vicinity of wood pellet storage containers, and data were then compared to those of homes using fossil fuel systems. The homes monitored in this study provided a diverse set of housing stock spanning two and a half centuries of construction, with homes built from 1774 to 2013, representing a range of air exchange rates. The CO concentration data from each home was averaged hourly and then compared to a threshold of 9 ppm. While concentrations of CO were generally low for the homes studied, the need to properly design storage locations for pellets is and will remain a necessary component of wood pellet heating systems to minimize the risk of CO exposure. This paper is an assessment of carbon monoxide (CO) exposure from bulk wood pellet storage in homes in New Hampshire and Massachusetts. Understanding the CO concentrations in homes allows for better designs for storage bins and ventilation for storage areas. Hence, uniform policies for stored wood pellets in homes, schools, and businesses can be framed to ensure occupant safety. Currently in New York State rebates for the installation of wood pellet boilers are only provided if the bulk pellet storage is outside of the home, yet states such as New Hampshire, Vermont, and Maine currently do not have these restrictions.

SPINS-IND: Pellet injector for fuelling of magnetically confined fusion systems.

PubMed

Gangradey, R; Mishra, J; Mukherjee, S; Panchal, P; Nayak, P; Agarwal, J; Saxena, Y C

2017-06-01

Using a Gifford-McMahon cycle cryocooler based refrigeration system, a single barrel hydrogen pellet injection (SPINS-IND) system is indigenously developed at Institute for Plasma Research, India. The injector is based on a pipe gun concept, where a pellet formed in situ in the gun barrel is accelerated to high speed using high pressure light propellant gas. The pellet size is decided by considering the Greenwald density limit and its speed is decided by considering a neutral gas shielding model based scaling law. The pellet shape is cylindrical of dimension (1.6 mm ℓ × 1.8 mm φ). For pellet ejection and acceleration, a fast opening valve of short opening duration is installed at the breech of the barrel. A three-stage differential pumping system is used to restrict the flow of the propellant gas into the plasma vacuum vessel. Diagnostic systems such as light gate and fast imaging camera (240 000 frames/s) are employed to measure the pellet speed and size, respectively. A trigger circuit and a programmable logic controller based integrated control system developed on LabVIEW enables to control the pellet injector remotely. Using helium as a propellant gas, the pellet speed is varied in the range 650 m/s-800 m/s. The reliability of pellet formation and ejection is found to be more than 95%. This paper describes the details of SPINS-IND and its test results.

Sintering of wax for controlling release from pellets.

PubMed

Singh, Reena; Poddar, S S; Chivate, Amit

2007-09-14

The purpose of the present study was to investigate incorporation of hydrophobic (ie, waxy) material into pellets using a thermal sintering technique and to evaluate the pellets in vitro for controlled release. Pellets prepared by extrusion-spheronization technology were formulated with a water-soluble drug, microcrystalline cellulose, and carnauba wax. Powdered carnauba wax (4%-20%) prepared by grinding or by emulsification was studied with an attempt to retard the drug release. The inclusion of ground or emulsified carnauba wax did not sustain the release of theophylline for more than 3 hours. Matrix pellets of theophylline prepared with various concentrations of carnauba wax were sintered thermally at various times and temperatures. In vitro drug release profiles indicated an increase in drug release retardation with increasing carnauba wax concentration. Pellets prepared with ground wax showed a higher standard deviation than did those prepared with emulsified wax. There was incomplete release at the end of 12 hours for pellets prepared with 20% ground or emulsified wax. The sintering temperature and duration were optimized to allow for a sustained release lasting at least 12 hours. The optimized temperature and duration were found to be 100 degrees C and 140 seconds, respectively. The sintered pellets had a higher hydrophobicity than did the unsintered pellets. Scanning electron micrographs indicated that the carnauba wax moved internally, thereby increasing the surface area of wax within the pellets.

Novel method to assess gastric emptying in humans: the Pellet Gastric Emptying Test

NASA Technical Reports Server (NTRS)

Choe, S. Y.; Neudeck, B. L.; Welage, L. S.; Amidon, G. E.; Barnett, J. L.; Amidon, G. L.

2001-01-01

To further validate the Pellet Gastric Emptying Test (PGET) as a marker of gastric emptying, a randomized, four-way crossover study was conducted with 12 healthy subjects. The study consisted of oral co-administration of enteric coated caffeine (CAFF) and acetaminophen (APAP) pellets in four treatment phases: Same Size (100 kcal), Fasted, Small Liquid Meal (100 kcal), and Standard Meal (847 kcal). The time of first appearance of measurable drug marker in plasma, t(initial), was taken as the emptying time for the markers. Co-administration of same size enteric coated pellets of CAFF and APAP (0.7 mm in diameter) revealed no statistically significant differences in t(initial) values indicating that emptying was dependent only on size and not on chemical make-up of the pellets. Co-administration of different size pellets indicated that the smaller 0.7-mm diameter (CAFF) pellets were emptied and absorbed significantly earlier than the larger 3.6-mm diameter (APAP) pellets with both the Small Liquid Meal (by 35 min) and the Standard Meal (by 33 min) (P<0.05). The differences in emptying of the pellets were not significant in the Fasted Phase. The results suggest that the pellet gastric emptying test could prove useful in monitoring changes in transit times in the fasted and fed states and their impact on drug absorption.

SPINS-IND: Pellet injector for fuelling of magnetically confined fusion systems

NASA Astrophysics Data System (ADS)

Gangradey, R.; Mishra, J.; Mukherjee, S.; Panchal, P.; Nayak, P.; Agarwal, J.; Saxena, Y. C.

2017-06-01

Using a Gifford-McMahon cycle cryocooler based refrigeration system, a single barrel hydrogen pellet injection (SPINS-IND) system is indigenously developed at Institute for Plasma Research, India. The injector is based on a pipe gun concept, where a pellet formed in situ in the gun barrel is accelerated to high speed using high pressure light propellant gas. The pellet size is decided by considering the Greenwald density limit and its speed is decided by considering a neutral gas shielding model based scaling law. The pellet shape is cylindrical of dimension (1.6 mm ℓ × 1.8 mm φ). For pellet ejection and acceleration, a fast opening valve of short opening duration is installed at the breech of the barrel. A three-stage differential pumping system is used to restrict the flow of the propellant gas into the plasma vacuum vessel. Diagnostic systems such as light gate and fast imaging camera (240 000 frames/s) are employed to measure the pellet speed and size, respectively. A trigger circuit and a programmable logic controller based integrated control system developed on LabVIEW enables to control the pellet injector remotely. Using helium as a propellant gas, the pellet speed is varied in the range 650 m/s-800 m/s. The reliability of pellet formation and ejection is found to be more than 95%. This paper describes the details of SPINS-IND and its test results.

Flocculation mechanism of the actinomycete Streptomyces sp. hsn06 on Chlorella vulgaris.

PubMed

Li, Yi; Xu, Yanting; Zheng, Tianling; Wang, Hailei

2017-09-01

In this study, an actinomycete Streptomyces sp. hsn06 with the ability to harvest Chlorella vulgaris biomass was used to investigate the flocculation mechanism. Streptomyces sp. hsn06 exhibited flocculation activity on algal cells through mycelial pellets with adding calcium. Calcium was determined to promote flocculation activity of mycelial pellets as a bridge binding with mycelial pellets and algal cells, which implied that calcium bridging is the main flocculation mechanism for mycelial pellets. Characteristics of flocculation activity confirmed proteins in mycelial pellets involved in flocculation procedure. The morphology and structure of mycelial pellets also caused dramatic effects on flocculation activity of mycelial pellets. According to the results, Streptomyces sp. hsn06 can be used as a novel flocculating microbial resource for high-efficiency harvesting of microalgae biomass. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effect of Mitral Annular Calcium on Left Ventricular Diastolic Parameters.

PubMed

Codolosa, Jose N; Koshkelashvili, Nikoloz; Alnabelsi, Talal; Goykhman, Igor; Romero-Corral, Abel; Pressman, Gregg S

2016-03-01

Assessment of left ventricular (LV) diastolic function by Doppler flow imaging and tissue Doppler is an integral part of the echocardiographic examination. Mitral annular calcium (MAC) is frequently encountered on echocardiography. The aim of this study was to assess the impact of MAC, quantitatively measured by computed tomography scan, on echocardiographic LV diastolic parameters. We included 155 patients aged ≥65 years. Computed tomography reconstructions of the mitral annulus were created, and calcium identified and quantified by Agatston technique. Calcium locations were assigned using an overlaid template depicting the annular segments in relation to surrounding anatomic structures. Echocardiographic assessment of diastolic function was performed in standard fashion. Mean age was 77 years; 49% were men; and 43% were black. Patients with MAC had lower septal e' (p = 0.003), lateral e' (p = 0.04), and average e' (p = 0.01) compared with those without MAC. They also had a higher E-wave velocity (p = 0.01) and E/e' ratio (p <0.001). When evaluated by severity of MAC, and after adjustment for multiple clinical factors, there was a graded (inverse) relation between MAC severity and septal e' (p = 0.01), lateral e' (p = 0.01), and average e' (p = 0.01). In conclusion, LV diastolic parameters, as measured by Doppler echocardiography, are altered in the presence of MAC. This could be due to direct effects of MAC on annular function or might reflect truly reduced diastolic function. Interpretation of diastolic parameters in patients with MAC should be performed with caution. Copyright © 2016 Elsevier Inc. All rights reserved.

Carbon savings with transatlantic trade in pellets: accounting for market-driven effects

NASA Astrophysics Data System (ADS)

Wang, Weiwei; Dwivedi, Puneet; Abt, Robert; Khanna, Madhu

2015-11-01

Exports of pellets from the United States (US) are growing significantly to meet the demand for renewable energy in the European Union. This transatlantic trade in pellets has raised questions about the greenhouse gas (GHG) intensity of these pellets and their effects on conventional forest product markets in the US. This paper examines the GHG intensity of pellets exported from the US using either forest biomass only or forest and agricultural biomass combined. We develop an integrated dynamic, price-endogenous, partial equilibrium model of the forestry, agricultural, and transportation sectors in the US to investigate not only the direct life-cycle GHG intensity of pellets but also the accompanying indirect market and land use effects induced by changes in prices of forest and agricultural products over the 2007-2032 period. Across different scenarios of high and low pellet demand that can be met with either forest biomass only or with forest and agricultural biomass, we find that the GHG intensity of pellet based electricity is 74% to 85% lower than that of coal-based electricity. We also find that the GHG intensity of pellets produced using agricultural and forest biomass is 28% to 34% lower than that of pellets produced using forest biomass only. GHG effects due to induced direct and indirect changes in forest carbon stock caused by changes in harvest rotations, changes in land use and in conventional wood production account for 11% to 26% of the overall GHG intensity of pellets produced from forest biomass only; these effects are negative with the use of forest and agricultural biomass.

Simulation of cryogenic turbopump annular seals

NASA Astrophysics Data System (ADS)

Palazzolo, Alan B.

1992-12-01

The goal of the current work is to develop software that can accurately predict the dynamic coefficients, forces, leakage and horsepower loss for annular seals which have a potential for affecting the rotordynamic behavior of the pumps. The fruit of last year's research was the computer code SEALPAL which included capabilities for linear tapered geometry, Moody friction factor and inlet pre-swirl. This code produced results which in most cases compared very well with check cases presented in the literature. TAMUSEAL Icode, which was written to improve SEALPAL by correcting a bug and by adding more accurate integration algorithms and additional capabilities, was then used to predict dynamic coefficients and leakage for the NASA/Pratt and Whitney Alternate Turbopump Development (ATD) LOX Pump's seal.

Analytical and numerical study of the electro-osmotic annular flow of viscoelastic fluids.

PubMed

Ferrás, L L; Afonso, A M; Alves, M A; Nóbrega, J M; Pinho, F T

2014-04-15

In this work we present semi-analytical solutions for the electro-osmotic annular flow of viscoelastic fluids modeled by the Linear and Exponential PTT models. The viscoelastic fluid flows in the axial direction between two concentric cylinders under the combined influences of electrokinetic and pressure forcings. The analysis invokes the Debye-Hückel approximation and includes the limit case of pure electro-osmotic flow. The solution is valid for both no slip and slip velocity at the walls and the chosen slip boundary condition is the linear Navier slip velocity model. The combined effects of fluid rheology, electro-osmotic and pressure gradient forcings on the fluid velocity distribution are also discussed. Copyright © 2013 Elsevier Inc. All rights reserved.

Device for installing rocket engines

NASA Technical Reports Server (NTRS)

George, T. R., Jr. (Inventor)

1976-01-01

A device for installing rocket engines is reported that is supported at a cant relative to vertical by an axially extensible, tiltable pedestal. A lifting platform supports the rocket engine at its thrust chamber exit, including a mount having a concentric base characterized by a concave bearing surface, a plurality of uniformly spaced legs extended radially from the base, and an annular receiver coaxially aligned with the base and affixed to the distal ends of said legs for receiving the thrust chamber exit. The lifting platform rests on a seat concentrically related to the pedestal and affixed to an extended end portion thereof having a convex bearing surface mated in sliding engagement with the concave bearing surface of the annular base for accommodating a rocking motion of the platform.

Development of reflective optical systems for XUV projection lithography

NASA Astrophysics Data System (ADS)

Viswanathan, V. K.; Newnam, B. E.

We describe two full-field reflective reduction systems (1 and 6.25 sq cm image area) and one scanning system (25 mm x scan length image size) that meet the performance requirements for 0.1-micron resolution projection lithography using extreme-ultraviolet (XUV) wavelengths from 10 to 15 nm. These systems consist of two centered, symmetric, annular aspheric mirrors with 35 to 40 percent central obscuration, providing a reduction ratio of 3.3 x. Outstanding features include the remarkably low distortion (less than or = 10 nm) over the entire image field and the comparatively liberal tolerances on the mirror radii and alignment. While optimized annular illumination can improve the performance, the required performance can be met with full illumination, thereby allowing a simpler system design.

Large angle magnetic suspension test fixture

NASA Technical Reports Server (NTRS)

Britcher, Colin P.

1993-01-01

Progress made under the subject grant in the period from 1 Nov. 1992 to 31 May 1993 is presented. The research involves the continued development of the Large Angle Magnetic Suspension Test Fixture (LAMSTF) and also the recommissioning of an additional piece of exisiting hardware. During the period in question, the initial configuration of LAMSTF was completed and made routinely and reliably operational. A digital phase advance controller was completed and documented. The goal of a controlled 360 deg rotation was achieved. Work started on the recommissioning of the Annular Suspension and Pointing System (ASPS). Work completed during the report period included: modeling; position sensing; controller; support of the Second International Symposium on Magnetic Suspension Technology; and recommissioning of the Annular Suspension and Pointing System.

Cook stove assembly

DOEpatents

DeFoort, Morgan W; Willson, Bryan D; Lorenz, Nathan; Brady, Michael P; Marchese, Anthony; Miller-Lionberg, Daniel D

2014-12-02

A combustion chamber, having an upper part and a lower part, may include an annular constriction, in combination with the combustion chamber, to aid in directing partially combusted gases such as carbon monoxide away from the periphery of the combustion chamber back toward its center, and into the flame front. The annular constriction may also impede the flow of partially combusted gases located at the periphery, thus increasing the time these gases spend within the combustion chamber and increasing the likelihood that any products of incomplete combustion will undergo combustion. The combustion chamber may further comprise a dual burner cooktop for directing combustion gases and exhaust to multiple cooking vessels. In further embodiments, the combustion chamber may be made of, lined, or clad with a metal alloy comprising iron, chromium, and aluminum.

Fuel assembly for the production of tritium in light water reactors

DOEpatents

Cawley, W.E.; Trapp, T.J.

1983-06-10

A nuclear fuel assembly is described for producing tritium in a light water moderated reactor. The assembly consists of two intermeshing arrays of subassemblies. The first subassemblies comprise concentric annular elements of an outer containment tube, an annular target element, an annular fuel element, and an inner neutron spectrums shifting rod. The second subassemblies comprise an outer containment tube and an inner rod of either fuel, target, or neutron spectrum shifting neutral.

Fuel assembly for the production of tritium in light water reactors

DOEpatents

Cawley, William E.; Trapp, Turner J.

1985-01-01

A nuclear fuel assembly is described for producing tritium in a light water moderated reactor. The assembly consists of two intermeshing arrays of subassemblies. The first subassemblies comprise concentric annular elements of an outer containment tube, an annular target element, an annular fuel element, and an inner neutron spectrums shifting rod. The second subassemblies comprise an outer containment tube and an inner rod of either fuel, target, or neutron spectrum shifting neutral.

An experimental technique for performing 3-D LDA measurements inside whirling annular seals

NASA Technical Reports Server (NTRS)

Morrison, Gerald L.; Johnson, Mark C.; Deotte, Robert E., Jr.; Thames, H. Davis, III.; Wiedner, Brian G.

1992-01-01

During the last several years, the Fluid Mechanics Division of the Turbomachinery Laboratory at Texas A&M University has developed a rather unique facility with the experimental capability for measuring the flow field inside journal bearings, labyrinth seals, and annular seals. The facility consists of a specially designed 3-D LDA system which is capable of measuring the instantaneous velocity vector within 0.2 mm of a wall while the laser beams are aligned almost perpendicular to the wall. This capability was required to measure the flow field inside journal bearings, labyrinth seals, and annular seals. A detailed description of this facility along with some representative results obtained for a whirling annular seal are presented.

Electron Transport and Ion Acceleration in a Low-power Cylindrical Hall Thruster

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

A. Smirnov; Y. Raitses; N.J. Fisch

2004-06-24

Conventional annular Hall thrusters become inefficient when scaled to low power. Cylindrical Hall thrusters, which have lower surface-to-volume ratio, are therefore more promising for scaling down. They presently exhibit performance comparable with conventional annular Hall thrusters. Electron cross-field transport in a 2.6 cm miniaturized cylindrical Hall thruster (100 W power level) has been studied through the analysis of experimental data and Monte Carlo simulations of electron dynamics in the thruster channel. The numerical model takes into account elastic and inelastic electron collisions with atoms, electron-wall collisions, including secondary electron emission, and Bohm diffusion. We show that in order to explainmore » the observed discharge current, the electron anomalous collision frequency {nu}{sub B} has to be on the order of the Bohm value, {nu}{sub B} {approx} {omega}{sub c}/16. The contribution of electron-wall collisions to cross-field transport is found to be insignificant. The plasma density peak observed at the axis of the 2.6 cm cylindrical Hall thruster is likely to be due to the convergent flux of ions, which are born in the annular part of the channel and accelerated towards the thruster axis.« less

Portal Annular Pancreas

PubMed Central

Harnoss, Jonathan M.; Harnoss, Julian C.; Diener, Markus K.; Contin, Pietro; Ulrich, Alexis B.; Büchler, Markus W.; Schmitz-Winnenthal, Friedrich H.

2014-01-01

Abstract Portal annular pancreas (PAP) is an asymptomatic congenital pancreas anomaly, in which portal and/or mesenteric veins are encased by pancreas tissue. The aim of the study was to determine the role of PAP in pancreatic surgery as well as its management and potential complication, specifically, postoperative pancreatic fistula (POPF). On the basis of a case report, the MEDLINE and ISI Web of Science databases were systematically reviewed up to September 2012. All articles describing a case of PAP were considered. In summary, 21 studies with 59 cases were included. The overall prevalence of PAP was 2.4% and the patients' mean (SD) age was 55.9 (16.2) years. The POPF rate in patients with PAP (12 pancreaticoduodenectomies and 3 distal pancreatectomies) was 46.7% (in accordance with the definition of the International Study Group of Pancreatic Surgery). Portal annular pancreas is a quite unattended pancreatic variant with high prevalence and therefore still remains a clinical challenge to avoid postoperative complications. To decrease the risk for POPF, attentive preoperative diagnostics should also focus on PAP. In pancreaticoduodenectomy, a shift of the resection plane to the pancreas tail should be considered; in extensive pancreatectomy, coverage of the pancreatic remnant by the falciform ligament could be a treatment option. PMID:25207658

Permanent Magnet Ecr Plasma Source With Magnetic Field Optimization

DOEpatents

Doughty, Frank C.; Spencer, John E.

2000-12-19

In a plasma-producing device, an optimized magnet field for electron cyclotron resonance plasma generation is provided by a shaped pole piece. The shaped pole piece adjusts spacing between the magnet and the resonance zone, creates a convex or concave resonance zone, and decreases stray fields between the resonance zone and the workpiece. For a cylindrical permanent magnet, the pole piece includes a disk adjacent the magnet together with an annular cylindrical sidewall structure axially aligned with the magnet and extending from the base around the permanent magnet. The pole piece directs magnetic field lines into the resonance zone, moving the resonance zone further from the face of the magnet. Additional permanent magnets or magnet arrays may be utilized to control field contours on a local scale. Rather than a permeable material, the sidewall structure may be composed of an annular cylindrical magnetic material having a polarity opposite that of the permanent magnet, creating convex regions in the resonance zone. An annular disk-shaped recurve section at the end of the sidewall structure forms magnetic mirrors keeping the plasma off the pole piece. A recurve section composed of magnetic material having a radial polarity forms convex regions and/or magnetic mirrors within the resonance zone.