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Sample records for lvealyl forms microcrystalline

  1. On the compressibility of TiC in microcrystalline and nanoparticulate form

    International Nuclear Information System (INIS)

    Gu, Q F; Krauss, G; Steurer, W; Gramm, F

    2008-01-01

    The compressibility of TiC in microcrystalline and nanoparticulate (30-50 nm) form was studied by in situ high-pressure synchrotron radiation x-ray diffraction measurements up to 53.7 GPa using a diamond anvil cell. Both materials are structurally stable within the framework of the experiments applying quasihydrostatic pressure conditions. Under nonhydrostatic pressure conditions, the lattice of microcrystalline TiC is rhombohedrally distorted. Comparable values for the bulk modulus were found for both materials, i.e. K 0 = 254(7) GPa, K' = 4.8(4) for microcrystalline TiC and K 0 = 276(14) GPa, K' = 3.5(8) for nanoparticulate TiC, respectively. High-resolution transmission electron microscopy investigations revealed a nearly single-domain microstructure of the nanoparticles. The microstructure and size of the nanoparticles, making a size-induced effect on the mechanical properties negligible, explain well the observed similarity of the mechanical properties of microcrystalline and nanoparticulate TiC.

  2. Crystallization of II-VI semiconductor compounds forming long microcrystalline linear assemblies

    Directory of Open Access Journals (Sweden)

    Marcelino Becerril

    2013-04-01

    Full Text Available In this work we report the formation of long microcrystalline linear self-assemblies observed during the thin film growth of several II-VI compounds. Polycrystalline CdTe, CdS, CdCO3, and nanocrystalline CdTe:Al thin films were prepared on glass substrates by different deposition techniques. In order to observe these crystalline formations in the polycrystalline materials, the thin film growth was suspended before the grains reached to form a continuous layer. The chains of semiconductor crystals were observed among many isolated and randomly distributed grains. Since CdTe, CdTe:Al, CdS and CdCO3 are not ferroelectric and/or ferromagnetic materials, the relevant problem would be to explain what is the mechanism through which the grains are held together to form linear chains. It is well known that some nanocrystalline materials form rods and wires by means of electrostatic forces. This occurs in polar semiconductors, where it is assumed that the attraction forces between surface polar faces of the small crystals are the responsible for the chains formation. Since there are not too many mechanisms responsible for the attraction we assume that a dipolar interaction is the force that originates the formation of chain-like grain clusters. The study of this property can be useful for the understanding of nucleation processes in the growth of semiconductor thin films.

  3. Microcrystalline identification of selected designer drugs.

    Science.gov (United States)

    Elie, Leonie; Baron, Mark; Croxton, Ruth; Elie, Mathieu

    2012-01-10

    A microcrystalline test for the detection of 4-methylmethcathinone (mephedrone), benzylpiperazine (BZP) and 5,6-methylenedioxy-2-aminoindane (MDAI) using aqueous solutions of mercury chloride is described. Each of the compounds investigated formed specific drug-reagent crystals within minutes. The uniqueness of the test was confirmed by comparison of the microcrystalline response to that of other psychoactive stimulants and a common cutting agent. The limit of detection and cut-off levels for reference standards were established to 3 g/L and 5 g/L for mephedrone, 0.5 g/L for MDAI and 0.2 g/L and 0.3 g/L for BZP, respectively. Various mixtures of standards of either mephedrone, BZP or MDAI combined with caffeine were investigated for their microcrystalline response. Results showed that simultaneous detection of drug and cutting agent was possible with the concentrations tested but were dependant on the ratio of drug to cutting agent. BZP could be detected alongside caffeine from as low as 20% (v/v), MDAI from 40% (v/v) and mephedrone from 50% (v/v) and higher. Finally, seven samples of online purchased 'legal highs' were analysed using the developed test and the findings were compared to FTIR and GC-MS results. It was shown that 6 out of 7 samples did not contain the advertised active ingredient. Five samples consisted of BZP, caffeine and 1-[3-(trifluoromethyl)phenyl]piperazine (3-TFMPP). The microcrystalline tests carried out on these samples showed positive results for both BZP and caffeine without interference from other substances present. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  4. Evaluation of microcrystalline cellulose modifed from alpha ...

    African Journals Online (AJOL)

    Alpha cellulose was obtained from Costus afer and part of it was modified to microcrystalline cellulose (CAMCC). The physicochemical properties of the microcrystalline cellulose were determined and compared with those of commercial microcrystalline cellulose (Avicel 101). The swelling capacity, hydration capacity, loss ...

  5. Some Physical Characteristics of Microcrystalline Cellulose ...

    African Journals Online (AJOL)

    Purpose: The microcrystalline cellulose is an important ingredient in pharmaceutical, food, cosmetic and other industries. This study aimed at evaluating the physical characteristics of microcrystalline cellulose (CP-MCC), obtained from the raw cotton of Cochlospermum planchonii. Methods: CP-MCC was obtained from the ...

  6. Two-component self-assembly with solvent leading to "wet" and microcrystalline organogel fibers.

    Science.gov (United States)

    Löfman, Miika; Lahtinen, Manu; Rissanen, Kari; Sievänen, Elina

    2015-01-15

    The microcrystalline fibers of N-(2-aminoethyl)-3α-hydroxy-5β-cholan-24-amide 1 provided a useful model system for studying the complex relationship between morphology, experimental parameters, solvent, and the phenomenon of organogelation. The presence of solvents in the solid forms of 1 along with crystallization behavior suggested solvate formation and polymorphic behavior. Forty solid state- and xerogel samples of 1 formed in organic solvents and in three categories of experimental conditions were analyzed with single crystal X-ray diffraction (XRD), powder X-ray diffraction (PXRD), Raman microscopy, and attenuated total reflection Fourier-transform infrared spectroscopy (ATR FTIR). Two polymorphs and four isostructural aromatic solvates of 1 were found among some unknown forms in the samples. Single crystal X-ray structures of one polymorph and bromobenzene solvate were obtained, the latter from a xerogel. Multiple crystal forms could be present in a sample, and their contributions to gelation were estimated taking the experimental conditions into account. Gelator 1 could act as a variable component gelator, either alone or in combination with an aromatic solvent. The research brings new insight into the structures of microcrystalline organogel fibers, linking solvate/inclusion crystal formation with microcrystalline fibers of an organogelator for the first time. Copyright © 2014 Elsevier Inc. All rights reserved.

  7. Structure and properties of microcrystalline chitosan

    International Nuclear Information System (INIS)

    Pighinelli, Luciano; Guimaraes, Fernando Machado; Paz, Luan Rios; Zanin, Gabrielle Brehm; Kmiec, Marzena; Tedesco, Felipe Melleu; Reis, Victoria Oliva dos; Silva, Matheus Machado; Becker, Cristiane Miotto; Zehetmeyer, Gislene; Rasia, Gisele

    2016-01-01

    Full text: The microcrystalline chitosan is a modified form of chitosan; it has been elaborated from obtaining method of chitosan salts. It is characterized by special properties of the initial chitosan such as biocompatibility, bioactivity, non-toxic, biodegradability [1]. The objective of this study is to develop a different method to obtain the microcrystalline chitosan and the following characterization of the initial chitosan and MCCh. The material was characterized by FTIR, scanning of electron microscopy, SEM, nuclear magnetic resonance, NMR, and x-ray diffraction. The results indicate that the process to obtain MCCh, did not change the structure of the initial chitosan. The MCCh shows the same functional groups of the initial chitosan. The NMR results shows the acetylated and deacetylated groups. The morphology shows a homogeneous structure of surface. The X-ray diffraction shows the reduction of the crystallinity in the MCCh, indicating a bigger amorphous structure of the MCCh. The chitosan and its derivatives are polymers with excellent properties to be used in regenerative medicine because of ensure efficiency in healing process. This polysaccharide has a great potential to develop a new generation of biomaterials that can be used in regenerative medicine and tissue engineering [2]. References: [1]. LI, Q. et al. Applications and properties of chitosan. In: GOOSEN, M. F. A. (Ed.). Applications of chitin and chitosan. Basel: Technomic, 1997. p. 3-29; [2]. Luciano Pighinelli, Magdalena Kucharska, Dariuz Wawro. Preparation of Microcrystalline chitosan: (MCCh0/tricalcium phosphate complex with Hydroxyapatite in sponge and fibre from for hard tissue regeneration. (author)

  8. Structure and properties of microcrystalline chitosan

    Energy Technology Data Exchange (ETDEWEB)

    Pighinelli, Luciano; Guimaraes, Fernando Machado; Paz, Luan Rios; Zanin, Gabrielle Brehm; Kmiec, Marzena; Tedesco, Felipe Melleu; Reis, Victoria Oliva dos; Silva, Matheus Machado, E-mail: lpighinelli@hotmail.com [Universidade Luterana, Sao Paulo, SP (Brazil); Becker, Cristiane Miotto; Zehetmeyer, Gislene; Rasia, Gisele [Centro Universitario SENAI CIMATEC, Salvador, BA (Brazil). Instituto de Engenharia de Materiais Polimericos

    2016-07-01

    Full text: The microcrystalline chitosan is a modified form of chitosan; it has been elaborated from obtaining method of chitosan salts. It is characterized by special properties of the initial chitosan such as biocompatibility, bioactivity, non-toxic, biodegradability [1]. The objective of this study is to develop a different method to obtain the microcrystalline chitosan and the following characterization of the initial chitosan and MCCh. The material was characterized by FTIR, scanning of electron microscopy, SEM, nuclear magnetic resonance, NMR, and x-ray diffraction. The results indicate that the process to obtain MCCh, did not change the structure of the initial chitosan. The MCCh shows the same functional groups of the initial chitosan. The NMR results shows the acetylated and deacetylated groups. The morphology shows a homogeneous structure of surface. The X-ray diffraction shows the reduction of the crystallinity in the MCCh, indicating a bigger amorphous structure of the MCCh. The chitosan and its derivatives are polymers with excellent properties to be used in regenerative medicine because of ensure efficiency in healing process. This polysaccharide has a great potential to develop a new generation of biomaterials that can be used in regenerative medicine and tissue engineering [2]. References: [1]. LI, Q. et al. Applications and properties of chitosan. In: GOOSEN, M. F. A. (Ed.). Applications of chitin and chitosan. Basel: Technomic, 1997. p. 3-29; [2]. Luciano Pighinelli, Magdalena Kucharska, Dariuz Wawro. Preparation of Microcrystalline chitosan: (MCCh0/tricalcium phosphate complex with Hydroxyapatite in sponge and fibre from for hard tissue regeneration. (author)

  9. Properties of microcrystalline cellulose obtained from coconut ...

    African Journals Online (AJOL)

    The study revealed that the cellulose material compares favourably with Avicel PH 101 as well as official requirement specified in the British Pharmacopoeia 1993 for microcrystalline cellulose. Keywords: Coconut fruit fibre, microcrystalline cellulose, powder properties. Journal of Pharmacy and Bioresources Vol. 3 (1) 2006: ...

  10. Isolation and characterization of microcrystalline cellulose obtained ...

    African Journals Online (AJOL)

    In this study, microcrystalline cellulose, coded MCC-PNF, was obtained from palm nut (Elaeis guineensis) fibres. MCC-PNF was examined for its physicochemical and powder properties. The powder properties of MCC-PNF were compared to those of the best commercial microcrystalline cellulose grade, Avicel PH 101.

  11. Direct compression properties of microcrystalline cellulose and its ...

    African Journals Online (AJOL)

    The influence of silicified microcrystalline cellulose (SMCC) on the flow, compaction and tableting properties of metronidazole powder was investigated. The study compared medium grades of both SMCC and standard microcrystalline cellulose (MCC) as direct compressible excipients. The bulk densities, Hausner quotient ...

  12. Fe3O4 Modification of Microcrystalline Cellulose for Composite Materials

    OpenAIRE

    Dimitrov, Kiril; Herzog, Michael; Nenkova, Sanchi

    2013-01-01

    A new synthesis method for producing cellulose ferrite micro- and nano- composites was developed and new material properties were studied. Microcrystalline cellulose was modified with a mixture of Fe+2/Fe+3 to produce surface bonded nanoparticles magnetite (Fe3O4). Optimal conditions were determined. Microsized hematite (Fe2O3) was mixed with microcrystalline cellulose and used as a reference. The magnetite modified microcrystalline cellulose and hematite filled microcrystalline cellulose wer...

  13. Method for depositing high-quality microcrystalline semiconductor materials

    Science.gov (United States)

    Guha, Subhendu [Bloomfield Hills, MI; Yang, Chi C [Troy, MI; Yan, Baojie [Rochester Hills, MI

    2011-03-08

    A process for the plasma deposition of a layer of a microcrystalline semiconductor material is carried out by energizing a process gas which includes a precursor of the semiconductor material and a diluent with electromagnetic energy so as to create a plasma therefrom. The plasma deposits a layer of the microcrystalline semiconductor material onto the substrate. The concentration of the diluent in the process gas is varied as a function of the thickness of the layer of microcrystalline semiconductor material which has been deposited. Also disclosed is the use of the process for the preparation of an N-I-P type photovoltaic device.

  14. Evaluation of Chitosan-Microcrystalline Cellulose Blends as Direct Compression Excipients

    Directory of Open Access Journals (Sweden)

    Emmanuel O. Olorunsola

    2017-01-01

    Full Text Available This study was aimed at evaluating chitosan-microcrystalline cellulose blends as direct compression excipients. Crab shell chitosan, α-lactose monohydrate, and microcrystalline cellulose powders were characterized. Blends of the microcrystalline cellulose and chitosan in ratios 9 : 1, 4 : 1, 2 : 1, and 1 : 1 as direct compression excipients were made to constitute 60% of metronidazole tablets. Similar tablets containing blends of the microcrystalline cellulose and α-lactose monohydrate as well as those containing pure microcrystalline cellulose were also produced. The compact density, tensile strength, porosity, disintegration time, and dissolution rate of tablets were determined. Chitosan had higher moisture content (7.66% and higher moisture sorption capacity (1.33% compared to microcrystalline cellulose and lactose. It also showed better flow properties (Carr’s index of 18.9% and Hausner’s ratio of 1.23. Compact density of tablets increased but tensile strength decreased with increase in the proportion of chitosan in the binary mixtures. In contrast to lactose, the disintegration time increased and the dissolution rate decreased with increase in the proportion of chitosan. This study has shown that chitosan promotes flowability of powder mix and rapid disintegration of tablet. However, incorporation of equal proportions of microcrystalline cellulose and chitosan leads to production of extended-release tablet. Therefore, chitosan promotes tablet disintegration at low concentration and enables extended-release at higher concentration.

  15. Spherical composite particles of rice starch and microcrystalline cellulose: a new coprocessed excipient for direct compression.

    Science.gov (United States)

    Limwong, Vasinee; Sutanthavibul, Narueporn; Kulvanich, Poj

    2004-03-12

    Composite particles of rice starch (RS) and microcrystalline cellulose were fabricated by spray-drying technique to be used as a directly compressible excipient. Two size fractions of microcrystalline cellulose, sieved (MCS) and jet milled (MCJ), having volumetric mean diameter (D50) of 13.61 and 40.51 microm, respectively, were used to form composite particles with RS in various mixing ratios. The composite particles produced were evaluated for their powder and compression properties. Although an increase in the microcrystalline cellulose proportion imparted greater compressibility of the composite particles, the shape of the particles was typically less spherical with rougher surface resulting in a decrease in the degree of flowability. Compressibility of composite particles made from different size fractions of microcrystalline cellulose was not different; however, using MCJ, which had a particle size range close to the size of RS (D50 = 13.57 microm), provided more spherical particles than using MCS. Spherical composite particles between RS and MCJ in the ratio of 7:3 (RS-MCJ-73) were then evaluated for powder properties and compressibility in comparison with some marketed directly compressible diluents. Compressibility of RS-MCJ-73 was greater than commercial spray-dried RS (Eratab), coprocessed lactose and microcrystalline cellulose (Cellactose), and agglomerated lactose (Tablettose), but, as expected, lower than microcrystalline cellulose (Vivapur 101). Flowability index of RS-MCJ-73 appeared to be slightly lower than Eratab but higher than Vivapur 101, Cellactose, and Tablettose. Tablets of RS-MCJ-73 exhibited low friability and good self-disintegrating property. It was concluded that these developed composite particles could be introduced as a new coprocessed direct compression excipient.

  16. Some historical remarks on microcrystalline arthritis (gout and chondrocalcinosis

    Directory of Open Access Journals (Sweden)

    G. Pasero

    2012-01-01

    Full Text Available The history of microcrystalline arthritis only began in 1961 when Daniel McCarty and Joseph Lee Hollander demonstrated the presence of sodium monourate crystals in the synovial fluid of gouty patients. However, gout is a historical disease, thanks to the descriptions of Hippocrates, Caelius Aurelianus, Soranus of Ephesus and Araeteus of Cappadocia. The relationship between hyperuricemia and gout was first documented in the nineteenth century by Alfred Baring Garrod, who demonstrated deposits of uric acid crystals on a linen thread held dipped in acidified blood (the so-called “thread method”. Gout has always been considered a prerogative of the moneyed classes (arthritis divitum, and history is full of famous gouty personalities, including kings, emperors, popes, commanders, politicians, artists, writers, philosophers and scientists. Another form of microcrystalline arthritis, chondrocalcinosis, was identified as being a rheumatic disorder different from gout in the 1960s. As a specific clinical entity, it was first identified in 1958 by Dušan Žitnˇan and Štefan Sit’aj in a few Slovak families.

  17. Investigation into the suitability of capillary tubes for microcrystalline testing.

    Science.gov (United States)

    Elie, Leonie E; Baron, Mark G; Croxton, Ruth S; Elie, Mathieu P

    2013-07-01

    A comparison between microcrystalline tests performed on microscope slides and flat capillary tubes with inner diameters ranging from 0.1 to 0.7 mm was carried out to explore the appropriateness of tubes for rapid testing of suspected drugs of abuse in the laboratory as well as in the field. Tests for mephedrone, cocaine, and phencyclidine were chosen as examples to investigate the handling of the capillary tubes, the influence on crystal habit, size, and the effects on the limit of detection. Image stacking software was used to increase the depth of field of micrographs taken from developed microcrystals greatly enhancing the interpretability even months after carrying out the microcrystalline test. Additionally, the potential of seeding capillary tubes with a reagent was studied. Pre-treatment of tubes would allow microcrystalline tests to be carried out quicker and anywhere without the necessity of taking along expensive and hazardous reagents. The sealing of capillary tubes containing developed microcrystalline tests in order to preserve results for a long period of time was successfully done by applying paraffin wax to the open ends. Finally, it was concluded that capillary tubes are suitable vessels for performing microcrystalline tests. The increased portability of the improved set-up allows tests to be safely executed outside laboratories without impairing the quality of the result. Findings were applied to six legal high samples purchased online between May and August 2011. The active ingredients like MDAI as well as cutting agents like caffeine were successfully identified using the microcrystalline test technique in capillary tubes. Copyright © 2012 John Wiley & Sons, Ltd.

  18. Plasma processing of microcrystalline silicon films : filling in the gaps

    NARCIS (Netherlands)

    Bronneberg, A.C.

    2012-01-01

    Hydrogenated microcrystalline silicon (µc-Si:H) is a mixed-phase material consisting of crystalline silicon grains, hydrogenated amorphous silicon (a-Si:H) tissue, and voids. Microcrystalline silicon is extensively used as absorber layer in thin-film tandem solar cells, combining the advantages of a

  19. Low power high growth rate deposition of microcrystalline silicon

    OpenAIRE

    Feltrin, A; Bugnon, G; Meillaud, F; Bailat, J; Ballif, C

    2008-01-01

    Microcrystalline growth regimes and solar cells obtained in different pressure and silane depletion conditions are studied in a large area KAI-S plasma reactor. The microcrystalline material quality is systematically investigated by Fourier Transform Photocurrent Spectroscopy (FTPS) to evaluate the defect density. It is shown that higher pressure and silane depletion positively affect the material quality. A clear correlation between FTPS measurements and cell efficiency is established, showi...

  20. Physical and mechanical properties of microcrystalline cellulose prepared from local agricultural residues

    International Nuclear Information System (INIS)

    El-Sakhawy, M.M.; Hassan, M.L.

    2005-01-01

    Microcrystalline cellulose (MCC) was prepared from local agricultural residues, namely, bagasse, rice straw, and cotton stalks bleached pulps. Hydrolysis of bleached pulps was carried out using hydrochloric or sulfuric acid to study the effect of the acid used on the properties of produced microcrystalline cellulose such as degree of polymerization (DP), crystallinity index (CrI), crystallite size, bulk density, particle size, and thermal stability. The mechanical properties of tablets made from microcrystalline cellulose of the different agricultural residues were tested and compared to commercial grade MCC. The use of rice straw pulp in different proportions as a source of silica to prepare silicified microcrystalline cellulose (SMCC) was carried out. The effect of the percent of silica on the mechanical properties of tablets before and after wet granulation was tested

  1. Physical and mechanical properties of microcrystalline cellulose prepared from local agricultural residues

    Energy Technology Data Exchange (ETDEWEB)

    El-Sakhawy, M M; Hassan, M L [Cellulose and Paper Dept., National Research Center, Dokki, Cairo (Egypt)

    2005-07-01

    Microcrystalline cellulose (MCC) was prepared from local agricultural residues, namely, bagasse, rice straw, and cotton stalks bleached pulps. Hydrolysis of bleached pulps was carried out using hydrochloric or sulfuric acid to study the effect of the acid used on the properties of produced microcrystalline cellulose such as degree of polymerization (DP), crystallinity index (CrI), crystallite size, bulk density, particle size, and thermal stability. The mechanical properties of tablets made from microcrystalline cellulose of the different agricultural residues were tested and compared to commercial grade MCC. The use of rice straw pulp in different proportions as a source of silica to prepare silicified microcrystalline cellulose (SMCC) was carried out. The effect of the percent of silica on the mechanical properties of tablets before and after wet granulation was tested.

  2. Optical and electronic properties of microcrystalline silicon as a function of microcrystallinity

    International Nuclear Information System (INIS)

    Han, Daxing; Yue, Guozhen; Lorentzen, J. D.; Lin, Jing; Habuchi, H.; Wang, Qi

    2000-01-01

    Films were prepared by hot wire chemical vapor deposition at ∼240 degree sign C with varied hydrogen dilution ratios R=H 2 :SiH 4 from 1 to 20. The optical and electronic properties as a function of microcrystallinity were studied. We found: (a) At low H dilution R≤2, there is no measurable crystallinity by Raman spectroscopy and x-ray diffraction in the a-Si:H matrix, but an optical absorption peak at ∼1.25 eV appears; when R=2, the film shows the lowest subgap absorption, the highest photosensitivity, and the largest optical gap. (b) When R≥3, the c-Si phase is measurable by Raman and a low-energy photoluminescence (PL) band (0.84-1.0 eV) appears in addition to the high-energy band (1.3-1.4 eV). Meanwhile, all the absorption spectra show a featureless line shape. (c) An energy redshift is observed for both PL peaks as the film grows thicker. Finally, (d) the conductivity activation energy first decreases from 0.68 to 0.12 eV, then increases with increasing microcrystallinity. A mode of two sets of energy bands of electronic states for these two-phase materials is suggested. (c) 2000 American Institute of Physics

  3. Compaction mechanism and tablet strength of unlubricated and lubricated (silicified) microcrystalline cellulose

    NARCIS (Netherlands)

    van Veen, B; Bolhuis, G K; Wu, Y S; Zuurman, K; Frijlink, H W

    This paper describes the differences in compaction properties between microcrystalline cellulose (MCC) and microcrystalline cellulose co-processed with colloidal silicon dioxide (SMCC). The different compaction parameters are not only compared for the pure materials, but also for the lubricated

  4. Charge transport properties in microcrystalline KDyFe(China)6

    International Nuclear Information System (INIS)

    Aubert, P.H.; Goubard, F.; Chevrot, C.; Tabuteau, A.

    2007-01-01

    Microcrystalline solid dysprosium(III) hexacyanoferrate(II) was synthesized by co-precipitation in aqueous solution. The resulting solid has been studied by Fourier transform infrared spectroscopy, X-ray analysis and solid state electrochemistry. The use of a cavity microelectrode was necessary to explore a wide range of time scale and minimize the (undesired) capacitive currents. Cyclic voltametric experiments were very helpful to understand the kinetic of charge transfer in such microstructure. A structure-properties relationship has been established from the crystallographic and the electrochemical properties. A square-scheme is presented to explain the unique electrochemical behavior of hexacyanoferrate containing dysprosium since this compound exhibits a second redox system. The solid presents an open channel-like morphology in which the motion of charged species occurs during the redox processes. Precisely, the electronic transfer is accompanied by a cation diffusion inside the microcrystalline structure. The size of these channels strongly suggests that the kinetic of charge transfer is limited by the cation transport into these structures. - Graphical abstract: Dy and Fe polyhedra packing in the cell of KDyFe(China) 6 .3.5H 2 O shows occluded water molecules and potassium ions forming a pseudohexagonal 2D sub-lattice connected to each other by diffusion channels

  5. Physicotechnical, spectroscopic and thermogravimetric properties of powdered cellulose and microcrystalline cellulose derived from groundnut shells

    Directory of Open Access Journals (Sweden)

    Chukwuemeka P. Azubuike

    2012-09-01

    Full Text Available α-Cellulose and microcrystalline cellulose powders, derived from agricultural waste products, that have for the pharmaceutical industry, desirable physical (flow properties were investigated. α–Cellulose (GCN was extracted from groundnut shell (an agricultural waste product using a non-dissolving method based on inorganic reagents. Modification of this α -cellulose was carried out by partially hydrolysing it with 2N hydrochloric acid under reflux to obtain microcrystalline cellulose (MCGN. The physical, spectroscopic and thermal properties of the derived α-cellulose and microcrystalline cellulose powders were compared with Avicel® PH 101, a commercial brand of microcrystalline cellulose (MCCA, using standard methods. X-ray diffraction and infrared spectroscopy analysis showed that the α-cellulose had lower crystallinity. This suggested that treatment with 2N hydrochloric acid led to an increase in the crystallinity index. Thermogravimetric analysis showed quite similar thermal behavior for all cellulose samples, although the α-cellulose had a somewhat lower stability. A comparison of the physical properties between the microcrystalline celluloses and the α-cellulose suggests that microcrystalline cellulose (MCGN and MCCA might have better flow properties. In almost all cases, MCGN and MCCA had similar characteristics. Since groundnut shells are agricultural waste products, its utilization as a source of microcrystalline cellulose might be a good low-cost alternative to the more expensive commercial brand.

  6. Analysis of heating effect on the process of high deposition rate microcrystalline silicon

    International Nuclear Information System (INIS)

    Xiao-Dan, Zhang; He, Zhang; Chang-Chun, Wei; Jian, Sun; Guo-Fu, Hou; Shao-Zhen, Xiong; Xin-Hua, Geng; Ying, Zhao

    2010-01-01

    A possible heating effect on the process of high deposition rate microcrystalline silicon has been studied. It includes the discharge time-accumulating heating effect, discharge power, inter-electrode distance, and total gas flow rate induced heating effect. It is found that the heating effects mentioned above are in some ways quite similar to and in other ways very different from each other. However, all of them will directly or indirectly cause the increase of the substrate surface temperature during the process of depositing microcrystalline silicon thin films, which will affect the properties of the materials with increasing time. This phenomenon is very serious for the high deposition rate of microcrystalline silicon thin films because of the high input power and the relatively small inter-electrode distance needed. Through analysis of the heating effects occurring in the process of depositing microcrystalline silicon, it is proposed that the discharge power and the heating temperature should be as low as possible, and the total gas flow rate and the inter-electrode distance should be suitable so that device-grade high quality deposition rate microcrystalline silicon thin films can be fabricated

  7. Studies on Hydrotreating Process of Microcrystalline Wax Produced from Marine Belayim Crude Oil

    International Nuclear Information System (INIS)

    EI Karashi, S.; Marawan, H.

    2004-01-01

    Abstract Microcrystalline wax was produced from solvent dewaxing process of vacuum residue raffinate produced from Marine Belayim origin. The untreated microcrystalline wax contains trace amounts of sulfur, oxygen, nitrogen and organometallic compounds as well as heavy aromatics which affect the properties of wax applications in pharmaceutical and technical fields . Microcrystalline wax hydrotreating process was studied using digital controlled unit and Ni O-MoO 3 / Al 2 O 3 catalyst, where operating parameters that controlled the efficiency of the hydrotreated wax were studied separately at different values including reactor temperature, reactor pressure, liquid hourly space velocity and hydrogen to hydrocarbon ratio . Hydrotreated microcrystalline wax at operating conditions (temperature 300 degree C, pressure 73 kg/cm 2 , LHS V 0.52 h-l and H 2 /HC ratio 266.6 Nm 3 /m 3 ) has the best quality to be used as food grade wax

  8. Simultaneous solid phase extraction of cobalt, strontium and cesium from liquid radioactive waste using microcrystalline naphthalene

    International Nuclear Information System (INIS)

    Hamed, Mostafa Mohamed; Attallah, Mohamed Fathy; Metwally, Sayed Sayed

    2014-01-01

    Most of the procedures developed for the extraction of cobalt, strontium and cesium by solid phase extraction do not employ simultaneous extraction of them. In this study, rapid simultaneous removal of Co 2+ , Sr 2+ and Cs + on microcrystalline naphthalene as solid-phase extractant was investigated. These ions were allowed to form chelates with oxine and then adsorbed on freshly microcrystalline naphthalene from aqueous solutions. The solid phase extraction procedure (SPE) was optimized by using model solution containing Co 2+ , Sr 2+ and Cs + in batch system. The effects of different parameters such as variation in pH, reagent concentration, standing time, naphthalene solution concentration and contact time on the simultaneous removal of these ions was studied. The obtained results indicated that, sorption was found to be rapid, and the percentage removal of Co 2+ , Sr 2+ and Cs + was found to be 98, 79 and 68% within 10 min, respectively. The kinetics of the sorption process was investigated to understand the kinetic characteristics of sorption of metal chelates onto microcrystalline naphthalene. The developed procedure has been successfully applied to the removal and recovery of 60 Co and 134 Cs from liquid radioactive waste. The parameters can be used for designing a plant for treatment of wastewater economically.

  9. Evaluation of tablet disintegrant properties of microcrystalline ...

    African Journals Online (AJOL)

    This study was aimed at exploring the application of microcrystalline cellulose from cassava fermentation waste as a disintegrant in the formulation of paracetamol tablets for immediate release. Alkali delignification of the dried cassava fermentation fibres, followed by bleaching and acid depolymerisation was employed in ...

  10. Microcrystalline silicon carbide alloys prepared with HWCVD as highly transparent and conductive window layers for thin film solar cells

    International Nuclear Information System (INIS)

    Finger, F.; Astakhov, O.; Bronger, T.; Carius, R.; Chen, T.; Dasgupta, A.; Gordijn, A.; Houben, L.; Huang, Y.; Klein, S.; Luysberg, M.; Wang, H.; Xiao, L.

    2009-01-01

    Crystalline silicon carbide alloys have a very high potential as transparent conductive window layers in thin-film solar cells provided they can be prepared in thin-film form and at compatible deposition temperatures. The low-temperature deposition of such material in microcrystalline form (μc-Si:C:H) was realized by use of monomethylsilane precursor gas diluted in hydrogen with the Hot-Wire Chemical Vapor Deposition process. A wide range of deposition parameters has been investigated and the structural, electronic and optical properties of the μc-SiC:H thin films have been studied. The material, which is strongly n-type from unintentional doping, has been used as window layer in n-side illuminated microcrystalline silicon solar cells. High short-circuit current densities are obtained due to the high transparency of the material resulting in a maximum solar cell conversion efficiency of 9.2%.

  11. Adsorption of cationic amylopectin on microcrystalline cellulose.

    NARCIS (Netherlands)

    Steeg, van de H.G.M.; Keizer, de A.; Cohen Stuart, M.A.; Bijsterbosch, B.H.

    1993-01-01

    The effects of electrolyte concentration and pH on the adsorption of cationic amylopectin on microcrystalline cellulose were investigated. The adsorbed amount in the pseudo-plateau of the isotherm showed a maximum as a function of the electrolyte concentration. We compared the data with a recent

  12. Relationship between defect density and charge carrier transport in amorphous and microcrystalline silicon

    International Nuclear Information System (INIS)

    Astakhov, Oleksandr; Carius, Reinhard; Finger, Friedhelm; Petrusenko, Yuri; Borysenko, Valery; Barankov, Dmytro

    2009-01-01

    The influence of dangling-bond defects and the position of the Fermi level on the charge carrier transport properties in undoped and phosphorous doped thin-film silicon with structure compositions all the way from highly crystalline to amorphous is investigated. The dangling-bond density is varied reproducibly over several orders of magnitude by electron bombardment and subsequent annealing. The defects are investigated by electron-spin-resonance and photoconductivity spectroscopies. Comparing intrinsic amorphous and microcrystalline silicon, it is found that the relationship between defect density and photoconductivity is different in both undoped materials, while a similar strong influence of the position of the Fermi level on photoconductivity via the charge carrier lifetime is found in the doped materials. The latter allows a quantitative determination of the value of the transport gap energy in microcrystalline silicon. The photoconductivity in intrinsic microcrystalline silicon is, on one hand, considerably less affected by the bombardment but, on the other hand, does not generally recover with annealing of the defects and is independent from the spin density which itself can be annealed back to the as-deposited level. For amorphous silicon and material prepared close to the crystalline growth regime, the results for nonequilibrium transport fit perfectly to a recombination model based on direct capture into neutral dangling bonds over a wide range of defect densities. For the heterogeneous microcrystalline silicon, this model fails completely. The application of photoconductivity spectroscopy in the constant photocurrent mode (CPM) is explored for the entire structure composition range over a wide variation in defect densities. For amorphous silicon previously reported linear correlation between the spin density and the subgap absorption is confirmed for defect densities below 10 18 cm -3 . Beyond this defect level, a sublinear relation is found i.e., not

  13. Post-deposition thermal annealing studies of hydrogenated microcrystalline silicon deposited at 40 deg. C

    International Nuclear Information System (INIS)

    Bronsveld, P.C.P.; Wagt, H.J. van der; Rath, J.K.; Schropp, R.E.I.; Beyer, W.

    2007-01-01

    Post-deposition thermal annealing studies, including gas effusion measurements, measurements of infrared absorption versus annealing state, cross-sectional transmission electron microscopy (X-TEM) and atomic force microscopy (AFM), are used for structural characterization of hydrogenated amorphous and microcrystalline silicon films, prepared by very high frequency plasma enhanced chemical vapor deposition (VHF-PECVD) at low substrate temperature (T S ). Such films are of interest for application in thin semiconductor devices deposited on cheap plastics. For T S ∼ 40 deg. C, H-evolution shows rather complicated spectra for (near-) microcrystalline material, with hydrogen effusion maxima seen at ∼ 200-250 deg. C, 380 deg. C and ∼ 450-500 deg. C, while for the amorphous material typical spectra for good-quality dense material are found. Effusion experiments of implanted He demonstrate for the microcrystalline material the presence of a rather open (void-rich) structure. A similar tendency can be concluded from Ne effusion experiments. Fourier Transform infrared (FTIR) spectra of stepwise annealed samples show Si-H bond rupture already at annealing temperatures of 150 deg. C. Combined AFM/X-TEM studies reveal a columnar microstructure for all of these (near-) microcrystalline materials, of which the open structure is the most probable explanation of the shift of the H-effusion maximum in (near-) microcrystalline material to lower temperature

  14. Plasma deposition of microcrystalline silicon solar cells. Looking beyond the glass

    Energy Technology Data Exchange (ETDEWEB)

    Donker, M.N. van den

    2006-07-01

    Microcrystalline silicon emerged in the past decade as highly interesting material for application in efficient and stable thin film silicon solar cells. It consists of nanometer-sized crystallites embedded in a micrometer-sized columnar structure, which gradually evolves during the SiH{sub 4} based deposition process starting from an amorphous incubation layer. Understanding of and control over this transient and multi-scale growth process is essential in the route towards low-cost microcrystalline silicon solar cells. This thesis presents an experimental study on the technologically relevant high rate (5-10 Aa s{sup -1}) parallel plate plasma deposition process of state-of-the-art microcrystalline silicon solar cells. The objective of the work was to explore and understand the physical limits of the plasma deposition process as well as to develop diagnostics suitable for process control in eventual solar cell production. Among the developed non-invasive process diagnostics were a pyrometer, an optical spectrometer, a mass spectrometer and a voltage probe. Complete thin film silicon solar cells and modules were deposited and characterized. (orig.)

  15. Optimization of extraction of microcrystalline cellulose from orange ...

    African Journals Online (AJOL)

    This study investigated the optimum processing conditions for obtaining the maximum yield of microcrystalline cellulose (MCC) powder from orange peel waste (OPW) by use of response surface methodology (RSM). Central composite design (CCD) was used to evaluate the optimum process conditions for producing MCC ...

  16. Esterification of microcrystalline cellulose by binary mixture of pyromellitic dianhydride and boric acid

    International Nuclear Information System (INIS)

    Arslanov, Sh.S.; Petropavlovskij, G.A.

    1996-01-01

    The reaction between microcrystalline cellulose and boric acid in the medium of dimethyl-sulfoxide (DMSO) and in solid phase has been studied. By the methods of IR and 1 H NMR spectroscopy it has been shown that the triatment of cellulose with boric acid solution in DMSO, while the latter is removed under vacuum conditions and cellulose is heated up to 170 deg C, gives rise to formation of unstable esters of cellulose and boric acid. Pyromellitate-borates of cellulose are formed in the course of cellulose reaction with a mixture of boric acid and pyromellite dianhydride. 9 refs., 3 figs., 1 tab

  17. Long-living positron and positronium states in zeolites and microcrystalline oxides

    International Nuclear Information System (INIS)

    Kajcsos, Zs.; Liszkay, L.; Varga, L.; Lohonyai, L.; Lazar, K.

    1995-01-01

    Positron annihilation (PA) investigation were performed on zeolites (X, Y and ZSM-5) and on microcrystalline MgO, Al 2 O 3 and SiO 2 , providing long lifetime components attributed to o-Ps atoms. In addition to the positron lifetime (LT) measurements, the energy distribution (ED) of the annihilation gamma radiation spectrum was recorded in the 30 keV - 1.5 MeV range for different samples and was compared to reference distributions for Si and GaAs samples, where no long-living Ps states are formed. Apart from the strong correlation with the water content in the samples, the positron data collected testify much more pronounced positronium hosting features for powders of the mentioned oxides than for zeolites. Positron LT spectroscopy combined with recording of the ED of the annihilation radiation provides reliable information on the forming of long living 3γ states. (author) 15 refs.; 4 figs

  18. Spherical composite particles of rice starch and microcrystalline cellulose: A new coprocessed excipient for direct compression

    OpenAIRE

    Limwong, Vasinee; Sutanthavibul, Narueporn; Kulvanich, Poj

    2004-01-01

    Composite particles of rice starch (RS) and microcrystalline cellulose were fabricated by spray-drying technique to be used as a directly compressible excipient. Two size fractions of microcry stalline cellulose, sieved (MCS) and jet milled (MCJ), having volumetric mean diameter (D50) of 13.61 and 40.51 μm, respectively, were used to form composite particles with RS in various mixing ratios. The composite particles produced were evaluated for their powder and compression properties. Although ...

  19. EPR response of sucrose and microcrystalline cellulose to measure high doses of gamma radiation

    International Nuclear Information System (INIS)

    Torijano, E.; Cruz, L.; Gutierrez, G.; Azorin, J.; Aguirre, F.; Cruz Z, E.

    2015-10-01

    Solid dosimeters of sucrose and microcrystalline cellulose (Avicel Ph-102) were prepared, following the same process, in order to compare their EPR response against that of the l-alanine dosimeters considered as reference. All lots of dosimeters were irradiated with gamma radiation in Gamma beam irradiator with 8 kGy/h of the Nuclear Sciences Institute of UNAM. Doses ranged from 1 to 10 kGy respectively. We found that both the response of sucrose as microcrystalline cellulose were linear; however, the response intensity was, on average, twenty times more for sucrose. Comparing this against the EPR response of l-alanine in the range of doses, it was found that the response to sucrose is a third part; and microcrystalline cellulose is a sixtieth, approximately. The results agree with those found in the literature for sucrose, leaving open the possibility of investigating other dosage ranges for cellulose. (Author)

  20. Preparation and Characterization of Microcrystalline Cellulose (MCC from Kenaf and Cotton Stem

    Directory of Open Access Journals (Sweden)

    Farshad Mirehki

    2013-11-01

    Full Text Available Cellulose, microcrystalline cellulose (MCC and nanofiber cellulose are the ones of materials which are being used recently as biodegradable filler and reinforcing agent for making composites. In this research, microcrystalline cellulose were prepared from kenaf and cotton bast by hydrochloric acid hydrolysis. The effects of hydrolysis condition on amount of crystallinity and crystal size of MCC were investigated by infrared spectroscopy (FT-IR, X-ray diffraction (XRD and scanning electron microscopy (SEM. Results have shown that in both samples increasing the acid ratio increased the crystallinity; however, the size of crystals did not change. SEM results have shown that after hydrolysis the size of sample particles was micro.

  1. Carrier mobilities in microcrystalline silicon films

    International Nuclear Information System (INIS)

    Bronger, T.; Carius, R.

    2007-01-01

    For a better understanding of electronic transport mechanisms in thin-film silicon solar cell quality films, we have investigated the Hall mobility for electrons in microcrystalline/amorphous silicon over a range of crystallinities and doping concentrations. We find that Hall mobility increases with increasing doping concentration in accordance with earlier measurements. With increasing amorphous fraction, the measured mobility decreases suggesting a negative influence of the additional disorder. The results suggest a differential mobility model in which mobility depends on the energy level of the carriers that contribute to the electrical current

  2. Diagenetic Microcrystalline Opal Varieties from the Monterey Formation, CA: HRTEM Study of Structures and Phase Transformation Mechanisms

    Science.gov (United States)

    Cady, Sherry L.; Wenk, H.-R.; DeVincenzi, Don (Technical Monitor)

    1994-01-01

    Microcrystalline opal varieties form as intermediary precipitates during the diagenetic transformation of biogenically precipitated non-crystalline opal (opal-A) to microquartz. With regard to the Monterey Formation of California, X-ray powder diffraction studies have shown that a decrease in the primary d-spacing of opal-CT toward that of cristobalite occurs with increasing diagenesis. The initial timing of opal-CT/quartz formation and the value of the primary opal-CT d-spacing, are influenced by the sediment. lithology. Transmission electron microscopy methods (CTEM/HRTEM) were used to investigate the structure of the diagenetic phases and establish transformation mechanisms between the varieties of microcrystalline opals in charts and porcelanites from the Monterey Formation. HRTEM images revealed that the most common fibrous varieties of microcrystalline opals contain varying amounts of structural disorder. Finite lamellar units of cristobalite-and tridymite-type. layer sequences were found to be randomly stacked in a direction perpendicular to the fiber axis. Disordered and ordered fibers were found to have coprecipitated within the same radial fiber bundles that formed within the matrix of the Most siliceous samples. HRTEM images, which reveal that the fibers within radial and lepispheric fiber bundles branch non-crystallographically, support an earlier proposal that microspheres in chert grow via a spherulitic growth mechanism. A less common variety of opal-CT was found to be characterized by non-parallel (low-angle) stacking sequences that often contain twinned lamellae. Tabular-shaped crystals of orthorhombic tridymite (PO-2) were also identified in the porcelanite samples. A shift in the primary d-spacing of opal-CT has been interpreted as an indication of solid-state ordering g toward a predominantly cristobalite structure, (opal-C). Domains of opal-C were identified as topotactically-oriented overgrowths on discrete Sections of opal-CT fibers and as

  3. The atomic hydrogen flux during microcrystalline silicon solar cell deposition

    NARCIS (Netherlands)

    Sanden, van de M.C.M.; Dingemans, G.; van den Donker, M.N.; Hrunski, D.; Gordijn, A.; Kessels, W.M.M.

    2009-01-01

    Etch product detection by in situ optical emission spectroscopy is used to detect the phase transition from amorphous to microcrystalline silicon. In this contribution it is demonstrated that a calibrated version of this technique can be used to determine the absolute hydrogen flux under

  4. Properties of amorphous and microcrystalline superconductors

    International Nuclear Information System (INIS)

    Johnson, W.L.; Poon, S.J.

    1975-01-01

    Results of x-ray diffraction, electrical resistivity, critical field(H/sub c2/) and transport measurements are presented and discussed for bulk amorphous and microcrystalline transition metal alloys (Au--La, Nb--Rh, Nb--Ni--Rh, and Pd--Zr) obtained by liquid quenching. The transition temperature of the alloys is in the range 1.5 to 4.7 0 K. The J/sub c/--H/sub c2/--T/sub c/ relations are rather simple for this class of material and are compared with the theories of type II superconductors. The high resistance of bulk metallic glass to radiation damage might render them suitable for magnetic field applications in high radiation environments

  5. Microcrystalline silicon, grain boundaries and role of oxygen

    Czech Academy of Sciences Publication Activity Database

    Kočka, Jan; Stuchlíková, The-Ha; Ledinský, Martin; Stuchlík, Jiří; Mates, Tomáš; Fejfar, Antonín

    2009-01-01

    Roč. 93, č. 8 (2009), s. 1444-1447 ISSN 0927-0248 R&D Projects: GA MŠk(CZ) LC06040; GA AV ČR KAN400100701; GA ČR(CZ) GD202/05/H003; GA MŠk LC510; GA AV ČR IAA1010413 Institutional research plan: CEZ:AV0Z10100521 Keywords : microcrystalline silicon * grain boundaries * electronic transport * hydrogen * oxygen Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 3.858, year: 2009

  6. Patterning of hydrogenated microcrystalline silicon growth by magnetic field

    Czech Academy of Sciences Publication Activity Database

    Fejfar, Antonín; Stuchlík, Jiří; Mates, Tomáš; Ledinský, Martin; Honda, Shinya; Kočka, Jan

    2005-01-01

    Roč. 87, č. 1 (2005), 011901/1-011901/3 ISSN 0003-6951 R&D Projects: GA AV ČR(CZ) IAA1010316; GA AV ČR(CZ) IAA1010413; GA ČR(CZ) GD202/05/H003 Institutional research plan: CEZ:AV0Z10100521 Keywords : hydrogenated microcrystalline silicon * magnetic field growth Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 4.127, year: 2005

  7. FTIR spectroscopy and X-ray powder diffraction characterization of microcrystalline cellulose obtained from alfa fibers

    Directory of Open Access Journals (Sweden)

    Trache D.

    2013-07-01

    Full Text Available Many cereal straws have been used as raw materials for the preparation of microcrystalline cellulose (MCC. These raw materials were gradually replaced with wood products; nevertheless about 10% of the world overall pulp production is obtained from non-wood raw material. The main interest in pulp made from straw is that it provides excellent fibres for different industries with special properties, and that it is the major available source of fibrous raw material in some geographical areas. The aim of the present work was to characterize microcrystalline cellulose prepared from alfa fibers using the hydrolysis process. The products obtained are characterized with FTIR spectroscopy and X-ray powder diffraction. As a result, FTIR spectroscopy is an appropriate technique for studying changes occurred by any chemical treatment. The spectrum of alfa grass stems shows the presence of lignin and hemicelluloses. However, the cellulose spectrum indicates that the extraction of lignin and hemicellulose was effective. The X-ray analysis indicates that the microcrystalline cellulose is more crystalline than the source material.

  8. Optimisation of the composition and production of mannitol/microcrystalline cellulose tablets

    NARCIS (Netherlands)

    Westerhuis, J.A; de Haan, P; Zwinkels, J; Jansen, W.T; Coenegracht, P.M J; Lerk, C.F

    1996-01-01

    Mixtures of mannitol and microcrystalline cellulose (MCC) were investigated on a small-production scale by granulation in a high-shear mixer and compression into tablets. For both excipients only a few cases of incompatibilities with active ingredients are known. Tablets with only MCC as the filler

  9. Physical properties of P and B doped microcrystalline SI:H deposited by PECVD

    International Nuclear Information System (INIS)

    Rubino, A.; Addonizio, M.L.; Conte, G.; Nobile, G.; Terzini, E.

    1993-01-01

    Boron and phosphorus doped high conductivity microcrystalline thin films were deposited in a PECVD reactor. This paper reports conductivities as high as 3 and 41 S/cm for B and P doped materials respectively on films deposited at 210 degrees C. The conductivity, as well as, the microcrystalline fraction increase for the n layer with decreasing RF power, while, for the p material, an increase of power is needed to improve the film characteristics. The conductivity prefactor, as well as, the conductivity itself as a function of the activation energy show a slope inversion for both n and p materials at an activation energy of about 40 meV and 80 meV respectively. Different possible transport mechanisms are examined in order to explain the experimental data

  10. A novel method of producing a microcrystalline beta-sitosterol suspension in oil

    DEFF Research Database (Denmark)

    Christiansen, Leena I; Rantanen, Jukka T; von Bonsdorff, Anna K

    2002-01-01

    This paper describes a novel method of producing a microcrystalline oral suspension containing beta-sitosterol in oil for the treatment of hypercholesterolaemia. beta-Sitosterol pseudopolymorphs with different water contents were crystallized from acetone and acetone-water solutions. Structural...

  11. Carrier dynamics in microcrystalline silicon studied by time-resolved terahertz spectroscopy

    Czech Academy of Sciences Publication Activity Database

    Fekete, Ladislav; Němec, Hynek; Kadlec, Filip; Kužel, Petr; Stuchlík, Jiří; Fejfar, Antonín; Kočka, Jan

    2006-01-01

    Roč. 352, - (2006), s. 2846-2849 ISSN 0022-3093 R&D Projects: GA AV ČR(CZ) KJB100100512 Institutional research plan: CEZ:AV0Z10100520 Keywords : silicon * solar cells * dielectric properties * relaxation * electric modulus * chemical vapor deposition * microcrystallinity Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.362, year: 2006

  12. Microcrystalline silicon prepared at magnetic field modified nucleation

    Czech Academy of Sciences Publication Activity Database

    Kočka, Jan; Mates, Tomáš; Ledinský, Martin; Stuchlíková, The-Ha; Stuchlík, Jiří; Fejfar, Antonín

    2006-01-01

    Roč. 352, - (2006), s. 901-905 ISSN 0022-3093 R&D Projects: GA MŽP(CZ) SM/300/1/03; GA MŽP(CZ) SN/3/172/05; GA AV ČR(CZ) IAA1010316; GA AV ČR(CZ) IAA1010413; GA MŠk(CZ) LC510 Institutional research plan: CEZ:AV0Z10100521 Keywords : amorphous semiconductors * nucleation * electrical and electronic properties * chemical vapor deposition * atomic force and scanning tunneling microscopy * microcrystallinity * optical properties Subject RIV: BM - Solid Matter Physics ; Magnet ism Impact factor: 1.362, year: 2006

  13. Formation of microcrystalline germanium (μc-Ge:H) films from inductively coupled plasma CVD

    International Nuclear Information System (INIS)

    Okamoto, Y.; Makihara, K.; Higashi, S.; Miyazaki, S.

    2005-01-01

    Inductively coupled RF plasma of H 2 -diluted GeH 4 gas was applied to the growth of hydrogenated microcrystalline germanium (μc-Ge:H) films on quartz in a reactor with an external single-turn antenna placed on quartz plate window parallel to the substrate. The deposition rate, the crystallinity and the thickness of an amorphous incubation layer formed in the early stages of the film growth were evaluated as functions of GeH 4 concentration, gas flow rate, substrate temperature and the distance between the antenna and the grounded substrate susceptor. We demonstrated the growth of highly crystalized Ge films at a rate as high as 0.9 nm/s at 250 deg. C using a 8.3% GeH 4 diluted with H 2

  14. Microcrystalline thin-film solar cell deposition on moving substrates using a linear VHF-PECVD reactor and a cross-flow geometry

    International Nuclear Information System (INIS)

    Flikweert, A J; Zimmermann, T; Merdzhanova, T; Weigand, D; Appenzeller, W; Gordijn, A

    2012-01-01

    A concept for high-rate plasma deposition (PECVD) of hydrogenated microcrystalline silicon on moving substrates (dynamic deposition) is developed and evaluated. The chamber allows for substrates up to a size of 40 × 40 cm 2 . The deposition plasma is sustained between linear VHF electrodes (60 MHz) and a moving substrate. Due to the gas flow geometry and the high degree of source gas depletion, from the carrier's point of view the silane concentration varies when passing the electrodes. This is known to lead to different growth conditions which can induce transitions from microcrystalline to amorphous growth. The effect of different silane concentrations is simulated at a standard RF showerhead electrode by intentionally varying the silane concentration during deposition in static mode. This variation may decrease the layer quality of microcrystalline silicon, due to a shift of the crystallinity away from the optimum. However, adapting the input silane concentration, state-of-the-art solar cells are obtained. Microcrystalline cells (ZnO : Al/Ag back contacts) produced by the linear VHF plasma sources show an efficiency of 7.9% and 6.6% for depositions in static and dynamic mode, respectively. (paper)

  15. Surface studies of microcrystalline chitosan/poly(vinyl alcohol) mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Lewandowska, Katarzyna, E-mail: reol@chem.uni.torun.pl [Nicolaus Copernicus University, Faculty of Chemistry, Chair of Chemistry and Photochemistry of Polymers, 7 Gagarin Street, 87-100 Torun (Poland)

    2012-12-15

    Highlights: Black-Right-Pointing-Pointer The surface properties were investigated by AFM, SEM and FTIR. Black-Right-Pointing-Pointer The AFM images showed the lamellar structure of PVA in the blend. Black-Right-Pointing-Pointer SEM microscopy confirmed the existence of microphase separation of components. Black-Right-Pointing-Pointer FTIR analysis showed the existence of a weak interaction. - Abstract: In the present study, the surface properties of microcrystalline chitosan (MCCh), poly(vinyl alcohol) (PVA) and MCCh/PVA blends (made from acetic acid solutions with the MCCh concentration ranging from 20% to 80%) have been studied by the tapping-mode atomic force microscopy (AFM), scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) spectroscopy. The changes of topography images are considered by determining the root mean square (RMS, R{sub q}) deviation in the image data. For PVA samples, the transition between adjacent lamellae occurs through holes, islands, and bicontinuous structures. The AFM images showed also the lamellar structure of PVA in the blend. The crystalline topography of MCCh/PVA film surface suggests the presence of PVA on the top surface. The FTIR spectra of film blends, in the amide I and II region of MCCh and the hydroxyl stretching bands of PVA have been analyzed. FTIR analysis showed the existence of a weak interaction of the hydroxyl or amino groups of microcrystalline chitosan with hydroxyl groups of PVA.

  16. Surface studies of microcrystalline chitosan/poly(vinyl alcohol) mixtures

    International Nuclear Information System (INIS)

    Lewandowska, Katarzyna

    2012-01-01

    Highlights: ► The surface properties were investigated by AFM, SEM and FTIR. ► The AFM images showed the lamellar structure of PVA in the blend. ► SEM microscopy confirmed the existence of microphase separation of components. ► FTIR analysis showed the existence of a weak interaction. - Abstract: In the present study, the surface properties of microcrystalline chitosan (MCCh), poly(vinyl alcohol) (PVA) and MCCh/PVA blends (made from acetic acid solutions with the MCCh concentration ranging from 20% to 80%) have been studied by the tapping-mode atomic force microscopy (AFM), scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) spectroscopy. The changes of topography images are considered by determining the root mean square (RMS, R q ) deviation in the image data. For PVA samples, the transition between adjacent lamellae occurs through holes, islands, and bicontinuous structures. The AFM images showed also the lamellar structure of PVA in the blend. The crystalline topography of MCCh/PVA film surface suggests the presence of PVA on the top surface. The FTIR spectra of film blends, in the amide I and II region of MCCh and the hydroxyl stretching bands of PVA have been analyzed. FTIR analysis showed the existence of a weak interaction of the hydroxyl or amino groups of microcrystalline chitosan with hydroxyl groups of PVA.

  17. Simulation of the growth dynamics of amorphous and microcrystalline silicon

    OpenAIRE

    Bailat, Julien; Vallat-Sauvain, Evelyne; Vallat, A.; Shah, Arvind

    2008-01-01

    The qualitative description of the major microstructure characteristics of microcrystalline silicon is achieved through a three-dimensional discrete dynamical growth model. The model is based on three fundamental processes that determine surface morphology: (1) random deposition of particles, (2) local relaxation and (3) desorption. In this model, the incoming particle reaching the growing surface takes on a state variable representing a particular way of being incorporated into the material....

  18. Conventional and 360 degree electron tomography of a micro-crystalline silicon solar cell

    DEFF Research Database (Denmark)

    Duchamp, Martial; Ramar, Amuthan; Kovács, András

    2011-01-01

    Bright-field (BF) and annular dark-field (ADF) electron tomography in the transmission electron microscope (TEM) are used to characterize elongated porous regions or cracks (simply referred to as cracks thereafter) in micro-crystalline silicon (μc-Si:H) solar cell. The limitations of inferring...

  19. Microcrystalline diamond cylindrical resonators with quality-factor up to 0.5 million

    Energy Technology Data Exchange (ETDEWEB)

    Saito, Daisuke; Yang, Chen; Lin, Liwei [Department of Mechanical Engineering, University of California, Berkeley, California 94720 (United States); Heidari, Amir [Department of Mechanical and Aerospace Engineering, University of California, Davis, California 95616 (United States); Najar, Hadi [Department of Electrical and Computer Engineering, University of California, Davis, California 95616 (United States); Horsley, David A. [Department of Mechanical and Aerospace Engineering, University of California, Davis, California 95616 (United States); Department of Electrical and Computer Engineering, University of California, Davis, California 95616 (United States)

    2016-02-01

    We demonstrate high quality-factor 1.5 mm diameter batch-fabricated microcrystalline diamond cylindrical resonators (CR) with quality-factors limited by thermoelastic damping (TED) and surface loss. Resonators were fabricated 2.6 and 5.3 μm thick in-situ boron-doped microcrystalline diamond films deposited using hot filament chemical vapor deposition. The quality-factor (Q) of as-fabricated CR's was found to increase with the resonator diameter and diamond thickness. Annealing the CRs at 700 °C in a nitrogen atmosphere led to a three-fold increase in Q, a result we attribute to thinning of the diamond layer via reaction with residual O{sub 2} in the annealing furnace. Post-anneal Q exceeding 0.5 million (528 000) was measured at the 19 kHz elliptical wineglass modes, producing a ring-down time of 8.9 s. A model for Q versus diamond thickness and resonance frequency is developed including the effects of TED and surface loss. Measured quality factors are shown to agree with the predictions of this model.

  20. Microcrystalline bottom cells in large area thin film silicon MICROMORPH™ solar modules

    Czech Academy of Sciences Publication Activity Database

    Hoetzel, J.E.; Caglar, O.; Cashmore, J.S.; Goury, C.; Kalaš, J.; Klindworth, M.; Kupich, M.; Leu, G.F.; Lindic, M.H.; Losio, P.A.; Mates, Tomáš; Mereu, B.; Roschek, T.; Sinicco, I.

    2016-01-01

    Roč. 157, Dec (2016), s. 178-189 ISSN 0927-0248 R&D Projects: GA MŠk LM2015087 Institutional support: RVO:68378271 Keywords : microcrystalline silicon * material quality * PECVD * Raman crystallinity * grading * micromorph Subject RIV: BM - Solid Matter Physics ; Magnetism OBOR OECD: Condensed matter physics (including formerly solid state physics, supercond.) Impact factor: 4.784, year: 2016

  1. Water-in-oil Pickering emulsions stabilized by stearoylated microcrystalline cellulose.

    Science.gov (United States)

    Pang, Bo; Liu, Huan; Liu, Peiwen; Peng, Xinwen; Zhang, Kai

    2018-03-01

    Hydrophobic particles with static water contact angles larger than 90° are more like to stabilize W/O Pickering emulsions. In particular, high internal phase Pickering emulsions (HIPEs) are of great interest for diverse applications. However, W/O HIPEs have rarely been realized using sustainable biopolymers. Herein, we used stearoylated microcrystalline cellulose (SMCC) to stabilize W/O Pickering emulsions and especially, W/O HIPEs. Moreover, these W/O HIPEs can be further used as platforms for the preparation of porous materials, such as porous foams. Stearoylated microcrystalline cellulose (SMCC) was prepared by modifying MCC with stearoyl chloride under heterogeneous conditions. Using SMCC as emulsifiers, W/O medium and high internal phase Pickering emulsions (MIPEs and HIPEs) with various organic solvents as continuous phases were prepared using one-step and two-step methods, respectively. Polystyrene (PS) foams were prepared after polymerization of oil phase using HIPEs as templates and their oil/water separation capacity were studied. SMCC could efficiently stabilize W/O Pickering emulsions and HIPEs could only be prepared via the two-step method. The internal phase volume fraction of the SMCC-stabilized HIPEs reached as high as 89%. Diverse internal phase volume fractions led to distinct inner structures of foams with closed or open cells. These macroporous polystyrene (PS) foams demonstrated great potential for the effective absorption of organic solvents from underwater. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. Preconcentration of uranium, thorium, zirconium, titanium, molybdenum and vanadium with oxine supported on microcrystalline naphthalene and their determinations by ICP-AES

    International Nuclear Information System (INIS)

    Kumar, Naveen; Kumar, Sanjay; Kumar, Vijay; Nandakishore, S.S.; Bangroo, P.N.

    2013-01-01

    As an effective technique for separation and preconcentration of trace elements, solid-liquid extraction with microcrystalline naphthalene has received great attention in recent years. The application of the adsorption of the metal complexes on microcrystalline naphthalene has greatly enhanced the utility of solid-liquid extraction in trace analysis. A survey of the literature revealed that single element detection techniques such as spectrophotometry, atomic absorption spectrometry, and polarography were mostly combined with this separation method. However, multi-element simultaneous detection techniques, like ICP-AES and ICP-MS were seldom used as the detectors in this solid-liquid extraction method. The aim of this work was to attempt to adopt the reagent oxine for the separation and subsequent determination of U, Th, Zr, Ti, Mo and V by ICP-AES, after adsorption of their oxinate complexes on microcrystalline naphthalene

  3. Investigation of the powder flow behaviour of binary mixtures of microcrystalline celluloses and paracetamol

    Directory of Open Access Journals (Sweden)

    Ira Soppela

    2010-03-01

    Full Text Available The flow behaviour of binary mixtures of paracetamol and different grades of microcrystalline celluloses (Avicel® PH101, PH102 and PH200 was studied using a new testing method. The effect of physical characteristics of the powder including tribocharging and the addition of lubricant on the flow properties of the different mixtures was investigated. As expected, the flowability of the samples was affected both by the amount of paracetamol and the physical properties of microcrystalline celluloses (MCC and the mixtures. The effect of lubricant varied depending on the MCC grade: magnesium stearate was able to improve the flowability of the mixtures containing PH102 and PH200 while it did not affect the flowability of PH101. Multivariate analysis showed that the flow of the binary excipient-drug mixtures through an orifice is affected by several phenomena, such as charging, surface moisture, carrier payload and particle size.

  4. Raman mapping of microcrystalline silicon thin films with high spatial resolution

    Czech Academy of Sciences Publication Activity Database

    Ledinský, Martin; Vetushka, Aliaksi; Stuchlík, Jiří; Fejfar, Antonín; Kočka, Jan

    2010-01-01

    Roč. 7, 3-4 (2010), s. 704-707 ISSN 1862-6351 R&D Projects: GA MŠk(CZ) LC06040; GA AV ČR KAN400100701; GA MŠk LC510; GA AV ČR(CZ) IAA100100902 Institutional research plan: CEZ:AV0Z10100521 Keywords : Raman * atomic force microscopy * microcrystalline silicon Subject RIV: BM - Solid Matter Physics ; Magnetism http://www3.interscience.wiley.com/journal/123277609/abstract

  5. Characterization of microcrystalline I-layer for solar cells prepared in low temperature - plastic compatible process

    KAUST Repository

    Sliz, Rafal; Ahnood, Arman; Nathan, Arokia; Myllyla, Risto; Jabbour, Ghassan E.

    2012-01-01

    Microcrystalline silicon (mc-Si) lms deposited using a Plasma Enhanced Chemical Vapour Deposition (PECVD) process constitute an important material for manufacturing low-cost, large-area thin-lm devices, such as solar cells or thin-lm transistors

  6. The open-circuit voltage in microcrystalline silicon solar cells of different degrees of crystallinity

    International Nuclear Information System (INIS)

    Nath, Madhumita; Roca i Cabarrocas, P.; Johnson, E.V.; Abramov, A.; Chatterjee, P.

    2008-01-01

    We have used a detailed electrical-optical computer model (ASDMP) in conjunction with the experimental characterization of microcrystalline silicon thin-film solar cells of different degrees of crystallinity (but having identical P- and N-layers) to understand the observed decrease of the open-circuit voltage with increasing crystalline fraction. In order to model all aspects of the experimental current density-voltage and quantum efficiency characteristics of cells having low (∼ 75%) and high (over 90%) crystalline fraction, we had to assume both a higher mobility gap defect density and a lower band gap for the more crystallized material. The former fact is widely known to bring down the open-circuit voltage. Our calculations also reveal that the proximity of the quasi-Fermi levels to the energy bands in the cell based on highly crystallized (and assumed to have a lower band gap) microcrystalline silicon results in higher free and trapped carrier densities in this device. The trapped hole population is particularly high at and close to the P/I interface on account of the higher inherent defect density in this region and the fact that the hole quasi-Fermi level is close to the valence band edge here. This fact results in a strong interface field, a collapse of the field in the volume, and hence a lower open-circuit voltage. Thus a combination of higher mobility gap defects and a lower band gap is probably the reason for the lower open-circuit voltage in cells based on highly crystallized microcrystalline silicon

  7. Ultrafast carrier dynamics in microcrystalline silicon probed by time-resolved terahertz spectroscopy

    Czech Academy of Sciences Publication Activity Database

    Fekete, Ladislav; Kužel, Petr; Němec, Hynek; Kadlec, Filip; Deyneka, Alexander; Stuchlík, Jiří; Fejfar, Antonín

    2009-01-01

    Roč. 79, č. 11 (2009), 115306/1-115306/13 ISSN 1098-0121 R&D Projects: GA MŠk(CZ) LC06040; GA AV ČR(CZ) IAA100100902 Institutional research plan: CEZ:AV0Z10100520; CEZ:AV0Z10100521 Keywords : microcrystalline silicon * amorphous silicon * terahertz * ultrafast * photoconductivity Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 3.475, year: 2009

  8. Water-Protein Hydrogen Exchange in the Micro-Crystalline Protein Crh as Observed by Solid State NMR Spectroscopy

    International Nuclear Information System (INIS)

    Boeckmann, Anja; Juy, Michel; Bettler, Emmanuel; Emsley, Lyndon; Galinier, Anne; Penin, Francois; Lesage, Anne

    2005-01-01

    We report site-resolved observation of hydrogen exchange in the micro-crystalline protein Crh. Our approach is based on the use of proton T 2 ' -selective 1 H- 13 C- 13 C correlation spectra for site-specific assignments of carbons nearby labile protein protons. We compare the proton T 2 ' selective scheme to frequency selective water observation in deuterated proteins, and discuss the impacts of deuteration on 13 C linewidths in Crh. We observe that in micro-crystalline proteins, solvent accessible hydroxyl and amino protons show comparable exchange rates with water protons as for proteins in solution, and that structural constraints, such as hydrogen bonding or solvent accessibility, more significantly reduce exchange rates

  9. Amorphous and microcrystalline silicon applied in very thin tandem solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Schicho, Sandra

    2011-07-28

    Thin-film solar cells are fabricated by low-cost production processes, and are therefore an alternative to conventionally used wafer solar cells based on crystalline silicon. Due to the different band gaps, tandem cells that consist of amorphous (a-Si:H) and microcrystalline ({mu}c-Si:H) single junction solar cells deposited on top of each other use the solar spectrum much more efficient than single junction solar cells. The silicon layers are usually deposited on TCO (Transparent Conductive Oxide)-coated glass and metal- or plastic foils. Compared to the CdTe and CIGS based thin-film technologies, silicon thin-film solar cells have the advantage that no limitation of raw material supply is expected and no toxic elements are used. Nevertheless, the production cost per Wattpeak is the decisive factor concerning competitiveness and can be reduced by, e.g., shorter deposition times or reduced material consumption. Both cost-reducing conceptions are simultaneously achieved by reducing the a-Si:H and {mu}c-Si:H absorber layer thicknesses in a tandem device. In the work on hand, the influence of an absorber layer thickness reduction up to 77% on the photovoltaic parameters of a-Si:H/{mu}c-Si:H tandem solar cells was investigated. An industry-oriented Radio Frequency Plasma-Enhanced Chemical Vapour Deposition (RF-PECVD) system was used to deposit the solar cells on glass substrates coated with randomly structured TCO layers. The thicknesses of top and bottom cell absorber layers were varied by adjusting the deposition time. Reduced layer thicknesses lead to lower absorption and, hence, to reduced short-circuit current densities which, however, are partially balanced by higher open-circuit voltages and fill factors. Furthermore, by using very thin amorphous top cells, the light-induced degradation decreases tremendously. Accordingly, a thickness reduction of 75% led to an efficiency loss of only 21 %. By adjusting the parameters for the deposition of a-Si:H top cells, a

  10. 77 FR 25720 - Determination That GRIFULVIN V (Griseofulvin Microcrystalline) Tablets, 250 Milligrams, Was Not...

    Science.gov (United States)

    2012-05-01

    ... been discontinued from marketing for reasons other than safety or effectiveness. ANDAs that refer to... Sale for Reasons of Safety or Effectiveness AGENCY: Food and Drug Administration, HHS. ACTION: Notice... microcrystalline) tablets, 250 milligrams (mg), was not withdrawn from sale for reasons of safety or effectiveness...

  11. Antibody bond to the microcrystalline cellulose in progesterone radioimmunoassay

    International Nuclear Information System (INIS)

    Krnavek, B.

    1992-01-01

    A suspension of microcrystalline cellulose with bonded globulin fraction of the polyclonal antibody against progesterone was prepared and applied to the radioimmunoanalysis of progesterone in full milk and in blood serum. The results were compared with those obtained using RETRO-test kits; the comparison gave evidence that the novel technique can fully replace the RETRO-test, the elimination of the separating medium (activated carbon, polyethylene glycol) being an asset. The obtained correlation coefficient and regression equation for a simultaneous determination of 120 samples by the two methods were r = 0.964 and y = 1.113x - 0.939, respectively

  12. Nucleation of microcrystalline silicon: on the effect of the substrate surface nature and nano-imprint topography

    International Nuclear Information System (INIS)

    Palmans, J; Faraz, T; Verheijen, M A; Kessels, W M M; Creatore, M

    2016-01-01

    The nucleation of microcrystalline silicon thin-films has been investigated for various substrate natures and topographies. An earlier nucleation onset on aluminium-doped zinc oxide compared to glass substrates has been revealed, associated with a microstructure enhancement and reduced surface energy. Both aspects resulted in a larger crystallite density, following classical nucleation theory. Additionally, the nucleation onset was (plasma deposition) condition-dependent. Therefore, surface chemistry and its interplay with the plasma have been proposed as key factors affecting nucleation and growth. As such, preliminary proof of the substrate nature’s role in microcrystalline silicon growth has been provided. Subsequently, the impact of nano-imprint lithography prepared surfaces on the initial microcrystalline silicon growth has been explored. Strong topographies, with a 5-fold surface area enhancement, led to a reduction in crystalline volume fraction of ∼20%. However, no correlation between topography and microstructure has been found. Instead, the suppressed crystallization has been partially ascribed to a reduced growth flux, limited surface diffusion and increased incubation layer thickness, originating from the surface area enhancement when transiting from flat to nanostructured surfaces. Furthermore, fundamental plasma parameters have been reviewed in relation with surface topography. Strong topographies are not expected to affect the ion-to-growth flux ratio. However, the reduced ion flux (due to increasing surface area) further limited the already weak ion energy transfer to surface processes. Additionally, the atomic hydrogen flux, i.e. the driving force for microcrystalline growth, has been found to decrease by a factor of 10 when transiting from flat to nanostructured topography. This resulted in an almost 6-fold reduction of the hydrogen-to-growth flux ratio, a much stronger effect than the ion-to-growth flux ratio. Since previous studies regarding

  13. On the oxidation mechanism of microcrystalline silicon thin films studied by Fourier transform infrared spectroscopy

    NARCIS (Netherlands)

    Bronneberg, A. C.; Smets, A. H. M.; Creatore, M.; M. C. M. van de Sanden,

    2011-01-01

    Insight into the oxidation mechanism of microcrystalline silicon thin films has been obtained by means of Fourier transform infrared spectroscopy. The films were deposited by using the expanding thermal plasma and their oxidation upon air exposure was followed in time. Transmission spectra were

  14. Thermal Infrared Spectra of Microcrystalline Sedimentary Phases: Effects of Natural Surface Roughness on Spectral Feature Shape

    Science.gov (United States)

    Hardgrove, C.; Rogers, A. D.

    2012-03-01

    Thermal infrared spectral features of common microcrystalline phases (chert, alabaster, micrite) are presented. Spectra are sensitive to mineralogy and micron-scale (~1-25 µm) surface roughness. Roughness is on the scale of the average crystal size.

  15. Preparation and Characterisation of Amorphous-silicon Photovoltaic Devices Having Microcrystalline Emitters

    International Nuclear Information System (INIS)

    Gutierrez, M. T.; Gandia, J. J.; Carabe, J.

    1999-01-01

    The present work summarises the essential aspects of the research carried out so far at CIEMAT on amorphous-silicon solar cells. The experience accumulated on the preparation and characterisation of amorphous and microcrystalline silicon has allowed to start from intrinsic (absorbent) and p- and n-type (emitters) materials not only having excellent optoelectronic properties, but enjoying certain technological advantages with respect to those developed by other groups. Among these are absorbent-layer growth rates between 5 and 10 times as fast as conventional ones and microcrystalline emitters prepared without using hydrogen. The preparation of amorphous-silicon cells has required the solution of a number of problems, such as those related to pinholes, edge leak currents and diffusion of metals into the semiconductor. Once such constraints have been overcome, it has been demonstrated not only that the amorphous-silicon technology developed at CIEMAT is valid for making solar cells, but also that the quality of the semiconductor material is good for the application according to the partial results obtained. The development of thin-film laser-scribing technology is considered essential. Additionally it has been concluded that cross contamination, originated by the fact of using a single-chamber reactor, is the basic factor limiting the quality of the cells developed at CIEMAT. The present research activity is highly focused on the solution of this problem. (Author)23 refs

  16. Influence of Tableting on Enzymatic Activity of Papain along with Determination of Its Percolation Threshold with Microcrystalline Cellulose

    Science.gov (United States)

    Sharma, Manu; Sharma, Vinay; Majumdar, Dipak K.

    2014-01-01

    The binary mixture tablets of papain and microcrystalline cellulose (MCC), dicalcium phosphate dihydrate (DCP), carrageenan, tragacanth, and agar were prepared by direct compression. Carrageenan, tragacanth, and agar provided maximum protection to enzyme activity compared to MCC and DCP. However, stability studies indicated highest loss of enzyme activity with carrageenan, tragacanth, and agar. Therefore, compression behaviour of different binary mixtures of papain with MCC at different compaction pressures, that is, 40–280 MPa, was studied according to Heckel equation. The compressibility studies of binary mixtures indicated brittle behavior of papain. The application of percolation theory on the relationship between critical density as a function of enzyme activity and mixture composition revealed the presence of percolation threshold for binary mixture. Papain-MCC mixture composition showed significant percolation threshold at 18.48% (w/w) papain loading. Microcrystalline cellulose provided higher protection during stability study. However, higher concentrations of microcrystalline cellulose, probably as dominant particles, do not protect the enzyme with their plastic deformation. Below the percolation threshold, that is, 18.48% (w/w) papain amount in mixture with plastic excipient, activity loss increases strongly because of higher shearing forces during compaction due to system dominance of plastic particles. This mixture range should therefore be avoided to get robust formulation of papain. PMID:27350972

  17. Visible light activated TiO2/microcrystalline cellulose nanocatalyst to destroy organic contaminants in water.

    Science.gov (United States)

    Hybrid TiO2/microcrystalline cellulose (MC) nanophotocatalyst was prepared in situ by a facile and simple synthesis utilizing benign precursors such as MC and TiCl4. The as-prepared nanocomposite was characterized by XRD, XPS, BET surface area analyzer, UV–vis DRS and TGA. Surfac...

  18. Analysis of IV characteristics of solar cells made of hydrogenated amorphous, polymorphous and microcrystalline silicon

    International Nuclear Information System (INIS)

    Hamadeh, H.

    2009-03-01

    The IV characteristics of pin solar cells made of amorphous, polymorphous and microcrystalline silicon were investigated. The temperature dependence was measured in the temperature range between 150 K and 395 K. This range covers the most terrestrial applications condition. Using simplex procedure, the IV parameter of the cells were deduce using line fitting. It has been shown that polymorphous silicon shows electrical properties that are close to properties of microcrystalline silicon but as it is well known, polymorphous silicon shows higher absorption similar to amorphous silicon. The polymorphous silicon solar cells showed higher efficiencies, lower shunting and higher filling factors. In the above mentioned temperature range, polymorphous silicon is the better material for the manufacturing of thin film hydrogenated silicon pin solar cells. More investigations concerning the structural properties are necessary to make stronger conclusions in regards to the stability of the material, what we hope to do in the future. (author)

  19. Fenton chemistry-based detemplation of an industrially relevant microcrystalline beta zeolite. Optimization and scaling-up studies

    NARCIS (Netherlands)

    Ortiz-Iniesta, Maria Jesus; Melian-Cabrera, Ignacio

    A mild template removal of microcrystalline beta zeolite, based on Fenton chemistry, was optimized. Fenton detemplation was studied in terms of applicability conditions window, reaction rate and scale up. TGA and CHN elemental analysis were used to evaluate the detemplation effectiveness, while 'CP,

  20. [A study of the properties of tablets from mixtures of two size degrees of alpha-lactose monohydrate and microcrystalline cellulose].

    Science.gov (United States)

    Muzíková, J

    2006-03-01

    The paper examines the strength and disintegration time of compacts from the mixtures of two types of Tablettosas. Tablettosa 70 and Tablettosa 100 with microcrystalline cellulose represented by Vivapur 102. The mixtures of dry binders were prepared in the ratios of 3:1, 1:1, and 1:3. The effect of two concentrations of the lubricant magnesium stearate on the strength and disintegration time of compacts was also examined. Tablet strength increased with higher representation of microcrystalline cellulose in the mixture, and decreased with higher stearate concentration. The compacts from the mixtures with Tablettosa 100 showed higher strength. Disintegration time was highest in the compacts with the largest perccintage of microcrystalline cellulose, and longer in the case of the mixtures with Tablettosa 100. Stearate did not exert a negative effect on disintegration time. In the mixtures of Tablettosas with Vivapur 102 in a ratio of 1:1, the effect of the model active ingredient acetylsalicylic acid on the above-mentioned properties of tablets was tested. acetylsalicylic acid produced a further decrease in the strength of compacts and shortened the disintegration time in more instances in the cased of the mixtures with Tahlettosa 100.

  1. Antibacterial Modification of Microcrystalline Cellulose by Grafting Copolymerization

    Directory of Open Access Journals (Sweden)

    Ying Liu

    2015-11-01

    Full Text Available Microcrystalline cellulose (MCC has the advantage of a high specific surface area as compared to that of conventional cellulose fibers. In this study the monomer methacrylamide (MAM was used to treat MCC by grafting copolymerization. SEM, FTIR, and solid 13C NMR were used to characterize the morphology and composition of MAM-g-MCC. After the chlorination of MAM-g-MCC with 10% sodium hypochlorite solution, the grafted MCC exhibited antibacterial activity as a result of the formation of N-Cl bonds. The thermal stability, antibacterial ability, and storage stability of chlorinated MAM-g-MCC were also studied. The results showed that the chlorinated MAM-g-MCC had excellent storage stability and could inactivate all S. aureus and E. coli O157:H7 within 10 min.

  2. Physicochemical Characterization of Microcrystalline Cellulose Extracted from Kenaf Bast

    Directory of Open Access Journals (Sweden)

    N. A. Sri Aprilia

    2016-03-01

    Full Text Available Microcrystalline cellulose (MCC was successfully prepared from bleached kenaf bast fiber through hydrochloric acid hydrolysis. The influence of hydrolysis time (1 to 3 h on the MCC physicochemical properties was examined. Scanning electron microscopy (SEM, X-ray diffraction (XRD, particle size analysis, Fourier transform infrared spectroscopy (FT-IR, and thermal gravimetric analysis (TGA were utilized to characterize the isolated MCC. According to FTIR analysis, the chemical composition of MCC was not changed with the reaction time. The reaction times, however, did affect the thermal stability of MCC. The thermal stability decreased linearly with increasing hydrolysis time. The optimum hydrolysis time was determined based on the morphological, structural, and thermal properties of the kenaf bast MCC.

  3. Facile synthesis of TiO2/microcrystalline cellulose nanocomposites: photocatalytically active material under visible light irradiation

    Science.gov (United States)

    Doped TiO2 nanocomposites were prepared in situ by a facile and simple synthesis utilizing benign and renewable precursors such as microcrystalline cellulose (MC) and TiCl4 through hydrolysis in alkaline medium without the addition of organic solvents. The as-prepared nanocompos...

  4. Development of Doped Microcrystalline Silicon Oxide and its Application to Thin‑Film Silicon Solar Cells

    NARCIS (Netherlands)

    Lambertz, A.

    2015-01-01

    The aim of the present study is the development of doped microcrystalline silicon oxide (µc‑SiOx:H) alloys and its application in thin‑film silicon solar cells. The doped µc‑SiOx:H material was prepared from carbon dioxide (CO2), silane (SiH4), hydrogen (H2) gas mixtures using plasma enhanced

  5. Strongly Enhanced Free-Exciton Luminescence in Microcrystalline CsPbBr3 Films

    Science.gov (United States)

    Kondo, Shin-ichi; Kakuchi, Mitsugu; Masaki, Atsushi; Saito, Tadaaki

    2003-07-01

    The luminescence properties of CsPbBr3 films prepared via the amorphous phase by crystallization are dominated by free-exciton emission, and only a weak trace of emission due to trapped excitons was observed, in contrast to the case of bulk CsPbBr3 crystals. In particular, the films in the microcrystalline state show by more than an order of magnitude stronger free-exciton emission than in the polycrystalline state. The enhanced free-exciton emission is suggestive of excitonic superradiance.

  6. An XRPD and EPR spectroscopy study of microcrystalline calcite bioprecipitated by Bacillus subtilis

    Science.gov (United States)

    Perito, B.; Romanelli, M.; Buccianti, A.; Passaponti, M.; Montegrossi, G.; Di Benedetto, F.

    2018-05-01

    We report in this study the first XRPD and EPR spectroscopy characterisation of a biogenic calcite, obtained from the activity of the bacterium Bacillus subtilis. Microcrystalline calcite powders obtained from bacterial culture in a suitable precipitation liquid medium were analysed without further manipulation. Both techniques reveal unusual parameters, closely related to the biological source of the mineral, i.e., to the bioprecipitation process and in particular to the organic matrix observed inside calcite. In detail, XRPD analysis revealed that bacterial calcite has slightly higher c/a lattice parameters ratio than abiotic calcite. This correlation was already noticed in microcrystalline calcite samples grown by bio-mineralisation processes, but it had never been previously verified for bacterial biocalcites. EPR spectroscopy evidenced an anomalously large value of W 6, a parameter that can be linked to occupation by different chemical species in the next nearest neighbouring sites. This parameter allows to clearly distinguish bacterial and abiotic calcite. This latter achievement was obtained after having reduced the parameters space into an unbiased Euclidean one, through an isometric log-ratio transformation. We conclude that this approach enables the coupled use of XRPD and EPR for identifying the traces of bacterial activity in fossil carbonate deposits.

  7. Effect of silane/hydrogen ratio on microcrystalline silicon thin films by remote inductively coupled plasma

    Science.gov (United States)

    Guo, Y. N.; Wei, D. Y.; Xiao, S. Q.; Huang, S. Y.; Zhou, H. P.; Xu, S.

    2013-05-01

    Hydrogenated microcrystalline silicon (μc-Si:H) thin films were prepared by remote low frequency inductively coupled plasma (ICP) chemical vapor deposition system, and the effect of silane/hydrogen ratio on the microstructure and electrical properties of μc-Si:H films was systematically investigated. As silane/hydrogen ratio increases, the crystalline volume fraction Fc decreases and the ratio of the intensity of (220) peak to that of (111) peak drops as silane flow rate is increased. The FTIR result indicates that the μc-Si:H films prepared by remote ICP have a high optical response with a low hydrogen content, which is in favor of reducing light-induced degradation effect. Furthermore, the processing window of the phase transition region for remote ICP is much wider than that for typical ICP. The photosensitivity of μc-Si:H films can exceed 100 at the transition region and this ensures the possibility of the fabrication of microcrystalline silicon thin film solar cells with a open-circuit voltage of about 700 mV.

  8. Investigation of carrier density and mobility in microcrystalline silicon alloys using Hall effect and thermopower measurements; Untersuchung der Ladungstraegerkonzentration und -beweglichkeit in mikrokristallinen Siliziumlegierungen mit Hall-Effekt und Thermokraft

    Energy Technology Data Exchange (ETDEWEB)

    Sellmer, Christian

    2012-08-31

    The electronic properties of amorphous and microcrystalline silicon layers in thin-film solar cells significantly affect the efficiency of solar cells. An important property of the individual layer is the electronic transport, which is described by the variables conductivity, photoconductivity, mobility, and carrier concentration. In the past, individual characterization methods were typically used to determine the electronic properties. Using the combination of Hall effect, conductivity, and thermoelectric power measurements additional variables can be derived, such as the effective density of states at the valence and conduction band edge, making a more detailed description of the material possible. To systematically study the electronic properties - in particular carrier mobility and carrier concentration - various series of silicon films are prepared for this work including microcrystalline silicon layers of different doping and crystallinity and a series of silicon films where the Fermi level is moved by irradiation with high energy electrons on one and the same sample. The results show that the transition from amorphous to microcrystalline transport is relatively abrupt. If the electron transport takes place in only amorphous regions, it is marked by the sign anomaly of the Hall effect. If a continuous crystalline path exists, the electronic properties are dominated by the crystalline volume fraction. The results of the measurements of silicon layers are compared with those of microcrystalline silicon carbide samples. Silicon carbide is especially interesting for future applications in thin-film solar cells due to high transparency and high conductivity. It is shown that the effective density of states at the valence and conduction band edge as a function of temperature in p- and n-type microcrystalline silicon and silicon carbide samples largely coincide with those of crystalline silicon or silicon carbide. A square root shaped profile of the density of

  9. Characterization of microcrystalline I-layer for solar cells prepared in low temperature - plastic compatible process

    KAUST Repository

    Sliz, Rafal

    2012-06-01

    Microcrystalline silicon (mc-Si) lms deposited using a Plasma Enhanced Chemical Vapour Deposition (PECVD) process constitute an important material for manufacturing low-cost, large-area thin-lm devices, such as solar cells or thin-lm transistors. Although the deposition of electronic-grade mc-Si using the PECVD process is now well established, the high substrate temperature required (~400°C) does not lend itself to electronic devices with exible form factors fabricated on low-cost plastic substrates. In this study, we rst investigated an intrinsic mc-Si layer deposited at plastic-compatible substrate temperatures (~150°C) by characterising the properties of the lm and then evaluated its applicability to p-i-n solar cells though device characterisation. When the performance of the solar cell was correlated with lm properties, it was found that, although it compared unfavourably with mc-Si deposited at higher temperatures, it remained a very promising option. Nonetheless, further development is required to increase the overall eciency of mc-Si exible solar cells.

  10. The magnetic properties of powdered and compacted microcrystalline permalloy

    International Nuclear Information System (INIS)

    Kollar, P.; Oleksakova, D.; Fuezer, J.; Kovac, J.; Roth, S.; Polanski, K.

    2007-01-01

    The aim of this work is to investigate the magnetic properties of powdered and compacted microcrystalline Ni-Fe (81 wt% of Ni) permalloy. It was found by investigating the influence of mechanical milling on the magnetic properties of powder samples prepared by milling of the ribbon that the alloy remains a solid solution with stable structure during the whole milling process. With decreasing particle size the rotation of magnetization vector gradually becomes dominant magnetization process and thus coercivity increases. After compaction of the powder by uniaxial hot pressing the magnetic contact between powder particles is recreated and for resulting bulk the displacement of the domain walls becomes dominant magnetization process with coercivity of 11 A/m (comparable with the coercivity of conventional permalloy)

  11. Application of scanning Kelvin probe microscopy for the electrical characterization of microcrystalline silicon for photovoltaics

    International Nuclear Information System (INIS)

    Breymesser, A.

    2000-05-01

    In the last years microcrystalline silicon thin films have attracted great attention as a new photovoltaic material. With this material it is possible to combine simple and cheap low temperature deposition techniques known from amorphous silicon with the long-term stability of the photovoltaic performance like in bulk crystalline silicon solar cells. The critical point is the deposition procedure with numerous tunable parameters influencing the quality and character of the produced diode structures. Additionally there is a great uncertainty about unintentionally incorporated defects, which is not affected by the deposition parameters. Extended investigation of the material, diode and solar cell characteristics is essential in order to correlate the impact of deposition conditions with the quality of the devices. The situation is complicated due to the anisotropic and inhomogeneous character of microcrystalline silicon. Scanning Kelvin probe microscopy (SKPM) is a work function measurement method based on a scanning force microscope (SFM) and a modified Kelvin probe technique. Due to the excellent lateral resolution of the SFM work function measurements with resolutions far below the micrometer level can be carried out. Applied on doped microcrystalline silicon structures it is possible to visualize the position of the Fermi level within the band gap and the influence of the deposition conditions on it. Within this work a SKPM based on a commercially available SFM was constructed and built. Great effort was concentrated on the characterization of the SKPM experiment. On the basis of an extended knowledge about the performance investigations concentrated on cross sections of microcrystalline silicon diode structures produced by hot-wire chemical vapor deposition (HW-CVD). A pin structure for the diodes was chosen due to the low diffusion lengths within this rather defective material. The evolution of the built-in electric drift field within the intrinsic absorber is

  12. Substrate temperature dependence of microcrystallinity in plasma-deposited, boron-doped hydrogenated silicon alloys

    International Nuclear Information System (INIS)

    Rajeswaran, G.; Kampas, F.J.; Vanier, P.E.; Sabatini, R.L.; Tafto, J.

    1983-01-01

    The glow-discharge decomposition of silane diluted in hydrogen using diborane as a dopant results in the deposition of p-type microcrystalline silicon films at relatively low temperatures. The conductivity of these films is critically dependent on the substrate temperature when the ratio of silane flow rate to total gas flow rate is 1%. Electron micrographs show that highly conducting films contain numerous clusters of 2.5-nm crystallites that are embedded in an amorphous medium

  13. Influence of ion bombardment on microcrystalline silicon material quality and solar cell performances

    OpenAIRE

    Bugnon, G; Feltrin, A; Sculati-Meillaud, F; Bailat, J; Ballif, C

    2008-01-01

    Microcrystalline hydrogenated silicon growth with VHF-PECVD was examined in an industrial type parallel plate KAITM reactor. The influence of pressure on material quality was studied in single junction solar cells. Solar cells with their intrinsic layer prepared at higher pressures exhibit remarkable improvements, reaching 8.2% efficiency at 3.5 mbar. Further analyzes showed that μc- Si:H intrinsic layers grown at higher pressures have a significantly lower defect density. These results are a...

  14. Defect states in microcrystalline silicon probed by photoluminescence spectroscopy

    International Nuclear Information System (INIS)

    Merdzhanova, T.; Carius, R.; Klein, S.; Finger, F.; Dimova-Malinovska, D.

    2006-01-01

    Photoluminescence (PL) spectroscopy is used to investigate defects and localized band tail states within the band gap of hydrogenated microcrystalline silicon (μc-Si:H) prepared by plasma enhanced chemical vapor deposition (PECVD) and hot wire chemical vapor deposition (HWCVD). The effect of the substrate temperature (T S ), which influences mainly the defect density, and silane concentration (SC), as Key parameter to control the microstructure of the material were varied. In high quality μc-Si:H films (T S = 185-200 deg. C) a PL band ('μc'-Si-band) is observed at ∼ 0.9-1.05 eV which is attributed to radiative recombination via localized band tail states in the microcrystalline phase. In μc-Si:H films prepared at higher T S (> 300 deg. C), an additional PL band at ∼ 0.7 eV with a width of ∼ 0.17 eV is found for both PECVD and HWCVD material. This band maintains its position at ∼ 0.7 eV with increasing SC in contrast to the observed shift of the 'μc'-Si-band to higher energies. Studies of the temperature dependences of the PL peak energy and intensity for the two bands show: (i) the PL band at 0.7 eV remains unaffected upon increasing temperature, while the 'μc'-Si-band shifts to lower energies (ii) a much weaker quenching for the 0.7 eV band compared to the 'μc'-Si-band. It was also found that the PL band at 0.7 eV exhibits a slightly stronger temperature dependence of the PL intensity compared to 'defect' band at 0.9 eV in a-Si:H suggesting similar recombination transition via deeper trap states. Due to a similar PL properties of the emission band previously observed in Czochralski-grown silicon (Cz-Si), the 0.7 eV band in μc-Si:H is assigned tentatively to defect-related transitions in the crystalline phase

  15. Dielectric barrier discharge plasma pretreatment on hydrolysis of microcrystalline cellulose

    Science.gov (United States)

    Huang, Fangmin; Long, Zhouyang; Liu, Sa; Qin, Zhenglong

    2017-04-01

    Dielectric barrier discharge (DBD) plasma was used as a pretreatment method for downstream hydrolysis of microcrystalline cellulose (MCC). The degree of polymerization (DP) of MCC decreased after it was pretreated by DBD plasma under a carrier gas of air/argon. The effectiveness of depolymerization was found to be influenced by the crystallinity of MCC when under the pretreatment of DBD plasma. With the addition of tert-butyl alcohol in the treated MCC water suspension solution, depolymerization effectiveness of MCC was inhibited. When MCC was pretreated by DBD plasma for 30 min, the total reducing sugar concentration (TRSC) and liquefaction yield (LY) of pretreated-MCC (PMCC) increased by 82.98% and 34.18% respectively compared with those for raw MCC.

  16. Solution growth of microcrystalline silicon on amorphous substrates

    Energy Technology Data Exchange (ETDEWEB)

    Heimburger, Robert

    2010-07-05

    material is proposed. MoSi{sub 2} thin films on glass, produced by annealing near-stoichiometric Mo-Si multilayers, are shown to resist solution contact. Subsequent investigation of feasibility of the vapor-liquid-solid mechanism revealed the success of indium microdroplet formation to be determined by both, the multilayer deposition parameters and the substrate temperature during indium deposition. Steady-state solution growth at 610 C was utilized to enlarge silicon seed crystals to diameters of up to 200 {mu}m. The grown material has been subject of characterization regarding the crystallinity, orientation and purity. Additionally, morphological anomalies are considered. The outgrown material was found to be bound by {l_brace}111{r_brace} facets. Many of these microcrystallites contain at least two twin domains. Twin-assisted growth at formed re-entrant edges promotes high growth rates even at low supersaturation. Additionally, many crystallites exhibit hoppers at the center of their facets. This is explained by a solute concentration inhomogeneity within the diffusion boundary layer of the nutrient solution leading to solute depletion at the facet centers and to morphological instability. The feasibility of the process for growth of microcrystalline silicon on glass has been shown in principle. Nevertheless, limitations exist regarding the achievable crystalline solidity ratio and the size of crystallites grown under stable conditions. (orig.)

  17. AFM and FTIR characterization of microcrystalline Si obtained from isothermal annealing of Al/a-Si:H

    Energy Technology Data Exchange (ETDEWEB)

    Rojas-Lopez, M.; Orduna-Diaz, A.; Delgado-Macuil, R. [Centro de Investigacion en Biotecnologia Aplicada (CIBA), IPN, Tlaxcala, Tlax. 72197 (Mexico); Olvera-Hernandez, J. [Centro de Investigacion en Dispositivos Semiconductores (CIDS), BUAP, Puebla, Pue. 72570 (Mexico); Navarro-Contreras, H.; Vidal, M.A.; Saucedo, N.; Mendez-Garcia, V.H. [Instituto de Investigacion en Comunicacion Optica (IICO), UASLP, San Luis Potosi, S.L.P. 78100 (Mexico)

    2007-04-15

    Atomic force microscopy and Fourier transform infrared spectroscopy were used to investigate the morphology of the microcrystalline surface, and also the amorphous-crystalline structural transformation of a-Si:H films, isothermally annealed during several hours. Crystallization process was strongly influenced by the deposition of an Al layer on the surface of a-Si:H samples. Representative AFM images show the presence of grains, which increase in diameter with the annealing time. Relative crystallized fraction as a function of the annealing time can be described adequately by using the Avrami equation. The kinetic of this crystallization process suggest a two-dimensional growth of the Si nuclei. Fourier transform infrared measurements show the presence of an intense band near 512 cm{sup -1} associated to Si-Si bonding. We observed the relative diminishing of the intensity of the Si-H wagging mode at 694 cm{sup -1} with annealing time, suggesting effusion of hydrogen to the surface of microcrystalline films. (copyright 2007 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  18. Bioconversion of different sizes of microcrystalline cellulose pretreated by microwave irradiation with/without NaOH

    International Nuclear Information System (INIS)

    Peng, Huadong; Chen, Hongzhang; Qu, Yongshui; Li, Hongqiang; Xu, Jian

    2014-01-01

    Highlights: • High concentration of alkali or temperature was necessary in cellulose degradation. • Effects of alkali pretreatment could be enhanced with the addition of microwave irradiation. • The structures diversities of microcrystalline cellulose were eliminated in the fermentation. • The significance of particle size and treat condition varied with reaction time. - Abstract: The process of microwave irradiation (MWI) pretreatment on microcrystalline cellulose (MCC) with different sizes with/without NaOH was investigated on the variation of the ratio of degradated solid residue (R DS ), particle size, crystallinity index (CrI), crystallite size (Sc) and specific surface area (SSA). High concentration of alkali or high temperature was necessary in dissolving or decomposing the cellulose. Appropriate pretreatment severity eliminated the effects of structural diversities in feedstocks, which led to convergence in the ethanol fermentation. After the reaction proceeded to 120 h, the samples could be converted to glucose completely and the highest ethanol yield of the theoretical was 58.91% for all the samples pretreated by the combined treatment of MWI and NaOH. In addition, the statistical analysis implied that when reaction time got to 24 h, particle size and pretreatment condition affected much more significant than other factors

  19. Evaluation of several microcrystalline celluloses obtained from agricultural by-products

    Directory of Open Access Journals (Sweden)

    John Rojas

    2011-01-01

    Full Text Available Microcrystalline cellulose (MCCI has been widely used as an excipient for direct compression due to its good flowability, compressibility, and compactibility. In this study, MCCI was obtained from agricultural by-products, such as corn cob, sugar cane bagasse, rice husk, and cotton by pursuing acid hydrolysis, neutralization, clarification, and drying steps. Further, infrared spectroscopy (IR, X-ray diffraction (XRD, optical microscopy, degree of polymerization (DP, and powder and tableting properties were evaluated and compared to those of Avicel PH101, Avicel PH102, and Avicel PH200. Except for the commercial products, all materials showed a DP from 55 to 97. Particles of commercial products and corn cob had an irregular shape, whereas bagasse particles were elongated and thick. Rice and cotton particles exhibited a flake-like and fiber-like shape, respectively. MCCI as obtained from rice husk and cotton was the most densified material, while that produced from corn cob and bagasse was bulky, porous, and more compressible. All products had a moisture content of less than 10% and yields from 7.4% to 60.4%. MCCI as obtained from bagasse was the most porous and compressible material among all materials. This product also showed the best tableting properties along with Avicel products. Likewise, all MCCI products obtained from the above-mentioned sources showed a more rapid disintegration time than that of Avicel products. These materials can be used as a potential source of MCCI in the production of solid dosage forms.

  20. Superconducting Sweet-Spot in Microcrystalline Graphite Revealed by Point-Contact Spectroscopy

    Science.gov (United States)

    Arnold, F.; Nyéki, J.; Saunders, J.

    2018-05-01

    In this letter we describe the observation of a magnetic field dependent electronic gap, suggestive of local superconductivity, in the point-contact spectrum of micro-crystalline graphite. Magnetic field dependent point-contact spectroscopy was carried out at a temperature of 1.8K using an etched aluminium tip. At zero field a gap structure in the differential conductance is observed, showing a gap of Δ = 4.2 meV. On applying magnetic fields of up to 500mT, this gap gradually closes, following the theoretical prediction by Ginzburg and Landau for a fully flux-penetrated superconductor. By applying BCS-theory, we infer a critical superconducting temperature of 14K.

  1. A study of a novel coprocessed dry binder composed of α-lactose monohydrate, microcrystalline cellulose and corn starch.

    Science.gov (United States)

    Mužíková, Jitka; Srbová, Alena; Svačinová, Petra

    2017-12-01

    This paper deals with a study of the novel coprocessed dry binder Combilac®, which contains 70% of α-lactose monohydrate, 20% of microcrystalline cellulose and 10% of native corn starch. These tests include flow properties, compressibility, lubricant sensitivity, tensile strength and disintegration time of tablets. Compressibility is evaluated by means of the energy profile of compression process, test of stress relaxation and tablet strength. The above-mentioned parameters are also evaluated in the physical mixture of α-lactose monohydrate, microcrystalline cellulose and native corn starch and compared with Combilac. Combilac shows much better flowability than the physical mixture of the used dry binders. Its compressibility is better, tablets possess a higher tensile strength. Neither Combilac, nor the physical mixture can be compressed without lubricants due to high friction and sticking to the matrix. Combilac has a higher lubricant sensitivity than the physical mixture of the dry binders. Disintegration time of Combilac tablets is comparable with the disintegration time of tablets made from the physical mixture.

  2. Mussel-inspired fabrication of konjac glucomannan/microcrystalline cellulose intelligent hydrogel with pH-responsive sustained release behavior.

    Science.gov (United States)

    Wang, Lin; Du, Yu; Yuan, Yi; Mu, Ruo-Jun; Gong, Jingni; Ni, Yongsheng; Pang, Jie; Wu, Chunhua

    2018-07-01

    Intelligent hydrogels are attractive biomaterials for various applications, however, fabricating a hydrogel with both adequate self-healing ability and mechanical properties remains a challenge. Herein, a series of novel intelligent konjac glucomannan (KGM)/microcrystalline cellulose (MCC) hydrogels were prepared vis the mussel-inspired chemistry. MCC was firstly functionalized by the oxidative polymerization of dopamine, and the intelligent hydrogels were obtained by mixing aqueous solutions of KGM and functionalized MCC (PDMCC). By introducing PDMCC, a more compact interconnected porous structure formed for the resulting hydrogels. The self-healing ability and mechanical properties of intelligent hydrogels were dependence on the PDMCC content. Compared with KGM hydrogels, KGM/PDMCC hydrogels exhibited a more distinct pH sensitivity and a lower initial burst release, which was attributed to the compact structure and strong intermolecular hydrogen bond interaction between PDMCC and KGM. These results suggest that the KGM/PDMCC intelligent hydrogels may be promising carriers for controlled drug delivery. Copyright © 2018 Elsevier B.V. All rights reserved.

  3. Effect of environmental conditions on the mechanical properties and fungal degradation of polycaprolactone/microcrystalline cellulose/wood flour composites

    Science.gov (United States)

    Ronald Sabo; Liwei Jin; Nicole Stark; Rebecca E. Ibach

    2013-01-01

    Polycaprolactone (PCL) filled with microcrystalline cellulose (MCC), wood flour (WF), or both were characterized before and after exposure to various environmental conditions for 60 days. PCL/WF composites had the greatest tensile strength and modulus compared to neat PCL or PCL composites containing MCC. Electron microscopy indicated better adhesion between WF...

  4. EPR response of sucrose and microcrystalline cellulose to measure high doses of gamma radiation; Respuesta EPR de sacarosa y celulosa micro cristalina para medir altas dosis de radiacion gamma

    Energy Technology Data Exchange (ETDEWEB)

    Torijano, E.; Cruz, L.; Gutierrez, G.; Azorin, J.; Aguirre, F. [Universidad Autonoma Metropolitana, Unidad Iztapalapa, Av. San Rafael Atlixco 186, Col. Vicentina, 09340 Mexico D. F. (Mexico); Cruz Z, E., E-mail: eftc@xanum.uam.mx [UNAM, Instituto de Ciencias Nucleares, Circuito Exterior, Ciudad Universitaria, 04510 Mexico D. F. (Mexico)

    2015-10-15

    Solid dosimeters of sucrose and microcrystalline cellulose (Avicel Ph-102) were prepared, following the same process, in order to compare their EPR response against that of the l-alanine dosimeters considered as reference. All lots of dosimeters were irradiated with gamma radiation in Gamma beam irradiator with 8 kGy/h of the Nuclear Sciences Institute of UNAM. Doses ranged from 1 to 10 kGy respectively. We found that both the response of sucrose as microcrystalline cellulose were linear; however, the response intensity was, on average, twenty times more for sucrose. Comparing this against the EPR response of l-alanine in the range of doses, it was found that the response to sucrose is a third part; and microcrystalline cellulose is a sixtieth, approximately. The results agree with those found in the literature for sucrose, leaving open the possibility of investigating other dosage ranges for cellulose. (Author)

  5. Microcrystalline silicon deposition: Process stability and process control

    International Nuclear Information System (INIS)

    Donker, M.N. van den; Kilper, T.; Grunsky, D.; Rech, B.; Houben, L.; Kessels, W.M.M.; Sanden, M.C.M. van de

    2007-01-01

    Applying in situ process diagnostics, we identified several process drifts occurring in the parallel plate plasma deposition of microcrystalline silicon (μc-Si:H). These process drifts are powder formation (visible from diminishing dc-bias and changing spatial emission profile on a time scale of 10 0 s), transient SiH 4 depletion (visible from a decreasing SiH emission intensity on a time scale of 10 2 s), plasma heating (visible from an increasing substrate temperature on a time scale of 10 3 s) and a still puzzling long-term drift (visible from a decreasing SiH emission intensity on a time scale of 10 4 s). The effect of these drifts on the crystalline volume fraction in the deposited films is investigated by selected area electron diffraction and depth-profiled Raman spectroscopy. An example shows how the transient depletion and long-term drift can be prevented by suitable process control. Solar cells deposited using this process control show enhanced performance. Options for process control of plasma heating and powder formation are discussed

  6. Improved electrical and transport characteristics of amorphous silicon by enriching with microcrystalline silicon

    International Nuclear Information System (INIS)

    Mireshghi, A.; Hong, W.S.; Drewery, J.; Jing, T.; Kaplan, S.N.; Lee, H.K.; Perez-Mendez, V.

    1994-04-01

    The authors have deposited n-i-p diodes with microcrystalline intrinsic layers for radiation detection applications. The diodes show interesting electrical characteristics which have not been reported before. From TOF measurement for their best samples, the authors obtained μ e values which are about 3 times larger than their standard a-Si:H. for μτ values approximately a factor of 2 improvement was observed. The N* D values derived from hole-onset measurements show lower ionized dangling bond density than normal a-Si:H material. The authors propose a simple model which can very well explain the experimental results

  7. Modification and characterization of microcrystalline cellulose with succinic anhydride

    International Nuclear Information System (INIS)

    Santos, Clecio M.R.; Santos, Douglas C.; Freitas, Gizele B.; Cardoso, Giselia

    2011-01-01

    Cellulose is a natural polymer, non-toxic, biodegradable and renewable source. With increasing global attention to environmental problems, the chemical modification of cellulose has been evaluated with increasing applicability in various industrial sectors. The cellulose can be chemical modified through the hydroxyl present in their molecules. This paper aims to present the main results in the modification of microcrystalline cellulose. The sample was pure and modified chemically and morphologically characterized by absorption spectroscopy in the infrared (IR) and showed the band in the 1551cm -1 characterization modification made, X-ray diffraction (XRD) where it was observed that the change led to a reduction significant crystallinity, and determination of average pore radius through the analyzer porosity and surface area resulting in values of 6.97 angstrom for pure sample and 8.62 angstrom for the modified. In addition to these tests we determined the average degree of substitution finding the value of 1.67. (author)

  8. Influence of alkaline hydrogen peroxide pre-hydrolysis on the isolation of microcrystalline cellulose from oil palm fronds.

    Science.gov (United States)

    Owolabi, Abdulwahab F; Haafiz, M K Mohamad; Hossain, Md Sohrab; Hussin, M Hazwan; Fazita, M R Nurul

    2017-02-01

    In the present study, microcrystalline cellulose (MCC) was isolated from oil palm fronds (OPF) using chemo-mechanical process. Wherein, alkaline hydrogen peroxide (AHP) was utilized to extract OPF fibre at different AHP concentrations. The OPF pulp fibre was then bleached with acidified sodium chlorite solution followed by the acid hydrolysis using hydrochloric acid. Several analytical methods were conducted to determine the influence of AHP concentration on thermal properties, morphological properties, microscopic and crystalline behaviour of isolated MCC. Results showed that the MCC extracted from OPF fibres had fibre diameters of 7.55-9.11nm. X-ray diffraction (XRD) analyses revealed that the obtained microcrystalline fibre had both celluloses I and cellulose II polymorphs structure, depending on the AHP concentrations. The Fourier transmission infrared (FTIR) analyses showed that the AHP pre-hydrolysis was successfully removed hemicelluloses and lignin from the OPF fibre. The crystallinity of the MCC was increased with the AHP concentrations. The degradation temperature of MCC was about 300°C. The finding of the present study showed that pre-treatment process potentially influenced the quality of the isolation of MCC from oil palm fronds. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. On the crystalline structures of iron oxides formed during the removal process of iron in water

    International Nuclear Information System (INIS)

    Cho, Bongyeon; Fujita, Kenji; Oda, Katsuro; Ino, Hiromitsu

    1993-01-01

    The iron oxide samples collected from both filtration and batch reactors were analysed by X-ray diffraction and Moessbauer spectroscopy. In the filtration of water containing iron, the oxidized form of iron was determined to be ferrihydrite. In contrast, in the batch experiment without filtration, iron was oxidized to microcrystalline goethite. (orig.)

  10. Morphology-controlled electrodeposition of Cu2O microcrystalline particle films for application in photocatalysis under sunlight

    International Nuclear Information System (INIS)

    Wu, Guodong; Zhai, Wei; Sun, Fengqiang; Chen, Wei; Pan, Zizhao; Li, Weishan

    2012-01-01

    Graphical abstract: Display Omitted Highlights: ► PEG was used to electro-deposit Cu 2 O microcrystalline particle films. ► Morphologies of Cu 2 O microcrystals could be controlled by the amount of PEG. ► The films showed regularly varied photocatalytic activities under sunlight. ► The films could be recycled and showed stable activities. -- Abstract: Morphology-controlled Cu 2 O microcrystalline particle films had been successfully electrodeposited on tin-doped indium oxide glass substrates in CuSO 4 solutions containing different amounts of polyethylene glycol (PEG) additives. With an increase of PEG, microcrystals gradually changed from irregular shapes to cubes, octahedrons, and spherical shapes. Sizes increasingly became smaller with an increase of PEG under the same deposition time. These films had been first used as recyclable photocatalysts and showed excellent and photocatalytic activities in photodegradation of methylene blue (MB) under sunlight. Activities were regularly varied relative to the morphologies of films controlled by the amount of PEG and could be further enhanced by adding a little amount of hydrogen peroxide in the MB solution. The method for controllable preparation of Cu 2 O microcrystals with photocatalytic activities was simple and inexpensive. The as-prepared particle films could also be used in photodegradation of many other pollutants under sunlight.

  11. Extraction of the defect density of states in microcrystalline silicon from experimental results and simulation studies

    International Nuclear Information System (INIS)

    Tibermacine, T.; Ledra, M.; Ouhabab, N.; Merazga, A.

    2015-01-01

    The constant photocurrent method in the ac-mode (ac-CPM) is used to determine the defect density of states (DOS) in hydrogenated microcrystalline silicon (μc-Si:H) prepared by very high frequency plasma-enhanced chemical vapor deposition (VHF-PECVD). The absorption coefficient spectrum (ac-α(hv)), is measured under ac-CPM conditions at 60 Hz. The measured ac-α(hv) is converted by the CPM spectroscopy into a DOS distribution covering a portion in the lower energy range of occupied states. We have found that the density of valence band-tail states falls exponentially towards the gap with a typical band-tail width of 63 meV. Independently, computer simulations of the ac-CPM are developed using a DOS model that is consistent with the measured ac-α(hv) in the present work and a previously measured transient photocurrent (TPC) for the same material. The DOS distribution model suggested by the measurements in the lower and in the upper part of the energy-gap, as well as by the numerical modelling in the middle part of the energy-gap, coincide reasonably well with the real DOS distribution in hydrogenated microcrystalline silicon because the computed ac-α(hv) is found to agree satisfactorily with the measured ac-α(hv). (paper)

  12. An in situ Raman study of the intercalation of supercapacitor-type electrolyte into microcrystalline graphite

    International Nuclear Information System (INIS)

    Hardwick, Laurence J.; Hahn, Matthias; Ruch, Patrick; Holzapfel, Michael; Scheifele, Werner; Buqa, Hilmi; Krumeich, Frank; Novak, Petr; Koetz, Ruediger

    2006-01-01

    An initial Raman study on the effects of intercalation for aprotic electrolyte-based electrochemical double-layer capacitors (EDLCs) is reported. In situ Raman microscopy is employed in the study of the electrochemical intercalation of tetraethylammonium (Et 4 N + ) and tetrafluoroborate (BF 4 - ) into and out of microcrystalline graphite. During cyclic voltammetry experiments, the insertion of Et 4 N + into graphite for the negative electrode occurs at an onset potential of +1.0 V versus Li/Li + . For the positive electrode, BF 4 - was shown to intercalate above +4.3 V versus Li/Li + . The characteristic G-band doublet peak (E 2g2 (i) (1578 cm -1 ) and E 2g2 (b) (1600 cm -1 )) showed that various staged compounds were formed in both cases and the return of the single G-band (1578 cm -1 ) demonstrates that intercalation was fully reversible. The disappearance of the D-band (1329 cm -1 ) in intercalated graphite is also noted and when the intercalant is removed a more intense D-band reappears, indicating possible lattice damage. For cation intercalation, such irreversible changes of the graphite structure are confirmed by scanning electron microscopy (SEM)

  13. High efficiency high rate microcrystalline silicon thin-film solar cells deposited at plasma excitation frequencies larger than 100 MHz

    Czech Academy of Sciences Publication Activity Database

    Strobel, C.; Leszczynska, B.; Merkel, U.; Kuske, J.; Fischer, D.D.; Albert, M.; Holovský, Jakub; Michard, S.

    2015-01-01

    Roč. 143, Dec (2015), 347-353 ISSN 0927-0248 R&D Projects: GA MŠk 7E12029 EU Projects: European Commission(XE) 283501 - Fast Track Institutional support: RVO:68378271 Keywords : VHF * PECVD * microcrystalline silicon * solar cell * high rate * high efficiency Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 4.732, year: 2015

  14. Local photoconductivity of microcrystalline silicon thin films measured by conductive atomic force microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Ledinsky, Martin; Fejfar, Antonin; Vetushka, Aliaksei; Stuchlik, Jiri; Rezek, Bohuslav; Kocka, Jan [Institute of Physics, Academy of Sciences of the Czech Republic, v.v.i. Cukrovarnicka 10, 162 00 Praha 6 (Czech Republic)

    2011-11-15

    Local currents measured under standard conductive atomic force microscopy (C-AFM) conditions on microcrystalline silicon ({mu}c-Si:H) thin films were studied. It was shown that the AFM detection diode illuminating the AFM cantilever (see the figure on the right side) 100 x enhanced the current flows through the photosensitive {mu}c-Si:H layer. The local current map and current-voltage characteristics were measured under dark conditions. This study enables mapping of both the dark current and photocurrent. C-AFM cantilever illuminated by the detection diode during measurement on {mu}c-Si:H thin film. (copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  15. Fractal analysis of SEM images and mercury intrusion porosimetry data for the microstructural characterization of microcrystalline cellulose-based pellets

    International Nuclear Information System (INIS)

    Gomez-Carracedo, A.; Alvarez-Lorenzo, C.; Coca, R.; Martinez-Pacheco, R.; Concheiro, A.; Gomez-Amoza, J.L.

    2009-01-01

    The microstructure of theophylline pellets prepared from microcrystalline cellulose, carbopol and dicalcium phosphate dihydrate, according to a mixture design, was characterized using textural analysis of gray-level scanning electron microscopy (SEM) images and thermodynamic analysis of the cumulative pore volume distribution obtained by mercury intrusion porosimetry. Surface roughness evaluated in terms of gray-level non-uniformity and fractal dimension of pellet surface depended on agglomeration phenomena during extrusion/spheronization. Pores at the surface, mainly 1-15 μm in diameter, determined both the mechanism and the rate of theophylline release, and a strong negative correlation between the fractal geometry and the b parameter of the Weibull function was found for pellets containing >60% carbopol. Theophylline mean dissolution time from these pellets was about two to four times greater. Textural analysis of SEM micrographs and fractal analysis of mercury intrusion data are complementary techniques that enable complete characterization of multiparticulate drug dosage forms

  16. A new crystal growth form of vaterite, CaCO3

    International Nuclear Information System (INIS)

    Shaikh, A.M.

    1990-01-01

    Microcrystalline vaterite, CaCO 3 , has been synthesized by decomposition of ikaite, CaCO 3 .6H 2 O, crystals at room temperature. Scanning electron micrographs show that vaterite occurs as arborescent aggregates ≅30 to 40 μm in size. This growth form has not been described before. It is of interest that the overall morphology of the vaterite is reminiscent of some dendritic calcite tufas, although on a smaller scale. This similarity opens up the possibility that the calcitic tufas such as that associated with the Quaternary Lake Lahonton, Nevada, may have been deposited as vaterite that changed to calcite, while preserving the original growth form. (orig.)

  17. Physical and structural properties of polyaniline/microcrystalline cellulose nanocomposite

    Science.gov (United States)

    Abdi, Mahnaz M.; Liyana, Rawaida; Tahir, Paridah Md; Heng, Lee Yook; Sulaiman, Yusran; Waheeda, Nur Farhana; Hassan, Nabihah Abu

    2017-12-01

    A composite of Polyaniline/Microcrystalline Cellulose (PAni/MCC) was prepared via a chemical polymerization method in the presence of ammonium persulfate (NH4)2S2O8 as oxidant and cetyltrimethylammonium bromide (CTAB) as a cationic surfactant. The results of FESEM showed that the morphology of nanocomposite depends on the monomer concentration. Wire-like and porous nanostructure was observed for PAni/MCC/CTAB composite that could be suitable for enzyme immobilization and sensor applications. The electrochemical properties of the composites were studied using Cyclic Voltammetry (CV) and it was shown that PAni/MCC/CTAB composite generated a higher current response compared to the pure PAni. The synergy effect of MCC and CTAB on the physical and electrochemical properties of composite resulted in higher electron transferring in PAni/MCC/CTAB. The presence of significant peaks of PAni and MCC in FT-IR spectrum of nanocomposite indicating polymerization of aniline on the surface of MCC. Characteristic peaks of crystalline cellulose were observed at 22.8 and 14.7 2theta in XRD pattern.

  18. Solid state NMR sequential resonance assignments and conformational analysis of the 2x10.4 kDa dimeric form of the Bacillus subtilis protein Crh

    Energy Technology Data Exchange (ETDEWEB)

    Boeckmann, Anja [Institut de Biologie et Chimie des Proteines, C.N.R.S UMR 5086 (France)], E-mail: a.bockmann@ibcp.fr; Lange, Adam [Max-Planck-Institute for Biophysical Chemistry, Solid-state NMR (Germany); Galinier, Anne [Institut de Biologie Structurale et Microbiologie, C.N.R.S UPR 9043 (France); Luca, Sorin [Max-Planck-Institute for Biophysical Chemistry, Solid-state NMR (Germany); Giraud, Nicolas; Juy, Michel [Institut de Biologie et Chimie des Proteines, C.N.R.S UMR 5086 (France); Heise, Henrike [Max-Planck-Institute for Biophysical Chemistry, Solid-state NMR (Germany); Montserret, Roland; Penin, Francois [Institut de Biologie et Chimie des Proteines, C.N.R.S UMR 5086 (France); Baldus, Marc [Max-Planck-Institute for Biophysical Chemistry, Solid-state NMR (Germany)], E-mail: maba@mpibpc.mpg.de

    2003-12-15

    Solid state NMR sample preparation and resonance assignments of the U-[{sup 13}C,{sup 15}N] 2x10.4 kDa dimeric form of the regulatory protein Crh in microcrystalline, PEG precipitated form are presented. Intra- and interresidue correlations using dipolar polarization transfer methods led to nearly complete sequential assignments of the protein, and to 88% of all {sup 15}N, {sup 13}C chemical shifts. For several residues, the resonance assignments differ significantly from those reported for the monomeric form analyzed by solution state NMR. Dihedral angles obtained from a TALOS-based statistical analysis suggest that the microcrystalline arrangement of Crh must be similar to the domain-swapped dimeric structure of a single crystal form recently solved using X-ray crystallography. For a limited number of protein residues, a remarkable doubling of the observed NMR resonances is observed indicative of local static or dynamic conformational disorder. Our study reports resonance assignments for the largest protein investigated by solid state NMR so far and describes the conformational dimeric variant of Crh with previously unknown chemical shifts.

  19. Use of hexamethyldisiloxane for p-type microcrystalline silicon oxycarbide layers

    Directory of Open Access Journals (Sweden)

    Goyal Prabal

    2016-01-01

    Full Text Available The use of hexamethyldisiloxane (HMDSO as an oxygen source for the growth of p-type silicon-based layers deposited by Plasma Enhanced Chemical Vapor Deposition is evaluated. The use of this source led to the incorporation of almost equivalent amounts of oxygen and carbon, resulting in microcrystalline silicon oxycarbide thin films. The layers were examined with characterisation techniques including Spectroscopic Ellipsometry, Dark Conductivity, Fourier Transform Infrared Spectroscopy, Secondary Ion Mass Spectrometry and Transmission Electron Microscopy to check material composition and structure. Materials studies show that the refractive indices of the layers can be tuned over the range from 2.5 to 3.85 (measured at 600 nm and in-plane dark conductivities over the range from 10-8 S/cm to 1 S/cm, suggesting that these doped layers are suitable for solar cell applications. The p-type layers were tested in single junction amorphous silicon p-i-n type solar cells.

  20. Steady-state solution growth of microcrystalline silicon on nanocrystalline seed layers on glass

    Science.gov (United States)

    Bansen, R.; Ehlers, C.; Teubner, Th.; Boeck, T.

    2016-09-01

    The growth of polycrystalline silicon layers on glass from tin solutions at low temperatures is presented. This approach is based on the steady-state solution growth of Si crystallites on nanocrystalline seed layers, which are prepared in a preceding process step. Scanning electron microscopy and atomic force microscopy investigations reveal details about the seed layer surfaces, which consist of small hillocks, as well as about Sn inclusions and gaps along the glass substrate after solution growth. The successful growth of continuous microcrystalline Si layers with grain sizes up to several ten micrometers shows the feasibility of the process and makes it interesting for photovoltaics. Project supported by the German Research Foundation (DFG) (No. BO 1129/5-1).

  1. Advax™, a novel microcrystalline polysaccharide particle engineered from delta inulin, provides robust adjuvant potency together with tolerability and safety.

    Science.gov (United States)

    Petrovsky, Nikolai; Cooper, Peter D

    2015-11-04

    There is an ongoing need for new adjuvants to facilitate development of vaccines against HIV, tuberculosis, malaria and cancer, amongst many others. Unfortunately, the most potent adjuvants are often associated with toxicity and safety issues. Inulin, a plant-derived polysaccharide, has no immunological activity in its native soluble form but when crystallized into a stable microcrystalline particulate from (delta inulin) acquires potent adjuvant activity. Delta inulin has been shown to enhance humoral and cellular immune responses against a broad range of co-administered viral, bacterial, parasitic and toxin antigens. Inulin normally crystallizes as large heterogeneous particles with a broad size distribution and variable solubility temperatures. To ensure reproducible delta inulin particles with a consistent size distribution and temperature of solubility, a current Good Manufacturing Practice (cGMP) process was designed to produce Advax™ adjuvant. In its cCMP form, Advax™ adjuvant has proved successful in human trials of vaccines against seasonal and pandemic influenza, hepatitis B and insect sting anaphylaxis, enhancing antibody and T-cell responses while being safe and well tolerated. Advax™ adjuvant represents a novel human adjuvant that enhances both humoral and cellular immunity. This review describes the discovery and development of Advax™ adjuvant and research into its unique mechanism of action. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. A new view of microcrystalline silicon: The role of plasma processing in achieving a dense and stable absorber material for photovoltaic applicationsv

    Czech Academy of Sciences Publication Activity Database

    Bugnon, G.; Parascandolo, G.; Söderström, T.; Cuony, P.; Despeisse, M.; Hänni, S.; Holovský, Jakub; Meillaud, F.; Ballif, C.

    2012-01-01

    Roč. 22, č. 17 (2012), s. 3665-3671 ISSN 1616-301X Institutional research plan: CEZ:AV0Z10100521 Keywords : solar cell * microcrystalline silicon * nanoporous Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 9.765, year: 2012 http://onlinelibrary.wiley.com/doi/10.1002/adfm.201200299/pdf

  3. Synthesis and luminescence properties of YVO4:Eu3+ cobblestone - like microcrystalline phosphors obtained from the mixed solvent - thermal method

    International Nuclear Information System (INIS)

    Xiao Xiuzhen; Lu Guanzhong; Shen Shaodian; Mao Dongsen; Guo Yun; Wang Yanqin

    2011-01-01

    The mixed solvent-thermal method has been developed for the synthesis of YVO 4 :Eu 3+ luminescent materials in the N, N-dimethylformamide (DMF)/ de-ionized water (DIW) solution. The samples have been characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electronic microscope (TEM), UV/vis absorption and photoluminescence spectroscopies. The results demonstrate that we have obtained the uniform YVO 4 :Eu 3+ cobblestone - like microcrystalline phosphors in the mixed solution of DMF and DIW, which are different to the as-obtained YVO 4 :Eu 3+ nanoparticles in pure DIW. And the as - prepared YVO 4 :Eu 3+ microcrystalline particles are composed of numerous nanoparticles. The assembling phenomenon of the nanoparticles is strongly affected by the pH value of the solution and the volume ratio of DMF/DIW. Under UV excitation, the samples can emit the bright red light. While, the photoluminescence (PL) intensities of YVO 4 :Eu 3+ show some difference for samples obtained under the different reaction conditions. This is because that different microstructures of samples result in different combinative abilities between the surface and the adsorbed species so as to produce the different quenching abilities to the emission from Eu 3+ ions.

  4. Ammonia-free chemical bath method for deposition of microcrystalline cadmium selenide films

    International Nuclear Information System (INIS)

    Lokhande, C.D.; Lee, Eun-Ho; Jung, Kwang-Deog; Joo, Oh-Shim

    2005-01-01

    Chemical deposition of cadmium selenide (CdSe) films has been carried out from alkaline aqueous solution containing Cd 2+ and Se 2- ions. In general, the alkaline pH of the CdSe deposition bath has been adjusted by addition of liquid ammonia. However, the use of ammonia in large-scale chemical deposition method represents an environmental problem due to its volatility and toxicity. The volatility of ammonia changes the pH of deposition bath and results into irreproducible film properties. In the present paper, ammonia-free and weak alkaline (pH < 9.0) chemical method for cadmium selenide film has been developed. The cadmium selenide films are microcrystalline (grain size 0.5-0.7 μm) with hexagonal crystal structure. These films are photoactive and therefore, useful in photo conversion of light into electrical power

  5. Production of Starch Based Bioplastic from Cassava Peel Reinforced with Microcrystalline Celllulose Avicel PH101 Using Sorbitol as Plasticizer

    Science.gov (United States)

    Maulida; Siagian, M.; Tarigan, P.

    2016-04-01

    The production of starch based bioplastics from cassava peel reeinforced with microcrystalline cellulose using sorbitol as plasticizer were investigated. Physical properties of bioplastics were determined by density, water uptake, tensile strength and Fourier Transform Infrared Spectroscopy. Bioplastics were prepared from cassava peel starch plasticized using sorbitol with variation of 20; 25; 30% (wt/v of sorbitol to starch) reinforced with microcrystalline celllulose (MCC) Avicel PH101 fillers with range of 0 to 6% (wt/wt of MCC to starch). The results showed improvement in tensile strength with higher MCC content up to 9, 12 mpa compared to non-reinforced bioplastics. This could be mainly attributed to the strong hydrogen bonds between MCC and starch. On the contrary, the addition of MCC decreased the elongation at break, density and water uptake. Fourier Transform Infrared Spectroscopy showed the functional groups of bioplastics, which the majority of O-H groups were found at the bioplastics with reinforcing filler MCC that represented substantial hydrogen bonds. The highest tensile strength value was obtained for bioplastic with MCC content 6% and sorbitol content 20%. With good adhesion between MCC and starch the production of bioplastics could be widely used as a substitute for conventional plastics with more benefits to the environment.

  6. Production of Starch Based Bioplastic from Cassava Peel Reinforced with Microcrystalline Celllulose Avicel PH101 Using Sorbitol as Plasticizer

    International Nuclear Information System (INIS)

    Maulida; Siagian, M; Tarigan, P

    2016-01-01

    The production of starch based bioplastics from cassava peel reeinforced with microcrystalline cellulose using sorbitol as plasticizer were investigated. Physical properties of bioplastics were determined by density, water uptake, tensile strength and Fourier Transform Infrared Spectroscopy. Bioplastics were prepared from cassava peel starch plasticized using sorbitol with variation of 20; 25; 30% (wt/v of sorbitol to starch) reinforced with microcrystalline celllulose (MCC) Avicel PH101 fillers with range of 0 to 6% (wt/wt of MCC to starch). The results showed improvement in tensile strength with higher MCC content up to 9, 12 mpa compared to non-reinforced bioplastics. This could be mainly attributed to the strong hydrogen bonds between MCC and starch. On the contrary, the addition of MCC decreased the elongation at break, density and water uptake. Fourier Transform Infrared Spectroscopy showed the functional groups of bioplastics, which the majority of O-H groups were found at the bioplastics with reinforcing filler MCC that represented substantial hydrogen bonds. The highest tensile strength value was obtained for bioplastic with MCC content 6% and sorbitol content 20%. With good adhesion between MCC and starch the production of bioplastics could be widely used as a substitute for conventional plastics with more benefits to the environment. (paper)

  7. A new crystal growth form of vaterite, CaCO sub 3

    Energy Technology Data Exchange (ETDEWEB)

    Shaikh, A M [Kuwait Univ., Safat (Kuwait). Dept. of Geology

    1990-08-01

    Microcrystalline vaterite, CaCO{sub 3}, has been synthesized by decomposition of ikaite, CaCO{sub 3}.6H{sub 2}O, crystals at room temperature. Scanning electron micrographs show that vaterite occurs as arborescent aggregates {approx equal}30 to 40 {mu}m in size. This growth form has not been described before. It is of interest that the overall morphology of the vaterite is reminiscent of some dendritic calcite tufas, although on a smaller scale. This similarity opens up the possibility that the calcitic tufas such as that associated with the Quaternary Lake Lahonton, Nevada, may have been deposited as vaterite that changed to calcite, while preserving the original growth form. (orig.).

  8. Physical mechanical and tablet formation properties of hydroxypropylcellulose: In pure form and in mixtures

    OpenAIRE

    Picker-Freyer, Katharina M.; Dürig, Thomas

    2007-01-01

    The aim of the study was to analyze hydroxypropylcellulose (HPC) in pure form and in excipient mixtures and to relate its physical and chemical properties to tablet binder functionality. The materials used were Klucel hydroxypropylcellulose grades ranging from low to high molecular weight (80–1000 kDa) of regular particle size (250 µm mean size) and fine particle size (80 µm mean size). These were compared with microcrystalline cellulose, spray-dried lactose, and dicalcium phosphate dihydrate...

  9. Performance Improvement of Microcrystalline p-SiC/i-Si/n-Si Thin Film Solar Cells by Using Laser-Assisted Plasma Enhanced Chemical Vapor Deposition

    Directory of Open Access Journals (Sweden)

    Hsin-Ying Lee

    2014-01-01

    Full Text Available The microcrystalline p-SiC/i-Si/n-Si thin film solar cells treated with hydrogen plasma were fabricated at low temperature using a CO2 laser-assisted plasma enhanced chemical vapor deposition (LAPECVD system. According to the micro-Raman results, the i-Si films shifted from 482 cm−1 to 512 cm−1 as the assisting laser power increased from 0 W to 80 W, which indicated a gradual transformation from amorphous to crystalline Si. From X-ray diffraction (XRD results, the microcrystalline i-Si films with (111, (220, and (311 diffraction were obtained. Compared with the Si-based thin film solar cells deposited without laser assistance, the short-circuit current density and the power conversion efficiency of the solar cells with assisting laser power of 80 W were improved from 14.38 mA/cm2 to 18.16 mA/cm2 and from 6.89% to 8.58%, respectively.

  10. Top-gate microcrystalline silicon TFTs processed at low temperature (<200 deg. C)

    International Nuclear Information System (INIS)

    Saboundji, A.; Coulon, N.; Gorin, A.; Lhermite, H.; Mohammed-Brahim, T.; Fonrodona, M.; Bertomeu, J.; Andreu, J.

    2005-01-01

    N-type as well P-type top-gate microcrystalline silicon thin film transistors (TFTs) are fabricated on glass substrates at a maximum temperature of 200 deg. C. The active layer is an undoped μc-Si film, 200 nm thick, deposited by Hot-Wire Chemical Vapor. The drain and source regions are highly phosphorus (N-type TFTs) or boron (P-type TFTs)-doped μc-films deposited by HW-CVD. The gate insulator is a silicon dioxide film deposited by RF sputtering. Al-SiO 2 -N type c-Si structures using this insulator present low flat-band voltage,-0.2 V, and low density of states at the interface D it =6.4x10 10 eV -1 cm -2 . High field effect mobility, 25 cm 2 /V s for electrons and 1.1 cm 2 /V s for holes, is obtained. These values are very high, particularly the hole mobility that was never reached previously

  11. The effect of pulping concentration treatment on the properties of microcrystalline cellulose powder obtained from waste paper.

    Science.gov (United States)

    Okwonna, Okumneme O

    2013-10-15

    Microcrystalline cellulose (MCC) powder was isolated from three grades of waste paper: book, Groundwood/Newsprint and paperboard, through the processes of pulping and hydrolysis. Pulping treatment on these grades of waste paper was done using varying concentrations of caustic soda. Effects of the concentration of the pulping medium on the thermal and kinetic properties were investigated. Also determined were the effects of this on the physico-chemical properties. The chemical structure was characterized using an infrared spectroscopy (FTIR). Results showed these properties to be affected by the concentration of the pulping medium. Copyright © 2013 Elsevier Ltd. All rights reserved.

  12. Characterization of Polylactic Acid/ Microcrystalline Cellulose/ Montmorillonite Hybrid Composites

    International Nuclear Information System (INIS)

    Reza Arjmandi; Azman Hassan; Haafiz, M.K.M.; Zainoha Zakaria; Inuwa, I.M.

    2014-01-01

    The objective of this study is to investigate the effect of montmorillonite (MMT)/ microcrystalline cellulose (MCC) hybrid fillers on mechanical properties and morphological characteristics of polylactic acid (PLA) composites. PLA/ MMT nano composites and PLA/ MMT/ MCC hybrid composites were prepared by solution casting method. Morphology and tensile properties of PLA composites were investigated using Field emission scanning electron microscopy and Instron tensile testing machine. The maximum tensile strength of PLA/ MMT nano composites was obtained with 5 phr contents of MMT, which corresponding to 30.75 MPa. Based on optimized formulation of PLA/ MMT nano composites (5 phr MMT contents), various amounts of MCC (0 to 7 phr) were added into optimum formulation of PLA/ MMT in order to produce PLA/ MMT/ MCC hybrid composites. Fourier transform infrared spectroscopy revealed some level of interaction between PLA and both MMT and MCC in the hybrid composites. However, the percent elongation at break of the hybrid composites was generally higher than PLA/ MMT nano composites. Additionally, Young's modulus of the PLA/ MMT/ MCC hybrid composites increased gradually with increasing of MCC contents and was higher than PLA/ MMT at all compositions. The present results are the first among a series of experiments that have been designed in order to probe the effect of MMT and MCC in the PLA. (author)

  13. A study of the compressibility and properties of tablets from co-processed dry binder composed of microcrystalline cellulose and glyceryl monostearate.

    OpenAIRE

    Muchová, Sandra

    2013-01-01

    The paper studies the co-processed dry binder LubriTose™ MCC from the viewpoint of energy evaluation of the compression process, strength and disintegration time of tablets. The results were compared with the identical evaluation of physical mixtures of microcrystalline cellulose with several types of lubricants. LubriTose™ MCC showed the lowest value of energy for friction, the highest value of energy accumulated by the tablet, and the highest plasticity of all tableting materials under stud...

  14. Piezoelectric photothermal study of the optical properties of microcrystalline silicon near the bandgap

    International Nuclear Information System (INIS)

    Fukuyama, A.; Sakamoto, S.; Sonoda, S.; Wang, P.; Sakai, K.; Ikari, T.

    2006-01-01

    The optical absorption spectra of hydrogenated microcrystalline silicon (μc-Si:H) films deposited on glass and transparent conductive oxide (TCO) covered glass substrates were measured by using the piezoelectric photothermal (PPT) technique. The effects of the deposition rate on the optical absorption of μc-Si:H thin films were investigated from the nonradiative transition point of view. It was found that increasing the deposition rate resulted in a decrease of optical absorption and a shift of effective energy gap to the higher photon energy side. These changes in the optical properties of μc-Si:H cause the decrease of the number of carriers optically generated by absorbing sunlight, and results in a reduction in the photovoltaic conversion efficiency of the solar cells for high deposition rate samples. The usefulness of the PPT method for investigating the optical properties of thin and transparent μc-Si:H films was also demonstrated

  15. The Disintegration Process in Microcrystalline Cellulose Based Tablets, Part 1: Influence of Temperature, Porosity and Superdisintegrants

    Science.gov (United States)

    Yassin, Samy; Goodwin, Daniel J; Anderson, Andrew; Sibik, Juraj; Wilson, D Ian; Gladden, Lynn F; Zeitler, J Axel

    2015-01-01

    Disintegration performance was measured by analysing both water ingress and tablet swelling of pure microcrystalline cellulose (MCC) and in mixture with croscarmellose sodium using terahertz pulsed imaging (TPI). Tablets made from pure MCC with porosities of 10% and 15% showed similar swelling and transport kinetics: within the first 15 s, tablets had swollen by up to 33% of their original thickness and water had fully penetrated the tablet following Darcy flow kinetics. In contrast, MCC tablets with a porosity of 5% exhibited much slower transport kinetics, with swelling to only 17% of their original thickness and full water penetration reached after 100 s, dominated by case II transport kinetics. The effect of adding superdisintegrant to the formulation and varying the temperature of the dissolution medium between 20°C and 37°C on the swelling and transport process was quantified. We have demonstrated that TPI can be used to non-invasively analyse the complex disintegration kinetics of formulations that take place on timescales of seconds and is a promising tool to better understand the effect of dosage form microstructure on its performance. By relating immediate-release formulations to mathematical models used to describe controlled release formulations, it becomes possible to use this data for formulation design. © 2015 The Authors. Journal of Pharmaceutical Sciences published by Wiley Periodicals, Inc. and the American Pharmacists Association J Pharm Sci 104:3440–3450, 2015 PMID:26073446

  16. Isolation and characterization of microcrystalline cellulose from roselle fibers.

    Science.gov (United States)

    Kian, Lau Kia; Jawaid, Mohammad; Ariffin, Hidayah; Alothman, Othman Y

    2017-10-01

    In this study, microcrystalline cellulose (MCC) was extracted from roselle fiber through acid hydrolysis treatment and its properties were compared with those of commercially available MCC. The physicochemical and morphological characteristics, elemental composition, size distribution, crystallinity and thermal properties of the obtained MCC were analyzed in this work. Fourier transform infrared spectroscopy (FTIR) analysis provided clear evidence that the characteristic peak of lignin was absent in the spectrum of the MCC prepared from roselle fiber. Rough surface and slight aggregation of MCC were observed by scanning electron microscopy (SEM). Energy dispersive X-ray (EDX) analysis showed that pure MCC with small quantities of residues and impurities was obtained, with a similar elemental composition to that of commercial MCC. A mean diameter of approximately 44.28μm was measured for MCC by using a particle size analyzer (PSA). X-ray diffraction (XRD) showed the crystallinity increased from 63% in roselle pulp to 78% in roselle MCC, the latter having a slightly higher crystallinity than that of commercial MCC (74%). TGA and DSC results indicated that the roselle MCC had better thermal stability than the roselle pulp, whereas it had poorer thermal stability in comparison with commercial MCC. Thus, the isolated MCC from roselle fibers will be going to use as reinforcing element in green composites and may be a precursor for future roselle derived nanocellulose, and thus a promising subject in nanocomposite research. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Solar cell of 6.3% efficiency employing high deposition rate (8 nm/s) microcrystalline silicon photovoltaic layer

    Energy Technology Data Exchange (ETDEWEB)

    Sobajima, Yasushi; Nishino, Mitsutoshi; Fukumori, Taiga; Kurihara, Masanori; Higuchi, Takuya; Nakano, Shinya; Toyama, Toshihiko; Okamoto, Hiroaki [Department of Systems Innovation, Graduate School of Engineering Science, Osaka University, Toyonaka, Machikaneyama-cho 1-3, Osaka 560-8531 (Japan)

    2009-06-15

    Microcrystalline silicon ({mu}c-Si) films deposited at high growth rates up to 8.1 nm/s prepared by very-high-frequency-plasma-enhanced chemical vapor deposition (VHF-PECVD) at 18-24 Torr have been investigated. The relation between the deposition rates and input power revealed the depletion of silane. Under high-pressure deposition (HPD) conditions, the structural properties were improved. Furthermore, applying {mu}c-Si to n-i-p solar cells, short-circuit current density (J{sub SC}) was increased in accordance with the improvement of microstructure of i-layer. As a result, a conversion efficiency of 6.30% has been achieved employing the i-layer deposited at 8.1 nm/s under the HPD conditions. (author)

  18. Use of the microcrystalline limestone as building material: the "GrisPulpis"case

    Directory of Open Access Journals (Sweden)

    García del Cura, M. A.

    2005-03-01

    Full Text Available Gris Pulpis is a Jurassic microcrystalline limestone found in the Maestrazgo Area of the Iberian Mountain Range (province of Castellón, Spain. This paper reports the results of a detailed study of the mineralogical, pelrographic and chromatic characteristics, as well as the durability, of this stone, classified as a commercial marble for its polish ability. The study determined the relationship between the structural characteristics of the stone, with a proliferation of stylolites and veins, and its physical properties. Its flexura I strength was found to be greater than would normally be expected in a structure with such a dense web of stylolites and veins. This is due to the structural and mineralogical properties of these stylolites, characterised by an extremely wavy design, scant mineral infillings and, occasionally, subsequent cementation. The characteristics of the porous media of homogeneous microcrystalline limestones such as Gris Pulpis largely explain the durability of this stone when exposed to freeze-thaw cycles and salt crystallisation. These arc the properties that make Gris Pulpis limestone, quarried in the Spanish Region of Valencia, a valuable building material for both architectural and civil engineering applications

    En este trabajo se analizan las propiedades físicas y la durabilidad de una caliza microcristalina.El Gris Pulpis es una caliza microcristalina del Jurásico de la Cordillera Ibérica (Maestrazgo, cuyas características mineralógicas, petrográficas, cromáticas y alterabilidad se determinan detalladamente. Su aptitud para el pulido hace que sea un mármol comercial. Se establece la influencia de sus características estructurales (estilolitos, vénulas... en sus propiedades físicas. Su resistencia a flexión supera los valores que cabría esperar en función de la estructura de esta roca que, a veces, presenta abundantes estilolitos y vénulas. Esto es debido a las características estructurales y

  19. Study of carbide-forming element interlayers for diamond nucleation and growth on silicon and WC-Co substrates

    International Nuclear Information System (INIS)

    Tang, Y.; Li, Y.S.; Yang, Q.; Hirose, A.

    2010-01-01

    Diamond nucleation and growth on several typical carbide-forming elements (CFE) (Ti, Cr and W) coated Si and WC-Co substrates were studied. The ion beam sputtered CFE interlayers show an amorphous/nanocrystalline microstructure. The diamond formed on the CFE coated substrates shows higher nucleation density and rate and finer grain structure than on uncoated substrates. Consequently, nanocrystalline diamond thin films can be formed on the CFE coated substrates under conventional microcrystalline diamond growth conditions. Among the three tested CFE interlayers, diamond has the highest nucleation density and rate on W layer and the lowest on Ti layer. The diamond nucleation density and rate on CFE coated WC-Co are much higher than those on widely used metal nitride coated WC-Co.

  20. Application of hydrogen-doped In2O3 transparent conductive oxide to thin-film microcrystalline Si solar cells

    International Nuclear Information System (INIS)

    Koida, Takashi; Sai, Hitoshi; Kondo, Michio

    2010-01-01

    Hydrogen-doped In 2 O 3 (IO:H) films with high electron mobility and improved near-infrared (NIR) transparency have been applied as a transparent conducting oxide (TCO) electrode in substrate-type hydrogenated microcrystalline silicon (μc-Si:H) solar cells. The incorporation of IO:H, instead of conventional Sn-doped In 2 O 3 , improved the short-circuit current density (J sc ) and the resulting conversion efficiency. Optical analysis of the solar cells and TCO films revealed that the improvement in J sc is due to the improved spectral sensitivity in the visible and NIR wavelengths by reduction of absorption loss caused by free carriers in the TCO films.

  1. Conductivity percolation in loosely compacted microcrystalline cellulose: An in situ study by dielectric spectroscopy during densification.

    Science.gov (United States)

    Nilsson, Martin; Frenning, Göran; Gråsjö, Johan; Alderborn, Göran; Strømme, Maria

    2006-10-19

    The present study aims at contributing to a complete understanding of the water-induced ionic charge transport in cellulose. The behavior of this transport in loosely compacted microcrystalline cellulose (MCC) powder was investigated as a function of density utilizing a new type of measurement setup, allowing for dielectric spectroscopy measurement in situ during compaction. The ionic conductivity in MCC was found to increase with increasing density until a leveling-out was observed for densities above approximately 0.7 g/cm3. Further, it was shown that the ionic conductivity vs density followed a percolation type behavior signifying the percolation of conductive paths in a 3D conducting network. The density percolation threshold was found to be between approximately 0.2 and 0.4 g/cm3, depending strongly on the cellulose moisture content. The observed percolation behavior was attributed to the forming of interparticulate bonds in the MCC and the percolation threshold dependence on moisture was linked to the moisture dependence of particle rearrangement and plastic deformation in MCC during compaction. The obtained results add to the understanding of the density-dependent water-induced ionic transport in cellulose showing that, at given moisture content, the two major parameters determining the magnitude of the conductivity are the connectedness of the interparticluate bonds and the connectedness of pores with a diameter in the 5-20 nm size range. At densities between approximately 0.7 and 1.2 g/cm3 both the bond and the pore networks have percolated, facilitating charge transport through the MCC compact.

  2. The Disintegration Process in Microcrystalline Cellulose Based Tablets, Part 1: Influence of Temperature, Porosity and Superdisintegrants.

    Science.gov (United States)

    Yassin, Samy; Goodwin, Daniel J; Anderson, Andrew; Sibik, Juraj; Wilson, D Ian; Gladden, Lynn F; Zeitler, J Axel

    2015-10-01

    Disintegration performance was measured by analysing both water ingress and tablet swelling of pure microcrystalline cellulose (MCC) and in mixture with croscarmellose sodium using terahertz pulsed imaging (TPI). Tablets made from pure MCC with porosities of 10% and 15% showed similar swelling and transport kinetics: within the first 15 s, tablets had swollen by up to 33% of their original thickness and water had fully penetrated the tablet following Darcy flow kinetics. In contrast, MCC tablets with a porosity of 5% exhibited much slower transport kinetics, with swelling to only 17% of their original thickness and full water penetration reached after 100 s, dominated by case II transport kinetics. The effect of adding superdisintegrant to the formulation and varying the temperature of the dissolution medium between 20°C and 37°C on the swelling and transport process was quantified. We have demonstrated that TPI can be used to non-invasively analyse the complex disintegration kinetics of formulations that take place on timescales of seconds and is a promising tool to better understand the effect of dosage form microstructure on its performance. By relating immediate-release formulations to mathematical models used to describe controlled release formulations, it becomes possible to use this data for formulation design. © 2015 The Authors. Journal of Pharmaceutical Sciences published by Wiley Periodicals, Inc. and the American Pharmacists Association J Pharm Sci 104:3440-3450, 2015. © 2015 The Authors. Journal of Pharmaceutical Sciences published by Wiley Periodicals, Inc. and the American Pharmacists Association.

  3. Iron Oxide Nanoparticles Employed as Seeds for the Induction of Microcrystalline Diamond Synthesis

    Directory of Open Access Journals (Sweden)

    Resto Oscar

    2008-01-01

    Full Text Available AbstractIron nanoparticles were employed to induce the synthesis of diamond on molybdenum, silicon, and quartz substrates. Diamond films were grown using conventional conditions for diamond synthesis by hot filament chemical vapor deposition, except that dispersed iron oxide nanoparticles replaced the seeding. X-ray diffraction, visible, and ultraviolet Raman Spectroscopy, energy-filtered transmission electron microscopy , electron energy-loss spectroscopy, and X-ray photoelectron spectroscopy (XPS were employed to study the carbon bonding nature of the films and to analyze the carbon clustering around the seed nanoparticles leading to diamond synthesis. The results indicate that iron oxide nanoparticles lose the O atoms, becoming thus active C traps that induce the formation of a dense region of trigonally and tetrahedrally bonded carbon around them with the ensuing precipitation of diamond-type bonds that develop into microcrystalline diamond films under chemical vapor deposition conditions. This approach to diamond induction can be combined with dip pen nanolithography for the selective deposition of diamond and diamond patterning while avoiding surface damage associated to diamond-seeding methods.

  4. Wear resistance of nano- and micro-crystalline diamond coatings onto WC-Co with Cr/CrN interlayers

    Energy Technology Data Exchange (ETDEWEB)

    Polini, Riccardo [Dipartimento di Scienze e Tecnologie Chimiche, Universita di Roma Tor Vergata, Via della Ricerca Scientifica, 1, Rome, 00133 (Italy); Barletta, Massimiliano, E-mail: barletta@ing.uniroma2.i [Dipartimento di Ingegneria Meccanica, Universita di Roma Tor Vergata, Via del Politecnico, 1, Rome, 00133 (Italy); Cristofanilli, Giacomo [Dipartimento di Scienze e Tecnologie Chimiche, Universita di Roma Tor Vergata, Via della Ricerca Scientifica, 1, Rome, 00133 (Italy)

    2010-12-30

    Cr/CrN bi-layers have been used recently to promote the growth of high quality Hot Filament Chemical Vapour Deposition (HFCVD) diamond coatings onto Co-cemented tungsten carbide (WC-6 wt.%Co) substrates. In the present investigation, the influence of the crystalline size of the diamond coatings on their wear endurance is looked into. Nano- (NDC) and micro-crystalline Diamond Coatings (MDC) were deposited by HFCVD onto untreated and Fluidized Bed (FB) treated Cr/CrN interlayers. NDCs, characterized by a cauliflower-like morphology, showed improved wear resistance. However, the superimposition of NDCs onto Cr/CrN interlayers micro-corrugated by FB treatment was found to be the most promising choice, leading to the formation of highly adherent and wear resistant coatings.

  5. Process control of high rate microcrystalline silicon based solar cell deposition by optical emission spectroscopy

    International Nuclear Information System (INIS)

    Kilper, T.; Donker, M.N. van den; Carius, R.; Rech, B.; Braeuer, G.; Repmann, T.

    2008-01-01

    Silicon thin-film solar cells based on microcrystalline silicon (μc-Si:H) were prepared in a 30 x 30 cm 2 plasma-enhanced chemical vapor deposition reactor using 13.56 or 40.68 MHz plasma excitation frequency. Plasma emission was recorded by optical emission spectroscopy during μc-Si:H absorber layer deposition at deposition rates between 0.5 and 2.5 nm/s. The time course of SiH * and H β emission indicated strong drifts in the process conditions particularly at low total gas flows. By actively controlling the SiH 4 gas flow, the observed process drifts were successfully suppressed resulting in a more homogeneous i-layer crystallinity along the growth direction. In a deposition regime with efficient usage of the process gas, the μc-Si:H solar cell efficiency was enhanced from 7.9 % up to 8.8 % by applying process control

  6. Preparation and Characterisation of Amorphous-silicon Photovoltaic Devices Having Microcrystalline Emitters; Preparacion y Caracterizacion de Dispositivos Fotovoltaicos de Silicio Amorfo con Emisiones Microcristalinos

    Energy Technology Data Exchange (ETDEWEB)

    Gutierrez, M. T.; Gandia, J. J.; Carabe, J. [CIEMAT. Madrid (Spain)

    1999-11-01

    The present work summarises the essential aspects of the research carried out so far at CIEMAT on amorphous-silicon solar cells. The experience accumulated on the preparation and characterisation of amorphous and microcrystalline silicon has allowed to start from intrinsic (absorbent) and p-and n-type (emitters) materials not only having excellent optoelectronic properties, but enjoying certain technological advantages with respect to those developed by other groups. Among these are absorbent-layer growth rates between 5 and 10 times as fast as conventional ones and microcrystalline emitters prepared without using hydrogen. The preparation of amorphous-silicon cells has required the solution of a number of problems, such as those related to pinholes, edge leak currents and diffusion of metals into the semiconductor. Once such constraints have been overcome, it has been demonstrated not only that the amorphous-silicon technology developed at CIEMAT is valid for making solar cells, but also that the quality of the semiconductor material is good for the application according to the partial results obtained. The development of thin-film laser-scribing technology is considered essential. Additionally it has been concluded that cross contamination, originated by the fact of using a single-chamber reactor, is the basic factor limiting the quality of the cells developed at CIEMAT. The present research activity is highly focused on the solution of this problem. (Author)

  7. Combined effect of nitrogen doping and nanosteps on microcrystalline diamond films for improvement of field emission

    International Nuclear Information System (INIS)

    Mengui, U.A.; Campos, R.A.; Alves, K.A.; Antunes, E.F.; Hamanaka, M.H.M.O.; Corat, E.J.; Baldan, M.R.

    2015-01-01

    Highlights: • Hot filament chemical vapor deposition using methane, hydrogen and a solution of urea in methanol produced nitrogen-doped diamond films. • Diamonds had the grain morphology changed for long growth time (28 h), and the nitrogen doping were evaluated by Raman spectroscopy. • Field emission characterization shows a decrease up to 70% in threshold field, related to reference diamond layer. - Abstract: Nitrogen-doped microcrystalline diamond (N-MCD) films were grown on Si substrates using a hot filament reactor with methanol solution of urea as N source. Electrostatic self-assembly seeding of nanocrystalline diamond were used to obtain continuous and uniform films. Simultaneous changes in grains morphology and work function of diamond by nitrogen doping decreased the threshold field and the angular coefficient of Fowler–Nordhein plots. The field emission properties of our N-MCD films are comparable to carbon nanotube films

  8. Combined effect of nitrogen doping and nanosteps on microcrystalline diamond films for improvement of field emission

    Energy Technology Data Exchange (ETDEWEB)

    Mengui, U.A., E-mail: ursulamengui@gmail.com [INPE – Instituto Nacional de Pesquisas Espaciais Laboratório Associado de Sensores e Materiais – LAS, Av. dos Astronautas 1758, CP 515, CEP 12.245-970, São José dos Campos, SP (Brazil); Campos, R.A.; Alves, K.A.; Antunes, E.F. [INPE – Instituto Nacional de Pesquisas Espaciais Laboratório Associado de Sensores e Materiais – LAS, Av. dos Astronautas 1758, CP 515, CEP 12.245-970, São José dos Campos, SP (Brazil); Hamanaka, M.H.M.O. [Centro de Tecnologia da Informação Renato Archer, Divisão de Superfícies de Interação e Displays, Rodovia D. Pedro I (SP 65) km 143.6, CP 6162, CEP 13089-500, Campinas, SP (Brazil); Corat, E.J.; Baldan, M.R. [INPE – Instituto Nacional de Pesquisas Espaciais Laboratório Associado de Sensores e Materiais – LAS, Av. dos Astronautas 1758, CP 515, CEP 12.245-970, São José dos Campos, SP (Brazil)

    2015-04-15

    Highlights: • Hot filament chemical vapor deposition using methane, hydrogen and a solution of urea in methanol produced nitrogen-doped diamond films. • Diamonds had the grain morphology changed for long growth time (28 h), and the nitrogen doping were evaluated by Raman spectroscopy. • Field emission characterization shows a decrease up to 70% in threshold field, related to reference diamond layer. - Abstract: Nitrogen-doped microcrystalline diamond (N-MCD) films were grown on Si substrates using a hot filament reactor with methanol solution of urea as N source. Electrostatic self-assembly seeding of nanocrystalline diamond were used to obtain continuous and uniform films. Simultaneous changes in grains morphology and work function of diamond by nitrogen doping decreased the threshold field and the angular coefficient of Fowler–Nordhein plots. The field emission properties of our N-MCD films are comparable to carbon nanotube films.

  9. Fabrication of heterojunction solar cells by using microcrystalline hydrogenated silicon oxide film as an emitter

    International Nuclear Information System (INIS)

    Banerjee, Chandan; Sritharathikhun, Jaran; Konagai, Makoto; Yamada, Akira

    2008-01-01

    Wide gap, highly conducting n-type hydrogenated microcrystalline silicon oxide (μc-SiO : H) films were prepared by very high frequency plasma enhanced chemical vapour deposition at a very low substrate temperature (170 deg. C) as an alternative to amorphous silicon (a-Si : H) for use as an emitter layer of heterojunction solar cells. The optoelectronic properties of n-μc-SiO : H films prepared for the emitter layer are dark conductivity = 0.51 S cm -1 at 20 nm thin film, activation energy = 23 meV and E 04 = 2.3 eV. Czochralski-grown 380 μm thick p-type (1 0 0) oriented polished silicon wafers with a resistivity of 1-10 Ω cm were used for the fabrication of heterojunction solar cells. Photovoltaic parameters of the device were found to be V oc = 620 mV, J sc = 32.1 mA cm -2 , FF = 0.77, η = 15.32% (active area efficiency)

  10. Applicability of low-melting-point microcrystalline wax to develop temperature-sensitive formulations.

    Science.gov (United States)

    Matsumoto, Kohei; Kimura, Shin-Ichiro; Iwao, Yasunori; Itai, Shigeru

    2017-10-30

    Low-melting-point substances are widely used to develop temperature-sensitive formulations. In this study, we focused on microcrystalline wax (MCW) as a low-melting-point substance. We evaluated the drug release behavior of wax matrix (WM) particles using various MCW under various temperature conditions. WM particles containing acetaminophen were prepared using a spray congealing technique. In the dissolution test at 37°C, WM particles containing low-melting-point MCWs whose melting was starting at approx. 40°C (Hi-Mic-1045 or 1070) released the drug initially followed by the release of only a small amount. On the other hand, in the dissolution test at 20 and 25°C for WM particles containing Hi-Mic-1045 and at 20, 25, and 30°C for that containing Hi-Mic-1070, both WM particles showed faster drug release than at 37°C. The characteristic drug release suppression of WM particles containing low-melting-point MCWs at 37°C was thought attributable to MCW melting, as evidenced by differential scanning calorimetry analysis and powder X-ray diffraction analysis. Taken together, low-melting-point MCWs may be applicable to develop implantable temperature-sensitive formulations that drug release is accelerated by cooling at administered site. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Increasing the deposition rate of microcrystalline and amorphous silicon thin films for photovoltaic applications - Phase IV: 1997-1999

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-07-01

    This report on behalf of the Swiss Federal Office of Energy (SFOE) describes Phase IV of the project to test the feasibility and usefulness of Very High Frequency (VHF) plasma operation in large-area reactors suitable for the production of solar cell panels using thinly-deposited micro-crystalline silicon films. The report discusses the results of fast-deposition tests and trials using high-current DC arcs and VHF techniques to obtain deposition rates and film quality suitable for industrial processes for the production of thin-film solar cell panels. The effects of alternative plasma chemistry were also studied by adding silicon tetrafluoride to the standard silane/hydrogen mixtures. The report is concluded with calculations for optimum radio-frequency (RF) contact configuration for large area reactors with 1 m{sup 2} electrodes.

  12. Shape Modification and Size Classification of Microcrystalline Graphite Powder as Anode Material for Lithium-Ion Batteries

    Science.gov (United States)

    Wang, Cong; Gai, Guosheng; Yang, Yufen

    2018-03-01

    Natural microcrystalline graphite (MCG) composed of many crystallites is a promising new anode material for lithium-ion batteries (LiBs) and has received considerable attention from researchers. MCG with narrow particle size distribution and high sphericity exhibits excellent electrochemical performance. A nonaddition process to prepare natural MCG as a high-performance LiB anode material is described. First, raw MCG was broken into smaller particles using a pulverization system. Then, the particles were modified into near-spherical shape using a particle shape modification system. Finally, the particle size distribution was narrowed using a centrifugal rotor classification system. The products with uniform hemispherical shape and narrow size distribution had mean particle size of approximately 9 μm, 10 μm, 15 μm, and 20 μm. Additionally, the innovative pilot experimental process increased the product yield of the raw material. Finally, the electrochemical performance of the prepared MCG was tested, revealing high reversible capacity and good cyclability.

  13. Synthesis and photoluminescence properties of microcrystalline Sr{sub 2}ZnWO{sub 6}:RE{sup 3+} (RE = Eu, Dy, Sm and Pr) phosphors

    Energy Technology Data Exchange (ETDEWEB)

    Dabre, K.V. [Department of Physics, Arts, Commerce and Science College, Koradi, Nagpur 441111 (India); Park, K. [Faculty of Nanotechnology and Advanced Materials Engineering, Sejong University, Seoul 143-747 (Korea, Republic of); Dhoble, S.J., E-mail: sjdhoble@rediffmail.com [Department of Physics, R.T.M. Nagpur University, Nagpur 440033 (India)

    2014-12-25

    Graphical abstract: CIE chromaticity coordinate diagram (1931) indicating different colors of Sr{sub 2}ZnWO{sub 6}:RE{sup 3+} (RE = Eu (a), Dy (b and c), Sm (d–f) and Pr (g and h)) phosphor under different excitation 466 nm (a), 312 nm (b), 454 nm (c), 313 nm (d), 408 nm (e), 482 nm (f), 315 nm (g) and 450 nm (h). - Highlights: • Microcrystalline Sr{sub 2}ZnWO{sub 6}:RE{sup 3+} (RE = Eu, Dy, Sm and Pr) phosphors were synthesized by solid state method. • Photoluminescence properties of phosphor were investigated. • Color of the phosphor for different excitation has been verified by chromaticity diagram. • The host absorption and energy transfer were investigated. - Abstract: The novel microcrystalline Sr{sub 2}ZnWO{sub 6}:RE{sup 3+} (RE = Eu, Dy, Sm and Pr) phosphors were synthesized by solid-state reaction method at 1250 °C and their photoluminescence properties were investigated. The Eu{sup 3+} and Dy{sup 3+} activated phosphors show intense red (616 nm) and yellow (574 nm) emission respectively; which indicate that the rare earth ions are substituted at non-centrosymmetric site in the host lattice. Near white (Dy{sup 3+}) and reddish-orange (Sm{sup 3+}) emissions of rare earth ions in the host lattice show strong host absorption and energy transfer from the host to activator ion. Pr{sup 3+} activated phosphor shows a series of emission peaks in the visible region with the most intense peak in the blue region at 491 and 499 nm.

  14. Reducing the Entrainment of Gangue Fines in Low Grade Microcrystalline Graphite Ore Flotation Using Multi-Stage Grinding-Flotation Process

    Directory of Open Access Journals (Sweden)

    Xiaoqing Weng

    2017-03-01

    Full Text Available A suitable grinding fineness and flow-sheet could potentially reduce the mechanical entrainment of gangue minerals in the flotation process of microcrystalline graphite. In this study, the suitable grinding fineness of a commercial graphite ore was estimated by mineralogy analysis and laboratory grind-flotation tests. The target grind size of this ore should be 92% passing 74 μm based on the mineralogical evaluation and the flotation performance. A comparison of a single-stage and a three-stage grinding circuit was conducted. Experimental results demonstrated that the three-stage grinding circuit could effectively improve the separation effect, which was attributed to the reduction of slimes. In the end, a more desirable beneficiation result was obtained with the application of three-stage grinding-flotation process by minimizing gangue entrainment.

  15. FY 1999 research and development of technologies for commercialization of photovoltaic power generation systems. Development of technologies for fabrication of thin-film solar cells/materials and substrates (Development of technologies for fabrication of high-quality amorphous materials and substrates); 1999 nendo taiyoko hatsuden system jitsuyoka gijutsu kaihatsu seika hokokusho. Usumaku taiyo denchi no seizo gijutsu kaihatsu / zairyo kiban seizo gijutsu kaihatsu (kohinshitsu amorphous kei zairyo kiban no seizo gijutsu kaihatsu)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-03-01

    The research and development project is implemented for the amorphous/microcrystalline solar cells with the thin microcrystalline silicon film as the i layer, and the FY 1999 results are reported. The fabrication technologies are investigated for the microcrystalline silicon solar cells of pin or nip structure by RF or VHF plasma CVD using SiH{sub 4} and H{sub 2} as the stock gases. The tests are conducted for evaluating characteristics of the thin microcrystalline silicon film, to investigate the effects of film-making pressure, power and hydrogen dilution rate on the characteristics at a constant film-making temperature of 180 degrees C. The researches on the fabrication technologies for the microcrystalline solar cell of pin structure confirm that use of VHF plasma CVD improves crystallinity, electrical and optical characteristics of the p-type thin microcrystalline silicon film. The researches on the fabrication technologies for the microcrystalline solar cell of nip structure covers transparent substrates, film-making speed of the p layer, power and substrates, and a conversion efficiency of 7.5% is realized by the solar cell formed on a texture substrate. (NEDO)

  16. High-rate synthesis of microcrystalline silicon films using high-density SiH4/H2 microwave plasma

    International Nuclear Information System (INIS)

    Jia, Haijun; Saha, Jhantu K.; Ohse, Naoyuki; Shirai, Hajime

    2007-01-01

    A high electron density (> 10 11 cm -3 ) and low electron temperature (1-2 eV) plasma is produced by using a microwave plasma source utilizing a spoke antenna, and is applied for the high-rate synthesis of high quality microcrystalline silicon (μc-Si) films. A very fast deposition rate of ∼ 65 A/s is achieved at a substrate temperature of 150 deg. C with a high Raman crystallinity and a low defect density of (1-2) x 10 16 cm -3 . Optical emission spectroscopy measurements reveal that emission intensity of SiH and intensity ratio of H α /SiH are good monitors for film deposition rate and film crystallinity, respectively. A high flux of film deposition precursor and atomic hydrogen under a moderate substrate temperature condition is effective for the fast deposition of highly crystallized μc-Si films without creating additional defects as well as for the improvement of film homogeneity

  17. Preliminary viability studies of fibroblastic cells cultured on microcrystalline and nanocrystalline diamonds produced by chemical vapour deposition method

    Directory of Open Access Journals (Sweden)

    Ana Amélia Rodrigues

    2013-02-01

    Full Text Available Implant materials used in orthopedics surgery have demonstrated some disadvantages, such as metallic corrosion processes, generation of wear particles, inflammation reactions and bone reabsorption in the implant region. The diamond produced through hot-filament chemical vapour deposition method is a new potential biomedical material due to its chemical inertness, extreme hardness and low coefficient of friction. In the present study we analysis two samples: the microcrystalline diamond and the nanocrystalline diamond. The aim of this study was to evaluate the surface properties of the diamond samples by scanning electron microscopy, Raman spectroscopy and atomic force microscopy. Cell viability and morphology were assessed using thiazolyl blue tetrazolium bromide, cytochemical assay and scanning electron microscopy, respectively. The results revealed that the two samples did not interfere in the cell viability, however the proliferation of fibroblasts cells observed was comparatively higher with the nanocrystalline diamond.

  18. XMCD study of the local magnetic and structural properties of microcrystalline NdFeB-based alloys

    Science.gov (United States)

    Menushenkov, A. P.; Ivanov, V. G.; Shchetinin, I. V.; Zhukov, D. G.; Menushenkov, V. P.; Rudnev, I. A.; Ivanov, A. A.; Wilhelm, F.; Rogalev, A.; Savchenko, A. G.

    2017-01-01

    X-ray Magnetic Circular Dichroism (XMCD) technique was used to investigate local magnetic properties of microcrystalline Nd10.4Zr4.0Fe79.2B6.4 samples, oriented along either easy or hard magnetization direction. The Nd L 2,3 and Fe K edge XMCD spectra were measured at room temperature under a magnetic field of T. A very strong dependence of XMCD spectra on the sample orientation has been observed at the Nd L 2,3-edges, whereas the Fe K-edge XMCD spectra are found to be practically isotropic. This result indicates that magnetic anisotropy of NdFeB-based alloys originates from the Nd sublattice. In addition, element selective magnetization curves have been recorded by measuring the intensity of XMCD signals as a function of an applied magnetic field up to T. To find a correlation between local and macroscopic magnetic properties of studied samples we compared these data with magnetization curves, measured by vibrating sample magnetometer up to T. Results are important for understanding the origin of high-coercivity state in NdFeB-based intermetallic compounds.

  19. Effects of electron beam radiation dose on the compatibilization behaviour in recycled polypropylene/microcrystalline cellulose composites

    Science.gov (United States)

    Samat, N.; Motsidi, S. N. R.; Lazim, N. H. M.

    2018-01-01

    The purpose of this research was to evaluate the influence of dose level of electron beam on the compatibilization behavior of recycled polypropylene (rPP) in rPP/microcrystalline cellulose (MCC) composites. Initially, the rPP was irradiated with various dose of electron beam (5 kGy up to 250 kGy) which then mixed with unirradiated rPP (u-rPP) at a ratio of 30:70 respectively. The composites were prepared by incorporating a series wt% of MCC fibers into rPP (u-rPP : i-rPP) using extruder and finally moulded with an injection moulding machine. The compatibility behavior of irradiated rPP (i-rPP) were analysed with mechanical tensile and thermal methods. The results of mechanical analysis showed great improvement in tensile modulus but an increase in radiation dosage gradually decreased this property. Nevertheless, the tensile strength exhibited a minor effect. The thermal stability of composites is lowered with increase in the absorbed dose, more significantly at higher content of MCC. Fracture surface observations reveal adhesion between the cellulose and rPP matrix.

  20. Gas-temperature control in VHF- PECVD process for high-rate (>5 nm/s) growth of microcrystalline silicon thin films

    Energy Technology Data Exchange (ETDEWEB)

    Sobajima, Yasushi; Higuchi, Takuya; Chantana, Jakapan; Toyama, Toshihiko; Sada, Chitose; Matsuda, Akihisa; Okamoto, Hiroaki [Graduate School of Engineering Science, Osaka University, Toyonaka City (Japan)

    2010-04-15

    Surface-heating phenomenon by the radiation from high density plasma during growth of microcrystalline silicon ({mu}c-Si:H) thin films at high rate (> 5 nm/sec) is one of the crucial issues to be solved for obtaining high quality intrinsic-layer material for solar cells. We have utilized an optical emission spectroscopy (OES) in the plasma to observe the time evolution of gas temperature during film growth as well as the film-growth rate under {mu}c-Si:H deposition conditions at high rate. Gas temperature has been successfully controlled by changing total flow rate of monosilane (SiH{sub 4})/hydrogen (H{sub 2}) gas mixture, leading to a drastic improvement of optoelectronic properties in the resulting {mu}c-Si:H. (copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  1. A study of a co-processed dry binder composed of microcrystalline cellulose and glycerol monostearate.

    Science.gov (United States)

    Mužíková, Jitka; Muchová, Sandra

    2012-10-01

    The paper studies the co-processed dry binder LubriToseTM MCC from the viewpoint of energy evaluation of the compression process, strength and disintegration time of tablets. The results were compared with the identical evaluation of physical mixtures of microcrystalline cellulose with several types of lubricants. LubriTose MCC showed the lowest value of energy for friction, the highest value of energy accumulated by the tablet, and the highest plasticity of all tableting materials under study. There were no marked differences in the values of the energy of decompression. The tensile strength of tablets from LubriTose MCC was lower than in those from the mixture of Vivapur® 12 and glycerol monostearate, in the compression forces of 4 and 5 kN it was comparable with the tensile strength of tablets from Vivapur 12 with Poloxamer 407. Disintegration time of tablets from LubriTose MCC was shorter than that of those from Vivapur 12 with glycerol monostearate at the compression force of 3 kN, in the case of the compression forces of 4 and 5 kN no statistically significant difference was found between the values of these tableting materials.

  2. CVD of alternated microcrystalline (MCD) and nanocrystalline (NCD) diamond films on WC-TIC-CO substrates

    International Nuclear Information System (INIS)

    Campos, Raonei Alves; Contin, Andre; Trava-Airoldi, Vladimir J.; Corat, Evaldo Jose; Barquete, Danilo Maciel

    2010-01-01

    CVD Diamond coating of WC-TiC-Co cutting tools has been an alternative to increase tool lifetime. Experiments have shown that residual stresses produced during films growth on WC-TiC-Co substrates significantly increases with increasing film thickness up to 20 μm and usually leads to film delamination. In this work alternated micro- and nanocrystalline CVD diamond films have been used to relax interface stresses and to increase diamond coatings performance. WC-TiC-Co substrates have been submitted to a boronizing thermal diffusion treatment prior to CVD diamond films growth. After reactive heat treatment samples were submitted to chemical etching in acid and alkaline solution. The diamond films deposition was performed using HFCVD reactor with different gas concentrations for microcrystalline (MCD) and nano-crystalline (NCD) films growth. As a result, we present the improvement of diamond films adherence on WC-TiC-Co, evaluated by indentation and machining tests. Samples were characterized by Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray (EDX) for qualitative analysis of diamond films. X-ray Diffraction (XRD) was used for phases identification after boronizing process. Diamond film compressive residual stresses were analyzed by Raman Scattering Spectroscopy (RSS). (author)

  3. Large-scale synthesis of double cauliflower-like Sb2S3 microcrystallines by hydrothermal method

    International Nuclear Information System (INIS)

    Wu, Lei; Xu, Hanyue; Han, Qiaofeng; Wang, Xin

    2013-01-01

    Highlights: •Highly uniform double cauliflower-like Sb 2 S 3 particles were synthesized via hydrothermal method. •Influence of reaction conditions on the morphology of the products was discussed. •Double cauliflower-like Sb 2 S 3 superstructures revealed broad spectrum response. -- Abstract: The double cauliflower-like Sb 2 S 3 superstructures assembled by nanorods were prepared using SbCl 3 and Na 2 S⋅9H 2 O as raw materials, dodecyltrimethylammonium bromide (DTAB, C 15 H 31 BrN) as surfactant under acidic condition at 180 °C for 30 h. The structure, morphology and composition of the product were characterized by X-ray diffraction pattern (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and energy diffraction spectroscopy (EDS). The effect of reaction conditions including temperature, reaction time and surfactants on the sample morphology was discussed and a possible mechanism for the formation of cauliflower-like Sb 2 S 3 was proposed. The cauliflower-like Sb 2 S 3 microcrystallines revealed broad spectrum response, which may have a good application prospect in solar energy utilization and photoelectric conversion fields

  4. Fiscal 1998 New Sunshine Program achievement report. Development for practical application of photovoltaic system - Development of thin-film solar cell manufacturing technology (Development of material/substrate manufacturing technology - Development of high-quality amorphous material/substrate manufacturing technology); 1998 nendo taiyoko hatsuden system jitsuyoka gijutsu kaihatsu seika hokokusho. Usumaku taiyo denchi no seizo gijutsu kaihatsu / zairyo kiban seizo gijutsu kaihatsu (kohinshitsu amorphous kei zairyo kiban no seizo gijutsu kaihatsu)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-03-01

    A microcrystalline Si thin film is used to form the i-layer of a narrow gap a-Si based thin film solar cell. Since a microcrystalline p-layer is to act as the seeding crystal layer for the microcrystalline i-layer, it has to be very high in crystallinity and therefore is produced under high hydrogen dilution conditions. In this process, a problem arises of the darkening of the underlying transparent SnO{sub 2} electrode. Since this is due to chemical reaction on the SnO{sub 2} surface layer, blackening is prevented by shortening the film fabrication time, and then an excellently microcrystalline p-layer is obtained. Furthermore, by inserting a microcrystalline i-film buffer layer of low fabrication rate into the p/i boundary, plasma damage on the microcrystalline p-layer is inhibited for the fabrication of a microcrystalline i-layer high in crystallinity at high film fabrication rates. A high Voc is then obtained even when the microcrystalline p-layer is very thin. If the hydrogen dilution rate is too low when the i-layer film fabrication rate is high, the initially fabricated layer turns out to be thick to the detriment of film performance. On the other hand, the p-layer or the buffer layer will be etched when the hydrogen dilution rate is too high. The problem is solved by continuously varying the hydrogen dilution rate from high to low during i-layer fabrication. (NEDO)

  5. Development of Tandem Amorphous/Microcrystalline Silicon Thin-Film Large-Area See-Through Color Solar Panels with Reflective Layer and 4-Step Laser Scribing for Building-Integrated Photovoltaic Applications

    Directory of Open Access Journals (Sweden)

    Chin-Yi Tsai

    2014-01-01

    Full Text Available In this work, tandem amorphous/microcrystalline silicon thin-film large-area see-through color solar modules were successfully designed and developed for building-integrated photovoltaic applications. Novel and key technologies of reflective layers and 4-step laser scribing were researched, developed, and introduced into the production line to produce solar panels with various colors, such as purple, dark blue, light blue, silver, golden, orange, red wine, and coffee. The highest module power is 105 W and the highest visible light transmittance is near 20%.

  6. Prevalence and trends of cellulosics in pharmaceutical dosage forms.

    Science.gov (United States)

    Mastropietro, David J; Omidian, Hossein

    2013-02-01

    Many studies have shown that cellulose derivatives (cellulosics) can provide various benefits when used in virtually all types of dosage forms. Nevertheless, the popularity of their use in approved drug products is rather unknown. This research reports the current prevalence and trends of use for 15 common cellulosics in prescription drug products. The cellulosics were powdered and microcrystalline cellulose (MCC), ethyl cellulose, hydroxypropyl cellulose (HPC), hydroxyethyl cellulose (HEC), hypromellose (HPMC), HPMC phthalate, HPMC acetate succinate, cellulose acetate (CA), CA phthalate, sodium (Na) and calcium (Ca) carboxymethylcellulose (CMC), croscarmellose sodium (XCMCNa), methyl cellulose, and low substituted HPC. The number of brand drug products utilizing each cellulosics was determined using the online drug index Rxlist. A total of 607 brand products were identified having one or more of the cellulosics as an active or inactive ingredient. An array of various dosage forms was identified and revealed HPMC and MCC to be the most utilized cellulosics in all products followed by XCMCNa and HPC. Many products contained two or more cellulosics in the formulation (42% containing two, 23% containing three, and 4% containing 4-5). The largest combination occurrence was HPMC with MCC. The use of certain cellulosics within different dosage form types was found to contain specific trends. All injectables utilized only CMCNa, and the same with all ophthalmic solutions utilizing HPMC, and otic suspensions utilizing HEC. Popularity and trends regarding cellulosics use may occur based on many factors including functionality, safety, availability, stability, and ease of manufacturing.

  7. Development of Amorphous/Microcrystalline Silicon Tandem Thin-Film Solar Modules with Low Output Voltage, High Energy Yield, Low Light-Induced Degradation, and High Damp-Heat Reliability

    Directory of Open Access Journals (Sweden)

    Chin-Yi Tsai

    2014-01-01

    Full Text Available In this work, tandem amorphous/microcrystalline silicon thin-film solar modules with low output voltage, high energy yield, low light-induced degradation, and high damp-heat reliability were successfully designed and developed. Several key technologies of passivation, transparent-conducting-oxide films, and cell and segment laser scribing were researched, developed, and introduced into the production line to enhance the performance of these low-voltage modules. A 900 kWp photovoltaic system with these low-voltage panels was installed and its performance ratio has been simulated and projected to be 92.1%, which is 20% more than the crystalline silicon and CdTe counterparts.

  8. Production of bioplastic from jackfruit seed starch (Artocarpus heterophyllus) reinforced with microcrystalline cellulose from cocoa pod husk (Theobroma cacao L.) using glycerol as plasticizer

    Science.gov (United States)

    Lubis, M.; Gana, A.; Maysarah, S.; Ginting, M. H. S.; Harahap, M. B.

    2018-02-01

    The production of bioplastic from jackfruit seed starch reinforced with microcrystalline cellulose (MCC) cocoa pod husk using glycerol as plasticizer was investigated to determine the most optimum mass and volume of MCC and glycerol in producing bioplastics. To produce MCC, Cocoa pod husk was subjected to alkali treatment, bleaching, and hydrochloric acid hydrolysis. The degree of crystallinity of MCC, were determined by XRD, functional group by FT-IR and morphologycal analysis by SEM. Analysis of bioplastic mechanical properties includes tensile strength and elongation at break based on ASTM D882 standard. Bioplastics were produced by casting method from jackfruit seed starch and reinforced with MCC from cocoa pod husk at starch mass to MCC ratio of 6:4, 7:3, 8:2, and 9:1, using glycerol as plasticizer at 20%, 25%, 30% (wt/v of glycerol to starch). From the result, the isolated MCC from cocoa pod husk were in a form of rod-like shape of length 5-10 µm with diameter 11.635 nm and 74% crystallinity. The highest tensile strength of bioplastics was obtained at starch to MCC mass ratio of 8:2, addition of 20% glycerol with measured tensile strength of 0.637 MPa and elongation at break of 7.04%. Transform infrared spectroscopy showed the functional groups of bioplastics, which the majority of O-H groups were found at the bioplastics with reinforcing filler MCC that represented substantial hydrogen bonds.

  9. Green synthesis of hybrid graphene oxide/microcrystalline cellulose aerogels and their use as superabsorbents

    Energy Technology Data Exchange (ETDEWEB)

    Wei, Xiao; Huang, Ting; Yang, Jing-hui; Zhang, Nan; Wang, Yong, E-mail: yongwang1976@163.com; Zhou, Zuo-wan

    2017-08-05

    Highlights: • Hybrid GO/MCC aerogels were prepared using LiBr aqueous solution as the solvent. • GO was exfoliated by MCC through the strong interaction between them. • The adsorption ability of GO per unit mass in the hybrid aerogels was greatly enhanced. - Abstract: In this work, we developed a green synthesis method to prepare the hybrid aerogels containing graphene oxide (GO) and microcrystalline cellulose (MCC) using lithium bromide (LiBr) aqueous solution as the solvent, which insured the complete dissolution of MCC. The interaction between GO and MCC was investigated through different methods The results demonstrate that there is a strong interaction between GO and MCC molecules, which promotes the exfoliation of GO in the hybrid aerogels. The hybrid GO/MCC aerogels exhibit typical three dimensional porous structure and the pore morphology can be well adjusted by changing the content of GO. The adsorption ability of the hybrid aerogels was measured using methylene blue (MB) as an adsorbate. The results show that the adsorption ability of GO per unit mass is greatly enhanced compared with the pure GO aerogel, especially at relatively low GO content the adsorption amount of GO per unit mass is enhanced up to 2630 mg/g. Further results demonstrate that the hybrid GO/MCC aerogels still obey the pseudo-second-order adsorption model, which is similar to that of the pure GO aerogel. The mechanism for the amplified adsorption ability of GO in the hybrid GO/MCC aerogels is then analyzed.

  10. Green synthesis of hybrid graphene oxide/microcrystalline cellulose aerogels and their use as superabsorbents

    International Nuclear Information System (INIS)

    Wei, Xiao; Huang, Ting; Yang, Jing-hui; Zhang, Nan; Wang, Yong; Zhou, Zuo-wan

    2017-01-01

    Highlights: • Hybrid GO/MCC aerogels were prepared using LiBr aqueous solution as the solvent. • GO was exfoliated by MCC through the strong interaction between them. • The adsorption ability of GO per unit mass in the hybrid aerogels was greatly enhanced. - Abstract: In this work, we developed a green synthesis method to prepare the hybrid aerogels containing graphene oxide (GO) and microcrystalline cellulose (MCC) using lithium bromide (LiBr) aqueous solution as the solvent, which insured the complete dissolution of MCC. The interaction between GO and MCC was investigated through different methods The results demonstrate that there is a strong interaction between GO and MCC molecules, which promotes the exfoliation of GO in the hybrid aerogels. The hybrid GO/MCC aerogels exhibit typical three dimensional porous structure and the pore morphology can be well adjusted by changing the content of GO. The adsorption ability of the hybrid aerogels was measured using methylene blue (MB) as an adsorbate. The results show that the adsorption ability of GO per unit mass is greatly enhanced compared with the pure GO aerogel, especially at relatively low GO content the adsorption amount of GO per unit mass is enhanced up to 2630 mg/g. Further results demonstrate that the hybrid GO/MCC aerogels still obey the pseudo-second-order adsorption model, which is similar to that of the pure GO aerogel. The mechanism for the amplified adsorption ability of GO in the hybrid GO/MCC aerogels is then analyzed.

  11. Microstructure and initial growth characteristics of the low temperature microcrystalline silicon films on silicon nitride surface

    International Nuclear Information System (INIS)

    Park, Young-Bae; Rhee, Shi-Woo

    2001-01-01

    Microstructure and initial growth characteristics of the hydrogenated microcrystalline Si (μc-Si:H) films grown on hydrogenated amorphous silicon nitride (a-SiN x :H) surface at low temperature were investigated using high resolution transmission electron microscope and micro-Raman spectroscopy. With increasing the Si and Si - H contents in the SiN x :H surfaces, μc-Si crystallites, a few nanometers in size, were directly grown on amorphous nitride surfaces. It is believed that the crystallites were grown through the nucleation and phase transition from amorphous to crystal in a hydrogen-rich ambient of gas phase and growing surface. The crystallite growth characteristics on the dielectric surface were dependent on the stoichiometric (x=N/Si) ratio corresponding hydrogen bond configuration of the SiN x :H surface. Surface facetting and anisotropic growth of the Si crystallites resulted from the different growth rate on the different lattice planes of Si. No twins and stacking faults were observed in the (111) lattice planes of the Si crystallites surrounding the a-Si matrix. This atomic-scale structure was considered to be the characteristic of the low temperature crystallization of the μc-Si:H by the strain relaxation of crystallites in the a-Si:H matrix. [copyright] 2001 American Institute of Physics

  12. Ultrasound-assisted powder-coating technique to improve content uniformity of low-dose solid dosage forms

    DEFF Research Database (Denmark)

    Genina, Natalja; Räikkönen, Heikki; Antikainen, Osmo

    2010-01-01

    An ultrasound-assisted powder-coating technique was used to produce a homogeneous powder formulation of a low-dose active pharmaceutical ingredient (API). The powdered particles of microcrystalline cellulose (MCC; Avicel® PH-200) were coated with a 4% m/V aqueous solution of riboflavin sodium...

  13. Forming MOFs into spheres by use of molecular gastronomy methods.

    Science.gov (United States)

    Spjelkavik, Aud I; Aarti; Divekar, Swapnil; Didriksen, Terje; Blom, Richard

    2014-07-14

    A novel method utilizing hydrocolloids to prepare nicely shaped spheres of metal-organic frameworks (MOFs) has been developed. Microcrystalline CPO-27-Ni particles are dispersed in either alginate or chitosan solutions, which are added dropwise to solutions containing, respectively, either divalent group 2 cations or base that act as gelling agents. Well-shaped spheres are immediately formed, which can be dried into spheres containing mainly MOF (>95 wt %). The spheronizing procedures have been optimized with respect to maximum specific surface area, shape, and particle density of the final sphere. At optimal conditions, well-shaped 2.5-3.5 mm diameter CPO-27-Ni spheres with weight-specific surface areas <10 % lower than the nonformulated CPO-27-Ni precursor, and having sphere densities in the range 0.8 to 0.9 g cm(-3) and particle crushing strengths above 20 N, can be obtained. The spheres are well suited for use in fixed-bed catalytic or adsorption processes. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Luminescence properties of Nd{sup 3+}-doped Y{sub 2}Te{sub 4}O{sub 11} microcrystalline powder

    Energy Technology Data Exchange (ETDEWEB)

    Sobczyk, Marcin, E-mail: marcin.sobczyk@chem.uni.wroc.pl; Szymański, Damian

    2017-03-15

    In this paper, some spectroscopic properties of Y{sub 2}Te{sub 4}O{sub 11} microcrystalline powders, doped with Nd{sup 3+} ions are presented. The samples were successfully synthesized by the solid state reaction method. Absorption (300 K) and fluorescence (at 77 and 300 K) spectra as well as the fluorescence decay curves (300 K) of the {sup 4}F{sub 3/2} state are presented and analyzed. The phenomenological Ω{sub λ} (λ=2, 4, 6) Judd-Ofelt parameters were evaluated in order to determine radiative probabilities (A), branching ratios (β), the radiative lifetime (τ{sub R}) of the {sup 4}F{sub 3/2} level and the stimulated emission cross-section (σ{sub em}) for the {sup 4}F{sub 3/2} → {sup 4}I{sub J/2} (J=9 and 11) transitions of the Nd{sup 3+} ion. The fluorescence decay curves were single exponential for 0.01–5.0 at% of Nd{sup 3+} and became evidently non-exponential for higher Nd{sup 3+} ion concentration. With increasing activator concentration from 0.01 to 10.0 at%, the experimental lifetime of the emitting level decreases from 95 to 33 μs. The non-exponential fluorescence decay curve has been fitted by the Yokota-Tanimoto model, indicating that the energy migration process via a diffusion limited relaxation, plays a important role in the depopulation of the {sup 4}F{sub 3/2} level of Nd{sup 3+} ions doped in the Y{sub 2}Te{sub 4}O{sub 11} microcrystalline powder. The calculated absorption value (1.135×10{sup –19} cm{sup 2} at 807.5 nm) of the {sup 4}I{sub 9/2} → {sup 4}F{sub 5/2} transition as well as the value of the stimulated emission cross-section (1.196×10{sup –19} cm{sup 2} at 1063.5 nm) for that of {sup 4}F{sub 3/2} → {sup 4}I{sub 11/2} were compared with the corresponding values of other laser hosts. For the first time a very high σ{sub em} value of the {sup 4}F{sub 3/2} → {sup 4}I{sub 11/2} transition for TeO{sub 2}-based compounds, has been observed. From the presented spectroscopic properties follows that the Nd{sup 3+}:Y{sub 2

  15. Pembuatan Selulosa Mikrokristal dan Ekstrak Etanol Daun Nanas (Ananas Comosus (L.) Merr.) yang Diformulasikan Menjadi Sediaan Tablet

    OpenAIRE

    Kaban, Vera Estefania

    2016-01-01

    Background: The leaves of pineapple (Ananas comosus(L.) Merr.) including waste containing cellulose, can be isolate and made into a crystalline form. Microcrystalline cellulose is an additional ingredient that is often use in the manufacture of tablets by direct compression methods. Purpose: The aims of this study was isolated and characterize the microcrystalline cellulose and ethanol extract from pineapple leaves was formulated into dosage tablet. Methods: Dried material powder was ex...

  16. Comparative evaluation of the powder and compression properties of various grades and brands of microcrystalline cellulose by multivariate methods.

    Science.gov (United States)

    Haware, Rahul V; Bauer-Brandl, Annette; Tho, Ingunn

    2010-01-01

    The present work challenges a newly developed approach to tablet formulation development by using chemically identical materials (grades and brands of microcrystalline cellulose). Tablet properties with respect to process and formulation parameters (e.g. compression speed, added lubricant and Emcompress fractions) were evaluated by 2(3)-factorial designs. Tablets of constant true volume were prepared on a compaction simulator at constant pressure (approx. 100 MPa). The highly repeatable and accurate force-displacement data obtained was evaluated by simple 'in-die' Heckel method and work descriptors. Relationships and interactions between formulation, process and tablet parameters were identified and quantified by multivariate analysis techniques; principal component analysis (PCA) and partial least square regressions (PLS). The method proved to be able to distinguish between different grades of MCC and even between two different brands of the same grade (Avicel PH 101 and Vivapur 101). One example of interaction was studied in more detail by mixed level design: The interaction effect of lubricant and Emcompress on elastic recovery of Avicel PH 102 was demonstrated to be complex and non-linear using the development tool under investigation.

  17. Sub-bandgap optical absorption spectroscopy of hydrogenated microcrystalline silicon thin films prepared using hot-wire CVD (Cat-CVD) process

    International Nuclear Information System (INIS)

    Goktas, O.; Isik, N.; Okur, S.; Gunes, M.; Carius, R.; Klomfass, J.; Finger, F.

    2006-01-01

    Hydrogenated microcrystalline silicon (μc-Si:H) thin films with different silane concentration (SC) have been prepared using the HW-CVD technique. Dual beam photoconductivity (DBP), photothermal deflection spectroscopy (PDS), and transmission measurements have been used to investigate the optical properties of the μc-Si:H films. Two different sub-bandgap absorption, α(hν), methods have been applied and analyzed to obtain a better insight into the electronic states involved. A good agreement has been obtained in the absorption spectrum obtained from the PDS and DBP measurements at energies above the bandgap. Differences between PDS and DBP spectra exist below the bandgap energy where DBP spectra always give lower α(hν) values and show a dependence on the SC. For some films, differences exist in the α(hν) spectra when the DBP measurements are carried out through the film and substrate side. In addition, for some films, there remains fringe pattern left on the spectrum after the calculation of the fringe-free absorption spectrum, which indicates structural inhomogeneities present throughout the film

  18. Polyvinyl Chloride / Attapulgite / Micro-crystalline Cellulose (MCC Composites Preparation and Analysis of the Role of MCC as a Compatibilizer

    Directory of Open Access Journals (Sweden)

    Bo Wang

    2015-09-01

    Full Text Available To improve the performance of polyvinyl chloride (PVC, composites incorporating polyvinyl chloride (PVC, attapulgite nanoparticles (ANPs, and microcrystalline cellulose (MCC were successfully prepared. The composites had higher vicat softening temperatures (VSTs and the MCC had a great influence on mechanical properties of the composites. When MCC was added from 0 to 5 per hundred parts of PVC (phr, the mechanical properties of the composites increased, but the mechanical properties of the composites decreased when the MCC was more than 5 phr. The tensile breaking stress, tensile strength, and impact strength were maximized with increases of 19.76 N (4.1%, 29.66 MPa (15.5%, and 13.8 MPa (7% when 5 phr MCC was added. Infrared spectral analysis indicated that MCC and ANPs were present in the composites. Scanning electron microscopy showed that the composites system was distributed into two phases, which indicated that MCC in composites was dissolved in the PVC matrix, and some of MCC coated the surface of ANPs as a compatibilizer. Overall, this study provided a promising method for PVC modification to improve its performance.

  19. The relationship between I{sub H{sub {alpha}}} /(I{sub SiH}{sup *}){sup 2} and crystalline volume fraction in microcrystalline silicon growth

    Energy Technology Data Exchange (ETDEWEB)

    Chantana, Jakapan; Higuchi, Takuya; Nagai, Tomoyuki; Sasaki, Shota; Sobajima, Yasushi; Toyama, Toshihiko; Sada, Chitose; Matsuda, Akihisa; Okamoto, Hiroaki [Graduate School of Engineering Science, Osaka University, 1-3 Machikaneyama-cho, Toyonaka, Osaka 560-8531 (Japan)

    2010-03-15

    Optical-emission-intensity ratio of I{sub H{sub {alpha}}} /(I{sub SiH}{sup *}) during film growth has been used as a simple indicator to predict crystallinity (crystal-volume fraction: X{sub C}) in the resulting microcrystalline silicon ({mu}c-Si:H) thin films. The relationship between I{sub H{sub {alpha}}} /(I{sub SiH}{sup *}) and X{sub C} has been checked under a wide variety of film-preparation conditions including low-deposition-rate (<0.1 nm/s) and high-deposition-rate (>5 nm/s) cases. On the basis of theoretical consideration, we have proposed optical-emission-intensity ratio of I{sub H{sub {alpha}}} /(I{sub SiH}{sup *}) {sup 2} as a new indicator of X{sub C} during film growth of {mu}c-Si:H. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

  20. Large-scale synthesis of double cauliflower-like Sb{sub 2}S{sub 3} microcrystallines by hydrothermal method

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Lei [Key Laboratory for Soft Chemistry and Functional Materials, Ministry of Education (China); Xu, Hanyue [School of Electronic and Optical Engineering, Nanjing University of Science and Technology, Nanjing 210094 (China); Han, Qiaofeng, E-mail: hanqiaofeng@njust.edu.cn [Key Laboratory for Soft Chemistry and Functional Materials, Ministry of Education (China); Wang, Xin [Key Laboratory for Soft Chemistry and Functional Materials, Ministry of Education (China)

    2013-09-25

    Highlights: •Highly uniform double cauliflower-like Sb{sub 2}S{sub 3} particles were synthesized via hydrothermal method. •Influence of reaction conditions on the morphology of the products was discussed. •Double cauliflower-like Sb{sub 2}S{sub 3} superstructures revealed broad spectrum response. -- Abstract: The double cauliflower-like Sb{sub 2}S{sub 3} superstructures assembled by nanorods were prepared using SbCl{sub 3} and Na{sub 2}S⋅9H{sub 2}O as raw materials, dodecyltrimethylammonium bromide (DTAB, C{sub 15}H{sub 31}BrN) as surfactant under acidic condition at 180 °C for 30 h. The structure, morphology and composition of the product were characterized by X-ray diffraction pattern (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and energy diffraction spectroscopy (EDS). The effect of reaction conditions including temperature, reaction time and surfactants on the sample morphology was discussed and a possible mechanism for the formation of cauliflower-like Sb{sub 2}S{sub 3} was proposed. The cauliflower-like Sb{sub 2}S{sub 3} microcrystallines revealed broad spectrum response, which may have a good application prospect in solar energy utilization and photoelectric conversion fields.

  1. Extraction of microcrystalline cellulose from rice straw and its effect on polyvinyl alcohol biocomposites film

    Science.gov (United States)

    Chin, Kwok-Mern; Ting, Sam Sung; Lin, Ong Hui; Owi, Wei Tieng

    2017-07-01

    The poor management and underutilization of agricultural wastes had proliferated interest of researchers around the world to find alternatives to utilize them as potential value-added products. One of the green alternatives is by extracting cellulose from these waste materials and incorporating them in polymer as reinforcement fillers. The surging amount of plastic waste also posed major issues to the environment due to its recalcitrance to degrade. Microcrystalline cellulose (MCC-RS) was extracted from rice straw through cyclic alkaline and bleaching treatment to remove hemicellulose and lignin respectively. Polyvinyl alcohol (PVOH) was chosen as the matrix and different ratios of PVOH / MCC-RS films were prepared (2.5, 5.0, 7.5 and 10.0wt% of MCC) through solution casting method and its tensile, thermal and morphological properties were studied. X-ray powder diffraction (XRD) results showed increased crystallinity of MCC-RS after chemical treatment (from 44.5% to 60.8%) due to the successful removal of lignin and hemicellulose, which was then confirmed with Fourier transform infrared spectroscopy (FTIR) results. For the biocomposites, both tensile strength and Young's modulus of the films increased with increasing MCC-RS content up until 7.5wt%, supported with scanning electron microscopy (SEM) results which depicted improvement in the interfacial adhesion between MCC-RS and PVOH. From the overall results, the improvement in properties of biocomposite from cellulose-based microfiller had shown promising future in application of the water soluble plastic packaging industry.

  2. Microcrystalline silicon films and solar cells investigatet by photoluminescence spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Merdzhanova, T.

    2005-07-01

    A systematic investigation on photoluminescence (PL) properties of microcrystalline silicon ({mu}c-Si:H) films with structural composition changing from highly crystalline to predominantly amorphous is presented. The samples were prepared by PECVD and HWCVD with different silane concentration in hydrogen (SC). By using photoluminescence in combination with Raman spectroscopy the relationship between electronic properties and the microstructure of the material is studied. The PL spectra of {mu}c-Si:H reveal a rather broad ({proportional_to}0.13 eV) featureless band at about 1 eV ('{mu}c'-Si-band). In mixed phase material of crystalline and amorphous regions, a band at about 1.3 eV with halfwidth of about 0.3 eV is found in addition to '{mu}c'-Si-band, which is attributed to the amorphous phase ('a'-Si-band). Similarly to amorphous silicon, the '{mu}c'-Si-band is assigned to recombination between electrons and holes in band tail states. An additional PL band centred at about 0.7 eV with halfwidth slightly broader than the '{mu}c'-Si-band is observed only for films prepared at high substrate temperature and it is preliminarily assigned to defect-related transitions as in polycrystalline silicon. With decreasing crystalline volume fraction, the '{mu}c'-Si-band shifts continuously to higher energies for all {mu}c-Si:H films but the linewidth of the PL spectra is almost unaffected. This is valid for all deposition conditions investigated. The results are interpreted, assuming decrease of the density of band tail states with decreasing crystalline volume fraction. A simple model is proposed to simulate PL spectra and V{sub oc} in {mu}c-Si:H solar cells as a function of temperature, based on carrier distributions in quasi-equilibrium conditions. In the model is assumed symmetric density of states distributions for electrons and holes in the conduction and the valence band tail states. The best agreement between

  3. Functionalization of Microcrystalline Cellulose with N,N-dimethyldodecylamine for the Removal of Congo Red Dye from an Aqueous Solution

    Directory of Open Access Journals (Sweden)

    Dongying Hu

    2014-08-01

    Full Text Available Microcrystalline cellulose (MCC was functionalized with quaternary amine groups for use as an adsorbent to remove Congo Red dye (CR from aqueous solution. The ultrasonic pretreatment of MCC was investigated during its functionalization. Characterization was conducted using infrared spectroscopy (FT-IR, X-ray photoelectron spectroscopy (XPS, X-ray diffraction (XRD, and scanning electron microscopy (SEM. The batch adsorption of the functionalized MCC was studied to evaluate the effects of dye concentration, pH of solution, temperature, and NaCl concentration on the adsorption CR. The adsorbent (FM-1 obtained using ultrasonic pretreatment of MCC under 10.8 kJ•g–1 exhibited an adsorption capacity of 304 mg•g–1 at initial pH under a dose of 0.1 g•L–1 and initial concentration of 80 mg•L–1. After functionalization, the FT-IR and XPS results indicated that the quaternary amine group was successfully grafted onto the cellulose, the surface was transformed to be coarse and porous, and the crystalline structure of the original cellulose was disrupted. FM-1 has been shown to be a promising and efficient adsorbent for the removal of CR from an aqueous solution.

  4. A novel process for synthesis of spherical nanocellulose by controlled hydrolysis of microcrystalline cellulose using anaerobic microbial consortium.

    Science.gov (United States)

    Satyamurthy, P; Vigneshwaran, N

    2013-01-10

    Degradation of cellulose by anaerobic microbial consortium is brought about either by an exocellular process or by secretion of extracellular enzymes. In this work, a novel route for synthesis of nanocellulose is described where in an anaerobic microbial consortium enriched for cellulase producers is used for hydrolysis. Microcrystalline cellulose derived from cotton fibers was subjected to controlled hydrolysis by the anaerobic microbial consortium and the resultant nanocellulose was purified by differential centrifugation technique. The nanocellulose had a bimodal size distribution (43±13 and 119±9 nm) as revealed by atomic force microscopy. A maximum nanocellulose yield of 12.3% was achieved in a span of 7 days. While the conventional process of nanocellulose preparation using 63.5% (w/w) sulfuric acid resulted in the formation of whisker shaped nanocellulose with surface modified by sulfation, controlled hydrolysis by anaerobic microbial consortium yielded spherical nanocellulose also referred to as nano crystalline cellulose (NCC) without any surface modification as evidenced from Fourier transform infrared spectroscopy. Also, it scores over chemo-mechanical production of nanofibrillated cellulose by consuming less energy due to enzyme (cellulase) assisted catalysis. This implies the scope for use of microbial prepared nanocellulose in drug delivery and bio-medical applications requiring bio-compatibility. Copyright © 2012 Elsevier Inc. All rights reserved.

  5. Synthesis, characterization and adsorption properties of microcrystalline cellulose based nanogel for dyes and heavy metals removal.

    Science.gov (United States)

    El-Naggar, Mehrez E; Radwan, Emad K; El-Wakeel, Shaimaa T; Kafafy, Hany; Gad-Allah, Tarek A; El-Kalliny, Amer S; Shaheen, Tharwat I

    2018-07-01

    Recently, naturally occurring biopolymers have attracted the attention as potential adsorbents for the removal of water contaminants. In this work, we present the development of microcrystalline cellulose (MCC)-based nanogel grafted with acrylamide and acrylic acid in the presence of methylene bisacrylamide and potassium persulphate as a crosslinking agent and initiator, respectively. World-class facilities such as X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), surface analysis, field emission scanning electron microscopy (FE-SEM), high resolution transmission electron microscopy (HR-TEM) and zeta sizer were used to characterize the synthesized MCC based nanogel. The prepared nanogel was applied to remove reactive red 195 (RR195) dye and Cd (II) from aqueous medium at different operational conditions. The adsorption experiments showed that the feed concentration of monomers has a significant effect on the removal of RR195 which peaked (93% removal) after 10min of contact time at pH2 and a dose of 1.5g/L. On contrary, the feed concentration has insignificant effect on the removal of Cd (II) which peaked (97% removal) after 30min of contact time at pH6 and a dose of 0.5g/L. The adsorption equilibrium data of RR195 and Cd (II) was best described by Freundlich and Langmuir, respectively. Conclusively, the prepared MCC based nanogels were proved as promising adsorbents for the removal of organic pollutants as well as heavy metals. Copyright © 2018 Elsevier B.V. All rights reserved.

  6. Comparison between periodic and stochastic parabolic light trapping structures for thin-film microcrystalline Silicon solar cells.

    Science.gov (United States)

    Peters, M; Battaglia, C; Forberich, K; Bläsi, B; Sahraei, N; Aberle, A G

    2012-12-31

    Light trapping is of very high importance for silicon photovoltaics (PV) and especially for thin-film silicon solar cells. In this paper we investigate and compare theoretically the light trapping properties of periodic and stochastic structures having similar geometrical features. The theoretical investigations are based on the actual surface geometry of a scattering structure, characterized by an atomic force microscope. This structure is used for light trapping in thin-film microcrystalline silicon solar cells. Very good agreement is found in a first comparison between simulation and experimental results. The geometrical parameters of the stochastic structure are varied and it is found that the light trapping mainly depends on the aspect ratio (length/height). Furthermore, the maximum possible light trapping with this kind of stochastic structure geometry is investigated. In a second step, the stochastic structure is analysed and typical geometrical features are extracted, which are then arranged in a periodic structure. Investigating the light trapping properties of the periodic structure, we find that it performs very similar to the stochastic structure, in agreement with reports in literature. From the obtained results we conclude that a potential advantage of periodic structures for PV applications will very likely not be found in the absorption enhancement in the solar cell material. However, uniformity and higher definition in production of these structures can lead to potential improvements concerning electrical characteristics and parasitic absorption, e.g. in a back reflector.

  7. Microcrystalline silicon oxides for silicon-based solar cells: impact of the O/Si ratio on the electronic structure

    Science.gov (United States)

    Bär, M.; Starr, D. E.; Lambertz, A.; Holländer, B.; Alsmeier, J.-H.; Weinhardt, L.; Blum, M.; Gorgoi, M.; Yang, W.; Wilks, R. G.; Heske, C.

    2014-10-01

    Hydrogenated microcrystalline silicon oxide (μc-SiOx:H) layers are one alternative approach to ensure sufficient interlayer charge transport while maintaining high transparency and good passivation in Si-based solar cells. We have used a combination of complementary x-ray and electron spectroscopies to study the chemical and electronic structure of the (μc-SiOx:H) material system. With these techniques, we monitor the transition from a purely Si-based crystalline bonding network to a silicon oxide dominated environment, coinciding with a significant decrease of the material's conductivity. Most Si-based solar cell structures contain emitter/contact/passivation layers. Ideally, these layers fulfill their desired task (i.e., induce a sufficiently high internal electric field, ensure a good electric contact, and passivate the interfaces of the absorber) without absorbing light. Usually this leads to a trade-off in which a higher transparency can only be realized at the expense of the layer's ability to properly fulfill its task. One alternative approach is to use hydrogenated microcrystalline silicon oxide (μc-SiOx:H), a mixture of microcrystalline silicon and amorphous silicon (sub)oxide. The crystalline Si regions allow charge transport, while the oxide matrix maintains a high transparency. To date, it is still unclear how in detail the oxygen content influences the electronic structure of the μc-SiOx:H mixed phase material. To address this question, we have studied the chemical and electronic structure of the μc-SiOx:H (0 0.5, we observe a pronounced decrease of Si 3s - Si 3p hybridization in favor of Si 3p - O 2p hybridization in the upper valence band. This coincides with a significant increase of the material's resistivity, possibly indicating the breakdown of the conducting crystalline Si network. Silicon oxide layers with a thickness of several hundred nanometres were deposited in a PECVD (plasma-enhanced chemical vapor deposition) multi chamber system

  8. Disilane as a growth rate catalyst of plasma deposited microcrystalline silicon thin films

    Science.gov (United States)

    Dimitrakellis, P.; Kalampounias, A. G.; Spiliopoulos, N.; Amanatides, E.; Mataras, D.; Lahootun, V.; Coeuret, F.; Madec, A.

    2016-07-01

    The effect of small disilane addition on the gas phase properties of silane-hydrogen plasmas and the microcrystalline silicon thin films growth is presented. The investigation was conducted in the high pressure regime and for constant power dissipation in the discharge with the support of plasma diagnostics, thin film studies and calculations of discharge microscopic parameters and gas dissociation rates. The experimental data and the calculations show a strong effect of disilane on the electrical properties of the discharge in the pressure window from 2 to 3 Torr that is followed by significant raise of the electron number density and the drop of the sheaths electric field intensity. Deposition rate measurements show an important four to six times increase even for disilane mole fractions as low as 0.3 %. The deposition rate enhancement was followed by a drop of the material crystalline volume fraction but films with crystallinity above 40 % were deposited with different combinations of total gas pressure, disilane and silane molar ratios. The enhancement was partly explained by the increase of the electron impact dissociation rate of silane which rises by 40% even for 0.1% disilane mole fraction. The calculations of the gas usage, the dissociation and the deposition efficiencies show that the beneficial effect on the growth rate is not just the result of the increase of Si-containing molecules density but significant changes on the species participating to the deposition and the mechanism of the film growth are caused by the disilane addition. The enhanced participation of the highly sticking to the surface radical such as disilylene, which is the main product of disilane dissociation, was considered as the most probable reason for the significant raise of the deposition efficiency. The catalytic effect of such type of radical on the surface reactivity of species with lower sticking probability is further discussed, while it is also used to explain the restricted

  9. Disilane as a growth rate catalyst of plasma deposited microcrystalline silicon thin films

    International Nuclear Information System (INIS)

    Dimitrakellis, P.; Amanatides, E.; Mataras, D.; Kalampounias, A. G.; Spiliopoulos, N.; Lahootun, V.; Coeuret, F.; Madec, A.

    2016-01-01

    The effect of small disilane addition on the gas phase properties of silane-hydrogen plasmas and the microcrystalline silicon thin films growth is presented. The investigation was conducted in the high pressure regime and for constant power dissipation in the discharge with the support of plasma diagnostics, thin film studies and calculations of discharge microscopic parameters and gas dissociation rates. The experimental data and the calculations show a strong effect of disilane on the electrical properties of the discharge in the pressure window from 2 to 3 Torr that is followed by significant raise of the electron number density and the drop of the sheaths electric field intensity. Deposition rate measurements show an important four to six times increase even for disilane mole fractions as low as 0.3 %. The deposition rate enhancement was followed by a drop of the material crystalline volume fraction but films with crystallinity above 40 % were deposited with different combinations of total gas pressure, disilane and silane molar ratios. The enhancement was partly explained by the increase of the electron impact dissociation rate of silane which rises by 40% even for 0.1% disilane mole fraction. The calculations of the gas usage, the dissociation and the deposition efficiencies show that the beneficial effect on the growth rate is not just the result of the increase of Si-containing molecules density but significant changes on the species participating to the deposition and the mechanism of the film growth are caused by the disilane addition. The enhanced participation of the highly sticking to the surface radical such as disilylene, which is the main product of disilane dissociation, was considered as the most probable reason for the significant raise of the deposition efficiency. The catalytic effect of such type of radical on the surface reactivity of species with lower sticking probability is further discussed, while it is also used to explain the restricted

  10. Statistical Optimization for Acid Hydrolysis of Microcrystalline Cellulose and Its Physiochemical Characterization by Using Metal Ion Catalyst

    Directory of Open Access Journals (Sweden)

    Md. Ziaul Karim

    2014-10-01

    Full Text Available Hydrolyzing the amorphous region while keeping the crystalline region unaltered is the key technology for producing nanocellulose. This study investigated if the dissolution properties of the amorphous region of microcrystalline cellulose can be enhanced in the presence of Fe3+ salt in acidic medium. The process parameters, including temperature, time and the concentration of metal chloride catalyst (FeCl3, were optimized by using the response surface methodology (RSM. The experimental observation demonstrated that temperature and time play vital roles in hydrolyzing the amorphous sections of cellulose. This would yield hydrocellulose with higher crystallinity. The factors that were varied for the production of hydrocellulose were the temperature (x1, time (x2 and FeCl3 catalyst concentration (x3. Responses were measured in terms of percentage of crystallinity (y1 and the yield (y2 of the prepared hydrocellulose. Relevant mathematical models were developed. Analysis of variance (ANOVA was carried out to obtain the most significant factors influencing the responses of the percentage of crystallinity and yield. Under optimum conditions, the percentage of crystallinity and yield were 83.46% and 86.98% respectively, at 90.95 °C, 6 h, with a catalyst concentration of 1 M. The physiochemical characteristics of the prepared hydrocellulose were determined in terms of XRD, SEM, TGA and FTIR analyses. The addition of FeCl3 salt in acid hydrolyzing medium is a novel technique for substantially increasing crystallinity with a significant morphological change.

  11. Pain and microcrystalline arthritis

    Directory of Open Access Journals (Sweden)

    R. Ramonda

    2014-06-01

    Full Text Available Microcrystals are responsible for some of the most common and complex arthropathies which are often accompanied by intense, severe pain and inflammatory reactions. The main pathogens are crystals of monosodium urate (MSU, responsible for the gout, calcium pyrophosphate (CPP, which deposits also in various clinical forms of arthopathies, and basic calcium phosphate associated with osteoarthritis. In this context, the microcrystal arthritis is characterized by multiple, acute attacks followed by chronic pain, disability, impaired quality of life, and increased mortality. Given their chronic nature, they represent an ever more urgent public health problem. MSU and CPP crystals are also able to activate nociceptors. The pain in mycrocrystalline arthritis (MCA is an expression of the inflammatory process. In the course of these diseases there is an abundant release of inflammatory molecules, including prostaglandins 2 and kinins. Interleukin-1 represents the most important cytokine released during the crystal-induced inflammatory process. Therefore, clinically, pain is the most important component of MCA, which lead to functional impairment and disability in a large proportion of the population. It is fundamental to diagnose these diseases as early as possible, and to this aim, to identify appropriate and specific targets for a timely therapeutic intervention.

  12. Exploring the potential of polacrilin potassium as a novel superdisintegrant in microcrystalline cellulose based pellets prepared by extrusion-spheronization

    Directory of Open Access Journals (Sweden)

    Amita K Joshi

    2011-01-01

    Full Text Available Polacrilin potassium (PP, an ion exchange resin, was used as a superdisintegrant to improve the dissolution of rifampicin, from microcrystalline cellulose (MCC based pellets prepared by extrusion-spheronization. Production of fast release pellets by extrusion-spheronization using MCC is a complicated process. In the present study, pellets were prepared containing 50% w/w rifampicin (BCS class II drug and 40% w/w MCC as extrusion-spheronization aid. Different levels of PP and lactose ratio investigated were 0:10, 2:8, 4:6, 6:4, 8:2, and 10:0. Pellets were evaluated for yield, size, size distribution, shape, porosity, friability, residual moisture, and dissolution efficiency (DE at 30 minutes. Incorporation of this novel superdisintegrant had no adverse effect on the mechanical and micromeritic characteristics of pellets. All the batches of pellets showed high yields′, ~90%; narrow particle size distribution; aspect ratio, 1.0-1.1; friability, <1%; and porosity, 45.51-49.84%. Dissolution profiles were compared using model-independent approaches; DE and similarity factor, f 2 . Addition of Polacrilin results in significant improvement in the DE of rifampicin. The dissolution profiles were significantly different from the dissolution profile of pellets formulated without PP. This preliminary study indicates that PP can serve as an effective superdisintegrant in MCC pellets prepared by extrusion-spheronization.

  13. Water-induced charge transport in tablets of microcrystalline cellulose of varying density: dielectric spectroscopy and transient current measurements

    International Nuclear Information System (INIS)

    Nilsson, Martin; Alderborn, Goeran; Stroemme, Maria

    2003-01-01

    Room temperature dielectric frequency response data taken over 13 decades in frequency on microcrystalline cellulose (MCC) tablets of varying density are presented. The frequency response shows on three different processes: the first one is a high-frequency relaxation process whose magnitude increases and reaches a plateau as the tablet density increases. This process is associated with orientational motions of local chain segments via glycosidic bonds. The second relaxation process, related to the presence of water in the MCC matrix, is insensitive to changes in tablet density. At lower frequencies, dc-like imperfect charge transport dominates the dielectric spectrum. The dc conductivity was found to decrease with increasing tablet density and increase exponentially with increasing humidity. Transient current measurements indicated that two different ionic species, protons and OH - ions, lied behind the observed conductivity. At ambient humidity of 22%, only one in a billion of the water molecules present in the tablet matrix participated in long range dc conduction. The diffusion coefficient of the protons and OH - ions were found to be of the order of 10 -9 cm 2 /s, which is the same as for small salt building ions in MCC. This shows that ionic drugs leaving a tablet matrix may diffuse in the same manner as the constituent ions of water and, thus, elucidates the necessity to understand the water transport properties of excipient materials to be able to tailor the drug release process from pharmaceutical tablets

  14. Two-dimensional charge transport in self-organized, high-mobility conjugated polymers

    DEFF Research Database (Denmark)

    Sirringhaus, H.; Brown, P.J.; Friend, R.H.

    1999-01-01

    Self-organization in many solution-processed, semiconducting conjugated polymers results in complex microstructures, in which ordered microcrystalline domains are embedded in an amorphous matrix(I). This has important consequences for electrical properties of these materials: charge transport...... of the ordered microcrystalline domains in the conjugated polymer poly(3-hexylthiophene), P3HT, Self-organization in P3HT results in a lamella structure with two-dimensional conjugated sheets formed by interchain stacking. We find that, depending on processing conditions, the lamellae can adopt two different...... of polymer transistors in logic circuits(5) and active-matrix displays(4,6)....

  15. High alkaline tolerant electrolyte membrane with improved conductivity and mechanical strength via lithium chloride/dimethylacetamide dissolved microcrystalline cellulose for Zn-Air batteries

    International Nuclear Information System (INIS)

    Zhang, Yuansong; Li, Cong; Cai, Xiaoxia; Yao, Jinshui; Li, Mei; Zhang, Xian; Liu, Qinze

    2016-01-01

    LiCl/DMAc (dimethylacetamide) solution dissolved microcrystalline cellulose (LD-MCC) showed potential benefits to the alkaline solid polymer electrolyte (ASPE). High alkali tolerance (up to 70 wt% KOH loading), remarkable improvements in ionic conductivity (from 0.018 S cm −1 to 0.153 S cm −1 ) and mechanical properties (3-fold increase in tensile strength from 0.28 MPa to 0.76 MPa) were achieved just via an incorporation of 5 wt% of LD-MCC into the ASPE matrix. Wide-angle X-ray diffraction indicated that LD-MCC entrapped KOH and hindered its aggregation. X-ray Energy Dispersive Spectrometer revealed that K + was preferentially located on the LD-MCC surfaces rather than the polymeric matrix. Scanning Electron Microscopy of freeze-dry sample demonstrated a submicro-porous morphology with reduced average pore size (175 nm) after the incorporation of LD-MCC in ASPE matrix. The incorporated LD-MCC acted as KOH stabilizer, hydrophilicity agent and OH − transport media. Distinct micro-structures before and after the incorporation of LD-MCC were investigated to reveal the special role of LD-MCC in the performance improvement of ASPE membrane.

  16. Impact of microcrystalline silicon carbide growth using hot-wire chemical vapor deposition on crystalline silicon surface passivation

    International Nuclear Information System (INIS)

    Pomaska, M.; Beyer, W.; Neumann, E.; Finger, F.; Ding, K.

    2015-01-01

    Highly crystalline microcrystalline silicon carbide (μc-SiC:H) with excellent optoelectronic material properties is a promising candidate as highly transparent doped layer in silicon heterojunction (SHJ) solar cells. These high quality materials are usually produced using hot wire chemical vapor deposition under aggressive growth conditions giving rise to the removal of the underlying passivation layer and thus the deterioration of the crystalline silicon (c-Si) surface passivation. In this work, we introduced the n-type μc-SiC:H/n-type μc-SiO x :H/intrinsic a-SiO x :H stack as a front layer configuration for p-type SHJ solar cells with the μc-SiO x :H layer acting as an etch-resistant layer against the reactive deposition conditions during the μc-SiC:H growth. We observed that the unfavorable expansion of micro-voids at the c-Si interface due to the in-diffusion of hydrogen atoms through the layer stack might be responsible for the deterioration of surface passivation. Excellent lifetime values were achieved under deposition conditions which are needed to grow high quality μc-SiC:H layers for SHJ solar cells. - Highlights: • High surface passivation quality was preserved after μc-SiC:H deposition. • μc-SiC:H/μc-SiO x :H/a-SiO x :H stack a promising front layer configuration • Void expansion at a-SiO x :H/c-Si interface for deteriorated surface passivation • μc-SiC:H provides a high transparency and electrical conductivity.

  17. Preconcentration of uranium, thorium, zirconium, titanium, molybdenum and vanadium with oxine supported on microcrystalline naphthalene and their determinations by inductively coupled plasma atomic emission spectrometry

    International Nuclear Information System (INIS)

    Naveen Kumar, P.; Sanjay Kumar; Vijay Kumar; Nandakishore, S.S.; Bangroo, P.N.

    2013-01-01

    A sensitive and rapid method for the determination of uranium, thorium, zirconium, titanium, molybdenum and vanadium by inductively coupled plasma atomic emission spectrometry (ICP-AES) after solid-liquid extraction with microcrystalline naphthalene is developed. Analytes were quantitatively adsorbed as their oxinate complexes on naphthalene and determined by ICP-AES after stripping with 2 M HCl. The effect of various experimental parameters such as pH, reagent amounts, naphthalene amount and stripping conditions on the determination of these elements was investigated in detail. Under the optimized experimental conditions, the detection limits of this method for U (VI), Th (IV), Zr (IV), Ti (IV), Mo (VI) and V (V) were 20.0 ng mL -1 and the relative standard deviations obtained for three replicate determinations at a concentration of 1.0 µg mL -1 were 1.5-3.0%. The proposed method has been applied in the analysis of SY-2, SY-3 and pre-analysed samples for U, Th, Zr, Ti, Mo and V the analytical results are in good agreement with recommended values. (author)

  18. 13C, 15N Resonance Assignment of Parts of the HET-s Prion Protein in its Amyloid Form

    International Nuclear Information System (INIS)

    Siemer, Ansgar B.; Ritter, Christiane; Steinmetz, Michel O.; Ernst, Matthias; Riek, Roland; Meier, Beat H.

    2006-01-01

    The partial 15 N and 13 C solid-state NMR resonance assignment of the HET-s prion protein fragment 218-289 in its amyloid form is presented. It is based on experiments measured at MAS frequencies in the range of 20-40 kHz using exclusively adiabatic polarization-transfer schemes. The resonance assignment within each residue is based on two-dimensional 13 C-- 13 C correlation spectra utilizing the DREAM mixing scheme. The sequential linking of the assigned residues used a set of two- and three-dimensional 15 N-- 13 C correlation experiments. Almost all cross peaks visible in the spectra are assigned, but only resonances from 43 of the 78 amino-acid residues could be detected. The missing residues are thought to be highly disordered and/or highly dynamic giving rise to broad resonance lines that escaped detection in the experiments applied. The line widths of the observed resonances are narrow and comparable to line widths observed in micro-crystalline samples. The 43 assigned residues are located in two fragments of about 20 residues

  19. Secondary growth mechanism of SiGe islands deposited on a mixed-phase microcrystalline Si by ion beam co-sputtering.

    Science.gov (United States)

    Ke, S Y; Yang, J; Qiu, F; Wang, Z Q; Wang, C; Yang, Y

    2015-11-06

    We discuss the SiGe island co-sputtering deposition on a microcrystalline silicon (μc-Si) buffer layer and the secondary island growth based on this pre-SiGe island layer. The growth phenomenon of SiGe islands on crystalline silicon (c-Si) is also investigated for comparison. The pre-SiGe layer grown on μc-Si exhibits a mixed-phase structure, including SiGe islands and amorphous SiGe (a-SiGe) alloy, while the layer deposited on c-Si shows a single-phase island structure. The preferential growth and Ostwald ripening growth are shown to be the secondary growth mechanism of SiGe islands on μc-Si and c-Si, respectively. This difference may result from the effect of amorphous phase Si (AP-Si) in μc-Si on the island growth. In addition, the Si-Ge intermixing behavior of the secondary-grown islands on μc-Si is interpreted by constructing the model of lateral atomic migration, while this behavior on c-Si is ascribed to traditional uphill atomic diffusion. It is found that the aspect ratios of the preferential-grown super islands are higher than those of the Ostwald-ripening ones. The lower lateral growth rate of super islands due to the lower surface energy of AP-Si on the μc-Si buffer layer for the non-wetting of Ge at 700 °C and the stronger Si-Ge intermixing effect at 730 °C may be responsible for this aspect ratio difference.

  20. Influence of polyvinylpyrrolidone, microcrystalline cellulose and colloidal silicon dioxide on technological characteristics of a high-dose Petiveria alliacea tablet.

    Science.gov (United States)

    García-Pérez, Martha-Estrella; Lemus-Rodríguez, Zoe; Hung-Arbelo, Mario; Vistel-Vigo, Marlen

    2017-12-01

    Petiveria alliacea L. (Phytolaccaceae) is a perennial shrub used by its immunomodulatory, anticancerogenic and anti-inflammatory properties. This study determined the influence of polyvinylpyrrolidone (PVP), colloidal silicon dioxide (CSD) and microcrystalline cellulose (MC) on the technological characteristic of a high-dose P. alliacea tablet prepared by the wet granulation method. The botanical and pharmacognostic analysis of the plant material was firstly performed, followed by a 2 3 factorial design considering three factors at two levels: (a) the binder (PVP) incorporated in formulation at 10% and 15% (w/w); (b) the compacting agent (CSD) added at 10% and 15% (w/w) and; (c) the diluent (MC) included at 7.33% and 12.46% (w/w). The analysis of pharmaceutical performance and the accelerated and long-term stability of the best prototype were also completed. The binder, compacting agent and the interaction binder/diluent had a significant impact on breaking force of high-dose P. alliacea tablet. The optimum formula was found to contain 15% (w/w) of CSD, 7.33% (w/w) of MC and 10% (w/w) of PVP. At these conditions, the tablet shows a breaking force of 77.96 N, a friability of 0.39%, a total phenol content of 1.30 mg/tablet and a maximum disintegration time of 6 min. The use of adequate amounts of PVP, MC and CSD as per the factorial design allowed the preparation of a tablet suitable for administration, despite the inappropriate flow and compressibility properties of the P. alliacea powder.

  1. {sup 13}C, {sup 15}N Resonance Assignment of Parts of the HET-s Prion Protein in its Amyloid Form

    Energy Technology Data Exchange (ETDEWEB)

    Siemer, Ansgar B. [Physical Chemistry (Switzerland); Ritter, Christiane [Salk Institute, Structural Biology Laboratory (United States); Steinmetz, Michel O. [Paul Scherrer Institut, Biomolecular Research, Structural Biology (Switzerland); Ernst, Matthias [Physical Chemistry (Switzerland); Riek, Roland [Salk Institute, Structural Biology Laboratory (United States); Meier, Beat H. [Physical Chemistry (Switzerland)

    2006-02-15

    The partial {sup 15}N and {sup 13}C solid-state NMR resonance assignment of the HET-s prion protein fragment 218-289 in its amyloid form is presented. It is based on experiments measured at MAS frequencies in the range of 20-40 kHz using exclusively adiabatic polarization-transfer schemes. The resonance assignment within each residue is based on two-dimensional {sup 13}C--{sup 13}C correlation spectra utilizing the DREAM mixing scheme. The sequential linking of the assigned residues used a set of two- and three-dimensional {sup 15}N--{sup 13}C correlation experiments. Almost all cross peaks visible in the spectra are assigned, but only resonances from 43 of the 78 amino-acid residues could be detected. The missing residues are thought to be highly disordered and/or highly dynamic giving rise to broad resonance lines that escaped detection in the experiments applied. The line widths of the observed resonances are narrow and comparable to line widths observed in micro-crystalline samples. The 43 assigned residues are located in two fragments of about 20 residues.

  2. The effect of iron catalyzed graphitization on the textural properties of carbonized cellulose : Magnetically separable graphitic carbon bodies for catalysis and remediation

    NARCIS (Netherlands)

    Hoekstra, Jacco; Beale, Andrew M.; Soulimani, Fouad; Versluijs-Helder, Marjan; Van De Kleut, Dirk; Koelewijn, Jacobus M.; Geus, John W.; Jenneskens, Leonardus W.

    2016-01-01

    Whereas pyrolysis of pristine microcrystalline cellulose spheres yields nonporous amorphous carbon bodies, pyrolysis of microcrystalline cellulose spheres loaded with iron salts leads to the formation of magnetically separable mesoporous graphitic carbon bodies. The microcrystalline cellulose

  3. Adsorption mechanism of microcrystalline cellulose as green adsorbent for the removal of cationic methylene blue dye

    International Nuclear Information System (INIS)

    Tan, K.B.; Salamatinia, B.

    2016-01-01

    The adsorption mechanism of pure cellulose is yet to be explored. Thus, in this study, the adsorption mechanism of Microcrystalline Cellulose (MCC), a polysaccharide which is renewable, low cost and non-toxic, was studied on the adsorption of model dye Methylene blue (MB). It was found that the main adsorption mechanism of MB on MCC was due to the electrostatic attraction between the positively charged MB dye and negatively charged MCC. Thus, physical adsorption was the dominant effect, since electrostatic attraction is categorized as physical adsorption. This was verified by Dubinin-Radushkevich isotherm, whereby mean free energy adsorption value was found to be less than 8 kJ/mol. The values of Gibbs free energy for thermodynamics studies were found to be within the range of -20 kJ/mol and 0 kJ/mol, which also indicated physical adsorption. It was due to the electrostatic attraction as adsorption mechanism of this adsorption process which resulted rapid adsorption of MB dye. It was found that equilibrium dye concentration was achieved between 1-3 minutes, depending on the adsorption temperature. The rapid adsorption, as compared to a lot of materials, showed the potential of MCC as the future of green adsorbent. The adsorption of Methylene Blue on MCC fitted well in Langmuir Isotherm, with R2 values of higher than 0.99, while fitted moderately in Freundlich Isotherm, with R2 values between 0.9224 and 0.9223. Comparatively, the adsorption of MB on MCC fitted best Langmuir Isotherm as compared to Freundlich Isotherm which monolayer adsorption occurred at the homogenous surface of MCC. This also indicated adsorbed MB molecules do not interact with each other at neighboring adsorption sites. The maximum adsorption capacity calculated from Langmuir Isotherm was found to be 4.95 mg/g. Despite the potential of MCC as green adsorbent, the challenge of low adsorption capacity has to be addressed in the future. (author)

  4. A sirolimus-eluting bioabsorbable polymer-coated stent (MiStent) versus an everolimus-eluting durable polymer stent (Xience) after percutaneous coronary intervention (DESSOLVE III): a randomised, single-blind, multicentre, non-inferiority, phase 3 trial

    NARCIS (Netherlands)

    de Winter, Robbert J.; Katagiri, Yuki; Asano, Taku; Milewski, Krzysztof P.; Lurz, Philipp; Buszman, Pawel; Jessurun, Gillian A. J.; Koch, Karel T.; Troquay, Roland P. T.; Hamer, Bas J. B.; Ophuis, Ton Oude; Wöhrle, Jochen; Wyderka, Rafał; Cayla, Guillaume; Hofma, Sjoerd H.; Levesque, Sébastien; Żurakowski, Aleksander; Fischer, Dieter; Kośmider, Maciej; Goube, Pascal; Arkenbout, E. Karin; Noutsias, Michel; Ferrari, Markus W.; Onuma, Yoshinobu; Wijns, William; Serruys, Patrick W.

    2018-01-01

    Background MiStent is a drug-eluting stent with a fully absorbable polymer coating containing and embedding a microcrystalline form of sirolimus into the vessel wall. It was developed to overcome the limitation of current durable polymer drug-eluting stents eluting amorphous sirolimus. The clinical

  5. Multiple acquisition of magic angle spinning solid-state NMR experiments using one receiver: Application to microcrystalline and membrane protein preparations

    Science.gov (United States)

    Gopinath, T.; Veglia, Gianluigi

    2015-04-01

    Solid-state NMR spectroscopy of proteins is a notoriously low-throughput technique. Relatively low-sensitivity and poor resolution of protein samples require long acquisition times for multidimensional NMR experiments. To speed up data acquisition, we developed a family of experiments called Polarization Optimized Experiments (POE), in which we utilized the orphan spin operators that are discarded in classical multidimensional NMR experiments, recovering them to allow simultaneous acquisition of multiple 2D and 3D experiments, all while using conventional probes with spectrometers equipped with one receiver. POE allow the concatenation of multiple 2D or 3D pulse sequences into a single experiment, thus potentially combining all of the aforementioned advances, boosting the capability of ssNMR spectrometers at least two-fold without the addition of any hardware. In this perspective, we describe the first generation of POE, such as dual acquisition MAS (or DUMAS) methods, and then illustrate the evolution of these experiments into MEIOSIS, a method that enables the simultaneous acquisition of multiple 2D and 3D spectra. Using these new pulse schemes for the solid-state NMR investigation of biopolymers makes it possible to obtain sequential resonance assignments, as well as distance restraints, in about half the experimental time. While designed for acquisition of heteronuclei, these new experiments can be easily implemented for proton detection and coupled with other recent advancements, such as dynamic nuclear polarization (DNP), to improve signal to noise. Finally, we illustrate the application of these methods to microcrystalline protein preparations as well as single and multi-span membrane proteins reconstituted in lipid membranes.

  6. Synthesis and luminescence properties of Ce{sup 3+} doped MWO{sub 4} (M=Ca, Sr and Ba) microcrystalline phosphors

    Energy Technology Data Exchange (ETDEWEB)

    Dabre, K.V. [Department of Physics, Arts, Commerce and Science College, Koradi, Nagpur (India); Dhoble, S.J., E-mail: sjdhoble@rediffmail.com [Department of Physics, R.T.M. Nagpur University, Nagpur 440033 (India); Lochab, Jyoti [Radiotherapy Department, Safdarjung Hospital, New Delhi (India)

    2014-05-01

    The Ce{sup 3+} doped and undoped samples of alkali earth metal tungstate MWO{sub 4} (M=Ca, Sr, and Ba) phosphors are synthesized by a co-precipitation method in controlled pH environment. The resulting phosphors were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared (FTIR), photoluminescence (PL) and thermoluminescence (TL). XRD pattern and SEM micrographs reveal the formation of agglomerated microcrystalline phosphor. FTIR spectra show the strong absorption around 821 cm{sup −1} due to characteristic vibrations of (WO{sub 4}){sup 2−} complex. PL excitation spectra show broadband in the UV region having peak at 280 nm, and the emission spectrum shows broadband in the visible region with peak in the blue region. The PL emission intensity increases with Ce{sup 3+} concentration with the most effective concentration at 5 mol%. The complex TL glow curve of Ce{sup 3+} doped phosphors is deconvoluted by using a TLAnal computer program. The trap parameters obtained by TLAnal were compared with those calculated by Chen's method and a possible model for TL is discussed. - Highlights: • M{sub 1−x}WO{sub 4}:Ce{sub x} (M=Ca, Sr, and Ba) phosphors are synthesized by the co-precipitation method in controlled pH environment. • Phosphor exhibits broad emission band with maximum in the blue region. • Enhancement of PL emission intensity due to doping of Ce in a host lattice. • The complex TL glow curves were deconvoluted by TLAnal. • FTIR spectra show the main transmittance peaks related to v{sub 3} and v{sub 4} vibration modes of W–O bonds.

  7. Development of Hydrogenated Microcrystalline Silicon-Germanium Alloys for Improving Long-Wavelength Absorption in Si-Based Thin-Film Solar Cells

    Directory of Open Access Journals (Sweden)

    Yen-Tang Huang

    2014-01-01

    Full Text Available Hydrogenated microcrystalline silicon-germanium (μc-Si1-xGex:H alloys were developed for application in Si-based thin-film solar cells. The effects of the germane concentration (RGeH4 and the hydrogen ratio (RH2 on the μc-Si1-xGex:H alloys and the corresponding single-junction thin-film solar cells were studied. The behaviors of Ge incorporation in a-Si1-xGex:H and μc-Si1-xGex:H were also compared. Similar to a-Si1-xGex:H, the preferential Ge incorporation was observed in μc-Si1-xGex:H. Moreover, a higher RH2 significantly promoted Ge incorporation for a-Si1-xGex:H, while the Ge content was not affected by RH2 in μc-Si1-xGex:H growth. Furthermore, to eliminate the crystallization effect, the 0.9 μm thick absorbers with a similar crystalline volume fraction were applied. With the increasing RGeH4, the accompanied increase in Ge content of μc-Si1-xGex:H narrowed the bandgap and markedly enhanced the long-wavelength absorption. However, the bias-dependent EQE measurement revealed that too much Ge incorporation in absorber deteriorated carrier collection and cell performance. With the optimization of RH2 and RGeH4, the single-junction μc-Si1-xGex:H cell achieved an efficiency of 5.48%, corresponding to the crystalline volume fraction of 50.5% and Ge content of 13.2 at.%. Compared to μc-Si:H cell, the external quantum efficiency at 800 nm had a relative increase by 33.1%.

  8. Separation/enrichment of trace Zinc using potassium bromide-dimethylglyoxime-thymolphthalein system

    Science.gov (United States)

    Tu, Changqing; Wen, Xinrong

    2018-02-01

    A new method for the separation enrichment of trace Zn2+ using microcrystalline thymolphthalein as an adsorbent was established. The separation enrichment behaviour of Zn2+ and the conditions for the separation quantitatively of Zn2+ with other metal ions were investigated. The possible separation enrichment mechanism of Zn2+ was discussed in detail. The results showed that by controlling pH 10.0, in KBr-diacetydioxime(DMG)-thymolphthalein(TP) system, chelate settlement of Zn(DMG)2 which formed by Zn2+ and DMG was quantitatively adsorbed on the surface of microcrystalline thymolphthalein,and the liquid-solid phases were formed with clear interface, while Cu2+, Bi3+, Al3+, Hg2+ could not be adsorbed. The quantitative separation of Zn2+ from those metal ions was achieved. The proposed method has been successfully applied to the quantitative separation of trace Zn2+ in synthetic water samples with enrichment yield of 93.5%∼99.3%.

  9. Development of polymer-bound fast-dissolving metformin buccal film with disintegrants

    Directory of Open Access Journals (Sweden)

    Haque SE

    2015-10-01

    Full Text Available Shaikh Ershadul Haque, Angappan Sheela Materials Chemistry Division, Centre for Nanomaterials, School of Advanced Sciences, VIT University, Vellore, India Abstract: Fast-dissolving drug-delivery systems are considered advantageous over the existing conventional oral dosage forms like tablets, capsules, and syrups for being patient friendly. Buccal films are one such system responsible for systemic drug delivery at the desired site of action by avoiding hepatic first-pass metabolism. Metformin hydrochloride (Met, an antidiabetic drug, has poor bioavailability due to its high solubility and low permeability. The purpose of the study reported here was to develop a polymer-bound fast-dissolving buccal film of metformin to exploit these unique properties. In the study, metformin fast-dissolving films were prepared by the solvent-casting method using chitosan, a bioadhesive polymer. Further, starch, sodium starch glycolate, and microcrystalline cellulose were the disintegrants added to different ratios, forming various formulations (F1 to F7. The buccal films were evaluated for various parameters like weight variation, thickness, folding endurance, surface pH, content uniformity, tensile strength, and percentage of elongation. The films were also subjected to in vitro dissolution study, and the disintegration time was found to be less than 30 minutes for all formulations, which was attributed to the effect of disintegrants. Formulation F6 showed 92.2% drug release within 6 minutes due to the combined effect of sodium starch glycolate and microcrystalline cellulose. Keywords: chitosan, sodium starch glycolate, microcrystalline cellulose, drug-delivery system, immediate release

  10. Chapter 1.4: Spatially Resolved Characterization of CNC-Polypropylene composite by Confocal Raman Microscopy

    Science.gov (United States)

    Umesh Agarwal; Ronald Sabo; Richard Reiner; Craig Clemons; Alan Rudie

    2013-01-01

    Raman spectroscopy was used to analyze cellulose nanocrystal (CNC)-polypropylene (PP) composites and to investigate the spatial distribution of CNCs in extruded composite filaments. Three composites were made from two forms of nanocellulose (CNCs from wood pulp and the nanoscale fraction of microcrystalline cellulose), and two of the three composites...

  11. Spatially Resolved Characterization of Cellulose Nanocrystal-Polypropylene Composite by Confocal Raman Microscopy

    Science.gov (United States)

    Umesh P. Agarwal; Ronald Sabo; Richard S. Reiner; Craig M. Clemons; Alan W. Rudie

    2012-01-01

    Raman spectroscopy was used to analyze cellulose nanocrystal (CNC)–polypropylene (PP) composites and to investigate the spatial distribution of CNCs in extruded composite filaments. Three composites were made from two forms of nanocellulose (CNCs from wood pulp and the nanoscale fraction of microcrystalline cellulose) and two of the three composites investigated used...

  12. Molecular and vibrational structure of the extracellular bacterial signal compound N-butyryl-homoserine lactone (C4-HSL)

    DEFF Research Database (Denmark)

    Bak, Jimmy; Spanget-Larsen, Jens

    2009-01-01

    contributions from suspended micro-crystalline aggregates and dissolved monomeric species. The key vibrational bands of the monomeric form of C4-HSL are reported here for the first time: 3425cm−1 (ν(N-H)), 1784cm−1 (ν(C&dbnd;O), lactone), 1688cm−1 (amide I), and 1494cm−1 (amide II) (CCl4)....

  13. Influence of ambient moisture on the compaction behavior of microcrystalline cellulose powder undergoing uni-axial compression and roller-compaction: a comparative study using near-infrared spectroscopy.

    Science.gov (United States)

    Gupta, Abhay; Peck, Garnet E; Miller, Ronald W; Morris, Kenneth R

    2005-10-01

    This study evaluates the effect of variation in the ambient moisture on the compaction behavior of microcrystalline cellulose (MCC) powder. The study was conducted by comparing the physico-mechanical properties of, and the near infrared (NIR) spectra collected on, compacts prepared by roller compaction with those collected on simulated ribbons, that is, compacts prepared under uni-axial compression. Relative density, moisture content, tensile strength (TS), and Young modulus were used as key sample attributes for comparison. Samples prepared at constant roller compactor settings and feed mass showed constant density and a decrease in TS with increasing moisture content. Compacts prepared under uni-axial compression at constant pressure and compact mass showed the opposite effect, that is, density increased while TS remained almost constant with increasing moisture content. This suggests difference in the influence of moisture on the material under roller compaction, in which the roll gap (i.e., thickness and therefore density) remains almost constant, vs. under uni-axial compression, in which the thickness is free to change in response to the applied pressure. Key sample attributes were also related to the NIR spectra using multivariate data analysis by the partial least squares projection to latent structures (PLS). Good agreement was observed between the measured and the NIR-PLS predicted values for all key attributes for both, the roller compacted samples as well as the simulated ribbons. Copyright (c) 2005 Wiley-Liss, Inc. and the American Pharmacists Association

  14. Deposition of thin layers of boron nitrides and hydrogenated microcrystalline silicon assisted by high current direct current arc plasma; Deposition assistee par un plasma a arc a haut courant continu de couches minces de Nitrure de Bore et de Silicium microcristallin hydrogene

    Energy Technology Data Exchange (ETDEWEB)

    Franz, D. [Ecole Polytechnique Federale de Lausanne, Centre de Recherches en Physique des Plasmas (CRPP), CH-1015 Lausanne (Switzerland)

    1999-09-01

    In the frame of this thesis, a high current direct current arc (HCDCA) used for the industrial deposition of diamond, has been adapted to study the deposition of two types of coatings: a) boron nitride, whose cubic phase is similar to diamond, for tribological applications, b) hydrogenated microcrystalline silicon, for applications in the semiconductor fields (flat panel displays, solar cells,...). For the deposition of these coatings, the substrates were placed in the diffusion region of the arc. The substrate heating is mainly due to atomic species recombining on its surface. The deposition temperature, varying from 300 to 900 {sup o}C according to the films deposited, is determined by the substrate position, the arc power and the injected gas fluxes, without the use of any external heating or cooling system. Measurements performed on the arc plasma show that the electronic temperature is around 2 eV (23'000 K) while the gas temperature is lower than 5500 K. Typical electronic densities are in the range of 10{sup 12}-10{sup 1'}3 cm{sup -3}. For the deposition of boron nitride films, different boron precursors were used and a wide parameter range was investigated. The extreme difficulty of synthesising cubic boron nitride films by chemical vapour deposition (CVD) did not allow to stabilize the cubic phase of boron nitride in HCDCA. Coatings resulted in hexagonal or amorphous boron nitride with a chemical composition close to stoichiometric. The presence of hydrogen leads to the deposition of rough and porous films. Negative biasing of the samples, for positive ion bombardment, is commonly used to stabilize the cubic phase. In HCDCA and in our biasing range, only a densification of the films could be observed. A boron nitride deposition plasma study by infrared absorption spectroscopy in a capacitive radio frequency reactor has demonstrated the usefulness of this diagnostic for the understanding of the various chemical reactions which occur in this kind

  15. Formulation and Evaluation of Ascorbic acid Tablets by Direct ...

    African Journals Online (AJOL)

    Formulation and Evaluation of Ascorbic acid Tablets by Direct Compression using Microcrystalline Starch as a Direct Compression Excipient. ... Abstract. PURPOSE: To evaluate the tableting properties of microcrystalline starch (MCS) used as a direct ... RESULTS: Mechanical properties of tablets formulated with MCS were

  16. Improving the growth of Ge/Si islands by modulating the spacing between screen and accelerator grids in ion beam sputtering deposition system

    International Nuclear Information System (INIS)

    Yang, Jie; Zhao, Bo; Wang, Chong; Qiu, Feng; Wang, Rongfei; Yang, Yu

    2016-01-01

    Highlights: • Ge islands were prepared by ion beam sputtering with different grid-to-grid gaps. • Ge islands with larger sizes and low density are observed in 1-mm-spaced samples. • The island growth was determined by sputter energy and the quality of Si buffer. • The crystalline volume fraction of buffer must be higher than 72% to grow islands. - Abstract: Ge islands were fabricated on Si buffer layer by ion beam sputtering deposition with a spacing between the screen and accelerator grids of either 1 mm or 2 mm. The Si buffer layer exhibits mixed-phase microcrystallinity for samples grown with 1 mm spacing and crystallinity for those with 2 mm spacing. Ge islands are larger and less dense than those grown on the crystalline buffer because of the selective growth mechanism on the microcrystalline buffer. Moreover, the nucleation site of Ge islands formed on the crystalline Si buffer is random. Ge islands grown at different grid-to-grid gaps are characterized by two key factors, namely, divergence half angle of ion beam and crystallinity of buffer layer. High grid-to-grid spacing results in small divergence half angle, thereby enhancing the sputtering energy and redistribution of sputtered atoms. The crystalline volume fraction of the microcrystalline Si buffer was obtained based on the integrated intensity ratio of Raman peaks. The islands show decreased density with decreasing crystalline volume fraction and are difficult to observe at crystalline volume fractions lower than 72%.

  17. Improving the growth of Ge/Si islands by modulating the spacing between screen and accelerator grids in ion beam sputtering deposition system

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Jie; Zhao, Bo [Institute of Optoelectronic Information Materials, School of Materials Science and Engineering, Yunnan University, Kunming 650091 (China); Yunnan Key Laboratory for Micro/Nano Materials and Technology, Yunnan University, Kunming 650091 (China); Wang, Chong, E-mail: cwang@mail.sitp.ac.cn [Institute of Optoelectronic Information Materials, School of Materials Science and Engineering, Yunnan University, Kunming 650091 (China); Yunnan Key Laboratory for Micro/Nano Materials and Technology, Yunnan University, Kunming 650091 (China); Qiu, Feng; Wang, Rongfei [Institute of Optoelectronic Information Materials, School of Materials Science and Engineering, Yunnan University, Kunming 650091 (China); Yunnan Key Laboratory for Micro/Nano Materials and Technology, Yunnan University, Kunming 650091 (China); Yang, Yu, E-mail: yuyang@ynu.edu.cn [Institute of Optoelectronic Information Materials, School of Materials Science and Engineering, Yunnan University, Kunming 650091 (China); Yunnan Key Laboratory for Micro/Nano Materials and Technology, Yunnan University, Kunming 650091 (China)

    2016-11-15

    Highlights: • Ge islands were prepared by ion beam sputtering with different grid-to-grid gaps. • Ge islands with larger sizes and low density are observed in 1-mm-spaced samples. • The island growth was determined by sputter energy and the quality of Si buffer. • The crystalline volume fraction of buffer must be higher than 72% to grow islands. - Abstract: Ge islands were fabricated on Si buffer layer by ion beam sputtering deposition with a spacing between the screen and accelerator grids of either 1 mm or 2 mm. The Si buffer layer exhibits mixed-phase microcrystallinity for samples grown with 1 mm spacing and crystallinity for those with 2 mm spacing. Ge islands are larger and less dense than those grown on the crystalline buffer because of the selective growth mechanism on the microcrystalline buffer. Moreover, the nucleation site of Ge islands formed on the crystalline Si buffer is random. Ge islands grown at different grid-to-grid gaps are characterized by two key factors, namely, divergence half angle of ion beam and crystallinity of buffer layer. High grid-to-grid spacing results in small divergence half angle, thereby enhancing the sputtering energy and redistribution of sputtered atoms. The crystalline volume fraction of the microcrystalline Si buffer was obtained based on the integrated intensity ratio of Raman peaks. The islands show decreased density with decreasing crystalline volume fraction and are difficult to observe at crystalline volume fractions lower than 72%.

  18. Studies on the physicochemical and functional properties of ...

    African Journals Online (AJOL)

    This study was aimed at developing pharmaceutical grade microcrystalline cellulose from Khaya grandifolia wood flakes as a tablet excipient. The microcrystalline cellulose coded KG-MCC, was obtained from Khaya grandifolia wood flakes by a two-stage sodium hydroxide delignification process followed by sodium ...

  19. Virus-Like Particle (VLP Plus Microcrystalline Tyrosine (MCT Adjuvants Enhance Vaccine Efficacy Improving T and B Cell Immunogenicity and Protection against Plasmodium berghei/vivax

    Directory of Open Access Journals (Sweden)

    Gustavo Cabral-Miranda

    2017-05-01

    Full Text Available Vaccination is the most effective prophylactic tool against infectious diseases. Despite continued efforts to control malaria, the disease still generally represents a significant unmet medical need. Microcrystalline tyrosine (MCT is a well described depot used in licensed allergy immunotherapy products and in clinical development. However, its proof of concept in prophylactic vaccines has only recently been explored. MCT has never been used in combination with virus-like particles (VLPs, which are considered to be one of the most potent inducers of cellular and humoral immune responses in mice and humans. In the current study we assessed the potential of MCT to serve as an adjuvant in the development of a vaccine against malaria either alone or combined with VLP using Plasmodium vivax thrombospondin-related adhesive protein (TRAP as a target antigen. We chemically coupled PvTRAP to VLPs derived from the cucumber mosaic virus fused to a universal T-cell epitope of the tetanus toxin (CMVtt, formulated with MCT and compared the induced immune responses to PvTRAP formulated in PBS or Alum. The protective capacity of the various formulations was assessed using Plasmodium berghei expressing PvTRAP. All vaccine formulations using adjuvants and/or VLP increased humoral immunogenicity for PvTRAP compared to the antigen alone. The most proficient responder was the group of mice immunized with the vaccine formulated with PvTRAP-VLP + MCT. The VLP-based vaccine formulated in MCT also induced the strongest T cell response and conferred best protection against challenge with recombinant Plasmodium berghei. Thus, the combination of VLP with MCT may take advantage of the properties of each component and appears to be an alternative biodegradable depot adjuvant for development of novel prophylactic vaccines.

  20. Development of polymer-bound fast-dissolving metformin buccal film with disintegrants.

    Science.gov (United States)

    Haque, Shaikh Ershadul; Sheela, Angappan

    2015-01-01

    Fast-dissolving drug-delivery systems are considered advantageous over the existing conventional oral dosage forms like tablets, capsules, and syrups for being patient friendly. Buccal films are one such system responsible for systemic drug delivery at the desired site of action by avoiding hepatic first-pass metabolism. Metformin hydrochloride (Met), an antidiabetic drug, has poor bioavailability due to its high solubility and low permeability. The purpose of the study reported here was to develop a polymer-bound fast-dissolving buccal film of metformin to exploit these unique properties. In the study, metformin fast-dissolving films were prepared by the solvent-casting method using chitosan, a bioadhesive polymer. Further, starch, sodium starch glycolate, and microcrystalline cellulose were the disintegrants added to different ratios, forming various formulations (F1 to F7). The buccal films were evaluated for various parameters like weight variation, thickness, folding endurance, surface pH, content uniformity, tensile strength, and percentage of elongation. The films were also subjected to in vitro dissolution study, and the disintegration time was found to be less than 30 minutes for all formulations, which was attributed to the effect of disintegrants. Formulation F6 showed 92.2% drug release within 6 minutes due to the combined effect of sodium starch glycolate and microcrystalline cellulose.

  1. Formulation and Evaluation of Ascorbic acid Tablets by Direct ...

    African Journals Online (AJOL)

    PURPOSE: To evaluate the tableting properties of microcrystalline starch (MCS) used as a direct compression excipient in the formulation of ascorbic acid tablets and to compare with the properties of tablets produced using microcrystalline cellulose (MCC). METHODS: MCS was obtained by partial hydrolysis of cassava ( ...

  2. Compatibility studies of nevirapine in physical mixtures with excipients for oral HAART

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, G.G.G. de; Ferraz, H.G. [Department of Pharmacy, Faculty of Pharmaceutical Health, University of Sao Paulo, Sao Paulo 05508-900 (Brazil); Severino, P. [Department of Biotechnological Processes, School of Chemical Engineering, University of Campinas, Campinas 13083-970 (Brazil); Department of Pharmaceutical Technology, Faculty of Health Sciences, Fernando Pessoa University, Porto 4200-150 (Portugal); Souto, E.B., E-mail: eliana@ufp.edu.pt [Department of Pharmaceutical Technology, Faculty of Health Sciences, Fernando Pessoa University, Porto 4200-150 (Portugal); Institute for Biotechnology and Bioengineering, Centre for Genomics and Biotechnology, University of Tras-os-Montes e Alto Douro (IBB-CGB/UTAD), 5001-801 Vila Real (Portugal)

    2013-03-01

    Nevirapine is a hydrophobic non-nucleoside reverse transcriptase inhibitor, used in first line regimens of highly active antiretroviral therapy (HAART). The drug has more than one crystalline form, which may have implications for its behaviour during production and also for its in vivo performance. This study was aimed at exploring the suitability of thermoanalytical methods for the solid-state characterization of commercial crystalline forms of nevirapine. The drug powder was characterized by ultraviolet spectrophotometry, stereoscopy, scanning electron microscopy, wide-angle X-ray diffraction, measurements of density, flowability, solubility and intrinsic dissolution rate (IDR), differential scanning calorimetry, thermogravimetric analysis, and photostability measurements. The results showed that nevirapine has high stability and is not susceptible to degradation under light exposure. The drug showed compatibility with the excipients tested (lactose, microcrystalline cellulose, polyvinylpyrrolidone and polyvinyl acetate copolymer (PVP/PVA), and hydroxypropylmethylcellulose (HPMC)). Nevirapine has low solubility, an acid medium being the most appropriate medium for assessing the release of the drug from dosage forms. However, the data obtained from IDR testing indicate that dissolution is the critical factor for the bioavailability of this drug. - Graphical abstract: Bulk nevirapine powder analysed by scanning electron microscopy and the drug solubility profile in various buffer solutions. The pH values of the media in which the tests were conducted are also presented. Highlights: Black-Right-Pointing-Pointer Nevirapine shows more than one crystalline form, that influence its in vivo and in vitro behaviour. Black-Right-Pointing-Pointer DSC and TGA were used for solid-state characterization of crystalline forms of nevirapine. Black-Right-Pointing-Pointer Nevirapine is compatible with lactose, microcrystalline cellulose, PVP/PVA copolymers and HPMC. Black

  3. Compatibility studies of nevirapine in physical mixtures with excipients for oral HAART

    International Nuclear Information System (INIS)

    Oliveira, G.G.G. de; Ferraz, H.G.; Severino, P.; Souto, E.B.

    2013-01-01

    Nevirapine is a hydrophobic non-nucleoside reverse transcriptase inhibitor, used in first line regimens of highly active antiretroviral therapy (HAART). The drug has more than one crystalline form, which may have implications for its behaviour during production and also for its in vivo performance. This study was aimed at exploring the suitability of thermoanalytical methods for the solid-state characterization of commercial crystalline forms of nevirapine. The drug powder was characterized by ultraviolet spectrophotometry, stereoscopy, scanning electron microscopy, wide-angle X-ray diffraction, measurements of density, flowability, solubility and intrinsic dissolution rate (IDR), differential scanning calorimetry, thermogravimetric analysis, and photostability measurements. The results showed that nevirapine has high stability and is not susceptible to degradation under light exposure. The drug showed compatibility with the excipients tested (lactose, microcrystalline cellulose, polyvinylpyrrolidone and polyvinyl acetate copolymer (PVP/PVA), and hydroxypropylmethylcellulose (HPMC)). Nevirapine has low solubility, an acid medium being the most appropriate medium for assessing the release of the drug from dosage forms. However, the data obtained from IDR testing indicate that dissolution is the critical factor for the bioavailability of this drug. - Graphical abstract: Bulk nevirapine powder analysed by scanning electron microscopy and the drug solubility profile in various buffer solutions. The pH values of the media in which the tests were conducted are also presented. Highlights: ► Nevirapine shows more than one crystalline form, that influence its in vivo and in vitro behaviour. ► DSC and TGA were used for solid-state characterization of crystalline forms of nevirapine. ► Nevirapine is compatible with lactose, microcrystalline cellulose, PVP/PVA copolymers and HPMC. ► The acid form of nevirapine is the most appropriate for assessing release profile from

  4. A terahertz time-domain study on the estimation of opto-mechanical properties of pharmaceutical tablets using the Hashin-Shtrikman bounds for refractive index: a case study of microcrystalline cellulose and starch acetate compacts

    Science.gov (United States)

    Bawuah, Prince; Peiponen, Kai-Erik

    2016-06-01

    This work highlights the use of Hashin-Shtrikman (H-S) bounds in the prediction and verification of the effective refractive index, the height and the Young's modulus of given training sets of pharmaceutical compacts using the measured time delay of a THz pulse traversing the compacts. Set A consisted of 13 microcrystalline cellulose (MCC) compacts whereas set B was made up of 5 starch acetate (SA) compacts. MCC is a typical ingredient of many pharmaceutical tablets. In the case of the MCC compacts, tight and closely matched bounds were obtained between the experimental, the calculated upper, lower bound values for the effective refractive index, and the height values. This promising outcome has shown the high possibility of utilizing H-S bounds in the verification and prediction of the decision level of useful parameters, which can serve as a quality check for pharmaceutical tablets. For the SA compacts, although less tight bounds were observed, the experimental values for the effective refractive index and the Young's modulus were closely matched with the upper and the lower bounds, respectively. We therefore speculate based on the above observations that the MCC tablets contain an almost evenly distributed spherically shaped air voids whereas in the SA compacts, this assumption might not necessary be true.

  5. Synergy of Diflubenzuron Baiting and NHA Dusting on Mortality of Reticulitermes flavipes

    Science.gov (United States)

    F. III Green; R.A. Arango; G.R. Esenther; M.G. Rojas; J. Morales-Ramos

    2013-01-01

    The ability of N’N-naphthaloylhydroxylamine (NHA) to cause mortality in Reticulitermes flavipes workers pretreated with the chitin synthesis inhibitor diflubenzuron was tested by adding two NHA dusted workers to 100 (2:100) pretreated workers fed either pure microcrystalline alpha-cellulose or diflubenzuron (0.25%) treated microcrystalline cellulose...

  6. Teaching Form as Form

    DEFF Research Database (Denmark)

    Keiding, Tina Bering

    2012-01-01

    understanding of form per se, or, to use an expression from this text, of form as form. This challenge can be reduced to one question: how can design teaching support students in achieving not only the ability to recognize and describe different form-related concepts in existing design (i.e. analytical...

  7. Molecular weights and molecular weight distributions of irradiated cellulose fibers by gel permeation chromatography

    International Nuclear Information System (INIS)

    Kusama, Y.; Kageyama, E.; Shimada, M.; Nakamura, Y.

    1976-01-01

    Radiation degradation of cellulose fibers was investigated by gel permeation chromatography (GPC). Scoured cotton of Mexican variety (cellulose I), Polynosic rayon (cellulose II), and their microcrystalline celluloses obtained by hydrolysis of the original fibers were irradiated by Co-60 γ-rays under vacuum or humid conditions. The irradiated samples were then nitrated under nondegradative conditions. The molecular weights and molecular weight distributions were measured by GPC using tetrahydrofuran as solvent. The relationship between molecular weight and elution count was obtained with cellulose trinitrate standards fractionated by preparative GPC. The degree of polymerization of the fibers decreased with increasing irradiation dose, but their microcrystalline celluloses were only slightly degraded by irradiation, especially in microcrystalline cellulose from cellulose I. Degradation of the fibers irradiated under humid conditions was less than that irradiated under vacuum. It was found that the G-values for main-chain scission for the irradiated cellulose I, cellulose II, microcrystalline cellulose I, and microcrystalline cellulose II were 2.8, 2.9, less than 1, and 2.9, respectively, but the G-value for main-chain scission for the irradiated cellulose II was increased to 11.2 at irradiation doses above 3 Mrad. Consequently, it is inferred that cellulose molecules in the amorphous regions are degraded more readily, and the well-aligned molecules in crystalline regions are not as easily degraded by irradiation

  8. Quartz-coesite-stishovite relations in shocked metaquartzites from the Vredefort impact structure, South Africa

    Science.gov (United States)

    Spray, John G.; Boonsue, Suporn

    2018-01-01

    Coesite and stishovite are developed in shock veins within metaquartzites beyond a radius of 30 km from the center of the 2.02 Ga Vredefort impact structure. This work focuses on deploying analytical field emission scanning electron microscopy, electron backscattered diffraction, and Raman spectrometry to better understand the temporal and spatial relations of these silica polymorphs. α-Quartz in the host metaquartzites, away from shock veins, exhibits planar features, Brazil twins, and decorated planar deformation features, indicating a primary (bulk) shock loading of >5 < 35 GPa. Within the shock veins, coesite forms anhedral grains, ranging in size from 0.5 to 4 μm, with an average of 1.25 μm. It occurs in clasts, where it displays a distinct jigsaw texture, indicative of partial reversion to a less dense SiO2 phase, now represented by microcrystalline quartz. It is also developed in the matrix of the shock veins, where it is typically of smaller size (<1 μm). Stishovite occurs as euhedral acicular crystals, typically <0.5 μm wide and up to 15 μm in length, associated with clast-matrix or shock vein margin-matrix interfaces. In this context, the needles occur as radiating or subparallel clusters, which grow into/over both coesite and what is now microcrystalline quartz. Stishovite also occurs as more blebby, subhedral to anhedral grains in the vein matrix (typically <1 μm). We propose a model for the evolution of the veins (1) precursory frictional melting in a microfault ( 1 mm wide) generates a molten matrix containing quartz clasts. This is followed by (2) arrival of the main shock front, which shocks to 35 GPa. This generates coesite in the clasts and in the matrix. (3) On initial shock release, the coesite partly reverts to a less dense SiO2 phase, which is now represented by microcrystalline quartz. (4) With continued release, stishovite forms euhedral needle clusters at solid-liquid interfaces and as anhedral crystals in the matrix. (5) With

  9. To Evaluate the Effect of Solvents and Different Relative Humidity Conditions on Thermal and Rheological Properties of Microcrystalline Cellulose 101 Using METHOCEL™ E15LV as a Binder.

    Science.gov (United States)

    Jagia, Moksh; Trivedi, Maitri; Dave, Rutesh H

    2016-08-01

    The solvent used for preparing the binder solution in wet granulation can affect the granulation end point and also impact the thermal, rheological, and flow properties of the granules. The present study investigates the effect of solvents and percentage relative humidity (RH) on the granules of microcrystalline cellulose (MCC) with hydroxypropyl methyl cellulose (HPMC) as the binder. MCC was granulated using 2.5% w/w binder solution in water and ethanol/water mixture (80:20 v/v). Prepared granules were dried until constant percentage loss on drying, sieved, and further analyzed. Dried granules were exposed to different percentage RH for 48 h at room temperature. Powder rheometer was used for the rheological and flow characterization, while thermal effusivity and differential scanning calorimeter were used for thermal analysis. The thermal effusivity values for the wet granules showed a sharp increase beginning 50% w/w binder solution in both cases, which reflected the over-wetting of granules. Ethanol/water solvent batches showed greater resistance to flow as compared to the water solvent batches in the wet granule stage, while the reverse was true for the dried granule stage, as evident from the basic flowability energy values. Although the solvents used affected the equilibration kinetics of moisture content, the RH-exposed granules remained unaffected in their flow properties in both cases. This study indicates that the solvents play a vital role on the rheology and flow properties of MCC granules, while the different RH conditions have little or no effect on them for the above combination of solvent and binder.

  10. [Diagnosis: synovial fluid analysis].

    Science.gov (United States)

    Gallo Vallejo, Francisco Javier; Giner Ruiz, Vicente

    2014-01-01

    Synovial fluid analysis in rheumatological diseases allows a more accurate diagnosis in some entities, mainly infectious and microcrystalline arthritis. Examination of synovial fluid in patients with osteoarthritis is useful if a differential diagnosis will be performed with other processes and to distinguish between inflammatory and non-inflammatory forms. Joint aspiration is a diagnostic and sometimes therapeutic procedure that is available to primary care physicians. Copyright © 2014 Elsevier España, S.L. All rights reserved.

  11. Porovnání vlastností výlisků ze silicifikovaných mikrokrystalických celulos o různé velikosti částic

    OpenAIRE

    Nováková, Petra

    2007-01-01

    In the work is studied mechanical strength and disintegration time of tablets prepared by direct compression of the two form silicified microcrystalline celluloses - Prosolv SMCC 50 and Prosolv SMCC 90 according to the compression force (3; 3,5; 4kN), addition of lubricants (magnesium stearate, Pruv) and addition of model active substances (acetylsalicylic acid, ascorbic acid). Studied co-processed filler-binders differ by the size of elements. Used concentration of lubricants was 0,5 %, of m...

  12. Alloy Development, Processing and Characterization of Devitrified Titanium Base Microcrystalline Alloys.

    Science.gov (United States)

    1986-01-01

    1.5m wide by injecting the molten alloy onto a rotating copper ’. disk through the orifice at the bottom of the copper crucible under inert gas...icrocrystalline forms [10, 271. 7his technique adopts the combination of a water-cooled cold copper crucible with an arc heating scheme that uses non-consumable...are malted in the cold copper crucible and spun in an inert gas atmosphere. he ribbon produced has a uniform thickness of 20 to SOgm. 5’ -7 -. -F -i

  13. The corrosion performance of microcrystalline titanium-modified 316 stainless steel

    International Nuclear Information System (INIS)

    Saito, N.; Searson, P.C.; Latanision, R.M.

    1986-01-01

    The corrosion performance of rapidly solidified (RS), consolidated RS and conventionally processed titanium-modified nuclear grade 316 stainless steel was studied. As-solidified RS foils exhibited general corrosion behavior identical to that of the conventionally processed alloy, but inferior pitting resistance, due to the presence of dendritic microsegregation. The consolidated RS alloy exhibited inferior general and pitting corrosion performance due to the detrimental effect of the prior foil boundary formed during the consolidation process. The results of immersion tests in 6% FeC1 3 .6H 2 O solution showed that pit initiation occured primarily at the prior foil boundaries in the consolidated RS alloy. Studies of sensitization were inconclusive due to preferential attack on prior foil boundaries in the consolidated RS specimens which made the determination of the degree of sensitization difficult. (author)

  14. Effect of emulsifier type and concentration, aqueous phase volume and wax ratio on physical, material and mechanical properties of water in oil lipsticks.

    Science.gov (United States)

    Beri, A; Norton, J E; Norton, I T

    2013-12-01

    Water-in-oil emulsions in lipsticks could have the potential to improve moisturizing properties and deliver hydrophilic molecules to the lips. The aims of this work were (i) to investigate the effect of emulsifier type (polymer vs. monomer, and saturated vs. unsaturated chain) and concentration on droplet size and (ii) to investigate the effect of wax ratio (carnauba wax, microcrystalline wax, paraffin wax and performalene) and aqueous phase volume on material properties (Young's modulus, point of fracture, elastic modulus and viscous modulus). Emulsion formation was achieved using a high shear mixer. Results showed that the saturated nature of the emulsifier had very little effect on droplet size, neither did the use of an emulsifier with a larger head group (droplet size ~18-25 μm). Polyglycerol polyricinoleate (PGPR) resulted in emulsions with the smallest droplets (~3-5 μm), as expected from previous studies that show that it produces a thick elastic interface. The results also showed that both Young's modulus and point of fracture increase with increasing percentage of carnauba wax (following a power law dependency of 3), but decrease with increasing percentage of microcrystalline wax, suggesting that the carnauba wax is included in the overall wax network formed by the saturated components, whereas the microcrystalline wax forms irregular crystals that disrupt the overall wax crystal network. Young's modulus, elastic modulus and viscous modulus all decrease with increasing aqueous phase volume in the emulsions, although the slope of the decrease in elastic and viscous moduli is dependent on the addition of solid wax, as a result of strengthening the network. This work suggests the potential use for emulsions in lipstick applications, particularly when PGPR is used as an emulsifier, and with the addition of solid wax, as it increases network strength. © 2013 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

  15. Preparation of sustained release matrix pellets by melt agglomeration in the fluidized bed: influence of formulation variables and modelling of agglomerate growth.

    Science.gov (United States)

    Pauli-Bruns, Anette; Knop, Klaus; Lippold, Bernhard C

    2010-03-01

    The one-step preparation of sustained release matrix pellets, using a melting procedure in a fluidized bed apparatus, was tested in a 2(3) full factorial design of experiments, using microcrystalline wax as lipophilic binder, theophylline as model drug and talc as additional matrix forming agent. The three influence parameters were (A) size of binder particles, (B) fraction of theophylline in solid particles and (C) fraction of microcrystalline wax in formulation. The response variables were agglomerate size and size distribution, dissolution time, agglomerate crush resistance, sphericity, yield and porosity. Nearly spherical pellets comprising a smooth, closed surface could be obtained with the used method, exhibiting the hollow core typical for the immersion and layering mechanism. The reproducibility was very good concerning all responses. The size of agglomerates is proportional to the size of the binder particles, which serve as cores for pellet formation in the molten state in the fluidized bed. Additionally, the agglomerate size is influenced by the volume of the solid particles in relation to the binder particles, with more solid particles leading to larger agglomerates and vice versa. Dissolution times vary in a very wide range, resulting from the interplay between amount of drug in relation to the meltable matrix substance microcrystalline wax and the non-meltable matrix substance talc. The change of binder particle size does not lead to a structural change of the matrix; both dissolution times and porosity are not significantly altered. Agglomerate crush resistance is low due to the hollow core of the pellets. However, it is significantly increased if the volume fraction of microcrystalline wax in the matrix is high, which means that the matrix is mechanically better stabilized. A theoretical model has been established to quantitatively explain agglomerate growth and very good accordance of the full particle size distributions between predicted and

  16. The preparation by extrusion/spheronization and the properties of pellets containing drugs, microcrystalline cellulose and glyceryl monostearate.

    Science.gov (United States)

    Chatchawalsaisin, Jittima; Podczeck, Fridrun; Newton, J Michael

    2005-01-01

    Pellets have been prepared by extrusion and spheronization containing microcrystalline cellulose (MCC) and four model drugs with decreasing order of solubility, paracetamol (P), diclofenac sodium (D), ibuprofen (IB) and indomethacin (IN) at a 10% level with and without the addition of a range of levels of glyceryl monostearate (GMS). The drugs differed in their response to extrusion in that all formulations containing the drug D had a 'steady state' extrusion profile whereas the other three drugs exhibited 'forced flow' indicating the possibility of water migration during the process of ram extrusion. The presence of GMS did not influence this effect. The drug D also required consistently less water to function than the other three drugs. In spite of these differences in extrusion performance, it was possible to prepare satisfactory pellets from formulations of all the drugs with 0, 30 and 60% GMS combined with 90, 60 or 30% of MCC at a range of water levels. It was also possible to prepare pellets containing the drug D with 70, 80 and 90% GMS, with corresponding quantities of 20, 10 and 0% of MCC. It was also possible to prepare the pellet formulations by dispersing the drugs in molten GMS, grinding and processing this with MCC and water. Such systems retained the processing characteristics of the composition made by the blending of the powder. The presence of GMS in all cases reduced the quantity of water required for the process to function. The steady state or the mean of the range of the forces observed during forced flow, were dependent on the composition and the quantity of water added. The surface of the extrudate appeared smooth and measurements of surface roughness established that the value of the rugosity R(a) for any of the extrudates did not exceed 6 microm. The extrudate diameter was found to increase with the quantity of GMS in the formulation. The pellets produced were all within a relatively narrow size range (three sieve fractions of a root two

  17. Densified waste form and method for forming

    Science.gov (United States)

    Garino, Terry J.; Nenoff, Tina M.; Sava Gallis, Dorina Florentina

    2015-08-25

    Materials and methods of making densified waste forms for temperature sensitive waste material, such as nuclear waste, formed with low temperature processing using metallic powder that forms the matrix that encapsulates the temperature sensitive waste material. The densified waste form includes a temperature sensitive waste material in a physically densified matrix, the matrix is a compacted metallic powder. The method for forming the densified waste form includes mixing a metallic powder and a temperature sensitive waste material to form a waste form precursor. The waste form precursor is compacted with sufficient pressure to densify the waste precursor and encapsulate the temperature sensitive waste material in a physically densified matrix.

  18. Engineering-scale tests of in situ vitrification to PCB and radioactive contaminated soils

    International Nuclear Information System (INIS)

    Liikala, S.C.

    1991-01-01

    In Situ Vitrification (ISV) is a thermal treatment technology applicable to the remediation of hazardous chemical and radioactive contaminated soil and sludge sites. The ISV process utilizes electricity, through joule heating, to melt contaminated soil and form an inert glass and microcrystalline residual product. Applications of ISV to polychlorinated biphenyls (PCBs) and radionuclides have been demonstrated at engineering-scale in numerous tests (1,2,3). An updated evaluation of ISV applicability to treatment of PCBs and radionuclides, and recent test results are presented herein

  19. Extraction of cellulose microcrystalline from galam wood for biopolymer

    Science.gov (United States)

    Ismail, Ika; Sa'adiyah, Devy; Rahajeng, Putri; Suprayitno, Abdi; Andiana, Rocky

    2018-04-01

    Consumption of plastic raw materials tends to increase, but until now the meet of the consumption of plastic raw are still low, even some are still imported. Nowadays, Indonesia's plastic needs are supported by petrochemicals where raw materials are still dependent abroad and petropolymer raw materials are derived from petroleum which will soon be depleted due to rising petroleum needs. Therefore, various studies have been conducted to develop natural fiber-based polymers that are biodegradable and abundant in nature. It is because the natural polymer production process is very efficient and very environmentally friendly. There have been many studies of biopolymers especially natural fiber-based polymers from plants, due to plants containing cellulose, hemicellulose and lignin. However, cellulose is the only one who has crystalline structures. Cellulose has a high crystality compared to amorphous lignin and hemicellulose. In this study, extracted cellulose as biopolymer and amplifier on composite. The cellulose is extracted from galam wood from East Kalimantan. Cellulose extraction will be obtained in nano / micro form through chemical and mechanical treatment processes. The chemical treatment of cellulose extraction is alkalinization process using NaOH solution, bleaching using NaClO2 and acid hydrolysis using sulfuric acid. After chemical treatment, ultrasonic mechanical treatment is made to make cellulose fibers into micro or nano size. Besides, cellulose results will be characterized. Characterization was performed to analyze molecules of cellulose compounds extracted from plants using Fourier Transformation Infra Red (FTIR) testing. XRD testing to analyze cellulose crystallinity. Scanning Electron Microscope (SEM) test to analyze morphology and fiber size.

  20. Evaluation of the binding effect of human serum albumin on the properties of granules.

    Science.gov (United States)

    Kristó, Katalin; Bajdik, János; Eros, István; Pintye-Hódi, Klára

    2008-11-01

    The main objective of this study was the application of a solution of human serum albumin as a granulating fluid. The properties of the granules formed were evaluated and compared with those when a conventional binder was applied in the same concentration. The powder mixture contained a soluble (mannitol) and an insoluble component (different types of cellulose). The protein solution applied exerted an appropriate aggregating effect if the system contained microcrystalline celluloses. Powdered cellulose was not suitable for the granulation with human serum albumin solution. As compared with the same concentration of the conventionally applied cellulose ethers as binder, the prepared granules exhibited a larger particle size, a significantly better compressibility, a higher breaking hardness and a favourable deformation process. These findings mainly reflect the good adhesive properties of the protein. The best compressibility and mechanical behaviour were attained on the application of the microcrystalline cellulose Vivapur type 105. This favourable behaviour may be connected with the wettability of cellulose. These results suggest that the formulation of tablets may be easier from an active agent in the serum that binds to albumin (e.g. interferon) since the amount of additives (binder) can be reduced.

  1. Harmonic Maass forms and mock modular forms

    CERN Document Server

    Bringmann, Kathrin; Ono, Ken

    2017-01-01

    Modular forms and Jacobi forms play a central role in many areas of mathematics. Over the last 10-15 years, this theory has been extended to certain non-holomorphic functions, the so-called "harmonic Maass forms". The first glimpses of this theory appeared in Ramanujan's enigmatic last letter to G. H. Hardy written from his deathbed. Ramanujan discovered functions he called "mock theta functions" which over eighty years later were recognized as pieces of harmonic Maass forms. This book contains the essential features of the theory of harmonic Maass forms and mock modular forms, together with a wide variety of applications to algebraic number theory, combinatorics, elliptic curves, mathematical physics, quantum modular forms, and representation theory.

  2. Plasticized Biodegradable Poly(lactic acid) Based Composites Containing Cellulose in Micro- and Nanosize

    OpenAIRE

    Halász, Katalin; Csóka, Levente

    2013-01-01

    The aim of this work was to study the characteristics of thermal processed poly(lactic acid) composites. Poly(ethylene glycol) (PEG400), microcrystalline cellulose (MCC), and ultrasound-treated microcrystalline cellulose (USMCC) were used in 1, 3, and 5 weight percents to modify the attributes of PLA matrix. The composite films were produced by twin screw extrusion followed by film extrusion. The manufactured PLA-based films were characterized by tensile testing, differential scanning calorim...

  3. Solid-to-solid oxidation of a vanadium(IV) to a vanadium(V) compound: chemisty of a sulfur-containing siderophore.

    Science.gov (United States)

    Chatterjee, Pabitra B; Crans, Debbie C

    2012-09-03

    Visible light facilitates a solid-to-solid photochemical aerobic oxidation of a hunter-green microcrystalline oxidovanadium(IV) compound (1) to form a black powder of cis-dioxidovanadium(V) (2) at ambient temperature. The siderophore ligand pyridine-2,6-bis(thiocarboxylic acid), H(2)L, is secreted by a microorganism from the Pseudomonas genus. This irreversible transformation of a metal monooxo to a metal dioxo complex in the solid state in the absence of solvent is unprecedented. It serves as a proof-of-concept reaction for green chemistry occurring in solid matrixes.

  4. Petrography and Diagenesis of Palaeocene -Eocene Sandstones in the Siri Canyon, Danish North Sea

    DEFF Research Database (Denmark)

    Kazerouni, Afsoon Moatari

    cemented in two major phases - an early opal/microquartz phase and a late stage massive cementation by macroquartz.  This study explores the potential sources of SiO2 in the shale, and the timing of their active phases.   The main diagenetic phases recorded are smectite, heulandite, opal...... components results in successive stages of silica-release.  In shallow samples the alteration of volcanic ash has already been completed.  Released silica was partly consumed for the precipitation of smectite and heulandite.   In addition, a major part of the biogenic silica has been transformed into opal......-CT and partly to microcrystalline quartz.  The microcrystalline quartz is an internal sink for dissolved silica, but the shale may have been an active silica exporter during this transition.   With deeper depth of burial, opal-CT is fully transformed to microcrystalline quartz.  During this phase, silica has...

  5. Nanostructure characterization of high k materials by spectroscopic ellipsometry

    International Nuclear Information System (INIS)

    Pereira, L.; Aguas, H.; Fortunato, E.; Martins, R.

    2006-01-01

    In this work, the optical and structural properties of high k materials such as tantalum oxide and titanium oxide were studied by spectroscopic ellipsometry, where a Tauc-Lorentz dispersion model based in one (amorphous films) or two oscillators (microcrystalline films) was used. The samples were deposited at room temperature by radio frequency magnetron sputtering and then annealed at temperatures from 100 to 500 deg. C. Concerning the tantalum oxide films, the increase of the annealing temperature, up to 500 deg. C does not change the amorphous nature of the films, increasing, however, their density. The same does not happen with the titanium oxide films that are microcrystalline, even when deposited at room temperature. Data concerning the use of a four-layer model based on one and two Tauc-Lorentz dispersions is also discussed, emphasizing its use for the detection of an amorphous incubation layer, normally present on microcrystalline films grown by sputtering

  6. Influence of Excipients and Spray Drying on the Physical and Chemical Properties of Nutraceutical Capsules Containing Phytochemicals from Black Bean Extract.

    Science.gov (United States)

    Guajardo-Flores, Daniel; Rempel, Curtis; Gutiérrez-Uribe, Janet A; Serna-Saldívar, Sergio O

    2015-12-03

    Black beans (Phaseolus vulgaris L.) are a rich source of flavonoids and saponins with proven health benefits. Spray dried black bean extract powders were used in different formulations for the production of nutraceutical capsules with reduced batch-to-batch weight variability. Factorial designs were used to find an adequate maltodextrin-extract ratio for the spray-drying process to produce black bean extract powders. Several flowability properties were used to determine composite flow index of produced powders. Powder containing 6% maltodextrin had the highest yield (78.6%) and the best recovery of flavonoids and saponins (>56% and >73%, respectively). The new complexes formed by the interaction of black bean powder with maltodextrin, microcrystalline cellulose 50 and starch exhibited not only bigger particles, but also a rougher structure than using only maltodextrin and starch as excipients. A drying process prior to capsule production improved powder flowability, increasing capsule weight and reducing variability. The formulation containing 25.0% of maltodextrin, 24.1% of microcrystalline cellulose 50, 50% of starch and 0.9% of magnesium stearate produced capsules with less than 2.5% weight variability. The spray drying technique is a feasible technique to produce good flow extract powders containing valuable phytochemicals and low cost excipients to reduce the end-product variability.

  7. Silicon Thin-Film Solar Cells

    Directory of Open Access Journals (Sweden)

    Guy Beaucarne

    2007-01-01

    with plasma-enhanced chemical vapor deposition (PECVD. In spite of the fundamental limitation of this material due to its disorder and metastability, the technology is now gaining industrial momentum thanks to the entry of equipment manufacturers with experience with large-area PECVD. Microcrystalline Si (also called nanocrystalline Si is a material with crystallites in the nanometer range in an amorphous matrix, and which contains less defects than amorphous silicon. Its lower bandgap makes it particularly appropriate as active material for the bottom cell in tandem and triple junction devices. The combination of an amorphous silicon top cell and a microcrystalline bottom cell has yielded promising results, but much work is needed to implement it on large-area and to limit light-induced degradation. Finally thin-film polysilicon solar cells, with grain size in the micrometer range, has recently emerged as an alternative photovoltaic technology. The layers have a grain size ranging from 1 μm to several tens of microns, and are formed at a temperature ranging from 600 to more than 1000∘C. Solid Phase Crystallization has yielded the best results so far but there has recently been fast progress with seed layer approaches, particularly those using the aluminum-induced crystallization technique.

  8. Direct activation of microcrystalline zeolites

    NARCIS (Netherlands)

    Ortiz-Iniesta, Maria Jesus; Heeres, Hero Jan; Melian-Cabrera, Ignacio

    2013-01-01

    In this work a direct activation route of zeolites is assessed. It consists of NH4-exchanging the as-synthesized solids before removing the organic template. Calcination afterwards serves to combust the organic template and creates the Bronsted sites directly; thus applying merely a single thermal

  9. Analytical electron microscopy of Mg-SiO smokes - A comparison with infrared and XRD studies

    Science.gov (United States)

    Rietmeijer, F. J. M.; Nuth, J. A.; Mackinnon, I. D. R.

    1986-01-01

    Analytical electron microscopy conducted for Mg-SiO smokes (experimentally obtained from samples previously characterized by IR spectroscopy) indicates that the microcrystallinity content of unannealed smokes increases with increased annealing for up to 30 hr. The growth of forsterite microcrystallites in the initially nonstoichiometric smokes may give rise to the contemporaneous growth of the SiO polymorph tridymite and MgO; after 4 hr of annealing, these react to form enstatite. It is suggested that XRD analysis and IR spectroscopy should be conducted in conjunction with detailed analytical electron microscopy for the detection of emerging crystallinity in vapor-phase condensates.

  10. Competitive binding thyroid assay with improved bound-free separation step

    International Nuclear Information System (INIS)

    1979-01-01

    A competitive binding assay is described for serum thyroid hormone using 125 I-labelled thyroid hormone and exogenous thyroid hormone binding protein. The unbound thyroid hormone is separated from thyroid hormone bound to thyroid hormone binding protein using an intermediate base anion exchange resin. This resin comprises tertiary and quaternary amine groups on a polyalkyleneamine lattice and is compressed with microcrystalline cellulose in a tablet form. The assay technique of the present invention employing an intermediate base anion resin was found to give superior results compared with alternative assay techniques used in serum thyroid hormone estimation. (UK)

  11. Improving the forming capability of laser dynamic forming by using rubber as a forming medium

    Science.gov (United States)

    Shen, Zongbao; Liu, Huixia; Wang, Xiao; Wang, Cuntang

    2016-04-01

    Laser dynamic forming (LDF) is a novel high velocity forming technique, which employs laser-generated shock wave to load the sample. The forming velocity induced by the high energy laser pulse may exceed the critical forming velocity, resulting in the occurrence of premature fracture. To avoid the above premature fracture, rubber is introduced in LDF as a forming medium to prolong the loading duration in this paper. Laser induced shock wave energy is transferred to the sample in different forming stages, so the forming velocity can be kept below the critical forming velocity when the initial laser energy is high for fracture. Bulge forming experiments with and without rubber were performed to study the effect of rubber on loading duration. The experimental results show that, the shock wave energy attenuates during the propagation through the rubber layer, the rubber can avoid the premature fracture. So the plastic deformation can continue, the forming capability of LDF is improved. Due to the severe plastic deformation under rubber compression, adiabatic shear bands (ASB) occur in LDF with rubber. The material softening in ASB leads to the irregular fracture, which is different from the premature fracture pattern (regular fracture) in LDF without rubber. To better understand this deformation behavior, Johnson-Cook model is used to simulate the dynamic response and the evolution of ASB of copper sample. The simulation results also indicate the rubber can prolong the loading duration.

  12. Plasticized Biodegradable Poly(lactic acid Based Composites Containing Cellulose in Micro- and Nanosize

    Directory of Open Access Journals (Sweden)

    Katalin Halász

    2013-01-01

    Full Text Available The aim of this work was to study the characteristics of thermal processed poly(lactic acid composites. Poly(ethylene glycol (PEG400, microcrystalline cellulose (MCC, and ultrasound-treated microcrystalline cellulose (USMCC were used in 1, 3, and 5 weight percents to modify the attributes of PLA matrix. The composite films were produced by twin screw extrusion followed by film extrusion. The manufactured PLA-based films were characterized by tensile testing, differential scanning calorimetry (DSC, scanning electron microscopy (SEM, wide angle X-ray diffraction (WAXD, and degradation test.

  13. 75 FR 51093 - Agency Information Collection Activities: Form I-864, Form I-864A, Form I-864EZ, and Form I-864W...

    Science.gov (United States)

    2010-08-18

    ... DEPARTMENT OF HOMELAND SECURITY U.S. Citizenship and Immigration Services Agency Information... of Homeland Security, U.S. Citizenship and Immigration Services (USCIS) will be submitting the...: Form I-864, Form I-864A, Form I-864EZ, and Form I-864W; U.S. Citizenship and Immigration Services...

  14. The formation of microorganism communities in the soil under the effect of chitosan and runner bean (Phaseolus coccineus L. cultivation

    Directory of Open Access Journals (Sweden)

    Danuta Pięta

    2013-12-01

    Full Text Available The subject of the studies was the soil with introduced solutions containing 0,1% chitosan. These materials were obtained from the Institute of Chemical Fibres in L6d2 (in the form of a microcrystalline gel and also from the Department of Food Biochemistry and Chemistry of the University of Agriculture in Lublin (in a liquid form,i.e.dissolved in acetic acid. In order to set an experiment in a growth chamber, grey brown podzolic soil formed from loesses and taken from a mechanically treated belt of black fallow was used. The soil (1000 g was watered every 8 days with 100 ml of examined chitosan solutions per pot. Control soil was watered with sterile distilled water. Seven days after each watering, soil samples were taken for microbiological analysis. Then 25 runner bean seeds were sown into each pot. After six weeks of plants' growth the experiment was finished and the number of plants was counted, their healthiness determined and soil microbiological analysis was performed. Regardless of chitosan form introduced to the soil it stimulated the growth of bacteria and fungi, since in these experimental combinations was found a significantly higher number of microorganisms as compared with the control. A particular high increase in the number of microorganism colonies was observed with simultaneous growth of plants and the application of chitosan. A considerable increase of fungi colonies from the Trichoderma genus was found in the soil treated with chitosan in the form ofboth a microcrystalline gel and a liquid. The species of this genus are considered to be antagonists; it affects pathogenic fungi through competition, antibiosis and over-parasitism. An increase in colonies of saprophytic microorganisms, including antagonistic ones of Bacillus spp. and Pseudomonas spp. was observed in the soil treated with chitosan . On the other hand, in the soil after the growth of bean and treated watered with chitosan only few colonies of Fusarium oxysporum f

  15. Advances in metal forming expert system for metal forming

    CERN Document Server

    Hingole, Rahulkumar Shivajirao

    2015-01-01

    This comprehensive book offers a clear account of the theory and applications of advanced metal forming. It provides a detailed discussion of specific forming processes, such as deep drawing, rolling, bending extrusion and stamping. The author highlights recent developments of metal forming technologies and explains sound, new and powerful expert system techniques for solving advanced engineering problems in metal forming. In addition, the basics of expert systems, their importance and applications to metal forming processes, computer-aided analysis of metalworking processes, formability analysis, mathematical modeling and case studies of individual processes are presented.

  16. Cat-CVD-prepared oxygen-rich μc-Si:H for wide-bandgap material

    International Nuclear Information System (INIS)

    Matsumoto, Yasuhiro; Ortega, Mauricio; Peza, Juan-Manuel; Reyes, Mario-Alfredo; Escobosa, Arturo

    2005-01-01

    Microcrystalline phase-involved oxygen-rich a-Si:H (hydrogenated amorphous silicon) films have been obtained using catalytic chemical vapor deposition (Cat-CVD) process. Pure SiH 4 (silane), H 2 (hydrogen), and O 2 (oxygen) gases were introduced in the chamber by maintaining a pressure of 0.1 Torr. A tungsten catalyzer was fixed at temperatures of 1750 and 1950 deg. C for film deposition on glass and crystalline silicon substrates at 200 deg. C. As revealed from X-ray diffraction spectra, the microcrystalline phase appears for oxygen-rich a-Si:H samples deposited at a catalyzer temperature of 1950 deg. C. However, this microcrystalline phase tends to disappear for further oxygen incorporation. The oxygen content in the deposited films was corroborated by FTIR analysis revealing Si-O-Si bonds and typical Si-H bonding structures. The optical bandgap of the sample increases from 2.0 to 2.7 eV with oxygen gas flow and oxygen incorporation to the deposited films. In the present thin film deposition conditions, no strong tungsten filament degradation was observed after a number of sample preparations

  17. (EOI) Form

    International Development Research Centre (IDRC) Digital Library (Canada)

    Dorine Odongo

    COLLABORATING TECHNICAL AGENCIES: EXPRESSION OF INTEREST FORM. • Please read the information provided about the initiative and the eligibility requirements in the Prospectus before completing this application form. • Ensure all the sections of the form are accurately completed and saved in PDF format.

  18. Modular forms

    NARCIS (Netherlands)

    Edixhoven, B.; van der Geer, G.; Moonen, B.; Edixhoven, B.; van der Geer, G.; Moonen, B.

    2008-01-01

    Modular forms are functions with an enormous amount of symmetry that play a central role in number theory, connecting it with analysis and geometry. They have played a prominent role in mathematics since the 19th century and their study continues to flourish today. Modular forms formed the

  19. Thermoluminescence of the Z centre in Mg-doped KCl

    International Nuclear Information System (INIS)

    Kamavisdar, V.S.; Deshmukh, B.T.

    1980-01-01

    Optical absorption and thermoluminescence measurements on KCl:Mg 2+ are reported. Bleaching in F band introduces a new glow peak at 406 K in the glow curves. A similar peak is observed in microcrystalline powders. When this peak is thermally cleaned, the broadening of the absorption observed in prolonged F bleached crystals is removed. On the basis of these observations, the glow peak at 406 K is tentatively attributed to Z 1 centres. The glow peak at 394 K observed in microcrystalline powders is attributed to a combined effect of deformation and Z 1 centres. (author)

  20. Optical modelling of thin-film silicon solar cells deposited on textured substrates

    International Nuclear Information System (INIS)

    Krc, J.; Zeman, M.; Smole, F.; Topic, M.

    2004-01-01

    Optical modelling is used to investigate effects of light scattering in amorphous silicon and microcrystalline silicon solar cells. The role of enhanced haze parameter and different angular distribution function of scattered light is analyzed. Results of optical simulation show that enhanced haze parameter compared to that of Asahi U-type SnO 2 :F does not improve external quantum efficiency and short-circuit current density of amorphous silicon solar cell significantly, whereas for microcrystalline silicon solar cell the improvement is larger. Angular distribution function affects the external quantum efficiency and the short-circuit current density significantly

  1. Effect of the conditions of preparation on the properties of a cellulose exchanger containing salicylic acid as a functional group

    Energy Technology Data Exchange (ETDEWEB)

    Lieser, K H; Foerster, M; Burba, P [Technische Hochschule Darmstadt (Germany, F.R.). Fachbereich Anorganische Chemie und Kernchemie

    1977-04-01

    The preparation of a cellulose derivative containing salicylic acid as functional group was varied in order to find optimal conditions with respect to fast exchange as well as high capacity. Two kinds of cellulose (cross-linked and microcrystalline) and different reaction times were used. The properties of the products were investigated by titration curves to determine the capacity and by measuring the non-isotopic exchange Na/sup +//*Fe/sup 3 +/ and the isotopic exchange *Fe/sup 3 +//Fe/sup 3 +/ as a function of time. Microcrystalline cellulose and a reaction time of 15 min gave optimal results.

  2. Dependence of critical current density on crystalline direction in thin YBCO films

    DEFF Research Database (Denmark)

    Paturi, P.; Peurla, M.; Raittila, J.

    2005-01-01

    The dependence of critical current density (J(c)) on the angle between the current direction and the (100) direction in the ab-plane of thin YBCO films deposited on (001)-SrTiO3 from natiocrystalline and microcrystalline targets is studied using magneto-optical microscopy. In the films made from...... the nanocrystalline target it is found that J(c) does not depend on the angle whereas J(c) decreases with increasing angle in the films made from the microcrystalline target. The films were characterized by detailed X-ray diffraction measurements. The findings are explained in terms of a network of planar defects...

  3. Influence of current density on surface morphology and properties of pulse plated tin films from citrate electrolyte

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, Ashutosh; Bhattacharya, Sumit; Das, Siddhartha; Das, Karabi, E-mail: karabi@metal.iitkgp.ernet.in

    2014-01-30

    Bulk polycrystalline tin films have been processed by pulse electrodeposition technique from a simple solution containing triammonium citrate and stannous chloride. The cathodic investigations have been carried out by galvanostatic methods. As deposited samples are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). XRD analysis of the deposited films shows microcrystalline grains having β-Sn form. The surface morphology is very rough at lower current density, but becomes smooth at higher current density, and exhibits pyramid type morphology at all the current densities. The effect of current density on microhardness, melting behavior, and electrical resistivity are also reported here.

  4. Efficient MgO-based mesoporous CO2 trapper and its performance at high temperature.

    Science.gov (United States)

    Han, Kun Kun; Zhou, Yu; Chun, Yuan; Zhu, Jian Hua

    2012-02-15

    A novel MgO-based porous adsorbent has been synthesized in a facile co-precipitation method for the first time, in order to provide a candidate for trapping CO(2) in flue gas at high temperature. The resulting composite exhibits a mesoporous structure with a wide pore size distribution, due to the even dispersion and distribution of microcrystalline MgO in the framework of alumina to form a concrete-like structure. These sorbents can capture CO(2) at high temperature (150-400°C), possessing high reactivity and stability in cyclic adsorption-desorption processes, providing competitive candidates to control CO(2) emission. Copyright © 2011 Elsevier B.V. All rights reserved.

  5. New thermophilic anaerobes that decompose crystalline cellulose

    Energy Technology Data Exchange (ETDEWEB)

    Taya, M; Hinoki, H; Suzuki, Y; Yagi, T; Yap, M G.S.; Kobayashi, T

    1985-01-01

    Two strains (designated as 25A and 3B) of cellulolytic, thermophilic, anaerobic, spore-forming bacteria were newly isolated from an alkaline hot spring through enrichment cultures at 60/sup 0/C. Though strain 25A was nearly identical to Clostridium thermocellum ATCC 27405 as a reference strain, strain 3B had some characteristics different from the reference; no flagellation, alkalophilic growth property (optimum pH of 7.5-8) and orange-colored pigmentation of the cell mass. Strain 3B effectively decomposed micro-crystalline cellulose (Avicel) and raw cellulosics (rice straw, newspaper, and bagasse) without physical or chemical pretreatments. 20 references, 2 figures, 2 tables.

  6. {sup 10}Be in rhodochrosite nodules from Neogene sediments along the Galapagos Ridge, equatorial Pacific

    Energy Technology Data Exchange (ETDEWEB)

    Aldahan, A., E-mail: ala.aldahan@geo.uu.s [Department of Earth Sciences, Uppsala University, Uppsala (Sweden); Department of Geology, United Arab Emirates University, Al Ain (United Arab Emirates); Morad, S. [Department of Earth Sciences, Uppsala University, Uppsala (Sweden); Department of Petroleum Geosciences, Petroleum Institute, Abu Dhabi (United Arab Emirates); Possnert, G. [Tandem Laboratory, Uppsala University, Uppsala (Sweden); Sturesson, U. [Department of Earth Sciences, Uppsala University, Uppsala (Sweden); ElSaiy, A. [Department of Geology, United Arab Emirates University, Al Ain (United Arab Emirates)

    2010-04-15

    Microcrystalline, calcian rhodochrosite occurs as nodules around burrows in late Neogene pelagic sediments from the Galapagos Ridge in the Guatemala Basin, eastern equatorial Pacific (DSDP Leg 68; Site 503). {sup 10}Be isotope revealed that the rhodochrosite nodules have formed under growth conditions much faster than those reported for Fe-Mn nodules. The overall REE patterns of the nodules and host pelagic sediments indicate element derivation mainly from marine pore water. However, variations in the shale normalised Eu values suggest influx of hydrothermal fluids into mounds area at Galapagos, which is also evidenced by the similar minor and major element contents in the nodules and host sediments.

  7. 10Be in rhodochrosite nodules from Neogene sediments along the Galapagos Ridge, equatorial Pacific

    International Nuclear Information System (INIS)

    Aldahan, A.; Morad, S.; Possnert, G.; Sturesson, U.; ElSaiy, A.

    2010-01-01

    Microcrystalline, calcian rhodochrosite occurs as nodules around burrows in late Neogene pelagic sediments from the Galapagos Ridge in the Guatemala Basin, eastern equatorial Pacific (DSDP Leg 68; Site 503). 10 Be isotope revealed that the rhodochrosite nodules have formed under growth conditions much faster than those reported for Fe-Mn nodules. The overall REE patterns of the nodules and host pelagic sediments indicate element derivation mainly from marine pore water. However, variations in the shale normalised Eu values suggest influx of hydrothermal fluids into mounds area at Galapagos, which is also evidenced by the similar minor and major element contents in the nodules and host sediments.

  8. Against Logical Form

    Directory of Open Access Journals (Sweden)

    P N Johnson-Laird

    2010-10-01

    Full Text Available An old view in logic going back to Aristotle is that an inference is valid in virtue of its logical form. Many psychologists have adopted the same point of view about human reasoning: the first step is to recover the logical form of an inference, and the second step is to apply rules of inference that match these forms in order to prove that the conclusion follows from the premises. The present paper argues against this idea. The logical form of an inference transcends the grammatical forms of the sentences used to express it, because logical form also depends on context. Context is not readily expressed in additional premises. And the recovery of logical form leads ineluctably to the need for infinitely many axioms to capture the logical properties of relations. An alternative theory is that reasoning depends on mental models, and this theory obviates the need to recover logical form.

  9. Forming processes and mechanics of sheet metal forming

    NARCIS (Netherlands)

    Burchitz, I.A.

    2004-01-01

    The report is dealing with the numerical analysis of forming processes. Forming processes is the large group of manufacturing processes used to obtain various product shapes by means of plastic deformations. The report is organized as follows. An overview of the deformation processes and the

  10. Pre-form ceramic matrix composite cavity and method of forming and method of forming a ceramic matrix composite component

    Science.gov (United States)

    Monaghan, Philip Harold; Delvaux, John McConnell; Taxacher, Glenn Curtis

    2015-06-09

    A pre-form CMC cavity and method of forming pre-form CMC cavity for a ceramic matrix component includes providing a mandrel, applying a base ply to the mandrel, laying-up at least one CMC ply on the base ply, removing the mandrel, and densifying the base ply and the at least one CMC ply. The remaining densified base ply and at least one CMC ply form a ceramic matrix component having a desired geometry and a cavity formed therein. Also provided is a method of forming a CMC component.

  11. Simulation of High Efficiency Heterojunction Solar Cells with AFORS-HET

    International Nuclear Information System (INIS)

    Wang Lisheng; Chen Fengxiang; Ai Yu

    2011-01-01

    In this paper, the high efficiency TCO/a-Si:H (n)/a-Si:H(i)/c-Si(p)/uc-Si(p + )/Al HIT (heterojunction with intrinsic thin-layer) solar cells was analyzed and designed by AFORS-HET software. The influences of emitter, intrinsic layer and back surface field (BSF) on the photovoltaic characteristics of solar cell were discussed. The simulation results show that the key role of the intrinsic layer inserted between the a-Si:H and crystalline silicon substrate is to decrease the interface states density. If the interface states density is lower than 10 10 cm -2 V -1 thinner intrinsic layer is better than thicker one. The increase of the thickness of the emitter will decrease the short-current density and affect the conversion efficiency. Microcrystalline BSF can increase conversion efficiency more than 2 percentage points compared with HIT solar cell with no BSF. But this BSF requires the doping concentration must exceed 10 20 cm -3 . Considered the band mismatch between crystalline silicon and microcrystalline silicon, the optimal band gap of microcrystalline silicon BSF is about 1.4-1.6eV.

  12. Analysis of structure and defects in thin silicon films deposited from hydrogen diluted silane

    International Nuclear Information System (INIS)

    Elzakker, G. van; Nadazdy, V.; Tichelaar, F.D.; Metselaar, J.W.; Zeman, M.

    2006-01-01

    Thin silicon layers have been deposited from silane diluted with hydrogen. The dilution ratio R (R = [H 2 ]/[SiH 4 ]) has been varied between R = 0 and R = 40. The structural properties of Si:H films have been studied using transmission electron microscopy imaging and Raman spectroscopy. The phase evolution from the amorphous phase into the mixed and eventually microcrystalline phase strongly depends on the hydrogen dilution. The initiation of the microcrystalline growth occurs between R = 20 and R = 25. The phase transition becomes more abrupt with increasing hydrogen dilution. Optoelectronic properties of the layers have been determined. Increasing hydrogen dilution results in films with increasing effective defect density and Urbach energy, which is related to inhomogeneous growth. The charge deep-level transient spectroscopy technique (Q-DLTS) was applied for the first time on hydrogen diluted thin silicon films in order to investigate the energy distribution of the defect states in these layers as a function of the dilution ratio R. The Q-DLTS spectra indicate a difference in defect-state distribution when the films evolve from the amorphous phase into the microcrystalline phase

  13. Preparation, Characterization, and Cationic Functionalization of Cellulose-Based Aerogels for Wastewater Clarification

    Directory of Open Access Journals (Sweden)

    Yang Hu

    2016-01-01

    Full Text Available Aerogels are a series of materials with porous structure and light weight which can be applied to many industrial divisions as insulators, sensors, absorbents, and cushions. In this study, cellulose-based aerogels (aerocelluloses were prepared from cellulosic material (microcrystalline cellulose in sodium hydroxide/water solvent system followed by supercritical drying operation. The average specific surface area of aerocelluloses was 124 m2/g. The nitrogen gas (N2 adsorption/desorption isotherms revealed type H1 hysteresis loops for aerocelluloses, suggesting that aerocelluloses may possess a porous structure with cylindrically shaped pores open on both ends. FTIR and XRD analyses showed that the crystallinity of aerocelluloses was significantly decreased as compared to microcrystalline cellulose and that aerocelluloses exhibited a crystalline structure of cellulose II as compared to microcrystalline cellulose (cellulose I. To perform cationic functionalization, a cationic agent, (3-chloro-2-hydroxypropyl trimethylammonium chloride, was used to introduce positively charged sites on aerocelluloses. The cationized aerocelluloses exhibited a strong ability to remove anionic dyes from wastewater. Highly porous and low cost aerocelluloses prepared in this study would be also promising as a fast absorbent for environmental pollutants.

  14. On good ETOL forms

    DEFF Research Database (Denmark)

    Skyum, Sven

    1978-01-01

    This paper continues the study of ETOL forms and good EOL forms done by Maurer, Salomaa and Wood. It is proven that binary very complete ETOL forms exist, good synchronized ETOL forms exist and that no propagating or synchronized ETOL form can be very complete.......This paper continues the study of ETOL forms and good EOL forms done by Maurer, Salomaa and Wood. It is proven that binary very complete ETOL forms exist, good synchronized ETOL forms exist and that no propagating or synchronized ETOL form can be very complete....

  15. Designing usable web forms- Empirical evaluation of web form improvement guidelines

    DEFF Research Database (Denmark)

    Seckler, Mirjam; Heinz, Silvia; Bargas-Avila, Javier A.

    2014-01-01

    This study reports a controlled eye tracking experiment (N = 65) that shows the combined effectiveness of 20 guidelines to improve interactive online forms when applied to forms found on real company websites. Results indicate that improved web forms lead to faster completion times, fewer form...... submission trials, and fewer eye movements. Data from subjective questionnaires and interviews further show increased user satisfaction. Overall, our findings highlight the importance for web designers to improve their web forms using UX guidelines....

  16. Fabrication of Nanodiamond Coating on Steel

    Directory of Open Access Journals (Sweden)

    Rafael Velázquez

    2013-12-01

    Full Text Available The hardness, heat conductivity and low friction coefficient of microcrystalline diamond make it a suitable candidate for tribological applications. However, its roughness and high deposition temperature pose significant obstacles to these applications. We have successfully grown nanocrystalline diamond on steel at 400 °C by hot-filament chemical vapor deposition by employing a CrN interfacial layer. Nanocrystalline diamond combines hardness and surface smoothness required in tribological applications. Microcrystalline diamond and carbon nanotubes can also be grown by controlling the deposition parameters. The fabricated films were characterized with Raman spectroscopy, X-ray diffraction (XRD, Transmission electron microscopy (TEM, and scanning electron microscopy (SEM.

  17. Methods of forming semiconductor devices and devices formed using such methods

    Science.gov (United States)

    Fox, Robert V; Rodriguez, Rene G; Pak, Joshua

    2013-05-21

    Single source precursors are subjected to carbon dioxide to form particles of material. The carbon dioxide may be in a supercritical state. Single source precursors also may be subjected to supercritical fluids other than supercritical carbon dioxide to form particles of material. The methods may be used to form nanoparticles. In some embodiments, the methods are used to form chalcopyrite materials. Devices such as, for example, semiconductor devices may be fabricated that include such particles. Methods of forming semiconductor devices include subjecting single source precursors to carbon dioxide to form particles of semiconductor material, and establishing electrical contact between the particles and an electrode.

  18. Electroweak form factors

    International Nuclear Information System (INIS)

    Singh, S.K.

    2002-01-01

    The present status of electroweak nucleon form factors and the N - Δ transition form factors is reviewed. Particularly the determination of dipole mass M A in the axial vector form factor is discussed

  19. PowerForms

    DEFF Research Database (Denmark)

    Brabrand, Claus; Møller, Anders; Ricky, Mikkel

    2000-01-01

    All uses of HTML forms may benefit from validation of the specified input field values. Simple validation matches individual values against specified formats, while more advanced validation may involve interdependencies of form fields. There is currently no standard for specifying or implementing...

  20. Voice as Form of Life and Life Form

    Directory of Open Access Journals (Sweden)

    Sandra Laugier

    2015-10-01

    Full Text Available This paper studies the concept of form of life as central to ordinary language philosophy (as understood in Wittgenstein’s, Austin’s and Stanley Cavell’s work: philosophy of our language as spoken; pronounced by a human voice within a form of life. Such an approach to Wittgenstein’s later philosophy shifts the question of the common use of language – central to Wittgenstein’s Investigations – to the definition of the subject as voice, and to the reinvention of subjectivity in language. The voice is both a subjective and common expression: it is what makes it possible for my individual voice, or claim, to become shared and for our forms of life to be intertwined with a lifeform.

  1. 76 FR 21946 - Proposed Collection; Comment Request for Form 990-BL; Schedule A (Form 990-BL), Form 6069

    Science.gov (United States)

    2011-04-19

    ... Initial Excise Tax Return for Black Lung Benefit Trusts and Certain Related Persons, and Form 6069, Return of Excise Tax on Excess Contributions to Black Lung Benefit Trust Under Section 4953 and Computation...: Form 990-BL, Schedule A (Form 990-BL), Information and Initial Excise Tax Return for Black Lung Benefit...

  2. Crystalline islands of semiconductor films

    International Nuclear Information System (INIS)

    Zmievskaya, G. I.; Bondareva, A. L.

    2011-01-01

    Silicon carbide (SiC) nucleation in the form of powder in a discharge plasma and the formation of thin film islands on a Si(100) substrate in the course of gas-phase epitaxy are simulated numerically. Models of plasma-like media and nonequilibrium processes accompanying phase transitions of the first kind (such as condensation and crystallization) in the initial fast (fluctuation) stage are described. The nonstationary evolution of nuclei size distribution functions is modeled by solving kinetic equations in partial derivatives and stochastic Ito-Stratonovich analog equations. This makes it possible to refine the formation mechanisms of microcrystalline state polytypes and calculate the nucleation rate and the initial roughness of a SiC coating.

  3. Promotion of Crystal Growth on Biomass-based Carbon using Phosphoric Acid Treatments

    Directory of Open Access Journals (Sweden)

    Liwei Yu

    2015-02-01

    Full Text Available The effect of phosphoric acid treatments on graphitic microcrystal growth of biomass-based carbons was investigated using X-ray diffraction, infrared spectroscopy, and Raman spectroscopy. Although biomass-based carbons are believed to be hard to graphitize even after heat treatments well beyond 2000 °C, we found that graphitic microcrystals of biomass-based carbons were significantly promoted by phosphoric acid treatments above 800 °C. Moreover, twisted spindle-like whiskers were formed on the surface of the carbons. This suggests that phosphorus-containing groups turn graphitic microcrystalline domains into graphite during phosphoric acid treatments. In addition, the porous texture of the phosphoric acid-treated carbon has the advantage of micropore development.

  4. Micro metal forming

    CERN Document Server

    2013-01-01

    Micro Metal Forming, i. e. forming of parts and features with dimensions below 1 mm, is a young area of research in the wide field of metal forming technologies, expanding the limits for applying metal forming towards micro technology. The essential challenges arise from the reduced geometrical size and the increased lot size. In order to enable potential users to apply micro metal forming in production, information about the following topics are given: tribological behavior: friction between tool and work piece as well as tool wear mechanical behavior: strength and formability of the work piece material, durability of the work pieces size effects: basic description of effects occurring due to the fact, that the quantitative relation between different features changes with decreasing size process windows and limits for forming processes tool making methods numerical modeling of processes and process chains quality assurance and metrology All topics are discussed with respect to the questions relevant to micro...

  5. How does cellulosome composition influence deconstruction of lignocellulosic substrates in Clostridium (Ruminiclostridium) thermocellum DSM 1313?

    Science.gov (United States)

    Yoav, Shahar; Barak, Yoav; Shamshoum, Melina; Borovok, Ilya; Lamed, Raphael; Dassa, Bareket; Hadar, Yitzhak; Morag, Ely; Bayer, Edward A

    2017-01-01

    Bioethanol production processes involve enzymatic hydrolysis of pretreated lignocellulosic biomass into fermentable sugars. Due to the relatively high cost of enzyme production, the development of potent and cost-effective cellulolytic cocktails is critical for increasing the cost-effectiveness of bioethanol production. In this context, the multi-protein cellulolytic complex of Clostridium ( Ruminiclostridium ) thermocellum, the cellulosome, was studied here. C. thermocellum is known to assemble cellulosomes of various subunit (enzyme) compositions, in response to the available carbon source. In the current study, different carbon sources were used, and their influence on both cellulosomal composition and the resultant activity was investigated. Glucose, cellobiose, microcrystalline cellulose, alkaline-pretreated switchgrass, alkaline-pretreated corn stover, and dilute acid-pretreated corn stover were used as sole carbon sources in the growth media of C. thermocellum strain DSM 1313. The purified cellulosomes were compared for their activity on selected cellulosic substrates. Interestingly, cellulosomes derived from cells grown on lignocellulosic biomass showed no advantage in hydrolyzing the original carbon source used for their production. Instead, microcrystalline cellulose- and glucose-derived cellulosomes were equal or superior in their capacity to deconstruct lignocellulosic biomass. Mass spectrometry analysis revealed differential composition of catalytic and structural subunits (scaffoldins) in the different cellulosome samples. The most abundant catalytic subunits in all cellulosome types include Cel48S, Cel9K, Cel9Q, Cel9R, and Cel5G. Microcrystalline cellulose- and glucose-derived cellulosome samples showed higher endoglucanase-to-exoglucanase ratios and higher catalytic subunit-per-scaffoldin ratios compared to lignocellulose-derived cellulosome types. The results reported here highlight the finding that cellulosomes derived from cells grown on glucose

  6. Phase transitions of antibiotic clarithromycin forms I, IV and new form VII crystals.

    Science.gov (United States)

    Ito, Masataka; Shiba, Rika; Watanabe, Miteki; Iwao, Yasunori; Itai, Shigeru; Noguchi, Shuji

    2018-06-01

    Metastable crystal form I of the antibiotic clarithromycin has a pharmaceutically valuable characteristic that its crystalline phase transition can be applied for its sustained release from tablets. The phase transition of form I was investigated in detail by single crystal and powder X-ray analyses, dynamic vapor sorption analysis and thermal analysis. The single crystal structure of form I revealed that form I was not an anhydrate crystal but contained a partially occupied water molecule in the channel-like void space. Dynamic vapor sorption (DVS) analysis demonstrated that form I crystals reversibly sorbed water molecules in two steps when the relative humidity (RH) increased and finally transited to hydrate form IV at 95% RH. DVS analysis also showed that when the RH decreased form IV crystals lost water molecules at 40% RH and transited to the newly identified anhydrate crystal form VII. Form VII reversibly transited to form IV at lower RH than form I, suggesting that form I is more suitable for manufacturing a sustained-release tablet of CAM utilizing the crystalline phase transition. Copyright © 2018 Elsevier B.V. All rights reserved.

  7. Conjoint Forming - Technologies for Simultaneous Forming and Joining

    International Nuclear Information System (INIS)

    Groche, P; Wohletz, S; Mann, A; Krech, M; Monnerjahn, V

    2016-01-01

    The market demand for new products optimized for e. g. lightweight applications or smart components leads to new challenges in production engineering. Hybrid structures represent one promising approach. They aim at higher product performance by using a suitable combination of different materials. The developments of hybrid structures stimulate the research on joining of dissimilar materials. Since they allow for joining dissimilar materials without external heating technologies based on joining by plastic deformation seem to be of special attractiveness. The paper at hand discusses the conjoint forming approach. This approach combines forming and joining in one process. Two or more workpieces are joined while at least one workpiece is plastically deformed. After presenting the fundamental joining mechanisms, the conjoint forming approach is discussed comprehensively. Examples of conjoint processes demonstrate the effectiveness and reveal the underlying phenomena. (paper)

  8. Compressibility of tableting materials and properties of tablets with glyceryl behenate

    Directory of Open Access Journals (Sweden)

    Mužíková Jitka

    2015-03-01

    Full Text Available The paper studies the compressibility of directly compressible tableting materials with dry binders, spray-dried lactose and microcrystalline cellulose, and glyceryl dibehenate at various concentrations. Compressibility was evaluated by means of the energy profile of compression and tensile strength of tablets. Release rate of the active ingredient, salicylic acid, from the tablets was also examined. In the case of microcrystalline cellulose, a higher concentration of glyceryl dibehenate increased the strength of tablets, while this did not occur in the case of spray-dried lactose. Increasing concentration of glyceryl dibehenate prolonged the release of salicylic acid; however, no statistically significant difference was found compared to the type of the dry binder used

  9. Differential forms orthogonal to holomorphic functions or forms, and their properties

    CERN Document Server

    Aizenberg, L A

    1983-01-01

    The authors consider the problem of characterizing the exterior differential forms which are orthogonal to holomorphic functions (or forms) in a domain D\\subset {\\mathbf C}^n with respect to integration over the boundary, and some related questions. They give a detailed account of the derivation of the Bochner-Martinelli-Koppelman integral representation of exterior differential forms, which was obtained in 1967 and has already found many important applications. They study the properties of \\overline \\partial-closed forms of type (p, n - 1), 0\\leq p\\leq n - 1, which turn out to be the duals (with respect to the orthogonality mentioned above) to holomorphic functions (or forms) in several complex variables, and resemble holomorphic functions of one complex variable in their properties.

  10. A tracer diffusion model derived from microstructure

    International Nuclear Information System (INIS)

    Lehikoinen, Jarmo; Muurinen, Arto; Olin, Markus

    2012-01-01

    Document available in extended abstract form only. Full text of publication follows: Numerous attempts have been made to explain the tracer diffusion of various solutes in compacted clays. These attempts have commonly suffered from an inability to describe the diffusion of uncharged and charged solutes with a single unified model. Here, an internally consistent approach to describing the diffusion of solutes in a heterogeneous porous medium, such as compacted bentonite, in terms of its microstructure is presented. The microstructure is taken to be represented by a succession of unit cells, which consist of two consecutive regions (Do, 1996). In the first region, the diffusion is viewed to occur in two parallel paths: one through microcrystalline units (micropores) and the other through meso-pores between the microcrystalline units. Solutes exiting these two paths are then joined together to continue diffusing through the second, disordered, region, connecting the two adjacent microcrystalline units. Adsorption (incl. co-ion exclusion) is thought to occur in the micropores, whereas meso-pores and the disordered region accommodate free species alone. Co-ions are also assumed to experience transfer resistance into and out of the micropores, which is characterized in the model by a transmission coefficient. Although the model is not new per se, its application to compacted clays has never been attempted before. It is shown that in the limit of strong adsorption, the effective diffusivity is limited from above only by the microstructural parameters of the model porous medium. As intuitive and logical as this result may appear, it has not been proven before. In the limit of vanishing disordered region, the effective diffusivity is no longer explicitly constrained by any of the model parameters. The tortuosity of the diffusion path, i.e. the quotient of the actual diffusion path length in the porous-medium coordinates and the characteristic length of the laboratory frame

  11. Hot pressing of nanocrystalline tantalum using high frequency induction heating and pulse plasma sintering

    Science.gov (United States)

    Jakubowicz, J.; Adamek, G.; Sopata, M.; Koper, J. K.; Siwak, P.

    2017-12-01

    The paper presents the results of nanocrystalline powder tantalum consolidation using hot pressing. The authors used two different heating techniques during hot pressing: high-frequency induction heating (HFIH) and pulse plasma sintering (PPS). A comparison of the structure, microstructure, mechanical properties and corrosion resistance of the bulk nanocrystalline tantalum obtained in both techniques was performed. The nanocrystalline powder was made to start from the microcrystalline one using the high-energy ball milling process. The nanocrystalline powder was hot-pressed at 1000 °C, whereas, for comparison, the microcrystalline powder was hot pressed up to 1500 °C for proper consolidation. The authors found that during hot pressing, the powder partially reacts with the graphite die covered by boron nitride, which facilitated punches and powder displacement in the die during densification. Tantalum carbide and boride in the nanocrystalline material was found, which can improve the mechanical properties. The hardness of the HFIH and PPS nanocrystalline tantalum was as high as 625 and 615 HV, respectively. The microstructure was more uniform in the PPS nanomaterial. The corrosion resistance in both cases deteriorated, in comparison to the microcrystalline material, while the PPS material corrosion resistance was slightly better than that of the HFIH one.

  12. Unified form language

    DEFF Research Database (Denmark)

    Alnæs, Martin S.; Logg, Anders; Ølgaard, Kristian Breum

    2014-01-01

    We present the Unied Form Language (UFL), which is a domain-specic language for representing weak formulations of partial dierential equations with a view to numerical approximation. Features of UFL include support for variational forms and functionals, automatic dierentiation of forms and expres...... libraries to generate concrete low-level implementations. Some application examples are presented and libraries that support UFL are highlighted....

  13. Mesonic Form Factors

    Energy Technology Data Exchange (ETDEWEB)

    Frederic D. R. Bonnet; Robert G. Edwards; George T. Fleming; Randal Lewis; David Richards

    2003-07-22

    We have started a program to compute the electromagnetic form factors of mesons. We discuss the techniques used to compute the pion form factor and present preliminary results computed with domain wall valence fermions on MILC asqtad lattices, as well as Wilson fermions on quenched lattices. These methods can easily be extended to rho-to-gamma-pi transition form factors.

  14. Biomimicry of Palm Tree Leaves Form and Pattern on Building Form

    Directory of Open Access Journals (Sweden)

    Agus Salim N.A.

    2014-01-01

    Full Text Available This article is a study on biomimicry of palm tree towards a building form. It is to find a suitable form and pattern that can be applied to building shell to ease building maintenance operation beside to enhance the aesthetic value of a building architecture. The research has been carried out by observation and modeling on some various species of palm tree’s patterns and forms. The result expectation can be found at the end of this research by producing the best pattern of palm tree that can be adapted to building envelop as the whole form of a building.

  15. Method of forming aluminum oxynitride material and bodies formed by such methods

    Science.gov (United States)

    Bakas, Michael P [Ammon, ID; Lillo, Thomas M [Idaho Falls, ID; Chu, Henry S [Idaho Falls, ID

    2010-11-16

    Methods of forming aluminum oxynitride (AlON) materials include sintering green bodies comprising aluminum orthophosphate or another sacrificial material therein. Such green bodies may comprise aluminum, oxygen, and nitrogen in addition to the aluminum orthophosphate. For example, the green bodies may include a mixture of aluminum oxide, aluminum nitride, and aluminum orthophosphate or another sacrificial material. Additional methods of forming aluminum oxynitride (AlON) materials include sintering a green body including a sacrificial material therein, using the sacrificial material to form pores in the green body during sintering, and infiltrating the pores formed in the green body with a liquid infiltrant during sintering. Bodies are formed using such methods.

  16. Adaptive municipal electronic forms

    NARCIS (Netherlands)

    Kuiper, Pieternel; van Dijk, Elisabeth M.A.G.; Bondarouk, Tatiana; Ruel, Hubertus Johannes Maria; Guiderdoni-Jourdain, Karine; Oiry, Ewan

    Adaptation of electronic forms (e-forms) seems to be a step forward to reduce the burden for people who fill in forms. Municipalities more and more offer e-forms online that can be used by citizens to request a municipal product or service or by municipal employees to place a request on behalf of a

  17. Protonated form: the potent form of potassium-competitive acid blockers.

    Directory of Open Access Journals (Sweden)

    Hua-Jun Luo

    Full Text Available Potassium-competitive acid blockers (P-CABs are highly safe and active drugs targeting H+,K+-ATPase to cure acid-related gastric diseases. In this study, we for the first time investigate the interaction mechanism between the protonated form of P-CABs and human H+,K+-ATPase using homology modeling, molecular docking, molecular dynamics and binding free energy calculation methods. The results explain why P-CABs have higher activities with higher pKa values or at lower pH. With positive charge, the protonated forms of P-CABs have more competitive advantage to block potassium ion into luminal channel and to bind with H+,K+-ATPase via electrostatic interactions. The binding affinity of the protonated form is more favorable than that of the neutral P-CABs. In particular, Asp139 should be a very important binding site for the protonated form of P-CABs through hydrogen bonds and electrostatic interactions. These findings could promote the rational design of novel P-CABs.

  18. Protonated form: the potent form of potassium-competitive acid blockers.

    Science.gov (United States)

    Luo, Hua-Jun; Deng, Wei-Qiao; Zou, Kun

    2014-01-01

    Potassium-competitive acid blockers (P-CABs) are highly safe and active drugs targeting H+,K+-ATPase to cure acid-related gastric diseases. In this study, we for the first time investigate the interaction mechanism between the protonated form of P-CABs and human H+,K+-ATPase using homology modeling, molecular docking, molecular dynamics and binding free energy calculation methods. The results explain why P-CABs have higher activities with higher pKa values or at lower pH. With positive charge, the protonated forms of P-CABs have more competitive advantage to block potassium ion into luminal channel and to bind with H+,K+-ATPase via electrostatic interactions. The binding affinity of the protonated form is more favorable than that of the neutral P-CABs. In particular, Asp139 should be a very important binding site for the protonated form of P-CABs through hydrogen bonds and electrostatic interactions. These findings could promote the rational design of novel P-CABs.

  19. Forms Management Policy

    Science.gov (United States)

    To establish EPA’s Forms Management Program; to describe the requisite roles, responsibilities, and procedures necessary for the successful management of EPA forms; and to more clearly fulfill EPA’s obligations in this regard.

  20. Science on form

    International Nuclear Information System (INIS)

    Ishizaka, Shozo; Kato, Yoshihiro; Takaki, Ryuji; Toriwaki, Jun-ichiro

    1987-01-01

    The purpose of the Symposium was to discuss interdisciplinal science aspects of form. 'Form' depends on the material and the changes. But, it is the form that appears evident at once and endures. Form is absorbed from every field as media of information. One part of the work covers the description of non-periodic phenomena, morphogenesis or evolution. Irreducible stubborn facts as diseases or social problems, or whatever else that could not be analyzed are integrally challenged to be systematized by computer simulation. The other part covers the finding of laws for determining how systems behave. Attention should be paid to pattern recognition, image processing and pattern formation. The Symposium proceeded with no parallel sessions, and participants from various fields made exciting discussions in an interdisciplinal atmosphere. (Auth.)

  1. A comparative study on the direct deposition of μc-Si:H and plasma-induced recrystallization of a-Si:H: Insight into Si crystallization in a high-density plasma

    Science.gov (United States)

    Zhou, H. P.; Xu, M.; Xu, S.; Feng, Y. Y.; Xu, L. X.; Wei, D. Y.; Xiao, S. Q.

    2018-03-01

    Deep insight into the crystallization mechanism of amorphous silicon is of theoretical and technological significance for the preparation of high-quality microcrystalline/polycrystalline silicon. In this work, we intensively compare the present two plasma-involved routes, i.e., the direct deposition and recrystallization of precursor amorphous silicon (a-Si) films, to fabricate microcrystalline silicon. Both the directly deposited and recrystallized samples show multi-layered structures as revealed by electronic microscopy. High-density hydrogen plasma involved recrystallization process, which is mediated by the hydrogen diffusion into the deep region of the precursor a-Si film, displays significantly different nucleation configuration, interface properties, and crystallite shape. The underlying mechanisms are analyzed in combination with the interplay of high-density plasma and growing or treated surface.

  2. Reuse of the Reflective Light and the Recycle Heat Energy in Concentrated Photovoltaic System

    Directory of Open Access Journals (Sweden)

    Hsin-Chien Chen

    2013-01-01

    Full Text Available A complex solar unit with microcrystalline silicon solar cells placed around the centered GaAs triple junction solar cell has been proposed and carried out. With the same illumination area and intensity, the total resultant power shows that the excess microcrystalline silicon solar cells increase the total output power by 13.2% by absorbing the reflective light from the surface of optical collimators. Furthermore, reusing the residual heat energy generated from the above-mentioned mechanism helps to increase the output power by around 14.1%. This mechanism provides a simple method to enhance the utility rate of concentrated photovoltaic (CPV system. Such concept can be further applied to the aerospace industry and the development of more efficient CPV solar energy applications.

  3. Automorphic Forms and Mock Modular Forms in String Theory

    Science.gov (United States)

    Nazaroglu, Caner

    We study a variety of modular invariant objects in relation to string theory. First, we focus on Jacobi forms over generic rank lattices and Siegel forms that appear in N = 2, D = 4 compactifications of heterotic string with Wilson lines. Constraints from low energy spectrum and modularity are employed to deduce the relevant supersymmetric partition functions entirely. This procedure is applied on models that lead to Jacobi forms of index 3, 4, 5 as well as Jacobi forms over root lattices A2 and A3. These computations are then checked against an explicit orbifold model which can be Higgsed to the models under question. Models with a single Wilson line are then studied in detail with their relation to paramodular group Gammam as T-duality group made explicit. These results on the heterotic string side are then turned into predictions for geometric invariants using TypeII - Heterotic duality. Secondly, we study theta functions for indenite signature lattices of generic signature. Building on results in literature for signature (n-1,1) and (n-2,2) lattices, we work out the properties of generalized error functions which we call r-tuple error functions. We then use these functions to build such indenite theta functions and describe their modular completions.

  4. Forms of Arthritis

    Science.gov (United States)

    ... this page please turn Javascript on. Forms of Arthritis Past Issues / Fall 2006 Table of Contents Today, ... of Linda Saisselin Osteoarthritis (OA) — the form of arthritis typically occurring during middle or old age, this ...

  5. Directory of energy data collection forms. Forms in use as of October 1995

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-01-01

    This is an authoritative listing of selected public use forms currently used as basic energy information gathering tools by the Department of Energy (DOE). This directory provides an overview of DOE`s energy information collection programs for decisionmakers in Government and industry. Forms designed to collect energy information and used by the Energy Information Administration (EIA) as of October 1995 are included in this directory. For each form listed in this directory, an abstract is included that describes the form`s uses, its respondents, and the data collected. For the reader`s convenience in finding specific types of collections, several indices have been provided in this directory. A listing of the forms grouped by energy source and function begins on page 26. Beginning on page 38 are the publications derived from the collections, and on page 50, are the forms linked to general respondent categories.

  6. Radial-rotation profile forming: A new processing technology of incremental sheet metal forming

    Science.gov (United States)

    Laue, Robert; Härtel, Sebastian; Awiszus, Birgit

    2018-05-01

    Incremental forming processes (i.e., spinning) of sheet metal blanks into cylindrical cups are suitable for lower lot sizes. The produced cups were frequently used as preforms to produce workpieces in further forming steps with additional functions like profiled hollow parts [1]. The incremental forming process radial-rotation profile forming has been developed to enable the production of profiled hollow parts with low sheet thinning and good geometrical accuracy. The two principal forming steps are the production of the preform by rotational swing-folding [2] and the subsequent radial profiling of the hollow part in one clamping position. The rotational swing-folding process is based on a combination of conventional spinning and swing-folding. Therefore, a round blank rotates on a profiled mandrel and due to the swinging of a cylindrical forming tool, the blank is formed to a cup with low sheet thinning. In addition, thickening results at the edge of the blank and wrinkling occurs. However, the wrinkles are formed into the indentation of the profiled mandrel and can be reshaped as an advantage in the second process step, the radial profiling. Due to the rotation and continuous radial feed of a profiled forming tool to the profiled mandrel, the axial profile is formed in the second process step. Because of the minor relative movement in axial direction between tool and blank, low sheet thinning occurs. This is an advantage of the principle of the process.

  7. Oyeniyi and Achor (9)

    African Journals Online (AJOL)

    Timothy Ademakinwa

    Keywords: Microcrystalline Cellulose, Drying Techniques, Flow Properties, Compressional ... starches (Esezobo et al.,1982; Alebiowu and Itiola, .... The tablets were thereafter stored over silica gel in .... Sweet Potato and Cocoyam Starches as.

  8. Getting in-formed

    DEFF Research Database (Denmark)

    Hansbøl, Mikala

    det vi undersøger på form gennem vores beskrivelser. Paperet tager afsæt i empiriske eksempler fra et postdoc projekt om et såkaldt 'serious game' - Mingoville. Projektet følger circuleringer og etableringer af Mingoville 'på en global markedsplads'. I paperet diskuteres hvordan vi som forskere samler....../performer de fænomener vi forsker i. Aktør-Netværks-Teoretiker Bruno Latour (2005) pointerer at enhver beskrivelse også er en form for forklaring. En form for forklaring, der putter ting ind i et skript og dermed også putter ting på form. Paperet diskuterer to tilgange til at gøre serious games og derved skabe viden om...... engagementer med disse fænomener i serious games forskning: experimentel og etnografisk....

  9. Role of excipients in hydrate formation kinetics of theophylline in wet masses studied by near-infrared spectroscopy

    DEFF Research Database (Denmark)

    Jørgensen, Anna C; Airaksinen, Sari; Karjalainen, Milja

    2004-01-01

    . Anhydrous theophylline was chosen as the hydrate-forming model drug compound and two excipients, silicified microcrystalline cellulose (SMCC) and alpha-lactose monohydrate, with different water absorbing properties, were used in formulation. An early stage of wet massing was studied with anhydrous...... theophylline and its 1:1 (w/w) mixtures with alpha-lactose monohydrate and SMCC with 0.1g/g of purified water. The changes in the state of water were monitored using near-infrared spectroscopy, and the conversion of the crystal structure was verified using X-ray powder diffraction (XRPD). SMCC decreased...... the hydrate formation rate by absorbing water, but did not inhibit it. The results suggest that alpha-lactose monohydrate slightly increased the hydrate formation rate in comparison with a mass comprising only anhydrous theophylline....

  10. Pre-exposure to moving form enhances static form sensitivity.

    Directory of Open Access Journals (Sweden)

    Thomas S A Wallis

    Full Text Available BACKGROUND: Motion-defined form can seem to persist briefly after motion ceases, before seeming to gradually disappear into the background. Here we investigate if this subjective persistence reflects a signal capable of improving objective measures of sensitivity to static form. METHODOLOGY/PRINCIPAL FINDINGS: We presented a sinusoidal modulation of luminance, masked by a background noise pattern. The sinusoidal luminance modulation was usually subjectively invisible when static, but visible when moving. We found that drifting then stopping the waveform resulted in a transient subjective persistence of the waveform in the static display. Observers' objective sensitivity to the position of the static waveform was also improved after viewing moving waveforms, compared to viewing static waveforms for a matched duration. This facilitation did not occur simply because movement provided more perspectives of the waveform, since performance following pre-exposure to scrambled animations did not match that following pre-exposure to smooth motion. Observers did not simply remember waveform positions at motion offset, since removing the waveform before testing reduced performance. CONCLUSIONS/SIGNIFICANCE: Motion processing therefore interacts with subsequent static visual inputs in a way that can improve performance in objective sensitivity measures. We suggest that the brief subjective persistence of motion-defined forms that can occur after motion offsets is a consequence of the decay of a static form signal that has been transiently enhanced by motion processing.

  11. FORMS OF YOUTH TRAVEL

    OpenAIRE

    Moisã Claudia Olimpia; Moisã Claudia Olimpia

    2011-01-01

    Taking into account the suite of motivation that youth has when practicing tourism, it can be said that the youth travel takes highly diverse forms. These forms are educational tourism, volunteer programs and “work and travel”, cultural exchanges or sports tourism and adventure travel. In this article, we identified and analyzed in detail the main forms of youth travel both internationally and in Romania. We also illustrated for each form of tourism the specific tourism products targeting you...

  12. Preparation of fluconazole buccal tablet and influence of formulation expedients on its properties.

    Science.gov (United States)

    Mohamed, Saifulla P; Muzzammil, Shariff; Pramod, Kumar T M

    2011-04-01

    The aim of present study was to prepare buccal tablets of fluconazole for oral candidiasis. The dosage forms were designed to release the drug above the minimum inhibitory concentration for prolonged period of time so as to reduce the frequency of administration and to overcome the side effects of systemic treatment. The buccal tablets were prepared by using Carbopol 71G and Noveon AA-1 by direct compression method. Microcrystalline cellulose was used as the filler and its effect was also studied. The prepared dosage forms were evaluated for physicochemical properties, in vitro release studies and mucoadhesive properties using sheep buccal mucosa as a model tissue. Tablets containing 50% of polymers (Carbopol & Noveon) were found to be the best with moderate swelling along with favorable bioadhesion force, residence time and in vitro drug release. The in vitro drug release studies revealed that drug released for 8 h, which in turn may reduce dosing frequency and improved patient compliance in oral candidiasis patients.

  13. Giro form reading machine

    Science.gov (United States)

    Minh Ha, Thien; Niggeler, Dieter; Bunke, Horst; Clarinval, Jose

    1995-08-01

    Although giro forms are used by many people in daily life for money remittance in Switzerland, the processing of these forms at banks and post offices is only partly automated. We describe an ongoing project for building an automatic system that is able to recognize various items printed or written on a giro form. The system comprises three main components, namely, an automatic form feeder, a camera system, and a computer. These components are connected in such a way that the system is able to process a bunch of forms without any human interactions. We present two real applications of our system in the field of payment services, which require the reading of both machine printed and handwritten information that may appear on a giro form. One particular feature of giro forms is their flexible layout, i.e., information items are located differently from one form to another, thus requiring an additional analysis step to localize them before recognition. A commercial optical character recognition software package is used for recognition of machine-printed information, whereas handwritten information is read by our own algorithms, the details of which are presented. The system is implemented by using a client/server architecture providing a high degree of flexibility to change. Preliminary results are reported supporting our claim that the system is usable in practice.

  14. Photogeneration of charges in microcrystalline chlorophyll a

    International Nuclear Information System (INIS)

    Kassi, Hassan; Barazzouk, Said; Brullemans, Marc; Leblanc, Roger M.; Hotchandani, Surat

    2010-01-01

    The electric-field and temperature dependence of hole photogeneration in chlorophyll a (Chla) have been analyzed in terms of electric-field assisted thermal dissociation of charge pairs based on Onsager theory. An excellent agreement between the experimental and theoretical values of the slope-to-intercept ratio, S/I, for the plot of photogeneration efficiency vs. electric field at low field strengths provides a proof for the applicability of the Onsager approach to the photogeneration of charges in Chla. A value of 19 nm has been obtained for Coulomb capture radius, r c , from S/I. From the temperature dependence of photogeneration, the initial separation, r 0 , of photogenerated electron-hole has been evaluated, and has a value of 1.24 nm. This smaller r 0 compared to r c leads to a feeble dissociation probability of electron-hole pairs into free carriers, and may, among other factors, explain the low power conversion efficiencies of Chla photovoltaic cells.

  15. Photogeneration of charges in microcrystalline chlorophyll a

    Energy Technology Data Exchange (ETDEWEB)

    Kassi, Hassan [Scientech R and D, Inc., 2200 Rue Didbec S., Bureau 203, Trois-Rivieres, Trois-Rivieres, QC, G8Z 4H1 (Canada); Barazzouk, Said, E-mail: barazzos@uqtr.c [Groupe de Recherche en Biologie Vegetale, Universite du Quebec a Trois-Rivieres, Trois-Rivieres, QC, G9A 5H7 (Canada); Brullemans, Marc [Groupe de Recherche en Biologie Vegetale, Universite du Quebec a Trois-Rivieres, Trois-Rivieres, QC, G9A 5H7 (Canada); Leblanc, Roger M. [Department of Chemistry, University of Miami, P.O. Box 249118, Coral Gables, FL 33124-0431 (United States); Hotchandani, Surat [Groupe de Recherche en Biologie Vegetale, Universite du Quebec a Trois-Rivieres, Trois-Rivieres, QC, G9A 5H7 (Canada)

    2010-07-01

    The electric-field and temperature dependence of hole photogeneration in chlorophyll a (Chla) have been analyzed in terms of electric-field assisted thermal dissociation of charge pairs based on Onsager theory. An excellent agreement between the experimental and theoretical values of the slope-to-intercept ratio, S/I, for the plot of photogeneration efficiency vs. electric field at low field strengths provides a proof for the applicability of the Onsager approach to the photogeneration of charges in Chla. A value of 19 nm has been obtained for Coulomb capture radius, r{sub c}, from S/I. From the temperature dependence of photogeneration, the initial separation, r{sub 0}, of photogenerated electron-hole has been evaluated, and has a value of 1.24 nm. This smaller r{sub 0} compared to r{sub c} leads to a feeble dissociation probability of electron-hole pairs into free carriers, and may, among other factors, explain the low power conversion efficiencies of Chla photovoltaic cells.

  16. Two Contrasting Failure Modes of Enteric Coated Beads.

    Science.gov (United States)

    Shi, Galen H; Dong, Xia; Lytle, Michelle; Kemp, Craig A J; Behme, Robert J; Hinds, Jeremy; Xiao, Zhicheng

    2018-04-09

    This study aimed to elucidate the mechanisms and kinetics of coating failure for enteric coated beads exposed to high-humidity conditions at different storage temperatures. Enteric coated beads were placed on high-humidity conditions (75 to 98% relative humidity (RH)) in the temperature range of 5 to 40°C. These stability samples of beads were tested for acid dissolution and water activity and also analyzed with SEM, X-ray CT, and DMA. Exposure of enteric coated beads to high humidity led to increased gastric release of drug which eventually failed the dissolution specification. SEM showed visible cracks on the surface of beads exposed to 5°C/high humidity and fusion of enteric beads into agglomerates at 40°C/high humidity. In a non-destructive time elapse study, X-ray CT demonstrated swelling of microcrystalline cellulose cores, crack initiation, and propagation through the API layer within days under 5°C/98% RH storage conditions and ultimately fracture through the enteric coating. DMA data showed a marked reduction in T g of the enteric coating materials after exposure to humidity. At 5°C/high humidity, the hygroscopic microcrystalline cellulose core absorbed moisture leading to core swelling and consequent fracture through the brittle API and enteric layers. At 40°C (high humidity) which is above the T g of the enteric polymer, enteric coated beads coalesced into agglomerates due to melt flow of the enteric coating. We believe it is the first report on two distinct failure models of enteric coated dosage forms.

  17. The role seemingly of amorphous silica gel layers in chiral separations by planar chromatography

    International Nuclear Information System (INIS)

    Sajewicz, M.; Kowalska, T.

    2007-01-01

    In planar chromatography, silica gel appears as the most frequently used adsorbent. Its preference as planar chromatographic stationary phase is due to its high specific surface area (ca. 700 m2 gl) and relatively simple active sites (silanol groups =Si-OH). The high specific surface area of silica gel and a high density of coverage of its surface with the silanol active sites contribute jointly to an excellent separation performance of this adsorbent. In our experiments on chiral separation of the enantiomer pairs by planar chromatography, contradictory behavior of the silica gel layers versus the chiral compounds was observed. The migration tracks of chiral compounds in the ascending planar chromatographic mode were not vertical but bent on either side being a function of analyte chirality. This deviation of the analytes migration track was noticed, when using the densitometric scanner to quantify the respective chromatograms. In order to confirm the hypothesis as to the microcrystalline nature of silica gel used in liquid chromatography, it was further investigated through circular dichroism (CD) and the data thereof confirmed that the chromatographic silica gels are not amorphous but microcrystalline, contributing to the (partial) horizontal enantioseparation of the antimer pairs. This paper summarizes the results of our investigation on the microcrystalline nature of silica gels used in planar chromatography and their impact on enantioseparation of the selected pairs of antimers. (author)

  18. Method for forming materials

    Science.gov (United States)

    Tolle, Charles R [Idaho Falls, ID; Clark, Denis E [Idaho Falls, ID; Smartt, Herschel B [Idaho Falls, ID; Miller, Karen S [Idaho Falls, ID

    2009-10-06

    A material-forming tool and a method for forming a material are described including a shank portion; a shoulder portion that releasably engages the shank portion; a pin that releasably engages the shoulder portion, wherein the pin defines a passageway; and a source of a material coupled in material flowing relation relative to the pin and wherein the material-forming tool is utilized in methodology that includes providing a first material; providing a second material, and placing the second material into contact with the first material; and locally plastically deforming the first material with the material-forming tool so as mix the first material and second material together to form a resulting material having characteristics different from the respective first and second materials.

  19. A numerical analysis on forming limits during spiral and concentric single point incremental forming

    Science.gov (United States)

    Gipiela, M. L.; Amauri, V.; Nikhare, C.; Marcondes, P. V. P.

    2017-01-01

    Sheet metal forming is one of the major manufacturing industries, which are building numerous parts for aerospace, automotive and medical industry. Due to the high demand in vehicle industry and environmental regulations on less fuel consumption on other hand, researchers are innovating new methods to build these parts with energy efficient sheet metal forming process instead of conventionally used punch and die to form the parts to achieve the lightweight parts. One of the most recognized manufacturing process in this category is Single Point Incremental Forming (SPIF). SPIF is the die-less sheet metal forming process in which the single point tool incrementally forces any single point of sheet metal at any process time to plastic deformation zone. In the present work, finite element method (FEM) is applied to analyze the forming limits of high strength low alloy steel formed by single point incremental forming (SPIF) by spiral and concentric tool path. SPIF numerical simulations were model with 24 and 29 mm cup depth, and the results were compare with Nakajima results obtained by experiments and FEM. It was found that the cup formed with Nakajima tool failed at 24 mm while cups formed by SPIF surpassed the limit for both depths with both profiles. It was also notice that the strain achieved in concentric profile are lower than that in spiral profile.

  20. Adaptive Municipal e-forms

    NARCIS (Netherlands)

    Kuiper, P.M.; van Dijk, Elisabeth M.A.G.; Boerma, A.K.; Weibelzahl, S.; Cristea, A.

    2006-01-01

    Adaptation of electronic forms seems to be a step forward to reduce the burden for people who fill in forms. Municipalities more and more offer eforms online that can be used to request a municipal product or service. To create adaptive e-forms that satisfy the need of end-users, involvement of

  1. Simulation of forward dark current voltage characteristics of tandem solar cells

    International Nuclear Information System (INIS)

    Rubinelli, F.A.

    2012-01-01

    The transport mechanisms tailoring the shape of dark current–voltage characteristics of amorphous and microcrystalline silicon based tandem solar cell structures are explored with numerical simulations. Our input parameters were calibrated by fitting experimental current voltage curves of single and double junction structures measured under dark and illuminated conditions. At low and intermediate forward voltages the dark current–voltage characteristics show one or two regions with a current–voltage exponential dependence. The diode factor is unique in tandem cells with the same material in both intrinsic layers and two dissimilar diode factors are observed in tandem cells with different materials on the top and bottom intrinsic layers. In the exponential regions the current is controlled by recombination through gap states and by free carrier diffusion. At high forward voltages the current grows more slowly with the applied voltage. The current is influenced by the onset of electron space charge limited current (SCLC) in tandem cells where both intrinsic layers are of amorphous silicon and by series resistance of the bottom cell in tandem cells where both intrinsic layers are of microcrystalline silicon. In the micromorph cell the onset of SCLC becomes visible on the amorphous top sub-cell. The dark current also depends on the thermal generation of electron–hole (e–h) pairs present at the tunneling recombination junction. The highest dependence is observed in the tandem structure where both intrinsic layers are of microcrystalline silicon. The prediction of meaningless dark currents at low forward and reverse voltages by our code is discussed and one solution is given. - Highlights: ► Transport mechanisms shaping the dark current-voltage curves of tandem devices. ► The devices are amorphous and microcrystalline based tandem solar cells. ► Two regions with a current-voltage exponential dependence are observed. ► The tandem J-V diode factor is the

  2. SuperFormLab: showing SuperFormLab

    DEFF Research Database (Denmark)

    2013-01-01

    bachelor program, followed by two years of master studies. The courses are offered equally to students from other design disciplines, e.g. industrial design. Teaching is mainly in English as the program is attended by a relatively large group of non-Danish students, who seek exactly this combination......3D-printing in clay and ceramic objects shaped by your own sounds and movements! Digital form transferred via CNC-milling to ornamental ceramic wall-cladding. Brave New World… Students and their teacher at SuperFormLab, the new ceramic workshop of the School of Design at the Royal Danish Academy...... of Fine Arts in Copenhagen, will be showing results of their investigations into the potential of combining digital technologies with ceramic materials. It is now possible to shape the most complex mathematical, virtual 3D objects through the use of advanced software-programs. And more than that – you can...

  3. Method for forming ammonia

    Science.gov (United States)

    Kong, Peter C.; Pink, Robert J.; Zuck, Larry D.

    2008-08-19

    A method for forming ammonia is disclosed and which includes the steps of forming a plasma; providing a source of metal particles, and supplying the metal particles to the plasma to form metal nitride particles; and providing a substance, and reacting the metal nitride particles with the substance to produce ammonia, and an oxide byproduct.

  4. Forms of global governence

    Directory of Open Access Journals (Sweden)

    Maxim V. Kharkevich

    2014-01-01

    Full Text Available Global governance as a concept defines the meaning of contemporary world politics both as a discipline and as reality. Interdependent and globalized world requires governance, and a global government has not been formed yet. The theoretical possibility of global governance without global government is proved and justified. The purpose of this article is to analytically identify possible forms of global governance. Three such forms of global governance are identified: hierarchical, market and network. In a hierarchy the governance is due to the asymmetry of power between the parties. Market control happens via anonymous pricing mechanism. Network, in contrast to the market is characterized by a closer value link between the actors, but unlike the hierarchical relationship actors are free to leave the network. Global governance takes three forms and is being implemented by different actors. To determine the most efficient form of global governance is impossible. Efficiency depends on the match between a form and an object of government. It should be noted that meta governance is likely to remain a monopoly of institutionally strong states in global governance.

  5. Methods of forming single source precursors, methods of forming polymeric single source precursors, and single source precursors formed by such methods

    Science.gov (United States)

    Fox, Robert V.; Rodriguez, Rene G.; Pak, Joshua J.; Sun, Chivin; Margulieux, Kelsey R.; Holland, Andrew W.

    2014-09-09

    Methods of forming single source precursors (SSPs) include forming intermediate products having the empirical formula 1/2{L.sub.2N(.mu.-X).sub.2M'X.sub.2}.sub.2, and reacting MER with the intermediate products to form SSPs of the formula L.sub.2N(.mu.-ER).sub.2M'(ER).sub.2, wherein L is a Lewis base, M is a Group IA atom, N is a Group IB atom, M' is a Group IIIB atom, each E is a Group VIB atom, each X is a Group VIIA atom or a nitrate group, and each R group is an alkyl, aryl, vinyl, (per)fluoro alkyl, (per)fluoro aryl, silane, or carbamato group. Methods of forming polymeric or copolymeric SSPs include reacting at least one of HE.sup.1R.sup.1E.sup.1H and MER with one or more substances having the empirical formula L.sub.2N(.mu.-ER).sub.2M'(ER).sub.2 or L.sub.2N(.mu.-X).sub.2M'(X).sub.2 to form a polymeric or copolymeric SSP. New SSPs and intermediate products are formed by such methods.

  6. U-Form vs. M-Form: How to Understand Decision Autonomy Under Healthcare Decentralization?

    Science.gov (United States)

    Bustamante, Arturo Vargas

    2016-01-01

    For more than three decades healthcare decentralization has been promoted in developing countries as a way of improving the financing and delivery of public healthcare. Decision autonomy under healthcare decentralization would determine the role and scope of responsibility of local authorities. Jalal Mohammed, Nicola North, and Toni Ashton analyze decision autonomy within decentralized services in Fiji. They conclude that the narrow decision space allowed to local entities might have limited the benefits of decentralization on users and providers. To discuss the costs and benefits of healthcare decentralization this paper uses the U-form and M-form typology to further illustrate the role of decision autonomy under healthcare decentralization. This paper argues that when evaluating healthcare decentralization, it is important to determine whether the benefits from decentralization are greater than its costs. The U-form and M-form framework is proposed as a useful typology to evaluate different types of institutional arrangements under healthcare decentralization. Under this model, the more decentralized organizational form (M-form) is superior if the benefits from flexibility exceed the costs of duplication and the more centralized organizational form (U-form) is superior if the savings from economies of scale outweigh the costly decision-making process from the center to the regions. Budgetary and financial autonomy and effective mechanisms to maintain local governments accountable for their spending behavior are key decision autonomy variables that could sway the cost-benefit analysis of healthcare decentralization. PMID:27694684

  7. Forming of superplastic ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Lesuer, D.R.; Wadsworth, J.; Nieh, T.G.

    1994-05-01

    Superplasticity in ceramics has now advanced to the stage that technologically viable superplastic deformation processing can be performed. In this paper, examples of superplastic forming and diffusion bonding of ceramic components are given. Recent work in biaxial gas-pressure forming of several ceramics is provided. These include yttria-stabilized, tetragonal zirconia (YTZP), a 20% alumina/YTZP composite, and silicon. In addition, the concurrent superplastic forming and diffusion bonding of a hybrid ceramic-metal structure are presented. These forming processes offer technological advantages of greater dimensional control and increased variety and complexity of shapes than is possible with conventional ceramic shaping technology.

  8. Measuring the Thermophysical and Structural Properties of Glass-Forming and Quasicrystal-Forming Liquids

    Science.gov (United States)

    Hyers, Robert W.; Bradshaw, Richard C.; Rogers, Jan R.; Gangopadhyay, Anup K.; Kelton, Ken F.

    2006-01-01

    The thermophysical properties of glass-forming and quasicrystal-forming alloys show many interesting features in the undercooled liquid range. Some of the features in the thermophysical property curves are expected to reflect changes in the structure and coordination of the liquid. These measurements require containerless processing such as electrostatic levitation to access the undercooled liquid regime. An overview of the state of the art in measuring the thermophysical properties and structure of undercooled liquid glass-forming and quasicrystal-forming alloys will be presented, along with the status of current measurements.

  9. Diagenesis of a drapery speleothem from Castañar Cave: from dissolution to dolomitization

    Directory of Open Access Journals (Sweden)

    Martín-Pérez A.

    2012-07-01

    Full Text Available A drapery speleothem (DRA-1 from Castañar Cave in Spain was subjected to a detailed petrographical study in order to identify its primary and diagenetic features. The drapery’s present day characteristics are the result of the combined effects of the primary and diagenetic processes that DRA-1 underwent. Its primary minerals are calcite, aragonite and huntite. Calcite is the main constituent of the speleothem, whereas aragonite forms as frostwork over the calcite. Huntite is the main mineral of moonmilk which covers the tips of aragonite. These primary minerals have undergone a set of diagenetic processes, which include: 1 partial dissolution or corrosion that produces the formation of powdery matt-white coatings on the surface of the speleothem. These are seen under the microscope as dark and highly porous microcrystalline aggregates; 2 total dissolution produces pores of few cm2 in size; 3 calcitization and dolomitization of aragonite result in the thickening and lost of shine of the aragonite fibres. Microscopically, calcitization is seen as rhombohedral crystals which cover and replace aragonite forming mosaics that preserve relics of aragonite precursor. Dolomitization results in the formation of microcrystalline rounded aggregates over aragonite fibres. These aggregates are formed by dolomite crystals of around 1 μm size. The sequence of diagenetic processes follows two main pathways. Pathway 1 is driven by the increase of saturation degree and Mg/Ca ratio of the karstic waters and is visible in the NW side of the drapery. This sequence of processes includes: 1 aragonite and huntite primary precipitation and 2 dolomitization. Pathway 2 is driven by a decrease in the degree of saturation of calcite and aragonite and Mg/Ca ratio of the cave waters, and it is observed in the SE side of the drapery. The diagenetic processes of the second pathway include: 1 calcitization of aragonite; 2 incomplete dissolution (micritization of both

  10. Effect of multiple forming tools on geometrical and mechanical properties in incremental sheet forming

    Science.gov (United States)

    Wernicke, S.; Dang, T.; Gies, S.; Tekkaya, A. E.

    2018-05-01

    The tendency to a higher variety of products requires economical manufacturing processes suitable for the production of prototypes and small batches. In the case of complex hollow-shaped parts, single point incremental forming (SPIF) represents a highly flexible process. The flexibility of this process comes along with a very long process time. To decrease the process time, a new incremental forming approach with multiple forming tools is investigated. The influence of two incremental forming tools on the resulting mechanical and geometrical component properties compared to SPIF is presented. Sheets made of EN AW-1050A were formed to frustums of a pyramid using different tool-path strategies. Furthermore, several variations of the tool-path strategy are analyzed. A time saving between 40% and 60% was observed depending on the tool-path and the radii of the forming tools while the mechanical properties remained unchanged. This knowledge can increase the cost efficiency of incremental forming processes.

  11. 17 CFR 270.30a-2 - Certification of Form N-CSR and Form N-Q.

    Science.gov (United States)

    2010-04-01

    ... 17 Commodity and Securities Exchanges 3 2010-04-01 2010-04-01 false Certification of Form N-CSR... Form N-CSR and Form N-Q. (a) Each report filed on Form N-CSR (§§ 249.331 and 274.128 of this chapter) or Form N-Q (§§ 249.332 and 274.130 of this chapter) by a registered management investment company...

  12. Soil Forming Factors

    Science.gov (United States)

    It! What is Soil? Chip Off the Old Block Soil Forming Factors Matters of Life and Death Underneath It All Wise Choices A World of Soils Soil Forming Factors 2 A Top to Bottom Guide 3 Making a Soil Monolith 4 Soil Orders 5 State Soil Monoliths 6 Where in the Soil World Are You? >> A Top to

  13. A new high temperature resistant glass–ceramic coating for gas ...

    Indian Academy of Sciences (India)

    Unknown

    resultant coatings showed presence of a number of microcrystalline phases. SEM micrographs ... processing of two novel glass–ceramic coating materials, ... stainless steel tray to yield frit (a friable glassy material). .... Frit (– 20 mesh) powder.

  14. Sheet-bulk metal formingforming of functional components from sheet metals

    Directory of Open Access Journals (Sweden)

    Merklein Marion

    2015-01-01

    Full Text Available The paper gives an overview on the application of sheet-bulk metal forming operations in both scientific and industrial environment. Beginning with the need for an innovative forming technology, the definition of this new process class is introduced. The rising challenges of the application of bulk metal forming operations on sheet metals are presented and the demand on a holistic investigation of this topic is motivated. With the help of examples from established production processes, the latest state of technology and the lack on fundamental knowledge is shown. Furthermore, perspectives regarding new research topics within sheet-bulk metal forming are presented. These focus on processing strategies to improve the quality of functional components by the application of process-adapted semi-finished products as well as the local adaption of the tribological system.

  15. Confectionery-based dose forms.

    Science.gov (United States)

    Tangso, Kristian J; Ho, Quy Phuong; Boyd, Ben J

    2015-01-01

    Conventional dosage forms such as tablets, capsules and syrups are prescribed in the normal course of practice. However, concerns about patient preferences and market demands have given rise to the exploration of novel unconventional dosage forms. Among these, confectionery-based dose forms have strong potential to overcome compliance problems. This report will review the availability of these unconventional dose forms used in treating the oral cavity and for systemic drug delivery, with a focus on medicated chewing gums, medicated lollipops, and oral bioadhesive devices. The aim is to stimulate increased interest in the opportunities for innovative new products that are available to formulators in this field, particularly for atypical patient populations.

  16. INFORMATIONAL EFFECT OF A FORM

    Directory of Open Access Journals (Sweden)

    Kovalenko V.F.

    2016-02-01

    Full Text Available The study was conducted by method of light scattering of laser emission. The influence of the form field, mutual influence of mental informational and form torsional fields as well as the following exposure of water samples in the form field after the cease of informational influence on water structure were examined. Paper forms of a pyramid, a cylinder, and a prism were used. The experimental findings show that mechanism of mutual influence on water structure of the form and informational torsional fields depended on the initial conditions of spin restructuring process – the configuration of a form, the type of the form field (internal and external ones, and the initial water structure. The influence of the form field on informational aftereffect was determined, the character of which was defined by ratio of intensities of torsional form field and an informational soliton. The phenomenon of the abnormally large amplification of the informational aftereffect in the internal field of a pyramid demonstrating the attributes of positive reverse connection between the informational soliton and torsional field of water structure and selection of generated cluster sizes were discovered.

  17. Gravitation and quadratic forms

    International Nuclear Information System (INIS)

    Ananth, Sudarshan; Brink, Lars; Majumdar, Sucheta; Mali, Mahendra; Shah, Nabha

    2017-01-01

    The light-cone Hamiltonians describing both pure (N=0) Yang-Mills and N=4 super Yang-Mills may be expressed as quadratic forms. Here, we show that this feature extends to theories of gravity. We demonstrate how the Hamiltonians of both pure gravity and N=8 supergravity, in four dimensions, may be written as quadratic forms. We examine the effect of residual reparametrizations on the Hamiltonian and the resulting quadratic form.

  18. Three forms of relativity

    International Nuclear Information System (INIS)

    Strel'tsov, V.N.

    1992-01-01

    The physical sense of three forms of the relativity is discussed. The first - instant from - respects in fact the traditional approach based on the concept of instant distance. The normal form corresponds the radar formulation which is based on the light or retarded distances. The front form in the special case is characterized by 'observable' variables, and the known method of k-coefficient is its obvious expression. 16 refs

  19. Gravitation and quadratic forms

    Energy Technology Data Exchange (ETDEWEB)

    Ananth, Sudarshan [Indian Institute of Science Education and Research,Pune 411008 (India); Brink, Lars [Department of Physics, Chalmers University of Technology,S-41296 Göteborg (Sweden); Institute of Advanced Studies and Department of Physics & Applied Physics,Nanyang Technological University,Singapore 637371 (Singapore); Majumdar, Sucheta [Indian Institute of Science Education and Research,Pune 411008 (India); Mali, Mahendra [School of Physics, Indian Institute of Science Education and Research,Thiruvananthapuram, Trivandrum 695016 (India); Shah, Nabha [Indian Institute of Science Education and Research,Pune 411008 (India)

    2017-03-31

    The light-cone Hamiltonians describing both pure (N=0) Yang-Mills and N=4 super Yang-Mills may be expressed as quadratic forms. Here, we show that this feature extends to theories of gravity. We demonstrate how the Hamiltonians of both pure gravity and N=8 supergravity, in four dimensions, may be written as quadratic forms. We examine the effect of residual reparametrizations on the Hamiltonian and the resulting quadratic form.

  20. Visual search for motion-form conjunctions: is form discriminated within the motion system?

    Science.gov (United States)

    von Mühlenen, A; Müller, H J

    2001-06-01

    Motion-form conjunction search can be more efficient when the target is moving (a moving 45 degrees tilted line among moving vertical and stationary 45 degrees tilted lines) rather than stationary. This asymmetry may be due to aspects of form being discriminated within a motion system representing only moving items, whereas discrimination of stationary items relies on a static form system (J. Driver & P. McLeod, 1992). Alternatively, it may be due to search exploiting differential motion velocity and direction signals generated by the moving-target and distractor lines. To decide between these alternatives, 4 experiments systematically varied the motion-signal information conveyed by the moving target and distractors while keeping their form difference salient. Moving-target search was found to be facilitated only when differential motion-signal information was available. Thus, there is no need to assume that form is discriminated within the motion system.

  1. Polyphony and verb forms

    Directory of Open Access Journals (Sweden)

    Jelena Rajić

    2012-12-01

    Full Text Available This paper examines some special uses of indicative and subjunctive verb forms in Spanish, which contemporary linguistics explains using the notions of polyphony, evidentials, echoic representation, quotatives, etc. These terms, even though they refer to different characteristics and belong to different theoretical frameworks, share one common feature: they all refer to diverse linguistic forms (discourse markers, linguistic negation, quotatives, echoic utterances, etc. characterized by the presence and interaction of different voices or points of view in one discourse sequence. In this study we are interested in a description of quotative or polyphonic meanings expressed by specific verb forms and tenses, the imperfect and the conditional, and also by indicative forms in subordinate substantive clauses with a negative main verb and by subjunctive forms in subordinate concessive clauses. Our research focuses on the analysis of the linguistic conditions that make possible the evidential use of the conditional, the imperfect and the echoic (metarepresentative interpretation of indicative and subjunctive forms in the above-mentioned contexts. The examples we discuss show that evidential and echoic interpretations are inferential meanings derived from the extralinguistic situation and the knowledge that speakers have of the world.

  2. Neutron electromagnetic form factors

    International Nuclear Information System (INIS)

    Finn, J.M.; Madey, R.; Eden, T.; Markowitz, P.; Rutt, P.M.; Beard, K.; Anderson, B.D.; Baldwin, A.R.; Keane, D.; Manley, D.M.; Watson, J.W.; Zhang, W.M.; Kowalski, S.; Bertozzi, W.; Dodson, G.; Farkhondeh, M.; Dow, K.; Korsch, W.; Tieger, D.; Turchinetz, W.; Weinstein, L.; Gross, F.; Mougey, J.; Ulmer, P.; Whitney, R.; Reichelt, T.; Chang, C.C.; Kelly, J.J.; Payerle, T.; Cameron, J.; Ni, B.; Spraker, M.; Barkhuff, D.; Lourie, R.; Verst, S.V.; Hyde-Wright, C.; Jiang, W.-D.; Flanders, B.; Pella, P.; Arenhoevel, H.

    1992-01-01

    Nucleon form factors provide fundamental input for nuclear structure and quark models. Current knowledge of neutron form factors, particularly the electric form factor of the neutron, is insufficient to meet these needs. Developments of high-duty-factor accelerators and polarization-transfer techniques permit new experiments that promise results with small sensitivities to nuclear models. We review the current status of the field, our own work at the MIT/Bates linear accelerator, and future experimental efforts

  3. Forms of address in Isizulu

    OpenAIRE

    2014-01-01

    M.A. (African Studies) The study deals with forms of address in isiZulu. Therefore, the various aspects of speech that play roles when addressing a person, the factors affecting forms of address in isiZulu and the effect of languages such as English, Afrikaans and other African languages on the forms of address in isiZulu are of interest. Research was conducted on forms of address in isiZulu in parts of Soweto and it was discovered that form of address are determined by different factors i...

  4. 33 CFR 138.40 - Forms.

    Science.gov (United States)

    2010-07-01

    ...) § 138.40 Forms. All forms referred to in this subpart may be obtained from NPFC by requesting them in writing at the address given in § 138.45(a) or by clicking on the Forms link at the NPFC E-COFR Web site... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Forms. 138.40 Section 138.40...

  5. MAPS Appraisal Report Form

    CERN Multimedia

    HR Department

    2005-01-01

    As announced in Weekly Bulletin 48/2004, from now onwards, the paper MAPS appraisal report form has been replaced by an electronic form, which is available via EDH (on the EDH desktop under Other Tasks / HR & Training) No changes have been made to the contents of the form. Practical information will be available on the web page http://cern.ch/ais/projs/forms/maps/info.htm, and information meetings will be held on the following dates: 18 January 2005: MAIN AUDITORIUM (500-1-001) from 14:00 to 15:30. 20 January 2005: AB AUDITORIUM II (864-1-D02) from14:00 to 15:30. 24 January 2005: AT AUDITORIUM (30-7-018) from 10:00 to 11:30. Human Resources Department Tel. 73566

  6. Access Customized Forms

    OpenAIRE

    Cosma Emil; Jeflea Victor

    2010-01-01

    By using Word, Excel or PowerPoint one can automate routine operations using the VBA language (Visual Basic for Applications). This language is also used in Access, allowing access to data stored in tables or queries. Thus, Access and VBA resources can be used together. Access is designed for programming forms and reports (among other things), so there won’t be found any of the VBA editor’s specific forms.

  7. Forming Limits in Sheet Metal Forming for Non-Proportional Loading Conditions - Experimental and Theoretical Approach

    International Nuclear Information System (INIS)

    Ofenheimer, Aldo; Buchmayr, Bruno; Kolleck, Ralf; Merklein, Marion

    2005-01-01

    The influence of strain paths (loading history) on material formability is well known in sheet forming processes. Sophisticated experimental methods are used to determine the entire shape of strain paths of forming limits for aluminum AA6016-T4 alloy. Forming limits for sheet metal in as-received condition as well as for different pre-deformation are presented. A theoretical approach based on Arrieux's intrinsic Forming Limit Stress Curve (FLSC) concept is employed to numerically predict the influence of loading history on forming severity. The detailed experimental strain paths are used in the theoretical study instead of any linear or bilinear simplified loading histories to demonstrate the predictive quality of forming limits in the state of stress

  8. 48 CFR 53.204-1 - Safeguarding classified information within industry (DD Form 254, DD Form 441).

    Science.gov (United States)

    2010-10-01

    ... information within industry (DD Form 254, DD Form 441). 53.204-1 Section 53.204-1 Federal Acquisition....204-1 Safeguarding classified information within industry (DD Form 254, DD Form 441). The following... specified in subpart 4.4 and the clause at 52.204-2: (a) DD Form 254 (Department of Defense (DOD)), Contract...

  9. Star-forming Filament Models

    International Nuclear Information System (INIS)

    Myers, Philip C.

    2017-01-01

    New models of star-forming filamentary clouds are presented in order to quantify their properties and to predict their evolution. These 2D axisymmetric models describe filaments that have no core, one low-mass core, and one cluster-forming core. They are based on Plummer-like cylinders and spheroids that are bounded by a constant-density surface of finite extent. In contrast to 1D Plummer-like models, they have specific values of length and mass, they approximate observed column density maps, and their distributions of column density ( N -pdfs) are pole-free. Each model can estimate the star-forming potential of a core-filament system by identifying the zone of gas dense enough to form low-mass stars and by counting the number of enclosed thermal Jeans masses. This analysis suggests that the Musca central filament may be near the start of its star-forming life, with enough dense gas to make its first ∼3 protostars, while the Coronet filament is near the midpoint of its star formation, with enough dense gas to add ∼8 protostars to its ∼20 known stars. In contrast, L43 appears to be near the end of its star-forming life, since it lacks enough dense gas to add any new protostars to the two young stellar objectsalready known.

  10. Star-forming Filament Models

    Energy Technology Data Exchange (ETDEWEB)

    Myers, Philip C., E-mail: pmyers@cfa.harvard.edu [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)

    2017-03-20

    New models of star-forming filamentary clouds are presented in order to quantify their properties and to predict their evolution. These 2D axisymmetric models describe filaments that have no core, one low-mass core, and one cluster-forming core. They are based on Plummer-like cylinders and spheroids that are bounded by a constant-density surface of finite extent. In contrast to 1D Plummer-like models, they have specific values of length and mass, they approximate observed column density maps, and their distributions of column density ( N -pdfs) are pole-free. Each model can estimate the star-forming potential of a core-filament system by identifying the zone of gas dense enough to form low-mass stars and by counting the number of enclosed thermal Jeans masses. This analysis suggests that the Musca central filament may be near the start of its star-forming life, with enough dense gas to make its first ∼3 protostars, while the Coronet filament is near the midpoint of its star formation, with enough dense gas to add ∼8 protostars to its ∼20 known stars. In contrast, L43 appears to be near the end of its star-forming life, since it lacks enough dense gas to add any new protostars to the two young stellar objectsalready known.

  11. Comparative waste forms study

    International Nuclear Information System (INIS)

    Wald, J.W.; Lokken, R.O.; Shade, J.W.; Rusin, J.M.

    1980-12-01

    A number of alternative process and waste form options exist for the immobilization of nuclear wastes. Although data exists on the characterization of these alternative waste forms, a straightforward comparison of product properties is difficult, due to the lack of standardized testing procedures. The characterization study described in this report involved the application of the same volatility, mechanical strength and leach tests to ten alternative waste forms, to assess product durability. Bulk property, phase analysis and microstructural examination of the simulated products, whose waste loading varied from 5% to 100% was also conducted. The specific waste forms investigated were as follows: Cold Pressed and Sintered PW-9 Calcine; Hot Pressed PW-9 Calcine; Hot Isostatic Pressed PW-9 Calcine; Cold Pressed and Sintered SPC-5B Supercalcine; Hot Isostatic pressed SPC-5B Supercalcine; Sintered PW-9 and 50% Glass Frit; Glass 76-68; Celsian Glass Ceramic; Type II Portland Cement and 10% PW-9 Calcine; and Type II Portland Cement and 10% SPC-5B Supercalcine. Bulk property data were used to calculate and compare the relative quantities of waste form volume produced at a spent fuel processing rate of 5 metric ton uranium/day. This quantity ranged from 3173 L/day (5280 Kg/day) for 10% SPC-5B supercalcine in cement to 83 L/day (294 Kg/day) for 100% calcine. Mechanical strength, volatility, and leach resistance tests provide data related to waste form durability. Glass, glass-ceramic and supercalcine ranked high in waste form durability where as the 100% PW-9 calcine ranked low. All other materials ranked between these two groupings

  12. FORM version 4.0

    Science.gov (United States)

    Kuipers, J.; Ueda, T.; Vermaseren, J. A. M.; Vollinga, J.

    2013-05-01

    We present version 4.0 of the symbolic manipulation system FORM. The most important new features are manipulation of rational polynomials and the factorization of expressions. Many other new functions and commands are also added; some of them are very general, while others are designed for building specific high level packages, such as one for Gröbner bases. New is also the checkpoint facility, that allows for periodic backups during long calculations. Finally, FORM 4.0 has become available as open source under the GNU General Public License version 3. Program summaryProgram title: FORM. Catalogue identifier: AEOT_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEOT_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: GNU General Public License, version 3 No. of lines in distributed program, including test data, etc.: 151599 No. of bytes in distributed program, including test data, etc.: 1 078 748 Distribution format: tar.gz Programming language: The FORM language. FORM itself is programmed in a mixture of C and C++. Computer: All. Operating system: UNIX, LINUX, Mac OS, Windows. Classification: 5. Nature of problem: FORM defines a symbolic manipulation language in which the emphasis lies on fast processing of very large formulas. It has been used successfully for many calculations in Quantum Field Theory and mathematics. In speed and size of formulas that can be handled it outperforms other systems typically by an order of magnitude. Special in this version: The version 4.0 contains many new features. Most important are factorization and rational arithmetic. The program has also become open source under the GPL. The code in CPC is for reference. You are encouraged to upload the most recent sources from www.nikhef.nl/form/formcvs.php because of frequent bug fixes. Solution method: See "Nature of Problem", above. Additional comments: NOTE: The code in CPC is for reference. You are encouraged

  13. In vitro biocompatibility of titanium after plasma surface alloying with boron

    Energy Technology Data Exchange (ETDEWEB)

    Kaczmarek, Mariusz, E-mail: markacz@ump.edu.pl [Department of Immunology, Chair of Clinical Immunology, Poznan University of Medical Sciences, Rokietnicka 5D, 60-806 Poznan (Poland); Jurczyk, Mieczysława U. [Division Mother' s and Child' s Health, Poznan University of Medical Sciences, Polna 33, 60-535 Poznan (Poland); Miklaszewski, Andrzej [Institute of Materials Science and Engineering, Poznan University of Technology, Jana Pawla II 24, 61-138 Poznan (Poland); Paszel-Jaworska, Anna; Romaniuk, Aleksandra; Lipińska, Natalia [Department of Clinical Chemistry and Molecular Diagnostics, Poznan University of Medical Sciences, Przybyszewskiego 49, 60-355 Poznan (Poland); Żurawski, Jakub [Department of Immunobiochemistry, Chair of Biology and Environmental Sciences, Poznan University of Medical Sciences, Rokietnicka 8, 60-806 Poznan (Poland); Urbaniak, Paulina [Department of Cell Biology, Poznan University of Medical Sciences, Rokietnicka 5D, 60-806 Poznan (Poland); Jurczyk, Karolina [Department of Conservative Dentistry and Periodontology, Poznan University of Medical Sciences, Bukowska 70, 60-812 Poznan (Poland)

    2016-12-01

    Recently, the effect of different sizes of precursor powders during surface plasma alloying modification on the properties of titanium surface was studied. In this work we show in vitro test results of the titanium (α-Ti) after plasma surface alloying with boron (B). Ti-B nanopowders with 2 and 10 wt% B were deposited onto microcrystalline Ti substrate. The in vitro cytocompatibility of these biomaterials was evaluated and compared with a conventional microcrystalline Ti. During the studies, established cell line of human gingival fibroblasts and osteoblasts were cultured in the presence of tested materials, and its survival rate and proliferation activity were examined. For this purpose, MTT assay, flow cytometric and fluorescent microscopic evaluation were made. Biocompatibility tests carried out indicate that the Ti after plasma surface alloying with B could be a possible candidate for dental implants and other medicinal applications. Plasma alloying is a promising method for improving the properties of titanium, thus increasing the field of its applications. - Highlights: • this is first article carried out on the titanium after plasma surface alloying with different contents of boron; • microcrystalline titanium modified with boron changes the physicochemical features of conventional material; • Ti modified by boron is proper in terms of effects on survival and proliferative activity of cells of dental alveoli; • precursors with different content of boron in different ways influence the intensity and stability of cell growth;.

  14. The Role Seemingly of Amorphous Silica Gel Layers in Chiral Separations by Planar Chromatography

    Directory of Open Access Journals (Sweden)

    Teresa Kowalska

    2007-12-01

    Full Text Available In planar chromatography, silica gel appears as the most frequently used adsorbent. Its preference as planar chromatographic stationary phase is due to its high specific surface area (ca. 700 m2 g-1 and relatively simple active sites (silanol groups, Si-OH. The high specific surface area of silica gel and a high density of coverage of its surface with the silanol active sites contribute jointly to an excellent separation performance of this adsorbent. In our experiments on chiral separation of the enantiomer pairs by planar chromatography, contradictory behavior of the silica gel layers versus the chiral compounds was observed. The migration tracks of chiral compounds in the ascending planar chromatographic mode were not vertical but bent on either side being a function of analyte chirality. This deviation of the analyte’s migration track was noticed, when using the densitometric scanner to quantify the respective chromatograms. In order to confirm the hypothesis as to the microcrystalline nature of silica gel used in liquid chromatography, it was further investigated through circular dichroism (CD and the data thereof confirmed that the ‘chromatographic’ silica gels are not amorphous but microcrystalline, contributing to the (partial horizontal enantioseparation of the antimer pairs. This paper summarizes the results of our investigation on the microcrystalline nature of silica gels used in planar chromatography and their impact on enantioseparation of the selected pairs of antimers.

  15. Electromagnetic form factors of hadrons

    International Nuclear Information System (INIS)

    Zidell, V.S.

    1976-01-01

    A vector meson dominance model of the electromagnetic form factors of hadrons is developed which is based on the use of unstable particle propagators. Least-square fits are made to the proton, neutron, pion and kaon form factor data in both the space and time-like regions. A good fit to the low-energy nucleon form factor data is obtained using only rho, ω, and phi dominance, and leads to a determination of the vector meson resonance parameters in good agreement with experiment. The nucleon-vector meson coupling constants obey simple sum rules indicating that there exists no hard core contribution to the form factors within theoretical uncertainties. The prediction for the electromagnetic radii of the proton is in reasonable agreement with recent experiments. The pion and kaon charge form factors as deduced from the nucleon form factors assuming vector meson universality are compared to the data. The pion form factor agrees with the data in both the space and time-like regions. The pion charge radius is in agreement with the recent Dubna result, but the isovector P-wave pion-pion phase shift calculated from the theory disagrees with experiment. A possible contribution to the form factors from a heavy rho meson is also evaluated

  16. Thin film silicon modules: contributions to low cost industrial production

    Energy Technology Data Exchange (ETDEWEB)

    Shah, A. [Universite de Neuchatel, Neuchatel (Switzerland)

    2005-07-01

    This final report for the Swiss Federal Office of Energy (SFOE) discusses the research work done during the two-year period 2003-04 at the Thin-Film Solar Cell Laboratory of the Institute of Microtechnology (IMT) at the University of Neuchatel in Switzerland. The transition from fundamental research work to concrete industrialisation issues, and changes within the research staff are discussed. The main results of the work done are presented, including basic techniques for the production of p-i-n solar cells on glass, new technologies for the deposition of n-i-p cells on low-cost flexible substrates and the optimisation of zinc oxide deposition methods. The key role played by substrate chemistry and roughness in the nucleation and growth of micro-crystalline silicon layers is looked at and diagnostic tools for the analysis of micro-crystalline solar cells are discussed.

  17. Properties of native and immobilised preparations of. beta. -D-glucosidase from Aspergillus niger

    Energy Technology Data Exchange (ETDEWEB)

    Woodward, J.; Wohlpart, D.L.

    1982-01-01

    The enzyme ..beta..-D-glucosidase from Aspergillus niger has been immobilised through its carbohydrate moiety on concanavalin A-Sepharose and on cyanogen bromide-activated Sepharose after aminoalkylation of the carbohydrate side chains of the enzyme. For comparison, the enzyme was also immobilised on microcrystalline cellulose through its protein moiety. High retention of activity and a decrease in K/sub m/ and V/sub max/ were observed when ..beta..-D-glucosidase was immobilised by these methods. An increase in the thermal stability of the immobilised ..beta..-D-glucosidase preparations over the soluble enzyme was achieved if it was treated with glutaraldehyde before its adsorption on concanavalin A-Sepharose or if the enzyme immobilised on cyanogen bromide-activated Sepharose was subsequently treated with glutaralydehyde. Treatment of ..beta..-D-glucosidase immobilised on microcrystalline cellulose with glutaraldehyde hardy increased its thermal stability over the soluble enzyme.

  18. Properties of native and immobilised preparations of beta-d-glucosidase from Aspergillus niger

    Energy Technology Data Exchange (ETDEWEB)

    Woodward, J.; Wohlpart, D.L.

    1982-04-01

    The enzyme beta-glucosidase from Aspergillus niger has been immobilised through its carbohydrate moiety on concanavalin A-Sepharose and on cyanogen bromide-activated Sepharose after aminoalkylation of the carbohydrate side chains of the enzyme. For comparison, the enzyme was also immobilised on microcrystalline cellulose through its protein moiety. High retention of activity and a decrease in Km and Vmax were observed when beta-D-glucosidase was immobilised by these methods. An increase in the thermal stability of the immobilized beta-D-glucosidase preparations over the soluble enzyme was achieved if it was treated with glutaraldehyde before its adsorption on concanavalin A-Sepharose or if the enzyme immobilised on cyanogen bromide-activated Sepharose was subsequently treated with glutaraldehyde. Treatment of beta-D-glucosidase immobilised on microcrystalline cellulose with glutaraldehyde hardly increased its thermal stability over the soluble enzyme. (Refs. 24).

  19. Preparation and spectral properties of europium hydrogen squarate microcrystals

    Science.gov (United States)

    Kolev, T.; Danchova, N.; Shandurkov, D.; Gutzov, S.

    2018-04-01

    A simple scheme for preparation of europium hydrogen squarate octahydrate microcrystals, Eu(HSq)3·8H2O is demonstrated. The microcrystalline powders obtained have a potential application as non-centrosymmetric and UV radiation - protective hybrid optical material. The site-symmetry of the Eu - ion is C2V or lower, obtained from diffuse reflectance spectra. The formation of europium hydrogen squarate is supported by IR - spectroscopy, UV-vis spectroscopy, chemical analysis and X-ray diffraction. A detailed analysis of the UV-vis and IR spectra of the micropowders prepared is presented. The reaction between europium oxide and squaric acid leads to formation of microcrystalline plate-like crystals of europium hydrogen squarate Eu(HSq)3·8H2O, a non-centrosymmetric hybrid optical material with a potential application as UV radiation - protective coatings.

  20. Electromagnetic Hadronic Form-Factors

    International Nuclear Information System (INIS)

    Edwards, Robert G.

    2005-01-01

    We present a calculation of the nucleon electromagnetic form-factors as well as the pion and rho to pion transition form-factors in a hybrid calculation with domain wall valence quarks and improved staggered (Asqtad) sea quarks

  1. Directory of Energy Data Collection Forms: Forms in use as of October 1996

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-12-01

    This is the twentieth edition of the Directory of Energy Collection Data Forms, an authoritative listing of selected public use forms currently used as basic energy information gathering tools by the Department of Energy.

  2. Crystallization of HWCVD amorphous silicon thin films at elevated temperatures

    CSIR Research Space (South Africa)

    Muller, TFG

    2006-01-01

    Full Text Available conditions where the hydrogen content would be minimal and the films would still exhibit good optical properties. Experimental data shows that by varying deposition conditions the transition to the nano/microcrystalline phase can be achieved. Transitional...

  3. A compiler for variational forms

    OpenAIRE

    Kirby, Robert C.; Logg, Anders

    2011-01-01

    As a key step towards a complete automation of the finite element method, we present a new algorithm for automatic and efficient evaluation of multilinear variational forms. The algorithm has been implemented in the form of a compiler, the FEniCS Form Compiler FFC. We present benchmark results for a series of standard variational forms, including the incompressible Navier-Stokes equations and linear elasticity. The speedup compared to the standard quadrature-based approach is impressive; in s...

  4. Crystallization behavior of nuclear waste forms

    International Nuclear Information System (INIS)

    Rusin, J.M.; Lokken, R.O.; May, R.P.; Wald, J.W.

    1981-09-01

    Several waste form options have been or are being developed for the immobilization of high-level wastes. The final selection of a waste form must take into consideration both waste form product as well as process factors. Crystallization behavior has an important role in nuclear waste form technology. For glass or vitreous waste forms, crystallization is generally controlled to a minimum by appropriate glass formulation and heat treatment schedules. With glass ceramic waste forms, crystallization is essential to convert glass products to highly crystalline waste forms with a minimum residual glass content. In the case of ceramic waste forms, additives and controlled sintering schedules are used to contain the radionuclides in specific tailored crystalline phases

  5. Disjoint forms in graphical user interfaces

    NARCIS (Netherlands)

    Evers, S.; Achten, P.M.; Plasmeijer, M.J.; Loidl, H.W.

    Forms are parts of a graphical user interface (GUI) that show a set of values and allow the user to update them. The declarative form construction library FunctionalForms is extended with disjoint form combinators to capture some common patterns in which the form structure expresses a choice. We

  6. Form Filling with SCC in a Vertical Form

    DEFF Research Database (Denmark)

    Thrane, Lars Nyholm

    2004-01-01

    This paper presents the results obtained from two different vertical form filling experiments with SCC that have been completed as part of the experimental work in an ongoing Ph.D project. The project is carried out at the Danish Technological Institute in collaboration with the Technical...

  7. Determination of antimony in antimony oxide by EDXRF and NAA

    International Nuclear Information System (INIS)

    Ghosh, M.; Swain, K.K.; Wagh, D.N.; Verma, R.

    2015-01-01

    It is proposed to use 124 Sb - 9 Be neutron source for starting Proto Type Fast Breeder Reactor, IGCAR, Kalpakkam. 124 Sb (γ-ray energy = 1.69 MeV; t 1/2 = 60 d) is obtained by irradiating antimony oxide and as per specification, antimony content in the oxide should be ≥ 83.0 % i.e antimony should be in the form of trioxide. Although gravimetry is the most precise and accurate method for % level analysis, it is tedious and time consuming. In this work, the study reported the determination of antimony by energy dispersive X-ray fluorescence (EDXRF) spectrometry and validation of the result by neutron activation analysis (NAA) technique. Antimony oxide encapsulated in stainless steel tube (internal diameter = 0.5 mm) was received from BHAVINI, Kalpakkam. X-ray diffraction (XRD) measurement indicated that the sample was antimony trioxide. For EDXRF analysis, calibration standards were prepared by mixing spectroscopic grade antimony trioxide with microcrystalline cellulose (2.5 to 20 mg g -1 of antimony) and pellets were made by using hydraulic press. Sample pellets were also prepared by mixing with microcrystalline cellulose. EDXRF measurement was carried out using Jordan Valley, EX-3600 M spectrometer with a Rhodium X-ray source. Characteristic K α X-ray of Sb (26.35 keV) was used for quantification. A typical XRF spectrum of the sample is shown after XRF analysis, sample and standard pellets were sealed in clean polyethylene bags and were irradiated in AHWR critical facility reactor, BARC for 4 h. Gamma ray measurement of irradiated samples were carried out using HPGe detector and 564.2 keV gamma ray of 122 Sb was used for quantification

  8. Anticipation of visual form independent of knowing where the form will occur/

    DEFF Research Database (Denmark)

    Bruhn, Pernille; Bundesen, Claus

    2012-01-01

    We investigated how selective preparation for specific forms is affected by concurrent preknowledge of location when upcoming visual stimuli are anticipated. In three experiments, participants performed a two-choice response time (RT) task in which they discriminated between standard upright...... of our effects suggested that preknowledge of form and location, respectively, affected two functionally independent, serial stages of processing. We suggest that the two stages were, first, direction of attention to the stimulus location and, subsequently, discrimination between upright and rotated...... stimuli. Presumably, preknowledge of location advanced the point in time at which attention was directed at the stimulus location, whereas preknowledge of form reduced the time subsequently taken for stimulus discrimination....

  9. 46 CFR 308.409 - Standard form of War Risk Builder's Risk Insurance Policy, Form MA-283.

    Science.gov (United States)

    2010-10-01

    ... Policy, Form MA-283. 308.409 Section 308.409 Shipping MARITIME ADMINISTRATION, DEPARTMENT OF... of War Risk Builder's Risk Insurance Policy, Form MA-283. The standard form of War Risk Builder's Risk Insurance Policy, Form MA-283 may be obtained from the American War Risk Agency or MARAD. ...

  10. Undercuts by Laser Shock Forming

    International Nuclear Information System (INIS)

    Wielage, Hanna; Vollertsen, Frank

    2011-01-01

    In laser shock forming TEA-CO 2 -laser induced shock waves are used to form metal foils, such as aluminum or copper. The process utilizes an initiated plasma shock wave on the target surface, which leads to a forming of the foil. A challenge in forming technologies is the manufacturing of undercuts. By conventional forming methods these special forms are not feasible. In this article, it is presented that undercuts in the micro range can be produced by laser shock deep drawing. Different drawing die diameters, drawing die depths and the material aluminum in the thicknesses 20 and 50 μm were investigated. It will be presented that smaller die diameters facilitate undercuts compared to bigger die diameters. The phenomena can be explained by Barlow's formula. Furthermore, it is shown which maximum undercut depth at different die diameters can be reached. To this end, cross-sections of the different parameter combinations are displayed.

  11. Package materials, waste form

    International Nuclear Information System (INIS)

    Anon.

    1980-01-01

    The schedules for waste package development for the various host rocks were presented. The waste form subtask activities were reviewed, with the papers focusing on high-level waste, transuranic waste, and spent fuel. The following ten papers were presented: (1) Waste Package Development Approach; (2) Borosilicate Glass as a Matrix for Savannah River Plant Waste; (3) Development of Alternative High-Level Waste Forms; (4) Overview of the Transuranic Waste Management Program; (5) Assessment of the Impacts of Spent Fuel Disassembly - Alternatives on the Nuclear Waste Isolation System; (6) Reactions of Spent Fuel and Reprocessing Waste Forms with Water in the Presence of Basalt; (7) Spent Fuel Stabilizer Screening Studies; (8) Chemical Interactions of Shale Rock, Prototype Waste Forms, and Prototype Canister Metals in a Simulated Wet Repository Environment; (9) Impact of Fission Gas and Volatiles on Spent Fuel During Geologic Disposal; and (10) Spent Fuel Assembly Decay Heat Measurement and Analysis

  12. STUDI KOMPARASI KINERJA HULL FORM METODE SCHELTEMA DENGAN HULL FORM KAPAL IKAN TRADISIONAL TIPE DAERAH BATANG

    OpenAIRE

    A.F. Zakki; Parlindungan Manik

    2012-01-01

    This study comparation of hull form performance was analysed becaused there was suggestion that a ship was built by hull form scheming this time (Scheltema, Formdata, NPL Series) is better than a ship that was built traditionally because there is no basic erudite calculation in hull form design. So hull form design was result of natural adaptation. Such performance are ship’s resistance, stability, and ship’s navigation.This research about hull form performance is expected can giv...

  13. Fulvic acid-like organic compounds control nucleation of marine calcite under suboxic conditions

    NARCIS (Netherlands)

    Neuweiler, F.; D'Orazio, M.; Immenhauser, A.M.; Geipel, G.; Heise, K.H.; Cocozza, C.; Miano, T.M.

    2003-01-01

    Intracrystalline organic compounds, enclosed within in situprecipitated marine microcrystalline calcite (automicrite), might represent either an inclusion or the catalyst of such precipitation. We use evidence from a Lower Cretaceous deep-water carbonate mound to show (1) the original source, (2)

  14. Tropical Journal of Pharmaceutical Research, June 2002; 1 (1): 63-22

    African Journals Online (AJOL)

    Clinical Phamacy

    the well-known commercial microcrystalline cellulose grade, Avicel PH 101. Results: The extraction .... A sieve-shaker, (Retak 3D, Retsch GmbH and. Co KG, Haan, Germany) ... in each of four 15 ml plastic centrifuge tubes and 10 ml distilled ...

  15. Material, compressional and mechanical properties of Borassus ...

    African Journals Online (AJOL)

    The compressional and mechanical properties of tablet formulations incorporating native and modified Borassus aethiopum starches as binder were evaluated. The native Borassus aethiopum starch (BAS) was modified to yield fully gelatinised starch (FGBAS) and microcrystalline starch (MBAS). The compressional ...

  16. Cold-formed steel design

    CERN Document Server

    Yu, Wei-Wen

    2010-01-01

    The definitive text in the field, thoroughly updated and expanded Hailed by professionals around the world as the definitive text on the subject, Cold-Formed Steel Design is an indispensable resource for all who design for and work with cold-formed steel. No other book provides such exhaustive coverage of both the theory and practice of cold-formed steel construction. Updated and expanded to reflect all the important developments that have occurred in the field over the past decade, this Fourth Edition of the classic text provides you with more of the detailed, up-to-the-minute techni

  17. Secondary halite deposits in the Iranian salt karst: general description and origin

    Directory of Open Access Journals (Sweden)

    Filippi Michal

    2011-07-01

    Full Text Available This paper summaries 12 years of documentation of secondary halite deposits in the Iranian salt karst. A variety of secondary halitedeposits was distinguished and classified into several groups, on the basis of the site and mechanism of their origin. Deposits formed:i via crystallization in/on streams and pools, ii from dripping, splashing and aerosol water, iii from evaporation of seepage and capillarywater, and iv other types of deposits. The following examples of halite forms were distinguished in each of the above mentionedgroup: i euhedral crystals, floating rafts (raft cones, thin brine surface crusts and films; ii straw stalactites, macrocrystalline skeletaland hyaline deposits, aerosol deposits; iii microcrystalline forms (crusts, stalactites and stalagmites, helictites; iv macrocrystallinehelictites, halite bottom fibers and spiders, crystals in fluvial sediments, euhedral halite crystals in rock salt, combined or transientforms and biologically induced deposits. The occurrence of particular forms depends strongly on the environment, especially on thetype of brine occurrence (pool, drip, splashing brine, microscopic capillary brine, etc., flow rate and its variation, atmospheric humidity,evaporation rate and, in some cases, on the air flow direction. Combined or transitional secondary deposits can be observed if theconditions changed during the deposition. Euhedral halite crystals originate solely below the brine surface of supersaturated streamsand lakes. Macrocrystalline skeletal deposits occur at places with rich irregular dripping and splashing (i.e., waterfalls, places withstrong dripping from the cave ceilings, etc.. Microcrystalline (fine grained deposits are generated by evaporation of capillary brineat places where brine is not present in a macroscopically visible form. Straw stalactites form at places where dripping is concentratedin small spots and is frequent sufficient to assure that the tip of the stalactite will not be

  18. Floating matrix tablets based on low density foam powder: effects of formulation and processing parameters on drug release.

    Science.gov (United States)

    Streubel, A; Siepmann, J; Bodmeier, R

    2003-01-01

    The aim of this study was to develop and physicochemically characterize single unit, floating controlled drug delivery systems consisting of (i). polypropylene foam powder, (ii). matrix-forming polymer(s), (iii). drug, and (iv). filler (optional). The highly porous foam powder provided low density and, thus, excellent in vitro floating behavior of the tablets. All foam powder-containing tablets remained floating for at least 8 h in 0.1 N HCl at 37 degrees C. Different types of matrix-forming polymers were studied: hydroxypropyl methylcellulose (HPMC), polyacrylates, sodium alginate, corn starch, carrageenan, gum guar and gum arabic. The tablets eroded upon contact with the release medium, and the relative importance of drug diffusion, polymer swelling and tablet erosion for the resulting release patterns varied significantly with the type of matrix former. The release rate could effectively be modified by varying the "matrix-forming polymer/foam powder" ratio, the initial drug loading, the tablet geometry (radius and height), the type of matrix-forming polymer, the use of polymer blends and the addition of water-soluble or water-insoluble fillers (such as lactose or microcrystalline cellulose). The floating behavior of the low density drug delivery systems could successfully be combined with accurate control of the drug release patterns.

  19. Tectonics: The meaning of form

    DEFF Research Database (Denmark)

    Christiansen, Karl; Brandt, Per Aage

    Tectonics – The meaning of form deals with one of the core topics of architecture: the relationship between form and content. In the world of architecture, form is not only made from brick, glass and wood. Form means something. When a material is processed with sufficient technical skill and insi...... perspectives. You can read the chapters in any order you like – from the beginning, end or the middle. There is no correct order. The project is methodologically inductive: the more essays you read, the broader your knowledge of tectonics get....

  20. Functional analysis of the Glucan Degradation Locus (GDL) in Caldicellulosiruptor bescii reveals essential roles of component glycoside hydrolases in plant biomass deconstruction.

    Science.gov (United States)

    Conway, Jonathan M; McKinley, Bennett S; Seals, Nathaniel L; Hernandez, Diana; Khatibi, Piyum A; Poudel, Suresh; Giannone, Richard J; Hettich, Robert L; Williams-Rhaesa, Amanda M; Lipscomb, Gina L; Adams, Michael W W; Kelly, Robert M

    2017-10-06

    The ability to hydrolyze microcrystalline cellulose is an uncommon feature in the microbial world, but one that can be exploited for conversion of lignocellulosic feedstocks into bio-based fuels and chemicals. Understanding the physiological and biochemical mechanisms by which microorganisms deconstruct cellulosic material is key to achieving this objective. The Glucan Degradation Locus (GDL) in the genomes of extremely thermophilic Caldicellulosiruptor species encodes polysaccharide lyases (PLs), unique cellulose binding proteins (tāpirins), and putative post-translational modifying enzymes, in addition to multi-domain, multi-functional glycoside hydrolases (GHs), thereby representing an alternative paradigm for plant biomass degradation, as compared to fungal or cellulosomal systems. To examine the individual and collective in vivo roles of the glycolytic enzymes, the six GHs in the GDL of Caldicellulosiruptor bescii were systematically deleted, and the extent to which the resulting mutant strains could solubilize microcrystalline cellulose (Avicel) and plant biomasses (switchgrass or poplar) was examined. Three of the GDL enzymes, Athe_1867 (CelA) (GH9-CBM3-CBM3-CBM3-GH48), Athe_1859 (GH5-CBM3-CBM3-GH44), and Athe_1857 (GH10-CBM3-CBM3-GH48), acted synergistically in vivo and accounted for 92% of naked microcellulose (Avicel) degradation. However, the relative importance of the GDL GHs varied for the plant biomass substrates tested. Furthermore, mixed cultures of mutant strains showed switchgrass solubilization depended on the secretome-bound enzymes collectively produced by the culture and not on the specific strain from which they came. These results demonstrate that certain GDL GHs are primarily responsible for the degradation of microcrystalline-containing substrates by C. bescii and provide new insights into the workings of a novel microbial mechanism for lignocellulose utilization. Importance The efficient and extensive degradation of complex

  1. 8 CFR 265.1 - Forms.

    Science.gov (United States)

    2010-01-01

    ... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Forms. 265.1 Section 265.1 Aliens and Nationality DEPARTMENT OF HOMELAND SECURITY IMMIGRATION REGULATIONS NOTICES OF ADDRESS § 265.1 Forms. Except... under section 262 of the Act shall report each change of address and new address within 10 days on Form...

  2. 29 CFR 1904.29 - Forms.

    Science.gov (United States)

    2010-07-01

    ... OSHA 300 Log. Instead, enter “privacy case” in the space normally used for the employee's name. This...) Basic requirement. You must use OSHA 300, 300-A, and 301 forms, or equivalent forms, for recordable injuries and illnesses. The OSHA 300 form is called the Log of Work-Related Injuries and Illnesses, the 300...

  3. Methods of forming single source precursors, methods of forming polymeric single source precursors, and single source precursors and intermediate products formed by such methods

    Science.gov (United States)

    Fox, Robert V.; Rodriguez, Rene G.; Pak, Joshua J.; Sun, Chivin; Margulieux, Kelsey R.; Holland, Andrew W.

    2012-12-04

    Methods of forming single source precursors (SSPs) include forming intermediate products having the empirical formula 1/2{L.sub.2N(.mu.-X).sub.2M'X.sub.2}.sub.2, and reacting MER with the intermediate products to form SSPs of the formula L.sub.2N(.mu.-ER).sub.2M'(ER).sub.2, wherein L is a Lewis base, M is a Group IA atom, N is a Group IB atom, M' is a Group IIIB atom, each E is a Group VIB atom, each X is a Group VIIA atom or a nitrate group, and each R group is an alkyl, aryl, vinyl, (per)fluoro alkyl, (per)fluoro aryl, silane, or carbamato group. Methods of forming polymeric or copolymeric SSPs include reacting at least one of HE.sup.1R.sup.1E.sup.1H and MER with one or more substances having the empirical formula L.sub.2N(.mu.-ER).sub.2M'(ER).sub.2 or L.sub.2N(.mu.-X).sub.2M'(X).sub.2 to form a polymeric or copolymeric SSP. New SSPs and intermediate products are formed by such methods.

  4. A regression-based Kansei engineering system based on form feature lines for product form design

    Directory of Open Access Journals (Sweden)

    Yan Xiong

    2016-06-01

    Full Text Available When developing new products, it is important for a designer to understand users’ perceptions and develop product form with the corresponding perceptions. In order to establish the mapping between users’ perceptions and product design features effectively, in this study, we presented a regression-based Kansei engineering system based on form feature lines for product form design. First according to the characteristics of design concept representation, product form features–product form feature lines were defined. Second, Kansei words were chosen to describe image perceptions toward product samples. Then, multiple linear regression and support vector regression were used to construct the models, respectively, that predicted users’ image perceptions. Using mobile phones as experimental samples, Kansei prediction models were established based on the front view form feature lines of the samples. From the experimental results, these two predict models were of good adaptability. But in contrast to multiple linear regression, the predict performance of support vector regression model was better, and support vector regression is more suitable for form regression prediction. The results of the case showed that the proposed method provided an effective means for designers to manipulate product features as a whole, and it can optimize Kansei model and improve practical values.

  5. Chemical forms of radioiodine

    International Nuclear Information System (INIS)

    Tachikawa, Enzo

    1979-01-01

    Release of radioiodine built-up during reactor operations presents a potential problem from the standpoint of environmental safety. Among the chemical forms of radioiodine, depending upon the circumstances, organic iodides cast a most serious problem because of its difficulties in the trapping and because of its stability compared to other chemical forms. Furthermore, pellet-cladding interaction (PCl) fuel failures in LWR fuel rods are believed to be stress corrosion cracks caused by embrittling fission product species, radioiodine. To deal with these problems, knowledge is required on the chemical behaviors of radioiodine in and out of fuels, as well as the release behaviors from fuels. Here a brief review is given of these respects, in aiming at clearing-up the questions still remaining unknown. The data seem to indicate that radioiodine exists as a combined form in fuels. upon heating slightly irradiated fuels, the iodine atoms are released in a chemical form associated with uranium atoms. Experiments, however, as needed with specimen of higher burnup, where the interactions of radioiodine with metallic fission products could be favored. The dominant release mechanism of radioiodine under normal operating temperatures will be diffusion to grain boundaries leading to open surfaces. Radiation-induced internal traps, however, after the rate of diffusion significantly. The carbon sources of organic iodides formed under various conditions and its formation mechanisms have also been considered. (author)

  6. INVESTIGATION OF THE PHARMACO-TECHNOLOGICAL PROPERTIES OF SOLID DISPERSIONS OF THIOCTIC ACID, OBTAINED BY MICRONIZATION

    Directory of Open Access Journals (Sweden)

    Kovalevska, I. V.

    2018-04-01

    Full Text Available Introduction. Thioctic acid is used in the treatment of diseases that are characterized by lack of mitochondrial activity, which is responsible for the formation of free radicals. Widespread use of thioctic acid is due to the chemical structure. The thioctic acid exhibits biological activity in both hydrophilic and hydrophobic environments. Thioctic acid is an enzyme cofactor and a powerful antioxidant, it regulates the transcription of numerous genes, participates in regulation of glucose and lipid metabolism, increases insulin sensitivity, and forms complexes with heavy metals. Thioctic acid has a high pharmacological potential, which is confirmed by the evidence base of clinical trials. An analysis of the literature on the oral use of thioctic acid indicates that solid dosage forms can be used for long-term therapy. This route of administration is limited by factors such as reduced solubility in acidic environments and enzymatic degradation. For this reason, the search for various compositions of auxiliary substances and methods of obtaining drugs is an urgent task of pharmaceutical technology. Material & methods. Objects of study were solid dispersions of thioctic acid (SDTA on the basis of cellulose derivatives: microcrystalline (MCC, HPMC (hydroxypropyl methylcellulose and polyvinylpyrrolidone (PVP as compared to thioctic acid (TA. The samples were made by solid phase method using micronization in a laboratory shredder at a ratio of 1: 1. Pharmacological and technological parameters were determined according to generally accepted methods. Results & discussion. In appearance the resulting mixtures had lemon color, without inclusions and the formation of conglomerates, with homogeneous sized particles According to the pharmaco-technological studies, the samples do not have a satisfactory flowability. The values of the Carr index and the ratio of Hausner make it possible to conclude that there is a large force of cohesion between the

  7. Forms of Life

    Directory of Open Access Journals (Sweden)

    Peter Hacker

    2015-10-01

    Full Text Available The phrase ‘Lebensform’ (form of life had a long and varied history prior to Wittgenstein’s use of it on a mere three occasions in the Philosophical Investigations. It is not a pivotal concept in Wittgenstein’s philosophy. But it is a minor signpost of a major reorientation of philosophy, philosophy of language and logic, and philosophy of mathematics that Wittgenstein instigated. For Wittgenstein sought to replace the conception of a language as a meaning calculus (Frege, Russell, the Tractatus by an anthropological or ethnological conception. A language is not a class of sentences that can be formed from a set of axioms (definitions, formation and transformation rules and the meanings of which is given by their truth-conditions, but an open-ended series of interlocking language-games constituting a form of life or way of living (a culture. Wittgenstein’s uses of ‘Lebensform’ and its cognates, both in the Investigations and in his Nachlass are severally analysed, and various exegetical misinterpretations are clarified.

  8. Fabrication and characterization of contact layers in amorphous silicon solar cells

    International Nuclear Information System (INIS)

    Kolter, M.

    1993-04-01

    The production and characterisation of amorphous and microcrystalline n-doped layers (a-Si:H(n) and c-Si:H(n)) for thin film solar cells is described together contact investigations. The layers were produced in a plasma CVD. The electric conductivity was measured

  9. Size Effect on the Infrared Spectra of Condensed Media under Conditions of 1D, 2D, and 3D Dielectric Confinement

    KAUST Repository

    Shaganov, Igor I.; Perova, Tatiana S.; Melnikov, Vasily; Dyakov, Sergey A.; Berwick, Kevin

    2010-01-01

    with the calculated data. It is shown using simulations of the absorption spectrum of MgO powder that the approach suggested can be applied under certain conditions to the modeling of the spectra of microcrystalline particles of nonspheroidal shape. © 2010 American

  10. Derivative spectrophotometric determination of trace lead in alloys ...

    African Journals Online (AJOL)

    diethylaminophenol-ammonium tetraphenylborate with microcrystalline naphthalene or by a column method in the pH range 4.0–6.0 from a large volume of aqueous solutions of various samples. After filtration, the solid mass consisting of the lead complex and ...

  11. Variational principles for locally variational forms

    International Nuclear Information System (INIS)

    Brajercik, J.; Krupka, D.

    2005-01-01

    We present the theory of higher order local variational principles in fibered manifolds, in which the fundamental global concept is a locally variational dynamical form. Any two Lepage forms, defining a local variational principle for this form, differ on intersection of their domains, by a variationally trivial form. In this sense, but in a different geometric setting, the local variational principles satisfy analogous properties as the variational functionals of the Chern-Simons type. The resulting theory of extremals and symmetries extends the first order theories of the Lagrange-Souriau form, presented by Grigore and Popp, and closed equivalents of the first order Euler-Lagrange forms of Hakova and Krupkova. Conceptually, our approach differs from Prieto, who uses the Poincare-Cartan forms, which do not have higher order global analogues

  12. Aging phenomena of chitosan and chitosan-diclofenac sodium system detected by low-frequency dielectric spectroscopy.

    Science.gov (United States)

    Bodek, K H; Bak, G W

    1999-09-01

    The use of natural polymers for design of dosage form has received considerable attention recently, especially from the safety point of view. Among these polymers, chitosan shows very interesting biological, chemical and physical properties which makes it possible to use chitosan for various pharmaceutical applications. Microcrystalline chitosan (MCCh) is a special multifunctional polymeric material existing in the form of either of gelatinous water dispersion or a powder. Thermal aging of chitosan and chitosan-diclofenac sodium mixture have been studied using low-frequency dielectric measurements. The aging was carried out by annealing in ambient atmosphere in the temperature range between 25 degrees C and 100 degrees C. The dielectric losses in the aged samples proved to decrease by about one order of magnitude. The additional measurements of molecular weight distribution and infrared absorption were also carried out for better understanding of nature of the ageing phenomena. Partial evacuation of water, cross-linking and improvement of structural order may be suggested to be a result of thermal aging of the investigated materials.

  13. Metal ion analysis in contaminated water samples using anodic stripping voltammetry and a nanocrystalline diamond thin-film electrode

    International Nuclear Information System (INIS)

    Sonthalia, Prerna; McGaw, Elizabeth; Show, Yoshiyuki; Swain, Greg M.

    2004-01-01

    Boron-doped nanocrystalline diamond thin-film electrodes were employed for the detection and quantification of Ag (I), Cu (II), Pb (II), Cd (II), and Zn (II) in several contaminated water samples using anodic stripping voltammetric (ASV). Diamond is an alternate electrode that possesses many of the same attributes as Hg and, therefore, appears to be a viable material for this electroanalytical measurement. The nanocrystalline form has been found to perform slightly better than the more conventional microcrystalline form of diamond in this application. Differential pulse voltammetry (DPASV) was used to detect these metal ions in lake water, well water, tap water, wastewater treatment sludge, and soil. The electrochemical results were compared with data from inductively coupled plasma mass spectrometric (ICP-MS) and or atomic absorption spectrometric (AAS) measurements of the same samples. Diamond is shown to function well in this electroanalytical application, providing a wide linear dynamic range, a low limit of quantitation, excellent response precision, and good response accuracy. For the analysis of Pb (II), bare diamond provided a response nearly identical to that obtained with a Hg-coated glassy carbon electrode

  14. Electroweak form factors of the Skyrmion

    International Nuclear Information System (INIS)

    Braaten, E.; Sze-Man Tse; Willcox, C.

    1986-01-01

    The electroweak form factors of baryons are studied in the semiclassical approximation to the Skyrme model. General expressions for the form factors are given for arbitrary choices of the Skyrme-model Lagrangian. They are applied to the original two-parameter Skyrme model to compute the electric, magnetic, and axial-vector form factors of the nucleon and the electromagnetic nucleon-Δ transition form factors. The dependence of the form factors on the momentum transfer is compared with phenomenological dipole parametrizations

  15. Forms of Life, Forms of Reality

    Directory of Open Access Journals (Sweden)

    Piergiorgio Donatelli

    2015-10-01

    Full Text Available The article explores aspects of the notion of forms of life in the Wittgensteinian tradition especially following Iris Murdoch’s lead. On the one hand, the notion signals the hardness and inexhaustible character of reality, as the background needed in order to make sense of our lives in various ways. On the other, the hardness of reality is the object of a moral work of apprehension and deepening to the point at which its distinctive character dissolves into the family of connections we have gained for ourselves. The two movements of thought are connected and necessary.

  16. Form 6 - gas balancing agreement

    International Nuclear Information System (INIS)

    Anon.

    1990-01-01

    In 1988, a special Committee of the Rocky Mountain Mineral Law Foundation undertook a project to draft a model from gas balancing agreement. This project was initiated at the request of a number of Foundation members who felt that a model form gas balancing agreement would facilitate the negotiation of operating agreement, since gas balancing issues had become sticking points in the process. The Committee was composed of attorneys representing a wide cross-section of the oil and gas industry including both major and independent oil companies, production companies with interstate pipeline affiliates, and private practitioners. The Committee attempted to address the more controversial issues in gas balancing with optional provisions in the Form. To facilitate the negotiation process, the number of optional provisions was minimized. This form may be used as an Appendix to the new A.A.P.L. Form 610-1989 Model Form Operating Agreement. This book includes provision of this Form which are: Ownership of gas production; Balancing of production accounts; Cash balancing upon depletion; Deliverability tests; Nominations; Statements; Payment of taxes; Operating expenses; Overproducing allowable; Payment of leasehold burdens; Operator's liability; Successors and assigns; Audits; Arbitration; and Operator's fees

  17. Thin film silicon photovoltaics: Architectural perspectives and technological issues

    Energy Technology Data Exchange (ETDEWEB)

    Mercaldo, Lucia Vittoria; Addonizio, Maria Luisa; Noce, Marco Della; Veneri, Paola Delli; Scognamiglio, Alessandra; Privato, Carlo [ENEA, Portici Research Center, Piazzale E. Fermi, 80055 Portici (Napoli) (Italy)

    2009-10-15

    Thin film photovoltaics is a particularly attractive technology for building integration. In this paper, we present our analysis on architectural issues and technological developments of thin film silicon photovoltaics. In particular, we focus on our activities related to transparent and conductive oxide (TCO) and thin film amorphous and microcrystalline silicon solar cells. The research on TCO films is mainly dedicated to large-area deposition of zinc oxide (ZnO) by low pressure-metallorganic chemical vapor deposition. ZnO material, with a low sheet resistance (<8 {omega}/sq) and with an excellent transmittance (>82%) in the whole wavelength range of photovoltaic interest, has been obtained. ''Micromorph'' tandem devices, consisting of an amorphous silicon top cell and a microcrystalline silicon bottom cell, are fabricated by using the very high frequency plasma enhanced chemical vapor deposition technique. An initial efficiency of 11.1% (>10% stabilized) has been obtained. (author)

  18. 'Micromorph' solar cells; 'Mikromorphe' Solarzellen, basierend auf amorphem und mikrokristallinem Silizium

    Energy Technology Data Exchange (ETDEWEB)

    Shah, A.

    2000-07-01

    This report on behalf of the Swiss Federal Office of Energy (SFOE) describes the achievements made in a project carried out at the Institute of Microelectronics (IMT) in Neuchatel, Switzerland. The project, whose goal was to demonstrate the potential of tandem cells consisting of a combination of micro-crystalline and amorphous solar cells, has spawned world-wide interest and also initiated much research into the use of VHF-GD (Very High Frequency Glow-discharge) techniques to deposit thin films. Individual results achieved at IMT including those from investigations into micro-crystalline structures and textures and their absorption enhancement effects, electronic transport, improvement of open-circuit voltage, deposition rates, patterning techniques and increasing stabilised efficiencies are listed. A first Micromorph 23.6 cm{sup 2} mini-module using an integrated electric series connection concept is mentioned and advances in the IMT's infrastructure and facilities are described.

  19. 76 FR 82003 - Submission for Review: DD 1918 Establishment Information Form, DD 1919 Wage Data Collection Form...

    Science.gov (United States)

    2011-12-29

    ... OFFICE OF PERSONNEL MANAGEMENT Submission for Review: DD 1918 Establishment Information Form, DD 1919 Wage Data Collection Form, DD 1919C Wage Data Collection Continuation Form AGENCY: U.S. Office of... existing information collection request (ICR) 3206-0036, Establishment Information Form (DD 1918), Wage...

  20. 76 FR 50771 - Submission for Review: DD 1918 Establishment Information Form, DD 1919 Wage Data Collection Form...

    Science.gov (United States)

    2011-08-16

    ... OFFICE OF PERSONNEL MANAGEMENT Submission for Review: DD 1918 Establishment Information Form, DD 1919 Wage Data Collection Form, DD 1919C Wage Data Collection Continuation Form AGENCY: U.S. Office of... existing information collection request (ICR) 3206-0036, Establishment Information Form (DD 1918), Wage...

  1. Amorphous drugs and dosage forms

    DEFF Research Database (Denmark)

    Grohganz, Holger; Löbmann, K.; Priemel, P.

    2013-01-01

    The transformation to an amorphous form is one of the most promising approaches to address the low solubility of drug compounds, the latter being an increasing challenge in the development of new drug candidates. However, amorphous forms are high energy solids and tend to recry stallize. New...... formulation principles are needed to ensure the stability of amorphous drug forms. The formation of solid dispersions is still the most investigated approach, but additional approaches are desirable to overcome the shortcomings of solid dispersions. Spatial separation by either coating or the use of micro-containers...... before single molecules are available for the formation of crystal nuclei, thus stabilizing the amorphous form....

  2. Automated Test-Form Generation

    Science.gov (United States)

    van der Linden, Wim J.; Diao, Qi

    2011-01-01

    In automated test assembly (ATA), the methodology of mixed-integer programming is used to select test items from an item bank to meet the specifications for a desired test form and optimize its measurement accuracy. The same methodology can be used to automate the formatting of the set of selected items into the actual test form. Three different…

  3. Mastering HTML5 forms

    CERN Document Server

    Gupta, Gaurav

    2013-01-01

    This tutorial will show you how to create stylish forms, not only visually appealing, but interactive and customized, in order to gather valuable user inputs and information.Enhance your skills in building responsive and dynamic web forms using HTML5, CSS3, and related technologies. All you need is a basic understanding of HTML and PHP.

  4. 49 CFR 191.19 - Report forms.

    Science.gov (United States)

    2010-10-01

    ... forms. Copies of the prescribed report forms are available without charge upon request from the address... 49 Transportation 3 2010-10-01 2010-10-01 false Report forms. 191.19 Section 191.19 Transportation... size and kind of paper. In addition, the information required by these forms may be submitted by any...

  5. Microcrystalline cellulose and sisal fibre reinforced cementitious composites

    OpenAIRE

    Ferreira, Stephany Maria Vieira

    2016-01-01

    Dissertação de mestrado integrado em Engenharia Civil (área de especialização em Perfil de Construções) Nas últimas décadas tem existido um crescente interesse em métodos alternativos de reforçar compósitos cimentícios. A utilização de fibras naturais como elemento de reforço tem sido bastante explorada ao longo dos anos, sendo que origina compósitos cimentícios com uma resistência ao impacto e à fissuração superior quando comparados com compósitos cimentícios comuns. Por outro...

  6. Electron field emission from boron doped microcrystalline diamond

    International Nuclear Information System (INIS)

    Roos, M.; Baranauskas, V.; Fontana, M.; Ceragioli, H.J.; Peterlevitz, A.C.; Mallik, K.; Degasperi, F.T.

    2007-01-01

    Field emission properties of hot filament chemical vapor deposited boron doped polycrystalline diamond have been studied. Doping level (N B ) of different samples has been varied by the B/C concentration in the gas feed during the growth process and doping saturation has been observed for high B/C ratios. Threshold field (E th ) for electron emission as function of B/C concentration has been measured, and the influences of grain boundaries, doping level and surface morphology on field emission properties have been investigated. Carrier transport through conductive grains and local emission properties of surface sites have been figured out to be two independent limiting effects in respect of field emission. Emitter current densities of 500 nA cm -2 were obtained using electric fields less than 8 V/μm

  7. Ceramic and glass radioactive waste forms

    Energy Technology Data Exchange (ETDEWEB)

    Readey, D.W.; Cooley, C.R. (comps.)

    1977-01-01

    This report contains 14 individual presentations and 6 group reports on the subject of glass and polycrystalline ceramic radioactive waste forms. It was the general consensus that the information available on glass as a waste form provided a good basis for planning on the use of glass as an initial waste form, that crystalline ceramic forms could also be good waste forms if much more development work were completed, and that prediction of the chemical and physical stability of the waste form far into the future would be much improved if the basic synergistic effects of low temperature, radiation and long times were better understood. Continuing development of the polycrystalline ceramic forms was recommended. It was concluded that the leach rate of radioactive species from the waste form is an important criterion for evaluating its suitability, particularly for the time period before solidified waste is permanently placed in the geologic isolation of a Federal repository. Separate abstracts were prepared for 12 of the individual papers; the remaining two were previously abstracted.

  8. Secondary Waste Form Down-Selection Data Package—Fluidized Bed Steam Reforming Waste Form

    Energy Technology Data Exchange (ETDEWEB)

    Qafoku, Nikolla; Westsik, Joseph H.; Strachan, Denis M.; Valenta, Michelle M.; Pires, Richard P.

    2011-09-12

    The Hanford Site in southeast Washington State has 56 million gallons of radioactive and chemically hazardous wastes stored in 177 underground tanks (ORP 2010). The U.S. Department of Energy (DOE), Office of River Protection (ORP), through its contractors, is constructing the Hanford Tank Waste Treatment and Immobilization Plant (WTP) to convert the radioactive and hazardous wastes into stable glass waste forms for disposal. Within the WTP, the pretreatment facility will receive the retrieved waste from the tank farms and separate it into two treated process streams. These waste streams will be vitrified, and the resulting waste canisters will be sent to offsite (high-level waste [HLW]) and onsite (immobilized low-activity waste [ILAW]) repositories. As part of the pretreatment and ILAW processing, liquid secondary wastes will be generated that will be transferred to the Effluent Treatment Facility (ETF) on the Hanford Site for further treatment. These liquid secondary wastes will be converted to stable solid waste forms that will be disposed of in the Integrated Disposal Facility (IDF). To support the selection of a waste form for the liquid secondary wastes from WTP, Washington River Protection Solutions (WRPS) has initiated secondary waste form testing work at Pacific Northwest National Laboratory (PNNL). In anticipation of a down-selection process for a waste form for the Solidification Treatment Unit to be added to the ETF, PNNL is developing data packages to support that down-selection. The objective of the data packages is to identify, evaluate, and summarize the existing information on the four waste forms being considered for stabilizing and solidifying the liquid secondary wastes. At the Hanford Site, the FBSR process is being evaluated as a supplemental technology for treating and immobilizing Hanford LAW radioactive tank waste and for treating secondary wastes from the WTP pretreatment and LAW vitrification processes.

  9. High-Purity Hybrid Organolead Halide Perovskite Nanoparticles Obtained by Pulsed-Laser Irradiation in Liquid

    KAUST Repository

    Amendola, Vincenzo

    2016-11-17

    Nanoparticles of hybrid organic-inorganic perovskites have attracted a great deal of attention due to their variety of optoelectronic properties, their low cost, and their easier integration into devices with complex geometry, compared with microcrystalline, thin-film, or bulk metal halides. Here we present a novel one-step synthesis of organolead bromide perovskite nanocrystals based on pulsed-laser irradiation in a liquid environment (PLIL). Starting from a bulk CHNHPbBr crystal, our PLIL procedure does not involve the use of high-boiling-point polar solvents or templating agents, and runs at room temperature. The resulting nanoparticles are characterized by high crystallinity and are completely free of any microscopic product or organic coating layer. We also demonstrate the straightforward inclusion of laser-generated perovskite nanocrystals in a polymeric matrix to form a nanocomposite with single- and two-photon luminescence properties.

  10. Thermoelectric generator and method of forming same

    International Nuclear Information System (INIS)

    Wilson, K.T.

    1981-01-01

    A thermoelectric device is disclosed which comprises the formation of a multiplicity of thermocouples on a substrate in a narrow strip form, the thermocouples being formed by printing with first and second inks formed of suitable different powdered metals with a proper binder or flux. The thermocouples are formed in series and the opposed coupled areas are melted to form an intermingling of the two metals and the strips may be formed in substantial lengths and rolled onto a reel, or in relatively short strip form and disposed in a side-by-side abutting relationship in substantial numbers to define a generally rectangular panel form with opposed ends in electrical connection. The method of forming the panels includes the steps of feeding a suitable substrate, either in a continuous roll or sheet form, through first and second printers to form the series connected multiplicity of thermocouples thereon. From the printers the sheet or strip passes through a melter such as an induction furnace and from the furnace it passes through a sheeter, if the strip is in roll form. The sheets are then slit into narrow strips relative to the thermocouples, printed thereon and the strips are then formed into a bundle. A predetermined number of bundles are assembled into a panel form

  11. Waste-form development

    International Nuclear Information System (INIS)

    Neilson, R.M. Jr.; Colombo, P.

    1982-01-01

    Contemporary solidification agents are being investigated relative to their applications to major fuel cycle and non-fuel cycle low-level waste (LLW) streams. Work is being conducted to determine the range of conditions under which these solidification agents can be applied to specific LLW streams. These studies are directed primarily towards defining operating parameters for both improved solidification of problem wastes and solidification of new LLW streams generated from advanced volume reduction technologies. Work is being conducted to measure relevant waste form properties. These data will be compiled and evaluated to demonstrate compliance with waste form performance and shallow land burial acceptance criteria and transportation requirements

  12. Comparative analysis of JKR Sarawak form of contract and Malaysia Standard form of building contract (PWD203A)

    Science.gov (United States)

    Yunus, A. I. A.; Muhammad, W. M. N. W.; Saaid, M. N. F.

    2018-04-01

    Standard form of contract is normally being used in Malaysia construction industry in establishing legal relation between contracting parties. Generally, most of Malaysia federal government construction project used PWD203A which is a standard form of contract to be used where Bills of Quantities Form Part of the Contract and it is issued by Public Works Department (PWD/JKR). On the other hand in Sarawak, the largest state in Malaysia, the state government has issued their own standard form of contract namely JKR Sarawak Form of Contract 2006. Even both forms have been used widely in construction industry; there is still lack of understanding on both forms. The aim of this paper is to identify significant provision on both forms of contract. Document analysis has been adopted in conducting an in-depth review on both forms. It is found that, both forms of contracts have differences and similarities on several provisions specifically matters to definitions and general; execution of the works; payments, completion and final account; and delay, dispute resolution and determination.

  13. HPMC supplementation reduces abdominal fat content, intestinal permeability, inflammation, and insulin resistance in diet-induced obese mice

    Science.gov (United States)

    Cationic hydroxyethyl cellulose (cHEC) , was fed to hamsters to determine if this new soluble fiber had an effect on hypercholesterolemia and dyslipidemia associated with cardiovascular disease. In this study, Golden Syrian hamsters were supplemented with 3-8% cHEC or microcrystalline cellulose (MC...

  14. Micro-structure-mobility correlation in self-organised, conjugated polymer field-effect transistors

    NARCIS (Netherlands)

    Sirringhaus, H.; Brown, P.J.; Friend, R.H.; Nielsen, M.M.; Bechgaard, K.; Langeveld-Voss, B.M.W.; Spiering, A.J.H.; Janssen, R.A.J.; Meijer, E.W.

    2000-01-01

    We have investigated the correlation between polymer microstructure and charge carrier mobility in high-mobility, self-organised field-effect transistors of poly-3-hexyl-thiophene (P3HT). Two different preferential orientations of the microcrystalline P3HT domains with respect to the substrate have

  15. Quantitative characterization of agglomerate abrasion in a tumbling blender by using the Stokes number approach

    NARCIS (Netherlands)

    Willemsz, Tofan A.; Nguyen, Tien Thanh; Hooijmaijers, Ricardo; Frijlink, Henderik W.; Vromans, Herman; van der Voort Maarschalk, Kees

    2013-01-01

    Removal of microcrystalline cellulose agglomerates in a dry-mixing system (lactose, 100 M) predominantly occurs via abrasion. The agglomerate abrasion rate potential is estimated by the Stokes abrasion (StAbr) number of the system. The StAbrnumber equals the ratio between the kinetic energy density

  16. Microstructure-mobility correlation in self-organised, conjugated polymer field-effect transistors

    DEFF Research Database (Denmark)

    Sirringhaus, H.; Brown, P.J.; Friend, R.H.

    2000-01-01

    We have investigated the correlation between polymer microstructure and charge carrier mobility in high-mobility, self-organised field-effect transistors of poly-3-hexyl-thiophene (P3HT). Two different preferential orientations of the microcrystalline P3HT domains with respect to the substrate have...

  17. Development and Evaluation of Orally Disintegrating Tablets of ...

    African Journals Online (AJOL)

    designed and manufactured by direct compression method, using microcrystalline (Avicel PH-102), mannitol ... batch (FOB-01) reflected the successful development of new formulation of orally disintegrating ... investigate the product variables that influence product quality. .... thickness was high but was within limits of ± 5 %.

  18. Improvement of the Crystal Stability and Dissolution Profile of ...

    African Journals Online (AJOL)

    This study was undertaken to improve the solubility of metronidazole by modifying its crystal characteristics using pharmaceutical excipients. Metronidazole granules were formulated with cashew gum (2 – 8% w/w) and microcrystalline cellulose (10% w/w) via kneading, solid dispersion, or physical mixing. Resulting ...

  19. Physical forms of MIPs.

    Science.gov (United States)

    Biffis, Andrea; Dvorakova, Gita; Falcimaigne-Cordin, Aude

    2012-01-01

    The current state of the art in the development of methodologies for the preparation of MIPs in predetermined physical forms is critically reviewed, with particular attention being paid to the forms most widely employed in practical applications, such as spherical beads in the micro- to nanometer range, microgels, monoliths, membranes. Although applications of the various MIP physical forms are mentioned, the focus of the paper is mainly on the description of the various preparative methods. The aim is to provide the reader with an overview of the latest achievements in the field, as well as with a mean for critically evaluating the various proposed methodologies towards an envisaged application. The review covers the literature up to early 2010, with special emphasis on the developments of the last 10 years.

  20. TRASYS form factor matrix normalization

    Science.gov (United States)

    Tsuyuki, Glenn T.

    1992-01-01

    A method has been developed for adjusting a TRASYS enclosure form factor matrix to unity. This approach is not limited to closed geometries, and in fact, it is primarily intended for use with open geometries. The purpose of this approach is to prevent optimistic form factors to space. In this method, nodal form factor sums are calculated within 0.05 of unity using TRASYS, although deviations as large as 0.10 may be acceptable, and then, a process is employed to distribute the difference amongst the nodes. A specific example has been analyzed with this method, and a comparison was performed with a standard approach for calculating radiation conductors. In this comparison, hot and cold case temperatures were determined. Exterior nodes exhibited temperature differences as large as 7 C and 3 C for the hot and cold cases, respectively when compared with the standard approach, while interior nodes demonstrated temperature differences from 0 C to 5 C. These results indicate that temperature predictions can be artificially biased if the form factor computation error is lumped into the individual form factors to space.

  1. Effect of food service form on eating rate: meal served in a separated form might lower eating rate.

    Science.gov (United States)

    Suh, Hyung Joo; Jung, Eun Young

    2016-01-01

    In this study, we investigated the association between food form (mixed vs separated) and eating rate. The experiment used a within-subjects design (n=29, young healthy women with normal weight). Test meals (white rice and side dishes) with the same content and volume were served at lunch in a mixed or separated form. The form in which the food was served had significant effects on consumption volume and eating rate; subjects ate significantly more (p<0.05) when a test meal was served as a mixed form (285 g, 575 kcal) compared to a separated form (244 g, 492 kcal). Moreover, subjects also ate significantly faster (p<0.05) when the test meal was served as a mixed form (22.4 g/min) as compared to a separated form (16.2 g/min). Despite consuming more when the test meal was served as a mixed form than when served as a separated form, the subjects did not feel significantly fuller. In conclusion, we confirmed that meals served in a separated form might lower the eating rate and, moreover, slower eating might be associated with less energy intake, without compromising satiety.

  2. On the role of API in determining porosity, pore structure and bulk modulus of the skeletal material in pharmaceutical tablets formed with MCC as sole excipient.

    Science.gov (United States)

    Ridgway, Cathy; Bawuah, Prince; Markl, Daniel; Zeitler, J Axel; Ketolainen, Jarkko; Peiponen, Kai-Erik; Gane, Patrick

    2017-06-30

    The physical properties and mechanical integrity of pharmaceutical tablets are of major importance when loading with active pharmaceutical ingredient(s) (API) in order to ensure ease of processing, control of dosage and stability during transportation and handling prior to patient consumption. The interaction between API and excipient, acting as functional extender and binder, however, is little understood in this context. The API indomethacin is combined in this study with microcrystalline cellulose (MCC) at increasing loading levels. Tablets from the defined API/MCC ratios are made under conditions of controlled porosity and tablet thickness, resulting from different compression conditions, and thus compaction levels. Mercury intrusion porosimetry is used to establish the accessible pore volume, pore size distribution and, adopting the observed region of elastic intrusion-extrusion at high pressure, an elastic bulk modulus of the skeletal material is recorded. Porosity values are compared to previously published values derived from terahertz (THz) refractive index data obtained from exactly the same tablet sample sets. It is shown that the elastic bulk modulus is dependent on API wt% loading under constant tablet preparation conditions delivering equal dimensions and porosity. The findings are considered of novel value in respect to establishing consistency of tablet production and optimisation of physical properties. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Relationship Domain of Form Six Teachers Thinking in Teaching with External Factors of Form Six Teachers

    Science.gov (United States)

    bin Pet, Mokhtar; Sihes, Ahmad Johari Hj

    2015-01-01

    This study aims to examine the external factors of form six teachers who can influence thinking domain form six teachers in their teaching. This study was conducted using a quantitative approach using questionnaires. A total of 300 form six teacher schools in Johor were chosen as respondents. The findings were obtained as student background…

  4. Spin-forming Project Report

    Energy Technology Data Exchange (ETDEWEB)

    Switzner, Nathan; Henry, Dick

    2009-03-20

    In a second development order, spin-forming equipment was again evaluated using the test shape, a hemispherical shell. In this second development order, pure vanadium and alloy titanium (Ti-6Al-4V) were spin-formed, as well as additional copper and 21-6-9 stainless. In the first development order the following materials had been spin-formed: copper (alloy C11000 ETP), 6061 aluminum, 304L stainless steel, 21-6-9 stainless steel, and tantalum-2.5% tungsten. Significant challenges included properly adjusting the rotations-per-minute (RPM), cracking at un-beveled edges and laser marks, redressing of notches, surface cracking, non-uniform temperature evolution in the titanium, and cracking of the tailstock. Lessons learned were that 300 RPM worked better than 600 RPM for most materials (at the feed rate of 800 mm/min); beveling the edges to lower the stress reduces edge cracking; notches, laser marks, or edge defects in the preform doom the process to cracking and failure; coolant is required for vanadium spin-forming; increasing the number of passes to nine or more eliminates surface cracking for vanadium; titanium develops a hot zone in front of the rollers; and the tailstock should be redesigned to eliminate the cylindrical stress concentrator in the center.

  5. Methods for forming particles

    Science.gov (United States)

    Fox, Robert V.; Zhang, Fengyan; Rodriguez, Rene G.; Pak, Joshua J.; Sun, Chivin

    2016-06-21

    Single source precursors or pre-copolymers of single source precursors are subjected to microwave radiation to form particles of a I-III-VI.sub.2 material. Such particles may be formed in a wurtzite phase and may be converted to a chalcopyrite phase by, for example, exposure to heat. The particles in the wurtzite phase may have a substantially hexagonal shape that enables stacking into ordered layers. The particles in the wurtzite phase may be mixed with particles in the chalcopyrite phase (i.e., chalcopyrite nanoparticles) that may fill voids within the ordered layers of the particles in the wurtzite phase thus produce films with good coverage. In some embodiments, the methods are used to form layers of semiconductor materials comprising a I-III-VI.sub.2 material. Devices such as, for example, thin-film solar cells may be fabricated using such methods.

  6. Differential forms theory and practice

    CERN Document Server

    Weintraub, Steven H

    2014-01-01

    Differential forms are utilized as a mathematical technique to help students, researchers, and engineers analyze and interpret problems where abstract spaces and structures are concerned, and when questions of shape, size, and relative positions are involved. Differential Forms has gained high recognition in the mathematical and scientific community as a powerful computational tool in solving research problems and simplifying very abstract problems through mathematical analysis on a computer. Differential Forms, 2nd Edition, is a solid resource for students and professionals needing a solid g

  7. Forming Refractory Insulation On Copper Wire

    Science.gov (United States)

    Setlock, J.; Roberts, G.

    1995-01-01

    Alternative insulating process forms flexible coat of uncured refractory insulating material on copper wire. Coated wire formed into coil or other complex shape. Wire-coating apparatus forms "green" coat on copper wire. After wire coiled, heating converts "green" coat to refractory electrical insulator. When cured to final brittle form, insulating material withstands temperatures above melting temperature of wire. Process used to make coils for motors, solenoids, and other electrical devices to be operated at high temperatures.

  8. FormCalc 9 and extensions

    International Nuclear Information System (INIS)

    Hahn, T.; Passehr, S.; Schappacher, C.

    2016-04-01

    We present Version 9 of the Feynman-diagram calculator FormCalc and a flexible new suite of shell scripts and Mathematica packages based on FormCalc, which can be adapted and used as a template for calculations.

  9. Browse Title Index

    African Journals Online (AJOL)

    Items 51 - 100 of 149 ... Vol 31, No 2 (2015), Evaluation of tablet disintegrant properties of microcrystalline cellulose obtained from cassava fermentation waste, Abstract ... Vol 26, No 2 (2008), Formulation and In Vitro Evaluation of Release Retardant Diclofenac Sodium Tablets Using Hydrophilic and Waxy Matrices, Abstract.

  10. Chardonnay grape seed flour ameliorates hepatic steatosis and insulin resistance via altered hepatic gene expression for oxidative stress, inflammation, and lipid and ceramide synthesis in diet-induced obese mice

    Science.gov (United States)

    Diet-induced obese (DIO) mice were fed high-fat (HF) diets containing either partially defatted flavonoid-rich Chardonnay grape seed flour (ChrSd) or microcrystalline cellulose (MCC, control) for 5 weeks in order to determine whether ChrSd improved insulin resistance and the pathogenesis of hepatic ...

  11. Strategies for doped nanocrystalline silicon integration in silicon heterojunction solar cells

    Czech Academy of Sciences Publication Activity Database

    Seif, J.; Descoeudres, A.; Nogay, G.; Hänni, S.; de Nicolas, S.M.; Holm, N.; Geissbühler, J.; Hessler-Wyser, A.; Duchamp, M.; Dunin-Borkowski, R.E.; Ledinský, Martin; De Wolf, S.; Ballif, C.

    2016-01-01

    Roč. 6, č. 5 (2016), s. 1132-1140 ISSN 2156-3381 R&D Projects: GA MŠk LM2015087 Institutional support: RVO:68378271 Keywords : microcrystalline silicon * nanocrystalline silicon * silicon heterojunctions (SHJs) * solar cells Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 3.712, year: 2016

  12. Ore-forming environment and ore-forming system of carbonaceous-siliceous-pelitic rock type uranium deposit in China

    International Nuclear Information System (INIS)

    Qi Fucheng; Zhang Zilong; Li Zhixing; He Zhongbo; Wang Wenquan

    2012-01-01

    It is proposed that there are four types of ore-forming systems about carbonaceous-siliceous-pelitic rock type uranium deposit in China based on systematic study on structural environment and distribution regularity of uraniferous construction of marine carbonaceous-siliceous-pelitic rock in China: continental margin rift valley ore-forming systems, continental margin rifting deep fracture zone ore-forming systems, landmass boundary borderland basin ore-forming systems and epicontinental mobile belt downfaulted aulacogen ore-forming systems. It is propounded definitely that it is controlled by margin rift valley ore-forming systems and continental margin rifting deep fracture zone ore-forming systems for large-scale uranium mineralization of carbonaceous-siliceous-pelitic rock type uranium deposit in China, which is also controlled by uraniferous marine carbonaceous-siliceous-pelitic rock construction made up of silicalite, siliceous phosphorite and carbonaceous-siliceous-pelitic rock, which settled down accompany with submarine backwash and sub marine volcanic eruption in margin rift valley and continental margin rifting mineralizing environment. Continental mar gin rift valley and continental margin rifting thermal sedimentation or exhalation sedimentation is the mechanism of forming large-scale uraniferous marine carbonaceous-siliceous-pelitic rock construction Early Palaeozoic Era in China or large-scale uranium-polymetallic mineralization. (authors)

  13. Article and method of forming an article

    Science.gov (United States)

    Lacy, Benjamin Paul; Kottilingam, Srikanth Chandrudu; Dutta, Sandip; Schick, David Edward

    2017-12-26

    Provided are an article and a method of forming an article. The method includes providing a metallic powder, heating the metallic powder to a temperature sufficient to joint at least a portion of the metallic powder to form an initial layer, sequentially forming additional layers in a build direction by providing a distributed layer of the metallic powder over the initial layer and heating the distributed layer of the metallic powder, repeating the steps of sequentially forming the additional layers in the build direction to form a portion of the article having a hollow space formed in the build direction, and forming an overhang feature extending into the hollow space. The article includes an article formed by the method described herein.

  14. Form factors in (HI,HI') direct reactions

    International Nuclear Information System (INIS)

    Chu, Y.H.

    1981-01-01

    Using the semiclassical theory, the inelastic transition form factors are analyzed. For the first order form factors, we find that: (i) In the strong absorption limit, the Austern-Blair theory is a good approximation to the inelastic form factor--even in highly mismatched reactions. (ii) In weak to moderate absorption, the amplitude of the inelastic form factor oscillates due to overlapping potential resonances. The internal part of the form factor can be expressed in a simple form, which may easily be used to analyze heavy-ion inelastic scattering. (iii) In the presence of an isolated resonance, the inelastic form factor is enhanced greatly at the resonance due to multiple reflections inside the potential well. The second order form factors contain two terms, i.e. the one-step direct process (OSD) term and the two-step process (TS) term. It is found that: (i) In the strong absorption limit, OSD and TS form factors are equally important and interfere destructively near the grazing angular momentum. The Austern-Blair theory gives satisfactory results for well-matched reactions. The angular distributions of the mutual and double excitations are out of phase compared with that of the single excitation. (ii) For the weak absorption case, the internal part of the TS form factor is so enhanced that the OSD form factor can simply be neglected. The internal TS form factor can be parameterized in a form proportional to the internal-wave elastic Smatrix, where the angular distribution shows characteristically refractive phenomenon

  15. Standardized waste form test methods

    International Nuclear Information System (INIS)

    Slate, S.C.

    1984-01-01

    The Materials Characterization Center (MCC) is developing standard tests to characterize nuclear waste forms. Development of the first thirteen tests was originally initiated to provide data to compare different high-level waste (HLW) forms and to characterize their basic performance. The current status of the first thirteen MCC tests and some sample test results are presented: the radiation stability tests (MCC-6 and 12) and the tensile-strength test (MCC-11) are approved; the static leach tests (MCC-1, 2, and 3) are being reviewed for full approval; the thermal stability (MCC-7) and microstructure evaluation (MCC-13) methods are being considered for the first time; and the flowing leach test methods (MCC-4 and 5), the gas generation methods (MCC-8 and 9), and the brittle fracture method (MCC-10) are indefinitely delayed. Sample static leach test data on the ARM-1 approved reference material are presented. Established tests and proposed new tests will be used to meet new testing needs. For waste form production, tests on stability and composition measurement are needed to provide data to ensure waste form quality. In transporation, data are needed to evaluate the effects of accidents on canisterized waste forms. The new MCC-15 accident test method and some data are presented. Compliance testing needs required by the recent draft repository waste acceptance specifications are described. These specifications will control waste form contents, processing, and performance

  16. Standardized waste form test methods

    International Nuclear Information System (INIS)

    Slate, S.C.

    1984-11-01

    The Materials Characterization Center (MCC) is developing standard tests to characterize nuclear waste forms. Development of the first thirteen tests was originally initiated to provide data to compare different high-level waste (HLW) forms and to characterize their basic performance. The current status of the first thirteen MCC tests and some sample test results is presented: The radiation stability tests (MCC-6 and 12) and the tensile-strength test (MCC-11) are approved; the static leach tests (MCC-1, 2, and 3) are being reviewed for full approval; the thermal stability (MCC-7) and microstructure evaluation (MCC-13) methods are being considered for the first time; and the flowing leach tests methods (MCC-4 and 5), the gas generation methods (MCC-8 and 9), and the brittle fracture method (MCC-10) are indefinitely delayed. Sample static leach test data on the ARM-1 approved reference material are presented. Established tests and proposed new tests will be used to meet new testing needs. For waste form production, tests on stability and composition measurement are needed to provide data to ensure waste form quality. In transportation, data are needed to evaluate the effects of accidents on canisterized waste forms. The new MCC-15 accident test method and some data are presented. Compliance testing needs required by the recent draft repository waste acceptance specifications are described. These specifications will control waste form contents, processing, and performance. 2 references, 2 figures

  17. New CERN Health Insurance Scheme (CHIS) forms

    CERN Multimedia

    HR Department

    2015-01-01

    New versions of the following forms for claims and requests to the CERN Health Insurance Scheme (CHIS) have been released:   form for claiming reimbursement of medical expenses,   form for requesting advance reimbursement, and   dental estimate form (for treatments foreseen to exceed 800 CHF).   The new forms are available in French and English. They can either be completed electronically before being printed and signed, or completed in paper form. New detailed instructions can be found at the back of the claim form; CHIS members are invited to read them carefully. The electronic versions (PDF) of all the forms are available on the CHIS website and on the UNIQA Member Portal. CHIS Members are requested to use these new forms forthwith and to discard any previous version. Questions regarding the above should be addressed directly to UNIQA (72730 or 022.718 63 00 or uniqa.assurances@cern.ch).

  18. One-pot synthesis and photoluminescence properties of core/porous-shell olive-like BaWO4 microstructure by a template-assisted hydrothermal method

    Science.gov (United States)

    Zhang, Suyue; Wang, Yunlong; Wang, Cuiping; Zhang, Hui; Shen, Yuhua; Xie, Anjian

    2016-02-01

    Core/porous-shell olive-like crystalline BaWO4 is synthesized by a combined simple hydrothermal method and soft template approach. The prepared product shows an olive-like shape with diameter of ˜2 μm, length of ˜4 μm, and the thickness of the shell of about 65 nm, which are orderly assembled by many nanoparticles. A possible formation mechanism of olive-like BaWO4 microstructure involving interfacial recognization of ions, nucleation, aggregation, in situ growth and Ostwald ripening process is proposed. Polyacrylic acid sodium (PAAS) as a template plays an important role in inducing the nucleation and growth of olive-like BaWO4 microcrystalline. Other shapes of BaWO4 microcrystalline are also fabricated by varying the concentration of PAAS and Ba2+. The olive-like product with a core-shell structure which exists a large number of pores on crystal surface shows excellent photoluminescence property, which have potentially applied prospects in fields such as light display systems etc.

  19. [Theoretical modeling and experimental research on direct compaction characteristics of multi-component pharmaceutical powders based on the Kawakita equation].

    Science.gov (United States)

    Si, Guo-Ning; Chen, Lan; Li, Bao-Guo

    2014-04-01

    Base on the Kawakita powder compression equation, a general theoretical model for predicting the compression characteristics of multi-components pharmaceutical powders with different mass ratios was developed. The uniaxial flat-face compression tests of powder lactose, starch and microcrystalline cellulose were carried out, separately. Therefore, the Kawakita equation parameters of the powder materials were obtained. The uniaxial flat-face compression tests of the powder mixtures of lactose, starch, microcrystalline cellulose and sodium stearyl fumarate with five mass ratios were conducted, through which, the correlation between mixture density and loading pressure and the Kawakita equation curves were obtained. Finally, the theoretical prediction values were compared with experimental results. The analysis showed that the errors in predicting mixture densities were less than 5.0% and the errors of Kawakita vertical coordinate were within 4.6%, which indicated that the theoretical model could be used to predict the direct compaction characteristics of multi-component pharmaceutical powders.

  20. Electro-mechanical properties of hydrogel composites with micro- and nano-cellulose fillers

    International Nuclear Information System (INIS)

    Shahid U N, Mohamed; Deshpande, Abhijit P; Rao, C Lakshmana

    2015-01-01

    Stimuli responsive cross-linked hydrogels are of great interest for applications in diverse fields such as sensors and biomaterials. In this study, we investigate polymer composites filled with cellulose fillers. The celluloses used in making the composites were a microcrystalline cellulose of commercial grade and cellulose nano-whiskers obtained through acid hydrolysis of microcrystalline cellulose. The filler concentration was varied and corresponding physical, mechanical and electro-mechanical characterization was carried out. The electro-mechanical properties were determined using a quasi-static method. The fillers not only enhance the mechanical properties of the composite by providing better reinforcement but also provide a quantitative electric potential in the composite. The measurements reveal that the polymer composites prepared from two different cellulose fillers possess a quantitative electric potential which can be utilized in biomedical applications. It is argued that the mechanism behind the quantitative electric potential in the composites is due to streaming potentials arising due to electrical double layer formation. (paper)

  1. Progress in thin-film silicon solar cells based on photonic-crystal structures

    Science.gov (United States)

    Ishizaki, Kenji; De Zoysa, Menaka; Tanaka, Yoshinori; Jeon, Seung-Woo; Noda, Susumu

    2018-06-01

    We review the recent progress in thin-film silicon solar cells with photonic crystals, where absorption enhancement is achieved by using large-area resonant effects in photonic crystals. First, a definitive guideline for enhancing light absorption in a wide wavelength range (600–1100 nm) is introduced, showing that the formation of multiple band edges utilizing higher-order modes confined in the thickness direction and the introduction of photonic superlattice structures enable significant absorption enhancement, exceeding that observed for conventional random scatterers. Subsequently, experimental evidence of this enhancement is demonstrated for a variety of thin-film Si solar cells: ∼500-nm-thick ultrathin microcrystalline silicon cells, few-µm-thick microcrystalline silicon cells, and ∼20-µm-thick thin single-crystalline silicon cells. The high short-circuit current densities and/or efficiencies observed for each cell structure confirm the effectiveness of using multiple band-edge resonant modes of photonic crystals for enhancing broadband absorption in actual solar cells.

  2. In and Ga Codoped ZnO Film as a Front Electrode for Thin Film Silicon Solar Cells

    Directory of Open Access Journals (Sweden)

    Duy Phong Pham

    2014-01-01

    Full Text Available Doped ZnO thin films have attracted much attention in the research community as front-contact transparent conducting electrodes in thin film silicon solar cells. The prerequisite in both low resistivity and high transmittance in visible and near-infrared region for hydrogenated microcrystalline or amorphous/microcrystalline tandem thin film silicon solar cells has promoted further improvements of this material. In this work, we propose the combination of major Ga and minor In impurities codoped in ZnO film (IGZO to improve the film optoelectronic properties. A wide range of Ga and In contents in sputtering targets was explored to find optimum optical and electrical properties of deposited films. The results show that an appropriate combination of In and Ga atoms in ZnO material, followed by in-air thermal annealing process, can enhance the crystallization, conductivity, and transmittance of IGZO thin films, which can be well used as front-contact electrodes in thin film silicon solar cells.

  3. Thermophysical properties of lignocellulose: a cell-scale study down to 41 K.

    Science.gov (United States)

    Cheng, Zhe; Xu, Zaoli; Zhang, Lei; Wang, Xinwei

    2014-01-01

    Thermal energy transport is of great importance in lignocellulose pyrolysis for biofuels. The thermophysical properties of lignocellulose significantly affect the overall properties of bio-composites and the related thermal transport. In this work, cell-scale lignocellulose (mono-layer plant cells) is prepared to characterize their thermal properties from room temperature down to ∼ 40 K. The thermal conductivities of cell-scale lignocellulose along different directions show a little anisotropy due to the cell structure anisotropy. It is found that with temperature going down, the volumetric specific heat of the lignocellulose shows a slower decreasing trend against temperature than microcrystalline cellulose, and its value is always higher than that of microcrystalline cellulose. The thermal conductivity of lignocellulose decreases with temperature from 243 K to 317 K due to increasing phonon-phonon scatterings. From 41 K to 243 K, the thermal conductivity rises with temperature and its change mainly depends on the heat capacity's change.

  4. Thermophysical properties of lignocellulose: a cell-scale study down to 41 K.

    Directory of Open Access Journals (Sweden)

    Zhe Cheng

    Full Text Available Thermal energy transport is of great importance in lignocellulose pyrolysis for biofuels. The thermophysical properties of lignocellulose significantly affect the overall properties of bio-composites and the related thermal transport. In this work, cell-scale lignocellulose (mono-layer plant cells is prepared to characterize their thermal properties from room temperature down to ∼ 40 K. The thermal conductivities of cell-scale lignocellulose along different directions show a little anisotropy due to the cell structure anisotropy. It is found that with temperature going down, the volumetric specific heat of the lignocellulose shows a slower decreasing trend against temperature than microcrystalline cellulose, and its value is always higher than that of microcrystalline cellulose. The thermal conductivity of lignocellulose decreases with temperature from 243 K to 317 K due to increasing phonon-phonon scatterings. From 41 K to 243 K, the thermal conductivity rises with temperature and its change mainly depends on the heat capacity's change.

  5. Cubical version of combinatorial differential forms

    DEFF Research Database (Denmark)

    Kock, Anders

    2010-01-01

    The theory of combinatorial differential forms is usually presented in simplicial terms. We present here a cubical version; it depends on the possibility of forming affine combinations of mutual neighbour points in a manifold, in the context of synthetic differential geometry.......The theory of combinatorial differential forms is usually presented in simplicial terms. We present here a cubical version; it depends on the possibility of forming affine combinations of mutual neighbour points in a manifold, in the context of synthetic differential geometry....

  6. 48 CFR 53.301-1427 - Standard Form 1427, Inventory Schedule A-Construction Sheet (Metals in Mill Product Form).

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 2 2010-10-01 2010-10-01 false Standard Form 1427, Inventory Schedule A-Construction Sheet (Metals in Mill Product Form). 53.301-1427 Section 53.301-1427... Illustrations of Forms 53.301-1427 Standard Form 1427, Inventory Schedule A—Construction Sheet (Metals in Mill...

  7. 49 CFR 387.413 - Forms and procedure.

    Science.gov (United States)

    2010-10-01

    ... Forms and procedures. (f) Termination of Forms BMC-32 and BMC-34 for freight forwarders of property other than household goods. Form BMC-32 endorsements and Form BMC-34 certificates of insurance issued to...

  8. Waste form development

    International Nuclear Information System (INIS)

    Neilson, R.M. Jr.; Colombo, P.

    1982-01-01

    In this program, contemporary solidification agents are being investigated relative to their applications to major fuel cycle and non-fuel cycle low-level waste (LLW) streams. Work is being conducted to determine the range of conditions under which these solidification agents can be applied to specific LLW streams. These studies are directed primarily towards defining operating parameters for both improved solidification of problem wastes and solidification of new LLW streams generated from advanced volume reduction technologies. Work is being conducted to measure relevant waste form properties. These data will be compiled and evaluated to demonstrate compliance with waste form performance and shallow land burial acceptance criteria and transportation requirements (both as they exist and as they are modified with time). 6 tables

  9. Electromagnetic form factors

    International Nuclear Information System (INIS)

    Desplanques, B.

    1987-01-01

    Electromagnetic form factors, in first approximation, are sensitive to spatial distribution of nucleons and to their current. In second approximation, more precise effects are concerned, whose role is increasing with momentum transfer and participating essentially of short range nuclei description. They concern of course the nucleon-nucleon interaction while approaching each other and keeping their free-state identity, but also mutually polarizing one the other. In this last effect, radial and orbital excitations of nucleon, the nucleon mesonic cloud modification and the nucleon antinucleon pair excitation are included. In this paper, these contributions are discussed while trying to find the important elements for a good description of form factors. Current questions are also discussed. Light nuclei are essentially concerned [fr

  10. Review of high-level waste form properties

    International Nuclear Information System (INIS)

    Rusin, J.M.

    1980-12-01

    This report is a review of waste form options for the immobilization of high-level-liquid wastes from the nuclear fuel cycle. This review covers the status of international research and development on waste forms as of May 1979. Although the emphasis in this report is on waste form properties, process parameters are discussed where they may affect final waste form properties. A summary table is provided listing properties of various nuclear waste form options. It is concluded that proposed waste forms have properties falling within a relatively narrow range. In regard to crystalline versus glass waste forms, the conclusion is that either glass of crystalline materials can be shown to have some advantage when a single property is considered; however, at this date no single waste form offers optimum properties over the entire range of characteristics investigated. A long-term effort has been applied to the development of glass and calcine waste forms. Several additional waste forms have enough promise to warrant continued research and development to bring their state of development up to that of glass and calcine. Synthetic minerals, the multibarrier approach with coated particles in a metal matrix, and high pressure-high temperature ceramics offer potential advantages and need further study. Although this report discusses waste form properties, the total waste management system should be considered in the final selection of a waste form option. Canister design, canister materials, overpacks, engineered barriers, and repository characteristics, as well as the waste form, affect the overall performance of a waste management system. These parameters were not considered in this comparison

  11. High-level waste-form-product performance evaluation

    International Nuclear Information System (INIS)

    Bernadzikowski, T.A.; Allender, J.S.; Stone, J.A.; Gordon, D.E.; Gould, T.H. Jr.; Westberry, C.F. III.

    1982-01-01

    Seven candidate waste forms were evaluated for immobilization and geologic disposal of high-level radioactive wastes. The waste forms were compared on the basis of leach resistance, mechanical stability, and waste loading. All forms performed well at leaching temperatures of 40, 90, and 150 0 C. Ceramic forms ranked highest, followed by glasses, a metal matrix form, and concrete. 11 tables

  12. Current assisted superplastic forming of titanium alloy

    Directory of Open Access Journals (Sweden)

    Wang Guofeng

    2015-01-01

    Full Text Available Current assisted superplastic forming combines electric heating technology and superplastic forming technology, and can overcome some shortcomings of traditional superplastic forming effectively, such as slow heating rate, large energy loss, low production efficiency, etc. Since formability of titanium alloy at room temperature is poor, current assisted superplastic forming is suitable for titanium alloy. This paper mainly introduces the application of current assisted superplastic forming in the field of titanium alloy, including forming technology of double-hemisphere structure and bellows.

  13. Developing the Scale for Quality of Life in Pediatric Oncology Patients Aged 13-18: Adolescent Form and Parent Form.

    Science.gov (United States)

    Bektas, Murat; Akdeniz Kudubes, Aslı; Ugur, Ozlem; Vergin, Canan; Demirag, Bengü

    2016-06-01

    This study aimed to develop the Scale for Quality of Life in Pediatric Oncology Patients Aged 13-18: Adolescent Form and Parent Form. We used the child and parent information form, Visual Quality of Life Scale, and our own scale, the Scale for Quality of Life in Pediatric Oncology Patients Aged 13-18: Adolescent Form and Parent Form. We finalized the 35-item scale to determine the items, received opinions from 14 specialists on the scale, and pilot-tested the scale in 25 children and their parents. We used Pearson correlation analysis, Cronbach α coefficient, factor analysis and receiver operating characteristics analysis to analyze the data. The total Cronbach α of the parent form was .97, the total factor load was .60-.97 and the total variance was 80.4%. The cutoff point of the parent form was 85.50. The total Cronbach α of the adolescent form was .98, the total factor load was .62-.96, and the total variance explained was 83.4%. The cutoff point of the adolescent form was 75.50. As a result of the parent form factor analysis, we determined the Kaiser-Meyer-Olkin coefficient as .83, the Barlett test χ(2) as 12,615.92; the factor coefficients of all items of the parent form ranged from .63 to .98. The factor coefficients of all items of the adolescent form ranged from .34 to .99. As a result of the adolescent form factor analysis, we determined the KMO as .79, and the Barlett test χ(2) as 13,970.62. Conclusively, we found that the adolescent form and the parent form were valid and reliable in assessing the children's quality of life. Copyright © 2016. Published by Elsevier B.V.

  14. Comparative assessment of TRU waste forms and processes. Volume I. Waste form and process evaluations

    International Nuclear Information System (INIS)

    Ross, W.A.; Lokken, R.O.; May, R.P.; Roberts, F.P.; Timmerman, C.L.; Treat, R.L.; Westsik, J.H. Jr.

    1982-09-01

    This study provides an assesses seven waste forms and eight processes for immobilizing transuranic (TRU) wastes. The waste forms considered are cast cement, cold-pressed cement, FUETAP (formed under elevated temperature and pressure) cement, borosilicate glass, aluminosilicate glass, basalt glass-ceramic, and cold-pressed and sintered silicate ceramic. The waste-immobilization processes considered are in-can glass melting, joule-heated glass melting, glass marble forming, cement casting, cement cold-pressing, FUETAP cement processing, ceramic cold-pressing and sintering, basalt glass-ceramic processing. Properties considered included gas generation, chemical durability, mechanical strength, thermal stability, and radiation stability. The ceramic products demonstrated the best properties, except for plutonium release during leaching. The glass and ceramic products had similar properties. The cement products generally had poorer properties than the other forms, except for plutonium release during leaching. Calculations of the Pu release indicated that the waste forms met the proposed NRC release rate limit of 1 part in 10 5 per year in most test conditions. The cast-cement process had the lowest processing cost, followed closely by the cold-pressed and FUETAP cement processes. Joule-heated glass melting had the lower cost of the glass processes. In-can melting in a high-quality canister had the highest cost, and cold-pressed and sintered ceramic the second highest. Labor and canister costs for in-can melting were identified. The major contributor to costs of disposing of TRU wastes in a defense waste repository is waste processing costs. Repository costs could become the dominant cost for disposing of TRU wastes in a commercial repository. It is recommended that cast and FUETAP cement and borosilicate glass waste-form systems be considered. 13 figures, 16 tables

  15. Microdomain forming proteins in oncogenesis

    Directory of Open Access Journals (Sweden)

    I. B. Zborovskaya

    2016-01-01

    Full Text Available Lipid rafts are lateral assembles of cholesterol, sphingomyelin, glicosphingolipids and specific proteins within cell plasma membrane. These microdomains are involved into a number of important cellular processes including membrane rearrangement, protein internalization, signal transduction, entry of viruses into the cell. Some of lipid rafts are stabilized by special microdomain-forming proteins such as caveolins, SPFH domain containing superfamily, tetraspanins, galectins, which maintain integrity of rafts and regulate signal transduction via forming of “signalosomes”. Involvement of the different lipid rafts is necessary in many situations such as binding of growth factors with their receptors, integrin regulation, cytoskeleton and extracellular matrix rearrangements, vesicular transport, etc. However, such classes of microdomain-forming proteins are still considered separately from each other. In this review we tried to perform complex analysis of microdomain-forming proteins in regulation of cancer assotiated processes.

  16. 25 CFR 67.6 - Application forms.

    Science.gov (United States)

    2010-04-01

    ... application form is filed by a sponsor, the name and address of the sponsor and the sponsor's relationship to... the applicant's mailing address on the application form. Thereafter, the applicant or sponsor shall... applicant. Otherwise, the mailing address as stated on the application form shall be accepted as the address...

  17. 25 CFR 61.6 - Application forms.

    Science.gov (United States)

    2010-04-01

    ... is claimed. (2) If the application form is filed by a sponsor, the name and address of sponsor and... furnish the applicant's mailing address on the application form. Thereafter, the applicant or sponsor... identification of the application, otherwise the mailing address as stated on the form shall be acceptable as the...

  18. 19 CFR 143.24 - Preparation of Customs Form 7501 and Customs Form 368 or 368A (serially numbered).

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 2 2010-04-01 2010-04-01 false Preparation of Customs Form 7501 and Customs Form 368 or 368A (serially numbered). 143.24 Section 143.24 Customs Duties U.S. CUSTOMS AND BORDER... Informal Entry § 143.24 Preparation of Customs Form 7501 and Customs Form 368 or 368A (serially numbered...

  19. Method of forming composite fiber blends

    Science.gov (United States)

    McMahon, Paul E. (Inventor); Chung, Tai-Shung (Inventor); Ying, Lincoln (Inventor)

    1989-01-01

    The instant invention involves a process used in preparing fibrous tows which may be formed into polymeric plastic composites. The process involves the steps of (a) forming a tow of strong filamentary materials; (b) forming a thermoplastic polymeric fiber; (c) intermixing the two tows; and (d) withdrawing the intermixed tow for further use.

  20. Theory of Single Point Incremental Forming

    DEFF Research Database (Denmark)

    Martins, P.A.F.; Bay, Niels; Skjødt, Martin

    2008-01-01

    This paper presents a closed-form theoretical analysis modelling the fundamentals of single point incremental forming and explaining the experimental and numerical results available in the literature for the past couple of years. The model is based on membrane analysis with bi-directional in-plan......-plane contact friction and is focused on the extreme modes of deformation that are likely to be found in single point incremental forming processes. The overall investigation is supported by experimental work performed by the authors and data retrieved from the literature.......This paper presents a closed-form theoretical analysis modelling the fundamentals of single point incremental forming and explaining the experimental and numerical results available in the literature for the past couple of years. The model is based on membrane analysis with bi-directional in...

  1. Usability of Public Administration Electronic Forms

    Directory of Open Access Journals (Sweden)

    Miloslav Hub

    2015-06-01

    Full Text Available This paper is focused on the testing and evaluating of public administration electronic forms from the usability point of view. Its objective is to design a suitable methodology for usability testing of electronic forms and their description and distribution to public administration information systems professionals. Firstly, methods of usability engineering are summarized and a suitable method for usability testing and evaluation of electronic forms is selected. Farther, the methodology of electronic forms usability testing that uses the selected method is suggested. In the last part of the paper the case study that uses the proposed methodology is suggested and performed. The main benefit of the work is the design of testing methodology and proposition of the set of recommendations for new public administration electronic forms design.

  2. In-vitro Release Study of Carvedilol Phosphate Matrix Tablets ...

    African Journals Online (AJOL)

    Microcrystalline cellulose (Avicel PH 101), starch (Sta-Rx 1500) and lactose monohydrate were used as diluents in the formulations while the effect of sodium lauryl sulphate (wetting agent) was studied for some of the formulations. The tablets were characterized for carvedilol phosphate release in both simulated gastric and ...

  3. Processing, screening and microbiological characterization of ...

    African Journals Online (AJOL)

    Microcrystalline cellulose (MCC) obtained from the fresh stem of Laccosperma opacum (Rattan) found in coastal region of Niger Delta forest zones of West Africa was investigated to ascertain its microbiological standard for use as a potential pharmaceutical excipient. The product, coded LO-MCC, was prepared by treating ...

  4. Radionuclide Retention in Concrete Waste Forms

    Energy Technology Data Exchange (ETDEWEB)

    Mattigod, Shas V.; Bovaird, Chase C.; Wellman, Dawn M.; Wood, Marcus I.

    2010-09-30

    Assessing long-term performance of Category 3 waste cement grouts for radionuclide encasement requires knowledge of the radionuclide-cement interactions and mechanisms of retention (i.e., sorption or precipitation); the mechanism of contaminant release; the significance of contaminant release pathways; how waste form performance is affected by the full range of environmental conditions within the disposal facility; the process of waste form aging under conditions that are representative of processes occurring in response to changing environmental conditions within the disposal facility; the effect of waste form aging on chemical, physical, and radiological properties; and the associated impact on contaminant release. This knowledge will enable accurate prediction of radionuclide fate when the waste forms come in contact with groundwater. The information presented in the report provides data that 1) quantify radionuclide retention within concrete waste form materials similar to those used to encapsulate waste in the Low-Level Waste Burial Grounds (LLBG); 2) measure the effect of concrete waste form properties likely to influence radionuclide migration; and 3) quantify the stability of uranium-bearing solid phases of limited solubility in concrete.

  5. A Framework for Interactively Helpful Web Forms

    DEFF Research Database (Denmark)

    Bohøj, Morten; Bouvin, Niels Olof; Gammelmark, Henrik

    2012-01-01

    AdapForms is a framework for adaptive forms, consisting of a form definition language designating structure and constraints upon acceptable input, and a software architecture that continuously validates and adapts the form presented to the user. The validation is performed server-side, which enab...

  6. Education fees – New forms

    CERN Multimedia

    2015-01-01

    The application forms for the payment of education fees have been updated and are now available in the Admin e-guide (under the “Useful Documents” heading):   Payment of education fees (including language course fees) – AC12A (form to be used by staff members recruited before 1 January 2007, with the exception of former “local staff”).   Payment of education fees – AC12B (form to be used by staff members recruited on or after 1 January 2007, by fellows, scientific associates and guest professors and by former “local staff” whose contracts started before 1 January 2007). The Education Fees service will continue to accept the old forms until the end of the current academic year, i.e. until 31 August 2015. Members of the personnel are reminded that any false declaration or failure to declare information with a view to deceiving others or achieving a gain that would result in a financial loss for CERN or...

  7. Das Zeichen als Form und die Form des Rechtszeichens / The Sign as Form and the Form of the Law Sign

    Directory of Open Access Journals (Sweden)

    Thomas-M. Seibert

    2014-03-01

    Full Text Available Diskutiert wird Luhmanns Konzept vom „Zeichen als Form“ vor dem Hintergrund der Formgebungen bei Peirce und Serres mit einem Erbschaftsfall im Vordergrund. Die These lautet: Zweiteilung als Ergebnis amputiert die grundlegende Operation der Formbildung, indem der Operator ausgesperrt wird. Operator ist der Interpretant, den Luhmann als Beobachter (unterschiedlicher Stufe anschließend wieder einführt. Aber er lässt sich nicht aussperren, er ist fortwährend anwesend – als Parasit (Serres. An einem praktischen Fall wird das demonstriert: Eine Frau in einem Heim verfasst ein Testament und setzt den Heimleiter und seine Frau als Erben ein. Man benutzt die Rechtsform formularmäßig und meint, mit diesem Formular das Testament fachgerecht zu verfassen und die Interpretation auszusperren. Das spätere Rechtsverfahren der Verwandten gegen den Heimleiter kehrt die Verhältnisse um. Die Operation, sich auf Recht als ein Objekt so zu beziehen, dass die Operation sich wie dieses Objekt auf Recht bezieht und damit selbst zu einem Rechtszeichen wird (Peirce, ist parasitär. Sie plant ungeplante, überraschende Störungen ein. Luhmann’s concept of the „sign as form“ is discussed in the broader context of Peirce and Serres’ concepts of formation, with an inheritance in the foreground. The assertion is: bifurcation as a result amputates the fundamental operation of form-building by excluding the operator. The operator is the interpretant, who Luhmann subsequently re-introduces as an observer (at a different level. But the interpretant does not permit itself to be excluded; it is always present – as a parasite (Serres. This is demonstrated using a practical case: A woman living in a home writes her will, in which she instates the home warden and his wife as her heirs. One uses a standardized form in the assumption that one is adhering to the prescribed legal form and thereby eliminating any need for further interpretation. The legal proceedings

  8. 48 CFR 49.602-2 - Inventory forms.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 1 2010-10-01 2010-10-01 false Inventory forms. 49.602-2... TERMINATION OF CONTRACTS Contract Termination Forms and Formats 49.602-2 Inventory forms. Standard Form (SF) 1428, Inventory Disposal Schedule, and SF 1429, Inventory Disposal Schedule—Continuation Sheet, shall...

  9. Review on Cold-Formed Steel Connections

    Science.gov (United States)

    Tan, Cher Siang; Mohammad, Shahrin; Md Tahir, Mahmood; Shek, Poi Ngian

    2014-01-01

    The concept of cold-formed light steel framing construction has been widespread after understanding its structural characteristics with massive research works over the years. Connection serves as one of the important elements for light steel framing in order to achieve its structural stability. Compared to hot-rolled steel sections, cold-formed steel connections perform dissimilarity due to the thin-walled behaviour. This paper aims to review current researches on cold-formed steel connections, particularly for screw connections, storage rack connections, welded connections, and bolted connections. The performance of these connections in the design of cold-formed steel structures is discussed. PMID:24688448

  10. Synthesis and luminescence properties of nanocrystalline LiF:Mg,Cu,P phosphor

    Energy Technology Data Exchange (ETDEWEB)

    Sahare, P.D., E-mail: pdsahare@physics.du.ac.i [Department of Physics and Astrophysics, University of Delhi, Delhi 110 007 (India); Bakare, J.S. [SSGM College of Engineering, Amravati University, Shegaon 444 203, Maharashtra (India); Dhole, S.D. [Department of Physics, University of Pune, Ganeshkhind, Pune 411 007 (India); Ingale, N.B. [Department of Physics, Professor Ram Meghe Institute of Technology and Research, Badnera-Amravati 444 605, Maharashtra (India); Rupasov, A.A. [P. N. Lebedev Physical Institute, Russian Academy of Sciences, Leninsky pr-t 53, Moscow (Russian Federation)

    2010-02-15

    Nanocrystalline LiF:Mg,Cu,P phosphor material of different shapes and sizes (microcrystalline cubic shape, nanorod shape and nanocrystalline cubical shaped) have been prepared by the chemical co-precipitation method. Thermoluminescence (TL) and other dosimetric characteristics of the phosphor are studied and presented here. The formation of the materials was confirmed by the X-ray diffraction (XRD). Its shapes and sizes were also observed using scanning electron microscope (SEM). The TL glow curve of the microcrystalline powder shows a prominent single peak at 408 K along with another peak of lesser intensity at around 638 K. On the contrary, the nanocrystalline rod shaped particles show a peak of low intensity at 401 K and a prominent peak around 700 K while the nanocrystalline particles in cubical shapes again show two peaks, one at around 407 K and the other at around 617 K, of which the lower temperature (407 K) peak is more prominent. The glow curve structure changes at very high doses (100 kRad) and some new peaks appear at around 525 and 637 K also the first peak appearing at around 401 K becomes prominent. The observed changes in TL due to the change in the shape and sizes of the nanophosphor have been reported. The PL has also been studied and various excitation and emission peaks observed due to the presence of various impurities are explained. The observed results have been explained in the light of asymmetrical crystal field effects due to asymmetrical shapes of the nanocrystalline phosphor. The comparison of these properties with the microcrystalline material prepared by the same co-precipitation method is also done.

  11. Composite materials formed with anchored nanostructures

    Science.gov (United States)

    Seals, Roland D; Menchhofer, Paul A; Howe, Jane Y; Wang, Wei

    2015-03-10

    A method of forming nano-structure composite materials that have a binder material and a nanostructure fiber material is described. A precursor material may be formed using a mixture of at least one metal powder and anchored nanostructure materials. The metal powder mixture may be (a) Ni powder and (b) NiAl powder. The anchored nanostructure materials may comprise (i) NiAl powder as a support material and (ii) carbon nanotubes attached to nanoparticles adjacent to a surface of the support material. The process of forming nano-structure composite materials typically involves sintering the mixture under vacuum in a die. When Ni and NiAl are used in the metal powder mixture Ni.sub.3Al may form as the binder material after sintering. The mixture is sintered until it consolidates to form the nano-structure composite material.

  12. Disability and Bureaucratic Forms of Life

    Directory of Open Access Journals (Sweden)

    Thomas Abrams

    2015-06-01

    Full Text Available This paper employs a hybrid actor-network theory/phenomenological approach to a frequent bother in the lives of disabled persons: bureaucratic forms. I argue that these forms are key sites where disabled personhood emerges, something I examine through the lens of what philosopher Annemarie Mol calls ‘ontological politics’. To be disabled is to be entered into the bureaucratic form of life. These forms translate human existence into a categorize-able, transportable and combinable object, to be administered through ‘centers of calculation’. Combining Heidegger’s fundamental ontology with Latour’s theory of paperwork, I suggest that these forms represent disability in terms of ‘objective presence’, as a mere pre-existing thing, rather than a human way of being. I conclude with suggestions for further phenomenological research that takes embodied difference as its point of departure.

  13. Development in fiscal 1999 of technologies to put photovoltaic power generation systems into practical use. Development of thin film solar cell manufacturing technologies (Development of technologies to manufacture applied type thin film solar cells with new structure and development of high-efficiency hybrid thin film/sheet solar cells); 1999 nendo taiyoko hatsuden system jitsuyoka gijutsu kaihatsu seika hokokusho. Usumaku taiyo denchi no seizo gijutsu kaihatsu (oyogata shin kozo usumaku taiyo denchi no seizo gijutsu kaihatsu (kokoritsu hybrid gata usumaku / sheet taiyo denchi no seizo gijutsu kaihatsu))

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-03-01

    With an objective to develop low-cost and high-efficiency hybrid thin film/sheet solar cells, research and development has been performed. This paper summarizes the achievements in fiscal 1999. The research is related to a hybrid construction, in which the upper cells of amorphous silicon thin film are formed on the lower cells bonded with micro-crystalline silicon thin film relative to a poly-crystalline silicon sheet. In the technology to form the upper cells, a pin-construction using amorphous silicon thin film made by using the plasma CVD process was adopted, whereas an open circuit voltage of 1.45V, a short circuit current of 13.6 mA/cm{sup 2}, and a conversion efficiency of 13.5% were obtained. In the technology to form the substrate for the lower cells, formation of flat silicon thin plate that can be peeled off was identified as a result of adopting the construction in which a graphite substrate is provided on a rotating cooling body of 12-prism type. With regard to the technology to bond and form the lower cells, electrical properties of hetero-bonded cells were discussed, and an open circuit voltage of 0.605V and a conversion efficiency of 14.3% were obtained as a result of enhancing the film quality and optimizing the film thickness. (NEDO)

  14. Research needs in cement-based waste forms

    International Nuclear Information System (INIS)

    McDaniel, E.W.; Spence, R.D.; Tallent, O.K.

    1990-01-01

    Cement-based waste forms are one of the most widely used waste disposal options, yet definitive knowledge of the fate of the waste species inside the waste form is lacking. A fundamental understanding of the chemistry and microstructure of the waste forms would lead to a better understanding of the mass transfer of the waste species, more confidence in predicting and extrapolating waste form performance, and design of better waste forms. Better and cheaper leach tests would lead to quicker and more cost effective screening of waste form alternatives. In addition, assessment of durability may be important to predicting waste form performance in the field. It should be noted that the research needs discussed in this report are from the perspective of investigators working in applied waste management areas, while the proposed investigations are fundamental or basic. Details as to experimental methods and tools to be used in achieving the objectives of the proposed are research beyond the scope of this paper and are better filled in by others. In broad terms, the research topics discussed are correlation of cement-based waste form physical properties to performance, waste-form fundamental chemistry and microstructure, and product performance testing

  15. Waste forms for plutonium disposition

    International Nuclear Information System (INIS)

    Johnson, S.G.; O'Holleran, T.P.; Frank, S.M.; Meyer, M.K.; Hanson, M.; Staples, B.A.; Knecht, D.A.; Kong, P.C.

    1997-01-01

    The field of plutonium disposition is varied and of much importance, since the Department of Energy has decided on the hybrid option for disposing of the weapons materials. This consists of either placing the Pu into mixed oxide fuel for reactors or placing the material into a stable waste form such as glass. The waste form used for Pu disposition should exhibit certain qualities: (1) provide for a suitable deterrent to guard against proliferation; (2) be of minimal volume, i.e., maximize the loading; and (3) be reasonably durable under repository-like conditions. This paper will discuss several Pu waste forms that display promising characteristics

  16. Lie algebra of conformal Killing–Yano forms

    International Nuclear Information System (INIS)

    Ertem, Ümit

    2016-01-01

    We provide a generalization of the Lie algebra of conformal Killing vector fields to conformal Killing–Yano forms. A new Lie bracket for conformal Killing–Yano forms that corresponds to slightly modified Schouten–Nijenhuis bracket of differential forms is proposed. We show that conformal Killing–Yano forms satisfy a graded Lie algebra in constant curvature manifolds. It is also proven that normal conformal Killing–Yano forms in Einstein manifolds also satisfy a graded Lie algebra. The constructed graded Lie algebras reduce to the graded Lie algebra of Killing–Yano forms and the Lie algebras of conformal Killing and Killing vector fields in special cases. (paper)

  17. 48 CFR 13.307 - Forms.

    Science.gov (United States)

    2010-10-01

    ...) Other than commercial items. (1) Except when quotations are solicited electronically or orally, the SF 1449; SF 18, Request for Quotations; or an agency form/automated format may be used. Each agency request for quotations form/automated format should conform with the SF 18 or SF 1449 to the maximum...

  18. Channel-forming activities in the glycosomal fraction from the bloodstream form of Trypanosoma brucei.

    Directory of Open Access Journals (Sweden)

    Melisa Gualdron-López

    Full Text Available BACKGROUND: Glycosomes are a specialized form of peroxisomes (microbodies present in unicellular eukaryotes that belong to the Kinetoplastea order, such as Trypanosoma and Leishmania species, parasitic protists causing severe diseases of livestock and humans in subtropical and tropical countries. The organelles harbour most enzymes of the glycolytic pathway that is responsible for substrate-level ATP production in the cell. Glycolysis is essential for bloodstream-form Trypanosoma brucei and enzymes comprising this pathway have been validated as drug targets. Glycosomes are surrounded by a single membrane. How glycolytic metabolites are transported across the glycosomal membrane is unclear. METHODS/PRINCIPAL FINDINGS: We hypothesized that glycosomal membrane, similarly to membranes of yeast and mammalian peroxisomes, contains channel-forming proteins involved in the selective transfer of metabolites. To verify this prediction, we isolated a glycosomal fraction from bloodstream-form T. brucei and reconstituted solubilized membrane proteins into planar lipid bilayers. The electrophysiological characteristics of the channels were studied using multiple channel recording and single channel analysis. Three main channel-forming activities were detected with current amplitudes 70-80 pA, 20-25 pA, and 8-11 pA, respectively (holding potential +10 mV and 3.0 M KCl as an electrolyte. All channels were in fully open state in a range of voltages ±150 mV and showed no sub-conductance transitions. The channel with current amplitude 20-25 pA is anion-selective (P(K+/P(Cl-∼0.31, while the other two types of channels are slightly selective for cations (P(K+/P(Cl- ratios ∼1.15 and ∼1.27 for the high- and low-conductance channels, respectively. The anion-selective channel showed an intrinsic current rectification that may suggest a functional asymmetry of the channel's pore. CONCLUSIONS/SIGNIFICANCE: These results indicate that the membrane of glycosomes

  19. Electrically assisted forming modeling and control

    CERN Document Server

    Salandro, Wesley A; Bunget, Cristina; Mears, Laine; Roth, John T

    2015-01-01

    Maximizing reader insights into the latest research findings and applications of Electrically-Assisted Forming (EAF) – whereby metals are formed under an electric current field – this book explains how such a process produces immediate improved formability of metals beyond the extent of thermal softening, and allows metals to be formed to greater elongation with lower mechanical energy as well as allowing for lightweight brittle metals such as magnesium and titanium to be formed without external heating or annealing, enabling the more effective use of these lightweight metals in design. Including case studies that illustrate and support the theoretical content and real-world applications of the techniques discussed, this book also serves to enrich readers understanding of the underlying theories that influence electro-plastic behaviour. The authors have extensive experience in studying Electrically-Assisted Forming and have written extensively on the topic with publications including experimental works, t...

  20. Radiation shielding material

    International Nuclear Information System (INIS)

    Kawakubo, Takamasa; Yamada, Fumiyuki; Nakazato, Kenjiro.

    1976-01-01

    Purpose: To provide a material, which is used for printing a samples name and date on an X-ray photographic film at the same time an X-ray radiography. Constitution: A radiation shielding material of a large mass absorption coefficient such as lead oxide, barium oxide, barium sulfate, etc. is added to a solution of a radiation permeable substance capable of imparting cold plastic fluidity (such as microcrystalline wax, paraffin, low molecular polyethylene, polyvinyl chloride, etc.). The resultant system is agitated and then cooled, and thereafter it is press fitted to or bonded to a base in the form of a film of a predetermined thickness. This radiation shielding layer is scraped off by using a writing tool to enter information to be printed in a photographic film, and then it is laid over the film and exposed to X-radiation to thereby print the information on the film. (Seki, T.)

  1. High photoconductive hydrogenated silicon by reactive sputtering in helium containing atmosphere

    International Nuclear Information System (INIS)

    Ohbiki, Tohru; Imura, Takeshi; Hiraki, Akio

    1982-01-01

    Mixed phase of amorphous and microcrystalline silicon-hydrogen alloys has been fabricated by reactive sputtering in He containing H 2 of which mole fraction is less than about 5 mole%. The degree of the crystallization, evaluated by electron microscopy and optical absorption spectroscopy, becomes high as the amount of H 2 in the atmosphere increases. The conductivity in dark and photoconductivity increase as the partial pressure of H 2 increases (form 0 to 1 mole%) and also as the pressure during sputtering increases. This increase in conductivity and photoconductivity is supposed to be related to the development of microcrystals. The highest photoconductivity is observed at the H 2 mole fraction of about 1 mole%. This film contains a small amount of microcrystals and show the photoconductivity higher by 2 orders of magnitude than that in a film sputter-deposited in Ar and H 2 atmosphere in the same apparatus. (author)

  2. Influence of granitic aggregates from Northeast Brazil on the alkali-aggregate reaction

    Energy Technology Data Exchange (ETDEWEB)

    Gomes Neto, David de Paiva; Santana, Rodrigo Soares de; Barreto, Ledjane Silva, E-mail: pvgomes@uol.com.br [Universidade Federal de Sergipe (UFS), Sao Cristovao, SE (Brazil). Dept. de Ciencias dos Materiais e Engenharia; Conceicao, Herbert; Lisboa, Vinicios Anselmo Carvalho [Universidade Federal de Sergipe (UFS), Sao Cristovao, SE (Brazil). Dept. de Geologia

    2014-08-15

    The alkali-aggregate reaction (AAR) in concrete structures is a problem that has concerned engineers and researchers for decades. This reaction occurs when silicates in the aggregates react with the alkalis, forming an expanded gel that can cause cracks in the concrete and reduce its lifespan. The aim of this study was to characterize three coarse granitic aggregates employed in concrete production in northeastern Brazil, correlating petrographic analysis with the kinetics of silica dissolution and the evolution of expansions in mortar bars, assisted by SEM/EDS, XRD, and EDX. The presence of grains showing recrystallization into individual microcrystalline quartz subgrains was associated with faster dissolution of silica and greater expansion in mortar bars. Aggregates showing substantial deformation, such as stretched grains of quartz with strong undulatory extinction, experienced slower dissolution, with reaction and expansion occurring over longer periods that could not be detected using accelerated tests with mortar bars. (author)

  3. Normal form theory and spectral sequences

    OpenAIRE

    Sanders, Jan A.

    2003-01-01

    The concept of unique normal form is formulated in terms of a spectral sequence. As an illustration of this technique some results of Baider and Churchill concerning the normal form of the anharmonic oscillator are reproduced. The aim of this paper is to show that spectral sequences give us a natural framework in which to formulate normal form theory. © 2003 Elsevier Science (USA). All rights reserved.

  4. Chou-Yang model and PHI form factor

    Energy Technology Data Exchange (ETDEWEB)

    Fazal-e-Aleem; Saleem, M.; Rafique, M.

    1988-03-01

    By using the deduced differential cross-section data for PHIp elastic scattering at 175 GeV/c in the Chou-Yang model, the PHI form factor has been computed and parametrized. Then in conjunction with the proton form factor this form factor is used in the pristine Chou-Yang model to obtain differential cross-section data at Fermilab energies. The theoretical results agree with the experimental measurements, endorsing the conjecture that the hadronic form factor of neutral particle is proportional to its magnetic form factor.

  5. 17 CFR 239.14 - Form N-2 for closed end management investment companies registered on Form N-8A.

    Science.gov (United States)

    2010-04-01

    ... management investment companies registered on Form N-8A. 239.14 Section 239.14 Commodity and Securities... Registration Statements § 239.14 Form N-2 for closed end management investment companies registered on Form N... closed end management investment companies registered under the Investment Company Act of 1940 on form N...

  6. The effect of the model posture on the forming quality in the CNC incremental forming

    International Nuclear Information System (INIS)

    Zhu, H; Zhang, W; Bai, J L; Yu, C; Xing, Y F

    2015-01-01

    Sheet rupture caused by a sheet metal thickness non-uniformity persists in CNC (Computer Numerical Control) incremental forming. Because the forming half cone angle is determined by the orientation of the model to be formed, so is the sheet metal's uniformity. The finite element analysis models for the two kinds of the postures of the model were established, and the digital simulation was conducted by using the ANSYS/LA-DYNA software. The effect of the model's posture on the sheet thickness distribution and the sheet thickness thinning rate were studied by comparing the simulation results of two kinds of the finite elements analyzes. (paper)

  7. NETWORK CODING BY BEAM FORMING

    DEFF Research Database (Denmark)

    2013-01-01

    Network coding by beam forming in networks, for example, in single frequency networks, can provide aid in increasing spectral efficiency. When network coding by beam forming and user cooperation are combined, spectral efficiency gains may be achieved. According to certain embodiments, a method...... cooperating with the plurality of user equipment to decode the received data....

  8. 13 CFR 120.194 - Use of computer forms.

    Science.gov (United States)

    2010-01-01

    ... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false Use of computer forms. 120.194... Applying to All Business Loans Computerized Sba Forms § 120.194 Use of computer forms. Any Applicant or Participant may use computer generated SBA application forms, closing forms, and other forms designated by SBA...

  9. A comparative study of the flow enhancing properties of bentonite ...

    African Journals Online (AJOL)

    A comparative study of granule flow enhancing property of bentonite, magnesium stearate, talc and microcrystalline cellulose (MCC) was undertaken. Bentonite was processed into fine powder. A 10 %w/w of starch granules was prepared and separated into different sizes (˂180, 180-500, 500-710 and 710-850 μm).

  10. 56th Annual Meeting

    Indian Academy of Sciences (India)

    1991-01-01

    Jan 1, 1991 ... and water security, he cannot be considered to be self-sufficient. ... an open dissipative system organizes itself into a steady state showing ... by making it microcrystalline, using a combination of ..... Kanpur), described the methodology involved in ..... When the decision was taken to set up the. Centre for ...

  11. Substrate system for spray forming

    Energy Technology Data Exchange (ETDEWEB)

    Chu, Men G. (Export, PA); Chernicoff, William P. (Harrisburg, PA)

    2002-01-01

    A substrate system for receiving a deposit of sprayed metal droplets including a movable outer substrate on which the sprayed metal droplets are deposited. The substrate system also includes an inner substrate disposed adjacent the outer substrate where the sprayed metal droplets are deposited on the outer substrate. The inner substrate includes zones of differing thermal conductivity to resist substrate layer porosity and to resist formation of large grains and coarse constituent particles in a bulk layer of the metal droplets which have accumulated on the outer substrate. A spray forming apparatus and associated method of spray forming a molten metal to form a metal product using the substrate system of the invention is also provided.

  12. Size-dependent variation in plant form.

    Science.gov (United States)

    Niklas, Karl J; Cobb, Edward D

    2017-09-11

    The study of organic form has a long and distinguished history going at least as far back as Aristotle's Historia Anima¯lium, wherein he identified five basic biological processes that define the forms of animals (metabolism, temperature regulation, information processing, embryo development, and inheritance). Unfortunately, all of Aristotle's writings about plant forms are lost. We know of them only indirectly from his student Theophrastus's companion books, collectively called Historia Plantarum, wherein plant forms are categorized into annual herbs, herbaceous perennials, shrubs, and trees. The study of plant forms did not truly begin until the romantic poet and naturalist Goethe proposed the concept of a hypothetical 'Plant Archetype', declared "Alles ist Blatt", and first coined the word morphologie, which inspired the French anatomist Cuvier (who established the field of comparative morphology), the English naturalist Darwin (who saw his theory of evolution reinforced by it), and the Scottish mathematician D'Arcy Thompson (who attempted to quantify it). Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. 32 CFR 516.25 - DA Form 4.

    Science.gov (United States)

    2010-07-01

    ... 32 National Defense 3 2010-07-01 2010-07-01 true DA Form 4. 516.25 Section 516.25 National Defense... LITIGATION Reporting Legal Proceedings to HQDA § 516.25 DA Form 4. (a) General. The DA Form 4 (See figure C-2... properly prepared and sealed DA Form 4 are self-authenticating. (See Fed. R. Evid. 902). (b) Preparation at...

  14. Heavy meson form factors from QCD

    International Nuclear Information System (INIS)

    Falk, A.F.; Georgi, H.; Grinstein, B.

    1990-01-01

    We calculate the leading QCD radiative corrections to the relations which follow from the decoupling of the heavy quark spin as the quark mass goes infinity and from the symmetry between systems with different heavy quarks. One of the effects we calculate gives the leading q 2 -dependence of the form factor of a heavy quark, which in turn dominates the q 2 -dependence of the form factors of bound states of the heavy quark with light quarks. This, combined with the normalization of the form factor provided by symmetry, gives us a first principles calculation of the heavy meson (or baryon) form factors in the limit of very large heavy quark mass. (orig.)

  15. Make Projects Small Form Factor PCs

    CERN Document Server

    Wessels, Duane

    2006-01-01

    Shoebox sized and smaller, small-form-factor PCs can pack as much computing muscle as a full-sized desktop computer. They consumer less power, have few or no moving parts, and are very quiet. Whether you plan to use one as a standalone PC or want to embed it in your next hacking project, a small-form-factor PC can be a lot of fun to build. Make Projects: Small Form Factor PCs is the only book available that shows you how to build small-form-factor PCs -- from kits and from scratch -- that are more interesting and more personalized than what a full-sized PC can give you. Included in the book

  16. Special waste-form lysimeters: Arid

    International Nuclear Information System (INIS)

    Jones, T.L.; Serne, R.J.

    1987-08-01

    The release of contaminant from solidified low-level waste forms is being studied in a field lysimeter facility at the Hanford Site in southeastern Washington State. Duplicate samples of five different waste forms have been buried in 10 lysimeters since March 1984. Waste-form samples represent three different waste streams and four solidification agents (masonry cement, Portland III cement, Dow polymer /sup (a)/, and bitumen). Most precipitation at the Hanford Site arrives as winter snow; this contributes to a strong seasonal pattern in water storage and drainage observed in the lysimeters. The result is an annual range in the volumetric soil water content from 11% in late winter to 7% in the late summer and early fall, as well as annual changes in pore water velocities from approximately 1 cm/wk in early spring to less than 0.05 cm/wk in early fall. Measurable quantities of tritium and cobalt-60 are being collected in lysimeter drainage water. Approximately 30% of the original tritium inventory has been leached from two lysimeters originally containing tritium. Cobalt-60 is present in all waste forms; it is being collected in the leachate from five lysimeters. The total amount released varies, but in each case it is less than 0.1% of the original cobalt inventory of the waste sample. Nonradioactive constituents contained in the waste form, such as sodium, boron, and sulfate, are also being leached

  17. In Situ Monitoring and Modeling of the Solution-Mediated Polymorphic Transformation of Rifampicin: From Form II to Form I.

    Science.gov (United States)

    Guo, Nannan; Hou, Baohong; Wang, Na; Xiao, Yan; Huang, Jingjing; Guo, Yanmei; Zong, Shuyi; Hao, Hongxun

    2018-01-01

    In this article, the solution-mediated polymorphic transformation of rifampicin was investigated and simulated in 3 solvents at 30°C. The solid-state form I and form II of rifampicin was characterized by powder X-ray diffraction, scanning electron microscopy, thermogravimetric analysis, Raman spectroscopy, and Fourier transform infrared spectroscopy (FTIR). To explore the relative stability, solubility data of form I and form II of rifampicin in butan-1-ol were determined using a dynamical method. In addition, Raman spectroscopy and focused beam reflectance measurement were used to in situ monitor the transformation of rifampicin from form II to form I. The liquid state concentration of rifampicin was measured by UV spectroscopic method. To investigate the effect of solvent on transformation, the transformation experiments were carried out in 3 solvents. Furthermore, a mathematical model was built to describe the kinetics of dissolution, nucleation, and growth processes during transformation by using experimental data. By combination of experimental and simulation results, it was found that the transformation process of rifampicin is controlled by dissolution of form II in heptane, whereas the transformation in hexane and octane was firstly controlled by dissolution of solid-state form and then controlled by growth of form I. Copyright © 2018 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

  18. Sixth form pure mathematics

    CERN Document Server

    Plumpton, C

    1968-01-01

    Sixth Form Pure Mathematics, Volume 1, Second Edition, is the first of a series of volumes on Pure Mathematics and Theoretical Mechanics for Sixth Form students whose aim is entrance into British and Commonwealth Universities or Technical Colleges. A knowledge of Pure Mathematics up to G.C.E. O-level is assumed and the subject is developed by a concentric treatment in which each new topic is used to illustrate ideas already treated. The major topics of Algebra, Calculus, Coordinate Geometry, and Trigonometry are developed together. This volume covers most of the Pure Mathematics required for t

  19. Stainless steel-zirconium alloy waste forms

    International Nuclear Information System (INIS)

    McDeavitt, S.M.; Abraham, D.P.; Keiser, D.D. Jr.; Park, J.Y.

    1996-01-01

    An electrometallurgical treatment process has been developed by Argonne National Laboratory to convert various types of spent nuclear fuels into stable storage forms and waste forms for repository disposal. The first application of this process will be to treat spent fuel alloys from the Experimental Breeder Reactor-II. Three distinct product streams emanate from the electrorefining process: (1) refined uranium; (2) fission products and actinides extracted from the electrolyte salt that are processed into a mineral waste form; and (3) metallic wastes left behind at the completion of the electrorefining step. The third product stream (i.e., the metal waste stream) is the subject of this paper. The metal waste stream contains components of the chopped spent fuel that are unaffected by the electrorefining process because of their electrochemically ''noble'' nature; this includes the cladding hulls, noble metal fission products (NMFP), and, in specific cases, zirconium from metal fuel alloys. The selected method for the consolidation and stabilization of the metal waste stream is melting and casting into a uniform, corrosion-resistant alloy. The waste form casting process will be carried out in a controlled-atmosphere furnace at high temperatures with a molten salt flux. Spent fuels with both stainless steel and Zircaloy cladding are being evaluated for treatment; thus, stainless steel-rich and Zircaloy-rich waste forms are being developed. Although the primary disposition option for the actinides is the mineral waste form, the concept of incorporating the TRU-bearing product into the metal waste form has enough potential to warrant investigation

  20. A generalized definition for waste form durability

    International Nuclear Information System (INIS)

    Fanning, T. H.; Bauer, T. H.; Morris, E. E.; Wigeland, R. A.

    2002-01-01

    When evaluating waste form performance, the term ''durability'' often appears in casual discourse, but in the technical literature, the focus is often on waste form ''degradation'' in terms of mass lost per unit area per unit time. Waste form degradation plays a key role in developing models of the long-term performance in a repository environment, but other factors also influence waste form performance. These include waste form geometry; density, porosity, and cracking; the presence of cladding; in-package chemistry feedback; etc. The paper proposes a formal definition of waste form ''durability'' which accounts for these effects. Examples from simple systems as well as from complex models used in the Total System Performance Assessment of Yucca Mountain are provided. The application of ''durability'' in the selection of bounding models is also discussed