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

Carbon Dioxide Removal via Passive Thermal Approaches

NASA Technical Reports Server (NTRS)

Lawson, Michael; Hanford, Anthony; Conger, Bruce; Anderson, Molly

2011-01-01

A paper describes a regenerable approach to separate carbon dioxide from other cabin gases by means of cooling until the carbon dioxide forms carbon dioxide ice on the walls of the physical device. Currently, NASA space vehicles remove carbon dioxide by reaction with lithium hydroxide (LiOH) or by adsorption to an amine, a zeolite, or other sorbent. Use of lithium hydroxide, though reliable and well-understood, requires significant mass for all but the shortest missions in the form of lithium hydroxide pellets, because the reaction of carbon dioxide with lithium hydroxide is essentially irreversible. This approach is regenerable, uses less power than other historical approaches, and it is almost entirely passive, so it is more economical to operate and potentially maintenance- free for long-duration missions. In carbon dioxide removal mode, this approach passes a bone-dry stream of crew cabin atmospheric gas through a metal channel in thermal contact with a radiator. The radiator is pointed to reject thermal loads only to space. Within the channel, the working stream is cooled to the sublimation temperature of carbon dioxide at the prevailing cabin pressure, leading to formation of carbon dioxide ice on the channel walls. After a prescribed time or accumulation of carbon dioxide ice, for regeneration of the device, the channel is closed off from the crew cabin and the carbon dioxide ice is sublimed and either vented to the environment or accumulated for recovery of oxygen in a fully regenerative life support system.

Friction modifier using adherent metallic multilayered or mixed element layer conversion coatings

NASA Technical Reports Server (NTRS)

Schramm, Harry F. (Inventor); Defalco, Frank G. (Inventor); Starks, Sr., Lloyd L. (Inventor)

2012-01-01

A process for creating conversion coatings and spin, drawing, and extrusion finishes for surfaces, wherein the conversion coatings and spin, drawing, and extrusion finishes contain potassium, phosphorus, nitrogen, silicon, and one or more non-alkaline metals. The process comprises forming a first aqueous solution of silicate, potassium hydroxide, and ammonium hydroxide; forming a second aqueous solution of water, phosphoric acid, ammonium hydroxide, an alkali metal hydroxide, and one or more non-alkaline metals, and then combining the first solution with the second solution to form a final solution. This final solution forms an anti-friction multi-layer conversion coating or a spin, drawing, and extrusion finish on a surface when applied to the surface, either directly or as an additive in lubricating fluids.

Application of quality by design (QbD) to formulation and processing of naproxen pellets by extrusion-spheronization.

PubMed

Wang, Junlin; Kan, Shuling; Chen, Tong; Liu, Jianping

2015-03-01

The aim of this research was to apply quality by design (QbD) to the development of naproxen loaded core pellets which can be used as the potential core for colon-specific pellets. In the early stages of this study, prior knowledge and preliminary studies were systematically incorporated into the risk assessment using failure mode and effect analysis (FMEA) and fishbone diagram. Then Plackett-Burman design was used to screen eight potential high risk factors (spheronization speed, spheronization time, extrusion speed, drying method, CCMC-Na concentration, lactose concentration, water concentration and Tween 80 concentration) obtained from the above risk assessment. It was discovered that out of the eight potential high risk factors only three factors (spheronization speed, extrusion speed and CCMC-Na concentration) had significant effects on the quality of the pellets. This allowed the use of Box-Behnken design (BBD) to fully elucidate the relationship between the variables and critical quality attribute (CQA). Finally, the final control space was established within which the quality of the pellets can meet the requirement of colon-specific drug delivery system. This study demonstrated that naproxen loaded core pellets were successfully designed using QbD principle.

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.

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.

Using environmental chemistry technologies for the removal of arsenic from drinking water, and fat and oil based phase change materials for thermal energy storage

NASA Astrophysics Data System (ADS)

Sutterlin, William R.

The first four chapters of this dissertation involve the removal of arsenic from drinking water. Various forms of a macroporous char prepared by partial gasification of subbituminous coal were studied for removal of arsenic(V) and arsenic(III) from water. In increasing order of effectiveness for arsenic(V) removal were untreated char < acid-washed char < char impregnated with iron(III) and gasified < char impregnated with FeS < char impregnated with iron(III) hydroxide < char coated with zerovalent iron < char impregnated with iron(III) oxide. A mass of 10 g of iron(III) oxide char removed arsenic(V) and arsenic(III) from 10,000 mL of water containing 500 micrograms/L of arsenic to levels below 10 micrograms/L. The capacity of the solid to remove arsenic was significantly diminished in water containing 4 mg/L of phosphate. An electrical current passed over 4 g of iron(III) oxide char in a column enabled removal of arsenic(III) from 14,000 mL of 500 micrograms/L arsenic(III) to below 10 micrograms/liter and at significantly higher flow rates than could be employed without electrolysis. The fifth chapter in this dissertation focused on the retention of organics onto a char/concrete pellet. A mixture of naphthalene, pentachlorophenol, biphenyl, toluene, tetrachloroethane, and chlorobenzene were impregnated into a loose granular char, a char/concrete pellet and a sand/concrete pellet. The results showed that the char/concrete pellet had significant advantages over the other forms. Chapters 6--9 focus on phase change materials (PCMs). These PCMs are made from fats and oils. PCMs are perhaps the only proven method that can provide near 100% thermal energy storage. In chapter 7 a novel HPLC method was developed that could provide quantification and qualification of the resulting products formed after PCM synthesis. In chapter 8 thermal cycling studies were conducted on the fat and oil based PCMs. These thermal cycle demonstrated that these PCMs were capable of going through a multitude of freeze and melt processes with little to no degradation if the appropriate preservative is used. Finally in chapter 9 the PCM is incorporated into a simulated 100 th scale house. A traditional freon based evaporator is used to freeze the PCM at night during electrical-off-peak hours. During the peak-load of the day the evaporator is turned off and the PCM provides the cooling for the house.

Rapid green synthesis of ZnO nanoparticles using a hydroelectric cell without an electrolyte

NASA Astrophysics Data System (ADS)

Shah, Jyoti; Kumar Kotnala, Ravinder

2017-09-01

In this study, zinc oxide (ZnO) nanoparticles were synthesized using a novel environmentally friendly hydroelectric cell without an electrolyte or external current source. The hydroelectric cell comprised a nanoporous Li substituted magnesium ferrite pellet in contact with two electrodes, with zinc as the anode and silver as an inert cathode. The surface unsaturated cations and oxygen vacancies in the nanoporous ferrite dissociated water molecules into hydronium and hydroxide ions when the hydroelectric cell was dipped into deionized water. Hydroxide ions migrated toward the zinc electrode to form zinc hydroxide and the hydronium ions were evolved as H2 gas at the silver electrode. The zinc hydroxide collected as anode mud was converted into ZnO nanoparticles by heating at 250 °C. Structural analysis using Raman spectroscopy indicated the good crystallinity of the ZnO nanoparticles according to the presence of a high intensity E2-(high) mode. The nanoparticle size distribution was 5-20 nm according to high resolution transmission electron microscopy. An indirect band gap of 2.75 eV was determined based on the Tauc plot, which indicated the existence of an interstitial cation level in ZnO. Near band edge and blue emissions were detected in photoluminescence spectral studies. The blue emissions obtained from the ZnO nanoparticles could potentially have applications in blue lasers and LEDs. The ZnO nanoparticles synthesized using this method had a high dielectric constant value of 5 at a frequency of 1 MHz, which could be useful for fabricating nano-oscillators. This facile, clean, and cost-effective method obtained a significant yield of 0.017 g for ZnO nanoparticles without applying an external current source.

Three years experience of operating and selling recovered struvite from full-scale plant.

PubMed

Ueno, Y; Fujii, M

2001-11-01

The adoption of phosphorus removal at sewage treatment works (STW) creates two main problems. Firstly large amounts of sludge are produced and secondly the quantity of the effluent deteriorates due to the increase in the phosphorus load of the sidestream. Furthermore, these processes do not remove phosphorus in a form that would enable it to be recycled. Therefore in order to control these process difficulties and produce a recyclable phosphorus product a sidestream struvite crystallisation reactor was developed. The struvite was produced in a fluidised bed reactor using dewatered filtrate from anaerobic sludge digestion. Magnesium hydroxide was added in a magnesium to phosphate ratio of 1:1 and the pH was adjusted to between 8.2-8.8 with the addition of sodium hydroxide. A retention time of 10 days alowed the growth of pellets between 0.5-1.0 mm in size. The recovered struvite contained only minute traces of toxic substances and was sold to fertiliser companies for 27,000 yen tonne(-1). It is used to enhance existing fertilisers, which are widely used on paddy rice, vegetables and flowers.

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.

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.

Enhanced thermal conductivity of uranium dioxide-silicon carbide composite fuel pellets prepared by Spark Plasma Sintering (SPS)

NASA Astrophysics Data System (ADS)

Yeo, S.; Mckenna, E.; Baney, R.; Subhash, G.; Tulenko, J.

2013-02-01

Uranium dioxide (UO2)-10 vol% silicon carbide (SiC) composite fuel pellets were produced by oxidative sintering and Spark Plasma Sintering (SPS) at a range of temperatures from 1400 to 1600 °C. Both SiC whiskers and SiC powder particles were utilized. Oxidative sintering was employed over 4 h and the SPS sintering was employed only for 5 min at the highest hold temperature. It was noted that composite pellets sintered by SPS process revealed smaller grain size, reduced formation of chemical products, higher density, and enhanced interfacial contact compared to the pellets made by oxidative sintering. For given volume of SiC, the pellets with powder particles yielded a smaller grain size than pellets with SiC whiskers. Finally thermal conductivity measurements at 100 °C, 500 °C, and 900 °C revealed that SPS sintered UO2-SiC composites exhibited an increase of up to 62% in thermal conductivity compared to UO2 pellets, while the oxidative sintered composite pellets revealed significantly inferior thermal conductivity values. The current study points to the improved processing capabilities of SPS compared to oxidative sintering of UO2-SiC composites.

Bending testing and characterization of surrogate nuclear fuel rods made of Zircaloy-4 cladding and aluminum oxide pellets

DOE PAGES

Wang, Hong; Wang, Jy-An John

2016-07-20

We studied behavior of surrogate nuclear fuel rods made of Zircaloy-4 (Zry-4) cladding with alumina pellets under reversed cyclic bending. Tests were performed under load or moment control at 5 Hz, and an empirical correlation was established between rod fatigue life and amplitude of the applied moment. Fatigue response of Zry-4 cladding was further characterized by using flexural rigidity. Degradation of flexural rigidity was shown to depend on the moment applied and the prefatigue condition of specimens. Pellet-to-pellet interface (PPI), pellet-to-cladding interface (PCI), and pellet condition all affect surrogate rod failure. Bonding/debonding of PPI/PCI and pellet fracturing contribute to surrogatemore » rod bending fatigue. Also, the effect of sensor spacing on curvature measurement using three-point deflections was studied; the method based on effective specimen gauge length is effective in sensor spacing correction. Finally, we developed the database and gained understanding in this study such that it will serve as input to analysis of SNF vibration integrity.« less

Effects of residual feed intake classification and method of alfalfa processing on ewe intake and growth.

PubMed

Redden, R R; Surber, L M M; Grove, A V; Kott, R W

2014-02-01

The objective of this research was to evaluate the effects of residual feed intake (RFI) determined under ad libitum feeding conditions on DMI and performance of yearling ewes fed either chopped or pelleted alfalfa hay. In Exp. 1, 45 ewe-lambs had ad libitum access to a pelleted grower diet for 63 d and individual DMI was determined using an electronic feed delivery system. Residual feed intake values were assigned to each ewe-lamb as a measure of feed efficiency. Sixteen ewe-lambs with the most positive RFI values were classified as high RFI (inefficient) and 16 ewe-lambs with the most negative RFI values were classified as low RFI (efficient). In Exp. 2, half of the ewes from each efficiency group were placed into 1 of 2 pens and provided ad libitum access to either pelleted or chopped alfalfa hay. Individual DMI was again determined using an electronic feed delivery system. Body weight, LM area (LMA), and 12th-rib back fat thickness (BF) were measured at the beginning and end of both experiments. In Exp. 1, DMI by ewe-lambs in the low RFI group was 9% less (P = 0.01) than by ewe-lambs in the high RFI group (2.21 vs. 2.43 kg/d); however, ADG and initial and final BW, LMA, and BF did not differ (P > 0.27) among RFI groups. In Exp. 2, there were no feed processing × RFI group interactions (P > 0.14) for any trait. By design, RFI values were lower (P < 0.01) by yearling ewes in the low than high RFI group (-0.27 vs. 0.27); however, RFI values did not differ (P = 1.0) between yearling ewes fed chopped versus pelleted alfalfa. Dry matter intake was 22% less (P < 0.01) by yearling ewes in the low than high RFI group (2.5 vs. 3.2 kg/d) and 59% less (P < 0.01) by yearling ewes fed chopped versus pelleted alfalfa (2.2 vs. 3.5 kg/d). Initial and final BW, ADG, and G:F did not differ (P > 0.45) between RFI groups but were greater (P < 0.01) by yearling ewes fed pelleted alfalfa compared to chopped alfalfa. Final LMA did not differ (P = 0.77) between RFI groups, but final BF tended to be greater (P = 0.06) for high than low RFI yearling ewes (0.63 vs. 0.57 cm). Final LMA and BF were greater (P < 0.01) by yearling ewes fed pelleted than chopped alfalfa. Low RFI ewes had lower DMI and BF compared to high RFI ewes. Ewe efficiency as determined by RFI was repeatable on subsequent forage based diets; however, differences in intake and efficiency were more apparent when alfalfa was pelleted.

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

Wang, Hong; Wang, Jy-An John

We studied behavior of surrogate nuclear fuel rods made of Zircaloy-4 (Zry-4) cladding with alumina pellets under reversed cyclic bending. Tests were performed under load or moment control at 5 Hz, and an empirical correlation was established between rod fatigue life and amplitude of the applied moment. Fatigue response of Zry-4 cladding was further characterized by using flexural rigidity. Degradation of flexural rigidity was shown to depend on the moment applied and the prefatigue condition of specimens. Pellet-to-pellet interface (PPI), pellet-to-cladding interface (PCI), and pellet condition all affect surrogate rod failure. Bonding/debonding of PPI/PCI and pellet fracturing contribute to surrogatemore » rod bending fatigue. Also, the effect of sensor spacing on curvature measurement using three-point deflections was studied; the method based on effective specimen gauge length is effective in sensor spacing correction. Finally, we developed the database and gained understanding in this study such that it will serve as input to analysis of SNF vibration integrity.« less

Reduction Behavior of Dolomite-Fluxed Magnetite: Coke Composite Pellets at 1573 K (1300 °C)

NASA Astrophysics Data System (ADS)

Park, Hyunsik; Sohn, Il; Tsalapatis, John; Sahajwalla, Veena

2018-06-01

High-temperature behavior of magnetite—coke composite pellet fluxed with dolomite was investigated by customized thermogravimetric analyzer (TGA) at 1573 K (1300 °C). The overall reaction was influenced by C/O ratio and dolomite content. The reduction was accelerated by increased amount of dolomite, while the samples with higher C/O ratio showed the improved reduction degree. X-ray diffraction (XRD) pattern of reduced pellet showed the phase changes of the iron oxides. Noticeable iron peaks were observed when the sample reached the final stage of reduction. CO and CO2 gases released from the reaction were measured by Infrared (IR) gas analyzer. Relation between enhanced reducibility of pellets and larger CO gas evolution from the Boudouard reaction was confirmed from the analysis. Compressive strengths were studied for the practical assessment of reduced pellets. Samples with low-reduction degree showed better physical property. Excessive amount of dolomite also deteriorated the integrity of pellets.

Process for preparing active oxide powders

DOEpatents

Berard, Michael F.; Hunter, Jr., Orville; Shiers, Loren E.; Dole, Stephen L.; Scheidecker, Ralph W.

1979-02-20

An improved process for preparing active oxide powders in which cation hydroxide gels, prepared in the conventional manner are chemically dried by alternately washing the gels with a liquid organic compound having polar characteristics and a liquid organic compound having nonpolar characteristics until the mechanical water is removed from the gel. The water-free cation hydroxide is then contacted with a final liquid organic wash to remove the previous organic wash and speed drying. The dried hydroxide treated in the conventional manner will form a highly sinterable active oxide powder.

Experimental studies and simulations of hydrogen pellet ablation in the stellarator TJ-II

NASA Astrophysics Data System (ADS)

Panadero, N.; McCarthy, K. J.; Koechl, F.; Baldzuhn, J.; Velasco, J. L.; Combs, S. K.; de la Cal, E.; García, R.; Hernández Sánchez, J.; Silvagni, D.; Turkin, Y.; TJ-II Team; W7-X Team

2018-02-01

Plasma core fuelling is a key issue for the development of steady-state scenarios in large magnetically-confined fusion devices, in particular for helical-type machines. At present, cryogenic pellet injection is the most promising technique for efficient fuelling. Here, pellet ablation and fuelling efficiency experiments, using a compact pellet injector, are carried out in electron cyclotron resonance and neutral beam injection heated plasmas of the stellarator TJ-II. Ablation profiles are reconstructed from light emissions collected by silicon photodiodes and a fast-frame camera system, under the assumptions that such emissions are loosely related to the ablation rate and that pellet radial acceleration is negligible. In addition, pellet particle deposition and fuelling efficiency are determined using density profiles provided by a Thomson scattering system. Furthermore, experimental results are compared with ablation and deposition profiles provided by the HPI2 pellet code, which is adapted here for the stellarators Wendelstein 7-X (W7-X) and TJ-II. Finally, the HPI2 code is used to simulate ablation and deposition profiles for pellets of different sizes and velocities injected into relevant W7-X plasma scenarios, while estimating the plasmoid drift and the fuelling efficiency of injections made from two W7-X ports.

Characteristics of pellet injuries to the orbit.

PubMed

Kükner, A Sahap; Yilmaz, Turgut; Celebi, Serdal; Karslioğlu, Safak; Alagöz, Gürsoy; Serin, Didem; Acar, M Akif; Ozveren, M Faik

2009-01-01

To investigate the features of orbital injuries by pellets fired from the front. Retrospective, 4 cases of pellet injuries. Five orbits of 4 patients who sustained pellet injuries received from the front were reviewed retrospectively. The course of injury and results were assessed. Radiological examinations were reviewed. The patients were evaluated between December 1996 and June 2004. Five orbits of 4 patients sustained injuries caused by pellets fired from an anterior direction. The globe in the injured orbit was intact in 2 cases. Severe loss of vision was also present in these 2 globes due to optic nerve involvement. Final visual acuity was down to no light perception in 4 eyes and limited to light perception in 1 eye. The prognosis of orbital pellet injuries is, unfortunately, poor. A pellet passing through the floor of the orbit often causes double perforation of the globe and, once in the orbital aperture, it travels towards the apex as a result of the conical shape of the orbit and lodges in the optic canal or its entrance, severely damaging the optic nerve. Surgery or other treatments are usually unsuccessful. Even if the globe is intact, vision is usually severely impaired. Copyright 2009 S. Karger AG, Basel.

COMPARTMENTED REACTOR FUEL ELEMENT

DOEpatents

Cain, F.M. Jr.

1962-09-11

A method of making a nuclear reactor fuel element of the elongated red type is given wherein the fissionable fuel material is enclosed within a tubular metal cladding. The method comprises coating the metal cladding tube on its inside wall with a brazing alloy, inserting groups of cylindrical pellets of fissionable fuel material into the tube with spacing members between adjacent groups of pellets, sealing the ends of the tubes to leave a void space therewithin, heating the tube and its contents to an elevated temperature to melt the brazing alloy and to expand the pellets to their maximum dimensions under predetermined operating conditions thereby automatically positioning the spacing members along the tube, and finally cooling the tube to room temperature whereby the spacing disks become permanently fixed at their edges in the brazing alloy and define a hermetically sealed compartment for each fl group of fuel pellets. Upon cooling, the pellets contract thus leaving a space to accommodate thermal expansion of the pellets when in use in a reactor. The spacing members also provide lateral support for the tubular cladding to prevent collapse thereof when subjected to a reactor environment. (AEC)

Pyrolysis of chromium rich tanning industrial wastes and utilization of carbonized wastes in metallurgical process.

PubMed

Tôrres Filho, Artur; Lange, Liséte Celina; de Melo, Gilberto Caldeira Bandeira; Praes, Gustavo Eduardo

2016-02-01

Pyrolysis is the thermal degradation of organic material in oxygen-free or very lean oxygen atmosphere. This study evaluates the use of pyrolysis for conversion of leather wastes from chromium tanning processes into Carbonized Leather Residues (CLR), and the utilization of CLR in metallurgical processes through the production of iron ore pellets. CLR was used to replace mineral coal in proportions of 10% and 25% on fixed carbon basis content in the mixtures for pellets preparation. Experimental conversions were performed on a pilot scale pyrolysis plant and a pelletizing reactor of the "pot grate" type. The results demonstrated the technical feasibility of using the charcoal product from animal origin as an energy source, with recovery of up to 76.47% of chromium contained in CLR in the final produced of iron ore pellets. Pellets with 25% replacement of fixed carbon in the coal showed an enhanced compressive strength, with an average value of 344kgfpellet(-1), compared to 300kgfpellet(-1) for standard produced pellets. Copyright © 2015. Published by Elsevier Ltd.

Sequential soil transport and its influence on the spatial organisation of collective digging in leaf-cutting ants.

PubMed

Pielström, Steffen; Roces, Flavio

2013-01-01

The Chaco leaf-cutting ant Atta vollenweideri (Forel) inhabits large and deep subterranean nests composed of a large number of fungus and refuse chambers. The ants dispose of the excavated soil by forming small pellets that are carried to the surface. For ants in general, the organisation of underground soil transport during nest building remains completely unknown. In the laboratory, we investigated how soil pellets are formed and transported, and whether their occurrence influences the spatial organisation of collective digging. Similar to leaf transport, we discovered size matching between soil pellet mass and carrier mass. Workers observed while digging excavated pellets at a rate of 26 per hour. Each excavator deposited its pellets in an individual cluster, independently of the preferred deposition sites of other excavators. Soil pellets were transported sequentially over 2 m, and the transport involved up to 12 workers belonging to three functionally distinct groups: excavators, several short-distance carriers that dropped the collected pellets after a few centimetres, and long-distance, last carriers that reached the final deposition site. When initiating a new excavation, the proportion of long-distance carriers increased from 18% to 45% within the first five hours, and remained unchanged over more than 20 hours. Accumulated, freshly-excavated pellets significantly influenced the workers' decision where to start digging in a choice experiment. Thus, pellets temporarily accumulated as a result of their sequential transport provide cues that spatially organise collective nest excavation.

The effects of storage on the net calorific value of wood pellets

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

Lee, Jun Sian; Sokhansanj, S.; Lau, A. K.

The wood pellet export from Canada to Europe has been increasing steadily in recent years (roughly 1.8 million ton in 2013). Due to distances involved, wood pellets remain in transit and storage for months before their final consumption. The net calorific value determines the price of wood pellet purchase in Europe. There have been concerns about the changes of net calorific values over time. In this study, the effects of storage time, storage configuration, storage temperature, and wood pellet quality on the net calorific value of wood pellets for a period of 6 months were investigated. Storage configurations were openmore » or closed and storage temperatures were 25 °C, 35 °C and 45 °C. Two types of wood pellets used were whitewood and mixed. The results in closed storage indicated that storage time had a positive effect on the net calorific value where the net calorific value increased by 1% to 2% over the storage period. In open storage, the moisture content had the most significant impact on the net calorific value. The net calorific values of the two types of wood pellets were found to be significantly different at p < 0.001. A multivariable linear regression and analyses of variance performed verified the graphical results. Lastly, the authors postulated that the higher energy potential compounds, such as aldehyde and ketone, produced during pellet storage, caused the increase in net calorific values.« less

The effects of storage on the net calorific value of wood pellets

DOE PAGES

Lee, Jun Sian; Sokhansanj, S.; Lau, A. K.; ...

2015-06-30

The wood pellet export from Canada to Europe has been increasing steadily in recent years (roughly 1.8 million ton in 2013). Due to distances involved, wood pellets remain in transit and storage for months before their final consumption. The net calorific value determines the price of wood pellet purchase in Europe. There have been concerns about the changes of net calorific values over time. In this study, the effects of storage time, storage configuration, storage temperature, and wood pellet quality on the net calorific value of wood pellets for a period of 6 months were investigated. Storage configurations were openmore » or closed and storage temperatures were 25 °C, 35 °C and 45 °C. Two types of wood pellets used were whitewood and mixed. The results in closed storage indicated that storage time had a positive effect on the net calorific value where the net calorific value increased by 1% to 2% over the storage period. In open storage, the moisture content had the most significant impact on the net calorific value. The net calorific values of the two types of wood pellets were found to be significantly different at p < 0.001. A multivariable linear regression and analyses of variance performed verified the graphical results. Lastly, the authors postulated that the higher energy potential compounds, such as aldehyde and ketone, produced during pellet storage, caused the increase in net calorific values.« less

Nickel hydroxides and related materials: a review of their structures, synthesis and properties

PubMed Central

Hall, David S.; Lockwood, David J.; Bock, Christina; MacDougall, Barry R.

2015-01-01

This review article summarizes the last few decades of research on nickel hydroxide, an important material in physics and chemistry, that has many applications in engineering including, significantly, batteries. First, the structures of the two known polymorphs, denoted as α-Ni(OH)2 and β-Ni(OH)2, are described. The various types of disorder, which are frequently present in nickel hydroxide materials, are discussed including hydration, stacking fault disorder, mechanical stresses and the incorporation of ionic impurities. Several related materials are discussed, including intercalated α-derivatives and basic nickel salts. Next, a number of methods to prepare, or synthesize, nickel hydroxides are summarized, including chemical precipitation, electrochemical precipitation, sol–gel synthesis, chemical ageing, hydrothermal and solvothermal synthesis, electrochemical oxidation, microwave-assisted synthesis, and sonochemical methods. Finally, the known physical properties of the nickel hydroxides are reviewed, including their magnetic, vibrational, optical, electrical and mechanical properties. The last section in this paper is intended to serve as a summary of both the potentially useful properties of these materials and the methods for the identification and characterization of ‘unknown’ nickel hydroxide-based samples. PMID:25663812

Avoidance of Timeout from Response-Independent Food: Effects of Delivery Rate and Quality

ERIC Educational Resources Information Center

Richardson, Joseph V.; Baron, Alan

2008-01-01

In three experiments, a rat's lever presses could postpone timeouts from food pellets delivered on response-independent schedules. In Experiment 1, the pellets were delivered at variable-time (VT) rates ranging from VT 0.5 to VT 8 min. Experiment 2 replicated the VT 1 min and VT 8 min conditions of Experiment 1 with new subjects. Finally, subjects…

Effects of processing, particle size and moisturizing of sorghum-based feeds on pellet quality and broiler production.

PubMed

da Silva, Patrícia Garcia; Oliveira, Luana Martins Schaly; de Oliveira, Nayanne Rodrigues; de Moura Júnior, Fábio Ataides; Silva, Maura Regina Sousa; Cordeiro, Deibity Alves; Minafra, Cibele Silva; Dos Santos, Fabiana Ramos

2018-01-01

This study aimed to assess the effect of pelleted and expanded sorghum-based feeds prepared with different moisture levels and particle size of ingredients on metabolizable energy, ileal digestibility of amino acids and broiler performance. The experiment was performed with 720 male broiler chicks of the Cobb strain, with treatments of six replications, with 15 birds each; they were arranged in a completely randomized design and 2×2×2 factorial scheme (pelleted or expanded feed processing, 0.8% or 1.6% moisture addition in the mixer, and particle size of 650 or 850 microns). Higher pellet quality (pellets, % and pellet durability index [PDI]) was obtained in expanded diets and inclusion of 1.6% moisture. The particle size of 850 microns increased the PDI of final diet. All studied treatments had no significant effect on weight gain and broiler carcass and cut yields. Lower feed conversion occurred for birds fed pelleted feed at 42 d. The highest apparent metabolizable energy (AME) and apparent metabolizable energy corrected to zero nitrogen balance (AMEn) values of feed in the initial rearing phase (10 to 13 days) were observed in birds fed pelleted feed or for feed prepared with 1.6% moisture. The highest ileal digestibility coefficients of amino acids were obtained with the consumption of pelleted feed prepared with a particle size of 650 microns and 1.6% moisture. Pelleted feed prepared with a milling particle size of 650 microns and 1.6% moisture provided increased ileal digestibility of amino acids and AMEn in the starter period. However, the expanded feed improved pellet quality and feed conversion of broilers at 42 days of age. We conclude that factors such as moisture, particle size and processing affect the pellet quality, and therefore should be considered when attempting to optimize broiler performance.

Effects of processing, particle size and moisturizing of sorghum-based feeds on pellet quality and broiler production

PubMed Central

2018-01-01

Objective This study aimed to assess the effect of pelleted and expanded sorghum-based feeds prepared with different moisture levels and particle size of ingredients on metabolizable energy, ileal digestibility of amino acids and broiler performance. Methods The experiment was performed with 720 male broiler chicks of the Cobb strain, with treatments of six replications, with 15 birds each; they were arranged in a completely randomized design and 2×2×2 factorial scheme (pelleted or expanded feed processing, 0.8% or 1.6% moisture addition in the mixer, and particle size of 650 or 850 microns). Results Higher pellet quality (pellets, % and pellet durability index [PDI]) was obtained in expanded diets and inclusion of 1.6% moisture. The particle size of 850 microns increased the PDI of final diet. All studied treatments had no significant effect on weight gain and broiler carcass and cut yields. Lower feed conversion occurred for birds fed pelleted feed at 42 d. The highest apparent metabolizable energy (AME) and apparent metabolizable energy corrected to zero nitrogen balance (AMEn) values of feed in the initial rearing phase (10 to 13 days) were observed in birds fed pelleted feed or for feed prepared with 1.6% moisture. The highest ileal digestibility coefficients of amino acids were obtained with the consumption of pelleted feed prepared with a particle size of 650 microns and 1.6% moisture. Conclusion Pelleted feed prepared with a milling particle size of 650 microns and 1.6% moisture provided increased ileal digestibility of amino acids and AMEn in the starter period. However, the expanded feed improved pellet quality and feed conversion of broilers at 42 days of age. We conclude that factors such as moisture, particle size and processing affect the pellet quality, and therefore should be considered when attempting to optimize broiler performance. PMID:28920405

Fusible pellet transport and storage of heat

NASA Technical Reports Server (NTRS)

Bahrami, P. A.

1982-01-01

A new concept for both transport and storage of heat at high temperatures and heat fluxes is introduced and the first steps in analysis of its feasibility is taken. The concept utilizes the high energy storage capability of materials undergoing change of phase. The phase change material, for example a salt, is encapsulated in corrosion resistant sealed pellets and transported in a carrier fluid to heat source and storage. Calculations for heat transport from a typical solar collector indicate that the pellet mass flow rates are relatively small and that the required pumping power is only a small fraction of the energy transport capability of the system. Salts and eutectic salt mixtures as candidate phase change materials are examined and discussed. Finally, the time periods for melting or solidification of sodium chloride pellets is investigated and reported.

Fusible pellet transport and storage of heat

NASA Astrophysics Data System (ADS)

Bahrami, P. A.

1982-06-01

A new concept for both transport and storage of heat at high temperatures and heat fluxes is introduced and the first steps in analysis of its feasibility is taken. The concept utilizes the high energy storage capability of materials undergoing change of phase. The phase change material, for example a salt, is encapsulated in corrosion resistant sealed pellets and transported in a carrier fluid to heat source and storage. Calculations for heat transport from a typical solar collector indicate that the pellet mass flow rates are relatively small and that the required pumping power is only a small fraction of the energy transport capability of the system. Salts and eutectic salt mixtures as candidate phase change materials are examined and discussed. Finally, the time periods for melting or solidification of sodium chloride pellets is investigated and reported.

Characterization of reactive CaCO 3 crystallization in a fluidized bed reactor as a central process of direct air capture

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

Burhenne, Luisa; Giacomin, Caroline; Follett, Trevor

A laboratory-scale, fluidized-bed pellet reactor (BPR) was used to investigate a CaCO 3 crystallization process for the recovery of CO 2 in a Direct Air Capture (DAC) process. The BPR performance was validated against data from a pilot-scale unit. Subsequently, the pellet growth under process-relevant conditions was studied over a period of 144 h. The experimental results with the BPR, containing a bed of pellets sized between 0.65 and 0.84 mm, have shown that a calcium retention of 80% can be achieved at a fluidization velocity of 60 m h -1 and a calcium loading rate of 3 mol hmore » -1. This result is consistent with calcium retention observed at pilot scale operation and hence, results from the BPR are considered representative for the pilot scale unit. Starting with a bed of pellets sized between 0.15 and 0.5 mm, the average pellet growth rate, G, at the reactor bottom increased from 8.1E-10 to 11E–10 m s -1 at the onset and decreased to 4.9E–10 m s -1 over the course of a 144 h test. The calcium retention over the course the test showed the same trend (initial increase and final decrease) as the pellet growth rate. A theoretical bed growth model was developed and validated against data from the pilot scale and benchtop pellet reactors. The model was used to calculate the bed porosity and total pellet surface area in each control volume. Lastly, the pellet surface area growth at the bottom of the reactor reproduced the pellet growth and retention data trends.« less

Characterization of reactive CaCO 3 crystallization in a fluidized bed reactor as a central process of direct air capture

DOE PAGES

Burhenne, Luisa; Giacomin, Caroline; Follett, Trevor; ...

2017-10-25

A laboratory-scale, fluidized-bed pellet reactor (BPR) was used to investigate a CaCO 3 crystallization process for the recovery of CO 2 in a Direct Air Capture (DAC) process. The BPR performance was validated against data from a pilot-scale unit. Subsequently, the pellet growth under process-relevant conditions was studied over a period of 144 h. The experimental results with the BPR, containing a bed of pellets sized between 0.65 and 0.84 mm, have shown that a calcium retention of 80% can be achieved at a fluidization velocity of 60 m h -1 and a calcium loading rate of 3 mol hmore » -1. This result is consistent with calcium retention observed at pilot scale operation and hence, results from the BPR are considered representative for the pilot scale unit. Starting with a bed of pellets sized between 0.15 and 0.5 mm, the average pellet growth rate, G, at the reactor bottom increased from 8.1E-10 to 11E–10 m s -1 at the onset and decreased to 4.9E–10 m s -1 over the course of a 144 h test. The calcium retention over the course the test showed the same trend (initial increase and final decrease) as the pellet growth rate. A theoretical bed growth model was developed and validated against data from the pilot scale and benchtop pellet reactors. The model was used to calculate the bed porosity and total pellet surface area in each control volume. Lastly, the pellet surface area growth at the bottom of the reactor reproduced the pellet growth and retention data trends.« less

Plasma fuelling with cryogenic pellets in the stellarator TJ-II

NASA Astrophysics Data System (ADS)

McCarthy, K. J.; Panadero, N.; Velasco, J. L.; Combs, S. K.; Caughman, J. B. O.; Fontdecaba, J. M.; Foust, C.; García, R.; Hernández Sánchez, J.; Navarro, M.; Pastor, I.; Soleto, A.; the TJ-II Team

2017-05-01

Cryogenic pellet injection is a widely used technique for delivering fuel to the core of magnetically confined plasmas. Indeed, such systems are currently functioning on many tokamak, reversed field pinch and stellarator devices. A pipe-gun-type pellet injector is now operated on the TJ-II, a low-magnetic shear stellarator of the heliac type. Cryogenic hydrogen pellets, containing between 3  ×  1018 and 4  ×  1019 atoms, are injected at velocities between 800 and 1200 m s-1 from its low-field side into plasmas created and/or maintained in this device by electron cyclotron resonance and/or neutral beam injection heating. In this paper, the first systematic study of pellet ablation, particle deposition and fuelling efficiency is presented for TJ-II. From this, light-emission profiles from ablating pellets are found to be in reasonable agreement with simulated pellet ablation profiles (created using a neutral gas shielding-based code) for both heating scenarios. In addition, radial offsets between recorded light-emission profiles and particle deposition profiles provide evidence for rapid outward drifting of ablated material that leads to pellet particle loss from the plasma. Finally, fuelling efficiencies are documented for a range of target plasma densities (~4  ×  1018-  ~2  ×  1019 m-3). These range from ~20%-  ~85% and are determined to be sensitive to pellet penetration depth. Additional observations, such as enhanced core ablation, are discussed and planned future work is outlined.

Method for making polysilsesquioxanes and organohydridosilanes

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

Loy, Douglas A.; Rahimian, Kamyar

2001-01-01

A method for disproportionation of an oligohydridosiloxane to produce a polysilsesquioxane compound and an organohydridosilane compound when contacted with a basic catalyst. The basic catalyst can be a tetraalkylammonium hydroxide, an alkali metal hydroxide, and an alkali earth hydroxide. These basic catalysts are generally dissolved in an organic solvent for delivery. The hydroxide catalysts are attractive because many readily decompose by heating above 150.degree. C., thus being easily removed from the final materials. The oligohydridosiloxane is contacted with the basic catalyst under conditions effective to catalytically convert the oligohydridosiloxane into a polysilsesquioxane compound and an organohydridosilane compound. The reaction canmore » occur in either an inert or oxidative atmosphere and can occur without heating, at room temperature. Both polysilsesquioxane foams and gels of the formula (RSiO.sub.1.5).sub.n can be produced.« less

Evaluation of conditioning time and temperature on gelatinized starch and vitamin retention in a pelleted swine diet.

PubMed

Lewis, L L; Stark, C R; Fahrenholz, A C; Bergstrom, J R; Jones, C K

2015-02-01

Two key feed processing parameters, conditioning temperature and time, were altered to determine their effects on concentration of gelatinized starch and vitamin retention in a pelleted finishing swine diet. Diet formulation (corn–soybean meal based with 30% distillers dried grains with solubles) was held constant. Treatments were arranged in a 2 × 3 factorial design plus a control with 2 conditioning temperatures (77 vs. 88°C) and 3 conditioner retention times (15, 30, and 60 s). In addition, a mash diet not subjected to conditioning served as a control for a total of 7 treatments. Samples were collected after conditioning but before pelleting (hot mash), after pelleting but before cooling (hot pellet), and after pelleting and cooling (cold pellet) and analyzed for percentage total starch, percentage gelatinized starch, and riboflavin, niacin, and vitamin D3 concentrations. Total percentage starch was increased by greater conditioning temperature (P = 0.041) but not time (P > 0.10), whereas higher temperature and longer time both increased (P < 0.05) percentage gelatinized starch, with increasing time resulting in a linear increase in percentage starch gelatinization (P = 0.013). The interaction between conditioning temperature and time increased percentage gelatinized starch (P = 0.003) but not percentage total starch (P > 0.10). Sample location also affected both percentage total starch and gelatinized starch (P < 0.05), with the greatest increase in percentage gelatinized starch occurring between hot mash and hot pellet samples. As expected, the pelleting process increased percentage gelatinized starch (P = 0.035; 7.3 vs. 11.7% gelatinized starch for hot mash vs. hot pellet samples, respectively), but there was no difference in total starch concentrations (P > 0.10). Finally, neither conditioning temperature nor time affected riboflavin, niacin, or vitamin D3 concentrations (P > 0.10). In summary, both increasing conditioningtemperature and time effect percentage gelatinized starch, but not to the extent of forcing the diet through a pelleting die.

Research of interaction between technological and material parameters during densification of sunflower hulls

NASA Astrophysics Data System (ADS)

Križan, Peter; Matúš, Miloš; Beniak, Juraj; Šooš, Ľubomír

2018-01-01

During the biomass densification can be recognized various technological variables and also material parameters which significantly influences the final solid biofuels (pellets) quality. In this paper, we will present the research findings concerning relationships between technological and material variables during densification of sunflower hulls. Sunflower hulls as an unused source is a typical product of agricultural industry in Slovakia and belongs to the group of herbaceous biomass. The main goal of presented experimental research is to determine the impact of compression pressure, compression temperature and material particle size distribution on final biofuels quality. Experimental research described in this paper was realized by single-axis densification, which was represented by experimental pressing stand. The impact of mentioned investigated variables on the final briquettes density and briquettes dilatation was determined. Mutual interactions of these variables on final briquettes quality are showing the importance of mentioned variables during the densification process. Impact of raw material particle size distribution on final biofuels quality was also proven by experimental research on semi-production pelleting plant.

Development of multiple-unit pellet system tablets by employing the SeDeM expert diagram system I: pellets with different sizes.

PubMed

Hamman, Hannlie; Hamman, Josias; Wessels, Anita; Scholtz, Jacques; Steenekamp, Jan Harm

2017-07-03

Multiple-unit pellet systems (MUPS) provide several pharmacokinetic and pharmacodynamic advantages over single-unit dosage forms, however, compression of pellets into MUPS tablets present certain challenges. Although the SeDeM Expert Diagram System (SeDeM EDS) was originally developed to provide information about the most appropriate excipient and the minimum amount thereof that is required for producing direct compressible tablets, this study investigated the possibility to apply the SeDeM EDS in the production of MUPS tablets. In addition, the effect of pellet size (i.e. 0.5, 1.0, 1.5, 2.0, and 2.5 mm) on SeDeM EDS predictions regarding the MUPS tablet formulations was investigated. The compressibility incidence factor values were below the acceptable value (i.e. 5.00) for all the pellet sizes. Kollidon ® VA 64 was identified as the most appropriate excipient to improve compressibility. The compression indices, namely, the parameter index (IP), parametric profile index (IPP), and good compression index (GCI) indicated that acceptable MUPS tablets could be produced from the final pellet-excipient blends based on predictions from the SeDeM EDS. These MUPS tablets complied with specifications for friability, hardness, and mass variation. The SeDeM EDS system is therefore applicable to assist in the formulation of acceptable MUPS tablets.

Methods for the continuous production of plastic scintillator materials

DOEpatents

Bross, Alan; Pla-Dalmau, Anna; Mellott, Kerry

1999-10-19

Methods for producing plastic scintillating material employing either two major steps (tumble-mix) or a single major step (inline-coloring or inline-doping). Using the two step method, the polymer pellets are mixed with silicone oil, and the mixture is then tumble mixed with the dopants necessary to yield the proper response from the scintillator material. The mixture is then placed in a compounder and compounded in an inert gas atmosphere. The resultant scintillator material is then extruded and pelletized or formed. When only a single step is employed, the polymer pellets and dopants are metered into an inline-coloring extruding system. The mixture is then processed under a inert gas atmosphere, usually argon or nitrogen, to form plastic scintillator material in the form of either scintillator pellets, for subsequent processing, or as material in the direct formation of the final scintillator shape or form.

Agent neutralization study IV. VX-caustic peroxide reactions. Final report, August 1993-February 1994

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

Hovanec, J.W.; Albizo, J.M.; Henderson, V.D.

1994-08-01

The use of concentrated mixtures of hydrogen peroxide and sodium hydroxide for the chemical neutralization (detoxification) of VX has been examined. The reaction of VX in 4 N sodium hydroxide/11% hydrogen peroxide is rapid and exothermic. Care must be taken to avoid temperature increases which can induce peroxide decomposition. This can be done by controlling the addition of VX to the reaction. (Author).

Norwegian scabies in a malnourished young adult: a case report.

PubMed

Subramaniam, Girija; Kaliaperumal, Karthikeyan; Duraipandian, Jeyakumari; Rengasamy, Gopal

2010-06-03

A 19-year-old male was admitted to the medical ward with complaints of fever and swelling of the ankle and wrist joints of about two weeks duration. The patient developed hyperkeratotic lesions of the skin over the hands, elbow and back about three weeks after admission. Antistreptolysin O, rheumatoid factor, and Widal tests as well as Chickungunya, brucella, HIV and antinuclear antibodies were negative. Culture of blood sample and pus aspirate from the ankle and chest yielded a pure growth of Staphylococcus epidermidis. Potassium hydroxide (KOH) mount of the scrapings from crusted skin lesions showed plenty of adult mites, eggs and faecal pellets of Sarcoptes scabiei. A diagnosis of crusted scabies with secondary bacterial infection was made and the patient was treated successfully with oral ivermectin, topical permethrin and vancomycin.

Regenerable cement sorbent for recycle fluidized-bed combustion systems. Final report

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

Yoo, H.J.; Steinberg, M.

1985-04-01

Agglomerated cement sorbent pellets (ACS) were investigated as a regenerable sorbent for the purpose of removing SO/sub 2/ in a circulating fluidized-bed combustion (CFBC) system. The systems concept is to use an intermediate size sorbent pellet so that fine flyash can be separated from the sorbent at the top end of the CFBC and the coarse gangue can be separated from the sorbent remaining in the bottom end. In this study, basic experimental data were obtained on the sulfur capture capacity and regenerability of the ACS pellets as a function of the concentration of flyash mixed with the pellets andmore » as a function of temperature. Thermogravimetric Analysis (TGA) was used for this purpose. A 40 mm bench-scale fluidized-bed unit operated with a simulated combustion gas mixture was used to determine the attrition resistance of the pellets. The results indicate that 30-100 mesh ACS pellets at 958/sup 0/C (1756/sup 0/F) maintain a 55-60% sulfation capacity mixed with coal flyash concentration up to 75% by weight. The sorbent pellets were 100% regenerable and did not lose reactivity in repeated cyclical sulfation and regeneration tests. At higher temperatures up to 1158/sup 0/C (2116/sup 0/F) reactivity towards SO/sub 2/ declines due to sintering of the flyash on the surface of the ACS pellets. Tests showed good attrition resistance with only 1% loss per cycle in cyclical operation. These initial basic results indicate that ACS pellets are potentially useful as a recoverable and regenerable high capacity SO/sub 2/ sorbent in a circulating fluidized-bed combustion system. 5 refs., 7 figs., 8 tabs.« less

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.

An evaluation of total starch and starch gelatinization methodologies in pelleted animal feed.

PubMed

Zhu, L; Jones, C; Guo, Q; Lewis, L; Stark, C R; Alavi, S

2016-04-01

The quantification of total starch content (TS) or degree of starch gelatinization (DG) in animal feed is always challenging because of the potential interference from other ingredients. In this study, the differences in TS or DG measurement in pelleted swine feed due to variations in analytical methodology were quantified. Pelleted swine feed was used to create 6 different diets manufactured with various processing conditions in a 2 × 3 factorial design (2 conditioning temperatures, 77 or 88°C, and 3 conditioning retention times, 15, 30, or 60 s). Samples at each processing stage (cold mash, hot mash, hot pelletized feed, and final cooled pelletized feed) were collected for each of the 6 treatments and analyzed for TS and DG. Two different methodologies were evaluated for TS determination (the AOAC International method 996.11 vs. the modified glucoamylase method) and DG determination (the modified glucoamylase method vs. differential scanning calorimetry [DSC]). For TS determination, the AOAC International method 996.11 measured lower TS values in cold pellets compared with the modified glucoamylase method. The AOAC International method resulted in lower TS in cold mash than cooled pelletized feed, whereas the modified glucoamylase method showed no significant differences in TS content before or after pelleting. For DG, the modified glucoamylase method demonstrated increased DG with each processing step. Furthermore, increasing the conditioning temperature and time resulted in a greater DG when evaluated by the modified glucoamylase method. However, results demonstrated that DSC is not suitable as a quantitative tool for determining DG in multicomponent animal feeds due to interferences from nonstarch transformations, such as protein denaturation.

Design and optimization of disintegrating pellets of MCC by non-aqueous extrusion process using statistical tools.

PubMed

Gurram, Rajesh Kumar; Gandra, Suchithra; Shastri, Nalini R

2016-03-10

The objective of the study was to design and optimize a disintegrating pellet formulation of microcrystalline cellulose by non-aqueous extrusion process for a water sensitive drug using various statistical tools. Aspirin was used as a model drug. Disintegrating matrix pellets of aspirin using propylene glycol as a non-aqueous granulation liquid and croscarmellose as a disintegrant was developed. Plackett-Burman design was initially conducted to screen and identify the significant factors. Final optimization of formula was performed by response surface methodology using a central composite design. The critical attributes of the pellet dosage forms (dependent variables); disintegration time, sphericity and yield were predicted with adequate accuracy based on the regression model. Pareto charts and contour charts were studied to understand the influence of factors and predict the responses. A design space was constructed to meet the desirable targets of the responses in terms of disintegration time <5min, maximum yield, sphericity >0.95 and friability <1.7%. The optimized matrix pellets were enteric coated using Eudragit L 100. The drug release from the enteric coated pellets after 30min in the basic media was ~93% when compared to ~77% from the marketed pellets. The delayed release pellets stored at 25°C/60% RH were stable for a period of 10mo. In conclusion, it can be stated that the developed process for disintegrating pellets using non-aqueous granulating agents can be used as an alternative technique for various water sensitive drugs, circumventing the application of volatile organic solvents in conventional drug layering on inert cores. The scope of this study can be further extended to hydrophobic drugs, which may benefit from the rapid disintegration property and the use of various hydrophilic excipients used in the optimized pellet formulation to enhance dissolution and in turn improve bioavailability. Copyright © 2016 Elsevier B.V. All rights reserved.

[Selective feeding in fish: Effect of feeding and defensive motivations evoked by natural odors].

PubMed

Kasumyan, A O; Marusov, E A

2015-01-01

The effect of feeding and defensive motivations evoked by natural olfactory signals (the food odor, the alarm pheromone) on choice and consumption of food items different in color and taste, and the manifestation of foraging behavior were examined in fish (koi Cyprinus carpio, roach Rutilus rutilus). The agar-agar pellets of red and green color having one of the amino acids (glycine, L-proline, L-alanine; all in concentration of 0.1 M) were simultaneously offered to single fishes in pure water, and in water extract of Chironomidae larvae or in water extract of fish skin. It was found out that odors used have different effects on fish foraging activity and on pellet selection for both pellet choice and consumption. On background of food odor, fish grasped pellets more often than in pure water. The equal choice of red and green pellets in pure water shifted to the preference of red ones in the presence of food odor. Despite the increase in the absolute number of pellets grasped, the relative consumption reduced and was replaced by selective consumption of pellets with glycine regardless of their color. Increasing demand for the food quality, due to the increased feeding motivation in response to food odor, is an important adaptation enhancing selection and consumption of food with more appropriate sensory qualities for fish. Defensive motivation caused by alarm pheromone suppressed predisposition. of fish to feed. Fish grasped pellets several times less often than in pure water and refused most of them. Any changes in the color or taste preferences were absent. Feeding behavior of fish of both species was characterized by repeated intraoral pellet testing, but in koi handling was less typical than in roach. In both species, handling activity was higher in those cases when the pellet was finally rejected. This activity was enhanced also on the background of food odor.

Flash sintering of stoichiometric and hyper-stoichiometric urania

DOE PAGES

Valdez, James Anthony; Byler, Darrin David; Kardoulaki, Erofili; ...

2018-03-29

Flash sintering (FS), a novel fabrication technique belonging to the family of field assisted sintering (FAS) techniques, has been utilized in this study to fabricate uranium dioxide (UO 2) pellets. Stoichiometric (UO 2.00) and hyper-stoichiometric (UO 2.16) pellets were flash sintered at 600 °C within a few (2–3) minutes. This is in sharp contrast to conventional sintering where temperatures hundreds of degrees higher are necessary and the sintering time extends to hours. Relating this in terms of the homologous temperature ratio (T H) for both conditions shows that in the case of flash sintering at 600 °C, T H =more » 0.3 versus T H = 0.6 for conventional sintering at 1600 °C. The highest density achieved for a UO 2.00 pellet was 81% theoretical density (TD) when flash sintered at 600 °C for 184 s at a field of 188 V/cm and a current density of 442 mA/mm 2. For the UO 2.16 pellet, the highest achieved density was 92% TD when flash sintered at 600 °C for 140 s at a field of 188 V/cm and a current density of 632 mA/mm 2. X-ray diffraction (XRD) characterization of the sintered pellets showed the final sintered material to be single cubic fluorite phase. Scanning electron microscopy (SEM) of longitudinal sections revealed non-uniform microstructures with regions of high density where the grain size ranged from 1 to 15 μm. Comparisons between conventionally and flash sintered pellets that achieved equivalent shrinkage strains were also conducted. Lastly, in all cases, the flash sintered pellets achieved similar densification to the conventionally sintered pellets at much lower furnace temperatures and shorter times.« less

Flash sintering of stoichiometric and hyper-stoichiometric urania

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

Valdez, James Anthony; Byler, Darrin David; Kardoulaki, Erofili

Flash sintering (FS), a novel fabrication technique belonging to the family of field assisted sintering (FAS) techniques, has been utilized in this study to fabricate uranium dioxide (UO 2) pellets. Stoichiometric (UO 2.00) and hyper-stoichiometric (UO 2.16) pellets were flash sintered at 600 °C within a few (2–3) minutes. This is in sharp contrast to conventional sintering where temperatures hundreds of degrees higher are necessary and the sintering time extends to hours. Relating this in terms of the homologous temperature ratio (T H) for both conditions shows that in the case of flash sintering at 600 °C, T H =more » 0.3 versus T H = 0.6 for conventional sintering at 1600 °C. The highest density achieved for a UO 2.00 pellet was 81% theoretical density (TD) when flash sintered at 600 °C for 184 s at a field of 188 V/cm and a current density of 442 mA/mm 2. For the UO 2.16 pellet, the highest achieved density was 92% TD when flash sintered at 600 °C for 140 s at a field of 188 V/cm and a current density of 632 mA/mm 2. X-ray diffraction (XRD) characterization of the sintered pellets showed the final sintered material to be single cubic fluorite phase. Scanning electron microscopy (SEM) of longitudinal sections revealed non-uniform microstructures with regions of high density where the grain size ranged from 1 to 15 μm. Comparisons between conventionally and flash sintered pellets that achieved equivalent shrinkage strains were also conducted. Lastly, in all cases, the flash sintered pellets achieved similar densification to the conventionally sintered pellets at much lower furnace temperatures and shorter times.« less

Flash sintering of stoichiometric and hyper-stoichiometric urania

NASA Astrophysics Data System (ADS)

Valdez, J. A.; Byler, D. D.; Kardoulaki, E.; Francis, J. S. C.; McClellan, K. J.

2018-07-01

Flash sintering (FS), a novel fabrication technique belonging to the family of field assisted sintering (FAS) techniques, has been utilized in this study to fabricate uranium dioxide (UO2) pellets. Stoichiometric (UO2.00) and hyper-stoichiometric (UO2.16) pellets were flash sintered at 600 °C within a few (2-3) minutes. This is in sharp contrast to conventional sintering where temperatures hundreds of degrees higher are necessary and the sintering time extends to hours. Relating this in terms of the homologous temperature ratio (TH) for both conditions shows that in the case of flash sintering at 600 °C, TH = 0.3 versus TH = 0.6 for conventional sintering at 1600 °C. The highest density achieved for a UO2.00 pellet was 81% theoretical density (TD) when flash sintered at 600 °C for 185 s at a field of 188 V/cm and a current density of 442 mA/mm2. For the UO2.16 pellet, the highest achieved density was 91% TD when flash sintered at 600 °C for 123 s at a field of 188 V/cm and a current density of 632 mA/mm2. X-ray diffraction (XRD) characterization of the sintered pellets showed the final sintered material to be single cubic fluorite phase. Scanning electron microscopy (SEM) of longitudinal sections revealed non-uniform microstructures with regions of high density where the grain size ranged from 1 to 15 μm. Comparisons between conventionally and flash sintered pellets that achieved equivalent shrinkage strains were also conducted. In all cases, the flash sintered pellets achieved similar densification to the conventionally sintered pellets at much lower furnace temperatures and shorter times.

UO2 fuel pellets fabrication via Spark Plasma Sintering using non-standard molybdenum die

NASA Astrophysics Data System (ADS)

Papynov, E. K.; Shichalin, O. O.; Mironenko, A. Yu; Tananaev, I. G.; Avramenko, V. A.; Sergienko, V. I.

2018-02-01

The article investigates spark plasma sintering (SPS) of commercial uranium dioxide (UO2) powder of ceramic origin into highly dense fuel pellets using non-standard die instead of usual graphite die. An alternative and formerly unknown method has been suggested to fabricate UO2 fuel pellets by SPS for excluding of typical problems related to undesirable carbon diffusion. Influence of SPS parameters on chemical composition and quality of UO2 pellets has been studied. Also main advantages and drawbacks have been revealed for SPS consolidation of UO2 in non-standard molybdenum die. The method is very promising due to high quality of the final product (density 97.5-98.4% from theoretical, absence of carbon traces, mean grain size below 3 μm) and mild sintering conditions (temperature 1100 ºC, pressure 141.5 MPa, sintering time 25 min). The results are interesting for development and probable application of SPS in large-scale production of nuclear ceramic fuel.

Image analysis technique as a tool to identify morphological changes in Trametes versicolor pellets according to exopolysaccharide or laccase production.

PubMed

Tavares, Ana P M; Silva, Rui P; Amaral, António L; Ferreira, Eugénio C; Xavier, Ana M R B

2014-02-01

Image analysis technique was applied to identify morphological changes of pellets from white-rot fungus Trametes versicolor on agitated submerged cultures during the production of exopolysaccharide (EPS) or ligninolytic enzymes. Batch tests with four different experimental conditions were carried out. Two different culture media were used, namely yeast medium or Trametes defined medium and the addition of lignolytic inducers as xylidine or pulp and paper industrial effluent were evaluated. Laccase activity, EPS production, and final biomass contents were determined for batch assays and the pellets morphology was assessed by image analysis techniques. The obtained data allowed establishing the choice of the metabolic pathways according to the experimental conditions, either for laccase enzymatic production in the Trametes defined medium, or for EPS production in the rich Yeast Medium experiments. Furthermore, the image processing and analysis methodology allowed for a better comprehension of the physiological phenomena with respect to the corresponding pellets morphological stages.

Steam torrefaction of Eucalyptus globulus for producing black pellets: A pilot-scale experience.

PubMed

Arteaga-Pérez, Luis E; Grandón, Héctor; Flores, Mauricio; Segura, Cristina; Kelley, Stephen S

2017-08-01

Steam torrefaction of Eucalyptus globulus was performed at temperatures between 245°C and 265°C in a 100kg/h pilot plant. Torrefied biomass was then pelletized in a 300kg/h unit and the pellets were subject to durability, density and combustion tests. The structural changes measured with FTIR were studied along with the combustion behavior of the materials. Compositional analysis showed that increasing the torrefaction temperature reduced both hemicellulose fraction and overall mass yield (MY). Furthermore, there was a linear relationship between the energy yield (EY) and mass yield (EY=[1.04-0.9(1-MY)]) for these samples. The ignition and comprehensive indexes confirmed that the stability of the torrefied biomass in a combustion environment was higher than for untreated biomass. Finally, pellets showed high durability (98%), and had an energy density (13-14GJ/m 3 ), which is comparable to low-rank coals. Copyright © 2017 Elsevier Ltd. All rights reserved.

PREPARATION OF UO$sub 2$ FOR NUCLEAR REACTOR FUEL PELLETS

DOEpatents

Googin, J.M.

1962-06-01

A method is given for preparing high-density UO/sub 2/ compacts. An aqueous uranyl fluoride solution is contacted with an aqueous ammonium hydroxide solution at an ammonium to-uranium ratio of 25: 1 to 30:1 to form a precipitate. The precipitate is separated from the- mother liquor, dried, and contacted with steam at a uniform temperature within the range of 400 to 650 deg C to produce U/ sub 3/O/sub 8/. The U/sub 3/O/sub 8/ is red uced to UO/sub 2/ with hydrogen at a uniform temperature within the range of 550 to 600 deg C. The UO/sub 2/ is then compressed into compacts and sintered. High-density compacts are fabricated to close tolerances without use of a binder and without machining or grinding. (AEC)

Assessment of reduction behavior of hematite iron ore pellets in coal fines for application in sponge ironmaking

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

Kumar, M.; Patel, S.K.

2009-07-01

Studies on isothermal reduction kinetics (with F grade coal) in fired pellets of hematite iron ores, procured from four different mines of Orissa, were carried out in the temperature range of 850-1000C to provide information for the Indian sponge iron plants. The rate of reduction in all the fired iron ore pellets increased markedly with a rise of temperature up to 950C, and thereafter it decreased at 1000C. The rate was more intense in the first 30 minutes. All iron ores exhibited almost complete reduction in their pellets at temperatures of 900 and 950C in 2 hours' heating time duration,more » and the final product morphologies consisted of prominent cracks. The kinetic model equation 1-(1-a){sup 1/3}=kt was found to fit best to the experimental data, and the values of apparent activation energy were evaluated. Reductions of D. R. Pattnaik and M. G. Mohanty iron ore pellets were characterized by higher activation energies (183 and 150 kJ mol{sup -1}), indicating carbon gasification reaction to be the rate-controlling step. The results established lower values of activation energy (83 and 84 kJ mol{sup -1}) for the reduction of G. M. OMC Ltd. and Sakaruddin iron ore pellets, proposing their overall rates to be controlled by indirect reduction reactions.« less

Calcium silicate cement sorbent for H/sub 2/S removal and improved gasification processes. Final report

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

Yoo, H.J.; Steinberg, M.

1983-10-01

Based on the studies performed on the agglomerated cement sorbent (ACS) pellet for in-situ desulfurization of gases and for improved gasification, in low and medium Btu fluidized bed coal gasifier (FBG) systems, the following conclusions can be drawn: (1) The pelletization method by a drum pelletizer is a good way of agglomerating large sized (>20 US mesh) ACS pellets having high sorbent performance. (2) The ACS pellets have a sulfur capture capacity of about 60% at 950/sup 0/C, are 100% regenerable, and so not lose reactivity during cyclic use. (3) The rate of sulfidation increases linearly with H/sub 2/S concentrationmore » in the feed gas stream up to 1.0%. (4) The rate of sulfidation first increases with temperature in an Arrhenius fashion in the temperature range of 800/sup 0/C to 1000/sup 0/C and then decreases with further increase in temperatures, giving rise to an optimum sulfidation temperature of about 1000/sup 0/C. (5) The gasification of coal or coal char either with CO/sub 2/ gas or by partial oxidation in a 40 mm ID FBG shows that the gasification efficiency of coal (or coal char) is very much enhanced with the ACS pellets and with Greer limestone over the coal (or coal char) alone. There is, however, not much difference between the ACS pellets and Greer limestone in the degree of enhancement. (6) The gasification of coal by partial oxidation with air to low Btu gas in a 1-inch coal-fired FBG unit shows that in the temperature range of 800/sup 0/ to 900/sup 0/C the efficiency of coal gasification is improved by as much as 40% when ACS pellets are used compared to the use of Greer limestone. At the same time the sulfur removal efficiency is increased from 50 to 65% with Greer limestone to over 95% with the ACS pellets.« less

Applicability of near-infrared spectroscopy in the monitoring of film coating and curing process of the prolonged release coated pellets.

PubMed

Korasa, Klemen; Hudovornik, Grega; Vrečer, Franc

2016-10-10

Although process analytical technology (PAT) guidance has been introduced to the pharmaceutical industry just a decade ago, this innovative approach has already become an important part of efficient pharmaceutical development, manufacturing, and quality assurance. PAT tools are especially important in technologically complex operations which require strict control of critical process parameters and have significant effect on final product quality. Manufacturing of prolonged release film coated pellets is definitely one of such processes. The aim of the present work was to study the applicability of the at-line near-infrared spectroscopy (NIR) approach in the monitoring of pellet film coating and curing steps. Film coated pellets were manufactured by coating the active ingredient containing pellets with film coating based on polymethacrylate polymers (Eudragit® RS/RL). The NIR proved as a useful tool for the monitoring of the curing process since it was able to determine the extent of the curing and hence predict drug release rate by using partial least square (PLS) model. However, such approach also showed a number of limitations, such as low reliability and high susceptibility to pellet moisture content, and was thus not able to predict drug release from pellets with high moisture content. On the other hand, the at-line NIR was capable to predict the thickness of Eudragit® RS/RL film coating in a wide range (up to 40μm) with good accuracy even in the pellets with high moisture content. To sum up, high applicability of the at-line NIR in the monitoring of the prolonged release pellets production was demonstrated in the present study. The present findings may contribute to more efficient and reliable PAT solutions in the manufacturing of prolonged release dosage forms. Copyright © 2016 Elsevier B.V. All rights reserved.

A facile mechanochemical approach to synthesize Zn-Al layered double hydroxide

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

Qu, Jun, E-mail: forsjun@whut.edu.cn; He, Xiaoman; Chen, Min

2017-06-15

In this study, a mechanochemical route to synthesize Zn-Al layered double hydroxide (LDH) was introduced, in which Zn basic carbonate and Al hydroxide were first dry milled into an activated state and then agitated in water to obtain the final products. The as-prepared samples were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Thermogravimetry (TG) and Scanning electron microscopy (SEM). The products possessed a high crystallinity of Zn–Al LDH phase without any other impurities, proving a facile and effective preparation of Zn–Al LDH by using non-heating mechanochemical approach. - Highlights: • A non-heating mechanochemical route to synthesize Zn-Almore » LDH. • The products possessed high crystalline Zn-Al LDH phase. • No emission of other impurities or wastewater.« less

Leaching of aluminum and iron from boiler slag generated from a typical Chinese Steel Plant.

PubMed

Li, Jinping; Gan, Jinhua; Li, Xianwang

2009-07-30

This paper presents a new way of recycling aluminum and iron in boiler slag derived from coal combustion plants, which integrates efficient extraction and reuse of the leached pellets together. The boiler slag was pelletized together with washed coal and lime prior to sintering and then was sintered at 800-1200 degrees C for different periods to produce sintered pellets for the leaching test. An elemental analysis of aqueous solutions leached by sulfuric acid was determined by EDTA-Na(2)-ZnCl(2) titration method. The components and microstructures of the samples, sintered pellets and leached residue were examined by means of XRF, XRD and SEM. XRD analysis indicates that predominate minerals such as kaolinite, quartz, calcium silicide, hematate and metakoalin exist in the boiler slag. An aluminum extraction efficiency of 86.50% was achieved. The maximum extraction efficiency of Fe was 94.60% in the same conditions of that for the maximum extraction efficiency of Al. The extraction efficiencies of Al and Fe increased with an increase in temperature, leaching time and acidity. High Al extraction efficiency was obtained for pellets with high CaO content. The final product of alumina would be used directly for the production of metallic aluminum.

Hydrothermal Cold Sintering

NASA Astrophysics Data System (ADS)

Kang, Xiaoyu

Solid state sintering transforms particle compact to a physically robust and dense polycrystalline monolith driven by reduction of surface energy and curvature. Since bulk diffusion is required for neck formation and pore elimination, sintering temperature about 2/3 of melting point is needed. It thus places limitations for materials synthesis and integration, and contributes to significant energy consumption in ceramic processing. Furthermore, since surface transport requires lower temperature than bulk processes, grain growth is often rapid and can be undesired for physical properties. For these reasons, several techniques have been developed including Liquid Phase Sintering (LPS), Hot Pressing (HP) and Field Assisted Sintering Technique (FAST), which introduce either viscous melt, external pressure or electric field to speed up densification rates at lower temperature. However, because of their inherent reliability on bulk diffusion, temperatures required are often too high for integrating polymers and non-noble metals. Reduction of sintering temperature below 400 °C would require a different densification mechanism that is based on surface transport with external forces to drive volume shrinkage. Densification method combining uniaxial pressure and solution under hydrothermal condition was first demonstrated by Kanahara's group at Kochi University in 1986 and was brought to our attention by the work of Kahari, etc, from University of Oulu on densification of Li2MoO 4 in 2015. This relatively new process showed promising ultra-low densification temperature below 300 °C, however little was known about its fundamental mechanism and scope of applications, which became the main focus of this dissertation. In this work, a uniaxial hydraulic press, a standard stainless steel 1/2 inch diameter die with heating band were utilized in densifying metal oxides. Applied pressure and sintering temperature were between 100 MPa and 700 MPa and from room temperature to 300 °C, respectively. Process variables were defined and effects of individual parameters were studied systematically through control variable method with Li2MoO4-water system. Crystalline structure, fractured surface morphology and chemical bonding information of the cold sintered pellets were studied with X-ray diffraction (XRD), field effect scanning electron microscopy (FE-SEM) and Raman spectroscopy, etc. Densification mechanism studies were conducted on ZnO. Through comparison experiments, it was found that the Zn2+ concentration in the solution is critical for densification, while dissolution of grains only serves as a means to the former. Through pressure dependent studies, a critical value was found, which correlated well with the hydrostatic pressure keeping liquid water from thermal expansion. These results confirmed establishment of hydrothermal condition that would be important for mass transport in densification. Densification rate variations with process time was estimated and similar time dependence to Kingery's model was found. The densification process was proposed to be consist of three consecutive stages, which are quick initial compaction, grain rearrangement and dissolution-reprecipitation events. Binary metal oxides with different acidities were subjected to cold sintering with various aqueous solutions in establishing a criteria for material selection. It was found that in general materials with high solubility at around neutral pH, high dissolution kinetics and similar free energy to their hydroxides or hydrates at ambient would be more likely for full densification with high phase purity. The anions in solution should also be wisely selected to avoid stable compound or complex formation. To extend the applicable material list for full densification, non-aqueous solvent of dimethyl sulfoxide (DMSO) based solution was studied for cold sintering. Both improvement of pellet density and suppression of hydroxide formation were achieved for MnO by using DMSO-HOAc solution. With this strategy, densification of other metal oxides with strong hydroxide formation may also be improved, for example oxides of alkaline earth and many transition metals. Finally, the author's previous work on Zn1-xMg xO thin films is included in Chapter 7.

Time-resolved analysis of primary volatile emissions and secondary aerosol formation potential from a small-scale pellet boiler

NASA Astrophysics Data System (ADS)

Czech, Hendryk; Pieber, Simone M.; Tiitta, Petri; Sippula, Olli; Kortelainen, Miika; Lamberg, Heikki; Grigonyte, Julija; Streibel, Thorsten; Prévôt, André S. H.; Jokiniemi, Jorma; Zimmermann, Ralf

2017-06-01

Small-scale pellet boilers and stoves became popular as a wood combustion appliance for domestic heating in Europe, North America and Asia due to economic and environmental aspects. Therefore, an increasing contribution of pellet boilers to air pollution is expected despite their general high combustion efficiency. As emissions of primary organic aerosol (POA) and permanent gases of pellet boilers are well investigated, the scope of this study was to investigate the volatile organic emissions and the formation potential of secondary aerosols for this type of appliance. Fresh and aged emissions were analysed by a soot-particle aerosol time-of-flight mass spectrometry (SP-AMS) and the molecular composition of the volatile precursors with single-photon ionisation time-of-flight mass spectrometry (SPI-TOFMS) at different pellet boiler operation conditions. Organic emissions in the gas phase were dominated by unsaturated hydrocarbons while wood-specific VOCs, e.g. phenolic species or substituted furans, were only detected during the starting phase. Furthermore, organic emissions in the gas phase were found to correlate with fuel grade and combustion technology in terms of secondary air supply. Secondary organic aerosols of optimised pellet boiler conditions (OPT, state-of-the-art combustion appliance) and reduced secondary air supply (RSA, used as a proxy for pellet boilers of older type) were studied by simulating atmospheric ageing in a Potential Aerosol Mass (PAM) flow reactor. Different increases in OA mass (55% for OPT, 102% for RSA), associated with higher average carbon oxidation state and O:C, could be observed in a PAM chamber experiment. Finally, it was found that derived SOA yields and emission factors were distinctly lower than reported for log wood stoves.

Fabrication of (U,Am)O2 pellet with controlled porosity from oxide microspheres

NASA Astrophysics Data System (ADS)

Ramond, Laure; Coste, Philippe; Picart, Sébastien; Gauthé, Aurélie; Bataillea, Marc

2017-08-01

U1-xAmxO2±δ mixed-oxides are considered as promising compounds for americium heterogeneous transmutation in Sodium Fast Neutron Reactor. Porous microstructure is envisaged in order to facilitate helium and fission gas release and to reduce pellet swelling during irradiation and under self-irradiation. In this study, the porosity is created by reducing (U,Am)3O8 microspheres into (U,Am)O2 during the sintering. This reduction is accompanied by a decrease of the lattice volume that leads to the creation of open porosity. Finally, an (U0.90Am0.10)O2 porous ceramic pellet (D∼89% of the theoretical density TD) with controlled porosity (≥8% open porosity) was obtained from mixed-oxide microspheres obtained by the Weak Acid Resin (WAR) process.

Formulation and Optimization of Multiparticulate Drug Delivery System Approach for High Drug Loading.

PubMed

Shah, Neha; Mehta, Tejal; Gohel, Mukesh

2017-08-01

The aim of the present work was to develop and optimize multiparticulate formulation viz. pellets of naproxen by employing QbD and risk assessment approach. Mixture design with extreme vertices was applied to the formulation with high loading of drug (about 90%) and extrusion-spheronization as a process for manufacturing pellets. Independent variables chosen were level of microcrystalline cellulose (MCC)-X 1 , polyvinylpyrrolidone K-90 (PVP K-90)-X 2 , croscarmellose sodium (CCS)-X 3 , and polacrilin potassium (PP)-X 4 . Dependent variables considered were disintegration time (DT)-Y 1 , sphericity-Y 2 , and percent drug release-Y 3 . The formulation was optimized based on the batches generated by MiniTab 17 software. The batch with maximum composite desirability (0.98) proved to be optimum. From the evaluation of design batches, it was observed that, even in low variation, the excipients affect the pelletization property of the blend and also the final drug release. In conclusion, pellets with high drug loading can be effectively manufactured and optimized systematically using QbD approach.

Scabies.

PubMed

Hicks, Maria I; Elston, Dirk M

2009-01-01

Scabies is an ectoparasite caused by the mite Sarcoptes scabiei var hominis, an obligate human parasite. There are about 300 million cases of scabies in the world each year. Common predisposing factors are overcrowding, immigration, poor hygiene, poor nutritional status, homelessness, dementia, and sexual contact. Direct skin-to-skin contact between 15 and 20 minutes is needed to transfer the mites from one person to another. The diagnosis suspected with a clinical history of itch, worse at night, affecting other family members, clinical distribution, and appearance. Definite diagnosis relies on microscopic identification of the mites, eggs, or fecal pellets with 10% potassium hydroxide, ink enhancement, tetracycline fluorescence tests, or mineral oil; other methods include: epiluminescence light microscopy and S. scabiei DNA. The most commonly used treatment modalities are permethrin and ivermectin. Persistence of symptoms for 2-6 weeks after successful treatment is common. Most recurrences are because of reinfection from untreated contacts.

Metals removal from spent salts

DOEpatents

Hsu, Peter C.; Von Holtz, Erica H.; Hipple, David L.; Summers, Leslie J.; Brummond, William A.; Adamson, Martyn G.

2002-01-01

A method and apparatus for removing metal contaminants from the spent salt of a molten salt oxidation (MSO) reactor is described. Spent salt is removed from the reactor and analyzed to determine the contaminants present and the carbonate concentration. The salt is dissolved in water, and one or more reagents may be added to precipitate the metal oxide and/or the metal as either metal oxide, metal hydroxide, or as a salt. The precipitated materials are filtered, dried and packaged for disposal as waste or can be immobilized as ceramic pellets. More than about 90% of the metals and mineral residues (ashes) present are removed by filtration. After filtration, salt solutions having a carbonate concentration >20% can be spray-dried and returned to the reactor for re-use. Salt solutions containing a carbonate concentration <20% require further clean-up using an ion exchange column, which yields salt solutions that contain less than 1.0 ppm of contaminants.

The use of superoxide mixtures as air-revitalization chemicals in hyperbaric, self-contained, closed-circuit breathing apparatus

NASA Technical Reports Server (NTRS)

Wood, P. C.; Wydeven, T.

1985-01-01

In portable breathing apparatus applications at 1 atm, potassium superoxide (KO2) has exhibited low-utilization efficiency of the available oxygen (O2) and diminished carbon dioxide-(CO2) scrubbing capacity caused by the formation of a fused, hydrated-hydroxide/carbonate product coating on the superoxide granules. In earlier work, it was discovered that granules fabricated from an intimate mixture of KO2 and calcium superoxide, Ca(O2)2, did not exhibit formation of a fused product coating and the utilization efficiency with respect to both O2 release and CO2 absorption was superior to KO2 granules when both types of granules were reacted with humidified CO2 under identified conditions. In the work described here, single pellets of KO2, KO2/Ca(O2), mixtures and commercially available KO2 tables and granules were reacted with a flow of humidified CO2 in helium at 1- and 10-atm total pressure and at an initial temperature of 40 C. In the 1-atm flow tests, the reaction rates and utilization efficiency of the KO2/Ca(O2)2 pellets were markedly superior to the KO2 pellets, tablets, and granules when the samples were reacted under identical conditions. However, at 10 atm, the rates of O2 release and CO2 absorption, as well as the utilization efficiencies of all the superoxide samples, were one-third to one-eighth of the values observed at 1 atm. The decrease in reaction performance at 10 atm compared to that at 1 atm has been attributed principally to the lower bulk diffusivity of the CO2 and H2O reactants in helium at the higher pressure and secondarily to the moderation of the reaction temperature caused by the higher heat capacity of the 10-atm helium.

Palatability of water-soluble extracts of protein sources and replacement of fishmeal by a selected mixture of protein sources for juvenile turbot ( Scophthalmus maximus)

NASA Astrophysics Data System (ADS)

Dong, Chun; He, Gen; Mai, Kangsen; Zhou, Huihui; Xu, Wei

2016-06-01

Poor palatability is a limiting factor for replacing fishmeal with other protein sources in aquaculture. The water-soluble molecules with low molecular weights are the major determinants of the palatability of diets. The present study was conducted to investigate the palatability of water-soluble extracts from single protein source (single extract pellets) and the mixture of these extracts with different proportions (blended extract pellets) in juvenile turbot ( Scophthalmus maximus). Then according to the palatability of blended extract pellets, an optimal mixture proportion was selected, and a new protein source made from raw protein materials with the selected proportion was formulated to replace fishmeal. Summarily, the palatability of single extract pellets for turbot was descendent from fishmeal to pet-food grade poultry by-product meal, wheat gluten meal, soybean meal, peanut meal, meat and bone meal, and corn gluten meal. Subsequently, according to the palatability of single extract pellets, 52 kinds of blended extract pellets were designed to test their palatability. The results showed that the pellets presented remarkably different palatability, and the optimal one was diet 52 (wheat gluten meal: pet-food grade poultry by-product meal: meat and bone meal: corn gluten meal = 1:6:1:2). The highest ingestion ratio (the number of pellets ingested/the number of pellets fed) was 0.73 ± 0.03, which was observed in Diet 52. Then five isonitrogenous (52% crude protein) and isocaloric (20 kJ g-1 gross energy) diets were formulated by replacing 0 (control), 35%, 50%, 65% and 80% of fishmeal with No.52 blending proportion. After a 10-weeks feeding trial, a consistent feed intake was found among all replacement treatments. Replacement level of fishmeal up to 35% did not significantly influence final body weight, specific growth rate, feed efficiency ratio, and protein efficiency ratio of turbot. Therefore, the water-soluble extracts of protein sources play an important role in improving the palatability of non-fishmeal protein sources in aquafeed.

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.

Effect of rotary instrumentation and of the association of calcium hydroxide and chlorhexidine on the antisepsis of the root canal system in dogs.

PubMed

Soares, Janir Alves; Leonardo, Mario Roberto; da Silva, Léa Assed Bezerra; Tanomaru Filho, Mario; Ito, Izabel Yoko

2006-01-01

This study aimed at evaluating the antisepsis of the root canal system (RCS) and periapical region (PR) provided by rotary instrumentation associated with chlorhexidine + calcium hydroxide as intracanal medicament. Chronic periapical lesions were induced in 26 pre-molar roots in two dogs. After microbiological sampling, automatic instrumentation using the Profile system and irrigation with 5.25% sodium hypochlorite solution, with a final rinse of 14.3% EDTA followed by profuse irrigation with physiological saline were carried out in 18 root canals. After drying the canals, a paste based on calcium hydroxide associated with a 2% chlorhexidine digluconate solution was placed inside them. After 21 days, the medication was removed, leaving the root canals empty and coronally sealed. After 96 hours, a final microbiological sample was obtained, followed by histomicrobiological processing by the Brown & Brenn method. Eight untreated root canals represented the control group (C-G). Based on the Mann-Whitney test at a confidence level of 5% (p < 0.05), the procedures of antisepsis used offered significant efficacy (p < 0.05) resulting in 100.0% of the canals free of microorganisms. In the C-G, an elevated incidence of various microbial morphotypes was confirmed in all sites of the RCS, with the presence of microbial colonies in the periapical region. In contrast, the experimental group showed a similar pattern of infection in the RCS, although less intense and a reduced level of periapical infection (p < 0.05). It was concluded that adequate instrumentation followed by the application of calcium hydroxide + chlorhexidine offered significant elimination of microorganisms.

Cryopreservation of spermatozoa of black marlin, Makaira indica (Teleostei: Istiophoridae).

PubMed

van der Straten, K M; Leung, L K-P; Rossini, R; Johnston, S D

2006-01-01

As a first step towards the development of a method for the cryopreservation of black marlin spermatozoa, this study investigated the effect of dimethylsulfoxide (DMSO) concentration and pellet size on post-thaw spermatozoal motility. Spermatozoa were recovered from the spermatic duct of testes retrieved post-mortem from four adult black marlin caught in the Coral Sea spawning grounds of Australia. Undiluted spermatozoa were stored on ice for 4 to 10 hours during transport to shore, then evaluated for motility after activation in seawater (1:10 v:v). Spermatozoa were prepared for cryopreservation in pellets by extension (1:3 v:v) in a defined fish Ringer's solution to give two final DMSO concentrations of 2.5% or 5.0%. Diluted spermatozoa were frozen directly on a dry ice block in pellet sizes of either 0.25 ml or 0.50 ml. Frozen pellets were thawed in a water bath at 40 degrees C for 60 seconds and assessed for post-thaw motility following activation in seawater. Spermatozoa recovered within 50 minutes of death and chilled on ice for 4 to 10 hours showed a mean (+/- SEM) motility immediately following activation of 91.6 +/- 7.9%. 50% of the spermatozoa remained motile for approximately 4 to 5 minutes. Following cryopreservation, mean motility declined significantly across all cryoprotectant and pellet size combinations (P < 0.001) but spermatozoa frozen in 2.5% DMSO showed higher motility than those frozen in 5.0% DMSO (P = 0.014). Pellet size had no effect on post-thaw motility (P = 0.179).

Removal of phosphorus from agricultural wastewaters using adsorption media prepared from acid mine drainage sludge

USGS Publications Warehouse

Sibrell, Philip L.; Montgomery, Gary A.; Ritenour, Kelsey L.; Tucker, Travis W.

2009-01-01

Excess phosphorus in wastewaters promotes eutrophication in receiving waterways. A??cost-effective method for the removal of phosphorus from water would significantly reduce the impact of such wastewaters on the environment. Acid mine drainage sludge is a waste product produced by the neutralization of acid mine drainage, and consists mainly of the same metal hydroxides used in traditional wastewater treatment for the removal of phosphorus. In this paper, we describe a method for the drying and pelletization of acid mine drainage sludge that results in a particulate media, which we have termed Ferroxysorb, for the removal of phosphorus from wastewater in an efficient packed bed contactor. Adsorption capacities are high, and kinetics rapid, such that a contact time of less than 5 min is sufficient for removal of 60-90% of the phosphorus, depending on the feed concentration and time in service. In addition, the adsorption capacity of the Ferroxysorb media was increased dramatically by using two columns in an alternating sequence so that each sludge bed receives alternating rest and adsorption cycles. A stripping procedure based on treatment with dilute sodium hydroxide was also developed that allows for recovery of the P from the media, with the possibility of generating a marketable fertilizer product. These results indicate that acid mine drainage sludges - hitherto thought of as undesirable wastes - can be used to remove phosphorus from wastewater, thus offsetting a portion of acid mine drainage treatment costs while at the same time improving water quality in sensitive watersheds.

Pellets valorization of waste biomass harvested by coagulation of freshwater algae.

PubMed

Cancela, Ángeles; Sánchez, Ángel; Álvarez, Xana; Jiménez, Alejandro; Ortiz, Luis; Valero, Enrique; Varela, Paloma

2016-03-01

There is a comparison of different coagulants: calcium chloride (20, 60, 120 and 180 mg/L); sodium alginate (10 and 20 mg/L) and tannins of Eucalyptus globulus bark (10 and 20 mg/L) in order to make the most of each method. The results show that 20 mg/L of tannin achieved a recovery efficiency of 95.35±1.16, sodium alginate 90.49±0.53 and 84.04±2.29 for calcium chloride. Taking into account the economic side of the coagulants, obtaining tannins is a profitable process. Bark is waste biomass obtained in the forestry process; therefore it does not involve extra costs. Finally, the feasibility of making pellets from harvested algae was studied, and the results suggest that waste biomass pellets may be used as fuel in boilers in a mixture <54% with other waste sources as Eucalyptus g. branches. Copyright © 2016 Elsevier Ltd. All rights reserved.

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

Fabrication of Natural Uranium UO 2 Disks (Phase II): Texas A&M Work for Others Summary Document

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

Gerczak, Tyler J.; Baldwin, Charles A.; Schmidlin, Joshua E.

The steps to fabricate natural UO 2 disks for an irradiation campaign led by Texas A&M University are outlined. The process was initiated with stoichiometry adjustment of parent, U 3O 8 powder. The next stage of sample preparation involved exploratory pellet pressing and sintering to achieve the desired natural UO 2 pellet densities. Ideal densities were achieved through the use of a bimodal powder size blend. The steps involved with disk fabrication are also presented, describing the coring and thinning process executed to achieve final dimensionality.

Development of chemically vapor deposited rhenium emitters of (0001) preferred crystal orientation

NASA Technical Reports Server (NTRS)

Yang, L.; Hudson, R. G.

1973-01-01

Rhenium thermionic emitters were prepared by the pyrolysis of rhenium chlorides formed by the chlorination of rhenium pellets. The impurity contents, microstructures, degrees of (0001) preferred crystal orientation, and vacuum electron work functions of these emitters were determined as a function of deposition parameters, such as substrate temperature, rhenium pellet temperature and chlorine flow rate. A correlation between vacuum electron work function and degree of (0001) preferred crystal orientation was established. Conditions for depositing porosity-free rhenium emitters of high vacuum electron work functions were defined. Finally, three cylindrical rhenium emitters were prepared under the optimum deposition conditions.

Osmotic pellet system comprising osmotic core and in-process amorphized drug in polymer-surfactant layer for controlled delivery of poorly water-soluble drug.

PubMed

Saindane, Nilesh; Vavia, Pradeep

2012-09-01

The aim of the present investigation was to develop controlled porosity osmotic system for poorly water-soluble drug based on drug in polymer-surfactant layer technology. A poorly water-soluble drug, glipizide (GZ), was selected as the model drug. The technology involved core of the pellets containing osmotic agent coated with drug dispersed in polymer and surfactant layer, finally coated with release-retardant layer with pore former. The optimized drug-layer-coated pellets were evaluated for solubility of GZ at different pH conditions and characterized for amorphous nature of the drug by differential scanning calorimetry and X-ray powder diffractometry. The optimized release-retardant layer pellets were evaluated for in vitro drug release at different pH, hydrodynamic, and osmolality conditions. The optimized drug layer showed improvement in solubility (10 times in pH 1.2, 11 times in pH 4.5, and 21 times in pH 6.8), whereas pellets coated with cellulose acetate (15.0%, w/w, weight gain) with pore former triethyl citrate (10.0%, w/w, of polymer) demonstrated zero-order drug release for 24 h at different pH conditions; moreover, retardation of drug release was observed with increment of osmolality. This system could be a platform technology for controlled delivery of poorly water-soluble drugs. Copyright © 2012 Wiley Periodicals, Inc.

Sensor array for the detection of organic and inorganic contaminants in post-consumer recycled plastics for food contact.

PubMed

Davis, Nathan; Danes, Jeffrey E; Vorst, Keith

2017-10-01

Post-consumer recycled (PCR) plastic material is made by collecting used plastic products (e.g., bottles and other plastic packaging materials) and reprocessing them into solid-state pellets or flakes. Plastic recycling has positive environmental benefits, but may also carry potential drawbacks due to unwanted organic and inorganic contaminants. These contaminants can migrate into food packaging made from these recycled plastic materials. The purpose of this research was to identify economically viable real-time monitoring technologies that can be used during the conversion of virgin and recycled resin feedstocks (i.e., various blends of virgin pellets and recycled solid-state pellet or mechanically ground flake) to final articles to ensure the safety, quality and sustainability of packaging feedstocks. Baseline analysis (validation) of real-time technologies was conducted using industry-standard practices for polymer analysis. The data yielded supervised predictive models developed by training sessions completed in a controlled laboratory setting. This technology can be employed to evaluate compliance and aid converters in commodity sourcing of resin without exceeding regulatory thresholds. Furthermore, this technology allowed for real-time decision and diversion strategies during the conversion of resin and flake to final articles or products to minimise the negative impact on human health and environmental exposure.

Lightweight Small Arms Technologies

DTIC Science & Technology

2006-11-01

conducted using several methods. Initial measurements were obtained using a strand burner , followed by closed bomb measurements using both pressed... pellets and entire cases. Specialized fixtures were developed to measure primer and booster combustion properties. The final verification of interior

Hydroxide based Benzyltrimethylammonium degradation: Quantification of rates and degradation technique development

DOE PAGES

Sturgeon, Matthew R.; Macomber, Clay S.; Engtrakul, Chaiwat; ...

2015-01-21

Anion exchange membranes (AEMs) are of interest as hydroxide conducting polymer electrolytes in electrochemical devices like fuel cells and electrolyzers. AEMs require hydroxide stable covalently tetherable cations to ensure required conductivity. Benzyltrimethylammonium (BTMA) has been the covalently tetherable cation that has been most often employed in anion exchange membranes because it is reasonably basic, compact (limited number of atoms per charge), and easily/cheaply synthesized. Several reports exist that have investigated hydroxide stability of BTMA under specific conditions, but consistency within these reports and comparisons between them have not yet been made. While the hydroxide stability of BTMA has been believedmore » to be a limitation for AEMs, this stability has not been thoroughly reported. In this paper, we have found that several methods reported have inherent flaws in their findings due to the difficulty of performing degradation experiments at high temperature and high pH. In order to address these shortcomings, we have developed a reliable, standardized method of determining cation degradation under conditions similar/relevant to those expected in electrochemical devices. The experimental method has been employed to determine BTMA stabilities at varying cation concentrations and elevated temperatures, and has resulted in improved experimental accuracy and reproducibility. Finally and most notably, these results have shown that BTMA is quite stable at 80°C (half-life of ~4 years), a significant increase in stability over what had been reported previously.« less

Study of the Thermal Properties and the Fire Performance of Flame Retardant-Organic PCM in Bulk Form

PubMed Central

Palacios, Anabel; De Gracia, Alvaro

2018-01-01

The implementation of organic phase change materials (PCMs) in several applications such as heating and cooling or building comfort is an important target in thermal energy storage (TES). However, one of the major drawbacks of organic PCMs implementation is flammability. The addition of flame retardants to PCMs or shape-stabilized PCMs is one of the approaches to address this problem and improve their final deployment in the building material sector. In this study, the most common organic PCM, Paraffin RT-21, and fatty acids mixtures of capric acid (CA), myristic acid (MA), and palmitic acid (PA) in bulk, were tested to improve their fire reaction. Several flame retardants, such as ammonium phosphate, melamine phosphate, hydromagnesite, magnesium hydroxide, and aluminum hydroxide, were tested. The properties of the improved PCM with flame retardants were characterized by thermogravimetric analyses (TGA), the dripping test, and differential scanning calorimetry (DSC). The results for the dripping test show that fire retardancy was considerably enhanced by the addition of hydromagnesite (50 wt %) and magnesium hydroxide (50 wt %) in fatty acids mixtures. This will help the final implementation of these enhanced PCMs in building sector. The influence of the addition of flame retardants on the melting enthalpy and temperatures of PCMs has been evaluated. PMID:29329212

NiMg/Ceria-Zirconia Cylindrical Pellet Catalysts for Tri-reforming of Surrogate Biogas

DOE PAGES

Zhao, Xianhui; Walker, Devin; Maiti, Debtanu; ...

2017-12-22

Cylindrical NiMg/Ce 0.6Zr 0.4O 2 pellet catalysts with two different sizes (large: radius = 1.59 mm; and small: radius = 0.75 mm) were produced by extrusion of powder catalysts. The small catalyst pellets had a higher specific surface area, pore volume, average pore size, radial crush strength, and resistance to breakage than the large ones. Tri-reforming tests with surrogate biogas were conducted at 3 bar and 882 °C, with the feed molar ratios of CH 4: CO 2: air fixed at 1.0: 0.7: 0.95 and the H 2O/CH 4 molar feed ratio (0.35 – 1.16) varied. The small catalyst pelletsmore » exhibited lower internal mass transfer resistance and higher coking resistance, compared to the large ones. CO 2 conversion decreased and H 2/CO molar ratio increased with the increase of H 2O/CH 4 molar feed ratio, which are consistent with the trends predicted by thermodynamic equilibrium calculations. Finally, the results indicate that the NiMg/Ce 0.6Zr 0.4O 2 catalyst pellets are promising for commercial scale applications.« less

Lightning arrestor connector lead magnesium niobate qualification pellet test procedures.

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

Tuohig, W.; Mahoney, Patrick A.; Tuttle, Bruce Andrew

2009-02-01

Enhanced knowledge preservation for DOE DP technical component activities has recently received much attention. As part of this recent knowledge preservation effort, improved documentation of the sample preparation and electrical testing procedures for lead magnesium niobate--lead titanate (PMN/PT) qualification pellets was completed. The qualification pellets are fabricated from the same parent powders used to produce PMN/PT lightning arrestor connector (LAC) granules at HWF&T. In our report, the procedures for fired pellet surface preparation, electrode deposition, electrical testing and data recording are described. The dielectric measurements described in our report are an information only test. Technical reasons for selecting the electrodemore » material, electrode size and geometry are presented. The electrical testing is based on measuring the dielectric constant and dissipation factor of the pellet during cooling from 280 C to 220 C. The most important data are the temperature for which the peak dielectric constant occurs (Curie Point temperature) and the peak dielectric constant magnitude. We determined that the peak dielectric constant for our procedure would be that measured at 1 kHz at the Curie Point. Both the peak dielectric constant and the Curie point parameters provide semi-quantitative information concerning the chemical and microstructural homogeneity of the parent material used for the production of PMN/PT granules for LACs. Finally, we have proposed flag limits for the dielectric data for the pellets. Specifically, if the temperature of the peak dielectric constant falls outside the range of 250 C {+-} 30 C we propose that a flag limit be imposed that will initiate communication between production agency and design agency personnel. If the peak dielectric constant measured falls outside the range 25,000 {+-} 10,000 we also propose that a flag limit be imposed.« less

High-speed multishot pellet injector prototype for the Frascati Tokamak Upgrade

NASA Astrophysics Data System (ADS)

Frattolillo, A.; Migliori, S.; Scaramuzzi, F.; Angelone, G.; Baldarelli, M.; Capobianchi, M.; Cardoni, P.; Domma, C.; Mori, L.; Ronci, G.

1998-07-01

The Frascati Tokamak Upgrade (FTU) may require multiple high-speed pellet injection in order to achieve quasi-steady-state conditions. A research and development program was thus being pursued at ENEA Frascati, aimed at developing a multishot two-stage pellet injector (MPI), featuring eight "pipe gun" barrels and eight small two-stage pneumatic guns. According to FTU requirements, the final goal is to simultaneously produce up to eight D2 pellets, and then deliver them during a plasma pulse (1 s) with any time schedule, at speeds in the 1-2.5 km/s range. A prototype was constructed and tested to demonstrate the feasibility of the concept, and optimize pellet formation and firing sequences. This laboratory facility was automatically operated by means of a programmable logic controller (PLC), and had a full eight-shot capability. However, it was equipped as a first approach with only four two-stage guns. In this article we will describe in detail the guidelines of the MPI prototype design, which were strongly influenced by some external constraints. We will also report on the results of the experimental campaign, during which the feasibility of such a two-stage MPI was demonstrated. Sequences of four intact D2 pellets in the 1.2-1.6 mm size range, fired at time intervals of a few tens up to a few hundreds of ms, were routinely delivered in a laboratory experiment at injection speeds above 2.5 km/s, with good reproducibility and satisfactory aiming dispersion. Some preliminary effort to address the problem of propellant gas handling, based on an innovative approach, gave encouraging results, and work is in progress to carry out an experiment to definitely test the feasibility of this concept.

Influence of dietary nutrient density, feed form, and lighting on growth and meat yield of broiler chickens.

PubMed

Brickett, K E; Dahiya, J P; Classen, H L; Gomis, S

2007-10-01

The objective of this study was to examine main and interactive effects of nutrient density (ND), feed form (FF; mash, pellet), and lighting program (12L:12D, 20L:4D) on production characteristics and meat yield of broilers raised to 35 d of age. Diets (starter, grower, and finisher) were formulated so that amino acid levels were in proportion to the dietary energy level. Lighting programs were initiated at 4 d of age. Body weight was not affected by ND when diets were fed in a pellet form but decreased in a linear manner with lower ND when fed as a mash. Final BW of birds fed mash were less than those of birds fed pellet diets. Feed to gain ratio decreased with increasing ND but was not affected by FF. Feed intake decreased with increasing ND and was lower for birds fed mash. The effect of ND on feed intake was less when birds were fed mash in contrast to pellet diets (P(ND x F) < 0.0001). Dietary ND had no effect on mortality, but feeding mash decreased mortality (3.8%) compared with feeding pelleted feed (5.6%). Lighting programs affected production characteristics independently of ND and FF. Use of 12L:12D reduced BW, feed to gain ratio, feed intake, and mortality compared with 20L:4D. Similarly, carcass components were not affected by ND when fed in pellet form but decreased with lower ND when fed as a mash. Overall, carcass yields were reduced when broilers were fed mash or provided with 12L:12D. Female birds had higher carcass yields and increased proportional breast meat deposition compared with males.

Preliminary evaluation of an aqueous wax emulsion for controlled-release coating.

PubMed

Walia, P S; Stout, P J; Turton, R

1998-02-01

The purpose of this work was to evaluate the use of an aqueous carnauba wax emulsion (Primafresh HS, Johnson Wax) in a spray-coating process. This involved assessing the effectiveness of the wax in sustaining the release of the drug, theophylline. Second, the process by which the drug was released from the wax-coated pellets was modeled. Finally, a method to determine the optimum blend of pellets with different wax thicknesses, in order to yield a zero-order release profile of the drug, was addressed. Nonpareil pellets were loaded with theophylline using a novel powder coating technique. These drug-loaded pellets were then coated with different levels of carnauba wax in a 6-in. diameter Plexiglas fluid bed with a 3.5-in. diameter Wurster partition. Drug release was measured using a spin-filter dissolution device. The study resulted in continuous carnauba wax coatings which showed sustained drug release profile characteristics typical of a barrier-type, diffusion-controlled system. The effect of varying wax thickness on the release profiles was investigated. It was observed that very high wax loadings would be required to achieve long sustained-release times. The diffusion model, developed to predict the release of the drug, showed good agreement with the experimental data. However, the data exhibited an initial lag-time for drug release which could not be predicted a priori based on the wax coating thickness. A method of mixing pellets with different wax thicknesses was proposed as a way to approximate zero-order release.

Valorization of pellets from municipal WWTP sludge in lightweight clay ceramics

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

Cusido, Joan A., E-mail: joan.antoni.cusido@upc.edu; Soriano, Cecilia

2011-06-15

A direct result of the growing number of municipal wastewater-treatment plants (WWTPs) has been an increase in the generation of large amounts of sewage sludge that requires environmentally acceptable final destination. To decrease the volume of sludge, a common technique is drying the sludge at a low temperature in rotary kilns. The result of this process is a granulated material consisting of dehydrated sludge pellets. After this treatment, this pelletized material becomes easier to manipulate, but it also becomes a more toxic waste, containing dangerous substances, mostly of the lipid type. At its final stage, this material is usually incinerated,more » used as a comburent material, used as an agricultural fertilizer, or used in the cement industry. Each application has its own problems and requires remediation measures from the safety and environmental viewpoints. In this study, we looked beyond these possible applications and analyzed the transformation of sewage sludge through a ceramization process into a material similar to expanded clays; we subsequently explored its uses in the building industry or in the agriculture industry, among others. Both the properties of the product material and the production method were characterized, and an environmental analysis was conducted. The new, lightweight material had a microstructure with open porosity and low thermal conductivity. Environmental characterization such as the leaching test revealed that undetectable amounts of hazardous metals from the sludge were present in the leachate after the sludge went through a thermal treatment, despite their initial presence (with the exception of vanadium, which could pose some restrictions on some of the proposed uses for the final product). Toxicity tests also showed negative results. The study of gaseous emissions during production revealed emissions factors similar to those during the production of conventional clay ceramics, although with higher organic emissions. As for conventional clay ceramics, industrial production would require the implementation of some type of air-depuration system. The results showed that the ceramization of sludge pellets is a promising valorization technique worth considering from both the economic and technological perspectives.« less

Valorization of pellets from municipal WWTP sludge in lightweight clay ceramics.

PubMed

Cusidó, Joan A; Soriano, Cecilia

2011-06-01

A direct result of the growing number of municipal wastewater-treatment plants (WWTPs) has been an increase in the generation of large amounts of sewage sludge that requires environmentally acceptable final destination. To decrease the volume of sludge, a common technique is drying the sludge at a low temperature in rotary kilns. The result of this process is a granulated material consisting of dehydrated sludge pellets. After this treatment, this pelletized material becomes easier to manipulate, but it also becomes a more toxic waste, containing dangerous substances, mostly of the lipid type. At its final stage, this material is usually incinerated, used as a comburent material, used as an agricultural fertilizer, or used in the cement industry. Each application has its own problems and requires remediation measures from the safety and environmental viewpoints. In this study, we looked beyond these possible applications and analyzed the transformation of sewage sludge through a ceramization process into a material similar to expanded clays; we subsequently explored its uses in the building industry or in the agriculture industry, among others. Both the properties of the product material and the production method were characterized, and an environmental analysis was conducted. The new, lightweight material had a microstructure with open porosity and low thermal conductivity. Environmental characterization such as the leaching test revealed that undetectable amounts of hazardous metals from the sludge were present in the leachate after the sludge went through a thermal treatment, despite their initial presence (with the exception of vanadium, which could pose some restrictions on some of the proposed uses for the final product). Toxicity tests also showed negative results. The study of gaseous emissions during production revealed emissions factors similar to those during the production of conventional clay ceramics, although with higher organic emissions. As for conventional clay ceramics, industrial production would require the implementation of some type of air-depuration system. The results showed that the ceramization of sludge pellets is a promising valorization technique worth considering from both the economic and technological perspectives. Copyright © 2011 Elsevier Ltd. All rights reserved.

Evaluation of hydroxyl ion diffusion in dentin and injectable forms and a simple powder-water calcium hydroxide paste: an in vitro study.

PubMed

Eftekhar, Behrooz; Moghimipour, Eskandar; Eini, Ebrahim; Jafarzadeh, Mansour; Behrooz, Narges

2014-08-01

Intra canal medicaments are used to reduce the number of bacteria and reinfection in endodontic procedures. Calcium Hydroxide was introduced to endodontics by Herman as an intracanal antimicrobial agent. The aim of this study was to present an injectable formulation of calcium hydroxide then compare the final pH of this new formulation with Metapaste and evaluate the effect of a mixture of Calcium Hydroxide powder with water on human extracted teeth. A total of 49 extracted human single-canal roots without caries and visible microcracks were included in this study. The teeth were decoronated and length of teeth was measured 1 mm anatomic apex. The canals were prepared using step-back technique. A cavity was created in the middle third of the buccal surface of all roots. The teeth were randomly divided into five groups: Group A (n = 15): In this group the root canals were filled with a mixture of calcium hydroxide powder and distilled water. Group B (n = 15): Included roots that were filled with Metapaste. Group C (n = 15): Root canals of this group were filled with new formulation of calcium hydroxide paste. Group D (negative control, n = 2): Included roots that were filled with a mixture of calcium hydroxide powder and distilled water. Group E (positive control, n = 2): Root canals of this group were filled with a mixture of calcium hydroxide powder and distilled water. Each tooth was immersed in a separate closed container with 4 mL saline for 2 weeks, pH of liquids were measured with an electrical pH meter after 7 and 14 days. The SPSS software (version 13) was used for data analysis. Analysis of variance (ANOVA) and Tukey tests were used for the statistical evaluation of results. There was no significant difference at 7th day between the groups (P = 0.17) but at 14th day, a significant difference was observed between the groups (P = 0.04). The new formulation of calcium hydroxide with methylcellulose base has slower ionic dissolution, more durability and longevity of alkaline properties in comparison to combination of powder with distilled water and is comparable with other commercial products.

Quantification of rare earth elements using laser-induced breakdown spectroscopy

DOE PAGES

Martin, Madhavi; Martin, Rodger C.; Allman, Steve; ...

2015-10-21

In this paper, a study of the optical emission as a function of concentration of laser-ablated yttrium (Y) and of six rare earth elements, europium (Eu), gadolinium (Gd), lanthanum (La), praseodymium (Pr), neodymium (Nd), and samarium (Sm), has been evaluated using the laser-induced breakdown spectroscopy (LIBS) technique. Statistical methodology using multivariate analysis has been used to obtain the sampling errors, coefficient of regression, calibration, and cross-validation of measurements as they relate to the LIBS analysis in graphite-matrix pellets that were doped with elements at several concentrations. Each element (in oxide form) was mixed in the graphite matrix in percentages rangingmore » from 1% to 50% by weight and the LIBS spectra obtained for each composition as well as for pure oxide samples. Finally, a single pellet was mixed with all the elements in equal oxide masses to determine if we can identify the elemental peaks in a mixed pellet. This dataset is relevant for future application to studies of fission product content and distribution in irradiated nuclear fuels. These results demonstrate that LIBS technique is inherently well suited for the future challenge of in situ analysis of nuclear materials. Finally, these studies also show that LIBS spectral analysis using statistical methodology can provide quantitative results and suggest an approach in future to the far more challenging multielemental analysis of ~ 20 primary elements in high-burnup nuclear reactor fuel.« less

Ionic Liquids as Surfactants for Layered Double Hydroxide Fillers: Effect on the Final Properties of Poly(Butylene Adipate-Co-Terephthalate)

PubMed Central

Livi, Sébastien; Lins, Luanda Chaves; Peter, Jakub; Kredatusova, Jana; Pruvost, Sébastien

2017-01-01

In this work, phosphonium ionic liquids (ILs) based on tetra-alkylphosphonium cations combined with carboxylate, phosphate and phosphinate anions, were used for organic modification of layered double hydroxide (LDH). Two different amounts (2 and 5 wt %) of the organically modified LDHs were mixed with poly(butylene adipate-co-terephthalate) (PBAT) matrix by melt extrusion. All prepared PBAT/IL-modified-LDH composites exhibited increased mechanical properties (20–50% Young’s modulus increase), decreased water vapor permeability (30–50% permeability coefficient reduction), and slight decreased crystallinity (10–30%) compared to the neat PBAT. PMID:28956811

Use of Cement Kiln Dust, Blast Furnace Slag and Marble Sludge in the Manufacture of Sustainable Artificial Aggregates by Means of Cold Bonding Pelletization.

PubMed

Colangelo, Francesco; Cioffi, Raffaele

2013-07-25

In this work, three different samples of solid industrial wastes cement kiln dust (CKD), granulated blast furnace slag and marble sludge were employed in a cold bonding pelletization process for the sustainable production of artificial aggregates. The activating action of CKD components on the hydraulic behavior of the slag was explored by evaluating the neo-formed phases present in several hydrated pastes. Particularly, the influence of free CaO and sulfates amount in the two CKD samples on slag reactivity was evaluated. Cold bonded artificial aggregates were characterized by determining physical and mechanical properties of two selected size fractions of the granules for each studied mixture. Eighteen types of granules were employed in C28/35 concrete manufacture where coarser natural aggregate were substituted with the artificial ones. Finally, lightweight concretes were obtained, proving the suitability of the cold bonding pelletization process in artificial aggregate sustainable production.

Use of Cement Kiln Dust, Blast Furnace Slag and Marble Sludge in the Manufacture of Sustainable Artificial Aggregates by Means of Cold Bonding Pelletization

PubMed Central

Colangelo, Francesco; Cioffi, Raffaele

2013-01-01

In this work, three different samples of solid industrial wastes cement kiln dust (CKD), granulated blast furnace slag and marble sludge were employed in a cold bonding pelletization process for the sustainable production of artificial aggregates. The activating action of CKD components on the hydraulic behavior of the slag was explored by evaluating the neo-formed phases present in several hydrated pastes. Particularly, the influence of free CaO and sulfates amount in the two CKD samples on slag reactivity was evaluated. Cold bonded artificial aggregates were characterized by determining physical and mechanical properties of two selected size fractions of the granules for each studied mixture. Eighteen types of granules were employed in C28/35 concrete manufacture where coarser natural aggregate were substituted with the artificial ones. Finally, lightweight concretes were obtained, proving the suitability of the cold bonding pelletization process in artificial aggregate sustainable production. PMID:28811427

Preparation of acetaminophen capsules containing beads prepared by hot-melt direct blend coating.

PubMed

Pham, Loan; Christensen, John M

2014-02-01

Twelve hydrophobic coating agents were assessed for their effects on drug release after coating sugar cores by a flexible hot-melt coating method using direct blending. Drug-containing pellets were also produced and used as cores. The cores were coated with single or double wax layers containing acetaminophen (APAP). The harder the wax, the slower the resultant drug releases from single-coated beads. Wax coating can be deposited on cores up to 28% of the beads final weight and reaching 58% with wax and drug. Carnauba-coated beads dissolved in approximately 6 h releasing 80% of the loaded drug. Applying another wax layer extended drug release over 20 h, while still delivering 80% of the loaded drug. When drug-containing pellets (33-58% drug loading) were used as cores, double wax-coated pellets exhibited a near zero-order drug release for 16 h, releasing 80% of the loaded drug delivering 18 mg/h. The simple process of hot-melt coating by direct blending of pellet-containing drug-coated formulations provides excellent options for immediate and sustained release formulations when higher lipid coating or drug loading is warranted. Predicted plasma drug concentration time profiles using convolution and in vitro drug release properties of the beads were performed for optimal formulations.

Improved fabrication of electrolytic capacitors

NASA Technical Reports Server (NTRS)

Gamari, F. J.; Moresi, J. L.

1975-01-01

After processing parts for assembly, insulative cup is fitted to bottom of can, then electrolytic solution consisting of white sulfuric acid gel is inserted into can. Pellet is put in can and is fitted tightly into cup. Finally, bead weld is formed between can and header plug.

Demonstration of fuel resistant to pellet-cladding interaction. Phase I. Final report

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

Rosenbaum, H.S.

1979-03-01

This program has as its ultimate objective the demonstration of an advanced fuel design that is resistant to the failure mechanism known as fuel pellet-cladding interaction (PCI). Two fuel concepts are being developed for possible demonstration within this program: (a) Cu-barrier fuel, and (b) Zr-liner fuel. These advanced fuels (known collectively as barrier fuels) have special fuel cladding designed to protect the Zircaloy cladding tube from the harmful effects of localized stress, and reactive fission products during reactor service. This is the final report for PHASE 1 of this program. Support tests have shown that the barrier fuel resists PCImore » far better than does the conventional Zircaloy-clad fuel. Power ramp tests thus far have shown good PCI resistance for Cu-barrier fuel at burnup > 12 MWd/kg-U and for Zr-liner fuel > 16 MWd/kg-U. The program calls for continued testing to still higher burnup levels in PHASE 2.« less

A study on the applicability of in-line measurements in the monitoring of the pellet coating process.

PubMed

Hudovornik, Grega; Korasa, Klemen; Vrečer, Franc

2015-07-30

Special populations including paediatric and elderly patients often need advanced approaches in treatment, such as one-a-day dosing, which is achieved with modified release formulations or alternative routes of applications such as nasogastric route. Pellets are a dosage form that is frequently used in such formulations. The aim of the present work was to study the applicability of two in-line techniques, namely, Near Infrared Spectroscopy (NIR) and Spatial Filtering Technique (SFT) in the pellet coating process. The first objective of our work was to develop a prediction model for moisture content determination with the in-line NIR and to test its robustness in terms of sensitivity to changes in composition of the pellets and performance in wide range of moisture content. Secondly, the in-line SFT measurement was correlated with different off-line particle size methods. The third objective was to evaluate the ability of both in-line techniques for the detection of undesired deviations during the process, such as pellet attrition and agglomeration. Finally, the ability to predict coating thickness with the in-line NIR probe was evaluated. Results suggested that NIR prediction model for moisture content was less robust outside the calibration range and was also sensitive to changes in composition of the film coating. Nevertheless, satisfactory prediction was achieved in the case when coating composition was partially altered and adequate calibration range was used. The SFT probe results were in good correlation with off-line particle size measurement methods and proved to be an effective tool for coating thickness determination during the coating, however, the probe failed to accurately show the actual amount of the agglomerates formed during the process. In experiment when pellet attrition was initiated, both probes successfully detected abrasion of the pellet surface in real time. Furthermore, a predictive NIR model for coating thickness was made and showed a good potential to measure coating thickness in-line, suggesting that the NIR probe can be used as a single tool to monitor water content, coating thickness, and deviations in the coating process. Copyright © 2015 Elsevier B.V. All rights reserved.

Injectable self inflating hydrogel pellet expanders for the treatment of orbital volume deficiency in congenital microphthalmos: preliminary results with a new therapeutic approach

PubMed Central

Schittkowski, M P; Guthoff, R F

2006-01-01

Background/aim Children with congenital microphthalmos are usually able to wear an eye prosthesis but the cosmetic aspect is determined by the size of the orbital volume deficiency. Instead of using a ball shaped standard hydrogel expander or a regular orbital implant, which would necessitate enucleation of the microphthalmic eye, this study investigates the feasibility of volume augmentation with injectable pellet expanders, as formerly suggested for acquired anophthalmos in adults only. Method The pellet expander is made from a self inflating hydrogel that takes up water by osmosis (dry state: length 8 mm, diameter 2 mm, volume 0.025 ml; in vitro hydrated state after around 1 day: length 15 mm, diameter 4 mm, volume 0.24 ml; swelling capacity: 9.6‐fold). This report concerns six patients (two girls and four boys) aged between 4 months and 42 months with unilateral microphthalmos who were treated by injection of 4–14 pellet expanders into the retrobulbar orbital tissue. Volume augmentation was 1–3.5 ml. The pellets were injected using a customised trocar and placed behind the microphthalmos directed into the intraconal space. Results The increasing orbital volume was noticeable within 2 days and was confirmed by ultrasonography and magnetic resonance imaging. The final result can be anticipated by the volume augmentation effect produced by the amount of saline solution injected in the orbital apex region. All patients were fitted with an artificial eye, which was subsequently enlarged every 3–5 months. Anophthalmic enophthalmos was fully compensated with this technique. No complications have been encountered to date. Conclusions Orbital volume augmentation with injectable self inflating hydrogel expander pellets is apparently a safe, quick, and minimally invasive technique for various indications in orbital reconstructive surgery—for example, to treat an enophthalmic appearance in microphthalmos and congenital or acquired anophthalmos. PMID:16707526

Package for fragile objects

DOEpatents

Burgeson, Duane A.

1977-01-01

A package for fragile objects such as radioactive fusion pellets of micron size shipped in mounted condition or unmounted condition with a frangible inner container which is supported in a second inner container which in turn is supported in a final outer container, the second inner container having recesses for supporting alternate design inner containers.

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

Zhao, Xianhui; Walker, Devin; Maiti, Debtanu

Cylindrical NiMg/Ce 0.6Zr 0.4O 2 pellet catalysts with two different sizes (large: radius = 1.59 mm; and small: radius = 0.75 mm) were produced by extrusion of powder catalysts. The small catalyst pellets had a higher specific surface area, pore volume, average pore size, radial crush strength, and resistance to breakage than the large ones. Tri-reforming tests with surrogate biogas were conducted at 3 bar and 882 °C, with the feed molar ratios of CH 4: CO 2: air fixed at 1.0: 0.7: 0.95 and the H 2O/CH 4 molar feed ratio (0.35 – 1.16) varied. The small catalyst pelletsmore » exhibited lower internal mass transfer resistance and higher coking resistance, compared to the large ones. CO 2 conversion decreased and H 2/CO molar ratio increased with the increase of H 2O/CH 4 molar feed ratio, which are consistent with the trends predicted by thermodynamic equilibrium calculations. Finally, the results indicate that the NiMg/Ce 0.6Zr 0.4O 2 catalyst pellets are promising for commercial scale applications.« less

Remarks to SBS PCM based self-navigation of laser drivers

NASA Astrophysics Data System (ADS)

Kalal, M.; Matena, L.; Kong, HJ; Martinkova, M.; Cha, S.

2016-03-01

A novel technology of self-navigation of laser drivers on injected inertial fusion energy pellets employing phase conjugating mirrors based on stimulating Brillouin scattering was recently proposed. Its feasibility as well as various implications were gradually studied and working solutions to potential problems were always suggested. As this technology could help to overcome several burning key issues of inertial fusion (e.g., a sufficiently precise navigation of laser drivers on injected pellets in the case of a direct drive scheme and decreased requirements on high-repetition high-power lasers) it gradually started to attract a carefully measured tentative interest among the major inertial fusion oriented laboratories and projects. In this paper the next step in this research path will be reported. It concerns the resulting phase and amplitude structures created by multiple low energy drivers (glints) illuminating the pellet during the first stage of the process after their reflection and a subsequent superposition on the collecting/focusing final optics. It was demonstrated that with a large number of such drivers acting simultaneously from many angles the situation gets somewhat complicated and requires more detailed studies/suggestions of suitable configurations.

Extrusion-spheronization: process variables and characterization.

PubMed

Sinha, V R; Agrawal, M K; Agarwal, A; Singh, G; Ghai, D

2009-01-01

Multiparticulate systems have undergone great development in the past decade fueled by the better understanding of their multiple roles as a suitable delivery system. With the passage of time, significant advances have been made in the process of pelletization due to the incorporation of specialized techniques for their development. Extrusion-spheronization seems to be the most promising process for the optimum delivery of many potent drugs having high systemic toxicity. It also offers immense pharmaceutical applicability due to the benefits of high loading capacity of active ingredient(s), narrow size distribution, and cost-effectiveness. On application of a specific coat, these systems can also aid in site-specific delivery, thereby enhancing the bioavailability of many drugs. The current review focuses on the process of extrusion-spheronization and the operational (extruder types, screen pressure, screw speed, temperature, moisture content, spheronization load, speed and time) and formulation (excipients and drugs) variables, which may affect the quality of the final pellets. Various methods for the evaluation of the quality of the pellets with regard to the size distribution, shape, friability, granule strength, density, porosity, flow properties, and surface texture are discussed.

U.S. Forest Greenhouse Gas Impacts of a continued Expansion of E.U. Wood Pellet Demand

NASA Astrophysics Data System (ADS)

Latta, G.; Baker, J.; Ohrel, S. B.

2016-12-01

The United States has ambitious goals of greenhouse gas (GHG) reductions. A portion of these reductions are based on expected contributions from land use, land use change, and forestry (LULUCF). The European Union has similar goals which have resulted in a doubling of wood pellets exported from US ports destined for EU power plants over the last few years. There are potential conflicts between the GHG consequences of this pellet supply and the LULUCF contribution to US GHG goals. This study seeks to inform the discussion by modeling US forest GHG accounts using data measured on a grid of over 150,000 USDA Forest Service, Forest Inventory and Analysis (FIA) forestland plots across the conterminous United States. Empirical yield functions are estimate from plot log volume, biomass and carbon and provide the basis for changes in forest characteristics over time. Demand data based on a spatial database of over 2,000 forest product manufacturing facilities representing 11 intermediate and 13 final solid and pulpwood products. Manufacturing and logging costs are specific to slope, log size, and volume removed along with transportation costs based on fuel prices, FIA plot, and milling locations. The resulting partial spatial equilibrium model of the US forest sector is solved annually for the period 2010 - 2030 with demand shifted by energy prices and macroeconomic indicators from the US EIA's Annual Energy Outlook for a series of potential wood pellet export targets. For each wood pellet export level simulated, figures showing historic and scenario-specific forest products production are generated. Maps of the spatial allocation of both forest harvesting and carbon fluxes are presented at the National level and detail is given in both the US North and Southeast.

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.

Calcium hydroxide as a processing base in alkali-aided pH-shift protein recovery process.

PubMed

Paker, Ilgin; Jaczynski, Jacek; Matak, Kristen E

2017-02-01

Protein may be recovered by using pH shifts to solubilize and precipitate protein. Typically, sodium hydroxide is used as the processing base; however, this has been shown to significantly increase sodium in the final recovered protein. Protein was extracted from black bullhead catfish (Ameiurus melas) using a pH-shift method. Protein was solubilized using either sodium hydroxide (NaOH) or calcium hydroxide (Ca(OH) 2 ) and precipitated at pH 5.5 using hydrochloric acid (HCl). Protein solubility was greater when Ca(OH) 2 was used compared to NaOH during this process. Using Ca(OH) 2 as the processing base yielded the greatest lipid recovery (P < 0.05) at 77 g 100 g -1 , whereas the greatest (P < 0.05) protein recovery yield was recorded as 53 g 100 g -1 protein using NaOH. Protein solubilized with Ca(OH) 2 had more (P < 0.05) calcium in the protein fraction, whereas using NaOH increased (P < 0.05) sodium content. Results of our study showed that protein solubility was increased and the recovered protein had significantly more calcium when Ca(OH) 2 was used as the processing base. Results showed both NaOH and Ca(OH) 2 to be an effective processing base for pH-shift protein recovery processes. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

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.

Extraction of starch from hulled and hull-less barley with papain and aqueous sodium hydroxide.

PubMed

Sharma, Priyanka; Tejinder, S

2014-12-01

Starch was isolated from hulled (VJM 201) and hull-less (BL 134) barley with papain and aqueous sodium hydroxide treatments. For enzyme-assisted extraction, barley was steeped in water containing 0.2 % SO2 + 0.55 % lactic acid at 50° ± 2 °C for 4-5 h. The slurry was mixed with 0.4-2.0 g papain/kg barley and incubated at 50° ± 2 °C for 1-5 h. Aqueous sodium hydroxide (0.01-0.05 M) was added to the finely ground barley meal. The alkaline slurry was incubated at ambient temperature (25° ± 2 °C) for 15-60 min. The starch and grain fractions were isolated by screening and centrifugation. Increases in the time of treatment significantly affected the fiber, centrifugation and non-starch residue losses. Concentration of papain and sodium hydroxide had negligible effect on extraction losses. The enzyme-assisted extraction efficiency of starch was higher (80.7-84.6 %) than the alkaline method (70.9-83.7 %). The hulled barley showed higher extraction efficiency than the hull-less barley. The slurry treated with 0.4 g papain/kg barley for 5 h and 0.03 M sodium hydroxide for 60 min produced maximal yield of starch. Barley starch showed desirably high pasting temperature, water binding capacity and hold viscosity; and low final and setback viscosity compared with the commercial corn starch. The alkaline extracted hull-less barley starch showed exceptionally high peak and hold viscosities.

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.

Immobilization of 99-Technetium (VII) by Fe(II)-Goethite and Limited Reoxidation

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

Um, Wooyong; Chang, Hyun-Shik; Icenhower, Jonathan P.

2011-05-04

Synthesized goethite was successfully used with addition of Fe(II) to sequester Tc present in both deionized water and simulated off-gas scrubber waste solutions. Pertechnetate concentration in solution decreased immediately when the pH was raised above 7 by addition of sodium hydroxide. Removal of Tc(VII) from solution occurred most likely as a result of heterogeneous surface-catalyzed reduction to Tc(IV) and subsequent co-precipitation onto the goethite. The final Tc-bearing solid was identified as goethite-dominated Fe(III)-(oxy)hydroxide based on XRD analysis, confirming the widespread observation of its characteristic acicular habit by TEM/SEM images. Analysis of the solid precipitate by XAFS showed that the dominantmore » oxidation state of Tc was Tc(IV) and was in octahedral coordination with Tc-O, Fe-O, and Tc-Fe bond distances that are consistent with direct substitution of Tc for Fe in the goethite structure. In some experiments the final Tc-goethite product was subsequently armored with additional layers of freshly precipitated goethite. Successful incorporation of Tc(IV) within the goethite mineral lattice and subsequent goethite armoring can limit re-oxidation of Tc(IV) and its subsequent release from Tc-goethite waste forms, even when the final product is placed in oxidizing environments that typify shallow waste burial facilities.« less

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.

Characterization of UOP IONSIV IE-911

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

NYMAN, MAY D.; NENOFF, TINA M.; HEADLEY, THOMAS J.

2001-06-01

As a participating national lab in the inter-institutional effort to resolve performance issues of the non-elutable ion exchange technology for Cs extraction, they have carried out a series of characterization studies of UOP IONSIV{reg_sign} IE-911 and its component parts. IE-911 is a bound form (zirconium hydroxide-binder) of crystalline silicotitanate (CST) ion exchanger. The crystalline silicotitanate removes Cs from solutions by selective ion exchange. The performance issues of primary concern are: (1) excessive Nb leaching and subsequent precipitation of column-plugging Nb-oxide material, and (2) precipitation of aluminosilicate on IE-911 pellet surfaces, which may be initiated by dissolution of Si from themore » IE-911, thus creating a supersaturated solution with respect to silica. In this work, they have identified and characterized Si- and Nb-oxide based impurity phases in IE-911, which are the most likely sources of leachable Si and Nb, respectively. Furthermore, they have determined the criteria and mechanism for removal from IE-911 of the Nb-based impurity phase that is responsible for the Nb-oxide column plugging incidents.« less

Fabrication of ZnO and doped ZnO waveguides deposited by Spin Coating

NASA Astrophysics Data System (ADS)

Mohan, Rosmin Elsa; R, Neha P.; T, Shalu; C, Darshana K.; Sreelatha, K. S.

2015-02-01

In this paper, the synthesis of ZnO and doped Zn1-xAgxO (where x=0.03) nanoparticles by co- precipitation is reported. The precursors used were Zinc Nitrate and Potassium hydroxide pellets. For doping, 3% AgNO3 in ZnNO3 was considered as a separate buffer solution. The prepared nanoparticles were subsequently spin coated onto silica glass substrates at a constant chuck rate of 3000 rpm. The substrate acts as the lower cladding of a waveguide structure. The upper cladding is assumed to be air in the present investigation. The nanostructures of the ZnO powders in the doped and undoped cases were studied using X-ray Diffraction patterns. There was a decrease in the grain size with doping which increase the tunability of the powders to be used as photoluminescent devices. The optical characteristics of the sample were also investigated using UV-Visible spectrophotometer at 200-900 nm wavelengths. The photoluminescence peaks also report a dramatic increase in intensity at the same wavelength for the doped case compared to the undoped one.

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...

Aluminum Hydroxide and Magnesium Hydroxide

MedlinePlus

Aluminum Hydroxide, Magnesium Hydroxide are antacids used together to relieve heartburn, acid indigestion, and upset stomach. They ... They combine with stomach acid and neutralize it. Aluminum Hydroxide, Magnesium Hydroxide are available without a prescription. ...

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...

Methods of using adsorption media for separating or removing constituents

DOEpatents

Tranter, Troy J [Idaho Falls, ID; Herbst, R Scott [Idaho Falls, ID; Mann, Nicholas R [Blackfoot, ID; Todd, Terry A [Aberdeen, ID

2011-10-25

Methods of using an adsorption medium to remove at least one constituent from a feed stream. The method comprises contacting an adsorption medium with a feed stream comprising at least one constituent and removing the at least one constituent from the feed stream. The adsorption medium comprises a polyacrylonitrile (PAN) matrix and at least one metal hydroxide homogenously dispersed therein. The adsorption medium may comprise from approximately 15 wt % to approximately 90 wt % of the PAN and from approximately 10 wt % to approximately 85 wt % of the at least one metal hydroxide. The at least one metal hydroxide may be selected from the group consisting of ferric hydroxide, zirconium hydroxide, lanthanum hydroxide, cerium hydroxide, titanium hydroxide, copper hydroxide, antimony hydroxide, and molybdenum hydroxide.

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

Reduction of Iron-Oxide-Carbon Composites: Part II. Rates of Reduction of Composite Pellets in a Rotary Hearth Furnace Simulator

NASA Astrophysics Data System (ADS)

Halder, S.; Fruehan, R. J.

2008-12-01

A new ironmaking concept is being proposed that involves the combination of a rotary hearth furnace (RHF) with an iron-bath smelter. The RHF makes use of iron-oxide-carbon composite pellets as the charge material and the final product is direct-reduced iron (DRI) in the solid or molten state. This part of the research includes the development of a reactor that simulated the heat transfer in an RHF. The external heat-transport and high heating rates were simulated by means of infrared (IR) emitting lamps. The reaction rates were measured by analyzing the off-gas and computing both the amount of CO and CO2 generated and the degree of reduction. The reduction times were found to be comparable to the residence times observed in industrial RHFs. Both artificial ferric oxide (PAH) and naturally occurring hematite and taconite ores were used as the sources of iron oxide. Coal char and devolatilized wood charcoal were the reductants. Wood charcoal appeared to be a faster reductant than coal char. However, in the PAH-containing pellets, the reverse was found to be true because of heat-transfer limitations. For the same type of reductant, hematite-containing pellets were observed to reduce faster than taconite-containing pellets because of the development of internal porosity due to cracking and fissure formation during the Fe2O3-to-Fe3O4 transition. This is, however, absent during the reduction of taconite, which is primarily Fe3O4. The PAH-wood-charcoal pellets were found to undergo a significant amount of swelling at low-temperature conditions, which impeded the external heat transport to the lower layers. If the average degree of reduction targeted in an RHF is reduced from 95 to approximately 70 pct by coupling the RHF with a bath smelter, the productivity of the RHF can be enhanced 1.5 to 2 times. The use of a two- or three-layer bed was found to be superior to that of a single layer, for higher productivities.

X-ray tomography of feed-to-glass transition of simulated borosilicate waste glasses

DOE PAGES

Harris, William H.; Guillen, Donna P.; Klouzek, Jaroslav; ...

2017-05-10

The feed composition of a high level nuclear waste (HLW) glass melter affects the overall melting rate by influencing the chemical, thermophysical, and morphological properties of a relatively insulating cold cap layer over the molten phase where the primary feed vitrification reactions occur. Data from X ray computed tomography imaging of melting pellets comprised of a simulated high-aluminum HLW feed heated at a rate of 10°C/min reveal the distribution and morphology of bubbles, collectively known as primary foam, within this layer for various SiO 2/(Li 2CO 3+H 3BO 3+Na 2CO 3) mass fractions at temperatures between 600°C and 1040°C. Tomore » track melting dynamics, cross-sections obtained through the central profile of the pellet were digitally segmented into primary foam and a condensed phase. Pellet dimensions were extracted using Photoshop CS6 tools while the DREAM.3D software package was used to calculate pellet profile area, average and maximum bubble areas, and two-dimensional void fraction. The measured linear increase in the pellet area expansion rates – and therefore the increase in batch gas evolution rates – with SiO 2/(Li 2CO 3+H 3BO 3+Na 2CO 3) mass fraction despite an exponential increase in viscosity of the final waste glass at 1050°C and a lower total amount of gas-evolving species suggest that the retention of primary foam with large average bubble size at higher temperatures results from faster reaction kinetics rather than increased viscosity. However, viscosity does affect the initial foam collapse temperature by supporting the growth of larger bubbles. Because the maximum bubble size is limited by the pellet dimensions, larger scale studies are needed to understand primary foam morphology at high temperatures. This temperature-dependent morphological data can be used in future investigations to synthetically generate cold cap structures for use in models of heat transfer within a HLW glass melter.« less

X-ray tomography of feed-to-glass transition of simulated borosilicate waste glasses

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

Harris, William H.; Guillen, Donna P.; Klouzek, Jaroslav

The feed composition of a high level nuclear waste (HLW) glass melter affects the overall melting rate by influencing the chemical, thermophysical, and morphological properties of a relatively insulating cold cap layer over the molten phase where the primary feed vitrification reactions occur. Data from X ray computed tomography imaging of melting pellets comprised of a simulated high-aluminum HLW feed heated at a rate of 10°C/min reveal the distribution and morphology of bubbles, collectively known as primary foam, within this layer for various SiO 2/(Li 2CO 3+H 3BO 3+Na 2CO 3) mass fractions at temperatures between 600°C and 1040°C. Tomore » track melting dynamics, cross-sections obtained through the central profile of the pellet were digitally segmented into primary foam and a condensed phase. Pellet dimensions were extracted using Photoshop CS6 tools while the DREAM.3D software package was used to calculate pellet profile area, average and maximum bubble areas, and two-dimensional void fraction. The measured linear increase in the pellet area expansion rates – and therefore the increase in batch gas evolution rates – with SiO 2/(Li 2CO 3+H 3BO 3+Na 2CO 3) mass fraction despite an exponential increase in viscosity of the final waste glass at 1050°C and a lower total amount of gas-evolving species suggest that the retention of primary foam with large average bubble size at higher temperatures results from faster reaction kinetics rather than increased viscosity. However, viscosity does affect the initial foam collapse temperature by supporting the growth of larger bubbles. Because the maximum bubble size is limited by the pellet dimensions, larger scale studies are needed to understand primary foam morphology at high temperatures. This temperature-dependent morphological data can be used in future investigations to synthetically generate cold cap structures for use in models of heat transfer within a HLW glass melter.« less

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

Microbial Communities in Sunken Wood Are Structured by Wood-Boring Bivalves and Location in a Submarine Canyon

PubMed Central

Fagervold, Sonja K.; Romano, Chiara; Kalenitchenko, Dimitri; Borowski, Christian; Nunes-Jorge, Amandine; Martin, Daniel; Galand, Pierre E.

2014-01-01

The cornerstones of sunken wood ecosystems are microorganisms involved in cellulose degradation. These can either be free-living microorganisms in the wood matrix or symbiotic bacteria associated with wood-boring bivalves such as emblematic species of Xylophaga, the most common deep-sea woodborer. Here we use experimentally submerged pine wood, placed in and outside the Mediterranean submarine Blanes Canyon, to compare the microbial communities on the wood, in fecal pellets of Xylophaga spp. and associated with the gills of these animals. Analyses based on tag pyrosequencing of the 16S rRNA bacterial gene showed that sunken wood contained three distinct microbial communities. Wood and pellet communities were different from each other suggesting that Xylophaga spp. create new microbial niches by excreting fecal pellets into their burrows. In turn, gills of Xylophaga spp. contain potential bacterial symbionts, as illustrated by the presence of sequences closely related to symbiotic bacteria found in other wood eating marine invertebrates. Finally, we found that sunken wood communities inside the canyon were different and more diverse than the ones outside the canyon. This finding extends to the microbial world the view that submarine canyons are sites of diverse marine life. PMID:24805961

Microbial communities in sunken wood are structured by wood-boring bivalves and location in a submarine canyon.

PubMed

Fagervold, Sonja K; Romano, Chiara; Kalenitchenko, Dimitri; Borowski, Christian; Nunes-Jorge, Amandine; Martin, Daniel; Galand, Pierre E

2014-01-01

The cornerstones of sunken wood ecosystems are microorganisms involved in cellulose degradation. These can either be free-living microorganisms in the wood matrix or symbiotic bacteria associated with wood-boring bivalves such as emblematic species of Xylophaga, the most common deep-sea woodborer. Here we use experimentally submerged pine wood, placed in and outside the Mediterranean submarine Blanes Canyon, to compare the microbial communities on the wood, in fecal pellets of Xylophaga spp. and associated with the gills of these animals. Analyses based on tag pyrosequencing of the 16S rRNA bacterial gene showed that sunken wood contained three distinct microbial communities. Wood and pellet communities were different from each other suggesting that Xylophaga spp. create new microbial niches by excreting fecal pellets into their burrows. In turn, gills of Xylophaga spp. contain potential bacterial symbionts, as illustrated by the presence of sequences closely related to symbiotic bacteria found in other wood eating marine invertebrates. Finally, we found that sunken wood communities inside the canyon were different and more diverse than the ones outside the canyon. This finding extends to the microbial world the view that submarine canyons are sites of diverse marine life.

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.

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.

[Nonsurgical retreatment in a case of a radiolucent apical lesion].

PubMed

Vicente Gómez, A; Rodríguez Ponce, A

1989-01-01

We present a case of failure that was helpful solved without surgical endodontic treatment. We don't achieve clinical success besides endodontic treatment was twice remade. Finally we decided to put a temporary filling with calcium hydroxide and wait until apical radiolucency disappear and complete our treatment with gutta-percha, sealer and lateral condensation.

Evaluation of standard and alternative methods for the decontamination of VX and HD in chemical agent disposal facilities. Final report, February 1992-February 1993

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

Hovanec, J.W.; Szafraniec, L.L.; Albizo, J.M.

1993-04-01

Standard decontaminant formulations, aqueous sodium hydroxide and aqueous sodium hypochlorite, were providing slow and incomplete results when used to decontaminate certain operating facilities at the Johnston Atoll Chemical Agent Disposal System and the Chemical Agent Disposal System (Utah). A study was undertaken to define the capabilities and limitations of using concentrated sodium hydroxide to decontaminate VX, the effect of adding hydrogen peroxide to the sodium hydroxide for the decontamination of VX, the efficacy of aqueous oxone for the decontamination of VX, and the efficacy of oxone in a water/1-methyl-2-pyrrolidinone (MP) mixture for the decontamination of HD. Using aqueous sodium hydroxidemore » alone was not desirable since the formation of toxic EA2192 could not be averted. However, the addition of hydrogen peroxide resulted in effective VX decontamination without EA2192 formation. Aqueous oxone was also found to be effective for both VX and HD. The incorporation of MP did little to improve HD dissolution and reacted with the oxone to reduce the effective usable life of the decontamination solution. Thus, the use of MP in HD decontamination was not recommended.« less

Effect of alkali and oxidative treatments on the physicochemical, pasting, thermal and morphological properties of corn starch.

PubMed

Spier, Franciela; Zavareze, Elessandra da Rosa; Marques e Silva, Ricardo; Elias, Moacir Cardoso; Dias, Alvaro Renato Guerra

2013-07-01

Few studies on starch modifications using different chemical agents are available in the literature, and no reports were found on the combined effect of oxidation and alkaline treatment of corn starch. Thus this work evaluated the physicochemical, pasting, morphological, cystallinity and thermal properties of chemically modified corn starch, after either the isolated or combined action of alkaline (sodium hydroxide) and oxidative (sodium hypochlorite) treatments. The highest values for the sum of carbonyl and carboxyl and enzymatic hydrolysis occurred in starches submitted to oxidative treatment at high active chlorine concentrations. The alkali treatment in isolation modified the pasting properties, reduced the paste temperature and increased the peak viscosity, breakdown, final viscosity and setback of starches. Starch modified by the action of sodium hypochlorite and hydroxide in combination presented more severe damage on granule surfaces. The results show that corn starch modified by the combined action of oxidative and alkaline treatments should be studied more, especially at the concentration limit of sodium hydroxide where gelatinization occurs. Under these conditions the effect of oxidation can be more intense and thus allow the production of starches with different properties and an increase in their industrial applications. © 2013 Society of Chemical Industry.

Aerosol synthesis of nano and micro-scale zero valent metal particles from oxide precursors

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

Phillips, Jonathan; Luhrs, Claudia; Lesman, Zayd

2010-01-01

In this work a novel aerosol method, derived form the batch Reduction/Expansion Synthesis (RES) method, for production of nano / micro-scale metal particles from oxides and hydroxides is presented. In the Aerosol-RES (A-RES) method, an aerosol, consisting of a physical mixture of urea and metal oxide or hydroxides, is passed through a heated oven (1000 C) with a residence time of the order of 1 second, producing pure (zero valent) metal particles. It appears that the process is flexible regarding metal or alloy identity, allows control of particle size and can be readily scaled to very large throughput. Current workmore » is focused on creating nanoparticles of metal and metal alloy using this method. Although this is primarily a report on observations, some key elements of the chemistry are clear. In particular, the reducing species produced by urea decomposition are the primary agents responsible for reduction of oxides and hydroxides to metal. It is also likely that the rapid expansion that takes place when solid/liquid urea decomposes to form gas species influences the final morphology of the particles.« 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

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%.

Sodium Hydroxide and Calcium Hydroxide Hybrid Oxygen Bleaching with System

NASA Astrophysics Data System (ADS)

Doelle, K.; Bajrami, B.

2018-01-01

This study investigates the replacement of sodium hydroxide in the oxygen bleaching stage using a hybrid system consisting of sodium hydroxide calcium hydroxide. Commercial Kraft pulping was studied using yellow pine Kraft pulp obtained from a company in the US. The impact of sodium hydroxide, calcium hydroxide hybrid system in regard to concentration, reaction time and temperature for Kraft pulp was evaluated. The sodium hydroxide and calcium hydroxide dosage was varied between 0% and 15% based on oven dry fiber content. The bleaching reaction time was varied between 0 and 180 minutes whereas the bleaching temperature ranged between 70 °C and 110 °C. The ability to bleach pulp was measured by determining the Kappa number. Optimum bleaching results for the hybrid system were achieved with 4% sodium hydroxide and 2% calcium hydroxide content. Beyond this, the ability to bleach pulp decreased.

Contribution to the knowledge of nickel hydroxide electrodes. 5. Analysis and electrochemical behavior of cadmium nickel hydroxides

NASA Technical Reports Server (NTRS)

Bode, H.; Dennstedt, W.

1981-01-01

Electrochemical experiments performed at sintered and bulk electrodes show that beta nickel hydroxide contains an electrochemically inactive proportion of cadmium hydroxide of up to 10%. The electrochemically ineffective cadmium hydroxide is homogeneously dissolved in beta nickel hydroxide.

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.

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

Dietary Spirulina (Arthrospira platensis) and Thyme (Thymus vulgaris) supplementation to growing rabbits: effects on raw and cooked meat quality, nutrient true retention and oxidative stability.

PubMed

Dalle Zotte, Antonella; Cullere, Marco; Sartori, Alberto; Szendrő, Zsolt; Kovàcs, Melinda; Giaccone, Valerio; Dal Bosco, Alessandro

2014-10-01

The study evaluated the effect of Spirulina and Thyme dietary supplementation on rabbit meat quality, nutrient true retention and protection against oxidative stress. Rabbits in the control group (C-C) received a non-supplemented pellet throughout the experiment (5-11weeks of age). In the other groups, the pellet contained 5% Spirulina (S), 3% Thyme (T), or both (ST) for either the entire (groups S-S, T-T, ST-ST) or only the final part of the growing period (8-11weeks: groups C-S, C-T, C-ST). Spirulina supplementation increased the γ-linolenic acid content of rabbit meat, whereas Thyme improved the oxidative stability of raw and freeze-dried meat. Copyright © 2014 Elsevier Ltd. All rights reserved.

3D modeling of missing pellet surface defects in BWR fuel

DOE PAGES

Spencer, B. W.; Williamson, R. L.; Stafford, D. S.; ...

2016-07-26

One of the important roles of cladding in light water reactor fuel rods is to prevent the release of fission products. To that end, it is essential that the cladding maintain its integrity under a variety of thermal and mechanical loading conditions. Local geometric irregularities in fuel pellets caused by manufacturing defects known as missing pellet surfaces (MPS) can in some circumstances lead to elevated cladding stresses that are sufficiently high to cause cladding failure. Accurate modeling of these defects can help prevent these types of failures. The BISON nuclear fuel performance code developed at Idaho National Laboratory can bemore » used to simulate the global thermo-mechanical fuel rod behavior, as well as the local response of regions of interest, in either 2D or 3D. In either case, a full set of models to represent the thermal and mechanical properties of the fuel, cladding and plenum gas is employed. A procedure for coupling 2D full-length fuel rod models to detailed 3D models of the region of the rod containing a MPS defect is detailed in this paper. The global and local model each contain appropriate physics and behavior models for nuclear fuel. This procedure is demonstrated on a simulation of a boiling water reactor (BWR) fuel rod containing a pellet with an MPS defect, subjected to a variety of transient events, including a control blade withdrawal and a ramp to high power. The importance of modeling the local defect using a 3D model is highlighted by comparing 3D and 2D representations of the defective pellet region. Finally, parametric studies demonstrate the effects of the choice of gaseous swelling model and of the depth and geometry of the MPS defect on the response of the cladding adjacent to the defect.« less

Mathematical model of silicon smelting process basing on pelletized charge from technogenic raw materials

NASA Astrophysics Data System (ADS)

Nemchinova, N. V.; Tyutrin, A. A.; Salov, V. M.

2018-03-01

The silicon production process in the electric arc reduction furnaces (EAF) is studied using pelletized charge as an additive to the standard on the basis of the generated mathematical model. The results obtained due to the model will contribute to the analysis of the charge components behavior during melting with the achievement of optimum final parameters of the silicon production process. The authors proposed using technogenic waste as a raw material for the silicon production in a pelletized form using liquid glass and aluminum production dust from the electrostatic precipitators as a binder. The method of mathematical modeling with the help of the ‘Selector’ software package was used as a basis for the theoretical study. A model was simulated with the imitation of four furnace temperature zones and a crystalline silicon phase (25 °C). The main advantage of the created model is the ability to analyze the behavior of all burden materials (including pelletized charge) in the carbothermic process. The behavior analysis is based on the thermodynamic probability data of the burden materials interactions in the carbothermic process. The model accounts for 17 elements entering the furnace with raw materials, electrodes and air. The silicon melt, obtained by the modeling, contained 91.73 % wt. of the target product. The simulation results showed that in the use of the proposed combined charge, the recovery of silicon reached 69.248 %, which is in good agreement with practical data. The results of the crystalline silicon chemical composition modeling are compared with the real silicon samples of chemical analysis data, which showed the results of convergence. The efficiency of the mathematical modeling methods in the studying of the carbothermal silicon obtaining process with complex interphase transformations and the formation of numerous intermediate compounds using a pelletized charge as an additive to the traditional one is shown.

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...

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.

SEPARATION OF PLUTONIUM HYDROXIDE FROM BISMUTH HYDROXIDE

DOEpatents

Watt, G.W.

1958-08-19

An tmproved method is described for separating plutonium hydroxide from bismuth hydroxide. The end product of the bismuth phosphate processes for the separation amd concentration of plutonium is a inixture of bismuth hydroxide amd plutonium hydroxide. It has been found that these compounds can be advantageously separated by treatment with a reducing agent having a potential sufficient to reduce bismuth hydroxide to metalltc bisinuth but not sufficient to reduce the plutonium present. The resulting mixture of metallic bismuth and plutonium hydroxide can then be separated by treatment with a material which will dissolve plutonium hydroxide but not metallic bismuth. Sodiunn stannite is mentioned as a preferred reducing agent, and dilute nitric acid may be used as the separatory solvent.

Single pellet grasping following cervical spinal cord injury in adult rat using an automated full-time training robot

PubMed Central

Fenrich, Keith K.; May, Zacincte; Torres-Espín, Abel; Forero, Juan; Bennett, David J.; Fouad, Karim

2016-01-01

Task specific motor training is a common form of rehabilitation therapy in individuals with spinal cord injury (SCI). The single pellet grasping (SPG) task is a skilled forelimb motor task used to evaluate recovery of forelimb function in rodent models of SCI. The task requires animals to obtain food pellets located on a shelf beyond a slit at the front of an enclosure. Manually training and testing rats in the SPG task requires extensive time and often yields results with high outcome variability and small therapeutic windows (i.e., the difference between pre- and post-SCI success rates). Recent advances in automated SPG training using automated pellet presentation (APP) systems allow rats to train ad libitum 24 h a day, 7 days a week. APP trained rats have improved success rates, require less researcher time, and have lower outcome variability compared to manually trained rats. However, it is unclear whether APP trained rats can perform the SPG task using the APP system after SCI. Here we show that rats with cervical SCI can successfully perform the SPG task using the APP system. We found that SCI rats with APP training performed significantly more attempts, had slightly lower and less variable final score success rates, and larger therapeutic windows than SCI rats with manual training. These results demonstrate that APP training has clear advantages over manual training for evaluating reaching performance of SCI rats and represents a new tool for investigating rehabilitative motor training following CNS injury. PMID:26611563

Single pellet grasping following cervical spinal cord injury in adult rat using an automated full-time training robot.

PubMed

Fenrich, Keith K; May, Zacincte; Torres-Espín, Abel; Forero, Juan; Bennett, David J; Fouad, Karim

2016-02-15

Task specific motor training is a common form of rehabilitation therapy in individuals with spinal cord injury (SCI). The single pellet grasping (SPG) task is a skilled forelimb motor task used to evaluate recovery of forelimb function in rodent models of SCI. The task requires animals to obtain food pellets located on a shelf beyond a slit at the front of an enclosure. Manually training and testing rats in the SPG task requires extensive time and often yields results with high outcome variability and small therapeutic windows (i.e., the difference between pre- and post-SCI success rates). Recent advances in automated SPG training using automated pellet presentation (APP) systems allow rats to train ad libitum 24h a day, 7 days a week. APP trained rats have improved success rates, require less researcher time, and have lower outcome variability compared to manually trained rats. However, it is unclear whether APP trained rats can perform the SPG task using the APP system after SCI. Here we show that rats with cervical SCI can successfully perform the SPG task using the APP system. We found that SCI rats with APP training performed significantly more attempts, had slightly lower and less variable final score success rates, and larger therapeutic windows than SCI rats with manual training. These results demonstrate that APP training has clear advantages over manual training for evaluating reaching performance of SCI rats and represents a new tool for investigating rehabilitative motor training following CNS injury. Copyright © 2015 Elsevier B.V. All rights reserved.

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.

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

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).

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.

EC-18, a synthetic monoacetyldiglyceride (1-palmitoyl-2-linoleoyl-3-acetylglycerol), attenuates the asthmatic response in an aluminum hydroxide/ovalbumin-induced model of asthma.

PubMed

Shin, In-Sik; Shin, Na-Rae; Jeon, Chan-Mi; Kwon, Ok-Kyoung; Sohn, Ki-Young; Lee, Tae-Suk; Kim, Jae-Wha; Ahn, Kyung-Seop; Oh, Sei-Ryang

2014-01-01

EC-18 is a synthetic monoacetyldiaglyceride that is a major constituent in antlers of Sika deer (Cervus nippon Temmenick). In this study, we evaluated the protective effects of EC-18 on Th2-type cytokines, eosinophil infiltration, and other factors in an aluminum hydroxide/ovalbumin (OVA)-induced murine asthma model. Mice were sensitized on days 0 and 14 by intraperitoneal injection of OVA with aluminum hydroxide. On days 21, 22 and 23 after the initial sensitization, the mice received an airway challenge with OVA for 1h using an ultrasonic nebulizer. EC-18 was administered to mice by oral gavage at doses of 30mg/kg and 60mg/kg once daily from day 18 to 23. Methacholine responsiveness was measured 24h after the final OVA challenge, and the bronchoalveolar lavage fluid (BALF) was collected 48h after the final OVA challenge. EC-18 significantly reduced methacholine responsiveness, T helper type 2 (Th2) cytokines, eotaxin-1, immunoglobulin (Ig) E, IgG, and the number of inflammatory cells. In addition, EC-18-treated mice exhibited the reduction in the expression of inducible nitric oxide synthase (iNOS) in lung tissue. In the histological analysis using hematoxylin-eosin stain and periodic acid-Schiff stain, EC-18 attenuated the infiltration of inflammatory cells into the airway and reduced the level of mucus production. Our results showed that EC-18 effectively suppressed the asthmatic response induced by OVA challenge. These effects were considered to be associated with iNOS suppression. In conclusion, this study suggests that EC-18 may be a therapeutic agent for allergic asthma. Copyright © 2013 Elsevier B.V. All rights reserved.

On-line pH modification of carbonate eluents using an electrolytic potassium hydroxide generator for ion chromatography.

PubMed

Novic, Milko; Liu, Yan; Avdalovic, Nebojsa; Pihlar, Boris

2002-05-31

Classical gradient elution, based on the application of a gradient pump used for mixing two or more prepared eluent components in pre-determined concentrations, was replaced by a chromatography system equipped with an isocratic pump and an electrolytic KOH generator. The isocratic pump delivered a constant concentration eluent composed of pure hydrogencarbonate solution. Carbonate ions, the main component of carbonate/hydrogencarbonate-based eluents, were formed by titration of hydrogencarbonate with KOH formed on-line in the electrolytic KOH generator. By changing the concentration of electrolytically-generated KOH, the eluent composition could be changed from pure hydrogencarbonate to a carbonate/hydrogencarbonate buffer, and finally to a carbonate/hydroxide-based eluent. The described system was tested to achieve pH-based changes of retention behavior of phosphate under constant inflow eluent composition conditions.

Delaminating and restacking MgAl-layered double hydroxide monitored and characterized by a range of instrumental methods

NASA Astrophysics Data System (ADS)

Muráth, Szabolcs; Somosi, Zoltán; Tóth, Ildikó Y.; Tombácz, Etelka; Sipos, Pál; Pálinkó, István

2017-07-01

The delamination-restacking properties of MgAl-layered double hydroxide (MgAl-LDH) were studied in various solvents. The LDH samples were successfully delaminated in polar amides (formamide, N-methylformamide, N-methylacetamide). Usually, delamination was finalized by ultrasonic treatment. As rehydrating solutions, numerous Na-salts with single-, double- and triple-charged anions were used. Reconstruction was accomplished with anions of one or two negative charges, but triple-charged ones generally disrupted the rebuilding process, likely, because their salts with the metals of the LDH are very stable, and the thin layers can more readily transform to salts than the ordered materials. Samples and delamination-restacking processes were characterized by X-ray diffractometry (XRD), infrared spectroscopy (IR), dynamic light scattering (DLS), scanning electron microscopy (SEM) and energy-dispersive X-ray analysis (EDX).

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.

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...

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.

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.

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

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.

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.

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

Effects of adhesions of amorphous Fe and Al hydroxides on surface charge and adsorption of K+ and Cd2+ on rice roots.

PubMed

Liu, Zhao-Dong; Wang, Hai-Cui; Zhou, Qin; Xu, Ren-Kou

2017-11-01

Iron (Fe) and aluminum (Al) hydroxides in variable charge soils attached to rice roots may affect surface-charge properties and subsequently the adsorption and uptake of nutrients and toxic metals by the roots. Adhesion of amorphous Fe and Al hydroxides onto rice roots and their effects on zeta potential of roots and adsorption of potassium (K + ) and cadmium (Cd 2+ ) by roots were investigated. Rice roots adsorbed more Al hydroxide than Fe hydroxide because of the greater positive charge on Al hydroxide. Adhesion of Fe and Al hydroxides decreased the negative charge on rice roots, and a greater effect of the Al hydroxide. Consequently, adhesion of Fe and Al hydroxides reduced the K + and Cd 2+ adsorption by rice roots. The results of attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR) and desorption of K + and Cd 2+ from rice roots indicated that physical masking by Fe and Al hydroxides and diffuse-layer overlapping between the positively-charged hydroxides and negatively-charged roots were responsible for the reduction of negative charge on roots induced by adhesion of the hydroxides. Therefore, the interaction between Fe and Al hydroxides and rice roots reduced negative charge on roots and thus inhibited their adsorption of nutrient and toxic cations. Copyright © 2017 Elsevier Inc. All rights reserved.

Using Neutron Diffraction to Investigate Texture Evolution During Consolidation of Deuterated Triaminotrinitrobenzene (d-TATB) Explosive Powder

DOE PAGES

Luscher, Darby J.; Yeager, John D.; Clausen, Bjørn; ...

2017-05-14

Triaminotrinitrobenzene (TATB) is a highly anisotropic molecular crystal used in several plastic-bonded explosive (PBX) formulations. A complete understanding of the orientation distribution of TATB particles throughout a PBX charge is required to understand spatially variable, anisotropic macroscale properties of the charge. Although texture of these materials can be measured after they have been subjected to mechanical or thermal loads, measuring texture evolution in situ is important in order to identify mechanisms of crystal deformation and reorientation used to better inform thermomechanical models. Neutron diffraction measurements were used to estimate crystallographic reorientation while deuterated TATB (d-TATB) powder was consolidated into amore » cylindrical pellet via a uniaxial die-pressing operation at room temperature. Both the final texture of the pressed pellet and the in situ evolution of texture during pressing were measured, showing that the d-TATB grains reorient such that (001) poles become preferentially aligned with the pressing direction. A compaction model is used to predict the evolution of texture in the pellet during the pressing process, finding that the original model overpredicted the texture strength compared to these measurements. The theory was extended to account for initial particle shape and pore space, bringing the results into good agreement with the data.« less

Using Neutron Diffraction to Investigate Texture Evolution During Consolidation of Deuterated Triaminotrinitrobenzene (d-TATB) Explosive Powder

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

Luscher, Darby J.; Yeager, John D.; Clausen, Bjørn

Triaminotrinitrobenzene (TATB) is a highly anisotropic molecular crystal used in several plastic-bonded explosive (PBX) formulations. A complete understanding of the orientation distribution of TATB particles throughout a PBX charge is required to understand spatially variable, anisotropic macroscale properties of the charge. Although texture of these materials can be measured after they have been subjected to mechanical or thermal loads, measuring texture evolution in situ is important in order to identify mechanisms of crystal deformation and reorientation used to better inform thermomechanical models. Neutron diffraction measurements were used to estimate crystallographic reorientation while deuterated TATB (d-TATB) powder was consolidated into amore » cylindrical pellet via a uniaxial die-pressing operation at room temperature. Both the final texture of the pressed pellet and the in situ evolution of texture during pressing were measured, showing that the d-TATB grains reorient such that (001) poles become preferentially aligned with the pressing direction. A compaction model is used to predict the evolution of texture in the pellet during the pressing process, finding that the original model overpredicted the texture strength compared to these measurements. The theory was extended to account for initial particle shape and pore space, bringing the results into good agreement with the data.« less

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.

Nickel hydroxide electrode. 3: Thermogravimetric investigations of nickel (II) hydroxides

NASA Technical Reports Server (NTRS)

Dennstedt, W.; Loeser, W.

1982-01-01

Water contained in Ni hydroxide influences its electrochemical reactivity. The water content of alpha and beta Ni hydroxides is different with respect to the amount and bond strength. Thermogravimetric experiments show that the water of the beta Ni hydroxides exceeding the stoichiometric composition is completely removed at 160 deg. The water contained in the interlayers of the beta hydroxide, however, is removed only at higher temperatures, together with the water originating from the decomposition of the hydroxide. These differences are attributed to the formation of II bonds within the interlayers and between interlayers and adjacent main layers. An attempt is made to explain the relations between water content and the oxidizability of the Ni hydroxides.

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.

Adenosine 5′-triphosphate (ATP) supplements are not orally bioavailable: a randomized, placebo-controlled cross-over trial in healthy humans

PubMed Central

2012-01-01

Background Nutritional supplements designed to increase adenosine 5′-triphosphate (ATP) concentrations are commonly used by athletes as ergogenic aids. ATP is the primary source of energy for the cells, and supplementation may enhance the ability to maintain high ATP turnover during high-intensity exercise. Oral ATP supplements have beneficial effects in some but not all studies examining physical performance. One of the remaining questions is whether orally administered ATP is bioavailable. We investigated whether acute supplementation with oral ATP administered as enteric-coated pellets led to increased concentrations of ATP or its metabolites in the circulation. Methods Eight healthy volunteers participated in a cross-over study. Participants were given in random order single doses of 5000 mg ATP or placebo. To prevent degradation of ATP in the acidic environment of the stomach, the supplement was administered via two types of pH-sensitive, enteric-coated pellets (targeted at release in the proximal or distal small intestine), or via a naso-duodenal tube. Blood ATP and metabolite concentrations were monitored by HPLC for 4.5 h (naso-duodenal tube) or 7 h (pellets) post-administration. Areas under the concentration vs. time curve were calculated and compared by paired-samples t-tests. Results ATP concentrations in blood did not increase after ATP supplementation via enteric-coated pellets or naso-duodenal tube. In contrast, concentrations of the final catabolic product of ATP, uric acid, were significantly increased compared to placebo by ~50% after administration via proximal-release pellets (P = 0.003) and naso-duodenal tube (P = 0.001), but not after administration via distal-release pellets. Conclusions A single dose of orally administered ATP is not bioavailable, and this may explain why several studies did not find ergogenic effects of oral ATP supplementation. On the other hand, increases in uric acid after release of ATP in the proximal part of the small intestine suggest that ATP or one of its metabolites is absorbed and metabolized. Uric acid itself may have ergogenic effects, but this needs further study. Also, more studies are needed to determine whether chronic administration of ATP will enhance its oral bioavailability. PMID:22510240

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

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.

Chemically Driven Printed Textile Sensors Based on Graphene and Carbon Nanotubes

PubMed Central

Skrzetuska, Ewa; Puchalski, Michał; Krucińska, Izabella

2014-01-01

The unique properties of graphene, such as the high elasticity, mechanical strength, thermal conductivity, very high electrical conductivity and transparency, make them it an interesting material for stretchable electronic applications. In the work presented herein, the authors used graphene and carbon nanotubes to introduce chemical sensing properties into textile materials by means of a screen printing method. Carbon nanotubes and graphene pellets were dispersed in water and used as a printing paste in the screen printing process. Three printing paste compositions were prepared—0%, 1% and 3% graphene pellet content with a constant 3% carbon nanotube mass content. Commercially available materials were used in this process. As a substrate, a twill woven cotton fabric was utilized. It has been found that the addition of graphene to printing paste that contains carbon nanotubes significantly enhances the electrical conductivity and sensing properties of the final product. PMID:25211197

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.

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.

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.

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.

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.

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.

21 CFR 184.1428 - Magnesium hydroxide.

Code of Federal Regulations, 2012 CFR

2012-04-01

... is prepared as a white precipitate by the addition of sodium hydroxide to a water soluble magnesium... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Magnesium hydroxide. 184.1428 Section 184.1428... Listing of Specific Substances Affirmed as GRAS § 184.1428 Magnesium hydroxide. (a) Magnesium hydroxide...

21 CFR 184.1428 - Magnesium hydroxide.

Code of Federal Regulations, 2013 CFR

2013-04-01

... is prepared as a white precipitate by the addition of sodium hydroxide to a water soluble magnesium... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Magnesium hydroxide. 184.1428 Section 184.1428... Listing of Specific Substances Affirmed as GRAS § 184.1428 Magnesium hydroxide. (a) Magnesium hydroxide...

21 CFR 184.1631 - Potassium hydroxide.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Potassium hydroxide. 184.1631 Section 184.1631... GRAS § 184.1631 Potassium hydroxide. (a) Potassium hydroxide (KOH, CAS Reg. No. 1310-58-3) is also... powders. Potassium hydroxide is obtained commercially from the electrolysis of potassium chloride solution...

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.

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).

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.

Expanded Analysis of Hot Isostatic Pressed Iodine-Loaded Silver-Exchanged Mordenite

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

Jubin, R. T.; Bruffey, S. H.; Patton, K. K.

2014-09-30

Reduced silver-exchanged mordenite (Ag0Z) is being evaluated as a potential material to control the release of radioactive iodine that is released during the reprocessing of used nuclear fuel into the plant off-gas streams. The purpose of this study was to determine if hot pressing could directly convert this iodine loaded sorbent into a waste form suitable for long-term disposition. The minimal pretreatment required for production of pressed pellets makes hot pressing a technically and economically desirable process. Initial scoping studies utilized hot uniaxial pressing (HUPing) to prepare samples of non-iodine-loaded reduced silver exchanged mordenite (Ag0Z). The resulting samples were verymore » fragile due to the low pressure (~ 28 MPa) used. It was recommended that hot isostatic pressing (HIPing), performed at higher temperatures and pressures, be investigated. HIPing was carried out in two phases, with a third and final phase currently underway. Phase I evaluated the effects of pressure and temperature conditions on the manufacture of a pressed sample. The base material was an engineered form of silver zeolite. Six samples of Ag0Z and two samples of I-Ag0Z were pressed. It was found that HIPing produced a pressed pellet of high density. Analysis of each pressed pellet by scanning electron microscopy-energy dispersive spectrophotometry (SEM-EDS) and X-ray diffraction (XRD) demonstrated that under the conditions used for pressing, the majority of the material transforms into an amorphous structure. The only crystalline phase observed in the pressed Ag0Z material was SiO2. For the samples loaded with iodine (I-Ag0Z) iodine was present as AgI clusters at low temperatures, and transformed into AgIO4 at high temperatures. Surface mapping and EDS demonstrate segregation between silver iodide phases and silicon dioxide phases. Based on the results of the Phase I study, an expanded test matrix was developed to examine the effects of multiple source materials, compositional variations, and an expanded temperature range. Each sample was analyzed with the approach used in Phase I. In all cases, there is nothing in the SEM or XRD analyses that indicates creation of any AgI-containing silicon phase, with the samples being found to be largely amorphous. Phase III of this study has been initiated and is the final phase of scoping tests. It will expand upon the test matrix completed in Phase II and will examine the durability of the pressed pellets through product consistency testing (PCT) studies. Transformation of the component material into a well-characterized iodine-containing mineral phase would be desirable. This would limit the additional experimental testing and modeling required to determine the long-term stability of the pressed pellet, as much of that information has already been learned for several common iodine-containing minerals. However, this is not an absolute requirement, especially if pellets produced by hot isostatic pressing can be demonstrated through initial PCT studies to retain iodine well despite their amorphous composition.« less

Oxygen anion (O- ) and hydroxide anion (HO- ) reactivity with a series of old and new refrigerants.

PubMed

Le Vot, Clotilde; Lemaire, Joël; Pernot, Pascal; Heninger, Michel; Mestdagh, Hélène; Louarn, Essyllt

2018-04-01

The reactivity of a series of commonly used halogenated compounds (trihalomethanes, chlorofluorocarbon, hydrochlorofluorocarbon, fluorocarbons, and hydrofluoroolefin) with hydroxide and oxygen anion is studied in a compact Fourier transform ion cyclotron resonance. O - is formed by dissociative electron attachment to N 2 O and HO - by a further ion-molecule reaction with ammonia. Kinetic experiments are performed by increasing duration of introduction of the studied molecule at a constant pressure. Hydroxide anion reactions mainly proceed by proton transfer for all the acidic compounds. However, nucleophilic substitution is observed for chlorinated and brominated compounds. For fluorinated compounds, a specific elimination of a neutral fluorinated alkene is observed in our results in parallel with the proton transfer reaction. Oxygen anion reacts rapidly and extensively with all compounds. Main reaction channels result from nucleophilic substitution, proton transfer, and formal H 2 + transfer. We highlight the importance of transfer processes (atom or ion) in the intermediate ion-neutral complex, explaining part of the observed reactivity and formed ions. In this paper, we present the first reactivity study of anions with HFO 1234yf. Finally, the potential of O - and HO - as chemical ionization reagents for trace analysis is discussed. Copyright © 2017 John Wiley & Sons, Ltd.

Process development of itaconic acid production by a natural wild type strain of Aspergillus terreus to reach industrially relevant final titers.

PubMed

Krull, Susan; Hevekerl, Antje; Kuenz, Anja; Prüße, Ulf

2017-05-01

Itaconic acid is a promising organic acid and is commercially produced by submerged fermentation of Aspergillus terreus. The cultivation process of the sensitive filamentous fungus has been studied intensively since 1932, with respect to fermentation media components, oxygen supply, shearing rate, pH value, or culture method. Whereas increased final titers were achieved over the years, the productivity has so far remained quite low. In this study, the impact of the pH on the itaconic acid production was investigated in detail. The pH during the growth and production phase had a significant influence on the final itaconic acid concentration and pellet diameter. The highest itaconic acid concentration of 160 g/L was achieved at a 1.5-L scale within 6.7 days by raising and controlling the pH value to pH 3.4 in the production phase. An ammonia solution and an increased phosphate concentration were used with an itaconic acid yield of 0.46 (w/w) and an overall productivity of 0.99 g/L/h in a fed-batch mode. A cultivation with a lower phosphate concentration resulted in an equal final concentration with an increased yield of 0.58 (w/w) after 11.8 days and an overall productivity of 0.57 g/L/h. This optimized process was successfully transferred from a 1.5-L scale to a 15-L scale. After 9.7 days, comparable pellet morphology and a final concentration of 150 g/L itaconic acid was reached. This paper provides a process strategy to yield a final titer of itaconic acid from a wild-type strain of A. terreus which is in the same range as the well-known citric acid production.

Nanodesigning of Hierarchical Multifunctional Ceramics

DTIC Science & Technology

1993-09-28

transformations were determined by XRD. As in previous studies, the final particle size of BaTiO 3, obtair-0 trom either the titanium isopropoxide ...conditions by reacting nanosized titanium oxide or titanium alkoxides with a solution of barium hydroxide. The powders produced by this approach range in...optical ceramic-polymer composites using colloidal dispersion techniques. In our experiments, we used either a high purity titania sood or titanium

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

Spencer, B. W.; Williamson, R. L.; Stafford, D. S.

One of the important roles of cladding in light water reactor fuel rods is to prevent the release of fission products. To that end, it is essential that the cladding maintain its integrity under a variety of thermal and mechanical loading conditions. Local geometric irregularities in fuel pellets caused by manufacturing defects known as missing pellet surfaces (MPS) can in some circumstances lead to elevated cladding stresses that are sufficiently high to cause cladding failure. Accurate modeling of these defects can help prevent these types of failures. The BISON nuclear fuel performance code developed at Idaho National Laboratory can bemore » used to simulate the global thermo-mechanical fuel rod behavior, as well as the local response of regions of interest, in either 2D or 3D. In either case, a full set of models to represent the thermal and mechanical properties of the fuel, cladding and plenum gas is employed. A procedure for coupling 2D full-length fuel rod models to detailed 3D models of the region of the rod containing a MPS defect is detailed in this paper. The global and local model each contain appropriate physics and behavior models for nuclear fuel. This procedure is demonstrated on a simulation of a boiling water reactor (BWR) fuel rod containing a pellet with an MPS defect, subjected to a variety of transient events, including a control blade withdrawal and a ramp to high power. The importance of modeling the local defect using a 3D model is highlighted by comparing 3D and 2D representations of the defective pellet region. Finally, parametric studies demonstrate the effects of the choice of gaseous swelling model and of the depth and geometry of the MPS defect on the response of the cladding adjacent to the defect.« less

The Effects of the Monoamine Stabilizer (-)-OSU6162 on Binge-Like Eating and Cue-Controlled Food-Seeking Behavior in Rats.

PubMed

Feltmann, Kristin; Giuliano, Chiara; Everitt, Barry J; Steensland, Pia; Alsiö, Johan

2018-02-01

Binge-eating disorder (BED) is characterized by recurring episodes of excessive consumption of palatable food and an increased sensitivity to food cues. Patients with BED display an addiction-like symptomatology and the dopamine system might be a potential treatment target. The clinically safe monoamine stabilizer (-)-OSU6162 (OSU6162) restores dopaminergic dysfunction in long-term alcohol-drinking rats and shows promise as a novel treatment for alcohol use disorder. Here, the effects of OSU6162 on consummatory (binge-like eating) and appetitive (cue-controlled seeking) behavior motivated by chocolate-flavored sucrose pellets were evaluated in non-food-restricted male Lister Hooded rats. OSU6162 significantly reduced binge-like intake of chocolate-flavored sucrose pellets without affecting prior chow intake. Furthermore, OSU6162 significantly reduced the cue-controlled seeking of chocolate-flavored sucrose pellets under a second-order schedule of reinforcement before, but not after, the delivery and ingestion of reward, indicating a selective effect on incentive motivational processes. In contrast, the dopamine D2/D3 receptor antagonist raclopride reduced the seeking of chocolate-flavored sucrose pellets both pre- and post reward ingestion and also reduced responding under simpler schedules of seeking behavior. The D1/5 receptor antagonist SCH23390 had no effect on instrumental behavior under any reinforcement schedule tested. Finally, local administration of OSU6162 into the nucleus accumbens core, but not dorsolateral striatum, selectively reduced cue-controlled sucrose seeking. In conclusion, the present results show that OSU6162 reduces binge-like eating behavior and attenuates the impact of cues on seeking of palatable food. This indicates that OSU6162 might serve as a novel BED medication.

Trimethylsulfonium hydroxide as derivatization reagent for the chemical investigation of drying oils in works of art by gas chromatography.

PubMed

Dron, Julien; Linke, Robert; Rosenberg, Erwin; Schreiner, Manfred

2004-08-20

A procedure for the determination of fatty acids (FA) and glycerol in oils has been developed. The method includes a derivatization step of the FAs into their methyl esters or a transesterification of the triacylglycerols with trimethylsulfonium hydroxide (TMSH), respectively. The analysis is carried out by gas chromatography with parallel flame ionization and mass spectrometric detection. The parameters involved in the transesterification reaction were optimized. Only the stoichiometric ratio of TMSH:total FA amount showed a significant influence on the reaction yield. Relative standard deviations for 10 replicates were below 3% for all FAs studied and their linearity range was 0.5-50 mmol/L, when using heptadecanoic acid as an internal standard. The final procedure was rapid and required little sample handling. It was then tested on fresh oil samples and presented satisfying results, in agreement with previous works.

Unusual reaction of [NiFe]-hydrogenases with cyanide.

PubMed

Hexter, Suzannah V; Chung, Min-Wen; Vincent, Kylie A; Armstrong, Fraser A

2014-07-23

Cyanide reacts rapidly with [NiFe]-hydrogenases (hydrogenase-1 and hydrogenase-2 from Escherichia coli) under mild oxidizing conditions, inhibiting the electrocatalytic oxidation of hydrogen as recorded by protein film electrochemistry. Electrochemical, EPR, and FTIR measurements show that the final enzyme product, formed within a second (even under 100% H2), is the resting state known as Ni-B, which contains a hydroxido-bridged species, Ni(III)-μ(OH)-Fe(II), at the active site. "Cyanide inhibition" is easily reversed because it is simply the reductive activation of Ni-B. This paper brings back into focus an observation originally made in the 1940s that cyanide inhibits microbial H2 oxidation and addresses the interesting mechanism by which cyanide promotes the formation of Ni-B. As a much stronger nucleophile than hydroxide, cyanide binds more rapidly and promotes oxidation of Ni(II) to Ni(III); however, it is quickly replaced by hydroxide which is a far superior bridging ligand.

Production of edible carbohydrates from formaldehyde in a spacecraft. pH variations in the calcium hydroxide catalyzed formose reaction. Final Report, 1 Jul. 1973 - 30 Jun. 1974. M.S. Thesis

NASA Technical Reports Server (NTRS)

Weiss, A. H.; Kohler, J. T.; John, T.

1974-01-01

The study of the calcium hydroxide catalyzed condensation of formaldehyde was extended to a batch reactor system. Decreases in pH were observed, often in the acid regime, when using this basic catalyst. This observation was shown to be similar to results obtained by others using less basic catalysts in the batch mode. The relative rates of these reactions are different in a batch reactor than in a continuous stirred tank reactor. This difference in relative rates is due to the fact that at any degree of advancement in the batch system, the products have a history of previous products, pH, and dissolved catalyst. The relative rate differences can be expected to yield a different nature of product sugars for the two types of reactors.

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.

Thermochemical Concrete Pavement Scaling Mechanism: Navy F/A-18 Jet Aircraft Parking Apron Problem

DTIC Science & Technology

1998-06-01

boiling and recondensation) in hot, concentrated potassium hydroxide (E): Eqn 11 Alkaline Hydrolysis of Esters with Potassium Hydroxide KOH...RC02R’ -> KC02R + R’OH potassium alkyl ester (B) potassium ethanol(L) hydroxide (E) carboxylate (F) The overall reaction appears to make sense...carbonate (H) water 2. The parallel between calcium hydroxide and potassium hydroxide is not very accurate. Potassium hydroxide is a much stronger alkali

Tunable Diode Laser Atomic Absorption Spectroscopy for Detection of Potassium under Optically Thick Conditions.

PubMed

Qu, Zhechao; Steinvall, Erik; Ghorbani, Ramin; Schmidt, Florian M

2016-04-05

Potassium (K) is an important element related to ash and fine-particle formation in biomass combustion processes. In situ measurements of gaseous atomic potassium, K(g), using robust optical absorption techniques can provide valuable insight into the K chemistry. However, for typical parts per billion K(g) concentrations in biomass flames and reactor gases, the product of atomic line strength and absorption path length can give rise to such high absorbance that the sample becomes opaque around the transition line center. We present a tunable diode laser atomic absorption spectroscopy (TDLAAS) methodology that enables accurate, calibration-free species quantification even under optically thick conditions, given that Beer-Lambert's law is valid. Analyte concentration and collisional line shape broadening are simultaneously determined by a least-squares fit of simulated to measured absorption profiles. Method validation measurements of K(g) concentrations in saturated potassium hydroxide vapor in the temperature range 950-1200 K showed excellent agreement with equilibrium calculations, and a dynamic range from 40 pptv cm to 40 ppmv cm. The applicability of the compact TDLAAS sensor is demonstrated by real-time detection of K(g) concentrations close to biomass pellets during atmospheric combustion in a laboratory reactor.

Arsenic removal from water using lignocellulose adsorption medium (LAM).

PubMed

Kim, Juyoung; Mann, Justin D; Spencer, Jesse G

2006-01-01

Arsenate in water is readily adsorbed on lignocellulose adsorption medium (LAM) which is cotton-based and has been coated with iron(III) by soaking cotton pellets in ferric chloride solution. Capacities achieved with LAM average 32.8 mg As/g of medium at influent arsenic concentrations ranging from 20-30 mg As/L. Adsorption follows (R2 = 0.993) a Freundlich isotherm, (x/M) = 22.845 Ce0.25, where (x/M) is the ratio of milligrams of contaminant adsorbed per gram of adsorbent and Ce is the equilibrium concentration. As is often the case with adsorption from solution, the fit using a Langmuir isotherm was not as good (R2 = 0.8786). The adsorbent when saturated can be regenerated by treatment with dilute sodium hydroxide. After five regenerations, the capacity dropped by 11.5%. Arsenate washed off the adsorbent after regeneration, as well as that left on the medium, may be concentrated and disposed of properly or perhaps recycled. Consideration of costs shows that one ton of iron(III)-treated adsorbent can be used to remove arsenate at toxic levels from drinking water at a cost of about 3.20/ton US dollars plus the cost of media without regeneration.

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.

21 CFR 184.1428 - Magnesium hydroxide.

Code of Federal Regulations, 2014 CFR

2014-04-01

... addition of sodium hydroxide to a water soluble magnesium salt or by hydration of reactive grades of... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Magnesium hydroxide. 184.1428 Section 184.1428... GRAS § 184.1428 Magnesium hydroxide. (a) Magnesium hydroxide (Mg(OH)2, CAS Reg. No. 1309-42-8) occurs...

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.

Effects of Antiseptics on Pulpal Healing under Calcium Hydroxide Pulp Capping: A Pilot Study

PubMed Central

Bal, Cenkhan; Alacam, Alev; Tuzuner, Tamer; Tirali, Resmiye Ebru; Baris, Emre

2011-01-01

Objectives: The objective of this pilot study was to evaluate the effects of three different antiseptic materials on healing processes of direct pulp therapies with Ca(OH)2 histopathologically. Methods: Twenty-eight upper and lower first molar teeth from 7 male Wistar rats were used in this study. Four cavities were prepared in each rat in four quadrants, and each quadrant represented different experimental groups. In Group I: 0.5% sodium hypochlorite (NaOCl); in Group II: 2% chlorhexidine digluconate (CHX); in Group III: 0.1% octenidine dihydrochloride (OCT); and in Group IV 0.9% sterile saline was applied to the exposure site with a sterile cotton pellet for 3 minutes. After hemorrhage control, the pulps were capped with hard setting Ca(OH)2 and, finally, restored with IRM. The animals were euthanized at 21 days post-operatively. After sacrificing, routine histological procedures were performed and evaluated statistically with non-parametric Kruskal-Wallis test among the groups and two-by-two comparisons by using the Mann-Whitney U test for inflammatory response and tissue organization scores at the confidence interval of 95%. Results: There were significant differences in inflammatory response and tissue organization scores between the groups (P<.05). Statistical evaluation of inflammatory response showed that Group IV was significantly different from Groups I, II and III separately with a higher inflammatory cell response (P<.05) whereas no significant differences were detected between the other groups in two-by-two comparisons (P>.05). Healthy coronal and radicular pulp tissue organization scores indicated that the Group I has better pulp tissue organization than Group IV and this was significantly different (P<.05) whereas no significant differences were observed between the other groups separately (P>.05). Conclusions: The antiseptic materials used in this study created an environment that, rather than saline solution, may affect clinical and histological success in a positive way. PMID:21769267

Dissolution mechanism of aluminum hydroxides in acid media

NASA Astrophysics Data System (ADS)

Lainer, Yu. A.; Gorichev, I. G.; Tuzhilin, A. S.; Gololobova, E. G.

2008-08-01

The effects of the concentration, temperature, and potential at the hydroxide/electrolyte interface on the aluminum hydroxide dissolution in sulfuric, hydrochloric, and perchloric acids are studied. The limiting stage of the aluminum hydroxide dissolution in the acids is found to be the transition of the complexes that form on the aluminum hydroxide surface from the solid phase into the solution. The results of the calculation of the acid-base equilibrium constants at the oxide (hydroxide)/solution interface using the experimental data on the potentiometric titration of Al2O3 and AlOOH suspensions are analyzed. A mechanism is proposed for the dissolution of aluminum hydroxides in acid media.

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).

Synthesis of high capacity cathodes for lithium-ion batteries by morphology-tailored hydroxide co-precipitation

NASA Astrophysics Data System (ADS)

Wang, Dapeng; Belharouak, Ilias; Ortega, Luis H.; Zhang, Xiaofeng; Xu, Rui; Zhou, Dehua; Zhou, Guangwen; Amine, Khalil

2015-01-01

Nickel manganese hydroxide co-precipitation inside a continuous stirred tank reactor was studied with sodium hydroxide and ammonium hydroxide as the precipitation agents. The ammonium hydroxide concentration had an effect on the primary and secondary particle evolution. The two-step precipitation mechanism proposed earlier was experimentally confirmed. In cell tests, Li- and Mn-rich composite cathode materials based on the hydroxide precursors demonstrated good electrochemical performance in terms of cycle life over a wide range of lithium content.

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.

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

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.

[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.

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

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.

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.

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.

Advances in aluminum hydroxide-based adjuvant research and its mechanism.

PubMed

He, Peng; Zou, Yening; Hu, Zhongyu

2015-01-01

In the past few decades, hundreds of materials have been tried as adjuvant; however, only aluminum-based adjuvants continue to be used widely in the world. Aluminum hydroxide, aluminum phosphate and alum constitute the main forms of aluminum used as adjuvants. Among these, aluminum hydroxide is the most commonly used chemical as adjuvant. In spite of its wide spread use, surprisingly, the mechanism of how aluminum hydroxide-based adjuvants exert their beneficial effects is still not fully understood. Current explanations for the mode of action of aluminum hydroxide-based adjuvants include, among others, the repository effect, pro-phagocytic effect, and activation of the pro-inflammatory NLRP3 pathway. These collectively galvanize innate as well as acquired immune responses and activate the complement system. Factors that have a profound influence on responses evoked by aluminum hydroxide-based adjuvant applications include adsorption rate, strength of the adsorption, size and uniformity of aluminum hydroxide particles, dosage of adjuvant, and the nature of antigens. Although vaccines containing aluminum hydroxide-based adjuvants are beneficial, sometimes they cause adverse reactions. Further, these vaccines cannot be stored frozen. Until recently, aluminum hydroxide-based adjuvants were known to preferentially prime Th2-type immune responses. However, results of more recent studies show that depending on the vaccination route, aluminum hydroxide-based adjuvants can enhance both Th1 as well as Th2 cellular responses. Advances in systems biology have opened up new avenues for studying mechanisms of aluminum hydroxide-based adjuvants. These will assist in scaling new frontiers in aluminum hydroxide-based adjuvant research that include improvement of formulations, use of nanoparticles of aluminum hydroxide and development of composite adjuvants.

Advances in aluminum hydroxide-based adjuvant research and its mechanism

PubMed Central

He, Peng; Zou, Yening; Hu, Zhongyu

2015-01-01

In the past few decades, hundreds of materials have been tried as adjuvant; however, only aluminum-based adjuvants continue to be used widely in the world. Aluminum hydroxide, aluminum phosphate and alum constitute the main forms of aluminum used as adjuvants. Among these, aluminum hydroxide is the most commonly used chemical as adjuvant. In spite of its wide spread use, surprisingly, the mechanism of how aluminum hydroxide-based adjuvants exert their beneficial effects is still not fully understood. Current explanations for the mode of action of aluminum hydroxide-based adjuvants include, among others, the repository effect, pro-phagocytic effect, and activation of the pro-inflammatory NLRP3 pathway. These collectively galvanize innate as well as acquired immune responses and activate the complement system. Factors that have a profound influence on responses evoked by aluminum hydroxide-based adjuvant applications include adsorption rate, strength of the adsorption, size and uniformity of aluminum hydroxide particles, dosage of adjuvant, and the nature of antigens. Although vaccines containing aluminum hydroxide-based adjuvants are beneficial, sometimes they cause adverse reactions. Further, these vaccines cannot be stored frozen. Until recently, aluminum hydroxide-based adjuvants were known to preferentially prime Th2-type immune responses. However, results of more recent studies show that depending on the vaccination route, aluminum hydroxide-based adjuvants can enhance both Th1 as well as Th2 cellular responses. Advances in systems biology have opened up new avenues for studying mechanisms of aluminum hydroxide-based adjuvants. These will assist in scaling new frontiers in aluminum hydroxide-based adjuvant research that include improvement of formulations, use of nanoparticles of aluminum hydroxide and development of composite adjuvants. PMID:25692535

[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.

Antibacterial action of calcium hydroxide vehicles and calcium hydroxide pastes.

PubMed

Pacios, María Gabriela; Silva, Clara; López, María Elena; Cecilia, Marta

2012-11-01

To evaluate the in vitro action of vehicles alone and with calcium hydroxide against different bacterial species. Agar plates were inoculated with the microbial suspensions, and wells were made and filled with the calcium hydroxide pastes and the vehicles used to prepare the pastes. The zones of inhibited bacterial growth were recorded, and the resulting measurements were statistically analyzed. Enterococcus faecalis was the most resistant microorganism to all medicaments. Calcium hydroxide + p-monochlorophenol; calcium hydroxide + p-monochlorophenol-propylene glycol pastes; and p-monochlorophenol, p-monochlorophenol-propylene glycol, and chlorhexidine gluconate gel alone showed the largest zones of inhibition against all the tested microorganisms. The vehicle used to prepare the calcium hydroxide paste might contribute to its antibacterial action. Chlorhexidine gluconate gel used alone, and camphorated p-monochlorophenol and camphorated p-monochlorophenol-propylene glycol as vehicles of calcium hydroxide, could be recommended, in an antimicrobial sense. © 2012 Wiley Publishing Asia Pty Ltd.

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.

Recovery of Lithium from Geothermal Brine with Lithium–Aluminum Layered Double Hydroxide Chloride Sorbents

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

Paranthaman, Mariappan Parans; Li, Ling; Luo, Jiaqi

In this paper, we report a three-stage bench-scale column extraction process to selectively extract lithium chloride from geothermal brine. The goal of this research is to develop materials and processing technologies to improve the economics of lithium extraction and production from naturally occurring geothermal and other brines for energy storage applications. A novel sorbent, lithium aluminum layered double hydroxide chloride (LDH), is synthesized and characterized with X-ray powder diffraction, scanning electron microscopy, inductively coupled plasma optical emission spectrometry (ICP-OES), and thermogravimetric analysis. Each cycle of the column extraction process consists of three steps: (1) loading the sorbent with lithium chloridemore » from brine; (2) intermediate washing to remove unwanted ions; (3) final washing for unloading the lithium chloride ions. Our experimental analysis of eluate vs feed concentrations of Li and competing ions demonstrates that our optimized sorbents can achieve a recovery efficiency of ~91% and possess excellent Li apparent selectivity of 47.8 compared to Na ions and 212 compared to K ions, respectively in the brine. Finally, the present work demonstrates that LDH is an effective sorbent for selective extraction of lithium from brines, thus offering the possibility of effective application of lithium salts in lithium-ion batteries leading to a fundamental shift in the lithium supply chain.« less

Recovery of Lithium from Geothermal Brine with Lithium–Aluminum Layered Double Hydroxide Chloride Sorbents

DOE PAGES

Paranthaman, Mariappan Parans; Li, Ling; Luo, Jiaqi; ...

2017-10-27

In this paper, we report a three-stage bench-scale column extraction process to selectively extract lithium chloride from geothermal brine. The goal of this research is to develop materials and processing technologies to improve the economics of lithium extraction and production from naturally occurring geothermal and other brines for energy storage applications. A novel sorbent, lithium aluminum layered double hydroxide chloride (LDH), is synthesized and characterized with X-ray powder diffraction, scanning electron microscopy, inductively coupled plasma optical emission spectrometry (ICP-OES), and thermogravimetric analysis. Each cycle of the column extraction process consists of three steps: (1) loading the sorbent with lithium chloridemore » from brine; (2) intermediate washing to remove unwanted ions; (3) final washing for unloading the lithium chloride ions. Our experimental analysis of eluate vs feed concentrations of Li and competing ions demonstrates that our optimized sorbents can achieve a recovery efficiency of ~91% and possess excellent Li apparent selectivity of 47.8 compared to Na ions and 212 compared to K ions, respectively in the brine. Finally, the present work demonstrates that LDH is an effective sorbent for selective extraction of lithium from brines, thus offering the possibility of effective application of lithium salts in lithium-ion batteries leading to a fundamental shift in the lithium supply chain.« 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 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

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.

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.

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.

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.

Cu2+ ions as a paramagnetic probe to study the surface chemical modification process of layered double hydroxides and hydroxide salts with nitrate and carboxylate anions.

PubMed

Arizaga, Gregorio Guadalupe Carbajal; Mangrich, Antonio Salvio; Wypych, Fernando

2008-04-01

A layered zinc hydroxide nitrate (Zn5(OH)8(NO3)2.2H2O) and a layered double hydroxide (Zn/Al-NO3) were synthesized by coprecipitation and doped with different amounts of Cu2+ (0.2, 1, and 10 mol%), as paramagnetic probe. Although the literature reports that the nitrate ion is free (with D3h symmetry) between the layers of these two structures, the FTIR spectra of two zinc hydroxide nitrate samples show the C2v symmetry for the nitrate ion, whereas the g ||/A || value in the EPR spectra of Cu2+ is high. This fact suggests bonding of some nitrate ions to the layers of the zinc hydroxide nitrate. The zinc hydroxide nitrate was used as matrix in the intercalation reaction with benzoate, o-chlorobenzoate, and o-iodobenzoate ions. FTIR spectra confirm the ionic exchange reaction and the EPR spectroscopy reveals bonding of the organic ions to the inorganic layers of the zinc hydroxide nitrate, while the layered double hydroxides show only exchange reactions.

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.

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.

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)

Chondrogenic properties of collagen type XI, a component of cartilage extracellular matrix.

PubMed

Li, Ang; Wei, Yiyong; Hung, Clark; Vunjak-Novakovic, Gordana

2018-08-01

Cartilage extracellular matrix (ECM) has been used for promoting tissue engineering. However, the exact effects of ECM on chondrogenesis and the acting mechanisms are not well understood. In this study, we investigated the chondrogenic effects of cartilage ECM on human mesenchymal stem cells (MSCs) and identified the contributing molecular components. To this end, a preparation of articular cartilage ECM was supplemented to pellets of chondrogenically differentiating MSCs, pellets of human chondrocytes, and bovine articular cartilage explants to evaluate the effects on cell proliferation and the production of cartilaginous matrix. Selective enzymatic digestion and screening of ECM components were conducted to identify matrix molecules with chondrogenic properties. Cartilage ECM promoted MSC proliferation, production of cartilaginous matrix, and maturity of chondrogenic differentiation, and inhibited the hypertrophic differentiation of MSC-derived chondrocytes. Selective digestion of ECM components revealed a contributory role of collagens in promoting chondrogenesis. The screening of various collagen subtypes revealed strong chondrogenic effect of collagen type XI. Finally, collagen XI was found to promote production and inhibit degradation of cartilage matrix in human articular chondrocyte pellets and bovine articular cartilage explants. Our results indicate that cartilage ECM promotes chondrogenesis and inhibits hypertrophic differentiation in MSCs. Collagen type XI is the ECM component that has the strongest effects on enhancing the production and inhibiting the degradation of cartilage matrix. Copyright © 2018 Elsevier Ltd. All rights reserved.

Disruption of Cell-Cell Contact-mediated Notch Signaling via Hydrogel Encapsulation Reduces Mesenchymal Stem Cell Chondrogenic Potential

PubMed Central

Chen, Amanda X.; Hoffman, Michael D.; Chen, Caressa S.; Shubin, Andrew D.; Reynolds, Daniel S.; Benoit, Danielle S. W.

2015-01-01

Cell-cell contact-mediated Notch signaling is essential for mesenchymal stem cell (MSC) chondrogenesis during development. However, subsequent deactivation of Notch signaling is also required to allow for stem cell chondrogenic progression. Recent literature has shown that Notch signaling can also influence Wnt/β-catenin signaling, critical for MSC differentiation, through perturbations in cell-cell contacts. Traditionally, abundant cell-cell contacts, consistent with development, are emulated in vitro using pellet cultures for chondrogenesis. However, cells are often encapsulated within biomaterials-based scaffolds, such as hydrogels, to improve therapeutic cell localization in vivo. To explore the role of Notch and Wnt/β-catenin signaling in the context of hydrogel-encapsulated MSC chondrogenesis, we compared signaling and differentiation capacity of MSCs in both hydrogels and traditional pellet cultures. We demonstrate that encapsulation within poly(ethylene glycol) (PEG) hydrogels reduces cell-cell contacts, and both Notch (7.5-fold) and Wnt/β-catenin (84.7-fold) pathway activation. Finally, we demonstrate that following establishment of cell-cell contacts and transient Notch signaling in pellet cultures, followed by Notch signaling deactivation, resulted in a 1.5-fold increase in MSC chondrogenesis. Taken together, these findings support that cellular condensation, and the establishment of initial cell-cell contacts is critical for MSC chondrogenesis, and this process is inhibited by hydrogel encapsulation. PMID:25504509

Role of Polymeric Excipients in the Stabilization of Olanzapine when Exposed to Aqueous Environments.

PubMed

Paisana, Maria; Wahl, Martin; Pinto, João

2015-12-12

Hydrate formation is a phase transition which can occur during manufacturing processes involving water. This work considers the prevention of hydration of anhydrous olanzapine and hydrate conversions in the presence of water and polymers (polyethyleneglycol; hydroxypropylcellulose; polyvinylpyrrolidone) in forming pellets by wet extrusion and spheronisation. Anhydrous olanzapine was added to water with or without those polymers prior to extrusion with microcrystalline cellulose. Assessment of olanzapine conversion was made by XRP-Diffraction; FTIR spectroscopy; calorimetry (DSC) and microscopy (SEM for crystal size and shape). The addition of water converted the anhydrous form into dihydrate B and higher hydrate; whereas polyethyleneglycol promoted a selective hydrate conversion into the higher hydrate olanzapine form. Both polyvinylpyrrolidone and hydroxypropylcellulose prevented the hydrate transformations of the anhydrous drug; the latter even in the presence of hydrate seeds. This may be explained by the higher H-bond ability; higher network association and higher hydrophobicity of hydroxypropylcellulose by comparison with polyethyleneglycol and polyvinylpyrrolidone; which could contribute to its higher affinity to the crystal surfaces of the hydrate nuclei/initial crystals and promoting steric hindrance to the incorporation of other drug molecules into the crystal lattice; thus, preventing the crystal growth. The addition of microcrystalline cellulose needed for the pellets production (final product) did not eliminate the protector effect of both hydroxypropylcellulose and polyvinylpyrrolidone during pellets' processing and dissolution evaluation.

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.

Fuel rod with annular nuclear fuel pellets having same U-235 enrichment and different annulus sizes for graduated enrichment loading

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

Mildrum, C.M.

1987-08-18

A fuel rod is described for a nuclear reactor fuel assembly, comprising: (a) a hollow cladding tube; (b) a pair of end plugs connected to and sealing the cladding tube at opposite ends thereof; (c) a plurality of fuel pellets contained on the tube and being composed of fissile material having a single enrichment the value of which is at the level of the maximum enrichment loading of the rod, the pellets having provided in a stack having one end disposed adjacent to one of the end plugs and an opposite end disposed remote from the other of the endmore » plugs; and (d) a plenum spring disposed in the tube between the other end plug and the opposite end of the pellet stack for retaining the pellets in a stack form; (e) at least some of the fuel pellets having an annular configuration and at least other of the fuel pellets having a solid configuration; (f) each of some of the annular fuel pellets having an annulus of a first size; (e) each of other of the annual fuel pellets having an annulus of a second size different from the first size, whereby graduation of axial enrichment loading is provided between the annual fuel pellets of the fuel rod.« less

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.

Method and system for producing hydrogen using sodium ion separation membranes

DOEpatents

Bingham, Dennis N; Klingler, Kerry M; Turner, Terry D; Wilding, Bruce M; Frost, Lyman

2013-05-21

A method of producing hydrogen from sodium hydroxide and water is disclosed. The method comprises separating sodium from a first aqueous sodium hydroxide stream in a sodium ion separator, feeding the sodium produced in the sodium ion separator to a sodium reactor, reacting the sodium in the sodium reactor with water, and producing a second aqueous sodium hydroxide stream and hydrogen. The method may also comprise reusing the second aqueous sodium hydroxide stream by combining the second aqueous sodium hydroxide stream with the first aqueous sodium hydroxide stream. A system of producing hydrogen is also disclosed.

The effect of polymers onto the size of zinc layered hydroxide salt and its calcined product

NASA Astrophysics Data System (ADS)

Hussein, Mohd Zobir bin; Ghotbi, Mohammad Yeganeh; Yahaya, Asmah Hj; Abd Rahman, Mohd Zaki

2009-02-01

Zinc hydroxide nitrate, a brucite-like layered material was synthesized using pH control method. Poly(vinyl alcohol) and poly(ethylene glycol) were used at various percentages as size decreasing agents during the synthesis of zinc hydroxide nitrate. SEM and PXRD showed the decrease of size and thickness of the resultant zinc hydroxide nitrates. TG and surface area data confirmed the decrease of the particle sizes, too. When zinc hydroxide nitrates were heat treated at 500 °C, the physical properties of nano zinc oxides obtained depended on the parent material, zinc hydroxide nitrate.

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.

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.

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.

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.

40 CFR 415.310 - Applicability; description of the calcium hydroxide production subcategory.

Code of Federal Regulations, 2011 CFR

2011-07-01

... calcium hydroxide production subcategory. 415.310 Section 415.310 Protection of Environment ENVIRONMENTAL... SOURCE CATEGORY Calcium Hydroxide Production Subcategory § 415.310 Applicability; description of the calcium hydroxide production subcategory. The provisions of this subpart are applicable to discharges...

40 CFR 415.310 - Applicability; description of the calcium hydroxide production subcategory.

Code of Federal Regulations, 2010 CFR

2010-07-01

... calcium hydroxide production subcategory. 415.310 Section 415.310 Protection of Environment ENVIRONMENTAL... SOURCE CATEGORY Calcium Hydroxide Production Subcategory § 415.310 Applicability; description of the calcium hydroxide production subcategory. The provisions of this subpart are applicable to discharges...

40 CFR 415.310 - Applicability; description of the calcium hydroxide production subcategory.

Code of Federal Regulations, 2012 CFR

2012-07-01

... calcium hydroxide production subcategory. 415.310 Section 415.310 Protection of Environment ENVIRONMENTAL... SOURCE CATEGORY Calcium Hydroxide Production Subcategory § 415.310 Applicability; description of the calcium hydroxide production subcategory. The provisions of this subpart are applicable to discharges...

40 CFR 415.310 - Applicability; description of the calcium hydroxide production subcategory.

Code of Federal Regulations, 2014 CFR

2014-07-01

... calcium hydroxide production subcategory. 415.310 Section 415.310 Protection of Environment ENVIRONMENTAL... SOURCE CATEGORY Calcium Hydroxide Production Subcategory § 415.310 Applicability; description of the calcium hydroxide production subcategory. The provisions of this subpart are applicable to discharges...

40 CFR 415.310 - Applicability; description of the calcium hydroxide production subcategory.

Code of Federal Regulations, 2013 CFR

2013-07-01

... calcium hydroxide production subcategory. 415.310 Section 415.310 Protection of Environment ENVIRONMENTAL... SOURCE CATEGORY Calcium Hydroxide Production Subcategory § 415.310 Applicability; description of the calcium hydroxide production subcategory. The provisions of this subpart are applicable to discharges...

Heterotrophic bacteria associated with the degradation of zooplankton fecal pellets in Lake Michigan. [Mysis relicta, pseudomonas

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

Ferrante, J.G.; Ptak, D.J.

1978-01-01

Heterotrophic microbes decompose most of the calanoid copepod fecal pellets produced in Lake Michigan before they reach the sediment. Rod-shaped nonfermenters isolated from copepod and Mysis relicta fecal pellets were identified as Pseudomonas maltophilia and Pseudomonas fluorescens species. No enterobacteriaceae or fungal hyphae were found on or in any pellets. This investigation suggests that Pseudomonas species are attached to and may degrade Mysis relicta and calanoid copepod fecal pellets in the water column of Lake Michigan.

An automatic pellet dispenser for precise control of feeding topography in granivorous birds

PubMed Central

Berkhoudt, H.; Van Der Reijden, D.; Heijmans, M.

1987-01-01

Design and construction of an automatic pellet dispenser for granivorous birds are described. The dispenser permits rapid pneumatic delivery of pellets (five pellets per second maximum) to one controlled position and does not interfere with simultaneous electrophysiological recording. In addition, the device continuously indicates presence or absence of a pellet in the delivery position. This automatic dispenser proved very effective in our studies of stereotyped topographies of feeding in granivorous birds, such as pigeons and chickens. PMID:16812503

Apparatus for producing laser targets

DOEpatents

Jarboe, T.R.; Baker, W.R.

1975-09-23

This patent relates to an apparatus and method for producing deuterium targets or pellets of 25u to 75u diameter. The pellets are sliced from a continuously spun solid deuterium thread at a rate of up to 10 pellets/second. The pellets after being sliced from the continuous thread of deuterium are collimated and directed to a point of use, such as a laser activated combustion or explosion chamber wherein the pellets are imploded by laser energy or laser produced target plasmas for neutral beam injection. (auth)

Upgrading of consumer characteristics of granulated solid fuel from mixture of low-grade coal and biomass

NASA Astrophysics Data System (ADS)

Kuzmina, J. S.; Milovanov, O. Yu; Sinelshchikov, V. A.; Sytchev, G. A.; Zaichenko, V. M.

2015-11-01

Effect of torrefaction on consumer characteristics of fuel pellets made of low-grade and agricultural waste is shown. Data on the volatile content, ash content, calorific value and hygroscopicity for initial pellets and pellets, heat-treated at various temperatures are presented. The experimental study of the combustion process of initial and heat-treated pellets showed that torrefaction of pellets leads to a decreasing of the ignition temperature and an increasing of the efficiency of boiler plant.

Long-term persistence of spent lead shot in tundra wetlands

USGS Publications Warehouse

Flint, Paul L.; Schamber, Jason L.

2010-01-01

We seeded experimental plots with number 4 lead pellets and sampled these plots for 10 years to assess the settlement rate of pellets in tundra wetland types commonly used by foraging waterfowl. After 10 years, about 10% of pellets remained within 6 cm of the surface, but >50% remained within 10 cm. We predict that spent lead pellets will eventually become unavailable to waterfowl; however, it will likely require >25 years for all pellets to exceed depths at which waterfowl species may forage.

An Overview of Novel Power Sources for Advanced Munitions

DTIC Science & Technology

2009-04-27

selected gas when desired. Prevention of rapid heat loss is a critical factor in prolonging operating lifetime as molten salt thermal batteries...4c. A higher number of end heat pellets not only provides more heat for bringing the battery internals above the eutectic point of the electrolyte but...maintenance. Finally, the combination of high vapor pressure and high ionic salt content typically found in catholyte formulations has caused foul- ing

Pellet injection research on the HT-6M and HT-7 tokamaks

NASA Astrophysics Data System (ADS)

Yang, Yu; Bao, Yi; Li, Jiangang; Gu, Xuemao; He, Yexi

1999-11-01

A multishot in situ pellet injection system has been constructed in the Institute of Plasma Physics. Single- and multi-pellet injection experiments were performed on the HT-6M and superconducting HT-7 tokamaks. The system proved to be convenient and reliable to operate. Pellets were fired into ohmically and LHCD and ICRF heated plasmas. Single pellet injection in ohmic discharge was found to increase the central density of HT-7 by about one half, while two pellet injection increased the central density in a step-like fashion by one half with each shot. Peaking of the electron density profile and a hollow electron temperature profile were obtained.

Underwater sympathetic detonation of pellet explosive

NASA Astrophysics Data System (ADS)

Kubota, Shiro; Saburi, Tei; Nagayama, Kunihito

2017-06-01

The underwater sympathetic detonation of pellet explosives was taken by high-speed photography. The diameter and the thickness of the pellet were 20 and 10 mm, respectively. The experimental system consists of the precise electric detonator, two grams of composition C4 booster and three pellets, and these were set in water tank. High-speed video camera, HPV-X made by Shimadzu was used with 10 Mfs. The underwater explosions of the precise electric detonator, the C4 booster and a pellet were also taken by high-speed photography to estimate the propagation processes of the underwater shock waves. Numerical simulation of the underwater sympathetic detonation of the pellet explosives was also carried out and compared with experiment.

Methods to ensure optimal off-bottom and drill bit distance under pellet impact drilling

NASA Astrophysics Data System (ADS)

Kovalyov, A. V.; Isaev, Ye D.; Vagapov, A. R.; Urnish, V. V.; Ulyanova, O. S.

2016-09-01

The paper describes pellet impact drilling which could be used to increase the drilling speed and the rate of penetration when drilling hard rock for various purposes. 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 paper presents the survey of methods ensuring an optimal off-bottom and a drill bit distance. The analysis of methods shows that the issue is topical and requires further research.

Effects of redox-active interlayer anions on the oxygen evolution reactivity of NiFe-layered double hydroxide nanosheets

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

Zhou, Daojin; Cai, Zhao; Bi, Yongmin

Nickel-iron layered double hydroxide (NiFe-LDH) nanosheets have shown optimal oxygen evolution reaction (OER) performance; however, the role of the intercalated ions in the OER activity remains unclear. In this work, we show that the activity of the NiFe-LDHs can be tailored by the intercalated anions with different redox potentials. The intercalation of anions with low redox potential (high reducing ability), such as hypophosphites, leads to NiFe-LDHs with low OER overpotential of 240 mV and a small Tafel slope of 36.9 mV/dec, whereas NiFe-LDHs intercalated with anions of high redox potential (low reducing ability), such as fluorion, show a high overpotentialmore » of 370 mV and a Tafel slope of 80.8 mV/dec. The OER activity shows a surprising linear correlation with the standard redox potential. Density functional theory calculations and X-ray photoelectron spectroscopy analysis indicate that the intercalated anions alter the electronic structure of metal atoms which exposed at the surface. Anions with low standard redox potential and strong reducing ability transfer more electrons to the hydroxide layers. Finally, this increases the electron density of the surface metal sites and stabilizes their high-valence states, whose formation is known as the critical step prior to the OER process.« less

A chemical rationalization of the processing and application of the mortar coatings: Structural, thermodynamic, and fluorescence properties

NASA Astrophysics Data System (ADS)

Lima, Nathan B.; Rogerio, V. A.; Belarmino, Marcia K. D. L.; Silva, Anderson I. S.; Ioras, Renan U. F.; Oliveira, Romilde A.; Lima, Nathalia B. D.

2018-07-01

A chemical rationalization of the processing and application of the roughcast and plaster mortar coatings was advanced. The results revealed that the structural and thermodynamic nature of the hydrogen-bonded complexes between the inorganic precursors and water molecules are associated with the physical properties of both coatings. In this sense, the workability and curing time of the roughcast and the plaster mortars studied, seemingly, are related to the nature of the water solvation in the main components of these materials: calcium hydroxide and silicon dioxide. In addition, PM7 and PM7/COSMO results indicate that the enthalpy of solvation of water by hydrogen bonds in calcium hydroxide is stronger when compared with silicon dioxide systems. Therefore, the presence of free hydrated lime (calcium hydroxide) in the precursor mixture of plaster mortar leads to the large workability and elapsed curing time of this material. On the other hand, the absence of free hydrated lime in the precursor mixture of the roughcast mortar leads to its poor workability and faster elapsed curing time. Further, fluorescence microscopy experiments revealed that the inorganic compounds present in the cement precursor were transformed into different materials, that exhibit red and blue fluorescence. Finally, mechanical tests showed a tensile strength average 0.67 MPa for the plaster mortar material, whereas for the roughcast material is 0.53 MPa.

Effects of redox-active interlayer anions on the oxygen evolution reactivity of NiFe-layered double hydroxide nanosheets

DOE PAGES

Zhou, Daojin; Cai, Zhao; Bi, Yongmin; ...

2018-02-02

Nickel-iron layered double hydroxide (NiFe-LDH) nanosheets have shown optimal oxygen evolution reaction (OER) performance; however, the role of the intercalated ions in the OER activity remains unclear. In this work, we show that the activity of the NiFe-LDHs can be tailored by the intercalated anions with different redox potentials. The intercalation of anions with low redox potential (high reducing ability), such as hypophosphites, leads to NiFe-LDHs with low OER overpotential of 240 mV and a small Tafel slope of 36.9 mV/dec, whereas NiFe-LDHs intercalated with anions of high redox potential (low reducing ability), such as fluorion, show a high overpotentialmore » of 370 mV and a Tafel slope of 80.8 mV/dec. The OER activity shows a surprising linear correlation with the standard redox potential. Density functional theory calculations and X-ray photoelectron spectroscopy analysis indicate that the intercalated anions alter the electronic structure of metal atoms which exposed at the surface. Anions with low standard redox potential and strong reducing ability transfer more electrons to the hydroxide layers. Finally, this increases the electron density of the surface metal sites and stabilizes their high-valence states, whose formation is known as the critical step prior to the OER process.« less

Manufacture of Regularly Shaped Sol-Gel Pellets

NASA Technical Reports Server (NTRS)

Leventis, Nicholas; Johnston, James C.; Kinder, James D.

2006-01-01

An extrusion batch process for manufacturing regularly shaped sol-gel pellets has been devised as an improved alternative to a spray process that yields irregularly shaped pellets. The aspect ratio of regularly shaped pellets can be controlled more easily, while regularly shaped pellets pack more efficiently. In the extrusion process, a wet gel is pushed out of a mold and chopped repetitively into short, cylindrical pieces as it emerges from the mold. The pieces are collected and can be either (1) dried at ambient pressure to xerogel, (2) solvent exchanged and dried under ambient pressure to ambigels, or (3) supercritically dried to aerogel. Advantageously, the extruded pellets can be dropped directly in a cross-linking bath, where they develop a conformal polymer coating around the skeletal framework of the wet gel via reaction with the cross linker. These pellets can be dried to mechanically robust X-Aerogel.

GLOBAL WOOD PELLET INDUSTRY AND MARKET – CURRENT DEVELOPMENTS AND OUTLOOK

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

Thrän, Daniela; Peetz, David; Schaubach, Kay

The wood pellet use in the heating and electricity sector has recorded a steady growth in the last years. IEA bioenergy task 40 carried out an update of the situation on the national pellet markets in the most relevant pellet producing countries and the global development as well. Various country specific data is collected and compiled for more than 30 countries, containing updated information about regulatory framework, production, consumption, price trends, quality standards and trade aspects. The analysis confirmed the positive development in terms of production and consumption of wood pellets in almost all countries. In 2015 more than 26more » Mt of wood pellets have been produced and consumed worldwide. Technologies and markets become more mature. Increased international pellet trade needs to be supported by adequate frame condition not only for commerce, but also with regard to sustainability issues.« less

Initiation Capacity of a Specially Shaped Booster Pellet and Numerical Simulation of Its Initiation Process

NASA Astrophysics Data System (ADS)

Hu, Li-Shuang; Hu, Shuang-Qi; Cao, Xiong; Zhang, Jian-Ren

2014-01-01

The insensitive main charge explosive is creating new requirements for the booster pellet of detonation trains. The traditional cylindrical booster pellet has insufficient energy output to reliably initiate the insensitive main charge explosive. In this research, a concave spherical booster pellet was designed. The initiation capacity of the concave spherical booster pellet was studied using varied composition and axial steel dent methods. The initiation process of the concave spherical booster pellet was also simulated by ANSYS/LS-DYNA. The results showed that using a concave spherical booster allows a 42% reduction in the amount of explosive needed to match the initiation capacity of a conventional cylindrical booster of the same dimensions. With the other parameters kept constant, the initiation capacity of the concave spherical booster pellet increases with decreased cone angle and concave radius. The numerical simulation results are in good agreement with the experimental data.

Use of implantable pellets to administer low levels of methyl mercury to fish

USGS Publications Warehouse

Arnold, B.S.; Jagoe, C.H.; Gross, T.S.

1999-01-01

Implantable pellets of methyl mercury chloride were tested in Nile Tilapia (Oreochromis niloticus) to appraise the effectiveness of the method for chronic studies of mercury. Two dosing regimes of 15 and 1.5 grams/CH3HgCl pellet (test 1) and 1 and 0.1 grams/pellet (test 2-3) of methyl mercury chloride were used in three tests. Additional pellets containing only matrix were used as controls. The pellets were inserted into the peritoneal cavity along with a microchip for identification. Three methods of incision closure: sutures and two types of surgical glue, were tested. Pellets used in test one released the dose too fast, resulting in premature death of the fish. Results from test 2 and 3 show blood mercury concentrations over time and tissue levels at necropsy consistent with dose suggesting that this is a viable method of dosing fish.

Microstructure of bentonite in iron ore green pellets.

PubMed

Bhuiyan, Iftekhar U; Mouzon, Johanne; Schröppel, Birgit; Kaech, Andres; Dobryden, Illia; Forsmo, Seija P E; Hedlund, Jonas

2014-02-01

Sodium-activated calcium bentonite is used as a binder in iron ore pellets and is known to increase strength of both wet and dry iron ore green pellets. In this article, the microstructure of bentonite in magnetite pellets is revealed for the first time using scanning electron microscopy. The microstructure of bentonite in wet and dry iron ore pellets, as well as in distilled water, was imaged by various imaging techniques (e.g., imaging at low voltage with monochromatic and decelerated beam or low loss backscattered electrons) and cryogenic methods (i.e., high pressure freezing and plunge freezing in liquid ethane). In wet iron ore green pellets, clay tactoids (stacks of parallel primary clay platelets) were very well dispersed and formed a voluminous network occupying the space available between mineral particles. When the pellet was dried, bentonite was drawn to the contact points between the particles and formed solid bridges, which impart strength to the solid compact.

Biomass Feedstocks | Bioenergy | NREL

Science.gov Websites

publications. Photo of a group of smiling men and women posing in a casual office setting. Thermochemical xylose) from bioconversion of pelleted and non-pelleted corn stover (CS), Switchgrass (SWG), and Hybrid Variety on the x-axis, showing Non-pelleted (yellow) and Pelleted (orange) results for five groups of data

A Review of Pellets from Different Sources

PubMed Central

Miranda, Teresa; Montero, Irene; Sepúlveda, Francisco José; Arranz, José Ignacio; Rojas, Carmen Victoria; Nogales, Sergio

2015-01-01

The rise in pellet consumption has resulted in a wider variety of materials for pellet manufacture. Thus, pellet industry has started looking for alternative products, such as wastes from agricultural activities, forestry and related industries, along with the combination thereof, obtaining a broad range of these products. In addition, the entry into force of EN ISO 17225 standard makes wood pellet market (among other types) possible for industry and household purposes. Therefore, wastes that are suitable for biomass use have recently increased. In this study, the main characteristics of ten kinds of laboratory-made pellets from different raw materials were analyzed. Thus, we have focused on the most limiting factors of quality standards that determine the suitability for biomass market, depending on the kind of pellet. The results showed considerable differences among the analyzed pellets, exceeding the limits established by the standard in almost all cases, especially concerning ash content and N and S composition. The requirements of the studied standard, very demanding for certain factors, disable the entry of these densified wastes in greater added value markets. PMID:28788009

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

High Burn-Up Spent Nuclear Fuel Vibration Integrity Study

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

Wang, Jy-An John; Wang, Hong; Jiang, Hao

2015-01-01

The Oak Ridge National Laboratory (ORNL) has developed the cyclic integrated reversible-bending fatigue tester (CIRFT) approach to successfully demonstrate the controllable fatigue fracture on high burnup (HBU) spent nuclear fuel (SNF) in a normal vibration mode. CIRFT enables examination of the underlying mechanisms of SNF system dynamic performance. Due to the inhomogeneous composite structure of the SNF system, the detailed mechanisms of the pellet-pellet and pellet-clad interactions and the stress concentration effects at the pellet-pellet interface cannot be readily obtained from a CIRFT system measurement. Therefore, finite element analyses (FEAs) are used to translate the global moment-curvature measurement into localmore » stress-strain profiles for further investigation. The major findings of CIRFT on the HBU SNF are as follows: SNF system interface bonding plays an important role in SNF vibration performance. Fuel structure contributes to SNF system stiffness. There are significant variations in stress and curvature of SNF systems during vibration cycles resulting from segment pellets and clad interactions. SNF failure initiates at the pellet-pellet interface region and appears to be spontaneous.« less

Steam explosion of oil palm residues for the production of durable pellets

DOE PAGES

Lam, Pak Sui; Lam, Pak Yiu; Sokhansanj, Shahab; ...

2015-01-03

Here we investigated the effect of steam explosion pretreatment on the physical and mechanical properties of the pellets made from empty fruit bunch (EFB) and palm kernel shell (PKS) and we compared to that of softwood Douglas fir (DF). We found that the high heating value of the empty fruit bunch was increased by 21% after steam explosion pretreatment. The pellet density of EFB and Douglas fir pellets did not change while the pellet density of PKS increased from 1.13 to 1.21 g/cm 3 after steam explosion. That may be attributed to the rapid volatilization of high mass fraction extractivesmore » during high pressure steaming and lead to the shrinkage of micropores of the PKS fibers. The maximum brealdng strength of steam exploded EFB and PKS were increased by 63% and 45%, respectively. The required compaction energy for the steam exploded EFB pellet is 44.50 J/g while that of the untreated EFB pellet is 30.15 J/g. Similar to Douglas fir, the required extrusion energy for the steam exploded EFB pellet was about 6 times than that of the untreated EFB pellet. The increased extrusion energy is mainly contributed by the increase in mono-saccharides by auto-hydrolysis during steam explosion pretreatment.« less

Co-pelletization of sewage sludge and agricultural wastes.

PubMed

Yilmaz, Ersel; Wzorek, Małgorzata; Akçay, Selin

2018-06-15

This paper concerns the process of production and properties of pellets based on biomass wastes. Co-pelletization was performed for sewage sludge from municipal wastewater treatment plant and other biomass material such as animal and olive wastes. The aim of the present study was to identify the key factors affecting on the sewage sludge and agricultural residues co-pelletization processes conditions. The impact of raw material type, pellet length, moisture content and particle size on the physical properties was investigated. The technic and technological aspects of co-pelletization were discussed in detail. The physical parameters of pellets, i.e.: drop strength, absorbability and water resistance were determined. Among others, also energy parameters: low and high heat value, content of ash and volatiles were presented. Results showed the range of raw materials moisture, which is necessary to obtain good quality biofuels and also ratio of sewage sludge in pelletizing materials. The analysis of the energetic properties has indicated that the pellet generated on the basis of the sewage sludge and another biomass materials can be applied in the processes of co-combustion with coal. Those biofuels are characterised with properties making them suitable for use in thermal processes and enabling their transport and storage. Copyright © 2017 Elsevier Ltd. All rights reserved.

Steam explosion of oil palm residues for the production of durable pellets

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

Lam, Pak Sui; Lam, Pak Yiu; Sokhansanj, Shahab

Here we investigated the effect of steam explosion pretreatment on the physical and mechanical properties of the pellets made from empty fruit bunch (EFB) and palm kernel shell (PKS) and we compared to that of softwood Douglas fir (DF). We found that the high heating value of the empty fruit bunch was increased by 21% after steam explosion pretreatment. The pellet density of EFB and Douglas fir pellets did not change while the pellet density of PKS increased from 1.13 to 1.21 g/cm 3 after steam explosion. That may be attributed to the rapid volatilization of high mass fraction extractivesmore » during high pressure steaming and lead to the shrinkage of micropores of the PKS fibers. The maximum brealdng strength of steam exploded EFB and PKS were increased by 63% and 45%, respectively. The required compaction energy for the steam exploded EFB pellet is 44.50 J/g while that of the untreated EFB pellet is 30.15 J/g. Similar to Douglas fir, the required extrusion energy for the steam exploded EFB pellet was about 6 times than that of the untreated EFB pellet. The increased extrusion energy is mainly contributed by the increase in mono-saccharides by auto-hydrolysis during steam explosion pretreatment.« less

Comparison of arsenic content in pelletized poultry house waste and biosolids fertilizer.

PubMed

Nachman, Keeve E; Mihalic, Jana N; Burke, Thomas A; Geyh, Alison S

2008-03-01

Managers of human biosolids have been incorporating the practice of waste pelletization for use as fertilizer since the mid 1920s, and waste pelletization has recently been embraced by some poultry producers as a way to move nutrients away from saturated agricultural land. However, the presence of arsenic in pelletized poultry house waste (PPHW) resulting from the use of organoarsenical antimicrobial drugs in poultry production raises concerns regarding additional incremental population exposures. Arsenic concentrations were determined in PPHW and pelletized biosolids fertilizer (PBF) samples. Pellets were processed using strong acid microwave digestion and analyzed by graphite furnace atomic absorption spectroscopy. The mean arsenic concentration in PPHW (20.1 ppm) fell within the lower part of the range of previously report arsenic concentrations in unpelletized poultry house waste. Arsenic concentrations in PBF, the source of which is less clear than for PPHW, were approximately a factor of 5 times lower than those in PPHW, with a mean concentration of 4.1 ppm. The pelletization and sale of these biological waste fertilizers present new pathways of exposure to arsenic in consumer populations who would otherwise not come into contact with these wastes. Arsenic exposures in humans resulting from use of these fertilizer pellets should be quantified to avoid potential unintended negative consequences of managing wastes through pelletization.

21 CFR 582.1428 - Magnesium hydroxide.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Magnesium hydroxide. 582.1428 Section 582.1428 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1428 Magnesium hydroxide. (a) Product. Magnesium hydroxide. (b) Conditions of use. This...

40 CFR 721.10504 - Surface modified magnesium hydroxide (generic).

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Surface modified magnesium hydroxide... Specific Chemical Substances § 721.10504 Surface modified magnesium hydroxide (generic). (a) Chemical... as surface modified magnesium hydroxide (PMN P-06-682) is subject to reporting under this section for...

21 CFR 582.1428 - Magnesium hydroxide.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Magnesium hydroxide. 582.1428 Section 582.1428 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1428 Magnesium hydroxide. (a) Product. Magnesium hydroxide. (b) Conditions of use. This...

21 CFR 582.1428 - Magnesium hydroxide.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Magnesium hydroxide. 582.1428 Section 582.1428 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1428 Magnesium hydroxide. (a) Product. Magnesium hydroxide. (b) Conditions of use. This...

40 CFR 721.10573 - Magnesium hydroxide surface treated with substituted alkoxysilanes (generic).

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Magnesium hydroxide surface treated... SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.10573 Magnesium hydroxide surface... to reporting. (1) The chemical substance identified generically as magnesium hydroxide surface...

21 CFR 582.1428 - Magnesium hydroxide.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Magnesium hydroxide. 582.1428 Section 582.1428 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1428 Magnesium hydroxide. (a) Product. Magnesium hydroxide. (b) Conditions of use. This...

40 CFR 721.10504 - Surface modified magnesium hydroxide (generic).

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Surface modified magnesium hydroxide... Specific Chemical Substances § 721.10504 Surface modified magnesium hydroxide (generic). (a) Chemical... as surface modified magnesium hydroxide (PMN P-06-682) is subject to reporting under this section for...

40 CFR 721.10573 - Magnesium hydroxide surface treated with substituted alkoxysilanes (generic).

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Magnesium hydroxide surface treated... SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.10573 Magnesium hydroxide surface... to reporting. (1) The chemical substance identified generically as magnesium hydroxide surface...

21 CFR 582.1428 - Magnesium hydroxide.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Magnesium hydroxide. 582.1428 Section 582.1428 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1428 Magnesium hydroxide. (a) Product. Magnesium hydroxide. (b) Conditions of use. This...

21 CFR 582.1205 - Calcium hydroxide.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Calcium hydroxide. 582.1205 Section 582.1205 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1205 Calcium hydroxide. (a) Product. Calcium hydroxide. (b) Conditions of use. This...

21 CFR 582.1631 - Potassium hydroxide.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Potassium hydroxide. 582.1631 Section 582.1631 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1631 Potassium hydroxide. (a) Product. Potassium hydroxide. (b) Conditions of use. This...

21 CFR 582.1631 - Potassium hydroxide.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Potassium hydroxide. 582.1631 Section 582.1631 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1631 Potassium hydroxide. (a) Product. Potassium hydroxide. (b) Conditions of use. This...

21 CFR 582.1631 - Potassium hydroxide.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Potassium hydroxide. 582.1631 Section 582.1631 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1631 Potassium hydroxide. (a) Product. Potassium hydroxide. (b) Conditions of use. This...

21 CFR 582.1631 - Potassium hydroxide.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Potassium hydroxide. 582.1631 Section 582.1631 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1631 Potassium hydroxide. (a) Product. Potassium hydroxide. (b) Conditions of use. This...

21 CFR 582.1631 - Potassium hydroxide.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Potassium hydroxide. 582.1631 Section 582.1631 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1631 Potassium hydroxide. (a) Product. Potassium hydroxide. (b) Conditions of use. This...

Characterization of fly ash ceramic pellet for phosphorus removal.

PubMed

Li, Shiyang; Cooke, Richard A; Wang, Li; Ma, Fang; Bhattarai, Rabin

2017-03-15

Phosphorus has been recognized as a leading pollutant for surface water quality deterioration. In the Midwestern USA, subsurface drainage not only provides a pathway for excess water to leave the field but it also drains out nutrients like nitrogen (N) and phosphorus (P). Fly ash has been identified as one of the viable materials for phosphorus removal from contaminated waters. In this study, a ceramic pellet was manufactured using fly ash for P absorption. Three types of pellet with varying lime and clay proportions by weight (type 1: 10% lime + 30% clay, type 2: 20% lime + 20% clay, and type 3: 30% lime + 10% clay) were characterized and evaluated for absorption efficiency. The result showed that type 3 pellet (60% fly ash with 30% lime and 10% clay) had the highest porosity (14%) and absorption efficiency and saturated absorption capacity (1.98 mg P/g pellet) compared to type 1 and 2 pellets. The heavy metal leaching was the least (30 μg/L of chromium after 5 h) for type 3 pellet compared to other two. The microcosmic structure of pellet from scanning electron microscope showed the type 3 pellet had the better distribution of aluminum and iron oxide on the surface compared other two pellets. This result indicates that addition of lime and clay can improve P absorption capacity of fly ash while reducing the potential to reduce chromium leaching. Copyright © 2016 Elsevier Ltd. All rights reserved.

Process for changing caking coals to noncaking coals

DOEpatents

Beeson, Justin L.

1980-01-01

Caking coals are treated in a slurry including alkaline earth metal hydroxides at moderate pressures and temperatures in air to form noncaking carbonaceous material. Hydroxides such as calcium hydroxide, magnesium hydroxide or barium hydroxide are contemplated for slurrying with the coal to interact with the agglomerating constituents. The slurry is subsequently dewatered and dried in air at atmospheric pressure to produce a nonagglomerating carbonaceous material that can be conveniently handled in various coal conversion and combustion processes.

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

Controllable synthesis of layered Co-Ni hydroxide hierarchical structures for high-performance hybrid supercapacitors

NASA Astrophysics Data System (ADS)

Yuan, Peng; Zhang, Ning; Zhang, Dan; Liu, Tao; Chen, Limiao; Ma, Renzhi; Qiu, Guanzhou; Liu, Xiaohe

2016-01-01

A facile solvothermal method is developed for synthesizing layered Co-Ni hydroxide hierarchical structures by using hexamethylenetetramine (HMT) as alkaline reagent. The electrochemical measurements reveal that the specific capacitances of layered bimetallic (Co-Ni) hydroxides are generally superior to those of layered monometallic (Co, Ni) hydroxides. The as-prepared Co0.5Ni0.5 hydroxide hierarchical structures possesses the highest specific capacitance of 1767 F g-1 at a galvanic current density of 1 A g-1 and an outstanding specific capacitance retention of 87% after 1000 cycles. In comparison with the dispersed nanosheets of Co-Ni hydroxide, layered hydroxide hierarchical structures show much superior electrochemical performance. This study provides a promising method to construct hierarchical structures with controllable transition-metal compositions for enhancing the electrochemical performance in hybrid supercapacitors.

Pellet injection technology

NASA Astrophysics Data System (ADS)

Combs, S. K.

1993-07-01

During the last 10 to 15 years, significant progress has been made worldwide in the area of pellet injection technology. This specialized field of research originated as a possible solution to the problem of depositing atoms of fuel deep within magnetically confined, hot plasmas for refueling of fusion power reactors. Using pellet injection systems, frozen macroscopic (millimeter-size) pellets composed of the isotopes of hydrogen are formed, accelerated, and transported to the plasma for fueling. The process and benefits of plasma fueling by this approach have been demonstrated conclusively on a number of toroidal magnetic confinement configurations; consequently, pellet injection is the leading technology for deep fueling of magnetically confined plasmas for controlled thermonuclear fusion research. Hydrogen pellet injection devices operate at very low temperatures (≂10 K) at which solid hydrogen ice can be formed and sustained. Most injectors use conventional pneumatic (light gas gun) or centrifuge (mechanical) acceleration concepts to inject hydrogen or deuterium pellets at speeds of ≂1-2 km/s. Pellet injectors that can operate at quasi-steady state (pellet delivery rates of 1-40 Hz) have been developed for long-pulse fueling. The design and operation of injectors with the heaviest hydrogen isotope, tritium, offer some special problems because of tritium's radioactivity. To address these problems, a proof-of-principle experiment was carried out in which tritium pellets were formed and accelerated to speeds of 1.4 km/s. Tritium pellet injection is scheduled on major fusion research devices within the next few years. Several advanced accelerator concepts are under development to increase the pellet velocity. One of these is the two-stage light gas gun, for which speeds of slightly over 4 km/s have already been reported in laboratory experiments with deuterium ice. A few two-stage pneumatic systems (single-shot) have recently been installed on tokamak experiments. This article reviews the equipment and instruments that have been developed for pellet injection with emphasis on recent advances. Prospects for future development are addressed, as are possible applications of this technology to other areas of research.

Variable food absorption by Antarctic krill: Relationships between diet, egestion rate and the composition and sinking rates of their fecal pellets

NASA Astrophysics Data System (ADS)

Atkinson, A.; Schmidt, K.; Fielding, S.; Kawaguchi, S.; Geissler, P. A.

2012-01-01

The kinetics of food processing by zooplankton affects both their energy budgets and the biogeochemical fate of their fecal pellets. We sampled 40 schools of krill across the Scotia Sea during spring, summer and autumn and found that in all 3 seasons, every aspect of their absorption and defecation varied greatly. The C content of fecal pellets varied from 0.85% to 29% of their dry mass (median 9.8%) and C egestion rates varied 75-fold. C:N mass ratios of pellets ranged from 4.9 to 13.2 (median 7.8), higher than values of 3.9 in the krill and 5.4 in their food, pointing to enhanced uptake of N. Pellet sinking rates equated to 27-1218 m d -1 (median 304 m d -1), being governed mainly by pellet diameter (80-600 μm, mean 183 μm) and density (1.038-1.391 g cm -3, mean 1.121 g cm -3). Pellets showed little loss of C or N in filtered seawater over the first 2 days and were physically robust. When feeding rates were low, slow gut passage time and high absorption efficiency resulted in low egestion rates of pellets that were low in C and N content. These pellets were compact, dense and fast-sinking. Conversely, in good feeding conditions much food tended to pass quickly through the gut and was not efficiently absorbed, producing C and N-rich, slow-sinking pellets. Such "superfluous feeding" probably maximises the absolute rates of nutrient absorption. Food composition was also important: diatom-rich diets depressed the C content of the pellets but increased their sinking rates, likely due to silica ballasting. So depending on how krill process food, their pellets could represent both vehicles for rapid export and slow sinking, C and N-rich food sources for pelagic scavengers. C egestion rates by krill averaged 3.4% of summer primary production (and ingestion rates would be 2-10-fold higher than this) so whatever the fate of the pellets, krill are an important re-packager within the food web. While salp pellets tend to sink faster than those of krill, it is the latter that tend to prevail in sediment traps. We suggest that this is because krill schools are more compact, producing "rain showers" of pellets that exceed the capacity of pelagic scavengers to reprocess them.

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.

Administration of CREON® pancrelipase pellets via gastrostomy tube is feasible with no loss of gastric resistance or lipase activity: an in vitro study.

PubMed

Shlieout, George; Koerner, Andreas; Maffert, Mario; Forssmann, Kristin; Caras, Steven

2011-01-01

In clinical practice, the need sometimes arises to administer pancreatic enzyme replacement therapy via gastrostomy tube (G-tube) by mixing the pellets contained in the capsules with soft food. The objective of this study was to identify G-tubes that allow administration of pancrelipase gastro-resistant pellets without clogging, sticking, pellet damage or loss of enteric coating integrity. In this in vitro study, CREON® (pancrelipase) Delayed-Release Capsules were opened and the pellets sprinkled onto a small amount of baby food of pH <4.5 (applesauce and bananas manufactured by both Gerber and Beech-Nut). The mixture was stirred gently and after 15 minutes poured into a 35 mL syringe and pushed slowly (~15 mL in 10-15 seconds) through a G-tube. Pellets were collected and the tube flushed with water. G-tubes were inspected visually for clogging/sticking and damage to pellets was assessed. If there was none with all four foods, pellet integrity (gastric resistance and lipase activity) was assessed by an in vitro dissolution method with a 2-hour gastric simulation step. The activity required to confirm integrity was ≥80% of actual US Pharmacopeia lipase activity per capsule. G-tubes initially tested were Kimberly-Clark MIC Bolus® size 14 French (Fr) and upwards and Kimberly-Clark MIC-KEY® 14 Fr and upwards. Following successful testing, assessment of Bard® Tri-Funnel 18 Fr and Bard® Button 18 Fr G-tubes was carried out. Based on the absence of clogging, sticking and visible damage to pellets, and the maintenance of pellet integrity, administration of CREON® pancrelipase pellets was feasible through the following G-tubes: Kimberly-Clark MIC Bolus® size 18 Fr, Kimberly-Clark MIC-KEY® 16 Fr, Bard® Tri-Funnel 18 Fr and Bard® Button 18 Fr. Lipase activity met the predetermined specification and was ≥90% for all four tubes and all four foods, with no differences versus untreated pellets (i.e. pellets not mixed with baby food or pushed through a G-tube). These data apply to all CREON® pancrelipase capsule formulations, regardless of their strength in lipase units, as pellet composition, size and quality are identical. CREON® pancrelipase pellets can be mixed with baby food of pH <4.5 and administered via the following G-tubes without clogging, sticking or visible pellet damage, and with no loss of gastric resistance or lipase activity: Kimberly-Clark MIC Bolus® size 18 Fr and larger, Kimberly-Clark MIC-KEY® 16 Fr and larger, Bard® Tri-Funnel 18 Fr and larger and Bard® Button 18 Fr and larger.

Development of a Tritium Extruder for ITER Pellet Injection

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

M.J. Gouge; P.W. Fisher

As part of the International Thermonuclear Experimental Reactor (ITER) plasma fueling development program, Oak Ridge National Laboratory (ORNL) has fabricated a pellet injection system to test the mechanical and thermal properties of extruded tritium. Hydrogenic pellets will be used in ITER to sustain the fusion power in the plasma core and may be crucial in reducing first-wall tritium inventories by a process of "isotopic fueling" in which tritium-rich pellets fuel the burning plasma core and deuterium gas fuels the edge. This repeating single-stage pneumatic pellet injector, called the Tritium-Proof-of-Principle Phase II (TPOP-II) Pellet Injector, has a piston-driven mechanical extruder andmore » is designed to extrude and accelerate hydrogenic pellets sized for the ITER device. The TPOP-II program has the following development goals: evaluate the feasibility of extruding tritium and deuterium-tritium (D-T) mixtures for use in future pellet injection systems; determine the mechanical and thermal properties of tritium and D-T extrusions; integrate, test, and evaluate the extruder in a repeating, single-stage light gas gun that is sized for the ITER application (pellet diameter -7 to 8 mm); evaluate options for recycling propellant and extruder exhaust gas; and evaluate operability and reliability of ITER prototypical fueling systems in an environment of significant tritium inventory that requires secondary and room containment systems. In tests with deuterium feed at ORNL, up to 13 pellets per extrusion have been extruded at rates up to 1 Hz and accelerated to speeds of 1.0 to 1.1 km/s, using hydrogen propellant gas at a supply pressure of 65 bar. Initially, deuterium pellets 7.5 mm in diameter and 11 mm in length were produced-the largest cryogenic pellets produced by the fusion program to date. These pellets represent about a 10% density perturbation to ITER. Subsequently, the extruder nozzle was modified to produce pellets that are almost 7.5-mm right circular cylinders. Tritium and D-T pellets have been produced in experiments at the Los Alamos National Laboratory Tritium Systems Test Assembly. About 38 g of tritium have been utilized in the experiment. The tritium was received in eight batches, six from product containers and two from the Isotope Separation System. Two types of runs were made: those in which the material was only extruded and those in which pellets were produced and fired with deuterium propellant. A total of 36 TZ runs and 28 D-T runs have been made. A total of 36 pure tritium runs and 28 D-T mixture runs were made. Extrusion experiments indicate that both T2 and D-T will require higher extrusion forces than D2 by about a factor of two.« less

40 CFR 721.4600 - Recovered metal hydroxide.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Recovered metal hydroxide. 721.4600... Substances § 721.4600 Recovered metal hydroxide. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a recovered metal hydroxide (PMN P-91-809...

Polysulfide intercalated layered double hydroxides for metal capture applications

DOEpatents

Kanatzidis, Mercouri G.; Ma, Shulan

2017-04-04

Polysulfide intercalated layered double hydroxides and methods for their use in vapor and liquid-phase metal capture applications are provided. The layered double hydroxides comprise a plurality of positively charged host layers of mixed metal hydroxides separated by interlayer spaces. Polysulfide anions are intercalated in the interlayer spaces.

21 CFR 73.1010 - Alumina (dried aluminum hydroxide).

Code of Federal Regulations, 2010 CFR

2010-04-01

... GENERAL LISTING OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION Drugs § 73.1010 Alumina (dried aluminum hydroxide). (a) Identity. (1) The color additive alumina (dried aluminum hydroxide) is a white, odorless, tasteless, amorphous powder consisting essentially of aluminum hydroxide (Al2 O3· XH2 O). (2) Color additive...

21 CFR 73.1326 - Chromium hydroxide green.

Code of Federal Regulations, 2010 CFR

2010-04-01

... COLOR ADDITIVES EXEMPT FROM CERTIFICATION Drugs § 73.1326 Chromium hydroxide green. (a) Identity. (1) The color additive chromium hydroxide green is principally hydrated chromic sesquioxide (Cr2O3·XH2O). (2) Color additive mixtures for drug use made with chromium hydroxide green may contain only those...

40 CFR 415.60 - Applicability; description of the chlorine and sodium or potassium hydroxide production subcategory.

Code of Federal Regulations, 2010 CFR

2010-07-01

... chlorine and sodium or potassium hydroxide production subcategory. 415.60 Section 415.60 Protection of... MANUFACTURING POINT SOURCE CATEGORY Chlor-alkali Subcategory (Chlorine and Sodium or Potassium Hydroxide Production) § 415.60 Applicability; description of the chlorine and sodium or potassium hydroxide production...

40 CFR 415.60 - Applicability; description of the chlorine and sodium or potassium hydroxide production subcategory.

Code of Federal Regulations, 2012 CFR

2012-07-01

... chlorine and sodium or potassium hydroxide production subcategory. 415.60 Section 415.60 Protection of... MANUFACTURING POINT SOURCE CATEGORY Chlor-alkali Subcategory (Chlorine and Sodium or Potassium Hydroxide Production) § 415.60 Applicability; description of the chlorine and sodium or potassium hydroxide production...

21 CFR 184.1428 - Magnesium hydroxide.

Code of Federal Regulations, 2011 CFR

2011-04-01

... salt or by hydration of reactive grades of magnesium oxide. (b) The ingredient meets the specifications... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Magnesium hydroxide. 184.1428 Section 184.1428... Listing of Specific Substances Affirmed as GRAS § 184.1428 Magnesium hydroxide. (a) Magnesium hydroxide...

21 CFR 184.1428 - Magnesium hydroxide.

Code of Federal Regulations, 2010 CFR

2010-04-01

... hydration of reactive grades of magnesium oxide. (b) The ingredient meets the specifications of the Food... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Magnesium hydroxide. 184.1428 Section 184.1428 Food... Specific Substances Affirmed as GRAS § 184.1428 Magnesium hydroxide. (a) Magnesium hydroxide (Mg(OH)2, CAS...

21 CFR 582.1763 - Sodium hydroxide.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Sodium hydroxide. 582.1763 Section 582.1763 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1763 Sodium hydroxide. (a) Product. Sodium hydroxide. (b) Conditions of use. This substance...

21 CFR 582.1763 - Sodium hydroxide.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Sodium hydroxide. 582.1763 Section 582.1763 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1763 Sodium hydroxide. (a) Product. Sodium hydroxide. (b) Conditions of use. This substance...

21 CFR 582.1763 - Sodium hydroxide.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Sodium hydroxide. 582.1763 Section 582.1763 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1763 Sodium hydroxide. (a) Product. Sodium hydroxide. (b) Conditions of use. This substance...

21 CFR 582.1763 - Sodium hydroxide.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Sodium hydroxide. 582.1763 Section 582.1763 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1763 Sodium hydroxide. (a) Product. Sodium hydroxide. (b) Conditions of use. This substance...

21 CFR 582.1763 - Sodium hydroxide.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Sodium hydroxide. 582.1763 Section 582.1763 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1763 Sodium hydroxide. (a) Product. Sodium hydroxide. (b) Conditions of use. This substance...

40 CFR 415.60 - Applicability; description of the chlorine and sodium or potassium hydroxide production subcategory.

Code of Federal Regulations, 2011 CFR

2011-07-01

... chlorine and sodium or potassium hydroxide production subcategory. 415.60 Section 415.60 Protection of... MANUFACTURING POINT SOURCE CATEGORY Chlor-alkali Subcategory (Chlorine and Sodium or Potassium Hydroxide Production) § 415.60 Applicability; description of the chlorine and sodium or potassium hydroxide production...

40 CFR 415.60 - Applicability; description of the chlorine and sodium or potassium hydroxide production subcategory.

Code of Federal Regulations, 2014 CFR

2014-07-01

... chlorine and sodium or potassium hydroxide production subcategory. 415.60 Section 415.60 Protection of... MANUFACTURING POINT SOURCE CATEGORY Chlor-alkali Subcategory (Chlorine and Sodium or Potassium Hydroxide Production) § 415.60 Applicability; description of the chlorine and sodium or potassium hydroxide production...

40 CFR 415.60 - Applicability; description of the chlorine and sodium or potassium hydroxide production subcategory.

Code of Federal Regulations, 2013 CFR

2013-07-01

... chlorine and sodium or potassium hydroxide production subcategory. 415.60 Section 415.60 Protection of... MANUFACTURING POINT SOURCE CATEGORY Chlor-alkali Subcategory (Chlorine and Sodium or Potassium Hydroxide Production) § 415.60 Applicability; description of the chlorine and sodium or potassium hydroxide production...

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.)

CFD Modeling of Flow, Temperature, and Concentration Fields in a Pilot-Scale Rotary Hearth Furnace

NASA Astrophysics Data System (ADS)

Liu, Ying; Su, Fu-Yong; Wen, Zhi; Li, Zhi; Yong, Hai-Quan; Feng, Xiao-Hong

2014-01-01

A three-dimensional mathematical model for simulation of flow, temperature, and concentration fields in a pilot-scale rotary hearth furnace (RHF) has been developed using a commercial computational fluid dynamics software, FLUENT. The layer of composite pellets under the hearth is assumed to be a porous media layer with CO source and energy sink calculated by an independent mathematical model. User-defined functions are developed and linked to FLUENT to process the reduction process of the layer of composite pellets. The standard k-ɛ turbulence model in combination with standard wall functions is used for modeling of gas flow. Turbulence-chemistry interaction is taken into account through the eddy-dissipation model. The discrete ordinates model is used for modeling of radiative heat transfer. A comparison is made between the predictions of the present model and the data from a test of the pilot-scale RHF, and a reasonable agreement is found. Finally, flow field, temperature, and CO concentration fields in the furnace are investigated by the model.

Effectiveness of purging on preventing gas emission buildup in wood pellet storage

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

Yazdanpanah, Fahimeh; Sokhansanj, Shahab; Lim, Choon Jim

Storage of wood pellets has resulted in deadly accidents in connection with off-gassing and self-heating. A forced ventilation system should be in place to sweep the off-gases and control the thermal conditions. In this study, multiple purging tests were conducted in a pilot scale silo to evaluate the effectiveness of a purging system and quantify the time and volume of the gas needed to sweep the off-gases. To identify the degree of mixing, residence time distribution of the tracer gas was also studied experimentally. Large deviations from plug flow suggested strong gas mixing for all superficial velocities. As the velocitymore » increased, the system dispersion number became smaller, which indicated less degree of mixing with increased volume of the purging gas. Finally, one-dimensional modelling and numerical simulation of the off-gas concentration profile gave the best agreement with the measured gas concentration at the bottom and middle of the silo.« less

The effect of precipitation and calcination parameters on oxalate derived ThO2 pellets

NASA Astrophysics Data System (ADS)

Wangle, Tadeas; Tyrpekl, Vaclav; Cagno, Simone; Delloye, Thierry; Larcher, Olivier; Cardinaels, Thomas; Vleugels, Jozef; Verwerft, Marc

2017-11-01

Thorium oxalate is easy to prepare, but the derived oxide powders retain the platelet morphology of the primary oxalate. This negatively impacts packing and sintering. If powder milling is to be avoided, powder synthesis needs to be optimized. That is the goal of this paper, where different precipitation strategies were used and their effect on powder characteristics and pellet synthesis was investigated. Oxalates prepared by adding a thorium nitrate solution to an oxalic acid solution proved most promising. Further optimizing of the calcination temperature revealed that with increasing calcination temperature the packing density improved significantly. This came at the cost of decreased early stage sintering and a higher frequency of end-capping during compaction. The calcination temperature at which the highest final density can be reached was dependent on the sintering cycle. Furthermore, the ThO2 powders had less surface area and thus adsorbed less gases during storage when calcined at higher temperatures.

Influence of calcium on fungal growth, hyphal morphology and citric acid production in Aspergillus niger.

PubMed

Pera, L M; Callieri, D A

1997-01-01

Addition of 0.5 g/L CaCl2 to the fermentation medium lowered the final biomass dry mass by 35% and increased the uptake of phosphate and sucrose, and the production of citric acid by 15, 35 and 50%, respectively. In a medium deprived of Ca2+ the microorganism displayed both a pelleted and a filamentous form of growth, the hyphae being scarcely branched, without bulbous cells. An addition of Ca2+ induced a pelleted form of growth, highly branched hyphae and numerous bulbous cells. Bulbous cells growing in the presence of Ca2+ exhibited cell walls composed of laminated layers, and featured vesicles associated with the wall and/or the cell membrane, containing numerous inclusions. The cytotoxic effect of high concentrations of citric acid in the medium as well as an increase of the activity of N-acetyl-beta-D-glucosaminidase, a lytic enzyme, might be involved in these morphological changes.

Effectiveness of purging on preventing gas emission buildup in wood pellet storage

DOE PAGES

Yazdanpanah, Fahimeh; Sokhansanj, Shahab; Lim, Choon Jim; ...

2015-04-24

Storage of wood pellets has resulted in deadly accidents in connection with off-gassing and self-heating. A forced ventilation system should be in place to sweep the off-gases and control the thermal conditions. In this study, multiple purging tests were conducted in a pilot scale silo to evaluate the effectiveness of a purging system and quantify the time and volume of the gas needed to sweep the off-gases. To identify the degree of mixing, residence time distribution of the tracer gas was also studied experimentally. Large deviations from plug flow suggested strong gas mixing for all superficial velocities. As the velocitymore » increased, the system dispersion number became smaller, which indicated less degree of mixing with increased volume of the purging gas. Finally, one-dimensional modelling and numerical simulation of the off-gas concentration profile gave the best agreement with the measured gas concentration at the bottom and middle of the silo.« less

Effects of carbonization conditions on properties of bamboo pellets

Treesearch

Zhijia Liu; Zehui Jiang; Zhiyong Cai; Benhua Fei; Yan Yu; Xing' e Liu

2013-01-01

Bamboo is a biomass material and has great potential as a bio-energy resource of the future in China. Bamboo pellets were successfully manufactured using a laboratory pellet mill in preliminary work. This study was therefore carried out to investigate the effect of carbonization conditions (temperature and time) on properties of bamboo pellets and to evaluate product...

Greenhouse germination trials of pelletized western redcedar and red alder seeds

Treesearch

Nabil Khadduri

2007-01-01

Pelletized western redcedar (Thuja plicata Donn ex D. Don) and red alder (Alnus rubra Bong.) seeds exhibited lower total germination and delayed germination speed (G50 or days to 50% germination) when compared to non-pelletized “raw” seeds in greenhouse trials. Averaged across two lots of western redcedar, pelletizing decreased...

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.

Technique for controlling shrinkage distortion in cold-pressed annular pellets

DOEpatents

Johnson, R.G.R.; Burke, T.J.

1982-06-28

A process and apparatus are described for the production of annular fuel pellets comprising locating particulate fuel material in a compaction chamber having side walls, a moveable punch located opposite a fixed member and a frustoconical element having a taper of between about 0.010 to 0.015 inches/inch located in about the center of the chamber. The punch is moved toward the fixed surface to compact the particulate material. The compacted pellet is fired to produce sintered pellets having substantially straight inner side walls essentially parallel to the pellet axis.

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.

Processing of surrogate nuclear fuel pellets for better dimensional control with dry bag isostatic pressing

DOE PAGES

Hoggan, Rita E.; Zuck, Larry D.; Cannon, W. Roger; ...

2016-05-26

A study of improved methods of processing fuel pellets was undertaken using ceria and zirconia/yttria/alumina as surrogates. Through proper granulation and vertical vibration (tapping) of the parts bag prior to dry bag isostatic pressing (DBIP), reproducibility of diameter profiles among multiple pellets of ceria was improved by almost an order of magnitude. Reproducibility of sintered pellets was sufficiently good to possibly avoid grinding. Deviation from the mean diameter along the length of multiple pellets, as well as, deviation from roundness, decreased after sintering. This is not generally observed with dry pressed pellets. Thus it is possible to machine to tolerancemore » before sintering if grinding is necessary.« less

Antimicrobial Activity of Calcium Hydroxide in Endodontics: A Review

PubMed Central

Shalavi, S; Yazdizadeh, M

2012-01-01

The purpose of endodontic therapy is to preserve the patient's natural teeth without compromising the patient's local or systemic health. Calcium hydroxide has been included in several materials and antimicrobial formulations that are used in several treatment modalities in endodontics, such as inter-appointment intracanal medicaments. The purpose of this article was to review the antimicrobial properties of calcium hydroxide in endodontics. Calcium hydroxide has a high pH (approximately 12.5-12.8) and is classified chemically as a strong base. The lethal effects of calcium hydroxide on bacterial cells are probably due to protein denaturation and damage to DNA and cytoplasmic membranes. Calcium hydroxide has a wide range of antimicrobial activity against common endodontic pathogens but is less effective against Enterococcus faecalis and Candida albicans. Calcium hydroxide is also a valuable anti-endotoxin agent. However, its effect on microbial biofilms is controversial. PMID:23323217

21 CFR 872.3250 - Calcium hydroxide cavity liner.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Calcium hydroxide cavity liner. 872.3250 Section... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3250 Calcium hydroxide cavity liner. (a) Identification. A calcium hydroxide cavity liner is a device material intended to be applied to the interior of a...

21 CFR 872.3250 - Calcium hydroxide cavity liner.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Calcium hydroxide cavity liner. 872.3250 Section... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3250 Calcium hydroxide cavity liner. (a) Identification. A calcium hydroxide cavity liner is a device material intended to be applied to the interior of a...

21 CFR 184.1763 - Sodium hydroxide.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Sodium hydroxide. 184.1763 Section 184.1763 Food... Specific Substances Affirmed as GRAS § 184.1763 Sodium hydroxide. (a) Sodium hydroxide (NaOH, CAS Reg. No. 1310-73-2) is also known as sodium hydrate, soda lye, caustic soda, white caustic, and lye. The...

21 CFR 184.1763 - Sodium hydroxide.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Sodium hydroxide. 184.1763 Section 184.1763 Food... Specific Substances Affirmed as GRAS § 184.1763 Sodium hydroxide. (a) Sodium hydroxide (NaOH, CAS Reg. No. 1310-73-2) is also known as sodium hydrate, soda lye, caustic soda, white caustic, and lye. The...

21 CFR 184.1763 - Sodium hydroxide.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Sodium hydroxide. 184.1763 Section 184.1763 Food... Specific Substances Affirmed as GRAS § 184.1763 Sodium hydroxide. (a) Sodium hydroxide (NaOH, CAS Reg. No. 1310-73-2) is also known as sodium hydrate, soda lye, caustic soda, white caustic, and lye. The...

21 CFR 184.1763 - Sodium hydroxide.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Sodium hydroxide. 184.1763 Section 184.1763 Food... Specific Substances Affirmed as GRAS § 184.1763 Sodium hydroxide. (a) Sodium hydroxide (NaOH, CAS Reg. No. 1310-73-2) is also known as sodium hydrate, soda lye, caustic soda, white caustic, and lye. The...

21 CFR 872.3250 - Calcium hydroxide cavity liner.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Calcium hydroxide cavity liner. 872.3250 Section... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3250 Calcium hydroxide cavity liner. (a) Identification. A calcium hydroxide cavity liner is a device material intended to be applied to the interior of a...

21 CFR 872.3250 - Calcium hydroxide cavity liner.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Calcium hydroxide cavity liner. 872.3250 Section... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3250 Calcium hydroxide cavity liner. (a) Identification. A calcium hydroxide cavity liner is a device material intended to be applied to the interior of a...

21 CFR 872.3250 - Calcium hydroxide cavity liner.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Calcium hydroxide cavity liner. 872.3250 Section... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3250 Calcium hydroxide cavity liner. (a) Identification. A calcium hydroxide cavity liner is a device material intended to be applied to the interior of a...

21 CFR 73.1326 - Chromium hydroxide green.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 1 2011-04-01 2011-04-01 false Chromium hydroxide green. 73.1326 Section 73.1326... COLOR ADDITIVES EXEMPT FROM CERTIFICATION Drugs § 73.1326 Chromium hydroxide green. (a) Identity. (1) The color additive chromium hydroxide green is principally hydrated chromic sesquioxide (Cr2O3·XH2O...

Ytterbium coating of spherical Ni(OH) 2 cathode materials for Ni-MH batteries at elevated temperature

NASA Astrophysics Data System (ADS)

He, Xiangming; Wang, Li; Li, Wen; Jiang, Changyin; Wan, Chunrong

The Yb/Co coated nickel hydroxides were prepared by precipitation of Yb(OH) 3 on the surface of spherical nickel hydroxide, followed by precipitation of Co(OH) 2 on its surface. The optimum coating content of ytterbium was around 2% (atomic concentration) to obtain high discharge capacity at 60 °C. It was shown that the discharge capacity of nickel hydroxide at high temperatures was improved by coating of ytterbium and cobalt hydroxide. The high temperature performances of the sealed AAA-sized Ni-MH batteries using Yb/Co coated nickel hydroxide as positive electrodes were carried out, showing much better than those using the un-coated and only Co(OH) 2 coated nickel hydroxide electrodes. The charge acceptance of the battery using 2% Yb and 2% Co coated nickel hydroxide reached 92% at 60 °C, where the charge acceptances for the un-coated and only cobalt coated ones were only 42 and 46%, respectively. It has shown that the Yb/Co coating is an effective way to improve the high temperature performance of nickel hydroxide for nickel-metal hydride batteries.

Comparison of phenol and sodium hydroxide chemical matricectomies for the treatment of ingrowing toenails.

PubMed

Bostanci, Seher; Kocyigit, Pelin; Gürgey, Erbak

2007-06-01

Chemical matricectomy is performed mainly by two agents: phenol and sodium hydroxide. Both agents have excellent cure rates, but there are no data about the comparison of postoperative healing periods. This study was designed to compare the postoperative morbidity rates of sodium hydroxide and phenol matricectomies. Forty-six patients with 154 ingrowing nail sides were treated with either sodium hydroxide or phenol matricectomy. In the postoperative period, the patients were evaluated for the duration and severity of pain, drainage, and peripheral tissue destruction; complete healing periods; and overall success rates. The incidence of pain was higher in the sodium hydroxide group on the first visit, on the second day, but all patients became pain-free after that. The incidence and duration of drainage and peripheral tissue destruction was significantly higher in the phenol group. The mean period for complete recovery was 10.8 days in the sodium hydroxide group, whereas it was 18.02 days in the phenol group. The overall success rates in the sodium hydroxide and phenol groups were found to be 95.1 and 95.8%, respectively. Both sodium hydroxide and phenol are effective agents giving high success rates, but sodium hydroxide causes less postoperative morbidity and provides faster recovery.

Formulation and process strategies to minimize coat damage for compaction of coated pellets in a rotary tablet press: A mechanistic view.

PubMed

Xu, Min; Heng, Paul Wan Sia; Liew, Celine Valeria

2016-02-29

Compaction of multiple-unit pellet system (MUPS) tablets has been extensively studied in the past few decades but with marginal success. This study aims to investigate the formulation and process strategies for minimizing pellet coat damage caused by compaction and elucidate the mechanism of damage sustained during the preparation of MUPS tablets in a rotary tablet press. Blends containing ethylcellulose-coated pellets and cushioning agent (spray dried aggregates of micronized lactose and mannitol), were compacted into MUPS tablets in a rotary tablet press. The effects of compaction pressure and dwell time on the physicomechanical properties of resultant MUPS tablets and extent of pellet coat damage were systematically examined. The coated pellets from various locations at the axial and radial peripheral surfaces and core of the MUPS tablets were excavated and assessed for their coat damage individually. Interestingly, for a MUPS tablet formulation which consolidates by plastic deformation, the tablet mechanical strength could be enhanced without exacerbating pellet coat damage by extending the dwell time in the compaction cycle during rotary tableting. However, the increase in compaction pressure led to faster drug release rate. The location of the coated pellets in the MUPS tablet also contributed to the extent of their coat damage, possibly due to uneven force distribution within the compact. To ensure viability of pellet coat integrity, the formation of a continuous percolating network of cushioning agent is critical and the applied compaction pressure should be less than the pellet crushing strength. Copyright © 2015 Elsevier B.V. All rights reserved.

Influence of moisture content, particle size and forming temperature on productivity and quality of rice straw pellets

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

Ishii, Kazuei, E-mail: k-ishii@eng.hokudai.ac.jp; Furuichi, Toru

Highlights: • Optimized conditions were determined for the production of rice straw pellets. • The moisture content and forming temperature are key factors. • High quality rice pellets in the lower heating value and durability were produced. - Abstract: A large amount of rice straw is generated and left as much in paddy fields, which causes greenhouse gas emissions as methane. Rice straw can be used as bioenergy. Rice straw pellets are a promising technology because pelletization of rice straw is a form of mass and energy densification, which leads to a product that is easy to handle, transport, storemore » and utilize because of the increase in the bulk density. The operational conditions required to produce high quality rice straw pellets have not been determined. This study determined the optimal moisture content range required to produce rice straw pellets with high yield ratio and high heating value, and also determined the influence of particle size and the forming temperature on the yield ratio and durability of rice straw pellets. The optimal moisture content range was between 13% and 20% under a forming temperature of 60 or 80 °C. The optimal particle size was between 10 and 20 mm, considering the time and energy required for shredding, although the particle size did not significantly affect the yield ratio and durability of the pellets. The optimized conditions provided high quality rice straw pellets with nearly 90% yield ratio, ⩾12 MJ/kg for the lower heating value, and >95% durability.« less

Bacterial Colonization of Pellet Softening Reactors Used during Drinking Water Treatment▿

PubMed Central

Hammes, Frederik; Boon, Nico; Vital, Marius; Ross, Petra; Magic-Knezev, Aleksandra; Dignum, Marco

2011-01-01

Pellet softening reactors are used in centralized and decentralized drinking water treatment plants for the removal of calcium (hardness) through chemically induced precipitation of calcite. This is accomplished in fluidized pellet reactors, where a strong base is added to the influent to increase the pH and facilitate the process of precipitation on an added seeding material. Here we describe for the first time the opportunistic bacterial colonization of the calcite pellets in a full-scale pellet softening reactor and the functional contribution of these colonizing bacteria to the overall drinking water treatment process. ATP analysis, advanced microscopy, and community fingerprinting with denaturing gradient gel electrophoretic (DGGE) analysis were used to characterize the biomass on the pellets, while assimilable organic carbon (AOC), dissolved organic carbon, and flow cytometric analysis were used to characterize the impact of the biological processes on drinking water quality. The data revealed pellet colonization at concentrations in excess of 500 ng of ATP/g of pellet and reactor biomass concentrations as high as 220 mg of ATP/m3 of reactor, comprising a wide variety of different microorganisms. These organisms removed as much as 60% of AOC from the water during treatment, thus contributing toward the biological stabilization of the drinking water. Notably, only a small fraction (about 60,000 cells/ml) of the bacteria in the reactors was released into the effluent under normal conditions, while the majority of the bacteria colonizing the pellets were captured in the calcite structures of the pellets and were removed as a reusable product. PMID:21148700

Data analysis on physical and mechanical properties of cassava pellets.

PubMed

Oguntunde, Pelumi E; Adejumo, Oluyemisi A; Odetunmibi, Oluwole A; Okagbue, Hilary I; Adejumo, Adebowale O

2018-02-01

In this data article, laboratory experimental investigation results carried out at National Centre for Agricultural Mechanization (NCAM) on moisture content, machine speed, die diameter of the rig, and the outputs (hardness, durability, bulk density, and unit density of the pellets) at different levels of cassava pellets were observed. Analysis of variance using randomized complete block design with factorial was used to perform analysis for each of the outputs: hardness, durability, bulk density, and unit density of the pellets. A clear description on each of these outputs was considered separately using tables and figures. It was observed that for all the output with the exception of unit density, their main factor effects as well as two and three ways interactions is significant at 5% level. This means that the hardness, bulk density and durability of cassava pellets respectively depend on the moisture content of the cassava dough, the machine speed, the die diameter of the extrusion rig and the combinations of these factors in pairs as well as the three altogether. Higher machine speeds produced more quality pellets at lower die diameters while lower machine speed is recommended for higher die diameter. Also the unit density depends on die diameter and the three-way interaction only. Unit density of cassava pellets is neither affected by machine parameters nor moisture content of the cassava dough. Moisture content of cassava dough, speed of the machine and die diameter of the extrusion rig are significant factors to be considered in pelletizing cassava to produce pellets. Increase in moisture content of cassava dough increase the quality of cassava pellets.

Revealing accumulation zones of plastic pellets in sandy beaches.

PubMed

Moreira, Fabiana T; Balthazar-Silva, Danilo; Barbosa, Lucas; Turra, Alexander

2016-11-01

Microplastics such as pellets are reported worldwide on sandy beaches, and have possible direct and indirect impacts on the biota and physical characteristics of the habitats where they accumulate. Evaluations of their standing stock at different spatial scales generate data on levels of contamination. This information is needed to identify accumulation zones and the specific beach habitats and communities that are likely to be most affected. Standing stocks of plastic pellets were evaluated in 13 sandy beaches in São Paulo state, Brazil. The sampling strategy incorporated across-shore transects from coastal dunes and backshores, and vertical profiles of the accumulated pellets down to 1 m depth below the sediment surface. Accumulation zones were identified at regional (among beaches) and local (between compartments) scales. At the regional scale pellet density tended to increase at beaches on the central and southwestern coast, near ports and factories that produce and transport the largest amounts of pellets in the country. At the local scale coastal dunes showed larger accumulations of pellets than backshores. For both compartments pellets tended to occur deeper in areas where standing stocks were larger. Most of the pellets were concentrated from the surface down to 0.4 m depth, suggesting that organisms inhabiting this part of the sediment column are more exposed to the risks associated with the presence of pellets. Our findings shed light on the local and regional scales of spatial variability of microplastics and their consequences for assessment and monitoring schemes in coastal compartments. Copyright © 2016. Published by Elsevier Ltd.

Bacterial colonization of pellet softening reactors used during drinking water treatment.

PubMed

Hammes, Frederik; Boon, Nico; Vital, Marius; Ross, Petra; Magic-Knezev, Aleksandra; Dignum, Marco

2011-02-01

Pellet softening reactors are used in centralized and decentralized drinking water treatment plants for the removal of calcium (hardness) through chemically induced precipitation of calcite. This is accomplished in fluidized pellet reactors, where a strong base is added to the influent to increase the pH and facilitate the process of precipitation on an added seeding material. Here we describe for the first time the opportunistic bacterial colonization of the calcite pellets in a full-scale pellet softening reactor and the functional contribution of these colonizing bacteria to the overall drinking water treatment process. ATP analysis, advanced microscopy, and community fingerprinting with denaturing gradient gel electrophoretic (DGGE) analysis were used to characterize the biomass on the pellets, while assimilable organic carbon (AOC), dissolved organic carbon, and flow cytometric analysis were used to characterize the impact of the biological processes on drinking water quality. The data revealed pellet colonization at concentrations in excess of 500 ng of ATP/g of pellet and reactor biomass concentrations as high as 220 mg of ATP/m(3) of reactor, comprising a wide variety of different microorganisms. These organisms removed as much as 60% of AOC from the water during treatment, thus contributing toward the biological stabilization of the drinking water. Notably, only a small fraction (about 60,000 cells/ml) of the bacteria in the reactors was released into the effluent under normal conditions, while the majority of the bacteria colonizing the pellets were captured in the calcite structures of the pellets and were removed as a reusable product.

Novel borate glass/chitosan composite as a delivery vehicle for teicoplanin in the treatment of chronic osteomyelitis.

PubMed

Jia, Wei-Tao; Zhang, Xin; Luo, Shi-Hua; Liu, Xin; Huang, Wen-Hai; Rahaman, Mohamed N; Day, Delbert E; Zhang, Chang-Qing; Xie, Zong-Ping; Wang, Jian-Qiang

2010-03-01

Composite materials composed of borate bioactive glass and chitosan (designated BGC) were investigated in vitro and in vivo as a new delivery system for teicoplanin in the treatment of chronic osteomyelitis induced by methicillin-resistant Staphylococcus aureus (MRSA). In vitro, the release of teicoplanin from BGC pellets into phosphate-buffered saline (PBS), as well as its antibacterial activity, were determined. The compressive strength of the pellets was measured after specific immersion times, and the structure of the pellets was characterized using scanning electron microscopy and X-ray diffraction. In vivo, the tibial cavity of New Zealand White rabbits was injected with MRSA strain to induce chronic osteomyelitis, treated by debridement after 4weeks, implanted with teicoplanin-loaded BGC pellets (designated TBGC) or BGC pellets, or injected intravenously with teicoplanin. After 12weeks' implantation, the efficacy of the TBGC pellets for treating osteomyelitis was evaluated using hematological, radiological, microbiological and histological techniques. When immersed in PBS, the TBGC pellets provided a sustained release of teicoplanin, while the surface of the pellets was converted to hydroxyapatite (HA). In vivo, the best therapeutic effect was observed in animals implanted with TBGC pellets, resulting in significantly lower radiological and histological scores, a lower positive rate of MRSA culture, and an excellent bone defect repair, without local or systemic side effects. The results indicate that TBGC pellets are effective in treating chronic osteomyelitis by providing a sustained release of teicoplanin, in addition to participating in bone regeneration. Copyright 2009 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Antimicrobial activity of calcium hydroxide and chlorhexidine on intratubular Candida albicans

PubMed Central

Jacques Rezende Delgado, Ronan; Helena Gasparoto, Thaís; Renata Sipert, Carla; Ramos Pinheiro, Claudia; Gomes de Moraes, Ivaldo; Brandão Garcia, Roberto; Antônio Hungaro Duarte, Marco; Monteiro Bramante, Clóvis; Aparecido Torres, Sérgio; Pompermaier Garlet, Gustavo; Paula Campanelli, Ana; Bernardineli, Norberti

2013-01-01

This study investigated the efficacy of calcium hydroxide and chlorhexidine gel for the elimination of intratubular Candida albicans (C. albicans). Human single-rooted teeth contaminated with C. albicans were treated with calcium hydroxide, 2% chlorhexidine gel, calcium hydroxide plus 2% chlorhexidine gel, or saline (0.9% sodium chloride) as a positive control. The samples obtained at depths of 0–100 and 100–200 µm from the root canal system were analyzed for C. albicans load by counting the number of colony forming units and for the percentage of viable C. albicans using fluorescence microscopy. First, the antimicrobial activity of calcium hydroxide and the 2% chlorhexidine gel was evaluated by counting the number of colony forming units. After 14 days of intracanal medication, there was a significant decrease in the number of C. albicans colony forming units at a depth of 0–100 µm with chlorhexidine treatment either with or without calcium hydroxide compared with the calcium hydroxide only treatment. However, there were no differences in the number of colony forming units at the 100–200 µm depth for any of the medications investigated. C. albicans viability was also evaluated by vital staining techniques and fluorescence microscopy analysis. Antifungal activity against C. albicans significantly increased at both depths in the chlorhexidine groups with and without calcium hydroxide compared with the groups treated with calcium hydroxide only. Treatments with only chlorhexidine or chlorhexidine in combination with calcium hydroxide were effective for elimination of C. albicans. PMID:23538639

Evaluation of calcium ion, hydroxyl ion release and pH levels in various calcium hydroxide based intracanal medicaments: An in vitro study

PubMed Central

Fulzele, Punit; Baliga, Sudhindra; Thosar, Nilima; Pradhan, Debaprya

2011-01-01

Aims: Evaluation of calcium ion and hydroxyl ion release and pH levels in various calcium hydroxide based intracanal medicaments. Objective: The purpose of this study was to evaluate calcium and hydroxyl ion release and pH levels of calcium hydroxide based products, namely, RC Cal, Metapex, calcium hydroxide with distilled water, along with the new gutta-percha points with calcium hydroxide. Materials and Methods: The materials were inserted in polyethylene tubes and immersed in deionized water. The pH variation, Ca++ and OH- release were monitored periodically for 1 week. Statistical Analysis Used: Statistical analysis was carried out using one-way analysis of variance and Tukey's post hoc tests with PASW Statistics version 18 software to compare the statistical difference. Results: After 1 week, calcium hydroxide with distilled water and RC Cal raised the pH to 12.7 and 11.8, respectively, while a small change was observed for Metapex, calcium hydroxide gutta-percha points. The calcium released after 1 week was 15.36 mg/dL from RC Cal, followed by 13.04, 1.296, 3.064 mg/dL from calcium hydroxide with sterile water, Metapex and calcium hydroxide gutta-percha points, respectively. Conclusions: Calcium hydroxide with sterile water and RC Cal pastes liberate significantly more calcium and hydroxyl ions and raise the pH higher than Metapex and calcium hydroxidegutta-percha points. PMID:22346155

Encapsulated heterogeneous base catalysts onto SBA-15 nanoporous material as highly active catalysts in the transesterification of sunflower oil to biodiesel

NASA Astrophysics Data System (ADS)

Albayati, Talib M.; Doyle, Aidan M.

2015-02-01

Alkali metals and their hydroxides, Na, NaOH, Li, and LiOH, were encapsulated onto SBA-15 nanoporous material as highly active catalysts for the production of biodiesel fuel from sunflower oil. The incipient wetness impregnation method was adopted for the prepared catalysts. The characterization properties of the catalysts and unmodified SBA-15 were determined using X-ray diffraction, scanning electron microscopy, EDAX, nitrogen adsorption-desorption porosimetry (Brunauer-Emmett-Teller), Fourier-transform infrared spectroscopy, and transmission electron microscopy. Transesterification was conducted in a batch reactor at atmospheric pressure and 65 °C. The catalysts were highly active with yields of fatty acid methyl ester (FAME) in the range 96-99 %. Na/SBA-15 catalyst was reused for seven consecutive cycles under the same reaction conditions; the yield to FAME on the final cycle was 96 %. This study shows that the alkali metals and their hydroxides supported on SBA-15-based catalyst are excellent catalysts for the biodiesel reaction.

Synthesis of alumina ceramic encapsulation for self-healing materials on thermal barrier coating

NASA Astrophysics Data System (ADS)

Golim, O. P.; Prastomo, N.; Izzudin, H.; Hastuty, S.; Sundawa, R.; Sugiarti, E.; Thosin, K. A. Z.

2018-03-01

Durability of Thermal Barrier Coating or TBC can be optimized by inducing Self-Healing capabilities with intermetallic materials MoSi2. Nevertheless, high temperature operation causes the self-healing materials to become oxidized and lose its healing capabilities. Therefore, a method to introduce ceramic encapsulation for MoSi2 is needed to protect it from early oxidation. The encapsulation process is synthesized through a simple precipitation method with colloidal aluminum hydroxide as precursor and variations on calcination process. Semi-quantitative analysis on the synthesized sample is done by using X-ray diffraction (XRD) method. Meanwhile, qualitative analysis on the morphology of the encapsulation was carried out by using Scanning Electron Microscope (SEM) and Field Emission Scanning Electron Microscope (FESEM) equipped with dual Focus Ion Beam (FIB). The result of the experiment shows that calcination process significantly affects the final characteristic of encapsulation. The optimum encapsulation process was synthesized by colloidal aluminum hydroxide as a precursor, with a double step calcination process in low pressure until 900 °C.

Used Pallets as a Source of Pellet Fuel: Current Industry Status

Treesearch

P.B. Aruna; Jan G. Laarman; Philip A. Araman; Edward Coulter; Frederick Cubbage

1997-01-01

U.S. companies discard approximately 4 billion board feet per year of wood pallets and containers. Manufacturing fuel pellets from this wasted wood may be an alternative to disposal. This study traces the development of biomass energy and the wood pellet industry in the United States and considers the production aspects of making pellets from used pallets. In addition...

Physical characteristics of sinking and floating extruded and expansion-steam pelleted feeds and their effects on water quality and growth of rainbow trout in a commercial setting

USDA-ARS?s Scientific Manuscript database

To determine the effects of feed pellet processing (extrusion and expansion-steam pelleting) and on feed physico-chemical characteristics, fecal stability, water quality, and growth performance in rainbow trout, three types of trout feed pellets (compressed sinking, extruded sinking, and extruded fl...

Preparation and characterization compatible pellets for immobilization of colloidal sulphur nanoparticles

NASA Astrophysics Data System (ADS)

Adlim, M.; Zarlaida, F.; Khaldun, I.; Dewi, R.; Jamilah, M.

2018-03-01

Mercury pollution in atmosphere is dominated by mercury vapour release from coal burning and gold-amalgam separation in gold mining. The initial steps in formulating a compatible mercury absorbent for mercury stabilization was fabrication of pellet supported colloidal sulphur. Sulphur is used to stabilize mercury vapour by formation of metacinnabar that has much lower toxicity. The sulphur reactivity toward mercury vapour can be enhanced by using colloidal sulphur nanoparticles immobilized on compatible pellets. Clay pellets would have heat resistance but in fact, they were less stable in aqueous solution although their stability increased with inclusion of rice husk ash and sawdust or pineapple leaf fibre in the composite. Pellets made of rice husk ash and polyvinyl acetate were stable in water at least for 24 hours. Sulphur from thiosulfate precursor that immobilized onto surface of pellet using chitosan as the stabilizer and the binding agent gave lower sulphur content compared to sulphur from other precursors (sulphur powder and sulphur-CS2). Sulphur from thiosulfate precursor was in form of colloid, has nanosize, and disperse particles on the surface of rice husk ash pellets. Sulphur immobilization methods affect on sulphur particles exposure on the pellet surface.

Size, shape and flow characterization of ground wood chip and ground wood pellet particles

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

Rezaei, Hamid; Lim, C. Jim; Lau, Anthony

Size, shape and density of biomass particles influence their transportation, fluidization, rates of drying and thermal decomposition. Pelleting wood particles increases the particle density and reduces the variability of physical properties among biomass particles. In this study, pine chips prepared for pulping and commercially produced pine pellets were ground in a hammer mill using grinder screens of 3.2, 6.3, 12.7 and 25.4mmperforations. Pellets consumed about 7 times lower specific grinding energy than chips to produce the same size of particles. Grinding pellets produced the smaller particles with narrower size distribution than grinding chips. Derived shape factors in digital image analysismore » showed that chip particles were rectangular and had the aspect ratios about one third of pellet particles. Pellet particles were more circular shape. The mechanical sieving underestimated the actual particle size and did not represent the size of particles correctly. Instead, digital imaging is preferred. Angle of repose and compressibility tests represented the flow properties of ground particles. Pellet particles made a less compacted bulk, had lower cohesion and did flow easier in a pile of particles. In conclusion, particle shape affected the flow properties more than particle size« less

Comparative net energy ratio analysis of pellet produced from steam pretreated biomass from agricultural residues and energy crops

DOE PAGES

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

2016-04-05

Here, a process model was developed to determine the net energy ratio (NER) for production of pellets from steam pretreated agricultural residue (AR) and energy crop (i.e. switchgrass in this case). The NER is a ratio of the net energy output to the total net energy input from non-renewable energy sources into a system. Scenarios were developed to measure the effects of temperature and level of steam pretreatment on the NER of steam pretreated AR- and switch grass-based pellets. The NER for the base case at 6 kg h -1 is 1.76 and 1.37 for steam-pretreated AR- and switchgrass-based pellets,more » respectively. The reason behind the difference is that more energy is required to dry switchgrass pellets than AR pellets. The sensitivity analysis for the model shows that the optimum temperature for steam pretreatment is 160 C with 50% pretreatment (half the feedstock is pretreated, while the rest is undergoes regular pelletization). The uncertainty results for NER for steam pretreated AR and switch grass pellets are 1.62 ± 0.10 and 1.42 ± 0.11, respectively.« less

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.

Lead pellet retention time and associated toxicity in northern bobwhite quail (Colinus virginianus).

PubMed

Kerr, Richard; Holladay, Steven; Jarrett, Timothy; Selcer, Barbara; Meldrum, Blair; Williams, Susan; Tannenbaum, Lawrence; Holladay, Jeremy; Williams, Jamie; Gogal, Robert

2010-12-01

Birds are exposed to Pb by oral ingestion of spent Pb shot as grit. A paucity of data exists for retention and clearance of these particles in the bird gastrointestinal tract. In the current study, northern bobwhite quail (Colinus virginianus) were orally gavaged with 1, 5, or 10 Pb shot pellets, of 2-mm diameter, and radiographically followed over time. Blood Pb levels and other measures of toxicity were collected, to correlate with pellet retention. Quail dosed with either 5 or 10 pellets exhibited morbidity between weeks 1 and 2 and were removed from further study. Most of the Pb pellets were absorbed or excreted within 14 d of gavage, independent of dose. Pellet size in the ventriculus decreased over time in radiographs, suggesting dissolution caused by the acidic pH. Birds dosed with one pellet showed mean blood Pb levels that exceeded 1,300 µg/dl at week 1, further supporting dissolution in the gastrointestinal tract. Limited signs of toxicity were seen in the one-pellet birds; however, plasma δ-aminolevulinic acid dehydratase (d-ALAD) activity was persistently depressed, suggesting possible impaired hematological function. © 2010 SETAC.

Size, shape and flow characterization of ground wood chip and ground wood pellet particles

DOE PAGES

Rezaei, Hamid; Lim, C. Jim; Lau, Anthony; ...

2016-07-11

Size, shape and density of biomass particles influence their transportation, fluidization, rates of drying and thermal decomposition. Pelleting wood particles increases the particle density and reduces the variability of physical properties among biomass particles. In this study, pine chips prepared for pulping and commercially produced pine pellets were ground in a hammer mill using grinder screens of 3.2, 6.3, 12.7 and 25.4mmperforations. Pellets consumed about 7 times lower specific grinding energy than chips to produce the same size of particles. Grinding pellets produced the smaller particles with narrower size distribution than grinding chips. Derived shape factors in digital image analysismore » showed that chip particles were rectangular and had the aspect ratios about one third of pellet particles. Pellet particles were more circular shape. The mechanical sieving underestimated the actual particle size and did not represent the size of particles correctly. Instead, digital imaging is preferred. Angle of repose and compressibility tests represented the flow properties of ground particles. Pellet particles made a less compacted bulk, had lower cohesion and did flow easier in a pile of particles. In conclusion, particle shape affected the flow properties more than particle size« less

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.

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.

Hybrid nuclear reactor grey rod to obtain required reactivity worth

DOEpatents

Miller, John V.; Carlson, William R.; Yarbrough, Michael B.

1991-01-01

Hybrid nuclear reactor grey rods are described, wherein geometric combinations of relatively weak neutron absorber materials such as stainless steel, zirconium or INCONEL, and relatively strong neutron absorber materials, such as hafnium, silver-indium cadmium and boron carbide, are used to obtain the reactivity worths required to reach zero boron change load follow. One embodiment includes a grey rod which has combinations of weak and strong neutron absorber pellets in a stainless steel cladding. The respective pellets can be of differing heights. A second embodiment includes a grey rod with a relatively thick stainless steel cladding receiving relatively strong neutron absorber pellets only. A third embodiment includes annular relatively weak netron absorber pellets with a smaller diameter pellet of relatively strong absorber material contained within the aperture of each relatively weak absorber pellet. The fourth embodiment includes pellets made of a homogeneous alloy of hafnium and a relatively weak absorber material, with the percentage of hafnium chosen to obtain the desired reactivity worth.

Numerical characterization of micro-cell UO2sbnd Mo pellet for enhanced thermal performance

NASA Astrophysics Data System (ADS)

Lee, Heung Soo; Kim, Dong-Joo; Kim, Sun Woo; Yang, Jae Ho; Koo, Yang-Hyun; Kim, Dong Rip

2016-08-01

Metallic micro-cell UO2 pellet with high thermal conductivity has received attention as a promising accident-tolerant fuel. Although experimental demonstrations have been successful, studies on the potency of current metallic micro-cell UO2 fuels for further enhancement of thermal performance are lacking. Here, we numerically investigated the thermal conductivities of micro-cell UO2sbnd Mo pellets in terms of the amount of Mo content, the unit cell size, and the aspect ratio of the micro-cells. The results showed good agreement with experimental measurements, and more importantly, indicated the importance of optimizing the unit cell geometries of the micro-cell pellets for greater increases in thermal conductivity. Consequently, the micro-cell UO2sbnd Mo pellets (5 vol% Mo) with modified geometries increased the thermal conductivity of the current UO2 pellets by about 2.5 times, and lowered the temperature gradient within the pellets by 62.9% under a linear heat generation rate of 200 W/cm.

Colour spectrum and resin-type determine the concentration and composition of Polycyclic Aromatic Hydrocarbons (PAHs) in plastic pellets.

PubMed

Fisner, Mara; Majer, Alessandra; Taniguchi, Satie; Bícego, Márcia; Turra, Alexander; Gorman, Daniel

2017-09-15

This study assessed the concentration and composition of Polycyclic Aromatic Hydrocarbons (PAHs) in plastic pellets, collected from sandy beaches and considered different resin and colour tones. Results showed that polyethylene pellets, while displaying a greater range of total PAH concentrations did not differ significantly from polypropylene pellets. More importantly, both resin types demonstrated predictable increases in total PAH across a spectrum of darkening colour tones. Multivariate comparisons of 36 PAH groups, further showed considerable variability across resin type and colour, with lighter coloured pellets comprising lower molecular weight, while darker pellets contained higher weight PAHs. Overall, we show predictable variation in PAH concentrations and compositions of plastic pellets of different ages and resin types that will directly influence the potential for toxicological effects. Our findings suggest that monitoring programs should take these attributes into account when assessing the environmental risks of microplastic contamination of marine and coastal habitats. Copyright © 2017 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

Carbon Monoxide Off-Gassing From Bags of Wood Pellets.

PubMed

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

2018-02-13

Wood pellets are increasingly used for space heating in the United States and globally. Prior work has shown that stored bulk wood pellets produce sufficient carbon monoxide (CO) to represent a health concern and exceed regulatory standards for occupational exposures. However, most of the pellets used for residential heating are sold in 40-pound (18.1 kg) plastic bags. This study measured CO emission factors from fresh, bagged-wood pellets as a function of temperature and relative humidity. CO concentrations increased with increasing temperature and moisture in the container. CO measurements in a pellet mill warehouse with stored pallets of bagged pellets had 8-h average CO concentrations up to 100 ppm exceeding occupational standards for worker exposure. Thus, manufacturers, distributors, and home owners should be aware of the potential for CO in storage areas and design facilities with appropriate ventilation and CO sensors. © The Author(s) 2017. Published by Oxford University Press on behalf of the British Occupational Hygiene Society.

Effect of Formalin Toxoiding on Pseudomonas Aeruginosa Toxin A: Biological Chemical and Immunochemical Studies

DTIC Science & Technology

1981-01-01

incubated for an additional 10 min at 22°C. Immune rene test tubes. Samples were withdrawn aseptically complexes were collected by centrifugation at 3.000... tested imme- of assay buffer, and the final pellets were counted with diately in an assay, and the other was frozen at -70°C. a Beckman Biogamma counter... tested before and after activation immunoadsorbent for immune complexes containing with urea and dithiothreitol (13). Enzyme neutraliza

Color measurement of plastics - From compounding via pelletizing, up to injection molding and extrusion

NASA Astrophysics Data System (ADS)

Botos, J.; Murail, N.; Heidemeyer, P.; Kretschmer, K.; Ulmer, B.; Zentgraf, T.; Bastian, M.; Hochrein, T.

2014-05-01

The typical offline color measurement on injection molded or pressed specimens is a very expensive and time-consuming process. In order to optimize the productivity and quality, it is desirable to measure the color already during the production. Therefore several systems have been developed to monitor the color e.g. on melts, strands, pellets, the extrudate or injection molded part already during the process. Different kinds of inline, online and atline methods with their respective advantages and disadvantages will be compared. The criteria are e.g. the testing time, which ranges from real-time to some minutes, the required calibration procedure, the spectral resolution and the final measuring precision. The latter ranges between 0.05 to 0.5 in the CIE L*a*b* system depending on the particular measurement system. Due to the high temperatures in typical plastics processes thermochromism of polymers and dyes has to be taken into account. This effect can influence the color value in the magnitude of some 10% and is barely understood so far. Different suitable methods to compensate thermochromic effects during compounding or injection molding by using calibration curves or artificial neural networks are presented. Furthermore it is even possible to control the color during extrusion and compounding almost in real-time. The goal is a specific developed software for adjusting the color recipe automatically with the final objective of a closed-loop control.

Preparation of gastro-resistant pellets containing chitosan microspheres for improvement of oral didanosine bioavailability

PubMed Central

Severino, Patrícia; de Oliveira, George G.G.; Ferraz, Humberto G.; Souto, Eliana B.; Santana, Maria H.A.

2012-01-01

The purpose of this work was to introduce a new concept of coated pellets containing chitosan microspheres loaded with didadosine for oral administration, aiming at reducing the frequency of administration and improving the bioavailability by a suitable release profile. Chitosan microspheres were produced under fluidized bed, followed by extrusion and spheronization to obtain pellets with a mean diameter of about 1 mm. The pellets were then coated with Kollidon® VA64 and Kollicoat® MAE100P in water dispersion to depict a sustained release profile. Conventional hard gelatine capsules were loaded with these pellets and tested in vitro for their release profile of didadosine. Dissolution testing confirmed that chitosan microsphere pellets provides appropriate sustained release up to 2 h behavior for didanosine. PMID:29403741

A comparative analysis of double-crested cormorant diets from stomachs and pellets from two Lake Ontario colonies

USGS Publications Warehouse

Johnson, James H.; Ross, Robert M.; McCullough, Russell D.; Mathers, Alastair

2010-01-01

Double-crested cormorant (Phalacrocorax auritus) diets were compared with evidence from the stomachs of shot birds and from regurgitated pellets at High Bluff Island and Little Galloo Island, Lake Ontario. The highest similarity in diets determined by stomach and pellet analyses occurred when both samples were collected on the same day. Diet overlap dropped substantially between the two methods when collection periods were seven to ten days apart, which suggested differences in prey availability between the two periods. Since the average number of fish recovered in pellets was significantly higher than that in stomachs, use of pellets to determine fish consumption of double-crested cormorants may be more valid than stomach analysis because pellet content represent an integrated sampling of food consumed over approximately 24 hours.

Shock and vibration tests of uranium mononitride fuel pellets for a space power nuclear reactor

NASA Technical Reports Server (NTRS)

Adams, D. W.

1972-01-01

Shock and vibration tests were conducted on cylindrically shaped, depleted, uranium mononitride (UN) fuel pellets. The structural capabilities of the pellets were determined under exposure to shock and vibration loading which a nuclear reactor may encounter during launching into space. Various combinations of diametral and axial clearances between the pellets and their enclosing structures were tested. The results of these tests indicate that for present fabrication of UN pellets, a diametral clearance of 0.254 millimeter and an axial clearance of 0.025 millimeter are tolerable when subjected to launch-induced loads.

Manufacturing and Application of Metalized Ore-Coal Pellets in Synthetic Pig Iron Smelting

NASA Astrophysics Data System (ADS)

Nokhrina, O. I.; Rozhikhina, I. D.; Khodosov, I. E.

2016-08-01

The article presents research data on manufacturing and application of metalized ore-coal pellets in synthetic pig iron smelting. A technology of pellets metallization by means of solid-phase reduction of iron from oxides using hematite-magnetite iron ore and low-caking coal as raw materials is described. Industrial testing of replacing 10, 15, and 20% of waste metal by the metalized ore-coal pellets in the coreless induction furnace IST-1 is described. Optimal temperature and time conditions of feeding the metalized pellets into the furnace in smelting pig iron of SCh-40-60 grade are determined.

21 CFR 184.1205 - Calcium hydroxide.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Calcium hydroxide. 184.1205 Section 184.1205 Food... Specific Substances Affirmed as GRAS § 184.1205 Calcium hydroxide. (a) Calcium hydroxide (Ca(OH)2, CAS Reg. No. 1305-62-0) is also known as slaked lime or calcium hydrate. It is produced by the hydration of...

21 CFR 184.1763 - Sodium hydroxide.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Sodium hydroxide. 184.1763 Section 184.1763 Food... GRAS § 184.1763 Sodium hydroxide. (a) Sodium hydroxide (NaOH, CAS Reg. No. 1310-73-2) is also known as sodium hydrate, soda lye, caustic soda, white caustic, and lye. The empirical formula is NaOH. Sodium...

21 CFR 184.1205 - Calcium hydroxide.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Calcium hydroxide. 184.1205 Section 184.1205 Food... GRAS § 184.1205 Calcium hydroxide. (a) Calcium hydroxide (Ca(OH)2, CAS Reg. No. 1305-62-0) is also known as slaked lime or calcium hydrate. It is produced by the hydration of lime. (b) The ingredient...

The alpha-form of the hydroxides of bivalent metals

NASA Technical Reports Server (NTRS)

Feitknecht, W.

1984-01-01

X-ray analyses were made of the hydroxides of the bivalent metals. The freshly pptd. hydroxide is usually in the alpha-form, which on standing is converted to another form or other forms. The alpha and c grating dimensions of the alpha-form and the C6-type of Co, Zn, C, Co-Zn and Ni-Zn hydroxides are tabulated. Ni hydroxide does not exhibit an alpha-form. The alpha-Co(OH)2, the blue form, is stabilized by sugar or by the higher alcohols: these compounds do not stabilize alpha-Zn(OH)2.

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

Using DNA to test the utility of pellet-group counts as an index of deer counts

Treesearch

T. J. Brinkman; D. K. Person; W. Smith; F. Stuart Chapin; K. McCoy; M. Leonawicz; K. Hundertmark

2013-01-01

Despite widespread use of fecal pellet-group counts as an index of ungulate density, techniques used to convert pellet-group numbers to ungulate numbers rarely are based on counts of known individuals, seldom evaluated across spatial and temporal scales, and precision is infrequently quantified. Using DNA from fecal pellets to identify individual deer, we evaluated the...

Pelletized ponderosa pine bark for adsorption of toxic heavy metals from water

Treesearch

Miyoung Oh; Mandla A. Tshabalala

2007-01-01

Bark flour from ponderosa pine (Pinus ponderosa) was consolidated into pellets using citric acid as cross-linking agent. The pellets were evaluated for removal of toxic heavy metals from synthetic aqueous solutions. When soaked in water, pellets did not leach tannins, and they showed high adsorption capacity for Cu(ll), Zn(ll), Cd(ll). and Ni(ll) under both equilibrium...

Ammonium hydroxide poisoning

MedlinePlus

Ammonium hydroxide is a colorless liquid chemical solution. It is in a class of substances called caustics. Ammonium hydroxide forms when ammonia dissolves in water. This article discusses poisoning from ...

Motivation for hay: effects of a pelleted diet on behavior and physiology of horses.

PubMed

Elia, Jamie B; Erb, Hollis N; Houpt, Katherine Albro

2010-12-02

The natural diet of free-ranging horses is grass, which is typically high in fiber and calorically dilute, however diets for high performance domestic horses are often low in fiber and calorically dense. The aim of the study was to determine the motivation of horses for hay when fed a low roughage diet. Their motivation could be used to determine if low roughage diets compromise the welfare of horses. Eight mares were fed two different diets in counterbalanced order: ad libitum orchard grass hay; a complete pelleted feed (pellets). Each trial lasted three weeks, with a one-week transition period between diets. To determine the motivation of horses for fiber they were taught to press a panel to obtain a food reward. The fixed ratio (FR) was increased using a progressive ratio ((1,2,4,7,11…) technique. When fed pellets, the horses worked for a median FR of 1 (Range=1-497) to attain pellets, and when fed hay, they worked for a median FR of 25.5 (4-497) to attain pellets. When fed hay, the horses worked for a median FR of 0 (0-0) to attain hay, and when fed pellets, they worked for a FR of 13 (2-79) to attain hay. These results indicate a greater motivation for hay, a high fiber diet, when fed a low fiber diet. The horses spent 10 (5-19.4)% of their time during a 24-hour period eating pellets compared to 61.5 (29-76) % of their time eating hay. Horses spent 58% of their time standing when fed the pellets and only 37% of their time standing when fed hay. Searching behavior (i.e. sifting through wood shaving bedding for food particles) took up 11.5 (1.4-32) % of the horse's day when fed pellets, but only 1.2 (0-3.5) % of the daily time budget when fed hay. Horses chew more times when eating a hay diet (43,476chews/day) than when eating a pellet diet (10,036chews/day). Fecal pH was lower in horses fed the pelleted diet. Copyright © 2010 Elsevier Inc. All rights reserved.

Nano-Hydroxyapatite/Fluoridated and Unfluoridated Bioactive Glass Composites: Structural Analysis and Bioactivity Evaluation

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

Batra, Uma; Kapoor, Seema; Sharma, J. D.

2011-12-12

Biphasic bioceramic composites containing nano-hydroxyapatite (HAP) and nanosized bioactive glasses have been prepared in the form of pellets and have been examined for the effects of bioglass concentrations and sintering temperature on the structural transformations and bioactivity behavior. Pure stoichiometric nano-HAP was synthesized using sol-gel technique. Two bioglasses synthesized in this work--fluoridated bioglass (Cao-P{sub 2}O{sub 5}-Na{sub 2}O{sub 3}-CaF{sub 2}) and unfluoridated bioglass (Cao-P{sub 2}O{sub 5}-Na{sub 2}O{sub 3}) designated as FBG and UFBG respectively, were added to nano-HAP with concentrations of 5, 10, 12 and 15%. The average particle sizes of synthesized HAP and bioglasses were 23 nm and 35 nm,more » respectively. The pellets were sintered at four different temperatures i.e. 1000 deg. C, 1150 deg. C, 1250 deg. C and 1350 deg. C. The investigations involved study of structural and bioactivity behavior of green and sintered pellets and their deviations from original materials i.e. HAP, FBG and UFBG, using X-ray diffraction (XRD) and scanning electron microscopy (SEM). The phase composition of the sintered pellets was found to be non-stoichiometric HAP with {alpha}-TCP (tricalcium phosphate) and {beta}-TCP. It was revealed from SEM images that bonding mechanism was mainly solid state sintering for all pellets sintered at 1000 deg. C and 1150 deg. C and also for pellets with lower concentrations of bioglass i.e. 5% and 10% sintered at 1250 deg. C. Partly liquid phase sintering was observed for pellets with higher bioglass concentrations of 12% and 15% sintered at 1250 deg. C and same behaviour was noted for pellets at all concentrations of bioglasses at 1350 deg. C. The sintered density, hardness and compression strength of pellets have been influenced both by the concentration of the bioglasses and sintering temperature. It was observed that the biological HAP layer formation was faster on the green pellets surface than on pure HAP and sintered pellets, showing higher bioactivity in the green pellets.« less

Persistent organic pollutants monitoring in marine coastal environment using beached plastic resin pellets and effective risk communication via International Pellet Watch (IPW) as a tool.

NASA Astrophysics Data System (ADS)

Yeo, B. G. M.; Takada, H.; Hosoda, J.

2014-12-01

International Pellet Watch (IPW) is an ongoing global monitoring of persistent organic pollutants (POPs) using preproduction plastic resin pellets. These pellets are easily collected and transported allowing the general public worldwide to get involved. Thus, risk communication toward the pellet collectors is a significant part of IPW to ensure continuous effort and interest. The pellet samples were analyzed for polychlorinated biphenyl (PCBs), dichlorodiphenyltrichloroethane and degradation products (DDTs), and hexachlorocyclohexanes (HCHs). Additional pollutants such as polycyclic aromatic hydrocarbons (PAHs) and Hopanes were also analyzed for some samples. Analytical results showed distinct patterns with high concentrations (< 200ng/g-pellet) of PCBs in urban and industrialized areas mainly in the United States, Japan, and some European countries. These countries are prone to legacy pollution where PCBs were used extensively before the ban in the late 1980's. Pesticide DDTs instead were found to be higher in developing countries such as Brazil and Vietnam (> 500ng/g-pellet). These countries may still be using DDTs as a vector control mostly to combat malaria. High concentrations of DDTs were also found in Greece, China and Australia (> 100ng/g-pellet) suggesting the possibility of illegal usage as pesticide or anti fouling paint. HCHs concentrations were mostly low due to its low retention in the environment. However, high HCHs concentrations were mostly found in the southern hemisphere. Very high concentration of PAHs in pellet samples can be utilized for early identification of recent oil pollution. High PAHs concentration in Tauranga, New Zealand was found to be caused by local oil spill. Hopanes in pellets can be used for source identification of oil pollution. Global mapping and comparison among IPW data can be used to provide better explanations to IPW volunteers by sorting concentrations into pollution categories. Communication reports are tailor written based on the volunteers familiarity to IPW's issues, educational background, occupation and their potential to further spread awareness. Based on feedbacks, the volunteers were grateful to receive reports of their samples felt personally involved in IPW. This was shown to empowered and encouraged efforts from the volunteers.

Effects of temperature and diet on length-weight relationship and condition factor of the juvenile Malabar blood snapper (Lutjanus malabaricus Bloch & Schneider, 1801).

PubMed

Mazumder, Sabuj Kanti; Das, Simon Kumar; Bakar, Yosni; Ghaffar, Mazlan Abd

2016-08-01

In this study we aimed to analyze the effects of water temperature and diet on the length-weight relationship and condition of juvenile Malabar blood snapper Lutjanus malabaricus over a 30-d experimental period. The experiment was conducted in the laboratory using a flow-through-sea-water system. The fish were subjected to four different temperatures (22, 26, 30, and 34 °C) and two diets (commercial pellet and natural shrimp). Fish were fed twice daily. L. malabaricus exhibited negative allometric growth (b<3) at the beginning of the experiment (Day 0) at all temperatures and both diets except for 22 °C fed with shrimp, which showed isometric growth (b=3). Conversely, at the end of the experiment (Day 30) fish showed isometric growth (b=3) at 30 °C fed with the pellet diet, indicating that the shape of the fish did not change with increasing weight and length, and a positive allometric growth (b>3) at 30 °C fed with shrimp diet, which indicated that fish weight increases faster than their length. The rest of the temperatures represented negative allometric growth (b<3) on both diet, meaning that fish became lighter with increasing size. The condition factors in the initial and final measurements were greater than 1, indicating the state of health of the fish, except for those fed on a pellet diet at 34 °C. However, the best condition was obtained at 30 °C on both diets. Nevertheless, diets did not have a significant effect on growth and condition of juvenile L. malabaricus. The data obtained from this study suggested culturing L. malabaricus at 30 °C and feeding on the pellet or shrimp diet, which will optimize the overall production and condition of this commercially important fish species.

Developing a Treatment Planning Software Based on TG-43U1 Formalism for Cs-137 LDR Brachytherapy.

PubMed

Sina, Sedigheh; Faghihi, Reza; Soleimani Meigooni, Ali; Siavashpour, Zahra; Mosleh-Shirazi, Mohammad Amin

2013-08-01

The old Treatment Planning Systems (TPSs) used for intracavitary brachytherapy with Cs-137 Selectron source utilize traditional dose calculation methods, considering each source as a point source. Using such methods introduces significant errors in dose estimation. As of 1995, TG-43 is used as the main dose calculation formalism in treatment TPSs. The purpose of this study is to design and establish a treatment planning software for Cs-137 Solectron brachytherapy source, based on TG-43U1 formalism by applying the effects of the applicator and dummy spacers. Two softwares used for treatment planning of Cs-137 sources in Iran (STPS and PLATO), are based on old formalisms. The purpose of this work is to establish and develop a TPS for Selectron source based on TG-43 formalism. In this planning system, the dosimetry parameters of each pellet in different places inside applicators were obtained by MCNP4c code. Then the dose distribution around every combination of active and inactive pellets was obtained by summing the doses. The accuracy of this algorithm was checked by comparing its results for special combination of active and inactive pellets with MC simulations. Finally, the uncertainty of old dose calculation formalism was investigated by comparing the results of STPS and PLATO softwares with those obtained by the new algorithm. For a typical arrangement of 10 active pellets in the applicator, the percentage difference between doses obtained by the new algorithm at 1cm distance from the tip of the applicator and those obtained by old formalisms is about 30%, while the difference between the results of MCNP and the new algorithm is less than 5%. According to the results, the old dosimetry formalisms, overestimate the dose especially towards the applicator's tip. While the TG-43U1 based software perform the calculations more accurately.

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

Reduction of ELM Intensity on DIII-D by On-demand Triggering With High Frequency Pellet Injection and Implications for ITER

NASA Astrophysics Data System (ADS)

Baylor, L. R.

2012-10-01

Deuterium pellet injection was used on the DIII-D tokamak to successfully demonstrate for the first time the on-demand triggering of ELMs at a 10x higher rate, and with much smaller intensity, than natural edge localized modes (ELMs). The triggering of small ELMs by high frequency pellet injection has been proposed as a method to prevent large ELMs that can erode the ITER plasma facing components [1]. The demonstration was made by injecting slow (<200 m/s) 1.3 mm diameter deuterium pellets at 60 Hz from the low field side in an ITER similar plasma with 5 Hz natural ELM frequency. The input power was only slightly above the H-mode threshold. Similar non-pellet discharges had ELM energy losses up to 55 kJ (˜8% of total stored energy), while the case with pellets demonstrated ELMs with an average energy loss less than 3 kJ (<1% of the total). Total divertor ELM heat flux was reduced by more than a factor of 10. Central accumulation of Ni was significantly reduced in the pellet triggered ELM case. No significant increase in density or decrease in energy confinement was observed. Stability analysis of these discharges shows that the pedestal parameters are approaching the peeling unstable region just before a natural ELM crash. In the rapid pellet small ELM case, the pedestal conditions are well within the stable region with a narrower pedestal width observed. This narrower width is consistent with a picture in which the pellets are triggering the ELMs before the width expands to the critical ELM width. Nonlinear MHD simulations of the pellet ELM triggering show destabilization of ballooning modes by a local pressure perturbation. The implications of these results for pellet ELM pacing in ITER will be discussed. 6pt [1] P.T. Lang et al., Nucl. Fusion 44, 665 (2004).

Wood pellets, what else? Greenhouse gas parity times of European electricity from wood pellets produced in the south-eastern United States using different softwood feedstocks

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

Hanssen, Steef V.; Duden, Anna S.; Junginger, Martin

Several EU countries import wood pellets from the south-eastern United States. The imported wood pellets are (co-)fired in power plants with the aim of reducing overall greenhouse gas (GHG) emissions from electricity and meeting EU renewable energy targets. To assess whether GHG emissions are reduced and on what timescale, we construct the GHG balance of wood-pellet electricity. This GHG balance consists of supply chain and combustion GHG emissions, carbon sequestration during biomass growth, and avoided GHG emissions through replacing fossil electricity. We investigate wood pellets from four softwood feedstock types: small roundwood, commercial thinnings, harvest residues, and mill residues. Permore » feedstock, the GHG balance of wood-pellet electricity is compared against those of alternative scenarios. Alternative scenarios are combinations of alternative fates of the feedstock material, such as in-forest decomposition, or the production of paper or wood panels like oriented strand board (OSB). Alternative scenario composition depends on feedstock type and local demand for this feedstock. Results indicate that the GHG balance of wood-pellet electricity equals that of alternative scenarios within 0 to 21 years (the GHG parity time), after which wood-pellet electricity has sustained climate benefits. Parity times increase by a maximum of twelve years when varying key variables (emissions associated with paper and panels, soil carbon increase via feedstock decomposition, wood-pellet electricity supply chain emissions) within maximum plausible ranges. Using commercial thinnings, harvest residues or mill residues as feedstock leads to the shortest GHG parity times (0-6 years) and fastest GHG benefits from wood-pellet electricity. Here, we find shorter GHG parity times than previous studies, for we use a novel approach that differentiates feedstocks and considers alternative scenarios based on (combinations of) alternative feedstock fates, rather than on alternative land-uses. This novel approach is relevant for bioenergy derived from low-value feedstocks.« less

Evaluation of ground grain versus pre- and post-pellet whole grain additions to poultry diets via a response surface design.

PubMed

Moss, Amy F; Chrystal, Peter V; Truong, Ha H; Selle, Peter H; Liu, Sonia Yun

2017-12-01

1. The objective of this study was to compare the effects of pre- and post-pellet whole grain wheat additions to diets on growth performance, gizzard and pancreas development, nutrient utilisation and starch and protein (N) digestibility coefficients in broiler chickens via an equilateral triangle response surface design. 2. The three apical treatments of the equilateral triangle comprised (1A) a standard diet containing 600 g/kg ground wheat, (2B) the same diet containing 600 g/kg pre-pellet whole wheat and (3C) the same diet containing 300 g/kg ground wheat and 300 g/kg post-pellet whole wheat. Seven blends of the three apical diets were located within the triangle to complete the design and a total of 360 male Ross 308 chicks were offered the ten experimental diets from 7 to 28 d post-hatch. Model prediction and response surface plots were generated with R 3.0.3 software. 3. The most efficient FCR of 1.466 was observed in birds offered an almost equal mixture of the pre- and post-pellet whole grain apical dietary treatments, which corresponded to 172 g/kg ground grain, 256 g/kg pre-pellet whole grain, 172 g/kg post-pellet whole grain in a diet containing 600 g/kg wheat. 4. The most efficient energy utilisation (ME:GE ratio of 0.766) was observed in birds offered a blend of the ground grain and pre-pellet whole grain apical dietary treatments which corresponded to a mixture of 384 g/kg pre-pellet whole grain and 216 g/kg ground grain. 5. Pre-pellet whole grain feeding generated the most pronounced responses in increased relative gizzard contents, reduced gizzard pH and increased relative pancreas weights. Consideration is given to the likely differences between pre- and post-pellet whole grain feeding.

Power plant wastes capitalization as geopolymeric building materials

NASA Astrophysics Data System (ADS)

Ciobanu, Gabriela; Litu, Loredana; Harja, Maria

2017-11-01

In this innovative study, we are present an investigation over the properties of geopolymeric materials prepared using ash supplied by power plant Iasi, Romania and sodium hydroxide solutions/pellets. Having as objective a minimum consumption of energy and materials was developed a class of advanced eco-materials. New synthesized materials can be used as a binder for cement replacement or for the removal/immobilization of pollutants from waste waters or soils. It offers an advanced and low cost-effective solution too many problems, where waste must be capitalized. The geopolymer formation, by hydrothermal method, is influenced by: temperature (20-600°C), alkali concentration (2M-6M), solid /liquid ratio (1-2), ash composition, time of heating (2-48 h), etc. The behaviour of the FTIR peak of 6M sample indicated upper quantity of geopolymer formation at the first stage of the reaction. XRD spectra indicated phases like sodalite, faujasite, Na-Y, which are known phases of geopolymer/zeolite. Advanced destroyed of ash particles due to geopolymerisation reaction were observed when the temperature was higher. At the constant temperature the percentage of geopolymer increases with increasing of curing time, from 4-48 h. Geopolymer materials are environmentally friendly, for its obtaining energy consumption, and CO2 emission is reduced compared to cement binder.

Decomposition of oak leaf litter and millipede faecal pellets in soil under temperate mixed oak forest

NASA Astrophysics Data System (ADS)

Tajovský, Karel; Šimek, Miloslav; Háněl, Ladislav; Šantrůčková, Hana; Frouz, Jan

2015-04-01

The millipedes Glomeris hexasticha (Diplopoda, Glomerida) were maintained under laboratory conditions and fed on oak leaf litter collected from a mixed oak forest (Abieto-Quercetum) in South Bohemia, Czech Republic. Every fourth day litter was changed and produced faecal pellets were separated and afterwards analysed. Content of organic carbon and C:N ratio lowered in faecal pellets as compared with consumed litter. Changes in content of chemical elements (P, K, Ca, Mg, Na) were recognised as those characteristic for the first stage of degradation of plant material. Samples of faecal pellets and oak leaf litter were then exposed in mesh bags between the F and H layers of forest soil for up to one year, subsequently harvested and analysed. A higher rate of decomposition of exposed litter than that of faecal pellets was found during the first two weeks. After 1-year exposure, the weight of litter was reduced to 51%, while that of pellets to 58% only, although the observed activity of present biotic components (algae, protozoans, nematodes; CO2 production, nitrogenase activity) in faecal pellets was higher as compared with litter. Different micro-morphological changes were observed in exposed litter and in pellets although these materials originated from the same initial sources. Comparing to intact leaf litter, another structural and functional processes occurred in pellets due to the fragmentation of plant material by millipedes. Both laboratory and field experiments showed that the millipede faecal pellets are not only a focal point of biodegradation activity in upper soil layers, but also confirmed that millipede feces undergo a slower decomposition than original leaf litter.

The influence of Surelease and sodium alginate on the in-vitro release of tamsulosin hydrochloride in pellet dosage form.

PubMed

Kim, Min-Soo; Jun, Seoung Wook; Lee, Sibeum; Lee, Tae Wan; Park, Jeong-Sook; Hwang, Sung-Joo

2005-06-01

The objective of this study was to prepare controlled-release pellets containing 0.2 mg tamsulosin hydrochloride using a pelletizer-equipped piston extruder and double-arm counter-rotating rollers with Surelease and sodium alginate. The release of tamsulosin HCl from pellets coated with the commercial aqueous ethylcellulose dispersion (Surelease) was investigated at different coating loads. In addition, the effect of sodium alginate on drug release was investigated by varying the ratio of sodium alginate to microcrystalline cellulose (MCC). Dissolution studies were first performed in 500 mL simulated gastric fluid (pH 1.2) containing 0.003% (w/w) polysorbate 80 and then in simulated intestinal fluids (pH 7.2). The morphology of pellet surfaces and cross sections were examined by scanning electron microscopy (SEM). Apparently, the spherical pellets were prepared using a pelletizer-equipped piston extruder and double-arm counter-rotating rollers. The release profiles of tamsulosin HCl from Surelease-coated pellets were significantly affected by changing the content of Surelease, the pH of the dissolution medium and the ratio of sodium alginate to MCC. The drug release rates not only decreased with increase in the coating load, but also increased when the pH of the dissolution medium was increased from 1.2 to 7.2 regardless of the sodium alginate-to-MCC ratio. Moreover, the drug release rate at pH 7.2 was gradually increased by increasing the ratio of sodium alginate to MCC. SEM showed smooth surfaces of Surelease-coated pellets. These results suggest that Surelease and sodium alginate would be useful excipients in the preparation of controlled-release pellets with the desired release profiles.

Pharmacokinetics and correlation between in vitro release and in vivo absorption of bio-adhesive pellets of panax notoginseng saponins.

PubMed

Li, Ying; Zhang, Yun; Zhu, Chun-Yan

2017-02-01

The present study was designed to prepare and compare bio-adhesive pellets of panax notoginseng saponins (PNS) with hydroxy propyl methyl cellulose (HPMC), chitosan, and chitosan : carbomer, explore the influence of different bio-adhesive materials on pharmacokinetics behaviors of PNSbio-adhesive pellets, and evaluate the correlation between in vivo absorption and in vitro release (IVIVC). In order to predict the in vivo concentration-time profile by the in vitro release data of bio-adhesive pellets, the release experiment was performed using the rotating basket method in pH 6.8 phosphate buffer. The PNS concentrations in rat plasma were analyzed by HPLC-MS-MS method and the relative bioavailability and other pharmacokinetic parameters were estimated using Kinetica4.4 pharmacokinetic software. Numerical deconvolution method was used to evaluate IVIVC. Our results indicated that, compared with ordinary pellets, PNS bio-adhesive pellets showed increased oral bioavailability by 1.45 to 3.20 times, increased C max , and extended MRT. What's more, the release behavior of drug in HPMC pellets was shown to follow a Fickian diffusion mechanism, a synergetic function of diffusion and skeleton corrosion. The in vitro release and the in vivo biological activity had a good correlation, demonstrating that the PNS bio-adhesive pellets had a better sustained release. Numerical deconvolution technique showed the advantage in evaluation of IVIVC for self-designed bio-adhesive pellets with HPMC. In conclusion, the in vitro release data of bio-adhesive pellets with HPMC can predict its concentration-time profile in vivo. Copyright © 2017 China Pharmaceutical University. Published by Elsevier B.V. All rights reserved.

Numerical Investigation of the Effect of C/O Mole Ratio on the Performance of Rotary Hearth Furnace Using a Combined Model

NASA Astrophysics Data System (ADS)

Liu, Ying; Wen, Zhi; Lou, Guofeng; Li, Zhi; Yong, Haiquan; Feng, Xiaohong

2014-12-01

In a rotary hearth furnace (RHF) the direct reduction of composite pellets and processes of heat and mass transfer as well as combustion in the chamber of RHF influence each other. These mutual interactions should be considered when an accurate model of RHF is established. This paper provides a combined model that incorporates two sub-models to investigate the effects of C/O mole ratio in the feed pellets on the reduction kinetics and heat and mass transfer as well as combustion processes in the chamber of a pilot-scale RHF. One of the sub-models is established to describe the direct reduction process of composite pellets on the hearth of RHF. Heat and mass transfer within the pellet, chemical reactions, and radiative heat transfer from furnace walls and combustion gas to the surface of the pellet are considered in the model. The other sub-model is used to simulate gas flow and combustion process in the chamber of RHF by using commercial CFD software, FLUENT. The two sub-models were linked through boundary conditions and heat, mass sources. Cases for pellets with different C/O mole ratio were calculated by the combined model. The calculation results showed that the degree of metallization, the total amounts of carbon monoxide escaping from the pellet, and heat absorbed by chemical reactions within the pellet as well as CO and CO2 concentrations in the furnace increase with the increase of C/O mole ratio ranging from 0.6 to 1.0, when calculation conditions are the same except for C/O molar ratio. Carbon content in the pellet has little influence on temperature distribution in the furnace under the same calculation conditions except for C/O mole ratio in the feed pellets.

Arsenic behavior in river sediments under redox gradient: a review.

PubMed

Gorny, Josselin; Billon, Gabriel; Lesven, Ludovic; Dumoulin, David; Madé, Benoît; Noiriel, Catherine

2015-02-01

The fate of arsenic - a redox sensitive metalloid - in surface sediments is closely linked to early diagenetic processes. The review presents the main redox mechanisms and final products of As that have been evidenced over the last years. Oxidation of organic matter and concomitant reduction of oxidants by bacterial activity result in redox transformations of As species. The evolution of the sediment reactivity will also induce secondary abiotic reactions like complexation/de-complexation, sorption, precipitation/dissolution and biotic reactions that could, for instance, lead to the detoxification of some As species. Overall, abiotic redox reactions that govern the speciation of As mostly involve manganese (hydr)-oxides and reduced sulfur species produced by the sulfate-reducing bacteria. Bacterial activity is also responsible for the inter-conversion between As(V) and As(III), as well as for the production of methylated arsenic species. In surficial sediments, sorption processes also control the fate of inorganic As(V), through the formation of inner sphere complexes with iron (hydr)-oxides, that are biologically reduced in buried sediment. Arsenic species can also be bound to organic matter, either directly to functional groups or indirectly through metal complexes. Finally, even if the role of reduced sulfur species in the cycling of arsenic in sediments has been evidenced, some of the transformations remain hypothetical and deserve further investigation. Copyright © 2014 Elsevier B.V. All rights reserved.

Reduction of Iron-Oxide-Carbon Composites: Part III. Shrinkage of Composite Pellets during Reduction

NASA Astrophysics Data System (ADS)

Halder, S.; Fruehan, R. J.

2008-12-01

This article involves the evaluation of the volume change of iron-oxide-carbon composite pellets and its implications on reduction kinetics under conditions prevalent in a rotary hearth furnace (RHF) that were simulated in the laboratory. The pellets, in general, were found to shrink considerably during the reduction due to the loss of carbon and oxygen from the system, sintering of the iron-oxide, and formation of a molten slag phase at localized regions inside the pellets due to the presence of binder and coal/wood-charcoal ash at the reduction temperatures. One of the shortcomings of the RHF ironmaking process has been the inability to use multiple layers of composite pellets because of the impediment in heat transport to the lower layers of a multilayer bed. However, pellet shrinkage was found to have a strong effect on the reduction kinetics by virtue of enhancing the external heat transport to the lower layers. The volume change of the different kinds of composite pellets was studied as a function of reduction temperature and time. The estimation of the change in the amount of external heat transport with varying pellet sizes for a particular layer of a multilayer bed was obtained by conducting heat-transfer tests using inert low-carbon steel spheres. It was found that if the pellets of the top layer of the bed shrink by 30 pct, the external heat transfer to the second layer increases by nearly 6 times.

MST Pellet Injector Upgrades to Probe Beta and Density Limits and Impurity Particle Transport

NASA Astrophysics Data System (ADS)

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

2012-10-01

Upgrades to the pellet injector on MST will allow for significantly increased fueling capability enabling density limit studies for previously unavailable density regimes. Thus far, Greenwald fractions of 1.2 and 1.5 have been achieved in 500 kA and 200 kA improved confinement plasmas, respectively. The size of the pellet guide tubes, which constrain the lateral motion of the pellet in flight, was increased to accommodate pellets of up to 4.0 mm in diameter, capable of fueling to Greenwald fractions > 2.0 for MST's peak current of 600 kA. Exploring the effect of increased density on NBI deposition shows that for MST's NBI, core deposition of 25 keV neutrals is optimized for densities of 2 -- 3 x 10^19 m-3. This is key for beta limit studies in pellet fueled discharges with improved confinement where maximum NBI heating is desired. In addition, a modification to the injector has allowed operation using alternative pellet fuels with triple points significantly higher than that of deuterium (18.7 K). A small flow of helium into the pellet formation vacuum chamber introduces a controllable heat source capable of elevating the operating temperature of the injector. Injection of methane pellets with a triple point of 90.7 K results in a 12-fold increase in the core carbon impurity density. The flow rate is easily adjusted to optimize injector operating temperature for other fuel gases as well. Work supported by US DoE.

Preparation and evaluation of Vinpocetine self-emulsifying pH gradient release pellets.

PubMed

Liu, Mengqi; Zhang, Shiming; Cui, Shuxia; Chen, Fen; Jia, Lianqun; Wang, Shu; Gai, Xiumei; Li, Pingfei; Yang, Feifei; Pan, Weisan; Yang, Xinggang

2017-11-01

The main objective of this study was to develop a pH gradient release pellet with self-emulsifying drug delivery system (SEDDS), which could not only improve the oral bioavailability of Vinpocetine (VIN), a poor soluble drug, but reduce the fluctuation of plasma concentration. First, the liquid VIN SEDDS formulation was prepared. Then the self-emulsifying pH gradient release pellets were prepared by extrusion spheronization technique, and formulation consisted by the liquid SEDDS, absorbent (colloidal silicon dioxide), penetration enhancer (sodium chloride), microcrystalline cellulose, ethyl alcohol, and three coating materials (HPMC, Eudragit L30D55, Eudragit FS30D) were eventually selected. Three kinds of coated pellets were mixed in capsules with the mass ratio of 1:1:1. The release curves of capsules were investigated in vitro under the simulated gastrointestinal conditions. In addition, the oral bioavailability and pharmacokinetics of VIN self-emulsifying pH gradient release pellets, commercial tablets and liquid VIN SEDDS were evaluated in Beagle dogs. The oral bioavailability of self-emulsifying pH gradient release pellets was about 149.8% of commercial VIN tablets, and it was about 86% of liquid VIN SEDDS, but there were no significant difference between liquid SEDDS and self-emulsifying pH gradient release pellets. In conclusion, the self-emulsifying pH gradient release pellets could significantly enhance the absorption of VIN and effectively achieve a pH gradient release. And the self-emulsifying pH gradient release pellet was a promising method to improve bioavailability of insoluble drugs.

A New Four-Barrel Pellet Injection System for the TJ-II Stellarator

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

Combs, Stephen Kirk; Foust, Charles R; McGill, James M

2011-01-01

A new pellet injection system for the TJ-II stellarator has been developed/constructed as part of a collaboration between the Oak Ridge National Laboratory (ORNL) and the Centro de Investigaciones Energ ticas, Medioambientales y Tecnol gicas (CIEMAT). ORNL is providing most of the injector hardware and instrumentation, the pellet diagnostics, and the pellet transport tubes; CIEMAT is responsible for the injector stand/interface to the stellarator, cryogenic refrigerator, vacuum pumps/ballast volumes, gas manifolds, remote operations, plasma diagnostics, and data acquisition. The pellet injector design is an upgraded version of that used for the ORNL injector installed on the Madison Symmetric Torus (MST).more » It is a four-barrel system equipped with a cryogenic refrigerator for in situ hydrogen pellet formation and a combined mechanical punch/propellant valve system for pellet acceleration (speeds ~100 to 1000 m/s). On TJ-II, it will be used as an active diagnostic and for fueling. To accommodate the plasma experiments planned for TJ-II, pellet sizes significantly smaller than those typically used for the MST application are required. The system will initially be equipped with four different pellet sizes, with the gun barrel bores ranging between ~0.5 to 1.0 mm. The new system is almost complete and is described briefly here, highlighting the new features added since the original MST injector was constructed. Also, the future installation on TJ-II is reviewed.« less

Neuromechanical factors involved in the formation and propulsion of fecal pellets in the guinea-pig colon.

PubMed

Costa, M; Wiklendt, L; Simpson, P; Spencer, N J; Brookes, S J; Dinning, P G

2015-10-01

The neuromechanical processes involved in the formation and propulsion of fecal pellets remain incompletely understood. We analyzed motor patterns in isolated segments of the guinea-pig proximal and distal colon, using video imaging, during oral infusion of liquid, viscous material, or solid pellets. Colonic migrating motor complexes (CMMCs) in the proximal colon divided liquid or natural semisolid contents into elongated shallow boluses. At the colonic flexure these boluses were formed into shorter, pellet-shaped boluses. In the non-distended distal colon, spontaneous CMMCs produced small dilations. Both high- and low-viscosity infusions evoked a distinct motor pattern that produced pellet-shaped boluses. These were propelled at speeds proportional to their surface area. Solid pellets were propelled at a speed that increased with diameter, to a maximum that matched the diameter of natural pellets. Pellet speed was reduced by increasing resistive load. Tetrodotoxin blocked all propulsion. Hexamethonium blocked normal motor patterns, leaving irregular propagating contractions, indicating the existence of neural pathways that did not require nicotinic transmission. Colonic migrating motor complexes are responsible for the slow propulsion of the soft fecal content in the proximal colon, while the formation of pellets at the colonic flexure involves a content-dependent mechanism in combination with content-independent spontaneous CMMCs. Bolus size and consistency affects propulsion speed suggesting that propulsion is not a simple reflex but rather a more complex process involving an adaptable neuromechanical loop. © 2015 John Wiley & Sons Ltd.

DOUBLE SHELL TANK (DST) HYDROXIDE DEPLETION MODEL FOR CARBON DIOXIDE ABSORPTION

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

OGDEN DM; KIRCH NW

2007-10-31

This document generates a supernatant hydroxide ion depletion model based on mechanistic principles. The carbon dioxide absorption mechanistic model is developed in this report. The report also benchmarks the model against historical tank supernatant hydroxide data and vapor space carbon dioxide data. A comparison of the newly generated mechanistic model with previously applied empirical hydroxide depletion equations is also performed.

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

Hurt, Christopher J.; Freels, James D.; Hobbs, Randy W.

There has been a considerable effort over the previous few years to demonstrate and optimize the production of plutonium-238 ( 238Pu) at the High Flux Isotope Reactor (HFIR). This effort has involved resources from multiple divisions and facilities at the Oak Ridge National Laboratory (ORNL) to demonstrate the fabrication, irradiation, and chemical processing of targets containing neptunium-237 ( 237Np) dioxide (NpO 2)/aluminum (Al) cermet pellets. A critical preliminary step to irradiation at the HFIR is to demonstrate the safety of the target under irradiation via documented experiment safety analyses. The steady-state thermal safety analyses of the target are simulated inmore » a finite element model with the COMSOL Multiphysics code that determines, among other crucial parameters, the limiting maximum temperature in the target. Safety analysis efforts for this model discussed in the present report include: (1) initial modeling of single and reduced-length pellet capsules in order to generate an experimental knowledge base that incorporate initial non-linear contact heat transfer and fission gas equations, (2) modeling efforts for prototypical designs of partially loaded and fully loaded targets using limited available knowledge of fabrication and irradiation characteristics, and (3) the most recent and comprehensive modeling effort of a fully coupled thermo-mechanical approach over the entire fully loaded target domain incorporating burn-up dependent irradiation behavior and measured target and pellet properties, hereafter referred to as the production model. These models are used to conservatively determine several important steady-state parameters including target stresses and temperatures, the limiting condition of which is the maximum temperature with respect to the melting point. The single pellet model results provide a basis for the safety of the irradiations, followed by parametric analyses in the initial prototypical designs that were necessary due to the limiting fabrication and irradiation data available. The calculated parameters in the final production target model are the most accurate and comprehensive, while still conservative. Over 210 permutations in irradiation time and position were evaluated, and are supported by the most recent inputs and highest fidelity methodology. The results of these analyses show that the models presented in this report provide a robust and reliable basis for previous, current and future experiment safety analyses. In addition, they reveal an evolving knowledge of the steady-state behavior of the NpO 2/Al pellets under irradiation for a variety of target encapsulations and potential conditions.« less

Bench Scale Development and Testing of Aerogel Sorbents for CO 2 Capture Final Technical Report

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

Begag, Redouane

The primary objective of this project was scaling up and evaluating a novel Amine Functionalized Aerogel (AFA) sorbent in a bench scale fluidized bed reactor. The project team (Aspen Aerogels, University of Akron, ADA-ES, and Longtail Consulting) has carried out numerous tests and optimization studies to demonstrate the CO 2 capture performance of the AFA sorbent in all its forms: powder, pellet, and bead. The CO 2 capture target performance of the AFA sorbent (all forms) were set at > 12 wt.% and > 6 wt.% for total and working CO 2 capacity, respectively (@ 40 °C adsorption / 100more » – 120 °C desorption). The optimized AFA powders outperformed the performance targets by more than 30%, for the total CO 2 capacity (14 - 20 wt.%), and an average of 10 % more for working CO 2 capacity (6.6 – 7.0 wt.%, and could be as high as 9.6 wt. % when desorbed at 120 °C). The University of Akron developed binder formulations, pellet production methods, and post treatment technology for increased resistance to attrition and flue gas contaminants. In pellet form the AFA total CO 2 capacity was ~ 12 wt.% (over 85% capacity retention of that of the powder), and there was less than 13% degradation in CO 2 capture capacity after 20 cycles in the presence of 40 ppm SO 2. ADA-ES assessed the performance of the AFA powder, pellet, and bead by analyzing sorption isotherms, water uptake analysis, cycling stability, jet cup attrition and crush tests. At bench scale, the hydrodynamic and heat transfer properties of the AFA sorbent pellet in fluidized bed conditions were evaluated at Particulate Solid Research, Inc. (PSRI). After the process design requirements were completed, by Longtail Consulting LLC, a techno-economic analysis was achieved using guidance from The National Energy Technology Laboratory (NETL) report. This report provides the necessary framework to estimate costs for a temperature swing post combustion CO 2 capture process using a bituminous coal fired, super-critical steam cycle power plant producing 550 MWe net generation with 90% CO 2 capture using a methylethylamine (MEA) solvent. Using the NETL report as guidance, the designed CO 2 capture system was analyzed on a cost basis to determine relative cost estimates between the benchmark MEA system and the AFA sorbent system.« less

APPARATUS FOR CLEANING GASES WITH ELECTROSTATICALLY CHARGED PARTICLES

DOEpatents

Johnstone, H.F.

1960-02-01

An apparatus is described for cleaning gases with the help of electrostatically charged pellets. The pellets are blown past baffles in a conduit and into the center of a rotuting body of the gas to be cleaned. The pellets are charged electrostatically by impinging on the baffles. The pellets collect the particles suspended in the gas in their passage from the center of the rotating body to its edge.

Combinations of Foliar- and Soil-Applied Herbicides For Controlling Hardwood Brush

Treesearch

James D. Haywood

1979-01-01

Triclopyr and 2,4,5-T esters at 1.0 lb a/A; and hexazinone, picloram, and tebuthiuron pellets at 3.0 lb a/A were applied either separately or in liquid and pellet herbicide combinations to l/60-acre plots for mixed hardwood brush control. Only two treatments - triclopyr ester with picloram pellets and 2,4,5-T ester with picloram pellets - gave acceptable topkill of...

Durable zinc ferrite sorbent pellets for hot coal gas desulfurization

DOEpatents

Jha, Mahesh C.; Blandon, Antonio E.; Hepworth, Malcolm T.

1988-01-01

Durable, porous sulfur sorbents useful in removing hydrogen sulfide from hot coal gas are prepared by water pelletizing a mixture of fine zinc oxide and fine iron oxide with inorganic and organic binders and small amounts of activators such as sodium carbonate and molybdenite; the pellets are dried and then indurated at a high temperature, e.g., 1800.degree. C., for a time sufficient to produce crush-resistant pellets.

21 CFR 582.1139 - Ammonium hydroxide.

Code of Federal Regulations, 2010 CFR

2010-04-01

... Additives § 582.1139 Ammonium hydroxide. (a) Product. Ammonium hydroxide. (b) Conditions of use. This substance is generally recognized as safe when used in accordance with good manufacturing or feeding...

21 CFR 582.1205 - Calcium hydroxide.

Code of Federal Regulations, 2010 CFR

2010-04-01

... Additives § 582.1205 Calcium hydroxide. (a) Product. Calcium hydroxide. (b) Conditions of use. This substance is generally recognized as safe when used in accordance with good manufacturing or feeding...

Magnesium Hydroxide

MedlinePlus

Magnesium hydroxide is used on a short-term basis to treat constipation.This medication is sometimes prescribed ... Magnesium hydroxide come as a tablet and liquid to take by mouth. It usually is taken as ...

Aluminum Hydroxide

MedlinePlus

Aluminum hydroxide is used for the relief of heartburn, sour stomach, and peptic ulcer pain and to ... Aluminum hydroxide comes as a capsule, a tablet, and an oral liquid and suspension. The dose and ...

21 CFR 582.1205 - Calcium hydroxide.

Code of Federal Regulations, 2013 CFR

2013-04-01

... Additives § 582.1205 Calcium hydroxide. (a) Product. Calcium hydroxide. (b) Conditions of use. This substance is generally recognized as safe when used in accordance with good manufacturing or feeding...

21 CFR 582.1139 - Ammonium hydroxide.

Code of Federal Regulations, 2012 CFR

2012-04-01

... Additives § 582.1139 Ammonium hydroxide. (a) Product. Ammonium hydroxide. (b) Conditions of use. This substance is generally recognized as safe when used in accordance with good manufacturing or feeding...

21 CFR 582.1205 - Calcium hydroxide.

Code of Federal Regulations, 2012 CFR

2012-04-01

... Additives § 582.1205 Calcium hydroxide. (a) Product. Calcium hydroxide. (b) Conditions of use. This substance is generally recognized as safe when used in accordance with good manufacturing or feeding...

21 CFR 582.1139 - Ammonium hydroxide.

Code of Federal Regulations, 2013 CFR

2013-04-01

... Additives § 582.1139 Ammonium hydroxide. (a) Product. Ammonium hydroxide. (b) Conditions of use. This substance is generally recognized as safe when used in accordance with good manufacturing or feeding...

21 CFR 582.1139 - Ammonium hydroxide.

Code of Federal Regulations, 2014 CFR

2014-04-01

... Additives § 582.1139 Ammonium hydroxide. (a) Product. Ammonium hydroxide. (b) Conditions of use. This substance is generally recognized as safe when used in accordance with good manufacturing or feeding...

21 CFR 582.1139 - Ammonium hydroxide.

Code of Federal Regulations, 2011 CFR

2011-04-01

... Additives § 582.1139 Ammonium hydroxide. (a) Product. Ammonium hydroxide. (b) Conditions of use. This substance is generally recognized as safe when used in accordance with good manufacturing or feeding...

21 CFR 582.1205 - Calcium hydroxide.

Code of Federal Regulations, 2014 CFR

2014-04-01

... Additives § 582.1205 Calcium hydroxide. (a) Product. Calcium hydroxide. (b) Conditions of use. This substance is generally recognized as safe when used in accordance with good manufacturing or feeding...

Sustained Release of Lidocaine from Solvent-Free Biodegradable Poly[(d,l)-Lactide-co-Glycolide] (PLGA): In Vitro and In Vivo Study.

PubMed

Kau, Yi-Chuan; Liao, Chia-Chih; Chen, Ying-Chi; Liu, Shih-Jung

2014-09-16

Local anesthetics are commonly used for pain relief by regional nerve blocking. In this study, we fabricated solvent-free biodegradable pellets to extend the duration of lidocaine release without any significant local or systemic toxicity levels. To manufacture the pellets, poly[(d,l)-lactide-co-glycolide] (PLGA) was first pre-mixed with lidocaine powder into different ratios. The powder mixture was then compressed with a mold (diameter of 1, 5, 8 or 10 mm) and sintered at 65 °C to form pellets. The in vitro release study showed that the lidocaine/PLGA pellets exhibited a tri-phase release behavior (a burst, a diffusion-controlled release and a degradation-dominated release) and reached completion around day 28. Scanning electron microscope (SEM) photos show that small channels could be found on the surfaces of the pellets on day 2. Furthermore, the polymer matrix swelled and fell apart on day 7, while the pellets became viscous after 10 days of in vitro elution. Perineural administration of the lidocaine/PLGA pellets produced anti-hypersensitivity effects lasting for at least 24 h in rats, significant when compared to the control group (a pure PLGA was pellet administered). In addition, no inflammation was detected within the nerve and in the neighboring muscle by histopathology.

Influence of pellet seating on the external ballistic parameters of spring-piston air guns.

PubMed

Werner, Ronald; Schultz, Benno; Frank, Matthias

2016-09-01

In firearm examiners' and forensic specialists' casework as well as in air gun proof testing, reliable measurement of the weapon's muzzle velocity is indispensable. While there are standardized and generally accepted procedures for testing the performance of air guns, the method of seating the diabolo pellets deeper into the breech of break barrel spring-piston air guns has not found its way into standardized test procedures. The influence of pellet seating on the external ballistic parameters was investigated using ten different break barrel spring-piston air guns. Test shots were performed with the diabolo pellets seated 2 mm deeper into the breech using a pellet seater. The results were then compared to reference shots with conventionally loaded diabolo pellets. Projectile velocity was measured with a high-precision redundant ballistic speed measurement system. In eight out of ten weapons, the muzzle energy increased significantly when the pellet seater was used. The average increase in kinetic energy was 31 % (range 9-96 %). To conclude, seating the pellet even slightly deeper into the breech of spring-piston air guns might significantly alter the muzzle energy. Therefore, it is strongly recommended that this effect is taken into account when accurate and reliable measurements of air gun muzzle velocity are necessary.

Pyrolysis of ground pine chip and ground pellet particles

DOE PAGES

Rezaei, Hamid; Yazdanpanah, Fahimeh; Lim, C. Jim; ...

2016-08-04

In addition to particle size, biomass density influences heat and mass transfer rates during the thermal treatment processes. In this research, thermal behaviour of ground pine chip particles and ground pine pellet particles in the range of 0.25–5 mm was investigated. A single particle from ground pellets was almost 3 to 4 times denser than a single particle from ground chips at a similar size and volume of particle. Temperature was ramped up from room temperature (~25 °C) to 600 °C with heating rates of 10, 20, 30, and 50 °C/min. Pellet particles took 25–88 % longer time to drymore » than the chip particles. Microscopic examination of 3 mm and larger chip particles showed cracks during drying. No cracks were observed for pellet particles. The mass loss due to treatment at temperatures higher than 200 °C was about 80% both for chip and pellet particles. It took 4 min for chip and pellet particles to lose roughly 63% of their dry mass at a heating rate of 50 °C/min. The SEM structural analysis showed enlarged pores and cracks in cell walls of the pyrolyzed wood chips. As a result, these pores were not observed in pyrolyzed pellet particles.« less

Multispectral UV imaging for surface analysis of MUPS tablets with special focus on the pellet distribution.

PubMed

Novikova, Anna; Carstensen, Jens M; Rades, Thomas; Leopold, Prof Dr Claudia S

2016-12-30

In the present study the applicability of multispectral UV imaging in combination with multivariate image analysis for surface evaluation of MUPS tablets was investigated with respect to the differentiation of the API pellets from the excipients matrix, estimation of the drug content as well as pellet distribution, and influence of the coating material and tablet thickness on the predictive model. Different formulations consisting of coated drug pellets with two coating polymers (Aquacoat ® ECD and Eudragit ® NE 30 D) at three coating levels each were compressed to MUPS tablets with various amounts of coated pellets and different tablet thicknesses. The coated drug pellets were clearly distinguishable from the excipients matrix using a partial least squares approach regardless of the coating layer thickness and coating material used. Furthermore, the number of the detected drug pellets on the tablet surface allowed an estimation of the true drug content in the respective MUPS tablet. In addition, the pellet distribution in the MUPS formulations could be estimated by UV image analysis of the tablet surface. In conclusion, this study revealed that UV imaging in combination with multivariate image analysis is a promising approach for the automatic quality control of MUPS tablets during the manufacturing process. Copyright © 2016 Elsevier B.V. All rights reserved.

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.

Pretreatment of rapeseed straw by sodium hydroxide.

PubMed

Kang, Kyeong Eop; Jeong, Gwi-Taek; Park, Don-Hee

2012-06-01

Pretreatment method for rapeseed straw by sodium hydroxide was investigated for production of bioethanol and biobutanol. Various pretreatment parameters, including temperature, time, and sodium hydroxide concentration were optimized using a statistical method which is a central composite design of response surface methodology. In the case of sodium hydroxide pretreatment, optimal pretreatment conditions were found to be 7.9% sodium hydroxide concentration, 5.5 h of reaction time, and 68.4 °C of reaction temperature. The maximum glucose yield which can be recovered by enzymatic hydrolysis at the optimum conditions was 95.7% and the experimental result was 94.0 ± 4.8%. This experimental result was in agreement with the model prediction. An increase of surface area and pore size in pretreated rapeseed straw by sodium hydroxide pretreatment was observed by scanning electron microscope.

Use of pellet guns for crowd control in Kashmir: How lethal is "non-lethal"?

PubMed

David, Siddarth

2017-01-01

The use of pellet guns during the recent unrest in Kashmir as a method of crowd control has been questioned because of several deaths and numerous injuries. Across the world, these rubber pellets have been shown to inflict serious injuries, permanent disability, and death. The volatility of mob violence, inaccuracies in aim of the pellets, over-use of the pellet guns, and the perception of their harmlessness enhances the destructive potential of these so-called non-lethal weapons. There is also the larger ethical question whether any form of pain, however minimal, could be inflicted to control violent crowds.

Fast Ignition Thermonuclear Fusion: Enhancement of the Pellet Gain by the Colossal-Magnetic-Field Shells

NASA Astrophysics Data System (ADS)

Stefan, V. Alexander

2013-10-01

The fast ignition fusion pellet gain can be enhanced by a laser generated B-field shell. The B-field shell, (similar to Earth's B-field, but with the alternating B-poles), follows the pellet compression in a frozen-in B-field regime. A properly designed laser-pellet coupling can lead to the generation of a B-field shell, (up to 100 MG), which inhibits electron thermal transport and confines the alpha-particles. In principle, a pellet gain of few-100s can be achieved in this manner. Supported in part by Nikola Tesla Labs, Stefan University, 1010 Pearl, La Jolla, CA 92038-1007.

Preparation and evaluation of metoprolol tartrate sustained-release pellets using hot melt extrusion combined with hot melt coating.

PubMed

Yang, Yan; Shen, Lian; Li, Juan; Shan, Wei-Guang

2017-06-01

The objective of this study was to prepare and evaluate metoprolol tartrate sustained-release pellets. Cores were prepared by hot melt extrusion and coated pellets were prepared by hot melt coating. Cores were found to exist in a single-phase state and drug in amorphous form. Plasticizers had a significant effect on torque and drug content, while release modifiers and coating level significantly affected the drug-release behavior. The mechanisms of drug release from cores and coated pellets were Fickian diffusion and diffusion-erosion. The coated pellets exhibited sustained-release properties in vitro and in vivo.

Looking Southeast from Second Floor Mezzanine of Pellet Plant to ...

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

Looking Southeast from Second Floor Mezzanine of Pellet Plant to Erbia Mixing Area and Poreformer and Acrawax Mixing Station - Hematite Fuel Fabrication Facility, Pellet Plant, 3300 State Road P, Festus, Jefferson County, MO

Sodium hydroxide poisoning

MedlinePlus

Sodium hydroxide is a very strong chemical. It is also known as lye and caustic soda. This ... poisoning from touching, breathing in (inhaling), or swallowing sodium hydroxide. This article is for information only. Do ...

New proteoliposome vaccine formulation from N. meningitidis serogroup B, without aluminum hydroxide, retains its antimeningococcal protectogenic potential as well as Th-1 adjuvant capacity

PubMed Central

2013-01-01

Proteoliposomes purified from the Outer Membrane of Neisseria meningitidis B, have been successfully used as core for adjuvants and vaccine formulations. We have tried to increase their structural definition and to conserve their efficacy and stability avoiding the addition of the aluminum hydroxide to the final formulation. Liposomal particle systems were prepared from components of defined molecular structure, such as a Neisseria meningitidis B protein complex, extracted and purified without forming vesicle structures. Liposomes were prepared from a mixture of dioleoyl phosphatidyl serine and cholesterol, using the classical dehydration-rehydration method. Transmission Electron Microscopy (TEM) was used to characterize the liposomes. BALB/c mice were used for animal testing procedures. Analysis of specific IgG response, serum bactericidal activity as well as DTH reaction was carried out. Isolation and purification of mRNA and real-time PCR, was performed to determine the dominating Th lymphokine pattern. The new antimeningococcal formulation without aluminum hydroxide prepared with components of defined molecular structure assembled itself into Neoproteoliposomes (NPL) ranging from 50 to 70 nm in diameter. The extraction and purification of selected membrane proteins to provide the antigen for this new formulation (PD-Tp), as well as the NPL-formulation favors a Th1 response pattern, suggested by the higher percentages of DTH, increased expression of proinflamatory lymphokine mRNAs when administered by intramuscular and intranasal routes. It stimulates a systemic bactericidal antibody response against Neisseria meningitidis B and immunologic memory similar to the Cuban VA-MENGOC-BC® vaccine, even at lower dosages and is less reactogenic at the injection site in comparison with the formulation with aluminum hydroxide. This new adjuvant formulation could be applicable to the development of new and improved vaccines against meningococcal disease, and eventually as modulators of the immune response against other diseases. PMID:23458443

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.

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

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

Here, a process model was developed to determine the net energy ratio (NER) for production of pellets from steam pretreated agricultural residue (AR) and energy crop (i.e. switchgrass in this case). The NER is a ratio of the net energy output to the total net energy input from non-renewable energy sources into a system. Scenarios were developed to measure the effects of temperature and level of steam pretreatment on the NER of steam pretreated AR- and switch grass-based pellets. The NER for the base case at 6 kg h -1 is 1.76 and 1.37 for steam-pretreated AR- and switchgrass-based pellets,more » respectively. The reason behind the difference is that more energy is required to dry switchgrass pellets than AR pellets. The sensitivity analysis for the model shows that the optimum temperature for steam pretreatment is 160 C with 50% pretreatment (half the feedstock is pretreated, while the rest is undergoes regular pelletization). The uncertainty results for NER for steam pretreated AR and switch grass pellets are 1.62 ± 0.10 and 1.42 ± 0.11, respectively.« less

Preparation of Cu and Fly Ash Composite by Powder Metallurgy Technique

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

Chew, P. Y.; Lim, P. S.; Ng, M. C.

2011-03-30

Cu and Fly Ash (FA) mixtures with different weight percentages were prepared. Pellets of the mixture powder were produced with the dimension of 17.7 mm in diameter and 10-15 mm in height. These different composites were compacted at a constant pressure of 280 MPa. One of the selected weight percentages was then compacted to form into pellet and sintered at different temperatures which were at 900, 950 and 1000 deg. C respectively for 2 hours. Density of green pellet was measured before sintered in furnace. After sintering, all the pellets with different temperatures were re-weighed and sintered density were calculated.more » The densification of the green and sintered pellets was required to be measured as one of the parameter in selection of the best material properties. Porosity of the pellet shall not be ignored in order to analyze the close-packed particles stacking in the pellet. SEM micrograph had been captured to observe the presence of pores and agglomeration of particles in the sample produced.« less

Bending testing and characterization of surrogate nuclear fuel rods made of Zircaloy-4 cladding and aluminum oxide pellets

NASA Astrophysics Data System (ADS)

Wang, Hong; Wang, Jy-An John

2016-10-01

Behavior of surrogate nuclear fuel rods made of Zircaloy-4 (Zry-4) cladding with alumina pellets under reversed cyclic bending was studied. Tests were performed under load or moment control at 5 Hz. The surrogate rods fractured under moment amplitudes greater than 10.16 Nm with fatigue lives between 2.4 × 103 and 2.2 × 106 cycles. Fatigue response of Zry-4 cladding was characterized by using flexural rigidity. Degradation of flexural rigidity was shown to depend on the moment and the prefatigue condition of specimens. Pellet-to-pellet interface (PPI), pellet-to-cladding interface (PCI), and pellet condition affect surrogate rod failure. Both debonding of PPI/PCI and pellet fracturing contribute to surrogate rod bending fatigue. The effect of sensor spacing on curvature measurement using three-point deflections was studied; the method based on effective gauge length is effective in sensor spacing correction. The database developed and the understanding gained in this study can serve as input to analysis of SNF (spent nuclear fuel) vibration integrity.

The impact of chewing gum resistance on immediate free recall.

PubMed

Rickman, Sarah; Johnson, Andrew; Miles, Christopher

2013-08-01

Although the facilitative effects of chewing gum on free recall have proved contentious (e.g., Tucha, Mecklinger, Maier, Hammerl, & Lange, 2004; Wilkinson, Scholey, & Wesnes, 2002), there are strong physiological grounds, for example, increased cerebral activity and blood flow following the act of mastication, to suppose facilitation. The present study manipulated resistance to mastication, that is, chewing four pellets versus one pellet of gum, with the assumption that increased resistance will accentuate cerebral activity and blood flow. Additionally, chewing rate was recorded for all participants. In a within-participants design, participants performed a series of immediate free recall tasks while chewing gum at learning (one or four pellets) and recall (one or four pellets). Increased chewing resistance was not associated with increased memory performance, despite consistent chewing rates for both the one and four pellet conditions at both learning and recall. However, a pattern of recall consistent with context-dependent memory was observed. Here, participants who chewed the equivalent number of gum pellets at both learning and recall experienced significantly superior word recall compared to those conditions where the number of gum pellets differed. ©2012 The British Psychological Society.

The Cassini project: Lessons learned through operations

NASA Astrophysics Data System (ADS)

McCormick, Egan D.

1998-01-01

The Cassini space probe requires 180 238Pu Light-weight Radioisotopic Heater Units (LWRHU) and 216 238Pu General Purpose Heat Source (GPHS) pellets. Additional LWRHU and GPHS pellets required for non-destructive (NDA) and destructive assay purposes were fabricated bringing the original pellet requirement to 224 LWRHU and 252 GPHS. Due to rejection of pellets resulting from chemical impurities in the fuel and/or failure to meet dimensional specifications a total of 320 GPHS pellets were fabricated for the mission. Initial plans called for LANL to process a total of 30 kg of oxide powder for pressing into monolithic ceramic pellets. The original 30 kg commitment was processed within the time frame allotted; an additional 8 kg were required to replace fuel lost due to failure to meet Quality Assurance specifications for impurities and dimensions. During the time frame allotted for pellet production, operations were impacted by equipment failure, unacceptable fuel impurities levels, and periods of extended down time, >30 working days during which little or no processing occurred. Throughout the production process, the reality of operations requirements varied from the theory upon which production schedules were based.

Lifetime of Sodium Beta-Alumina Membranes in Molten Sodium Hydroxide

DTIC Science & Technology

2008-07-01

ABSTRACT Summary: Sodium metal can be made by electrolysis of molten sodium hydroxide in sodium beta-alumina membrane electrolysis cells... electrolysis of molten sodium hydroxide in sodium ”-alumina membrane electrolysis cells. However, there are some uncertainties about the lifetime of the...the properties of the membrane degrade upon long term contact with molten sodium hydroxide. Electrolysis cells were designed, but it proved

Strategy for pH control and pH feedback-controlled substrate feeding for high-level production of L-tryptophan by Escherichia coli.

PubMed

Cheng, Li-Kun; Wang, Jian; Xu, Qing-Yang; Zhao, Chun-Guang; Shen, Zhi-Qiang; Xie, Xi-Xian; Chen, Ning

2013-05-01

Optimum production of L-tryptophan by Escherichia coli depends on pH. Here, we established conditions for optimizing the production of L-tryptophan. The optimum pH range was 6.5-7.2, and pH was controlled using a three-stage strategy [pH 6.5 (0-12 h), pH 6.8 (12-24 h), and pH 7.2 (24-38 h)]. Specifically, ammonium hydroxide was used to adjust pH during the initial 24 h, and potassium hydroxide and ammonium hydroxide (1:2, v/v) were used to adjust pH during 24-38 h. Under these conditions, NH4 (+) and K(+) concentrations were kept below the threshold for inhibiting L-tryptophan production. Optimization was also accomplished using ratios (v/v) of glucose to alkali solutions equal to 4:1 (5-24 h) and 6:1 (24-38 h). The concentration of glucose and the pH were controlled by adjusting the pH automatically. Applying a pH-feedback feeding method, the steady-state concentration of glucose was maintained at approximately 0.2 ± 0.02 g/l, and acetic acid accumulated to a concentration of 1.15 ± 0.03 g/l, and the plasmid stability was 98 ± 0.5 %. The final, optimized concentration of L-tryptophan was 43.65 ± 0.29 g/l from 52.43 ± 0.38 g/l dry cell weight.

Effect of sorbent attrition on utilization. Final report, August 1, 1991--August 31, 1992

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

Keener, T.C.; Khang, S.J.; Lee, S.K.

1992-10-01

During this period, the project has focused on two aspects of attrition; (1) mechanical attrition which is responsible for particle fracture whenever particles are moving with respect to a fixed reference frame, and (2) chemical attrition which can be responsible for particle fracture whenever particles undergo reactions. The experiments were conducted with calcium based sorbent materials. Two specific project objectives were identified and studied. The first of these was to determine the effect of temperature, particle velocity, and particle surface area on the extent of attrition in a circulating fluidized reactor. The second was to investigate if attrition could improvemore » sorbent utilization of typical calcium based sorbents of small size (<20 {mu}m). A sample of sulfated calcium hydroxide sorbent was obtained for attrition tests in a circulating fluidized bed reactor. Attempts at attriting this material in the fluidized bed were not successful, and no improvements in sorbent utilization were measured in subsequent TGA tests with the solids. However, an analysis of the other constituents in the particles revealed that a major portion of the hydroxide had been converted to calcium carbonate. This gave rise to the possibility that dolomitic hydroxide may have characteristics which may be beneficial and that improvements in utilization could be realized by means of chemical attrition. This is due to the thermal instability of magnesium carbonate at temperatures above 650{degree}F which means that magnesium oxide will be the major unreacted magnesium species in spent sorbent.« less

Molecular Dynamics Simulations of the Interfacial Region between Boehmite and Gibbsite Basal Surfaces and High Ionic Strength Aqueous Solutions

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

Shen, Zhizhang; Ilton, Eugene S.; Prange, Micah P.

Classical molecular dynamics (MD) simulations were used to study the interactions of up to 2 M NaCl and NaNO3 aqueous solutions with the presumed inert boehmite (010) and gibbsite (001) surfaces. The force field parameters used in these simulations were validated against density functional theory calculations of Na+ and Cl- hydrated complexes adsorbed at the boehmite (010) surface. In all the classical MD simulations and regardless of the ionic strength or the nature of the anion, Na+ ions were found to preferably form inner-sphere complexes over outer-sphere complexes at the aluminum (oxy)hydroxide surfaces, adsorbing closer to the surface than bothmore » water molecules and anions. In contrast, Cl- ions were distributed almost equally between inner- and outer-sphere positions. The resulting asymmetry in adsorption strengths offers molecular-scale evidence for the observed isoelectric point (IEP) shift to higher pH at high ionic strength for aluminum (oxy)hydroxides. As such, the MD simulations also provided clear evidence against the assumption that the basal surfaces of boehmite and gibbsite are inert to background electrolytes. Finally, the MD simulations indicated that, although the adsorption behavior of Na+ in NaNO3 and NaCl solutions was similar, the different affinities of NO3- and Cl- for the aluminum (oxy)hydroxide surfaces might have macroscopic consequences, such as difference in the sensitivity of the IEP to the electrolyte concentration.« less

Effects of diet form and feeder adjustment on growth performance of nursery and finishing pigs.

PubMed

Nemechek, J E; Tokach, M D; Dritz, S S; Fruge, E D; Hansen, E L; Goodband, R D; DeRouchey, J M; Woodworth, J C

2015-08-01

Three experiments were conducted to determine the effects of feeder adjustment and diet form on growth performance of nursery (Exp. 1 and 2) and finishing (Exp. 3) pigs. Treatments were arranged as a 2 × 3 factorial with the main effects of feeder adjustment and diet form. The 2 feeder adjustments were a narrow and wide feeder adjustment (minimum gap opening of 1.27 and 2.54 cm, respectively). The 3 diet forms were meal, poor-quality pellets (70% pellets and 30% fines for Exp. 1 and 2 and 50% pellets and 50% fines for Exp. 3), and screened pellets with minimal fines (3 to 10%). In Exp. 1, 210 pigs (initially 11.9 kg BW) were used in a 21-d trial with 7 pigs per pen and 5 pens per treatment. No feeder adjustment × diet form interactions were observed. There were no differences in ADG, ADFI, or G:F due to feeder adjustment. Pigs fed the meal diet had increased ( < 0.05) ADG and ADFI compared with pigs fed the poor-quality or screened pellets. Pigs fed meal or poor-quality pellets had decreased ( < 0.05) G:F compared with pigs fed screened pellets. In Exp. 2, 1,005 nursery pigs (initially 14.1 kg BW) were used in a 28-d trial with 26 to 28 pigs per pen and 6 pens per treatment. Pigs fed from the narrow feeder adjustment had decreased ( < 0.05) ADG and ADFI compared with pigs fed from the wide adjustment with no differences in G:F. Pigs fed the meal diet had decreased ( < 0.05) ADG compared with pigs fed poor-quality or screened pellets. Pigs fed meal or poor-quality pellets had decreased ( < 0.05) G:F compared with pigs fed screened pellets. In Exp. 3, 246 pigs (initially 56.8 kg BW) were used in a 69-d trial with 5 pens per treatment and 6 or 7 pigs per pen. Overall, ADFI decreased ( < 0.05) and G:F increased ( < 0.05) for pigs fed from the narrow adjusted feeders compared with the wide adjustment with no differences in ADG. Overall, pigs fed meal diets tended to have decreased ( < 0.10) ADG and had decreased ( < 0.05) G:F compared with pigs fed screened pellets; ADG and G:F in those fed poor-quality pellets were intermediate. Feeding meal or poor-quality pellets increased ( < 0.05) ADFI compared with pigs fed screened pellets. In conclusion, feeding nursery pigs from a wide feeder gap may increase ADG and ADFI with no negative effects on G:F. For finishing pigs, reducing feeder gap reduced feed disappearance and improved G:F. In all experiments, the greatest G:F improvements from pelleting were observed when the percentage of fines was minimized.

Surface Enhanced Raman Spectroscopy for the Rapid Detection and Identification of Microbial Pathogens in Human Serum

DTIC Science & Technology

2014-12-11

and 1 mm depth. Bacterial culture and cell count determination Bacterial species of Acinetobacter baumannii (A. baumannii, ST-3), Escherichia coli...remove all broth components followed by a final resuspension of the pellet in ddH2O back to 1 OD. Cell count was determined by plating the 10 4 , 10 3...10 2 and 10 1 cell dilutions on TSB Nutrient Agar media. Colony forming units (CFU) were counted the following day to confirm bacterial species

Nuclear fuel element

DOEpatents

Zocher, Roy W.

1991-01-01

A nuclear fuel element and a method of manufacturing the element. The fuel element is comprised of a metal primary container and a fuel pellet which is located inside it and which is often fragmented. The primary container is subjected to elevated pressure and temperature to deform the container such that the container conforms to the fuel pellet, that is, such that the container is in substantial contact with the surface of the pellet. This conformance eliminates clearances which permit rubbing together of fuel pellet fragments and rubbing of fuel pellet fragments against the container, thus reducing the amount of dust inside the fuel container and the amount of dust which may escape in the event of container breach. Also, as a result of the inventive method, fuel pellet fragments tend to adhere to one another to form a coherent non-fragmented mass; this reduces the tendency of a fragment to pierce the container in the event of impact.

Mathematical model of the direct reduction of dust composite pellets containing zinc and iron

NASA Astrophysics Data System (ADS)

An, Xiu-wei; Wang, Jing-song; She, Xue-feng; Xue, Qing-guo

2013-07-01

Direct reduction of dust composite pellets containing zinc and iron was examined by simulating the conditions of actual production process of a rotary hearth furnace (RHF) in laboratory. A mathematical model was constructed to study the reduction kinetics of iron oxides and ZnO in the dust composite pellets. It was validated by comparing the calculated values with experimental results. The effects of furnace temperature, pellet radius, and pellet porosity on the reduction were investigated by the model. It is shown that furnace temperature has obvious influence on both of the reduction of iron oxides and ZnO, but the influence of pellet radius and porosity is much smaller. Model calculations suggest that both of the reduction of iron oxides and ZnO are under mixed control with interface reactions and Boudouard reaction in the early stage, but only with interface reactions in the later stage.

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.

The Self-Reducing Pellet Production from Organic Household Waste

NASA Astrophysics Data System (ADS)

Nogueira, Alberto; Takano, Cyro; Mourão, Marcelo; Pillihuaman, Adolfo

The organic household waste has a growing disposal problem, requiring costly disposal systems. It is necessary to find new applications for these materials; one could be the steelmaking raw material production. In this paper is studied the development of self-reducing pellets from the organic waste pyrolysis, where is generated carbon and condensable and non-condensable volatiles. Non-condensable volatiles were burned and condensable volatiles were recovered. The resulting tar was mixed with iron ore, coal powder and flux (CaO), to then be pelletized together. Compression, falls and tumbler tests were conducted to characterize the pellets before and after heat treatment and reduction processes. The reduction curve and their physical and morphological characterization were measured. The results were as was expected, the fluidized coal create sufficient adhesion that pellets earned resistance with an equivalent resistance of common pellets, showing a good feasibility of this process.

Renal Capsule Xenografting and Subcutaneous Pellet Implantation for the Evaluation of Prostate Carcinogenesis and Benign Prostatic Hyperplasia

PubMed Central

Nicholson, Tristan M.; Uchtmann, Kristen S.; Valdez, Conrad D.; Theberge, Ashleigh B.; Miralem, Tihomir; Ricke, William A.

2013-01-01

New therapies for two common prostate diseases, prostate cancer (PrCa) and benign prostatic hyperplasia (BPH), depend critically on experiments evaluating their hormonal regulation. Sex steroid hormones (notably androgens and estrogens) are important in PrCa and BPH; we probe their respective roles in inducing prostate growth and carcinogenesis in mice with experiments using compressed hormone pellets. Hormone and/or drug pellets are easily manufactured with a pellet press, and surgically implanted into the subcutaneous tissue of the male mouse host. We also describe a protocol for the evaluation of hormonal carcinogenesis by combining subcutaneous hormone pellet implantation with xenografting of prostate cell recombinants under the renal capsule of immunocompromised mice. Moreover, subcutaneous hormone pellet implantation, in combination with renal capsule xenografting of BPH tissue, is useful to better understand hormonal regulation of benign prostate growth, and to test new therapies targeting sex steroid hormone pathways. PMID:24022657

Occurrence, distribution and characteristics of beached plastic production pellets on the island of Malta (central Mediterranean).

PubMed

Turner, Andrew; Holmes, Luke

2011-02-01

The distribution, abundance and chemical characteristics of plastic production pellets on beaches of the island of Malta have been determined. Pellets were observed at all locations visited and were generally most abundant (> 1000m⁻² at the surface) on the backshores of beaches with a westerly aspect. Most pellets were disc-shaped or flattened cylinders and could be categorised as white, yellow, amber or brown. The polymeric matrix of all pellets analysed by infrared spectroscopy was polyethylene and the degree of yellowing or darkening was associated with an increase in the carbonyl index, hence extent of photo-oxidation or aging. Qualitatively, pellets are similar to those reported for other regions of the Mediterranean in surveys spanning three decades, suggesting that they are a general and persistent characteristic of the region. Copyright © 2010 Elsevier Ltd. All rights reserved.