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Sample records for prepared bi-mo-ti mixed

  1. Analysis of Azodicarbonamide in Wheat Flour and Prepared Flour Mixes.

    PubMed

    Yasui, Akiko; Oishi, Mitsuo; Hayafuji, Chieko; Kobayashi, Chigusa; Shindo, Tetsuya; Ozawa, Hideki; Nakazato, Mitsuo

    2016-01-01

    Azodicarbonamide (ADA) is used in some countries as a flour bleaching agent and a dough conditioner. However, ADA is prohibited for use as a food additive in Japan. Therefore, it is necessary to establish an efficient and sensitive method to determine ADA in wheat flour. A simple and practical procedure to analyze ADA in wheat flour and prepared flour mixes was developed. ADA was extracted from samples by ultrasonication with acetone. ADA in the solution was derivatized with triphenylphosphine (TPP). The ADA-TPP derivative was concentrated and cleaned up using a reversed-phase solid-phase extraction cartridge, and the ADA-TPP derivative was analyzed using HPLC for determination and LC-MS/MS for identification. Good linearity was achieved over the concentration range of 0.25-100 ppm ADA in wheat flour and prepared flour mixes. The mean recoveries from wheat flour and prepared flour mixes fortified at the levels of 1 and 10 ppm ranged from 86.9 to 101.0%, and the coefficients of variation ranged from 1.9 to 3.4%.

  2. Remote waste handling and feed preparation for Mixed Waste Management

    SciTech Connect

    Couture, S.A.; Merrill, R.D.; Densley, P.J.

    1995-05-01

    The Mixed Waste Management Facility (MWMF) at the Lawrence Livermore National Laboratory (LLNL) will serve as a national testbed to demonstrate mature mixed waste handling and treatment technologies in a complete front-end to back-end --facility (1). Remote operations, modular processing units and telerobotics for initial waste characterization, sorting and feed preparation have been demonstrated at the bench scale and have been selected for demonstration in MWMF. The goal of the Feed Preparation design team was to design and deploy a robust system that meets the initial waste preparation flexibility and productivity needs while providing a smooth upgrade path to incorporate technology advances as they occur. The selection of telerobotics for remote handling in MWMF was made based on a number of factors -- personnel protection, waste generation, maturity, cost, flexibility and extendibility. Modular processing units were selected to enable processing flexibility and facilitate reconfiguration as new treatment processes or waste streams are brought on line for demonstration. Modularity will be achieved through standard interfaces for mechanical attachment as well as process utilities, feeds and effluents. This will facilitate reconfiguration of contaminated systems without drilling, cutting or welding of contaminated materials and with a minimum of operator contact. Modular interfaces also provide a standard connection and disconnection method that can be engineered to allow convenient remote operation.

  3. Mixing apparatus for preparing NMR samples under pressure

    NASA Astrophysics Data System (ADS)

    Wu, Wen-Jin; Vidugiris, Gediminas; Mooberry, Ed S.; Westler, William M.; Markley, John L.

    2003-09-01

    The size limit for protein NMR spectroscopy in solution arises in large part from line broadening caused by slow molecular tumbling. One way to alleviate this problem is to increase the effective tumbling rate by reducing the viscosity of the solvent. Because proteins generally require an aqueous environment to remain folded, one approach has been to encapsulate hydrated proteins in reverse micelles formed by a detergent and to dissolve the encapsulated protein in a low-viscosity fluid. The high volatility of suitable low-viscosity fluids requires that the samples be prepared and maintained under pressure. We describe a novel apparatus used for the preparation of such samples. The apparatus includes a chamber for mixing the detergent with the low-viscosity solvent, a second chamber for mixing this with hydrated protein, and a 5-mm (o.d.) zirconium oxide NMR sample tube with shut-off valves designed to contain pressures on the order of 10 bar, sufficient for liquid propane. Liquids are moved from one location to another by introducing minor pressure differentials between two pressurization vessels. We discuss the operation of this apparatus and illustrate this with data on a 30-kDa protein complex (chymotrypsin:turkey ovomucoid third domain) encapsulated in reverse micelles of the detergent, sodium bis (2-ethylhexyl) sulfosuccinate, aerosol-ot (AOT), dissolved in liquid propane.

  4. Successful treatment of mixed (mainly cancer) pain by tramadol preparations.

    PubMed

    Kawahito, Shinji; Soga, Tomohiro; Mita, Naoji; Satomi, Shiho; Kinoshita, Hiroyuki; Arase, Tomoko; Kondo, Akira; Miki, Hitoshi; Takaishi, Kazumi; Kitahata, Hiroshi

    2017-01-01

    The patient, a 70-year-old Japanese woman diagnosed with parotid gland cancer, underwent wide excision and reconstruction (facial nerve ablation, nerve transposition). At 1 month after the surgery, she was brought to our hospital's pain medicine department because her postoperative pain and cancer-related pain were poorly controlled. She had already been prescribed a tramadol (37.5 mg)/acetaminophen (325 mg) combination tablet (5 tablets/day). However, in addition to the continuous pain in her face and lower limbs, she was troubled by a trigeminal neuralgia-like prominence ache. Because this pain could not be controlled by an increase to eight combination tablets per day, we switched her medication to a tramadol capsule. At 11 months post-surgery, we then switched her medication to an orally disintegrating tramadol tablet to improve medication adherence of the drug. From 14 months post-surgery, the patient also used a sustained-release tramadol preparation, and she was then able to sleep well. Her current regimen is an orally disintegrating sustained-release tablet combination (total 300 mg tramadol) per day, and she achieved sufficient pain relief. Because tramadol is not classified as a medical narcotic drug, it widely available and was shown here to be extremely useful for the treatment of our patient's mixed (mainly cancer) pain. J. Med. Invest. 64: 311-312, August, 2017.

  5. Rapid Mix Preparation of Bioinspired Nanoscale Hydroxyapatite for Biomedical Applications.

    PubMed

    Wilcock, Caroline J; Gentile, Piergiorgio; Hatton, Paul V; Miller, Cheryl A

    2017-02-23

    Hydroxyapatite (HA) has been widely used as a medical ceramic due to its good biocompatibility and osteoconductivity. Recently there has been interest regarding the use of bioinspired nanoscale hydroxyapatite (nHA). However, biological apatite is known to be calcium-deficient and carbonate-substituted with a nanoscale platelet-like morphology. Bioinspired nHA has the potential to stimulate optimal bone tissue regeneration due to its similarity to bone and tooth enamel mineral. Many of the methods currently used to fabricate nHA both in the laboratory and commercially, involve lengthy processes and complex equipment. Therefore, the aim of this study was to develop a rapid and reliable method to prepare high quality bioinspired nHA. The rapid mixing method developed was based upon an acid-base reaction involving calcium hydroxide and phosphoric acid. Briefly, a phosphoric acid solution was poured into a calcium hydroxide solution followed by stirring, washing and drying stages. Part of the batch was sintered at 1,000 °C for 2 h in order to investigate the products' high temperature stability. X-ray diffraction analysis showed the successful formation of HA, which showed thermal decomposition to β-tricalcium phosphate after high temperature processing, which is typical for calcium-deficient HA. Fourier transform infrared spectroscopy showed the presence of carbonate groups in the precipitated product. The nHA particles had a low aspect ratio with approximate dimensions of 50 x 30 nm, close to the dimensions of biological apatite. The material was also calcium deficient with a Ca:P molar ratio of 1.63, which like biological apatite is lower than the stoichiometric HA ratio of 1.67. This new method is therefore a reliable and far more convenient process for the manufacture of bioinspired nHA, overcoming the need for lengthy titrations and complex equipment. The resulting bioinspired HA product is suitable for use in a wide variety of medical and consumer health

  6. Addition of Sulfometuron Methyl to Fall Site Preparation Tank Mixes Improves Herbaceous Weed Control

    Treesearch

    A.W. Ezell

    2002-01-01

    A total of 12 herbicide treatments were applied to a recently harvested forest site in Winston County, MS. All treatments were representative of forest site preparation tank mixtures and were applied early September, 1999. Three ounces of Oust7 were included in two of the tank mixes, and 19 ounces of Oustar7 were included in two of the mixes. All treatments were...

  7. Temporal and spatial allocation of motor preparation during a mixed-strategy game.

    PubMed

    Mikulić, Areh; Dorris, Michael C

    2008-10-01

    Adopting a mixed response strategy in competitive situations can prevent opponents from exploiting predictable play. What drives stochastic action selection is unclear given that choice patterns suggest that, on average, players are indifferent to available options during mixed-strategy equilibria. To gain insight into this stochastic selection process, we examined how motor preparation was allocated during a mixed-strategy game. If selection processes on each trial reflect a global indifference between options, then there should be no bias in motor preparation (unbiased preparation hypothesis). If, however, differences exist in the desirability of options on each trial then motor preparation should be biased toward the preferred option (biased preparation hypothesis). We tested between these alternatives by examining how saccade preparation was allocated as human subjects competed against an adaptive computer opponent in an oculomotor version of the game "matching pennies." Subjects were free to choose between two visual targets using a saccadic eye movement. Saccade preparation was probed by occasionally flashing a visual distractor at a range of times preceding target presentation. The probability that a distractor would evoke a saccade error, and when it failed to do so, the probability of choosing each of the subsequent targets quantified the temporal and spatial evolution of saccade preparation, respectively. Our results show that saccade preparation became increasingly biased as the time of target presentation approached. Specifically, the spatial locus to which saccade preparation was directed varied from trial to trial, and its time course depended on task timing.

  8. Preparation of Mixed Perovskite Oxides for Blue-Green Lasers

    DTIC Science & Technology

    1984-02-01

    higher for oxide or fluoride . 𔃽. A high radiative lifetime and high fluorescent quantum yield for Ce or the rare earth are desirable. 3 + 4...for all of our single crystal -4- preparations are lanthanum oxide (La„0 ), aluminum oxide (Al^O^) , scandium oxide (Sc„0-.) , and cerium oxide (Ce...crystal material is highly important. Ideally, oxides should be grown in O2, fluorides in ?„, and so forth in order to prevent defects such as

  9. Shelf stable multigrain halwa mixes: preparation of halwa, their textural and sensory studies.

    PubMed

    Itagi, Hameedabanu N; Singh, Vasudeva; Indiramma, A R; Prakash, Maya

    2013-10-01

    Multigrain halwa mixes (four types) were prepared from cereals, millets, legumes, nuts and condiments. These mixes had around 4% initial moisture content (IMC), during storage studies they had 23 to 32% as equilibrium relative humidity (ERH); 5 to 8% as the critical moisture content (CMC) and critical relative humidity (CRH) for these mixes were ~ 60%. Packaging material for storing these mixes was 75 μm thickness LDPE pouches. Under accelerated storage, these mixes picked up moisture up to 9% and at ambient up to 6.4%. Free fatty acids ~18% was developed under accelerated condition for 90 days; under ambient condition ~14% for 180 days. Ragi based spicy halwa mix could develop FFA up to 120%, which was due to the presence of tricarboxylic acid as one of the ingredient in this particular mix. Halwa mixes can be stored for 75 days under accelerated and 180 days under ambient conditions. Halwa prepared from these mixes had 26 to 31% moisture; protein, fat, carbohydrates and ash content were 5.7 to 6.3%, 7.9 to 8.7%, 54 to 58%, 1.6 to 3.3%, respectively. Energy derived from these ranged from 1,318 to 1,380 kJ/100 g. Ragi based spicy multigrain halwa was harder and chewy in texture; while wheat based multigrain halwa was softer. Dark brown colour persisted for Ragi based spicy multi grain halwa because of the inherent colour of the finger millet, ghee aroma and sweetness was insignificant for all the 4 types of halwa.

  10. MAPLE preparation and characterization of mixed arylenevinylene based oligomers:C60 layers

    NASA Astrophysics Data System (ADS)

    Stanculescu, A.; Socol, G.; Vacareanu, L.; Socol, M.; Rasoga, O.; Breazu, C.; Girtan, M.; Stanculescu, F.

    2016-06-01

    This paper presents some studies about the preparation by matrix-assisted pulsed laser evaporation (MAPLE) of mixed layers based on two arylenevinylene oligomers, 1,4-bis [4-(N,N‧-diphenylamino)phenylvinyl] benzene (L78) and 3,3‧-bis(N-hexylcarbazole)vinylbenzene (L13) as donor and buckminsterfullerene (C60) as acceptor, blended in three different weight ratios: 1:1, 1:2 and 1:3. The optical, morphological, structural and electrical properties of these mixed layers have been investigated emphasizing the effect of the layer composition and of the significant degree of disorder. I-V characteristics have revealed typically solar cell behaviour for the heterostructures prepared with mixed layers containing L78 (L13) and fullerene blended in a weight ratio of 1:2. The solar cell structure glass/ITO/L13:C60/Al has shown the best parameters.

  11. Preparation of mixed metal thin films by a PVD method using several kinds of powder targets

    NASA Astrophysics Data System (ADS)

    Suda, Yoshiaki; Kawasaki, Hiroharu; Ohshima, Tamiko; Yagyu, Yoshihito; Ihara, Takeshi; Yamauchi, Makiko; Plasma process; application Team

    2015-09-01

    Bismuth iron garnet (Bi3Fe5O12) and aluminum doped zinc oxide (AZO) thin films were prepared by a physical vapor deposition method using mixed metal powder targets. The X-ray powder diffraction and X-ray photoelectron spectroscopy results suggest that crystalline thin films can be prepared using powder targets with quality similar to that of the films prepared using bulk targets. Bi3Fe5O12 films prepared using the pulsed laser deposition method were Bi rich, which may be due to the lower melting temperature of Bi (544 K) compared with that of Fe (1811 K). The mean transparency and resistivity of the AZO films prepared by the sputtering method were approximately 79%-84% and 0.5 - 1.4 ohm/cm, respectively.

  12. Mixed mosaic membranes prepared by layer-by-layer assembly for ionic separations.

    PubMed

    Rajesh, Sahadevan; Yan, Yu; Chang, Hsueh-Chia; Gao, Haifeng; Phillip, William A

    2014-12-23

    Charge mosaic membranes, which possess distinct cationic and anionic domains that traverse the membrane thickness, are capable of selectively separating dissolved salts from similarly sized neutral solutes. Here, the generation of charge mosaic membranes using facile layer-by-layer assembly methodologies is reported. Polymeric nanotubes with pore walls lined by positively charged polyethylenimine moieties or negatively charged poly(styrenesulfonate) moieties were prepared via layer-by-layer assembly using track-etched membranes as sacrificial templates. Subsequently, both types of nanotubes were deposited on a porous support in order to produce mixed mosaic membranes. Scanning electron microscopy demonstrates that the facile deposition techniques implemented result in nanotubes that are vertically aligned without overlap between adjacent elements. Furthermore, the nanotubes span the thickness of the mixed mosaic membranes. The effects of this unique nanostructure are reflected in the transport characteristics of the mixed mosaic membranes. The hydraulic permeability of the mixed mosaic membranes in piezodialysis operations was 8 L m(-2) h(-1) bar(-1). Importantly, solute rejection experiments demonstrate that the mixed mosaic membranes are more permeable to ionic solutes than similarly sized neutral molecules. In particular, negative rejection of sodium chloride is observed (i.e., the concentration of NaCl in the solution that permeates through a mixed mosaic membrane is higher than in the initial feed solution). These properties illustrate the ability of mixed mosaic membranes to permeate dissolved ions selectively without violating electroneutrality and suggest their utility in ionic separations.

  13. Flow properties of ice cream mix prepared from palm oil: anhydrous milk fat blends.

    PubMed

    Rosnani, A I Wan; Aini, I Nor; Yazid, A M M; Dzulkifly, M H

    2007-05-15

    Ice cream mixes containing 33.4% total solids including 10% fat, 11.1% milk solid-non fat (MSNF), 12% sugar, 0.35% commercial blend of emulsifier/ stabiliser and water were produced. The blending of PO with AMF were conducted at three different ratios 30: 70, 50: 50 and 70: 30, respectively. The experimental ice cream mixes were compared with a control ice cream mix prepared from AMF. The flow properties were measured after ageing at 0, 1, 1.5, 2 and 24 h and determined using a controlled stress rheometer (Haake RS 100). The Power Law and Casson equation was employed to estimate the yield stress of an ice cream mixes. The regression coefficients (r) was represented well by the Casson model (r > 0.99) for all the samples, indicating goodness of fit. The profiles of the consistency coefficients (K(c)) were quite similar for all experimental samples, which could be attributed to the fact that all the samples exhibited similar viscoelastic behaviour. The flow behaviour index (n) of an ice cream mix prepared from PO and their blends with AMF were less then 1.0 (range 0.04-0.08) indicating that they were psuedoplastic fluid. The eta(o) at shear rate 20(-1) indicated higher degree of viscosity in AMF.

  14. Using jet mixing to prepare polyelectrolyte complexes: complex properties and their interaction with silicon oxide surfaces.

    PubMed

    Ankerfors, Caroline; Ondaral, Sedat; Wågberg, Lars; Odberg, Lars

    2010-11-01

    The influence of mixing procedure on the properties of polyelectrolyte complexes (PECs) was investigated using two complexation techniques, polyelectrolyte titration and jet mixing, the latter being a new method for PEC preparation. For the low-molecular-weight polyelectrolytes polyacrylic acid (PAA) and polyallyl amine hydrochloride (PAH), shorter mixing times produced smaller PECs, whereas for higher molecular weights of the same polyelectrolytes, PEC size first decreased with decreasing mixing time to a certain level, after which it started increasing again. This pattern was likely due to the diffusion-controlled formation of "pre-complexes", which, in the case of low-molecular-weight polymers, occurs sufficiently quickly to form stable complexes; when polyelectrolytes are larger, however, non-equilibrium pre-complexes, more prone to aggregation, are formed. Comparing the techniques revealed that jet mixing produced smaller complexes, allowing PEC size to be controlled by mixing time, which was not the case with polyelectrolyte titration. Higher polyelectrolyte concentration during jet mixing led to the formation of larger PECs. It was also demonstrated that PEC size could be changed after preparation: increasing the pH of the PEC dispersion led to an irreversible increase in PEC size, whereas lowering the pH did not influence PEC size. The adsorption behavior of PECs formed from weak polyelectrolytes on model substrates was studied using QCM-D, SPAR, and AFM imaging; the results indicated that increasing the pH increased the amount of PECs adsorbed to model surfaces. However, the amount of PECs adsorbed to the model surfaces was low compared with other systems in all studied cases. Copyright 2010 Elsevier Inc. All rights reserved.

  15. Nanodispersive mixed oxides for destruction of warfare agents prepared by homogeneous hydrolysis with urea

    NASA Astrophysics Data System (ADS)

    Daněk, Ondřej; Štengl, Václav; Bakardjieva, Snejana; Murafa, Nataliya; Kalendová, Andrea; Opluštil, Frantisek

    2007-05-01

    Nanocrystalline mixed oxides of Ti, Zn, Al and Fe were prepared by a homogeneous hydrolysis of sulphates with urea at temperature of 100 °C in an aqueous solution. The prepared samples were characterized by BET and BJH measurements, an X-ray powder diffraction and scanning electron microscopy. These oxides were taken for an experimental evaluation of their reactivity with yperite (2,2‧-dichloroethyl sulphide), soman (3,3-dimethyl-2-butyl methylphosphonofluoridate) and matter VX (O-ethyl S-2-(diisopropylamino)ethyl methylphosphonothionate). An excellent activity in decomposition of chemical warfare agents was observed in these materials (conversion degree higher then 96%/h).

  16. Nanocasting of Periodic Mesoporous Materials as an Effective Strategy to Prepare Mixed Phases of Titania.

    PubMed

    Mahoney, Luther; Rasalingam, Shivatharsiny; Wu, Chia-Ming; Koodali, Ranjit T

    2015-12-08

    Mesoporous titanium dioxide materials were prepared using a nanocasting technique involving silica SBA-15 as the hard-template. At an optimal loading of titanium precursor, the hexagonal periodic array of pores in SBA-15 was retained. The phases of titanium dioxide could be easily varied by the number of impregnation cycles and the nature of titanium alkoxide employed. Low number of impregnation cycles produced mixed phases of anatase and TiO₂(B). The mesoporous TiO₂ materials were tested for solar hydrogen production, and the material consisting of 98% anatase and 2% TiO₂(B) exhibited the highest yield of hydrogen from the photocatalytic splitting of water. The periodicity of the pores was an important factor that influenced the photocatalytic activity. This study indicates that mixed phases of titania containing ordered array of pores can be prepared by using the nanocasting strategy.

  17. Preparation and properties of mixed-oxide pellets synthetized by GSP (gel supported precipitation) method

    SciTech Connect

    Centi, G.; Perathoner, S.; Marella, M.

    1995-12-01

    The preparation of TiO{sub 2}, ZrO{sub 2}, Al{sub 2}O{sub 3} or TiO{sub 2}-Al{sub 2}O{sub 3} and ZrO{sub 2}-Al{sub 2}O{sub 3} pellets synthesized by GSP (Gel Supported Method), their textural and physico-chemical characteristics and some examples of their use in cleanup technologies for the removal of nitrogen-oxide pollutants are reported, showing how this preparation methodology is well suited for the production of pure and mixed oxide supports for catalytic applications in fluid- or mobile-bed reactor technologies. The advantages in using mixed oxide for the promotion of the characteristics of zirconia or titania samples are also discussed. In comparison with sol-gel approach, the GSP method is based on the precipitation of the hydroxide of the element(s) with organic additives that allow to obtain hard spherical pellets.

  18. Investigation into mixing capability and solid dispersion preparation using the DSM Xplore Pharma Micro Extruder.

    PubMed

    Sakai, Toshiro; Thommes, Markus

    2014-02-01

    The goal of this investigation was to qualify the DSM Xplore Pharma Micro Extruder as a formulation screening tool for early-stage hot-melt extrusion. Dispersive and distributive mixing was investigated using soluplus, copovidone or basic butylated methacrylate copolymer with sodium chloride (NaCl) in a batch size of 5 g. Eleven types of solid dispersions were prepared using various drugs and carriers in batches of 5 g in accordance with the literature. The dispersive mixing was a function of screw speed and recirculation time and the particle size was remarkably reduced after 1 min of processing, regardless of the polymers. An inverse relationship between the particle size and specific mechanical energy (SME) was also found. The SME values were higher than those in large-scale extruders. After 1 min recirculation at 200 rpm, the uniformity of NaCl content met the criteria of the European Pharmacopoeia, indicating that distributive mixing was achieved in this time. For the solid dispersions preparations, the results from different scanning calorimetry, powder X-ray diffractometry and in-vitro dissolution tests confirmed that all solid-dispersion systems were successfully prepared. These findings demonstrated that the extruder is a useful tool to screen solid-dispersion formulations and their material properties on a small scale. © 2013 Royal Pharmaceutical Society.

  19. Preparation of anatase/rutile mixed-phase titania nanoparticles for dye-sensitized solar cells.

    PubMed

    Hwang, Yong-Kyung; Park, Sung Soo; Lim, Jun-Heok; Won, Yong Sun; Huh, Seong

    2013-03-01

    Acid-labile high surface mesoporous ZnO/Zn(OH)2 composite material is used as a novel hard template for the preparation of mesoporous amorphous TiO2. The template-free amorphous TiO2 material is then thermally crystallized at suitable temperature to control the relative ratio of anatase and rutile phases in a particle. Four different anatase/rutile (AR) mixed-phase TiO2 nanoparticles (AR-3, AR-15, AR-20, and AR-23 denoted for the samples of 3%, 15%, 20%, and 23% rutile phase, respectively) are prepared and characterized by powder X-ray diffraction (PXRD) and transmission electron microscopy (TEM). The coexistence of anatase and rutile phases in a TiO2 nanoparticle is visually confirmed by HRTEM analysis. These mixed-phase TiO2 nanoparticles are examined as candidates for photoelectrodes of dye-sensitized solar cells (DSSCs). The J-V curves and IPCE spectra for the DSSCs prepared from the mixed-phase TiO2 nanoparticles are obtained, and their photovoltaic properties are investigated. The photo-conversion efficiency (eta) indicates the highest value of 5.07% for AR-20. The synergistic effect of coexisting anatase and rutile phases with an optimal ratio in a TiO2 nanoparticle of AR-20 for an efficient interfacial transfer of photo-generated electrons is likely to lead to the highest efficiency among the AR-n samples.

  20. Preparation of uniform nanoparticles of ultra-high purity metal oxides, mixed metal oxides, metals, and metal alloys

    DOEpatents

    Woodfield, Brian F.; Liu, Shengfeng; Boerio-Goates, Juliana; Liu, Qingyuan; Smith, Stacey Janel

    2012-07-03

    In preferred embodiments, metal nanoparticles, mixed-metal (alloy) nanoparticles, metal oxide nanoparticles and mixed-metal oxide nanoparticles are provided. According to embodiments, the nanoparticles may possess narrow size distributions and high purities. In certain preferred embodiments, methods of preparing metal nanoparticles, mixed-metal nanoparticles, metal oxide nanoparticles and mixed-metal nanoparticles are provided. These methods may provide tight control of particle size, size distribution, and oxidation state. Other preferred embodiments relate to a precursor material that may be used to form nanoparticles. In addition, products prepared from such nanoparticles are disclosed.

  1. MAPLE prepared heterostructures with oligoazomethine: Fullerene derivative mixed layer for photovoltaic applications

    NASA Astrophysics Data System (ADS)

    Stanculescu, A.; Rasoga, O.; Socol, M.; Vacareanu, L.; Grigoras, M.; Socol, G.; Stanculescu, F.; Breazu, C.; Matei, E.; Preda, N.; Girtan, M.

    2017-09-01

    Mixed layers of azomethine oligomers containing 2,5-diamino-3,4-dicyanothiophene as central unit and triphenylamine (LV5) or carbazol (LV4) at both ends as donor and fullerene derivative, [6,6]-phenyl-C61 butyric acid butyl ester ([C60]PCB-C4) as acceptor, have been prepared by Matrix Assisted Pulsed Laser Evaporation (MAPLE) on glass/ITO and Si substrates. The effect of weight ratio between donor and acceptor (1:1; 1:2) and solvent type (chloroform, dimethylsulphoxide) on the optical (UV-vis transmission/absorption, photoluminescence) and morphological properties of LV4 (LV5): [C60]PCB-C4 mixed layers has been evidenced. Dark and under illumination I-V characteristics of the heterostructures realized with these mixed layers sandwiched between ITO and Al electrodes have revealed a solar cell behavior for the heterostructures prepared with both LV4 and LV5 using chloroform as matrix solvent. The solar cell structure realized with oligomer LV5, glass/ITO/LV5: [C60]PCB-C4 (1:1) has shown the best parameters.

  2. Mixed chimerism and permanent specific transplantation tolerance induced by a nonlethal preparative regimen

    SciTech Connect

    Sharabi, Y.; Sachs, D.H.

    1989-02-01

    The use of allogeneic bone marrow transplantation as a means of inducing donor-specific tolerance across MHC barriers could provide an immunologically specific conditioning regimen for organ transplantation. However, a major limitation to this approach is the toxicity of whole body irradiation as currently used to abrogate host resistance and permit marrow engraftment. The present study describes methodology for abrogating host resistance and permitting marrow engraftment without lethal irradiation. Our preparative protocol involves administration of anti-CD4 and anti-CD8 mAbs in vivo, 300-rad WBI, 700-rad thymic irradiation, and unmanipulated fully MHC-disparate bone marrow. B10 mice prepared by this regimen developed stable mixed lymphohematopoetic chimerism without any clinical evidence of graft-vs.-host disease. Engraftment was accompanied by induction of specific tolerance to donor skin grafts (B10.D2), while third-party skin grafts (B10.BR) were promptly rejected. Mice treated with the complete regimen without bone marrow transplantation appeared healthy and enjoyed long-term survival. This study therefore demonstrates that stable mixed chimerism with donor-specific tolerance can be induced across an MHC barrier after a nonlethal preparative regimen, without clinical GVHD and without the risk of aplasia.

  3. Porous structures of polymer films prepared by spin coating with mixed solvents under humid condition.

    PubMed

    Park, Min Soo; Joo, Wonchul; Kim, Jin Kon

    2006-05-09

    We investigate the effects of interfacial energy between water and solvent as well as polymer concentration on the formation of porous structures of polymer films prepared by spin coating of cellulose acetate butyrate (CAB) in mixed solvent of tetrahydrofuran (THF) and chloroform under humid condition. The interfacial energy between water and the solvent was gradually changed by the addition of chloroform to the solvent. At a high polymer concentration (0.15 g/cm3 in THF), porous structures were limited only at the top surfaces of CAB films, regardless of interfacial energies, due to the high viscosity of the solution. At a medium concentration (approximately 0.08 g/cm3 in THF), CAB film had relatively uniform pores at the top surface and very small pores inside the film because of the mixing of the water droplets with THF solution. When chloroform was added to THF, pores at the inner CAB film had a comparable size with those at the top surface because of the reduced degree of the mixing between the water droplets and the mixed solvent. A further decrease in polymer concentration (0.05 g/cm3 in THF) caused the final films to have a two-layer porous structure, and the size of pores at each layer was almost the same.

  4. Preparation and properties of uniform mixed and coated colloidal particles. Part 5. Zirconium compounds

    SciTech Connect

    Alken, B.; Hsu, W.P.; Matijevic, E.

    1990-01-01

    Colloidal dispersions of uniform spherical particles by zirconium basic sulphate and zirconium oxy-basic carbonate were prepared by ageing zirconium sulphate solutions at elevated temperatures in the presence of urea. Different chemical compositions of the above products resulted when the ageing temperature was altered. Depending on the nature of the original solids, calcination at 800 C resulted in the formation of tetragonal or monoclinic zirconia. Under certain conditions a mixed phase, including cubic zirconia, has also been identified. The particle morphology was retained during these transformations. Coprecipitation in mixed solutions of zirconium and yttrium salts aged at 80 C yielded composite spherical particles of basic carbonate with a zirconium to yttrium ratio of the solid similar to that used in the initial solution.

  5. Dielectric properties of mixed composites prepared from nanodisperse silica and triglycine sulfate

    NASA Astrophysics Data System (ADS)

    Milovidova, S. D.; Rogazinskaya, O. V.; Sidorkin, A. S.; Vorotnikov, E. V.; Nguen, Kh. T.; Lazarev, A. P.

    2015-03-01

    The dielectric properties of mixed composites prepared from the nanodisperse silica and ferroelectrics triglycine sulfate have been studied. The performed investigations have demonstrated that, for the composites containing silica in the hydrosol state, the temperature shift of the maximum dielectric permeability is more significant in the case of composites with smaller silica nanoparticles. There is another maximum at lower temperatures in the temperature dependence of the dielectric permeability of the composite containing silica in the gel state, in addition to the maximum detected in the sol-based composite, which is attributed to ordering of the silica particles in the gels in cross-linked structures.

  6. Preparation and internal stress estimation of BN films by ion mixing and vapour deposition technique

    NASA Astrophysics Data System (ADS)

    Hanaki, S.; Leng, B.; Uchida, H.

    2010-07-01

    Boron Nitride (BN) films were synthesized onto silicone wafer by depositing B metal vapour under simultaneous irradiation of N ions. Here, film thickness, ion beam energy and transport ratio (B/N) were selected as a preparation parameter and they were controlled in the range of 0.2-1μm, 0.2~2keV and 1~5, respectively. The BN films prepared were characterized using several analytical techniques and their internal stresses were estimated using Stoney's equation. From Fourier transform infrared spectroscopy, it was found that use of low energy N ions is effective for the formation of cubic BN (cBN) phase using ion mixing and vapour deposition (IVD) technique. At this condition, high compressive stress is measured and strong correlations were found among crystal structure, internal stress and Knoop hardness of BN films.

  7. Studies on preparation of mixed fruit toffee from Fig and Guava fruits.

    PubMed

    Kohinkar, S N; Chavan, U D; Pawar, V D; Amarowicz, R

    2014-09-01

    Studies were carried out to develop a technology for preparation of mixed fruit toffee from fig and guava fruit pulp and to evaluate the changes in quality of prepared toffees during storage under ambient as well as refrigerated conditions for 180 days. Among the various combinations of fig and guava fruit pulp, toffee prepared from75:25 w/w (fig: guava) ratios was found better than other combinations in respect to yield, organoleptic properties and nutritional quality. The cost of toffee prepared from higher level of fig pulp i.e. 75:25 (fig:guava) ratio was higher (Rs. 71.84/kg). The storage studies of toffees packed in 200 gauge polyethylene bags indicated that the TSS, reducing and total sugars increased with the advancement of storage period, while moisture and acidity content decreased. The rate of reactions was relatively higher at ambient temperature than refrigerated temperature. Though the sensory quality of toffees also decreased at faster rate during 180 days storage period at ambient condition than the refrigerated condition yet the toffees were found to be acceptable even after 180 days at both the conditions.

  8. NOVEL PREPARATION AND MAGNETO CHEMICAL CHARACTERIZATION OF NANO-PARTICLE MIXED ALCOHOL CATALYSTS

    SciTech Connect

    Seetala V. Naidu; Upali Siriwardane; Akundi N. Murty

    2004-02-23

    formation of carbides is higher for iron compared to cobalt. In the Fe/Co mixed catalyst, it is observed that the presence of iron enhances the cobalt oxide reduction. Catalyst with mixed metal Fe/Co compositions at 12% nitrate solutions (prepared by sol-gel/oil-drop) showed the best conversion rates for the syngas (CO+H{sub 2}). Nano-particle catalysts on sol-gel prepared mesoporous {gamma}-alumina (particularly the nano-particle metal oxide co-entrapped-sol-gel) showed higher conversion rates compared to conventional catalysts prepared by coprecipitation methods.

  9. Human primary mixed brain cultures: preparation, differentiation, characterization and application to neuroscience research.

    PubMed

    Ray, Balmiki; Chopra, Nipun; Long, Justin M; Lahiri, Debomoy K

    2014-09-16

    Culturing primary cortical neurons is an essential neuroscience technique. However, most cultures are derived from rodent brains and standard protocols for human brain cultures are sparse. Herein, we describe preparation, maintenance and major characteristics of a primary human mixed brain culture, including neurons, obtained from legally aborted fetal brain tissue. This approach employs standard materials and techniques used in the preparation of rodent neuron cultures, with critical modifications. This culture has distinct differences from rodent cultures. Specifically, a significant numbers of cells in the human culture are derived from progenitor cells, and the yield and survival of the cells grossly depend on the presence of bFGF. In the presence of bFGF, this culture can be maintained for an extended period. Abundant productions of amyloid-β, tau and proteins make this a powerful model for Alzheimer's research. The culture also produces glia and different sub-types of neurons. We provide a well-characterized methodology for human mixed brain cultures useful to test therapeutic agents under various conditions, and to carry forward mechanistic and translational studies for several brain disorders.

  10. Preparing Future Scholars for Academia and Beyond: A Mixed Method Investigation of Doctoral Students' Preparedness for Multiple Career Paths

    ERIC Educational Resources Information Center

    Cason, Jennifer

    2016-01-01

    This action research study is a mixed methods investigation of doctoral students' preparedness for multiple career paths. PhD students face two challenges preparing for multiple career paths: lack of preparation and limited engagement in conversations about the value of their research across multiple audiences. This study focuses on PhD students'…

  11. Preparing Future Scholars for Academia and Beyond: A Mixed Method Investigation of Doctoral Students' Preparedness for Multiple Career Paths

    ERIC Educational Resources Information Center

    Cason, Jennifer

    2016-01-01

    This action research study is a mixed methods investigation of doctoral students' preparedness for multiple career paths. PhD students face two challenges preparing for multiple career paths: lack of preparation and limited engagement in conversations about the value of their research across multiple audiences. This study focuses on PhD students'…

  12. A mixed solvent system for preparation of spherically agglomerated crystals of ascorbic acid.

    PubMed

    Ren, Fuzheng; Zhou, Yaru; Liu, Yan; Fu, Jinping; Jing, Qiufang; Ren, Guobin

    2017-09-01

    The objective of this research was to develop a novel solvent system to prepare spherically agglomerated crystals (SAC) of ascorbic acid with improved flowability for direct compression. A spherical agglomeration method was developed by selecting the mixed solvents (n-butyl and ethyl acetate) as a poor solvent and the process was further optimized by using triangular phase diagram and particle vision measurement. Physiochemical properties of SAC were characterized and compared with original drug crystals. It showed that amount of poor solvent, ratio of solvent mixture, and drug concentration are critical for preparation of SAC with desirable properties. The solid state of SAC was same as original crystals according to DSC, XRD, and FT-IR results. There was no significant difference in solubility and dissolution rate of drug between SAC and original crystals. The flowability and packability of SAC as well as the tensile strength and elastic recovery of tablets made from SAC were all significantly improved when compared with original crystals and tablets from crystals. It is concluded that the present method was suitable to prepare SAC of ascorbic acid for direct compression.

  13. Preparation and performance study of a novel liquid scintillator with mixed solvent as the matrix

    NASA Astrophysics Data System (ADS)

    Zheng, Zhanlong; Zhu, Jiayi; Luo, Xuan; Xu, Yewei; Zhang, Qianfeng; Zhang, Xing; Bi, Yutie; Zhang, Lin

    2017-04-01

    A novel liquid scintillator with the mixed solvent as the matrix was prepared for obtaining a good comprehensive performance. In this ternary liquid scintillator, the combination of 20% pseudocumene (PC) and 80% linear-alkyl benzene (LAB) by volume was chosen as the mixed solvent, and 2,5-diphenyloxazole (PPO) and 1,4-bis(2-Methylstyryl) benzene (bis-MSB) were as the primary fluor and wavelength shifter, respectively. The optimum prescription was obtained with regard to the light yield. Some characterizations based on the optimal formulation were conducted. The fluorescence emission spectra and wavelength-dependent optical attenuation length of the sample were measured by the fluorescence spectrophotometer and an UV-Vis spectrometer, respectively. The light yield was characterized by adopting the home-made optical platform device. The decay time was tested by adopting the time-correlated single photon counting (TCSPC) technique featured in high dynamic range of several orders of magnitude in light intensity. The experimental test results showed that the sample had a fairly good comprehensive performance.

  14. Self-assembled hybrid metal oxide base catalysts prepared by simply mixing with organic modifiers

    NASA Astrophysics Data System (ADS)

    Tamura, Masazumi; Kishi, Ryota; Nakagawa, Yoshinao; Tomishige, Keiichi

    2015-10-01

    Multidentate materials formed by simply mixing heterogeneous and homogeneous components are promising for construction of versatile active sites on the surface of heterogeneous compounds, however, to the best of our knowledge, there are no reports on such materials. Self-assembly of hetero-hybrid catalytic materials occurs when heterogeneous catalysts having adjacent Lewis acid-Lewis base sites are mixed with an organic modifier that contains at least two Lewis base functional groups. Here we demonstrate the strategy by combining cerium oxide and 2-cyanopyridine that self-assembles to form a charge-transfer complex in methanol that exhibits a 2,000-fold increase in reaction rate for hydromethoxylation of acrylonitrile with high selectivity compared with cerium oxide or 2-cyanopyridine alone. The catalytic system is applied to the transesterification and Knoevenagel condensation affording 14-fold and 11-fold higher activity, respectively, than cerium oxide alone. These results demonstrate the potential versatility of the catalytic system and the generality of the catalyst preparation strategy.

  15. Preparation of extrusions of bulk mixed oxide compounds with high macroporosity and mechanical strength

    DOEpatents

    Flytzani-Stephanopoulos, Maria; Jothimurugesan, Kandaswami

    1990-01-01

    A simple and effective method for producing bulk single and mixed oxide absorbents and catalysts is disclosed. The method yields bulk single oxide and mixed oxide absorbent and catalyst materials which combine a high macroporosity with relatively high surface area and good mechanical strength. The materials are prepared in a pellet form using as starting compounds, calcined powders of the desired composition and physical properties these powders are crushed to broad particle size distribution, and, optionally may be combined with an inorganic clay binder. The necessary amount of water is added to form a paste which is extruded, dried and heat treated to yield and desired extrudate strength. The physical properties of the extruded materials (density, macroporosity and surface area) are substantially the same as the constituent powder is the temperature of the heat treatment of the extrudates is approximately the same as the calcination temperature of the powder. If the former is substantially higher than the latter, the surface area decreases, but the macroporosity of the extrusions remains essentially constant.

  16. Self-assembled hybrid metal oxide base catalysts prepared by simply mixing with organic modifiers

    PubMed Central

    Tamura, Masazumi; Kishi, Ryota; Nakagawa, Yoshinao; Tomishige, Keiichi

    2015-01-01

    Multidentate materials formed by simply mixing heterogeneous and homogeneous components are promising for construction of versatile active sites on the surface of heterogeneous compounds, however, to the best of our knowledge, there are no reports on such materials. Self-assembly of hetero-hybrid catalytic materials occurs when heterogeneous catalysts having adjacent Lewis acid-Lewis base sites are mixed with an organic modifier that contains at least two Lewis base functional groups. Here we demonstrate the strategy by combining cerium oxide and 2-cyanopyridine that self-assembles to form a charge-transfer complex in methanol that exhibits a 2,000-fold increase in reaction rate for hydromethoxylation of acrylonitrile with high selectivity compared with cerium oxide or 2-cyanopyridine alone. The catalytic system is applied to the transesterification and Knoevenagel condensation affording 14-fold and 11-fold higher activity, respectively, than cerium oxide alone. These results demonstrate the potential versatility of the catalytic system and the generality of the catalyst preparation strategy. PMID:26436638

  17. Preparation of the sludge activated carbon with domestic sludge mixed agricultural straw

    NASA Astrophysics Data System (ADS)

    Wang, Laifu; Wang, Yan; Lian, Jingyan

    2017-01-01

    Urban sewage sludge with complicated composition produce largely each year, pollution problem and resource utilization has increasingly become the focus of attention. Sewage sludge is utilized to prepare adsorbent that is a new type method. Agricultural stalks was added to material (urban sewage sludge) and activator (ZnCl2), calcined under the condition of no inert gas, and obtained domestic sludge activated carbon. The properties were measured by iodine adsorption value and BET, discussed influence factors of sludge activated carbon preparation, including activator concentration, solid-liquid ratio, calcific temperature and calcific time. The best process condition of orthogonal experiment had explored that activated time is 10 minutes, calcific temperature is 350°C, the activator concentration ZnCl2 is 3 mol/L and the mixing ratio of raw materials and activator is approximately 1:5. The iodine adsorption value and the optimal BET of as-obtained domestic sludge activated carbon is 445.06 mg/g, 525.31m2/g, respectively.

  18. Preparing students to practice evidence-based dentistry: a mixed methods conceptual framework for curriculum enhancement.

    PubMed

    Palcanis, Kent G; Geiger, Brian F; O'Neal, Marcia R; Ivankova, Nataliya V; Evans, Retta R; Kennedy, Lasonja B; Carera, Karen W

    2012-12-01

    This article describes a mixed methods conceptual framework for evidence-based dentistry to enhance the curriculum at the University of Alabama at Birmingham School of Dentistry. A focus of recent curriculum reform has been to prepare students to integrate evidence-based dentistry into clinical practice. The authors developed a framework consisting of four conceptual phases to introduce curriculum innovation: 1) exploration of the phenomenon; 2) development of two new instruments; 3) data collection, analysis, outcomes, and evaluation; and 4) application to curricular reform. Eight sequential procedural steps (literature review; focus group discussions; development of themes; survey design; internal review; data collection, analysis, and evaluation; development of recommendations with external review; and implementation of recommendations for curricular enhancement) guided the curricular enhancement. Faculty members supported the concept of teaching evidence-based dentistry to facilitate major curriculum reform, and course directors incorporated evidence-based teaching to prepare scientist-practitioners who meet dental performance standards. The new curriculum implemented following completion of the study is in its third year. Much of its structure is based on evidence-based teaching methodologies, and approximately one-third of the content consists of small groups researching clinical problems with applied science and discussing the findings. The framework described in this article proved useful to guide revision of predoctoral clinical education at one dental school and may be useful in other settings.

  19. Bile salt/phospholipid mixed micelle precursor pellets prepared by fluid-bed coating.

    PubMed

    Dong, Fuxia; Xie, Yunchang; Qi, Jianping; Hu, Fuqiang; Lu, Yi; Li, Sanming; Wu, Wei

    2013-01-01

    Bile salt/phospholipid mixed micelles (MMs) are potent carriers used for oral absorption of drugs that are poorly soluble in water; however, there are many limitations associated with liquid formulations. In the current study, the feasibility of preparing bile salt/phospholipid MM precursor (preMM) pellets with high oral bioavailability, using fluid-bed coating technology, was examined. In this study, fenofibrate (FB) and sodium deoxycholate (SDC) were used as the model drug and the bile salt, respectively. To prepare the MMs and to serve as the micellular carrier, a weight ratio of 4:6 was selected for the sodium deoxycholate/phospholipids based on the ternary phase diagram. Polyethylene glycol (PEG) 6000 was selected as the dispersion matrix for precipitation of the MMs onto pellets, since it can enhance the solubilizing ability of the MMs. Coating of the MMs onto the pellets using the fluid-bed coating technology was efficient and the pellets were spherical and intact. MMs could be easily reconstituted from preMM pellets in water. Although they existed in a crystalline state in the preMM pellets, FB could be encapsulated into the reconstituted MMs, and the MMs were redispersed better than solid dispersion pellets (FB:PEG = 1:3) and Lipanthyl®. The redispersibility of the preMM pellets increased with the increase of the FB/PEG/micellar carrier. PreMM pellets with a FB:PEG:micellar carrier ratio of 1:1.5:1.5 showed 284% and 145% bioavailability relative to Lipanthyl® and solid dispersion pellets (FB:PEG = 1:3), respectively. Fluid-bed coating technology has considerable potential for use in preparing sodium deoxycholate/phospholipid preMM pellets, with enhanced oral bioavailability for poorly water-soluble drugs.

  20. Magnetic resonance imaging of the phase separation in mixed preparations of moisturizing cream and steroid ointment after centrifugation.

    PubMed

    Onuki, Yoshinori; Funatani, Chiaki; Yokawa, Takashi; Yamamoto, Yoshihisa; Fukami, Toshiro; Koide, Tatsuo; Obata, Yasuko; Takayama, Kozo

    2015-01-01

    A mixed preparation consisting of a water-in-oil emulsion-type moisturizing cream and a steroid ointment is frequently prescribed for the treatment of atopic dermatitis. We have investigated the compatibility of moisturizing creams and ointments because there are concerns regarding the physical stability of these mixed preparations. The key technology used in this study was magnetic resonance imaging (MRI). A commercial moisturizing cream and white petrolatum or clobetasone butyrate (CLB) ointment samples were mixed in a weight ratio of 1 : 1. A centrifugation test protocol (20000×g for 3 min) was implemented to accelerate the destabilization processes in the samples. After centrifugation, the mixed preparations separated into three distinct layers (upper, middle, and lower), while no phase separation was observed using moisturizing cream alone. The phase separation was monitored using chemical shift selective images of water and oil and quantitative T2 maps. In addition, MR and near-infrared spectroscopy were employed for component analysis of each phase-separated layer. Collectively, it was confirmed that the lower layer contained water, oils, and organic solvent, while the upper and middle layers were composed solely of oils. Furthermore, this study investigated the distribution of CLB in the phase-separated samples and showed that a heterogeneous distribution existed. From our results, it was confirmed that the mixed preparation became unstable because of the incompatibility of the moisturizing cream and ointment.

  1. Preparation of mixed molecularly imprinted polymer magnetic nanoparticles and its application in separation of Chinese traditional medicine

    NASA Astrophysics Data System (ADS)

    Xie, Yihui; Ma, Yajuan; Bai, Wenting; Zhu, Xiaofang; Liu, Min; Huang, Liping

    2017-08-01

    A mixed imprinted polymer which can rapidly adsorb all flavonoids from raspberry extract was prepared and recycled. The hybrid molecular surface imprinted polymers were prepared by using quercetin as the template molecule and Fe3O4 magnetic nanospheres as the carrier. The molecular imprinting polymer was prepared by using the "initial template molecule, molecularly imprinted polymer, mixed template molecule, molecularly imprint ted polymers (MIPS)". The adsorption performance and durability of the hybrid molecularly imprinted polymers were investigated by using the fingerprints of the ethyl acetate fraction of raspberry as an index. The adsorption of flavonoids from raspberry extract, lindenoside, cis-lindenin, quercetin, kaempferol and other flavonoids was completely adsorbed by mixed molecular-imprinted polymer, and the other components were basically adsorbed. When Mix-IMPs were repeatedly used 10 times, the fingerprints showed that the content and content of flavonoids were basically the same. The experimental results show that Mix-IMPs has good adsorption performance, can be recycled and used for rapid enrichment of flavonoids in raspberry.

  2. Self-Efficacy and Preparation of Scholarly Writing: Online Doctoral Coursework to Comprehensive Examination--a Mixed Method Study

    ERIC Educational Resources Information Center

    Thomas, Sonya C.

    2013-01-01

    Writing is seldom explicitly taught, most specifically, in academic and scholarly writing. Therefore, this mixed methods correlational phenomenology research study explored the correlation between self-efficacy perception and course room preparation for the comprehensive examination, APA standards in the course room, APA standards evaluation for…

  3. Self-Efficacy and Preparation of Scholarly Writing: Online Doctoral Coursework to Comprehensive Examination--a Mixed Method Study

    ERIC Educational Resources Information Center

    Thomas, Sonya C.

    2013-01-01

    Writing is seldom explicitly taught, most specifically, in academic and scholarly writing. Therefore, this mixed methods correlational phenomenology research study explored the correlation between self-efficacy perception and course room preparation for the comprehensive examination, APA standards in the course room, APA standards evaluation for…

  4. Delphi`s DETOXSM process: Preparing to treat high organic content hazardous and mixed wastes

    SciTech Connect

    Robertson, D.T.; Rogers, T.W.; Goldblatt, S.D.

    1998-12-31

    The US Department of Energy (DOE) Federal Energy Technology Center is sponsoring a full-scale technology demonstration of Delphi Research, Inc.`s patented DETOX{sup SM} catalytic wet chemical oxidation waste treatment process at the Savannah River Site (SRS) in South Carolina. The process is being developed primarily to treat hazardous and mixed wastes within the DOE complex as an alternative to incineration, but it has significant potential to treat wastes in the commercial sector. The results of the demonstration will be intensively studied and used to validate the technology. A critical objective in preparing for the demonstration was the successful completion of a programmatic Operational Readiness Review. Readiness Reviews are required by DOE for all new process startups. The Readiness Review provided the vehicle to ensure that Delphi was ready to start up and operate the DETOX{sup SM} process in the safest manner possible by implementing industry accepted management practices for safe operation. This paper provides an overview of the DETOX{sup SM} demonstration at SRS, and describes the crucial areas of the Readiness Review that marked the first steps in Delphi`s transition from a technology developer to an operating waste treatment services provider.

  5. A new and improved method for the preparation of drug nanosuspension formulations using acoustic mixing technology.

    PubMed

    Leung, Dennis H; Lamberto, David J; Liu, Lina; Kwong, Elizabeth; Nelson, Todd; Rhodes, Timothy; Bak, Annette

    2014-10-01

    Drug discovery and development is a challenging area. During the drug optimization process, available drug compounds often have poor physicochemical and biopharmaceutical properties, making the proper in vivo evaluation of these compounds difficult. To address these challenges, drug nanoparticles of poorly soluble compounds have emerged as a promising formulation approach. Herein, we report on a new drug sparing technology utilizing low shear acoustic mixing to rapidly identify optimized nanosuspension formulations for a wide range of compounds with dramatically improved material and time efficiencies. This approach has several key advantages over typical methods of preparing nanoparticles, including miniaturization of the milling process, the ability to evaluate multiple formulation conditions in a high throughput manner, and direct translation to optimized formulation scale-up for in vivo studies. Furthermore, there are additional benefits obtained with this new approach resulting in nanosuspension formulations with significant stability and physical property enhancements over those obtained using traditional media milling techniques. These advantages make this approach highly suitable for the rapid evaluation of potential drug candidates in the discovery and development space. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. [Preparation and characterization of cucurbitacin B sodium deoxycholate/phospholipid-mixed oral fast dissolving film and antitumor activity study].

    PubMed

    Yu, Chao; Xiao, Yun-Zhi; Xun, Ping-Hua; Dai, Ling; Han, Jin; Yuan, Hai-Long

    2014-05-01

    A novel drug delivery system combining oral fast dissolving film with sodium deoxycholate/phospholipid mixed micelles was prepared to increase the absorption of cucurbitacin B that is a poor aqueous solubility substance. Encapsulation efficiency, particle size, zeta potential, polydispersity coefficient, investigated the morphology, disintegration time of oral fast dissolving film and the pharmacodynamic properties of cucurbitacin B sodium deoxycholate/phospholipid-mixed micelles before and after solidified in mice were evaluated and compared. The oral fast dissolving film prepared in this study showed a homogeneous pale yellow and could completely disintegrated in the 30 s. It could meet the requirements of rapidly disintegrating fully. The encapsulation efficiency, particle size, zeta potential, polydispersity coefficient of cucurbitacin B sodium deoxycholate/phospholipid-mixed micelles loaded in oral fast dissolving film were (43.36 +/- 2.12)%, (108.82 +/- 5.2) nm, (-34.18 +/- 1.07) mV, 0.088 +/- 0.012, respectively. The encapsulation efficiency, particle size, zeta potential, polydispersity coefficient of cucurbitacin B sodium deoxycholate/phospholipid-mixed micelles in solution were (41.26 +/- 2.22)%, (181.82 +/- 4.48) nm, (-30.67 +/- 0.81) mV, 0.092 +/- 0.012, respectively. The difference of pharmacodynamics among film of cucurbitacin B-loaded micelles, cucurbitacin B-loaded micelles and free cucurbitacin B in vivo was compared. Solubility of cucurbitacin B loaded in sodium deoxycholate/phospholipid-mixed micelles has also been greatly improved. The tumor inhibition rate of cucurbitacin B loaded in sodium deoxycholate/phospholipid-mixed micelles was significantly improved and did not change significantly before and after solidified. These showed that the sodium deoxycholate/phospholipid-mixed micelles could enhance the antitumor activities of cucurbitacin B and the stability of cucurbitacin B sodium deoxycholate/phospholipid-mixed micelles was improved

  7. NOVEL PREPARATION AND MAGNETO CHEMICAL CHARACTERIZATION OF NANO-PARTICLE MIXED ALCOHOL CATALYSTS

    SciTech Connect

    Seetala V. Naidu; Upali Siriwardane

    2005-01-14

    We have developed effective nanoparticle incorporated heterogeneous F-T catalysts starting with the synthesis of Fe, Co, Cu nanoparticles using Fe(acac){sub 3}, Co(acac){sub 2}, and Cu(acac){sub 2} precursors and incorporating the nanoparticles into alumina sol-gel to yield higher alkanes production. SEM/EDX, XRD, BET, VSM and SQUID experimental techniques were used to characterize the catalysts, and GC/MS were used for catalytic product analysis. The nanoparticle oxide method gave the highest metal loading. In case of mixed metals it seems that Co or Cu interferes and reduces Fe metal loading. The XRD pattern for nanoparticle mixed metal oxides show alloy formation between cobalt and iron, and between copper and iron in sol-gel prepared alumina granules. The alloy formation is also supported by DTA and VMS data. The magnetization studies were used to estimate the catalyst activity in pre- and post-catalysts. A lower limit of {approx}40% for the reduction efficiency was obtained due to hydrogenation at 450 C for 4 hrs. About 85% of the catalyst has become inactive after 25 hrs of catalytic reaction, probably by forming carbides of Fe and Co. The low temperature (300 K to 4.2 K) SQUID magnetometer results indicate a superparamagnetic character of metal nanoparticles with a wide size distribution of < 20 nm nanoparticles. We have developed an efficient and economical procedure for analyzing the F-T products using low cost GC-TCD system with hydrogen as a carrier gas. Two GC columns DC 200/500 and Supelco Carboxen-1000 column were tested for the separation of higher alkanes and the non-condensable gases. The Co/Fe on alumina sol-gel catalyst showed the highest yield for methane among Fe, Co, Cu, Co/Fe, Cu/Co, Fe/Cu. The optimization of CO/H{sub 2} ratio indicated that 1:1 ratio gave more alkanes distribution in F-T process with Co/Fe (6% each) impregnated on alumina mesoporous catalyst.

  8. Preparative separation and purification of rebaudioside a from steviol glycosides using mixed-mode macroporous adsorption resins.

    PubMed

    Liu, Yongfeng; Di, Duolong; Bai, Qingqing; Li, Jintian; Chen, Zhenbin; Lou, Song; Ye, Helin

    2011-09-14

    Preparative separation and purification of rebaudioside A from steviol glycosides using mixed-mode macroporous adsorption resins (MARs) were systematically investigated. Mixed-mode MARs were prepared by a physical blending method. By evaluation of the adsorption/desorption ratio and adsorption/desorption capacity of mixed-mode MARs with different proportions toward RA and ST, the mixed-mode MAR 18 was chosen as the optimum strategy. On the basis of the static tests, it was found that the experimental data fitted best to the pseudosecond-order kinetics and Temkin-Pyzhev isotherm. Furthermore, the dynamic adsorption/desorption experiments were performed on the mini column packed with mixed-mode MAR 18. After one run treatment, the purity of rebaudioside A in purified product increased from 40.77 to 60.53%, with a yield rate of 38.73% (W/W), and that in residual product decreased from 40.77 to 36.17%, with a recovery yield of 57.61% (W/W). The total recovery yield reached 96.34% (W/W). The results showed that this method could be utilized in large-scale production of rebaudioside A from steviol glycosides in industry.

  9. Stability of Mixed Preparations Consisting of Commercial Moisturizing Creams with an Ointment Base Investigated by Magnetic Resonance Imaging.

    PubMed

    Onuki, Yoshinori; Funatani, Chiaki; Yamamoto, Yoshihisa; Fukami, Toshiro; Koide, Tatsuo; Hayashi, Yoshihiro; Takayama, Kozo

    2017-01-01

    A moisturizing cream mixed with a steroid ointment is frequently prescribed to patients suffering from atopic dermatitis. However, there is a concern that the mixing operation causes destabilization. The present study was performed to investigate the stability of such preparations closely using magnetic resonance imaging (MRI). As sample preparations, five commercial moisturizing creams that are popular in Japan were mixed with an ointment base, a white petrolatum, at a volume ratio of 1 : 1. The mixed preparations were stored at 60°C to accelerate the destabilization processes. Subsequently, the phase separations induced by the storage test were monitored using MRI. Using advanced MR technologies including spin-spin relaxation time (T2) mapping and MR spectroscopy, we successfully characterized the phase-separation behavior of the test samples. For most samples, phase separations developed by the bleeding of liquid oil components. From a sample consisting of an oil-in-water-type cream, Urepearl Cream 10%, a distinct phase-separation mode was observed, which was initiated by the aqueous component separating from the bottom part of the sample. The resultant phase separation was the most distinct among the test samples. To investigate the phase separation quantitatively and objectively, we conducted a histogram analysis on the acquired T2 maps. The water-in-oil type creams were found to be much more stable after mixing with ointment base than those of oil-in-water type creams. This finding strongly supported the validity of the mixing operation traditionally conducted in pharmacies.

  10. Comparison of slurry mixing and dry milling in laboratory sample preparation for determination of ochratoxin A and deoxynivalenol in wheat.

    PubMed

    Lippolis, Vincenzo; Pascale, Michelangelo; Valenzano, Stefania; Visconti, Angelo

    2012-01-01

    The significance of laboratory sample preparation for the determination of two important mycotoxins, ochratoxin A (OTA) and deoxynivalenol (DON), in wheat was investigated by comparing water-slurry mixing and dry-milling procedures. The distribution of OTA and DON in 10 kg samples of naturally contaminated wheat was established by analyzing one hundred 100 g subsamples of each sample. A normal distribution and a good repeatability of DON measurements was observed for both water-slurry mixing (mean 2290 microg/kg, CV 4.6%, median 2290 microg/kg) and dry milling (mean 2310 microg/kg, CV 6.4%, median 2290 microg/kg) procedures. For OTA determinations, reliable results could be obtained only by slurry mixing sample preparation (mean 2.62 microg/kg, CV 4.0%, median 2.62 microg/kg), whereas dry-milling comminution resulted in an inhomogeneous distribution with a high variability (mean 0.83 microg/kg, CV 75.2%, median 0.60 microg/kg) and a positive skewness (2.12). Ad hoc experiments were performed on different size portions of the same sample (10 kg) to assess accuracy and precision of the comminution/homogenization procedures (slurry mixing and dry milling). Very good results were obtained for DON determination with both procedures in terms of accuracy (>98.7% of the "weighted value") and precision (CV <3%). For OTA determination good results were only obtained by slurry mixing (99.4% of the "weighted value," CV 10%), whereas dry milling provided results with low accuracy (43.2% of the "weighted value") and high variability (CV 110%). This study clearly demonstrated that sample preparation by slurry mixing is strictly necessary to obtain reliable laboratory samples for OTA determination in wheat to minimize misclassification of acceptable/rejectable lots, mainly within official control.

  11. NOVEL PREPARATION AND MAGNETO CHEMICAL CHARACTERIZATION OF NANOPARTICLE MIXED ALCOHOL CATALYSTS

    SciTech Connect

    Seetala V. Naidu; Upali Siriwardane

    2005-05-24

    We have developed and streamlined the experimental systems: (a) Laser-induced solution deposition (LISD) photosynthesis, ball-milling, and chemical synthesis of Fe, Co, and Cu nanoparticle catalysts; (b) Sol-gel method for mesoporous {gamma}-Al{sub 2}O{sub 3}, SiO{sub 2}, hybrid alumina/silica granular supports; (c) Three sol-gel/oil-drop catalyst preparation methods to incorporate metal nanoparticles into mesoporous 1 mm granular supports; (d) Low-cost GC-TCD system with hydrogen as carrier gas for the determination of wide spectrum of alkanes produced during the F-T reactions; and (e) Gas-flow reactor and microchannel reactor for fast screening of catalysts. The LISD method could produce Co, Cu, and Fe (5 nm) nanoparticles, but in milligram quantities. We could produce nanoparticles in gram quantities using high-energy ball milling and chemical synthesis methods. Ball milling gave wide particle size distribution compared to the chemical synthesis method that gave almost uniform size ({approx}5 nm) particles. Metal nanoparticles Cu, Co, Fe, Cu/Co, Cu/Fe and Co/Fe were loaded (2-12 wt%) uniformly into {gamma}-Al{sub 2}O{sub 3}, SiO{sub 2}, or alumina/silica hybrid supports by combined sol-gel/oil-drop methods followed by calcination and hydrogenation steps, prior to syngas FT reaction studies. The properties of metal loaded {gamma}-Al{sub 2}O{sub 3} granules were compared for the two precursors: aluminum tri-sec-butoxide (ALTSB) and aluminum tri-iso-propoxide (ALTIP). The effect of solgel supports alumina, silica, and alumina/silica hybrid were examined on catalytic properties. Metal loading efficiencies for pure metal catalysts increased in the order Co, Cu and Fe in agreement with solubility of metal hydroxides. In case of mixed metals, Co and Cu seams to interfere and reduce Fe metal loading when metal nitrate solutions are used. The solubility differences of metal hydroxides would not allow precise control of metal loading. We have overcome this problem by

  12. Preparation, spectroscopic characterization and antimicrobial activities of mixed metal (Sb and Bi) bridged derivatives with mixed sulfur donor ligands

    NASA Astrophysics Data System (ADS)

    Joshi, Sapana; Chauhan, H. P. S.; Carpenter, Nitin

    2017-01-01

    This article explores the syntheses of six mixed metal derivatives of antimony(III) and bismuth(III) by the reaction of ethane-1,2-dithiol and metal bis derivatives of dithiocarbamates and/or dithiophosphates ligands in 1:1:1 M stoichiometry. These derivatives have been characterized by physicochemical [elemental analysis (C, H, N, S, Sb and Bi), molecular weight and melting point determinations], spectral [UV-Visible, FTIR, NMR (1H, 13C and 31P)], powder X-ray diffraction studies. These derivatives have nano-ranged crystallite size (8.18-18.04 nm) with monoclinic crystal system. All the synthesized derivatives have two metal centers (Sb and Bi) which elevate the zone of inhibition against four bacterial and two fungal species as compared to single metal species (metal precursors) as well as standard drugs.

  13. Why should I prepare? A mixed method study exploring the motives of medical undergraduate students to prepare for clinical skills training sessions.

    PubMed

    Aalbers, Marlien W; Hommes, Juliette; Rethans, Jan-Joost; Imbos, Tjaart; Muijtjens, Arno M M; Verwijnen, Maarten G M

    2013-02-22

    Although preparation for educational activities is considered beneficial for student learning, many students do not perform preparatory assignments. This phenomenon has received little attention in the literature although it might provide medical educators with the opportunity to enhance student learning. Therefore, we explored why students prepare or not prepare. An explorative mixed methods study was performed. In a qualitative study, 24 short group interviews with medical undergraduate students (n=209) were conducted on why they prepared for skills training sessions. In a subsequent quantitative study the resulting themes were used to construct a questionnaire. The questionnaire was presented to all undergraduate medical students at Maastricht University and 847 students completed it. Scales were constructed by a combination of exploratory factor analysis, reliability analysis, and content analysis. Between-class differences in the scale scores were investigated using ANOVA. The qualitative study showed that students' opinions on preparation are influenced by both personal factors, categorized as 'personal learning style', 'attitudes and beliefs', and 'planning and organization', as well as external factors, including 'preparatory advice', 'pressure, consequence, and checking of preparation', 'teacher-related motivations', and 'contents and schedule of the training sessions'. The quantitative study showed that 'the objective structured clinical examination' and 'facilitation of both understanding and memorizing the learning material', were the two most motivating items. The two most demotivating aspects were 'other students saying that preparation was not useful' and 'indistinct preparatory advices'. Factor analyses yielded three scales: 'urge to learn', 'expected difficulties', and 'lack of motivation'. Between group differences were found between the three classes on the first two scales. Students make an active and complex choice whether to prepare or not

  14. Preparation of N-doped graphene by reduction of graphene oxide with mixed microbial system and its haemocompatibility.

    PubMed

    Fan, Mengmeng; Zhu, Chunlin; Feng, Zhang-Qi; Yang, Jiazhi; Liu, Lin; Sun, Dongping

    2014-05-07

    A steady, effective and environment friendly method of introducing nitrogen into graphene is by microbial reduction of graphene oxide with mixed microorganisms from the anode chamber of microbial fuel cells (MFC). Using this method, N-doped graphene is easily obtained under mild conditions and by simple treatment processes, with the N/C ratio reaching 8.14%. Various characterizations demonstrate that the as-prepared N-doped graphene has excellent properties and is comparable with, and in some aspects, even better than, pristine graphene (containing only elemental C) prepared by chemical methods. The N-doped graphene (mainly substitution of C in the plane of the graphene sheet) with uniform distribution of N was haemocompatible, nontoxic, and water-dispersible, all of which are desirable properties for biomaterials and attributable to a synergetic metabolic effect of mixed microorganisms.

  15. Nanoporous composites prepared by a combination of SBA-15 with Mg–Al mixed oxides. Water vapor sorption properties

    PubMed Central

    Pérez-Verdejo, Amaury; Pfeiffer, Heriberto; Ruiz-Reyes, Mayra; Santamaría, Juana-Deisy; Fetter, Geolar

    2014-01-01

    Summary This work presents two easy ways for preparing nanostructured mesoporous composites by interconnecting and combining SBA-15 with mixed oxides derived from a calcined Mg–Al hydrotalcite. Two different Mg–Al hydrotalcite addition procedures were implemented, either after or during the SBA-15 synthesis (in situ method). The first procedure, i.e., the post-synthesis method, produces a composite material with Mg–Al mixed oxides homogeneously dispersed on the SBA-15 nanoporous surface. The resulting composites present textural properties similar to the SBA-15. On the other hand, with the second procedure (in situ method), Mg and Al mixed oxides occur on the porous composite, which displays a cauliflower morphology. This is an important microporosity contribution and micro and mesoporous surfaces coexist in almost the same proportion. Furthermore, the nanostructured mesoporous composites present an extraordinary water vapor sorption capacity. Such composites might be utilized as as acid-base catalysts, adsorbents, sensors or storage nanomaterials. PMID:25161858

  16. Nanoporous composites prepared by a combination of SBA-15 with Mg-Al mixed oxides. Water vapor sorption properties.

    PubMed

    Pérez-Verdejo, Amaury; Sampieri, Alvaro; Pfeiffer, Heriberto; Ruiz-Reyes, Mayra; Santamaría, Juana-Deisy; Fetter, Geolar

    2014-01-01

    This work presents two easy ways for preparing nanostructured mesoporous composites by interconnecting and combining SBA-15 with mixed oxides derived from a calcined Mg-Al hydrotalcite. Two different Mg-Al hydrotalcite addition procedures were implemented, either after or during the SBA-15 synthesis (in situ method). The first procedure, i.e., the post-synthesis method, produces a composite material with Mg-Al mixed oxides homogeneously dispersed on the SBA-15 nanoporous surface. The resulting composites present textural properties similar to the SBA-15. On the other hand, with the second procedure (in situ method), Mg and Al mixed oxides occur on the porous composite, which displays a cauliflower morphology. This is an important microporosity contribution and micro and mesoporous surfaces coexist in almost the same proportion. Furthermore, the nanostructured mesoporous composites present an extraordinary water vapor sorption capacity. Such composites might be utilized as as acid-base catalysts, adsorbents, sensors or storage nanomaterials.

  17. Release profiles of dexamethasone dipropionate from admixtures of steroid and heparinoid ointments prepared by different mixing methods.

    PubMed

    Suzuki, Tsuneyoshi; Uchino, Tomonobu; Miyazaki, Yasunori; Kagawa, Yoshiyuki

    2012-01-01

    Characterization and release profiles of commercial dexamethasone dipropionate (DDP) from an innovator and 2 generic ointments (Methaderm (IM), Promethasone (GP), and Mainvate (GM)) and their admixtures with heparinoid ointment (Hirudoid Soft) were investigated. The admixtures were prepared using 2 mixing methods (slab or rotation/revolution mixer). Microscopic and FT-Raman spectrometric analyses revealed that the ointments, except for IM, contained DDP crystals. A silicone membrane was used for the evaluation of the DDP permeation. The permeated DDP amounts from GP and GM were lower than that from IM, indicating that DDP solubility in the ointment vehicle affected the release of DDP from the ointment. No significant differences were observed in DDP release between IM alone and its admixture prepared using a slab; however, DDP release from the admixture prepared using a rotation/revolution mixer was significantly lower than those from IM alone and its admixture by slab. In the GP system, DDP release from the admixtures by the 2 mixing methods was higher than that from GP alone, whereas no significant difference in DDP release between the 2 mixing methods was observed. No significant differences were observed between the GM and admixtures. The apparent solubility of DDP in the admixtures as determined by the ultracentrifugal separation method indicated that the DDP amount in the liquid phase of admixtures with GP was 6 times higher than that of admixtures with IM or GM. Therefore, the apparent solubility of DDP in the liquid phase in the GP system might influence the DDP release in admixtures.

  18. Preparation and characterization of pure and mixed monolayers of poly(ethylene glycol) brushes chemically adsorbed to silica surfaces.

    PubMed

    McNamee, Cathy E; Yamamoto, Shinpei; Higashitani, Ko

    2007-04-10

    We prepared pure and mixed monolayers of methoxy-terminated poly(ethylene glycol)s (m-PEG's) chemically attached to silica surfaces by using m-PEG silane coupling agents of three different molecular weights. These films were subsequently characterized in water by atomic force microscopy (AFM). Images of pure m-PEG monolayers showed the formation of polymer brushes on silica. Force curves between two modified surfaces suggested that an increase in the number of oxyethylene (OE) groups from 6 (PEG6 surface) to 43 (PEG43 surface) to 113 (PEG113 surface) decreased the flexibility of the m-PEG chains in the m-PEG brushes. Frictional force measurements also showed that the friction increased in the order PEG6 < PEG43 Mixed monolayers of PEG6 and PEG113 were prepared using various fractions of PEG6 and PEG113. Images of mixed PEG6 and PEG113 monolayers showed that the size of the PEG113 islands in the film decreased as the fraction of PEG113 decreased. The force curves between two modified surfaces suggested that the flexibility of the mixed monolayers decreased as the fraction of PEG113 increased. Frictional force measurements also showed that the friction decreased as the fraction of PEG6 in the PEG6-PEG113 mixed film increased. Entanglements were therefore thought to decrease as the fraction of PEG113 in the mixed monolayer decreased.

  19. Preparation and evaluation of novel mixed micelles as nanocarriers for intravenous delivery of propofol

    NASA Astrophysics Data System (ADS)

    Li, Xinru; Zhang, Yanhui; Fan, Yating; Zhou, Yanxia; Wang, Xiaoning; Fan, Chao; Liu, Yan; Zhang, Qiang

    2011-12-01

    Novel mixed polymeric micelles formed from biocompatible polymers, poly(ethylene glycol)-poly(lactide) (mPEG-PLA) and polyoxyethylene-660-12-hydroxy stearate (Solutol HS15), were fabricated and used as a nanocarrier for solubilizing poorly soluble anesthetic drug propofol. The solubilization of propofol by the mixed micelles was more efficient than those made of mPEG-PLA alone. Micelles with the optimized composition of mPEG-PLA/Solutol HS15/propofol = 10/1/5 by weight had particle size of about 101 nm with narrow distribution (polydispersity index of about 0.12). Stability analysis of the mixed micelles in bovine serum albumin (BSA) solution indicated that the diblock copolymer mPEG efficiently protected the BSA adsorption on the mixed micelles because the hydrophobic groups of the copolymer were efficiently screened by mPEG, and propofol-loaded mixed micelles were stable upon storage for at least 6 months. The content of free propofol in the aqueous phase for mixed micelles was lower by 74% than that for the commercial lipid emulsion. No significant differences in times to unconsciousness and recovery of righting reflex were observed between mixed micelles and commercial lipid formulation. The pharmacological effect may serve as pharmaceutical nanocarriers with improved solubilization capacity for poorly soluble drugs.

  20. Why should I prepare? a mixed method study exploring the motives of medical undergraduate students to prepare for clinical skills training sessions

    PubMed Central

    2013-01-01

    Background Although preparation for educational activities is considered beneficial for student learning, many students do not perform preparatory assignments. This phenomenon has received little attention in the literature although it might provide medical educators with the opportunity to enhance student learning. Therefore, we explored why students prepare or not prepare. Methods An explorative mixed methods study was performed. In a qualitative study, 24 short group interviews with medical undergraduate students (n=209) were conducted on why they prepared for skills training sessions. In a subsequent quantitative study the resulting themes were used to construct a questionnaire. The questionnaire was presented to all undergraduate medical students at Maastricht University and 847 students completed it. Scales were constructed by a combination of exploratory factor analysis, reliability analysis, and content analysis. Between-class differences in the scale scores were investigated using ANOVA. Results The qualitative study showed that students’ opinions on preparation are influenced by both personal factors, categorized as ‘personal learning style’, ‘attitudes and beliefs’, and ‘planning and organization’, as well as external factors, including ‘preparatory advice’, ‘pressure, consequence, and checking of preparation’, ‘teacher-related motivations’, and ‘contents and schedule of the training sessions’. The quantitative study showed that ‘the objective structured clinical examination’ and ‘facilitation of both understanding and memorizing the learning material’, were the two most motivating items. The two most demotivating aspects were ‘other students saying that preparation was not useful’ and ‘indistinct preparatory advices’. Factor analyses yielded three scales: ‘urge to learn’, ‘expected difficulties’, and ‘lack of motivation‘. Between group differences were found between the three classes on the first

  1. Preparation of radioactive ''mixed'' waste samples for measurement of RCRA (Resource Conservation and Recovery Act) organic compounds. [Mixed waste containing alpha-, beta-, or gamma-emitting radionuclides

    SciTech Connect

    Tomkins, B.A.; Caton, J.E.

    1987-01-01

    A radioactive ''mixed'' waste typically contains alpha-, beta-, or gamma-emitting radionuclides and varying quantities of semivolatile or volatile organic species, some or all of which may be named specifically by the Resource Conservation and Recovery Act (RCRA). Because there are no acceptable means available currently for disposing of these mixed wastes, they are presently stored above-ground in sealed drums. For this reason, analytical procedures which can determine RCRA organics in radioactive waste are necessary for deciding the proper approach for disposal. An important goal of this work is the development of methods for preparing mixed waste samples in a manner which allows the RCRA organics to be measured in conventional organic analysis laboratories without special precautions. Analytical procedures developed for handling mixed waste samples must satisfy not only the usual constraints present in any trace-level organic chemical determination, but also those needed to insure the protection of the operator from radioactive contamination. Consequently, procedures should be designed to use the least amount of radioactive sample commensurate with achieving acceptable sensitivity with the RCRA analytical methods. Furthermore, the unusual laboratory glassware which would normally be used should be replaced with disposable materials wherever possible, in order to reduce the ''clean-up'' time required, and thereby reduce the operator's exposure to radioactivity. Actual sample handling should be reduced to the absolute minimum. Finally, the final isolate must exhibit a sufficiently low level of alpha, beta, or gamma activity to permit detailed characterization in a conventional organic analysis laboratory. 4 refs., 5 tabs.

  2. PREPARATION AND APPLICATION OF HIGH PERFORMANCE SILICONE RUBBER MIXED MATRIX MEMBRANES FOR ETHANOL-WATER PERVAPORATION

    EPA Science Inventory

    Polydimethyl siloxane (PDMS) and zeolite incorporated mixed matrix materials are gaining importance in a variety of applications including membrane separation. PDMS based membranes are used in pervaporation (PV), a membrane technology, for the selective removal of organics such ...

  3. PREPARATION AND APPLICATION OF HIGH PERFORMANCE SILICONE RUBBER MIXED MATRIX MEMBRANES FOR ETHANOL-WATER PERVAPORATION

    EPA Science Inventory

    Polydimethyl siloxane (PDMS) and zeolite incorporated mixed matrix materials are gaining importance in a variety of applications including membrane separation. PDMS based membranes are used in pervaporation (PV), a membrane technology, for the selective removal of organics such ...

  4. Plant growth response in experimental soilless mixes prepared from coal combustion products and organic waste materials

    SciTech Connect

    Bardhan, S.; Watson, M.; Dick, W.A.

    2008-07-15

    Large quantities of organic materials such as animal manures, yard trimmings, and biosolids are produced each year. Beneficial use options for them are often limited, and composting has been proposed as a way to better manage these organic materials. Similarly, burning of coal created 125 million tons of coal combustion products (CCP) in the United States in 2006. An estimated 53 million tons of CCP were reused, whereas the remainder was deposited in landfills. By combining CCP and composted organic materials (COM), we were able to create soilless plant growth mixes with physicochemical conditions that can support excellent plant growth. An additional benefit is the conservation of natural raw materials, such as peat, which is generally used for making soilless mixes. Experimental mixes were formulated by combining CCP and COM at ratios ranging from 2:8 to 8:2 (vol/vol), respectively. Water content at saturation for the created mixes was 63% to 72%, whereas for the commercial control, it was 77%. pH values for the best performing mixes ranged between 5.9 and 6.8. Electrical conductivity and concentrations of required plant nutrient were also within plant growth recommendations for container media. Significantly (P < 0.0001) higher plant biomass growth (7%-130%) was observed in the experimental mixes compared with a commercial mix. No additional fertilizers were provided during the experiment, and reduced fertilization costs can thus accrue as an added benefit to the grower. In summary, combining CCP and COM, derived from source materials often viewed as wastes, can create highly productive plant growth mixes.

  5. A mixed-solvent strategy for facile and green preparation of graphene by liquid-phase exfoliation of graphite

    NASA Astrophysics Data System (ADS)

    Yi, Min; Shen, Zhigang; Ma, Shulin; Zhang, Xiaojing

    2012-08-01

    A versatile and scalable mixed-solvent strategy, by which two mediocre solvents could be combined into good solvents for exfoliating graphite, is demonstrated for facile and green preparation of graphene by liquid-phase exfoliation of graphite. Mild sonication of crystal graphite powder in a mixture of water and alcohol could yield graphene nanosheets, which formed a highly stable suspension in the mixed solvents. The graphene yield was estimated as 10 wt%. The optimum mass fraction of ethanol in water-ethanol mixtures and isopropanol in water-isopropanol mixtures was experimentally determined as 40 and 55 % respectively, which could be roughly predicted by the theory of Hansen solubility parameters. Statistics based on atomic force microscopic analysis show that up to 86 % of the prepared nanosheets were less than 10-layer thick with a monolayer fraction of 8 %. High resolution transmission electron microscopy, infrared spectroscopy, X-ray diffraction, and Raman spectrum analysis of the vacuum-filtered films suggest the graphene sheets to be largely free of defects and oxides. The proposed mixed-solvent strategy here extends the scope for liquid-phase processing graphene and gives researchers great freedom in designing ideal solvent systems for specific applications.

  6. Formulation and Characterization of Solid Dispersion Prepared by Hot Melt Mixing: A Fast Screening Approach for Polymer Selection

    PubMed Central

    Enose, Arno A.; Dasan, Priya K.; Sivaramakrishnan, H.; Shah, Sanket M.

    2014-01-01

    Solid dispersion is molecular dispersion of drug in a polymer matrix which leads to improved solubility and hence better bioavailability. Solvent evaporation technique was employed to prepare films of different combinations of polymers, plasticizer, and a modal drug sulindac to narrow down on a few polymer-plasticizer-sulindac combinations. The sulindac-polymer-plasticizer combination that was stable with good film forming properties was processed by hot melt mixing, a technique close to hot melt extrusion, to predict its behavior in a hot melt extrusion process. Hot melt mixing is not a substitute to hot melt extrusion but is an aid in predicting the formation of molecularly dispersed form of a given set of drug-polymer-plasticizer combination in a hot melt extrusion process. The formulations were characterized by advanced techniques like optical microscopy, differential scanning calorimetry, hot stage microscopy, dynamic vapor sorption, and X-ray diffraction. Subsequently, the best drug-polymer-plasticizer combination obtained by hot melt mixing was subjected to hot melt extrusion process to validate the usefulness of hot melt mixing as a predictive tool in hot melt extrusion process. PMID:26556187

  7. Facile preparation of nanofiller-paper using mixed office paper without deinking

    Treesearch

    Qianqian Wang; J.Y. Zhu

    2015-01-01

    Mixed office paper (MOP) pulp without deinking with an ash content of 18.1 ± 1.5% was used as raw material to produce nanofiller-paper. The MOP pulp with filler was mechanically fibrillated using a laboratory stone grinder. Scanning electron microscope imaging revealed that the ground filler particles were wrapped by cellulose nanofibrils (CNFs), which substantially...

  8. Facile preparation of highly-dispersed cobalt-silicon mixed oxide nanosphere and its catalytic application in cyclohexane selective oxidation

    PubMed Central

    2011-01-01

    Highly dispersed cobalt-silicon mixed oxide [Co-SiO2] nanosphere was successfully prepared with a modified reverse-phase microemulsion method. This material was characterized in detail by X-ray diffraction, transmission electron microscopy, Fourier transform infrared, ultraviolet-visible diffuse reflectance spectra, X-ray absorption spectroscopy near-edge structure, and N2 adsorption-desorption measurements. High valence state cobalt could be easily obtained without calcination, which is fascinating for the catalytic application for its strong oxidation ability. In the selective oxidation of cyclohexane, Co-SiO2 acted as an efficient catalyst, and good activity could be obtained under mild conditions. PMID:22067075

  9. Single photon self-interference via inelastic two-wave mixing in a coherently prepared cold medium

    NASA Astrophysics Data System (ADS)

    Payne, M. G.; Deng, L.

    2007-03-01

    We investigate a coherently prepared cold medium for efficient single-photon inelastic two-wave mixing (ITWM), maximum Fock state entanglement and single photon self-interference. We show the possibility of generating maximally entangled single-photon state, and near 100% conversion efficiency for generating a frequency shifted TWM photon by proper choice of medium length and concentration. In addition, we demonstrate a new type of transparency effect produced by an efficient single photon self-interference, a transparency effect that is very different from the conventional electromagnetically induced transparency (EIT) process.

  10. Enhanced magnetization in highly crystalline and atomically mixed bcc Fe-Co nanoalloys prepared by hydrogen reduction of oxide composites

    NASA Astrophysics Data System (ADS)

    Sharif, Md Jafar; Yamauchi, Miho; Toh, Shoichi; Matsumura, Syo; Noro, Shin-Ichiro; Kato, Kenichi; Takata, Masaki; Tsukuda, Tatsuya

    2013-01-01

    FexCo100-x nanoalloys (NAs) with 20 <= x <= 80 were prepared by hydrogen reduction of Fe-Co oxide nano-composites, which were composed of mixed phases (or domains) of Fe2O3 and CoO. In situ X-ray diffraction (XRD) measurements using synchrotron radiation clearly showed development of a solid-solution Fe-Co phase by hydrogen reduction from the oxide composites. High-resolution transmission electron microscopy (TEM), high-angle annular dark-field scanning TEM and powder XRD revealed that Fe-Co NAs form a single crystal structure and the two elements are mixed homogeneously. The saturation magnetization depends on the size and metal composition and shows the highest value (250 emu g-1) for the Fe70Co30 NA in the size range of 30-55 nm, which is comparable to that of the Fe70Co30 bulk alloy (245 emu g-1). This high magnetization is attributable to high crystallinity and homogeneous mixing of constituent atoms, which are attained by thermal treatment of oxide phases under a hydrogen atmosphere.FexCo100-x nanoalloys (NAs) with 20 <= x <= 80 were prepared by hydrogen reduction of Fe-Co oxide nano-composites, which were composed of mixed phases (or domains) of Fe2O3 and CoO. In situ X-ray diffraction (XRD) measurements using synchrotron radiation clearly showed development of a solid-solution Fe-Co phase by hydrogen reduction from the oxide composites. High-resolution transmission electron microscopy (TEM), high-angle annular dark-field scanning TEM and powder XRD revealed that Fe-Co NAs form a single crystal structure and the two elements are mixed homogeneously. The saturation magnetization depends on the size and metal composition and shows the highest value (250 emu g-1) for the Fe70Co30 NA in the size range of 30-55 nm, which is comparable to that of the Fe70Co30 bulk alloy (245 emu g-1). This high magnetization is attributable to high crystallinity and homogeneous mixing of constituent atoms, which are attained by thermal treatment of oxide phases under a hydrogen

  11. Enhanced magnetization in highly crystalline and atomically mixed bcc Fe-Co nanoalloys prepared by hydrogen reduction of oxide composites.

    PubMed

    Sharif, Md Jafar; Yamauchi, Miho; Toh, Shoichi; Matsumura, Syo; Noro, Shin-ichiro; Kato, Kenichi; Takata, Masaki; Tsukuda, Tatsuya

    2013-02-21

    Fe(x)Co(100-x) nanoalloys (NAs) with 20 ≤ x ≤ 80 were prepared by hydrogen reduction of Fe-Co oxide nano-composites, which were composed of mixed phases (or domains) of Fe(2)O(3) and CoO. In situ X-ray diffraction (XRD) measurements using synchrotron radiation clearly showed development of a solid-solution Fe-Co phase by hydrogen reduction from the oxide composites. High-resolution transmission electron microscopy (TEM), high-angle annular dark-field scanning TEM and powder XRD revealed that Fe-Co NAs form a single crystal structure and the two elements are mixed homogeneously. The saturation magnetization depends on the size and metal composition and shows the highest value (250 emu g(-1)) for the Fe(70)Co(30) NA in the size range of 30-55 nm, which is comparable to that of the Fe(70)Co(30) bulk alloy (245 emu g(-1)). This high magnetization is attributable to high crystallinity and homogeneous mixing of constituent atoms, which are attained by thermal treatment of oxide phases under a hydrogen atmosphere.

  12. A Simplified Direct Lipid Mixing Lipoplex Preparation: Comparison of Liposomal-, Dimethylsulfoxide-, and Ethanol-Based Methods

    PubMed Central

    Meisel, Joseph W.; Gokel, George W.

    2016-01-01

    Established transfection methodology often uses commercial reagents, which must be formed into liposomes in a sequence of about half a dozen steps. The simplified method reported here is a direct lipid mixing approach that requires fewer steps, less manipulation, and is less time-consuming. Results are comparable to those obtained with more commonly used methods, as judged by a variety of analytical techniques and by comparisons of transfection results. The method reported here may be applied to non-liposome-forming compounds, thereby greatly expanding the range of structures that can be tested for transfection ability. PMID:27323668

  13. Food safety knowledge, practices and beliefs of primary food preparers in families with young children. A mixed methods study.

    PubMed

    Meysenburg, Rebecca; Albrecht, Julie A; Litchfield, Ruth; Ritter-Gooder, Paula K

    2014-02-01

    Food preparers in families with young children are responsible for safe food preparation and handling to prevent foodborne illness. To explore the food safety perceptions, beliefs, and practices of primary food preparers in families with children 10 years of age and younger, a mixed methods convergent parallel design and constructs of the Health Belief Model were used. A random sampling of 72 primary food handlers (36.2±8.6 years of age, 88% female) within young families in urban and rural areas of two Midwestern states completed a knowledge survey and participated in ten focus groups. Quantitative data were analyzed using SPSS. Transcribed interviews were analyzed for codes and common themes. Forty-four percent scored less than the average knowledge score of 73%. Participants believe children are susceptible to foodborne illness but perceive its severity to be low with gastrointestinal discomfort as the primary outcome. Using safe food handling practices and avoiding inconveniences were benefits of preventing foodborne illness. Childcare duties, time and knowledge were barriers to practicing food safety. Confidence in preventing foodborne illness was high, especially when personal control over food handling is present. The low knowledge scores and reported practices revealed a false sense of confidence despite parental concern to protect their child from harm. Food safety messages that emphasize the susceptibility and severity of foodborne illness in children are needed to reach this audience for adoption of safe food handling practices.

  14. Unexpected differences in dissolution behavior of tablets prepared from solid dispersions with a surfactant physically mixed or incorporated.

    PubMed

    de Waard, H; Hinrichs, W L J; Visser, M R; Bologna, C; Frijlink, H W

    2008-02-12

    In a previous study, it was shown that the incorporation of poorly soluble drugs (BCS class II) in sugar glasses could largely increase the drug's dissolution rate [van Drooge, D.J., Hinrichs, W.L.J., Frijlink, H.W., 2004 b. Anomalous dissolution behaviour of tablets prepared from sugar glass-based solid dispersions. J. Control. Release 97, 441-452]. However, the application of this technology had little effect when high drug loads or fast dissolving sugars were applied due to uncontrolled crystallization of the drug in the near vicinity of the dissolving tablet. To solve this problem a surfactant, sodium lauryl sulphate (SLS), was incorporated in the sugar glass or physically mixed with it. Diazepam and fenofibrate were used as model drugs in this study. The dissolution behavior of tablets prepared from solid dispersions in which SLS was incorporated was strongly improved. Surprisingly, the dissolution rate of tablets prepared from physical mixtures of SLS and the solid dispersion was initially fast, but slowed down after about 10 min. The solid dispersions were characterized by DSC to explain this unexpected difference. These measurements revealed the existence of interaction of SLS with both the drug and the sugar in the solid dispersion when SLS was incorporated. It is hypothesized that due to this interaction, the dissolution of SLS was slowed down by which a high solubility of the drug in the near vicinity of the dissolving tablet is maintained during the whole dissolution process. Therefore, uncontrolled crystallization is effectively prevented.

  15. Preparation of durable hydrophobic cellulose fabric from water glass and mixed organosilanes

    NASA Astrophysics Data System (ADS)

    Shang, Song-Min; Li, Zhengxiong; Xing, Yanjun; Xin, John H.; Tao, Xiao-Ming

    2010-12-01

    Durable superhydrophobic cellulose fabric was prepared from water glass and n-octadecyltriethoxysilane (ODTES) with 3-glycidyloxypropyltrimethoxysilane (GPTMS) as crosslinker by sol-gel method. The result showed that the addition of GPTMS could result in a better fixation of silica coating from water glass on cellulose fabric. The silanization of hydrolyzed ODTES at different temperatures and times was studied and optimized. The results showed that silanization time was more important than temperature in forming durable hydrophobic surface. The durability of superhydrophobicity treatment was analyzed by XPS. As a result, the superhydrophobic cotton treated under the optimal condition still remained hydrophobic properties after 50 washing cycles.

  16. The Preparation, Characterization and Photocatalytic Activity of Mixed P25/CeO2 Nanocomposites

    NASA Astrophysics Data System (ADS)

    Liu, I.-Tsan; Hon, Min-Hsiung; Teoh, Lay Gaik

    2017-03-01

    This study uses the wet chemical method to synthesize P25 (TiO2)/CeO2 composites by mixing P25 and Ce(NO3)3·6H2O at different volumetric concentrations. X-ray diffraction, transmission electron microscopy and ultraviolet-visible diffuse reflectance spectroscopy are used to analyze the structure, morphology, optical properties and photocatalytic activity of the TiO2/CeO2 composites with different compositions. The pollutant, methylene blue solution, was used for analysis. The results show that the photocatalytic activity of the composite catalysts is greater than that of pure TiO2 or pure CeO2. The catalyst, TiO2 55%/CeO2 (v/v), exhibits the greatest level of photocatalytic activity.

  17. The Preparation, Characterization and Photocatalytic Activity of Mixed P25/CeO2 Nanocomposites

    NASA Astrophysics Data System (ADS)

    Liu, I.-Tsan; Hon, Min-Hsiung; Teoh, Lay Gaik

    2017-01-01

    This study uses the wet chemical method to synthesize P25 (TiO2)/CeO2 composites by mixing P25 and Ce(NO3)3·6H2O at different volumetric concentrations. X-ray diffraction, transmission electron microscopy and ultraviolet-visible diffuse reflectance spectroscopy are used to analyze the structure, morphology, optical properties and photocatalytic activity of the TiO2/CeO2 composites with different compositions. The pollutant, methylene blue solution, was used for analysis. The results show that the photocatalytic activity of the composite catalysts is greater than that of pure TiO2 or pure CeO2. The catalyst, TiO2 55%/CeO2 (v/v), exhibits the greatest level of photocatalytic activity.

  18. Single-step preparation of the mixed Ba(II)-Nb(V) oxides from a heteropolynuclear oxalate complex.

    PubMed

    Jurić, Marijana; Popović, Jasminka; Šantić, Ana; Molčanov, Krešimir; Brničević, Nevenka; Planinić, Pavica

    2013-02-18

    A novel oxalate-based complex of the formula {Ba(2)(H(2)O)(5)[NbO(C(2)O(4))(3)]HC(2)O(4)}·H(2)O (1) was prepared from an aqueous solution containing the [NbO(C(2)O(4))(3)](3-) and Ba(2+) entities in the molar ratio 1:2, and characterized by X-ray single-crystal diffraction, IR spectroscopy, and thermal analysis. The crystal packing of 1 reveals a complex three-dimensional (3D) network: the Nb polyhedron is connected to eight neighboring Ba polyhedra through the oxalate ligands and the oxo-oxygen group, whereas the Ba polyhedra share edges and vertices. The ability of compound 1 to act as a single-source precursor for the formation of bimetallic oxides was investigated by the thermal analysis (TGA and DSC) and X-ray powder diffraction. Thermal processing of 1 resulted in the formation of mixed-metal oxide phases, Ba(4)Nb(2)O(9) and Ba(5)Nb(4)O(15). Three stable polymorphs of Ba(4)Nb(2)O(9) were isolated: the known, hexagonal α- and orthorhombic γ-Ba(4)Nb(2)O(9), and another one, not previously reported, hexagonal δ-Ba(4)Nb(2)O(9) polymorph. The new, δ-Ba(4)Nb(2)O(9) polymorph has the 6H-perovskite structure (space group P6(3)/m), in which the Nb(2)O(9)(8-) face-sharing octahedral dimers are interconnected via corners to the regular BaO(6)(10-) octahedra. Formation of the mixed-metal oxides takes place at different temperatures: the Ba(5)Nb(4)O(15) oxide occurred at ∼700 °C, as the major crystalline oxide phase; by heating the sample up to 1135 °C, the α-Ba(4)Nb(2)O(9) form was obtained, whereas the heating at 1175 °C caused the crystallization of two polymorphs, γ-Ba(4)Nb(2)O(9) and δ-Ba(4)Nb(2)O(9). Special focus was set on the electrical properties of the prepared mixed Ba(II)-Nb(V) oxides obtained by this molecular pathway in a single-step preparation.

  19. NOVEL PREPARATION AND MAGNETO CHEMICAL CHARACTERIZATION OF NANO-PARTICLE MIXED ALCOHOL CATALYSTS

    SciTech Connect

    Setala V. Naidu

    2003-01-01

    We have produced Co, Cu, and Fe nano-particles by Laser-induced solution deposition (LISD) as evidenced by TEM investigations. Sizes of the nano-particles created are in the order of 5 nm. The LISD system could generate nano-particles in quantities only in the order of a milligram. This may be mainly due to the limited photo induced reactions taking place on the surface of the solutions. We have designed experiments to use drop flow technique with LISD for nano-particle deposition on microreactors. Preliminary work has been done on Co and Fe thin film deposited microreactors. We are also investigating the catalytic properties of nano-particles of FeO and CoO prepared by ball milling and dispersed into sol-gel prepared alumina granules. We have continued our investigation of catalytic reactions of Cu, Co, Fe, Cu/Co, Cu/Fe and Co/Fe on alumina support. The metal oxides were first reduced with hydrogen and used for the conversion of CO/H{sub 2}. The surface area of the catalysts has been determined by nitrogen disorption. They are in the range of 200-300 m{sup 2}/g. Cu, Co, Fe, Co/Fe, Cu/Co and Cu/Fe showed increasing order of catalytic activity for CO/H{sub 2} conversion. We are also studying catalytic conversion rates for CO{sub 2}/H{sub 2} and CO/CO{sub 2}/H{sub 2} mixtures using these catalysts. Our investigations of Co and Fe thin film deposited microreactors showed higher CO/H{sub 2} conversion for Fe compared to Co. We have used vibrating sample magnetometer (VSM) to study the magnetic characteristics of as prepared, reduced, post-reaction catalysts. Comparative study of the ferromagnetic component of these samples gives the reduction efficiency and the changes in metal centers during catalytic reactions. Magnetic studies of post-reaction Co and Fe micro-reactors show that more carbide formation occurs for iron compared to cobalt.

  20. Preparation and in vitro evaluation of povidone-sodium cholate-phospholipid mixed micelles for the solubilization of poorly soluble drugs.

    PubMed

    Zhu, Yuan; Yu, Jiangnan; Tong, Shanshan; Wang, Li; Peng, Min; Cao, Xia; Xu, Ximing

    2010-06-01

    Mixed micelles made of polyvinylpyrrolidone (PVP), sodium cholate, and phospholipids were prepared to improve the solubility of poorly water-soluble drugs. Sylibin, a drug used in treating liver diseases, was incorporated into the mixed micelles. The formulation of sylibin containing PVP-sodium cholate-phospholipid mixed micelles with an optimized composition (PVP/sodium cholate/phospholipid/silybin = 3:3:4:1 approximately 2 by weight) was obtained based on the study of pseudoternary phase diagrams. The critical micelle concentration was used to evaluate the micellar stability towards dilution. The results showed that addition of PVP to sodium-cholate-phospholipid mixed micelles increased stability. The solubility of sylibin in PVP-sodium cholate-phospholipid mixed micelles was higher than that in pure water or in sodium cholate-phospholipid mixed micelles. In a stability study, we found that PVP-sodium cholate-phospholipid mixed micelles showed good stability. After 3 months storage at 40 degrees C, just 2.6% sylibin was lost with only minor changes of the particle size when compared to a reference formulation containing sodium cholate and phospholipid mixed micelles. In addition, the developed formulation significantly improved in vitro drug release. The time required to release 50% sylibin (t50%) from sodium cholate and phospholipid mixed micelles was 326 h, while the t50% from PVP-sodium cholate-phospholipid mixed micelles was only 51.1 h. Our results suggest that these mixed micelles might have significant potential application to the biomedical field.

  1. Characterisation of adsorbents prepared by pyrolysis of sludge and sludge/disposal filter cake mix.

    PubMed

    Velghe, I; Carleer, R; Yperman, J; Schreurs, S; D'Haen, Jan

    2012-05-15

    Copper and zinc removal from water (pH = 5.0) using adsorbents produced from slow and fast pyrolysis of industrial sludge and industrial sludge mixed with a disposal filter cake (FC), post treated with HCl, is investigated in comparison with a commercial adsorbent F400. The results show that a pseudo-second order kinetics model is followed. The Langmuir-Freundlich isotherm model is found to fit the data best. The capacity for heavy metal removal of studied adsorbents is generally better than that of commercial F400. The dominant heavy metal removal mechanism is cation exchange. Higher heavy metal removal capacity is associated with fast pyrolysis adsorbents and sludge/FC derived adsorbents, due to enhanced cation exchange. Improvement of Zn(2+) removal via 1 N HCl post-treatment is only effective when exchangeable cations of the adsorbent are substituted with H(+) ions, which boost the cation exchange capacity. Increase of temperature also enhances metal removal capacity. Fast pyrolysis sludge-based adsorbents can be reused after several adsorption-desorption cycles.

  2. Preparation and characterization of ceramic products by thermal treatment of sewage sludge ashes mixed with different additives.

    PubMed

    Merino, Ignacio; Arévalo, Luis F; Romero, Fernando

    2007-01-01

    The study of the ceramic characteristics of sludge ashes, alone or mixed with additives (kaolin, montmorillonite, illitic clay, powdered flat glass) includes characterization of additives, preparation of probes (dry or wet mixed), thermal treatment (up to 1200 degrees C, except melting or deformation) and control (densities, compressive strengths and water absorption). Thermal treatment increases the density and compressive strength of probes (both parameters go through maxima, with later decreases) and decreases the absorption of water. The densification is also revealed by the evolution of the ratio of decrease of volume/loss of mass. The maximum values of compressive strengths were obtained for 25% of illitic clay, montmorillonite and glass powder. Densification concerning probes with sludge ashes alone does not occur with kaolin. Experimental data were adjusted to exponential relationships between compressive strengths and densities for every composition, and also to a general equation for all probes. The apparent density obtained was adjusted to a non-linear dependence with temperature, leading to a maximum in density and permitting calculating the temperature of occurrence of this maximum. The adjustment was not possible for probes containing kaolin, requiring presumably higher temperatures to densify. Water absorption has low values for ashes or kaolin probes, intermediate values for illite and powdered flat glass probes and high values for montmorillonite probes. Excepting with kaolin, ceramic materials with better characteristics than sludge ashes without additives were obtained at lower treatment temperatures.

  3. Size- and morphology-controlled NH2-MIL-53(Al) prepared in DMF-water mixed solvents.

    PubMed

    Cheng, Xinquan; Zhang, Anfeng; Hou, Keke; Liu, Min; Wang, Yingxia; Song, Chunshan; Zhang, Guoliang; Guo, Xinwen

    2013-10-07

    We present here a simple solvothermal method to fabricate metal-organic framework NH2-MIL-53(Al) crystals with controllable size and morphology just by altering the ratio of water in the DMF-water mixed solvent system without the addition of any surfactants or capping agents. With increasing the volume ratio of water in the mixed solvents, a series of NH2-MIL-53(Al) crystals with different sizes and morphologies were synthesized. The average size of the smallest crystal is 76 ± 20 nm, which provides us a simple and environmentally friendly way to prepare nanoscale MOFs. The largest BET surface area of these samples is 1882 m(2) g(-1) that is mainly contributed by its micropore surface area, and its corresponding micropore volume is 0.83 cm(3) g(-1), which have greatly extended its application in the fields of gas adsorption and postsynthetic modification. All these samples were characterized by SEM, XRD, N2 adsorption/desorption, TGA and FT-IR. Then a mechanism for the impact of the water ratio on the crystal size and morphology is presented and discussed.

  4. A new process for preparation of soybean protein concentrate with hexane-aqueous ethanol mixed solvents.

    PubMed

    Zhang, Wei-Nong; Liu, Da-Chuan

    2005-01-01

    A new process for the preparation of soybean protein concentrate (SPC) by directly extracting full-fat soy flour with a mixture of hexane and aqueous ethanol was established. Compared with conventional methods, it has some advantages, such as saving energy and reducing protein denaturation caused by heat action during solvent recovery, because this process saves one step of solvent recovery. The effects of aqueous ethanol concentration and the mixure ratio (hexane to ethanol) on the degree of protein denaturation and product quality were investigated, on the basis of which the orthogonal tests were performed. The optimum technical parameters were obtained by analyzing the results of the orthogonal tests with statistical methods. We found that SPC can be obtained by extracting full-fat soy flour under the following conditions: mixture ratio hexane: 90% ethanol, 9:1, v/v; extraction temperature, 45 degrees C; ratio of solid to solvents, (1:2 w/v); and 5 repeated extractions (15 min each time). The results of quality analysis showed that solubility of the product was improved significantly [nitrogen solubility index (NSI) 46.6%] compared with that for ethanol washing of protein concentrate (NSI 8.7%).

  5. Preparation of trimers and tetramers of mixed sequence oligodeoxynucleoside methylphosphonates and assignment of configurations at the chiral phosphorus.

    PubMed Central

    Vyazovkina, E V; Rife, J P; Lebedev, A V; Wickstrom, E

    1993-01-01

    Synthesis of stereoregular DNA methylphosphonates has been accomplished for homo-oligomers, but remains a formidable problem for oligomers of a defined antisense target sequence. In this work, four trimer and tetramer deoxynucleoside methylphosphonates of mixed sequence (dACA, dCCAA, dAGGG, and dGCAT) were prepared by block coupling of diastereomerically pure dimers with either monomers or other diastereomerically pure dimers. These oligomers were separated chromatographically into individual diastereomers, and the configurations of the chiral methylphosphonate linkages were assigned. Three types of methods were used to assign configuration of a new methylphosphonate linkage: preparation of the same diastereomer through multiple synthetic pathways, base hydrolysis, and acid hydrolysis. Hydrolysis of the diastereomerically pure oligomers into component dimers and monomers was followed by chromatographic comparison with control dimers of known configuration. In all cases studied, oligomers with R configurations displayed faster elution from silica gel than did oligomers with the respective S configuration. NMR spectra of individual diastereomers of dACA were studied, revealing characteristic differences in chemical shifts which may prove useful in configurational assignments of longer oligomers. Thus, these data provide a methodological basis for synthesis and configurational assignment of longer methylphosphonate oligomers to use as antisense probes. PMID:8290358

  6. Looking back and moving forward: A mixed methods study of elementary science teacher preparation

    NASA Astrophysics Data System (ADS)

    Hulings, Melissa

    This study sought to understand how science learning experiences, and their potential influence, had on preservice elementary teachers' self-efficacy and perceptions of science teaching and learning at the beginning of their science methods course. Following an explanatory sequential mixed methods design, this study first involved the collection of quantitative data and then the collection of more in-depth qualitative data. In the first phase, the quantitative data included the Draw-a-Science-Teacher-Test Checklist (DASTT-C) and the Science Teaching Efficacy Belief Instrument (STEBI-B) of preservice elementary teachers (n = 69). Findings from this phase indicated preservice elementary teachers had a higher level of belief in their abilities to teach science (PSTE subscale) than to affect student outcomes in science (STOE subscale). However, the STOE was not found to be a reliable measure for this group of preservice elementary teachers and was not included in any further analysis. Findings from the DASTT-C images indicated the majority of these drawings could not be classified as student-centered. In the second phase of this study, the researcher explored selected science autobiographies written by these same preservice elementary teachers (n = 19), based on extremely high or low scores on the PSTE subscale and DASTT-C. Analysis of the science autobiographies revealed commonalities and differences. Commonalities included (a) the difficulty in remembering science from elementary school; (b) a mixture of positive and negative experiences in secondary school and college science classes; (c) the descriptions of good science days and good science teachers; and (d) the descriptions of bad science days and bad science teachers. Differences included (a) the people who influenced their attitudes toward science; (b) the types of experiences, when remembered, from elementary school; and (c) visions of their future classrooms. Based on these findings, these preservice

  7. Foaming of amorphous drug delivery systems prepared by hot melt mixing and extrusion

    NASA Astrophysics Data System (ADS)

    Terife, Graciela

    Currently there is considerable interest from both academe and pharmaceutical industry in exploring foaming processes and their products in drug delivery applications. However, there is still little knowledge of the impact of the morphology of the foamed structures on the performance of drug products in spite of some publications in this area. Therefore, the main objective of this dissertation is to gain a fundamental understanding of the correlation between foam morphology and performance of amorphous drug delivery systems, which are comprised of an Active Pharmaceutical Ingredient (API) and Polymer excipient. The Hot Melt Extrusion (HME) process is used to compound the following API / polymer binary systems: Indomethacin (INM) with SoluplusRTM (PVCap-PVAc-PEG); Carbamazepine (CBZ) with PVCap-PVAc-PEG; and INM with EudragitRTM EPO. Comprehensive characterization of these binary systems carried out by combining Differential Scanning Calorimetry, Fourier Transform Infrared spectroscopy, X-Ray Diffraction, and Scanning Electron Microscopy, shows that in all HME-prepared and foamed samples the APIs are amorphous and dissolved in the polymer excipients. The most important contributions of this dissertation can be grouped into three areas: (a) an understanding of the mechanisms by which foamed dosage forms can lead to faster API release, as well as the key morphological aspects of the cellular structures to achieve this, (b) an understanding of the correlation between the mechanism controlling the release of an API from an amorphous dosage and the enhancement in its release rate upon foaming, and (c) an understanding of the impact of the morphology of the cellular structures in the milling efficiency of HME products and the dissolution performance of the particles produced. In the first area, foamed amorphous solid solutions with three different morphologies are produced through the batch foaming process. A strong correlation between foam morphology and the enhancement

  8. Novel low temperature preparation methods for mixed complex oxide catalysts and their characterisation using in situ SR techniques

    NASA Astrophysics Data System (ADS)

    Beale, Andrew Michael

    The crystallisation of complex mixed oxide and metal phosphate oxidation catalysts prepared using a number of synthetic methods have been studied using in situ synchrotron radiation techniques. Some of these synthesis procedures have previously been employed to produce catalysts whilst others were new methods, making use of hydrothermal technology and zeolite precursors. For the iron phosphates catalysts studied it was observed that all of the synthetic methods employed produced a catalyst precursor having the chemical composition FePO4.2H2O. During calcination this phase transformed into the tridymite and quartz forms of FePO4 although, the material produced by hydrothermal methods was found to be the most phase pure and possess a higher surface area. A comparative study of the three catalytically active forms of bismuth molybdate revealed similar findings with two of the three phases observed (by EDXRD) to form directly from a precursor gel with an Avrami-Erofe'ev kinetic analysis of the crystallisation process suggesting that the mechanisms of formation were different for each phase. Hydrothermal methods were also used to prepare cobalt and manganese substituted aluminophosphate structures API and AEI, which were found to be efficient catalysts for the methanol to olefin reaction. However, it was also observed that during calcination to remove the structure-directing agent, that some of the cobalt and manganese in the tetrahedral framework sites underwent oxidation from 2+ to 3+ although the extent of this was found to be dependent upon both structure type and metal ion. Finally an investigation was carried out into the use of ion-exchanged zeolites as precursors for the low temperature crystallisation of the spinel structure CoA12O4. The results from this study suggested that very small spinel particles formed within the XRD amorphous collapsed zeolites although both zeolite structure type and cobalt salt were thought to have an effect on phase formation.

  9. Luminescence of (Mg,Zn)Al2O4:Tb mixed spinel thin films prepared by spin-coating

    NASA Astrophysics Data System (ADS)

    Kroon, R. E.; Tabaza, W. A. I.; Swart, H. C.

    2015-03-01

    MgAl2O4 and ZnAl2O4 both have the spinel structure and similar lattice constants, but the bandgap of MgAl2O4 is about double that of ZnAl2O4, making it interesting to consider the mixed spinel (MgxZn1-x)Al2O4 as a possible host for luminescent ions. Prior to preparing thin films, the Mg:Zn ratio and Tb concentration were optimized for green luminescence from the 5D4 - 7F5 transition of Tb3+ ions using nanocrystalline samples prepared by combustion synthesis. Thin films with x = 0.75 and 0.5 mol% Tb were spin-coated on Si(100) substrates using a solution of the nitrates of Mg, Zn, Al and Tb in ethanol, with ethylene glycol as complexing agent. Samples about 200 nm thick were obtained by sequentially depositing 10 layers at 3000 rpm for 30 s. Samples were annealed for 1 h in air before measuring their luminescence properties. For the sample annealed at 600 °C, x-ray diffraction showed the thin film had a strong (111) preferential orientation. Atomic force microscopy revealed a root means square roughness of 1 nm and Auger electron spectroscopy depth profiles showed a uniform layer with a sharp interface at the Si substrate. With an increase in annealing temperature up to 1000 °C, the luminescence increased while the surface became slightly rougher and the layer-substrate interface more interdiffused. Annealing the samples at 1200 °C resulted in diffusion of Si through the layer and the formation of an additional phase. While the green Tb emission was slightly reduced, blue emission from the 5D3 level of Tb3+ was greatly enhanced in these samples.

  10. Influencing Selectivity to Cancer Cells with Mixed Nanoparticles Prepared from Albumin-Polymer Conjugates and Block Copolymers.

    PubMed

    Jiang, Yanyan; Wong, Sandy; Chen, Fan; Chang, Ted; Lu, Hongxu; Stenzel, Martina H

    2017-04-19

    Albumin-based nanoparticles are widely used to delivery anticancer drug because they promote the accumulation of drugs in tumor sites. Nanoparticles with surface immobilized albumin are widely described in literature, although mixed nanoparticles with systematically modified ratios between albumin and PEG-based material are less common. In this work, hybrid nanoparticles were prepared by coassembly of a PEG-based amphiphilic block copolymer together with a polymer-protein conjugate. Poly(oligo(ethylene glycol) methyl ether acrylate)-poly(ε-caprolactone) (POEGMEA-PCL) was prepared by a combination of ring-opening polymerization and reversible addition-fragmentation chain transfer (RAFT) polymerization, while the polymer-protein conjugate was obtained by reacting poly(ε-caprolactone) with bovine serum albumin (BSA-PCL). Co-assembly of both amphiphiles at different ratios, with and without curcumin as a drug, led to hybrid nanoparticles with various amount of albumin on the particle surface. The resulting hybrid nanoparticles were similar in size (100-120 nm), but increasing the amount of albumin on the surface led to a more-negative ζ potential. The cytotoxicity of the curcumin-loaded nanoparticles was examined on several cell lines. The curcumin-loaded nanoparticles with high amount of albumin led to high cytotoxicity against breast cancer cell lines (MDA-MB-231 and MCF-7), which coincided with high cellular uptake. However, the cytotoxicity of the curcumin-loaded nanoparticles against CHO cells and RAW264.7 cells was reduced, suggesting that albumin can facilitate selectivity toward cancer cells.

  11. Instruction via Web-Based Modules in Early Childhood Personnel Preparation: A Mixed-Methods Study of Effectiveness and Learner Perspectives

    ERIC Educational Resources Information Center

    Hollingsworth, Heidi L.; Lim, Chih-Ing

    2015-01-01

    Effective personnel preparation is critical to the development of a high quality early childhood workforce that provides optimal care and education for young children. This mixed-methods study examined the effectiveness of, and learner perspectives on, instruction via web-based modules within face-to-face early childhood personnel preparation…

  12. Instruction via Web-Based Modules in Early Childhood Personnel Preparation: A Mixed-Methods Study of Effectiveness and Learner Perspectives

    ERIC Educational Resources Information Center

    Hollingsworth, Heidi L.; Lim, Chih-Ing

    2015-01-01

    Effective personnel preparation is critical to the development of a high quality early childhood workforce that provides optimal care and education for young children. This mixed-methods study examined the effectiveness of, and learner perspectives on, instruction via web-based modules within face-to-face early childhood personnel preparation…

  13. Effects of pre- and post-harvest site preparation treatments on natural regeneration success in a mixed hardwood stand after 10 years

    Treesearch

    Wayne K. Clatterbuck; Martin R. Schubert

    2010-01-01

    Advance regeneration, sprouts and seeds are sources of reproduction in the regeneration of mixed hardwood stands following harvest. The control of undesirable, non-commercial, competing vegetation is a common technique in site preparation to promote the establishment and growth of desirable species. This study was designed to evaluate the effectiveness of pre- and post...

  14. Effects of Processing Parameters on Internal Stress of BN Films Prepared by Ion Mixing and Vapor Deposition

    SciTech Connect

    Hanaki, Satoshi; Leng, Bo; Uchida, Hitoshi

    2010-10-13

    Boron nitride (BN) films have been attractive due to their excellent properties such as high hardness, thermal conductivity and chemical stability. In this study, BN films were prepared by depositing B vapor under simultaneous irradiation of N ions, that is ion mixing and vapor deposition (IVD) technique. The effects of processing parameters such as, acceleration voltage of N ions, transport ratio B/N and substrate temperature, on the internal stress of BN films were investigated. As a result, compressive internal stress increases at low acceleration voltage and high transport ratio B/N, which corresponded to the condition for formation of cBN phase. The hardness also becomes high at this condition and there is a strong correlation between internal stress and hardness of BN film. In addition to that, relaxation of internal stress by inserting inner layer between substrate and cBN layer has been carried out. It is confirmed that internal stress can be decreased by inner layer. Especially, relaxation of internal stress without degradation of high hardness can be achieved when the crystal structure of inner layer is hBN.

  15. [Research on standardized preparation of traditional Chinese medicine (III): difference of extracting quantity of anthraquinones from mixed decoction of rhubarb with TCMs containing different ingredients].

    PubMed

    Zeng, Lingna; Wang, Jiabo; Zhang, Pin; Zhao, Yanling; Li, Baocai; Liu, Feifei; Chu, Xiaohui; Xiao, Xiaohe

    2012-01-01

    To detect the influence of compatibility of rhubarb with different traditional Chinese medicines (TCM) on extracted quantities of AQs, and to provide scientific basis for the clinical code for rhubarb preparation. The influence of compatibility of rhubarb with different traditional Chinese medicines (saponin, alkaloids, flavonoids TCMs, animal medicines and mineral medicines) on decocting volume of anthraquinone substance was detected using ultra performance liquid chromatography. In comparable conditions, more AQs were extracted from mixed decoction of rhubarb and saponin medicinal materials (Astragali Radix, Notoginseng Radix et Rhizoma, Glycyrrhizae Radix et Rhizoma, Polygalae Radix, Ginseng Radix et Rhizoma) than single decocting of rhubarb. The mixed decoction of rhubarb and alkaloid medicinal materials (Coptidis Rhizoma, Sophorae Flavescentis Radix, Prepared Aconiti Lateralis Radix Praeparata, Phellodendri Chinensis Cortex, Aconiti Lateralis Radix) caused a remarkable decrease in extracted quantities of AQs. And the mixed decoction of rhubarb and mineral medicines (Natrii Sulfas, Gypsum Fibrosum, Ostreae Concha, Alumen) also resulted in less extracted quantities of AQs to varying degrees. Besides, more rhubarb AQs were extracted from mixed decoction with Curcuma than single decoction. But less rhubarb AQs were observed in mixed decoction with Lonicerae Flos, Rehmanniae, Artemisiae Herb and Forsythiae Fructus than single decoction to varying degrees. In the study, the maximum extracted quantities of AQs is 2. 3-fold higher than the minimum, the largest difference existed in the extracted quantity of physcion which was 13.5 times. In compatibility between rhubarb and different TMCs, mixed decoction and single decoction show different influences on extracted quantity of rhubarb AQs. It is proved that more AQs may be extracted from mixed decoction between rhubarb and saponin medicinal materials, whereas less AQs may be observed in mixed decoction between rhubarb

  16. Mixed matrix membranes with HF acid etched ZSM-5 for ethanol/water separation: Preparation and pervaporation performance

    NASA Astrophysics Data System (ADS)

    Zhan, Xia; Lu, Juan; Tan, Tingting; Li, Jiding

    2012-10-01

    The mixed matrix membranes (MMMs) were prepared from crosslinked PDMS incorporated with HF acid etched ZSM-5. ZSM-5 zeolite was etched with a series of HF aqueous-acetone solution and characterized by SEM, BET, XRD and FT-IR. It was found that HF etching process was very effective for removing organic impurities in zeolite and micro-pores were observed out of the surface of zeolite particles, which enhanced the hydrophobicity and surface roughness of ZSM-5 successfully. Both tensile strength and swelling resistance of ZSM-5/PDMS MMMs increased with the rising concentration of HF solution, which can mainly be attributed to the improved zeolite-PDMS interfacial adhesion resulted from the intrusion of PDMS into micro-pores out of the ZSM-5 surface. Subsequently, the sorption experiment was performed with the results suggesting preferential sorption of ethanol by MMMs. Moreover, the sorption selectivity of ZSM-5/PDMS MMMs increased notably as the concentration of HF solution increased. The pervaporation performance of ethanol/water mixtures using MMMs was also investigated in detail. The MMMs filled with etched ZSM-5 showed much better selectivity than that filled with non-etched ones, with a little expense of permeability. It was found that with the same zeolite loading, increasing the HF acid concentration in etching process enhanced the zeolite-PDMS interfacial adhesion which promoted the ethanol selectivity of MMMs, while depressed the total permeation flux a little. In addition, both ethanol permeation and the selectivity increased with an increase of the zeolite loading from 10% to 30%. Nevertheless, excessive zeolite loading or decreasing thickness of selective layer led to the poor selectivity to ethanol. A decline of the ethanol selectivity was also observed as the feed ethanol concentration as well as feed temperature increased.

  17. Extreme Rapid Weight Loss and Rapid Weight Gain Observed in UK Mixed Martial Arts Athletes Preparing for Competition.

    PubMed

    Matthews, Joseph John; Nicholas, Ceri

    2016-10-06

    There is a lack of research documenting the weight-making practices of mixed-martial-arts (MMA) competitors. The purpose of the investigation was to quantify the magnitude and identify the methods of rapid weight loss (RWL) and rapid weight gain (RWG) in MMA athletes preparing for competition. Seven athletes (mean ± SD, age 24.6 ± 3.5 yrs, body mass 69.9 ± 5.7 kg, competitive experience 3.1 ± 2.2 yrs) participated in a repeated-measures design. Measures of dietary intake, urinary hydration status, and body mass were recorded in the week preceding competition. Body mass decreased significantly (p<0.0005) from baseline by 5.6 ± 1.4 kg (8 ± 1.8%). During the RWG period (32 ± 1 hours) body mass increased significantly (p<0.001) by 7.4 ± 2.8 kg (11.7 ± 4.7%), exceeding RWL. Mean energy and carbohydrate intake were 3176 ± 482 kcal·day(-1) and 471 ± 124 g·day(-1), respectively. At the official weigh-in 57% of athletes were dehydrated (1033 ± 19 mOsmol·kg(-1)) and the remaining 43% were severely dehydrated (1267 ± 47 mOsmol·kg(-1)). Athletes reported using harmful dehydration-based RWL strategies, including sauna (43%) and training in plastic suits (43%). Results demonstrated RWG greater than RWL, this is a novel finding and may be attributable to the 32 hour duration from weigh-in till competition. The observed magnitude of RWL and strategies used are comparable to those which have previously resulted in fatalities. Rule changes which make RWL impractical should be implemented with immediate effect to ensure the health, safety and wellbeing of competitors.

  18. Preparation and characterization of long-circulating PELMD/mPEG-PLGA-mixed micelles for 10-hydroxycamptothecin

    NASA Astrophysics Data System (ADS)

    Yin, Shaoping; Li, Juan; Li, Nannan; Wang, Guangji; Gu, Xiaochen

    2014-02-01

    A novel long-circulating nano-delivery system was constructed using block copolymers of poly monomethoxy-(ethylene glycol)-poly( d,l-lactic- co-glycolic acid)-poly(3( S)-methyl-morpholine-2,5-dione) (PELMD) and poly-monomethoxy (ethylene glycol)-poly-( d,l-lactic- co-glycolic acid) (mPEG-PLGA). The two copolymers possessed satisfactory critical micelle concentration and hemolytic effect. Antitumor compound 10-hydroxycamptothecin (HCPT) was loaded to the mixed micelles to further characterize in vitro and in vivo properties. HCPT-mixed micelles were measured 165-205 nm in particle size, with spherical core-shell structure and uniform-size distribution. The zeta potentials of the mixed micelles ranged 15-20 mV, attributed to the polydesipeptide. Stability of the mixed micelles was improved without complex synthesis. Drug release from the mixed micelles was pH-dependent, which was beneficial for improving specific drug targeting to tumor tissues. HCPT-mixed micelles demonstrated prolonged retention and tissue targeting in animal models. Mean residence time (MRT0→∞) of HCPT-mixed micelles was significantly longer than that of HCPT injection, and biodistribution of the mixed micelles showed specific drug disposition in liver and lungs. The results indicated that PELMD/mPEG-PLGA-mixed micelles could become a potential drug delivery system for anticancer drugs to improve therapeutic efficacy and minimize adverse effects.

  19. Development of a novel and customizable two-solution mixing type spray nozzle for one-step preparation of nanoparticle-containing microparticles.

    PubMed

    Ozeki, Tetsuya; Akiyama, Yusuke; Takahashi, Norimitsu; Tagami, Tatsuaki; Tanaka, Toshiyuki; Fujii, Masashi; Okada, Hiroaki

    2012-01-01

    Production of drug nanoparticles is an effective strategy to enhance solubility and oral absorption of water-insoluble drugs. The handling of drug nanoparticles has been an important issue in drug formulation because nanoparticles easily aggregate each other and redispersion of these particles is very difficult. In the present study, we developed a unique two-solution mixing type spray nozzle that can prepare drug nanoparticles in microparticles in one step without any common solvent and surfactant, and then, the prepared formulation were evaluated. Ethylcellulose (EC) and mannitol (MAN) were used as a model polymer of water-insoluble compound and a water-soluble carrier, respectively. We characterized the EC/MAN microparticles produced by the novel spray nozzle when customizing the nozzle parts to mix EC and MAN solution. Relatively smaller EC nanoparticles (<110 nm) in MAN microparticles (approximately 3 µm) were obtained by changing the customizable parts in the nozzle. In addition, the core of EC nanoparticles (<50 nm) was also observed by atomic force microscopy. We also found that the mixing time in the nozzle parts affected the size and the standard deviation of EC nanoparticles. These results suggest that the size of EC nanoparticles in MAN microparticles is controllable by using this unique nozzle. After all, we could prepare MAN microparticles containing EC nanoparticles in one step by using the novel nozzle. The drug/MAN microparticles formulation produced by the nozzle may be useful for the handling of drug nanoparticles.

  20. Preparation of hydrophilic interaction/ion-exchange mixed-mode chromatographic stationary phase with adjustable selectivity by controlling different ratios of the co-monomers.

    PubMed

    Bo, Chunmiao; Wang, Xiaomeng; Wang, Chaozhan; Wei, Yinmao

    2017-03-03

    Development of mixed-mode chromatography (MMC) stationary phase with adjustable selectivity is beneficial to meet the needs of complex samples. In this work, surface-initiated atom transfer radical polymerization (SI-ATRP) using the mixture of two functional monomers was proposed as a new preparation strategy for MMC stationary phase with adjustable selectivity. The mixture of sodium 4-styrenesulfonate (NASS) and dimethylaminoethyl methacrylate (DMAEMA) underwent SI-ATRP to bond poly(NASS-co-DMAEMA) on the surface of silica to prepare hydrophilic interaction/ion-exchange mixed-mode stationary phase. Various analytes (neutral, acidic, basic analytes and strong polar nucleosides) were employed to investigate the retention behaviors. The influences of water content and pH of the mobile phase on the retention validated the mixed-mode retention mechanisms of HILIC and ion-exchange. The charge and polarity of stationary phase as well as the separation selectivity were conveniently manipulated by the ratio of NASS to DMAEMA monomer, and the use of DMAEMA in the mixture additionally endowed the column with the temperature-responsive characteristics. Moreover, the application of the developed column was demonstrated by the successful separation of nucleosides, β-agonists and safflower injection. In a word, the proposed strategy can be potentially applied in the controllable preparation of MMC stationary phase with adjustable selectivity.

  1. Structural and spectroscopic properties of high temperature prepared ZrO2-TiO2 mixed oxides

    NASA Astrophysics Data System (ADS)

    Gionco, Chiara; Battiato, Alfio; Vittone, Ettore; Paganini, Maria Cristina; Giamello, Elio

    2013-05-01

    ZrO2-TiO2 mixed oxides of various composition, with the molar fraction of TiO2 ranging from 0.1% to 15%, have been prepared via sol-gel synthesis and then calcined at 1273 K to check both their thermal stability and physicochemical properties. These solids are usually employed in photocatalytic processes and as active phase supports in heterogeneous catalysis. As indicated by X-ray diffraction and Raman spectroscopy, solid solutions based on Ti ions diluted in the ZrO2 matrix are formed in the whole range of Ti molar fraction examined. Materials with low Ti loading (0.1%-1%) are basically constituted by the monoclinic phase of ZrO2 while the tetragonal phase becomes prevalent at 15% of TiO2 molar fraction. The presence of Ti ions modify the electronic structure of the solid as revealed by investigation of the optical properties. The typical band gap transition of ZrO2 undergoes, in fact, a red shift roughly proportional to the Ti loading which reach the remarkable value of 1.6 eV for the sample with 10% of molar Ti concentration. Comparing chemical analysis of the solids with XPS data it has been put into evidence that the titanium ions distribution into the solid is not uniform and the concentration of Ti4+ tend to be higher in subsurface layers than in the crystal bulk. The introduction of titanium ions in the structure increases the reducibility of the solid. Annealing under vacuum at various temperatures causes oxygen depletion with consequent reduction of the solid which shows up mainly in terms of formation of Ti3+ reduced centres which are characterized by a typical EPR signal. Ti3+ defects forms, as also forecast by theoretical modelling of the solid, as their energy is lower than that of other possible reduced defective centers. The reduced solids are able to transfer electrons to adsorbed oxygen molecules in mild condition resulting in the formation of surface superoxide anions (O2•-) which are stabilized on surface Zr4+ or, alternatively, on Ti4+ ions

  2. Evidence summaries (decision boxes) to prepare clinicians for shared decision-making with patients: a mixed methods implementation study.

    PubMed

    Giguere, Anik M C; Labrecque, Michel; Haynes, R Brian; Grad, Roland; Pluye, Pierre; Légaré, France; Cauchon, Michel; Greenway, Matthew; Carmichael, Pierre-Hugues

    2014-10-05

    Decision boxes (Dboxes) provide clinicians with research evidence about management options for medical questions that have no single best answer. Dboxes fulfil a need for rapid clinical training tools to prepare clinicians for clinician-patient communication and shared decision-making. We studied the barriers and facilitators to using the Dbox information in clinical practice. We used a mixed methods study with sequential explanatory design. We recruited family physicians, residents, and nurses from six primary health-care clinics. Participants received eight Dboxes covering various questions by email (one per week). For each Dbox, they completed a web questionnaire to rate clinical relevance and cognitive impact and to assess the determinants of their intention to use what they learned from the Dbox to explain to their patients the advantages and disadvantages of the options, based on the theory of planned behaviour (TPB). Following the 8-week delivery period, we conducted focus groups with clinicians and interviews with clinic administrators to explore contextual factors influencing the use of the Dbox information. One hundred clinicians completed the web surveys. In 54% of the 496 questionnaires completed, they reported that their practice would be improved after having read the Dboxes, and in 40%, they stated that they would use this information for their patients. Of those who would use the information for their patients, 89% expected it would benefit their patients, especially in that it would allow the patient to make a decision more in keeping with his/her personal circumstances, values, and preferences. They intended to use the Dboxes in practice (mean 5.6±1.2, scale 1-7, with 7 being "high"), and their intention was significantly related to social norm, perceived behavioural control, and attitude according to the TPB (P<0.0001). In focus groups, clinicians mentioned that co-interventions such as patient decision aids and training in shared decision

  3. Preparation and characterization of Mg-Zr mixed oxide aerogels and their application as aldol condensation catalysts.

    PubMed

    Sádaba, Irantzu; Ojeda, Manuel; Mariscal, Rafael; Richards, Ryan; López Granados, Manuel

    2012-10-08

    A series of Mg-Zr mixed oxides with different nominal Mg/(Mg+Zr) atomic ratios, namely 0, 0.1, 0.2, 0.4, 0.85, and 1, is prepared by alcogel methodology and fundamental insights into the phases obtained and resulting active sites are studied. Characterization is performed by X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy, N(2) adsorption-desorption isotherms, and thermal and chemical analysis. Cubic Mg(x)Zr(1-x)O(2-x) solid solution, which results from the dissolution of Mg(2+) cations within the cubic ZrO(2) structure, is the main phase detected for the solids with theoretical Mg/(Mg+Zr) atomic ratio ≤0.4. In contrast, the cubic periclase (c-MgO) phase derived from hydroxynitrates or hydroxy precursors predominates in the solid with Mg/(Mg+Zr)=0.85. c-MgO is also incipiently detected in samples with Mg/(Mg+Zr)=0.2 and 0.4, but in these solids the c-MgO phase mostly arises from the segregation of Mg atoms out of the alcogel-derived c-Mg(x)Zr(1-x)O(2-x) phase during the calcination process, and therefore the species c-MgO and c-Mg(x)Zr(1-x)O(2-x) are in close contact. Regarding the intrinsic activity in furfural-acetone aldol condensation in the aqueous phase, these Mg-O-Zr sites located at the interface between c-Mg(x)Zr(1-x)O(2-x) and segregated c-MgO display a much larger intrinsic activity than the other noninterface sites that are present in these catalysts: Mg-O-Mg sites on c-MgO and Mg-O-Zr sites on c-Mg(x)Zr(1-x)O(2-x). The very active Mg-O-Zr sites rapidly deactivate in the furfural-acetone condensation due to the leaching of active phases, deposition of heavy hydrocarbonaceous compounds, and hydration of the c-MgO phase. Nonetheless, these Mg-Zr materials with very high specific surface areas would be suitable solid catalysts for other relevant reactions catalyzed by strong basic sites in nonaqueous environments. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. The preparation and characterization of nanostructured TiO{sub 2}-ZrO{sub 2} mixed oxide electrode for efficient dye-sensitized solar cells

    SciTech Connect

    Kitiyanan, Athapol; Ngamsinlapasathian, Supachai; Pavasupree, Soropong; Yoshikawa, Susumu . E-mail: s-yoshi@iae.kyoto-u.ac.jp

    2005-04-15

    The preparation of nanostructured mixed metal oxide based on a sol-gel method with surfactant-assisted mechanism, and its application for dye-sensitized solar cell (DSSC) are reported. The mixed zirconia (ZrO{sub 2}) and titania (TiO{sub 2}) mesoporous powder possessed larger surface area than the corresponding titania. For the UV action spectra of unsensitized photochemical cell, the mixed zirconia/titania electrode can absorb UV light below 380nm, corresponding to band gap (E{sub g}) around 3.27eV, which is higher than that of pure component of titania (E{sub g}=3.2eV). Both of these improved properties, i.e., BET surface area and band gap, contributed to the improvement on a short-circuit photocurrent up to 11%, an open-circuit voltage up to 4%, and a solar energy conversion efficiency up to 17%, for the DSSC fabricated by mesoporous zirconia/titania mixed system when compared to the cell that was fabricated only by nanostructured TiO{sub 2}. The cell fabricated by 5{mu}m thick mixed TiO{sub 2}-ZrO{sub 2} electrode gave the short-circuit photocurrent about 13mA/cm{sup 2}, open-circuit voltage about 600 mV and the conversion efficiency 5.4%.

  5. Development of PVP/PEG mixtures as appropriate carriers for the preparation of drug solid dispersions by melt mixing technique and optimization of dissolution using artificial neural networks.

    PubMed

    Barmpalexis, Panagiotis; Koutsidis, Ioannis; Karavas, Evangelos; Louka, Dimitra; Papadimitriou, Sofia A; Bikiaris, Dimitrios N

    2013-11-01

    The effect of plasticizer's (PEG) molecular weight (MW) on PVP based solid dispersions (SDs), prepared by melt mixing, was evaluated in the present study using Tibolone as a poorly water soluble model drug. PEGs with MW of 400, 600, and 2000 g/mol were tested, and the effect of drug content, time and temperature of melt mixing on the physical state of Tibolone, and the dissolution characteristics from SDs was investigated. PVP blends with PEG400 and PEG600 were completely miscible, while blends were heterogeneous. Furthermore, a single Tg recorded in all samples, indicating that Tibolone was dispersed in a molecular lever (or in the form of nanodispersions), varied with varying PEG's molecular weight, melt mixing temperature, and drug content, while FTIR analysis indicated significant interactions between Tibolone and PVP/PEG matrices. All prepared solid dispersion showed long-term physical stability (18 months in room temperature). The extent of interaction between mixture components was verified using Fox and Gordon-Taylor equations. Artificial neural networks, used to correlate the studied factors with selected dissolution characteristics, showed good prediction ability.

  6. Preparation of a silica stationary phase co-functionalized with Wulff-type phenylboronate and C12 for mixed-mode liquid chromatography.

    PubMed

    Li, Hengye; Zhang, Xuemeng; Zhang, Lin; Wang, Xiaojin; Kong, Fenying; Fan, Dahe; Li, Lei; Wang, Wei

    2017-04-15

    A silica stationary phase was designed and synthesized through the co-functionalization of silica with Wulff-type phenylboronate and C12 for mixed-mode liquid chromatography applications. The as-synthesized stationary phase was characterized by elemental analysis and Fourier Transform-InfraRed Spectroscopy (FT-IR). Retention mechanisms, including boronate affinity (BA), reversed-phase (RP) and anion-exchange (AE), were involved. Retention mechanism switching was easily realized by adjustment of the mobile phase constitution. Cis-diol compounds could be selectively captured under neutral conditions in BA mode and off-line separated in RP mode. Neutral, basic, acidic and amphiprotic compounds were chromatographed on the column in RP chromatography, while inorganic anions were chromatographed in AE chromatography to characterize the mixed-mode nature of the prepared stationary phase. In addition, the RP performance was compared with an octadecyl silica column in terms of column efficiency (N/m), asymmetry factor (Af), retention factor (k) and resolution (Rs). The prepared stationary phase offered multiple interactions with analytes in addition to hydrophobic interactions under RP elution conditions. Based on the mixed-mode properties, off-line 2D-LC, for selective capture and separation of urinary nucleosides, was successfully realized on a single column, demonstrating its powerful application potential for complex samples. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Preparative separation and purification of Rebaudioside A from Stevia rebaudiana Bertoni crude extracts by mixed bed of macroporous adsorption resins.

    PubMed

    Li, Jie; Chen, Zhenbin; Di, Duolong

    2012-05-01

    The separation and purification of Rebaudioside A (RA) from Stevia rebaudiana Bertoni crude extracts (Steviosides) by macroporous adsorption resin (MAR) mixed bed were systematically investigated. MAR mixed bed of HPD750-LSA40-LSA30-DS401 was selected due to its better separation degree. Based on the kinetics/thermodynamics experiment of the mixed bed, it was found that the experimental data fitted better to the pseudo-second-order model, and intra-particle diffusion was rate-limiting step. The adsorption isotherm was consistent with IV equilibrium adsorption isotherm classified by Brunauer. Furthermore, the influencing factors for the separation of RA based on HPLC were also investigated. Under the optimal conditions, the separation degree for RA (DAS) increased from 0.771 to 1.54. Moreover, the experimental results showed that the purity of the obtained product increased from 60% to 97%.

  8. Preparation of platinum nanoparticles on carbon black with mixed binary surfactants: Characterization and evaluation as anode catalyst for low-temperature fuel cell

    NASA Astrophysics Data System (ADS)

    Lim, Dong-Ha; Lee, Weon-Doo; Choi, Dong-Hyeok; Park, Dal-Ryung; Lee, Ho-In

    Platinum nanoparticles supported on Vulcan XC-72R prepared by a surfactant-stabilized colloidal method exhibit excellent properties as an anode catalyst for a low-temperature fuel cell. A Pt/C catalyst prepared with a 10-fold critical micelle concentration of mixed non-ionic surfactants [polyoxyethylene (23) lauryl ether + polyoxyethylene (20) sorbitan monolaurate (Brij 35 + Tween 20)] shows the highest catalytic activity and the greatest electrochemical surface-active area among those prepared. The maximum current density of this catalyst is much higher than that of a commercial Pt/C catalyst (E-TEK). Moreover, X-ray diffraction and transmission electron microscopy analyses reveal that Pt/C prepared with Brij 35 + Tween 20 has an average particle size of 2.4 nm with quite a narrow distribution between 2 and 3 nm, which is the smallest among all the catalysts prepared. This is attributed to the formation of more compact micelles. Mixtures of non-ionic and anionic surfactants result in less compact micelles.

  9. The economic value of a new insulin preparation, Humalog Mix 25. Measured by a willingness-to-pay approach.

    PubMed

    Dranitsaris, G; Longo, C J; Grossman, L D

    2000-09-01

    To measure the economic value of a new insulin formulation consisting of rapid-acting insulin lispro and intermediate-acting neutral protamine lispro in a 25:75 ratio (Humalog Mix 25). A cost-benefit analysis using a consumer-based willingness-to-pay (WTP) approach was used. The study sample consisted of 80 Canadian taxpayers randomly selected from Ontario and Quebec. After background information on the differences between Humalog Mix 25 and human 30/70 insulin were presented, respondents were asked what their preferred product would be if they were diagnosed with diabetes mellitus. Respondents were then asked the maximum premium that they would pay per month in the form of a user's fee for the insulin of their choice. Canadian taxpayer perspective. The WTP survey instrument was simple to administer and easily understood by participants. Approximately 84% of the sample of taxpayers preferred to use Humalog Mix 25 rather than human 30/70 insulin and were willing to pay for it (p = 0.012). They were willing to pay a mean of $Can35.28 [95% confidence interval (CI): $Can27.50 to $Can43.07] per month for the benefits offered by Humalog Mix 25, which was at least 2-fold higher than the incremental monthly cost of the drug (1999 values). The results of the study revealed that Canadians prefer to use Humalog Mix 25 instead of human 30/70 insulin, and they would be willing to pay for it. Compared with other drugs, this overall net gain suggests that Humalog Mix 25 represents good value for money and should be considered for reimbursement by government formularies and other third-party payers.

  10. A simple mechanical mixing method for preparation of visible-light-sensitive NiO-CaO composite photocatalysts with high photocatalytic activity.

    PubMed

    Song, Limin; Zhang, Shujuan

    2010-02-15

    Composite photocatalysts composed of NiO and CaO have been prepared via mechanically mixing of the two powders. The as-synthesized NiO-CaO products were characterized by X-ray diffraction (XRD) and UV-vis spectrometry. The experimental results showed that the absorption wavelength range of the mixed NiO-CaO sample was notably extended towards the visible-light region (400-450 nm). Photocatalytic activity of the NiO-CaO composite was evaluated based on the decomposition of methylene blue under visible-light irradiation. The effects of CaO doping and the duration of heat treatment on the durability of the NiO-CaO products have been investigated in detail. Factors influencing photocatalytic activity and the mechanism of photocatalysis were also addressed.

  11. Preparation of liposomes via detergent removal from mixed micelles by dilution. The effect of bilayer composition and process parameters on liposome characteristics.

    PubMed

    Jiskoot, W; Teerlink, T; Beuvery, E C; Crommelin, D J

    1986-10-17

    Liposomes were prepared from mixed micelles by a dilution method. Mixed micellar solutions, containing constant octyl glucoside and egg phosphatidylcholine concentrations and varying amounts of cholesterol and/or a charged compound, were diluted at defined rates. After dilution, the resulting liposome dispersions were sequentially concentrated, washed or dialysed, and filtered. The effect of lipid composition and experimental conditions on physicochemical characteristics was studied. Fairly homogeneous liposome dispersions with mean diameters ranging from 100 to over 200 nm could be obtained. The particle size was dependent on cholesterol content and surface charge, and could be reproducibly controlled by adjustment of the dilution rate. Liposomes with a mean diameter below 100 nm could also be obtained, but were heterodisperse and unstable. The incorporation of charged compounds was monitored by microelectrophoresis. 31P-NMR measurements indicated that the liposomes were unilamellar. Dialysis appeared to be more convenient than washing to remove octyl glucoside.

  12. Teacher Education Preparation and Implementation for Multicultural and Diverse School Environments in the 21st Century: A Mixed Methods Study

    ERIC Educational Resources Information Center

    Cole, Patricia Ann

    2013-01-01

    This sequential explanatory mixed methods study investigated 24 college and university syllabi for content consisting of multicultural education that used the framework for multicultural education devised by James A. Banks (2006). This framework was used to analyze data collected using descriptive statistics for quantitative phase one. The four…

  13. Reduction of Sn-Bearing Iron Concentrate with Mixed H2/CO Gas for Preparation of Sn-Enriched Direct Reduced Iron

    NASA Astrophysics Data System (ADS)

    You, Zhixiong; Li, Guanghui; Wen, Peidan; Peng, Zhiwei; Zhang, Yuanbo; Jiang, Tao

    2017-02-01

    The development of manufacturing technology of Sn-bearing stainless steel inspires a novel concept for using Sn-bearing complex iron ore via reduction with mixed H2/CO gas to prepare Sn-enriched direct reduced iron (DRI). The thermodynamic analysis of the reduction process confirms the easy reduction of stannic oxide to metallic tin and the rigorous conditions for volatilizing SnO. Although the removal of tin is feasible by reduction of the pellet at 1223 K (950 °C) with mixed gas of 5 vol pct H2, 28.5 vol pct CO, and 66.5 vol pct CO2 (CO/(CO + CO2) = 30 pct), it is necessary that the pellet be further reduced for preparing DRI. In contrast, maintaining Sn in the metallic pellet is demonstrated to be a promising way to effectively use the ore. It is indicated that only 5.5 pct of Sn is volatilized when the pellet is reduced at 1223 K (950 °C) for 30 minutes with the mixed gas of 50 vol pct H2, 50 vol pct CO (CO/(CO + CO2) = 100 pct). A metallic pellet (Sn-bearing DRI) with Sn content of 0.293 pct, Fe metallization of 93.5 pct, and total iron content of 88.2 pct is prepared as a raw material for producing Sn-bearing stainless steel. The reduced tin in the Sn-bearing DRI either combines with metallic iron to form Sn-Fe alloy or it remains intact.

  14. Reduction of Sn-Bearing Iron Concentrate with Mixed H2/CO Gas for Preparation of Sn-Enriched Direct Reduced Iron

    NASA Astrophysics Data System (ADS)

    You, Zhixiong; Li, Guanghui; Wen, Peidan; Peng, Zhiwei; Zhang, Yuanbo; Jiang, Tao

    2017-06-01

    The development of manufacturing technology of Sn-bearing stainless steel inspires a novel concept for using Sn-bearing complex iron ore via reduction with mixed H2/CO gas to prepare Sn-enriched direct reduced iron (DRI). The thermodynamic analysis of the reduction process confirms the easy reduction of stannic oxide to metallic tin and the rigorous conditions for volatilizing SnO. Although the removal of tin is feasible by reduction of the pellet at 1223 K (950 °C) with mixed gas of 5 vol pct H2, 28.5 vol pct CO, and 66.5 vol pct CO2 (CO/(CO + CO2) = 30 pct), it is necessary that the pellet be further reduced for preparing DRI. In contrast, maintaining Sn in the metallic pellet is demonstrated to be a promising way to effectively use the ore. It is indicated that only 5.5 pct of Sn is volatilized when the pellet is reduced at 1223 K (950 °C) for 30 minutes with the mixed gas of 50 vol pct H2, 50 vol pct CO (CO/(CO + CO2) = 100 pct). A metallic pellet (Sn-bearing DRI) with Sn content of 0.293 pct, Fe metallization of 93.5 pct, and total iron content of 88.2 pct is prepared as a raw material for producing Sn-bearing stainless steel. The reduced tin in the Sn-bearing DRI either combines with metallic iron to form Sn-Fe alloy or it remains intact.

  15. Synthesis, spectral, thermal and biological studies of mixed ligand complexes with newly prepared Schiff base and 1,10-phenanthroline ligands

    NASA Astrophysics Data System (ADS)

    Abd El-Halim, Hanan F.; Mohamed, Gehad G.; Khalil, Eman A. M.

    2017-10-01

    A series of mixed ligand complexes were prepared from the Schiff base (L1) as a primary ligand, prepared by condensation of oxamide and furan-2-carbaldehyde, and 1,10-phenanthroline (1,10-phen) as a secondary ligand. The Schiff base ligand and its mixed ligand chelates were characterized based on elemental analysis, IR, 1H NMR, thermal analysis, UV-Visible, mass, molar conductance, magnetic moment. X-ray diffraction, solid reflectance and ESR also have been studied. The mixed ligand complexes were found to have the formulae of [M(L1) (1,10-phen)]Clm.nH2O (M = Cr(III) and Fe(III) (m = 3) (n = 0); M = Mn(II), Cu(II) and Cd(II) (m = 2) (n = 0); and M = Co(II) (m = 2) (n = 1), Ni(II) (m = 2) (n = 2) and Zn(II) (m = 2) (n = 3)) and that the geometrical structure of the complexes were octahedral. The parameters of thermodynamic using Coats-Redfern and Horowitz-Metzger equations were calculated. The synthesized Schiff base ligand, 1,10-phenanthroline ligand and Their mixed ligand complexes were also investigated for their antibacterial and antifungal activity against bacterial species (Gram-Ve bacteria: Pseudomonas aeruginosa and Escherichia coli) and (Gram + Ve bacteria: Bacillus subtilis and Streptococcus pneumonia) and fungi (Aspergillus fumigates and Candida albicans). The anticancer activity of the new compounds had been tested against breast (MFC7) and colon (HCT-116) cell lines. The results showed high activity for the synthesized compounds.

  16. Co-Al mixed metal oxides/carbon nanotubes nanocomposite prepared via a precursor route and enhanced catalytic property

    SciTech Connect

    Fan Guoli; Wang Hui; Xiang Xu; Li Feng

    2013-01-15

    The present work reported the synthesis of Co-Al mixed metal oxides/carbon nanotubes (CoAl-MMO/CNT) nanocomposite from Co-Al layered double hydroxide/CNTs composite precursor (CoAl-LDH/CNT). The materials were characterized by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), low temperature nitrogen adsorption-desorption experiments, thermogravimetric and differential thermal analyses (TG-DTA), Raman spectra and X-ray photoelectron spectroscopy (XPS). The results revealed that in CoAl-MMO/CNT nanocomposite, the nanoparticles of cobalt oxide (CoO) and Co-containing spinel-type complex metal oxides could be well-dispersed on the surface of CNTs, thus forming the heterostructure of CoAl-MMO and CNTs. Furthermore, as-synthesized CoAl-MMO/CNT nanocomposite was utilized as additives for catalytic thermal decomposition of ammonium perchlorate (AP). Compared to those for pure AP and CoAl-MMO, the peak temperature of AP decomposition for CoAl-MMO/CNT was significantly decreased, which is attributed to the novel heterostructure and synergistic effect of multi-component metal oxides of nanocomposite. - Graphical abstract: Hybrid Co-Al mixed metal oxides/carbon nanotubes nanocomposite showed the enhanced catalytic activity in the thermal decomposition of ammonium perchlorate, as compared to carbon nanotubes and pure Co-Al mixed metal oxides. Highlights: Black-Right-Pointing-Pointer Co-Al mixed metal oxides/carbon nanotubes nanocomposite was synthesized. Black-Right-Pointing-Pointer Co-Al mixed metal oxides consisted of cobalt oxide and Co-containing spinels. Black-Right-Pointing-Pointer Nanocomposite exhibited excellent catalytic activity for the decomposition of AP. Black-Right-Pointing-Pointer The superior catalytic property is related to novel heterostructure and composition.

  17. Preparation and characterization of vanadia-titania mixed oxide for immobilization of Serratia rubidaea CCT 5732 and Klebsiella marcescens bacteria

    SciTech Connect

    Saragiotto Colpini, Leda Maria Correia Goncalves, Regina A.; Goncalves, Jose Eduardo; Maieru Macedo Costa, Creusa

    2008-08-04

    Vanadia-titania mixed oxide was synthesized by sol-gel method and characterized by several techniques. Texturally, it is formed by mesopores and presents high-specific surface area and controlled porosity. Scanning electron microscopy revealed that vanadium is homogeneously distributed in the material. Structurally, it was possible to identify characteristic V=O stretching bands by IR. The analysis of X-ray diffraction showed that the material, particularly vanadium, is highly dispersed. Application experiments were carried out through the immobilization of Serratia rubidae CCT 5732 and Klebsiella marcescens bacteria by adsorption on the surface of mixed oxide. The micrographies revealed that the bacteria were adsorbed on the entire support, with average surface densities of 8.55 x 10{sup 11} cells/m{sup 2} (Serratia rubidae CCT 5732) and 3.40 x 10{sup 11} cells/m{sup 2} (K. marcescens)

  18. Photon pair-state preparation with tailored spectral properties by spontaneous four-wave mixing in photonic-crystal fiber.

    PubMed

    Garay-Palmett, K; McGuinness, H J; Cohen, Offir; Lundeen, J S; Rangel-Rojo, R; U'ren, A B; Raymer, M G; McKinstrie, C J; Radic, S; Walmsley, I A

    2007-10-29

    We study theoretically the generation of photon pairs by spontaneous four-wave mixing (SFWM) in photonic crystal optical fiber. We show that it is possible to engineer two-photon states with specific spectral correlation ("entanglement") properties suitable for quantum information processing applications. We focus on the case exhibiting no spectral correlations in the two-photon component of the state, which we call factorability, and which allows heralding of single-photon pure-state wave packets without the need for spectral post filtering. We show that spontaneous four wave mixing exhibits a remarkable flexibility, permitting a wider class of two-photon states, including ultra-broadband, highly-anticorrelated states.

  19. Cu-Ce-O mixed oxides from Ce-containing layered double hydroxide precursors: Controllable preparation and catalytic performance

    SciTech Connect

    Chang Zheng; Zhao Na; Liu Junfeng; Li Feng; Evans, David G.; Duan Xue; Forano, Claude; Roy, Marie de

    2011-12-15

    Cu/Zn/Al layered double hydroxide (LDH) precursors have been synthesized using an anion exchange method with anionic Ce complexes containing the dipicolinate (pyridine-2,6-dicarboxylate) ligand. Cu-Ce-O mixed oxides were obtained by calcination of the Ce-containing LDHs. The materials were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, thermogravimetry-differential thermal analysis, elemental analysis, and low temperature N{sub 2} adsorption/desorption measurements. The results reveal that the inclusion of Ce has a significant effect on the specific surface area, pore structure, and chemical state of Cu in the resulting Cu-Ce-O mixed metal oxides. The resulting changes in composition and structure, particularly the interactions between Cu and Ce centers, significantly enhance the activity of the Ce-containing materials as catalysts for the oxidation of phenol by hydrogen peroxide. - Graphical Abstract: Cu-Ce-O mixed oxides calcined from [Ce(dipic){sub 3}]{sup 3-}- intercalated Cu/Zn/Al layered double hydroxides were synthesized and displayed good catalytic performances in phenol oxidation due to the Cu-Ce interactions. Highlights: Black-Right-Pointing-Pointer [Ce(dipic){sub 3}]{sup 3-}-intercalated Cu/Zn/Al layered double hydroxides were synthesized. Black-Right-Pointing-Pointer Cu-Ce-O mixed oxides derivated from the LDHs were characterized as catalysts. Black-Right-Pointing-Pointer Presence of Ce influenced physicochemical property and catalytic performance. Black-Right-Pointing-Pointer Cu-Ce interaction was largely responsible for enhanced catalytic ability.

  20. Preparation, characterization and application of a reversed phase liquid chromatography/hydrophilic interaction chromatography mixed-mode C18-DTT stationary phase.

    PubMed

    Wang, Qing; Long, Yao; Yao, Lin; Xu, Li; Shi, Zhi-Guo; Xu, Lanying

    2016-01-01

    A mixed-mode chromatographic stationary phase, C18-DTT (dithiothreitol) silica (SiO2) was prepared through "thiol-ene" click chemistry. The obtained material was characterized by fourier transform infrared spectroscope, nitrogen adsorption analysis and contact angle analysis. Chromatographic performance of the C18-DTT was systemically evaluated by studying the effect of acetonitrile content, pH, buffer concentration of the mobile phase and column temperature. It was demonstrated that the novel stationary phase possessed reversed phase liquid chromatography (RPLC)/hydrophilic interaction liquid chromatography (HILIC) mixed-mode property. The stop-flow test revealed that C18-DTT exhibited excellent compatibility with 100% aqueous mobile phase. Additionally, the stability and column-to-column reproducibility of the C18-DTT material were satisfactory, with relative standard deviations of retention factor of the tested analytes (verapamil, fenbufen, guanine, tetrandrine and nicotinic acid) in the range of 1.82-3.72% and 0.85-1.93%, respectively. Finally, the application of C18-DTT column was demonstrated in the separation of non-steroidal anti-inflammatory drugs, aromatic carboxylic acids, alkaloids, nucleo-analytes and polycyclic aromatic hydrocarbons. It had great resolving power in the analysis of various compounds in HILIC and RPLC chromatographic conditions and was a promising RPLC/HILIC mixed-mode stationary phase.

  1. Preparation of silica-magnetite nanoparticle mixed hemimicelle sorbents for extraction of several typical phenolic compounds from environmental water samples.

    PubMed

    Zhao, Xiaoli; Shi, Yali; Wang, Thanh; Cai, Yaqi; Jiang, Guibin

    2008-04-25

    A novel type of superparamagnetic silica-coated (Fe3O4/SiO2 core/shell) magnetite nanoparticle modified by surfactants has been successfully synthesized and was applied as an effective sorbent material for the pre-concentration of several typical phenolic compounds (bisphenol A (BPA), 4-tert-octylphenol (4-OP) and 4-n-nonylphenol (4-NP)) from environmental water samples. Compared with pure magnetic particles, a thin and dense silica layer would protect the iron oxide core from leaching out in acidic conditions. In order to enhance their adsorptive tendency towards organic compounds, cetylpyridinium chloride (CPC) or cetyltrimethylammonium bromide (CTAB) were added, which adsorbed on the surface of the Fe3O4/SiO2 nanoparticles (Fe3O4/SiO2 NPs) and formed mixed hemimicelles. Main factors affecting the adsolubilization of analytes were optimized and comparative study on the use of CPC and CTAB-coated Fe3O4/SiO2 NPs mixed hemimicelles-based SPE was also carried out. CPC-coated Fe3O4/SiO2 NPs system was selected due to lower elution volume required and more effective adsorption of the target compounds. Under selected conditions, concentration factor of 1600 was achieved by using this method to extract 800 mL of different environmental water samples. The detection limits obtained for BPA, 4-OP and 4-NP with HPLC-FLD were 7, 14, and 20 ng/L, respectively.

  2. Zirconia-based mixed potential sensor with Pt electrode prepared by spin-coating of polymeric precursor

    NASA Astrophysics Data System (ADS)

    Chrzan, A.; Woźniak, Ł.; Szymczewska, D.; Jasiński, P.

    2016-11-01

    Many types of yttria-stabilized zirconia (YSZ) based gas sensors have been explored extensively in recent years. Great attention have been directed to mixed-potential-type gas sensors. It is due to growing concerns with environmental issues. Not without a significance is the fact of very attractive performance of this type of sensor allowing to detect low concentration of pollutant gases. In this paper two types of YSZ based mixed-potential planar sensors were investigated, with platinum electrode painted using commercial paste and with spin coated platinum layer. Both types had second electrode in the form of porous gold. Measurements were performed at 400 °C in synthetic air and different concentrations of SO2. Gas flow was set to 100 cm3min-1 and the concentration of 50 ppm SO2 was tested. During this measurements the sensor was sintered in-situ at increasing temperatures. Sensor with 100 nm spin-coated platinum layer sintered at 700 °C was shown to exhibit two times smaller response than sensor with 5 μm porous electrode, while consisting of over 20 times smaller amount of Pt. The influence of sintering temperature on electrical conductivity of platinum films was also examined. Moreover, the platinum microstructure was investigated using SEM microscopy.

  3. Facile preparation of mono-, di- and mixed-carboxylato platinum(IV) complexes for versatile anticancer prodrug design.

    PubMed

    Zhang, Jenny Z; Bonnitcha, Paul; Wexselblatt, Ezequiel; Klein, Alice V; Najajreh, Yousef; Gibson, Dan; Hambley, Trevor W

    2013-01-28

    Facile strategies were developed for the versatile functionalization of platinum(IV) axial sites, allowing for easy accessibility to unsymmetric mono- and mixed-carboxylato, as well as symmetric di-substituted platinum(IV) complexes. The first method involves the direct oxidation and carboxylation of the platinum(II) center using an appropriate peroxide and the carboxylate of choice to firstly yield a monocarboxylato monohydroxido platinum(IV) complex. This platinum(IV) intermediate can undergo further carboxylation to give rise to a mixed-carboxylato platinum(IV) complex. The second method involves the activation of the carboxylate of choice by a common carbodiimide coupling reagent, and its reaction with a dihydroxido platinum(IV) precursor to give the monocarboxylato platinum(IV) complex. Uronium salts can be employed to promote efficient dicarboxylation of the dihydroxido platinum(IV) precursor. Lastly, an axial azide pendant group was demonstrated to be suitable for orthogonal "click" conjugation reactions. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Comparison of preparation techniques of mixed samples (fungi-helminth eggs) for scanning electron microscopy by critical point drying.

    PubMed

    Sarmiento, P L; Ciarmela, María L; Sánchez Thevenet, P; Minvielle, M C; Basualdo, J A

    2006-09-01

    We compared three preparation techniques for critical point drying of fungus Paecilomyces lilacinus (Thom) Samson with Toxocara canis (Werner) Johnston and Taenia hydatigena Linneo eggs by scanning electron microscopy. We evaluated filtration (first), centrifugation (second), and phytoplankton network (third) in critical point drying methods. The first and third methods were advantageous for T. canis eggs because they preserved the quantity and quality of samples to obtain better images definition. The best technique for T. hydatigena eggs was the addition of phytoplankton network in critical point drying which preserved these helminth eggs.

  5. Antiosteoporosis Activity of New Oriental Medicine Preparation (Kyungokgo Mixed with Water Extract of Hovenia dulcis) on the Ovariectomized Mice.

    PubMed

    Hwang, Yun-Ho; Kim, Kwang-Jin; Kim, Jong-Jin; Kang, Kyung-Yun; Lee, Sung-Ju; Jeong, Gil-Yeon; Choi, Kyung-Hee; Son, Young-Jin; Yee, Sung-Tae

    2015-01-01

    Protective effect of new oriental medicine (Kyungokgo mixed with water extract of Hovenia dulcis, KOGHD) was assessed on the bone loss induced mice by ovariectomy. In the in vivo experiments, antiosteoporosis effect of KOGHD was investigated using ovariectomized osteoporosis mice model. After 6 weeks of treatment, the mice were euthanized, and the effect of Kyungokgo (KOG) and KOGHD on body weight, spleen weigh, thymus weight, uterine weight, serum biochemical indicators, bone weight and length, immune cell population, bone morphometric parameters, and histological stains was observed. Our results showed that KOGHD prevented the deterioration of trabecular microarchitecture caused by ovariectomy, which were accompanied by the lower levels of bone turnover markers and immune cell population as evidenced by the inhibition of RANKL-mediated osteoclast differentiation without cytotoxic effect on bone marrow derived macrophages (BMMs). Therefore, these results suggest that the Hovenia dulcis (HD) supplementation in the KOG may also prevent and treat bone loss.

  6. Antiosteoporosis Activity of New Oriental Medicine Preparation (Kyungokgo Mixed with Water Extract of Hovenia dulcis) on the Ovariectomized Mice

    PubMed Central

    Hwang, Yun-Ho; Kim, Kwang-Jin; Kim, Jong-Jin; Kang, Kyung-Yun; Lee, Sung-Ju; Jeong, Gil-Yeon; Choi, Kyung-Hee; Son, Young-Jin; Yee, Sung-Tae

    2015-01-01

    Protective effect of new oriental medicine (Kyungokgo mixed with water extract of Hovenia dulcis, KOGHD) was assessed on the bone loss induced mice by ovariectomy. In the in vivo experiments, antiosteoporosis effect of KOGHD was investigated using ovariectomized osteoporosis mice model. After 6 weeks of treatment, the mice were euthanized, and the effect of Kyungokgo (KOG) and KOGHD on body weight, spleen weigh, thymus weight, uterine weight, serum biochemical indicators, bone weight and length, immune cell population, bone morphometric parameters, and histological stains was observed. Our results showed that KOGHD prevented the deterioration of trabecular microarchitecture caused by ovariectomy, which were accompanied by the lower levels of bone turnover markers and immune cell population as evidenced by the inhibition of RANKL-mediated osteoclast differentiation without cytotoxic effect on bone marrow derived macrophages (BMMs). Therefore, these results suggest that the Hovenia dulcis (HD) supplementation in the KOG may also prevent and treat bone loss. PMID:25737735

  7. Amperometric enzyme electrodes for aerobic and anaerobic glucose monitoring prepared by glucose oxidase immobilized in mixed ferrocene-cobaltocenium dendrimers.

    PubMed

    Alonso, Beatriz; Armada, Pilar García; Losada, José; Cuadrado, Isabel; González, Blanca; Casado, Carmen M

    2004-07-15

    The enzyme glucose oxidase (GOx) has been immobilized electrostatically onto carbon and platinum electrodes modified with mixed ferrocene-cobaltocenium dendrimers. The ferrocene units have been used successfully as mediators between the GOx and the electrode under anaerobic conditions. In experiments carried out in the presence of oxygen, the cobaltocenium moieties act as electrocatalysts in the reduction of the oxygen in the solution, thus making possible the determination of the oxygen variation due to the enzymatic reaction, with high sensitivity. The current response of the electrode was determined by measuring steady-state current values obtained applying a constant potential. The effect of the substrate concentration, the dendrimer generation, the thickness of the dendrimer layer, interferences, and storage on the response of the sensors were investigated.

  8. Investigation of Tribological Behavior of a Novel Hybrid Composite Prepared with Al-Coconut Shell Ash Mixed with Graphite

    NASA Astrophysics Data System (ADS)

    Siva Sankara Raju, R.; Panigrahi, M. K.; Ganguly, R. I.; Srinivasa Rao, G.

    2017-08-01

    The present investigation develops a next-generation hybrid Al metal matrix composite using coconut shell ash (CSA) and graphite (Gr) reinforcement. Stir-casting is adapted to prepare an Al-1100-based composite. Three other composites of Al-Al2O3, Al-Al2O3-Gr, and Al-CSA are prepared that contain equivalent volume fractions of Al2O3, CSA, and Gr. These assist in comparisons among the three composites and the developed hybrid Al-CSA-Gr composite. The study reveals that the addition of 3 pct Gr improves the specific strength, toughness, and tribological properties. The Al-CSA composite shows better mechanical properties, such as tensile strength and hardness, than the other three composites. Gr addition helps the hybrid Al-CSA-Gr composite to attain better tribological properties with a slightly lower specific strength. Scanning electron microscopy studies of the worn material surfaces corroborate the findings of the abrasion testing. Elemental analyses by energy-dispersive X-ray spectroscopy of the debris from the counter-face of the tribo surface confirm the presence of Al, O, Si, Fe, Mn, and C.

  9. Acid and redox properties of mixed oxides prepared by calcination of chromate-containing layered double hydroxides

    SciTech Connect

    Arco, M. del; Carriazo, D.; Martin, C.; Perez-Grueso, A.M.; Rives, V. . E-mail: vrives@usal.es

    2005-11-15

    Layered double hydroxides (LDHs) with Mg and Al in the layers and carbonate, nitrate or chloride in the interlayer, or with Zn and Al in the layers and chloride in the interlayer, have been prepared by coprecipitation, and have been used as precursors to prepare chromate-containing LDHs. All these systems, as well as those obtained upon their calcination up to 800 deg. C, have been characterised by powder X-ray diffraction, FT-IR and vis-UV spectroscopies, temperature-programmed reduction (TPR), nitrogen adsorption at -196 deg. C for surface texture and porosity assessment, and FT-IR monitoring of pyridine adsorption for surface acidity determination. The results obtained show that the crystallinity of the chromate-containing LDH depends on the precursor used. The layered structure of the Mg, Al systems is stabilised up to 400 deg. C upon incorporation of chromate; however, the Zn,Al-chromate samples collapse between 200 and 300 deg. C, with simultaneous formation of ZnO. Calcination of the samples above 400 deg. C gives rise to a reduction of Cr(VI) to Cr(III), as concluded from vis-UV spectroscopic studies. The TPR profiles show that chromate in ZnAl hydrotalcite is more easily reduced than that incorporated in the magnesium ones. Moderately strong surface Lewis acid sites exist in all samples calcined below 500 deg. C.

  10. Acid and redox properties of mixed oxides prepared by calcination of chromate-containing layered double hydroxides

    NASA Astrophysics Data System (ADS)

    del Arco, M.; Carriazo, D.; Martín, C.; Pérez-Grueso, A. M.; Rives, V.

    2005-11-01

    Layered double hydroxides (LDHs) with Mg and Al in the layers and carbonate, nitrate or chloride in the interlayer, or with Zn and Al in the layers and chloride in the interlayer, have been prepared by coprecipitation, and have been used as precursors to prepare chromate-containing LDHs. All these systems, as well as those obtained upon their calcination up to 800 °C, have been characterised by powder X-ray diffraction, FT-IR and vis-UV spectroscopies, temperature-programmed reduction (TPR), nitrogen adsorption at -196 °C for surface texture and porosity assessment, and FT-IR monitoring of pyridine adsorption for surface acidity determination. The results obtained show that the crystallinity of the chromate-containing LDH depends on the precursor used. The layered structure of the Mg, Al systems is stabilised up to 400 °C upon incorporation of chromate; however, the Zn,Al-chromate samples collapse between 200 and 300 °C, with simultaneous formation of ZnO. Calcination of the samples above 400 °C gives rise to a reduction of Cr(VI) to Cr(III), as concluded from vis-UV spectroscopic studies. The TPR profiles show that chromate in ZnAl hydrotalcite is more easily reduced than that incorporated in the magnesium ones. Moderately strong surface Lewis acid sites exist in all samples calcined below 500 °C.

  11. Specific tolerance induction across a xenogeneic barrier: Production of mixed rat/mouse lymphohematopoietic chimeras using a nonlethal preparative regimen

    SciTech Connect

    Sharabi, Y.; Aksentijevich, I.; Sundt, T.M. 3d.; Sachs, D.H.; Sykes, M. )

    1990-07-01

    The development of safe methods for inducing donor-specific tolerance across xenogeneic barriers could potentially relieve the critical shortage of allograft donors that currently limits the applicability of organ transplantation. We report here that such tolerance can be induced in a xenogeneic combination (rat----mouse) using a nonmyeloablative and nonlethal preparative regimen. Successful induction of chimerism and donor-specific transplantation tolerance required pretreatment of recipients with monoclonal antibodies (mAbs) against NK1.1, Thy-1.2, CD4 and CD8, followed by administration of 3 Gy whole body radiation (WBI), 7 Gy thymic irradiation, and infusion of T cell-depleted rat bone marrow cells (BMC). Rat cells appeared among peripheral blood lymphocytes (PBL) of such recipients by 2-3 wk, and rat T cells by 2-5 wk following bone marrow transplantation (BMT). Donor-type rat skin grafts placed 4 mo after BMT were accepted, while simultaneously placed non-donor-type rat skin grafts were promptly rejected. In addition to its clinical potential, the ability to induce donor-specific tolerance across xenogeneic barriers using such a nonlethal preparative regimen provides a valuable model for the study of mechanisms of xenogeneic transplantation tolerance.

  12. Cytotoxics compounded sterile preparation control by HPLC during a 16-month assessment in a French university hospital: importance of the mixing bags step.

    PubMed

    Castagne, Vincent; Habert, Hélène; Abbara, Chadi; Rudant, Eric; Bonhomme-Faivre, Laurence

    2011-09-01

    The Centralized Chemotherapy Reconstitution Unit (CCRU) of Paul Brousse Hospital Pharmacy Department assessed the reliability of its Cytotoxics Compounded Sterile Products (CCSP) preparation method in order to improve its CCSP quality assurance system. Five cytotoxic drugs - gemcitabine, 5-fluorouracil, docetaxel, paclitaxel, and oxaliplatin - were assayed by high performance liquid chromatography (HPLC) to determine CCSP concentration. During the observation period, 23,892 CCSP were prepared. Overall, 12,964 preparations contained one of the five analyzed drugs; 7382 (56.9%) out of 12,964 CCSP were analyzed by HPLC; 646 (8.8%) out of 7382 concentrations were outside ± 20% of the prescribed dose; 544 (84.2%) out of 646 were post-administration results and could not be verified. Out of 102 (15.8%) pre-administration results that were re-tested after re-shaking, 94 (92.2%) were found to be acceptable upon re-testing, and 8 (7.8%) were confirmed to be unacceptable and needed to be re-compounded. The 8.8% of tested CCSP were outside ± 20% of the prescribed dose, but extrapolating the results on re-tested CCSP, we can say that our CCSP preparation is reliable with an estimation of only 0.7% of 7382 CCSP analyzed, confirmed as being ± 20% outside the prescribed dose. Nevertheless, this ± 20% magnitude of error should be reduced. Based on pre-administration results, the primary cause of concentration errors appeared to be insufficient mixing of the finished product. Most CCSP dosages occurred after it had been administered, the organization should, therefore, be improved to include testing all CCSP prior to administration. Pharmaceutical companies should endeavor to manufacture compounded injectible drugs in a 'ready to use' form and provide vehicles in accurate volumes in order to improve compounding precision.

  13. Preparation, characterization and photocatalytic property of nanosized K-Ta mixed oxides via a sol-gel method

    SciTech Connect

    Zhang, Gaoke; Jiang, Wei; Yu, Shujie

    2010-11-15

    Pyrochlore-type K{sub 2}Ta{sub 2}O{sub 6} compound cannot be obtained by a conventional solid-state reaction. Here, we report the synthesis of K{sub 2}Ta{sub 2}O{sub 6} and tetragonal tungsten bronze (TTB)-type K{sub 6}Ta{sub 10.8}O{sub 30} nanopowders using a facile and low-cost sol-gel method at low temperature. The as-prepared samples were characterized by XRD, TG-DSC, FESEM, UV-vis diffuse reflectance spectrum and XPS. The compound K{sub 2}Ta{sub 2}O{sub 6} was formed at 700 {sup o}C and reached complete crystallization at 750 {sup o}C, and decomposed into pure K{sub 6}Ta{sub 10.8}O{sub 30} with the volatilization of K{sub 2}O at 900 {sup o}C. The transformation of K{sub 2}Ta{sub 2}O{sub 6} to K{sub 6}Ta{sub 10.8}O{sub 30} is reported for the first time. The band gap of the pure K{sub 2}Ta{sub 2}O{sub 6} and K{sub 6}Ta{sub 10.8}O{sub 30} samples was found to be about 4.16 and 3.63 eV, respectively. The as-prepared K{sub 2}Ta{sub 2}O{sub 6} sample exhibited an efficient photocatalytic activity for the decomposition of azo dye acid red G (ARG) and 4-nitrophenol (4-NP, a typical persistent organic pollutant) solution under UV irradiation. According to the experimental results, the mechanism of the photocatalytic reaction over K{sub 2}Ta{sub 2}O{sub 6} was discussed.

  14. Preparation and evaluation of 2-methylimidazolium-functionalized silica as a mixed-mode stationary phase for hydrophilic interaction and anion-exchange chromatography.

    PubMed

    Yang, Beibei; Liu, Houmei; Chen, Jia; Guan, Ming; Qiu, Hongdeng

    2016-10-14

    In this paper, a novel 2-methylimidazolium-functionalized silica stationary phase was prepared and further used for hydrophilic interaction and anion-exchange mixed-mode chromatography. The stationary phase was characterized by elemental analysis and Fourier transform infrared spectrometry. The chromatographic properties of this stationary phase were investigated by hydrophilic chromatography for the separation of nucleosides, nucleobases, water soluble vitamins, sulfonamides and saccharides, and ion chromatography for the separation of inorganic anions. The effect of acetonitrile content, salt concentration and pH values of the mobile phase on the retention of the stationary phases was also investigated. Compared with 1-methylimidazolium-functionalized silica stationary phase, this new stationary phase demonstrated similar or better separation selectivity. This new column demonstrated good performance and separation selectivity even better than a commercial hydrophilic column. Besides, 2-methylimidazolium-functionalized silica is possible to be modified again and used as a precursor to derivate some new stationary phases from the 3-position nitrogen.

  15. Facile preparation of titania hollow spheres by combination of the mixed solvent method and the sol-gel process and post-calcination

    SciTech Connect

    Du Xin; He Junhui

    2009-06-03

    Polystyrene (core)-titania (shell) composite spheres consisting were readily prepared by a sol-gel process of titanium tetrabutoxide (TBOT) in a mixed solvent of ethanol/acetonitrile (3:1, v/v). Smooth and homogeneous titania coatings formed when the mixed solvent was dehydrated by anhydrous sodium sulfate. The thickness and surface roughness of titania coating increase with increase of the TBOT concentration. By adjusting the TBOT concentration in the range of 5.8-29.0 mM, the size of titania-coated PS spheres could be varied from 990 to 1125 nm. Calcination at elevated temperature gave dense, homogeneous, robust shells of anatase titania. The sizes of titania hollow spheres are 11.3-16.9% smaller than those of the titania-coated PS spheres as a result of calcination-induced shrinkage. The composite and hollow spheres were characterized by scanning electron microscopy, transmission electron microscopy and electron diffraction measurements. These core-shell organic-inorganic spheres and hollow ceramic spheres may have wide applications in catalysts, adsorbents, lightweight fillers, capsules, etc.

  16. [Changes in the content of plasma lipoproteins in persons subjected to diets prepared with sunflower oil alone or mixed with palm olein].

    PubMed

    Giacopini de Z, María Isabel; Alonso, Hilda V; Sánchez, Josefina; García, Ninoska; Veliz, Lilia; Golfetto, Iván; Bosch, Virgilio

    2013-06-01

    We analyzed in 31 subjects, regular guests of the University food service of the Central University of Venezuela (UCVFS), in Caracas, the effects of replacing sunflower oil, commonly used in the preparation of meals, by a mix of sunflower oil and palm olein 70/30 (v/v) respectively. Plasma concentrations of total cholesterol, low and very low density lipoproteins were not changed after 40 days of the substitution. On the contrary, concentrations of high density lipoprotein and total triglycerides increased. The resistance to the oxidation of low-density lipoproteins increased considerably (p < 0.01). Today this resistance is considered as a protective factor of great importance in the prevention of the initiation of the atherogenic process. Taking into account the favorable modifications of HDL cholesterol and the clear increased resistance to the oxidation of LDL, we think that palm olein, mixed with other oils with a high ratio linoleic/palmitic (sunflower, corn, soya an the likes), can be used as a healthy alternative in human nutrition.

  17. Preparation of conversion coating on Ti-6Al-4V alloy in mixed solution of phytic acid and ammonium fluoride through chemical modification

    NASA Astrophysics Data System (ADS)

    Li, Lanlan; He, Jian; Yang, Xu

    2016-05-01

    Conversion coatings on Ti-6Al-4V alloy was prepared through chemical modification in phytic acid and ammonium fluoride mixed solution. The influences of pH, time and the composition of solution on the microstructure of alloy surface were investigated. Scanning electron microscopy was used to observe the microstructure. The chemical composition of alloy surface before and after modification was investigated by energy dispersive X-ray spectroscopy. The results indicated that a conversion coating could be formed on the Ti-6Al-4V alloy in a mixed solution of phytic acid and ammonium fluoride, the growth and microstructure of the conversion coatings were critically dependent on the pH, time and concentration of phytic acid and ammonium fluoride. In 100 mg/ml phytic acid containing 125 mg/ml ammonium fluoride solution with a pH of 6, a compact conversion coating with the thickness of about 4.7 μm formed after 30 min immersion on Ti-6Al-4V alloy surface. The preliminary evaluation of bioactivity of conversion coating was performed by in vitro cell experiments. The results showed that this chemical modification method is a promising surface modification technique for Ti-6Al-4V alloy inplants.

  18. Hybrid Langmuir and Langmuir-Blodgett films of a viologen derivative and TCNQ in a mixed valence state: preparation route and characterization

    NASA Astrophysics Data System (ADS)

    Martín, Santiago; Cea, Pilar; Lafuente, Carlos; Royo, Félix M.; López, María. C.

    2004-08-01

    Hybrid Langmuir and Langmuir-Blodgett (LB) films containing two moieties of great chemical and electrochemical interest, namely a viologen derivative and tetracyanoquinodimethane (TCNQ) in a mixed valence state, were fabricated. To do so, positively ionized monolayers of 1,1 '-dioctadecyl 4,4 '-bipyridilium were prepared onto aqueous solutions of tetracyanoquinodimethane in a mixed valence state. Surface pressure vs. area ( π- A), surface potential vs. area (Δ V- A), and Brewster angle microscope (BAM) images were recorded and interpreted in terms of molecular interactions as well as the incorporation of the hydrophobic anions into the monolayer. After a comprehensive study, a 10 -6 M TCNQ aqueous solution was chosen as the best one to build hybrid LB films. Thus, the floating films were transferred onto solid substrates that were characterized using several techniques including ultraviolet-visible (UV-vis), infrared (IR), scanning electron microscopy (SEM), and atomic force microscopy (AFM) proving the incorporation of the TCNQ onto the film. These films show a good optical conductivity as well as a high degree of order and layers with a constant architecture.

  19. Feasibility of a nursing intervention to prepare frail older patients for cardiac surgery: a mixed-methods study.

    PubMed

    Ettema, Roelof; Schuurmans, Marieke J; Schutijser, Bernadette; van Baar, Mark; Kamphof, Nicole; Kalkman, Cor J

    2015-08-01

    Given the growing number of vulnerable, older cardiac surgery patients, the preadmission PREvention Decline in Older Cardiac Surgery patients (PREDOCS) programme was developed to reduce the incidence of postoperative complications. Before the clinical effects of such a complex multicomponent intervention can be evaluated, the feasibility needs to be determined to detect possible problems with the acceptability, compliance and delivery. The purpose of this study was to test the PREDOCS programme on its feasibility and estimate theoretical cost savings. In a mixed-methods multicentre study, the Medical Research Council (MRC) guidelines concerning testing feasibility were followed, and theoretical cost savings were calculated. We used data from interviews and the continuous data registry at three hospitals. The results were reported following the criteria for reporting the feasibility of complex interventions (CReDECI). Twenty-one females and 49 males out of 114 eligible patients completed the intervention and provided full data. Patients were equally satisfied with the usual care and the PREDOCS programme (satisfaction rate respectively standard deviation (SD): 7.5 (95% confidence interval (CI): 6.4-8.7) and 7.6 (6.6-8.6)). The involved nurses were satisfied with the tools for guiding patients to reduce their risk of postoperative complications and considered the PREDOCS programme as complementary to usual care. Integrating PREDOCS into current hospital structures appeared to be difficult. Both patients and nurses indicated that the additional consult was tiresome for the patient. The PREDOCS programme will be cost-effective when postoperative complications are prevented in six to sixteen of 1000 cardiac surgery patients. The PREDOCS programme is acceptable for patients and nurses but should be built into the hospital's cardiac surgery pathway or applied in home care. © The European Society of Cardiology 2014.

  20. One-pot preparation of a mixed-mode organic-silica hybrid monolithic capillary column and its application in determination of endogenous gibberellins in plant tissues.

    PubMed

    Zhang, Zheng; Hao, Yan-Hong; Ding, Jun; Xu, Sheng-Nan; Yuan, Bi-Feng; Feng, Yu-Qi

    2015-10-16

    A newly improved one-pot method, based on "thiol-ene" click chemistry and sol-gel approach in microemulsion system, was developed for the preparation of C8/PO(OH)2-silica hybrid monolithic capillary column. The prepared monolith possesses large specific surface area, narrow mesopore size distribution and high column efficiency. The monolithic column was demonstrated to have cation exchange/reversed-phase (CX/RP) mixed-mode retention for analytes on nano-liquid chromatography (nano-LC). On the basis of the developed nano-LC system with MS detector coupled to pipette tip solid phase extraction (PT-SPE) and derivatization process, we then realized simultaneous determination of 10 gibberellins (GAs) with low limits of detection (LODs, 0.003-0.025 ng/mL). Furthermore, 6 endogenous GAs in only 5mg rice leaves (fresh weight) were successfully detected and quantified. The developed PT-SPE-nano-LC-MS strategy may offer promising applications in the determination of low abundant bioactive molecules from complex matrix. Copyright © 2015 Elsevier B.V. All rights reserved.

  1. One-pot preparation of mercaptotetrazole-silica hybrid monoliths by the thiol-ene click reaction for mixed-mode capillary liquid chromatography.

    PubMed

    Wang, Haojiang; Hu, Wenli; Zheng, Qiong; Bian, Wei; Lin, Zian

    2017-06-01

    A novel mercaptotetrazole-silica hybrid monolithic column was prepared for capillary liquid chromatography, in which the thiol-end mercaptotetrazole was mixed with hydrolyzed γ-methacryloxypropyltrimethoxysilane and tetramethyloxysilane for the co-polycondensation and thiol-ene click reaction in a one-pot process. The effects of the molar ratio of silanes, the amount of mercaptotetrazole, and the volume of porogen on the morphology, permeability and pore properties of the as-prepared mercaptotetrazole-silica hybrid monoliths were investigated in detail. A series of test compounds including alkylbenzenes, amides and anilines were employed for evaluating the retention behaviors of the mercaptotetrazole-silica hybrid monolithic columns. The results demonstrated that the mercaptotetrazole-silica hybrid monoliths exhibited hydrophobic, hydrophilic as well as ion-exchange interaction. The run-to-run, column-to-column and batch-to-batch reproducibilities of the mercaptotetrazole-silica hybrid monoliths were satisfactory with the relative standard deviations less than 1.4 (n = 5), 3.9 (n = 3) and 4.0% (n = 5), respectively. In addition, the mercaptotetrazole-silica hybrid monolith was further applied to the separation of sulfonamides, nucleobases and protein tryptic digests. These successful applications confirmed the promising potential of the mercaptotetrazole-silica hybrid monolith in the separation of complex samples. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Preparation, characterization and cytotoxicity studies of some transition metal complexes with ofloxacin and 1,10-phenanthroline mixed ligand

    NASA Astrophysics Data System (ADS)

    Sadeek, S. A.; El-Hamid, S. M. Abd

    2016-10-01

    [Zn(Ofl)(Phen)(H2O)2](CH3COO)·2H2O (1), [ZrO(Ofl)(Phen)(H2O)]NO3·2H2O (2) and [UO2(Ofl)(Phen)(H2O)](CH3COO)·H2O (3) complexes of fluoroquinolone antibacterial agent ofloxacin (HOfl), containing a nitrogen donor heterocyclic ligand, 1,10-phenathroline monohydrate (Phen), were prepared and their structures were established with the help of elemental analysis, molar conductance, magnetic properties, thermal studies and different spectroscopic studies like IR, UV-Vis., 1H NMR and Mass. The IR data of HOfl and Phen ligands suggested the existing of a bidentate binding involving carboxylate O and pyridone O for HOfl ligand and two pyridine N atoms for Phen ligand. The coordination geometries and electronic structures are determined from electronic absorption spectra and magnetic moment measurements. From molar conductance studies reveals that metal complexes are electrolytes and of 1:1 type. The calculated bond length and force constant, F(Udbnd O), in the uranyl complex are 1.751 Å and 641.04 Nm-1. The thermal properties of the complexes were investigated by thermogravimetry (TGA) technique. The activation thermodynamic parameters are calculated using Coats-Redfern and Horowitz-Metzger methods. Antimicrobial activity of the compounds was evaluated against some bacteria and fungi species. The activity data show that most metal complexes have antibacterial activity than that of the parent HOfl drug. The in vitro cytotoxicities of ligands and their complexes were also evaluated against human breast and colon carcinoma cells.

  3. Selective catalytic reduction of NOx with NH3 over iron-cerium-tungsten mixed oxide catalyst prepared by different methods

    NASA Astrophysics Data System (ADS)

    Xiong, Zhi-bo; Liu, Jing; Zhou, Fei; Liu, Dun-yu; Lu, Wei; Jin, Jing; Ding, Shi-fa

    2017-06-01

    A series of magnetic Fe0.85Ce0.10W0.05Oz catalysts were synthesized by three different methods(Co-precipitation(Fe0.85Ce0.10W0.05Oz-CP), Hydrothermal treatment assistant critic acid sol-gel method(Fe0.85Ce0.10W0.05Oz-HT) and Microwave irradiation assistant critic acid sol-gel method(Fe0.85Ce0.10W0.05Oz-MW)), and the catalytic activity was evaluated for selective catalytic reduction of NO with NH3. The catalyst was characterized by XRD, N2 adsorption-desorption, XPS, H2-TPR and NH3-TPD. Among the tested catalysts, Fe0.85Ce0.10W0.05Oz-MW shows the highest NOx conversion over per gram in unit time with NOx conversion of 60.8% at 350 °C under a high gas hourly space velocity of 1,200,000 ml/(g h). Different from Fe0.85Ce0.10W0.05Oz-CP catalyst, there exists a large of iron oxide crystallite(γ-Fe2O3 and α-Fe2O3) scattered in Fe0.85Ce0.10W0.05Oz catalysts prepared through hydrothermal treatment or microwave irradiation assistant critic acid sol-gel method, and higher iron atomic concentration on their surface. And Fe0.85Ce0.10W0.05Oz-MW shows higher surface absorbed oxygen concentration and better dispersion compared with Fe0.85Ce0.10W0.05Oz-HT catalyst. These features were favorable for the high catalytic performance of NO reduction with NH3 over Fe0.85Ce0.10W0.05Oz-MW catalyst.

  4. One-pot preparation of glutathione-silica hybrid monolith for mixed-mode capillary liquid chromatography based on "thiol-ene" click chemistry.

    PubMed

    Lin, Zian; Tan, Xiaoqing; Yu, Ruifang; Lin, Jiashi; Yin, Xiaofei; Zhang, Lan; Yang, Huanghao

    2014-08-15

    A novel glutathione (GSH)-silica hybrid monolithic column synthesized via a combination of thiol-ene click reaction and one-pot process was described, where thiol-end GSH organic monomer and 2,2-azobisisobutyronitrile (AIBN) were mixed with hydrolyzed tetramethyloxysilane (TMOS) and γ-methacryloxypropyltrimethoxysilane (γ-MAPS) and then introduced into a fused-silica capillary for simultaneous polycondensation and "thiol-ene" click reaction to form the GSH-silica hybrid monolith. The effects of the molar ratio of TMOS/γ-MAPS, the amount of GSH, and the volume of porogen on the morphology, permeability and pore properties of the prepared GSH-silica hybrid monoliths were studied in detail. A uniform monolithic network with high porosity was obtained. A series of test compounds including alkylbenzenes, amides, and anilines were used to evaluate the retention behaviors of the GSH-silica hybrid monolithic column. The results demonstrated that the prepared GSH-silica hybrid monolith exhibited multiple interactions including hydrophobicity, hydrophilicity, as well as cation exchange interaction. The run-to-run, column-to-column and batch-to-batch reproducibilities of the GSH-silica hybrid monolith for phenols' retention were satisfactory with the relative standard deviations (RSDs) less than 1.3% (n=5), 2.6% (n=3) and 3.2% (n=3), respectively, indicating the effectiveness and practicability of the proposed method. In addition, the GSH-silica hybrid monolith was applied to the separation of nucleotides, peptides and protein tryptic digests, respectively. The successful applications suggested the potential of the GSH-silica hybrid monolith in complex sample analysis.

  5. A novel preparation of three-dimensionally ordered macroporous M/Ti (M=Zr or Ta) mixed oxide nanoparticles with enhanced photocatalytic activity.

    PubMed

    Wang, Changhua; Geng, Aifang; Guo, Yihang; Jiang, Shujuan; Qu, Xuesong; Li, Li

    2006-09-01

    Three-dimensionally ordered macroporous (3 DOM) M/Ti (M=Zr or Ta) mixed oxides were prepared by cohydrolysis of a mixture of Zr(n-OC(4)H(9))(4)/TTIP or TaCl(5)/TTIP (TTIP=titanium isopropoxide) combined with a polystyrene (PS) latex sphere templating technique. The resulting products exhibited homogeneous wall compositions, namely, Zr or Ta was uniformly dispersed into the TiO(2) framework with the loading levels of 5, 10, and 20 mol% for Zr and 2.5, 5.0, and 7.5 mol% for Ta, respectively. The estimated macropore diameter, wall thickness, and particle size of the products ranged from 280 to 290 nm, from 30 to 50 nm, and from 10 to 12 nm, respectively. The products showed only anatase phase structure although their starting solitary metal oxides exhibited suitable crystalline structures under the same preparation conditions. Raman scattering spectroscopy showed that the crystal structure of titania had a slight interference due to the incorporation of Zr or Ta, and UV-vis diffuse reflectance spectroscopy (DRS) showed the narrower band gap of the products compared with that of pure anatase TiO(2). The products exhibited mesoporous wall structures, and their BET surface areas were higher than those of the corresponding pure 3 DOM metal oxides. The UV-light photocatalytic activity of the products was assessed by monitoring the photodegradation of two organic molecules including 4-nitrophenol (4-NP) and rhodamine B (RB). Both the photocatalytic reactions confirmed that the presence of the second metal oxide in the titania framework resulted in enhanced photocatalytic activity compared with the pure titania framework.

  6. Effect of Applying Molasses and Propionic Acid on Fermentation Quality and Aerobic Stability of Total Mixed Ration Silage Prepared with Whole-plant Corn in Tibet

    PubMed Central

    Chen, Lei; Guo, Gang; Yuan, Xianjun; Shimojo, Masataka; Yu, Chengqun; Shao, Tao

    2014-01-01

    The objective of this study was to evaluate the effects of molasses and propionic acid on the fermentation quality and aerobic stability of total mixed ration (TMR) silages prepared with whole-plant corn in Tibet. TMR (354 g/kg DM) was ensiled with four different treatments: no additive (control), molasses (M), propionic acid (P), and molasses+propionic acid (PM), in laboratory silos (250 mL) and fermented for 45 d. Silos were opened and silages were subjected to an aerobic stability test for 12 days, in which chemical and microbiological parameters of TMR silages were measured to determined the aerobic deterioration. After 45 d of ensiling, the four TMR silages were of good quality with low pH value and ammonia/total N (AN), and high lactic acid (LA) content and V-scores. M silage showed the highest (p<0.05) LA content and higher dry matter (DM) recovery than the control and P silages. P silage had lower (p<0.05) LA content than the control silage. During aerobic exposure, lactic acid contents decreased gradually in the control and M silages, while that of P and PM silages increased, and the peak values were observed after 9 d. M silage had similar yeast counts with the control silage (>105 cfu/g FM), however, it appeared to be more stable as indicated by a delayed pH value increase. P and PM silages showed fewer yeasts (<105 cfu/g FM) (p<0.05) and were more stable than the control and M silages during aerobic exposure. It was concluded that M application increased LA content and improved aerobic stability of TMR silage prepared with whole-plant corn in Tibet. P application inhibited lactic acid production during ensiling, and apparently preserved available sugars which stimulated large increases in lactic acid during aerobic exposure stage, which resulted in greater aerobic stability of TMR silage. PMID:25049961

  7. Selective detergent-extraction from mixed detergent/lipid/protein micelles, using cyclodextrin inclusion compounds: a novel generic approach for the preparation of proteoliposomes.

    PubMed Central

    Degrip, W J; Vanoostrum, J; Bovee-Geurts, P H

    1998-01-01

    A novel generic approach is described for the selective extraction of detergents from mixed detergent/lipid/protein micelles for the preparation of proteoliposomes of defined lipid-protein ratio. The approach is based on the much higher affinity of inclusion compounds of the cyclodextrin type for detergents in comparison with bilayer-forming lipids. This approach has distinct advantages over other procedures currently in use. It produces good results with all detergents tested, independent of type and critical micelle concentration, and appears to be generally applicable. It yields nearly quantitative recovery of membrane protein in the proteoliposome fraction. Finally, no large excess of lipid is required; a molar ratio of lipid to protein of 100 to 1 already produces proteoliposomes with functional membrane protein, but higher ratios are well tolerated. The size of the vesicles thus obtained depends on the detergent used. Separation of the resulting proteoliposomes from the detergent-cyclodextrin complexes was most easily achieved by centrifugation through a discontinuous sucrose gradient. A variety of detergents was tested in this procedure on the bovine rod visual pigment rhodopsin in combination with retina lipids. In all cases good yields of proteoliposomes were obtained, which contained fully functional rhodopsin. PMID:9480873

  8. Optimizing the ability of PVP/PEG mixtures to be used as appropriate carriers for the preparation of drug solid dispersions by melt mixing technique using artificial neural networks: I.

    PubMed

    Papadimitriou, Sofia A; Barmpalexis, Panagiotis; Karavas, Evangelos; Bikiaris, Dimitrios N

    2012-09-01

    In the present study, the efficiency of PVP/PEG200 mixtures as appropriate carries for the preparation of solid dispersions by melt mixing was evaluated. Felodipine (FELO) was used as a poorly water soluble model drug. The effect of several melt mixing parameters, (PVP/PEG ratio, time and temperature of melt mixing, and drug content), on the physical state of FELO and the dissolution characteristics of the dispersions were investigated. DSC, XRD, and SEM analysis revealed that in all cases, amorphous drug nanodispersions were prepared. This was attributed to the increased miscibility of the PVP-FELO system, induced by the presence of PEG200, which acted as plasticizer. FT-IR analysis showed hydrogen bonding between FELO (NH) and the PVP carrier (CO). The release rate of the drug depends mainly on the drug content and is higher in solid dispersions with low drug content and ratio of carrier to plasticizer (PVP/PEG200). The melt mixing variations (time and temperature of mixing) had lower impact on FELO release rate. Finally, artificial neural networks, used to correlate the examined formulation and process variables of hot melt mixing with dissolution parameters, showed good prediction ability.

  9. Effect of chromium substitution on the dielectric properties of mixed Ni-Zn ferrite prepared by WOWS sol–gel technique

    SciTech Connect

    Ashtar, M.; Munir, A.; Anis-ur-Rehman, M.; Maqsood, A.

    2016-07-15

    Graphical abstract: Variation of AC conductivity (σ{sub AC}) as a function of natural log of angular frequency (lnω) for Ni{sub 0.5}Zn{sub 0.5}Fe{sub 2-x}Cr{sub x}O{sub 4} nanoferrites at room temperature. - Highlights: • Cr doped mixed Ni-Zn ferrites were successfully synthesized by a newly developed WOWS sol gel technique. • The specific surface area and specific surface area to volume ratio increased with decrease in particle size. • The resonance peaks appeared in dielectric loss graphs, shifting towards low frequency with the increase in Cr concentration. • The prepared samples have the lowest values of the dielectric constant. • The dielectric constant were observed to be inversely proportional to square root of the AC resistivity. - Abstract: Cr{sup +3} doped Ni-Zn nanoferrite samples with composition Ni{sub 0.5}Zn{sub 0.5}Fe{sub 2-x}Cr{sub x}O{sub 4}(x = 0.1, 0.2, 0.3, 0.4) were synthesized With Out Water and Surfactant (WOWS) sol-gel technique. The structural, morphological and dielectric properties of the samples were investigated. The lattice constant, crystallite size, theoretical density and porosity of each sample were obtained from X-ray diffraction (XRD) data. The specific surface area and specific surface area to volume ratio increased with the decrease in the size of Cr{sup +3} doped Ni-Zn ferrite nanoparticles, as the concentration of Cr{sup +3} increased. The SEM analysis revealed that the particles were of nano size and of spherical shape. The dielectric parameters such as dielectric constant (ε′) and dielectric loss (tanδ) of all the samples as a function of frequency at room temperature were measured. The AC conductivity (σ{sub AC}) was determined from the dielectric parameters, which showed increasing trend with the rise in frequency.

  10. A Mixed Methods Study of Special Education Teachers' Knowledge of Reading Instruction and Perceptions Concerning Their Preparation to Teach Reading

    ERIC Educational Resources Information Center

    Blakeslee, Cynthia Darden

    2012-01-01

    Significant changes in requirements for reading instruction and special education teacher preparation have occurred in recent years due to provisions found in the No Child Left Behind legislation of 2001 and the 2004 Individuals with Disabilities Education Improvement Act. This study examined the preparation for reading instruction that…

  11. A Mixed Methods Study of Special Education Teachers' Knowledge of Reading Instruction and Perceptions Concerning Their Preparation to Teach Reading

    ERIC Educational Resources Information Center

    Blakeslee, Cynthia Darden

    2012-01-01

    Significant changes in requirements for reading instruction and special education teacher preparation have occurred in recent years due to provisions found in the No Child Left Behind legislation of 2001 and the 2004 Individuals with Disabilities Education Improvement Act. This study examined the preparation for reading instruction that…

  12. Platinum nanoparticles on carbon-nanotube support prepared by room-temperature reduction with H2 in ethylene glycol/water mixed solvent as catalysts for polymer electrolyte membrane fuel cells

    NASA Astrophysics Data System (ADS)

    Zheng, Yuying; Dou, Zhengjie; Fang, Yanxiong; Li, Muwu; Wu, Xin; Zeng, Jianhuang; Hou, Zhaohui; Liao, Shijun

    2016-02-01

    Polyol approach is commonly used in synthesizing Pt nanoparticles in polymer electrolyte membrane fuel cells. However, the application of this process consumes a great deal of time and energy, as the reduction of precursors requires elevated temperatures and several hours. Moreover, the ethylene glycol and its oxidizing products bound to Pt are difficult to remove. In this work, we utilize the advantages of ethylene glycol and prepare Pt nanoparticles through a room-temperature hydrogen gas reduction in an ethylene glycol/water mixed solvent, which is followed by subsequent harvesting by carbon nanotubes as electrocatalysts. This method is simple, facile, and time-efficient, as the entire room-temperature reduction process is completed in a few minutes. As the solvent changes from water to an ethylene glycol/water mix, the size of Pt nanoparticles varies from 10 to 3 nm and their shape transitions from polyhedral to spherical. Pt nanoparticles prepared in a 1:1 volume ratio mixture of ethylene glycol/water are uniformly dispersed with an average size of ∼3 nm. The optimized carbon nanotube-supported Pt electrocatalyst exhibits excellent methanol oxidation and oxygen reduction activities. This work demonstrates the potential use of mixed solvents as an approach in materials synthesis.

  13. Orientation control of (K,Na)NbO3 ceramics using platelike NaNbO3 templates prepared by single-step molten salt synthesis with mixed salt

    NASA Astrophysics Data System (ADS)

    Ishii, Keisuke; Tashiro, Shinjiro

    2016-10-01

    In order to shorten the firing time for sintering textured (K,Na)NbO3 system ceramics, the fabrication method of the single-step molten salt synthesis for preparing platelike NaNbO3 single-crystal particles was improved. An uneven shape was formed on the surfaces of platelike NaNbO3 single-crystal particles obtained by single-step molten salt synthesis in the mixed salts of KCl and NaCl. Using these single-crystal particles as the templates, textured (K,Na)NbO3 ceramics were fabricated. The sinterability of the textured ceramics and their piezoelectricity were compared between two kinds of templates synthesized in the mixed salt and in the conventional NaCl salt. The diffusivity of K atoms into these templates from the matrix powder of (K,Na)NbO3 during firing was also compared.

  14. Preparation of a weak anion exchange/hydrophobic interaction dual-function mixed-mode chromatography stationary phase for protein separation using click chemistry.

    PubMed

    Zhao, Kailou; Yang, Fan; Xia, Hongjun; Wang, Fei; Song, Qingguo; Bai, Quan

    2015-03-01

    In this study, 3-diethylamino-1-propyne was covalently bonded to the azide-silica by a click reaction to obtain a novel dual-function mixed-mode chromatography stationary phase for protein separation with a ligand containing tertiary amine and two ethyl groups capable of electrostatic and hydrophobic interaction functionalities, which can display hydrophobic interaction chromatography character in a high-salt-concentration mobile phase and weak anion exchange character in a low-salt-concentration mobile phase employed for protein separation. As a result, it can be employed to separate proteins with weak anion exchange and hydrophobic interaction modes, respectively. The resolution and selectivity of the stationary phase were evaluated in both hydrophobic interaction and ion exchange modes with standard proteins, respectively, which can be comparable to that of conventional weak anion exchange and hydrophobic interaction chromatography columns. Therefore, the synthesized weak anion exchange/hydrophobic interaction dual-function mixed-mode chromatography column can be used to replace two corresponding conventional weak anion exchange and hydrophobic interaction chromatography columns to separate proteins. Based on this mixed-mode chromatography stationary phase, a new off-line two-dimensional liquid chromatography technology using only a single dual-function mixed-mode chromatography column was developed. Nine kinds of tested proteins can be separated completely using the developed method within 2.0 h.

  15. Mixing kaons with mixed action chiral perturbation theory

    NASA Astrophysics Data System (ADS)

    Aubin, Christopher

    2006-12-01

    We calculate the neutral kaon mixing parameter, BK , to next-to-leading order in mixed action (domain-wall valence with staggered sea quarks) chiral perturbation theory. We find the expres- sion for BK in this mixed-action case only differs from the continuum partially quenched expres- sion by an additional analytic term. Additionally, in preparation for a lattice calculation of BK with a mixed action, we discuss quantitatively the effects of the taste violations as well as finite volume effects.

  16. Preparation-free method for detecting Escherichia coli O157:H7 in the presence of spinach, spring lettuce mix, and ground beef particulates.

    PubMed

    Maraldo, David; Mutharasan, Raj

    2007-11-01

    We show the detection of 100 cells per ml of Escherichia coli O157:H7 in the presence of spinach, spring lettuce mix, and ground beef washes and particulate matter with piezoelectric-excited millimeter-sized cantilever (PEMC) sensors. The PEMC sensors (sensing area, 2 mm2) were immobilized with polyclonal antibody specific to E. coli O157:H7 (EC) and were exposed to 10 aqueous washes of locally purchased spinach, spring lettuce mix, and ground beef for testing if EC was present. Absence of resonance frequency shift indicated that EC was not present in the 30 samples tested. Following the last sample in each food matrix, 1,000 cells per ml of EC were spiked into the sample container, and resonance frequency change was monitored. The total resonance frequency change was 880 +/- 5, 1,875 +/- 8, and 1,417 +/- 4 Hz for spinach, spring lettuce mix, and ground beef, respectively. A mixture of the three food matrices spiked with 100 cells per ml of EC gave a sensor response of 260 +/- 15 Hz. The resonance frequency changes are approximately 40% lower than our previously reported study on ground beef. It is suggested that the reduction in sensitivity is due to differences in pathogen adherence to food matrices, which affects target binding to the sensor surface. We conclude that detection selectivity is conserved in the three food matrices examined and that the magnitude of sensor response is a function of the food matrix.

  17. Single column comprehensive analysis of pharmaceutical preparations using dual-injection mixed-mode (ion-exchange and reversed-phase) and hydrophilic interaction liquid chromatography.

    PubMed

    Kazarian, Artaches A; Taylor, Mark R; Haddad, Paul R; Nesterenko, Pavel N; Paull, Brett

    2013-12-01

    The comprehensive separation and detection of hydrophobic and hydrophilic active pharmaceutical ingredients (APIs), their counter-ions (organic, inorganic) and excipients, using a single mixed-mode chromatographic column, and a dual injection approach is presented. Using a mixed-mode Thermo Fisher Acclaim Trinity P1 column, APIs, their counter-ions and possible degradants were first separated using a combination of anion-exchange, cation-exchange and hydrophobic interactions, using a mobile phase consisting of a dual organic modifier/salt concentration gradient. A complementary method was also developed using the same column for the separation of hydrophilic bulk excipients, using hydrophilic interaction liquid chromatography (HILIC) under high organic solvent mobile phase conditions. These two methods were then combined within a single gradient run using dual sample injection, with the first injection at the start of the applied gradient (mixed-mode retention of solutes), followed by a second sample injection at the end of the gradient (HILIC retention of solutes). Detection using both ultraviolet absorbance and refractive index enabled the sensitive detection of APIs and UV-absorbing counter-ions, together with quantitative determination of bulk excipients. The developed approach was applied successfully to the analysis of a dry powder inhalers (Flixotide(®), Spiriva(®)), enabling comprehensive quantification of all APIs and excipients in the sample.

  18. Web-Based Evidence Based Practice Educational Intervention to Improve EBP Competence among BSN-Prepared Pediatric Bedside Nurses: A Mixed Methods Pilot Study

    ERIC Educational Resources Information Center

    Laibhen-Parkes, Natasha

    2014-01-01

    For pediatric nurses, their competence in EBP is critical for providing high-quality care and maximizing patient outcomes. The purpose of this pilot study was to assess and refine a Web-based EBP educational intervention focused on improving EBP beliefs and competence in BSN-prepared pediatric bedside nurses, and to examine the feasibility,…

  19. Web-Based Evidence Based Practice Educational Intervention to Improve EBP Competence among BSN-Prepared Pediatric Bedside Nurses: A Mixed Methods Pilot Study

    ERIC Educational Resources Information Center

    Laibhen-Parkes, Natasha

    2014-01-01

    For pediatric nurses, their competence in EBP is critical for providing high-quality care and maximizing patient outcomes. The purpose of this pilot study was to assess and refine a Web-based EBP educational intervention focused on improving EBP beliefs and competence in BSN-prepared pediatric bedside nurses, and to examine the feasibility,…

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

    USDA-ARS?s Scientific Manuscript database

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

  1. Toward realization of 'mix-and-use' approach in ⁶⁸Ga radiopharmacy: preparation, evaluation and preliminary clinical utilization of ⁶⁸Ga-labeled NODAGA-coupled RGD peptide derivative.

    PubMed

    Chakraborty, Sudipta; Chakravarty, Rubel; Vatsa, Rakhee; Bhusari, Priya; Sarma, H D; Shukla, Jaya; Mittal, B R; Dash, Ashutosh

    2016-01-01

    The present article demonstrates a 'mix-and-use' approach for radiolabeling RGD peptide derivative with (68)Ga, which is easily adaptable in hospital radiopharmacy practice. The radiotracer thus formulated was successfully used for positron emission tomography (PET) imaging of breast cancer in human patients. The conditions for radiolabeling NODAGA-coupled dimeric cyclic RGD peptide derivative [NODAGA-(RGD)2] with (68)Ga were optimized using (68)Ga obtained from a (68)Ge/(68)Ga generator developed in-house with CeO2-PAN composite sorbent as well as from a commercial (68)Ge/(68)Ga generator obtained from ITG, Germany. Preclinical studies were carried out in C57BL/6 mice bearing melanoma tumors. The radiotracer was prepared in a hospital radiopharmacy using (68)Ga obtained from ITG generator and used for monitoring breast cancer patients by positron emission tomography (PET) imaging. (68)Ga-NODAGA-(RGD)2 could be prepared with high radiolabeling yield (>98%) and specific activity (~50 GBq/μmol) within 10 min at room temperature by mixing (68)Ga with the solution of the peptide conjugate. In vivo biodistribution studies showed significant uptake (5.24±0.39% ID/g) in melanoma tumor at 30 min post-injection, with high tumor-to-background contrast. The integrin αvβ3 specificity of the tracer was corroborated by blocking study. Preliminary clinical studies in locally advanced breast cancer (LABC) patients indicated specifically high tumor uptake (SUVmax 10-15) with good contrast. This is one of the very few reports which presents preliminary clinical data on use of (68)Ga-NODAGA-(RGD)2 and the developed 'mix-and-use' holds tremendous prospect in clinical PET imaging using (68)Ga. Copyright © 2015 Elsevier Inc. All rights reserved.

  2. Impact tests of the tungsten coated stainless steels prepared by using magnetron sputtering with ion beam mixing or electron beam alloying treatment

    NASA Astrophysics Data System (ADS)

    Zou, Yu; Zhan, Chang-Yong; Yang, Bin; Wu, Jian-Chun

    2013-05-01

    Tungsten films were deposited on stainless steel (SS) with ion beam mixing (IBM) or electron beam alloying (EBA) treatment. The ductile-brittle transition behaviors of the specimens were investigated by means of instrumented Charpy impact test at a series of temperature, and SEM was used to observe the morphology of the cross section. Impact tests show that different treatment methods with W films do not have much influence on crack initiation, while EBA treatment with W films can more effectively prevent crack propagation, namely improve the impact toughness of SS than using IBM treatment. The reason that caused this difference was discussed.

  3. Preparation of Pluronic/Bile salt/Phospholipid Mixed Micelles as Drug Solubility Enhancer and Study the Effect of the PPO Block Size on the Solubility of Pyrene.

    PubMed

    Wang, Li; Peng, Min; Zhu, Yuan; Tong, Shan-Shan; Cao, Xia; Xu, Xi-Ming; Yu, Jiang-Nan

    2014-01-01

    Pluronic/bile salt/phospholipid mixed micelles (Pluronic/BS/PS-MM) drug carrier system for solubilization hydrophobic drugs was developed. A typical hydrophobic compound, pyrene, was selected as a representative hydrophobic compound to model the hydrophobic drugs. Five Pluronics, F68, F88, F98, F108, and F127 with different PPO chain length were studied. CMC data and solubilization capacities were obtained from a pyrene solubilization method. A closed association model was used to obtain the thermodynamic parameters: Gibbs free energy (ΔG°), enthalpy, (ΔH°) and entropy (ΔS°) of micellization. The results obtained from these experiments suggest that the mixed micelles was more stable and solubilize more pyrene than single one; and the solubilization of pyrene was strong effected by the PPO block size, thus accentuating synergistic interaction mechanism in Pluronic/BS/PS-MM. The study generated an important dataset so as to compare the effect of different Pluronics on solubility capacity of Pluronic/BS/PS-MM.

  4. High-mix insulins

    PubMed Central

    Kalra, Sanjay; Farooqi, Mohammad Hamed; El-Houni, Ali E.

    2015-01-01

    Premix insulins are commonly used insulin preparations, which are available in varying ratios of different molecules. These drugs contain one short- or rapid-acting, and one intermediate- or long-acting insulin. High-mix insulins are mixtures of insulins that contain 50% or more than 50% of short-acting insulin. This review describes the clinical pharmacology of high-mix insulins, including data from randomized controlled trials. It suggests various ways, in which high-mix insulin can be used, including once daily, twice daily, thrice daily, hetero-mix, and reverse regimes. The authors provide a rational framework to help diabetes care professionals, identify indications for pragmatic high-mix use. PMID:26425485

  5. A study of the tribological characteristics of titanium nitride film prepared by the dynamic ion beam mixing method for application on sliding bearings

    SciTech Connect

    Nagasaka, H.; Koizumi, T.

    1997-12-01

    Titanium nitride (TiN) film for the bearings and seals used in rotating machinery has been developed by the dynamic-ion-beam-mixing (DM) process, which combines Ti vapor deposition with simultaneous nitrogen ion beam irradiation. In this study, the tribological properties of the DM-TiN film on martensitic stainless steel (SS) were investigated for application on the bearings of submerged pumps. The critical contact pressure for seizure, wear resistance and friction coefficient properties of DM-TiN film paired with cast iron were investigated under practical sliding conditions, and compared with the hard surface materials of nitriding AISI 420 SS and nitriding 41CrAlMo74 (CrAlMo) steel. The results show that DM-TiN film is superior to these nitriding steels in surface contact pressure for seizure and wear resistance.

  6. Structural characteristics and gasification reactivity of chars prepared from K{sub 2}CO{sub 3} mixed HyperCoals and coals

    SciTech Connect

    Atul Sharma; Hiroyuki Kawashima; Ikuo Saito; Toshimasa Takanohashi

    2009-04-15

    HyperCoal is a clean coal with mineral matter content <0.05 wt %. Oaky Creek (C = 82%), and Pasir (C = 68%) coals were subjected to solvent extraction method to prepare Oaky Creek HyperCoal, and Pasir HyperCoal. Experiments were carried out to compare the gasification reactivity of HyperCoals and parent raw coals with 20, 40, 50 and 60% K{sub 2}CO{sub 3} as a catalyst at 600, 650, 700, and 775{sup o}C with steam. Gasification rates of coals and HyperCoals were strongly influenced by the temperature and catalyst loading. Catalytic steam gasification of HyperCoal chars was found to be chemical reaction controlled in the 600-700{sup o}C temperature range for all catalyst loadings. Gasification rates of HyperCoal chars were found to be always higher than parent coals at any given temperature for all catalyst loadings. However, X-ray diffraction results showed that the microstructures of chars prepared from coals and HyperCoals were similar. Results from nuclear magnetic resonance spectroscopy show no significant difference between the chemical compositions of the chars. Significant differences were observed from scanning electron microscopy images, which showed that the chars from HyperCoals had coral-reef like structures whereas dense chars were observed for coals. 26 refs., 8 figs., 2 tabs.

  7. Radial Mixing in Turbomachines

    DTIC Science & Technology

    1991-03-31

    Belgium March 31, 1991 Final Scientific Report June 1, 1989 - July 31, 1990 VUB -STR -17 Approved for public release; distribution unlimited. - Prepared ...secondary flows and turbulence as sources of mixing was investigated by conducting experiments using hot-wire anemometry and ehtylene tracer gas

  8. Phase Evolution and Nucleus Growth Observation of Solid-State BaTiO3 Powder Prepared by High-Energy Bead Milling for Raw Material Mixing

    NASA Astrophysics Data System (ADS)

    Lee, Ting-Tai; Huang, Chi-Yuen; Chang, Che-Yuan; Lin, Shih-Pin; Su, Che-Yi; Lee, Chun-Te; Fujimoto, Masayuki

    2011-09-01

    The solid-state synthesis, phase evolution, and nucleus growth of the barium titanate (BaTiO3, BT) powder were investigated in this study. Rapid nucleus growth and precursor phase formation of BT were observed at a relatively low temperature of 600 °C by mixing BaCO3 (2 m2/g) and TiO2 (7 m2/g) with a high-energy bead mill. The decomposition of BaCO3 and the formation of the Ba2TiO4 phase were identified by transmission electron microscopy (TEM). On the basis of this observation, the weight loss observed at 600 °C in the derivative thermogravimetry (DTG) curve could also be explained. Furthermore, with increasing calcination temperature, single cubic BT with less than 80 nm fine nuclei/crystallites was observed at 900 °C, and tetragonal BT (c/a > 1.008) with an average particle size of 0.4 µm was obtained at 1000 °C. With regard to the dielectric properties of sintered ceramics, the relative permittivity (ɛr) increased with calcination temperature, and the Curie point also shifted to a progressively higher temperature. However, BT nucleus samples (with low calcination temperatures of 800 and 900 °C) could not satisfy the X7R requirement (Electric Industries Association Standard, the tolerance of capacitance from -55 to +125 °C is ±15%) until calcination temperature increased to 1000 °C.

  9. Preparation and formation mechanism of BiOCl0.75I0.25 nanospheres by precipitation method in alcohol-water mixed solvents.

    PubMed

    Wang, Xiaoning; Chen, Hongche; Li, Hongjing; Mailhot, Gilles; Dong, Wenbo

    2016-09-15

    BiOCl0.75I0.25 crystals with irregular three-dimensional (3D) flower-like and hierarchical nanosphere-like structures were successfully synthesized in different alcohol-water mixed solvents by precipitation method. The primary formation mechanism of BiOCl0.75I0.25 nanospheres was investigated by taking water, monohydric alcohols (ethanol and isopropanol), and polyhydric alcohols (ethylene glycol, diethylene glycol, and glycerol) as solvents in the synthesis process. The obtained BiOCl0.75I0.25 samples were characterized by powder X-ray diffraction, Raman spectroscopy, field emission scanning electron microscopy, and nitrogen adsorption. Results showed that the alcohol solvents with different physical and chemical properties used in the synthesis process performed significant functions in directing the morphology and surface pore structure of BiOCl0.75I0.25 crystals. Meanwhile, BiOCl0.75I0.25 synthesized in various solvents exhibited morphology-dependent adsorption and photocatalytic degradation abilities in removing p-hydroxyphenylacetic acid (p-HPA), which was used as a model pollutant, in aqueous solutions under simulated solar light (λ⩾290nm). In addition, the fabrication process of the crystal products was proposed through a series of time-dependent experiments.

  10. Evaluation of HACCP system implementation on the quality of mixed fresh-cut salad prepared in a university canteen: a case study.

    PubMed

    Osimani, Andrea; Aquilanti, Lucia; Clementi, Francesca

    2015-01-01

    The increasing awareness that foods can represent vehicles for health risk factors has caused scientists and public authorities to multiply their efforts to reduce these risks to within acceptable limits. Nevertheless, some challenging issues still remain unsolved and new ones have recently emerged, such as the increase in outbreaks of foodborne diseases originating from the consumption of meals at catering facilities. The study described in this article was aimed at evaluating the microbiological quality of mixed fresh-cut salads at an Italian university canteen operating in conformity with the hazard analysis and critical control point (HACCP) system. The effectiveness of the preventive and corrective measures taken was also assessed with respect to the frequency of unsatisfactory salad samples. During the investigation, E. coli, Salmonella spp., and Listeria monocytogenes were never detected. By contrast, a high number of samples exceeded the mandatory or suggested limits for food processing hygiene (in terms of mesophilic aerobes, coliforms, Staphylococcus aureus, Bacillus cereus, and sulfite-reducing clostridia counts). Despite the introduction of a series of preventive and corrective actions, the results were only partially satisfactory; this was most likely due to the impossibility of having available an adequate level of human resources that are indispensable to correctly putting the HACCP procedures into daily practice.

  11. Structural and superconducting aspects in REBa2Cu3O7-δ (RE = Nd, Gd, Eu) superconductors prepared by wet-mixing method and varying sintering temperature

    NASA Astrophysics Data System (ADS)

    Suharta, W. G.; Suasmoro, S.; Pratapa, S.; Darminto

    2013-09-01

    The rare-earth copper oxide superconductors of Nd1Ba2Cu3O7-δ, Nd0.5Gd0.5Ba2Cu3O7-δ and Nd0.33Eu0.33Gd0.33Ba2Cu3O7-δ have successfully been synthesized by introducing a wet-mixing method. Sintering was carried out at varying temperatures of 920, 940, 960 and 970°C for 10 hours in air. The effects of sintering temperature on the structural and crystallinity of the synthesized powders was studied using X-ray diffraction techniques. Rietveld analyses gave clearly separated diffraction (013) and (110) peaks at respectively 32.2° and 32.5°, decreasing Goodness-of-Fit, increasing average crystal size and increasing orthorhombicity with increasing sintering temperature from 920 to 970°C. In this research, the superconducting critical temperatures of Nd0.5Gd0.5Ba2Cu3O7-δ and Nd0.33Eu0.33Gd0.33Ba2Cu3O7-δ powders sintered at 970°C and measured using a SQUID magnetometer was obtained to be about 88-91 K.

  12. Controlled Thermoresponsive Hydrogels by Stereocomplexed PLA-PEG-PLA Prepared via Hybrid Micelles of Pre-Mixed Copolymers with Different PEG Lengths

    SciTech Connect

    Abebe, Daniel G.; Fujiwara, Tomoko

    2012-09-05

    The stereocomplexed hydrogels derived from the micelle mixture of two enantiomeric triblock copolymers, PLLA-PEG-PLLA and PDLA-PEG-PDLA, reported in 2001 exhibited sol-to-gel transition at approximately body temperature upon heating. However, the showed poor storage modulus (ca. 1000 Pa) determined their insufficiency as injectable implant biomaterials for many applications. In this study, the mechanical property of these hydrogels was significantly improved by the modifications of molecular weights and micelle structure. Co-micelles composed of block copolymers with two sizes of PEG block length were shown to possess unique and dissimilar properties from the micelles composed of single-sized block copolymers. The stereomixture of PLA-PEG-PLA comicelles showed a controllable sol-to-gel transition at a wide temperature range of 4 and 80 C. The sol-gel phase diagram displays a linear relationship of temperature versus copolymer composition; hence, a transition at body temperature can be readily achieved by adjusting the mixed copolymer ratio. The resulting thermoresponsive hydrogels exhibit a storage modulus notably higher (ca. 6000 Pa) than that of previously reported hydrogels. As a physical network solely governed by self-reorganization of micelles, followed by stereocomplexation, this unique system offers practical, safe, and simple implantable biomaterials.

  13. Development and evaluation of training resources to prepare health professionals for counselling pregnant women about non-invasive prenatal testing for Down syndrome: a mixed methods study.

    PubMed

    Oxenford, Kerry; Daley, Rebecca; Lewis, Celine; Hill, Melissa; Chitty, Lyn S

    2017-04-27

    The availability of non-invasive prenatal testing (NIPT) for aneuploidies is expanding rapidly throughout the world. Training health professionals to offer NIPT in a way that supports informed choice is essential for implementation. The aim of this study was to develop and evaluate a training package for health professionals to support the introduction of NIPT into clinical practice. Training on NIPT was offered to health professionals, primarily midwives, involved in Down syndrome screening and testing in eight hospitals located in England and Scotland as part of a research study evaluating the implementation of NIPT in the UK National Health Service. Training was evaluated using a mixed methods approach that included quantitative questionnaires at three time points and post-training qualitative interviews. The questionnaires measured confidence, self-perceived knowledge and actual knowledge about NIPT for Down syndrome. Interviews explored opinions about the training and experiences of offering NIPT. The training provided to the health professionals was found to positively impact on their confidence in discussing NIPT with women in their clinic, and both their perceived and actual knowledge and understanding of NIPT was improved. Knowledge remained weak in four areas; cell-free fetal DNA levels increase with gestation; turnaround time for NIPT results; cell-free fetal DNA is placental in origin; and NIPT false positive rate. Training materials, including a lesson plan, PowerPoint presentation and written factsheet on NIPT, have been developed and evaluated for use in educating midwives and supporting the introduction of NIPT. Implementation of training should include a greater focus on the areas where knowledge remained low. Some groups of midwives will need additional training or support to optimise their confidence in discussing NIPT with women.

  14. Preparation of a mixed-mode hydrophilic interaction/anion-exchange polymeric monolithic stationary phase for capillary liquid chromatography of polar analytes.

    PubMed

    Lin, Jian; Lin, Jia; Lin, Xucong; Xie, Zenghong

    2009-01-30

    A novel cationic hydrophilic interaction monolithic stationary phase based on the copolymerization of 2-(methacryloyloxy)ethyltrimethylammonium methyl sulfate (META) and pentaerythritol triacrylate (PETA) in a binary porogenic solvent consisting of cyclohexanol/ethylene glycol was designed for performing capillary liquid chromatography. While META functioned as both the ion-exchange sites and polar ligand provider, the PETA, a trivinyl monomer, was introduced as cross-linker. The monolithic stationary phases with different properties were easily prepared by adjusting the amount of META in the polymerization solution as well as the composition of the porogenic solvent. The hydrophilicity of the monolith increased with increasing content of META in the polymerization mixture. A typical hydrophilic interaction chromatography mechanism was observed when the content of acetonitrile in the mobile phase was higher than 20%. The poly(META-co-PETA) monolith showed very good selectivity for neutral, basic and acidic polar analytes. For polar-charged analytes, both hydrophilic interaction and electrostatic interaction contributed to their retention. Peak tailing of basic compounds was avoided and the efficient separation of benzoic acid derivatives was obtained.

  15. Temperature influence on deuterium retention for Be-W mixed thin films prepared by Thermionic Vacuum Arc method exposed to PISCES B plasma

    NASA Astrophysics Data System (ADS)

    Jepu, I.; Doerner, R. P.; Baldwin, M. J.; Porosnicu, C.; Lungu, C. P.

    2015-08-01

    Beryllium-tungsten thin films with well controlled elemental composition were prepared using Thermionic Vacuum Arc (TVA) technique and subsequently exposed to steady state, high ion flux (5.5 - 9.8 × 1022 ions m-2 s-1) deuterium (D) plasma in the PISCES-B facility to consistent fluences of 2.3 × 1026 m-2. Six types of layers were studied, ranging from pure Be, composite Be-W, having the atomic ratios of 9:1; 7:3; 1:1; 3:7; to pure W with a total deposited layer thickness of 2 μm. The sample exposure temperatures, namely 300 K, 473 K, 573 K and 773 K, respectively, were measured in situ with a thermocouple placed on the back of the sample. Morphological and structural examinations were undertaken before and after plasma exposure. Results show an influence of temperature on the subsequent morphology of the surface. Thermal Desorption Spectrometry (TDS) spectra showed a change in the D release behavior for different Be-W ratio for a certain exposure temperature.

  16. Effects of applying molasses, lactic acid bacteria and propionic acid on fermentation quality, aerobic stability and in vitro gas production of total mixed ration silage prepared with oat-common vetch intercrop on the Tibetan Plateau.

    PubMed

    Chen, Lei; Guo, Gang; Yuan, Xianjun; Zhang, Jie; Li, Junfeng; Shao, Tao

    2016-03-30

    The objective of this study was to investigate the effect of molasses, lactic acid bacteria and propionic acid on the fermentation quality, aerobic stability and in vitro gas production of total mixed ration (TMR) silage prepared with oat-common vetch intercrop on the Tibetan plateau. TMR (436 g kg(-1) dry matter (DM)) was ensiled with six experimental treatments: (1) no additives (control); (2) molasses (M); (3) an inoculant (Lactobacillus plantarum) (L); (4) propionic acid (P); (5) molasses + propionic acid (MP); (6) inoculant + propionic acid (LP). All silages were well preserved with low pH (< 4.19) and NH3-N contents, and high lactic acid contents after ensiling for 45 days. L and PL silages underwent a more efficient fermentation than silages without L. P and MP silages inhibited lactic acid production. Under aerobic conditions, M and L silage reduced aerobic stability for 15 and 74 h, respectively. All silages that had propionic acid in their treatments markedly (P < 0.05) improved the aerobic stability. After 72 h incubation, all additives treatments increased (P < 0.05) the 72 h cumulative gas production and in vitro DM digestibility (IVDMD) as compared with the control. L treatment decreased (P < 0.05) in vitro neutral detergent fibre degradability. Our findings show that TMR prepared with oat-common vetch intercrop can be well preserved. Although propionic acid is compatible with lactic acid bacteria, and when used together, they had minor effects on fermentation, aerobic stability and in vitro digestibility of TMR silage prepared with oat-common vetch intercrop. © 2015 Society of Chemical Industry.

  17. Preparation and evaluation of a multimodal minoxidil microemulsion versus minoxidil alone in the treatment of androgenic alopecia of mixed etiology: a pilot study

    PubMed Central

    Sakr, Farouk M; Gado, Ali MI; Mohammed, Haseebur R; Adam, Abdel Nasser Ismail

    2013-01-01

    Background: The variable success of topical minoxidil in the treatment of androgenic alopecia has led to the hypothesis that other pathways could mediate this form of hair loss, including infection and/or microinflammation of the hair follicles. In this study, we prepared a multimodal microemulsion comprising minoxidil (a dihydrotestosterone antagonist), diclofenac (a nonsteroidal anti-inflammatory agent), and tea tree oil (an anti-infective agent). We investigated the stability and physicochemical properties of this formulation, and its therapeutic efficacy compared with a formulation containing minoxidil alone in the treatment of androgenic alopecia. Methods: We developed a multimodal oil/water (o/w) microemulsion, a formulation containing minoxidil alone, and another containing vehicle. A three-phase diagram was constructed to obtain the optimal concentrations of the selected oil, surfactant, and cosurfactant. Thirty-two men aged 18–30 years were randomized to apply 1 mL of microemulsion containing the multimodal formulation (formulation A, n = 11), minoxidil alone (formulation B, n = 11) or placebo (formulation C, n = 10) twice daily to the affected area for 32 weeks. Efficacy was evaluated by mean hair count, thickness, and weight on the targeted area of the scalp. Global photographs were taken, changes in the area of scalp coverage were assessed by patients and external investigators, and the benefits and safety of the study medications were evaluated. The physical stability of formula A was examined after a shelf storage period of 24 months. Results: Formulation A achieved a significantly superior response than formulations B and C in terms of mean hair count (P < 0.001), mean hair weight (P < 0.001), and mean hair thickness (P < 0.05). A patient self-assessment questionnaire demonstrated that the multimodal minoxidil formulation significantly (P < 0.001) slowed hair loss, increased hair growth, and improved appearance, and showed no appreciable side

  18. Preparation and evaluation of a multimodal minoxidil microemulsion versus minoxidil alone in the treatment of androgenic alopecia of mixed etiology: a pilot study.

    PubMed

    Sakr, Farouk M; Gado, Ali Mi; Mohammed, Haseebur R; Adam, Abdel Nasser Ismail

    2013-01-01

    The variable success of topical minoxidil in the treatment of androgenic alopecia has led to the hypothesis that other pathways could mediate this form of hair loss, including infection and/or microinflammation of the hair follicles. In this study, we prepared a multimodal microemulsion comprising minoxidil (a dihydrotestosterone antagonist), diclofenac (a nonsteroidal anti-inflammatory agent), and tea tree oil (an anti-infective agent). We investigated the stability and physicochemical properties of this formulation, and its therapeutic efficacy compared with a formulation containing minoxidil alone in the treatment of androgenic alopecia. We developed a multimodal oil/water (o/w) microemulsion, a formulation containing minoxidil alone, and another containing vehicle. A three-phase diagram was constructed to obtain the optimal concentrations of the selected oil, surfactant, and cosurfactant. Thirty-two men aged 18-30 years were randomized to apply 1 mL of microemulsion containing the multimodal formulation (formulation A, n = 11), minoxidil alone (formulation B, n = 11) or placebo (formulation C, n = 10) twice daily to the affected area for 32 weeks. Efficacy was evaluated by mean hair count, thickness, and weight on the targeted area of the scalp. Global photographs were taken, changes in the area of scalp coverage were assessed by patients and external investigators, and the benefits and safety of the study medications were evaluated. The physical stability of formula A was examined after a shelf storage period of 24 months. Formulation A achieved a significantly superior response than formulations B and C in terms of mean hair count (P < 0.001), mean hair weight (P < 0.001), and mean hair thickness (P < 0.05). A patient self-assessment questionnaire demonstrated that the multimodal minoxidil formulation significantly (P < 0.001) slowed hair loss, increased hair growth, and improved appearance, and showed no appreciable side effects, such as itching and

  19. ADVANCED MIXING MODELS

    SciTech Connect

    Lee, S; Dimenna, R; Tamburello, D

    2011-02-14

    height from zero to 10 ft. The sludge has been characterized and modeled as micron-sized solids, typically 1 to 5 microns, at weight fractions as high as 20 to 30 wt%, specific gravities to 1.4, and viscosities up to 64 cp during motion. The sludge is suspended and mixed through the use of submersible slurry jet pumps. To suspend settled sludge, water is added to the tank as a slurry medium and stirred with the jet pump. Although there is considerable technical literature on mixing and solid suspension in agitated tanks, very little literature has been published on jet mixing in a large-scale tank. One of the main objectives in the waste processing is to provide feed of a uniform slurry composition at a certain weight percentage (e.g. typically {approx}13 wt% at SRS) over an extended period of time. In preparation of the sludge for slurrying, several important questions have been raised with regard to sludge suspension and mixing of the solid suspension in the bulk of the tank: (1) How much time is required to prepare a slurry with a uniform solid composition? (2) How long will it take to suspend and mix the sludge for uniform composition in any particular waste tank? (3) What are good mixing indicators to answer the questions concerning sludge mixing stated above in a general fashion applicable to any waste tank/slurry pump geometry and fluid/sludge combination?

  20. ADVANCED MIXING MODELS

    SciTech Connect

    Lee, S; Richard Dimenna, R; David Tamburello, D

    2008-11-13

    schedule savings. The focus of the present work is to establish mixing criteria associated with the waste processing at SRS and to quantify the mixing time required to suspend sludge particles with the submersible jet pump. Literature results for a turbulent jet flow are reviewed briefly, since the decay of the axial jet velocity and the evolution of the jet flow patterns are important phenomena affecting sludge suspension and mixing operations. One of the main objectives in the waste processing is to provide the DWPF a uniform slurry composition at a certain weight percentage (typically {approx}13 wt%) over an extended period of time. In preparation of the sludge for slurrying to DWPF, several important questions have been raised with regard to sludge suspension and mixing of the solid suspension in the bulk of the tank: (1) How much time is required to prepare a slurry with a uniform solid composition for DWPF? (2) How long will it take to suspend and mix the sludge for uniform composition in any particular waste tank? (3) What are good mixing indicators to answer the questions concerning sludge mixing stated above in a general fashion applicable to any waste tank/slurry pump geometry and fluid/sludge combination? Grenville and Tilton (1996) investigated the mixing process by giving a pulse of tracer (electrolyte) through the submersible jet nozzle and by monitoring the conductivity at three locations within the cylindrical tank. They proposed that the mixing process was controlled by the turbulent kinetic energy dissipation rate in the region far away from the jet entrance. They took the energy dissipation rates in the regions remote from the nozzle to be proportional to jet velocity and jet diameter at that location. The reduction in the jet velocity was taken to be proportional to the nozzle velocity and distance from the nozzle. Based on their analysis, a correlation was proposed. The proposed correlation was shown to be valid over a wide range of Reynolds numbers

  1. On-line two-dimensional countercurrent chromatography×high performance liquid chromatography system with a novel fragmentary dilution and turbulent mixing interface for preparation of coumarins from Cnidium monnieri.

    PubMed

    Wang, Dong; Chen, Long-Jiang; Liu, Jing-Lan; Wang, Xin-Yuan; Wu, Yun-Long; Fang, Mei-Juan; Wu, Zhen; Qiu, Ying-Kun

    2015-08-07

    This study describes a novel on-line two-dimensional countercurrent chromatography×high performance liquid chromatography (2D CCC×HPLC) system for one-step preparative isolation of coumarins from the fruits of Cnidium monnieri. An optimal biphasic solvent system composed of n-heptane/acetone/water (31:50:19, v/v) with suitable Kd values and a higher retention of the stationary phase was chosen to separate target compounds. In order to address the solvent incompatibility problem between CCC and RP-HPLC, a novel fragmentary dilution and turbulent mixing (FD-TM) interface was successfully developed. In detail, the eluent from the first dimensional CCC column was divided into fractions to form 'sample-dilution' stripes in the two switching sample loops, by the dilution water from the makeup pump. Following this, a long, thin tube was applied to mix the CCC eluent with water by in-tube turbulence, to reduce the solvent effect. Each CCC fraction was alternately trapped on the two holding columns for further preparative HPLC separation. This nationally designed FD-TM strategy effectively reduced post-column pressure and allowed a higher water dilution ratio at the post end of CCC, leading to improved sample recovery and a robust 2D CCC×HPLC isolation system. As a result, in a single 2D separation run (6.5h), eight target compounds (1-8) were isolated from 0.5g crude extract of C. monnieri, in overall yields of 1.3, 2.0, 0.5, 0.5, 0.8, 1.5, 8.2, and 15.0%, with HPLC purity of 90.1, 91.1, 94.7, 99.1, 99.2, 98.2, 97.9, and 91.9%, respectively. We anticipate that this improved 2D CCC×HPLC system, based on the novel FD-TM interface, has broad application for simultaneous isolation and purification of multiple components from other complex plant-derived natural products.

  2. Mixed waste: Proceedings

    SciTech Connect

    Moghissi, A.A.; Blauvelt, R.K.; Benda, G.A.; Rothermich, N.E.

    1993-12-31

    This volume contains the peer-reviewed and edited versions of papers submitted for presentation a the Second International Mixed Waste Symposium. Following the tradition of the First International Mixed Waste Symposium, these proceedings were prepared in advance of the meeting for distribution to participants. The symposium was organized by the Mixed Waste Committee of the American Society of Mechanical Engineers. The topics discussed at the symposium include: stabilization technologies, alternative treatment technologies, regulatory issues, vitrification technologies, characterization of wastes, thermal technologies, laboratory and analytical issues, waste storage and disposal, organic treatment technologies, waste minimization, packaging and transportation, treatment of mercury contaminated wastes and bioprocessing, and environmental restoration. Individual abstracts are catalogued separately for the data base.

  3. Mixed Dementia

    MedlinePlus

    ... community Use our Virtual Library Treatment and outcomes back to top Because most people with mixed dementia are diagnosed with a single type of dementia, physicians often base their prescribing decisions on the type of dementia ...

  4. Preparation and antitumor evaluation of self-assembling oleanolic acid-loaded Pluronic P105/d-α-tocopheryl polyethylene glycol succinate mixed micelles for non-small-cell lung cancer treatment

    PubMed Central

    Wu, Hao; Zhong, Qingxiang; Zhong, Rongling; Huang, Houcai; Xia, Zhi; Ke, Zhongcheng; Zhang, Zhenhai; Song, Jie; Jia, Xiaobin

    2016-01-01

    Oleanolic acid (OA) is a triterpenoid found in various fruits and vegetables and used in traditional Chinese medicine. OA plays a crucial role in the treatment of several cancers, but poor water solubility, low permeability, and significant efflux have limited its widespread clinical use. Vitamin E-d-α-tocopheryl polyethylene glycol succinate (vitamin E-TPGS) and Pluronic P105 were used to improve the solubility and permeability and to decrease the efflux of OA. OA-loaded mixed micelles were prepared by ethanol thin-film hydration. The physicochemical properties of the micelles, including zeta potential, morphology, particle size, solubility, drug loading, and drug entrapment efficiency were characterized. OA release from micelles was slower than that from the free drug system. OA uptake by A549 non-small-cell lung cancer (NSCLC) cells was enhanced by the micelles. A tumor model was established by injecting A549 cells into nude mice. In vivo imaging showed that OA-micelles could accumulate in the tumors of nude mice. Additionally, smaller tumor size and increased expression of pro-apoptotic proteins were observed in OA-micelle-treated mice, indicating that OA-micelles are more effective than free OA in treating cancer. In vitro experiments were performed using two NSCLC cell lines (A549 and PC-9). Cytotoxicity evaluations showed that the half-maximal inhibitory concentrations of free OA and OA-micelles were 36.8±4.8 and 20.9±3.7 μM, respectively, in A549 cells and 82.7±7.8 and 56.7±4.7 μM, respectively, in PC-9 cells. Apoptosis assays revealed that the apoptotic rate of OA-micelle-treated A549 and PC-9 cells was higher than that of cells treated with the same concentration of free OA. Wound healing and transwell assays showed that migration and invasion were significantly suppressed in OA-micelle-treated cells. Immunofluorescence and Western blot analyses confirmed that the epithelial–mesenchymal transition was reversed in OA-micelle-treated cells. Mixed

  5. Preparation and antitumor evaluation of self-assembling oleanolic acid-loaded Pluronic P105/d-α-tocopheryl polyethylene glycol succinate mixed micelles for non-small-cell lung cancer treatment.

    PubMed

    Wu, Hao; Zhong, Qingxiang; Zhong, Rongling; Huang, Houcai; Xia, Zhi; Ke, Zhongcheng; Zhang, Zhenhai; Song, Jie; Jia, Xiaobin

    Oleanolic acid (OA) is a triterpenoid found in various fruits and vegetables and used in traditional Chinese medicine. OA plays a crucial role in the treatment of several cancers, but poor water solubility, low permeability, and significant efflux have limited its widespread clinical use. Vitamin E-d-α-tocopheryl polyethylene glycol succinate (vitamin E-TPGS) and Pluronic P105 were used to improve the solubility and permeability and to decrease the efflux of OA. OA-loaded mixed micelles were prepared by ethanol thin-film hydration. The physicochemical properties of the micelles, including zeta potential, morphology, particle size, solubility, drug loading, and drug entrapment efficiency were characterized. OA release from micelles was slower than that from the free drug system. OA uptake by A549 non-small-cell lung cancer (NSCLC) cells was enhanced by the micelles. A tumor model was established by injecting A549 cells into nude mice. In vivo imaging showed that OA-micelles could accumulate in the tumors of nude mice. Additionally, smaller tumor size and increased expression of pro-apoptotic proteins were observed in OA-micelle-treated mice, indicating that OA-micelles are more effective than free OA in treating cancer. In vitro experiments were performed using two NSCLC cell lines (A549 and PC-9). Cytotoxicity evaluations showed that the half-maximal inhibitory concentrations of free OA and OA-micelles were 36.8±4.8 and 20.9±3.7 μM, respectively, in A549 cells and 82.7±7.8 and 56.7±4.7 μM, respectively, in PC-9 cells. Apoptosis assays revealed that the apoptotic rate of OA-micelle-treated A549 and PC-9 cells was higher than that of cells treated with the same concentration of free OA. Wound healing and transwell assays showed that migration and invasion were significantly suppressed in OA-micelle-treated cells. Immunofluorescence and Western blot analyses confirmed that the epithelial-mesenchymal transition was reversed in OA-micelle-treated cells. Mixed

  6. Combustor with fuel preparation chambers

    NASA Technical Reports Server (NTRS)

    Zelina, Joseph (Inventor); Myers, Geoffrey D. (Inventor); Srinivasan, Ram (Inventor); Reynolds, Robert S. (Inventor)

    2001-01-01

    An annular combustor having fuel preparation chambers mounted in the dome of the combustor. The fuel preparation chamber comprises an annular wall extending axially from an inlet to an exit that defines a mixing chamber. Mounted to the inlet are an air swirler and a fuel atomizer. The air swirler provides swirled air to the mixing chamber while the atomizer provides a fuel spray. On the downstream side of the exit, the fuel preparation chamber has an inwardly extending conical wall that compresses the swirling mixture of fuel and air exiting the mixing chamber.

  7. Ion mixing

    NASA Technical Reports Server (NTRS)

    Matteson, S.; Nicolet, M.-A.

    1983-01-01

    Recent experimental studies of the ion-mixing phenomenon are summarized. Ion mixing is differentiated from ion implantation and shown to be a useful technique for overcoming the sputter-dependent limitations of implantation processes. The fundamental physical principles of ion/solid interactions are explored. The basic experimental configurations currently in use are characterized: bilayered samples, multilayered samples, and samples with a thin marker layer. A table listing the binary systems (metal-semiconductor or metal-metal) which have been investigated using each configuration is presented. Results are discussed, and some sample data are plotted. The prospects for future application of ion mixing to the alteration of solid surface properties are considered. Practical applications are seen as restricted by economic considerations to the production of small, expensive components or to fields (such as the semiconductor industry) which already have facilities for ion implantation.

  8. Polymeric Micelles for Delivery of Poorly Soluble Drugs: Preparation and Anticancer Activity In Vitro of Paclitaxel Incorporated into Mixed Micelles Based on Poly(ethylene Glycol)-Lipid Conjugate and Positively Charged Lipids

    PubMed Central

    WANG, JUNPING; MONGAYT, DIMITRY; TORCHILIN, VLADIMIR P.

    2006-01-01

    Paclitaxel-loaded mixed polymeric micelles consisting of poly(ethylene glycol)-distearoyl phosphoethanolamine conjugates (PEG-PE), solid triglycerides (ST), and cationic Lipofectin® lipids (LL) have been prepared. Micelles with the optimized composition (PEG-PE/ST/LL/paclitaxel = 12/12/2/1 by weight) had an average micelle size of about 100 nm, and zeta-potential of about 26 mV. Micelles were stable and did not release paclitaxel when stored at 4°C in the darkness (just 2.9% of paclitaxel have been lost after 4 months with the particle size remaining unchanged). The release of paclitaxel from such micelles at room temperature was also insignificant. However, at 37°C, approx. 16% of paclitaxel was released from PEG-PE/ST/LL/paclitaxel micelles in 72 h, probably, because of phase transition in the ST-containing micelle core. In vitro anticancer effects of PEG-PE/ST/LL/paclitaxel and control micelles were evaluated using human mammary adenocarcinoma (BT-20) and human ovarian carcinoma (A2780) cell lines. Paclitaxel in PEG-PE/ST/LL micelles demonstrated the maximum anti-cancer activity. Cellular uptake of fluorescently-labeled paclitaxel-containing micelles by BT-20 cells was investigated using a fluorescence microscopy. It seems that PEG-PE/ST/LL micelles, unlike micelles without the LL component, could escape from endosomes and enter the cytoplasm of BT-20 cancer cells thus increasing the anticancer efficiency of the micellar paclitaxel. PMID:15848957

  9. Lateral Mixing

    DTIC Science & Technology

    2011-09-30

    ocean as it responds to mesoscale forcing. APPROACH Figure 1: MVP system deployed from stern of R/V Endeavor in Sargasso Sea . My approach for...therefore requires integrative efforts with other sea -going investigators and numerical modelers. The Lateral Mixing Experiment project was an ideal...also participated in the sea -going part of this project, taking my group on the R/V Endeavor in June 2011. Our role was to sample around the center of

  10. CASKAD. Manual Mixing in Bioreactor

    NASA Image and Video Library

    2013-10-05

    ISS037-E-005694 (5 Oct. 2013) --- Russian cosmonaut Sergey Ryazanskiy, Expedition 37 flight engineer, prepares to manually mix samples in a Bioreactor for the CASKAD experiment in the Poisk Mini-Research Module 2 (MRM2) of the International Space Station.

  11. CASKAD. Manual Mixing in Bioreactor

    NASA Image and Video Library

    2013-10-05

    ISS037-E-005692 (5 Oct. 2013) --- Russian cosmonaut Sergey Ryazanskiy, Expedition 37 flight engineer, prepares to manually mix samples in a Bioreactor for the CASKAD experiment in the Poisk Mini-Research Module 2 (MRM2) of the International Space Station.

  12. Training Teachers for Mixed Ability Classes

    ERIC Educational Resources Information Center

    Wragg, E. C.

    1978-01-01

    Discusses the preparation of student teachers for mixed ability classes, based on the Nottingham/Leicester project. Outlines a ten-point attack highlighting the areas in which young teachers need to acquire professional skills. (Author/RK)

  13. Process for preparing sand cores and molds

    SciTech Connect

    Varnum, N.C.; Kraemer, J.F.

    1984-11-27

    An improved process for preparing foundry cores and molds using a foundry aggregate and a binder therefor wherein the aggregate is mixed with an aqueous suspension of cereal flour and then with a core oil, the improvement comprising mixing the aggregate with phosphoric acid or sulfuric acid before mixing with the aqueous suspension of the cereal flour.

  14. Mixed cryoglobulinemia

    PubMed Central

    Ferri, Clodoveo

    2008-01-01

    Mixed cryoglobulinemia (MC), type II and type III, refers to the presence of circulating cryoprecipitable immune complexes in the serum and manifests clinically by a classical triad of purpura, weakness and arthralgias. It is considered to be a rare disorder, but its true prevalence remains unknown. The disease is more common in Southern Europe than in Northern Europe or Northern America. The prevalence of 'essential' MC is reported as approximately 1:100,000 (with a female-to-male ratio 3:1), but this term is now used to refer to a minority of MC patients only. MC is characterized by variable organ involvement including skin lesions (orthostatic purpura, ulcers), chronic hepatitis, membranoproliferative glomerulonephritis, peripheral neuropathy, diffuse vasculitis, and, less frequently, interstitial lung involvement and endocrine disorders. Some patients may develop lymphatic and hepatic malignancies, usually as a late complication. MC may be associated with numerous infectious or immunological diseases. When isolated, MC may represent a distinct disease, the so-called 'essential' MC. The etiopathogenesis of MC is not completely understood. Hepatitis C virus (HCV) infection is suggested to play a causative role, with the contribution of genetic and/or environmental factors. Moreover, MC may be associated with other infectious agents or immunological disorders, such as human immunodeficiency virus (HIV) infection or primary Sjögren's syndrome. Diagnosis is based on clinical and laboratory findings. Circulating mixed cryoglobulins, low C4 levels and orthostatic skin purpura are the hallmarks of the disease. Leukocytoclastic vasculitis involving medium- and, more often, small-sized blood vessels is the typical pathological finding, easily detectable by means of skin biopsy of recent vasculitic lesions. Differential diagnoses include a wide range of systemic, infectious and neoplastic disorders, mainly autoimmune hepatitis, Sjögren's syndrome, polyarthritis, and B

  15. Mixed cryoglobulinemia.

    PubMed

    Ferri, Clodoveo

    2008-09-16

    Mixed cryoglobulinemia (MC), type II and type III, refers to the presence of circulating cryoprecipitable immune complexes in the serum and manifests clinically by a classical triad of purpura, weakness and arthralgias. It is considered to be a rare disorder, but its true prevalence remains unknown. The disease is more common in Southern Europe than in Northern Europe or Northern America. The prevalence of 'essential' MC is reported as approximately 1:100,000 (with a female-to-male ratio 3:1), but this term is now used to refer to a minority of MC patients only. MC is characterized by variable organ involvement including skin lesions (orthostatic purpura, ulcers), chronic hepatitis, membranoproliferative glomerulonephritis, peripheral neuropathy, diffuse vasculitis, and, less frequently, interstitial lung involvement and endocrine disorders. Some patients may develop lymphatic and hepatic malignancies, usually as a late complication. MC may be associated with numerous infectious or immunological diseases. When isolated, MC may represent a distinct disease, the so-called 'essential' MC. The etiopathogenesis of MC is not completely understood. Hepatitis C virus (HCV) infection is suggested to play a causative role, with the contribution of genetic and/or environmental factors. Moreover, MC may be associated with other infectious agents or immunological disorders, such as human immunodeficiency virus (HIV) infection or primary Sjögren's syndrome. Diagnosis is based on clinical and laboratory findings. Circulating mixed cryoglobulins, low C4 levels and orthostatic skin purpura are the hallmarks of the disease. Leukocytoclastic vasculitis involving medium- and, more often, small-sized blood vessels is the typical pathological finding, easily detectable by means of skin biopsy of recent vasculitic lesions. Differential diagnoses include a wide range of systemic, infectious and neoplastic disorders, mainly autoimmune hepatitis, Sjögren's syndrome, polyarthritis, and B

  16. PREPARATION OF URANIUM HEXAFLUORIDE

    DOEpatents

    Lawroski, S.; Jonke, A.A.; Steunenberg, R.K.

    1959-10-01

    A process is described for preparing uranium hexafluoride from carbonate- leach uranium ore concentrate. The briquetted, crushed, and screened concentrate is reacted with hydrogen fluoride in a fluidized bed, and the uranium tetrafluoride formed is mixed with a solid diluent, such as calcium fluoride. This mixture is fluorinated with fluorine and an inert diluent gas, also in a fluidized bed, and the uranium hexafluoride obtained is finally purified by fractional distillation.

  17. Iodine-Catalyzed Synthesis of Mixed Cellulose Esters

    USDA-ARS?s Scientific Manuscript database

    A novel method for the preparation of cellulose mixed acetate is described herein, involving the concurrent use of iodine and mixed anhydride. The method is simple, rapid, efficient, and solvent-less. With this method, cellulose mixed esters has been synthesized. ...

  18. 9 CFR 319.701 - Mixed fat shortening.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... § 319.701 Mixed fat shortening. Shortening prepared with a mixture of meat fats and vegetable oils may be identified either as “Shortening Prepared with Meat Fats and Vegetable Oils” or “Shortening Prepared with Vegetable Oils and Meat Fats” depending on the predominance of the fat and oils used, or...

  19. 9 CFR 319.701 - Mixed fat shortening.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... § 319.701 Mixed fat shortening. Shortening prepared with a mixture of meat fats and vegetable oils may be identified either as “Shortening Prepared with Meat Fats and Vegetable Oils” or “Shortening Prepared with Vegetable Oils and Meat Fats” depending on the predominance of the fat and oils used, or...

  20. 9 CFR 319.701 - Mixed fat shortening.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... § 319.701 Mixed fat shortening. Shortening prepared with a mixture of meat fats and vegetable oils may be identified either as “Shortening Prepared with Meat Fats and Vegetable Oils” or “Shortening Prepared with Vegetable Oils and Meat Fats” depending on the predominance of the fat and oils used, or...

  1. 9 CFR 319.701 - Mixed fat shortening.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... § 319.701 Mixed fat shortening. Shortening prepared with a mixture of meat fats and vegetable oils may be identified either as “Shortening Prepared with Meat Fats and Vegetable Oils” or “Shortening Prepared with Vegetable Oils and Meat Fats” depending on the predominance of the fat and oils used, or...

  2. 9 CFR 319.701 - Mixed fat shortening.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... § 319.701 Mixed fat shortening. Shortening prepared with a mixture of meat fats and vegetable oils may be identified either as “Shortening Prepared with Meat Fats and Vegetable Oils” or “Shortening Prepared with Vegetable Oils and Meat Fats” depending on the predominance of the fat and oils used, or...

  3. A new non-synchronous preparative counter-current centrifuge-the next generation of dynamic extraction/chromatography devices with independent mixing and settling control, which offer a step change in efficiency.

    PubMed

    Ignatova, Svetlana; Hawes, David; van den Heuvel, Remco; Hewitson, Peter; Sutherland, Ian A

    2010-01-01

    A new and significantly more robust design of non-synchronous coil planet centrifuge is introduced where the degree of mixing between two immiscible phases can be changed independently from the "g" field required to separate out the phases. A hypothesis that an optimum ratio between the speed of the bobbin and the speed of the rotor can be found to optimise the efficiency of the separation for a given force field is upheld for an intermediate polarity phase system. This paves the way for extensive further research to find the optimum non-synchronous conditions for a range of different phase systems that are desirable for the separation of large molecules, proteins and biologics but can tend to emulsify in the standard "J" type centrifuge systems currently available and routinely in use for aqueous organic phase systems. A step change of up to 30% in resolution and 90% in plate efficiency is demonstrated.

  4. Vocational Preparation.

    ERIC Educational Resources Information Center

    Mansell, Jack

    Continuing education policy in England should produce a coherent curriculum framework, alleviating the somewhat divisive response and unequal provisions currently being made in this area. Vocational preparation should be available to all young people--with priority given to those who are not already preparing for higher education nor are engaged…

  5. PROCESS OF PREPARING ZIRCONIUM OXYCHLORIDE

    DOEpatents

    Wilhelm, H.A.; Andrews, M.L.

    1960-06-28

    A process is given for preparing zirconyl chloride by mixing solid zirconyl chloride octahydrate and solid zirconium tetrachloride at room temperature whereby both chlorides are converted to zirconyl chloride trinydrate and hydrogen chloride is formed and volatilized by the reaction heat.

  6. Method to prepare Semtex

    SciTech Connect

    Alcaraz, A; Dougan, A

    2006-11-26

    This procedure requires the binder and uncoated RDX be prepared in separate steps, see Figure 1: (1) The binder and dye are mixed by agitation with a water-insoluble organic solvent (e.g., toluene), I; (2) The RDX/PETN is agitated thoroughly with water, II; (3) The binder solution I is added to the RDX/water mixture at II with thorough mixing to form a slurry III; (4) In the next step the solvent is distilled off at IV leaving resulting granules; (5) The next step is followed by filtration at V, which may be done by vacuum; (6) The composition is then dried at VI to a dough-like consistency.

  7. Advances in compressible turbulent mixing

    SciTech Connect

    Dannevik, W.P.; Buckingham, A.C.; Leith, C.E.

    1992-01-01

    This volume includes some recent additions to original material prepared for the Princeton International Workshop on the Physics of Compressible Turbulent Mixing, held in 1988. Workshop participants were asked to emphasize the physics of the compressible mixing process rather than measurement techniques or computational methods. Actual experimental results and their meaning were given precedence over discussions of new diagnostic developments. Theoretical interpretations and understanding were stressed rather than the exposition of new analytical model developments or advances in numerical procedures. By design, compressibility influences on turbulent mixing were discussed--almost exclusively--from the perspective of supersonic flow field studies. The papers are arranged in three topical categories: Foundations, Vortical Domination, and Strongly Coupled Compressibility. The Foundations category is a collection of seminal studies that connect current study in compressible turbulent mixing with compressible, high-speed turbulent flow research that almost vanished about two decades ago. A number of contributions are included on flow instability initiation, evolution, and transition between the states of unstable flow onset through those descriptive of fully developed turbulence. The Vortical Domination category includes theoretical and experimental studies of coherent structures, vortex pairing, vortex-dynamics-influenced pressure focusing. In the Strongly Coupled Compressibility category the organizers included the high-speed turbulent flow investigations in which the interaction of shock waves could be considered an important source for production of new turbulence or for the enhancement of pre-existing turbulence. Individual papers are processed separately.

  8. Personnel Preparation.

    ERIC Educational Resources Information Center

    Career Development for Exceptional Individuals, 1982

    1982-01-01

    The section on personnel preparation contains two articles--"Teachers-in-Training Conduct Field Trips for Special Class Students" by S. Squires and "A State-Wide, Inservice Project for Special Needs Personnel" by G. Markel and others. (SB)

  9. Solution preparation

    SciTech Connect

    Seitz, M.G.

    1982-01-01

    Reviewed in this statement are methods of preparing solutions to be used in laboratory experiments to examine technical issues related to the safe disposal of nuclear waste from power generation. Each approach currently used to prepare solutions has advantages and any one approach may be preferred over the others in particular situations, depending upon the goals of the experimental program. These advantages are highlighted herein for three approaches to solution preparation that are currently used most in studies of nuclear waste disposal. Discussion of the disadvantages of each approach is presented to help a user select a preparation method for his particular studies. Also presented in this statement are general observations regarding solution preparation. These observations are used as examples of the types of concerns that need to be addressed regarding solution preparation. As shown by these examples, prior to experimentation or chemical analyses, laboratory techniques based on scientific knowledge of solutions can be applied to solutions, often resulting in great improvement in the usefulness of results.

  10. A randomized, open-label 3-way crossover study to investigate the relative bioavailability and bioequivalence of crushed sildenafil 20 mg tablets mixed with apple sauce, extemporaneously prepared suspension (EP), and intact sildenafil 20 mg tablets in healthy volunteers under fasting conditions.

    PubMed

    Gao, Xiang; Ndongo, Marie-Noella; Checchio, Tina M; Cook, Jack; Duncan, Barbara; LaBadie, Robert R

    2015-01-01

    The relative bioavailability and bioequivalence of 20-mg doses of a pediatric formulation of sildenafil extemporaneous preparation suspension (EP; 10 mg/mL), the sildenafil 20-mg intact tablet and the crushed sildenafil 20-mg tablet mixed with apple sauce were assessed in a single-dose, randomized, open-label, 3-way crossover study with 18 healthy adult volunteers. Blood samples were collected at predefined times and analyzed for sildenafil plasma concentrations. Natural log-transformed sildenafil pharmacokinetic parameters (Cmax , AUClast , and AUCinf ) were used to estimate relative bioavailability and construct 90% confidence intervals (CI) using a mixed-effects model. Bioequivalence was concluded among the three formulations with one exception, in which the EP suspension showed a 15% decrease in Cmax with a lower 90% CI of 76% compared with the intact tablet. The 15% decrease in sildenafil Cmax is not considered to be clinically relevant. Therefore, the EP suspension is considered to be an appropriate pediatric formulation. All 3 formulations were well tolerated in healthy adult volunteers.

  11. Preparation of a durable superhydrophobic membrane by electrospinning poly (vinylidene fluoride) (PVDF) mixed with epoxy-siloxane modified SiO2 nanoparticles: a possible route to superhydrophobic surfaces with low water sliding angle and high water contact angle.

    PubMed

    Wang, Shuai; Li, Yapeng; Fei, Xiaoliang; Sun, Mingda; Zhang, Chaoqun; Li, Yaoxian; Yang, Qingbiao; Hong, Xia

    2011-07-15

    A durable superhydrophobic surface with low water sliding angle (SA) and high water contact angle (CA) was obtained by electrospinning poly (vinylidene fluoride) (PVDF) which was mixed with epoxy-siloxane modified SiO(2) nanoparticles. To increase the roughness, modified SiO(2) nanoparticles were introduced into PVDF precursor solution. Then in the electrospinning process, nano-sized SiO(2) particles irregularly inlayed (it could also be regard as self-assembly) in the surface of the micro-sized PVDF mini-islands so as to form a dual-scale structure. This structure was responsible for the superhydrophobicity and self-cleaning property. In addition, epoxy-siloxane copolymer was used to modify the surface of SiO(2) nanoparticles so that the SiO(2) nanoparticles could stick to the surface of the micro-sized PVDF mini-islands. Through the underwater immersion test, the SiO(2) nanoparticles cannot be separated from PVDF easily so as to achieve the effect of durability. We chiefly explore the surface wettability and the relationship between the mass ratio of modified SiO(2) nanoparticles/PVDF and the CA, SA of electrospun mat. As the content of modified SiO(2) nanoparticles increased, the value of CA increased, ranging from 145.6° to 161.2°, and the water SA decreased to 2.17°, apparently indicating that the membrane we fabricated has a perfect effect of superhydrophobicity. Copyright © 2011 Elsevier Inc. All rights reserved.

  12. Mixing in explosions

    SciTech Connect

    Kuhl, A.L.

    1993-12-01

    Explosions always contain embedded turbulent mixing regions, for example: boundary layers, shear layers, wall jets, and unstable interfaces. Described here is one particular example of the latter, namely, the turbulent mixing occurring in the fireball of an HE-driven blast wave. The evolution of the turbulent mixing was studied via two-dimensional numerical simulations of the convective mixing processes on an adaptive mesh. Vorticity was generated on the fireball interface by baroclinic effects. The interface was unstable, and rapidly evolved into a turbulent mixing layer. Four phases of mixing were observed: (1) a strong blast wave phase; (2) and implosion phase; (3) a reshocking phase; and (4) an asymptotic mixing phase. The flowfield was azimuthally averaged to evaluate the mean and r.m.s. fluctuation profiles across the mixing layer. The vorticity decayed due to a cascade process. This caused the corresponding enstrophy parameter to increase linearly with time -- in agreement with homogeneous turbulence calculations of G.K. Batchelor.

  13. Mixing in astrophysics

    SciTech Connect

    Fryer, Christopher Lee

    2011-01-07

    Turbulent mixing plays a vital role in many fields in astronomy. Here I review a few of these sites, discuss the importance of this turbulent mixing and the techniques used by astrophysicists to solve these problems.

  14. Mixed methods research.

    PubMed

    Halcomb, Elizabeth; Hickman, Louise

    2015-04-08

    Mixed methods research involves the use of qualitative and quantitative data in a single research project. It represents an alternative methodological approach, combining qualitative and quantitative research approaches, which enables nurse researchers to explore complex phenomena in detail. This article provides a practical overview of mixed methods research and its application in nursing, to guide the novice researcher considering a mixed methods research project.

  15. Mixed Stationary Liquid Phases for Gas-Liquid Chromatography.

    ERIC Educational Resources Information Center

    Koury, Albert M.; Parcher, Jon F.

    1979-01-01

    Describes a laboratory technique for use in an undergraduate instrumental analysis course that, using the interpretation of window diagrams, prepares a mixed liquid phase column for gas-liquid chromatography. A detailed procedure is provided. (BT)

  16. Mixed Stationary Liquid Phases for Gas-Liquid Chromatography.

    ERIC Educational Resources Information Center

    Koury, Albert M.; Parcher, Jon F.

    1979-01-01

    Describes a laboratory technique for use in an undergraduate instrumental analysis course that, using the interpretation of window diagrams, prepares a mixed liquid phase column for gas-liquid chromatography. A detailed procedure is provided. (BT)

  17. Mixing and compaction temperatures for Superpave mixes

    NASA Astrophysics Data System (ADS)

    Yildirim, Yetkin

    According to Superpave mixture design, gyratory specimens are mixed and compacted at equiviscous binder temperatures corresponding to viscosities of 0.17 and 0.28 Pa.s. respectively. These were the values previously used in the Marshal mix design method to determine optimal mixing and compaction temperatures. In order to estimate the appropriate mixing and compaction temperatures for Superpave mixture design, a temperature-viscosity relationship for the binder needs to be developed (ASTM D 2493, Calculation of Mixing and Compaction Temperatures). The current approach is simple and provides reasonable temperatures for unmodified binders. However, some modified binders have exhibited unreasonably high temperatures for mixing and compaction using this technique. These high temperatures can result in construction problems, damage of asphalt, and production of fumes. Heating asphalt binder to very high temperatures during construction oxidizes the binder and separates the polymer from asphalt binder. It is known that polymer modified asphalt binders have many benefits to the roads, such as; increasing rutting resistance, enhancing low temperature cracking resistance, improving traction, better adhesion and cohesion, elevating tensile strength which are directly related to the service life of the pavement. Therefore, oxidation and separation of the polymer from the asphalt binder results in reduction of the service life. ASTM D 2493 was established for unmodified asphalt binders which are Newtonian fluids at high temperatures. For these materials, viscosity does not depend on shear rate. However, most of the modified asphalt binders exhibit a phenomenon known as pseudoplasticity, where viscosity does depend on shear rate. Thus, at the high shear rates occurring during mixing and compaction, it is not necessary to go to very high temperatures. This research was undertaken to determine the shear rate during compaction such that the effect of this parameter could be

  18. Mixed Alcohol Synthesis Catalyst Screening

    SciTech Connect

    Gerber, Mark A.; White, James F.; Stevens, Don J.

    2007-09-03

    National Renewable Energy Laboratory (NREL) and Pacific Northwest National Laboratory (PNNL) are conducting research to investigate the feasibility of producing mixed alcohols from biomass-derived synthesis gas (syngas). PNNL is tasked with obtaining commercially available or preparing promising mixed-alcohol catalysts and screening them in a laboratory-scale reactor system. Commercially available catalysts and the most promising experimental catalysts are provided to NREL for testing using a slipstream from a pilot-scale biomass gasifier. From the standpoint of producing C2+ alcohols as the major product, it appears that the rhodium catalyst is the best choice in terms of both selectivity and space-time yield (STY). However, unless the rhodium catalyst can be improved to provide minimally acceptable STYs for commercial operation, mixed alcohol synthesis will involve significant production of other liquid coproducts. The modified Fischer-Tropsch catalyst shows the most promise for providing both an acceptable selectivity to C2+ alcohols and total liquid STY. However, further optimization of the Fischer-Tropsch catalysts to improve selectivity to higher alcohols is highly desired. Selection of a preferred catalyst will likely entail a decision on the preferred coproduct slate. No other catalysts tested appear amenable to the significant improvements needed for acceptable STYs.

  19. Preparation Matters

    ERIC Educational Resources Information Center

    Dougherty, Chrys; Mellor, Lynn

    2009-01-01

    In "Orange Juice or Orange Drink?," the authors provided evidence that many students are receiving credit for courses with little indication that they have learned the content implied by the course titles (Dougherty, Mellor, & Jian, 2006). Yet in pursuit of the goal of preparing all students for college and careers, many policymakers…

  20. Mixed oxide solid solutions

    DOEpatents

    Magno, Scott; Wang, Ruiping; Derouane, Eric

    2003-01-01

    The present invention is a mixed oxide solid solution containing a tetravalent and a pentavalent cation that can be used as a support for a metal combustion catalyst. The invention is furthermore a combustion catalyst containing the mixed oxide solid solution and a method of making the mixed oxide solid solution. The tetravalent cation is zirconium(+4), hafnium(+4) or thorium(+4). In one embodiment, the pentavalent cation is tantalum(+5), niobium(+5) or bismuth(+5). Mixed oxide solid solutions of the present invention exhibit enhanced thermal stability, maintaining relatively high surface areas at high temperatures in the presence of water vapor.

  1. Cement mixing with vibrator

    SciTech Connect

    Allen, T.E.

    1991-07-09

    This patent describes a method of cementing a casing string in a bore hole of a well. It comprises introducing water and dry cement material into a mixing vessel; mixing the water and dry cement material in the mixing vessel to form a cement slurry, the slurry including lumps of the dry cement material, the mixing including steps of: agitating the slurry; and while agitating the slurry, transmitting vibrational energy into the slurry and thereby aiding disintegration and subsequent wetting of the lumps of the dry cement material in the slurry; and pumping the slurry into an annulus between the casing string and the bore hole.

  2. Mixed waste minimization/mixed waste avoidance

    SciTech Connect

    Todisco, L.R.

    1994-12-31

    This presentation describes methods for the minimization and volume reduction of low-level radioactive and mixed wastes. Many methods are presented including: source reduction, better waste monitoring activities, waste segregation, recycling, administrative controls, and optimization of waste-generating processes.

  3. Preparation of energy storage materials

    DOEpatents

    Li, Lin Song; Jia, Quanxi

    2003-01-01

    A process is provided for the preparation of a metallic oxide composite including mixing an aqueous solution of a water-soluble metal compound and colloidal silica, depositing the mixture upon a substrate, heating the mixture-coated substrates at temperatures from about 150.degree. C. to about 300.degree. C. for time sufficient to form a metallic oxide film, and, removing the silica from the metallic oxide film whereby a porous metal oxide structure is formed.

  4. Preparation Of Energy Storage Materials

    DOEpatents

    Li, Lin Song; Jia, Quanxi

    2003-12-02

    A process is provided for the preparation of a metallic oxide composite including mixing an aqueous solution of a water-soluble metal compound and colloidal silica, depositing the mixture upon a substrate, heating the mixture-coated substrates at temperatures from about 150.degree. C. to about 300.degree. C. for time sufficient to form a metallic oxide film, and, removing the silica from the metallic oxide film whereby a porous metal oxide structure is formed.

  5. Admission mixing duct assembly

    NASA Technical Reports Server (NTRS)

    Orlando, Robert J. (Inventor); Dunbar, Lawrence W. (Inventor)

    1995-01-01

    A variable cycle jet engine is provided with a mixing duct assembly which mixes core engine exhaust gas with bypass air when the engine is operating in a turbofan mode and which blocks flow from the core engine and isolates the core engine from the bypass flow when the engine is operating as a ramjet.

  6. Dilution Zone Mixing

    NASA Technical Reports Server (NTRS)

    Holdeman, J. D.

    1983-01-01

    Studies to characterize dilution zone mixing; experiments on the effects of free-stream turbulence on a jet in crossflow; and the development of an interactive computer code for the analysis of the mixing of jets with a confined crossflow are reviewed.

  7. Microfluidic Mixing: A Review

    PubMed Central

    Lee, Chia-Yen; Chang, Chin-Lung; Wang, Yao-Nan; Fu, Lung-Ming

    2011-01-01

    The aim of microfluidic mixing is to achieve a thorough and rapid mixing of multiple samples in microscale devices. In such devices, sample mixing is essentially achieved by enhancing the diffusion effect between the different species flows. Broadly speaking, microfluidic mixing schemes can be categorized as either “active”, where an external energy force is applied to perturb the sample species, or “passive”, where the contact area and contact time of the species samples are increased through specially-designed microchannel configurations. Many mixers have been proposed to facilitate this task over the past 10 years. Accordingly, this paper commences by providing a high level overview of the field of microfluidic mixing devices before describing some of the more significant proposals for active and passive mixers. PMID:21686184

  8. Theory for Neutrino Mixing

    NASA Astrophysics Data System (ADS)

    He, Xiao-Gang

    2016-07-01

    Since the discovery of neutrino oscillations, for which Takaaki Kajita and Arthur B. McDonald were awarded the 2015 Nobel prize in physics, tremendous progresses have been made in measuring the mixing angles which determine the oscillation pattern. A lot of theoretical efforts have been made to understand how neutrinos mix with each other. Present data show that in the standard parameterization of the mixing matrix, θ23 is close to π/4 and the CP violating phase is close to - π/2. In this talk I report results obtained in arXiv:1505.01932 (Phys. Lett. B750(2015)620) and arXive:1404.01560 (Chin. J. Phys.53(2015)100101) and discuss some implications for theoretical model buildings for such mixing pattern. Specific examples for neutrino mixing based on A4 family symmetry are given.

  9. MHD turbulent mixing layers

    SciTech Connect

    Esquivel, A.; Lazarian, A.; Benjamin, R.A.; Cho, J.; Leitner, S.N.

    2005-09-28

    Turbulent mixing layers have been proposed to explain observations of line ratios of highly ionized elements in the interstellar medium. We present preliminary results of numerical simulations of turbulent mixing layers in a magnetized medium. We developed a MHD code with radiative cooling. The magnetic field is expected to be a controlling factor by suppressing instabilities that lead to the turbulent mixing. Our results suggest that the difference in turbulent mixing in the unmagnetized case as compared to the case of a weak magnetic field, {beta} = Pgas/Pmag {approx} 10, is insignificant. With a more thorough exploration of parameter space, this work will provide more reliable diagnostics of turbulent mixing layers than those available today.

  10. [Mixed Waste Focus Area]. Monthly progress report summary

    SciTech Connect

    1994-11-01

    During November 1994, a Call for Proposals to lead the implementation team of the Mixed Waste Focus Area was issued by DOE-HQ. Interested Sites prepared proposals to lead the MWFA and responded to DOE-HQ on December 1, 1994. DOE-ID was selected to lead the MWFA on December 15, 1994. As this report is being published, the Mixed Waste Integrated Program is being transitioned to the Mixed Waste Focus Area. Transition is scheduled to be complete by March 31, 1995. This report contains summaries of individual research projects which demonstrate the development of technology to treat mixed waste throughout the DOE complex.

  11. Preparation, Characterization, and Selectivity Study of Mixed-Valence Sulfites

    ERIC Educational Resources Information Center

    Silva, Luciana A.; de Andrade, Jailson B.

    2010-01-01

    A project involving the synthesis of an isomorphic double sulfite series and characterization by classical inorganic chemical analyses is described. The project is performed by upper-level undergraduate students in the laboratory. This compound series is suitable for examining several chemical concepts and analytical techniques in inorganic…

  12. Preparation, Characterization, and Selectivity Study of Mixed-Valence Sulfites

    ERIC Educational Resources Information Center

    Silva, Luciana A.; de Andrade, Jailson B.

    2010-01-01

    A project involving the synthesis of an isomorphic double sulfite series and characterization by classical inorganic chemical analyses is described. The project is performed by upper-level undergraduate students in the laboratory. This compound series is suitable for examining several chemical concepts and analytical techniques in inorganic…

  13. Mixing in Microfluidic Systems

    NASA Astrophysics Data System (ADS)

    Beskok, A.

    Flow and species transport in micro-scales experience laminar, even Stokes flow conditions. In absence of turbulence, species mixing becomes diffusion dominated, and requires very long mixing length scales (l m ). This creates significant challenges in the design of Lab-on-a-chip (LOC) devices, where mixing of macromolecules and biological species with very low mass diffusivities are often desired. The objectives of this chapter are to introduce concepts relevant to mixing enhancement in microfluidic systems, and guide readers in the design of new mixers via numerical simulations. A distinguishing feature is the identification of flow kinematics that enhance mixing, followed with systematic characterization of mixing as a function of the Schmidt number at fixed kinematic conditions. In this chapter, we briefly review the routes to achieve chaotic advection in Stokes flow, and then illustrate the characteri-zation of a continuous flow chaotic stirrer via appropriate numerical tools, including the Poincaré section, finite time Lyapunov exponent, and mixing index.

  14. The mixing of fluids

    SciTech Connect

    Ottino, J.M.

    1989-01-01

    What do the eruption of Krakatau, the manufacture of puff pastry and the brightness of stars have in common Each involves some aspect of mixing. Mixing also plays a critical role in modern technology. Chemical engineers rely on mixing to ensure that substances react properly, to produce polymer blends that exhibit unique properties and to disperse drag-reducing agents in pipelines. Yet in spite of its of its ubiquity in nature and industry, mixing is only imperfectly under-stood. Indeed, investigators cannot even settle on a common terminology: mixing is often referred to as stirring by oceanographers and geophysicists, as blending by polymer engineers and as agitation by process engineers. Regardless of what the process is called, there is little doubt that it is exceedingly complex and is found in a great variety of systems. In constructing a theory of fluid mixing, for example, one has to take into account fluids that can be miscible or partially miscible and reactive or inert, and flows that are slow and orderly or very fast and turbulent. It is therefore not surprising that no single theory can explain all aspect of mixing in fluids and that straightforward computations usually fail to capture all the important details. Still, both physical experiments and computer simulations can provide insight into the mixing process. Over the past several years the authors and his colleague have taken both approaches in an effort to increase understanding of various aspect of the process-particularly of mixing involving slow flows and viscous fluids such as oils.

  15. Nearly discontinuous chaotic mixing

    SciTech Connect

    Sharp, David Howland; Lim, Hyun K; Yu, Yan; Glimm, James G

    2009-01-01

    A new scientific approach is presented for a broad class of chaotic problems involving a high degree of mixing over rapid time scales. Rayleigh-Taylor and Richtmyer-Meshkov unstable flows are typical of such problems. Microscopic mixing properties such as chemical reaction rates for turbulent mixtures can be obtained with feasible grid resolution. The essential dependence of (some) fluid mixing observables on transport phenomena is observed. This dependence includes numerical as well as physical transport and it includes laminar as well as turbulent transport. A new approach to the mathematical theory for the underlying equations is suggested.

  16. Liquid air mixing system

    NASA Technical Reports Server (NTRS)

    Martin, Robert B. (Inventor)

    1997-01-01

    A device for mixing liquid nitrogen and liquid oxygen to form liquid air. The mixing device consists of a tube for transferring liquid oxygen positioned within a tube for transferring liquid nitrogen. Supply vessels for liquid oxygen and liquid nitrogen are equally pressurized and connected to the appropriate tubes. Liquid oxygen and nitrogen flow from the supply vessels through the respective tubes and are mixed to form liquid air upon exiting the outlets of the tube. The resulting liquid air is transferred to a holding vessel.

  17. Mixing method and apparatus

    DOEpatents

    Green, Norman W.

    1982-06-15

    Method of mixing particulate materials comprising contacting a primary source and a secondary source thereof whereby resulting mixture ensues; preferably at least one of the two sources has enough motion to insure good mixing and the particulate materials may be heat treated if desired. Apparatus for such mixing comprising an inlet for a primary source, a reactor communicating therewith, a feeding means for supplying a secondary source to the reactor, and an inlet for the secondary source. Feeding means is preferably adapted to supply fluidized materials.

  18. Remotely controllable mixing system

    NASA Technical Reports Server (NTRS)

    Belew, R. R. (Inventor)

    1986-01-01

    This invention relates to a remotely controllable mixing system in which a plurality of mixing assemblies are arranged in an annular configuration, and wherein each assembly employs a central chamber and two outer, upper and lower chambers. Valves are positioned between chambers, and these valves for a given mixing assembly are operated by upper and lower control rotors, which in turn are driven by upper and lower drive rotors. Additionally, a hoop is compressed around upper control rotors and a hoop is compressed around lower control rotors to thus insure constant frictional engagement between all control rotors and drive rotors. The drive rollers are driven by a motor.

  19. Impurities, inclusions, and dislocations in multicrystalline silicon grown from well-mixed and poorly mixed melts

    NASA Astrophysics Data System (ADS)

    Funke, C.; Schmid, E.; Gärtner, G.; Reißenweber, S.; Fütterer, W.; Poklad, A.; Raabe, L.; Pätzold, O.; Stelter, M.

    2014-09-01

    This paper presents an experimental study on the interaction between impurities, inclusions, and dislocations in multi-crystalline silicon ingots grown from well-mixed and poorly mixed melts. The ingots were grown in a high-vacuum induction furnace by the vertical Bridgman method and the degree of impurity mixing within the melt was modified by changing the growth rate. Vertical and horizontal slices were prepared from the ingots and analyzed by Fourier transform IR spectroscopy, as well as reflected-light and IR transmission microscopy to measure the axial carbon concentration and the distribution of dislocations or inclusions, respectively. The correlation between individual inclusions and dislocations has been investigated by correlative reflected-light/IR transmission and scanning electron microscopy. The influence of the melt mixing on the segregation of carbon is demonstrated and discussed with respect to the consequences for the formation of inclusions and dislocation clusters in multi-crystalline silicon.

  20. Meeting Report: Hackathon-Workshop on Darwin Core and MIxS Standards Alignment (February 2012).

    PubMed

    Tuama, Eamonn Ó; Deck, John; Dröge, Gabriel; Döring, Markus; Field, Dawn; Kottmann, Renzo; Ma, Juncai; Mori, Hiroshi; Morrison, Norman; Sterk, Peter; Sugawara, Hideaki; Wieczorek, John; Wu, Linhuan; Yilmaz, Pelin

    2012-10-10

    The Global Biodiversity Information Facility and the Genomic Standards Consortium convened a joint workshop at the University of Oxford, 27-29 February 2012, with a small group of experts from Europe, USA, China and Japan, to continue the alignment of the Darwin Core with the MIxS and related genomics standards. Several reference mappings were produced as well as test expressions of MIxS in RDF. The use and management of controlled vocabulary terms was considered in relation to both GBIF and the GSC, and tools for working with terms were reviewed. Extensions for publishing genomic biodiversity data to the GBIF network via a Darwin Core Archive were prototyped and work begun on preparing translations of the Darwin Core to Japanese and Chinese. Five genomic repositories were identified for engagement to begin the process of testing the publishing of genomic data to the GBIF network commencing with the SILVA rRNA database.

  1. Effective mixing strategies with microbubble streaming flows

    NASA Astrophysics Data System (ADS)

    Wang, Cheng; Rallabandi, Bhargav; Guo, Lin; Hilgenfeldt, Sascha

    2013-11-01

    Homogeneous mixing of chemical/biological samples and reagents is one of the essential preparation steps for lab-on-a-chip systems. As effective Stokes flows driven by fast time scale oscillatory flows, microbubble streaming flows are a tool uniquely positioned between passive and active mixing approaches. Guided by thorough theoretical understanding of the flows and of micromixing itself, we investigate various designs of microbubble mixers, employing two key strategies: (a) introducing controlled unsteadiness in the acoustic driving pattern, e.g. by duty-cycling and driving frequency modulation, and (b) optimizing the arrangement of multiple bubbles, such as the number, position, and orientation of the microbubbles, particularly to generate 3D chaotic flow patterns. Both of these approaches significantly improve mixing over that of previous steady 2D bubble micro-mixers, and the strategies can be combined for greater effect. Current address: Department of Mechanical and Aerospace Engineering, Missouri University of Science and Technology

  2. Guidelines for mixed waste minimization

    SciTech Connect

    Owens, C.

    1992-02-01

    Currently, there is no commercial mixed waste disposal available in the United States. Storage and treatment for commercial mixed waste is limited. Host States and compacts region officials are encouraging their mixed waste generators to minimize their mixed wastes because of management limitations. This document provides a guide to mixed waste minimization.

  3. Shaken, not Stirred: Mixing Organic Aerosol

    NASA Astrophysics Data System (ADS)

    Donahue, N. M.; Robinson, E.; Trump, E. R.; Saleh, R.

    2013-12-01

    For organic vapors to condense onto or into existing particles in the atmosphere, the compounds must have a positive thermodynamic driving force. Their activity (saturation ratio) in the gas phase must exceed their activity (modified mole fraction) at the particle surface. Organic-aerosol production rates are generally quite small -- a few μg m-3 per hour at most -- and thus gas-phase saturation ratios are correspondingly small. Most experiments are conducted with far higher production rates and thus far higher saturation ratios. Consequently, experiments may or may not constrain whether organics coat particles in the real world. In addition, surface activity is often assumed to equal bulk activity for most species, meaning that particles are well mixed. However, if particles are viscous and coating rates high, diffusion through the bulk of even 100 nm particles may be slow. Again, matching experimental timescales to real-world timescales is important. Here we describe organic particle mixing experiments in which two organic particle populations are prepared separately and then intermingled by transferring the contents of one preparation chamber into another. Constituents of one population are isotopically labeled, making the mass spectra of the two particle types completely orthogonal. Following the intermingling, single-particle mass spectra allow us to track individual particle composition as the populations mix via gas-phase exchange. This allows us to explore the mixing and coating behavior of organic-aerosol populations under conditions much closer to concentrations found in the real world.

  4. Mixed-Media Owls

    ERIC Educational Resources Information Center

    Schultz, Kathy

    2010-01-01

    The fun of creating collages is there are unlimited possibilities for the different kinds of materials one can use. In this article, the author describes how her eighth-grade students created an owl using mixed media.

  5. Mixed-Media Owls

    ERIC Educational Resources Information Center

    Schultz, Kathy

    2010-01-01

    The fun of creating collages is there are unlimited possibilities for the different kinds of materials one can use. In this article, the author describes how her eighth-grade students created an owl using mixed media.

  6. Artificial upwelling and mixing

    SciTech Connect

    Not Available

    1989-01-01

    The authors present results related to artificial upwelling and coastal mariculture using deep ocean water and mixing in coastal waters. They discuss the application of research results for marine waste disposal.

  7. Asymmetric antiproton debuncher: No bad mixing, more good mixing

    SciTech Connect

    Visnjic, V.

    1994-07-01

    An asymmetric lattice for the Fermilab Antiproton Debuncher is designed. The lattice has zero mixing between the pickups and the kickers (bad mixing) while the mixing in the rest of the machine (good mixing) can be varied (even during the operation of the machine) in order to optimize the stochastic cooling. As an example, a lattice with zero bad mixing and twice the good mixing is presented. The betatron cooling rate in this lattice is twice its present value.

  8. Chaotic Mixing of Granitic and Basaltic Liquids

    NASA Astrophysics Data System (ADS)

    Decampos, C.; Ingrisch, W. E.; Perugini, D.; Dingwell, D. B.; Poli, G.

    2008-12-01

    Chaotic mixing in magma chambers may play a central role in determining the timing and dynamics of volcanic eruptions. The dynamics of such chaotic mixing has been investigated solely in analog systems and in numerical simulations to date. Here we report the first experimental study of the dynamics of chaotic mixing in molten silicates of geological relevance. A newly developed device for the simulation of chaotic dynamics has been successfully employed for this purpose. Its development is based on the importance of chaotic dynamics for mixing processes; and previous studies evidencing that chaotic dynamics could equally control magma mixing processes in nature (Perugini et al., 2006. EPSL, 234: 669-680 and references therein). The special device for chaotic mixing silicate melts at high temperatures (up to 1700°C) has been built after the journal-bearing or eccentric-cylinder geometry for viscous fluids for the study of chaotic mixing in slow flows (Swanson and Ottino, 1990. J. Fluid Mech., 213:227-249). In order to generate chaos in a flow, the streamlines must be time dependent, resulting from alternating movements between the two cylinders. The mixing experiments were performed using end-members of: haplogranite [In wt.%: SiO2(71.6), Al2O3(12.4), Na2O(7.0), K2O(9.0)] and haplobasalt [SiO2(48.6), Al2O3(16.3), CaO(23.8), MgO (11.4)]. The haplogranite was doped with trace amounts of Rb, Sr, Ba, Zr and REE oxides. The experimental protocol started with a single run of alternating movements of spindle and crucible. It lasted for 110 minutes at a temperature of 1400°C. The experiment terminated by stopping all movement and letting the sample cool to room temperature. A cylinder of the resultant mixed glassy sample was recovered by drilling. Horizontal sections of this cylinder at varying heights were prepared for microprobe and ICP-MS- Laser Ablation analyses. Preliminary optical and microprobe studies reveal crystal-free filaments of intermediary compositions

  9. Mixing of Supersonic Streams

    NASA Technical Reports Server (NTRS)

    Hawk, C. W.; Landrum, D. B.; Muller, S.; Turner, M.; Parkinson, D.

    1998-01-01

    The Strutjet approach to Rocket Based Combined Cycle (RBCC) propulsion depends upon fuel-rich flows from the rocket nozzles and turbine exhaust products mixing with the ingested air for successful operation in the ramjet and scramjet modes. It is desirable to delay this mixing process in the air-augmented mode of operation present during low speed flight. A model of the Strutjet device has been built and is undergoing test to investigate the mixing of the streams as a function of distance from the Strutjet exit plane during simulated low speed flight conditions. Cold flow testing of a 1/6 scale Strutjet model is underway and nearing completion. Planar Laser Induced Fluorescence (PLIF) diagnostic methods are being employed to observe the mixing of the turbine exhaust gas with the gases from both the primary rockets and the ingested air simulating low speed, air augmented operation of the RBCC. The ratio of the pressure in the turbine exhaust duct to that in the rocket nozzle wall at the point of their intersection is the independent variable in these experiments. Tests were accomplished at values of 1.0, 1.5 and 2.0 for this parameter. Qualitative results illustrate the development of the mixing zone from the exit plane of the model to a distance of about 10 rocket nozzle exit diameters downstream. These data show the mixing to be confined in the vertical plane for all cases, The lateral expansion is more pronounced at a pressure ratio of 1.0 and suggests that mixing with the ingested flow would be likely beginning at a distance of 7 nozzle exit diameters downstream of the nozzle exit plane.

  10. Mixing of Supersonic Streams

    NASA Technical Reports Server (NTRS)

    Hawk, C. W.; Landrum, D. B.; Muller, S.; Turner, M.; Parkinson, D.

    1998-01-01

    The Strutjet approach to Rocket Based Combined Cycle (RBCC) propulsion depends upon fuel-rich flows from the rocket nozzles and turbine exhaust products mixing with the ingested air for successful operation in the ramjet and scramjet modes. It is desirable to delay this mixing process in the air-augmented mode of operation present during low speed flight. A model of the Strutjet device has been built and is undergoing test to investigate the mixing of the streams as a function of distance from the Strutjet exit plane during simulated low speed flight conditions. Cold flow testing of a 1/6 scale Strutjet model is underway and nearing completion. Planar Laser Induced Fluorescence (PLIF) diagnostic methods are being employed to observe the mixing of the turbine exhaust gas with the gases from both the primary rockets and the ingested air simulating low speed, air augmented operation of the RBCC. The ratio of the pressure in the turbine exhaust duct to that in the rocket nozzle wall at the point of their intersection is the independent variable in these experiments. Tests were accomplished at values of 1.0, 1.5 and 2.0 for this parameter. Qualitative results illustrate the development of the mixing zone from the exit plane of the model to a distance of about 19 equivalent rocket nozzle exit diameters downstream. These data show the mixing to be confined in the vertical plane for all cases, The lateral expansion is more pronounced at a pressure ratio of 1.0 and suggests that mixing with the ingested flow would be likely beginning at a distance of 7 nozzle exit diameters downstream of the nozzle exit plane.

  11. Mixing of Supersonic Streams

    NASA Technical Reports Server (NTRS)

    Hawk, C. W.; Landrum, D. B.; Muller, S.; Turner, M.; Parkinson, D.

    1998-01-01

    The Strutjet approach to Rocket Based Combined Cycle (RBCC) propulsion depends upon fuel-rich flows from the rocket nozzles and turbine exhaust products mixing with the ingested air for successful operation in the ramjet and scramjet modes. It is desirable to delay this mixing process in the air-augmented mode of operation present during low speed flight. A model of the Strutjet device has been built and is undergoing test to investigate the mixing of the streams as a function of distance from the Strutjet exit plane during simulated low speed flight conditions. Cold flow testing of a 1/6 scale Strutjet model is underway and nearing completion. Planar Laser Induced Fluorescence (PLIF) diagnostic methods are being employed to observe the mixing of the turbine exhaust gas with the gases from both the primary rockets and the ingested air simulating low speed, air augmented operation of the RBCC. The ratio of the pressure in the turbine exhaust duct to that in the rocket nozzle wall at the point of their intersection is the independent variable in these experiments. Tests were accomplished at values of 1.0, 1.5 and 2.0 for this parameter. Qualitative results illustrate the development of the mixing zone from the exit plane of the model to a distance of about 19 equivalent rocket nozzle exit diameters downstream. These data show the mixing to be confined in the vertical plane for all cases, The lateral expansion is more pronounced at a pressure ratio of 1.0 and suggests that mixing with the ingested flow would be likely beginning at a distance of 7 nozzle exit diameters downstream of the nozzle exit plane.

  12. Microreactor and method for preparing a radiolabeled complex or a biomolecule conjugate

    SciTech Connect

    Reichert, David E; Kenis, Paul J. A.; Wheeler, Tobias D; Desai, Amit V; Zeng, Dexing; Onal, Birce C

    2015-03-17

    A microreactor for preparing a radiolabeled complex or a biomolecule conjugate comprises a microchannel for fluid flow, where the microchannel comprises a mixing portion comprising one or more passive mixing elements, and a reservoir for incubating a mixed fluid. The reservoir is in fluid communication with the microchannel and is disposed downstream of the mixing portion. A method of preparing a radiolabeled complex includes flowing a radiometal solution comprising a metallic radionuclide through a downstream mixing portion of a microchannel, where the downstream mixing portion includes one or more passive mixing elements, and flowing a ligand solution comprising a bifunctional chelator through the downstream mixing portion. The ligand solution and the radiometal solution are passively mixed while in the downstream mixing portion to initiate a chelation reaction between the metallic radionuclide and the bifunctional chelator. The chelation reaction is completed to form a radiolabeled complex.

  13. Mixed waste management options

    SciTech Connect

    Owens, C.B.; Kirner, N.P.

    1991-12-31

    Disposal fees for mixed waste at proposed commercial disposal sites have been estimated to be $15,000 to $40,000 per cubit foot. If such high disposal fees are imposed, generators may be willing to apply extraordinary treatment or regulatory approaches to properly dispose of their mixed waste. This paper explores the feasibility of several waste management scenarios and attempts to answer the question: Can mixed waste be managed out of existence? Existing data on commercially generated mixed waste streams are used to identify the realm of mixed waste known to be generated. Each waste stream is evaluated from both a regulatory and technical perspective in order to convert the waste into a strictly low-level radioactive or a hazardous waste. Alternative regulatory approaches evaluated in this paper include a delisting petition, no migration petition, and a treatability variance. For each waste stream, potentially available treatment options are identified that could lead to these variances. Waste minimization methodology and storage for decay are also considered. Economic feasibility of each option is discussed broadly.

  14. [Mixed states and schizophrenia].

    PubMed

    Fakra, E; Belzeaux, R; Pringuey, D; Cermolacce, M; Corréard, N; Micoulaud-Franchi, J-A; Azorin, J-M

    2013-12-01

    Because of their compilation of contrasted symptoms and their variable clinical presentation, mixed episodes have been withdrawn from the DSM. However, mixed states question not only the bonds between depression and mania, but also the distinction between bipolar disorders and schizophrenia. Indeed, doubts about the dichotomy introduced by Kraepelin between bipolar disorders and schizophrenia is as old as the nosolgy itself, as attest the later works of this author revealing his hesitations on his own classification. But findings here reviewed issued from recent technical advances, particularly in the imaging and genetic fields, offer a better understanding of the boundaries between these two disorders. Yet, when confronted to an acute episode, clinicians may find it challenging to distinguish a mixed state from a schizophrenic relapse. Indeed, there is no pathognomonic manifestation allowing to retain a diagnosis with confidence. The physician will therefore have to identify a pattern of signs, which will orient his assessment with no certainty. Thus, negative rather than affective or psychotic symptomatology appears to be useful in discriminating schizophrenia (or schizoaffective) disorders from mixed mania. However, a conclusion during this acute stage appears in definitive a formal exercise, first because the final diagnosis will only be ascertained once the symptoms are amended, and second because, according to our classifications, a mood episode, including mania and mixed mania, can be observed without ruling out the diagnosis of schizophrenia. Copyright © 2013 L’Encéphale. Published by Elsevier Masson SAS.. All rights reserved.

  15. Prepared salads and public health.

    PubMed

    Little, C L; Gillespie, I A

    2008-12-01

    In recent years the importance of prepared salads as potential vehicles of gastrointestinal infection has been highlighted by several large outbreaks both nationally and across international boundaries. Between 1992 and 2006, 2274 foodborne general outbreaks of infectious intestinal disease were reported in England and Wales, of which 4% were associated with the consumption of prepared salads. In total, 3434 people were affected, with 66 hospitalizations and one death reported. The attribution of prepared salad types and pathogens among prepared salad associated outbreaks are presented and discussed. Findings from UK studies on salad vegetables, fruit and mixed salads from 1995 to 2007 (21 247 samples) indicate that most bacteria of concern with regard to human health are relatively rare in these products (98.6% of satisfactory quality); however, outbreaks of salmonellosis were uncovered associated with bagged salad leaves and fresh herbs during two such studies. Although it is known that fresh salad vegetables, herbs or fruit may become contaminated from environmental sources, only in recent years has the association of foods of nonanimal origin, such as salad vegetables, with foodborne illness become evident and recurrent, demonstrating that major health problems can arise from consumption of contaminated prepared salads if hygiene practices breakdown.

  16. Natural convective mixing flows

    NASA Astrophysics Data System (ADS)

    Ramos, Eduardo; de La Cruz, Luis; del Castillo, Luis

    1998-11-01

    Natural convective mixing flows. Eduardo Ramos and Luis M. de La Cruz, National University of Mexico and Luis Del Castillo San Luis Potosi University. The possibility of mixing a fluid with a natural convective flow is analysed by solving numerically the mass, momentum and energy equations in a cubic container. Two opposite vertical walls of the container are assumed to have temperatures that oscillate as functions of time. The phase of the oscillations is chosen in such a way that alternating corrotating vortices are formed in the cavity. The mixing efficiency of this kind of flow is examined with a Lagrangian tracking technique. This work was partially financed by CONACyT-Mexico project number GE0044

  17. Remotely controllable mixing system

    NASA Technical Reports Server (NTRS)

    Belew, Robert R. (Inventor)

    1987-01-01

    A remotely controllable mixing system (210) in which a plurality of mixing assemblies (10a-10e) are arranged in an annular configuration, and wherein each assembly (10) employs a central chamber (16) and two outer, upper and lower, chambers (12, 14). Valves (18, 20) are positioned between chambers, and these valves (18, 20) for a given mixing assembly (10) are operated by upper and lower control rotors (29), which in turn are driven by upper and lower drive rotors (270, 270b). Additionally, a hoop (278) is compressed around upper control rotors (29) and a hoop (278b) is compressed around lower control rotors (29) to thus insure constant frictional engagement between all control rotors (29) and drive rotors (270, 270b). The drive rollers (270, 270b) are driven by a motor (213).

  18. Dilution jet mixing program

    NASA Technical Reports Server (NTRS)

    Srinivasan, R.; Coleman, E.; Johnson, K.

    1984-01-01

    Parametric tests were conducted to quantify the mixing of opposed rows of jets (two-sided injection) in a confined cross flow. Results show that jet penetrations for two sided injections are less than that for single-sided injections, but the jet spreading rates are faster for a given momentum ratio and orifice plate. Flow area convergence generally enhances mixing. Mixing characteristics with asymmetric and symmetric convergence are similar. For constant momentum ratio, the optimum S/H(0) with in-line injections is one half the optimum value for single sided injections. For staggered injections, the optimum S/H(0) is twice the optimum value for single-sided injection. The correlations developed predicted the temperature distributions within first order accuracy and provide a useful tool for predicting jet trajectory and temperature profiles in the dilution zone with two-sided injections.

  19. Preparation and properties of uniform size colloids

    SciTech Connect

    Matijevic, E. )

    1993-04-01

    The achievements and problems in the preparation of uniform colloids by precipitation from homogeneous electrolyte solutions are reviewed. Specifically, the syntheses of [open quotes]monodispersed[close quotes] particles of simple and mixed compositions as well as of coated and hollow particles of different shapes are described, and the physical and chemical mechanisms of their formation are discussed. 126 refs., 25 figs., 1 tab.

  20. Here's Your Blunt Critique of Administrator Preparation.

    ERIC Educational Resources Information Center

    Heller, Robert W.; And Others

    1988-01-01

    As participants in an annual survey, most school executives rated their graduate preparation as impractical, and few had found mentors among their professors. Mixed reviews were given on-the-job training through internships, assessment centers, workshops, seminars, and staff development programs. Lack of sufficient funding affected participation…

  1. Student Readiness: Preparing Children for Kindergarten

    ERIC Educational Resources Information Center

    Buchanan, Daphonnie R.

    2010-01-01

    This study examined if children who participated in prekindergarten education programs were better prepared for the kindergarten classroom. Children enter the kindergarten setting at various levels of readiness. A mixed method concurrent transformative study design was employed. Data were collected that provided clarity on how preschool…

  2. Mixed crystal organic scintillators

    DOEpatents

    Zaitseva, Natalia P; Carman, M Leslie; Glenn, Andrew M; Hamel, Sebastien; Hatarik, Robert; Payne, Stephen A; Stoeffl, Wolfgang

    2014-09-16

    A mixed organic crystal according to one embodiment includes a single mixed crystal having two compounds with different bandgap energies, the organic crystal having a physical property of exhibiting a signal response signature for neutrons from a radioactive source, wherein the signal response signature does not include a significantly-delayed luminescence characteristic of neutrons interacting with the organic crystal relative to a luminescence characteristic of gamma rays interacting with the organic crystal. According to one embodiment, an organic crystal includes bibenzyl and stilbene or a stilbene derivative, the organic crystal having a physical property of exhibiting a signal response signature for neutrons from a radioactive source.

  3. Mixing navigation on networks

    NASA Astrophysics Data System (ADS)

    Zhou, Tao

    2008-05-01

    In this article, we propose a mixing navigation mechanism, which interpolates between random-walk and shortest-path protocol. The navigation efficiency can be remarkably enhanced via a few routers. Some advanced strategies are also designed: For non-geographical scale-free networks, the targeted strategy with a tiny fraction of routers can guarantee an efficient navigation with low and stable delivery time almost independent of network size. For geographical localized networks, the clustering strategy can simultaneously increase efficiency and reduce the communication cost. The present mixing navigation mechanism is of significance especially for information organization of wireless sensor networks and distributed autonomous robotic systems.

  4. Turbulence and Interfacial Mixing

    SciTech Connect

    Glimm, James; Li, Xiaolin

    2005-03-15

    The authors study mix from analytical and numerical points of view. These investigations are linked. The analytical studies (in addition to laboratory experiments) provide bench marks for the direct simulation of mix. However, direct simulation is too detailed to be useful and to expensive to be practical. They also consider averaged equations. Here the major issue is the validation of the closure assumptions. They appeal to the direct simulation methods for this step. They have collaborated with several NNSA teams; moreover, Stony Brook alumni (former students, faculty and research collaborators) presently hold staff positions in NNSA laboratories.

  5. Atomization and Mixing Study

    NASA Technical Reports Server (NTRS)

    Ferrenberg, A.; Hunt, K.; Duesberg, J.

    1985-01-01

    The primary objective was the obtainment of atomization and mixing performance data for a variety of typical liquid oxygen/hydrocarbon injector element designs. Such data are required to establish injector design criteria and to provide critical inputs to liquid rocket engine combustor performance and stability analysis, and computational codes and methods. Deficiencies and problems with the atomization test equipment were identified, and action initiated to resolve them. Test results of the gas/liquid mixing tests indicated that an assessment of test methods was required. A series of 71 liquid/liquid tests were performed.

  6. Atomization and mixing study

    NASA Technical Reports Server (NTRS)

    Ferrenberg, A.; Jaqua, V. W.

    1983-01-01

    The state of the art in atomization and mixing for triplet, pentad, and coaxial injectors is described. Injectors that are applicable for LOX/hydrocarbon propellants and main chamber and fuel rich preburner/gas generator mixture ratios are of special interest. Various applicable correlating equations and parameters as well as test data found in the literature are presented. The validity, utility, and important aspects of these data and correlations are discussed and the measurement techniques used are evaluated. Propellant mixing tests performed are described and summarized, results are reported, and tentative conclusions are included.

  7. Development and quality evaluation of value added instant rab mixes.

    PubMed

    Mogra, Renu; Choudhry, Maya

    2014-06-01

    Rab is a traditional Rajasthani preparation prepared by boiling maize grits and or flour in buttermilk for 2-3 h. It is sour in taste with curd and cumin seed flavour and has thick soup like consistency. Two instant mixes of rab were developed using two types of curds prepared from two different culture combination (i) S. lactis + S. thermophilus + S. diacetylactis and (ii) L. bulgaricus + S. diacetylactis. Processed greengram dhal and spinach leaves powder were added to the mixes for their value addition. In all, six mixes were developed from two types of curd. The mixes were analysed for nutritional composition at zero month and sensory characteristics and shelf life was evaluated for 4 months. The rab mixes provided moisture 4.0-5.5 g; protein 15.1-17.6 g; carbohydrate 62.3-70.29 g; energy 357-394 kcal; fat 4.4-6.1 g; iron 3.15-3.89 mg and calcium 346-386 mg per 100 g of mixes. There was an increase in protein, ash, fiber and iron content of mixes through value addition. Sensory evaluation of rab reconstituted from mixes revealed that the scores ranged between 7 and 8 depicting that rab was liked very much. The mixes were free from coliforms and S.aureus bacteria and the counts for TVC, yeast and molds were within safe limits during storage of 4 months at 28-30°C and RH 55-65%.

  8. Sylgard® Mixing Study

    SciTech Connect

    Bello, Mollie; Welch, Cynthia F.; Goodwin, Lynne Alese; Keller, Jennie

    2014-08-22

    Sylgard® 184 and Sylgard® 186 silicone elastomers form Dow Corning® are used as potting agents across the Nuclear Weapons Complex. A standardized mixing procedure is required for filled versions of these products. The present study is a follow-up to a mixing study performed by MST-7 which established the best mixing procedure to use when adding filler to either 184 or 186 base resins. The most effective and consistent method of mixing resin and curing agent for three modified silicone elastomer recipes is outlined in this report. For each recipe, sample size, mixing type, and mixing time was varied over 10 separate runs. The results show that the THINKY™ Mixer gives reliable mixing over varying batch sizes and mixing times. Hand Mixing can give improved mixing, as indicated by reduced initial viscosity; however, this method is not consistent.

  9. Stabilizer for mixed fuels

    SciTech Connect

    Yamamura, M.; Igarashi, T.; Ukigai, T.

    1984-03-13

    A stabilizer for mixed fuels containing a reaction product obtained by reacting (1) a polyol having at least 3 hydroxyl groups in the molecule and a molecular weight of 400-10,000 with (2) an epihalohydrin, as the principal component.

  10. Mixing and Transport.

    ERIC Educational Resources Information Center

    Ditmars, John D.

    1978-01-01

    Presents a literature review of longitudinal dispersion, mixing and transport in streams, rivers, lakes, reservoirs, estuaries, and oceans. This review covers also: (1) fluid-solid mixtures and (2) oil spill behavior. A list of 189 references published in 1976 and 1977 is presented. (HM)

  11. True Anonymity Without Mixes

    NASA Astrophysics Data System (ADS)

    Molina-Jimenez, C.; Marshall, L.

    2002-04-01

    Anonymizers based on mix computers interposed between the sender and the receiver of an e-mail message have been used in the Internet for several years by senders of e-mail messages who do not wish to disclose their identity. Unfortunately, the degree of anonymity provided by this paradigm is limited and fragile. First, the messages sent are not truly anonymous but pseudo-anonymous since one of the mixes, at least, always knows the sender's identity. Secondly, the strength of the system to protect the sender's identity depends on the ability and the willingness of the mixes to keep the secret. If the mixes fail, the sender/'s anonymity is reduced to pieces. In this paper, we propose a novel approach for sending truly anonymous messages over the Internet where the anonymous message is sent from a PDA which uses dynamically assigned temporary, non-personal, random IP and MAC addresses. Anonymous E-cash is used to pay for the service.

  12. Mixed-Initiative Clustering

    ERIC Educational Resources Information Center

    Huang, Yifen

    2010-01-01

    Mixed-initiative clustering is a task where a user and a machine work collaboratively to analyze a large set of documents. We hypothesize that a user and a machine can both learn better clustering models through enriched communication and interactive learning from each other. The first contribution or this thesis is providing a framework of…

  13. Mixed-Initiative Clustering

    ERIC Educational Resources Information Center

    Huang, Yifen

    2010-01-01

    Mixed-initiative clustering is a task where a user and a machine work collaboratively to analyze a large set of documents. We hypothesize that a user and a machine can both learn better clustering models through enriched communication and interactive learning from each other. The first contribution or this thesis is providing a framework of…

  14. Mixing and Transport.

    ERIC Educational Resources Information Center

    Ditmars, John D.

    1978-01-01

    Presents a literature review of longitudinal dispersion, mixing and transport in streams, rivers, lakes, reservoirs, estuaries, and oceans. This review covers also: (1) fluid-solid mixtures and (2) oil spill behavior. A list of 189 references published in 1976 and 1977 is presented. (HM)

  15. Mixed valent metals

    NASA Astrophysics Data System (ADS)

    Riseborough, P. S.; Lawrence, J. M.

    2016-08-01

    We review the theory of mixed-valent metals and make comparison with experiments. A single-impurity description of the mixed-valent state is discussed alongside the description of the nearly-integer valent or Kondo limit. The degeneracy N of the f-shell plays an important role in the description of the low-temperature Fermi-liquid state. In particular, for large N, there is a rapid cross-over between the mixed-valent and the Kondo limit when the number of f electrons is changed. We discuss the limitations on the application of the single-impurity description to concentrated compounds such as those caused by the saturation of the Kondo effect and those due to the presence of magnetic interactions between the impurities. This discussion is followed by a description of a periodic lattice of mixed-valent ions, including the role of the degeneracy N. The article concludes with a comparison of theory and experiment. Topics covered include the single-impurity Anderson model, Luttinger’s theorem, the Friedel sum rule, the Schrieffer-Wolff transformation, the single-impurity Kondo model, Kondo screening, the Wilson ratio, local Fermi-liquids, Fermi-liquid sum rules, the Noziéres exhaustion principle, Doniach’s diagram, the Anderson lattice model, the Slave-Boson method, etc.

  16. Preparation of superconductor precursor powders

    DOEpatents

    Bhattacharya, Raghunath

    1998-01-01

    A process for the preparation of a precursor metallic powder composition for use in the subsequent formation of a superconductor. The process comprises the steps of providing an electrodeposition bath comprising an electrolyte medium and a cathode substrate electrode, and providing to the bath one or more soluble salts of one or more respective metals which are capable of exhibiting superconductor properties upon subsequent appropriate treatment. The bath is continually energized to cause the metallic and/or reduced particles formed at the electrode to drop as a powder from the electrode into the bath, and this powder, which is a precursor powder for superconductor production, is recovered from the bath for subsequent treatment. The process permits direct inclusion of all metals in the preparation of the precursor powder, and yields an amorphous product mixed on an atomic scale to thereby impart inherent high reactivity. Superconductors which can be formed from the precursor powder include pellet and powder-in-tube products.

  17. Enhanced solubilization of curcumin in mixed surfactant vesicles.

    PubMed

    Kumar, Arun; Kaur, Gurpreet; Kansal, S K; Chaudhary, Ganga Ram; Mehta, S K

    2016-05-15

    Self-assemblies of equimolar double and single chain mixed ionic surfactants, with increasing numbers of carbon atoms of double chain surfactant, were analyzed on the basis of fluorescence and conductivity results. Attempts were also made to enhance the solubilization of curcumin in aqueous equimolar mixed surfactant systems. Mixed surfactant assembly was successful in retarding the degradation of curcumin in alkaline media (only 25-28 40% degraded in 10h at pH 13). Fluorescence spectroscopy and fluorescence quenching methods were employed to predict the binding position and mechanism of curcumin with self-assemblies. Results indicate that the interactions take place according to both dynamic and static quenching mechanisms and curcumin was distributed in a palisade layer of mixed aggregates. Antioxidant activity (using DPPH radical) and biocompatibility (using calf-thymus DNA) of curcumin-loaded mixed surfactant formulations were also evaluated. The prepared systems improved the stability, solubility and antioxidant activity of curcumin and additionally are biocompatible.

  18. Electrostatic charge interactions in ordered powder mixes.

    PubMed

    Staniforth, J N; Rees, J E

    1982-02-01

    A method is described for measuring the electrostatic charge generated in powders following contact with a plane substrate. The method uses a Faraday well connected to an electrometer and allows the specific charge of powders to be determined. Of the various drugs and excipients studied, most charged electronegatively following contact with glass surfaces, but became electropositive after contact with polyethylene surfaces. The charge interactions of drug and excipient powders modified the behaviour of ordered mixes formed in similar conditions to those of charge measurement. Powders with like charges formed less stable ordered mixes than those in which drug and excipient particles carried opposite charges. Following triboelectrification in an air cyclone constructed of brass, powders had charges at least 100 times greater than those formed after contact with glass surfaces. Optimization of the triboelectric charging conditions allowed ordered mixes to be prepared in which a maximum electronegative charge was applied to the excipient whilst the drug was given a maximum electropositive charge. Studies of segregation/stability showed that ordered mixes subjected to triboelectrification were less prone to segregation than uncharged powders.

  19. Loblolly Pine Growth 16 Years After Four Site Preparation Treatments

    Treesearch

    John C. Adams; Clyde Vidrine

    2002-01-01

    Thirteen-year growth results of 1-0 planted loblolly pine seedlings (Pinus taeda L.) on differently prepared upland mixed pine-hardwood sites located in north western Louisiana are presented. The study was designed as a randomized complete block consisting of three blocks of four site preparation treatments, which included: chop and burn, windrow,...

  20. Experiments in mixed reality

    NASA Astrophysics Data System (ADS)

    Krum, David M.; Sadek, Ramy; Kohli, Luv; Olson, Logan; Bolas, Mark

    2010-01-01

    As part of the Institute for Creative Technologies and the School of Cinematic Arts at the University of Southern California, the Mixed Reality lab develops technologies and techniques for presenting realistic immersive training experiences. Such experiences typically place users within a complex ecology of social actors, physical objects, and collections of intents, motivations, relationships, and other psychological constructs. Currently, it remains infeasible to completely synthesize the interactivity and sensory signatures of such ecologies. For this reason, the lab advocates mixed reality methods for training and conducts experiments exploring such methods. Currently, the lab focuses on understanding and exploiting the elasticity of human perception with respect to representational differences between real and virtual environments. This paper presents an overview of three projects: techniques for redirected walking, displays for the representation of virtual humans, and audio processing to increase stress.

  1. Mixing by individual swimmers

    NASA Astrophysics Data System (ADS)

    Pushkin, Dmitri; Shum, Henry; Yeomans, Julia

    2012-11-01

    Despite their evolutionary and technological importance, different biomixing mechanisms, their effectiveness and universality remain poorly understood. In this talk we focus on the Lagrangian transport of the surrounding fluid by swimmers. Low Re passive tracers advected by swimmers move in loops that are, in general, almost closed. We analyze the reasons for this behavior and, as non-closedness of the loops is a natural requirement for an efficient mixing, propose a classification of possible mechanisms for biogenic mixing. Next, we discuss the universal (common to all swimmers) and the swimmer-dependent features of the resulting tracer displacements and analyze the Darwin drift, the total fluid volume displaced by a swimmer passing from and to infinity. We show that the Darwin drift is finite for force-free swimmers and can be decomposed into a universal and a swimmer-dependent part. We illustrate our consideration with examples for model swimmers and biological data.

  2. Nozzle mixing apparatus

    SciTech Connect

    Mensink, D.L.

    1992-12-31

    This invention is comprised of a nozzle device for causing two fluids to mix together. In particular, a spray nozzle comprise two hollow, concentric housings, an inner housing and an outer housing. The inner housing has a channel formed therethrough for a first fluid. Its outer surface cooperates with the interior surface of the outer housing to define the second channel for a second fluid. The outer surface of the inner housing and the inner surface of the outer housing each carry a plurality of vanes that interleave but do not touch, each vane of one housing being between two vanes of the other housing. The vanes are curved and the inner surface of the outer housing and the outer surface of the inner housing converge to narrow the second channel. The shape of second channel results in a swirling, accelerating second fluid that will impact the first fluid just past the end of the nozzle where mixing will take place.

  3. Neutrino-Modulino Mixing

    SciTech Connect

    Benakli, K.; Smirnov, A.Y.

    1997-12-01

    We suggest an existence of light singlet fermion, S, which interacts with observable matter only via Planck mass suppressed interaction: {approximately}m{sub 3/2}/M{sub P}, where m{sub 3/2} is the supergravity gravitino mass. If the mass of the singlet equals {approximately}m{sup 2}{sub 3/2}/M{sub P}, then {nu}{sub e}{r_arrow}S resonance conversion solves the solar neutrino problem or leads to observable effects. The {nu}S mixing changes supernova neutrino fluxes and has an impact on the primordial nucleosynthesis. The singlet S can originate as the supersymmetric partner of the moduli fields in supergravity or low energy effective theory stemming from superstrings. The {nu}S mixing may be accompanied by observable R-parity breaking effects. {copyright} {ital 1997} {ital The American Physical Society}

  4. Magnetically driven surface mixing

    NASA Astrophysics Data System (ADS)

    Belkin, M.; Snezhko, A.; Aranson, I. S.; Kwok, W.-K.

    2009-07-01

    Magnetic microparticles suspended on the surface of liquid and energized by vertical alternating magnetic field exhibit complex collective behavior. Various immobile and self-propelled self-assembled structures have been observed. Here, we report on experimental studies of mixing and surface diffusion processes in this system. We show that the pattern-induced surface flows have properties of quasi-two-dimensional turbulence. Correspondingly, the surface advection of tracer particle exhibits properties of Brownian diffusion.

  5. Stochastic neutrino mixing mechanism

    NASA Astrophysics Data System (ADS)

    Guzzo, M. M.; de Holanda, P. C.; Peres, O. L. G.; Zavanin, E. M.

    2013-05-01

    We propose a mechanism which provides an explanation of the Gallium and antineutrino reactor anomalies. Differently from original Pontecorvo’s hypothesis, this mechanism is based on the phenomenological assumption in which the admixture of neutrino mass eigenstates in the moments of neutrino creation and detection can assume different configurations around the admixture parametrized by the usual values of the mixing angles θ12, θ23, and θ13. For simplicity, we assume a Gaussian distribution for the mixing angles in such a way that the average value of this distribution is given by the usual values of the mixing angles, and the width of the Gaussian is denoted by α. We show that the proposed mechanism provides a possible explanation for very short-baseline neutrino disappearance, necessary to accommodate Gallium and antineutrino reactor anomalies, which is not allowed in usual neutrino oscillations based on Pontecorvo’s original hypotheses. We also can describe high-energy oscillation experiments, like LSND, Fermi, and NuTeV, assuming a weakly energy dependent width parameter, α(E), that nicely fits all experimental results.

  6. Flows, Turbulence, and Mixing

    NASA Astrophysics Data System (ADS)

    Lazarian, Alex

    2003-07-01

    HST and FUSE spectra of distant UV-bright sources reveal interstellar absorption lines of high stages of ionization {O VI, C IV, N V, Si IV} arising in many different astrophysical environments such as superbubbles, interstellar chimneys, high-velocity clouds, galaxy halos and cosmic filaments. Turbulence, always present in the magnetized ISM, must mix the hot { 10^6 K} gas with cooler gas within "turbulent mixing layers". Present theory, based on 1D steady-state flows, suggest the line ratios in these layers differ significantly from photoionized gas, radiative shocks, cooling zones, or conduction fronts. These models are use to infer mass and energy fluxes important to understanding the ISM. We propose to develop a suite of 3D time-dependent models that properly calculate turbulent mixing. We will produce synthetic UV absorption lines and optical emission lines directly relevant to HST observations that use GHRS, STIS, and eventually, COS. These models will allow us to explore the sensitivity of the spectral diagnostics to magnetic field strength, turbulence intensity, and relative velocity of the hot and cold gas. We will publish the resulting grid of spectral diagnostics and make them available through the Web.

  7. MixSIAR: advanced stable isotope mixing models in R

    EPA Science Inventory

    Background/Question/Methods The development of stable isotope mixing models has coincided with modeling products (e.g. IsoSource, MixSIR, SIAR), where methodological advances are published in parity with software packages. However, while mixing model theory has recently been ex...

  8. MixSIAR: advanced stable isotope mixing models in R

    EPA Science Inventory

    Background/Question/Methods The development of stable isotope mixing models has coincided with modeling products (e.g. IsoSource, MixSIR, SIAR), where methodological advances are published in parity with software packages. However, while mixing model theory has recently been ex...

  9. The Value of Mixed Methods Research: A Mixed Methods Study

    ERIC Educational Resources Information Center

    McKim, Courtney A.

    2017-01-01

    The purpose of this explanatory mixed methods study was to examine the perceived value of mixed methods research for graduate students. The quantitative phase was an experiment examining the effect of a passage's methodology on students' perceived value. Results indicated students scored the mixed methods passage as more valuable than those who…

  10. Effect of mixing time and speed on experimental baking and dough testing with a 200g pin-mixer

    USDA-ARS?s Scientific Manuscript database

    Under mixing or over mixing the dough results in varied experimental loaf volumes. Bread preparation requires a trained baker to evaluate dough development and determine stop points of mixer. Instrumentation and electronic control of the dough mixer would allow for automatic mixing. This study us...

  11. Mixed marriages. Some key questions.

    PubMed

    Barbara, A

    1994-01-01

    The author discusses various aspects of intercultural or mixed marriage. Factors considered include trends in different countries; determinants of mixed marriage; cultural and social class differences; and mate selection. (SUMMARY IN FRE AND SPA)

  12. Cornell Mixing Zone Expert System

    EPA Pesticide Factsheets

    This page provides an overview Cornell Mixing Zone Expert System water quality modeling and decision support system designed for environmental impact assessment of mixing zones resulting from wastewater discharge from point sources

  13. 38. DETAIL OF RUINS OF CYANIDE MIXING AND EXTRACTION SHED, ...

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

    38. DETAIL OF RUINS OF CYANIDE MIXING AND EXTRACTION SHED, LOOKING SOUTHEAST. CYANIDE SOLUTION WAS PREPARED HERE AND PUMPED UP INTO THE PROCESSING TANKS, AND THE PREGNANT SOLUTION WAS ALSO EXTRACTED HERE AFTER THE LEACHING PROCESS WAS COMPLETE - Skidoo Mine, Park Route 38 (Skidoo Road), Death Valley Junction, Inyo County, CA

  14. Maximally entangled mixed-state generation via local operations

    SciTech Connect

    Aiello, A.; Puentes, G.; Voigt, D.; Woerdman, J. P.

    2007-06-15

    We present a general theoretical method to generate maximally entangled mixed states of a pair of photons initially prepared in the singlet polarization state. This method requires only local operations upon a single photon of the pair and exploits spatial degrees of freedom to induce decoherence. We report also experimental confirmation of these theoretical results.

  15. ACE H2 Hardware Configuration and Mix Part 1

    NASA Image and Video Library

    2016-01-04

    ISS046e005678 (01/04/2016) ---- ESA (European Space Agency) astronaut Tim Peake works on the Advanced Colloids Experiment 2 (ACE H2) Hardware Configuration and Mix Part 1. Peake sent out a Twitter message with this image: Stirring samples using a bar magnet to turn a tiny metal rod - preparing for today's @ISS_Research. #Principia".

  16. Dissociating restart cost and mixing cost in task switching.

    PubMed

    Poljac, Edita; Koch, Iring; Bekkering, Harold

    2009-05-01

    Three experiments investigated the cognitive mechanisms underlying the restart cost and mixing cost in task switching. To this aim, the predictability of task order was varied (unpredictable in Experiment 1 and predictable in Experiments 2 and 3) across experiments, which employed a multiple-trial paradigm. Verbal cues for color and shape matching tasks were presented before a run of four trials. Focusing on task-repetition runs only, we measured restart cost as the difference in performance between trials 1 and 2 and mixing cost as the difference in performance on the non-cued trials under mixed-tasks conditions (Experiments 1 and 2) and single-task conditions (Experiment 3). The restart cost was observed under mixed-tasks conditions with both unpredictable and predictable task orders but not under the single-task condition. In contrast, the mixing cost was observed under the mixed-tasks condition with unpredictable task order only (Experiment 1). This finding implies that the optimal task execution on repetition trials depends on how predictable the identity of the approaching task is. Therefore, we suggest that mixing cost arises from limited preparation on repetition trials when task order is unpredictable, while restart cost arises from processes involved in cue-based task activation that is needed to resolve task interference. Together, these data suggest that restart cost and mixing cost are based on dissociable mechanisms.

  17. Life Cycle Cost Analysis of Ready Mix Concrete Plant

    NASA Astrophysics Data System (ADS)

    Topkar, V. M.; Duggar, A. R.; Kumar, A.; Bonde, P. P.; Girwalkar, R. S.; Gade, S. B.

    2013-11-01

    India, being a developing nation is experiencing major growth in its infrastructural sector. Concrete is the major component in construction. The requirement of good quality of concrete in large quantities can be fulfilled by ready mix concrete batching and mixing plants. The paper presents a technique of applying the value engineering tool life cycle cost analysis to a ready mix concrete plant. This will help an investor or an organization to take investment decisions regarding a ready mix concrete facility. No economic alternatives are compared in this study. A cost breakdown structure is prepared for the ready mix concrete plant. A market survey has been conducted to collect realistic costs for the ready mix concrete facility. The study establishes the cash flow for the ready mix concrete facility helpful in investment and capital generation related decisions. Transit mixers form an important component of the facility and are included in the calculations. A fleet size for transit mixers has been assumed for this purpose. The life cycle cost has been calculated for the system of the ready mix concrete plant and transit mixers.

  18. Mixing order of glidant and lubricant – Influence on powder and tablet properties

    PubMed Central

    Pingali, Kalyana; Mendez, Rafael; Lewis, Daniel; Michniak-Kohn, Bozena; Cuitino, Alberto; Muzzio, Fernando

    2014-01-01

    The main objective of the present work was to study the effect of mixing order of Cab-O-Sil (CS) and magnesium stearate (MgSt) and microlayers during mixing on blend and tablet properties. A first set of pharmaceutical blend containing Avicel PH200, Pharmatose and micronized acetaminophen was prepared with three mixing orders (mixing order-1: CS added first; mixing order-2: MgSt added first; mixing order-3: CS and MgSt added together). All the blends were subjected to a shear rate of 80 rpm and strain of 40, 160 and 640 revolutions in a controlled shear environment resulting in nine different blends. A second set of nine blends was prepared by replacing Avicel PH200 with Avicel PH102. A total of eighteen blends thus prepared were tested for powder hydrophobicity, powder flow, tablet weight, tablet hardness and tablet dissolution. Results indicated that powder hydrophobicity increased significantly for mixing order-1. Intermediate hydrophobic behavior was found for mixing order-3. Additionally, mixing order 1 resulted in improved powder flow properties, low weight variability, higher average tablet weight and slow drug release rates. Dissolution profiles obtained were found to be strongly dependent not only on the mixing order of flowing agents, but also on the strain and the resulting hydrophobicity. PMID:21356286

  19. Effect of mixing techniques on bacterial attachment and disinfection time of polyether impression material

    PubMed Central

    Guler, Umut; Budak, Yasemin; Ruh, Emrah; Ocal, Yesim; Canay, Senay; Akyon, Yakut

    2013-01-01

    Objective: The aim of this study was 2-fold. The first aim was to evaluate the effects of mixing technique (hand-mixing or auto-mixing) on bacterial attachment to polyether impression materials. The second aim was to determine whether bacterial attachment to these materials was affected by length of exposure to disinfection solutions. Materials and Methods: Polyether impression material samples (n = 144) were prepared by hand-mixing or auto-mixing. Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa were used in testing. After incubation, the bacterial colonies were counted and then disinfectant solution was applied. The effect of disinfection solution was evaluated just after the polymerization of impression material and 30 min after polymerization. Differences in adherence of bacteria to the samples prepared by hand-mixing and to those prepared by auto-mixing were assessed by Kruskal-Wallis and Mann-Whitney U-tests. For evaluating the efficiency of the disinfectant, Kruskal-Wallis multiple comparisons test was used. Results: E. coli counts were higher in hand-mixed materials (P < 0.05); no other statistically significant differences were found between hand- and auto-mixed materials. According to the Kruskal-Wallis test, significant differences were found between the disinfection procedures (Z > 2.394). Conclusion: The methods used for mixing polyether impression material did not affect bacterial attachment to impression surfaces. In contrast, the disinfection procedure greatly affects decontamination of the impression surface. PMID:24966729

  20. Mixed waste focus area alternative technologies workshop

    SciTech Connect

    Borduin, L.C.; Palmer, B.A.; Pendergrass, J.A.

    1995-05-24

    This report documents the Mixed Waste Focus Area (MWFA)-sponsored Alternative Technology Workshop held in Salt Lake City, Utah, from January 24--27, 1995. The primary workshop goal was identifying potential applications for emerging technologies within the Options Analysis Team (OAT) ``wise`` configuration. Consistent with the scope of the OAT analysis, the review was limited to the Mixed Low-Level Waste (MLLW) fraction of DOE`s mixed waste inventory. The Los Alamos team prepared workshop materials (databases and compilations) to be used as bases for participant review and recommendations. These materials derived from the Mixed Waste Inventory Report (MWIR) data base (May 1994), the Draft Site Treatment Plan (DSTP) data base, and the OAT treatment facility configuration of December 7, 1994. In reviewing workshop results, the reader should note several caveats regarding data limitations. Link-up of the MWIR and DSTP data bases, while representing the most comprehensive array of mixed waste information available at the time of the workshop, requires additional data to completely characterize all waste streams. A number of changes in waste identification (new and redefined streams) occurred during the interval from compilation of the data base to compilation of the DSTP data base with the end result that precise identification of radiological and contaminant characteristics was not possible for these streams. To a degree, these shortcomings compromise the workshop results; however, the preponderance of waste data was linked adequately, and therefore, these analyses should provide useful insight into potential applications of alternative technologies to DOE MLLW treatment facilities.

  1. Magnetically coupled system for mixing

    DOEpatents

    Miller, III, Harlan; Meichel, George; Legere, Edward; Malkiel, Edwin; Woods, Robert Paul; Ashley, Oliver; Katz, Joseph; Ward, Jason; Petersen, Paul

    2014-04-01

    The invention provides a mixing system comprising a magnetically coupled drive system and a foil for cultivating algae, or cyanobacteria, in an open or enclosed vessel. The invention provides effective mixing, low energy usage, low capital expenditure, and ease of drive system component maintenance while maintaining the integrity of a sealed mixing vessel.

  2. Magnetically coupled system for mixing

    DOEpatents

    Miller, III, Harlan; Meichel, George; Legere, Edward; Malkiel, Edwin; Woods, Robert Paul; Ashley, Oliver; Katz, Joseph; Ward, Jason; Petersen, Paul

    2015-09-22

    The invention provides a mixing system comprising a magnetically coupled drive system and a foil for cultivating algae, or cyanobacteria, in an open or enclosed vessel. The invention provides effective mixing, low energy usage, low capital expenditure, and ease of drive system component maintenance while maintaining the integrity of a sealed mixing vessel.

  3. Mix/Cast Contamination Control

    NASA Technical Reports Server (NTRS)

    Wallentine, M.

    2005-01-01

    Presented is a training handbook for Mix/Cast Contamination Control; a part of a series of training courses to qualify access to Mix/Cast facilities. Contents: List Contamination Control Requirements; Identify foreign objects debris (FOD), Control Areas and their guidelines; Describe environmental monitoring; List Contamination Control Initiatives; Describe concern for Controlled Materials; Identify FOD Controlled Areas in Mix/Cast.

  4. Error Estimates for Mixed Methods.

    DTIC Science & Technology

    1979-03-01

    This paper presents abstract error estimates for mixed methods for the approximate solution of elliptic boundary value problems. These estimates are...then applied to obtain quasi-optimal error estimates in the usual Sobolev norms for four examples: three mixed methods for the biharmonic problem and a mixed method for 2nd order elliptic problems. (Author)

  5. The mixed chemistry problem

    NASA Astrophysics Data System (ADS)

    Guzman-Ramirez, L.; Zijlstra, A. A.; Gesicki, K.; Lagadec, E.; Jones, D.; Millar, T. J.; Woods, P. M.; Chuimin, R. N.

    2014-04-01

    Planetary nebulae (PNe) represent the last stage of evolution of intermediate mass stars (0.8 to 8M⊙) and, hence, by their very nature are fundamental to galactic evolution. The massive envelopes ejected during their earlier evolution (AGB phase) are an important source of recycled material in the form of dust and molecular gas into the interstellar medium. A small fraction of PNe show both O- and C-rich features and are therefore classified as mixed-chemistry objects. The origin of their mixed-chemistry is still uncertain. Our chemical models show that the PAHs may form in irradiated dense tori, and HST images confirm the presence of such tori in some of the objects. Using the VISIR/VLT, we spatially resolved the precise location of the PAHs. We find a dense dusty structures in all of the objects observed. The ionised [SIV] material is located inside the dusty tori, while the PAHs are present at the outer edges of these tori. This confirms that the PAHs formation is due to the photodissociation of CO. In the Galactic Disk, very few PNe have shown to harbour these mixed-chemistry phenomenon. We propose to observe the tori of a sample of bipolar PNe from the Galactic Disk that harbour a close binary system inside them. The chemical models show that the formation of long C-chain molecules is possible to occur in O-rich environments, but the formation of these C-rich molecules require a very dense region (Av˜4). To test this theory we propose to observe the very dense tori of these Galactic Disk PNe and compare these sample with the already observed sample of PNe in the Galactic Bulge (Guzman-Ramirez, et al., 2011;Guzman-Ramirez, et al., 2013, submitted).

  6. Mixed Matrix Silicone and Fluorosilicone/Zeolite 4A Membranes for Ethanol Dehydration by Pervaporation

    EPA Science Inventory

    The ability of homogeneous and mixed matrix membranes prepared using standard silicone rubber, poly(dimethylsiloxane) (PDMS), and fluorosilicone rubber, poly(trifluoropropylmethylsiloxane) (PTFPMS), to dehydrate ethanol by pervaporation was evaluated. Although PDMS is generally c...

  7. Mixed Matrix Silicone and Fluorosilicone/Zeolite 4A Membranes for Ethanol Dehydration by Pervaporation

    EPA Science Inventory

    The ability of homogeneous and mixed matrix membranes prepared using standard silicone rubber, poly(dimethylsiloxane) (PDMS), and fluorosilicone rubber, poly(trifluoropropylmethylsiloxane) (PTFPMS), to dehydrate ethanol by pervaporation was evaluated. Although PDMS is generally c...

  8. Single crystal particles of a mesoporous mixed transition metal oxide with a wormhole structure.

    PubMed

    Lee, B; Lu, D; Kondo, J N; Domen, K

    2001-10-21

    A new type of mesoporous mixed transition metal oxide of Nb and Ta (NbTa-TIT-1) has been prepared through a two-step calcination, which consists of single crystal particles with wormhole mesoporous structure.

  9. The boundary is mixed

    NASA Astrophysics Data System (ADS)

    Bianchi, Eugenio; Haggard, Hal M.; Rovelli, Carlo

    2017-08-01

    We show that in Oeckl's boundary formalism the boundary vectors that do not have a tensor form represent, in a precise sense, statistical states. Therefore the formalism incorporates quantum statistical mechanics naturally. We formulate general-covariant quantum statistical mechanics in this language. We illustrate the formalism by showing how it accounts for the Unruh effect. We observe that the distinction between pure and mixed states weakens in the general covariant context, suggesting that local gravitational processes are naturally statistical without a sharp quantal versus probabilistic distinction.

  10. B Lifetimes and Mixing

    SciTech Connect

    Evans, Harold G.; /Indiana U.

    2009-05-01

    The Tevatron experiments, CDF and D0, have produced a wealth of new B-physics results since the start of Run II in 2001. We've observed new B-hadrons, seen new effects, and increased many-fold the precision with which we know the properties of b-quark systems. In these proceedings, we will discuss two of the most fruitful areas in the Tevatron B-physics program: lifetimes and mixing. We'll examine the experimental issues driving these analyses, present a summary of the latest results, and discuss prospects for the future.

  11. Radial Mixing in Turbomachines.

    DTIC Science & Technology

    1988-02-01

    entrainment rate F force defect thickness f blade force, wake model function (eq 9.3) g wake model function (eq 9.4) H shape factor , H Head’s shape factor h...and wake predictions . A new mixing procedure based on the explicit computation of the full transport equation is proposed. This full computation...8217 caused by an overall non-uniform inlet flow as predicted by a through-flow computation, and an ’end-wall boundary layer passage vortex’. 2.2

  12. Mixed feed evaporator

    DOEpatents

    Vakil, Himanshu B.; Kosky, Philip G.

    1982-01-01

    In the preparation of the gaseous reactant feed to undergo a chemical reaction requiring the presence of steam, the efficiency of overall power utilization is improved by premixing the gaseous reactant feed with water and then heating to evaporate the water in the presence of the gaseous reactant feed, the heating fluid utilized being at a temperature below the boiling point of water at the pressure in the volume where the evaporation occurs.

  13. Intrinsically mixed states: an appreciation

    NASA Astrophysics Data System (ADS)

    Ruetsche, Laura

    An "intrinsically mixed" state is a mixed state of a system that is (in a sense to be elaborated) 'orthogonal' to every pure state of that system. Although the presence of such states in the quantum theories of infinite systems is well known to those who work with such theories, intrinsically mixed states are virtually unheralded in the philosophical literature. Rob Clifton was thoroughly familiar with intrinsically mixed states. I aim here to introduce them to a wider audience-and to encourage that audience to cultivate their acquaintance by suggesting that intrinsically mixed states undermine assumptions framing standard discussions of the quantum measurement problem.

  14. Mixing incompatibilities and toxic exposures.

    PubMed

    Olson, K R; Shusterman, D J

    1993-01-01

    A number of consumer and commercial products may react, upon inappropriate mixing, to produce substances of greater toxicity than the starting materials. Consumer product mixing incompatibilities have been well documented and warning labels appear on high-risk products. In industry, a wider array of potential mixing incompatibilities exists and includes potential accidents in chemical storage and hazardous material handling. Emergency response personnel are a group who often deal with inadvertent mixing related to transportation and other hazardous materials incidents. This article assembles some better-known examples of toxicologically significant exposures resulting from inadvertent or deliberate mixing of incompatible materials.

  15. Transition mixing study

    NASA Technical Reports Server (NTRS)

    Reynolds, R.; White, C.

    1986-01-01

    A computer model capable of analyzing the flow field in the transition liner of small gas turbine engines is developed. A FORTRAN code has been assembled from existing codes and physical submodels and used to predict the flow in several test geometries which contain characteristics similar to transition liners, and for which experimental data was available. Comparisons between the predictions and measurements indicate that the code produces qualitative results but that the turbulence models, both K-E and algebraic Reynolds Stress, underestimate the cross-stream diffusion. The code has also been used to perform a numerical experiment to examine the effect of a variety of parameters on the mixing process in transition liners. Comparisons illustrate that geometries with significant curvature show a drift of the jet trajectory toward the convex wall and weaker wake region vortices and decreased penetration for jets located on the convex wall of the liner, when compared to jets located on concave walls. Also shown were the approximate equivalency of angled slots and round holes and a technique by which jet mixing correlations developed for rectangular channels can be used for can geometries.

  16. [Mixed states and neuroimaging].

    PubMed

    Kaladjian, A; Belzeaux, R; Micoulaud-Franchi, J A; Cermolacce, M; Fakra, E; Azorin, J-M

    2013-12-01

    Despite the growing number of neuroimaging studies in bipolar disorder over the past years, the brain regions involved in mood dysregulation in this disease are still poorly understood. If some neurofunctional abnormalities seem to be independent of mood state, others were preferentially associated with mania or depression, involving the amygdala and other limbic regions as well as ventral frontal regions, with a likely hemispheric lateralization of these abnormalities according to the thymic state that was examined. Very few imaging studies became interested in bipolar patients in a mixed state, making it harder to connect brain malfunction to a given mood state. However, data obtained so far support the hypothesis of a lateralization of brain abnormalities in relation to bipolar symptomatology, suggesting that neurofonctional abnormalities preferentially located in the right ventral frontal and limbic areas may underlie the depressive component, associated with abnormalities of the left similar regions for the manic component. Identification of brain dysfunctions that may explain the emergence of mixed symptoms will likely provide useful information to better understand the respective roles of each hemisphere in the pathophysiology of bipolar disorder. Copyright © 2013 Sociedade Brasileira de Farmacognosia. Published by Elsevier Masson SAS.. All rights reserved.

  17. Collisional atomic mixing

    NASA Astrophysics Data System (ADS)

    Biersack, Jochen P.

    The collisional mixing of thin metal markers in silicon is investigated with the computer program TRIM-DYNAMIC (T-DYN). This code assumes that at high dose irradiation, the substrate Si or Ge, will get fully amorphized, and the recoil atom can stop in any position after slowing down below a certain final energy Ef (taken here as 3 eV). In order to avoid chemical effects, the system Au marker in a silicon matrix was chosen for the TRIM simulation. The results are in good agreement with the experimental findings, as compiled in the review article by Paine and Averback. Similar collisional mixing effects occur in the process of SIMS or Auger electron depth profiling, and cannot be avoided. An example is given here for a thin layer of arsenic vapor deposited on Si and covered by amorphous silicon. The analysing ion beam in this case was 14.5 keV Cs+ incident at 37° towards the surface normal. In comparison with the SIMS measurements by modern depth profiling equipment, again good agreement was found between the T-DYN results and the experiment.

  18. Wave mixing spectroscopy

    SciTech Connect

    Smith, R.W.

    1980-08-01

    Several new aspects of nonlinear or wave mixing spectroscopy were investigated utilizing the polarization properties of the nonlinear output field and the dependence of this field upon the occurrence of multiple resonances in the nonlinear susceptibility. First, it is shown theoretically that polarization-sensitive detection may be used to either eliminate or controllably reduce the nonresonant background in coherent anti-Stokes Raman spectroscopy, allowing weaker Raman resonances to be studied. The features of multi-resonant four-wave mixing are examined in the case of an inhomogeneously broadened medium. It is found that the linewidth of the nonlinear output narrows considerably (approaching the homogeneous width) when the quantum mechanical expressions for the doubly- and triply-resonant susceptibilities are averaged over a Doppler or strain broadened profile. Experimental studies of nonlinear processes in Pr/sup +3/:LaF/sub 3/ verify this linewidth narrowing, but indicate that this strain broadened system cannot be treated with a single broadening parameter as in the case of Doppler broadening in a gas. Several susceptibilities are measured from which are deduced dipole matrix elements and Raman polarizabilities related to the /sup 3/H/sub 4/, /sup 3/H/sub 6/, and /sup 3/P/sub 0/ levels of the praseodymium ions.

  19. BENCH SCALE SALTSTONE PROCESS DEVELOPMENT MIXING STUDY

    SciTech Connect

    Cozzi, A.; Hansen, E.

    2011-08-03

    shearing was shown to reduce the rheological properties of the grout as it was processed through the transfer line. Samples taken at the static feed tank showed that gelling impacted the rheological properties of the grout before it was fed into the pump and transfer line. A comparison of the rheological properties of samples taken at the feed tank and transfer line discharge indicated shearing of the grout was occurring in the transfer line. Bench scale testing of different mixing methods with three different salt solutions showed that method of mixing influences the rheological properties of the grouts. The paddle blade mixing method of the salt solution used for the BMSR testing provided comparable rheological properties of the grout prepared in the BMSR after 14 minutes of processing, B3. The paddle blade mixing method can be used to represent BMSR results and mixing time can be adjusted to represent larger scale mixing.

  20. Faithful Transfer Arbitrary Pure States with Mixed Resources

    NASA Astrophysics Data System (ADS)

    Luo, Ming-Xing; Li, Lin; Ma, Song-Ya; Chen, Xiu-Bo; Yang, Yi-Xian

    2013-09-01

    In this paper, we show that some special mixed quantum resource experience the same property of pure entanglement such as Bell state for quantum teleportation. It is shown that one mixed state and three bits of classical communication cost can be used to teleport one unknown qubit compared with two bits via pure resources. The schemes are easily implement with model physical techniques. Moreover, these resources are also optimal and typical for faithfully remotely prepare an arbitrary qubit, two-qubit and three-qubit states with mixed quantum resources. Our schemes are completed as same as those with pure quantum entanglement resources except only 1 bit additional classical communication cost required. The success probability is independent of the form of the mixed resources.

  1. Mixed-bed affinity chromatography: principles and methods.

    PubMed

    Boschetti, Egisto; Righetti, Pier Giorgio

    2015-01-01

    Mixed-bed chromatography is far from being a well-established technology within the panoply of bioseparation tools. Composed of an assembly of distinct sorbents that are mixed in a single bed, they have been mostly developed in the last decade for the reduction of dynamic concentration range where they allowed discovering many low-copy proteins within very complex proteomes. Other interesting preparative applications of mixed-bed chromatography have since been developed. In this chapter the basic concepts first and then detailed application recipes are described for (1) the reduction of protein dynamic concentration range, (2) the removal of impurity traces at the last stage of a biopurification process, and (3) the selection and use of sorbents as mixed bed in protein purification.

  2. 21 CFR 184.1027 - Mixed carbohydrase and protease enzyme product.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Mixed carbohydrase and protease enzyme product... enzyme product. (a) Mixed carbohydrase and protease enzyme product is an enzyme preparation that includes... current good manufacturing practice conditions of use: (1) The ingredient is used as an enzyme, as defined...

  3. 21 CFR 184.1027 - Mixed carbohydrase and protease enzyme product.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Mixed carbohydrase and protease enzyme product... enzyme product. (a) Mixed carbohydrase and protease enzyme product is an enzyme preparation that includes... current good manufacturing practice conditions of use: (1) The ingredient is used as an enzyme, as defined...

  4. 21 CFR 184.1027 - Mixed carbohydrase and protease enzyme product.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Mixed carbohydrase and protease enzyme product... enzyme product. (a) Mixed carbohydrase and protease enzyme product is an enzyme preparation that includes... current good manufacturing practice conditions of use: (1) The ingredient is used as an enzyme, as defined...

  5. 21 CFR 184.1027 - Mixed carbohydrase and protease enzyme product.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Mixed carbohydrase and protease enzyme product. 184... enzyme product. (a) Mixed carbohydrase and protease enzyme product is an enzyme preparation that includes... current good manufacturing practice conditions of use: (1) The ingredient is used as an enzyme, as defined...

  6. Optimization of dexamethasone mixed nanomicellar formulation.

    PubMed

    Cholkar, Kishore; Hariharan, Sudharshan; Gunda, Sriram; Mitra, Ashim K

    2014-12-01

    The purpose of this study was to develop a clear aqueous mixed nanomicellar formulation (MNF) of dexamethasone utilizing both D-α-tocopherol polyethylene glycol-1000 succinate (Vit E TPGS) and octoxynol-40 (Oc-40). In this study, Vit E TPGS and Oc-40 are independent variables. Formulations were prepared following solvent evaporation method. A three level full-factorial design was applied to optimize the formulation based on entrapment efficiency, size, and polydispersity index (PDI). A specific blend of Vit E TPGS and Oc-40 at a particular wt% ratio (4.5:2.0) produced excellent drug entrapment, loading, small mixed nanomicellar size and narrow PDI. Solubility of DEX in MNF is improved by ~6.3-fold relative to normal aqueous solubility. Critical micellar concentration (CMC) for blend of polymers (4.5:2.0) was found to be lower (0.012 wt%) than the individual polymers (Vit E TPGS (0.025 wt%) and Oc-40 (0.107 wt%)). No significant effect on mixed nanomicellar size and PDI with one-factor or multi-factor interactions was observed. Qualitative (1)H NMR studies confirmed absence of free drug in the outer aqueous MNF medium. MNF appeared to be highly stable. Cytotoxicity studies on rabbit primary corneal epithelial cells did not indicate any toxicity suggesting MNF of dexamethasone is safe and suitable for human topical ocular drops after further in vivo evaluations.

  7. Chromium silicide formation by ion mixing

    NASA Technical Reports Server (NTRS)

    Shreter, U.; So, F. C. T.; Nicolet, M.-A.

    1984-01-01

    The formation of CrSi2 by ion mixing was studied as a function of temperature, silicide thickness and irradiated interface. Samples were prepared by annealing evaporated couples of Cr on Si and Si on Cr at 450 C for short times to form Si/CrSi2/Cr sandwiches. Xenon beams with energies up to 300 keV and fluences up to 8 x 10 to the 15th per sq cm were used for mixing at temperatures between 20 and 300 C. Penetrating only the Cr/CrSi2 interface at temperatures above 150 C induces further growth of the silicide as a uniform stoichiometric layer. The growth rate does not depend on the thickness of the initially formed silicide at least up to a thickness of 150 nm. The amount of growth depends linearly on the density of energy deposited at the interface. The growth is temperature dependent with an apparent activation energy of 0.2 eV. Irradiating only through the Si/CrSi2 interface does not induce silicide growth. It is concluded that the formation of CrSi2 by ion beam mixing is an interface-limited process and that the limiting reaction occurs at the Cr/CrSi2 interface.

  8. Chromium silicide formation by ion mixing

    NASA Technical Reports Server (NTRS)

    Shreter, U.; So, F. C. T.; Nicolet, M.-A.

    1984-01-01

    The formation of CrSi2 by ion mixing was studied as a function of temperature, silicide thickness and irradiated interface. Samples were prepared by annealing evaporated couples of Cr on Si and Si on Cr at 450 C for short times to form Si/CrSi2/Cr sandwiches. Xenon beams with energies up to 300 keV and fluences up to 8 x 10 to the 15th per sq cm were used for mixing at temperatures between 20 and 300 C. Penetrating only the Cr/CrSi2 interface at temperatures above 150 C induces further growth of the silicide as a uniform stoichiometric layer. The growth rate does not depend on the thickness of the initially formed silicide at least up to a thickness of 150 nm. The amount of growth depends linearly on the density of energy deposited at the interface. The growth is temperature dependent with an apparent activation energy of 0.2 eV. Irradiating only through the Si/CrSi2 interface does not induce silicide growth. It is concluded that the formation of CrSi2 by ion beam mixing is an interface-limited process and that the limiting reaction occurs at the Cr/CrSi2 interface.

  9. Mixed methods, mixed methodology health services research in practice.

    PubMed

    Johnstone, P Lynne

    2004-02-01

    Mixed methods, mixed methodology research is a little documented but increasingly accepted approach employed to investigate organizational phenomena. The author presents a synthesis of literature that informed the decision to adopt a mixed methods, mixed methodology, dominantly naturalistic study approach to health services research in which she explored the process and organizational consequences of new artifact adoption in surgery. She describes the way whereby a collective case study involving five Australian hospitals yielded quantitative and qualitative data that were analyzed using inductive and/or deductive reasoning. She goes beyond the theoretical rational for employing a mixed methods, mixed methodology approach to present a summative conceptual model of the research process and describe the structural aspects of the dissertation in which the research was reported that should benefit researchers contemplating the value of such an approach.

  10. Improved mixing and sampling systems for vitrification melter feeds

    SciTech Connect

    Ebadian, M.A.

    1998-01-01

    This report summarizes the methods used and results obtained during the progress of the study of waste slurry mixing and sampling systems during fiscal year 1977 (FY97) at the Hemispheric Center for Environmental Technology (HCET) at Florida International University (FIU). The objective of this work is to determine optimal mixing configurations and operating conditions as well as improved sampling technology for defense waste processing facility (DWPF) waste melter feeds at US Department of Energy (DOE) sites. Most of the research on this project was performed experimentally by using a tank mixing configuration with different rotating impellers. The slurry simulants for the experiments were prepared in-house based on the properties of the DOE sites` typical waste slurries. A sampling system was designed to withdraw slurry from the mixing tank. To obtain insight into the waste mixing process, the slurry flow in the mixing tank was also simulated numerically by applying computational fluid dynamics (CFD) methods. The major parameters investigated in both the experimental and numerical studies included power consumption of mixer, mixing time to reach slurry uniformity, slurry type, solids concentration, impeller type, impeller size, impeller rotating speed, sampling tube size, and sampling velocities. Application of the results to the DWPF melter feed preparation process will enhance and modify the technical base for designing slurry transportation equipment and pipeline systems. These results will also serve as an important reference for improving waste slurry mixing performance and melter operating conditions. These factors will contribute to an increase in the capability of the vitrification process and the quality of the waste glass.

  11. Insights of Mixing on the Assembly of DNA Nanoparticles

    NASA Astrophysics Data System (ADS)

    Williams, Manda S.

    Size is a crucial parameter in the delivery of nanoparticle therapeutics, affecting mechanisms such as tissue delivery, clearance, and cellular uptake. The morphology of nanoparticles is dependent both upon chemistry and the physical process of assembly. Polyplexes, a major class of non-viral gene delivery vectors, are conventionally prepared by vortex mixing, resulting in non-uniform nanoparticles and poor reproducibility. Better understanding and control of the physical process of assembly, and mixing in particular, will produce polyplexes of a more uniform and reliable size, optimizing their efficiency for laboratory and clinical use. "Mixing" is the reduction of length scale of a system to accelerate diffusion until a uniform concentration is achieved. Vortex mixing is poorly characterized and sensitive to protocols. Microfluidic systems are notable for predictable fluid behavior, and are ideal for analyzing and controlling the physical interaction of reagents on the microscale, realm where mixing occurs. Several microdevices for the preparation of DNA polyplexes are explored here. Firstly, the staggered herringbone mixer, a chaotic advection micromixer, is used to observe the effects of mixing time on nanoparticle size. Next, a novel device to surround the reagent flows with a sheath of buffer, preventing interaction with the walls and confining the complexation to a zone of lower, less variable shear and residence time, is used to demonstrate the role of shear in nanoparticle assembly. Lastly, uneven diffusion between ion pairs produces a small separation of charge at fluid interfaces; this short-lived electric field has a significant impact on the transport of DNA over the time scales of mixing and complexation. The effects of common buffers on the transport of DNA are examined for possible applications to mixing and complexation. These three investigations demonstrate the importance of the physical process in polyplex assembly, and indicate several

  12. Radioactive mixed waste disposal

    SciTech Connect

    Jasen, W.G.; Erpenbeck, E.G.

    1993-02-01

    Various types of waste have been generated during the 50-year history of the Hanford Site. Regulatory changes in the last 20 years have provided the emphasis for better management of these wastes. Interpretations of the Atomic Energy Act of 1954 (AEA), the Resource Conservation and Recovery Act of 1976 (RCRA), and the Hazardous and Solid Waste Amendments (HSWA) have led to the definition of radioactive mixed wastes (RMW). The radioactive and hazardous properties of these wastes have resulted in the initiation of special projects for the management of these wastes. Other solid wastes at the Hanford Site include low-level wastes, transuranic (TRU), and nonradioactive hazardous wastes. This paper describes a system for the treatment, storage, and disposal (TSD) of solid radioactive waste.

  13. Mixed Mode Matrix Multiplication

    SciTech Connect

    Meng-Shiou Wu; Srinivas Aluru; Ricky A. Kendall

    2004-09-30

    In modern clustering environments where the memory hierarchy has many layers (distributed memory, shared memory layer, cache,...), an important question is how to fully utilize all available resources and identify the most dominant layer in certain computations. When combining algorithms on all layers together, what would be the best method to get the best performance out of all the resources we have? Mixed mode programming model that uses thread programming on the shared memory layer and message passing programming on the distributed memory layer is a method that many researchers are using to utilize the memory resources. In this paper, they take an algorithmic approach that uses matrix multiplication as a tool to show how cache algorithms affect the performance of both shared memory and distributed memory algorithms. They show that with good underlying cache algorithm, overall performance is stable. When underlying cache algorithm is bad, superlinear speedup may occur, and an increasing number of threads may also improve performance.

  14. Nation's water picture mixed

    NASA Astrophysics Data System (ADS)

    The nation's water picture for April showed mixed trends: More than half of the index gaging stations reported normal streamflow conditions during the month, while the spring snowmelt boosted streamflow in the Northeast and Northwest to well above normal levels. Parts of the Southeast, however, from West Virginia south to the Carolinas, reported well-below normal streamflow conditions, according to a month-end check on water resources conditions by the U.S. Geological Survey, Department of the Interior.After nearly 2 years of drought conditions the three major reservoirs supplying New York City reached full storage capacity and were spilling during April. Combined contents of the three reservoirs on May 1, 1982, was 272 billion gallons, 101% of their full usable capacity. The full reservoirs and the generally good surface and groundwater conditions throughout the Delaware River basin allowed the Delaware River Basin Commission to lift its drought emergency warning on April 27.

  15. Biogenic inputs to ocean mixing.

    PubMed

    Katija, Kakani

    2012-03-15

    Recent studies have evoked heated debate about whether biologically generated (or biogenic) fluid disturbances affect mixing in the ocean. Estimates of biogenic inputs have shown that their contribution to ocean mixing is of the same order as winds and tides. Although these estimates are intriguing, further study using theoretical, numerical and experimental techniques is required to obtain conclusive evidence of biogenic mixing in the ocean. Biogenic ocean mixing is a complex problem that requires detailed understanding of: (1) marine organism behavior and characteristics (i.e. swimming dynamics, abundance and migratory behavior), (2) mechanisms utilized by swimming animals that have the ability to mix stratified fluids (i.e. turbulence and fluid drift) and (3) knowledge of the physical environment to isolate contributions of marine organisms from other sources of mixing. In addition to summarizing prior work addressing the points above, observations on the effect of animal swimming mode and body morphology on biogenic fluid transport will also be presented. It is argued that to inform the debate on whether biogenic mixing can contribute to ocean mixing, our studies should focus on diel vertical migrators that traverse stratified waters of the upper pycnocline. Based on our understanding of mixing mechanisms, body morphologies, swimming modes and body orientation, combined with our knowledge of vertically migrating populations of animals, it is likely that copepods, krill and some species of gelatinous zooplankton and fish have the potential to be strong sources of biogenic mixing.

  16. Honoring Voices from Beginning Special Educators for Making Changes in Teacher Preparation

    ERIC Educational Resources Information Center

    Conderman, Greg; Johnston-Rodriguez, Sarah; Hartman, Paula; Walker, David

    2013-01-01

    Through a mixed-methods study, teacher educators investigated recent graduates' perceptions of their preparation program. Beginning special education teachers completed surveys and indicated (a) their level of preparation and confidence associated with 25 core competencies, (b) the most beneficial components of their preparation program, (c)…

  17. Fluid mixing in stratified gravity currents: the Prandtl mixing length.

    PubMed

    Odier, P; Chen, J; Rivera, M K; Ecke, R E

    2009-04-03

    Shear-induced vertical mixing in a stratified flow is a key ingredient of thermohaline circulation. We experimentally determine the vertical flux of momentum and density of a forced gravity current using high-resolution velocity and density measurements. A constant eddy-viscosity model provides a poor description of the physics of mixing, but a Prandtl mixing length model relating momentum and density fluxes to mean velocity and density gradients works well. For the average gradient Richardson number Ri(g) approximately 0.08 and a Taylor Reynolds number Re(lambda) approximately 100, the mixing lengths are fairly constant, about the same magnitude, comparable to the turbulent shear length.

  18. Affective and schizoaffective mixed states.

    PubMed

    Marneros, Andreas; Röttig, Stephan; Wenzel, Andreas; Blöink, Raffaela; Brieger, Peter

    2004-04-01

    Although both DSM-IV and ICD-10 define schizoaffective mixed states, they have not received much attention-neither in the clinical nor in research context. We present preliminary results of a prospective study of bipolar affective (n = 100) and bipolar schizoaffective (n = 177) patients. 25% of the bipolar affective and 32% of the bipolar schizoaffective patients had at least one (schizo)mixed episode during the illness course. Nevertheless, (schizo)mixed episodes were rare-only 5.6% of all episodes. There was a trend that patients with (schizo)mixed episodes were more often women and exhibited more disability (reflected by higher rates of disability payments). Nevertheless, these differences failed to reach significance. Overall, schizo-mixed episodes are as frequent as "pure" affective mixed episodes. They might be linked to a less favourable course. Nevertheless, while their diagnostic criteria are problematic, they are systematically underdiagnosed.

  19. Authoring Immersive Mixed Reality Experiences

    NASA Astrophysics Data System (ADS)

    Misker, Jan M. V.; van der Ster, Jelle

    Creating a mixed reality experience is a complicated endeavour. From our practice as a media lab in the artistic domain we found that engineering is “only” a first step in creating a mixed reality experience. Designing the appearance and directing the user experience are equally important for creating an engaging, immersive experience. We found that mixed reality artworks provide a very good test bed for studying these topics. This chapter details three steps required for authoring mixed reality experiences: engineering, designing and directing. We will describe a platform (VGE) for creating mixed reality environments that incorporates these steps. A case study (EI4) is presented in which this platform was used to not only engineer the system, but in which an artist was given the freedom to explore the artistic merits of mixed reality as an artistic medium, which involved areas such as the look and feel, multimodal experience and interaction, immersion as a subjective emotion and game play scenarios.

  20. Test Preparation: Your Role

    MedlinePlus

    ... common types of preparation required for testing is fasting (to go without all or certain foods) for ... tests that require advance preparation include: Glucose tolerance, fasting, and two-hour post-prandial blood glucose tests : ...

  1. Preparing for Multiple Births

    MedlinePlus

    ... Video Games, and the Internet Preparing for Multiple Births KidsHealth > For Parents > Preparing for Multiple Births Print ... a combination of both. The Risks of Multiple Births The most common risk involved with multiple births ...

  2. Petition Preparation Help

    EPA Pesticide Factsheets

    Preparing a part 75 Petition provides useful information and answers to common questions that will help the designated representative for a unit subject to part 75 prepare and submit a complete petition under §75.66.

  3. Estimating beta-mixing coefficients

    PubMed Central

    McDonald, Daniel J.; Shalizi, Cosma Rohilla; Schervish, Mark

    2015-01-01

    The literature on statistical learning for time series assumes the asymptotic independence or “mixing” of the data-generating process. These mixing assumptions are never tested, and there are no methods for estimating mixing rates from data. We give an estimator for the beta-mixing rate based on a single stationary sample path and show it is L1-risk consistent. PMID:26279742

  4. Optimal broadcasting of mixed states

    SciTech Connect

    Dang Guifang; Fan Heng

    2007-08-15

    The N to M (M{>=}N) universal quantum broadcasting of mixed states {rho}{sup xN} is proposed for a qubit system. The broadcasting of mixed states is universal and optimal in the sense that the shrinking factor is independent of the input state and achieves the upper bound. The quantum broadcasting of mixed qubits is a generalization of the universal quantum cloning machine for identical pure input states. A pure state decomposition of the identical mixed qubits {rho}{sup xN} is obtained.

  5. Research Preparation in Kinesiology

    ERIC Educational Resources Information Center

    Silverman, Stephen

    2012-01-01

    This article addresses research preparation for graduate students. A major assumption is that preparation needs to be differentiated based on a student's goals. Since this is a personal proposal for research preparation, based on experience and the literature, I begin the article providing my perspective since that frames what follows. The next…

  6. Research Preparation in Kinesiology

    ERIC Educational Resources Information Center

    Silverman, Stephen

    2012-01-01

    This article addresses research preparation for graduate students. A major assumption is that preparation needs to be differentiated based on a student's goals. Since this is a personal proposal for research preparation, based on experience and the literature, I begin the article providing my perspective since that frames what follows. The next…

  7. Microfluidic Sample Preparation for Immunoassays

    SciTech Connect

    Visuri, S; Benett, W; Bettencourt, K; Chang, J; Fisher, K; Hamilton, J; Krulevitch, P; Park, C; Stockton, C; Tarte, L; Wang, A; Wilson, T

    2001-08-09

    Researchers at Lawrence Livermore National Laboratory are developing means to collect and identify fluid-based biological pathogens in the forms of proteins, viruses, and bacteria. to support detection instruments, they are developing a flexible fluidic sample preparation unit. The overall goal of this Microfluidic Module is to input a fluid sample, containing background particulates and potentially target compounds, and deliver a processed sample for detection. They are developing techniques for sample purification, mixing, and filtration that would be useful to many applications including immunologic and nucleic acid assays. Many of these fluidic functions are accomplished with acoustic radiation pressure or dielectrophoresis. They are integrating these technologies into packaged systems with pumps and valves to control fluid flow through the fluidic circuit.

  8. Overview of Neutrino Mixing Models and Their Mixing Angle Predictions

    SciTech Connect

    Albright, Carl H.

    2009-11-01

    An overview of neutrino-mixing models is presented with emphasis on the types of horizontal flavor and vertical family symmetries that have been invoked. Distributions for the mixing angles of many models are displayed. Ways to differentiate among the models and to narrow the list of viable models are discussed.

  9. Mixed voltage VLSI design

    NASA Technical Reports Server (NTRS)

    Panwar, Ramesh; Rennels, David; Alkalaj, Leon

    1993-01-01

    A technique for minimizing the power dissipated in a Very Large Scale Integration (VLSI) chip by lowering the operating voltage without any significant penalty in the chip throughput even though low voltage operation results in slower circuits. Since the overall throughput of a VLSI chip depends on the speed of the critical path(s) in the chip, it may be possible to sustain the throughput rates attained at higher voltages by operating the circuits in the critical path(s) with a high voltage while operating the other circuits with a lower voltage to minimize the power dissipation. The interface between the gates which operate at different voltages is crucial for low power dissipation since the interface may possibly have high static current dissipation thus negating the gains of the low voltage operation. The design of a voltage level translator which does the interface between the low voltage and high voltage circuits without any significant static dissipation is presented. Then, the results of the mixed voltage design using a greedy algorithm on three chips for various operating voltages are presented.

  10. Mixed cryoglobulinemia: new concepts.

    PubMed

    Ramos-Casals, M; Trejo, O; García-Carrasco, M; Cervera, R; Font, J

    2000-01-01

    The most documented extrahepatic manifestation of hepatitis C virus (HCV) infection is mixed cryoglobulinemia (MC). MC is characterised by the presence of temperature-sensitive protein complexes: in type II MC, cryoglobulins are composed of a monoclonal rheumatoid factor (usually, IgMkappa) against polyclonal IgG. In type III MC, all components are polyclonal. The presence of microheterogeneity and other new types of cryoglobulins is a novel and recent observation. The production of different autoantibodies and circulating immune complexes, including the cryoglobulins, are responsible for systemic vasculitis and various organ damage. In a limited number of MC patients, a malignancy, that is B-cell non-Hodgkin's lymphoma or hepatocellular carcinoma, may also develop. Finally, results of interferon and/or ribavirin treatments in MC patients represent an indirect proof for the pathogenetic link between MC and HVC infection. The discovery of the relation between HCV infection and MC shows the striking association between a viral infection and an autoimmune disease and, thus, a potential link between the systemic autoimmune and lymphoproliferative disorders.

  11. Measures on mixing angles

    SciTech Connect

    Gibbons, Gary W.; Gielen, Steffen; Pope, C. N.; Turok, Neil

    2009-01-01

    We address the problem of the apparently very small magnitude of CP violation in the standard model, measured by the Jarlskog invariant J. In order to make statements about probabilities for certain values of J, we seek to find a natural measure on the space of Kobayashi-Maskawa matrices, the double quotient U(1){sup 2}/SU(3)/U(1){sup 2}. We review several possible, geometrically motivated choices of the measure, and compute expectation values for powers of J for these measures. We find that different choices of the measure generically make the observed magnitude of CP violation appear finely tuned. Since the quark masses and the mixing angles are determined by the same set of Yukawa couplings, we then do a second calculation in which we take the known quark mass hierarchy into account. We construct the simplest measure on the space of 3x3 Hermitian matrices which reproduces this known hierarchy. Calculating expectation values for powers of J in this second approach, we find that values of J close to the observed value are now rather likely, and there does not seem to be any fine-tuning. Our results suggest that the choice of Kobayashi-Maskawa angles is closely linked to the observed mass hierarchy. We close by discussing the corresponding case of neutrinos.

  12. Neutrino Masses and Mixing

    SciTech Connect

    Ishikawa, K.; Tobita, Y.

    2008-05-21

    We report (1) the current status of neutrino parameters and (2) our recent work on implications of particle's coherence, which are weakly related each others. In the first part, current status of the neutrino parameters obtained from oscillation experiments and their prospects are briefly reviewed. From various oscillation experiments, existence of three mass scales have been confirmed. One value of the difference of mass squared is around 10{sup -3}eV{sup 2} and another is around 10{sup -5}eV{sup 2}. Although mixing angles are partly found, one important angle, {theta}{sub 13} is left unknown.In the second part, implications of coherence length of particles in the scattering of ultra-high energy cosmic rays (UHCR) with cosmic background radiations (CBR) is discussed. Although coherence length is regarded usually irrelevant to observations, its role is important in several situations of recent experiments which include that of the ultra-high energy charged particles. Here we discuss the scattering of UHCR with CBR.

  13. Postictal mixed transcortical aphasia.

    PubMed

    Yankovsky, A E; Treves, T A

    2002-06-01

    Postictal aphasia has been described in left temporal lobe seizures. It may be of fluent, non-fluent or global type. We present here a patient who displayed signs of mixed transcortical aphasia (MTCA). The patient was a 67 year old man who underwent excision of a left frontal parasagittal meningioma in 1987. Since then he has been treated with phenytoin for generalized tonic-clonic seizures (GTCS). He was admitted in status epilepticus. On awakening, the patient was non-fluent with palilalia and echolalia. His repetition was relatively preserved but all the other language functions were impaired. This picture faded away within a few hours. Brain CT, performed during this postictal state, was normal except for signs related to frontal craniotomy. SPECT, which was performed after language functions returned to normal, displayed left frontal, cingular and insular hypoperfusion. The postictal language dysfunction of the patient corresponded to MTCA. Although our case has frontal, he had no other structural lesion that could explain either diffuse ischemia of the left hemisphere or watershed areas secondary to the generalized seizures. The uniqueness of this case is the combination of postictal MTCA with good prognosis. Copyright 2002 BEA Trading Ltd. Published by Elsevier Science Ltd. All rights reserved.

  14. Mixed oxide fuel development

    SciTech Connect

    Leggett, R.D.; Omberg, R.P.

    1987-05-08

    This paper describes the success of the ongoing mixed-oxide fuel development program in the United States aimed at qualifying an economical fuel system for liquid metal cooled reactors. This development has been the cornerstone of the US program for the past 20 years and has proceeded in a deliberate and highly disciplined fashion with high emphasis on fuel reliability and operational safety as major features of an economical fuel system. The program progresses from feature testing in EBR-II to qualifying full size components in FFTF under fully prototypic conditions to establish a basis for extending allowable lifetimes. The development program started with the one year (300 EFPD) core, which is the FFTF driver fuel, continued with the demonstration of a two year (600 EFPD) core and is presently evaluating a three year (900 EFPD) fuel system. All three of these systems, consistent with other LMR fuel programs around the world, use fuel pellets gas bonded to a cladding tube that is assembled into a bundle and fitted into a wrapper tube or duct for ease of insertion into a core. The materials of construction progressed from austenitic CW 316 SS to lower swelling austenitic D9 to non swelling ferritic/martensitic HT9. 6 figs., 2 tabs.

  15. Multivariate multilevel nonlinear mixed effects models for timber yield predictions.

    PubMed

    Hall, Daniel B; Clutter, Michael

    2004-03-01

    Nonlinear mixed effects models have become important tools for growth and yield modeling in forestry. To date, applications have concentrated on modeling single growth variables such as tree height or bole volume. Here, we propose multivariate multilevel nonlinear mixed effects models for describing several plot-level timber quantity characteristics simultaneously. We describe how such models can be used to produce future predictions of timber volume (yield). The class of models and methods of estimation and prediction are developed and then illustrated on data from a University of Georgia study of the effects of various site preparation methods on the growth of slash pine (Pinus elliottii Engelm.).

  16. Optical and electrical studies of cerium mixed oxides

    SciTech Connect

    Sherly, T. R.; Raveendran, R.

    2014-10-15

    The fast development in nanotechnology makes enthusiastic interest in developing nanomaterials having tailor made properties. Cerium mixed oxide materials have received great attention due to their UV absorption property, high reactivity, stability at high temperature, good electrical property etc and these materials find wide applications in solid oxide fuel cells, solar control films, cosmetics, display units, gas sensors etc. In this study cerium mixed oxide compounds were prepared by co-precipitation method. All the samples were doped with Zn (II) and Fe (II). Preliminary characterizations such as XRD, SEM / EDS, TEM were done. UV - Vis, Diffuse reflectance, PL, FT-IR, Raman and ac conductivity studies of the samples were performed.

  17. Optical and electrical studies of cerium mixed oxides

    NASA Astrophysics Data System (ADS)

    Sherly, T. R.; Raveendran, R.

    2014-10-01

    The fast development in nanotechnology makes enthusiastic interest in developing nanomaterials having tailor made properties. Cerium mixed oxide materials have received great attention due to their UV absorption property, high reactivity, stability at high temperature, good electrical property etc and these materials find wide applications in solid oxide fuel cells, solar control films, cosmetics, display units, gas sensors etc. In this study cerium mixed oxide compounds were prepared by co-precipitation method. All the samples were doped with Zn (II) and Fe (II). Preliminary characterizations such as XRD, SEM / EDS, TEM were done. UV - Vis, Diffuse reflectance, PL, FT-IR, Raman and ac conductivity studies of the samples were performed.

  18. Mixed-mode chromatography and its applications to biopolymers.

    PubMed

    Yang, Yun; Geng, Xindu

    2011-12-09

    Mixed-mode chromatography is a type of chromatography in which a chromatographic stationary phase interacts with solutes through more than one interaction mode. This technique has been growing rapidly because of its advantages over conventional chromatography, such as its high resolution, high selectivity, high sample loading, high speed, and the ability to replace two conventionally corresponding columns in certain circumstances. In this work, some aspects of the development of mixed-mode chromatography are reviewed, such as stationary phase preparation, combinations of various separation modes, separation mechanisms, typical applications to biopolymers and peptides, and future prospects. Copyright © 2011 Elsevier B.V. All rights reserved.

  19. Mixing in polymeric microfluidic devices.

    SciTech Connect

    Schunk, Peter Randall; Sun, Amy Cha-Tien; Davis, Robert H.; Brotherton, Christopher M. (University of Colorado at Boulder, Boulder, CO)

    2006-04-01

    This SAND report describes progress made during a Sandia National Laboratories sponsored graduate fellowship. The fellowship was funded through an LDRD proposal. The goal of this project is development and characterization of mixing strategies for polymeric microfluidic devices. The mixing strategies under investigation include electroosmotic flow focusing, hydrodynamic focusing, physical constrictions and porous polymer monoliths. For electroosmotic flow focusing, simulations were performed to determine the effect of electroosmotic flow in a microchannel with heterogeneous surface potential. The heterogeneous surface potential caused recirculations to form within the microchannel. These recirculations could then be used to restrict two mixing streams and reduce the characteristic diffusion length. Maximum mixing occurred when the ratio of the mixing region surface potential to the average channel surface potential was made large in magnitude and negative in sign, and when the ratio of the characteristic convection time to the characteristic diffusion time was minimized. Based on these results, experiments were performed to evaluate the manipulation of surface potential using living-radical photopolymerization. The material chosen to manipulate typically exhibits a negative surface potential. Using living-radical surface grafting, a positive surface potential was produced using 2-(Dimethylamino)ethyl methacrylate and a neutral surface was produced using a poly(ethylene glycol) surface graft. Simulations investigating hydrodynamic focusing were also performed. For this technique, mixing is enhanced by using a tertiary fluid stream to constrict the two mixing streams and reduce the characteristic diffusion length. Maximum mixing occurred when the ratio of the tertiary flow stream flow-rate to the mixing streams flow-rate was maximized. Also, like the electroosmotic focusing mixer, mixing was also maximized when the ratio of the characteristic convection time to the

  20. Anomalous Sediment Mixing by Bioturbation

    NASA Astrophysics Data System (ADS)

    Roche, K. R.; Aubeneau, A. F.; Xie, M.; Packman, A. I.

    2013-12-01

    Bioturbation, the reworking of sediments by animals and plants, is the dominant mode of sediment mixing in low-energy environments, and plays an important role in sedimentary biogeochemical processes. Mixing resulting from bioturbation has historically been modeled as a diffusive process. However, diffusion models often do not provide a sufficient description of sediment mixing due to bioturbation. Stochastic models, such as the continuous time random walk (CTRW) model, provide more general descriptions of mixing behavior that are applicable even when regular diffusion assumptions are not met. Here we present results from an experimental investigation of anomalous sediment mixing by bioturbation in freshwater sediments. Clean and heavy-metal-contaminated sediments were collected from Lake DePue, a backwater lake of the Illinois River. The burrowing worm species Lumbriculus variegatus was introduced to homogenized Lake DePue sediments in aerated aquaria. We then introduced inert fine fluorescent particles to the sediment-water interface. Using time-lapse photography, we observed the mixing of the fluorescent particles into the sediment bed over a two-week period. We developed image analysis software to characterize the concentration distribution of the fluorescent particles as a function of sediment depth, and applied this to the time-series of images to evaluate sediment mixing. We fit a one-dimensional CTRW model to the depth profiles to evaluate the underlying statistical properties of the mixing behavior. This analysis suggests that the sediment mixing caused by L. variegatus burrowing is subdiffusive in time and superdiffusive in space. We also found that heavy metal contamination significantly reduces L. variegatus burrowing, causing increasingly anomalous sediment mixing. This result implies that there can be important feedbacks between sediment chemistry, organism behavior, and sediment mixing that are not considered in current environmental models.

  1. Innovative Equipment and Production Method for Mixed Fodder in the Conditions of Agricultural Enterprises

    NASA Astrophysics Data System (ADS)

    Sabiev, U. K.; Demchuk, E. V.; Myalo, V. V.; Soyunov, A. S.

    2017-07-01

    It is recommended to feed the cattle and poultry with grain fodder in the form of feed mixture balanced according to the content. Feeding of grain fodder in the form of stock feed is inefficient and economically unreasonable. The article is devoted to actual problem - the preparation of mixed fodder in the conditions of agricultural enterprises. Review and critical analyses of mixed fodder assemblies and aggregates are given. Structural and technical schemes of small-size mixed fodder aggregate with intensified attachments of vibrating and percussive action for preparation of bulk feed mixture in the conditions of agricultural enterprises were developed. The mixed fodder aggregate for its preparation in the places of direct consumption from own grain fodder production and purchased protein and vitamin supplements is also suggested. Mixed fodder aggregate allows to get prepared mixed fodder of high uniformity at low cost of energy and price of production that is becoming profitable for livestock breeding. Model line-up of suggested mixed fodder aggregate with different productivity both for small and big agricultural enterprises is considered.

  2. Target preparation techniques for PIXE and XRF

    NASA Astrophysics Data System (ADS)

    de Rooij, F. A. J.; Kivits, H. P. M.; Castelijns, C. A. M.; Wijnhoven, G. P. J.; de Goeij, J. J. M.

    1981-03-01

    For PIXE and XRF fast, simple and reproducible target preparation techniques for liquid and solid samples have been developed. Liquids which behave like a real solution are mixed with an alcohol. Aliquots of 50 μl are dispensed on a rotating (18 000 rpm) cellulose acetate filter and air dried afterwards (preparation times less than 1 min). By changing the physical behaviour of suspensions into that of a real solution, this target preparation technique may also be used for suspensions: blood, for instance, after pretreatment with NaOH. The resulting targets are homogeneous (inhomogeneity less than 2%) and uniform (non-uniformity less than 3%). It is shown that trace-element losses may occur during irradiation. These losses can be prevented by adequate fixation or sealing procedures which do not deteriorate the original homogeneity and uniformity. For pulverised solid samples a thin target preparation technique is developed. Pulverised solid material (particle size below 10 μm) is mixed with a Formvar-dioxane solution. Aliquots of 200 μl are dispensed on a water wetted rotating cellulose acetate filter. Afterwards the resulting Formvar foil (less than 1 mg/cm 2), in which the solid sample is embedded, is pulled from the filter.

  3. International perspectives on coal preparation

    SciTech Connect

    1997-12-31

    The report consists of the vugraphs from the presentations which covered the following topics: Summaries of the US Department of Energy`s coal preparation research programs; Preparation trends in Russia; South African coal preparation developments; Trends in hard coal preparation in Germany; Application of coal preparation technology to oil sands extraction; Developments in coal preparation in China; and Coal preparation in Australia.

  4. Microfluidic mixing using contactless dielectrophoresis.

    PubMed

    Salmanzadeh, Alireza; Shafiee, Hadi; Davalos, Rafael V; Stremler, Mark A

    2011-09-01

    The first experimental evidence of mixing enhancement in a microfluidic system using contactless dielectrophoresis (cDEP) is presented in this work. Pressure-driven flow of deionized water containing 0.5 μm beads was mixed in various chamber geometries by imposing a dielectrophoresis (DEP) force on the beads. In cDEP the electrodes are not in direct contact with the fluid sample but are instead capacitively coupled to the mixing chamber through thin dielectric barriers, which eliminates many of the problems encountered with standard DEP. Four system designs with rectangular and circular mixing chambers were fabricated in PDMS. Mixing tests were conducted for flow rates from 0.005 to 1 mL/h subject to an alternating current signal range of 0-300 V at 100-600 kHz. When the time scales of the bulk fluid motion and the DEP motion were commensurate, rapid mixing was observed. The rectangular mixing chambers were found to be more efficient than the circular chambers. This approach shows potential for mixing low diffusivity biological samples, which is a very challenging problem in laminar flows at small scales.

  5. Iowa City Ready Mix, Inc.

    EPA Pesticide Factsheets

    The EPA is providing notice of a proposed Administrative Penalty Assessment against Iowa City Ready Mix, Inc., for alleged violations at a facility located at 1854 South Riverside, Iowa City, IA (“facility”). The facility produces and transports ready mixe

  6. Mixed Waste Working Group report

    SciTech Connect

    Not Available

    1993-11-09

    The treatment of mixed waste remains one of this country`s most vexing environmental problems. Mixed waste is the combination of radioactive waste and hazardous waste, as defined by the Resource Conservation and Recovery Act (RCRA). The Department of Energy (DOE), as the country`s largest mixed waste generator, responsible for 95 percent of the Nation`s mixed waste volume, is now required to address a strict set of milestones under the Federal Facility Compliance Act of 1992. DOE`s earlier failure to adequately address the storage and treatment issues associated with mixed waste has led to a significant backlog of temporarily stored waste, significant quantities of buried waste, limited permanent disposal options, and inadequate treatment solutions. Between May and November of 1993, the Mixed Waste Working Group brought together stakeholders from around the Nation. Scientists, citizens, entrepreneurs, and bureaucrats convened in a series of forums to chart a course for accelerated testing of innovative mixed waste technologies. For the first time, a wide range of stakeholders were asked to examine new technologies that, if given the chance to be tested and evaluated, offer the prospect for better, safer, cheaper, and faster solutions to the mixed waste problem. In a matter of months, the Working Group has managed to bridge a gap between science and perception, engineer and citizen, and has developed a shared program for testing new technologies.

  7. Mixed-Methods Research Methodologies

    ERIC Educational Resources Information Center

    Terrell, Steven R.

    2012-01-01

    Mixed-Method studies have emerged from the paradigm wars between qualitative and quantitative research approaches to become a widely used mode of inquiry. Depending on choices made across four dimensions, mixed-methods can provide an investigator with many design choices which involve a range of sequential and concurrent strategies. Defining…

  8. Preparation and characterization of low-temperature expandable graphite

    SciTech Connect

    Ying Zongrong Lin Xuemei; Qi Yu; Luo Jie

    2008-10-02

    The low-temperature expandable graphite was successfully prepared with perchloric acid, phosphoric acid and KMnO{sub 4} by chemical process. The optimum weight ratio of perchloric acid to phosphoric acid in mixed acid was 1:0.2, and the weight ratio of the mixed acid, KMnO{sub 4} and natural flake graphite was preferably 1.5:0.1:1. The expanded volume can reach 260 mL/g at a relatively low temperature of 300 deg. C. Meanwhile, the prepared samples were characterized by means of Fourier transform infrared, thermogravimetry-differential scanning calorimetry and X-ray diffraction.

  9. Electrochemical slurry compositions and methods for preparing the same

    SciTech Connect

    Doherty, Tristan; Limthongkul, Pimpa; Butros, Asli; Duduta, Mihai; Cross, III, James C.

    2016-11-01

    Embodiments described herein generally relate to semi-solid suspensions, and more particularly to systems and methods for preparing semi-solid suspensions for use as electrodes in electrochemical devices such as, for example batteries. In some embodiments, a method for preparing a semi-solid electrode includes combining a quantity of an active material with a quantity of an electrolyte to form an intermediate material. The intermediate material is then combined with a conductive additive to form an electrode material. The electrode material is mixed to form a suspension having a mixing index of at least about 0.80 and is then formed into a semi-solid electrode.

  10. Mixed connective tissue disease.

    PubMed

    Gunnarsson, Ragnar; Hetlevik, Siri Opsahl; Lilleby, Vibke; Molberg, Øyvind

    2016-02-01

    The concept of mixed connective tissue disease (MCTD) as a separate connective tissue disease (CTD) has persisted for more than four decades. High titers of antibodies targeting the U1 small nuclear ribonucleoprotein particle (U1 snRNP) in peripheral blood are a sine qua non for the diagnosis of MCTD, in addition to distinct clinical features including Raynaud's phenomenon (RP), "puffy hands," arthritis, myositis, pleuritis, pericarditis, interstitial lung disease (ILD), and pulmonary hypertension (PH). Recently, population-based epidemiology data from Norway estimated the point prevalence of adult-onset MCTD to be 3.8 per 100,000 and the mean annual incidence to be 2.1 per million per year, supporting the notion that MCTD is the least common CTD. Little is known about the etiology of MCTD, but recent genetic studies have confirmed that MCTD is a strongly HLA (​human leukocyte antigen)-linked disease, as the HLA profiles of MCTD differ distinctly from the corresponding profiles of ethnically matched healthy controls and other CTDs. In the first section of this review, we provide an update on the clinical, immunological, and genetic features of MCTD and discuss the relationship between MCTD and the other CTDs. Then we proceed to discuss the recent advances in therapy and our current understanding of prognosis and prognostic factors, especially those that are associated with the more serious pulmonary and cardiovascular complications of the disease. In the final section, we discuss some of the key, unresolved questions related to anti-RNP-associated diseases and indicate how these questions may be approached in future studies.

  11. Effect of Cement on Properties of Over-Burnt Brick Bituminous Concrete Mixes

    NASA Astrophysics Data System (ADS)

    Sarkar, Dipankar; Pal, Manish

    2016-06-01

    The present investigation is carried out to propose the use of cement coated over burnt brick aggregate in the preparation of bituminous concrete mix. The effect of cement on various mechanical properties such as Marshall stability, flow, Marshall quotient (stability to flow ratio), indirect tensile strength, stripping, rutting and fatigue life of bituminous concrete overlay has been evaluated. In this study, different cement percentages such as 2, 3, 4 and 5 % by weight of aggregate have been mixed with Over Burnt Brick Aggregate (OBBA). The laboratory results indicate that bituminous concrete prepared by 4 % cement coated OBBA gives the highest Marshall stability. The bituminous concrete mix with 4 % cement shows considerable improvement in various mechanical properties of the mix compared to the plain OBBA concrete mix.

  12. Biomass conversion to mixed alcohols

    SciTech Connect

    Holtzapple, M.T.; Loescher, M.; Ross, M.

    1996-10-01

    This paper discusses the MixAlco Process which converts a wide variety of biomass materials (e.g. municipal solid waste, sewage sludge, agricultural residues) to mixed alcohols. First, the biomass is treated with lime to enhance its digestibility. Then, a mixed culture of acid-forming microorganisms converts the lime-treated biomass to volatile fatty acids (VFA) such as acetic, propionic, and butyric acids. To maintain fermentor pH, a neutralizing agent (e.g. calcium carbonate or lime) is added, so the fermentation actually produces VFA salts such as calcium acetate, propionate, and butyrate. The VFA salts are recovered and thermally converted to ketones (e.g. acetone, methylethyl ketone, diethyl ketone) which are subsequently hydrogenated to mixed alcohols (e.g. isopropanol, isobutanol, isopentanol). Processing costs are estimated at $0.72/gallon of mixed alcohols making it potentially attractive for transportation fuels.

  13. CHARACTERIZING PULSATING MIXING OF SLURRIES

    SciTech Connect

    Bamberger, Judith A.; Meyer, Perry A.

    2007-12-01

    This paper describes the physical properties for defining the operation of a pulse jet mixing system. Pulse jet mixing operates with no moving parts located in the vessel to be mixed. Pulse tubes submerged in the vessel provide a pulsating flow due to a controlled combination of applied pressure to expel the fluid from the pulse tube nozzle followed by suction to refill the pulse tube through the same nozzle. For mixing slurries nondimensional parameters to define mixing operation include slurry properties, geometric properties and operational parameters. Primary parameters include jet Reynolds number and Froude number; alternate parameters may include particle Galileo number, particle Reynolds number, settling velocity ratio, and hindered settling velocity ratio. Rating metrics for system performance include just suspended velocity, concentration distribution as a function of elevation, and blend time.

  14. Mixing in confined stratified aquifers

    NASA Astrophysics Data System (ADS)

    Bolster, Diogo; Valdés-Parada, Francisco J.; LeBorgne, Tanguy; Dentz, Marco; Carrera, Jesus

    2011-03-01

    Spatial variability in a flow field leads to spreading of a tracer plume. The effect of microdispersion is to smooth concentration gradients that exist in the system. The combined effect of these two phenomena leads to an 'effective' enhanced mixing that can be asymptotically quantified by an effective dispersion coefficient (i.e. Taylor dispersion). Mixing plays a fundamental role in driving chemical reactions. However, at pre-asymptotic times it is considerably more difficult to accurately quantify these effects by an effective dispersion coefficient as spreading and mixing are not the same (but intricately related). In this work we use a volume averaging approach to calculate the concentration distribution of an inert solute release at pre-asymptotic times in a stratified formation. Mixing here is characterized by the scalar dissipation rate, which measures the destruction of concentration variance. As such it is an indicator for the degree of mixing of a system. We study pre-asymptotic solute mixing in terms of explicit analytical expressions for the scalar dissipation rate and numerical random walk simulations. In particular, we divide the concentration field into a mean and deviation component and use dominant balance arguments to write approximate governing equations for each, which we then solve analytically. This allows us to explicitly evaluate the separate contributions to mixing from the mean and the deviation behavior. We find an approximate, but accurate expression (when compared to numerical simulations) to evaluate mixing. Our results shed some new light on the mechanisms that lead to large scale mixing and allow for a distinction between solute spreading, represented by the mean concentration, and mixing, which comes from both the mean and deviation concentrations, at pre-asymptotic times.

  15. Baroclinic mixing in HE fireballs

    SciTech Connect

    Kuhl, A.L.; Ferguson, R.E.; Priolo, F.; Chien, K.Y.; Collins, J.P.

    1993-08-01

    Numerical simulations of the turbulent mixing in the fireball of an HE blast wave were performed with a second-order Godunov code. Adaptive mesh refinement was used to capture the convective mixing processes on the computational grid. The calculations revealed that the interface between the shock-compressed air and the dense detonation products was unstable. Vorticity was generated in that region by baroclinic effects. This caused the interface to roll-up into a turbulent mixing layer. Four phases of mixing were identified: a strong blast wave phase, where the mixing region was swept outward by the shockinduced flow; an implosion phase, that stretched the inner boundary of the mixing region back toward the origin; a re-shocking phase, where the imploding shock expands back outward from the origin and re-energizes the mixing later by RichtmyerMeshkov effects; and an asymptotic mixing phase, where line-scale structures are continually recreated by folding effects but the overall vorticity decays through a cascade process. The flowfield was azimuthally averaged to evaluate the mean-flow profiles and r.m.s. fluctuation profiles across the mixing layer. The mean kinetic energy rapidly approached zero as the blast wave decayed, but the fluctuating kinetic energy asymptotically approached a small constant value. This represents the rotational kinetic energy driven by the vorticity field, that continued to mix the fluid at late times. It was shown that the vorticity field corresponds to a function that fluctuates between plus and minus values-with a volume-averaged mean of zero.

  16. Preparation of superconductor precursor powders

    DOEpatents

    Bhattacharya, Raghunath; Blaugher, Richard D.

    1995-01-01

    A process for the preparation of a precursor metallic powder composition for use in the subsequent formation of a superconductor. The process comprises the steps of providing an electrodeposition bath comprising an electrolyte medium and a cathode substrate electrode, and providing to the bath one or more soluble salts of one or more respective metals, such as nitrate salts of thallium, barium, calcium, and copper, which are capable of exhibiting superconductor properties upon subsequent appropriate treatment. The bath is continually energized to cause the metallic particles formed at the electrode to drop as a powder from the electrode into the bath, and this powder, which is a precursor powder for superconductor production, is recovered from the bath for subsequent treatment. The process permits direct inclusion of thallium in the preparation of the precursor powder, and yields an amorphous product mixed on an atomic scale to thereby impart inherent high reactivity. Superconductors which can be formed from the precursor powder include pellet and powder-in-tube products.

  17. Preparation of superconductor precursor powders

    DOEpatents

    Bhattacharya, R.

    1998-08-04

    A process for the preparation of a precursor metallic powder composition for use in the subsequent formation of a superconductor. The process comprises the steps of providing an electrodeposition bath comprising an electrolyte medium and a cathode substrate electrode, and providing to the bath one or more soluble salts of one or more respective metals which are capable of exhibiting superconductor properties upon subsequent appropriate treatment. The bath is continually energized to cause the metallic and/or reduced particles formed at the electrode to drop as a powder from the electrode into the bath, and this powder, which is a precursor powder for superconductor production, is recovered from the bath for subsequent treatment. The process permits direct inclusion of all metals in the preparation of the precursor powder, and yields an amorphous product mixed on an atomic scale to thereby impart inherent high reactivity. Superconductors which can be formed from the precursor powder include pellet and powder-in-tube products. 7 figs.

  18. Mixing In a Compounding Pharmacy in the 21st Century.

    PubMed

    Standridge, Rob

    2015-01-01

    When it comes to combining ingredients for topical preparations, compounding pharmacists utilize either the manual methods such as a spatula and pill tile or a mortar and pestle, typically an electronic mortar and pestle. If a topical preparation must be pre-ground or requires trituration, or any level of particle-size reduction, historically the manual method of combining ingredients in such a preparation would include the initial use of a mortar and pestle; however with micronized substances this is not as much a concern today as in the past. There is, of course, the concern of a lack of reproducibility, knowing that each compounder might utilize the equipment differently, would mix for varying times, and would also mix with varying amounts of physical pressure applied to the pestle. If the discipline of uniform usage is great enough in the lab, this method could probably produce consistent results, but, because of the preparation and cleanup time and the fact that newer technology is available, this method is not recommended as the common compounding method in a compounding pharmacy that does more than a handful of compounded topical preparations per week. This article is not meant to say these methods are not appropriate, but, rather, to point out that newer technology is available and might be preferable in order to provide a cleaner, more efficient, and more reproducible lab environment.

  19. Potential of fire extinguisher powder as a filler in bituminous mixes.

    PubMed

    Praticò, Filippo Giammaria; Moro, Antonino; Ammendola, Rachele

    2010-01-15

    Fire extinguishers must be maintained at regular intervals and many problems arise when fire-resistant dry powders need replacement. We analyze the potential of fire extinguisher powder (termed REP) as a filler in bituminous mixes. REP and REP-admixed bituminous mixes were subjected to chemical analysis, and the mechanical properties and environmental performances of the mixes were tested. Mixes with different REP contents were prepared. Mechanical performance was adequate and environmental compatibility was achieved. Practical applications and perspectives in rehabilitation, maintenance, and research are outlined.

  20. Determination of Stability from Multicomponent Pesticide Mixes.

    PubMed

    Dorweiler, Kelly J; Gurav, Jagdish N; Walbridge, James S; Ghatge, Vishwas S; Savant, Rahul H

    2016-08-10

    A study was conducted to evaluate the stability of 528 pesticides, metabolites, and contaminants prepared in large multicomponent mixes to enhance laboratory efficiency by allowing maximum use of the useful shelf life of the mixtures. Accelerated aging at 50 °C simulated 6 month, 1 year, and 2 year storage periods at -20 °C. Initial mixture composition was based on the instrument of analysis. After preliminary stability data had been obtained, mixtures were reformulated and re-evaluated. In all, 344 compounds showed satisfactory stability across all treatment groups, 100 compounds showed statistically significant changes between the control and the 6 month simulated storage period (27 with losses >20%), and the remainder showed borderline stability or were tested in one protocol. Stability behavior for organophosphates agreed with the proposed reaction mechanism responsible for acetylcholinesterase inhibition. A small number of compounds increased in response over time, suggesting the occurrence of degradation of precursor pesticides into these respective compounds.

  1. Practical recommendations for mixing allergy immunotherapy extracts

    PubMed Central

    Daigle, Barbara J.

    2015-01-01

    Critical aspects of formulating allergy immunotherapy vaccines include the selection, total number, and proportions of each allergen component in therapeutic mixtures. The immunotherapy prescription, determined by a medical provider, details the dosing and schedule for treatment as well as the specific composition of the treatment vials. Allergen extracts are composed of many components such as proteins, glycoproteins, and proteases. Some components in allergen extracts are cross-reactive, meaning that treatment with an extract from one species may confer partial protection against a triggering allergen from another species. Conversely, some allergen extracts are incompatible with other extracts when combined in a mixture for treatment, resulting in lowered therapeutic potential for the patient. Therefore, knowledge of allergen extract cross-reactivities and incompatibilities guides the preparation of subcutaneous immunotherapy prescriptions. In a clinical setting, an understanding of what can and can not be mixed is one critical element in improving treatment outcomes. PMID:25860164

  2. Turbidity Current Head Mixing

    NASA Astrophysics Data System (ADS)

    Hernandez, David; Sanchez, Miguel Angel; Medina, Pablo

    2010-05-01

    coastal diffusion using image analysis. Applied Scientific Research 59,.191-204. 1998. [5] J.M. Redondo. Turbulent mixing in the Atmosphere and Ocean. Fluid Physics. 584-597. World Scientific. New York. 1994

  3. Nano-emulsions prepared by the phase inversion composition method: preparation variables and scale up.

    PubMed

    Solè, Isabel; Pey, Carmen M; Maestro, Alicia; González, Carmen; Porras, Montserrat; Solans, Conxita; Gutiérrez, José M

    2010-04-15

    The aim of this work is to study, through experimental design, the effect of vessel geometry and scale-up in the properties of nano-emulsions prepared through the phase inversion composition method (PIC). Results show that a proper mixing is crucial for small droplet-sized nano-emulsions, especially when remaining free oil is found together with the key liquid crystal phase formed during the emulsification process. In these cases, mixing must be near the perfect mixed model. Proper geometries must be selected to promote a good mixture. Small addition rates V(ad) and high mixing rates omega promote the necessary mixing level. However, results indicate that, if free oil remains together with liquid crystal formed during emulsification, a too high omega could promote coalescence of oil droplets. When a cubic liquid crystal phase Pm3n is formed instead during emulsification, without free oil, coalescence is not promoted, probably due to the extremely high viscosity. For the system where Pm3n is formed during emulsification, scale-up cannot be done, as it would be expected, maintaining adimensional variables--Reynolds, Re, and adimensional time. A perfect correspondence between scales is observed when the total addition time and the lineal mixing rate are maintained between scales instead. Re, i.e. the ratio between inertial and viscous forces, does not seem adequate to describe the system, as inertial forces are worthless due to the extremely high viscosity.

  4. Compressibility effects on turbulent mixing

    NASA Astrophysics Data System (ADS)

    Panickacheril John, John; Donzis, Diego

    2016-11-01

    We investigate the effect of compressibility on passive scalar mixing in isotropic turbulence with a focus on the fundamental mechanisms that are responsible for such effects using a large Direct Numerical Simulation (DNS) database. The database includes simulations with Taylor Reynolds number (Rλ) up to 100, turbulent Mach number (Mt) between 0.1 and 0.6 and Schmidt number (Sc) from 0.5 to 1.0. We present several measures of mixing efficiency on different canonical flows to robustly identify compressibility effects. We found that, like shear layers, mixing is reduced as Mach number increases. However, data also reveal a non-monotonic trend with Mt. To assess directly the effect of dilatational motions we also present results with both dilatational and soleniodal forcing. Analysis suggests that a small fraction of dilatational forcing decreases mixing time at higher Mt. Scalar spectra collapse when normalized by Batchelor variables which suggests that a compressive mechanism similar to Batchelor mixing in incompressible flows might be responsible for better mixing at high Mt and with dilatational forcing compared to pure solenoidal mixing. We also present results on scalar budgets, in particular on production and dissipation. Support from NSF is gratefully acknowledged.

  5. Langmuir Mixing Affects Global Climate

    NASA Astrophysics Data System (ADS)

    Li, Q.; Webb, A.; Fox-Kemper, B.; Arbetter, T. E.; Craig, A.; Danabasoglu, G.; Large, W.; Vertenstein, M.

    2016-02-01

    The effects of Langmuir turbulence on the surface ocean mixing and thereby the global climate are assessed in the CESM earth system model by adding a parameterization of Langmuir mixing to the K-Profile Parameterization (KPP). A global wave field is needed by this Langmuir mixing parameterization to provide the Stokes drift that drives Langmuir mixing. Both a prognostic wave model, WAVEWATCH III, and a climatological data wave model have been coupled with CESM and tested. Nearly identical and substantial improvements in the simulated mixed layer depth and intermediate water ventilation are found in both cases when Langmuir mixing is included. The greatest improvement occurs in the Southern Ocean. A climatological data wave model, which responds to simulated winds, but with fixed wind-wave relationships, can therefore reproduce the primary improvements of Langmuir mixing, but with much less computational cost than even a coarse-resolution prognostic wave model. Progress toward an improved wave-induced entrainment through the bottom of ocean surface boundary layer will also be discussed.

  6. Mixed features in bipolar disorder.

    PubMed

    Solé, Eva; Garriga, Marina; Valentí, Marc; Vieta, Eduard

    2016-12-29

    Mixed affective states, defined as the coexistence of depressive and manic symptoms, are complex presentations of manic-depressive illness that represent a challenge for clinicians at the levels of diagnosis, classification, and pharmacological treatment. The evidence shows that patients with bipolar disorder who have manic/hypomanic or depressive episodes with mixed features tend to have a more severe form of bipolar disorder along with a worse course of illness and higher rates of comorbid conditions than those with non-mixed presentations. In the updated Diagnostic and Statistical Manual of Mental Disorders (5th ed.; DSM-5), the definition of "mixed episode" has been removed, and subthreshold nonoverlapping symptoms of the opposite pole are captured using a "with mixed features" specifier applied to manic, hypomanic, and major depressive episodes. However, the list of symptoms proposed in the DSM-5 specifier has been widely criticized, because it includes typical manic symptoms (such as elevated mood and grandiosity) that are rare among patients with mixed depression, while excluding symptoms (such as irritability, psychomotor agitation, and distractibility) that are frequently reported in these patients. With the new classification, mixed depressive episodes are three times more common in bipolar II compared with unipolar depression, which partly contributes to the increased risk of suicide observed in bipolar depression compared to unipolar depression. Therefore, a specific diagnostic category would imply an increased diagnostic sensitivity, would help to foster early identification of symptoms and ensure specific treatment, as well as play a role in suicide prevention in this population.

  7. Mixed Hydrotropy: Novel Science of Solubility Enhancement

    PubMed Central

    Maheshwari, R. K.; Jagwani, Y.

    2011-01-01

    Conventional furosemide tablets are practically insoluble in water, have slow onset of action (45-60 min) and poor bioavailability (39-53%), and therefore cannot be given in emergency clinical situations like hypertension or pulmonary edema. So purpose of research was to provide a fast dissolving oral dosage form of furosemide, which can provide quick onset of action by using concept of mixed hydrotropy. Initially solubility of furosemide was determined individually in 4 hydrotropic agents namely urea, sodium acetate, sodium benzoate, sodium citrate at concentration of 10, 20, 30 and 40% w/v solutions using purified water as solvent. Highest solubility was obtained in 40% sodium benzoate solution. Then different combinations of 2, 3 and 4 hydrotropic agents in different ratios were used to determine solubility, so that total concentration of hydrotropic agents was always 40%. Highest solubility was obtained in solution of urea+sodium benzoate+sodium citrate at optimum ratio of 15:20:5. This optimized combination was utilized in preparing solid dispersions by common solvent technique using distilled water as solvent. Solid dispersions were evaluated for flow properties, XRD, DSC, SEM and were also compressed to form tablets. Dissolution studies of conventional and prepared tablets were done using USP Type II apparatus. It was concluded that the concept of mixed hydrotropic solid dispersion is novel, safe and cost-effective technique for enhancing bioavailability of poorly water-soluble drugs by dissolving drug in nonionized form. The magical enhancement in solubility of furosemide is clear indication of its potential to be used in future for other poorly water-soluble drugs in which low bioavailability is major concern. PMID:22303061

  8. Mapping the Mixed Methods–Mixed Research Synthesis Terrain

    PubMed Central

    Sandelowski, Margarete; Voils, Corrine I.; Leeman, Jennifer; Crandell, Jamie L.

    2012-01-01

    Mixed methods–mixed research synthesis is a form of systematic review in which the findings of qualitative and quantitative studies are integrated via qualitative and/or quantitative methods. Although methodological advances have been made, efforts to differentiate research synthesis methods have been too focused on methods and not focused enough on the defining logics of research synthesis—each of which may be operationalized in different ways—or on the research findings themselves that are targeted for synthesis. The conduct of mixed methods–mixed research synthesis studies may more usefully be understood in terms of the logics of aggregation and configuration. Neither logic is preferable to the other nor tied exclusively to any one method or to any one side of the qualitative/quantitative binary. PMID:23066379

  9. Reactive control processes contributing to residual switch cost and mixing cost across the adult lifespan.

    PubMed

    Whitson, Lisa R; Karayanidis, Frini; Fulham, Ross; Provost, Alexander; Michie, Patricia T; Heathcote, Andrew; Hsieh, Shulan

    2014-01-01

    In task-switching paradigms, performance is better when repeating the same task than when alternating between tasks (switch cost) and when repeating a task alone rather than intermixed with another task (mixing cost). These costs remain even after extensive practice and when task cues enable advanced preparation (residual costs). Moreover, residual reaction time mixing cost has been consistently shown to increase with age. Residual switch and mixing costs modulate the amplitude of the stimulus-locked P3b. This mixing effect is disproportionately larger in older adults who also prepare more for and respond more cautiously on these "mixed" repeat trials (Karayanidis et al., 2011). In this paper, we analyze stimulus-locked and response-locked P3 and lateralized readiness potentials to identify whether residual switch and mixing cost arise from the need to control interference at the level of stimulus processing or response processing. Residual mixing cost was associated with control of stimulus-level interference, whereas residual switch cost was also associated with a delay in response selection. In older adults, the disproportionate increase in mixing cost was associated with greater interference at the level of decision-response mapping and response programming for repeat trials in mixed-task blocks. These findings suggest that older adults strategically recruit greater proactive and reactive control to overcome increased susceptibility to post-stimulus interference. This interpretation is consistent with recruitment of compensatory strategies to compensate for reduced repetition benefit rather than an overall decline on cognitive flexibility.

  10. The Mixed Waste Management Facility. Preliminary design review

    SciTech Connect

    1995-12-31

    This document presents information about the Mixed Waste Management Facility. Topics discussed include: cost and schedule baseline for the completion of the project; evaluation of alternative options; transportation of radioactive wastes to the facility; capital risk associated with incineration; radioactive waste processing; scaling of the pilot-scale system; waste streams to be processed; molten salt oxidation; feed preparation; initial operation to demonstrate selected technologies; floorplans; baseline revisions; preliminary design baseline; cost reduction; and project mission and milestones.

  11. Nondestructive Estimation of the Eigenvectors of Mixed State

    NASA Astrophysics Data System (ADS)

    Gao, Jingliang

    2017-02-01

    Given n qubits prepared according to the same mixed state ρ, we propose a measuring scheme which approximately yields the eigenvectors of ρ. By performing a sequence of measurements, we can scan the Bloch sphere like radar to search for the eigenvectors. It is shown that this scheme is nondestructive when n is large. This result is based on the quantum typical subspace theory and it actually reveals an interesting mathematical structure of the n-fold Hilbert space.

  12. [Marketing mix in health service].

    PubMed

    Ameri, Cinzia; Fiorini, Fulvio

    2015-01-01

    The marketing mix is the combination of the marketing variables that a firm employs with the purpose to achieve the expected volume of business within its market. In the sale of goods, four variables compose the marketing mix (4 Ps): Product, Price, Point of sale and Promotion. In the case of providing services, three further elements play a role: Personnel, Physical Evidence and Processes (7 Ps). The marketing mix must be addressed to the consumers as well as to the employees of the providing firm. Furthermore, it must be interpreted as employees ability to satisfy customers (interactive marketing).

  13. Waveguide Four-Wave Mixing

    DTIC Science & Technology

    1991-10-01

    PL-TR--91-1045 /’--"PL-TR-- AD-A243 555 91-1045 WAVEGUIDE FOUR -WAVE MIXING Thomas B. Simpson Jia-ming Liu JAYCOR San Diego, CA 92186-5154 October...Final Report; May 88 - Mar 91 4. TITLE AND SUBTITLE 5. FUNDING NUMBERS WAVEGUIDE FOUR -WAVE MIXING C: F29601-88-C-0023 PE: 62601F PR: 3326 6. AUTHOR(S...for public release; distribution unlimited. 13. ABSTRACT (Maximum 200 words) This program has investigated four -wave mixing (4-win) in non- linear

  14. Mixed deterministic and probabilistic networks

    PubMed Central

    Dechter, Rina

    2010-01-01

    The paper introduces mixed networks, a new graphical model framework for expressing and reasoning with probabilistic and deterministic information. The motivation to develop mixed networks stems from the desire to fully exploit the deterministic information (constraints) that is often present in graphical models. Several concepts and algorithms specific to belief networks and constraint networks are combined, achieving computational efficiency, semantic coherence and user-interface convenience. We define the semantics and graphical representation of mixed networks, and discuss the two main types of algorithms for processing them: inference-based and search-based. A preliminary experimental evaluation shows the benefits of the new model. PMID:20981243

  15. Toddler test or procedure preparation

    MedlinePlus

    Preparing toddler for test/procedure; Test/procedure preparation - toddler; Preparing for a medical test or procedure - toddler ... Before the test, know that your child will probably cry. Even if you prepare, your child may feel some discomfort or ...

  16. New Mix Explosives for Explosive Welding

    NASA Astrophysics Data System (ADS)

    Andreevskikh, Leonid

    2011-06-01

    Suggested and tested were some mix explosives--powder mixtures of a brisant high explosive (HE = RDX, PETN) and an inert diluent (baking soda)--for use in explosive welding. RDX and PETN were selected in view of their high throwing ability and low critical diameter. Since the decomposition of baking soda yields a huge amount of gaseous products, its presence ensures (even at a low HE percentage) a throwing speed that is sufficient for realization of explosive welding, at a reduced brisant action of charge. Mix chargers containing 30-70 wt % HE (the rest baking soda) have been tested experimentally and optimized. For study of possibility to reduce critical diameter of HE mixture, the mixture was prepared where HE crystal sizes did not exceed 10 μm. The tests, which were performed with this HE, revealed that the mixture detonated stably with the velocity D ~ 2 km/s, if the layer thickness was d = 2 mm. The above explosives afford to markedly diminish deformations within the oblique impact zone and thus to carry out explosive welding of hollow items and thin metallic foils.

  17. Optimal sequential state discrimination between two mixed quantum states

    NASA Astrophysics Data System (ADS)

    Namkung, Min; Kwon, Younghun

    2017-08-01

    Recently, sequential state discrimination, as a quantum-key distribution protocol, has been proposed for multiple receivers. A previous study [J. A. Bergou et al., Phys. Rev. Lett. 111, 100501 (2013), 10.1103/PhysRevLett.111.100501] showed that every receiver could successfully perform a sequential state discrimination of two pure states with identical prior probabilities. In this study, we extend the sequential state discrimination to mixed states with arbitrary prior probability. First, we analytically obtain the condition of the receiver's optimal measurement. In addition, we show that the optimal probability for every receiver to share the mixed state prepared by the sender is not zero. Furthermore, we compare the sequential state discrimination to the strategies of quantum reproducing and quantum broadcasting. We find that there are cases in which, unlike that of the pure state, the sequential state discrimination of mixed states shows a better performance than the other strategies.

  18. Mixed ionic and electronic conducting ceramic membranes for hydrocarbon processing

    DOEpatents

    Van Calcar, Pamela; Mackay, Richard; Sammells, Anthony F.

    2002-01-01

    The invention relates to mixed phase materials for the preparation of catalytic membranes which exhibit ionic and electronic conduction and which exhibit improved mechanical strength compared to single phase ionic and electronic conducting materials. The mixed phase materials are useful for forming gas impermeable membranes either as dense ceramic membranes or as dense thin films coated onto porous substrates. The membranes and materials of this invention are useful in catalytic membrane reactors in a variety of applications including synthesis gas production. One or more crystalline second phases are present in the mixed phase material at a level sufficient to enhance the mechanical strength of the mixture to provide membranes for practical application in CMRs.

  19. Biodegradation of mixed pesticides by mixed pesticide enriched cultures.

    PubMed

    Krishna, K Rama; Philip, Ligy

    2009-01-01

    This paper discusses the degradation kinetics of mixed (lindane, methyl parathion and carbofuran) pesticides by mixed pesticide enriched cultures (MEC) under various environmental conditions. The bacterial strains isolated from the mixed microbial consortium were identified as Pseudomonas aeruginosa (MTCC 9236), Bacillus sp. (MTCC 9235) and Chryseobacterium joostei (MTCC 9237). Batch studies were conducted to estimate the biokinetic parameters like the maximum specific growth rate (mu(max)), Yield Coefficient (Y(T)), half saturation concentration (K(s)) and inhibition concentration (Ki) for individual and mixed pesticide enriched cultures. The cultures enriched in a particular pollutant always showed high growth rate and low inhibition in that particular pollutant compared to MEC. After seven weeks of incubation, mixed pesticide enriched cultures were able to degrade 72% lindane, 95% carbofuran and 100% of methyl parathion in facultative co-metabolic conditions. In aerobic systems, degradation efficiencies of lindane methyl parathion and carbofuran were increased by the addition of 2g L(- 1) of dextrose. Though many metabolic compounds of mixed pesticides were observed at different time intervals, none of the metabolites were persistent. Based on the observed metabolites, a degradation pathway was postulated for different pesticides under various environmental conditions.

  20. Understanding Bowel Preparation

    MedlinePlus

    ... Center International Pairing Program ASGE Ambassador Program InterLink Maintenance of Certification (MOC/CME) Online Learning Products Endoscopic ... come as a powder to be mixed with water before use. They are available only by prescription ...

  1. Evaluation of permanent deformation and durability of epoxidized natural rubber modified asphalt mix

    NASA Astrophysics Data System (ADS)

    Al-Mansob, Ramez A.; Ismail, Amiruddin; Rahmat, Riza Atiq O. K.; Nazri Borhan, Muhamad; Alsharef, Jamal M. A.; Albrka, Shaban Ismael; Rehan Karim, Mohamed

    2017-09-01

    The road distresses have caused too much in maintenance cost. However, better understandings of the behaviours and properties of asphalt, couples with greater development in technology, have allowed paving technologists to examine the benefits of introducing additives and modifiers. As a result, modifiers such as polymers are the most popular modifiers used to improve the performance of asphalt mix. This study was conducted to investigate the use of epoxidized natural rubber (ENR) to be mixed with asphalt mix. Tests were conducted to investigate the performance characteristics of ENR-asphalt mixes, where the mixes were prepared according to the wet process. Mechanical testing on the ENR-asphalt mixes have demonstrated that the asphalt mix permanent deformation performance at high temperature was found to be improved compared to the base mixes. However, the durability studies have indicated that ENR-asphalt mixes are slightly susceptible with the presence of moisture. The durability of the ENR-asphalt mixes were found to be enhanced in term of permanent deformation at high and intermediate temperatures compared to the base asphalt mixes. As conclusion, asphalt pavement performance can be enhanced by using ENR as modifier to face the major road distresses.

  2. The influence of operational parameters and feed preparation in a convective batch ribbon powder mixer.

    PubMed

    Yeow, Sin Tung; Shahar, Asnawi; Abdul Aziz, Norashikin; Anuar, Mohd Shamsul; Yusof, Yus Aniza; Taip, Farah Saleena

    2011-01-01

    To investigate the effect of feed preparation characteristics and operational parameters on mixing homogeneity in a convective batch ribbon mixer. Lactose 100M, lactose 200M, ascorbic acid, and zinc oxide powders were used for the mixing study. Operational parameters studied were rotational speed and mixing time. The feed preparations studied were the use of preblending and the particle size of the feed materials. The blends of ascorbic acid, zinc oxide, and lactose were prepared with preblending and without preblending, prior to mixing at different blender rotation speeds and mixing times. Chemical tests were performed to measure the homogeneity of the ascorbic acid in the model mixture. With preblending, a mixture with lactose 200M achieved the required homogeneity in a shorter period of time at a lower rotational speed. The results indicated that the homogeneity of the mixtures was influenced by the blender rotation speed and mixing time. Better mixing can be obtained with higher rotation speeds and longer mixing time. It was also observed that preblending and smaller feed particle size achieved the required homogeneity in a shorter period of time at a lower rotational speed. These results illustrate that using binders with a smaller particle size and a preblending technique improves the mixing process in a convective batch ribbon powder mixer. However, prolonged periods of high-speed mixing will lead to mixture segregation.

  3. The influence of operational parameters and feed preparation in a convective batch ribbon powder mixer

    PubMed Central

    Yeow, Sin Tung; Shahar, Asnawi; Aziz, Norashikin Abdul; Anuar, Mohd Shamsul; Yusof, Yus Aniza; Taip, Farah Saleena

    2011-01-01

    Purpose To investigate the effect of feed preparation characteristics and operational parameters on mixing homogeneity in a convective batch ribbon mixer. Methods Lactose 100M, lactose 200M, ascorbic acid, and zinc oxide powders were used for the mixing study. Operational parameters studied were rotational speed and mixing time. The feed preparations studied were the use of preblending and the particle size of the feed materials. The blends of ascorbic acid, zinc oxide, and lactose were prepared with preblending and without preblending, prior to mixing at different blender rotation speeds and mixing times. Chemical tests were performed to measure the homogeneity of the ascorbic acid in the model mixture. Results With preblending, a mixture with lactose 200M achieved the required homogeneity in a shorter period of time at a lower rotational speed. Conclusion The results indicated that the homogeneity of the mixtures was influenced by the blender rotation speed and mixing time. Better mixing can be obtained with higher rotation speeds and longer mixing time. It was also observed that preblending and smaller feed particle size achieved the required homogeneity in a shorter period of time at a lower rotational speed. These results illustrate that using binders with a smaller particle size and a preblending technique improves the mixing process in a convective batch ribbon powder mixer. However, prolonged periods of high-speed mixing will lead to mixture segregation. PMID:22162640

  4. Preparation and Characterization of Polypropylene / MWCNT Dispersions

    NASA Astrophysics Data System (ADS)

    Pujari, Saswati; Burghardt, Wesley; Ramanathan, Thillaiyan; Brinson, L. Catherine; Kasimatis, Kosmas; Torkelson, John

    2008-03-01

    Dispersions of multiwall carbon nanotubes in polypropylene are prepared via melt batch mixing and solid-state shear pulverization, and characterized via linear viscoelastic measurements, SEM, polypropylene crystallization kinetics, electrical conductivity and dynamic mechanical analysis. Increasing the intensity or duration of the melt mixing leads to higher dispersion, evidenced by increases in a low-frequency elastic plateau and accelerated PP crystallization kinetics attributed to more effective heterogeneous nucleation. The sample prepared by pulverization exhibits faster crystallization kinetics than any of the melt blended samples, but in contrast shows no measurable low frequency elastic plateau. Electrical conductivity measurements similarly show higher conductivity in melt blended samples. This may be attributable to scission of the nanotubes during pulverization, such that even well dispersed tubes cannot form an entangled network at a given concentration. At the same time, pulverized composites show marked increase in stiffness at low loadings, indicating that tube scission due to pulverization is not catastrophic. Conversely, long mixing times required in melt blending cause substantial thermal degradation of the polymer matrix with a corresponding loss of mechanical properties.

  5. Modeling Mix in ICF Implosions

    NASA Astrophysics Data System (ADS)

    Weber, C. R.; Clark, D. S.; Chang, B.; Eder, D. C.; Haan, S. W.; Jones, O. S.; Marinak, M. M.; Peterson, J. L.; Robey, H. F.

    2014-10-01

    The observation of ablator material mixing into the hot spot of ICF implosions correlates with reduced yield in National Ignition Campaign (NIC) experiments. Higher Z ablator material radiatively cools the central hot spot, inhibiting thermonuclear burn. This talk focuses on modeling a ``high-mix'' implosion from the NIC, where greater than 1000 ng of ablator material was inferred to have mixed into the hot spot. Standard post-shot modeling of this implosion does not predict the large amounts of ablator mix necessary to explain the data. Other issues are explored in this talk and sensitivity to the method of radiation transport is found. Compared with radiation diffusion, Sn transport can increase ablation front growth and alter the blow-off dynamics of capsule dust. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

  6. Mixed-mu superconducting bearings

    DOEpatents

    Hull, J.R.; Mulcahy, T.M.

    1998-03-03

    A mixed-mu superconducting bearing is disclosed including a ferrite structure disposed for rotation adjacent a stationary superconductor material structure and a stationary permanent magnet structure. The ferrite structure is levitated by said stationary permanent magnet structure. 9 figs.

  7. Is the tribimaximal mixing accidental?

    SciTech Connect

    Abbas, Mohammed; Smirnov, A. Yu.

    2010-07-01

    The tribimaximal (TBM) mixing is not accidental if structures of the corresponding leptonic mass matrices follow immediately from certain (residual or broken) flavor symmetry. We develop a simple formalism which allows one to analyze effects of deviations of the lepton mixing from TBM on the structure of the neutrino mass matrix and on the underlying flavor symmetry. We show that possible deviations from the TBM mixing can lead to strong modifications of the mass matrix and strong violation of the TBM-mass relations. As a result, the mass matrix may have an 'anarchical' structure with random values of elements or it may have some symmetry that differs from the TBM symmetry. Interesting examples include matrices with texture zeros, matrices with certain 'flavor alignment' as well as hierarchical matrices with a two-component structure, where the dominant and subdominant contributions have different symmetries. This opens up new approaches to understanding the lepton mixing.

  8. Mixed-mu superconducting bearings

    DOEpatents

    Hull, John R.; Mulcahy, Thomas M.

    1998-01-01

    A mixed-mu superconducting bearing including a ferrite structure disposed for rotation adjacent a stationary superconductor material structure and a stationary permanent magnet structure. The ferrite structure is levitated by said stationary permanent magnet structure.

  9. Cutaneous mixed infections in AIDS.

    PubMed

    Piérard, G E; Piérard-Franchimont, C; Estrada, J A; Rurangirwa, A; Dosal, F L

    1990-02-01

    We report a new case of mixed infection occurring at the same site of the skin in a human immune deficiency virus-positive patient. Hyperkeratotic and crusted erosions contained fusospirochetal organisms, Cryptococcus neoformans, and another unidentified fungus.

  10. Barium Stars and Thermohaline Mixing

    SciTech Connect

    Husti, Laura

    2008-01-24

    Barium stars are formed in binary systems through mass transfer from the carbon and s-element rich primary in the AGB phase, to the secondary star which is in a less evolved evolutionary stage. The mixing of the accreted material from the AGB donor with the envelope of the secondary results in a dilution of the s-element abundances. Dilution in red giants is explained by the occurence of the first dredge up, while in case of dwarfs thermohaline mixing would determine it. A comparison between the theoretical predictions of the AGB stellar models and the spectroscopical observations of a large sample of barium stars has been made. Dilution due to thermohaline mixing was taken into account when searching for best fits of the observational data. The importance of thermohaline mixing in barium dwarfs is discussed.

  11. Incorporation of Multiwalled Carbon Nanotubes into High Temperature Resin Using Dry Mixing Techniques

    NASA Technical Reports Server (NTRS)

    Ghose, Sayata; Watson, Kent A.; Delozier, Donavon M.; Working, Dennis C.; Siochi, Emilie J.; Connell, John W.

    2006-01-01

    As part of an ongoing effort to develop multifunctional advanced composites, blends of PETI330 and multiwalled carbon nanotubes (MWNTs) were prepared and characterized. Dry mixing techniques were employed and the maximum loading level of the MWNT chosen was based primarily on its effect on melt viscosity. The PETI330/ MWNT mixtures were prepared at concentrations ranging from 3 to 25 wt %. The resulting powders were characterized for homogeneity, thermal and rheological properties and extrudability as continuous fibers. Based on the characterization results, samples containing 10, 15 and 20 wt % MWNTs were chosen for more comprehensive evaluation. Samples were also prepared using in situ polymerization and solution mixing techniques and their properties were compared with the ball-mill prepared samples. The preparation and characterization of PETI330/ MWNT nanocomposites are discussed herein.

  12. Mixed jamming method for SAR

    NASA Astrophysics Data System (ADS)

    Zhao, Hong-feng; Zhang, Peng; Wang, Yong-sheng

    2007-11-01

    The mixed jamming method of synthetic aperture radar is analyzed and discussed. The methods of active noise and deception jamming and the signal model of transmitting is described. The raw echo signal of SAR and the model of jammed echo signal are expatiated, the characteristic of SAR and the evaluating method of jamming effect are established. Finally, the mixed jamming imaging of SAR is simulated.

  13. Perspectives on dilution jet mixing

    NASA Technical Reports Server (NTRS)

    Holdeman, J. D.

    1986-01-01

    A microcomputer code which displays 3-D oblique and 2-D plots of the temperature distribution downstream of jets mixing with a confined crossflow has been used to investigate the effects of varying the several independent flow and geometric parameters on the mixing. Temperature profiles calculated with this empirical model are presented to show the effects of orifice size and spacing, momentum flux ratio, density ratio, variable temperature mainstream, flow area convergence, orifice aspect ratio, and opposed and axially staged rows of jets.

  14. Preparation of zinc orthotitanate

    NASA Technical Reports Server (NTRS)

    Gates, D. W.; Gilligan, J. E.; Harada, Y.; Logan, W. R.

    1977-01-01

    Use of decomposable precursors to enhance zinc oxide-titanium dioxide reaction and rapid fixing results in rapid preparation of zinc orthotitanate powder pigment. Preparation process allows production under less stringent conditions. Elimination of powder grinding results in purer that is less susceptible to color degradation.

  15. Site preparation for wildlife

    Treesearch

    Ralph W. Dimmick

    1989-01-01

    Site preparation-whether for timber and/or wildlife objectives - can influence the quality of wildlife habitat on the site and surrounding forest for the entire rotation period of the regenerated stand. The site preparation you select will help determine the species and numbers of wildlife that use the stand as the stand progresses from regeneration through maturity....

  16. Study Blasts Leadership Preparation

    ERIC Educational Resources Information Center

    Archer, Jeff

    2005-01-01

    A far-reaching study offers a damning assessment of the programs that prepare most of the nation's principals and superintendents. Led by Arthur E. Levine, the president of Teachers College, Columbia University, the report says most university-based preparation programs for administrators range in quality from "inadequate to appalling." The…

  17. Wood fuel preparation

    Treesearch

    L. H. Reineke

    1965-01-01

    This report gives information on the preparation of wood fuel from wood residues and other wood raw materials. Types of wood fuel discussed are cordwood, stovewood, slabwood, kindling, chips, hogged fuel, sawdust and shavings, bark, charcoal, alcohol, and briquets. Related information is given on types of machinery for preparing wood fuel and on possible markets for...

  18. Studies on production, physiochemical and sensory properties of a standard kilishi ingredient mix powder.

    PubMed

    Badau, M H; Igene, J O; Collison, E K; Nkama, I

    1997-05-01

    The quality of kilishi, a sun dried roasted meat product vary considerably due to lack of consistent standardized non meat ingredient portion (spices and condiments) used for its preparation. In this study, an instant standard kilishi ingredient mix powder was developed. The mix powder contained 9.1% moisture, 49.7% protein, 8.3% fat, 3.2% fibre, and 4.4% ash. Particle size of the mix developed was finer than the traditional one. Yield of kilishi increased with increasing concentration of the standard mix powder used for infusion. The highest yield (87%) was obtained at 60% slurry concentration of the mix compared to 59% yield when the traditional paste was used for infusion. Sensory attributes of kilishi produced using 60% slurry concentration of the standard mix was rated better than a commercial kilishi product (P < 0.05).

  19. Mixing of discontinuously deforming media.

    PubMed

    Smith, L D; Rudman, M; Lester, D R; Metcalfe, G

    2016-02-01

    Mixing of materials is fundamental to many natural phenomena and engineering applications. The presence of discontinuous deformations-such as shear banding or wall slip-creates new mechanisms for mixing and transport beyond those predicted by classical dynamical systems theory. Here, we show how a novel mixing mechanism combining stretching with cutting and shuffling yields exponential mixing rates, quantified by a positive Lyapunov exponent, an impossibility for systems with cutting and shuffling alone or bounded systems with stretching alone, and demonstrate it in a fluid flow. While dynamical systems theory provides a framework for understanding mixing in smoothly deforming media, a theory of discontinuous mixing is yet to be fully developed. New methods are needed to systematize, explain, and extrapolate measurements on systems with discontinuous deformations. Here, we investigate "webs" of Lagrangian discontinuities and show that they provide a template for the overall transport dynamics. Considering slip deformations as the asymptotic limit of increasingly localised smooth shear, we also demonstrate exactly how some of the new structures introduced by discontinuous deformations are analogous to structures in smoothly deforming systems.

  20. Quantifying mixing using equilibrium reactions

    NASA Astrophysics Data System (ADS)

    Wheat, Philip M.; Posner, Jonathan D.

    2009-03-01

    A method of quantifying equilibrium reactions in a microchannel using a fluorometric reaction of Fluo-4 and Ca2+ ions is presented. Under the proper conditions, equilibrium reactions can be used to quantify fluid mixing without the challenges associated with constituent mixing measures such as limited imaging spatial resolution and viewing angle coupled with three-dimensional structure. Quantitative measurements of CaCl and calcium-indicating fluorescent dye Fluo-4 mixing are measured in Y-shaped microchannels. Reactant and product concentration distributions are modeled using Green's function solutions and a numerical solution to the advection-diffusion equation. Equilibrium reactions provide for an unambiguous, quantitative measure of mixing when the reactant concentrations are greater than 100 times their dissociation constant and the diffusivities are equal. At lower concentrations and for dissimilar diffusivities, the area averaged fluorescence signal reaches a maximum before the species have interdiffused, suggesting that reactant concentrations and diffusivities must be carefully selected to provide unambiguous, quantitative mixing measures. Fluorometric equilibrium reactions work over a wide range of pH and background concentrations such that they can be used for a wide variety of fluid mixing measures including industrial or microscale flows.

  1. [Study on key physical properties of granulated products of Andrographis mixed powder by high-speed mixing wet method].

    PubMed

    Liao, Zheng-Gen; Li, Zhe; Ming, Liang-Shan; Luo, Juan; Jiang, Qie-Ying; Zhao, Guo-Wei; Liang, Xin-Li

    2014-10-01

    The impact of key physical properties on granulated products by the high-speed mixing wet method was studied. Andrographis extracts were utilized as the model drug. Four processing methods were adopted to prepare mixed powder of microcrystalline cellulose (MCC) and starch with the mass ratio 1:0.5, 1:1 and 1:2 by the high-speed mixing wet method. The properties of the prepared granules were evaluated with such indexes as granule yield, the ratio of lumps and fine powder, granule-AOR and granule-HR. The impact of key physical properties on granulated products was analyzed through stepwise regression analysis. The results showed that angle of repose, moisture content, pore volume, density and contact angle with water were key physical properties of the powder. The key physical properties of Chinese medical extracts powder are the important factor impacting granulated products made by the high-speed mixing wet method. In this study, the impact of key physical properties on granulated products of Chinese medical extracts was analyzed from the physical angle.

  2. [Preparation of antineoplastic agents].

    PubMed

    Descoutures, J-M

    2006-01-01

    In the last fifteen years, the preparation of antineoplastic agents has tended to be centralized in the hospital pharmacy for two main reasons: to enable better protection for the staff, to enable better safety for the patient. The consequences of this organization have led to standardization of techniques, implementation of a quality system and also a better use of antineoplastic agents. After protocols have been standardized by the physician and validated by the pharmacist, four main steps are necessary: phamaceutical validation of the prescription, preparation of IV admixtures according to a production file, control of the final product, dispatching of the preparation to the patient. Computer-controlled processes guarantee the safety of these different steps. The centralized preparations are made either with a vertical laminar flow hood or with an isolator. With the implementation of the National Cancer Plan, antineoplastic agents for patients on home treatments will also be prepared in centralized hospital pharmacies.

  3. Synthetic process for preparation of high surface area electroactive compounds for battery applications

    DOEpatents

    Evenson, Carl; Mackay, Richard

    2013-07-23

    A process is disclosed for the preparation of electroactive cathode compounds useful in lithium-ion batteries, comprising exothermic mixing of low-cost precursors and calcination under appropriate conditions. The exothermic step may be a spontaneous flameless combustion reaction. The disclosed process can be used to prepare any lithium metal phosphate or lithium mixed metal phosphate as a high surface area single phase compound.

  4. Effect of composition and calcination temperature of ceria-zirconia-alumina mixed oxides on catalytic performances of ethanol conversion

    NASA Astrophysics Data System (ADS)

    Chuklina, S. G.; Maslenkova, S. A.; Pylinina, A. I.; Podzorova, L. I.; Ilyicheva, A. A.

    2017-02-01

    In the present study, we investigated the effect of preparation method, phase composition and calcination temperature of the (Ce-TZP) - Al2O3 mixed oxides on their structural features and catalytic performance in ethanol conversion. Ceria-zirconia-alumina mixed oxides with different (Ce+Zr)/Al atomic ratios were prepared via sol-gel method. Catalytic activity and selectivity were investigated for ethanol conversion to acetaldehyde, ethylene and diethyl ether.

  5. Preparation and properties of monodispersed colloidal particles of lanthanide compounds

    SciTech Connect

    Aiken, B.; Hsu, W.P.; Matijevic, E.

    1988-10-01

    Colloidal dispersions of uniform spherical particles of yttrium basic carbonate and rodlike particles of yttrium ammine carbonate were prepared by aging at elevated temperatures yttrium salt solutions in the presence of urea. Different composition and morphology were achieved by altering the aging temperature and time. Coprecipitation in mixed solutions of yttrium(III) and cerium(III) salts under similar experimental conditions yielded composite spherical particles of basic carbonate. The content of the two metals in the solids followed closely the initial composition of the reacting solutions. On calcination all prepared solids converted to their corresponding oxides while retaining their particle morphology. The so-prepared powders were characterized by various techniques.

  6. Preservice Teachers: Teacher Preparation, Multicultural Curriculum and Culturally Relevant Teaching

    ERIC Educational Resources Information Center

    Hopkins-Gillispie, Delphina

    2009-01-01

    This study is part of a larger study that uses mixed methods (qualitative and quantitative methods) to investigate preservice teachers' knowledge and understanding of multiculturalism and to prepare preservice teachers to work in diverse classrooms. The results indicate two findings: 1) that preservice teachers come from homogeneous backgrounds;…

  7. Preparation of {alpha}, {beta}-unsaturated carboxylic acids and anhydrides

    DOEpatents

    Spivey, J.J.; Gogate, M.R.; Zoeller, J.R.; Tustin, G.C.

    1998-01-20

    Disclosed is a process for the preparation of {alpha},{beta}-unsaturated carboxylic acids and anhydrides thereof which comprises contacting formaldehyde or a source of formaldehyde with a carboxylic anhydride in the presence of a catalyst comprising mixed oxides of vanadium, phosphorus and, optionally, a third component selected from titanium, aluminum or, preferably silicon.

  8. Preparation of .alpha., .beta.-unsaturated carboxylic acids and anhydrides

    DOEpatents

    Spivey, James Jerry; Gogate, Makarand Ratnakav; Zoeller, Joseph Robert; Tustin, Gerald Charles

    1998-01-01

    Disclosed is a process for the preparation of .alpha.,.beta.-unsaturated carboxylic acids and anhydrides thereof which comprises contacting formaldehyde or a source of formaldehyde with a carboxylic anhydride in the presence of a catalyst comprising mixed oxides of vanadium, phosphorus and, optionally, a third component selected from titanium, aluminum or, preferably silicon.

  9. Preparing to Teach Online as Transformative Faculty Development

    ERIC Educational Resources Information Center

    McQuiggan, Carol A.

    2011-01-01

    An action research study was conducted at a campus college of a large Research I institution of higher education to explore transformative learning among higher education faculty as a result of participating in a blended program to prepare them to teach online. The purposeful sample included six full-time and one adjunct faculty, teaching a mix of…

  10. Redesigning a Principal Preparation Program: A Continuous Improvement Model

    ERIC Educational Resources Information Center

    Hernandez, Rosalinda; Roberts, Maria; Menchaca Velma

    2012-01-01

    The paper describes a mixed methods approach to the process of redesigning a principal preparation program. A qualitative approach was used to gather data from superintendents within the geographic area using a focused group approach, whereas, quantitative data, were gathered through a survey of program graduates with questions aligned to the…

  11. Using Informal Learning Environments to Prepare Preservice Teachers

    ERIC Educational Resources Information Center

    Jackson, Christa; Mohr-Schroeder, Margaret; Little, David L., II.

    2014-01-01

    This mixed methods study examined the influence informal learning experiences had on secondary STEM preservice teachers' preparation as they worked with students who struggle in mathematics. The quantitative data sources included a Teacher Self-Reflection Survey, Mathematics Clinic Tutor Survey, and a Student Survey, while the qualitative data…

  12. Preservice Teachers: Teacher Preparation, Multicultural Curriculum and Culturally Relevant Teaching

    ERIC Educational Resources Information Center

    Hopkins-Gillispie, Delphina

    2009-01-01

    This study is part of a larger study that uses mixed methods (qualitative and quantitative methods) to investigate preservice teachers' knowledge and understanding of multiculturalism and to prepare preservice teachers to work in diverse classrooms. The results indicate two findings: 1) that preservice teachers come from homogeneous backgrounds;…

  13. Preparing to Teach Online as Transformative Faculty Development

    ERIC Educational Resources Information Center

    McQuiggan, Carol A.

    2011-01-01

    An action research study was conducted at a campus college of a large Research I institution of higher education to explore transformative learning among higher education faculty as a result of participating in a blended program to prepare them to teach online. The purposeful sample included six full-time and one adjunct faculty, teaching a mix of…

  14. Preparing Language Teachers for Blended Teaching of Summary Writing

    ERIC Educational Resources Information Center

    Yang, Yu-Fen

    2014-01-01

    Research on preparing language teachers for blended teaching of summary writing, a mix of on-site and online instruction for college students to grasp the gist of the texts, is scarce in higher education. This study examined the problems encountered and solutions proposed by six language teachers, who altogether instructed 214 college students on…

  15. Preparing Language Teachers for Blended Teaching of Summary Writing

    ERIC Educational Resources Information Center

    Yang, Yu-Fen

    2014-01-01

    Research on preparing language teachers for blended teaching of summary writing, a mix of on-site and online instruction for college students to grasp the gist of the texts, is scarce in higher education. This study examined the problems encountered and solutions proposed by six language teachers, who altogether instructed 214 college students on…

  16. Stability of nizatidine in extemporaneous oral liquid preparations.

    PubMed

    Lantz, M D; Wozniak, T J

    1990-12-01

    The stability of nizatidine in extemporaneous oral liquid preparations stored at room and refrigerated temperatures was studied. Preparations containing nizatidine in a final concentration of approximately 2.5 mg/mL were made by mixing the contents of a 300-mg nizatidine capsule with commercial juices (Gatorade, Stokely-Van Camp; Cran-Grape, Ocean Spray; apple juice, Sundor Brands; and V8 vegetable juice, Campbell Soup) and with aluminum hydroxide-magnesium hydroxide suspension (Maalox, Rorer). A control solution was prepared in water. Samples of each preparation were stored at 15-30 degrees C and at 5 degrees C. Initially and after 4, 8, 24, and 48 hours of storage, the samples were visually inspected, tested for pH, and analyzed in triplicate by high-performance liquid chromatography for nizatidine content. No appreciable changes in appearance or pH occurred. The only extemporaneous preparations with greater than 10% loss of nizatidine potency at 48 hours were the Cran-Grape and V8 preparations at room temperature. There was no correlation between pH of the preparations and changes in drug concentration. In the Maalox and V8 preparations, the drug powder did not dissolve uniformly. In all the preparations tested, nizatidine was stable for at least eight hours at refrigerated and room temperatures. In all except the Cran-Grape and V8 preparations, the drug was stable for 48 hours under both storage conditions.

  17. Chemically prepared lead magnesium niobate dielectrics

    SciTech Connect

    Tuttle, B.A.; Voigt, J.A.; Sipola, D.L.; Olson, W.R.; Goy, D.M.

    1998-11-01

    A chemical solution powder synthesis technique has been developed that produces first, uniform powders of lead magnesium niobate (PMN) with 60 to 80 nm crystallite size. The synthesis technique was based on the dissolution of lead acetate and alkoxide precursors in acetic acid followed by precipitation with oxalic acid/propanol solutions. Lead magnesium niobate ceramics fabricated from these chemically derived powders had smaller, more uniform grain size and higher dielectric constants than ceramics fabricated from mixed oxide powders that were processed under similar thermal conditions. Chem-prep PMN dielectrics with peak dielectric constants greater than 22,000 and polarizations in excess of 29 {micro}C/cm{sup 2} were obtained for 1,100 C firing treatments. Substantial decreases in dielectric constant and polarization were measured for chemically prepared PMN ceramics fired at lower temperatures, consistent with previous work on mixed oxide materials.

  18. Compositional changes in red and violet smoke mixes after combustion

    SciTech Connect

    Buchanan, M.V.; Rubin, I.B.; Moneyhun, J.H.

    1983-01-01

    Anthraquinone-derived dyes are commonly used in colored dye mixes prepared for signal smoke grenades. Biological studies have shown, however, that a number of these dyes exhibit bacterial mutagenicity. In addition, these dyes are similar in structure to several polycyclic aromatic hydrocarbons which are well-known carcinogens. The grenades contain not only anthraquinone-derived dyes, but also a pyrotechnic fuel and cooling and starting mixes consisting primarily of potassium chlorate and nitrate, sodium bicarbonate, and sulfur. These dyes are volatilized at temperatures up to 550/sup 0/C during the detonation of the grenade, which could subject the dyes to oxidative and pyrolytic reactions that could result in a variety of reaction by-products. As part of a program to investigate possible environmental and occupational risks of the colored smoke dyes and in signal grenades, two colored smoke mixes, red and violet, have been studied both before and after detonation to evaluate any differences in composition due to the combustion process. This report focuses primarily on the separation and identification of the components of the original and combusted red and violet smoke mixes. The conditions for the detonation of the smoke grenades and sampling of the combusted smoke mixes are also discussed.

  19. Reactive control processes contributing to residual switch cost and mixing cost across the adult lifespan

    PubMed Central

    Whitson, Lisa R.; Karayanidis, Frini; Fulham, Ross; Provost, Alexander; Michie, Patricia T.; Heathcote, Andrew; Hsieh, Shulan

    2014-01-01

    In task-switching paradigms, performance is better when repeating the same task than when alternating between tasks (switch cost) and when repeating a task alone rather than intermixed with another task (mixing cost). These costs remain even after extensive practice and when task cues enable advanced preparation (residual costs). Moreover, residual reaction time mixing cost has been consistently shown to increase with age. Residual switch and mixing costs modulate the amplitude of the stimulus-locked P3b. This mixing effect is disproportionately larger in older adults who also prepare more for and respond more cautiously on these “mixed” repeat trials (Karayanidis et al., 2011). In this paper, we analyze stimulus-locked and response-locked P3 and lateralized readiness potentials to identify whether residual switch and mixing cost arise from the need to control interference at the level of stimulus processing or response processing. Residual mixing cost was associated with control of stimulus-level interference, whereas residual switch cost was also associated with a delay in response selection. In older adults, the disproportionate increase in mixing cost was associated with greater interference at the level of decision-response mapping and response programming for repeat trials in mixed-task blocks. These findings suggest that older adults strategically recruit greater proactive and reactive control to overcome increased susceptibility to post-stimulus interference. This interpretation is consistent with recruitment of compensatory strategies to compensate for reduced repetition benefit rather than an overall decline on cognitive flexibility. PMID:24817859

  20. Ureilite Thin Section Preparation

    NASA Technical Reports Server (NTRS)

    Harrington, R.; Righter, K.

    2014-01-01

    Preparing thin and thick sections of ureilite type meteorites is a challenge that can confound even the most experienced section preparer. A common characteristic of these samples is the presence of carbon phases, particularly nanodiamonds, in the matrix along silicate grain boundaries, fractures, and cleavage plains [1]. The extreme hardness of the nanodiamonds presents a challenge to the section preparer in the form of high surface relief on the section. This hard material also causes considerable wear and tear on equipment and materials that are used for making the sections. These issues will be discussed and potentially helpful measures will be presented.

  1. Isolation of Salmonella typhimurium from outbreak-associated cake mix.

    PubMed

    Zhang, Guodong; Ma, Li; Patel, Nehal; Swaminathan, Bala; Wedel, Stephanie; Doyle, Michael P

    2007-04-01

    During May and June of 2005, 26 persons in several states were infected by a single strain (isolates indistinguishable by pulsed-field gel electrophoresis) of Salmonella enterica serotype Typhimurium after eating cake batter ice cream. The cake mix used to prepare the cake batter in the ice cream was implicated by epidemiologic investigation as the source of Salmonella contamination. Initial tests did not detect Salmonella in cake mix collected during the outbreak investigation. The objective of this study was to evaluate different procedures to isolate Salmonella from the implicated cake mix, cake, and ice cream. All outbreak-associated food samples (14 samples) were collected during the outbreak investigation by health departments of several of the states involved. Different combinations of Salmonella isolation procedures, including sample size, preenrichment broth, enrichment broth, enrichment temperature, and isolation medium, were used. Salmonella Typhimurium was isolated from two cake mix samples; the food isolates were indistinguishable from the outbreak pattern by pulsed-field gel electrophoresis subtyping. Universal preenrichment broth was substantially better than was lactose broth for preenrichment, and tetrathionate broth was better than was Rappaport-Vassiliadis broth for isolating Salmonella from the two positive cake mix samples. Although more typical Salmonella colonies were observed on plates from enrichment cultures grown at 35 degrees C, more confirmed Salmonella isolates were obtained from plates of enrichment cultures grown at 42 degrees C. Brilliant green agar, xylose lysine tergitol 4 agar, xylose lysine desoxycholate agar, Hektoen enteric agar, and bismuth sulfite agar plates were equally effective in isolating Salmonella from cake mix. The best combination of preenrichment-enrichment conditions for isolating the outbreak strain of Salmonella was preenrichment of cake mix samples in universal preenrichment broth at 35 degrees C for 24 h

  2. Mixed-dimensional Bose polaron

    NASA Astrophysics Data System (ADS)

    Loft, Niels Jakob Søe; Wu, Zhigang; Bruun, G. M.

    2017-09-01

    A new generation of cold atom experiments trapping atomic mixtures in species-selective optical potentials opens up the intriguing possibility to create systems in which different atoms live in different spatial dimensions. Inspired by this, we investigate a mixed-dimensional Bose polaron consisting of an impurity particle moving in a two-dimensional (2D) layer immersed in a 3D Bose-Einstein condensate (BEC), using a theory that includes the mixed-dimensional vacuum scattering between the impurity and the bosons exactly. We show that similarly to the pure 3D case, this system exhibits a well-defined polaron state for attractive boson-impurity interaction that evolves smoothly into a mixed-dimensional dimer for strong attraction, as well as a well-defined polaron state for weak repulsive interaction, which becomes overdamped for strong interaction. We furthermore find that the properties of the polaron depend only weakly on the gas parameter of the BEC as long as the Bogoliubov theory remains a valid description for the BEC. This indicates that higher-order correlations between the impurity and the bosons are suppressed by the mixed-dimensional geometry in comparison to a pure 3D system, which led us to speculate that the mixed-dimensional polaron has universal properties in the unitarity limit of the impurity-boson interaction.

  3. Studies of the B-Z transition of DNA: The temperature dependence of the free-energy difference, the composition of the counterion sheath in mixed salt, and the preparation of a sample of the 5'-d[T-(m(5) C-G)12 -T] duplex in pure B-DNA or Z-DNA form.

    PubMed

    Guéron, Maurice; Plateau, Pierre; Filoche, Marcel

    2016-07-01

    It is often envisioned that cations might coordinate at specific sites of nucleic acids and play an important structural role, for instance in the transition between B-DNA and Z-DNA. However, nucleic acid models explicitly devoid of specific sites may also exhibit features previously considered as evidence for specific binding. Such is the case of the "composite cylinder" (or CC) model which spreads out localized features of DNA structure and charge by cylindrical averaging, while sustaining the main difference between the B and Z structures, namely the better immersion of the B-DNA phosphodiester charges in the solution. Here, we analyze the non-electrostatic component of the free-energy difference between B-DNA and Z-DNA. We also compute the composition of the counterion sheath in a wide range of mixed-salt solutions and of temperatures: in contrast with the large difference of composition between the B-DNA and Z-DNA forms, the temperature dependence of sheath composition, previously unknown, is very weak. In order to validate the model, the mixed-salt predictions should be compared to experiment. We design a procedure for future measurements of the sheath composition based on Anomalous Small-Angle X-ray Scattering and complemented by (31) P NMR. With due consideration for the kinetics of the B-Z transition and for the capacity of generating at will the B or Z form in a single sample, the 5'-d[T-(m(5) C-G)12 -T] 26-mer emerges as a most suitable oligonucleotide for this study. Finally, the application of the finite element method to the resolution of the Poisson-Boltzmann equation is described in detail. © 2016 Wiley Periodicals, Inc. Biopolymers 105: 369-384, 2016.

  4. Preparation of deglycosylated egg white avidin.

    PubMed

    Bayer, E A; De Meester, F; Kulik, T; Wilchek, M

    1995-04-01

    A simple procedure for the preparation of deglycosylated avidin is described. Commercially obtained avidin was treated with a mixed microbial culture. The cells were capable of growing on the oligosaccharide residues, but generally ignored the polypeptide portion of the egg white glycoprotein. The resultant deglycosylated avidin retained its biotin-binding characteristics. The major bacterial strain (strain BECH080), responsible for the deglycosylation, was isolated. On the basis of elementary biochemical tests, fatty acid, and phenotypic analyses, the isolate was identified as a strain of Flavobacterium meningosepticum. The primary enzymatic activity that caused the removal of the oligosaccharide residues of avidin appeared to be similar to endoglycosidase F.

  5. METHOD OF PREPARING A CERAMIC FUEL ELEMENT

    DOEpatents

    Ross, W.T.; Bloomster, C.H.; Bardsley, R.E.

    1963-09-01

    A method is described for preparing a fuel element from -325 mesh PuO/ sub 2/ and -20 mesh UO/sub 2/, and the steps of screening --325 mesh UO/sub 2/ from the -20 mesh UO/sub 2/, mixing PuO/sub 2/ with the --325 mesh UO/sub 2/, blending this mixture with sufficient --20 mesh UO/sub 2/ to obtain the desired composition, introducing the blend into a metal tube, repeating the procedure until the tube is full, and vibrating the tube to compact the powder are included. (AEC)

  6. Preparation of Clay Brick Using Coal Waste

    SciTech Connect

    Yoo, Jung W.; Jung, Jin H.; Kim, Jae M.; Lee, Sung M.; Kim, Hyung T.

    2004-03-31

    A great deal of coal waste produced during the development of a mine was accumulated around the mine, which caused many problems such as traffic, acid mine drainage and damage of forest and scenery. Carbon in the coal waste helps calcination of the brick even at low temperature. Considering the reuse of natural waste and energy saving, clay brick was prepared using coal waste under various conditions, including particle size, amount of coal waste mixed, calcination temperature and pressing pressure. The specimens were characterized by XRD, SEM and TG-DTA and interpreted in terms of water absorption and compressive strength.

  7. Method of preparing zinc orthotitanate pigment

    NASA Technical Reports Server (NTRS)

    Gates, D. W.; Harada, Y.; Logan, W. R.; Gilligan, J. E. (Inventor)

    1977-01-01

    Zinc orthotitanate suitable for use as a pigment for spacecraft thermal control coatings is prepared by heating a slightly zinc deficient reaction mixture of precipitated oxalates of zinc and titanium. The reaction mixture can be formed by coprecipitation of zinc and titanium oxalates from chloride solution or by mixing separately precipitated oxalates. The mixture is first heated to 400 to 600 C to remove volatiles and is then rapidly heated at 900 to 1200 C. Zinc orthotitanate produced by this method exhibits the very fine particle size needed for thermal control coatings as well as stability in a space environment.

  8. Method of preparing coals for coking

    SciTech Connect

    Perch, M.; Peterson, A.J.

    1980-09-30

    A method of preparing coals for coking in a conventional coke oven includes agglomerating the loose coal, in combination with a binder, into flakes, mixing the flakes with non-agglomerated coal, and charging the mixture into the coke oven in the conventional manner is described. The method provides for the utilization in a conventional coke oven, of coals that are marginal in coking quality, greater bulk densities of the coal as charged into a conventional coke oven, acceptable shatter resistance and physical stability of the coke produced, and acceptable carbonization pressure on the coke oven walls.

  9. Preparation of counterion stabilized concentrated silver sols.

    PubMed

    LaPlante, Sylas; Halaciuga, Ionel; Goia, Dan V

    2011-07-01

    A strategy for obtaining stable concentrated silver dispersions without dedicated stabilizing agents is presented. This approach consists of rapidly mixing aqueous solutions of silver salicylate and ascorbic acid. By using salicylate as Ag(+) counterion, it is possible to prepare stable sols with metal concentrations up to two orders of magnitude higher than with silver nitrate. The stabilizing effect of the counterion is the result of a decreased ionic strength due to salicylate protonation and its adsorption on the surface of silver. Both effects increase the range of the electrostatic repulsive forces by expanding the electrical double layer. Copyright © 2011 Elsevier Inc. All rights reserved.

  10. Preparing for Extremes.

    ERIC Educational Resources Information Center

    Herman, Dan

    1998-01-01

    Describes some basic maintenance and proper preparations for changing weather that can help keep school bus operations moving. Provides advice on diesel engine usage that can lengthen engine life and maintain all weather performance is provided. (GR)

  11. Objectives and Preparing Tests.

    ERIC Educational Resources Information Center

    Purohit, Anal A.; Bober, Kenneth F.

    1984-01-01

    The concepts behind, and construction of, specific behavioral objectives are examined as steps that are preliminary to evaluating student performance through tests. A taxonomy of educational objectives and guidelines in preparing them are outlined in detail. (MSE)

  12. The Preparation of Lucigenin.

    ERIC Educational Resources Information Center

    Amiet, R. G.

    1982-01-01

    Outlines and discusses procedures for the preparation of lucigenin, a powerfully chemiluminescent compound. Major techniques (requiring three 4-hour sessions) involving nucleophilic and electrophilic aromatic substitution, nucleophilic aliphatic substitution, reductive coupling, and oxidation reactions include steam distillation, decolorization…

  13. The Preparation of Lucigenin.

    ERIC Educational Resources Information Center

    Amiet, R. G.

    1982-01-01

    Outlines and discusses procedures for the preparation of lucigenin, a powerfully chemiluminescent compound. Major techniques (requiring three 4-hour sessions) involving nucleophilic and electrophilic aromatic substitution, nucleophilic aliphatic substitution, reductive coupling, and oxidation reactions include steam distillation, decolorization…

  14. Thyroid preparation overdose

    MedlinePlus

    Thyroid preparations are medicines used to treat thyroid gland disorders. Overdose occurs when someone takes more than the normal or recommended amount of this medicine. This can be by accident or ...

  15. Preparing for Extremes.

    ERIC Educational Resources Information Center

    Herman, Dan

    1998-01-01

    Describes some basic maintenance and proper preparations for changing weather that can help keep school bus operations moving. Provides advice on diesel engine usage that can lengthen engine life and maintain all weather performance is provided. (GR)

  16. Process for preparing hydrocarbons

    SciTech Connect

    Breuker, J.H.; De H.H.; Kwant, P.B.

    1980-01-15

    A process for preparing light distillate fractions and medicinal oil from heavy hydrocarbon oils comprises two-stage hydrocracking, fractionation distillation and catalytic hydrotreatment of at least part of the fractionation residue.

  17. Aspects of Leptonic Flavour Mixing

    NASA Astrophysics Data System (ADS)

    Feruglio, Ferruccio

    2017-09-01

    Since the discovery of neutrino oscillations many ideas have been put forward to explain the special features of the leptonic mixing and the differences with respect to the quark sector. In this talk I review some of these proposals, emphasizing especially their predictability. In the light of the new data, I first revisit fixed-point relations among mixing angles and phases. Then I briefly comment on radiative neutrino masses. Finally I discuss the role of flavour symmetries. Given the very many existing models I focus on two classes of models. On the one hand I illustrate the ability of models based on a generalization of the anarchy idea in reproducing the main features of both the quark and the lepton spectrum, also in a GUT framework. On the other hand I discuss less ambitious but more predictive models based on discrete flavour symmetries, centered on the properties of the leptonix mixing matrix.

  18. Turbulent mix experiments and simulations

    SciTech Connect

    Dimonte, G.; Schneider, M.; Frerking, C.E.

    1995-08-01

    Hydrodynamic instabilities produce material mixing that can significantly degrade weapons performance. We investigate the Richtmyer-Meshkov (RM) and Rayleigh-Taylor (RT) instabilities in the turbulent regime in two experimental venues. RM experiments are conducted on the Nova laser with strong radiatively driven shocks (Mach > 20) in planar, two fluid targets. Interfacial perturbations are imposed with single sinusoidal modes to test linear theory and with three dimensional (3D) random modes to produce turbulent mix. RT experiments are conducted on a new facility, the Linear Electric Motor (LEM), in which macroscopic fluids are accelerated with arbitrary temporal profiles. This allows detailed diagnosis of the turbulence over a wide range of conditions. The Nova experiments study the high compression regime whereas the LEM experiments are incompressible. The results are compared to hydrodynamic simulations with the arbitrary Lagrangian-Eulerian code (CALE). The goal is to develop and test engineering models of mix.

  19. Investigation of Turbulent Mixing Processes

    NASA Technical Reports Server (NTRS)

    Viktorin, K.

    1946-01-01

    With water as driving medium and delivered medium in a device similar to a simple jet apparatus, the pressure and velocity fields of the mixing zone were explored with a pitot bar; the ratio of delivered to driving volume ranged between the values 0, 1, 2, and 4. An attempt was also made to analyze the mixing flow mathematically by integration of the equation of motion, with the aid of conventional formulas for the turbulent shearing stress, but this succeeded only approximately for the very simplified case that a driving jet is introduced in an unlimited parallel flow, while the pressure over the whole mixing field is assumed to be constant. In spite of these dissimilar assumptions for the theory and the experiment, the form of the measured and the computed velocity profiles indicates a very high degree of approximation. The pressure rise, which was approximated by Flugel's formulas, disclosed good agreement with the measured values.

  20. Preparing spherical lignin from rice husk.

    PubMed

    Zhang, Hongxi; Zhao, Xu; Ding, Xuefeng; Lei, Hong; Wang, Zichen

    2013-08-01

    Lignin is one of the important branched amorphous polymers, which generally has the irregular and fractal morphology. The preparation of regular sphere of lignin needs long steps and special conditions. In this study, the regular sphere of lignin can be simply prepared from rice husk (RH) under certain conditions. Namely, RH is mixed with 35% ethanol aqueous solution in the proportion of 1:10 (g:mL), non-isothermally heated to 493 K and kept for 5 h. After filtration and air-drying at room temperature, the regular lignin sphere with the diameter of 100-400 nm is obtained. The regular sphere of lignin has the potential utilization in fields such as reactive functional materials, photo sensing materials and surface active materials in cosmetics. The mechanism of formation of the regular spherical lignin is proposed and discussed in this paper.

  1. Automating Index Preparation

    DTIC Science & Technology

    1987-03-23

    Automating Index Preparation* Pehong Chent Michael A. Harrison Computer Science Division University of CaliforniaI Berkeley, CA 94720 March 23, 1987...Abstract Index preparation is a tedious and time-consuming task. In this paper we indicate * how the indexing process can be automated in a way which...identified and analyzed. Specifically, we describe a framework for placing index commands in the document and a general purpose index processor which

  2. Nonideal Rayleigh–Taylor mixing

    PubMed Central

    Lim, Hyunkyung; Iwerks, Justin; Glimm, James; Sharp, David H.

    2010-01-01

    Rayleigh–Taylor mixing is a classical hydrodynamic instability that occurs when a light fluid pushes against a heavy fluid. The two main sources of nonideal behavior in Rayleigh–Taylor (RT) mixing are regularizations (physical and numerical), which produce deviations from a pure Euler equation, scale invariant formulation, and nonideal (i.e., experimental) initial conditions. The Kolmogorov theory of turbulence predicts stirring at all length scales for the Euler fluid equations without regularization. We interpret mathematical theories of existence and nonuniqueness in this context, and we provide numerical evidence for dependence of the RT mixing rate on nonideal regularizations; in other words, indeterminacy when modeled by Euler equations. Operationally, indeterminacy shows up as nonunique solutions for RT mixing, parametrized by Schmidt and Prandtl numbers, in the large Reynolds number (Euler equation) limit. Verification and validation evidence is presented for the large eddy simulation algorithm used here. Mesh convergence depends on breaking the nonuniqueness with explicit use of the laminar Schmidt and Prandtl numbers and their turbulent counterparts, defined in terms of subgrid scale models. The dependence of the mixing rate on the Schmidt and Prandtl numbers and other physical parameters will be illustrated. We demonstrate numerically the influence of initial conditions on the mixing rate. Both the dominant short wavelength initial conditions and long wavelength perturbations are observed to play a role. By examination of two classes of experiments, we observe the absence of a single universal explanation, with long and short wavelength initial conditions, and the various physical and numerical regularizations contributing in different proportions in these two different contexts. PMID:20615983

  3. Ion mixing of semiconductor superlattices

    NASA Astrophysics Data System (ADS)

    Xia, W.; Hsu, S. N.; Han, C. C.; Pappert, S. A.; Zhu, B.; Cozzolino, C.; Yu, P. K. L.; Lau, S. S.; Poker, D. B.; White, C. W.; Schwarz, S. A.

    1991-07-01

    Compositional disordering of III-V compound superlattice structures has received considerable attention recently due to its potential application for photonic devices. The conventional method to induce compositional disorder is to implant a moderate dose of impurity ions (˜ 10 15 cm -2) into the structure at room temperature, followed by a high-temperature annealing step (this process is referred to as IA here). Ion irradiation at room temperature alone does not cause any significant intermixing of layers. The subsequent high-temperature annealing step tends to restrict device processing flexibility. Ion mixing (IM) is capable of enhancing compositional disordering of layers at a rate which increases exponentially with the ion irradiation temperature. As a processing technique to planarize devices, ion mixing appears to be an attractive technology. In this work, we investigate compositional disordering in the AlGaAs/GaAs and the InGaAs/InP systems using ion mixing. We found that the ion mixing behavior of these two systems shows a thermally activated regime as well as an athermal regime, similar to that observed for metal-metal and metal-semiconductor systems. Ion mixing is observed to induce compositional disordering at significantly lower temperatures than that for the IA process. We have compared the two processes in terms of four parameters (1) irradiation temperature, (2) dose dependence, (3) annealing, and (4) electrically active ions. We found that the IM process is more efficient in utilizing the defects generated by ion irradiation to cause disordering. Both the physical mechanism of ion mixing and possible device implications will be discussed.

  4. Ion mixing of semiconductor superlattices

    NASA Astrophysics Data System (ADS)

    Xia, W.; Hsu, S. N.; Han, C. C.; Pappert, S. A.; Zhu, B.; Cozzolino, C.; Yu, P. K. L.; Lau, S. S.; Poker, D. B.; White, C. W.

    Compositional disordering of III-V compound superlattice structures has received considerable attention recently due to its potential application for photonic devices. The conventional method in induce compositional disorder is to implant a moderate dose of impurity ions (approx. 10 (exp 15)/sq cm) into the structure at room temperature, followed by a high temperature annealing step (this process is referred to as IA here). Ion irradiation at room temperature alone does not cause any significant intermixing of layers. The subsequent high temperature annealing step tends to restrict device processing flexibility. Ion mixing (IM) is capable of enhancing compositional disordering of layers at a rate which increases exponentially with the ion irradiation temperature. As a processing technique to planarize devices, ion mixing appears to be an attractive technology. Compositional disordering was studied disordering in the AlGaAs/GaAs and the InGaAs/InP systems using ion mixing. It was found that the ion mixing behavior of these two systems shows a thermally activated regime as well as an athermal regime, similar to that observed for metal-metal and metal-semiconductor systems. Ion mixing is observed to induce compositional disordering at significantly lower temperatures than that for the IA process. The two processes were compared in terms of five parameters (1) irradiation temperature, (2) dose dependence (3) annealing, and (4) electrically active ions. It was found that the IM process is more efficient in utilizing the defects generated by ion irradiation to cause disordering. Both the physical mechanism of ion mixing and possible device implications will be discussed.

  5. Further evidence for mixed emotions.

    PubMed

    Larsen, Jeff T; McGraw, A Peter

    2011-06-01

    Emotion theorists have long debated whether valence, which ranges from pleasant to unpleasant states, is an irreducible aspect of the experience of emotion or whether positivity and negativity are separable in experience. If valence is irreducible, it follows that people cannot feel happy and sad at the same time. Conversely, if positivity and negativity are separable, people may be able to experience such mixed emotions. The authors tested several alternative interpretations for prior evidence that happiness and sadness can co-occur in bittersweet situations (i.e., those containing both pleasant and unpleasant aspects). One possibility is that subjects who reported mixed emotions merely vacillated between happiness and sadness. The authors tested this hypothesis in Studies 1-3 by asking subjects to complete online continuous measures of happiness and sadness. Subjects reported more simultaneously mixed emotions during a bittersweet film clip than during a control clip. Another possibility is that subjects in earlier studies reported mixed emotions only because they were explicitly asked whether they felt happy and sad. The authors tested this hypothesis in Studies 4-6 with open-ended measures of emotion. Subjects were more likely to report mixed emotions after the bittersweet clip than the control clip. Both patterns occurred even when subjects were told that they were not expected to report mixed emotions (Studies 2 and 5) and among subjects who did not previously believe that people could simultaneously feel happy and sad (Studies 3 and 6). These results provide further evidence that positivity and negativity are separable in experience.

  6. Mixing in Magnetized Turbulent Media

    NASA Astrophysics Data System (ADS)

    Sur, Sharanya; Pan, Liubin; Scannapieco, Evan

    2014-04-01

    Turbulent motions are essential to the mixing of entrained fluids and are also capable of amplifying weak initial magnetic fields by small-scale dynamo action. Here we perform a systematic study of turbulent mixing in magnetized media, using three-dimensional magnetohydrodynamic simulations that include a scalar concentration field. We focus on how mixing depends on the magnetic Prandtl number, Pm, from 1 to 4 and the Mach number, { {M}}, from 0.3 to 2.4. For all subsonic flows, we find that the velocity power spectrum has a k -5/3 slope in the early kinematic phase, but steepens due to magnetic back reactions as the field saturates. The scalar power spectrum, on the other hand, flattens compared to k -5/3 at late times, consistent with the Obukohov-Corrsin picture of mixing as a cascade process. At higher Mach numbers, the velocity power spectrum also steepens due to the presence of shocks, and the scalar power spectrum again flattens accordingly. Scalar structures are more intermittent than velocity structures in subsonic turbulence, whereas for supersonic turbulence, velocity structures appear more intermittent than the scalars only in the kinematic phase. Independent of the Mach number of the flow, scalar structures are arranged in sheets in both the kinematic and saturated phases of the magnetic field evolution. For subsonic turbulence, scalar dissipation is hindered in the strong magnetic field regions, probably due to Lorentz forces suppressing the buildup of scalar gradients, whereas for supersonic turbulence, scalar dissipation increases monotonically with increasing magnetic field strength. At all Mach numbers, mixing is significantly slowed by the presence of dynamically important small-scale magnetic fields, implying that mixing in the interstellar medium and in galaxy clusters is less efficient than modeled in hydrodynamic simulations.

  7. Nonideal Rayleigh-Taylor mixing.

    PubMed

    Lim, Hyunkyung; Iwerks, Justin; Glimm, James; Sharp, David H

    2010-07-20

    Rayleigh-Taylor mixing is a classical hydrodynamic instability that occurs when a light fluid pushes against a heavy fluid. The two main sources of nonideal behavior in Rayleigh-Taylor (RT) mixing are regularizations (physical and numerical), which produce deviations from a pure Euler equation, scale invariant formulation, and nonideal (i.e., experimental) initial conditions. The Kolmogorov theory of turbulence predicts stirring at all length scales for the Euler fluid equations without regularization. We interpret mathematical theories of existence and nonuniqueness in this context, and we provide numerical evidence for dependence of the RT mixing rate on nonideal regularizations; in other words, indeterminacy when modeled by Euler equations. Operationally, indeterminacy shows up as nonunique solutions for RT mixing, parametrized by Schmidt and Prandtl numbers, in the large Reynolds number (Euler equation) limit. Verification and validation evidence is presented for the large eddy simulation algorithm used here. Mesh convergence depends on breaking the nonuniqueness with explicit use of the laminar Schmidt and Prandtl numbers and their turbulent counterparts, defined in terms of subgrid scale models. The dependence of the mixing rate on the Schmidt and Prandtl numbers and other physical parameters will be illustrated. We demonstrate numerically the influence of initial conditions on the mixing rate. Both the dominant short wavelength initial conditions and long wavelength perturbations are observed to play a role. By examination of two classes of experiments, we observe the absence of a single universal explanation, with long and short wavelength initial conditions, and the various physical and numerical regularizations contributing in different proportions in these two different contexts.

  8. Nonideal Rayleigh-Taylor mixing

    SciTech Connect

    Sharp, David Howland; Lin, Hyun K; Iwerks, Justin G; Gliman, James G

    2009-01-01

    Rayleigh-Taylor mixing is a classical hydrodynamic Instability, which occurs when a light fluid pushes against a heavy fluid. The two main sources of nonideal behavior in Rayleigh-Taylor (RT) mixing are regularizations (physical and numerical) which produce deviations from a pure Euler equation, scale Invariant formulation, and non Ideal (i.e. experimental) initial conditions. The Kolmogorov theory of turbulence predicts stirring at all length scales for the Euler fluid equations without regularization. We Interpret mathematical theories of existence and non-uniqueness in this context, and we provide numerical evidence for dependence of the RT mixing rate on nonideal regularizations, in other words indeterminacy when modeled by Euler equations. Operationally, indeterminacy shows up as non unique solutions for RT mixing, parametrized by Schmidt and Prandtl numbers, In the large Reynolds number (Euler equation) limit. Verification and validation evidence is presented for the large eddy simulation algorithm used here. Mesh convergence depends on breaking the nonuniqueness with explicit use of the laminar Schmidt and PrandtJ numbers and their turbulent counterparts, defined in terms of subgrid scale models. The dependence of the mixing rate on the Schmidt and Prandtl numbers and other physical parameters will be illustrated. We demonstrate numerically the influence of initial conditions on the mixing rate. Both the dominant short wavelength Initial conditions and long wavelength perturbations are observed to playa role. By examination of two classes of experiments, we observe the absence of a single universal explanation, with long and short wavelength initial conditions, and the various physical and numerical regularizations contributing In different proportions In these two different contexts.

  9. Mixing in magnetized turbulent media

    SciTech Connect

    Sur, Sharanya; Scannapieco, Evan; Pan, Liubin E-mail: evan.scannapieco@asu.edu

    2014-04-01

    Turbulent motions are essential to the mixing of entrained fluids and are also capable of amplifying weak initial magnetic fields by small-scale dynamo action. Here we perform a systematic study of turbulent mixing in magnetized media, using three-dimensional magnetohydrodynamic simulations that include a scalar concentration field. We focus on how mixing depends on the magnetic Prandtl number, Pm, from 1 to 4 and the Mach number, M, from 0.3 to 2.4. For all subsonic flows, we find that the velocity power spectrum has a k {sup –5/3} slope in the early kinematic phase, but steepens due to magnetic back reactions as the field saturates. The scalar power spectrum, on the other hand, flattens compared to k {sup –5/3} at late times, consistent with the Obukohov-Corrsin picture of mixing as a cascade process. At higher Mach numbers, the velocity power spectrum also steepens due to the presence of shocks, and the scalar power spectrum again flattens accordingly. Scalar structures are more intermittent than velocity structures in subsonic turbulence, whereas for supersonic turbulence, velocity structures appear more intermittent than the scalars only in the kinematic phase. Independent of the Mach number of the flow, scalar structures are arranged in sheets in both the kinematic and saturated phases of the magnetic field evolution. For subsonic turbulence, scalar dissipation is hindered in the strong magnetic field regions, probably due to Lorentz forces suppressing the buildup of scalar gradients, whereas for supersonic turbulence, scalar dissipation increases monotonically with increasing magnetic field strength. At all Mach numbers, mixing is significantly slowed by the presence of dynamically important small-scale magnetic fields, implying that mixing in the interstellar medium and in galaxy clusters is less efficient than modeled in hydrodynamic simulations.

  10. Mixe de Tlahuitoltepec, Oaxaca (Mixe of Tlahuitoltepec, Oaxaca).

    ERIC Educational Resources Information Center

    Mexico Coll. (Mexico City)

    This document is one of 17 volumes on indigenous Mexican languages and is the result of a project undertaken by the Archivo de Lenguas Indigenas de Mexico. This volume contains information on Mixe, an indigenous language of Mexico spoken in Tlahuitoltepec, in the state of Oaxaca. The objective of collecting such a representative sampling of the…

  11. Use and abuse of mixing models (MixSIAR)

    EPA Science Inventory

    Background/Question/MethodsCharacterizing trophic links in food webs is a fundamental ecological question. In our efforts to quantify energy flow through food webs, ecologists have increasingly used mixing models to analyze biological tracer data, often from stable isotopes. Whil...

  12. Use and abuse of mixing models (MixSIAR)

    EPA Science Inventory

    Background/Question/MethodsCharacterizing trophic links in food webs is a fundamental ecological question. In our efforts to quantify energy flow through food webs, ecologists have increasingly used mixing models to analyze biological tracer data, often from stable isotopes. Whil...

  13. Polarization mixing optical parametric oscillator.

    SciTech Connect

    Pearl, Shaul; Smith, Arlee Virgil; Arie, Ady; Blau, Pinhas; Kalmani, Gal

    2005-05-01

    We report the experimental realization of a new type of optical parametric oscillator in which oscillation is achieved by polarization rotation in a linear retarder, followed by nonlinear polarization mixing. The mixing is performed by a type II degenerate parametric downconversion in a periodically poled KTP crystal pumped by a 1064 nm pulsed Nd:YAG pump. A single, linearly polarized beam, precisely at the degenerate wavelength is generated. The output spectrum has a narrow linewidth (below the instrumentation bandwidth of 1 nm) and is highly stable with respect to variations in the crystal temperature.

  14. Bs Mixing at the Tevatron

    SciTech Connect

    Gomez-Ceballos, Guillelmo; /Cantabria Inst. of Phys.

    2006-04-01

    The Tevatron collider at Fermilab provides a very rich environment for the study of B{sub s} mesons. B{sub s} Mixing is the most important analysis within the B Physics program of both experiments. In this paper they summarize the most recent results on this topic from both D0 and CDF experiments. There were very important updates in both experiments after his last talk, hence the organizers warmly recommended me to include the latest available results on B{sub s} mixing, instead of what he presents there.

  15. Mixed ternary heterojunction solar cell

    DOEpatents

    Chen, Wen S.; Stewart, John M.

    1992-08-25

    A thin film heterojunction solar cell and a method of making it has a p-type layer of mixed ternary I-III-VI.sub.2 semiconductor material in contact with an n-type layer of mixed binary II-VI semiconductor material. The p-type semiconductor material includes a low resistivity copper-rich region adjacent the back metal contact of the cell and a composition gradient providing a minority carrier mirror that improves the photovoltaic performance of the cell. The p-type semiconductor material preferably is CuInGaSe.sub.2 or CuIn(SSe).sub.2.

  16. Mixing of atmospheric gas concentrations.

    PubMed

    Clement, C F; Ford, I J; Twohy, C H

    2000-04-24

    Atmospheric gas concentrations were measured at 1 s intervals in the upper troposphere during a flight through and near the anvil of a storm. The observed very high correlations between the concentrations of CO and CH4 are interpreted as arising from the mixing of two distinct air masses with differing concentrations of each species, and is due to the nearly identical diffusivities of CO and CH4 in air. We find that the correlations depend on the period over which each concentration measurement was made. Correlations in measurements made over short periods decay with time, while correlations over larger scales remain high. We interpret this using a simple mixing model.

  17. An Efficient Alternative Mixed Randomized Response Procedure

    ERIC Educational Resources Information Center

    Singh, Housila P.; Tarray, Tanveer A.

    2015-01-01

    In this article, we have suggested a new modified mixed randomized response (RR) model and studied its properties. It is shown that the proposed mixed RR model is always more efficient than the Kim and Warde's mixed RR model. The proposed mixed RR model has also been extended to stratified sampling. Numerical illustrations and graphical…

  18. A Literature Review of the Strengths and Limitations of Premarital Preparation: Implications for a Canadian Context

    ERIC Educational Resources Information Center

    Green, Amy R.; Miller, Lynn D.

    2013-01-01

    The adverse effects of marital dissolution and dissatisfaction point to a need for interventions, such as premarital preparation, to improve marital quality. Although several studies support the potential for premarital preparation to improve couples' marital satisfaction and interpersonal skills, results from other studies are mixed. Moreover,…

  19. Paving the Pathway: Exploring Student Perceptions of Professional Development Preparation in Doctoral Education

    ERIC Educational Resources Information Center

    Heflinger, Craig Anne; Doykos, Bernadette

    2016-01-01

    The breadth of doctoral education has expanded to include professional development activities in order to prepare students for academic and nonacademic careers. This mixed methods study focused on students' perceptions of professional development opportunities at a Research One university. The findings suggest that most students feel prepared in…

  20. A Literature Review of the Strengths and Limitations of Premarital Preparation: Implications for a Canadian Context

    ERIC Educational Resources Information Center

    Green, Amy R.; Miller, Lynn D.

    2013-01-01

    The adverse effects of marital dissolution and dissatisfaction point to a need for interventions, such as premarital preparation, to improve marital quality. Although several studies support the potential for premarital preparation to improve couples' marital satisfaction and interpersonal skills, results from other studies are mixed. Moreover,…

  1. Process for preparing energetic materials

    DOEpatents

    Simpson, Randall L [Livermore, CA; Lee, Ronald S [Livermore, CA; Tillotson, Thomas M [Tracy, CA; Hrubesh, Lawrence W [Pleasanton, CA; Swansiger, Rosalind W [Livermore, CA; Fox, Glenn A [Livermore, CA

    2011-12-13

    Sol-gel chemistry is used for the preparation of energetic materials (explosives, propellants and pyrotechnics) with improved homogeneity, and/or which can be cast to near-net shape, and/or made into precision molding powders. The sol-gel method is a synthetic chemical process where reactive monomers are mixed into a solution, polymerization occurs leading to a highly cross-linked three dimensional solid network resulting in a gel. The energetic materials can be incorporated during the formation of the solution or during the gel stage of the process. The composition, pore, and primary particle sizes, gel time, surface areas, and density may be tailored and controlled by the solution chemistry. The gel is then dried using supercritical extraction to produce a highly porous low density aerogel or by controlled slow evaporation to produce a xerogel. Applying stress during the extraction phase can result in high density materials. Thus, the sol-gel method can be used for precision detonator explosive manufacturing as well as producing precision explosives, propellants, and pyrotechnics, along with high power composite energetic materials.

  2. Guidelines for generators of hazardous chemical waste at LBL and guidelines for generators of radioactive and mixed waste at LBL

    SciTech Connect

    Not Available

    1991-09-01

    In part one of this document the Governing Documents and Definitions sections provide general guidelines and regulations applying to the handling of hazardous chemical wastes. The remaining sections provide details on how you can prepare your waste properly for transport and disposal. They are correlated with the steps you must take to properly prepare your waste for pickup. The purpose of the second part of this document is to provide the acceptance criteria for the transfer of radioactive and mixed waste to LBL's Hazardous Waste Handling Facility (HWHF). These guidelines describe how you, as a generator of radioactive or mixed waste, can meet LBL's acceptance criteria for radioactive and mixed waste.

  3. Preschooler test or procedure preparation

    MedlinePlus

    Preparing preschoolers for test/procedure; Test/procedure preparation - preschooler ... Preparing children for medical tests can reduce their anxiety. It can also make them less likely to cry and resist the procedure. Research shows that ...

  4. An assessment of encapsulated versus hand-mixed glass ionomer restoratives.

    PubMed

    Fleming, Garry J P; Zala, Dillon M

    2003-01-01

    Capsulation should enable uniform proportioning and mixing of dental restoratives so that functional properties of the cementitious mass will not be susceptible to clinically induced variability. Mechanical mixing induces a definite pore distribution determined by the viscosity of the system. This study evaluated the mixing process on the performance of a range of glass ionomer dental restoratives. Mean compressive fracture strengths and standard deviations and the associated Weibull Moduli (m) were determined for six glass ionomer restoratives that were either encapsulated or mixed by hand. Working characteristics were assessed using an oscillating rheometer. Scanning electron microscopy and image analysis was used to investigate the influence of the mixing method on pore distribution. The fracture strength data for some encapsulated restoratives resulted in significant differences compared with hand-mixing. Rotomix (compared with the Capmix mechanical agitator) resulted in increased Weibull moduli and 10% failure stress for the two restoratives that were investigated. Encapsulated restoratives that were prepared utilizing Rotomix or Capmix resulted in no significant differences for working characteristics; however, the setting time for the ChemFlex in Caps was extended compared with the hand-mixed ChemFlex. Not all restoratives had reduced porosity and improved performance following mixing with a Rotomix. This suggested that optimization of the initial viscosity of the system by manipulating the individual proportions of the constituents may not have been appropriate for all the restoratives investigated. The increased viscosity for hand-mixed ChemFlex prepared to a consistency of 3.8 g/ml compared with encapsulated ChemFlex in Caps prepared to a consistency of 3.5 g/ml was responsible for the reduced setting time.

  5. On the quantification of mixing in microfluidics.

    PubMed

    Hashmi, Ali; Xu, Jie

    2014-10-01

    Methods for quantifying mixing in microfluidics have varied largely in the past, and various indices have been employed to represent the extent of mixing. Mixing between two or more colored liquids is usually quantified using simple mathematical functions operated over a sequence of images. The function, usually termed mixing indices, involves a measure of standard deviation. Here, we first review some mixing indices and then experimentally verify the index most representative of a mixing event. It is observed that the relative mixing index is not affected by the lighting conditions, unlike other known mixing indices. Based on this finding, the use of a relative mixing index is advocated for further use in the lab-on-a-chip community for quantifying mixing events. © 2014 Society for Laboratory Automation and Screening.

  6. Tissue preparation for immunocytochemistry.

    PubMed Central

    Williams, J H; Mepham, B L; Wright, D H

    1997-01-01

    AIMS: To investigate the effect of tissue preparation on immunostaining and to establish whether there is a standard tissue preparation schedule that allows optimal demonstration of all antigens. METHODS: Blocks of tonsil were subjected to variations to a standard fixation, processing, and section preparation schedule. The sections were stained with five antibodies-L26 (CD20), UCHL1 (CD45RO), CD3, vimentin, and anti-kappa light chain--using the streptavidinbiotin immunostaining technique. When further investigation was necessary, other tissues and antibodies were used and where weak immunostaining was obtained the use of microwave pretreatment to improve staining was tested. RESULTS: Several factors involved in fixation were found to affect immunoreactivity. These included the duration, pH, and type of fixative used. In tissue processing only temperature and the duration of the dehydration and wax infiltration steps affected immunoreactivity. Of all the factors investigated, the temperature and duration of the section drying had the greatest effect. In contrast, long term storage of cut sections before immunostaining had no effect on the reactivity of the antibodies tested. Antibodies were found to be affected by alterations to tissue preparation by varying degrees, UCHL1 and vimentin being the most susceptible to changes in fixation and L26 to changes in processing. Where weak staining occurred, microwave pretreatment was generally found to eliminate the problem. CONCLUSIONS: There is no standard tissue preparation schedule for the optimal demonstration of all antigens. Factors involved in all aspects of tissue preparation can affect immunoreactivity, so it is important that precise details of the preparation schedule are given when reporting immunocytochemical studies, rather than using the general term "routinely fixed and processed". Images PMID:9215127

  7. Towards understanding turbulent scalar mixing

    NASA Technical Reports Server (NTRS)

    Girimaji, Sharath S.

    1992-01-01

    In an effort towards understanding turbulent scalar mixing, we study the effect of molecular mixing, first in isolation and then by accounting for the effects of the velocity field. The chief motivation for this approach stems from the strong resemblance of the scalar probability density function (PDF) obtained from the scalar field evolving from the heat conduction equation that arises in a turbulent velocity field. However, the evolution of the scalar dissipation is different for the two cases. We attempt to account for these differences, which are due to the velocity field, using a Lagrangian frame analysis. After establishing the usefulness of this approach, we use the heat-conduction simulations (HCS), in lieu of the more expensive direct numerical simulations (DNS), to study many of the less understood aspects of turbulent mixing. Comparison between the HCS data and available models are made whenever possible. It is established that the beta PDF characterizes the evolution of the scalar PDF during mixing from all types of non-premixed initial conditions.

  8. Simple rheology of mixed proteins

    USDA-ARS?s Scientific Manuscript database

    Mixing different proteins to form strong gel networks for food applications may create synergistic increases in viscoelasticity that cannot be achieved with a single protein. In this study, small amplitude oscillatory shear analyses were used to investigate the rheology of calcium caseinate (CC), e...

  9. Turbulent Mixing Chemistry in Disks

    NASA Astrophysics Data System (ADS)

    Semenov, D.; Wiebe, D.

    2006-11-01

    A gas-grain chemical model with surface reaction and 1D/2D turbulent mixing is available for protoplanetary disks and molecular clouds. Current version is based on the updated UMIST'95 database with gas-grain interactions (accretion, desorption, photoevaporation, etc.) and modified rate equation approach to surface chemistry (see also abstract for the static chemistry code).

  10. Racially Mixed People in America.

    ERIC Educational Resources Information Center

    Root, Maria P. P., Ed.

    This book offers a comprehensive look at the social and psychological adjustment of multiracial people, models for identity development, contemporary immigration and marriage patterns, and methodological issues involved in conducting research with mixed-race people, all in the context of America's multiracial past and present. The following 26…

  11. Racially Mixed People in America.

    ERIC Educational Resources Information Center

    Root, Maria P. P., Ed.

    This book offers a comprehensive look at the social and psychological adjustment of multiracial people, models for identity development, contemporary immigration and marriage patterns, and methodological issues involved in conducting research with mixed-race people, all in the context of America's multiracial past and present. The following 26…

  12. Bayesian stable isotope mixing models

    EPA Science Inventory

    In this paper we review recent advances in Stable Isotope Mixing Models (SIMMs) and place them into an over-arching Bayesian statistical framework which allows for several useful extensions. SIMMs are used to quantify the proportional contributions of various sources to a mixtur...

  13. [Treatment of depressive mixed states].

    PubMed

    Dubois, M; Dassa, D; Belzeaux, R; Fakra, E; Cermolacce, M; Corréard, N; Kaladjian, A; Azorin, J-M

    2013-12-01

    Mixed states are a frequent mood state characterized by the mixture of manic and depressive symptoms. Their clinical description has been studied for centuries but has known a renewal of interest recently. Several authors intend to redefine its diagnostic criteria to develop an appropriate therapeutic strategy. Current recommendations suggest to treat mixed depression as a mixed state whatever the dominant polarity is, and therefore according to the rules of therapeutic management of the manic state. Mood stabilizers and antipsychotic medications are indicated and have proven their effectiveness. Lithium, which was considered controversial, now appears to have some therapeutic value, especially in the prevention of suicidal behavior. The depressive component of mixed states, even pronounced, should not be an argument for a prescription of antidepressants, at the risk of aggravating clinical components such as irritability and impulsivity and increasing the danger of suicide attempt. Furthermore, electroconvulsivetherapy represents a real alternative ; psychotherapies have their place in relapse prevention and psychoeducation, but not during acute phases. Finally, an accurate assessment and appropriate management of suicide risk should be a constant concern for the clinicians. Copyright © 2013 L’Encéphale. Published by Elsevier Masson SAS.. All rights reserved.

  14. Mixing It Up with Acrylics.

    ERIC Educational Resources Information Center

    Laird, Shirley

    1999-01-01

    Presents an art activity for fifth-grade students in which they learn about basic shapes and what happens when shapes overlap, draw seven overlapping geometric shapes, review the use of acrylic paint and mixing colors, and finally paint with primary colors. (CMK)

  15. Mixed Ability Teaching Versus Streaming.

    ERIC Educational Resources Information Center

    Marklund, Sixten

    1984-01-01

    Discusses development of pupil grouping in European compulsory education into two opposite class organization types, mixed ability classes and ability-grouped classes. Categorizes the types along two dimensions with three program types and three grouping types, yielding nine teaching categories. Discusses comparative results of streaming and mixed…

  16. Colour Mixing Based on Daylight

    ERIC Educational Resources Information Center

    Meyn, Jan-Peter

    2008-01-01

    Colour science is based on the sensation of monochromatic light. In contrast to that, surface colours are caused by reflection of wide sections of the daylight spectrum. Non-spectral colours like magenta and purple appear homologous to colours with spectral hue, if the approach of mixing monochromatic light is abandoned. It is shown that a large…

  17. Mixing and transport. [Water pollution

    SciTech Connect

    Roberts, P.J.W.

    1982-06-01

    The mixing and transport of water pollution is the subject of this literature review with 110 references. The environmental transport of pollutants is examined in streams, rivers, reservoirs, ponds, estuaries, salt marshes and coastal waters. The dynamics of fluid flow, and the physical properties of jets, plumes, and stratified fluids are discussed. (KRM)

  18. Bayesian stable isotope mixing models

    EPA Science Inventory

    In this paper we review recent advances in Stable Isotope Mixing Models (SIMMs) and place them into an over-arching Bayesian statistical framework which allows for several useful extensions. SIMMs are used to quantify the proportional contributions of various sources to a mixtur...

  19. Colour Mixing Based on Daylight

    ERIC Educational Resources Information Center

    Meyn, Jan-Peter

    2008-01-01

    Colour science is based on the sensation of monochromatic light. In contrast to that, surface colours are caused by reflection of wide sections of the daylight spectrum. Non-spectral colours like magenta and purple appear homologous to colours with spectral hue, if the approach of mixing monochromatic light is abandoned. It is shown that a large…

  20. Mixing It Up with Acrylics.

    ERIC Educational Resources Information Center

    Laird, Shirley

    1999-01-01

    Presents an art activity for fifth-grade students in which they learn about basic shapes and what happens when shapes overlap, draw seven overlapping geometric shapes, review the use of acrylic paint and mixing colors, and finally paint with primary colors. (CMK)